JP2003021919A - Electrophotographic photoreceptor and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrophotographic photoreceptor where the correction of a density sensor is accurately performed and an image of appropriate density is stably outputted by controlling the density of a photoreceptor regarded as the reference of a density control to obtain intermediate density necessary to accurately control the density, to provide an image forming device and a process cartridge for the image forming device capable of stably outputting an image of good quality by using the electrophotographic photoreceptor, and to provide a method for manufacturing the electrophotographic photoreceptor capable of easily controlling the surface density of the electrophotographic photoreceptor to obtain the intermediate density. SOLUTION: As for the electrophotographic photoreceptor provided with at least an undercoat layer constituted of binding resin and particulates and a photoreceptive layer and formed on a conductive supporting body, the supporting body is an aluminum tube having a roughened surface, and the irregular reflectance of the photoreceptor surface is 50 to 60% for light in a wavelength region of 800 to 1300 nm.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an electrophotographic photoreceptor,
The present invention relates to a manufacturing method, an image forming apparatus using the method, and a process cartridge.

[0002]

2. Description of the Related Art Generally, an electrophotographic image forming apparatus is subject to a change in the environment in which it is used, the number of prints, etc.
It is known that the image density changes. In particular, a color image forming apparatus using a color toner having high transparency has a great influence, and when forming a color image by superimposing multiple colors, a color tone different from the original color tone is obtained due to a change in image density. Conventionally, as a method of controlling the image density,
A toner image (patch) for density measurement is formed on an electrophotographic photosensitive member or an intermediate transfer member, the density is detected by a density sensor, and the result is fed back to the exposure amount, developing bias, toner density, etc. It is known to perform control and has been put to practical use. By the way, the concentration sensor
The light emitting unit has a light emitting element such as an LED, and the light receiving unit has a light receiving element such as a photodiode. The infrared light emitted from the light emitting unit is applied to the patch, and the reflected light reflected by the patch is detected by the light receiving unit. However, a method of measuring the patch density from the reflectance is used. At this time, in order to detect the patch density with high accuracy, the density sensor detects the reflectance of the portion where the patch is formed and feeds it back as the reference density to control the toner adhesion amount. However, if the concentration sensor is used for a long period of time, the initial performance cannot be maintained due to deterioration of the light emitting element, contamination of the light receiving portion, and the like. Therefore, as disclosed in Japanese Patent Application Laid-Open No. 7-36230, etc., by periodically detecting the above-mentioned reference concentration and adjusting the output voltage of the sensor at that concentration to a predetermined value which is set in advance. A method of calibrating the output of the concentration sensor has been put into practical use. Further, at this time, the density of the photoconductor serving as the reference density needs to be an intermediate density as described later.

The photoconductor density means that the light emitted from the light emitting portion of the density sensor is reflected on the surface of the photoconductor, and the reflected light is received by the light receiving portion, and the output voltage of the sensor obtained from the intensity is replaced with the density. It is a thing. That is,
Controlling the photoreceptor density is nothing but controlling the reflectance of the photoreceptor surface. Therefore, when the photoconductor density is used as the reference of the toner density, it is necessary to control the reflectance of the photoconductor within a required range.

Here, the range required for the reflectance of the photoconductor is a range in which the photoconductor density is detected as an intermediate density. However, the conventional photoreceptor concentration may not always be an intermediate concentration, and in order to control the photoreceptor concentration to an intermediate concentration, as disclosed in JP-A-2000-105480, a photosensitive dye is used. Attempts have also been made to control the reflectance by addition. However, this method requires an extra material that is not required for the characteristics of the photoconductor, leading to an increase in cost. Further, since the light absorptance of the dye varies depending on the amount of the dye added, it is necessary to control it in the manufacturing process, which may cause an increase in cost and a decrease in the yield rate. Also, since the photoconductor is one of the parts of the image forming apparatus, it is possible to replace only the photoconductor if it deteriorates or gets scratched by repeated use, but the photoconductor density varies among individuals. If so, you have to change the setting of the density sensor according to the density of the photoconductor each time it is replaced. If this is not done, problems such as a change in the color tone of the image before and after the replacement of the photoconductor may occur.

Further, since the surface state of the photoconductor changes due to abrasion and scratches due to repeated use, it is necessary that the photoconductor density does not change due to these changes.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above conventional problems. That is, in view of the above-mentioned conventional technique, the first object of the present invention is to calibrate the density sensor by setting the density of the photosensitive member, which is the reference for the density control, to an intermediate density required for accurate density control. It is an object of the present invention to provide an electrophotographic photosensitive member that is properly processed and stably outputs an image having an appropriate density. A second object of the present invention is to provide an image forming apparatus and a process cartridge for the image forming apparatus, which can stably output a good image by using the electrophotographic photosensitive member. Further, a third object of the present invention is to provide a method for producing an electrophotographic photosensitive member which can easily control the surface density of the electrophotographic photosensitive member to an intermediate density.

[0007]

Means for Solving the Problems The inventors of the present invention have diligently studied the above problems, and as a result, electrophotographic having an undercoat layer comprising at least a binder resin and fine particles and a photosensitive layer on a conductive support. In the photoconductor, use is made of an electrophotographic photoconductor in which the support is an aluminum tube having a roughened surface, and the diffuse reflectance of the photoconductor surface is within a specific range for infrared light. The inventors have found that the above problems can be solved, and completed the first group of the present invention. Further, it is possible to solve the above problems by using an electrophotographic photoconductor in which the support is a nickel seamless belt, and the diffuse reflectance of the photoconductor surface is within a specific range for infrared light. Heading out, the present invention of the second group was completed.

That is, the above-mentioned problems are (1) the electrophotographic photosensitive member of the first group of the present invention which has an undercoating layer comprising at least a binder resin and fine particles and a photosensitive layer on a conductive support. The support is an aluminum tube having a roughened surface, and the diffuse reflectance of the surface of the photoconductor is 800 nm to 1
5 for light of any wavelength in the wavelength range of 300 nm
0% to 65% of the electrophotographic photoreceptor, (2) "the undercoat layer has a particle size of at least 0.5 µ.
The electrophotographic photosensitive member according to item (1) above, which contains particles of m to 3 μm, and (3) “fine particles contained in the undercoat layer contain a metal oxide as a main component. The electrophotographic photosensitive member according to item (1) or (2) above, which is an inorganic fine particle ", (4)" the surface of the roughened aluminum tube is cut. The electrophotographic photosensitive member according to any one of the above items (1) to (3), characterized in that the surface is roughened by.

A group of (5) "electrophotographic photoreceptor, charging means, exposing means, developing means, transfer means, means for forming a toner image for density measurement on the electrophotographic photoreceptor of the present invention, In the image forming apparatus having an optical density sensor including a light emitting section and a light receiving section, and a means for controlling image forming conditions by using information on the surface density of the photoconductor detected by the optical density sensor, An image forming apparatus characterized by using the electrophotographic photoconductor according to any one of the items (4) to (4), (6) "Feedback information on the photoconductor density detected by the optical density sensor". And (7) "the optical density sensor is a diffuse reflection type optical density sensor," which further comprises a calibrating means for calibrating the optical density sensor. sensor And the light of the wavelength emitted from the light emitting portion is the light of substantially the same wavelength as the light measured for the reflectance of the electrophotographic photosensitive member, and the spot of the emitted light is the cutting pitch of the conductive support. The image forming apparatus according to item (5) or (6) above, wherein the image forming apparatus sequentially superimposes toner images of a plurality of colors to form a color image. The image forming apparatus according to any one of the above items (5) to (7), which is a color image forming apparatus for forming the image ”, (9).
“The image forming apparatus includes a plurality of electrophotographic photoconductors, and the developed monochromatic toner images are sequentially superposed on the electrophotographic photoconductors to form a color image. The image forming apparatus according to item (8), (10) "the image forming apparatus primarily transfers a toner image developed on an electrophotographic photosensitive member onto an intermediate transfer member, and then transfers the toner image onto the intermediate transfer member. An image forming apparatus having an intermediate transfer unit for secondarily transferring a toner image onto a recording material, wherein toner images of a plurality of colors are sequentially superposed on an intermediate transfer member to form a color image, and the color image is recorded. The image forming apparatus according to the above (8) or (9), characterized in that the secondary transfer is collectively performed on the above. All layers,
An image forming apparatus according to item (10), which is an elastic belt in which a part of the belt is an elastic member. An image forming apparatus including a process cartridge, wherein the image forming apparatus is the image forming apparatus described in any one of (5) to (11) above. A process cartridge for a forming device.

The first group (13) of the present invention is a method for producing an electrophotographic photosensitive member having a photosensitive layer and an undercoat layer comprising at least a binder resin and fine particles on a conductive support. And controlling the irregular reflectance of the electrophotographic photosensitive member by the film thickness of the undercoat layer to obtain the electrophotographic photosensitive member according to any one of the items (1) to (4). And a method for producing an electrophotographic photosensitive member ”.

In addition, the above-mentioned problem is similarly solved in the second group of the present invention (14) "Electrophotographic photoreceptor having an undercoat layer comprising at least a binder resin and fine particles on a conductive support and a photosensitive layer. In the above, the support is a nickel seamless belt, and the diffuse reflectance of the surface of the photoconductor is 800 nm to 1
2 for light of any wavelength in the wavelength range of 300 nm
5% to 55%, the photoconductor for electrophotography, (15) "The particle size of the undercoat layer is at least 0.3.
The electrophotographic photosensitive member according to item (14) above, which contains particles having a size of from 3 to 3 μm ”, (16).
“The fine particles contained in the undercoat layer are inorganic fine particles containing a metal oxide as a main component.
4) or the electrophotographic photosensitive member according to item (15).

