JP2009037229A - Electrophotographic photoreceptor, electrophotographic cartridge and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high-performance electrophotographic photoreceptor which has enhanced wear resistance, low surface free energy and improved lubricity without adversely affecting electrical characteristics and image characteristics, and which maintains those characteristics even after repeated image formation. <P>SOLUTION: The electrophotographic photoreceptor has at least a photosensitive layer on a conductive support, wherein the photosensitive layer contains a resin having a polysiloxane component and also contains a polyarylate resin. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an electrophotographic photoreceptor excellent in surface slipperiness, abrasion resistance, and electrical characteristics, and to an electrophotographic photoreceptor using the same.

  In recent years, electrophotographic technology has been widely used and applied not only in the field of copying machines but also in the field of various printers because of its immediacy and high-quality images. Photoconductors, the core of electrophotographic technology, have been used as conventional photoconductive materials for inorganic photoconductors such as selenium, arsenic-selenium alloys, cadmium sulfide, and zinc oxide. A photoreceptor using an organic photoconductive material having advantages such as easy and easy manufacture has been developed.

  Organic photoreceptors have a wider selection range of materials than inorganic photoreceptors, and a highly sensitive photoreceptor can be obtained by combining a highly efficient charge generating substance and charge transporting substance. However, with conventional technologies, organic photoreceptors have sufficient performance in terms of electrical characteristics such as sensitivity and chargeability, but are insufficient in physical strength on the surface of the photoreceptor. At present, the printing performance remains limited.

  In order to increase the mechanical strength, for example, an overcoat layer has been proposed, and a binder polymer with high wear resistance has been proposed. The current situation includes problems that cannot be obtained. In addition, as the demand for high-quality printing in recent years has increased, electrophotographic photosensitive members have been required to have high image quality performance. One of them is a photoreceptor having a low surface free energy. An electrophotographic image is formed by charging, exposing, and developing the toner developed on the photosensitive member to the transfer target and further fixing the image. However, if this transfer is not performed efficiently, the image is formed. Image reproducibility deteriorates. In order to perform the transfer efficiently, it is important to reduce the adhesion between the photoconductor and the toner, and a photoconductor having a low surface free energy is desired. In addition, when the friction coefficient of the surface of the photoconductor is large, noise is generated, the cleaning blade is reversed, and density unevenness due to jitter occurs. From this point of view, a photoreceptor having low surface free energy is desired. Conventionally, a photoreceptor has an excellent surface property in the initial stage, but the surface free energy is lowered by repeated use, and the image is often deteriorated as a result.

  In order to improve surface slipperiness, a polysiloxane block copolymer is used as a binder (see, for example, Patent Document 1), a low molecular weight polysiloxane terminal compound is used (see, for example, Patent Document 2), and a polysiloxane compound is used. Use (for example, refer to Patent Document 3), use of fluorine atom-containing polycarbonate (for example, refer to Patent Document 4), etc. have been proposed, but none of these effects are sufficient, and electrical characteristics and printing durability are adversely affected. The current situation includes problems such as effects.

JP-A-2-240655 JP 7-261440 A JP 2000-171989 Japanese Patent Laid-Open No. 6-282094

  The present invention can improve the wear resistance of the photoconductor without adversely affecting the electric characteristics and image characteristics, and at the same time, can make the photoconductor with a low surface free energy, improve the slipping property, and repeat these characteristics. An object of the present invention is to provide a high-performance electrophotographic photosensitive member that persists even after image formation.

  As a result of intensive studies in view of these current situations, the inventor of the present invention uses a resin having a polysiloxane component in the photosensitive layer in combination with a polyarylate resin, thereby reducing wear even in repeated use over a long period of time. The present invention has led to the present invention, which can provide an electrophotographic photosensitive member having remarkably high slipperiness and excellent cleaning properties and transferability.

  That is, the gist of the present invention is an electrophotographic photosensitive member having at least a photosensitive layer on a conductive support, wherein the photosensitive layer contains a resin having a polysiloxane component and contains a polyarylate resin. Preferably, the resin having the polysiloxane component is a polycarbonate resin having a polysiloxane component (Claim 2), and the polyarylate resin is represented by the following formula ( It preferably has a dicarboxylic acid residue represented by 1).

(In formula (1), X ^{1 to} X ⁸ each independently represent a hydrogen atom, an alkyl group that may have a substituent, an aryl group that may have a substituent, a halogen group, or an alkoxy group, n represents an integer of 1 to 5.)

  Further, the gist of the present invention resides in an electrophotographic photoreceptor, wherein the resin having a polysiloxane component is a block copolymer of a polycarbonate component and a polysiloxane component (Claim 4), and more preferably. Is a block copolymer in which the resin having a polysiloxane component has a polysiloxane component at least at one end (Claim 5), the polycarbonate component has a structure of the following formula (2), and the poly More preferably, the siloxane component has a structure represented by the following formula (3).

(In Formula (2), Y ^{1 to} Y ⁸ each independently represent a hydrogen atom, an alkyl group that may have a substituent, an aryl group that may have a substituent, a halogen group, or an alkoxy group; In formula (3), R ¹³ represents a divalent organic group, W represents a divalent linking group, and R ^{8 to} R ¹² each independently have a substituent. Represents an alkyl group having 10 or less carbon atoms, and n is an integer of 1 to 500.)

  Still another subject matter of the present invention lies in an electrophotographic photosensitive member, wherein the photosensitive layer has a thickness of 15 μm or less.

  Another gist of the present invention is that, in an electrophotographic photosensitive member having a photosensitive layer on a conductive support, the surface free energy of the surface of the photosensitive layer is 20 mN / m or more and 35 mN / m or less, and the temperature The elastic deformation rate is 43% or more when measured under the conditions of a maximum indentation depth of 1 μm, a required load time of 20 s and an unloading time of 20 s using a Vickers indenter in an environment of 25 ° C. and a relative humidity of 50%. The present invention resides in an electrophotographic photosensitive member.

Another gist of the present invention is that, in an electrophotographic photosensitive member having a photosensitive layer on a conductive support, the surface free energy of the surface of the photosensitive layer is 20 mN / m or more and 35 mN / m or less, and the temperature The universal hardness at the maximum indentation depth when measured under the conditions of a maximum indentation depth of 1 μm, a load time of 20 s and an unloading time of 20 s using a Vickers indenter in an environment of 25 ° C. and a relative humidity of 50%, The electrophotographic photosensitive member is characterized by being 150 N / mm ² or more and 200 N / mm ² or less (claim 9).

Here, the photosensitive layer on the conductive support preferably contains a resin having a polysiloxane component and a polyarylate resin.
The resin having a polysiloxane component is preferably a polycarbonate resin having a polysiloxane component.
It is preferable that the polyarylate resin has a dicarboxylic acid residue represented by the formula (1) (claim 12).
It is preferable that the resin having a polysiloxane component is a block copolymer of a polycarbonate component and a polysiloxane component.
It is preferable that the resin having a polysiloxane component is a block copolymer having a polysiloxane component at least at one end.
It is preferable that the polycarbonate component has the structure of the formula (2) and the polysiloxane component has the structure of the formula (3).
The film thickness of the photosensitive layer is preferably 15 μm or less.

Still another subject matter of the present invention lies in the electrophotographic photosensitive member described above, which is used in an image forming apparatus having an exposure means having a resolution of 1200 dpi or more.

  Further, another gist of the present invention is the above-described electrophotographic photosensitive member, charging means for charging the electrophotographic photosensitive member, and image forming an electrostatic latent image by performing image exposure on the charged electrophotographic photosensitive member. An exposure unit; a developing unit that develops the electrostatic latent image with toner to form a toner image; a transfer unit that transfers the toner from the electrophotographic photosensitive member to a transfer target; and a toner image on the electrophotographic photosensitive member after transfer. An electrophotographic cartridge comprising: at least one of a charge eliminating unit that removes residual charge and a cleaning unit that removes toner remaining on the electrophotographic photosensitive member after transferring the toner image. (Claim 18).

  And a charging means for charging the electrophotographic photosensitive member, an image exposing means for performing image exposure on the charged electrophotographic photosensitive member to form an electrostatic latent image, and Developing means for developing the electrostatic latent image with toner to form a toner image, transfer means for transferring the toner image from the electrophotographic photosensitive member to the transfer target, and fixing the toner image transferred to the transfer target And an image forming apparatus characterized in that the exposure means is an exposure means with a resolution of 1200 dpi or higher. (Claim 19) 20).

  Furthermore, the toner used in the image forming apparatus of the present invention has an average circularity of 0.940 or more and 1.000 or less measured by a flow type particle image analyzer (claim 21). ), The toner is a toner produced in an aqueous medium (claim 22), and the toner undergoes a process of aggregating at least polymer primary particles and colorant particles to form particle aggregates. The toner is obtained (Claim 23), the toner further has a resin coating layer (Claim 24), and the resin coating layer contains a polysiloxane wax. (Claim 25) and paraffin wax is contained in the toner (Claim 26).

  According to the present invention, in an electrophotographic photosensitive member having a photosensitive layer on a conductive support, the photosensitive layer contains a resin having a polysiloxane component and contains a polyarylate resin. A photoconductor with high abrasion resistance and low surface free energy at the same time, and high slipperiness, and these properties persist even after repeated image formation. A high-performance electrophotographic photosensitive member can be provided. Further, by using this photoconductor or using a process cartridge using this photoconductor, it is possible to perform suitable exposure with various light input light sources, and even when used repeatedly for a long time, a good image is obtained. An image forming apparatus capable of forming the image can be provided.

Hereinafter, although an embodiment of the present invention is described in detail, the present invention is not limited to the following description, and can be appropriately implemented without departing from the gist of the present invention.
The electrophotographic photoreceptor of the present invention has a photosensitive layer on a conductive support, and the photosensitive layer contains a resin having a polysiloxane component and contains a polyarylate resin.

<Resin having a polysiloxane component>
The resin having a polysiloxane component used in the present invention may be any resin as long as the resin has a polysiloxane component as a partial structure.

  Examples of the resin component constituting the resin having a polysiloxane component include vinyl compounds such as butadiene resin, styrene resin, vinyl acetate resin, vinyl chloride resin, acrylate ester resin, methacrylate ester resin, vinyl alcohol resin, and ethyl vinyl ether. Polymers and copolymers, polyvinyl butyral resin, polyvinyl formal resin, partially modified polyvinyl acetal, polycarbonate resin, polyester resin, polyarylate resin, polyamide resin, polyurethane resin, cellulose ester resin, phenoxy resin, silicone resin, silicone-alkyd Resins, poly-N-vinylcarbazole resins, and resins obtained by copolymerizing a plurality of these resins are used. Among these, polycarbonate resin and polyarylate resin are preferable from the viewpoint of mechanical strength, and polycarbonate resin is particularly preferable from the viewpoint of electrical characteristics.

As the configuration of the resin having a polysiloxane component, the configuration of a resin having a known polysiloxane can be used. For example, when the resin component is A and the polysiloxane component is B, the following configuration is exemplified.
1. A block copolymer having a polysiloxane component at one end as in AB
2. A block copolymer having polysiloxane components at both ends as in B-A-B
3. A block copolymer having a resin component on both sides of a polysiloxane component, such as ABA
4). A block copolymer in which the polysiloxane component is branched from the main chain resin, such as AA (-B) -A

  Furthermore, it is possible to use a resin in which one of these or a plurality of configurations is combined. Among these, from the viewpoint of reducing the surface free energy of the photoreceptor, a resin having a polysiloxane component at least at one end, that is, a resin having a polysiloxane component at one end (Example 1 above), or both ends It is preferable to use a resin having a polysiloxane component (Example 2 above).

  As the resin having a polysiloxane component, the resin component of the resin having a polysiloxane component is a polycarbonate resin, and the polycarbonate resin preferably has a structure represented by the following formula (2). ).

In formula (2), Y ^{1 to} Y ⁸ each independently represent a hydrogen atom, an alkyl group that may have a substituent, an aryl group that may have a substituent, a halogen group, or an alkoxy group.

  The alkyl group is preferably an alkyl group having 10 or less carbon atoms, more preferably an alkyl group having 8 or less carbon atoms, particularly preferably an alkyl group having 1 or 2 carbon atoms, and most preferably an alkyl group having 1 carbon atom.

  Examples of the substituent that the alkyl group may have include: hydroxyl group; halogen atom such as fluorine atom, chlorine atom, bromine atom, iodine atom; methyl group, ethyl group, propyl group, butyl group, hexyl group, isopropyl group, cyclohexyl group Linear, branched and cyclic alkyl groups such as alkenyl groups; alkoxy groups such as methoxy groups, ethoxy groups and propyloxy groups; alkenyl groups such as allyl groups; aralkyl groups such as benzyl groups, naphthylmethyl groups and phenethyl groups Aryloxy groups such as phenoxy group and triloxy group; arylalkoxy groups such as benzyloxy group and phenethyloxy group; aryl groups such as phenyl group and naphthyl group; arylalkenyl groups such as styryl group and naphthylvinyl group; acetyl group; Acyl group such as benzoyl group; Dialkyl such as dimethylamino group and diethylamino group A diarylamino group such as a diphenylamino group or a dinaphthylamino group; a diaralkylamino group such as a dibenzylamino group or a diphenethylamino group; a diheterocyclic amino group such as a dipyridylamino group or a dithienylamino group; Examples include an amino group, or a disubstituted amino group in which substituents of the amino group such as an alkyl group, an aryl group, an aralkyl group, and a heterocyclic group are combined.

These substituents are condensed with each other to form a carbocyclic group via a single bond, a methylene group, an ethylene group, a carbonyl group, a vinylidene group, an ethylenylene group or the like; a heterocyclic group containing an oxygen atom, a sulfur atom, a nitrogen atom, etc. It may be formed.
The number of substituents is arbitrary, but is preferably an alkyl group having no substituent.

  Specific examples include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, n-pentyl group, sec-pentyl group, n-hexyl. Group, n-heptyl group and n-octyl group.

As the aryl group, an aryl group having 20 or less carbon atoms is preferable, an aryl group having 6 to 10 carbon atoms is more preferable, and a phenyl group is particularly preferable.
Examples of the substituent that the aryl group may have include the same substituents that the alkyl group may have, and the number of substituents that the aryl group has is arbitrary. Specifically, a phenyl group, a 4-methylphenyl group, and a naphthyl group are preferable.

  As the halogen group, a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom are preferable, and as the alkoxy group, a methoxy group, an ethoxy group, and a butoxy group are preferably used.

Among these, as Y ^{1 to} Y ⁸ , a hydrogen atom, a methyl group, an ethyl group, or a phenyl group is more preferably used. Among these, it is particularly preferable to use only a hydrogen atom or a methyl group.
X represents a linking group. As the linking group, a divalent group or a single bond is used, and considering the ease of producing a polycarbonate resin having a polysiloxane component, a linking group having 20 or less carbon atoms is preferable. A linking group having 10 or less is more preferable, and a linking group having 3 or less carbon atoms is particularly preferable. More specifically, a single bond, a divalent aromatic group, a divalent lactone group, a divalent fluorene group, or a divalent group represented below can be given.

In the above formula, R ^{1 to} R ⁷ each independently represent a hydrogen atom, an alkyl group that may have a substituent, an aryl group that may have a substituent, a halogen group, or an alkoxy group.

  As the alkyl group, an alkyl group having 10 or less carbon atoms is preferable, an alkyl group having 8 or less carbon atoms is more preferable, an alkyl group having 1 or 2 carbon atoms is further preferable, and an alkyl group having 1 carbon atom is particularly preferable.

  Examples of the substituent that the alkyl group may have include: hydroxyl group; halogen atom such as fluorine atom, chlorine atom, bromine atom, iodine atom; methyl group, ethyl group, propyl group, butyl group, hexyl group, isopropyl group, cyclohexyl group Linear, branched and cyclic alkyl groups such as alkenyl groups; alkoxy groups such as methoxy groups, ethoxy groups and propyloxy groups; alkenyl groups such as allyl groups; aralkyl groups such as benzyl groups, naphthylmethyl groups and phenethyl groups Aryloxy groups such as phenoxy group and triloxy group; arylalkoxy groups such as benzyloxy group and phenethyloxy group; aryl groups such as phenyl group and naphthyl group; arylalkenyl groups such as styryl group and naphthylvinyl group; acetyl group; Acyl group such as benzoyl group; Dialkyl such as dimethylamino group and diethylamino group A diarylamino group such as a diphenylamino group or a dinaphthylamino group; a diaralkylamino group such as a dibenzylamino group or a diphenethylamino group; a diheterocyclic amino group such as a dipyridylamino group or a dithienylamino group; Examples include an amino group, or a disubstituted amino group in which substituents of the amino group such as an alkyl group, an aryl group, an aralkyl group, and a heterocyclic group are combined.

These substituents are condensed with each other to form a carbocyclic group via a single bond, a methylene group, an ethylene group, a carbonyl group, a vinylidene group, an ethylenylene group or the like; a heterocyclic group containing an oxygen atom, a sulfur atom, a nitrogen atom, etc. It may be formed.
The number of substituents is arbitrary, but is preferably an alkyl group having no substituent.

Specific examples include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, n-pentyl group, sec-pentyl group, n-hexyl. Group, n-heptyl group and n-octyl group.
Furthermore, R ¹ and R ² may combine to form a ring, and the divalent group in that case is preferably a cyclohexylidene group or a cyclopentylidene group.

As the aryl group, an aryl group having 20 or less carbon atoms is preferable, an aryl group having 6 to 10 carbon atoms is more preferable, and a phenyl group is particularly preferable.
Examples of the substituent that the aryl group may have include the same substituents that the alkyl group may have, and the number of substituents that the aryl group has is arbitrary. Specifically, a phenyl group, a 4-methylphenyl group, and a naphthyl group are preferable.

As the halogen group, a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom are preferable, and as the alkoxy group, a methoxy group, an ethoxy group, and a butoxy group are preferably used.
Among these, as R ^{1 to} R ⁷ , a hydrogen atom, a methyl group, an ethyl group, or a phenyl group is more preferably used. Among these, it is particularly preferable to use only a hydrogen atom or a methyl group.
In the above formula, l represents an integer of 1 to 6, and m represents an integer of 2 to 20.

Among the above, those having the following structural formula can be particularly preferably used from the viewpoint of electrical characteristics. Among them, it is preferable that R ¹ and R ² are both alkyl groups since the slipping property of the photoreceptor is increased.

Specific examples of X include a single bond, —O—, —CO—, —CH ₂ —, —CH (CH ₃ ) —, —C (CH ₃ ) ₂ —, and a cyclohexylidene group. Among them from the viewpoints of electrical properties, preferably bonded group which consists of only _{hydrocarbon, -CH 2 -, - CH (} CH 3) -, - C (CH 3) 2 -, more preferably cyclohexylidene, 3 or less carbon atoms Particularly preferred are groups consisting of only hydrocarbons such as —CH ₂ —, —CH (CH ₃ ) —, and —C (CH ₃ ) ₂ —.

The structure represented by the formula (2) is a repeating unit usually derived from a bifunctional phenol compound.
Examples of the bifunctional phenol compound include bis- (4-hydroxyphenyl) methane, bis- (2-hydroxyphenyl) methane, (2-hydroxyphenyl) (4-hydroxyphenyl) methane, and bis- (4- Hydroxy-3-methylphenyl) methane, bis- (4-hydroxy-3,5-dimethylphenyl) methane, bis- (4-hydroxy-3,6-dimethylphenyl) methane, bis- (3-phenyl-4-) Hydroxyphenyl) methane, 1,1-bis- (4-hydroxyphenyl) ethane, 1,1-bis- (4-hydroxy-3-methylphenyl) ethane, 1,1-bis- (4-hydroxy-3, 5-dimethylphenyl) ethane, 1,1-bis- (4-hydroxy-3,6-dimethylphenyl) ethane, 1,1-bis- (3- Enyl-4-hydroxyphenyl) ethane, 1,1-bis- (4-hydroxyphenyl) propane, 2,2-bis- (4-hydroxyphenyl) propane, 1,1-bis- (4-hydroxy-3- Methylphenyl) propane, 2,2-bis- (4-hydroxy-3-methylphenyl) propane, 2,2-bis- (4-hydroxy-3-ethylphenyl) propane, 2,2-bis- (4- Hydroxy-3-isopropylphenyl) propane, 2,2-bis- (4-hydroxy-3-sec-butylphenyl) propane, 2,2-bis- (4-hydroxy-3,5-dimethylphenyl) propane, 1 1,2-bis- (3-phenyl-4-hydroxyphenyl) propane, 2,2-bis- (3-phenyl-4-hydroxyphenyl) propane, 2, -Bis- (4-hydroxyphenyl) butane, 2,2-bis- (4-hydroxyphenyl) pentane, 2,2-bis- (4-hydroxyphenyl) -3-methylbutane, 2,2-bis- (4 -Hydroxyphenyl) hexane, 2,2-bis- (4-hydroxyphenyl) -4-methylpentane, 1,1-bis- (4-hydroxyphenyl) cyclopentane, 1,1-bis- (4-hydroxyphenyl) ) Cyclohexane, 1,1-bis- (4-hydroxy-3-methylphenyl) cyclohexane, 1,1-bis- (4-hydroxy-3,5-dimethylphenyl) cyclohexane, bis- (4-hydroxyphenyl) phenyl Methane, 1,1-bis- (4-hydroxyphenyl) -1-phenylethane, 1,1-bis- (4-hydroxyphenyl) ) -1-phenylpropane, bis- (4-hydroxyphenyl) diphenylmethane, bis- (4-hydroxyphenyl) dibenzylmethane, bis (4-hydroxyphenyl) ether, (2-hydroxyphenyl) (4-hydroxyphenyl) Ether, bis (2-hydroxyphenyl) ether, bis (4-hydroxy-3-methylphenyl) ether, bis (4-hydroxy-3-ethylphenyl) ether, bis (4-hydroxy-3,5-dimethylphenyl) Ether, 4,4 ′-[1,4-phenylenebis (1-methylvinylidene)] bisphenol, 4,4 ′-[1,4-phenylenebis (1-methylvinylidene)] bis [2-methylphenol], 4,4′-dihydroxybiphenyl, 3,3 ′, 5,5′-tetramethyl-4,4′- Hydroxybiphenyl, and the like.

  Among these bifunctional phenol compounds, preferred examples include bis- (4-hydroxyphenyl) methane, bis- (4-hydroxy-3-methylphenyl) methane, and bis- (4-hydroxy-3,5- Dimethylphenyl) methane, 1,1-bis- (4-hydroxyphenyl) ethane, 1,1-bis- (4-hydroxy-3-methylphenyl) ethane, 1,1-bis- (4-hydroxy-3, 5-dimethylphenyl) ethane, 2,2-bis- (4-hydroxyphenyl) propane, 2,2-bis- (4-hydroxy-3-methylphenyl) propane, 2,2-bis- (4-hydroxy-) 3,5-dimethylphenyl) propane, 2,2-bis- (3-phenyl-4-hydroxyphenyl) propane, 1,1-bis- (4-hydroxyphenyl) Cyclohexane, 1,1-bis - (4-hydroxyphenyl) -1-phenylethane and the like.

  Among them, from the viewpoint of improving the mechanical properties of the photosensitive layer, bis- (4-hydroxy-3-methylphenyl) methane, 1,1-bis- (4-hydroxy-3-methylphenyl) ethane, 2, 2-bis- (4-hydroxy-3-methylphenyl) propane and 1,1-bis- (4-hydroxyphenyl) cyclohexane are preferred. Further, among these, 2,2-bis- (4-hydroxy-3-methylphenyl) propane is particularly preferable from the viewpoint of the slipperiness of the photosensitive layer.

