JP2006153953A - Layered type electrophotographic photoreceptor and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a layered type electrophotographic photoreceptor with little decrease in sensitivity characteristics and to provide an image forming apparatus equipped with the photoreceptor. <P>SOLUTION: The layered type electrophotographic photoreceptor contains an amine stilbene compound expressed by general formula (1) as a hole transporting agent. In general formula (1), each of A to D and R<SP>1</SP>to R<SP>14</SP>represents an independent substituent such as hydrogen, halogen, alkyl group, halogenated alkyl group, alkoxy group, aryl group or the like; each repeat number a to d is an independent integer of 0 to 4; each repeat number m and n is an independent integer of 0 to 2; however, two in R<SP>2</SP>to R<SP>6</SP>or two in R<SP>9</SP>to R<SP>13</SP>are substituents except hydrogen. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a multilayer electrophotographic photosensitive member and an image forming apparatus provided with the same, and particularly, by using a specific hole transport agent, not only in an initial stage but also in a case of repeated use, it is excellent. The present invention relates to a multi-layer electrophotographic photosensitive member capable of obtaining sensitivity characteristics and an image forming apparatus including the same.

Conventionally, as an electrophotographic photosensitive member used for an image forming apparatus or the like, an organic photosensitive member made of an organic photosensitive material such as a charge transfer agent, a charge generating agent, and a binder resin (binder resin) has been used. Such an organic photoreceptor is advantageous in that it is easy to manufacture and has a wide degree of freedom in structural design because it has various options for the photoreceptor material as compared with conventional inorganic photoreceptors.
As such an organic photoreceptor, a multilayer electrophotographic photoreceptor comprising a charge generation layer containing a charge generation agent on a substrate and a charge transport layer containing a charge transfer agent and a binder resin is known. Yes. Such a laminated electrophotographic photosensitive member has a variety of options for the photosensitive material, and has an advantage that an electrophotographic photosensitive member having arbitrary characteristics such as sensitivity characteristics and durability can be produced relatively easily.

  Among such organic photoreceptor materials, as a charge transport agent having a predetermined charge mobility, an amine compound represented by the following general formula (19) and an electrophotographic photoreceptor using the same are known (for example, , See Patent Document 1).

(In the general formula (19), R ²⁰ and R ²¹ are each a hydrogen atom, a halogen atom, an alkoxy group, an aryl group, or at least two of R ¹⁶ , R ¹⁷ , R ¹⁸ and R ¹⁹ are represented by the general formula (20). In the case where the group represented by the general formula (20) is not represented among R ¹⁶ , R ¹⁷ , R ¹⁸ and R ¹⁹ , it represents a hydrogen atom.)

(In the general formula (20), R ²² represents a hydrogen atom, or a substituted or unsubstituted alkyl group or aryl group, and R ²³ and R ²⁴ each independently represents a hydrogen atom, or a substituted or unsubstituted alkyl group. Represents a group or an aryl group, and at least one of R ²³ and R ²⁴ represents a substituted or unsubstituted aryl group.)

  Further, an electrophotographic photoreceptor using an amine compound represented by the following general formula (21) is known as a charge transport agent having predetermined sensitivity characteristics and durability (see, for example, Patent Document 2).

(In general formula (21), R ^{25 to} R ³⁰ may each have a halogen atom, an alkyl group that may have a substituent, an alkoxy group that may have a substituent, or a substituent. Represents an aryl group or a substituted amino group, which may be the same or different from each other, and the repeating numbers p, q, r, s, t and u each represent an integer of 0 to 4 In the case of an integer of 2 or more, each of a plurality of R ^{25 to} R ³⁰ may be the same or different, and X ¹ represents a group represented by the following general formula (22), and X ² Represents a group represented by the following general formula (23), which may be the same or different.

(In general formulas (22) and (23), y represents an integer of 1 or 2, z represents an integer of 0 to 2, and R ^{31 to} R ⁴⁰ represent a hydrogen atom and a substituent, respectively. Represents an alkyl group which may have a substituent, an alkoxy group which may have a substituent, an aryl group which may have a substituent, or a heterocyclic group which may have a substituent. May be the same or different from each other; or the pair consisting of R ³⁴ and R ³⁵ or the pair consisting of R ³⁹ and R ⁴⁰ may be condensed to form a carbocyclic group or heterocyclic group, provided that In the pair consisting of R ³⁴ and R ³⁵ or the pair consisting of R ³⁹ and R ⁴⁰ , when one is a hydrogen atom or an alkyl group, the other is an aryl group or a heterocyclic group; Each of R ³¹ and R ³² may be the same or different; when z is 2, R ³⁹ and R ⁴⁰ respectively. May be the same or different.)
JP-A-7-36203 (Claims) JP-A-9-244278 (Claims)

  However, the amine compound described in Patent Document 1 has at least two substituted ethenyl groups represented by the formula (20) and four or less predetermined substituents in the phenylamino groups at the four molecular terminals. . Accordingly, in one of the terminal phenylamino groups having no substituted ethenyl group, the predetermined substituent is 1 or less. Therefore, the compatibility with the binder resin is poor, it is difficult to uniformly disperse in the photosensitive layer, charge transfer is difficult to occur, and crystallization is likely to occur.

  In addition, the amine compound described in Patent Document 2 includes one substituted ethenyl group represented by the formulas (22) and (23) in each of four molecular terminal phenylamino groups, and a predetermined substituent of 8 or less. Contains. Therefore, the predetermined substituent may be 1 or less in one of the terminal phenylamino groups having no substituted ethenyl group. Therefore, the compatibility with the binder resin is poor and it is difficult to uniformly disperse in the photosensitive layer. When such an amine compound is used in the charge transport agent layer of the laminated electrophotographic photosensitive member, the sensitivity characteristics are obtained when it is repeatedly used. There was a problem that it could not be maintained.

Therefore, the present inventors, in a specific amine compound, a molecular terminal phenylamino group having a specific substituent containing a double bond and a molecular terminal phenylamino group having two or more predetermined substituents. By including at least one, the compatibility with the binder resin and the solubility in the solvent are improved, and it is uniformly dispersed in the photosensitive layer to exhibit high charge mobility and effectively prevent crystallization. As a result, the present invention has been completed.
That is, an object of the present invention is to solve the above-mentioned technical problems, to have a superior sensitivity characteristic and durability over a long period of time, and to suppress the occurrence of exposure memory, and to such a multilayer electrophotographic photoreceptor. Another object of the present invention is to provide an image forming apparatus provided with such a laminated electrophotographic photosensitive member.

  According to the present invention, there is provided a multilayer electrophotographic photoreceptor comprising, on a substrate, a charge generation layer containing a charge generation agent, and a charge transport layer containing a hole transport agent and a binder resin, A laminated electrophotographic photosensitive member comprising an amine compound represented by the following general formula (1) as a hole transporting agent is provided, and the above-described problems can be solved.