The second group of the invention (17) "Electrophotographic photoreceptor, charging means, exposure means, developing means, transfer means,
A means for forming a toner image for density measurement on the electrophotographic photosensitive member, an optical density sensor including a light emitting portion and a light receiving portion, and an image using information on the surface density of the photosensitive material detected by the optical density sensor In the image forming apparatus having a unit for controlling the forming conditions, the items (14) to (1)
(6) An image forming apparatus characterized by using the electrophotographic photosensitive member according to any one of the items (6), (18) "Feedback information on the photosensitive member density detected by the optical density sensor, An image forming apparatus according to item (17), characterized in that it has a calibrating means for calibrating the optical density sensor ", (19)" wherein the optical density sensor is a diffuse reflection type optical density sensor. In the above item (17) or (18), the light of the wavelength emitted from the light emitting unit is the light of the substantially same wavelength as the light for which the reflectance of the electrophotographic photosensitive member is measured. (20) The image forming apparatus is a color image forming apparatus that sequentially forms toner images of a plurality of colors to form a color image. Item (19) Any one image forming apparatus according to "
(21) “After the image forming apparatus primarily transfers the toner image developed on the electrophotographic photosensitive member onto the intermediate transfer member,
An image forming apparatus having an intermediate transfer unit for secondarily transferring a toner image on the intermediate transfer member onto a recording material, wherein toner images of a plurality of colors are sequentially superposed on the intermediate transfer member to form a color image, (2) The image forming apparatus according to the item (20), wherein the color image is secondarily transferred onto a recording material all at once. The elastic belt in which all layers or a part of the belt is an elastic member is used.
The image forming apparatus according to item 1).

The second group (23) of the present invention is a process cartridge for an image forming apparatus having at least an electrophotographic photosensitive member, wherein the image forming apparatus is the above-mentioned (17).
And a process cartridge for an image forming apparatus, which is the image forming apparatus according to any one of items (22) to (22).

A second group of the present invention (24) is a method for producing an electrophotographic photosensitive member having a photosensitive layer and an undercoat layer comprising at least a binder resin and fine particles on a conductive support. The irregular reflectance of the electrophotographic photosensitive member is controlled by the film thickness of the undercoat layer, and the above (14) to (16)
The method for producing an electrophotographic photosensitive member according to any one of the items 1 to 4).

The present invention will be described in detail below. [First group of the present invention] The first group of the present invention comprises an electrophotographic photoreceptor for use in the present invention, which comprises a conductive support made of an aluminum tube having a roughened surface and at least a binder resin and fine particles. Having a pulling layer and a photosensitive layer, 800 nm to 13
Light in the wavelength region of 00 nm almost passes through the photosensitive layer, reaches the undercoat layer and the conductive support, and causes irregular reflection by the fine particles in the undercoat layer and the roughened support surface. In particular, when particles having a particle diameter of 0.5 μm to 3 μm are contained, light in the above wavelength region is appropriately diffusedly reflected, so that it is possible to more easily reflect light with diffused reflectance of 50% to 65%, and the density sensor The detected density of the surface of the electrophotographic photosensitive member can be set to an intermediate density. Further, by setting the infrared light emitted from the density sensor used in the image forming apparatus to have substantially the same wavelength as the light whose surface reflectance of the electrophotographic photosensitive member is measured, the density of the electrophotographic photosensitive member can be more accurately measured. Can be detected as an intermediate concentration. Furthermore, by making the spot of infrared light emitted from the density sensor larger than the cutting pitch of the surface of the support, the irregularities of the diffused light of the density sensor due to the surface shape can be suppressed, and the density of the photoconductor can be detected more accurately. Can be made.

If the irregular reflectance of the surface of the photoconductor is larger than 65%, the density of the photoconductor detected by the image forming apparatus becomes too large. When the density sensor is calibrated with such a photoconductor density, the output of the sensor also increases as the toner adhesion amount increases. The difference from the density is reduced, and the accuracy of density control is significantly reduced. If the irregular reflectance is less than 50%, the regular reflectance increases accordingly. This occurs when the surface of the conductive support is not sufficiently roughened and the thickness of the undercoat layer is small. As a result, in an image forming apparatus that uses coherent light as an exposure light source, light and shade stripes may occur in a halftone image due to interference.

Further, the light of the wavelength range described above in the first group of the present invention has a very good correlation between the diffuse reflectance of the photoconductor and the thickness of the undercoat layer. Therefore, it is possible to control the irregular reflectance on the surface of the photoconductor by the film thickness of the undercoat layer. That is, by increasing the film thickness, the diffuse reflectance can be increased, and conversely, by decreasing the film thickness, the diffuse reflectance can be decreased. Of course, since the reflectance can also be controlled uniformly by controlling the film thickness uniformly,
It is easy to control the reflectance between individual photoconductors. Furthermore, since the reflectance of light in this wavelength range is hardly affected by the difference in the surface roughness of the undercoat layer, changes in the surface roughness due to environmental changes at the time of photoconductor manufacturing, surface roughness due to the coating method, etc. Even if the surface roughness of the undercoat layer changes due to the difference in the above, if the film thickness is the same, the reflectance of the undercoat layer is almost the same. Moreover, controlling the film thickness of the undercoat layer has been conventionally performed in the production of a photoconductor, so that fluctuations in reflectance between individuals can be prevented without providing extra management and inspection steps. Since it can be greatly suppressed, it is also very useful in terms of manufacturing cost.

Furthermore, it can be said that the film thickness of the undercoat layer does not change due to repeated use of the photoconductor, and therefore the reflectance does not change.

When the diffused reflectance measurement wavelength region is smaller than 800 nm, the photosensitive layer approaches the region having the spectral sensitivity and may be exposed to the irradiation light of the density sensor, which is not preferable. In that case, the density of the photoconductor often does not show an intermediate density. On the other hand, if it is larger than 1300 nm, the rate of change in diffuse reflectance due to the change in the thickness of the undercoat layer becomes small, and the thickness of the undercoat layer may become excessively large in order to obtain the desired reflectance. Yes, it is not preferable.

As a method for roughening the surface of the conductive support, a cutting method, a sandblast method, a roughening method by polishing,
Although there is roughening by anodic oxidation, etc., the cutting method is effective as a method for forming a uniform rough surface. In the sandblasting method, a large roughness may be locally formed, which acts as a charge injection portion to the photosensitive layer, which causes an abnormal image such as black spots in the reversal development. There are cases. Further, roughening by anodic oxidation requires post-treatment such as sealing treatment, which is disadvantageous in terms of productivity. In addition, if the post-processing is insufficient, that portion may cause an abnormal image.

The present invention will be described in detail below with reference to the drawings. FIG. 2 is a sectional view showing an electrophotographic photosensitive member. An undercoat layer (32) containing a binder resin and fine particles, a charge generating substance and a charge transporting substance are provided on a conductive support (31). A single-layer photosensitive layer (33) as a main component is provided. FIG. 3 shows an undercoat layer (32) containing a binder resin and fine particles, a charge generation layer (35) containing a charge generation material as a main component, and a charge transport material on a conductive support (31). And a charge transport layer (37) containing as a main component are laminated in this order. FIG. 4 shows that on the conductive support (31),
An undercoat layer (32) containing a binder resin and fine particles, a charge transport layer (37) containing a charge transport substance as a main component, and a charge generating layer (35) containing a charge generating substance as a main component It is configured to be stacked in order. In FIG. 5, an undercoat layer (32) containing a binder resin and fine particles, a charge generating layer (35) containing a charge generating substance as a main component, and a charge transporting substance are mainly formed on a conductive support (31). Charge transport layer as a component (3
7) and 7) are laminated, and a protective layer (39) is further provided on the charge transport layer. The photosensitive layer may be a single layer type in which a charge generating substance is dispersed in a charge transporting layer or a laminated type in which a charge generating layer and a charge transporting layer are sequentially laminated.

First, a multi-layer type photoconductor in which a charge generation layer (35) and a charge transport layer (37) are sequentially laminated will be described. The charge generation layer is a layer containing a charge generation material as a main component,
A binder resin may be used if necessary. An inorganic material and an organic material can be used as the charge generating substance.

Examples of the inorganic material include crystalline selenium, amorphous selenium, selenium-tellurium, selenium-tellurium-halogen, selenium-arsenic compounds, and amorphous silicon. In amorphous silicon,
A dangling bond terminated with a hydrogen atom or a halogen atom or a dangling bond doped with a boron atom, a phosphorus atom or the like is preferably used.

On the other hand, as the organic material, known materials can be used. For example, phthalocyanine-based pigments such as metal phthalocyanine and metal-free phthalocyanine, azurenium salt pigment, squaric acid methine pigment, azo pigment having a carbazole skeleton, azo pigment having a triphenylamine skeleton, azo pigment having a diphenylamine skeleton, dibenzothiophene skeleton Having azo pigment, azo pigment having fluorenone skeleton, azo pigment having oxadiazole skeleton, azo pigment having bisstilbene skeleton, azo pigment having distyryl oxadiazole skeleton, azo pigment having distyryl carbazole skeleton, perylene Series pigments, anthraquinone series or polycyclic quinone series pigments, quinone imine series pigments, diphenylmethane and triphenylmethane series pigments, benzoquinone and naphthoquinone series pigments, cyanine and azomethine series pigments, Jigoido based pigments, and bisbenzimidazole pigments. These charge generating substances can be used alone or as a mixture of two or more kinds.

As the binder resin used in the charge generation layer as necessary, polyamide, polyurethane, epoxy resin, polyketone, polycarbonate, polyarylate, silicone resin, acrylic resin, polyvinyl butyral, polyvinyl formal, polyvinyl ketone, polystyrene, poly -N-vinylcarbazole, polyacrylamide, etc. are used. These binder resins can be used alone or as a mixture of two or more kinds. Further, a polymer charge transport material can be used as the binder resin of the charge generation layer. Furthermore, a low molecular weight charge transport material may be added if necessary.