The polycarbonate resin used in the present invention may include a polycarbonate structure other than that represented by the formula (2) as a partial structure. Further, the partial structure may include a structure other than the polycarbonate resin.
In the polycarbonate resin used in the present invention, the greater the weight ratio of the structural portion represented by the formula (2), the better the wear resistance and the longer the slipperiness. Expressed by the formula (2) with respect to the total weight of the resin component excluding the structural part represented by the formula (3) from the weight of the structural part represented by the formula (2) and the other structural parts. The structure to be formed is preferably 50% by weight or more, more preferably 70% by weight or more, still more preferably 80% by weight or more, and in particular, the resin component is a structure represented by the formula (2). Most preferred.

In formula (3), R ^{8 to} R ¹² each independently represents an alkyl group having 10 or less carbon atoms which may have a substituent, and preferably an alkyl group having 8 or less carbon atoms is used.
Examples of the substituent that the alkyl group may have include: hydroxyl group; halogen atom such as fluorine atom, chlorine atom, bromine atom, iodine atom; methyl group, ethyl group, propyl group, butyl group, hexyl group, isopropyl group, cyclohexyl group Linear, branched and cyclic alkyl groups such as alkenyl groups; alkoxy groups such as methoxy groups, ethoxy groups and propyloxy groups; alkenyl groups such as allyl groups; aralkyl groups such as benzyl groups, naphthylmethyl groups and phenethyl groups Aryloxy groups such as phenoxy group and triloxy group; arylalkoxy groups such as benzyloxy group and phenethyloxy group; aryl groups such as phenyl group and naphthyl group; arylalkenyl groups such as styryl group and naphthylvinyl group; acetyl group; Acyl group such as benzoyl group; Dialkyl such as dimethylamino group and diethylamino group A diarylamino group such as a diphenylamino group or a dinaphthylamino group; a diaralkylamino group such as a dibenzylamino group or a diphenethylamino group; a diheterocyclic amino group such as a dipyridylamino group or a dithienylamino group; Examples include an amino group, or a disubstituted amino group in which substituents of the amino group such as an alkyl group, an aryl group, an aralkyl group, and a heterocyclic group are combined.

These substituents are condensed with each other to form a carbocyclic group via a single bond, a methylene group, an ethylene group, a carbonyl group, a vinylidene group, an ethylenylene group or the like; a heterocyclic group containing an oxygen atom, a sulfur atom, a nitrogen atom, etc. It may be formed.
The number of substituents is arbitrary, but is preferably an alkyl group having no substituent. More specifically, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, n-pentyl group, sec-pentyl group, n- Examples thereof include unsubstituted alkyl groups such as a hexyl group, n-heptyl group, and n-octyl group.

R ¹³ represents a divalent organic group, and preferably a divalent organic residue containing an alkyl group or an aryl group is used. More preferably, a linking group having an alkyl group and an aryl group at the same time is used, and a group having an ether bond is more preferable. The alkyl group and aryl group used here may each independently have a substituent. Examples of the substituent that the alkyl group and aryl group used herein may have include a hydroxyl group; a halogen atom such as a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom; a methyl group, an ethyl group, a propyl group, a butyl group, Linear, branched and cyclic alkyl groups such as hexyl, isopropyl and cyclohexyl; alkoxy groups such as methoxy, ethoxy and propyloxy; alkenyl such as allyl; benzyl and naphthylmethyl Aralkyl groups such as phenethyl groups; aryloxy groups such as phenoxy groups and triloxy groups; arylalkoxy groups such as benzyloxy groups and phenethyloxy groups; aryl groups such as phenyl groups and naphthyl groups; styryl groups and naphthylvinyl groups Aryl alkenyl group; acyl group such as acetyl group and benzoyl group; aryl carbon Group, and the like.

More preferably, the following structure is used as R ¹³ .

In the above formula, R ¹⁴ and R ¹⁵ each independently represents a hydrogen atom or a hydrocarbon group. Among hydrocarbon groups, an alkyl group having 18 or less carbon atoms, an alkenyl group having 3 to 10 carbon atoms, a halogen, a halogenated alkyl group, an alkoxy group, or a substituent, which may have 6 to 20 carbon atoms Aryl groups are preferred. Further, in the above formula, Ar is an arylene group which may have a substituent, and more preferably contains 2 or more and 5 or less aromatic rings. B represents an integer of 1 or more and 20 or less. Examples of the substituent that the arylene group represented by Ar may have include: a hydroxyl group; a halogen atom such as a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom; a methyl group, an ethyl group, a propyl group, a butyl group, and a hexyl group. Linear, branched and cyclic alkyl groups such as isopropyl group and cyclohexyl group; alkoxy groups such as methoxy group, ethoxy group and propyloxy group; alkenyl groups such as allyl group; benzyl group, naphthylmethyl group and phenethyl Aralkyl groups such as phenoxy groups, aryloxy groups such as phenoxy groups and triloxy groups; arylalkoxy groups such as benzyloxy groups and phenethyloxy groups; aryl groups such as phenyl groups and naphthyl groups; arylalkenyl groups such as styryl groups and naphthylvinyl groups Groups; acyl groups such as acetyl and benzoyl groups; and arylcarbonyl groups

Particularly preferred structures for R ¹³ include the following, but the structure of R ^{13 according to} the present invention is not limited to these.

Among these, a group containing two or more aromatic rings as exemplified in S5 to S10 is preferable, a group containing a phenylene group having a substituent as exemplified in S5 to S8 is more preferable, and particularly in S7 and S8. A group containing a phenylene group having a ketone group as exemplified is preferable.
W is a divalent linking group, the divalent linking group, a single bond, O, CO, COO, NH , NHCO, S, SO, SO 2 and the like. Among these, a divalent linking group having an oxygen atom is preferable, and O and COO are more preferably used.

In the resin having a siloxane component contained in the photosensitive layer of the electrophotographic photoreceptor of the present invention, a polysiloxane moiety having a structure represented by the above formula (3) (from the structure represented by the formula (3), W and portion excluding the R ^13), the total binder resin to 0.1% by weight or more contained in the photosensitive layer, preferably 1 wt% or more, more preferably 4 wt% or more, and most preferably at least 6 wt%. Moreover, it is 20 weight% or less normally, Preferably it is 15 weight% or less, More preferably, it is 10 weight% or less. If it is less than 0.1% by weight, the effect of improving the slipperiness of the surface of the photoreceptor is insufficient, and if it exceeds 20% by weight, the transparency and electrical characteristics are adversely affected.

  n is usually 1 or more, preferably 10 or more, more preferably 20 or more, and 30 or more is most preferable. Further, n is usually 500 or less, preferably 300 or less, more preferably 100 or less and 50 or less. If n is small, the effect of improving the slip property cannot be sufficiently obtained, and if n is too large, the light transmittance of the charge transport layer is lowered, and the sensitivity of the electrophotographic photosensitive member in particular may be reduced. When forming an image using an electrophotographic photosensitive member, the resolution of the image may decrease due to light scattering, which is not preferable.

  The molecular weight of the resin having a polysiloxane component used in the electrophotographic photosensitive member of the present invention is not particularly limited, but when a polycarbonate resin is used as the resin component, the viscosity average molecular weight is 20,000 or more, preferably 25,000. Above, more preferably 30,000 or more, and particularly preferably 33,000 or more. If the molecular weight is low, the mechanical strength of the photosensitive layer may be lowered. In addition, when a polycarbonate resin is used as a resin component of a resin having a polysiloxane component, if the molecular weight is too low, it tends to bleed out when a photosensitive layer is formed, and initially shows good slipperiness, but repeatedly When the photosensitive layer is worn by image formation, the slipperiness may be extremely reduced. When a polycarbonate resin is used as the resin component of the resin having a polysiloxane component, the viscosity average molecular weight is usually 300,000 or less, preferably 100,000 or less, more preferably 60,000 or less. . If the molecular weight is too high, it may be difficult to apply a uniform film thickness when forming the photosensitive layer.

  When a polycarbonate resin is used as the resin component of the resin having a polysiloxane component used in the present invention, a known polycarbonate resin production method is applied as the method for producing a polycarbonate polymer having this polysiloxane component. be able to. For example, bifunctional hydroxy compound and phosgene are reacted to perform interfacial polycondensation. Bifunctional hydroxy compound is added to chloroformate obtained by reacting bifunctional hydroxy compound and phosgene to cause interfacial polycondensation. A method of polymerizing a reactive hydroxy compound by a transesterification reaction with a carbonate such as diphenyl carbonate can be used.

  Further, in the polymerization of the polycarbonate polymer, acid halides such as terephthalic acid chloride, isophthalic acid chloride, adipic acid chloride, sebacic acid chloride and diamines such as piperazine may coexist within a range that does not significantly adversely affect the reaction. A branching agent typified by a polyphenol such as phloroglysin, 1,1,1-tri (4-hydroxyphenyl) ethane, or tetra (4-hydroxyphenyl) methane may be allowed to coexist so as not to gel.

  As a method for producing a polycarbonate polymer having a polysiloxane component at the terminal, for example, a method in which a polysiloxane containing a monofunctional phenol structure is allowed to coexist during polymerization can be applied. Monofunctional phenols may be combined with polysiloxane alone in the polymerization system, or used with other monofunctional phenols such as p-tert-butylphenol, phenol, cumylphenol, octylphenol, nonylphenol, etc. May be. Alternatively, as another production method, it can also be produced by a hydrosilylation reaction of a polysiloxane having a one-terminal Si—H structure to a polycarbonate having a carbon double bond at the terminal.

<Polyarylate resin>
The photosensitive layer of the electrophotographic photosensitive member according to the present invention contains a resin having a polysiloxane component and a polyarylate resin. The polyarylate resin used in the present invention will be described below.

The polyarylate resin used in the present invention is not particularly limited as long as it is a polyarylate resin known to be used in the photosensitive layer of an electrophotographic photosensitive member, and a known polyarylate resin can be used. .
Among these, the polyarylate resin preferably has a dicarboxylic acid residue represented by the following formula (1).

In formula (1), X ^{1 to} X ⁸ each independently represent a hydrogen atom, an alkyl group that may have a substituent, an aryl group that may have a substituent, a halogen group, or an alkoxy group.

  The alkyl group which may have a substituent is preferably an alkyl group having 10 or less carbon atoms, more preferably an alkyl group having 8 or less carbon atoms, particularly preferably an alkyl group having 1 or 2 carbon atoms, and 1 carbon atom. The alkyl group is most preferred.

  Examples of the substituent that the alkyl group may have include: hydroxyl group; halogen atom such as fluorine atom, chlorine atom, bromine atom, iodine atom; methyl group, ethyl group, propyl group, butyl group, hexyl group, isopropyl group, cyclohexyl group Linear, branched and cyclic alkyl groups such as alkenyl groups; alkoxy groups such as methoxy groups, ethoxy groups and propyloxy groups; alkenyl groups such as allyl groups; aralkyl groups such as benzyl groups, naphthylmethyl groups and phenethyl groups Aryloxy groups such as phenoxy group and triloxy group; arylalkoxy groups such as benzyloxy group and phenethyloxy group; aryl groups such as phenyl group and naphthyl group; arylalkenyl groups such as styryl group and naphthylvinyl group; acetyl group; Acyl group such as benzoyl group; Dialkyl such as dimethylamino group and diethylamino group A diarylamino group such as a diphenylamino group or a dinaphthylamino group; a diaralkylamino group such as a dibenzylamino group or a diphenethylamino group; a diheterocyclic amino group such as a dipyridylamino group or a dithienylamino group; Examples include an amino group, or a disubstituted amino group in which substituents of the amino group such as an alkyl group, an aryl group, an aralkyl group, and a heterocyclic group are combined.

These substituents are condensed with each other to form a carbocyclic group via a single bond, a methylene group, an ethylene group, a carbonyl group, a vinylidene group, an ethylenylene group or the like; a heterocyclic group containing an oxygen atom, a sulfur atom, a nitrogen atom, etc. It may be formed.
The number of substituents is arbitrary, but is preferably an alkyl group having no substituent.

  Specific examples include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, n-pentyl group, sec-pentyl group, n-hexyl. Group, n-heptyl group and n-octyl group.

  The aryl group which may have a substituent is preferably an aryl group having 6 to 20 carbon atoms, more preferably an aryl group having 6 to 10 carbon atoms, and particularly preferably an aryl group having 6 carbon atoms.

  Examples of the substituent that the aryl group may have include: hydroxyl group; halogen atom such as fluorine atom, chlorine atom, bromine atom and iodine atom; methyl group, ethyl group, propyl group, butyl group, hexyl group, isopropyl group, cyclohexyl Linear, branched and cyclic alkyl groups such as alkenyl groups; alkoxy groups such as methoxy groups, ethoxy groups and propyloxy groups; alkenyl groups such as allyl groups; aralkyl groups such as benzyl groups, naphthylmethyl groups and phenethyl groups Aryloxy groups such as phenoxy group and triloxy group; arylalkoxy groups such as benzyloxy group and phenethyloxy group; aryl groups such as phenyl group and naphthyl group; arylalkenyl groups such as styryl group and naphthylvinyl group; acetyl group; Acyl group such as benzoyl group; Dialkyl such as dimethylamino group and diethylamino group A diarylamino group such as a diphenylamino group or a dinaphthylamino group; a diaralkylamino group such as a dibenzylamino group or a diphenethylamino group; a diheterocyclic amino group such as a dipyridylamino group or a dithienylamino group; Examples include an amino group, or a disubstituted amino group in which substituents of the amino group such as an alkyl group, an aryl group, an aralkyl group, and a heterocyclic group are combined.

  These substituents are condensed with each other to form a carbocyclic group via a single bond, a methylene group, an ethylene group, a carbonyl group, a vinylidene group, an ethylenylene group or the like; a heterocyclic group containing an oxygen atom, a sulfur atom, a nitrogen atom, etc. It may be formed. The number of substituents it has is arbitrary. Specific examples include a phenyl group, a 4-methylphenyl group, and a naphthyl group.

  As the halogen group, a fluorine atom, a chlorine atom, a bromine atom and an iodine atom are preferable, and as the alkoxy group, a methoxy group, an ethoxy group and a butoxy group are preferably used. Of these, a hydrogen atom, a methyl group, and an ethyl group are particularly preferably used. Furthermore, it is most preferable to use only hydrogen atoms from the viewpoint of wear resistance.

n represents an integer of 0 to 5. Among these, n is preferably 0 to 1 from the viewpoint of ease of production, and n is most preferably 1 from the viewpoint of wear resistance.
Specific examples of the dicarboxylic acid residue include a dicarboxylic acid residue having a structure in which the hydroxyl group is removed from the carboxyl group of the dicarboxylic acid compound exemplified below.
When n is 0, phthalic acid, isophthalic acid, terephthalic acid, toluene-2,5-dicarboxylic acid, and p-xylene-2,5-dicarboxylic acid are exemplified. Of these, isophthalic acid and terephthalic acid are preferable.

  When n is 1, diphenyl ether-2,2′-dicarboxylic acid, diphenyl ether-2,3′-dicarboxylic acid, diphenyl ether-2,4′-dicarboxylic acid, diphenyl ether-3,3′-dicarboxylic acid, diphenyl ether-3, 4'-dicarboxylic acid, diphenyl ether-4,4'-dicarboxylic acid, etc. are mentioned. Among these, diphenyl ether-2,2′-dicarboxylic acid, diphenyl ether-2,4′-dicarboxylic acid, and diphenyl ether-4,4′-dicarboxylic acid are preferable, considering the simplicity of production of the dicarboxylic acid compound. -4,4'-dicarboxylic acid is particularly preferred.

The carboxylic acid residues described above may be used alone or in combination of two or more in any combination and ratio.
However, in the polyarylate resin used in the present invention, the amount of dicarboxylic acid residues other than n is preferably 1 from the viewpoint of wear resistance. Although the specific ratio is not limited, the ratio of the dicarboxylic acid residue in which n is 1 in the total amount of the dicarboxylic acid residues in the ratio of the number of repeating units is usually 70% or more, preferably 80% or more, more preferably Is 90% or more, particularly preferably 100%.

The polyarylate resin used in the present invention has a repeating unit composed of a dicarboxylic acid residue represented by the formula (1) and a structure derived from a bifunctional phenol compound.
Examples of the bifunctional phenol compound include bis- (4-hydroxyphenyl) methane, bis- (2-hydroxyphenyl) methane, (2-hydroxyphenyl) (4-hydroxyphenyl) methane, and bis- (4- Hydroxy-3-methylphenyl) methane, bis- (4-hydroxy-3,5-dimethylphenyl) methane, bis- (4-hydroxy-3,6-dimethylphenyl) methane, bis- (3-phenyl-4-) Hydroxyphenyl) methane, 1,1-bis- (4-hydroxyphenyl) ethane, 1,1-bis- (4-hydroxy-3-methylphenyl) ethane, 1,1-bis- (4-hydroxy-3, 5-dimethylphenyl) ethane, 1,1-bis- (4-hydroxy-3,6-dimethylphenyl) ethane, 1,1-bis- (3 Phenyl-4-hydroxyphenyl) ethane, 1,1-bis- (4-hydroxyphenyl) propane, 2,2-bis- (4-hydroxyphenyl) propane, 1,1-bis- (4-hydroxy-3-) Methylphenyl) propane, 2,2-bis- (4-hydroxy-3-methylphenyl) propane, 2,2-bis- (4-hydroxy-3-ethylphenyl) propane, 2,2-bis- (4- Hydroxy-3-isopropylphenyl) propane, 2,2-bis- (4-hydroxy-3-sec-butylphenyl) propane, 2,2-bis- (4-hydroxy-3,5-dimethylphenyl) propane, 1 , 1-bis- (3-phenyl-4-hydroxyphenyl) propane, 2,2-bis- (3-phenyl-4-hydroxyphenyl) propane, 2 2-bis- (4-hydroxyphenyl) butane, 2,2-bis- (4-hydroxyphenyl) pentane, 2,2-bis- (4-hydroxyphenyl) -3-methylbutane, 2,2-bis- ( 4-hydroxyphenyl) hexane, 2,2-bis- (4-hydroxyphenyl) -4-methylpentane, 1,1-bis- (4-hydroxyphenyl) cyclopentane, 1,1-bis- (4-hydroxy) Phenyl) cyclohexane, 1,1-bis- (4-hydroxy-3-methylphenyl) cyclohexane, 1,1-bis- (4-hydroxy-3,5-dimethylphenyl) cyclohexane, bis- (4-hydroxyphenyl) Phenylmethane, 1,1-bis- (4-hydroxyphenyl) -1-phenylethane, 1,1-bis- (4-hydroxyphenyl) L) -1-phenylpropane, bis- (4-hydroxyphenyl) diphenylmethane, bis- (4-hydroxyphenyl) dibenzylmethane, bis (4-hydroxyphenyl) ether, (2-hydroxyphenyl) (4-hydroxyphenyl) ) Ether, bis (2-hydroxyphenyl) ether, bis (4-hydroxy-3-methylphenyl) ether, bis (4-hydroxy-3-ethylphenyl) ether, bis (4-hydroxy-3,5-dimethylphenyl) ) Ether, 4,4 ′-[1,4-phenylenebis (1-methylvinylidene)] bisphenol, 4,4 ′-[1,4-phenylenebis (1-methylvinylidene)] bis [2-methylphenol] 4,4′-dihydroxybiphenyl, 3,3 ′, 5,5′-tetramethyl-4,4 ′ Dihydroxybiphenyl and the like.

  Among these bifunctional phenol compounds, preferred examples include bis- (4-hydroxyphenyl) methane, bis- (4-hydroxy-3-methylphenyl) methane, and bis- (4-hydroxy-3,5- Dimethylphenyl) methane, bis- (4-hydroxy-3,6-dimethylphenyl) methane, 1,1-bis- (4-hydroxyphenyl) ethane, 1,1-bis- (4-hydroxy-3-methylphenyl) ) Ethane, 1,1-bis- (4-hydroxy-3,5-dimethylphenyl) ethane, 2,2-bis- (4-hydroxyphenyl) propane, 2,2-bis- (4-hydroxy-3-) Methylphenyl) propane, 2,2-bis- (4-hydroxy-3,5-dimethylphenyl) propane, 2,2-bis- (3-phenyl-4-hydroxyphenyl) Yl) propane, 1,1-bis - (4-hydroxyphenyl) cyclohexane, 1,1-bis - (4-hydroxyphenyl) -1-phenylethane and the like.

  Among these, from the viewpoint of mechanical properties, bis- (4-hydroxy-3-methylphenyl) methane, 1,1-bis- (4-hydroxy-3-methylphenyl) ethane, 2,2-bis- (4- Hydroxy-3-methylphenyl) propane and 1,1-bis- (4-hydroxyphenyl) cyclohexane are preferred. Furthermore, among these, 1,1-bis- (4-hydroxy-3-methylphenyl) ethane and 2,2-bis- (4-hydroxy-3-methylphenyl) propane are particularly preferable from the viewpoint of slipperiness.

  Although the repeating structure of the resin suitably used as the polyarylate resin used in the present invention is exemplified below, the polyarylate resin used in the present invention is not limited thereto.

・ Repeated structure when n is 0

・ Repeated structure when n is 1

  The polyarylate resin has a viscosity average molecular weight of 30,000 or more, preferably 35,000 or more, more preferably 40,000 or more. When the molecular weight is low, the mechanical strength of the photoreceptor is lowered, and desired abrasion resistance cannot be obtained. Moreover, normally, a viscosity average molecular weight is 300,000 or less, Preferably it is 100,000 or less, More preferably, it is 60,000 or less. When the molecular weight is too high, it is difficult to apply a uniform film thickness when forming the photosensitive layer.

  When the resin having a polysiloxane component used in the present invention and a polyarylate resin are used in combination, the use ratio is not limited and is arbitrary as long as the effects of the present invention are obtained. However, from the viewpoint of durability of the photoreceptor, the amount of the polysiloxane component used in the present invention relative to the total weight of the resin having the polysiloxane component used in the present invention and the above polyarylate as the amount contained in the photosensitive layer. The weight of the resin is 80% by weight or less, preferably 50% by weight or less, more preferably 30% by weight or less. From the viewpoint of slipperiness, it is 1% by weight or more, preferably 5% by weight or more, more preferably 10% by weight or more.

  Moreover, it is preferable from the surface of abrasion resistance and an electrical property that polyarylate resin does not have polysiloxane at the terminal.

<Other binder resins>
The resin having a polysiloxane component used in the present invention and the polyarylate resin function as a binder resin in the photosensitive layer. However, other resins may be used in the photosensitive layer in addition to the resin used in the present invention. As the other resin used in combination, any resin can be used as long as the effects of the present invention are not significantly impaired. For example, vinyl polymers such as polymethyl methacrylate, polystyrene, polyvinyl chloride, and the like can be used. Examples thereof include thermoplastic resins such as polymers, polycarbonates, polyesters, polyester polycarbonates, polysulfones, phenoxy resins, epoxy resins, and silicone resins, and various thermosetting resins. Of these resins, polycarbonate resin is preferable.

In addition, other resin may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and a ratio.
In addition, the use ratio of the resin to be used in combination is not particularly limited. However, in order to sufficiently obtain the effects of the present invention, it is preferable to use the resin in a range not exceeding the ratio of the polyarylate resin used in the present invention. In particular, it is preferable not to use other resins in combination.