(In General Formula (1), A to D and R ^{1 to} R ¹⁴ are each an independent substituent, and are a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, and 1 carbon atom. A substituted or unsubstituted halogenated alkyl group having -20 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, a substituted or unsubstituted amino group, or , R ^{1 to} R ¹⁴ are carbocyclic structures formed by bonding or condensing any two of them, repeating numbers a to d are independent integers of 0 to 4, and repeating numbers m and n are Each independently represents an integer of 0 to ^2. However, at least two of R ^{2 to} R ⁶ and / or at least two of R ^{9 to} R ¹³ are the substituents other than a hydrogen atom.

  In constituting the multilayer electrophotographic photoreceptor of the present invention, it is preferable that m and n in the general formula (1) are 1.

In constituting the multilayer electrophotographic photosensitive member of the present invention, at least two of R ^{2 to} R ⁶ and at least two of R ^{9 to} R ^{13 in} the general formula (1) are those having 1 to 1 carbon atoms. It is preferably a substituted or unsubstituted alkyl group having 10 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 10 carbon atoms, or a bonded or condensed carbocyclic structure having 3 to 7 carbon atoms.

Further, in constituting the multilayer electrophotographic photoreceptor of the present invention, R ² , R ⁶ , R ⁹ and R ^{13 in} the general formula (1) are substituted or unsubstituted alkyl groups having 1 to 6 carbon atoms, Or it is preferable that it is a C1-C6 substituted or unsubstituted alkoxy group.

  Further, in constituting the multilayer electrophotographic photosensitive member of the present invention, the amount of the hole transport agent added may be set to a value within the range of 60 to 100 parts by weight with respect to 100 parts by weight of the binder resin. preferable.

  In constituting the multilayer electrophotographic photosensitive member of the present invention, it is preferable to include titanyl phthalocyanine (Y type) as a charge generating agent.

  In constituting the multilayer electrophotographic photosensitive member of the present invention, an intermediate layer is preferably formed on the substrate.

  Another aspect of the present invention includes any one of the above-described laminated electrophotographic photosensitive members, and for performing a charging step, an exposure step, a developing step, and a transfer step around the electrophotographic photosensitive member. An image forming apparatus in which a part is arranged.

  According to the multilayer electrophotographic photosensitive member of the present invention, by using a specific amine stilbene compound as a hole transporting agent, a predetermined sensitivity characteristic can be extended not only at the initial stage but also when repeatedly used. While maintaining over time, the occurrence of exposure memory can be suppressed.

Further, according to the multilayer electrophotographic photosensitive member of the present invention, by using a hole transporting agent having two terminal double bonds, intramolecular conjugation spreads evenly at both ends, and charge mobility is further increased. Can be increased.
Therefore, by using such an amine stilbene compound as a charge transporting agent (hole transporting agent) in an electrophotographic photosensitive member, the amine stilbene compound can be uniformly dispersed in the photosensitive layer, and has excellent sensitivity. An electrophotographic photosensitive member having characteristics and charging characteristics can be provided. In addition, since such a structure is relatively easy to introduce, a predetermined amine stilbene compound can be produced in a relatively high yield.

Further, according to the multilayer electrophotographic photosensitive member of the present invention, by using an amine stilbene compound having a specific substituent as a hole transporting agent, compatibility with a binder resin and solubility in a solvent are improved. It is possible to increase the charge mobility and prevent crystallization more effectively.
Therefore, by using an amine stilbene compound having such a substituent as a charge transport agent (hole transport agent) in an electrophotographic photoreceptor, an electrophotographic photoreceptor having excellent sensitivity characteristics and durability over a long period of time. Can be provided. Further, with such a substituent, it is relatively easy to introduce and a predetermined amine stilbene compound can be produced in a relatively high yield.

Further, according to the multilayer electrophotographic photosensitive member of the present invention, the use of an amine stilbene compound having a specific substituent at a specific position as a hole transporting agent results in compatibility with a binder resin and dissolution in a solvent. Can be further improved, charge mobility can be increased, and crystallization can be more effectively prevented.
Therefore, by using an amine stilbene compound having such a substituent as a charge transporting agent (hole transporting agent) in an electrophotographic photosensitive member, an electrophotographic photosensitive having excellent sensitivity characteristics and durability for a long time. The body can be provided. Further, with such a substituent, it is relatively easy to introduce and a predetermined amine stilbene compound can be produced in a relatively high yield.

  Further, according to the multilayer electrophotographic photosensitive member of the present invention, by controlling the addition amount of the hole transport agent within a predetermined range, mixing and dispersion are facilitated, and not only in the initial stage but also in the case of repeated use. Even in such a case, the predetermined sensitivity characteristic can be maintained for a long time.

  Further, according to the multilayer electrophotographic photosensitive member of the present invention, by using a specific charge generating agent, a predetermined sensitivity characteristic can be maintained for a long time even when a relatively small amount is added.

  Further, according to the multilayer electrophotographic photosensitive member of the present invention, the intermediate layer is formed on the substrate in advance, so that charges on the substrate side can be prevented from being easily injected into the photosensitive layer and photosensitive. The body layer can be firmly bonded onto the substrate, and defects on the substrate surface can be covered and smoothed.

  In addition, according to the image forming apparatus of the present invention, by providing a specific laminated electrophotographic photosensitive member, a predetermined sensitivity characteristic is maintained for a long time not only in the initial stage but also in the case of repeated use. It is possible to form a clear image with little exposure memory.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments relating to a multilayer electrophotographic photoreceptor and an image forming apparatus of the present invention will be specifically described below with reference to the drawings as appropriate.

[First embodiment]
The first embodiment is a multilayer electrophotographic photoreceptor comprising a charge generation layer containing a charge generation agent, a charge transport layer containing a hole transport agent and a binder resin on a substrate. And it contains the amine stilbene compound represented by following General formula (1) as a hole transport agent, It is characterized by the above-mentioned.

(In General Formula (1), A to D and R ^{1 to} R ¹⁴ are each an independent substituent, and are a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, and 1 carbon atom. A substituted or unsubstituted halogenated alkyl group having -20 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, a substituted or unsubstituted amino group, or , R ^{1 to} R ¹⁴ are carbocyclic structures formed by bonding or condensing any two of them, repeating numbers a to d are independent integers of 0 to 4, and repeating numbers m and n are Each independently represents an integer of 0 to ^2. However, at least two of R ^{2 to} R ⁶ and / or at least two of R ^{9 to} R ¹³ are the substituents other than a hydrogen atom.