The charge-transporting substances that can be used in combination with the charge-generating layer include electron-transporting substances and hole-transporting substances, and these further include low-molecular-weight charge-transporting substances and polymer-type charge-transporting substances. Hereinafter, in the present invention, a polymer type charge transport material is referred to as a polymer charge transport material.

Examples of the electron transport substance include chloranil, bromanil, tetracyanoethylene, tetracyanoquinodimethane, 2,4,7-trinitro-9-fluorenone, 2,4,5,7-tetranitro-9-fluorenone, 2,4,5,7-tetranitroxanthone,
2,4,8-trinitrothioxanthone, 2,6,8-
Examples thereof include electron-accepting substances such as trinitro-4H-indeno [1,2-b] thiophen-4-one and 1,3,7-trinitrodibenzothiophene-5,5-dioxide. These electron transport materials can be used alone or as a mixture of two or more kinds.

Examples of the hole-transporting substance include the electron-donating substances shown below, which are preferably used. For example, oxazole derivative, oxadiazole derivative, imidazole derivative, triphenylamine derivative, 9-
(P-diethylaminostyrylanthracene), 1,1
-Bis- (4-dibenzylaminophenyl) propane,
Styrylanthracene, styrylpyrazoline, phenylhydrazones, α-phenylstilbene derivatives, thiazole derivatives, triazole derivatives, phenazine derivatives,
Examples include acridine derivatives, benzofuran derivatives, benzimidazole derivatives, thiophene derivatives and the like. These hole transport materials can be used alone or as a mixture of two or more kinds.

Further, the polymer charge-transporting substances represented below can be used. For example, a polymer having a carbazole ring such as poly-N-vinylcarbazole, a polymer having a hydrazone structure exemplified in JP-A-57-78402, and JP-A-63-285552 are exemplified. Polysilylene polymer, JP-A-7-3254
Examples thereof include polymers having a triarylamine structure. These polymeric charge transport materials can be used alone or as a mixture of two or more.

The charge generating layer contains a charge generating substance, a solvent and a binder resin as main components, and contains any additives such as a sensitizer, a dispersant, a surfactant and a silicone oil. It may be.

As a method for forming the charge generating layer, a vacuum thin film forming method and a casting method from a solution dispersion system can be largely cited. The former method includes vacuum deposition method, glow discharge decomposition method, ion plating method, sputtering method,
A reactive sputtering method, a CVD method, or the like is used, and the above-mentioned inorganic material or organic material can be formed favorably. Further, in order to provide the charge generation layer by the casting method, the above-mentioned inorganic or organic charge generation material together with a binder resin, if necessary, tetrahydrofuran, cyclohexanone, dioxane, dichloroethane, butanone using a ball mill, attritor, It can be formed by dispersing with a sand mill or the like, diluting the dispersion appropriately and applying. The coating can be performed by using a dip coating method, a spray coating method, a bead coating method, or the like. The thickness of the charge generation layer provided as described above is appropriately about 0.01 to 5 μm, and preferably 0.05 to 2 μm.

The charge transport layer can be formed by dissolving or dispersing a mixture or copolymer containing a charge transport component and a binder component as main components in a suitable solvent, coating and drying the mixture. A suitable thickness of the charge transport layer is 5 to 100 μm, and 10 to 30 μm when resolution is required.
m is suitable.

Examples of the polymer compound that can be used as the binder component in the first group of the present invention include polystyrene, styrene / acrylonitrile copolymer, styrene / butadiene copolymer, and styrene / maleic anhydride copolymer. , Polyester, polyvinyl chloride, vinyl chloride / vinyl acetate copolymer, polyvinyl acetate, polyvinylidene chloride, polyarylate resin, polycarbonate, cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral, polyvinyl formal, polyvinyl toluene, acrylic resin, silicone Examples thereof include thermoplastic or thermosetting resins such as resins, fluororesins, epoxy resins, melamine resins, urethane resins, phenol resins, and alkyd resins, but are not limited thereto. These polymer compounds can be used alone or as a mixture of two or more kinds, or can be used by copolymerizing with a charge transport material.

Examples of the material that can be used as the charge transporting material include the above-mentioned low molecular weight electron transporting material, hole transporting material and polymer charge transporting material. When a low molecular weight charge transport material is used, the amount used is the polymer compound 10
20 to 200 parts by weight, preferably 50 parts by weight, relative to 0 parts by weight
It is preferably about 100 parts by weight. When a polymer charge transport material is used, a material in which a resin component is copolymerized at a ratio of about 0 to 500 parts by weight with respect to 100 parts by weight of the charge transport component is preferably used.

Examples of the dispersion solvent that can be used when preparing the coating liquid for the charge transport layer include ketones such as methyl ethyl ketone, acetone, methyl isobutyl ketone and cyclohexanone, ethers such as dioxane, tetrahydrofuran and ethyl cellosolve, toluene, Examples thereof include aromatics such as xylene, halogens such as chlorobenzene and dichloromethane, and esters such as ethyl acetate and butyl acetate. Further, if necessary, suitable antioxidants, plasticizers, lubricants, ultraviolet absorbers, low molecular weight compounds such as low molecular weight charge transport substances, and leveling agents may be added. These compounds can be used alone or as a mixture of two or more kinds. The amount of the low molecular compound used is 0.1 to 200 with respect to 100 parts by weight of the high molecular compound.
Parts by weight, preferably 0.1 to 30 parts by weight, and the amount of the leveling agent used is 0.
001 to 5 parts by weight is suitable.

Next, the case where the photosensitive layer has a single layer structure (33) will be described. The single-layer photosensitive layer can be formed by dissolving or dispersing the charge-generating substance, the charge-transporting substance and the binder resin in a suitable solvent, coating and drying the solution. If necessary, a plasticizer, a leveling agent, an antioxidant, etc. may be added.

As the binder resin, the charge transport layer (3
In addition to the binder resin mentioned in 7), the binder resin mentioned in the charge generation layer (35) may be mixed and used. Of course, the above-mentioned polymer charge transport materials can also be used favorably. The amount of the charge generation material is 5 to 40 parts by weight based on 100 parts by weight of the binder resin.
The amount of the charge transport material is preferably 0 to 190 parts by weight, more preferably 50 to 150 parts by weight. The single-layer photosensitive layer is a dip coating method, a spray coating method, a beading method, in which a charge generating substance and a binder resin are dispersed together with a charge transporting substance in a dispersing machine using a solvent such as tetrahydrofuran, dioxane, dichloroethane and cyclohexane. It can be formed by coating with a coat or the like. The film thickness of the single-layer photosensitive layer is preferably about 5 to 50 μm.

The protective layer (39) is provided for the purpose of protecting the photosensitive layer, and the materials used are ABS resin and ACS.
Resin, olefin-vinyl monomer copolymer, chlorinated polyether, allyl resin, phenol resin, polyacetal, polyamide, polyamideimide, polyacrylate, polyallyl sulfone, polybutylene, polybutylene terephthalate, polycarbonate, polyether sulfone, polyethylene, polyethylene Resins such as terephthalate, polyimide, acrylic resin, polymethylpentene, polypropylene, polyphenylene oxide, polysulfone, polystyrene, AS resin, butadiene-styrene copolymer, polyurethane, polyvinyl chloride, polyvinylidene chloride, epoxy resin, polyester and the like can be mentioned. .

A filler material may be added to the protective layer (39) for the purpose of improving wear resistance. As the filler material, the fine particles used in the above-mentioned undercoat layer can be similarly used. In this case, it is conceivable that the reflectance slightly changes depending on the protective layer, but the protective layer must have a high light transmittance due to its characteristics, and therefore the content of the fine particles in the protective layer is required. Must be small.
Therefore, there is almost no effect on the reflectance, and even if the reflectance changes due to the formation of the protective layer, the protective layer hardly wears because the protective layer hardly wears. Absent.

Further, the addition of the low molecular weight charge transporting substance or the polymer charge transporting substance mentioned in the charge transporting layer (37) to the protective layer is an effective means for improving the image quality. The protective layer can be formed by dip coating, spray coating,
Conventional methods such as beat coating, nozzle coating, spinner coating and ring coating can be used. The thickness of the protective layer is preferably about 0.1 to 10 μm. Also,
In addition to the above, aC, aS formed by the vacuum thin film forming method
A known material such as iC can also be used as the protective layer (39).

In the first group of the present invention, it is possible to provide an intermediate layer (not shown) between the photosensitive layer and the protective layer. The another intermediate layer generally uses a resin as a main component. Examples of these resins include polyamide, alcohol-soluble nylon resin, water-soluble butyral resin, polyvinyl butyral, and polyvinyl alcohol. As the method for forming the another intermediate layer, a usual coating method can be used as described above. The film thickness is 0.05-2μ
m is suitable.

In the first group of the present invention, a charge generating layer, a charge transporting layer, an undercoat layer, a protective layer, for the purpose of improving the environmental resistance, and particularly for the purpose of preventing a decrease in sensitivity and an increase in residual potential, Antioxidants, plasticizers, lubricants, ultraviolet absorbers, low molecular charge transport substances and leveling agents can be added to each layer such as the intermediate layer. Representative materials for these compounds are described below.