[Electrophotographic photoreceptor]
The electrophotographic photoreceptor of the present invention has a photosensitive layer containing a resin having a polysiloxane component and a polyarylate resin. The photosensitive layer is usually provided on a conductive support.

  As a specific configuration of the photosensitive layer, a charge generation material and a charge transport material are present in the same layer and dispersed or dissolved in a binder resin (single layer type or dispersion type) photosensitive layer; A mold (laminated layer) in which a functional material is separated into a charge generation layer in which a generation material is dispersed or dissolved in a binder resin and a charge transport layer in which a charge transport material is dispersed or dissolved in a binder resin. Type or function separation type). A photoreceptor having a single layer type photosensitive layer is a so-called single layer type photoreceptor (or a dispersion type photoreceptor), and a photoreceptor having a laminated type photosensitive layer is a so-called laminated type photoreceptor (or function separation). The photosensitive layer may be of any configuration.

Further, as the laminated photosensitive layer, a charge generating layer and a charge transport layer are laminated in this order from the conductive support side, and a charge transport layer and a charge generation layer are laminated in this order. There are reverse laminated type photosensitive layers, and any of them can be adopted. Among these, a forward laminated photosensitive layer that can exhibit the most balanced photoconductivity is preferable.
The resin used in the present invention is contained in the photosensitive layer. When the photosensitive layer is composed of two or more layers (for example, a charge generation layer and a charge transport layer), the resin of the present invention may be contained in at least one of the layers constituting the photosensitive layer. However, the outermost layer is preferably contained, and particularly preferably contained in the charge transport layer of the laminated photosensitive layer.

<Surface free energy>
The surface free energy of the electrophotographic photosensitive member of the present invention is usually 20 mN / m or more, preferably 25 mN / m or more, and usually 35 mN / m or less, preferably 32 mN / m or less. If the surface free energy is excessively high, the coefficient of friction with the contact member with the photosensitive member such as a cleaning blade or a charging roller becomes high, and an image defect is likely to occur due to jitter generated when the photosensitive member rotates. In addition, there is a concern about a decrease in toner transfer rate. On the other hand, if the surface free energy is excessively low, the adhesion between the photoconductor and the toner is weak, causing problems such as toner scattering.

  The surface free energy in the present invention can be determined by measuring the contact angle using three types of reagents whose surface free energy has a known dipole component, dispersion component, and hydrogen bond component. In the present invention, the surface free energy of the photoconductor was calculated using the surface free energy analysis software FAMAS from the contact angle measured using an automatic contact angle meter CA-VP manufactured by Kyowa Interface Science Co., Ltd. In the analysis, a three-component model of Kitazaki and Hata was used, and a method of handling each interaction of the dipole component, the dispersion component, and the hydrogen bond component as a geometric mean approximation was used. Three kinds of liquids, pure water, diiodomethane, and 1-bromonaphthalene, are used for the contact angle measurement. The values of each component of the surface free energy of the liquid used in the analysis are described in Journal of the Adhesion Society of Japan, 8, 131, The value described in (1972) was used. The measurement was performed in an environment at a temperature of 25 ° C. and a relative humidity of 50%.

  The electrophotographic photosensitive member having a surface free energy within the parameter range of the present invention is not limited in its configuration, but it is preferable to use the resin described in <resin having a polysiloxane component>. A preferable range when a resin having a polysiloxane component is used is the same as that described in the section <Resin having a polysiloxane component>. As another method for obtaining the surface free energy of the present invention, a method using fine particles of low surface free energy such as Teflon is known, but in this case, exposure light at the time of forming an image is scattered and resolution is lowered. It has been pointed out to do.

<Elastic deformation rate and universal hardness>
The elastic deformation rate of the electrophotographic photosensitive member of the present invention is usually 43% or more, preferably 45% or more, and usually 60% or less, preferably 50% or less. By setting the elastic deformation rate in the above range, the close contact with the cleaning member is improved, and it is possible to suppress the occurrence of defective cleaning even when toner having a high degree of circularity is used. The universal hardness in the present invention is usually 150 N / mm ² or more, preferably 160 N / mm ² or more, more preferably 170N / mm ² or more and usually 200 N / mm ² or less, preferably 190 N / mm ² or less, more Preferably it is 185 N / mm ² or less. By setting the universal hardness in the above range, the adhesion to the cleaning member is improved, and it is possible to suppress the occurrence of defective cleaning even when a toner with a high degree of circularity is used.

  The elastic deformation rate and universal hardness in the present invention are values measured using a micro hardness meter (Fischer: FISCHERSCOPE H100C) in an environment of a temperature of 25 ° C. and a relative humidity of 50%. For the measurement, a Vickers square pyramid diamond indenter having a facing angle of 136 ° is used. The measurement conditions are set as follows, and the load applied to the indenter and the indentation depth under the load are continuously read, and profiles as shown in FIG. 3 plotted on the Y axis and the X axis are obtained.

Measurement conditions Maximum indentation depth 1μm
Load time 20s
Unloading time 20s

The elastic deformation rate in the present invention is a value defined by the following equation, and is a ratio of work that the film performs by elasticity at the time of unloading with respect to the total work amount required for pushing.
Elastic deformation rate (%) = We / Wt * 100
In the above formula, the total work Wt (nJ) indicates the area surrounded by A-B-D-A in FIG. 3, and the elastic deformation work We (nJ) is the area surrounded by C-B-D-C. Is shown.
As the elastic deformation rate is larger, the deformation with respect to the load is less likely to remain, meaning that no deformation remains at 100.

In the present invention, universal hardness is a value when the maximum indentation depth is 1 μm, and is a value defined by the following formula from the load at that time.
Universal hardness (N / mm ² ) = Test load (N) / Vickers indenter surface area under test load (mm ² )

  As long as the photoconductor has an elastic deformation rate and a universal hardness within the scope of the present invention, the configuration is not limited, but the resin described in the section <Polyarylate resin> is preferably used. The preferred range when using a polyarylate resin is the same as that described in the section <Polyarylate resin>. When the resin of n = 1 of the compound represented by the formula (1) is used as the polyarylate resin, particularly preferable characteristics are exhibited in both elastic deformation rate and universal hardness.

<Conductive support>
There is no particular limitation on the conductive support, but for example, metal materials such as aluminum, aluminum alloy, stainless steel, copper, and nickel, and conductive powders such as metal, carbon, and tin oxide are added to impart conductivity. A resin material, a resin, glass, paper, or the like in which a conductive material such as aluminum, nickel, or ITO (indium tin oxide) is deposited or applied on the surface is mainly used. These may be used alone or in combination of two or more in any combination and ratio. As a form of the conductive support, a drum form, a sheet form, a belt form or the like is used. Furthermore, a conductive material having an appropriate resistance value may be used on a conductive support made of a metal material in order to control conductivity and surface properties and to cover defects.

Moreover, when using metal materials, such as an aluminum alloy, as an electroconductive support body, you may use, after giving an anodic oxide film. When an anodized film is applied, it is desirable to perform a sealing treatment by a known method.
The surface of the support may be smooth, or may be roughened by using a special cutting method or performing a polishing treatment. Further, it may be roughened by mixing particles having an appropriate particle diameter with the material constituting the support. In order to reduce the cost, it is possible to use the drawing tube as it is without performing the cutting process.

<Underlayer>
An undercoat layer may be provided between the conductive support and the photosensitive layer described later for improving adhesion and blocking properties. As the undercoat layer, a resin, a resin in which particles such as a metal oxide are dispersed, or the like is used.
Examples of metal oxide particles used for the undercoat layer include metal oxide particles containing one metal element such as titanium oxide, aluminum oxide, silicon oxide, zirconium oxide, zinc oxide, iron oxide, calcium titanate, titanium Examples thereof include metal oxide particles containing a plurality of metal elements such as strontium acid and barium titanate. One kind of these particles may be used alone, or a plurality of kinds of particles may be mixed and used. Among these metal oxide particles, titanium oxide and aluminum oxide are preferable, and titanium oxide is particularly preferable. The surface of the titanium oxide particles may be treated with an inorganic material such as tin oxide, aluminum oxide, antimony oxide, zirconium oxide, or silicon oxide, or an organic material such as stearic acid, polyol, or silicone. As the crystal form of the titanium oxide particles, any of rutile, anatase, brookite, and amorphous can be used. Moreover, the thing of a several crystal state may be contained.

In addition, various particle sizes of the metal oxide particles can be used. Among these, from the viewpoint of characteristics and liquid stability, the average primary particle size is usually 1 nm or more, preferably 10 nm or more, and usually 100 nm or less. Preferably it is 50 nm or less.
The undercoat layer is preferably formed in a form in which metal oxide particles are dispersed in a binder resin. As binder resin used for the undercoat layer, epoxy resin, polyethylene resin, polypropylene resin, acrylic resin, methacrylic resin, polyamide resin, vinyl chloride resin, vinyl chloride resin, vinyl acetate resin, phenol resin, polycarbonate resin, polyurethane resin, Polyimide resin, vinylidene chloride resin, polyvinyl acetal resin, vinyl chloride-vinyl acetate copolymer, polyvinyl alcohol resin, polyurethane resin, polyacrylic acid resin, polyacrylamide resin, polyvinyl pyrrolidone resin, polyvinyl pyridine resin, water-soluble polyester resin, nitro Cellulose ester resins such as cellulose, cellulose ether resins, casein, gelatin, polyglutamic acid, starch, starch acetate, amino starch, zirconium chelate Compounds, organic zirconium compounds such as zirconium alkoxide compounds, titanyl chelate compounds, organic titanyl compounds such as titanyl alkoxide compound, a known binder resin such as a silane coupling agent and the like. These may be used alone or in combination of two or more in any combination and ratio. Moreover, you may use with the hardening | curing form with the hardening | curing agent. Among these, alcohol-soluble copolymerized polyamides, modified polyamides, and the like are preferable because they exhibit good dispersibility and coatability.

The use ratio of the inorganic particles to the binder resin used in the undercoat layer can be arbitrarily selected, but is usually in the range of 10% by weight or more and 500% by weight or less from the viewpoint of dispersion stability and coatability. Is preferably used.
The thickness of the undercoat layer can be selected arbitrarily, but is usually preferably in the range of 0.1 μm or more and 20 μm or less from the viewpoint of improving the photoreceptor characteristics and coating properties.

A known antioxidant or the like may be mixed in the undercoat layer. For the purpose of preventing image defects, pigment particles, resin particles, and the like may be included and used.
It is also possible to use a plurality of undercoat layers in combination. In that case, functions can be separated into a plurality of layers. For example, charge blocking, adhesiveness, and moire prevention functions can be divided into different layers.

<Photosensitive layer>
As a type of the photosensitive layer, a charge generation material and a charge transport material are present in the same layer and are dispersed in a binder resin, a charge generation layer in which a charge generation material is dispersed in a binder resin, and a charge. A functional separation type (laminated type) composed of two layers of a charge transport layer in which a transport material is dispersed in a binder resin can be mentioned, but any type may be used.

  In addition, as the laminated photosensitive layer, a charge generation layer and a charge transport layer are laminated in this order from the conductive support side, and a charge transport layer and a charge generation layer are laminated in this order. There are reverse laminated type photosensitive layers, and any of them can be adopted, but a forward laminated type photosensitive layer capable of exhibiting the most balanced photoconductivity is preferable.

<Laminated photosensitive layer>
・ Charge generation layer
In the case of a laminated type photoreceptor (function separation type photoreceptor), the charge generation layer is formed by binding a charge generation material with a binder resin.

  Examples of the charge generation material include inorganic photoconductive materials such as selenium and its alloys, cadmium sulfide, and organic photoconductive materials such as organic pigments, but organic photoconductive materials are preferred, especially organic pigments. Is preferred. Examples of organic pigments include phthalocyanine pigments, azo pigments, dithioketopyrrolopyrrole pigments, squalene (squarylium) pigments, quinacridone pigments, indigo pigments, perylene pigments, polycyclic quinone pigments, anthanthrone pigments, and benzimidazole pigments. . Among these, phthalocyanine pigments or azo pigments are particularly preferable. When organic pigments are used as the charge generating substance, usually, fine particles of these organic pigments are used in the form of a dispersion layer bound with various binder resins.

  When a metal-free phthalocyanine compound or a metal-containing phthalocyanine compound is used as the charge generation material, a photosensitive member having a high sensitivity to a laser beam having a relatively long wavelength, for example, a laser beam having a wavelength around 780 nm, is obtained. When an azo pigment such as diazo or trisazo is used, it is sufficient for white light, laser light having a wavelength around 660 nm, or laser light having a relatively short wavelength, for example, laser having a wavelength around 450 nm or 400 nm. A photosensitive member having a high sensitivity can be obtained.

  When a phthalocyanine pigment is used as a charge generation material, specifically, metal-free phthalocyanine, copper, indium, gallium, tin, titanium, zinc, vanadium, silicon, germanium, aluminum or other metal or oxide thereof, halide, water Those having crystal forms of coordinated phthalocyanines such as oxides and alkoxides, and phthalocyanine dimers using oxygen atoms as bridging atoms are used. Particularly, titanyl phthalocyanines (also known as oxytitanium) such as X-type, τ-type metal-free phthalocyanine, A-type (also known as β-type), B-type (also known as α-type), and D-type (also known as Y-type), which are highly sensitive crystal types Phthalocyanine), vanadyl phthalocyanine, chloroindium phthalocyanine, hydroxyindium phthalocyanine, chlorogallium phthalocyanine such as type II, hydroxygallium phthalocyanine such as type V, μ-oxo-gallium phthalocyanine dimer such as type G and type I, type II, etc. The [mu] -oxo-aluminum phthalocyanine dimer is preferred.

  Among these phthalocyanines, A-type (also known as β-type), B-type (also known as α-type), and powder X-ray diffraction angle 2θ (± 0.2 °) are 27.1 ° or 27.3 °. D-type (Y-type) titanyl phthalocyanine, II-type chlorogallium phthalocyanine, V-type and 28.1 ° have the strongest peaks, and 26.2 ° have peaks Hydroxygallium phthalocyanine having a clear peak at 28.1 ° and a full width at half maximum W of 25.9 ° of 0.1 ° ≦ W ≦ 0.4 °, G-type μ-oxo -Gallium phthalocyanine dimer and the like are particularly preferable. Among these, D-type (Y-type) titanyl phthalocyanine is most preferable because it shows good sensitivity.

  As the phthalocyanine compound, a single compound may be used, or several mixed or mixed crystals may be used. As the mixed state that can be put in the phthalocyanine compound or crystal state here, those obtained by mixing the respective constituent elements later may be used, or they may be mixed in the production / treatment process of the phthalocyanine compound such as synthesis, pigmentation, and crystallization. It may be the one that caused the condition. As such treatment, acid paste treatment, grinding treatment, solvent treatment and the like are known. In order to generate a mixed crystal state, as described in JP-A-10-48859, two types of crystals are mixed, mechanically ground and made amorphous, and then converted into a specific crystal state by solvent treatment. The method of doing is mentioned.

When an azo pigment is used as the charge generation material, various bisazo pigments and trisazo pigments are preferably used.
When an organic pigment is used as the charge generation material, one kind may be used alone, or two or more kinds of pigments may be mixed and used. In this case, it is preferable to use a combination of two or more kinds of charge generating materials having spectral sensitivity characteristics in different spectral regions of the visible region and the near red region. Among them, a disazo pigment, a trisazo pigment and a phthalocyanine pigment are preferably used in combination. More preferred.

  The binder resin used for the charge generation layer is not particularly limited, but examples include polyvinyl butyral resin, polyvinyl formal resin, polyvinyl acetal type such as partially acetalized polyvinyl butyral resin in which a part of butyral is modified with formal, acetal, or the like. Resin, Polyarylate resin, Polycarbonate resin, Polyester resin, Modified ether type polyester resin, Phenoxy resin, Polyvinyl chloride resin, Polyvinylidene chloride resin, Polyvinyl acetate resin, Polystyrene resin, Acrylic resin, Methacrylic resin, Polyacrylamide resin, Polyamide Resin, polyvinyl pyridine resin, cellulose resin, polyurethane resin, epoxy resin, silicone resin, polyvinyl alcohol resin, polyvinyl pyrrolidone resin, casein, vinyl chloride Vinyl chloride-vinyl acetate, such as ru-vinyl acetate copolymer, hydroxy-modified vinyl chloride-vinyl acetate copolymer, carboxyl-modified vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinyl acetate-maleic anhydride copolymer Copolymer, styrene-butadiene copolymer, vinylidene chloride-acrylonitrile copolymer, styrene-alkyd resin, silicone-alkyd resin, phenol-formaldehyde resin and other insulating resins, poly-N-vinylcarbazole, polyvinylanthracene, Examples include organic photoconductive polymers such as polyvinyl perylene. Any one of these binder resins may be used alone, or two or more thereof may be mixed and used in any combination.

  Specifically, the charge generation layer is prepared by dispersing a charge generation material in a solution obtained by dissolving the above-described binder resin in an organic solvent, and preparing a coating solution on the conductive support (when an undercoat layer is provided). Is formed by coating (on the undercoat layer).

  The solvent used for preparing the coating solution is not particularly limited as long as it dissolves the binder resin. For example, saturated aliphatic solvents such as pentane, hexane, octane, and nonane, and aromatics such as toluene, xylene, and anisole. Group solvents, halogenated aromatic solvents such as chlorobenzene, dichlorobenzene, chloronaphthalene, amide solvents such as dimethylformamide, N-methyl-2-pyrrolidone, methanol, ethanol, n-propanol, isopropanol, n-butanol, Alcohol solvents such as benzyl alcohol, aliphatic polyhydric alcohols such as glycerin and polyethylene glycol, chain or cyclic ketone solvents such as acetone, cyclohexanone and methyl ethyl ketone, ester systems such as methyl formate, ethyl acetate and n-butyl acetate solvent Halogenated hydrocarbon solvents such as methylene chloride, chloroform, 1,2-dichloroethane, chain or cyclic ether solvents such as diethyl ether, dimethoxyethane, tetrahydrofuran, 1,4-dioxane, methyl cellosolve, ethyl cellosolve, Aprotic polar solvents such as acetonitrile, dimethyl sulfoxide, sulfolane, hexamethylphosphoric triamide, n-butylamine, isopropanolamine, diethylamine, triethanolamine, nitrogen-containing compounds such as ethylenediamine, triethylenediamine, triethylamine, mineral oils such as ligroin, Water etc. are mentioned. Any one of these may be used alone, or two or more of these may be used in combination. In addition, when providing the above-mentioned undercoat layer, what does not melt | dissolve this undercoat layer is preferable.

  In the charge generation layer, the compounding ratio (weight) of the binder resin and the charge generation material is usually 10 parts by weight or more, preferably 30 parts by weight or more, and usually 1000 parts by weight with respect to 100 parts by weight of the binder resin. The film thickness is usually 0.1 μm or more, preferably 0.15 μm or more, and usually 10 μm or less, preferably 0.6 μm or less. If the ratio of the charge generation material is excessively high, the stability of the coating solution may be reduced due to aggregation of the charge generation material.On the other hand, if the ratio of the charge generation material is excessively low, the sensitivity as a photoreceptor may be decreased. There is a risk of inviting.

As a method for dispersing the charge generation material, a known dispersion method such as a ball mill dispersion method, an attritor dispersion method, or a sand mill dispersion method can be used. At this time, it is effective to refine the particles to a particle size in the range of 0.5 μm or less, preferably 0.3 μm or less, more preferably 0.15 μm or less.
It is also possible to use a plurality of charge generation layers in combination.

・ Charge transport layer
The charge transport layer of the multilayer photoreceptor contains a charge transport material and usually contains a binder resin and other components used as necessary. Specifically, such a charge transport layer is prepared by, for example, preparing a coating solution by dissolving or dispersing a charge transport material or the like and a binder resin in a solvent. In addition, in the case of a reverse lamination type photosensitive layer, it can be obtained by coating and drying on a conductive support (or on the undercoat layer when an undercoat layer is provided).

  The charge transport material is not particularly limited, and any material can be used. Examples of known charge transport materials include aromatic nitro compounds such as 2,4,7-trinitrofluorenone, cyano compounds such as tetracyanoquinodimethane, electron withdrawing materials such as quinone compounds such as diphenoquinone, and carbazole derivatives. , Indole derivatives, imidazole derivatives, oxazole derivatives, pyrazole derivatives, thiadiazole derivatives, heterocyclic compounds such as benzofuran derivatives, aniline derivatives, hydrazone derivatives, aromatic amine derivatives, stilbene derivatives, butadiene derivatives, enamine derivatives, and a plurality of these compounds Examples thereof include an electron donating substance such as a polymer in which a species is bonded, or a polymer having a group composed of these compounds in the main chain or side chain. Among these, carbazole derivatives, aromatic amine derivatives, stilbene derivatives, butadiene derivatives, enamine derivatives, and those in which a plurality of these compounds are bonded are preferable. Any one of these charge transport materials may be used alone, or two or more thereof may be used in any combination.

  The binder resin is used for securing the film strength. As the binder resin for the charge transport layer, the resin of the present invention is preferably used. When the resin of the present invention is not used for the charge transport layer, a commonly used resin can be used. For example, polymers and copolymers of vinyl compounds such as butadiene resin, styrene resin, vinyl acetate resin, vinyl chloride resin, acrylic ester resin, methacrylic ester resin, vinyl alcohol resin, ethyl vinyl ether, polyvinyl butyral resin, polyvinyl formal resin , Partially modified polyvinyl acetal, polycarbonate resin, polyester resin, polyarylate resin, polyamide resin, polyurethane resin, cellulose ester resin, phenoxy resin, silicone resin, silicone-alkyd resin, poly-N-vinylcarbazole resin, and the like. Of these, polycarbonate resins and polyarylate resins are preferred. These binder resins can also be used after being crosslinked by heat, light or the like using an appropriate curing agent. Any one of these binder resins may be used alone, or two or more thereof may be used in any combination.

  The ratio of the binder resin to the charge transport material is 20 parts by weight or more of the charge transport material with respect to 100 parts by weight of the binder resin. Among these, 30 parts by weight or more is preferable from the viewpoint of residual potential reduction, and 40 parts by weight or more is more preferable from the viewpoint of stability and charge mobility when repeatedly used. On the other hand, from the viewpoint of thermal stability of the photosensitive layer, the charge transport material is usually used at a ratio of 150 parts by weight or less. Among these, 110 parts by weight or less is preferable from the viewpoint of compatibility between the charge transport material and the binder resin, 80 parts by weight or less is more preferable from the viewpoint of printing durability, and 70 parts by weight or less is most preferable from the viewpoint of scratch resistance.

  The thickness of the charge transport layer is not particularly limited, but is usually 5 μm or more, preferably 10 μm or more, and usually 50 μm or less, preferably 45 μm or less, from the viewpoint of long life, image stability, and high resolution. Is in the range of 30 μm or less. It is also possible to use a plurality of charge transport layers in combination.

<Single layer type photosensitive layer>
The single-layer type photosensitive layer is formed using a binder resin in order to ensure film strength, in the same manner as the charge transport layer of the multilayer photoconductor, in addition to the charge generation material and the charge transport material. Specifically, a charge generation material, a charge transport material, and various binder resins are dissolved or dispersed in a solvent to prepare a coating solution, and on a conductive support (or an undercoat layer when an undercoat layer is provided). It can be obtained by coating and drying.