1. Basic Configuration (1) Basic Structure As shown in FIG. 1A, a multilayer electrophotographic photoreceptor 20 is a charge generation layer containing a charge generation agent on a substrate 12 by means such as vapor deposition or coating. 24, and then, on the charge generation layer 24, a coating liquid containing at least one amine stilbene compound (hole transport agent) represented by the general formula (1) and a binder resin is applied, It can be produced by drying it to form the charge transport layer 22.
In contrast to the above structure, as shown in FIG. 1B, the charge transport layer 22 may be formed on the substrate 12, and the charge generation layer 24 may be formed thereon.
However, since the charge generation layer 24 is much thinner than the charge transport layer 22, for protection, the charge transport layer 22 is formed on the charge generation layer 24 as shown in FIG. It is more preferable to form

  In addition, the positive or negative charge type of the multilayer electrophotographic photosensitive member is selected depending on the order in which the charge generation layer and the charge transport layer are formed and the type of charge transport agent used in the charge transport layer. For example, when a charge generation layer is formed on a substrate and a charge transport layer is formed thereon, when a hole transport agent such as an amine stilbene compound is used as the charge transport agent in the charge transport layer, The photoreceptor is of a negative charge type. In this case, the charge transport layer may contain an electron transport agent. In the case of a multilayer electrophotographic photoreceptor, the residual potential of the photoreceptor is greatly reduced, and the sensitivity can be improved.

Regarding the thickness of the photoreceptor layer in the multilayer electrophotographic photoreceptor, the charge generation layer is about 0.01 to 5 μm, preferably about 0.1 to 3 μm, and the charge transport layer is 2 to 100 μm, preferably It is about 5-50 micrometers.
And as a base | substrate with which such a photoreceptor layer is formed, various materials which have electroconductivity can be used, for example, iron, aluminum, copper, tin, platinum, silver, vanadium, molybdenum, chromium, cadmium Examples thereof include metals such as titanium, nickel, palladium, indium, stainless steel, and brass, plastic materials on which the above metal is vapor-deposited or laminated, glass coated with aluminum iodide, tin oxide, indium oxide, and the like.

In addition, as shown in FIG. 1C, it is also preferable to previously form the intermediate layer 25 on the substrate 12 before forming the photoreceptor layer. The reason for this is that by providing such an intermediate layer 25, it is possible to prevent the charge on the substrate side from being easily injected into the photoreceptor layer, and to firmly bond the photoreceptor layer onto the substrate 12, thereby This is because the above defects can be covered and smoothed.
Furthermore, the shape of the substrate may be any of a sheet shape, a drum shape, or the like according to the structure of the image forming apparatus to be used. The substrate itself has conductivity or the surface of the substrate has conductivity. If you do. Further, it is preferable that the substrate has a sufficient mechanical strength when used, such as aluminum, and is lightweight.

2. Charge transport layer (1) Hole transport agent (1) -1 type As a hole transport agent, an amine stilbene compound represented by the general formula (1) is contained.
The reason for this is to use an amine stilbene compound that includes at least one phenylamino group at the molecular end having a specific substituent containing a double bond and at least one phenylamino group at the molecular end having two or more predetermined substituents. This is because the compatibility with the binder resin and the solubility in the solvent can be improved.
Therefore, it can be uniformly dispersed in the photosensitive layer, exhibit high charge mobility, and can effectively prevent crystallization. For this reason, by using such an amine stilbene compound for a laminated electrophotographic photoreceptor, it is possible to suppress the occurrence of exposure memory over a long period of time and to perform stable image formation.
In addition, by using an amine stilbene compound in which a specific structure is introduced into the triphenylamine structure at the molecular end, not only the sensitivity characteristics can be further improved, but also the mechanical characteristics and film formability can be improved. It is.

Moreover, it is preferable that m and n of this amine stilbene compound are 1.
This is because the presence of two double bonds at the terminal of the amine stilbene compound allows intramolecular conjugation to spread at both ends, further increasing charge mobility and improving sensitivity characteristics.
Moreover, if m and n are 1, introduction is relatively easy, so that a predetermined amine stilbene compound can be produced in a relatively high yield.

Moreover, it is preferable that at least two of A, B, C and D of the amine stilbene compound are substituted or unsubstituted aryl groups having 6 to 15 carbon atoms.
This is because by having such a substituent, compatibility with the binder resin is improved, and electrical characteristics and heat resistance can be improved. In addition, since the electron distribution is delocalized and planarized, the charge mobility can be increased and the injection property of charges from the charge generating agent can be enhanced.

In addition, at least two of R ^{2 to} R ⁶ and at least two of R ^{9 to} R ¹³ of the amine stilbene compound are substituted or unsubstituted alkyl groups having 1 to 10 carbon atoms, and those having 1 to 10 carbon atoms. A substituted or unsubstituted alkoxy group, or a bonded or condensed carbocyclic structure having 3 to 7 carbon atoms is preferable. Furthermore, at least two of R ^{2 to} R ⁶ and at least two of R ^{9 to} R ¹³ are substituted or unsubstituted alkyl groups having 1 to 6 carbon atoms, substituted or unsubstituted alkoxy groups having 1 to 6 carbon atoms. It is more preferably a group or a bonded or condensed carbocyclic structure having 4 to 5 carbon atoms.
The reason for this is that by having such a substituent, the planarity of the hole transport agent is lowered due to steric hindrance, and crystallization is more effectively prevented. Further, this is because the compatibility with the binder resin is further excellent, and since it is uniformly dispersed in the photosensitive layer, it is possible to provide an effect of excellent sensitivity characteristics over a long period of time.

In addition, R ² , R ⁶ , R ⁹ and R ¹³ of the amine stilbene compound are a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms and a substituted or unsubstituted alkoxy group having 1 to 6 carbon atoms. Is preferred. Furthermore, R ² , R ⁶ , R ⁹ and R ¹³ are more preferably a substituted or unsubstituted alkyl group having 1 to 3 carbon atoms and a substituted or unsubstituted alkoxy group having 1 to 3 carbon atoms.
The reason for this is that by having such a substituent, the planarity of the hole transport agent is reduced due to steric hindrance, and more effectively prevents crystallization, and the compatibility with the binder resin is further excellent. This is because since it is uniformly dispersed in the photosensitive layer, it is possible to provide an effect of excellent sensitivity characteristics over a long period of time. In addition, such a structure is easy to manufacture, so that a laminated electrophotographic photosensitive member can be provided at a relatively low cost.

(1) -2 Specific Example In addition, as specific examples of the amine stilbene compound represented by the general formula (1), amine stilbene compounds represented by the following structural formulas (2) and (3) (HTM-1, 2) Indicates.

  It is also preferable to use a conventionally known hole transport agent in combination. Examples of such hole transporting agents include N, N, N ′, N′-tetraphenylbenzidine derivatives, N, N, N ′, N′-tetraphenylphenylenediamine derivatives, N, N, N ′, N ′. -Tetraphenylnaphthylenediamine derivatives, N, N, N ', N'-tetraphenylphenanthrylenediamine derivatives, 2,5-di (4-methylaminophenyl) -1,3,4-oxadiazole, etc. Oxadiazole compounds, styryl compounds such as 9- (4-diethylaminostyryl) anthracene, carbazole compounds such as polyvinylcarbazole, organic polysilane compounds, pyrazolines such as 1-phenyl-3- (p-dimethylaminophenyl) pyrazoline Compounds, hydrazone compounds, indole compounds, oxazole compounds, isoxazols System compounds, thiazole compounds, thiadiazole compounds, imidazole compounds, pyrazole compounds, and nitrogen-containing cyclic compounds such as triazole compounds, and condensed polycyclic compounds.