Examples of the antioxidant that can be added to each layer include, but are not limited to, the followings. (A) Phenol compound 2,6-di-t-butyl-p-cresol, butylated hydroxyanisole, 2,6-di-t-butyl-4-ethylphenol, n-octadecyl-3- (4 '-Hydroxy-3', 5'-di-t-butylphenol),
2,2'-methylene-bis- (4-methyl-6-t-butylphenol), 2,2'-methylene-bis- (4-
Ethyl-6-t-butylphenol), 4,4'-thiobis- (3-methyl-6-t-butylphenol),
4,4'-butylidene bis- (3-methyl-6-t-butylphenol), 1,1,3-tris- (2-methyl-4-hydroxy-5-t-butylphenyl) butane,
1,3,5-Trimethyl-2,4,6-tris (3,5
-Di-t-butyl-4-hydroxybenzyl) benzene, tetrakis- [methylene-3- (3 ', 5'-di-
t-butyl-4'-hydroxyphenyl) propionate] methane, bis [3,3'-bis (4'-hydroxy-3'-t-butylphenyl) butyric acid] glycol ester, tocopherols and the like.

(B) Para-phenylenediamine N-phenyl-N'-isopropyl-p-phenylenediamine, N, N'-di-sec-butyl-p-phenylenediamine, N-phenyl-N-sec-butyl- p-
Phenylenediamine, N, N'-di-isopropyl-p
-Phenylenediamine, N, N'-dimethyl-N, N '
-Di-t-butyl-p-phenylenediamine and the like.

(C) Hydroquinones 2,5-di-t-octylhydroquinone, 2,6-didodecylhydroquinone, 2-dodecylhydroquinone, 2-dodecyl-5-chlorohydroquinone, 2-t
-Octyl-5-methylhydroquinone, 2- (2-octadecenyl) -5-methylhydroquinone and the like.

(D) Organic Sulfur Compounds Dilauryl-3,3'-thiodipropionate, distearyl-3,3'-thiodipropionate, ditetradecyl-3,3'-thiodipropionate and the like.

(E) Organophosphorus compounds Triphenylphosphine, tri (nonylphenyl) phosphine, tri (dinonylphenyl) phosphine, tricresylphosphine, tri (2,4-dibutylphenoxy) phosphine and the like.

Examples of the plasticizer that can be added to each layer include, but are not limited to, the following. (A) Phosphate ester plasticizer triphenyl phosphate, tricresyl phosphate, trioctyl phosphate, octyl diphenyl phosphate, trichloroethyl phosphate, cresyl diphenyl phosphate, tributyl phosphate, tri-2-ethylhexyl phosphate, Triphenyl phosphate etc.

(B) Phthalate ester plasticizers dimethyl phthalate, diethyl phthalate, diisobutyl phthalate, dibutyl phthalate, diheptyl phthalate, di-2-ethylhexyl phthalate, diisooctyl phthalate, di-n-phthalate. Octyl, dinonyl phthalate, diisononyl phthalate, diisodecyl phthalate, diundecyl phthalate, ditridecyl phthalate, dicyclohexyl phthalate, butylbenzyl phthalate, butyllauryl phthalate, methyloleyl phthalate, octyldecyl phthalate, dibutyl fumarate, Dioctyl fumarate etc.

(C) Aromatic Carboxylate Plasticizers Trioctyl trimellitate, Tri-n trimellitate
-Octyl, octyl oxybenzoate and the like.

(D) Aliphatic dibasic acid ester plasticizer dibutyl adipate, di-n-hexyl adipate, di-2-ethylhexyl adipate, di-n-adipate
Octyl, adipic acid-n-octyl-n-decyl, diisodecyl adipate, dicapryl adipate, di-2-ethylhexyl azelate, dimethyl sebacate,
Diethyl sebacate, dibutyl sebacate, di-n-octyl sebacate, di-2-ethylhexyl sebacate, di-2-ethoxyethyl sebacate, dioctyl succinate, diisodecyl succinate, dioctyl tetrahydrophthalate, dihydrotetrahydrophthalate -N-octyl and the like.

(E) Fatty acid ester derivative butyl oleate, glycerin monooleate, methyl acetylricinoleate, pentaerythritol ester, dipentaerythritol hexaester,
Triacetin, tributyrin, etc.

(F) Oxyacid plasticizers such as methyl acetylricinoleate, butyl acetylricinoleate, butylphthalylbutyl glycolate and tributyl acetylcitrate.

(G) Epoxy plasticizer Epoxidized soybean oil, epoxidized linseed oil, epoxy butyl stearate, decyl epoxy stearate, octyl epoxy stearate, benzyl epoxy stearate, dioctyl epoxy hexahydrophthalate, epoxy hexahydrophthale Didecyl acid etc.

(H) Dihydric alcohol ester plasticizer such as diethylene glycol dibenzoate and triethylene glycol di-2-ethylbutyrate.

(I) Chlorine-containing plasticizer Chlorinated paraffin, chlorinated diphenyl, chlorinated fatty acid methyl, methoxychlorinated fatty acid methyl, etc.

(J) Polyester Plasticizer Polypropylene adipate, polypropylene sebacate, polyester, acetylated polyester, etc.

(K) Sulfonic acid derivative p-toluene sulfonamide, o-toluene sulfonamide, p-toluene sulfone ethylamide, o-toluene sulfone ethylamide, toluene sulfone-N-ethylamide, p-toluene sulfone-N-cyclohexyl Amide etc.

(L) Citric Acid Derivatives Triethyl citrate, triethyl acetyl citrate, tributyl citrate, tributyl acetyl citrate, tri-2-ethylhexyl acetyl citrate, -n-octyl decyl acetyl citrate and the like.

(M) Other terphenyls, partially hydrogenated terphenyls, camphor, 2
-Nitrodiphenyl, dinonylnaphthalene, methyl abietate and the like.

Examples of the lubricant that can be added to each layer include, but are not limited to, the following. (A) Hydrocarbon compound Liquid paraffin, paraffin wax, microwax, low-polymerization polyethylene, etc.

(B) Fatty acid type compounds Lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid and the like.

(C) Fatty acid amide compounds Stearyl amide, palmityl amide, olein amide, methylene bis stearamide, ethylene bis stearamide and the like.

(D) Ester-based compounds Lower alcohol esters of fatty acids, polyhydric alcohol esters of fatty acids, fatty acid polyglycol esters, etc.

(E) Alcohol compounds Cetyl alcohol, stearyl alcohol, ethylene glycol, polyethylene glycol, polyglycerol and the like.

(F) Metal soap Lead stearate, cadmium stearate, barium stearate, calcium stearate, zinc stearate, magnesium stearate, etc.

(G) Natural waxes Carnauba wax, candelilla wax, beeswax, whale wax, ivorot wax, montan wax and the like.

(H) Other Silicone compounds, fluorine compounds, etc.

Examples of the ultraviolet absorber that can be added to each layer include, but are not limited to, the followings. (A) Benzophenone-based 2-hydroxybenzophenone, 2,4-dihydroxybenzophenone, 2,2 ', 4-trihydroxybenzophenone, 2,2', 4,4'-tetrahydroxybenzophenone, 2,2'-dihydroxy-4- Methoxybenzophenone etc.

(B) Salsylate-type phenyl salicylate, 2,4 di-t-butylphenyl 3,5-di-t-butyl 4-hydroxybenzoate and the like.

(C) Benzotriazole (2'-hydroxyphenyl) benzotriazole,
(2'-hydroxy5'-methylphenyl) benzotriazole, (2'-hydroxy5'-methylphenyl)
Benzotriazole, (2'-hydroxy 3'-tert-butyl 5'-methylphenyl) 5-chlorobenzotriazole and the like.

(D) Cyanoacrylate type ethyl-2-cyano-3,3-diphenyl acrylate, methyl 2-carbomethoxy 3 (paramethoxy) acrylate and the like.

(E) Quencher (metal complex salt system) Nickel (2,2 'thiobis (4-t-octyl) phenolate) n-butylamine, nickel dibutyldithiocarbamate, nickel dibutyldithiocarbamate, cobalt dicyclohexyldithiophosphate and the like.

(F) HALS (hindered amine) bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, 1 -[2- [3-
(3,5-di-t-butyl-4-hydroxyphenyl)
Propionyloxy] ethyl] -4- [3- (3,5-
Di-t-butyl-4-hydroxyphenyl) propionyloxy] -2,2,6,6-tetramethylpyridine,
8-benzyl-7,7,9,9-tetramethyl-3-octyl-1,3,8-triazaspiro [4,5] undecane-2,4-dione, 4-benzoyloxy-2,
2,6,6-tetramethylpiperidine and the like.

The respective points relating to the constitutions of the photosensitive layer and the protective layer are the same as in the case of the second group of the present invention.

The electrophotographic photoreceptor used in the first group of the present invention is provided with an undercoat layer (32) comprising a binder resin and fine particles between the conductive support (31) and the photosensitive layer. The resin used for the undercoat layer (32) is preferably a resin having high solvent resistance to general organic solvents, considering that the photosensitive layer is coated thereon with a solvent. Such resins include polyvinyl alcohol, casein, water-soluble resins such as sodium polyacrylate, copolymer nylon, alcohol-soluble resins such as methoxymethylated nylon, polyurethane, melamine resin, phenol resin, alkyd-melamine resin, epoxy. Examples of the resin include curable resins that form a three-dimensional network structure, such as resins. The fine particles used for the undercoat layer include fluororesin powder such as polytetrafluoroethylene, silicone resin powder, a-
Organic fine particles such as carbon powder, metal powder such as copper, tin, aluminum and indium, silica, tin oxide, zirconium oxide, zinc oxide, titanium oxide, alumina, indium oxide, antimony oxide, bismuth oxide, calcium oxide and antimony. Examples thereof include metal oxides such as doped tin oxide and tin-doped indium oxide, metal fluorides such as tin fluoride, calcium fluoride and aluminum fluoride, and inorganic fine particles such as potassium titanate and boron nitride. Among them, not only the photoconductor has an intermediate density,
Titanium oxide, silica, alumina, zirconium oxide, tin oxide, which also has the effect of preventing moire and reducing residual potential,
Inorganic fine powder pigments containing a metal oxide such as indium oxide as a main component are preferable. The undercoat layer can be formed by using an appropriate solvent and coating method as in the above-mentioned photosensitive layer. In the present invention, 800 nm to 1300 nm
Wavelength range, preferably 900 nm to 1100 nm wavelength range, more preferably 950 nm wavelength light reflectance of 50% to 65%, and its film thickness is 0.5 to 50% depending on the electrostatic characteristics of the photoreceptor. 20 μm is suitable,
Preferably 2 to 20 μm, more preferably 3 to 10 μm
m.