The types of the charge transport material and the binder resin and the use ratios thereof are the same as those described for the charge transport layer of the multilayer photoreceptor. A charge generation material is further dispersed in a charge transport medium comprising these charge transport materials and a binder resin.
As the charge generation material, the same materials as those described for the charge generation layer of the multilayer photoreceptor can be used. However, in the case of a photosensitive layer of a single-layer type photoreceptor, it is necessary to sufficiently reduce the particle size of the charge generating material. Specifically, the range is usually 1 μm or less, preferably 0.5 μm or less.

If the amount of the charge generating material dispersed in the single-layer type photosensitive layer is too small, sufficient sensitivity cannot be obtained, but if it is too large, there are adverse effects such as a decrease in chargeability and a decrease in sensitivity. It is usually used in the range of 0.5% by weight or more, preferably 1% by weight or more, and usually 50% by weight or less, preferably 20% by weight or less based on the whole layer-type photosensitive layer.
Further, the use ratio of the binder resin and the charge generating material in the single-layer type photosensitive layer is such that the charge generating material is usually 0.1 parts by weight or more, preferably 1 part by weight or more, based on 100 parts by weight of the binder resin. It is 30 parts by weight or less, preferably 10 parts by weight or less.

  The film thickness of the single-layer type photosensitive layer is usually 5 μm or more, preferably 10 μm or more, and usually 100 μm or less, preferably 50 μm or less.

<Photosensitive layer thickness>
The film thickness of the photosensitive layer is preferably 20 μm or less, more preferably 16 μm or less, and even more preferably 13 μm or less in order to obtain a high-quality image. The smaller the film thickness, the better the reproducibility of fine lines.

  However, the photosensitive layer referred to here represents a charge generation layer and a charge transport layer in the case of a multilayer type photoreceptor, and a single layer photosensitive layer in the case of a single layer type photosensitive layer. That is, the undercoat layer is not included in the photosensitive layer. However, the protective layer is considered as a part of the photosensitive layer.

<Other functional layers>
For the purpose of improving the film formability, flexibility, coatability, contamination resistance, gas resistance, light resistance, etc., in both the photosensitive layer and each layer constituting it, both in the multilayer type photoreceptor and the single layer type photoreceptor. Additives such as well-known antioxidants, plasticizers, ultraviolet absorbers, electron-withdrawing compounds, leveling agents, and visible light shielding agents may be included.

Further, in both the laminated type photoreceptor and the single layer type photoreceptor, the photosensitive layer formed by the above procedure may be the uppermost layer, that is, the surface layer, but another layer may be provided on the photosensitive layer and used as the surface layer. Good.
For example, a protective layer may be provided for the purpose of preventing the photosensitive layer from being worn out or preventing or reducing the deterioration of the photosensitive layer due to discharge products generated from a charger or the like.
The protective layer is formed by containing a conductive material in a suitable binder resin, or has a charge transporting ability such as a triphenylamine skeleton described in JP-A Nos. 9-190004 and 10-252377. A copolymer using a compound can be used.

Examples of the conductive material used for the protective layer include aromatic amino compounds such as TPD (N, N′-diphenyl-N, N′-bis- (m-tolyl) benzidine), antimony oxide, indium oxide, tin oxide, and oxide. Metal oxides such as titanium, tin oxide-antimony oxide, aluminum oxide, and zinc oxide can be used, but are not limited thereto.
As the binder resin used for the protective layer, known resins such as polyamide resin, polyurethane resin, polyester resin, epoxy resin, polyketone resin, polycarbonate resin, polyvinyl ketone resin, polystyrene resin, polyacrylamide resin, and siloxane resin can be used. Also, a copolymer of the above resin and a skeleton having a charge transporting ability such as a triphenylamine skeleton as described in JP-A-9-190004 and JP-A-10-252377 can be used.

The electrical resistance of the protective layer is usually in the range of 10 ⁹ Ω · cm to 10 ¹⁴ Ω · cm. If the electric resistance is higher than the above range, the residual potential is increased, resulting in an image with a lot of fog. Further, the protective layer must be configured so as not to substantially prevent transmission of light irradiated during image exposure.

  In addition, for the purpose of reducing the frictional resistance and wear on the surface of the photoconductor, and increasing the transfer efficiency of the toner from the photoconductor to the transfer belt and paper, etc., the surface layer is made of fluorine resin, silicone resin, polyethylene resin, or the like. Particles made of this resin or inorganic compound particles may be contained in the surface layer. Alternatively, a layer containing these resins and particles may be newly formed as a surface layer.

<Method for forming each layer>
Each layer constituting these photoconductors is formed by immersing, coating, spraying, nozzle coating, bar coating, roll coating, blade coating, etc., a coating solution obtained by dissolving or dispersing a substance to be contained in a solvent. In this method, the coating and drying steps are sequentially repeated for each layer.

  There are no particular restrictions on the solvent or dispersion medium used in the preparation of the coating liquid, but specific examples include saturated aliphatic solvents such as pentane, hexane, octane, and nonane, and aromatics such as benzene, toluene, xylene, and anisole. Group solvents, halogenated aromatic solvents such as chlorobenzene, dichlorobenzene, chloronaphthalene, amide solvents such as dimethylformamide, N-methyl-2-pyrrolidone, methanol, ethanol, n-propanol, isopropanol, n-butanol, Alcohol solvents such as benzyl alcohol, aliphatic polyhydric alcohols such as glycerin and polyethylene glycol, chain or cyclic ketone solvents such as acetone, cyclohexanone and methyl ethyl ketone, ester systems such as methyl formate, ethyl acetate and n-butyl acetate Solvent, methyl chloride Halogenated hydrocarbon solvents such as ethylene, chloroform, 1,2-dichloroethane, chain or cyclic ether solvents such as diethyl ether, dimethoxyethane, tetrahydrofuran, 1,4-dioxane, methyl cellosolve, ethyl cellosolve, acetonitrile , Aprotic polar solvents such as dimethyl sulfoxide, sulfolane, hexamethylphosphoric triamide, n-butylamine, isopropanolamine, diethylamine, triethanolamine, nitrogen-containing compounds such as ethylenediamine, triethylenediamine, triethylamine, mineral oil such as ligroin, water Etc. Any one of these may be used alone, or two or more of these may be used in combination.

The amount of the solvent or the dispersion medium used is not particularly limited, but considering the purpose of each layer and the properties of the selected solvent / dispersion medium, it is appropriately determined so that the physical properties such as the solid content concentration and viscosity of the coating liquid are within a desired range. It is preferable to adjust.
For example, in the case of a single layer type photoreceptor and a charge transport layer of a function separation type photoreceptor, the solid content concentration of the coating solution is usually 5% by weight or more, preferably 10% by weight or more, and usually 40% by weight. Hereinafter, the range is preferably 35% by weight or less. Further, the viscosity of the coating solution is usually 10 mPa · s or higher, preferably 50 mPa · s or higher, and usually 500 mPa · s or lower, preferably 400 mPa · s or lower.

  In the case of a charge generating layer of a multilayer photoreceptor, the solid content concentration of the coating solution is usually 0.1% by weight or more, preferably 1% by weight or more, and usually 15% by weight or less, preferably 10% by weight. % Or less. Further, the viscosity of the coating solution is usually 0.01 mPa · s or more, preferably 0.1 mPa · s or more, and usually 20 mPa · s or less, preferably 10 mPa · s or less.

Examples of the coating method include a dip coating method, a spray coating method, a spinner coating method, a bead coating method, a wire bar coating method, a blade coating method, a roller coating method, an air knife coating method, and a curtain coating method. Other known coating methods can also be used.
The coating solution is preferably dried by touching at room temperature, followed by heating and drying in a temperature range of usually 30 ° C. or higher and 200 ° C. or lower for 1 minute to 2 hours, either statically or under ventilation. The heating temperature may be constant or the heating may be performed while changing the temperature during drying.

[toner]
<Toner type>
The toner used in the present invention is not limited as long as it has the above average circularity. Various types of toner are usually obtained depending on the production method, and any of them can be used in the present invention.

Hereinafter, the toner manufacturing method and the type of toner will be described.
The toner used in the present invention may be produced by any conventionally known method, and examples thereof include a polymerization method and a melt suspension method, but a so-called polymerization method that generates toner particles in an aqueous medium. Toner is preferred. Examples of the polymerization toner include suspension polymerization toner and emulsion polymerization aggregation toner. In particular, the emulsion polymerization aggregation method is a method for producing toner by aggregating polymer resin fine particles and a colorant in a liquid medium, and adjusting the particle size and circularity of the toner by controlling the aggregation conditions. Is preferable.

  In order to improve the releasability, low-temperature fixing property, high-temperature offset property, filming resistance and the like of the toner, a method of adding a low softening point substance (so-called wax) to the toner has been proposed. In the melt-kneading pulverization method, it is difficult to increase the amount of wax contained in the toner, and the limit is about 5% by weight with respect to the polymer (binder resin). In contrast, the polymerized toner can contain a low softening point substance in a large amount (5 to 30% by weight). The polymer here is one of the materials constituting the toner. For example, in the case of a toner manufactured by an emulsion polymerization aggregation method described later, the polymer is obtained by polymerizing a polymerizable monomer.

Hereinafter, the toner produced by the emulsion polymerization aggregation method will be described in more detail.
When a toner is produced by an emulsion polymerization aggregation method, the production process usually includes a polymerization process, a mixing process, an aggregation process, a fusion process, and a washing / drying process. That is, generally, polymer primary particles are obtained by emulsion polymerization (polymerization step), and if necessary, a colorant (pigment), wax, charge control agent, etc. are dispersed in a dispersion containing the polymer primary particles. The body is mixed (mixing step), and a flocculant is added to the dispersion to agglomerate the primary particles to form particle aggregates (aggregation step). Thus, particles are obtained (fusion process), and the obtained particles are washed and dried (washing / drying process) to obtain mother particles.

1. Polymerization process
The polymer fine particles (polymer primary particles) are not particularly limited. Therefore, either a fine particle obtained by polymerizing a polymerizable monomer in a liquid medium by a suspension polymerization method, an emulsion polymerization method or the like, or a fine particle obtained by pulverizing a lump of a polymer such as a resin is a polymer. It may be used as primary particles. However, a polymerization method, particularly an emulsion polymerization method, in particular, a method using wax as a seed in emulsion polymerization is preferable. When wax is used as a seed in emulsion polymerization, fine particles having a structure in which the polymer wraps the wax can be produced as polymer primary particles. According to this method, the wax can be contained in the toner without being exposed on the surface of the toner. For this reason, there is no contamination of the apparatus member by the wax, the chargeability of the toner is not impaired, and the low temperature fixing property, high temperature offset property, filming resistance, releasability, etc. of the toner can be improved. it can.

Hereinafter, a description will be given of a method of performing emulsion polymerization using wax as a seed, thereby obtaining polymer primary particles.
The emulsion polymerization method may be performed according to a conventionally known method. Usually, a wax is dispersed in a liquid medium in the presence of an emulsifier to form wax fine particles, and a polymerization initiator, a polymerizable monomer that gives a polymer by polymerization, that is, a polymerizable carbon-carbon double bond. Polymerization is carried out by mixing and stirring a compound having a chain transfer agent, a pH adjusting agent, a polymerization degree adjusting agent, an antifoaming agent, a protective colloid, an internal additive, and the like as necessary. As a result, an emulsion is obtained in which polymer fine particles (that is, polymer primary particles) having a structure in which the polymer wraps the wax are dispersed in the liquid medium. Examples of the structure in which the polymer wraps the wax include a core-shell type, a phase separation type, and an occlusion type, and the core-shell type is preferable.

(I. Wax)
As the wax, any known wax that can be used for this purpose can be used. For example, olefin waxes such as low molecular weight polyethylene, low molecular weight polypropylene and copolymer polyethylene; paraffin wax; silicone wax having an alkyl group; fluororesin wax such as low molecular weight polytetrafluoroethylene; higher fatty acids such as stearic acid; eicosanol Long-chain aliphatic alcohols such as behenate behenate, montanic acid ester, stearic acid ester ester wax having a long-chain aliphatic group; distearyl ketone and other long-chain alkyl group ketones; hydrogenated castor oil, Plant waxes such as carnauba wax; esters or partial esters obtained from polyhydric alcohols such as glycerin and pentaerythritol and long chain fatty acids; higher fatty acid amides such as oleic acid amide and stearic acid amide; Ester, and the like. Especially, what has at least 1 the endothermic peak by a differential thermal analysis (DSC) in 50-100 degreeC is preferable.

Among the waxes, for example, ester waxes, paraffin waxes, olefin waxes such as low molecular weight polypropylene and copolymer polyethylene, silicone waxes, and the like are preferable because a release effect can be obtained in a small amount. Paraffin wax is particularly preferable.
In addition, 1 type may be used for wax and it may use 2 or more types together by arbitrary combinations and a ratio.

  When using wax, the amount used is arbitrary. However, it is desirable that the wax is usually 3 parts by weight or more, preferably 5 parts by weight or more, and usually 40 parts by weight or less, preferably 30 parts by weight or less based on 100 parts by weight of the polymer. If the amount of wax is too small, the fixing temperature range may be insufficient. If the amount is too large, the apparatus member may be contaminated and image quality may be deteriorated.

(Ii. Emulsifier)
There is no restriction | limiting in an emulsifier, Arbitrary things can be used in the range which does not impair the effect of this invention remarkably. For example, any of nonionic, anionic, cationic and amphoteric surfactants can be used.
Examples of the nonionic surfactant include polyoxyalkylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyalkylene alkyl phenyl ethers such as polyoxyethylene octylphenyl ether, and sorbitan fatty acid esters such as sorbitan monolaurate. And the like.

Examples of the anionic surfactant include fatty acid salts such as sodium stearate and sodium oleate, alkylaryl sulfonates such as sodium dodecylbenzene sulfonate, and alkyl sulfate salts such as sodium lauryl sulfate. .
Furthermore, examples of the cationic surfactant include alkylamine salts such as laurylamine acetate and quaternary ammonium salts such as lauryltrimethylammonium chloride.

Examples of amphoteric surfactants include alkylbetaines such as lauryl betaine.
Among these, nonionic surfactants and anionic surfactants are preferable.
In addition, 1 type may be used for an emulsifier and it may use 2 or more types together by arbitrary combinations and a ratio.

  Furthermore, the amount of the emulsifier is arbitrary as long as the effects of the present invention are not significantly impaired, but the emulsifier is usually used at a ratio of 1 to 10 parts by weight with respect to 100 parts by weight of the polymerizable monomer.

(Iii. Liquid medium)
As the liquid medium, an aqueous medium is usually used, and water is particularly preferably used. However, the quality of the liquid medium is also related to the coarsening due to reaggregation of particles in the liquid medium. When the conductivity of the liquid medium is high, the dispersion stability with time tends to deteriorate. Therefore, when an aqueous medium such as water is used as the liquid medium, it is preferable to use ion-exchanged water or distilled water that has been desalted so that the electrical conductivity is usually 10 μS / cm or less, preferably 5 μS / cm or less. preferable. The conductivity is measured at 25 ° C. using a conductivity meter (personal SC meter model SC72 and detector SC72SN-11 manufactured by Yokogawa Electric Corporation).

Moreover, although there is no restriction | limiting in the usage-amount of a liquid medium, The quantity of about 1-20 weight times is normally used with respect to a polymerizable monomer.
In addition, a liquid medium may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and a ratio.
By dispersing the wax in the liquid medium in the presence of an emulsifier, fine wax particles are obtained. The order of blending the emulsifier and the wax into the liquid medium is arbitrary, but usually the emulsifier is first blended into the liquid medium, and then the wax is mixed. Moreover, you may mix | blend an emulsifier with a liquid medium continuously.

(Iv. Polymerization initiator)
After preparing the wax fine particles, a polymerization initiator is blended in the liquid medium. Any polymerization initiator can be used as long as the effects of the present invention are not significantly impaired. For example, persulfates such as sodium persulfate and ammonium persulfate; organic peroxides such as t-butyl hydroperoxide, cumene hydroperoxide and p-menthane hydroperoxide; inorganics such as hydrogen peroxide Examples thereof include peroxides. Of these, inorganic peroxides are preferable. In addition, 1 type may be used for a polymerization initiator and it may use 2 or more types together by arbitrary combinations and a ratio.

  In addition, other examples of polymerization initiators include persulfates, organic or inorganic peroxides, and reducing organic compounds such as ascorbic acid, tartaric acid, citric acid, sodium thiosulfate, sodium bisulfite, metabisulfate. A redox initiator can also be used in combination with reducing inorganic compounds such as sodium sulfite. In this case, reducing inorganic compounds may be used alone or in combination of two or more in any combination and ratio.

  Moreover, there is no restriction | limiting in the usage-amount of a polymerization initiator, It is arbitrary. However, the polymerization initiator is usually used at a ratio of 0.05 to 2 parts by weight with respect to 100 parts by weight of the polymerizable monomer.

(V. Polymerizable monomer)
After the wax fine particles are prepared, a polymerizable monomer is blended in the liquid medium in addition to the polymerization initiator. There is no particular limitation on the polymerizable monomer, but for example, styrenes, (meth) acrylic acid esters, acrylamides, monomers having Bronsted acidic groups (hereinafter simply referred to as “acidic monomers”) ), A monofunctional monomer such as a monomer having a Bronsted basic group (hereinafter sometimes simply referred to as “basic monomer”). Further, a monofunctional monomer can be used in combination with a polyfunctional monomer.

Examples of styrenes include styrene, methyl styrene, chlorostyrene, dichlorostyrene, p-tert-butyl styrene, pn-butyl styrene, pn-nonyl styrene, and the like.
Examples of the (meth) acrylic acid ester include methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, isobutyl acrylate, hydroxyethyl acrylate, 2-ethylhexyl acrylate, and methyl methacrylate. , Ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, hydroxyethyl methacrylate, and 2-ethylhexyl methacrylate.

Examples of acrylamides include acrylamide, N-propyl acrylamide, N, N-dimethyl acrylamide, N, N-dipropyl acrylamide, N, N-dibutyl acrylamide, and the like.
Furthermore, examples of the acidic monomer include monomers having a carboxyl group such as acrylic acid, methacrylic acid, maleic acid, fumaric acid and cinnamic acid; monomers having a sulfonic acid group such as sulfonated styrene; vinylbenzenesulfonamide and the like. Examples thereof include a monomer having a sulfonamide group.

Examples of the basic monomer include aromatic vinyl compounds having an amino group such as aminostyrene, nitrogen-containing heterocycle-containing monomers such as vinylpyridine and vinylpyrrolidone; amino groups such as dimethylaminoethyl acrylate and diethylaminoethyl methacrylate. Examples include (meth) acrylic acid esters.
The acidic monomer and the basic monomer may exist as a salt with a counter ion.

  Furthermore, as the polyfunctional monomer, for example, divinylbenzene, hexanediol diacrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, neopentyl glycol dimethacrylate, neopentyl glycol diacrylate, Examples include diallyl phthalate. It is also possible to use a monomer having a reactive group such as glycidyl methacrylate, N-methylolacrylamide, or acrolein. Among these, radically polymerizable bifunctional monomers, particularly divinylbenzene and hexanediol diacrylate are preferable.

  Among these, the polymerizable monomer is preferably composed of at least styrenes, (meth) acrylic acid esters, and acidic monomers having a carboxyl group. In particular, styrene is preferred as the styrene, butyl acrylate is preferred as the (meth) acrylic acid ester, and acrylic acid is preferred as the acidic monomer having a carboxyl group.

In addition, 1 type may be used for a polymerizable monomer and it may use 2 or more types together by arbitrary combinations and a ratio.
When emulsion polymerization is performed using wax as a seed, it is preferable to use an acidic monomer or a basic monomer in combination with a monomer other than these. This is because the dispersion stability of the polymer primary particles can be improved by using an acidic monomer or a basic monomer in combination.

  In this case, the amount of the acidic monomer or basic monomer is arbitrary, but the amount of the acidic monomer or basic monomer used is usually 0.05 parts by weight or more, preferably 0, relative to 100 parts by weight of the total polymerizable monomer. It is desirable that the amount be 5 parts by weight or more, more preferably 1 part by weight or more, and usually 10 parts by weight or less, preferably 5 parts by weight or less. If the blending amount of the acidic monomer or basic monomer is below the above range, the dispersion stability of the polymer primary particles may be deteriorated, and if it exceeds the upper limit, the chargeability of the toner may be adversely affected.

  Moreover, when using a polyfunctional monomer together, the compounding quantity is arbitrary, However, The compounding quantity of the polyfunctional monomer with respect to 100 weight part of polymeric monomers is 0.005 weight part or more normally, Preferably it is 0.00. 1 part by weight or more, more preferably 0.3 part by weight or more, and usually 5 parts by weight or less, preferably 3 parts by weight or less, more preferably 1 part by weight or less. By using a polyfunctional monomer, the fixability of the toner can be improved. At this time, if the blending amount of the polyfunctional monomer is below the above range, the high temperature offset resistance may be inferior, and if it exceeds the upper limit, the low temperature fixability may be inferior.

  The method for blending the polymerizable monomer into the liquid medium is not particularly limited. For example, any of batch blending, continuous blending, and intermittent blending may be used, but it is preferable to blend continuously from the viewpoint of reaction control. Moreover, when using several polymerizable monomer together, each polymerizable monomer may be mix | blended separately, and may be mix | blended after mixing beforehand. Furthermore, you may mix | blend, changing the composition of a monomer mixture.

(Vi. Chain transfer agent, etc.)
After preparing the above wax fine particles, the liquid medium may include a chain transfer agent, a pH adjuster, a polymerization degree adjuster, an antifoaming agent in addition to the polymerization initiator and the polymerizable monomer as necessary. Additives such as protective colloids and internal additives. Any of these additives can be used as long as the effects of the present invention are not significantly impaired. Moreover, these additives may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and ratios.

Any known chain transfer agent can be used. Specific examples include t-dodecyl mercaptan, 2-mercaptoethanol, diisopropylxanthogen, carbon tetrachloride, trichlorobromomethane and the like. Moreover, a chain transfer agent is normally used in the ratio of 5 weight part or less with respect to 100 weight part of polymerizable monomers.
Further, any known colloid that can be used for this purpose can be used. Specific examples include partially or fully saponified polyvinyl alcohols such as polyvinyl alcohol, and cellulose derivatives such as hydroxyethyl cellulose.

  Examples of the internal additive include those for modifying the adhesiveness, cohesiveness, fluidity, chargeability, surface resistance and the like of toners such as silicone oil, silicone varnish, and fluorine oil.

(Vii. Polymer primary particles)
Polymer initiators, polymerizable monomers, and additives as necessary are mixed in a liquid medium containing wax fine particles, stirred, and polymerized to obtain polymer primary particles. The polymer primary particles can be obtained in the form of an emulsion in a liquid medium.

There is no restriction | limiting in the order which mixes a polymerization initiator, a polymerizable monomer, an additive, etc. with a liquid medium. Further, the mixing and stirring methods are not limited and are arbitrary.
Furthermore, the reaction temperature of the polymerization (emulsion polymerization reaction) is arbitrary as long as the reaction proceeds. However, the polymerization temperature is usually 50 ° C. or higher, preferably 60 ° C. or higher, more preferably 70 ° C. or higher, and usually 120 ° C. or lower, preferably 100 ° C. or lower, more preferably 90 ° C. or lower.