(1) -3 Addition amount Further, regarding the addition amount of the hole transport agent, it is preferable to set the value within a range of 10 to 80 parts by weight with respect to 100 parts by weight of the binder resin.
The reason for this is that when the amount of the hole transport agent added is less than 10 parts by weight, the sensitivity is lowered and a practical problem may occur. On the other hand, when the added amount of the hole transport agent exceeds 80 parts by weight, the hole transport agent is likely to be crystallized, and an appropriate film as a photoreceptor may not be formed.
Therefore, it is more preferable to set the addition amount of the hole transport agent to a value within the range of 30 to 70 parts by weight.

(2) Binder resin Examples of the binder resin for dispersing the charge transport agent and the like include polycarbonate resins such as bisphenol Z type, bisphenol ZC type, bisphenol C type, bisphenol A type, polyarylate resin, and styrene-butadiene. Copolymer, styrene-acrylonitrile copolymer, styrene-maleic acid copolymer, acrylic copolymer, styrene-acrylic acid copolymer, polyethylene resin, ethylene-vinyl acetate copolymer, chlorinated polyethylene resin, polychlorinated Thermoplastic resins such as vinyl resin, polypropylene resin, ionomer resin, vinyl chloride-vinyl acetate copolymer, alkyd resin, polyamide resin, polyurethane resin, polysulfone resin, diallyl phthalate resin, ketone resin, polyvinyl butyral resin, polyether resin, Shi Can be used singly or in combination of two or more types of photocuring resins such as ricone resin, epoxy resin, phenol resin, urea resin, melamine resin, other crosslinkable thermosetting resin, epoxy acrylate, urethane acrylate, etc. is there.

(3) Electron Transfer Agent (3) -1 Type In addition, the charge transport layer of the multilayer electrophotographic photoreceptor of the present invention may further contain an electron transport agent. The reason for this is that by including an electron transport agent in the charge transport layer, electrons accumulated in the electron transport layer can be transported efficiently, and the residual potential can be lowered to improve sensitivity characteristics.
Examples of the electron transport agent include various compounds having high electron transport ability, such as compounds (ET-1 to ET-6) represented by the following formulas (4) to (9).

It is also preferable to use a conventionally known electron transport agent in combination. Examples of such electron transporting agents include diphenoquinone derivatives, benzoquinone derivatives, anthraquinone derivatives, malononitrile derivatives, thiopyran derivatives, trinitrothioxanthone derivatives, 3,4,5,7-tetranitro-9-fluorenone derivatives, dinitroanthracene derivatives, Dinitroacridine derivatives, nitroantharaquinone derivatives, dinitroanthraquinone derivatives, tetracyanoethylene, 2,4,8-trinitrothioxanthone, dinitrobenzene, dinitroanthracene, dinitroacridine, nitroanthraquinone, dinitroanthraquinone, succinic anhydride, maleic anhydride And various compounds having electron-accepting properties such as dibromomaleic anhydride, and preferably used alone or in combination of two or more.
Of these compounds, compounds having an electron mobility of 1.0 × 10 ⁻⁸ cm ² / V / sec or more at an electric field strength of 5 × 10 ⁵ V / cm are more preferable.

(3) -2 Addition Amount The addition amount of the electron transport agent is preferably set to a value within a range of 10 to 100 parts by weight with respect to 100 parts by weight of the binder resin.
The reason for this is that when the added amount of the plurality of electron transfer agents is less than 10 parts by weight, the sensitivity is lowered and a practical problem may occur. On the other hand, when the added amount of the plurality of electron transfer agents exceeds 100 parts by weight, the electron transfer agent is likely to be crystallized, and an appropriate film as a photoreceptor may not be formed.
Therefore, it is more preferable to set the addition amount of the electron transfer agent to a value within the range of 20 to 80 parts by weight.

In addition, when determining the addition amount of an electron transport agent, it is preferable to consider the addition amount of the hole transport agent mentioned above. More specifically, the addition ratio (total ETM / total HTM) of the electron transport agent (total ETM) is a value within the range of 0.25 to 1.3 with respect to the hole transport agent (total HTM). It is preferable to do.
This is because if the ratio of all ETMs / all HTMs is outside this range, the sensitivity is lowered, which may cause practical problems.
Therefore, it is more preferable that the ratio of the total ETM / total HTM is set to a value within the range of 0.5 to 1.25.

3. Charge generation layer (1) Charge generation agent (1) -1 type As the charge generation agent used in the electrophotographic photosensitive member of the present invention, metal-free phthalocyanine (τ type or x type), titanyl phthalocyanine (α type or Y) Type), hydroxygallium phthalocyanine (V type), and at least one compound selected from the group consisting of chlorogallium phthalocyanine (type II).
This is because by specifying the type of the charge generating agent, it is possible to provide a laminated electrophotographic photosensitive member with more excellent sensitivity characteristics, electrical characteristics, stability, and the like.

(1) -2 Specific Example Among these charge generators, it is more preferable to use phthalocyanine pigments (CGM-1 to CGM-4) represented by the following formulas (10) to (13). preferable.

Of the charge generating agents used in the electrophotographic photosensitive member of the present invention, it is preferable to use titanyl phthalocyanine (Y type).
This is because an electrophotographic photoreceptor having excellent sensitivity can be provided by using titanyl phthalocyanine (Y type).

Among the charge generating agents used in the electrophotographic photosensitive member of the present invention, titanyl phthalocyanine (Y type) represented by the formula (11) has at least a black angle of 2θ ± 0 .0 in the CuKα characteristic X-ray diffraction spectrum. 2 ° = 27.2 ° has a maximum peak, 26.2 ° has no peak, and in differential scanning calorimetry, a temperature from 50 ° C. to 400 ° C. other than the peak due to vaporization of adsorbed water It is preferable not to have a peak of change.
This is because when titanyl phthalocyanine (Y type) satisfies the above-described physical properties, the stability of the crystal of titanyl phthalocyanine in an organic solvent is excellent, and crystal transition can be suppressed. By using such titanyl phthalocyanine (Y type) in the photoreceptor coating solution, it is possible to provide an electrophotographic photoreceptor that maintains good sensitivity characteristics over a long period of time.