[Second group of the present invention] The electrophotographic photosensitive member used in the second group of the present invention has an undercoat layer comprising at least a binder resin and fine particles on a conductive support. ,
The conductive support reflects light of any wavelength in the wavelength range of 800 nm to 1300 nm with a reflectance of 25% to 55%. At this time, for light in the wavelength range,
There is a very good correlation between the magnitude of the irregular reflectance and the thickness of the undercoat layer, and the reflectance can be controlled by the thickness. That is, the diffuse reflectance can be increased by increasing the film thickness, and conversely, the reflectance can be decreased by decreasing the film thickness. As a matter of course, the reflectances are almost the same even if the photoconductors have the same film thickness.
Furthermore, since the reflectance of light in this wavelength range is hardly affected by the difference in the surface roughness of the undercoat layer, changes in the surface roughness due to environmental changes at the time of photoconductor manufacturing, surface roughness due to the coating method, etc. The reflectance of the undercoat layer hardly changes even if the surface roughness of the photoconductor changes due to the difference in. Moreover, controlling the film thickness of the undercoat layer has been conventionally performed in the production of a photoconductor, so that fluctuations in reflectance between individuals can be prevented without providing extra management and inspection steps. Since it can be greatly suppressed, it is also very useful in terms of manufacturing cost. Furthermore, it can be said that the film thickness of the undercoat layer does not change with repeated use of the photoconductor, and therefore the reflectance does not change.

According to the second group of the present invention, since the undercoat layer contains particles having a particle size of at least 0.5 μm to 3 μm, light in the wavelength region is sufficiently scattered,
% To 55%, and the film thickness of the undercoat layer required from the electrostatic characteristics and the crack resistance of the flexible belt are compatible with each other. In the second group of the present invention, as the conductive support,
Since a nickel seamless belt is used and the support, which is usually made by electroforming, has a very small surface roughness, diffuse reflection by the support hardly occurs. Further, if the scattering by the undercoat layer is insufficient, the diffuse reflectance becomes small. Therefore, it is necessary to increase the film thickness of the undercoat layer in order to obtain a sufficient reflectance. This is because the residual potential rises in the electrostatic characteristics and the photoconductor of the present invention has flexibility. May cause cracks in the photosensitive layer. In the present invention,
It is considered that when the undercoat layer contains particles having a particle size of at least 0.5 μm to 3 μm, scattering is effectively performed by the undercoat layer, and the reflectance and a suitable film thickness are compatible with each other.

Further, according to the second group of the present invention, by using inorganic fine particles containing a metal oxide as a main component as fine particles contained in the undercoat layer, a reflectance of 25% to 55% can be obtained. The film thickness of the undercoat layer required from the electrostatic characteristics is compatible. When the fine particles contained in the undercoat layer are inorganic fine particles containing a metal oxide as a main component, it is possible to easily achieve both the film thickness required from the reflectance and the electrostatic characteristics. For example, if the thickness of the undercoat layer is increased to obtain a sufficient reflectance, the residual potential is likely to increase. However, by using inorganic fine particles whose main component is a metal oxide, the volume of the undercoat layer can be increased. The resistance becomes low, and the rise in residual potential can be suppressed. Further, the difference in the refractive index with the binder resin, which is an organic substance, is large, the light scattering efficiency is also high, and in the image formation using the coherent light, the effect of suppressing the interference fringes in the halftone image and the moire image is also obtained. high.

The image forming apparatus of the second group of the present invention is
By making the infrared light emitted from the density sensor have substantially the same wavelength as the light measured for the surface reflectance of the electrophotographic photosensitive member, it is possible to detect the density of the electrophotographic photosensitive member as an intermediate density with higher accuracy. it can. When the wavelength range used for the density sensor and the wavelength range in which the reflectance of the undercoat layer is within the above range are different, even if the surface reflectance of the photoconductor is within the above range, the density of the photoconductor in the density sensor is desired. It may not be an intermediate concentration.

When the diffuse reflectance on the surface of the electrophotographic photosensitive member is less than 25%, the output of the sensor decreases as the toner adhesion amount increases. In the density control of the black toner, the reflectance of the photosensitive member and the maximum of the toner are controlled. The difference from the reflectance at the time of adhesion becomes small, and the accuracy of density control is significantly reduced. Further, when it is more than 55%, the difference between the reflectance of the photoconductor and the reflectance at the maximum adhesion of the toner in the density control of the color toner, which has the characteristic that the output of the sensor increases as the adhesion amount of the toner increases. As a result, the accuracy of density control is significantly reduced. Also, 800
In the wavelength region smaller than nm, the absorption wavelength region of the charge-generating substance overlaps with the absorption wavelength region, so that the diffuse reflectance becomes small and causes electrostatic fatigue of the charge-generating substance, which is not preferable.
Further, when light in a wavelength region larger than 1300 nm is used, the irregular reflectance on the surface of the photoconductor and the density measured by the P sensor may become large, which makes it difficult to control the intermediate density of the photoconductor.

In the second group of the present invention, a nickel seamless belt is used as the conductive support (31). The nickel seamless belt is formed by a known electroforming method, cut into a predetermined width and used as a support for an electrophotographic photoreceptor. The belt preferably has a thickness of 10 to 50 μm. The respective points relating to the composition of the photosensitive layer and the protective layer of the electrophotographic photosensitive member are the same as in the case of the first group of the present invention as described above, and the photosensitive layer is the same as that of the first group of the present invention. Similarly, it may be a single layer type in which a charge generating substance is dispersed in a charge transporting layer or a laminated type in which a charge generating layer and a charge transporting layer are sequentially laminated.

The electrophotographic photoreceptors used in the second group of the present invention also have an undercoat layer (32) comprising a binder resin and fine particles between the conductive support (31) and the photosensitive layer. Considering that the photosensitive layer is coated with a solvent on the resin used for the undercoat layer (32), it is desirable that the resin has high solvent resistance to general organic solvents. Such resins include polyvinyl alcohol, casein, water-soluble resins such as sodium polyacrylate, copolymer nylon, alcohol-soluble resins such as methoxymethylated nylon, polyurethane, melamine resin, phenol resin, alkyd-melamine resin, epoxy. Examples of the resin include curable resins that form a three-dimensional network structure, such as resins. The fine particles used for the undercoat layer include organic fine particles such as fluororesin powder such as polytetrafluoroethylene, silicone resin powder, and a-carbon powder, metal powder such as copper, tin, aluminum and indium, and silica. , Tin oxide, zirconium oxide, zinc oxide, titanium oxide, alumina, indium oxide, antimony oxide, bismuth oxide, calcium oxide, antimony-doped tin oxide, tin-doped indium oxide and other metal oxides, tin fluoride, Examples thereof include metal fluorides such as calcium fluoride and aluminum fluoride, and inorganic fine particles such as potassium titanate and boron nitride. Among them, not only the photoconductor has an intermediate density,
Titanium oxide, silica, alumina, zirconium oxide, tin oxide, which also has the effect of preventing moire and reducing residual potential,
Inorganic fine powder pigments containing a metal oxide such as indium oxide as a main component are preferable. The undercoat layer can be formed by using an appropriate solvent and coating method as in the above-mentioned photosensitive layer. In the second group of the present invention, 800 nm to 13 nm
The reflectance for any light in the wavelength region of 00 nm is 1
0% to 65%, and the film thickness is preferably 0.5 to 20 μm in view of the electrostatic characteristics of the photoreceptor, and preferably 1
10 to 10 μm.

[0084]

BEST MODE FOR CARRYING OUT THE INVENTION [First group of the present invention] FIG.
It is a schematic diagram for explaining the image forming apparatus of the present invention of the group, and the following modified examples also belong to the category of the present invention of the first group. In FIG. 6, the photoconductor (1) is provided with the electrophotographic photoconductor manufactured by the present invention. The photoconductor (1) has a drum shape, but a sheet shape,
It may be in the form of an endless belt. The charging charger (3), pre-transfer charger (7), transfer charger (10), separation charger (11), pre-cleaning charger (13) include corotron, scorotron, solid state charger (solid state charger), and charging. Well-known means such as rollers are used. Generally, the above-mentioned charger can be used as the transfer means, but it is effective to use a combination of a transfer charger and a separation charger as shown in the figure.

The light sources such as the image exposure section (5) and the static elimination lamp (2) include fluorescent lamps, tungsten lamps, halogen lamps, mercury lamps, sodium lamps, light emitting diodes (LED), semiconductor lasers (LD), electro Luminescent materials such as luminescence (EL) can be used in general. Further, various filters such as a sharp cut filter, a bandpass filter, a near infrared cut filter, a dichroic filter, an interference filter, and a color temperature conversion filter can be used to irradiate only light in a desired wavelength range.

Such a light source and the like are provided with a process such as a transfer process using light irradiation, a charge eliminating process, a cleaning process, or a pre-exposure process in addition to the process shown in FIG.
The photoconductor is irradiated with light.

The toner developed on the photoconductor (1) by the developing unit (6) is transferred to the transfer paper (9), but not all of the toner is transferred, and the photoconductor (1) is not transferred.
Toner that remains on top is also produced. Such toner is removed from the photoconductor by the fur brush (14) and the blade (15). Cleaning may be performed only with a cleaning brush, and known cleaning brushes such as a fur brush and a magfur brush are used.