  The volume average particle diameter of the polymer primary particles is not particularly limited, but is usually 0.02 μm or more, preferably 0.05 μm or more, more preferably 0.1 μm or more, and usually 3 μm or less, preferably 2 μm or less, more preferably Is 1 μm or less. If the volume average particle size is too small, it may be difficult to control the aggregation rate. If the volume average particle size is too large, the particle size of the toner obtained by aggregation tends to be large, and the target particles It may be difficult to obtain a toner having a diameter. The volume average particle diameter can be measured with a particle size analyzer using a dynamic light scattering method described later.

  In the present invention, the volume particle size distribution is measured by a dynamic light scattering method. This method obtains the particle size distribution by detecting the speed of Brownian motion of finely dispersed particles, irradiating the particles with laser light, and detecting light scattering (Doppler shift) with different phases according to the speed. It is. In actual measurement, the above volume particle size was measured using the following settings using an ultrafine particle size distribution measuring apparatus (Nikkiso Co., Ltd., UPA-EX150, hereinafter abbreviated as UPA) using a dynamic light scattering method. Do.

Measurement upper limit: 6.54 μm
Measurement lower limit: 0.0008 μm
Number of channels: 52
Measurement time: 100 sec.
Particle permeability: Absorption
Particle refractive index: N / A (not applicable)
Particle shape: Non-spherical
Density: 1 g / cm ³
Dispersion medium type: WATER
Dispersion medium refractive index: 1.333

  At the time of measurement, the dispersion of particles is diluted with a liquid medium so that the sample concentration index is in the range of 0.01 to 0.1, and the measurement is performed with a sample subjected to dispersion treatment with an ultrasonic cleaner. The volume average particle diameter according to the present invention is measured by using the result of the volume particle size distribution as an arithmetic average value.

  The polymer constituting the polymer primary particles has at least one of peak molecular weights in gel permeation chromatography, usually 3000 or more, preferably 10,000 or more, more preferably 30,000 or more, and usually 100,000 or less. , Preferably it is 70,000 or less, more preferably 60,000 or less. When the peak molecular weight is in the above range, the durability, storage stability, and fixability of the toner tend to be good. Here, as the peak molecular weight, a value converted to polystyrene is used, and components insoluble in a solvent are excluded in measurement. The peak molecular weight can be measured in the same manner as the toner described later.

  In particular, when the polymer is a styrene resin, the lower limit of the number average molecular weight of the polymer in gel permeation chromatography is usually 2,000 or more, preferably 2,500 or more, more preferably 3, The upper limit is usually 50,000 or less, preferably 40,000 or less, more preferably 35,000 or less. Furthermore, the lower limit of the weight average molecular weight of the polymer is usually 20,000 or more, preferably 30,000 or more, more preferably 50,000 or more, and the upper limit is usually 1,000,000 or less, preferably 500,000 or less. When a styrene resin in which at least one of the number average molecular weight and the weight average molecular weight, preferably both fall within the above ranges, is used as the polymer, the obtained toner has good durability, storage stability and fixability. is there. Further, the molecular weight distribution may have two main peaks. The styrene resin refers to a resin in which styrenes occupy usually 50% by weight or more, preferably 65% by weight or more in the whole polymer.

  Further, the softening point of the polymer (hereinafter sometimes abbreviated as “Sp”) is usually 150 ° C. or less, preferably 140 ° C. or less from the viewpoint of low energy fixing, and usually 80 ° C. or more. Preferably it is 100 degreeC or more from the point of high temperature offset resistance and durability. Here, the softening point of the polymer is determined by measuring 1.0 g of a sample with a nozzle 1 mm × 10 mm, a load of 30 kg, a preheating time of 50 ° C. for 5 minutes, and a temperature rising rate of 3 ° C./min in a flow tester. The temperature at the midpoint of the strand from the start to the end of the flow can be obtained.

  Furthermore, the glass transition temperature [Tg] of the polymer is usually 80 ° C. or lower, preferably 70 ° C. or lower. If the glass transition temperature [Tg] of the polymer is too high, there is a possibility that low energy fixing cannot be performed. The lower limit of the glass transition temperature [Tg] of the polymer is usually 40 ° C. or higher, preferably 50 ° C. or higher. If the glass transition temperature [Tg] of the polymer is too low, the blocking resistance may be lowered. Here, the glass transition temperature [Tg] of the polymer is the intersection of the two tangent lines by drawing a tangent line at the start of the transition (inflection) of the curve measured at a heating rate of 10 ° C./min in a differential scanning calorimeter. It can be calculated as the temperature.

  The softening point and glass transition temperature [Tg] of the polymer can be adjusted to the above ranges by adjusting the kind of polymer, the monomer composition ratio, the molecular weight, and the like.

2. Mixing process and agglomeration process
By mixing and aggregating pigment particles in the emulsion in which the polymer primary particles are dispersed, an emulsion of aggregates (aggregated particles) containing a polymer and a pigment is obtained. In this case, it is preferable to prepare a pigment particle dispersion in which the pigment is uniformly dispersed in advance in a liquid medium using a surfactant or the like, and mix this with an emulsion of polymer primary particles. At this time, an aqueous solvent such as water is usually used as the liquid medium of the pigment particle dispersion, and the pigment particle dispersion is prepared as an aqueous dispersion. At that time, if necessary, a wax, a charge control agent, a release agent, an internal additive and the like may be mixed into the emulsion. Moreover, in order to maintain the stability of the pigment particle dispersion, the above-described emulsifier may be added.

As the polymer primary particles, the polymer primary particles obtained by emulsion polymerization can be used. At this time, one type of polymer primary particles may be used, or two or more types may be used in any combination and ratio. Furthermore, polymer primary particles (hereinafter, referred to as “combined polymer particles” as appropriate) produced with raw materials and reaction conditions different from those of the emulsion polymerization described above may be used in combination.
Examples of the combined polymer particles include fine particles obtained by suspension polymerization or pulverization. Resin can be used as the material for such combined polymer particles. As this resin, for example, vinyl acetate, vinyl chloride, vinyl, in addition to the monomer (co) polymer used for the emulsion polymerization described above. Thermoplastics such as homopolymers or copolymers of vinyl monomers such as alcohol, vinyl butyral, vinyl pyrrolidone, saturated polyester resins, polycarbonate resins, polyamide resins, polyolefin resins, polyarylate resins, polysulfone resins, polyphenylene ether resins, etc. Examples thereof include thermosetting resins such as resins and unsaturated polyester resins, phenol resins, epoxy resins, urethane resins, and rosin-modified maleic resins. In addition, 1 type may also be used for these combined use polymer particles, and 2 or more types may be used together by arbitrary combinations and a ratio. However, the ratio of the combined polymer particles is usually 5% by weight or less, preferably 4% by weight or less, more preferably 3% by weight or less based on the total of the polymer primary particles and the polymer of the combined polymer particles. .

Moreover, there is no restriction | limiting in a pigment, According to the use, arbitrary things can be used. However, the pigment usually exists in the form of particles as colorant particles, but it is preferable that the pigment particles have a smaller density difference from the polymer primary particles in the emulsion polymerization aggregation method. This is because when the density difference is smaller, a uniform aggregated state is obtained when the polymer temporary particles and the pigment are aggregated, and thus the performance of the obtained toner is improved. The density of the polymer primary particles is usually 1.1 to 1.3 g / cm ³ .

From the above viewpoint, the true density of the pigment particles measured by the pycnometer method specified in JIS K 5101-11-1: 2004 is usually 1.2 g / cm ³ or more, preferably 1.3 g / cm ³ or more. Also, it is usually less than 2.0 g / cm ³ , preferably 1.9 g / cm ³ or less, more preferably 1.8 g / cm ³ or less. When the true density of the pigment is large, the sedimentation property in a liquid medium tends to deteriorate. In addition, considering problems such as storage stability and sublimation, the pigment is preferably carbon black or an organic pigment.

Examples of pigments that satisfy the above conditions include yellow pigments, magenta pigments, and cyan pigments shown below. Further, as the black pigment, carbon black or a mixture of the following yellow pigment / magenta pigment / cyan pigment mixed with black is used.
Among these, carbon black used as a black pigment exists as an aggregate of very fine primary particles, and when dispersed as a pigment particle dispersion, the carbon black particles are likely to become coarse due to reaggregation. . The degree of reagglomeration of carbon black particles is correlated with the amount of impurities contained in carbon black (the degree of residual undecomposed organic matter), and if there are many impurities, coarsening due to reaggregation after dispersion is significant. Show the trend.

For quantitative evaluation of the amount of impurities, the ultraviolet absorbance of the toluene extract of carbon black measured by the following measurement method is usually 0.05 or less, preferably 0.03 or less. In general, the carbon black of the channel method tends to have a large amount of impurities, and therefore, the carbon black used for the toner used in the present invention is preferably manufactured by the furnace method.
The ultraviolet absorbance (λc) of carbon black is determined by the following method. That is, first, 3 g of carbon black was sufficiently dispersed and mixed in 30 ml of toluene. Filter using 5C filter paper. Thereafter, the filtrate was placed in a quartz cell having a 1 cm square light absorption part, and the value (λs) measured for absorbance at a wavelength of 336 nm using a commercially available ultraviolet spectrophotometer, and the value obtained by measuring the absorbance of toluene alone as a reference using the same method. From (λo), the ultraviolet absorbance is obtained by λc = λs−λo. Examples of commercially available spectrophotometers include an ultraviolet-visible spectrophotometer (UV-3100PC) manufactured by Shimadzu Corporation.

Moreover, as a yellow pigment, the compound represented by the condensed azo compound, the isoindolinone compound, etc. is used, for example. Specifically, C.I. I. Pigment Yellow 12, 13, 14, 15, 17, 62, 74, 83, 93, 94, 95, 109, 110, 111, 128, 129, 147, 168, 180, 185 and the like are preferably used.
Further, examples of magenta pigments include condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinones, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds, and perylene compounds.

  Specifically, C.I. I. Pigment Red 2, 3, 5, 6, 7, 23, 48: 2, 48: 3, 48: 4, 57: 1, 81: 1, 122, 144, 146, 166, 169, 177, 184, 185, 202, 206, 207, 209, 220, 221, 238, 254, C.I. I. Pigment Violet 19 or the like is preferably used.

  Among them, C.I. I. Pigment red 122, 202, 207, 209, C.I. I. A quinacridone pigment represented by pigment violet 19 is particularly preferred. This quinacridone pigment is suitable as a magenta pigment because of its clear hue and high light resistance. Among the quinacridone pigments, C.I. I. A compound represented by CI Pigment Red 122 is particularly preferable.

Examples of cyan pigments that can be used include copper phthalocyanine compounds and derivatives thereof, anthraquinone compounds, basic dye lake compounds, and the like. Specifically, C.I. I. Pigment Blue 1, 7, 15, 15: 1, 15: 2, 15: 3, 15: 4, 60, 62, 66 and the like can be used particularly preferably.
In addition, 1 type may be used for a pigment and it may use 2 or more types together by arbitrary combinations and a ratio.

  The above pigment is dispersed in a liquid medium, and is then mixed with an emulsion containing polymer primary particles after forming a pigment particle dispersion. At this time, the amount of the pigment particles used in the pigment particle dispersion is usually 3 parts by weight or more, preferably 5 parts by weight or more, and usually 50 parts by weight or less, preferably 40 parts by weight with respect to 100 parts by weight of the liquid medium. Or less. If the blending amount of the colorant exceeds the above range, the pigment concentration is high, which is not preferable because the probability of reaggregation of the pigment particles in the dispersion increases. It is not preferable because it is difficult to obtain a distribution.

The ratio of the amount of the pigment used relative to the polymer contained in the polymer primary particles is usually 1% by weight or more, preferably 3% by weight or more, and usually 20% by weight or less, preferably 15% by weight or less. If the amount of the pigment used is too small, the image density may become thin, and if it is too large, the aggregation control may be difficult.
Further, the pigment particle dispersion may contain a surfactant. Although there is no restriction | limiting in particular in this surfactant, For example, the thing similar to the surfactant illustrated as an emulsifier in description of an emulsion polymerization method is mentioned. Of these, nonionic surfactants, anionic surfactants such as alkylaryl sulfonates such as sodium dodecylbenzenesulfonate, and polymer surfactants are preferably used. In this case, one type of surfactant may be used, or two or more types may be used in any combination and ratio.

The proportion of the pigment in the pigment particle dispersion is usually 10% to 50% by weight.
Further, as the liquid medium of the pigment particle dispersion, an aqueous medium is usually used, and preferably water is used. At this time, the water quality of the polymer primary particles and the pigment particle dispersion is also related to the coarsening due to reaggregation of each particle, and when the conductivity is high, the dispersion stability with time tends to deteriorate. Therefore, it is preferable to use ion-exchanged water or distilled water that has been desalted so that the electrical conductivity is usually 10 μS / cm or less, preferably 5 μS / cm or less. The conductivity is measured at 25 ° C. using a conductivity meter (personal SC meter model SC72 and detector SC72SN-11 manufactured by Yokogawa Electric Corporation).

Further, when the pigment is mixed with the emulsion containing the polymer primary particles, a wax may be mixed with the emulsion. As the wax, the same waxes described in the explanation of the emulsion polymerization method can be used. The wax may be mixed before, during or after mixing the pigment with the emulsion containing the polymer primary particles.
Further, when the pigment is mixed with the emulsion containing the polymer primary particles, a charge control agent may be mixed with the emulsion.

  As the charge control agent, any known charge control agent can be used. Examples of the positively chargeable charge control agent include nigrosine dyes, quaternary ammonium salts, triphenylmethane compounds, imidazole compounds, polyamine resins, and the like. Examples of negative charge control agents include azo complex dyes containing atoms such as Cr, Co, Al, Fe, and B; metal salts or metal complexes of salicylic acid or alkylsalicylic acid; curixarene compounds, benzyl Examples include metal salts or metal complexes of acids, amide compounds, phenol compounds, naphthol compounds, phenol amide compounds, and the like. Among these, colorless or light-colored ones are preferably selected in order to avoid color tone problems as toners, and quaternary ammonium salts and imidazole compounds are particularly preferable as positively chargeable charge control agents, and negatively chargeable charge control agents. As these, alkyl salicylic acid complex compounds and curixarene compounds containing atoms such as Cr, Co, Al, Fe and B are preferred. In addition, 1 type may be used for a charge control agent and it may use 2 or more types together by arbitrary combinations and a ratio.

Although there is no restriction | limiting in the usage-amount of a charge control agent, Usually 0.01 weight part or more with respect to 100 weight part of polymers, Preferably it is 0.1 weight part or more, Moreover, 10 weight part or less, Preferably it is 5 weight part or less. It is. If the amount of the charge control agent used is too small or too large, the desired charge amount may not be obtained.
The charge control agent may be mixed before, during or after mixing the pigment with the emulsion containing the polymer primary particles.

Moreover, it is desirable that the charge control agent is mixed at the time of aggregation in the state of being emulsified in a liquid medium (usually an aqueous medium) in the same manner as the pigment particles.
After the pigment is mixed in the emulsion containing the polymer primary particles, the polymer primary particles and the pigment are aggregated. As described above, at the time of mixing, the pigment is usually mixed in the state of a pigment particle dispersion.

The aggregation method is not limited and is arbitrary, and examples thereof include heating, electrolyte mixing, pH adjustment, and the like. Especially, the method of mixing electrolyte is preferable.
Examples of the electrolyte when the agglomeration is performed by mixing the electrolyte include chlorides such as NaCl, KCl, LiCl, MgCl ₂ , CaCl ₂ ; Na ₂ SO ₄ , K ₂ SO ₄ , Li ₂ SO ₄ , MgSO ₄ , Inorganic salts such as sulfates such as CaSO ₄ , ZnSO ₄ , Al ₂ (SO ₄ ) ₃ , Fe ₂ (SO ₄ ) ₃ ; organic salts such as CH ₃ COONa and C ₆ H ₅ SO ₃ Na. Of these, inorganic salts having a divalent or higher polyvalent metal cation are preferred.

In addition, 1 type may be used for electrolyte and 2 or more types may be used together by arbitrary combinations and a ratio.
The amount of electrolyte used varies depending on the type of electrolyte, but is usually 0.05 parts by weight or more, preferably 0.1 parts by weight or more, and usually 25 parts by weight or less, based on 100 parts by weight of the solid component in the emulsion. Preferably it is 15 weight part or less, More preferably, it is 10 weight part or less. When agglomeration is performed by mixing electrolytes, if the amount of electrolyte used is too small, the agglomeration reaction proceeds slowly and fine particles of 1 μm or less remain after the agglomeration reaction, and the average particle size of the obtained agglomerates is the target. There is a possibility that the particle size will not be reached, and if the amount of electrolyte used is too large, the agglomeration reaction will occur rapidly, making it difficult to control the particle size. May be included.

The obtained agglomerates are preferably subsequently spheroidized by heating in a liquid medium, similarly to the secondary agglomerates (agglomerates that have undergone the melting step) described later. Heating may be performed under the same conditions as in the case of the secondary aggregate (same conditions as described in the description of the fusion process).
On the other hand, when the aggregation is performed by heating, the temperature condition is arbitrary as long as the aggregation proceeds. Specific temperature conditions are usually 15 ° C. or higher, preferably 20 ° C. or higher, and aggregation is performed under a temperature condition of a polymer primary particle polymer glass transition temperature [Tg] or lower, preferably 55 ° C. or lower. . Although the time for agglomeration is arbitrary, it is usually 10 minutes or longer, preferably 60 minutes or longer, and usually 300 minutes or shorter, preferably 180 minutes or shorter.

  In addition, stirring is preferably performed when the aggregation is performed. Although the apparatus used for stirring is not specifically limited, What has a double helical blade is preferable.

  The obtained agglomerates may proceed directly to the next step of forming a resin coating layer (encapsulation step), or may proceed to the encapsulation step after subsequent fusion treatment by heating in a liquid medium. . Desirably, after the aggregation step, the encapsulation step is performed, and the fusion step is performed by heating at a temperature equal to or higher than the glass transition temperature [Tg] of the encapsulated resin fine particles. It is preferable because it does not cause deterioration (thermal deterioration, etc.).

3. Encapsulation process
After obtaining the aggregate, it is preferable to form a resin coating layer on the aggregate as necessary. The encapsulation process for forming a resin coating layer on the aggregate is a process for coating the aggregate with a resin by forming a resin coating layer on the surface of the aggregate. Thereby, the manufactured toner is provided with the resin coating layer. In the encapsulation process, the entire toner may not be completely covered, but the pigment makes it possible to obtain a toner that is not substantially exposed on the surface of the toner particles. Although there is no restriction | limiting in the thickness of the resin coating layer in this case, Usually, it is the range of 0.01 micrometer-0.5 micrometer.

The method for forming the resin coating layer is not particularly limited, and examples thereof include a spray drying method, a mechanical particle composite method, an in-situ polymerization method, and a submerged particle coating method.
As a method for forming the resin coating layer by the spray drying method, for example, an aggregate forming an inner layer and resin fine particles forming a resin coating layer are dispersed in an aqueous medium to prepare a dispersion, A resin coating layer can be formed on the surface of the aggregate by spraying and drying.

  In addition, as a method for forming a resin coating layer by the mechanical particle composite method, for example, an aggregate that forms an inner layer and resin fine particles that form a resin coating layer are dispersed in a gas phase and mechanically formed in a narrow gap. In this method, resin fine particles are formed into a film on the surface of the aggregate by applying a strong force. For example, a device such as a hybridization system (manufactured by Nara Machinery Co., Ltd.), a mechanofusion system (manufactured by Hosokawa Micron Corporation), or the like can be used.

Further, as the in-situ polymerization method, for example, the aggregate is dispersed in water, the monomer and the polymerization initiator are mixed, adsorbed on the surface of the aggregate, and heated to polymerize the monomer. Thus, a resin coating layer is formed on the surface of the aggregate that is the inner layer.
The submerged particle coating method includes, for example, reacting or bonding an aggregate forming an inner layer and resin fine particles forming an outer layer in an aqueous medium to form a resin coating layer on the surface of the aggregate forming the inner layer. Is a method of forming

  The resin fine particles used for forming the outer layer are particles mainly having a resin component smaller than the aggregate. The resin fine particles are not particularly limited as long as they are particles composed of a polymer. However, from the viewpoint that the thickness of the outer layer can be controlled, it is preferable to use resin fine particles similar to the above-described polymer primary particles, aggregates, or fused particles obtained by fusing the aggregates. The fine resin particles similar to these polymer primary particles can be produced in the same manner as the polymer primary particles in the aggregate used for the inner layer.

The amount of resin fine particles used is arbitrary, but it is usually 1% by weight or more, preferably 5% by weight or more, and usually 50% by weight or less, preferably 25% by weight or less based on the toner particles. Is desirable.
Furthermore, in order to effectively fix or fuse the resin fine particles to the aggregate, the resin fine particles usually have a particle size of preferably about 0.04 μm to 1 μm.

  The glass transition temperature [Tg] of the polymer component (resin component) used in the resin coating layer is usually 60 ° C. or higher, preferably 70 ° C. or higher, and usually 110 ° C. or lower. Further, the glass transition temperature [Tg] of the polymer component used in the resin coating layer is preferably higher by 5 ° C. or higher than the glass transition temperature [Tg] of the polymer primary particles, and is higher by 10 ° C. or higher. It is more preferable. If the glass transition temperature [Tg] is too low, storage in a general environment is difficult, and if it is too high, sufficient meltability cannot be obtained.

Furthermore, it is preferable to contain polysiloxane wax in the resin coating layer. Thereby, the advantage of improvement in high temperature offset resistance can be obtained. Examples of the polysiloxane wax include silicone wax having an alkyl group.
The content of the polysiloxane wax is not limited, but is usually 0.01% by weight or more, preferably 0.05% by weight or more, more preferably 0.08% by weight or more, and usually 2% by weight or less in the toner. Preferably it is 1 weight% or less, More preferably, you may be 0.5 weight% or less. If the amount of the polysiloxane wax in the resin coating layer is too small, the high temperature offset resistance may be insufficient, and if it is too large, the blocking resistance may be lowered.

  The method for containing the polysiloxane wax in the resin coating phase is arbitrary. For example, emulsion polymerization is performed using the polysiloxane wax as a seed, and the obtained resin fine particles and the aggregates forming the inner layer are mixed in an aqueous medium. And a resin coating layer containing polysiloxane wax on the surface of the agglomerate forming the inner layer.

4). Fusion process
In the fusing step, the aggregates are melt-integrated by heat-treating the aggregates.
In addition, when encapsulating resin fine particles are formed by forming a resin coating layer on the aggregate, the polymer constituting the aggregate and the resin coating layer on the surface thereof are integrated by heat treatment. It will be. Thereby, the pigment particles are obtained in a form that is not substantially exposed on the surface.

  The temperature of the heat treatment in the fusion step is set to a temperature equal to or higher than the glass transition temperature [Tg] of the polymer primary particles constituting the aggregate. Moreover, when a resin coating layer is formed, it is set as the temperature more than the glass transition temperature [Tg] of the polymer component which forms a resin coating layer. Although specific temperature conditions are arbitrary, it is preferable that it is normally 5 (degreeC) or more higher than the glass transition temperature [Tg] of the polymer component which forms a resin coating layer. Although there is no restriction | limiting in the upper limit, below "the temperature 50 (degreeC) higher than the glass transition temperature [Tg] of the polymer component which forms a resin coating layer" is preferable.

  In addition, although the time of heat processing is based also on processing capacity and a manufacturing amount, it is 0.5 to 6 hours normally.