Among the charge generating agents used in the electrophotographic photosensitive member of the present invention, the method for producing titanyl phthalocyanine (Y type) represented by the formula (11) includes the following steps (1) and (2). It is preferable.
Step (1): A titanyl phthalocyanine compound is added to a water-soluble organic solvent, and the mixture is stirred for a certain period of time under heating, and then the liquid is allowed to stand for a certain period of time under a temperature condition lower than that of the agitation process to be stabilized. Step (2) of pigmentation pretreatment to be treated: After dissolving the crude crystals of titanyl phthalocyanine compound obtained by removing the water-soluble organic solvent in a solvent, this solution is dropped into a poor solvent and the titanyl phthalocyanine compound is added. Step of pigmentation in which recrystallization is carried out, followed by milling in a non-aqueous solvent in the presence of water

Moreover, it is also preferable to use the manufacturing method represented by the following process (2 ') for the process (2) of this titanyl phthalocyanine manufacturing method.
Step (2 ′): A crude crystal of a titanyl phthalocyanine compound obtained by removing the water-soluble organic solvent from the pigmentation pretreatment liquid obtained in the above step (1) was treated by an acid paste method, and obtained. Milling a low crystalline titanyl phthalocyanine compound in a non-aqueous solvent in the presence of water

Various organic solvents can be used as the water-soluble organic solvent used in the step (1). For example, 1 type, or 2 or more types, such as alcohol, such as methanol, ethanol, and isopropanol, N, N-dimethylformamide, N, N-dimethylacetamide, propionic acid, acetic acid, N-methylpyrrolidone, ethylene glycol, etc. are mentioned. Note that a water-insoluble organic solvent may be added to the water-soluble organic solvent in a small amount.
Moreover, although the conditions of stirring treatment are not specifically limited among pigmentation pre-processing, It is preferable to perform stirring processing for about 1 to 3 hours on the fixed temperature conditions of about 70-200 degreeC temperature range.
Further, the conditions for the stabilization treatment after the stirring treatment are not particularly limited, but the solution is about 5 to 10 hours under a constant temperature condition of about 10 to 50 ° C., particularly preferably about 23 ± 1 ° C. It is preferable to stand and stabilize.

Further, after completion of the pre-pigmentation treatment, the crude crystal of the titanyl phthalocyanine compound obtained by removing the water-soluble organic solvent is further dissolved in a solvent according to a conventional method, and then dropped into a poor solvent for recrystallization, It is preferable to form a pigment through steps such as filtration, washing with water, milling, filtration, and drying.
Here, the milling process is a process of dispersing and stirring in a non-aqueous solvent in a state where water is present without drying the solid after washing with water. Examples of the solvent for dissolving the crude crystals include halogenated hydrocarbons such as dichloromethane, chloroform, ethyl bromide and butyl bromide, trihaloacetic acids such as trifluoroacetic acid, trichloroacetic acid and tribromoacetic acid, and sulfuric acid. Or arbitrary combinations of 2 or more types are mentioned.
Examples of the poor solvent for recrystallization include water, alcohols such as methanol, ethanol, and isopropanol, and water-soluble organic solvents such as acetone and dioxane. Used in any combination of two or more. Furthermore, examples of non-aqueous solvents for milling include halogen solvents such as chlorobenzene and dichloromethane.

  In addition, examples of the acid used in the acid paste method include concentrated sulfuric acid and sulfonic acid. The non-aqueous solvent used for the milling treatment is the same as described above.

  The titanyl phthalocyanine represented by the formula (11) comprises a phthalonitrile represented by the formula (14) and a titanium alkoxide represented by the formula (15) as shown in the following reaction formula (1). Or, as shown in the following reaction formula (2), 1,3-diiminoindoline represented by formula (16) and titanium alkoxide represented by formula (15) are reacted, It is preferable to synthesize.

(R ¹⁵ in the reaction formula (1) is an alkyl group having 1 to 6 carbon atoms.)

(R ¹⁵ in the reaction formula (2) is an alkyl group having 1 to 6 carbon atoms.)

  It is also preferable to use a conventionally known charge generating agent. Such charge generators include phthalocyanine pigments such as oxo titanyl phthalocyanine, perylene pigments, bisazo pigments, diketopyrrolopyrrole pigments, metal-free naphthalocyanine pigments, metal naphthalocyanine pigments, squaraine pigments, trisazo pigments, indigo Organic photoconductors such as pigments, azulenium pigments, cyanine pigments, pyrylium pigments, ansanthrone pigments, triphenylmethane pigments, selenium pigments, toluidine pigments, pyrazoline pigments, quinacridone pigments, selenium, selenium-tellurium, selenium- Examples of the inorganic photoconductive agent material such as arsenic, cadmium sulfide, and amorphous silicon may be used singly or as a mixture of two or more.

In the method of forming the charge generation layer by forming a charge generation layer coating solution and applying and drying the charge generation layer, the charge generation agent is added in an amount of 0.5 to 150 weights per 100 parts by weight of the binder resin. The value is preferably within the range of parts.
The reason for this is that when the added amount of the plurality of charge generating agents is less than 0.5 parts by weight, the effect of increasing the quantum yield becomes insufficient, and the sensitivity, electrical characteristics, stability, etc. of the electrophotographic photosensitive member are reduced. This is because it cannot be improved. On the other hand, when the added amount of the plurality of charge generating agents exceeds 150 parts by weight, the extinction coefficient for light having an absorption wavelength in the infrared or near infrared region decreases, and the sensitivity, electrical characteristics, This is because the stability and the like may decrease accordingly.
Therefore, it is more preferable to set the amount of the charge generating agent to a value within the range of 0.5 to 120 parts by weight.

(2) Binder Resin As the binder resin used for the charge generation layer, various resins used for the photoreceptor layer can be used. As a kind of binder resin, what was described by description of the binder resin mentioned above is mentioned, for example. This is because by using such a binder resin, the charge generating agent can be uniformly dispersed and electrical characteristics can be improved.

(3) Electron Transfer Agent (3) -1 Type Further, an electron transfer agent may be further included in the charge generation layer of the multilayer electrophotographic photoreceptor of the present invention. The reason for this is that by including an electron transport agent in the charge generation layer, electrons accumulated in the charge generation layer can be efficiently transported to the support substrate, and the residual potential can be lowered to improve the sensitivity characteristics. It is.
Moreover, what is described with the electron transport agent mentioned above as an electron transport agent is mentioned.

(3) -2 Addition Amount The addition amount of the electron transport agent is preferably set to a value within a range of 10 to 100 parts by weight with respect to 100 parts by weight of the binder resin.
The reason for this is that when the added amount of the plurality of electron transfer agents is less than 10 parts by weight, the sensitivity is lowered and a practical problem may occur. On the other hand, when the added amount of the plurality of electron transfer agents exceeds 100 parts by weight, the electron transfer agent is likely to be crystallized, and an appropriate film as a photoreceptor may not be formed.
Therefore, it is more preferable to set the addition amount of the electron transfer agent to a value within the range of 20 to 80 parts by weight.

4). Additives In addition to the above-mentioned components, various other conventionally known additives such as hydrolysis inhibitors, antioxidants, radical scavengers are included in the photoreceptor layer as long as they do not adversely affect the electrophotographic characteristics. , Singlet quenchers, ultraviolet absorbers, softeners, plasticizers, surface modifiers, extenders, thickeners, dispersion stabilizers, waxes, acceptors, donors, and the like. In order to improve the sensitivity of the photoreceptor layer, known sensitizers such as terphenyl, halonaphthoquinones, and acenaphthylene may be used in combination with the charge generator.