When the electrophotographic photoreceptor is positively (negatively) charged and imagewise exposed, a positive (negative) electrostatic latent image is formed on the surface of the photoreceptor. If this is developed with a toner of negative (positive) polarity (electrodetection fine particles), a positive image is obtained, and if it is developed with a toner of positive (negative) polarity, a negative image is obtained.

A publicly known method is applied to the developing means, and a publicly known method is also used for the charge eliminating means.

Here, the image density control by the P sensor will be described. First, P obtained from the reflectance of the photoconductor
The concentration sensor is calibrated by automatically adjusting the sensor output Vsg to a preset voltage. This calibration is performed after an arbitrary period of time, thereby reducing the influence on the image due to contamination of the P sensor, aging, and the like. Next, patch pattern latent images with different densities are formed on the photoconductor, and the photoconductor surface potential is detected by a potential sensor (not shown) and stored. Further, the patch pattern latent image is developed with toner, and the P sensor detects the density of the developed patch pattern. The toner concentration on the photoconductor is calculated using the detected P sensor output result and the arithmetic expression stored in the image forming apparatus. The relationship between the development potential and the toner adhesion amount is obtained from the photoreceptor surface potential of the patch pattern latent image thus obtained, the development bias value at the time of patch pattern development, and the calculated toner concentration. The optimum VD (dark portion potential), VL (light portion potential), and VB (developing bias) values are determined from the potential table stored in the forming apparatus to control the image density.

Further, when the P sensor is a diffuse reflection type P sensor which detects only the diffuse reflection component, it does not receive the specular reflection component on the surface of the photoconductor, so that the relationship between the toner adhesion amount and the reflectance is simple especially for color toners. Can be approximated to a linear equation, and the measurement accuracy of concentration can be improved. In addition, the black toner exhibits a characteristic that the output of the P sensor decreases as the toner adhesion amount increases, which is almost the same as when the specular reflection type sensor is used.

FIG. 7 is an example of another process of the image forming apparatus according to the first group of the present invention. Recently, full color has been required to be as fast as monochrome, and such a tandem type is drawing attention. The tandem type image forming apparatus generally has four types of cyan, magenta, yellow and black.
Color toners can be developed on different photoreceptors, and toners of a plurality of colors can be transferred while the recording material passes once, so that a color image is formed, so that a substantially monochromatic image is formed. You only need the same amount of time. Therefore, it is very effective in speeding up color image formation. Further, the photoconductor of the present invention, since the photoconductor reflectance is controlled even between individuals, for example, even if only a part of the plurality of photoconductors are replaced, the change in reflectance is small,
The influence on the toner density control is small, and the change in the image color tone can be suppressed.

Further, in FIG. 7, the image on each photoconductor is temporarily transferred to the intermediate transfer body (110) by the primary transfer device (62) and then the image on the intermediate transfer body (110) is secondarily transferred. It shows an indirect transfer method in which a device (122) collectively transfers to a recording material. The transfer device (122) is a transfer / transport belt, but there is also a roller-shaped transfer device. As an advantage of performing the intermediate transfer, in the direct transfer method without the intermediate transfer member, the sheet feeding device (49) is provided on the upstream side of the tandem type image forming apparatus (120) with the photosensitive member and the fixing device (is provided on the downstream side). 125) has to be arranged, and has the disadvantage of increasing the size in the recording material conveyance direction, whereas the indirect transfer method via an intermediate transfer member allows the secondary transfer position for transferring to the recording material to be set relatively freely. Therefore, it is possible to arrange the paper feeding device (49) and the fixing device (125) so as to overlap the tandem type image forming device (120), which is advantageous in that the device can be easily downsized. . Further, in the direct transfer method, the fixing device (125) is arranged close to the tandem type image forming apparatus (120) in order not to increase the size in the recording material conveyance direction. for that reason,
The fixing device (125) cannot be arranged with a sufficient margin that allows the recording material to bend, and the impact when the leading end of the recording material enters the fixing device (125) (especially noticeable with thick recording material) Also, there is a drawback that the fixing device (125) is likely to affect the image formation on the upstream side due to the speed difference between the recording material conveying speed when passing through the fixing device (125) and the sheet conveying speed by the transfer conveying belt. On the other hand, in the indirect transfer method, since the fixing device (125) can be arranged with a sufficient margin that the recording material can bend, the fixing device (125) hardly affects the image formation. As described above, also in the tandem type image forming apparatus, the indirect transfer method having the intermediate transfer body is more preferable.

Here, there are belt-shaped and drum-shaped intermediate transfer members, but the degree of freedom in layout is high,
An intermediate transfer belt that is advantageous for downsizing the apparatus is preferable.

The intermediate transfer belt, especially the intermediate transfer belt having an elastic layer will be described below. For the intermediate transfer belt, a fluorine resin, a polycarbonate resin, a polyimide resin, etc. have been conventionally used, but in recent years, an elastic belt in which all layers of the belt or a part of the belt is an elastic member has been used.

The transfer of a color image using a resin belt has the following problems. Color images are usually formed with four color toners. One to four toner layers are formed on one color image. The toner layer receives pressure by passing through the primary transfer (transfer from the photoconductor to the intermediate transfer belt) and the secondary transfer (transfer from the intermediate transfer belt to the sheet), and the cohesive force between the toners becomes high. If the cohesive force between the toners becomes high, the phenomenon of hollow characters or missing edges of solid images is likely to occur. Since the resin belt has a high hardness and is not deformed according to the toner layer, the toner layer is likely to be compressed and the hollow character of the character is likely to occur. Also,
Recently, there is an increasing demand for forming full-color images on various papers, such as Japanese papers and papers with intentionally unevenness. However, paper with poor smoothness is likely to cause voids with the toner during transfer, which easily causes transfer omission. If the transfer pressure of the secondary transfer portion is increased in order to improve the adhesiveness, the condensing force of the toner layer is increased, which causes the hollow character as described above.

The elastic belt is used for the following purposes. Since the elastic belt has a hardness lower than that of the resin belt, the elastic belt is deformed in the transfer portion in accordance with the toner layer and the paper having poor smoothness. That is,
Since the elastic belt deforms following local unevenness, good adhesion can be obtained without excessively increasing the transfer pressure to the toner layer, and there is no void in characters, and for paper with poor flatness. However, it is possible to obtain a transferred image with excellent uniformity.

The resin of the elastic belt is polycarbonate, fluorine resin (ETFE, PVDF), polystyrene, chloropolystyrene, poly-α-methylstyrene, styrene-butadiene copolymer, styrene-vinyl chloride copolymer, styrene-vinyl acetate. Copolymer, styrene-maleic acid copolymer, styrene-acrylic acid ester copolymer (styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene- Octyl acrylate copolymer and styrene-phenyl acrylate copolymer, etc.), styrene-methacrylic acid ester copolymer (styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-phenyl methacrylate) Copolymer, etc.), styrene-α-qua Styrene resins such as methyl chloroacrylate copolymer, styrene-acrylonitrile-acrylic acid ester copolymer (styrene or styrene-substituted homopolymer or copolymer), methyl methacrylate resin, butyl methacrylate resin, acrylic Ethyl acid resin, butyl acrylate resin, modified acrylic resin (silicone modified acrylic resin, vinyl chloride resin modified acrylic resin, acrylic urethane resin, etc.), vinyl chloride resin, styrene-vinyl acetate copolymer, vinyl chloride-vinyl acetate copolymer Polymer, rosin-modified maleic acid resin, phenol resin, epoxy resin, polyester resin, polyester polyurethane resin, polyethylene, polypropylene,
Polybutadiene, polyvinylidene chloride, ionomer resin, polyurethane resin, silicone resin, ketone resin,
One kind or two or more kinds selected from the group consisting of ethylene-ethyl acrylate copolymer, xylene resin, polyvinyl butyral resin, polyamide resin, modified polyphenylene oxide resin and the like can be used.
However, it goes without saying that the material is not limited to the above.

Examples of elastic rubber and elastomer include butyl rubber, fluorine rubber, acrylic rubber, EPDM, NB
R, acrylonitrile-butadiene-styrene rubber, natural rubber, isoprene rubber, styrene-butadiene rubber,
Butadiene rubber, ethylene-propylene rubber, ethylene-propylene terpolymer, chloroprene rubber, chlorosulfonated polyethylene, chlorinated polyethylene, urethane rubber, syndiotactic 1,2-polybutadiene,
Epichlorohydrin rubber, ricone rubber, fluororubber, polysulfide rubber, polynorbornene rubber, hydrogenated nitrile rubber, thermoplastic elastomer (for example, polystyrene, polyolefin, polyvinyl chloride, polyurethane, polyamide, polyurea, polyester) System, a fluororesin system, etc., can be used alone or in combination of two or more. However, it goes without saying that the material is not limited to the above materials.

There is no particular limitation on the conductive agent for adjusting the resistance value,
For example, carbon black, graphite, metal powder such as aluminum and nickel, tin oxide, titanium oxide, antimony oxide, indium oxide, potassium titanate, antimony oxide-tin oxide composite oxide (ATO), indium oxide-tin oxide composite oxide. The conductive metal oxide such as a material (ITO) and the conductive metal oxide may be coated with insulating fine particles such as barium sulfate, magnesium silicate, and calcium carbonate. Of course, the conductive agent is not limited to the above.

The surface layer material is not limited, but it is required to reduce the adhesion of the toner to the surface of the transfer belt to improve the secondary transfer property. For example, one or more kinds of polyurethane, polyester, epoxy resin, etc. are used to reduce surface energy and improve lubricity, for example, powder of fluororesin, fluorine compound, fluorocarbon, titanium dioxide, silicon carbide, etc. It is possible to disperse and use one kind or two or more kinds of particles or particles having different particle diameters. It is also possible to use a fluorine-containing rubber material which has a fluorine-rich layer formed on its surface by heat treatment to have a small surface energy.