5). Cleaning / drying process
When the above-described steps are performed in a liquid medium, after the fusing step, the encapsulated resin particles obtained are washed and dried to remove the liquid medium, thereby obtaining a toner. There are no restrictions on the washing and drying methods, and they are arbitrary.

<Physical properties of toner>
・ Average toner circularity
The shape of the toner used in the present invention is such that the shape of each particle included in the particle group constituting the toner is closer to each other, and the closer to a spherical shape, the more the charge amount is localized in the toner particles. It tends to be difficult and developability tends to be uniform, which is preferable for improving image quality. In particular, if the shape of the toner is a perfect spherical shape, the contact area with the electrophotographic photosensitive member may be reduced, the toner transfer rate may be increased, and the toner consumption may be reduced. . On the other hand, it is difficult to manufacture a perfect spherical toner, and the cost of the toner increases. Therefore, it is sufficient that the toner is close to a sphere under a certain condition, and it is not necessary to be a perfect sphere.
Therefore, specifically, the toner used in the present invention has an average circularity measured by a flow particle image analyzer of usually 0.940 or more, preferably 0.950 or more, more preferably 0.960 or more. Particularly preferred is 0.970 or more. The upper limit of the average circularity is not limited as long as it is 1.000 or less, but is preferably 0.998 or less, more preferably 0.995 or less from the viewpoint of ease of production.

The average circularity is used as a simple method for quantitatively expressing the shape of toner particles. In the present invention, the average circularity is measured using a flow type particle image analyzer FPIA-2000 manufactured by Sysmex Corporation. Then, the circularity [a] of the measured particle is obtained by the following equation (A).
Circularity a = L0 / L (A)
(In Formula (A), L0 represents the perimeter of a circle having the same projected area as the particle image, and L represents the perimeter of the particle image when image processing is performed.)
The circularity is an index of the degree of unevenness of the toner particles, and indicates 1.00 when the toner is a perfect sphere. The more complicated the surface shape, the smaller the circularity.

  A specific method for measuring the average circularity is as follows. That is, a surfactant (preferably alkylbenzene sulfonate) is added as a dispersant to 20 ml of water from which impurities in the container have been removed in advance, and about 0.05 g of a measurement sample (toner) is further added. The suspension in which this sample is dispersed is irradiated with ultrasonic waves for 30 seconds, the dispersion concentration is set to 3.0 to 8.0 thousand pieces / μl, and the above flow-type particle image measuring apparatus is used. The circularity distribution of the particles having the equivalent circle diameter is measured.

・ Physical properties related to toner particle size
There is no restriction on the volume average particle diameter [Dv] of the toner used in the present invention, and it is optional as long as the effect of the present invention is not significantly impaired, but it is usually 4 μm or more, preferably 5 μm or more, and usually 10 μm or less, preferably 8 μm or less. If the volume average particle diameter [Dv] of the toner is too small, the stability of the image quality may be lowered, and if it is too large, the resolution may be lowered.

  The toner used in the present invention has a value [Dv / Dn] obtained by dividing the volume average particle diameter [Dv] by the number average particle diameter [Dn], usually 1.0 or more, and usually 1.25 or less. Preferably it is 1.20 or less, more preferably 1.15 or less. The value of [Dv / Dn] represents the state of the particle size distribution, and the closer this value is to 1.0, the sharper the particle size distribution. A sharper particle size distribution is desirable because the chargeability of the toner becomes uniform.

  Furthermore, the toner used in the present invention has a volume fraction of 25 μm or more in particle size, usually 1% or less, preferably 0.5% or less, more preferably 0.1% or less, and still more preferably 0.05% or less. It is. The smaller this value, the better. This means that the ratio of the coarse powder contained in the toner is small. If the coarse powder is small, the amount of toner consumed during continuous development is small and the image quality is stable. Although it is most preferable that there is no coarse powder having a particle size of 25 μm or more, it is difficult in actual production, and it is usually not necessary to make it 0.005% or less.

The toner used in the present invention has a volume fraction of a particle size of 15 μm or more, usually 2% or less, preferably 1% or less, more preferably 0.1% or less. Although it is most preferable that there is no coarse powder having a particle size of 15 μm or more, it is difficult in actual production, and it is usually not necessary to make it 0.01% or less.
Furthermore, it is desirable that the toner used in the present invention has a number fraction with a particle size of 5 μm or less, usually 15% or less, preferably 10% or less, because this is effective in improving image fog.

  Here, the volume average particle diameter [Dv], number average particle diameter [Dn], volume fraction, number fraction, and the like of the toner can be measured as follows. That is, as the toner particle size measuring device, a multisizer type II or type III (manufactured by Beckman Coulter, Inc.) of a Coulter counter is used, and an interface for outputting the number distribution / volume distribution and a general personal computer are connected. To use. In addition, Isoton II is used as the electrolytic solution. As a measuring method, 0.1 ml to 5 ml of a surfactant (preferably alkylbenzenesulfonate) is added as a dispersant to 100 ml to 150 ml of the electrolytic solution, and further 2 mg to 20 mg of a measurement sample (toner) is added. Then, the electrolytic solution in which the sample is suspended is subjected to a dispersion treatment with an ultrasonic disperser for about 1 minute to 3 minutes, and is measured using a multisizer type II or type III of the Coulter counter using a 100 μm aperture. Thus, the number and volume of the toner are measured to calculate the number distribution and the volume distribution, respectively, and the volume average particle diameter [Dv] and the number average particle diameter [Dn] are obtained, respectively.

・ Physical properties related to the molecular weight of the toner
At least one of the peak molecular weights in the gel permeation chromatography (hereinafter sometimes abbreviated as GPC) of the THF soluble content of the toner used in the present invention is usually 10,000 or more, preferably 20,000 or more, more preferably. Is 30,000 or more, usually 150,000 or less, preferably 100,000 or less, more preferably 70,000 or less. THF refers to tetrahydrofuran. When the peak molecular weight is lower than the above range, the mechanical durability in the non-magnetic one-component development method may be deteriorated. When the peak molecular weight is higher than the above range, the low temperature fixability and the fixing strength are deteriorated. There is a case.

Further, the THF-insoluble content of the toner is usually 10% or more, preferably 20% or more, and usually 60% or less, preferably 50% or less, as measured by a weight method by Celite filtration described later. If it is not within the above range, it may be difficult to achieve both mechanical durability and low-temperature fixability.
The peak molecular weight of the toner used in the present invention is measured under the following conditions using a measuring apparatus: HLC-8120GPC (manufactured by Tosoh Corporation).

That is, the column is stabilized in a heat chamber at 40 ° C., and tetrahydrofuran (THF) as a solvent is allowed to flow through the column at this temperature at a flow rate of 1 ml per minute. Next, the toner is dissolved in THF and filtered through a 0.2 μm filter, and the filtrate is used as a sample.
The measurement is performed by injecting 50 to 200 μl of a THF solution of a resin with the sample concentration (resin concentration) adjusted to 0.05 to 0.6 mass% into the measuring device. In measuring the molecular weight of the sample (resin component in the toner), the molecular weight distribution of the sample is calculated from the relationship between the logarithmic value of the calibration curve created by several monodisperse polystyrene standard samples and the number of counts. As a standard polystyrene sample for preparing a calibration curve, for example, Pressure Chemical Co. Manufactured by Toyo Soda Kogyo Co., Ltd., with molecular weights of 6 × 10 ² , 2.1 × 10 ³ , 4 × 10 ³ , 1.75 × 10 ⁴ , 5.1 × 10 ⁴ , 1.1 × 10 ⁵ , It is appropriate to use 3.9 × 10 ⁵ , 8.6 × 10 ⁵ , 2 × 10 ⁶ , 4.48 × 10 ⁶ , and use at least about 10 standard polystyrene samples. An RI (refractive index) detector is used as the detector.

Furthermore, as a column used in the measurement method, in order to accurately measure a molecular weight region of 10 ³ to 2 × 10 ⁶ , it is preferable to combine a plurality of commercially available polystyrene gel columns, for example, manufactured by Waters A combination of μ-styrel 500, 103, 104, 105 and a combination of shodex KA801, 802, 803, 804, 805, 806, 807 manufactured by Showa Denko KK are preferable.

  Further, the measurement of the insoluble content of tetrahydrofuran (THF) in the toner can be performed as follows. That is, 1 g of a sample (toner) was added to 100 g of THF, and allowed to stand still at 25 ° C. for 24 hours. After filtration using 10 g of Celite, the solvent of the filtrate was distilled off to determine the THF-soluble matter, and subtracted from 1 g. Insoluble matter can be calculated.

・ Softening point and glass transition temperature of toner
There is no restriction on the softening point [Sp] of the toner used in the present invention, and it is optional as long as the effects of the present invention are not significantly impaired. From the viewpoint of fixing with low energy, it is usually 150 ° C. or lower, preferably 140 ° C. or lower. is there. Further, from the viewpoint of high temperature offset resistance and durability, the softening point is usually 80 ° C. or higher, preferably 100 ° C. or higher.

The toner softening point [Sp] was measured with a flow tester under the conditions of 1.0 g of a sample of 1 mm × 10 mm nozzle, a load of 30 kg, a preheating time of 50 ° C. for 5 minutes, and a heating rate of 3 ° C./min. The temperature at the midpoint of the strand from the start to the end of the flow can be obtained.
Further, the glass transition temperature [Tg] of the toner used in the present invention is not limited and may be arbitrary as long as the effects of the present invention are not significantly impaired. However, when the temperature is usually 80 ° C. or lower, preferably 70 ° C. or lower, low energy It is desirable because it can be fixed by. The glass transition temperature [Tg] is usually 40 ° C. or higher, preferably 50 ° C. or higher, from the viewpoint of blocking resistance.

The glass transition temperature [Tg] of the toner is obtained by drawing a tangent line at the start of the transition (inflection) of the curve measured with a differential scanning calorimeter at a temperature rising rate of 10 ° C./min. It can be determined as temperature.
The softening point [Sp] and glass transition temperature [Tg] of the toner are greatly affected by the type and composition ratio of the polymer contained in the toner. Therefore, the softening point [Sp] and the glass transition temperature [Tg] of the toner can be adjusted by appropriately optimizing the type and composition of the polymer. It can also be adjusted by the molecular weight of the polymer, the gel content, the type of low melting point components such as wax, and the blending amount.

<Wax in toner>
When the toner used in the present invention contains a wax, the dispersed particle diameter of the wax in the toner particles is usually 0.1 μm or more, preferably 0.3 μm or more as an average particle diameter, and the upper limit is usually 3 μm. Hereinafter, it is preferably 1 μm or less. If the dispersed particle size is too small, the effect of improving the filming resistance of the toner may not be obtained. If the dispersed particle size is too large, the wax will be easily exposed on the surface of the toner, and the chargeability and heat resistance will be reduced. May be reduced.

The dispersed particle diameter of the wax is not limited to the method in which the toner is sliced and observed with an electron microscope, or the toner polymer is eluted with an organic solvent in which the wax does not dissolve, and then filtered through a filter. Can be confirmed by a method of measuring with a microscope.
Further, the ratio of the wax in the toner is arbitrary as long as the effects of the present invention are not significantly impaired, but is usually 0.05% by weight or more, preferably 0.1% by weight or more, and usually 20% by weight or less, preferably Is 15% by weight or less. If the amount of wax is too small, the fixing temperature range may be insufficient. If the amount is too large, the apparatus member may be contaminated and the image quality may deteriorate.

<Externally added fine particles>
In order to improve toner fluidity, charging stability, anti-blocking property at high temperature, and the like, external additive fine particles may be attached to the surface of the toner particles.
As a method for attaching the externally added fine particles to the toner particle surface, for example, in the above-described toner manufacturing method, the secondary aggregate and the externally added fine particles are mixed in a liquid medium and then heated to externally add the toner particles onto the toner particles. Examples include a method of fixing fine particles; a method of mixing or fixing externally added fine particles to toner particles obtained by separating, washing, and drying secondary aggregates from a liquid medium.

  Examples of the mixer used when the toner particles and the externally added fine particles are mixed in a dry process include a Henschel mixer, a super mixer, a nauter mixer, a V-type mixer, a Redige mixer, a double cone mixer, and a drum type mixer. Can be mentioned. In particular, it is preferable to use a high-speed agitation type mixer such as a Henschel mixer or a super mixer, and appropriately mix the mixture by stirring and mixing uniformly by appropriately setting the blade shape, the number of revolutions, the time, the number of times of driving and stopping, and the like.

In addition, as a device used for fixing toner particles and externally added fine particles in a dry manner, a compression shearing device capable of applying compressive shear stress, a particle surface melting device capable of melting the particle surface, etc. Is mentioned.
A compression shearing apparatus generally has a narrow gap portion composed of a head surface and a head surface, a head surface and a wall surface, or a wall surface and a wall surface that move relatively while maintaining a gap, and particles to be processed are disposed in the gap. By being forced to pass through the portion, compressive stress and shear stress are applied to the particle surface without substantial pulverization. An example of such a compression shearing apparatus is a mechanofusion apparatus manufactured by Hosokawa Micron.

On the other hand, the particle surface melting treatment apparatus is generally configured so as to fix the externally added fine particles by instantaneously heating the mixture of the basic fine particles and the externally added fine particles above the melting start temperature of the basic fine particles using a hot air stream or the like. The Examples of such a particle surface melting apparatus include a surfing system manufactured by Nippon Pneumatic Co., Ltd.
As the externally added fine particles, known fine particles that can be used for this purpose can be used. Examples thereof include inorganic fine particles and organic fine particles.

  Examples of the inorganic fine particles include silicon carbide, boron carbide, titanium carbide, zirconium carbide, hafnium carbide, vanadium carbide, tantalum carbide, niobium carbide, tungsten carbide, chromium carbide, molybdenum carbide, calcium carbide and the like, boron nitride, nitriding Nitride such as titanium, zirconium nitride, silicon nitride, boride such as zirconium boride, silica, colloidal silica, titanium oxide, aluminum oxide, calcium oxide, magnesium oxide, zinc oxide, copper oxide, zirconium oxide, cerium oxide, talc , Oxides and hydroxides such as hydrotalcite, various titanate compounds such as calcium titanate, magnesium titanate, strontium titanate, barium titanate, tricalcium phosphate, calcium dihydrogen phosphate, monohydrogen phosphate calcium Phosphoric compounds such as substituted calcium phosphates in which a portion of the phosphate ions is replaced by anions, sulfides such as molybdenum disulfide, fluorides such as magnesium fluoride and fluorocarbon, aluminum stearate, calcium stearate, stearic acid Various carbon blacks including metal soaps such as zinc and magnesium stearate, talc, bentonite, and conductive carbon black can be used. Furthermore, magnetic materials such as magnetite, maghematite, and an intermediate between magnetite and maghematite may be used.

On the other hand, as the organic fine particles, for example, styrene resin, acrylic resin such as polymethyl acrylate and polymethyl methacrylate, epoxy resin, melamine resin, tetrafluoroethylene resin, trifluoroethylene resin, polyvinyl chloride, Fine particles such as polyethylene and polyacrylonitrile can be used.
Among these externally added fine particles, silica, titanium oxide, alumina, zinc oxide, carbon black and the like are particularly preferably used.

In addition, 1 type may be used for an external addition fine particle, and 2 or more types may be used together by arbitrary combinations and a ratio.
In addition, the surface of these inorganic or organic fine particles may be a silane coupling agent, titanate coupling agent, silicone oil, modified silicone oil, silicone varnish, fluorine silane coupling agent, fluorine silicone oil, amino group or fourth group. Surface treatment such as hydrophobization may be performed by a treating agent such as a coupling agent having a quaternary ammonium base. In addition, 1 type may be used for a processing agent and it may use 2 or more types together by arbitrary combinations and a ratio.

  Further, the number average particle diameter of the externally added fine particles is arbitrary as long as the effect of the present invention is not significantly impaired, but is usually 0.001 μm or more, preferably 0.005 μm or more, and usually 3 μm or less, preferably 1 μm or less. A plurality of those having different average particle diameters may be blended. The average particle diameter of the externally added fine particles can be determined by observation with an electron microscope, conversion from the value of the BET specific surface area, or the like.

  The ratio of the externally added fine particles to the toner is arbitrary as long as the effects of the present invention are not significantly impaired. However, the ratio of the externally added fine particles to the total weight of the toner and the externally added fine particles is usually 0.1% by weight or more, preferably 0.3% by weight or more, more preferably 0.5% by weight or more, and usually 10%. It is desirable that the content is not more than wt%, preferably not more than 6 wt%, more preferably not more than 4 wt%. If the amount of the externally added fine particles is too small, the fluidity and the charging stability may be insufficient, and if the amount is too large, the fixability may be deteriorated.

<Other toner properties>
The charging characteristics of the toner used in the present invention may be negatively charged or positively charged, and can be set according to the method of the image forming apparatus used. The charging characteristics of the toner can be adjusted by the selection and composition ratio of toner base particle components such as a charge control agent, the selection and composition ratio of externally added fine particles, and the like.

The toner used in the present invention can be used as a one-component developer or mixed with a carrier to be used as a two-component developer.
When used as a two-component developer, the carrier that is mixed with the toner to form the developer may be, for example, a known magnetic substance such as an iron powder, ferrite, or magnetite carrier, or a resin on the surface thereof. A coated one or a magnetic resin carrier can be used.

As the carrier coating resin, for example, generally known styrene resins, acrylic resins, styrene acrylic copolymer resins, silicone resins, modified silicone resins, fluorine resins, and the like can be used. Is not to be done.
The average particle diameter of the carrier is not particularly limited, but those having an average particle diameter of 10 to 200 μm are preferable. These carriers are preferably used in a ratio of 5 to 100 parts by weight with respect to 1 part by weight of the toner.

  The formation of a full color image by electrophotography can be carried out by a conventional method using magenta, cyan and yellow color toners and, if necessary, black toner.

[Image forming apparatus and electrophotographic cartridge]
Next, an embodiment of an image forming apparatus using the electrophotographic photosensitive member of the present invention (an image forming apparatus of the present invention) will be described with reference to FIG. However, the embodiment is not limited to the following description, and can be arbitrarily modified without departing from the gist of the present invention.

As shown in FIG. 1, the image forming apparatus includes an electrophotographic photosensitive member 1, a charging device 2, an exposure device 3, and a developing device 4, and further, a transfer device 5, a cleaning device 6 and a fixing device as necessary. A device 7 is provided.
The electrophotographic photoreceptor 1 is not particularly limited as long as it is the above-described electrophotographic photoreceptor of the present invention, but in FIG. 1, as an example, a drum in which the above-described photosensitive layer is formed on the surface of a cylindrical conductive support. The photoconductor is shown. A charging device 2, an exposure device 3, a developing device 4, a transfer device 5, and a cleaning device 6 are arranged along the outer peripheral surface of the electrophotographic photoreceptor 1.

  The charging device 2 charges the electrophotographic photosensitive member 1 and uniformly charges the surface of the electrophotographic photosensitive member 1 to a predetermined potential. Examples of the charging device include a corona charging device such as corotron and scorotron, a direct charging device (contact type charging device) for charging a direct charging member to which a voltage is applied by contacting the photosensitive member surface, and a contact type charging device such as a charging brush. Often used. Examples of the direct charging means include a contact charger such as a charging roller and a charging brush. In FIG. 1, a roller-type charging device (charging roller) is shown as an example of the charging device 2. As the direct charging means, either charging with air discharge or injection charging without air discharge is possible. In addition, as a voltage applied at the time of charging, in the case of only a direct current voltage, an alternating current can be superimposed on a direct current.

  The type of the exposure apparatus 3 is not particularly limited as long as it can expose the electrophotographic photoreceptor 1 to form an electrostatic latent image on the photosensitive surface of the electrophotographic photoreceptor 1. Specific examples include halogen lamps, fluorescent lamps, lasers such as semiconductor lasers and He—Ne lasers, LEDs, and the like. Further, exposure may be performed by a photoreceptor internal exposure method. The light used for the exposure is arbitrary. For example, the exposure may be performed using monochromatic light with a wavelength of 780 nm, monochromatic light with a wavelength slightly shorter than 600 nm to 700 nm, or monochromatic light with a wavelength shorter than 380 nm to 500 nm. . Among these, it is preferable to use light having a short wavelength of 380 to 500 nm because the resolution becomes high. Among these, 405 nm monochromatic light is preferable.

  Moreover, the writing resolution is mainly 600 dpi or more at present, but there is a high-performance model having 1200 dpi. The resolution of the electrostatic latent image and the toner image is determined depending on the writing resolution, and the higher the resolution, the clearer the image is obtained. Therefore, a resolution of 1200 dpi or higher is preferable. For example, when writing is performed with an LED having a resolution of 600 dpi and 1200 dpi, the minimum dot formation interval is 42 μm and 21 μm, respectively.

  The type of the developing device 4 is not particularly limited, and an arbitrary device such as a dry development method such as cascade development, one-component insulating toner development, one-component conductive toner development, or two-component magnetic brush development, or a wet development method is used. be able to. In FIG. 1, the developing device 4 includes a developing tank 41, an agitator 42, a supply roller 43, a developing roller 44, and a regulating member 45, and is configured to store toner T inside the developing tank 41. . Further, a replenishing device (not shown) for replenishing the toner T may be attached to the developing device 4 as necessary. This replenishing device is configured to be able to replenish toner T from a container such as a bottle or a cartridge. In the present embodiment, it is preferable to use the toner described above as the toner T.

  The supply roller 43 is formed from a conductive sponge or the like. The developing roller 44 is made of a metal roll such as iron, stainless steel, aluminum, or nickel, or a resin roll obtained by coating such a metal roll with a silicone resin, a urethane resin, a fluorine resin, or the like. The surface of the developing roller 44 may be smoothed or roughened as necessary.

  The developing roller 44 is disposed between the electrophotographic photosensitive member 1 and the supply roller 43 and is in contact with the electrophotographic photosensitive member 1 and the supply roller 43, respectively. The supply roller 43 and the developing roller 44 are rotated by a rotation drive mechanism (not shown). The supply roller 43 carries the stored toner T and supplies it to the developing roller 44. The developing roller 44 carries the toner T supplied by the supply roller 43 and contacts the surface of the electrophotographic photosensitive member 1.

  The regulating member 45 is formed of a resin blade such as a silicone resin or a urethane resin, a metal blade such as stainless steel, aluminum, copper, brass, phosphor bronze, or a blade obtained by coating such a metal blade with a resin. The regulating member 45 contacts the developing roller 44 and is pressed against the developing roller 44 side with a predetermined force by a spring or the like (a general blade linear pressure is 5 to 500 g / cm). If necessary, the regulating member 45 may be provided with a function of imparting charging to the toner T by frictional charging with the toner T.

  The agitator 42 is rotated by a rotation driving mechanism, and agitates the toner T and conveys the toner T to the supply roller 43 side. A plurality of agitators 42 may be provided with different blade shapes and sizes.

  The type of the transfer device 5 is not particularly limited, and an apparatus using an arbitrary system such as an electrostatic transfer method such as corona transfer, roller transfer, or belt transfer, a pressure transfer method, or an adhesive transfer method can be used. . Here, it is assumed that the transfer device 5 includes a transfer charger, a transfer roller, a transfer belt, and the like disposed so as to face the electrophotographic photoreceptor 1. The transfer device 5 applies a predetermined voltage value (transfer voltage) having a polarity opposite to the charging potential of the toner T, and transfers the toner image formed on the electrophotographic photosensitive member 1 to a recording paper (paper, medium) P. Is.