5. Intermediate layer In constituting the multilayer electrophotographic photosensitive member of the present invention, an intermediate layer is preferably formed on the substrate. The reason for this is that by forming an intermediate layer on the substrate, the adhesion between the photoreceptor layer and the substrate can be improved and the surface of the substrate can be smoothed. This is because it can be coated and the residual potential can be further reduced.

(1) Binder Resin As the binder resin used for the intermediate layer, various resins conventionally used for the photoreceptor layer can be used. As a kind of binder resin, what was described by description of the binder resin mentioned above is mentioned, for example.
Moreover, as the binder resin used for the intermediate layer, a resin excellent in solvent resistance is more preferable. The reason for this is that if the solvent resistance of the binder resin used in the intermediate layer is low, it will be dissolved in the photoreceptor layer applied on the intermediate layer, making it difficult to properly form the intermediate layer. Because there are cases. Specifically, resins that form a three-dimensional network structure such as acrylic resin, alkyd resin, polyurethane, melamine resin, epoxy resin, phenol resin, urea resin, polyamide, polyester, maleic acid resin, isocyanate resin, and silicon resin Is mentioned. Moreover, since it is further excellent in solvent resistance, a phenol resin and polyamide are more preferable.

(2) Additives Additives to be added to the intermediate layer are in a range where sedimentation at the time of production does not become a problem, and light scattering is caused to prevent the generation of interference fringes or to improve dispersibility. It is also preferable to add a small amount of various additives (organic fine powder or inorganic fine powder) for the purpose of improving conductivity.
In addition, the types of additives contained in the intermediate layer include inorganic pigments such as white pigments such as titanium oxide, zinc oxide, zinc white, zinc sulfide, lead white, and lithopone, and extender pigments such as alumina, calcium carbonate, and barium sulfate. Examples thereof include pigments, fluorine resin particles, benzoguanamine resin particles, and styrene resin particles.
Moreover, when adding additives, such as a fine powder, it is preferable to make the average particle diameter into the value within the range of 0.01-3 micrometers. This is because if the particle size is too large, the unevenness of the intermediate layer may increase, an electrically non-uniform portion may occur, and image quality defects may easily occur. On the other hand, if the particle size is too small, a sufficient light scattering effect may not be obtained.
In addition, when adding additives, such as a fine powder, the addition amount shall be the value of 70 weight% or less in a weight conversion with respect to solid content of an intermediate | middle layer, and the value within the range of 0.01-50 weight%. It is more preferable to set the value within the range of 0.01 to 30% by weight.

  In addition, it is also preferable that the intermediate layer contains a conventionally known charge transport agent, charge generator and the like. These compounds may be used alone or in combination of two or more. For example, examples of the charge transporting agent and the charge generating agent include those described in the above description of the hole transporting agent, the electron transporting agent, and the charge generating agent.

(3) Film thickness In addition, since the concealability of the unevenness in the support base material is increased by increasing the film thickness of the intermediate layer, spot-like image quality defects are preferred in the direction of reduction, but on the contrary, Electrical characteristics such as an increase in residual potential tend to decrease.
Accordingly, the thickness of the intermediate layer is preferably set to a value within the range of 0.1 to 50 μm, and more preferably set to a value within the range of 1 to 30 μm.

6). Manufacturing Method Regarding the manufacturing method of the multilayer photoreceptor layer of the present invention, a charge transport layer coating solution and a charge generation layer coating solution are prepared as described below, applied onto a substrate, and then dried. It is preferable to manufacture.

(1) Coating liquid preparation process The coating liquid preparation process includes, for example, a coating liquid for a charge transport layer comprising a binder resin, a hole transport agent, and a solvent, a binder resin, a charge generator, and a solvent. And a charge generation layer coating solution comprising: For example, it is preferable to disperse and mix using a roll mill, a ball mill, an attritor, a paint shaker, an ultrasonic disperser or the like to obtain a coating solution.
More specifically, the solid content concentration of the charge transport layer coating solution is within the range of 10 to 30% by weight, and the solid content concentration of the charge generation layer coating solution is within the range of 1 to 10% by weight. It is preferable to prepare a coating solution. The reason for this is that if the solid content concentration of the coating solution for the charge transport layer is less than 10% by weight, a coating defect may occur, whereas the solid content concentration of the coating solution exceeds 30% by weight. This is because unevenness of layers is likely to occur, and it may be difficult to form a thin film having a uniform thickness as a photoreceptor. Similarly, if the solid content concentration of the coating solution for the charge generation layer is less than 1% by weight, film defects may occur. If the solid content concentration exceeds 10% by weight, unevenness of the layer is likely to occur. It may be difficult to form a thin film having a uniform thickness as a body.
Various organic solvents can be used as the solvent for preparing the charge transport layer coating solution and the charge generation layer coating solution. For example, alcohols such as methanol, ethanol, isopropanol and butanol; aliphatic hydrocarbons such as n-hexane, octane and cyclohexane; aromatic hydrocarbons such as benzene, toluene and xylene; dichloromethane, dichloroethane, chloroform and tetrachloride Halogenated hydrocarbons such as carbon and chlorobenzene; ethers such as dimethyl ether, diethyl ether, tetrahydrofuran, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, dioxane and dioxolane; ketones such as acetone, methyl ethyl ketone and cyclohexanone; esters such as ethyl acetate and methyl acetate Class, dimethylformaldehyde, dimethylformamide, dimethylsulfoxide, etc., alone or in combination of two or more. That.
Furthermore, in order to improve the dispersibility of the charge transport agent, the charge generator, etc. and the smoothness on the surface of the photoreceptor layer, it is also preferable to add a surfactant, a leveling agent or the like when preparing the coating solution.

(2) Coating step and drying step The first coating step and the first drying step, the second coating step and the second drying step may be provided to form a photoreceptor layer comprising a charge transport layer and a charge generation layer. preferable. For example, as shown in FIG. 1A, the charge generation layer 24 is formed on the substrate 12 by the first coating process and the first drying process, and then, by the second coating process and the second drying process, It is preferable to form the charge transport layer 22 on the charge generation layer 24.

(2) -1 Application Step In carrying out the application step, it is also preferable to apply the application liquid directly on the substrate, or to apply it indirectly via an intermediate layer.
As a coating method, it is preferable to use, for example, a spin coater, an applicator, a spray coater, a bar coater, a dip coater, a doctor blade, etc., in order to form a photoreceptor layer having a uniform thickness.
The charge generation layer preferably has a thinner coating than the charge transport layer in order to reduce the residual potential.