The manufacturing method of the belt is not limited. For example, a centrifugal molding method in which a material is poured into a rotating cylindrical mold to form a belt, a spray coating method for forming a thin film on the surface layer, a dipping method in which a cylindrical mold is immersed in a solution of a material and pulled up, an inner mold There are, but not limited to, a casting method of injecting into an outer die, a method of winding a compound around a cylindrical die and vulcanizing and polishing, but not limited to this, a belt is produced by combining a plurality of production methods. Of course, you can.

A method of manufacturing the elastic belt used in this example will be described. 18 parts by weight of carbon black, 3 parts by weight of dispersant, 400 parts of toluene based on 100 parts by weight of PVDF
Dip a cylindrical mold in a dispersion liquid in which parts by weight are evenly dispersed,
It was gently pulled up at 10 mm / sec and dried at room temperature to form a 75 μm PVDF uniform film. 75μ
The mold in which the m film was formed was repeated, and the cylindrical mold was dipped in the solution under the above conditions, gently pulled up at 10 mm / sec and dried at room temperature to form a PVDF belt of 150 μm. 100 parts by weight of polyurethane prepolymer,
Dip the cylindrical mold having 150 μm PVDF formed therein in a dispersion liquid in which 3 parts by weight of a curing agent (isocyanate), 20 parts by weight of carbon black, 3 parts by weight of a dispersant, and 500 parts by weight of MEK are uniformly dispersed, and pull up at 30 mm / sec. Then, it was naturally dried. After drying, the process was repeated to form a targeted 150 μm urethane polymer layer.

Further, 100 parts by weight of a polyurethane prepolymer for the surface layer, 3 parts by weight of a curing agent (isocyanate),
Fine PTFE powder 50 parts by weight, dispersant 4 parts by weight, ME
500 parts by weight of K were uniformly dispersed. Immerse the cylindrical mold on which the 150 μm urethane prepolymer is formed,
It was pulled up at 30 mm / sec and naturally dried. After drying, the step was repeated to form a surface layer of urethane polymer in which 5 μm of PTFE was uniformly dispersed. After drying at room temperature, crosslinking is carried out at 130 ° C. for 2 hours to obtain a resin layer;
A transfer belt having a three-layer structure of 150 μm, elastic layer; 150 μm, surface layer: 5 μm was obtained.

As a method for preventing elongation as an elastic belt, there are a method of forming a rubber layer on a core resin layer having a small elongation as in the above example, a method of adding a material for preventing elongation to the core layer, and the like. It is not particularly related to the manufacturing method.

The material constituting the core layer for preventing elongation is
For example, natural fibers such as cotton and silk, polyester fibers,
Nylon fiber, acrylic fiber, polyolefin fiber, polyvinyl alcohol fiber, polyvinyl chloride fiber, polyvinylidene chloride fiber, polyurethane fiber, polyacetal fiber, polyfluoroethylene fiber, synthetic fiber such as phenol fiber, carbon fiber, glass fiber, boron fiber, etc. A woven fabric or a thread can be obtained by using one kind or two or more kinds selected from the group consisting of inorganic fibers, iron fibers, metal fibers such as copper fibers. Of course, the material is not limited to the above.

The yarn may be twisted in one or a plurality of filaments, one-twisted yarn, ply-twisted yarn, twin yarn, or any other twisting method. Further, for example, fibers of a material selected from the above material group may be mixed and spun. Of course, the thread may be used after being subjected to an appropriate conductive treatment. On the other hand, as the woven fabric, any woven fabric such as knitted fabric can be used, and of course, woven woven fabric can also be used, and naturally, conductive treatment can also be applied.

The manufacturing method for providing the core layer is not particularly limited. For example, a method in which a woven fabric woven in a tubular shape is covered with a mold or the like and a coating layer is provided thereon, or a woven fabric woven in a tubular shape is dipped in liquid rubber or the like to form a coating layer on one or both sides of the core layer. Examples thereof include a method of providing the thread, a method of spirally winding the thread around a mold or the like at an arbitrary pitch, and providing a coating layer on the thread.

The thickness of the elastic layer depends on the hardness of the elastic layer, but if it is too thick, the expansion and contraction of the surface will increase and cracks will easily occur in the surface layer. In addition, it is not preferable that the thickness is too thick (about 1 mm or more) because the amount of expansion and contraction becomes large and the image becomes more stretched.

The proper range of hardness of the elastic layer is 10 ≦ HS ≦
It is 65 ° (JIS-A). It is necessary to adjust the optimum hardness depending on the layer thickness of the belt. If the hardness is less than 10 ° JIS-A, it is very difficult to mold with high dimensional accuracy. This is because it is susceptible to shrinkage and expansion during molding. Further, in the case of softening, it is a general method to add an oil component to the base material, but there is a drawback that the oil component exudes when continuously operated in a pressurized state. As a result, it was found that the photoconductor that comes into contact with the surface of the intermediate transfer member was contaminated and horizontal stripe unevenness was generated.
Generally, a surface layer is provided to improve releasability, but in order to provide a complete exudation prevention effect, the surface layer has high required quality such as durability quality, so it is necessary to select materials and secure characteristics. It will be difficult. On the other hand, hardness 65 ° JIS-
Those with A or higher can be molded with high accuracy due to the increased hardness, and can contain or reduce the oil content, so the contamination of the photoconductor can be reduced. The effect of improving transferability such as omission cannot be obtained, and it becomes difficult to stretch the roller.

At least the electrophotographic photosensitive member (40)
May be provided, and the process cartridge may be formed by the whole or a part of the portion forming the image forming unit. This has an advantage that the maintainability is greatly improved by making it detachable from the image forming apparatus main body at once.

By using the electrophotographic photosensitive member and the image forming apparatus according to the first group of the present invention as described above, it is possible to easily and precisely control the density of the photosensitive member serving as the reference of the P sensor. It has been found that a good image with stable density can be provided because the density of the photoreceptor does not change even after long-term use.

[Second Group of the Present Invention] FIG. 8 is a schematic view for explaining an image forming apparatus of the second group of the present invention. The photoconductor (16) has the nickel seamless belt-shaped electrophotographic photoconductor manufactured according to the present invention, and includes the drive roller (1
Driven by the transfer roller (28) and the driven roller (2).
By 3), it rotates smoothly without slack or slippage. This photoconductor (16) is charged by a charger (18), image exposure by a light source (19), development (not shown), transfer using a charger (20), cleaning by a brush (21), light source (22). The static elimination by is repeated. As the charger, known means such as a corotron, a scorotron, a solid state charger (solid state charger) and a charging roller are used.

Further, the light sources such as the image exposure section (19) and the static elimination lamp (22) include a fluorescent lamp, a tungsten lamp,
It is possible to use general light emitting materials such as a halogen lamp, a mercury lamp, a sodium lamp, a light emitting diode (LED), a semiconductor laser (LD), and an electroluminescence (EL). Further, various filters such as a sharp cut filter, a bandpass filter, a near infrared cut filter, a dichroic filter, an interference filter, and a color temperature conversion filter can be used to irradiate only light in a desired wavelength range.

The toner developed on the photosensitive member (1) by the developing unit (not shown) is transferred to the transfer member, but not all of the toner is transferred, and the toner is transferred onto the photosensitive member (1). Residual toner is also produced. Such toner is removed from the photoconductor by a cleaning brush (21) or a blade. Cleaning may be performed only with a cleaning brush, and known cleaning brushes such as a fur brush and a magfur brush are used.

When the electrophotographic photosensitive member is positively (negatively) charged and imagewise exposed, a positive (negative) electrostatic latent image is formed on the surface of the photosensitive member. If this is developed with negative (positive) polarity toner (electrodetection fine particles), a positive image is obtained, and positive (negative)
A negative image can be obtained by developing with polar toner.

A known method is applied to the developing means, and a known method is used for the charge removing means.

This process also has a step of temporarily transferring the toner image formed on the photoconductor onto an intermediate transfer body (not shown), and the toner images of a plurality of colors are formed on the intermediate transfer body. Can also be used as an intermediate transfer type color image forming apparatus having a secondary transfer step in which a full-color image is formed by sequentially superimposing the two on each other and then the full-color image is collectively transferred to a transfer material. By using the intermediate transfer method, a full-color image can be output without selecting the type of transfer target material. Further, by accurately aligning the intermediate transfer member, color misregistration can be greatly reduced, and a high-quality full-color image can be obtained.

Here, there are belt-shaped and drum-shaped intermediate transfer members, but the flexibility of layout is high,
An intermediate transfer belt that is advantageous for downsizing the apparatus is preferable. As the intermediate transfer belt, of course, an intermediate transfer belt having an elastic layer may be used as in the case of the image forming apparatus according to the first group of the present invention.

The image forming apparatus shown in these figures exemplifies the embodiments in the first group of the present invention and the second group of the present invention, and of course other embodiments are possible. For example, in FIG. 8, pre-cleaning exposure may be performed between the transfer step and the cleaning step.

On the other hand, in the light irradiation step, image exposure and charge removal exposure are shown, but in addition, pre-transfer exposure, image exposure pre-exposure, and other known light irradiation steps are provided to irradiate the photoreceptor with light. You can also do

[0122]

The present invention will be described in more detail below with reference to examples, but the embodiments of the present invention are not limited thereby. All parts are by weight.