  There is no restriction | limiting in particular about the cleaning apparatus 6, Arbitrary cleaning apparatuses, such as a brush cleaner, a magnetic brush cleaner, an electrostatic brush cleaner, a magnetic roller cleaner, a blade cleaner, can be used. The cleaning device 6 scrapes the residual toner adhering to the electrophotographic photosensitive member 1 with a cleaning member and collects the residual toner. However, when there is little or almost no toner remaining on the surface of the photoreceptor, the cleaning device 6 may be omitted.

  The fixing device 7 includes an upper fixing member (fixing roller) 71 and a lower fixing member (fixing roller) 72, and a heating device 73 is provided inside the fixing member 71 or 72. FIG. 1 shows an example in which a heating device 73 is provided inside the upper fixing member 71. Each of the upper and lower fixing members 71 and 72 includes a fixing roll in which a metal base tube such as stainless steel or aluminum is coated with silicon rubber, a fixing roll in which Teflon (registered trademark) resin is coated, a fixing sheet, or the like. A member can be used. Further, each of the fixing members 71 and 72 may be configured to supply a release agent such as silicone oil in order to improve releasability, or may be configured to forcibly apply pressure to each other by a spring or the like.

When the toner transferred onto the recording paper P passes between the upper fixing member 71 and the lower fixing member 72 heated to a predetermined temperature, the toner is heated to a molten state and cooled after passing through the recording paper. Toner is fixed on P.
The type of the fixing device is not particularly limited, and a fixing device of an arbitrary system such as the one used here, heat roller fixing, flash fixing, oven fixing, pressure fixing, or the like can be provided.

In the image forming apparatus configured as described above, an image is recorded as follows. That is, first, the surface (photosensitive surface) of the electrophotographic photosensitive member 1 is charged to a predetermined potential (for example, −600 V) by the charging device 2. At this time, charging may be performed by a DC voltage, or charging may be performed by superimposing an AC voltage on the DC voltage.
Subsequently, the photosensitive surface of the charged electrophotographic photosensitive member 1 is exposed by the exposure device 3 according to the image to be recorded, and an electrostatic latent image is formed on the photosensitive surface. Then, development of the electrostatic latent image formed on the photosensitive surface of the electrophotographic photoreceptor 1 is performed by the developing device 4.

The developing device 4 thins the toner T supplied by the supply roller 43 with a regulating member (developing blade) 45 and has a predetermined polarity (here, the same polarity as the charging potential of the electrophotographic photosensitive member 1). Negatively charged) and conveyed while being carried on the developing roller 44 and brought into contact with the surface of the electrophotographic photosensitive member 1.
When the charged toner T carried on the developing roller 44 contacts the surface of the electrophotographic photoreceptor 1, a toner image corresponding to the electrostatic latent image is formed on the photosensitive surface of the electrophotographic photoreceptor 1. This toner image is transferred onto the recording paper P by the transfer device 5. Thereafter, the toner remaining on the photosensitive surface of the electrophotographic photosensitive member 1 without being transferred is removed by the cleaning device 6.

After the transfer of the toner image onto the recording paper P, the final image is obtained by passing the fixing device 7 and thermally fixing the toner image onto the recording paper P.
In addition to the above-described configuration, the image forming apparatus may be configured to perform, for example, a static elimination process. The neutralization process is a process of neutralizing the electrophotographic photosensitive member 1 by exposing the electrophotographic photosensitive member 1, and a fluorescent lamp, an LED, or the like is used as the neutralizing device. In addition, the light used in the static elimination process is often light having an exposure energy that is at least three times that of the exposure light.

The image forming apparatus may be further modified. For example, the image forming apparatus may be configured to perform a pre-exposure process, an auxiliary charging process, or the like, or may be configured to perform offset printing. A full-color tandem system configuration using toner may be used.
The electrophotographic photosensitive member 1 is combined with one or more of the charging device 2, the exposure device 3, the developing device 4, the transfer device 5, the cleaning device 6, and the fixing device 7 to form an integrated cartridge ( The electrophotographic cartridge may be configured to be detachable from the image forming apparatus main body such as a copying machine or a laser beam printer. In this case, for example, when the electrophotographic photosensitive member 1 or other member is deteriorated, this electrophotographic cartridge is removed from the main body of the image forming apparatus, and another new electrophotographic cartridge is mounted on the main body of the image forming apparatus. Equipment maintenance and management are easy.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to the following examples unless it exceeds the gist.

Production Example-1
[Manufacture of polycarbonate]
1- (1). Production of bisphenol C oligomer
・ 2,2-bis (4-hydroxy-3-methylphenyl) propane (= bisphenol C) 100 parts ・ sodium hydroxide 78 parts ・ water 922 parts ・ methylene chloride 412 parts The above mixture was charged into a reactor equipped with a stirrer. Stir. 87 parts of phosgene was blown into this to carry out the reaction. After completion of the reaction, only the methylene chloride solution containing the polycarbonate oligomer was collected. The analysis results of the resulting oligomeric methylene chloride solution were as follows.

Oligomer concentration (Note 1) 25.2% by weight
Terminal chloroformate group concentration (Note 2) 0.56 N Terminal phenolic hydroxyl group concentration (Note 3) 0.33 N

(Note 1) Measured by evaporating to dryness.
(Note 2) Aniline hydrochloride obtained by reacting with aniline was subjected to neutralization titration with a 0.1 N aqueous sodium hydroxide solution.
(Note 3) Color development was measured colorimetrically at 546 nm when dissolved in methylene chloride, titanium tetrachloride and acetic acid solutions.

1- (2). Polymerization of polycarbonate 1- (1) bisphenol C oligomer solution 268mL
・ Methylene chloride 232mL
2-benzoyl-5- (3-polydimethylsiloxane propoxy) phenol (average polysiloxane degree of polymerization n = 37) 17.9 g

An aqueous solution obtained by dissolving 9.57 g of sodium hydroxide in 167 mL of water and 5.4 mL of a 2 wt% triethylamine aqueous solution were charged into a 2 L polymerization tank equipped with a stirrer, stirred at 20 ° C., and subjected to interfacial polymerization for 4 hours.
Subsequently, 830 mL of water and 456 mL of methylene chloride were added and stirred for 30 minutes, and then the reaction solution was separated. The methylene chloride solution containing the polycarbonate resin was washed twice with a 0.1N aqueous sodium hydroxide solution, a 0.1N aqueous hydrochloric acid solution and demineralized water in sequence. The precipitate obtained by pouring the washed methylene chloride solution into 5 times (volume) of methanol was taken out by filtration and dried to obtain the desired terminal polysiloxane polycarbonate. This resin is referred to as Resin X.

In the above formula, A has the following structure.

When the viscosity average molecular weight of this resin was measured according to the following annual average molecular weight measurement method, the viscosity average molecular weight was 33,200. Furthermore, the siloxane content was 16.5% by weight as measured by H ¹ -NMR.

(Measurement method of viscosity average molecular weight)
A sample was dissolved in methylene chloride to prepare a solution having a concentration C of 6.00 g / L. The flow time t of the sample solution was measured in a constant temperature water bath set at 20.0 ° C. using an Ubbelohde capillary viscometer with a flow time t ₀ of the solvent (methylene chloride) of 136.21 seconds. The viscosity average molecular weight _Mv was calculated according to the following formula.

a = 0.438 × η _sp +1
b = 100 × η _sp / C
η _sp = t / t ₀ −1
C = 6.00 (g / L)
η = b / a
M _v = 3207 × η ^1.205

Production Example-2
2- (1). Production of bisphenol P oligomer
・ 100 parts of 1,1-bis (4-hydroxyphenyl) -1-phenylethane (= bisphenol P)
・ 46 parts of sodium hydroxide
・ 1,000 parts of water
・ 420 parts of methylene chloride

The above mixture was charged into a reactor equipped with a stirrer and stirred. 87 parts of phosgene was blown into this to carry out the reaction. After completion of the reaction, only the methylene chloride solution containing the polycarbonate oligomer was collected. The analysis results of the resulting oligomeric methylene chloride solution were as follows.
Oligomer concentration 22.6% by weight
Terminal chloroformate group concentration 0.322 N Terminal phenolic hydroxyl group concentration 0.016 N * Measured in the same manner as in Production Example 1.

2- (2). Polycarbonate polymerization
・ Bisphenol C oligomer solution obtained in 1- (1) 127.6 mL
-Bisphenol P oligomer solution obtained in 2- (1) 156.4 mL
・ 216 ml of methylene chloride
2-benzoyl-5- (3-polydimethylsiloxanepropoxy) phenol (average degree of polymerization of polysiloxane n = 37) 17.0 g
An aqueous solution prepared by dissolving 9.06 g of sodium hydroxide in 167 mL of water and 5.4 mL of a 2 wt% triethylamine aqueous solution were charged into a 2 L polymerization tank equipped with a stirrer, stirred at 20 ° C., and subjected to interfacial polymerization for 4 hours.

  Further, the same operation as in Production Example 1 was performed to obtain the desired terminal polysiloxane polycarbonate. Hereinafter, this resin is referred to as “resin Y”. When the viscosity average molecular weight and the siloxane content were measured in the same manner as in Production Example 1, the viscosity average molecular weight of this resin was 32,900 and the siloxane content was 16.1% by weight.

  In the above formula, A has the following structure:

<Manufacture of electrophotographic photoreceptor>
<Manufacture of photoreceptor sheet>
[Example 1]
In accordance with the following procedure, a photoreceptor sheet as one form of the electrophotographic photoreceptor was produced. First, the undercoat layer dispersion was produced as follows. That is, a rutile type titanium oxide having an average primary particle size of 40 nm (“TTO55N” manufactured by Ishihara Sangyo Co., Ltd.) and 3% by weight of methyldimethoxysilane (“TSL8117” manufactured by Toshiba Silicone Co., Ltd.) with respect to the titanium oxide were flowed at high speed. In a mixed solvent of methanol / 1-propanol in a mixed solvent of methanol / 1-propanol, which was introduced into a mixing kneader (“SMG300” manufactured by Kawata Co., Ltd.) and mixed at a high rotational speed of 34.5 m / sec. Then, a dispersion slurry of hydrophobized titanium oxide was obtained by dispersing with a ball mill. The dispersion slurry, a mixed solvent of methanol / 1-propanol / toluene, and ε-caprolactam / bis (4-amino-3-methylcyclohexyl) methane / hexamethylenediamine / decamethylenedicarboxylic acid / octadecamethylenedicarboxylic acid The copolyamide pellets having a composition molar ratio of 60% / 15% / 5% / 15% / 5% are stirred and mixed while heating to dissolve the polyamide pellets, and then subjected to ultrasonic dispersion treatment. The weight ratio of methanol / 1-propanol / toluene is 7/1/2 and the hydrophobically treated titanium oxide / copolymerized polyamide is contained at a weight ratio of 3/1. A layer dispersion was obtained.
The undercoat layer-forming coating solution thus obtained was applied onto a polyethylene terephthalate sheet having aluminum deposited on the surface with a wire bar so that the film thickness after drying was 1.2 μm, dried and subtracted. A layer was provided.

Next, 10 parts by weight of oxytitanium phthalocyanine having the powder X-ray diffraction spectrum shown in FIG. In addition to 150 parts by weight of 2-dimethoxyethane, pulverization and dispersion treatment was performed with a sand grind mill to prepare a pigment dispersion. 160 parts by weight of the pigment dispersion thus obtained was added to 100 parts by weight of a 5% 1,2-dimethoxyethane solution of polyvinyl butyral (trade name # 6000C, manufactured by Denki Kagaku Kogyo Co., Ltd.), and an appropriate amount of 1,2 -Dimethoxyethane was added to finally prepare a coating solution for forming a charge generation layer having a solid content concentration of 4.0% by weight.
This charge generation layer forming coating solution was applied on the above-described undercoat layer with a wire bar so that the film thickness after drying was 0.4 μm, and then dried to form a charge generation layer.

  Next, as a charge transport material, a mixture composed of a compound group of geometric isomers having a structure represented by the following formula (4) as a main component and shown in Example 1 of JP-A No. 2002-80432 is disclosed. 50 parts by weight of resin X produced in Production Example 1, 50 parts by weight of polyarylate resin A (viscosity average molecular weight 41,000) having the following repeating structure, 0.05 part by weight of silicone oil as a leveling agent, tetrahydrofuran The mixture was mixed with 640 parts by weight of a mixed solvent of toluene and toluene (80% by weight of tetrahydrofuran, 20% by weight of toluene) to prepare a coating solution for forming a charge transport layer.

This charge transport layer forming coating solution is applied onto the above-described charge generation layer using an applicator so that the film thickness after drying is 20 μm, and dried at 125 ° C. for 20 minutes to form a charge transport layer. A photoreceptor sheet was prepared.
This photoreceptor sheet was evaluated for slipperiness by a surface property test described later. In addition, the electrical characteristics were evaluated by a photoreceptor characteristic tester (model EPA8100 manufactured by Kawaguchi Electric Co., Ltd.) described later. The results are shown in Table 1.

[Example 2]
A photoreceptor sheet was prepared in the same manner as in Example 1 except that 25 parts by weight of the resin X used in the charge transport layer forming coating solution of Example 1 and 75 parts by weight of the polyarylate resin A were used. This photoreceptor sheet was evaluated in the same manner as in Example 1, and the results are shown in Table 1.

[Example 3]
Instead of the resin A used for the charge transport layer forming coating solution of Example 1, polyarylate resin B (viscosity average molecular weight 32,000) having the following repeating structure was used, and the same procedure as in Example 1 was performed. A photoreceptor sheet was prepared. This photoreceptor sheet was evaluated in the same manner as in Example 1, and the results are shown in Table 1.

[Example 4]
A photoreceptor sheet was prepared in the same manner as in Example 3 except that 25 parts by weight of the resin X used in the charge transport layer forming coating solution of Example 3 and 75 parts by weight of the polyarylate resin B were used. This photoreceptor sheet was evaluated in the same manner as in Example 1, and the results are shown in Table 1.

[Example 5]
A photoreceptor sheet was produced in the same manner as in Example 2 except that the resin Y produced in Production Example 2 was used instead of the resin X used in the coating solution for forming the charge transport layer of Example 2. This photoreceptor sheet was evaluated in the same manner as in Example 1, and the results are shown in Table 1.

[Example 6]
A photoreceptor sheet was produced in the same manner as in Example 4 except that the resin Y produced in Production Example 2 was used instead of the resin X used in the charge transport layer forming coating solution of Example 4. This photoreceptor sheet was evaluated in the same manner as in Example 1, and the results are shown in Table 1.

[Comparative Example 1]
A photoreceptor sheet was produced in the same manner as in Example 1 except that the resin A used in the charge transport layer forming coating solution of Example 1 was not used and the resin X was 100 parts by weight. This photoreceptor sheet was evaluated in the same manner as in Example 1, and the results are shown in Table 1.

[Comparative Example 2]
A photoreceptor sheet was prepared in the same manner as in Example 1, except that the resin X and resin A used in the charge transport layer forming coating solution of Example 1 were not used, but 100 parts by weight of the resin Y produced in Production Example 2 was used. Produced. This photoreceptor sheet was evaluated in the same manner as in Example 1, and the results are shown in Table 1.

[Comparative Example 3]
A photoreceptor sheet was prepared in the same manner as in Example 1 except that the resin X used in the coating liquid for forming the charge transport layer of Example 1 was not used and the resin A was 100 parts by weight. This photoreceptor sheet was evaluated in the same manner as in Example 1, and the results are shown in Table 1.

[Comparative Example 4]
A photoreceptor sheet was prepared in the same manner as in Example 3 except that the resin X used in the charge transport layer forming coating solution of Example 3 was not used and the resin B was changed to 100 parts by weight. This photoreceptor sheet was evaluated in the same manner as in Example 1, and the results are shown in Table 1.

[Comparative Example 5]
In the same manner as in Example 1, except that 50 parts by weight of polycarbonate resin C (viscosity average molecular weight 49,000) having the following repeating structure was used instead of resin A used in the charge transport layer forming coating solution of Example 1. Thus, a photoreceptor sheet was prepared. This photoreceptor sheet was evaluated in the same manner as in Example 1, and the results are shown in Table 1.

[Comparative Example 6]
Example except that 50 parts by weight of the resin Y used in the coating liquid for forming the charge transport layer of Example 5 was used, and that 50 parts by weight of the polycarbonate resin C (viscosity average molecular weight 49,000) was used instead of the resin A. In the same manner as in Example 5, a photoreceptor sheet was produced. This photoreceptor sheet was evaluated in the same manner as in Example 1, and the results are shown in Table 1.

<Evaluation of surface properties>
The above photoreceptor sheets (Examples 1 to 6, Comparative Examples 1 to 6) were cut into a size of 60 mm in width and 130 mm in length, and on a reciprocating table of an abrasion tester (FR-2 type manufactured by Suga Test Instruments Co., Ltd.). Fixed with adhesive tape. A load of 7.8 N was applied, and polishing was performed by reciprocating 300 times on the electrophotographic photosensitive member with a 3M company's Wetdry Tri-M-ite Paper 2000. Thereafter, a load of 7.8 N was applied and polished on the electrophotographic photosensitive member 300 times by JK Wiper (registered trademark) 150-S manufactured by Crecia Co., Ltd.

  About these photoreceptor sheets before and after surface polishing, the coefficient of friction was measured using a surface property tester (Heidon-14 type, manufactured by Shinto Kagaku Co., Ltd.). At this time, a non-woven fabric having a width of 10 mm and a length of 12 mm (SONPADS manufactured by Dynic Co., Ltd.) was used as the friction body, and measurement was performed under a load of 2.9 N and a sweep speed of 100 mm / min. The results are shown in Table 1.

<Electrical characteristics evaluation>
The photoreceptor sheets prepared in the above-described examples and comparative examples (Examples 1 to 6 and Comparative Examples 1 to 6) are mounted on a photoreceptor characteristic tester (model EPA8100 manufactured by Kawaguchi Electric Co., Ltd.), and dark place. After negatively charging the photosensitive sheet with a corona current of 35 μA, a half-exposure amount (E1 / 2) required to continuously irradiate 780 nm light and reduce the surface potential from −700 V to −350 V, and The residual potential (Vr) when irradiated with 10 μJ / cm ² was measured. The results are shown in Table 1.

  As shown in Table 1, when the electrophotographic photosensitive member obtained by the present invention is used, the slipperiness of the surface of the electrophotographic photosensitive member is remarkably improved while keeping the electric characteristics at a good value as compared with the conventional electrophotographic photosensitive member. Is possible. In particular, when Example 1 and Comparative Example 5 are compared, the electrophotographic photosensitive member of the present invention contains a polyarylate resin, so that excellent surface properties can be maintained even if the surface of the electrophotographic photosensitive member is worn. I understand that.

<Abrasion test>
The photoreceptor sheets of the above examples and comparative examples (Examples 1 to 6, Comparative Examples 1, 2, 5, and 6) were each cut into a circular shape having a diameter of 10 cm, and a Taber abrasion tester (manufactured by Taber). Wear evaluation was performed. Test conditions were measured by comparing the weight before and after the test with 1000 wheels without load (the weight of the wear wheel) under the atmosphere of 23 ° C. and 50% RH and without wear (self-weight of the wear wheel). did. The results are shown in Table 2.

  As shown in Table 2, when a resin having a siloxane unit is used alone, the wear resistance is remarkably poor and there is no practicality. In addition to good slipperiness when other resins, particularly polyarylate resins, especially polyarylate resins having a viscosity average molecular weight of 40,000 or more are contained, wear resistance is also preferred. In particular, it can be seen that the polyarylate resin is preferable when n = 1 in the formula (1). A resin having a siloxane unit is particularly good when X in the formula (2) is composed of only aliphatic hydrocarbons.

<Manufacture of developing toner>
Preparation of wax / long chain polymerizable monomer dispersion A1
Paraffin wax (Nippon Seiki Co., Ltd. HNP-9, surface tension 23.5 mN / m, melting point 82 ° C., heat of fusion 220 J / g, melting peak half width 8.2 ° C., crystallization peak half width 13.0 ° C.) 27 Part (540 g), stearyl acrylate (manufactured by Tokyo Chemical Industry Co., Ltd.) 2.8 parts, 20% by weight sodium dodecylbenzenesulfonate aqueous solution (Daiichi Kogyo Seiyaku Co., Ltd., Neogen S20A, hereinafter abbreviated as “20% DBS aqueous solution” as appropriate) 1.9 parts and 68.3 parts of demineralized water were heated to 90 ° C. and stirred with a homomixer (Mark II f model, manufactured by Tokushu Kika Kogyo Co., Ltd.) at a rotation speed of 8000 rpm for 10 minutes.

  Subsequently, this dispersion was heated to 90 ° C., and circulation emulsification was started under a pressure condition of about 25 MPa using a homogenizer (manufactured by Gorin, 15-M-8PA type). The volume average particle size was dispersed to 250 nm while measuring with “Microtrack UPA”) to prepare a wax / long-chain polymerizable monomer dispersion A1 (emulsion solid content concentration = 30.2 wt%). .

-Preparation of silicone wax dispersion A2
27 parts (540 g) of alkyl-modified silicone wax (melting point: 72 ° C.), 1.9 parts of 20% DBS aqueous solution and 71.1 parts of demineralized water are placed in a 3 L stainless steel container and heated to 90 ° C. to homomixer (Special Machine Industries) The product was stirred for 10 minutes at a rotational speed of 8000 rpm using a Mark II f model manufactured by the company.

  Next, this dispersion was heated to 99 ° C., and circulation emulsification was started under a pressure condition of about 45 MPa using a homogenizer (manufactured by Gorin Co., Ltd., 15-M-8PA type). A silicone wax dispersion A2 (emulsion solid content concentration = 27.4% by weight) was prepared by dispersing until the particle diameter reached 240 nm.

-Preparation of polymer primary particle dispersion A1
A reactor equipped with a stirrer (three blades), a heating / cooling device, a concentrating device, and a raw material / auxiliary charging device (with an internal volume of 21 liters, an inner diameter of 250 mm, and a height of 420 mm) was combined with a wax / long chain polymerizable single unit. The monomer dispersion A1 was charged with 35.6 parts by weight (712.12 g) and 259 parts of demineralized water, and the temperature was raised to 90 ° C. in a nitrogen stream while stirring at 103 rpm.

  Thereafter, a mixture of the following monomers and an aqueous emulsifier solution was added over 5 hours from the start of polymerization. The time when the mixture of the monomers and the aqueous emulsifier solution was started to be dropped was set as the polymerization start, and the following initiator aqueous solution was added over 4.5 hours from 30 minutes after the start of the polymerization. The aqueous agent solution was added over 2 hours, and the mixture was further maintained for 1 hour while maintaining the rotation speed of 103 rpm and the internal temperature of 90 ° C.

[Monomers]
Styrene 76.8 parts (1535.0 g)
Butyl acrylate 23.2 parts Acrylic acid 1.5 parts Trichlorobromomethane 1.0 part Hexanediol diacrylate 0.7 part [Emulsifier aqueous solution]
20% DBS aqueous solution 1.0 part
67.1 parts of demineralized water [initiator aqueous solution]
8% hydrogen peroxide aqueous solution 15.5 parts 8% L (+)-ascorbic acid aqueous solution 15.5 parts [additional initiator aqueous solution]
8% L (+)-ascorbic acid aqueous solution 14.2 parts

  After the completion of the polymerization reaction, the mixture was cooled to obtain a milky white polymer primary particle dispersion A1. The volume average particle diameter measured by Microtrac UPA was 280 nm, and the solid content concentration was 21.1% by weight.