(2) -2 Drying step Further, after the coating step, in the drying step, it is preferable to dry at a drying temperature of, for example, 60 ° C. to 150 ° C. using a high-temperature dryer, a vacuum dryer or the like. This is because when the drying temperature is less than 60 ° C., the drying time becomes excessively long, and it may be difficult to efficiently form a photoreceptor layer having a uniform thickness. is there. On the other hand, if the drying temperature exceeds 150 ° C., the photoconductor may be thermally decomposed.

In forming the multilayer electrophotographic photosensitive member of the present invention, when forming an intermediate layer on the substrate, as shown in FIG. 1 (c), an intermediate layer 25 is formed on the substrate 12, Next, it is preferable to form a charge generation layer and a charge transport layer.
In addition, about the conditions of a coating liquid preparation process, a coating process, and a drying process, it can apply to the manufacturing method of a charge generation layer and a charge transport layer. The intermediate layer coating solution is preferably prepared from, for example, a binder resin and an additive.

[Second Embodiment]
The second embodiment is an image forming apparatus including the electrophotographic photosensitive member of the first embodiment.
In this example of the image forming apparatus, the case where the multilayer electrophotographic photosensitive member of the present invention is used as an electrophotographic photosensitive member will be described.

(1) Configuration In carrying out the image forming method of the second embodiment, a copying machine 40 that is an image forming apparatus as shown in FIG. 2 can be suitably used. The copying machine 40 includes an image forming unit 41, a paper discharge unit 42, an image reading unit 43, and a document feeding unit 44. The image forming unit 41 further includes an image forming unit 41a and a paper feeding unit 41b. In the illustrated example, the document feeding unit 44 includes a document placing tray 44a, a document feeding mechanism 44b, and a document discharge tray 44c, and the document placed on the document placing tray 44a. Is sent to the image reading position P by the document feeding mechanism 44b and then discharged to the document discharge tray 44c.

Then, when the document is sent to the document reading position P, the image reading unit 43 reads the image on the document using the light from the light source 43a. That is, an image signal corresponding to the image on the document is formed using an optical element 43b such as a CCD.
On the other hand, recording sheets (hereinafter simply referred to as “sheets”) S stacked on the sheet feeding unit 41b are sent one by one to the image forming unit 41a. The image forming unit 41a is provided with a photosensitive drum 51 as an image carrier, and around the photosensitive drum 51, a charger 52, an exposure unit 53, a developing unit 54, and a transfer roller. 55 and a cleaning device 56 are arranged along the rotation direction of the photosensitive drum 51.

  Among these components, the photosensitive drum 51 is rotationally driven in the direction indicated by the solid line arrow in the drawing, and the surface thereof is uniformly charged by the charger 52. Thereafter, an exposure process is performed on the photosensitive drum 51 by the exposure device 53 based on the above-described image signal, and an electrostatic latent image is formed on the surface of the photosensitive drum 51. Based on the electrostatic latent image, the developing device 54 attaches toner and develops it, thereby forming a toner image on the surface of the photosensitive drum 51. The toner image is transferred as a transfer image onto the sheet S conveyed to the nip portion between the photosensitive drum 51 and the transfer roller 55. Next, the sheet S on which the transferred image is transferred is conveyed to the fixing unit 57 and a fixing process is performed.

Here, the paper S after fixing is sent to the paper discharge unit 42. However, when performing post-processing (for example, stapling processing), the paper S is sent to the intermediate tray 42a and then back. Processing is performed. Thereafter, the sheet S is discharged to a discharge tray portion (not shown) provided on the side surface of the image forming apparatus. On the other hand, when no post-processing is performed, the sheet S is discharged to a discharge tray 42b provided below the intermediate tray 42a.
The intermediate tray 42a and the paper discharge tray 42b are configured as a so-called in-body paper discharge unit.
After the transfer is performed as described above, the residual toner (and paper dust) remaining on the photosensitive drum 51 is removed by the cleaning device 56. That is, while the photosensitive drum 51 is cleaned, residual toner is collected in a waste toner container (not shown).

  Hereinafter, the present invention will be described in detail with reference to Examples and Comparative Examples.

[Example 1]
(1) Preparation of laminated electrophotographic photosensitive member (1) -1 Formation of intermediate layer 60 parts by weight of phenol resin (Dai Nippon Ink Co., Ltd., J325) as binder resin and titanium oxide as pigment (Fuji Titanium Industry) Manufactured by TA-300) and 100 parts by weight of methanol as a dispersion medium were processed by a ball mill (using zirconia beads having a diameter of 1 mm) for 24 hours to disperse the coating solution for the intermediate layer. Next, the obtained coating solution was applied onto an aluminum base tube having a diameter of 30 mm and a length of 254 mm using a fluororesin blade, and then dried at 150 ° C. for 30 minutes, so that the average film thickness was 10 μm. An intermediate layer was formed.

(1) -2 Formation of Charge Generation Layer In an ultrasonic dispersion machine, 1 part by weight of Y-type titanyl phthalocyanine (CGM-2) represented by formula (5) as a charge generation agent and isopropyl alcohol as a dispersion medium After containing 39 parts by weight, it was treated with an ultrasonic disperser for 5 minutes to be primarily dispersed to obtain a dispersion. Further, a solution prepared by dissolving 1 part by weight of polyvinyl butyral (BM-1 manufactured by Sekisui Chemical Co., Ltd.) in 9 parts by weight of ethyl cellosolve as a binder resin was added to this dispersion, and again with an ultrasonic disperser. The coating solution for the charge generation layer of the laminated photoreceptor layer was prepared by processing for 10 minutes and secondary dispersion. Next, this coating solution was applied onto the intermediate layer using a fluorine resin blade and dried at 110 ° C. for 5 minutes to form a charge generation layer having a thickness of 0.3 μm.

(1) -3 Formation of Charge Transport Layer In the ultrasonic disperser, 80 parts by weight of the amine stilbene compound (HTM-1) represented by the formula (2) as a hole transport agent and Z as a binder resin 100 parts by weight of a polycarbonate resin (Pantelite TS2020 manufactured by Teijin Chemicals) and 600 parts by weight of tetrahydrofuran as a dispersion medium were stored and then dispersed and treated for 10 minutes with an ultrasonic disperser. A coating solution was prepared. Next, the obtained coating solution was applied onto the charge generation layer using a fluororesin blade, and then dried at 110 ° C. for 30 minutes to form a charge transport layer having a thickness of 25 μm. In this way, the multilayer electrophotographic photoreceptor of Example 1 was prepared and subjected to the following evaluation.

(2) Evaluation (2) -1 Charge Measurement and Sensitivity Measurement The obtained electrophotographic photosensitive member was mounted on a printer (Laser Printer LBP-450, manufactured by Canon Inc.), negatively charged to −650 V, and black The potential at the development position during solid image formation was read and used as the initial charging potential and initial sensitivity. Thereafter, 1000 sheets were continuously printed, and the charging potential and sensitivity were measured again to obtain the post-running charging potential and the post-running sensitivity. The obtained results are shown in Table 1.