-Preparation of polymer primary particle dispersion A2
Into a reactor equipped with a stirrer (three blades), a heating / cooling device, a concentrating device, and a raw material / auxiliary charging device (inner volume 21 liters, inner diameter 250 mm, height 420 mm), the silicone wax dispersion A2 .6 parts by weight (472.3 g), 1.5% by weight of 20% DBS aqueous solution, and 324 parts of demineralized water were heated to 90 ° C. under a nitrogen stream and 8% peroxidized while stirring at 103 rpm. 3.2 parts of an aqueous hydrogen solution and 3.2 parts of an 8% L (+)-ascorbic acid aqueous solution were added all at once.

  5 minutes later, polymerization of the following mixture of monomers and emulsifier aqueous solution was started (from the time when 3.2 parts of 8% hydrogen peroxide aqueous solution and 3.2 parts of 8% L (+)-ascorbic acid aqueous solution were added all at once. After 5 minutes, the following initiator aqueous solution was added over 6 hours from the start of polymerization, and the mixture was further maintained for 1 hour while maintaining the rotation speed at 103 rpm and the internal temperature of 90 ° C.

[Monomers]
92.5 parts of styrene (1850.0 g)
Butyl acrylate 7.5 parts Acrylic acid 1.5 parts Trichlorobromomethane 0.6 parts [Emulsifier aqueous solution]
20% DBS aqueous solution 1.5 parts Demineralized water 66.2 parts [Initiator aqueous solution]
8% aqueous hydrogen peroxide solution 18.9 parts 8% L (+)-ascorbic acid aqueous solution 18.9 parts

  After completion of the polymerization reaction, the mixture was cooled to obtain a milky white polymer primary particle dispersion A2. The volume average particle size measured by Microtrac UPA was 290 nm, and the solid content concentration was 19.0% by weight.

-Preparation of colorant dispersion A
A carbon black (Mitsubishi Chemical Corporation) manufactured in a 300 L inner vessel equipped with a stirrer (propeller blade) and manufactured by a furnace method in which the toluene extract has an ultraviolet absorbance of 0.02 and a true density of 1.8 g / cm ^3. Mitsubishi Carbon Black MA100S, 20 parts (40 kg), 20% DBS aqueous solution, 1 part, nonionic surfactant (manufactured by Kao Corporation, Emulgen 120), 4 parts, ion-exchanged water with an electric conductivity of 2 μS / cm, 75 parts And predispersed to obtain a pigment premix solution. The conductivity was measured using a conductivity meter (a personal SC meter model SC72 and a detector SC72SN-11 manufactured by Yokogawa Electric Corporation).

The volume cumulative 50% diameter Dv ₅₀ of the carbon black in the dispersion after the premix was about 90 μm. The premix solution was supplied as a raw material slurry to a wet bead mill and subjected to one-pass dispersion. In addition, the inner diameter of the stator was 75 mmφ, the separator diameter was 60 mmφ, the distance between the separator and the disk was 15 mm, and zirconia beads having a diameter of 50 μm (true density 6.0 g / cm ³ ) were used as the dispersion medium. The effective internal volume of the stator is about 0.5 liters, and the media filling volume is 0.35 liters, so the media filling rate is 70%. The rotation speed of the rotor is constant (the peripheral speed of the rotor tip is about 11 m / sec), and the premix slurry is continuously supplied from the supply port by a non-pulsating metering pump at a supply rate of about 50 liters / hr, and from the discharge port. By continuously discharging, a black colorant dispersion A was obtained. The volume average particle diameter measured by Microtrac UPA was 150 nm, and the solid content concentration was 24.2% by weight.

-Production of developing mother particles A Polymer primary particle dispersion A1 95 parts as solids (998.2 g as solids)
Polymer primary particle dispersion A2 5 parts colorant fine particle dispersion A as solid content 6 parts 20% DBS aqueous solution as colorant solid content 0.1 part as solid content Using the above components, the toner was prepared according to the following procedure. Manufactured.

Polymer primary particle dispersions A1 and 20 were placed in a mixer (volume 12 liter, inner diameter 208 mm, height 355 mm) equipped with a stirrer (double helical blade), heating / cooling device, concentrating device, and raw material / auxiliary charging device. % DBS aqueous solution was charged and mixed uniformly at an internal temperature of 12 ° C. and 40 rpm for 5 minutes. Subsequently, the stirring rotation speed was increased to 250 rpm at an internal temperature of 12 ° C., and 0.52 part of FeSO ₄ .7H ₂ O as a 5% aqueous solution of ferrous sulfate was added over 5 minutes. Was added uniformly over 5 minutes at an internal temperature of 12 ° C. while maintaining 250 rpm, and a 0.5% aqueous solution of aluminum sulfate was added dropwise under the same conditions (the solid content with respect to the resin solid content was 0.00). 10 parts). Thereafter, the temperature was raised to 53 ° C. over 75 minutes at 250 rpm, and then raised to 56 ° C. over 170 minutes.

Here, when the particle size was measured with a precision particle size distribution measuring apparatus (multisizer III: manufactured by Beckman Coulter, Inc .; hereinafter abbreviated as “multisizer” as appropriate) with an aperture diameter of 100 μm, the 50% volume diameter was 6. It was 7 μm.
Thereafter, the polymer primary particle dispersion A2 was added at 250 rpm over 3 minutes and held for 60 minutes, and the rotation speed was reduced to 168 rpm and immediately 20% DBS aqueous solution (6 parts as solid content) was taken over 10 minutes. Added. Further, the internal temperature was raised to 90 ° C. over 30 minutes while maintaining 168 rpm and held for 60 minutes (hereinafter, this step may be referred to as a fusion step).

  Thereafter, the slurry obtained by cooling to 30 ° C. over 20 minutes was extracted, and suction filtration was performed with an aspirator using 5 types C (No5C manufactured by Toyo Roshi Kaisha, Ltd.) filter paper. The cake remaining on the filter paper is transferred to a stainless steel container having an internal volume of 10 L equipped with a stirrer (propeller blade), added with 8 kg of ion-exchanged water having an electric conductivity of 1 μS / cm, and uniformly dispersed by stirring at 50 rpm. Stirred for 30 minutes.

  After that, again using 5 kinds C (Toyo Filter Paper No. 5C) filter paper, suction filtration is performed with an aspirator, and the solid matter remaining on the filter paper is again equipped with a stirrer (propeller blade) and has an electric conductivity of 1 μS / cm. It was transferred to a 10 L container with 8 kg of ion-exchanged water, and evenly dispersed by stirring at 50 rpm and kept stirring for 30 minutes. When this process was repeated 5 times, the electrical conductivity of the filtrate was 2 μS / cm. The conductivity was measured using a conductivity meter (a personal SC meter model SC72 and a detector SC72SN-11 manufactured by Yokogawa Electric Corporation).

  The cake obtained here was spread on a stainless steel pad so as to have a height of about 20 mm, and dried in a blow dryer set at 40 ° C. for 48 hours to obtain developing mother particles A.

-Production of developing toner A In a Henschel mixer with an internal volume of 10 L (diameter: 230 mm, height: 240 mm) equipped with a stirrer (Z / A ₀ blade) and a deflector oriented perpendicularly to the wall surface from above, the developing mother particles A part (1,000 g) of A was added, followed by 0.5 part of silica fine particles having a volume average primary particle size of 0.04 μm hydrophobized with silicone oil, and volume average primary particles hydrophobized with silicone oil. Toner A for development was obtained by adding 2.0 parts of silica fine particles having a diameter of 0.012 μm, stirring and mixing at 3000 rpm for 10 minutes, and sieving through 150 mesh. The volume average particle diameter of the toner A measured by Multisizer II was 7.05 μm, Dv / Dn was 1.14, and the average circularity measured by FPIA2000 was 0.963.

-Production of developing toner B The fusion process in the production of developing mother particles A was raised from 90 ° C and held for 60 minutes, except that the temperature was raised to 96 ° C and held for 90 minutes. The developing mother particle B was produced in the same manner as the developing mother particle A. Developing toner B was produced in the same manner as developing toner A except that developing mother particle B was used instead of developing mother particle A used in the production of developing toner A. The volume average particle diameter of the toner B measured by Multisizer II was 6.98 μm, Dv / Dn was 1.14, and the average circularity measured by FPIA2000 was 0.981.

<Manufacture of photosensitive drum>
[Example 7]
In accordance with the following procedure, a photosensitive drum as one form of an electrophotographic photosensitive member was produced. First, the surface of an aluminum cylinder having a mirror-finished outer diameter of 30 mm, a length of 376 mm, and a wall thickness of 0.75 mm is anodized, and then sealed with a sealing agent mainly composed of nickel acetate. By performing the hole treatment, an anodized film (alumite film) of about 6 μm was formed. This cylinder was dip coated in the charge generation layer forming coating solution prepared in Example 1 to form a charge generation layer so that the film thickness after drying was about 0.4 μm.

  Next, 20 parts by weight of the resin X produced in Production Example 1, 80 parts by weight of the resin A, 50 parts by weight of the charge transport material represented by the following structural formula (5), and the oxidation represented by the following structural formula (6) 8 parts by weight of an inhibitor and 0.05 parts by weight of silicone oil as a leveling agent are mixed with 640 parts by weight of a mixed solvent of tetrahydrofuran and toluene (80% by weight of tetrahydrofuran, 20% by weight of toluene), and applied for forming a charge transport layer. A liquid was prepared.

The charge transport layer-forming coating solution was dip-coated with the cylinder in which the charge generation layer was previously formed to form a 22 μm-thick charge transport layer after drying to produce a photoreceptor drum. The surface free energy, elastic deformation rate, and universal hardness of this photosensitive drum were measured, and the results are shown in Table 3.
The photosensitive drum produced here and the developing toner A are mounted on a black drum cartridge and a black toner cartridge of a color printer (MICROLINE Pro 9800PS-E manufactured by Oki Data Corporation), respectively. Attached to the printer.

Specifications of MICROLINE Pro 9800PS-E
Quadruple tandem
Color 36ppm, Monochrome 40ppm
1200 dpi
Contact roller charging (DC voltage applied)
LED exposure
With static elimination light

10,000 images of a text document having a printing area of about 5% were formed under conditions of a temperature of 25 ° C. and a humidity of 50%. Table 3 shows the results of the film reduction amount of the photosensitive drum at that time. Here, the film reduction amount is shown as a relative value with the film reduction amount of the photosensitive drum of Comparative Example 7 described later as 1. The lower the value, the better the wear resistance. Table 3 also shows the results of evaluating halftone images printed after the initial image formation and after 10,000 sheets were formed.
Further, when TestTarget (rev4) manufactured by QEA was printed, an image with good gradation was obtained after 10,000 initial image formation.

[Example 8]
A photosensitive drum was prepared in the same manner as in Example 7 except that the thickness of the charge transport layer after drying was changed from 22 μm to 12 μm in Example 7, and evaluation was performed in the same manner. The results are also shown in Table 3.
Further, when TestTarget (rev4) manufactured by QEA was printed, an image with good gradation was obtained after 10,000 initial image formation. The reproducibility of fine lines was better than that of a 22 μm photosensitive drum.

[Example 9]
A photosensitive drum was prepared in the same manner as in Example 7 except that the resin A used in Example 7 was changed to Resin B, and evaluation was performed in the same manner. The results are also shown in Table 3.
Further, when TestTarget (rev4) manufactured by QEA was printed, an image with good gradation was obtained after 10,000 initial image formation.

[Example 10]
Evaluation was performed in the same manner as in Example 7 except that the developing toner A used in Example 7 was changed to developing toner B. The results are also shown in Table 3.
When TestTarget (rev4) manufactured by QEA was printed, the gradation image after the initial 10,000 image formation was better than that of Example 7.

[Comparative Example 7]
A photosensitive drum was prepared in the same manner as in Example 7 except that the resin X used in Example 7 was not used and the resin A was changed to 100 parts by weight, and evaluation was performed in the same manner. The results are also shown in Table 3.

[Comparative Example 8]
A photosensitive drum was prepared in the same manner as in Example 7 except that the resin A used in Example 7 was changed to Resin C, and evaluation was performed in the same manner. The results are also shown in Table 3.

[Example 11]
A photoconductor drum was produced in the same manner as in Example 7, except that the aluminum cylinder used in the production of the photoconductor drum in Example 7 was replaced with one having an outer diameter of 30 mm, a length of 351 mm, and a wall thickness of 1.0 mm. did.
The photosensitive drum obtained here was mounted on a black drum cartridge of a color printer (MICROLINE 3050c manufactured by Oki Data Corporation) and mounted on the printer. As the toner, a commercially available toner manufactured by the melt kneading and pulverizing method for the printer was used. The average circularity of the toner was 0.935.

<Specifications of MICROLINE 3050c>
Quadruple tandem
Color 21ppm, Monochrome 26ppm
1200 dpi
Contact roller charging (DC voltage applied)
LED exposure
No static elimination light

A text document having a printing area of about 5% under the conditions of a temperature of 25 ° C. and a humidity of 50% was formed on 10,000 images, and halftone images were printed after the initial image formation and after 10,000 images were formed. As a result of evaluation, a uniform image was obtained.
When a test target (rev4) manufactured by QEA was printed, after 10,000 images were formed, the gradation in the low density region was deteriorated.

[Example 12]
The aluminum cylinder used in the manufacture of the photosensitive drum of Example 7 was changed to one having an outer diameter of 30 mm, a length of 246 mm, and a thickness of 0.75 mm, and the thickness of the charge transport layer was changed to 18 μm. A photoconductor drum was produced in the same manner as in Example 7.
The photosensitive drum obtained here was mounted on a black drum cartridge of a color printer (C3100 manufactured by Oki Data Corporation) and mounted on the printer.

<Specifications of C3100>
Quadruple tandem
Color 12ppm, Monochrome 20ppm
600 dpi
Contact roller charging (DC voltage applied)
LED exposure

10,000 images of a text document having a printing area of about 5% were formed under conditions of a temperature of 25 ° C. and a humidity of 50%. Table 4 shows the results of the film reduction amount of the photosensitive drum at that time. Here, the film reduction amount is shown as a relative value with the film reduction amount of the photoconductive drum of Comparative Example 9 as 1. The lower the value, the better the wear resistance. Table 4 also shows the results of evaluating halftone images printed after the initial image formation and after 10,000 sheets were formed.
Further, when TestTarget (rev4) manufactured by QEA was printed, after the initial formation of 10,000 images, images with good gradation were obtained in all cases.

[Comparative Example 9]
The aluminum cylinder used in the manufacture of the photosensitive drum of Comparative Example 7 was changed to one with an outer diameter of 30 mm, a length of 246 mm, and a wall thickness of 0.75 mm, and the thickness of the charge transport layer was 18 μm. A photoconductor drum was produced in the same manner as in Example 7. This photosensitive drum was evaluated in the same manner as in Example 12, and the results are shown in Table 4.

  As described above, when the photosensitive drum of the present invention is used (Examples 7 to 12), the same abrasion resistance as when the polyarylate resin A, which has been conventionally used for high printing durability (Comparative Example 7), is used. It can be seen that a high-quality image having wear characteristics can be obtained.

  When the surface free energy was excessively high (Comparative Example 7), uneven density due to jitter during rotation of the photosensitive drum was observed. Even when the surface free energy was low, when the elastic deformation rate was excessively small and the universal hardness was excessively large (Comparative Example 8), uneven density due to poor cleaning was observed.

By the above, the surface is free energy 20mN / m~35mN / m, the universal hardness of ^{150N / mm 2 ~200N / mm 2} , or an electrophotographic photosensitive member the elastic deformation rate is 43% or more, excellent It is possible to achieve both wear resistance and image characteristics.

  When Example 7 to Example 10 and Example 11 are compared, toners (developing toner A and developing toner B) produced by an emulsion polymerization aggregation method having a high degree of circularity are used (Examples 7 to Examples). 10) it was found that a particularly high quality image can be obtained.

  Furthermore, in the case of Example 12 and Comparative Example 9, since the resolution of the color printer (C3100) is as low as 600 dpi, image degradation is difficult to detect. On the other hand, in the case of Example 7 to Example 10, the color printer (MICROLINE 3050c) has a high resolution of 1,200 dpi and can provide a high-quality image without image defects.

  The present invention can be used in any field where an electrophotographic photosensitive member is used, and is particularly suitable for use in an image forming apparatus such as a printer or a copying machine.

1 is a schematic diagram illustrating a main configuration of an embodiment of an image forming apparatus of the present invention. It is an X-ray diffraction diagram showing a powder X-ray diffraction spectrum of oxytitanium phthalocyanine used in Examples and Comparative Examples of the present invention. It is an indentation depth-load curve.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Electrophotographic photoreceptor, 2 ... Charging device (charging roller), 3 ... Exposure device, 4 ... Developing device, 5 ... Transfer device, 6 ... Cleaning device, 7 ... Fixing device, 41 ... Developing tank, 42 ... Agitator, DESCRIPTION OF SYMBOLS 43 ... Supply roller, 44 ... Developing roller, 45 ... Restriction member, 71 ... Upper fixing member (pressure roller), 72 ... Lower fixing member (fixing roller), 73 ... Heating device, T ... Toner, P ... Recording paper

Claims (26)

  An electrophotographic photosensitive member having at least a photosensitive layer on a conductive support, wherein the photosensitive layer contains a resin having a polysiloxane component and a polyarylate resin.   The electrophotographic photosensitive member according to claim 1, wherein the resin having a polysiloxane component is a polycarbonate resin having a polysiloxane component. The electrophotographic photosensitive member according to claim 1, wherein the polyarylate resin has a dicarboxylic acid residue represented by the following formula (1).

(In formula (1), X ^{1 to} X ⁸ each independently represent a hydrogen atom, an alkyl group that may have a substituent, an aryl group that may have a substituent, a halogen group, or an alkoxy group, n represents an integer of 1 to 5.)   4. The electrophotographic photosensitive member according to claim 1, wherein the resin having a polysiloxane component is a block copolymer of a polycarbonate component and a polysiloxane component.   The electrophotographic photosensitive member according to claim 4, wherein the resin having a polysiloxane component is a block copolymer having a polysiloxane component at least at one end. 6. The electrophotographic photoreceptor according to claim 4, wherein the polycarbonate component has a structure represented by the following formula (2), and the polysiloxane component has a structure represented by the following formula (3).

(In Formula (2), Y ^{1 to} Y ⁸ each independently represent a hydrogen atom, an alkyl group that may have a substituent, an aryl group that may have a substituent, a halogen group, or an alkoxy group; In formula (3), R ¹³ represents a divalent organic group, W represents a divalent linking group, and R ^{8 to} R ¹² each independently have a substituent. Represents an alkyl group having 10 or less carbon atoms, and n is an integer of 1 to 500.)   The electrophotographic photosensitive member according to claim 1, wherein the photosensitive layer has a thickness of 15 μm or less.   In an electrophotographic photosensitive member having a photosensitive layer on a conductive support, the surface free energy on the surface of the photosensitive layer is 20 mN / m or more and 35 mN / m or less, and the temperature is 25 ° C. and the relative humidity is 50%. An electrophotographic photosensitive member having an elastic deformation ratio of 43% or more measured using a Vickers indenter under the conditions of a maximum indentation depth of 1 μm, a required load time of 20 s, and an unloading required time of 20 s. In an electrophotographic photosensitive member having a photosensitive layer on a conductive support, the surface free energy on the surface of the photosensitive layer is 20 mN / m or more and 35 mN / m or less, and the temperature is 25 ° C. and the relative humidity is 50%. Then, using a Vickers indenter, the universal hardness at the maximum indentation depth is 150 N / mm ² or more and 200 N / mm ² or less when measured under the conditions of a maximum indentation depth of 1 μm, a load time of 20 s, and an unloading time of 20 s. An electrophotographic photoreceptor, characterized in that   10. The electrophotographic photosensitive member according to claim 8, wherein the photosensitive layer on the conductive support contains a resin having a polysiloxane component and a polyarylate resin.   The electrophotographic photosensitive member according to claim 10, wherein the resin having a polysiloxane component is a polycarbonate resin having a polysiloxane component. The electrophotographic photosensitive member according to claim 10 or 11, wherein the polyarylate resin has a dicarboxylic acid residue represented by the following formula (1).

(In formula (1), X ^{1 to} X ⁸ each independently represent a hydrogen atom, an alkyl group that may have a substituent, an aryl group that may have a substituent, a halogen group, or an alkoxy group, n represents an integer of 1 to 5.)   13. The electrophotographic photosensitive member according to claim 10, wherein the resin having a polysiloxane component is a block copolymer of a polycarbonate component and a polysiloxane component.   The electrophotographic photosensitive member according to claim 13, wherein the resin having a polysiloxane component is a block copolymer having a polysiloxane component at least at one end. The electrophotographic photosensitive member according to claim 13, wherein the polycarbonate component has a structure represented by the following formula (2) and the polysiloxane component has a structure represented by the following formula (3).

(In Formula (2), Y ^{1 to} Y ⁸ each independently represent a hydrogen atom, an alkyl group that may have a substituent, an aryl group that may have a substituent, a halogen group, or an alkoxy group; In formula (3), R ¹³ represents a divalent organic group, W represents a divalent linking group, and R ^{8 to} R ¹² each independently have a substituent. Represents an alkyl group having 10 or less carbon atoms, and n is an integer of 1 to 500.)   The electrophotographic photosensitive member according to claim 8, wherein the photosensitive layer has a thickness of 15 μm or less.   The electrophotographic photosensitive member according to claim 1, wherein the electrophotographic photosensitive member is used in an image forming apparatus having an exposure unit having a resolution of 1,200 dpi or more. An electrophotographic photoreceptor according to any one of claims 1 to 17,
A charging unit for charging the electrophotographic photosensitive member, an image exposing unit for performing image exposure on the charged electrophotographic photosensitive member to form an electrostatic latent image, and developing the electrostatic latent image with toner to form a toner image. Developing means, transfer means for transferring the toner image from the electrophotographic photosensitive member to the transfer target, charge eliminating means for removing the charge remaining on the electrophotographic photosensitive member after the transfer of the toner image, and transferring the toner image An electrophotographic cartridge comprising: at least one of cleaning means for removing toner remaining on the electrophotographic photosensitive member later. An electrophotographic photoreceptor according to any one of claims 1 to 17,
Charging means for charging the electrophotographic photoreceptor;
Image exposure means for performing image exposure on the charged electrophotographic photosensitive member to form an electrostatic latent image; and
Developing means for developing the electrostatic latent image with toner to form a toner image;
Transfer means for transferring the toner image from the electrophotographic photosensitive member to a transfer target;
An image forming apparatus comprising: a fixing unit that fixes the toner image transferred to the transfer target.   The image forming apparatus according to claim 19, wherein the image exposure unit is an exposure unit having a resolution of 1,200 dpi or more.   The image forming apparatus according to claim 19, wherein an average circularity of the toner measured by a flow particle image analyzer is 0.940 or more and 1.000 or less.   The image forming apparatus according to any one of claims 19 to 21, wherein the toner is a toner manufactured in an aqueous medium.   23. The toner according to any one of claims 19 to 22, wherein the toner is a toner obtained through a process of aggregating at least polymer primary particles and colorant particles to form a particle aggregate. Image forming apparatus.   24. The image forming apparatus according to claim 19, wherein the toner has a resin coating layer.   25. The image forming apparatus according to claim 24, wherein the resin coating layer contains polysiloxane wax.   The image forming apparatus according to any one of claims 19 to 25, wherein the toner contains paraffin wax.

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