(2) -2 Evaluation of Exposure Memory After the obtained electrophotographic photosensitive member is mounted on a printer (Laser Printer LBP-450 manufactured by Canon Inc.), the original for memory image evaluation shown in FIG. A4 sheets) were continuously printed, and whether or not a solid black image appeared in the gray portion of the memory image evaluation document was evaluated visually according to the following criteria. The first image evaluation of the memory image evaluation document was used as the initial exposure memory, and the 1000th image evaluation was used as the post-running exposure memory. The obtained results are shown in Table 1.
A: No black solid image is observed in the gray portion.
◯: Almost no black solid image is observed in the gray area.
Δ: A little black solid image is observed in the gray part, but there is no practical problem.
X: The remarkable generation | occurrence | production of a black solid image is observed in a gray part.

[Example 2]
In Example 2, a laminated electrophotographic photoreceptor was prepared and evaluated in the same manner as in Example 1 except that 60 parts by weight of the hole transport agent (HTM-1) used in Example 1 was used.

[Example 3]
In Example 3, a laminated electrophotographic photoreceptor was prepared and evaluated in the same manner as in Example 1 except that 40 parts by weight of the hole transport agent (HTM-1) used in Example 1 was used.

[Example 4]
In Example 4, instead of the hole transport agent (HTM-1) used in Example 1, 80 parts by weight of the hole transport agent (HTM-2) represented by Formula (3) was used. A multilayer electrophotographic photoreceptor was prepared and evaluated in the same manner as in Example 1.

[Example 5]
In Example 5, Example 1 was used except that 1 part by weight of X-type metal-free phthalocyanine represented by the formula (10) was used instead of Y-type titanyl phthalocyanine (CGM-2) used in Example 1. Similarly, a multilayer electrophotographic photosensitive member was prepared and evaluated.

[Example 6]
In Example 6, instead of the Y-type titanyl phthalocyanine (CGM-2) used in Example 1, 1 part by weight of an X-type metal-free phthalocyanine represented by the formula (10) was used, and a hole transport agent (HTM- A laminated electrophotographic photosensitive member was prepared and evaluated in the same manner as in Example 1 except that 80 parts by weight of the hole transport agent (HTM-2) represented by the formula (3) was used instead of 1). did.

[Comparative Example 1]
In Comparative Example 1, instead of the hole transport agent (HTM-1) used in Example 1, 80 parts by weight of the hole transport agent (HTM-3) represented by the formula (17) was used. A multilayer electrophotographic photoreceptor was prepared and evaluated in the same manner as in Example 1.

[Comparative Example 2]
In Comparative Example 2, instead of the hole transport agent (HTM-1) used in Example 1, 80 parts by weight of the hole transport agent (HTM-4) represented by the formula (18) was used. A multilayer electrophotographic photosensitive member was prepared and evaluated in the same manner as in Example 1.

＊ 表中のＢＭ−１はポリビニルブチラールを示し、Ｚ型ＰＣはＺ型ポリカーボネートを示している。

* BM-1 in the table indicates polyvinyl butyral, and Z-type PC indicates Z-type polycarbonate.

As described above in detail, according to the present invention, by using a specific hole transport agent, even in the initial state and when it is repeatedly used, there is little deterioration in sensitivity characteristics, and the exposure memory A multilayer electrophotographic photosensitive member with less generation and an image forming apparatus provided with the same have been obtained.
Therefore, the multilayer electrophotographic photosensitive member of the present invention is expected to contribute to cost reduction, high speed, high performance, etc. in various image forming apparatuses such as copying machines and printers.

(A)-(c) is a figure provided in order to demonstrate the basic structure and deformation | transformation structure of a laminated type electrophotographic photoreceptor. It is a figure provided in order to demonstrate the image forming apparatus provided with the lamination type electrophotographic photosensitive member. FIG. 5 is a diagram for explaining a memory image evaluation document.

Explanation of symbols

12: Substrate 20: Multilayer type photoreceptor 22: Charge transport layer 24: Charge generation layer 25: Intermediate layer 40: Copier 41: Image forming unit 41a: Image forming unit 41b: Paper feed unit 42: Paper discharge unit 43: Image Reading unit 43a: Light source 43b: Optical element 44: Document feeding unit 44a: Document loading tray 44b: Document feeding mechanism 44c: Document discharge tray 51: Photoreceptor drum 52: Charger 53: Exposure source 54: Developer 55 : Transfer roller 56: Cleaning device 57: Fixing unit 60: Memory image evaluation document 61: White portion 62: Black portion 63: Gray portion

Claims (8)

A laminated electrophotographic photoreceptor comprising a charge generation layer containing a charge generation agent and a charge transport layer containing a hole transfer agent and a binder resin on a substrate,
A laminated electrophotographic photosensitive member comprising an amine stilbene compound represented by the following general formula (1) as the hole transport agent.

(In General Formula (1), A to D and R ^{1 to} R ¹⁴ are each an independent substituent, and are a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, and 1 carbon atom. A substituted or unsubstituted halogenated alkyl group having -20 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, a substituted or unsubstituted amino group, or , R ^{1 to} R ¹⁴ are carbocyclic structures formed by bonding or condensing any two of them, repeating numbers a to d are independent integers of 0 to 4, and repeating numbers m and n are Each independently represents an integer of 0 to ^2. However, at least two of R ^{2 to} R ⁶ and / or at least two of R ^{9 to} R ¹³ are the substituents other than a hydrogen atom.   The multilayer electrophotographic photosensitive member according to claim 1, wherein m and n in the general formula (1) are each 1. In the general formula (1), at least two of R ^{2 to} R ⁶ and at least two of R ^{9 to} R ¹³ are substituted or unsubstituted alkyl groups having 1 to 10 carbon atoms, and 1 to 10 carbon atoms. The laminated electrophotographic photoreceptor according to claim 1 or 2, which is a substituted or unsubstituted alkoxy group, or a bonded or condensed carbocyclic structure having 3 to 7 carbon atoms. R ² , R ⁶ , R ⁹ and R ^{13 in the} general formula (1) are substituted or unsubstituted alkyl groups having 1 to 6 carbon atoms, or substituted or unsubstituted alkoxy groups having 1 to 6 carbon atoms. The laminated electrophotographic photosensitive member according to claim 1, wherein the laminated electrophotographic photosensitive member is provided.   The addition amount of the hole transport agent is set to a value within a range of 60 to 100 parts by weight with respect to 100 parts by weight of the binder resin. Multilayer electrophotographic photoreceptor.   The multilayer electrophotographic photosensitive member according to any one of claims 1 to 5, comprising titanyl phthalocyanine (Y type) as the charge generating agent.   The multilayer electrophotographic photosensitive member according to any one of claims 1 to 6, wherein an intermediate layer is formed on the substrate.   A portion for carrying out the charging step, the exposure step, the developing step, and the transfer step is provided around the electrophotographic photosensitive member, including the multilayer electrophotographic photosensitive member according to any one of claims 1 to 7. An image forming apparatus that is arranged.

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