[First group of the present invention] (Example 1) Alkyd resin (Beckolite M6401)
-50 (manufactured by Dainippon Ink and Chemicals, Inc.)) and 10 parts by weight of melamine resin (Super Beckamine G-821-60 (manufactured by Dainippon Ink and Chemicals, Inc.)) were dissolved in 150 parts by weight of methyl ethyl ketone. 80 parts by weight of titanium oxide powder (Taipaque CR-97 (manufactured by Ishihara Sangyo Co., Ltd.)) surface-treated with alumina and zirconium oxide, titanium oxide surface-treated with Alumina (Taipaque CR-67).
10 parts (manufactured by Ishihara Sangyo Co., Ltd.) were added and dispersed by a ball mill for 24 hours to prepare an undercoat layer coating liquid. This is φ90m
m, length 380 mm, thickness 2 mm, the surface of which was roughened by cutting was applied by an immersion coating method to an aluminum tube and dried at 130 ° C. for 20 minutes to form an undercoat layer having a thickness of 2 μm.

Next, polyvinyl butyral resin (S-REC HL-S (4 parts by weight manufactured by Sekisui Chemical Co., Ltd.) was dissolved in 150 parts by weight of cyclohexanone, which is shown in the following structural formula (1).

[0125]

[Chemical 1]

In addition to 10 parts by weight of trisazo pigment, it was dispersed in a ball mill for 48 hours, and then cyclohexanone 210 was added.
Parts by weight were added and dispersion was carried out for 3 hours. This was taken out into a container and diluted with cyclohexanone so that the solid content was 1.5% by weight. The charge generation layer coating solution thus obtained is applied onto the undercoat layer by a dip coating method at 130 ° C.
After drying for 20 minutes, a charge generation layer having a thickness of 0.2 μm was formed.

Next, 10 parts by weight of a bisphenol Z type polycarbonate resin and 0.002 parts by weight of silicon oil (KF-50 (manufactured by Shin-Etsu Chemical Co., Ltd.)) were dissolved in 100 parts by weight of tetrahydrofuran, and the following structural formula ( 8 parts by weight of the charge transport material of 2) was added to prepare a charge transport layer coating liquid. The charge-transporting layer coating liquid thus obtained is applied onto the charge-generating layer by a dip coating method, and then 1
It was dried at 10 ° C. for 20 minutes to form a charge transport layer having a thickness of 25 μm.

[0128]

[Chemical 2] As described above, the electrophotographic photosensitive member of Example 1 was manufactured.

(Examples 2 to 5) Examples 2 to 5 were carried out in the same manner as Example 1 except that the dip coating speed at the time of forming the undercoat layer was changed and the thickness of the undercoat layer was changed. The electrophotographic photosensitive member of No. 5 was produced.

(Examples 6 and 7) Example 1 was repeated except that a spray coating method was used in forming the undercoat layer and the thickness of the undercoat layer was changed by changing the number of times of coating at that time.
Electrophotographic photoreceptors of Examples 6 and 7 were produced in the same manner as in.

(Comparative Examples 1 and 2) As a conductive support, E
Electrophotographic photoreceptors of Comparative Examples 1 and 2 were produced in the same manner as in Examples 1 and 2 except that a non-cutting aluminum tube produced by Method D was used.

(Comparative Examples 3 and 4) Comparative Examples 3 and 4 were carried out in the same manner as in Example 1 except that the dip coating speed at the time of forming the undercoat layer was changed and the film thickness of the undercoat layer was changed. The electrophotographic photosensitive member of No. 4 was produced.

Comparative Example 5 An undercoat layer obtained by dissolving 2 parts by weight of a polyamide resin (Amilan CM8000 (manufactured by Toray Industries, Inc.) in a mixed solution of 40 parts by weight of n-butanol and 60 parts by weight of methanol was used as the undercoat layer. An electrophotographic photoreceptor of Comparative Example 4 was produced in the same manner as in Example 1 except that the coating liquid for layer formation was used.

These electrophotographic photoreceptors are color copying machines.
The image was mounted on a modified machine (using a polyvinylidene fluoride endless belt as an intermediate transfer belt) of imagio color 4000 (manufactured by Ricoh) to output a full-color image. Further, the diffuse reflectance of the surface of these photoconductors was measured using an integrating sphere unit of a spectrophotometer (manufactured by Shimadzu Corporation: UV-3100). The measurement condition is a measurement wavelength of 950n
m and the slit width was 20 nm. After measuring the reflectance,
The photosensitive layer was peeled off, and the surface roughness ten-point average roughness Rz of the undercoat layer surface was measured. Measurement of ten-point average roughness is JISB06
01, a surface roughness measuring device (manufactured by Tokyo Seimitsu Co., Ltd .: EM
D-S75A).

Table 1 shows the film thickness of the undercoat layer of the electrophotographic photoconductor thus obtained, the diffuse reflectance and film thickness of the photoconductor surface, the surface roughness, and the image results.

[0136]

[Table 1]

The relationship between the surface irregular reflectance of the electrophotographic photosensitive members of Examples 1 to 7 and the film thickness of the undercoat layer has a very good correlation as shown in FIG. It is possible to control the diffuse reflectance of the surface.

(Embodiments 8 and 9) The conductive support is 30 m in diameter.
m, length 340 mm, thickness 1 mm, electrophotographic photosensitive members of Examples 8 and 9 were prepared in the same manner as in Examples 1 and 5 except that the aluminum tube whose surface was cut was replaced.

These electrophotographic photoconductors were tandemly arranged in quadruplicate,
It is mounted on an intermediate transfer type image forming test device (an elastic belt in which a polyurethane rubber elastic layer is laminated on a polyvinylidene fluoride endless belt is used as an intermediate transfer belt).
When a full-color image was output, no matter which photoreceptor was used, a good image with improved worming was obtained.

[Second Group of the Invention] (Example 10) Manufacturing Example of Nickel Seamless Belt Support Outer diameter 92 mm, length 430 m in electroplating apparatus
m, the diameter difference between the upper and lower sides is 0.023 mm, and the surface roughness is Rz0.
Using a 1 μm stainless steel cylindrical mold, the plating solution composition and plating conditions are as follows: thickness 30 μm, length 367 m
m, a peripheral length of 289 mm, and a peripheral length difference between the upper and lower sides of 0.072 mm were manufactured.

[0141] (Plating solution composition)   60% nickel sulfamate liquid (manufactured by Nippon Kagaku Sangyo) 500 g / l   Nickel bromide (Nippon Kagaku Sangyo) 6g / l   Boric acid (Kanto Chemical) 35 g / l   Additive (Pitless S manufactured by Nippon Kagaku Sangyo) 3 cc / l   Naphthalene sulfonic acid 0.1g / l

(Plating Conditions) PH 4.1 Bath temperature 40 ° C. Current density 1 A / cm ² Plating time 160 minutes

The nickel seamless belt thus prepared was removed from the cylindrical mandrel and ultrasonically cleaned in ion-exchanged water (conductivity 1 μ / S or less) for 5 minutes. The nickel pieces in the anode basket are Co
0.2 wt% was used. The Vickers hardness of the seamless nickel belt was 490.

Alkyd resin (Beckolite M6401
-50 (manufactured by Dainippon Ink and Chemicals, Inc.)) and 10 parts by weight of melamine resin (Super Beckamine G-821-60 (manufactured by Dainippon Ink and Chemicals, Inc.)) are dissolved in 150 parts by weight of methyl ethyl ketone. 80 parts by weight of titanium oxide powder surface-treated with alumina and zirconium oxide (Taipaque CR-97 (manufactured by Ishihara Sangyo)), titanium oxide surface-treated with alumina (Taipaque CR-58).
10 parts (manufactured by Ishihara Sangyo Co., Ltd.) were added and dispersed by a ball mill for 24 hours to prepare an undercoat layer coating liquid. This was applied to the nickel seamless belt prepared above by a dip coating method and dried at 130 ° C. for 20 minutes to form an undercoat layer having a thickness of 8 μm.

Next, 4 parts by weight of polyvinyl butyral resin (S-REC HL-S (manufactured by Sekisui Chemical Co., Ltd.)) was dissolved in 150 parts by weight of cyclohexanone, which is represented by the following structural formula (1).

[0146]

[Chemical 3]

In addition to 10 parts by weight of trisazo pigment, it was dispersed in a ball mill for 48 hours, and then cyclohexanone 210 was added.
Parts by weight were added and dispersion was carried out for 3 hours. This was taken out into a container and diluted with cyclohexanone so that the solid content was 1.5% by weight. The charge generation layer coating solution thus obtained is applied onto the undercoat layer by a dip coating method at 130 ° C.
After drying for 20 minutes, a charge generation layer having a thickness of 0.2 μm was formed.

Next, 10 parts by weight of a bisphenol A type polycarbonate resin and 0.002 parts by weight of silicon oil (KF-50 (manufactured by Shin-Etsu Chemical Co., Ltd.)) were dissolved in 100 parts by weight of tetrahydrofuran, and the following structural formula ( 8 parts by weight of the charge transport material of 2) was added to prepare a charge transport layer coating liquid. The charge-transporting layer coating liquid thus obtained is applied onto the charge-generating layer by a dip coating method, and then 1
It was dried at 10 ° C. for 20 minutes to form a charge transport layer having a thickness of 25 μm.

[0149]

[Chemical 4] As described above, the electrophotographic photosensitive member of Example 10 was manufactured.

(Examples 11 to 13) Examples 11 to 13 were carried out in the same manner as Example 10 except that the dip coating speed at the time of forming the undercoat layer was changed and the thickness of the undercoat layer was changed.
No. 13 electrophotographic photosensitive member was produced.

(Examples 14 and 15) Example 10 was the same as Example 10 except that a spray coating method was used in forming the undercoat layer, and the thickness of the undercoat layer was changed by changing the number of times of coating at that time. Similarly, electrophotographic photoreceptors of Examples 14 and 15 were produced.

(Comparative Examples 5 and 6) Comparative Examples 5 and 6 were performed in the same manner as in Example 10 except that the dip coating speed at the time of forming the undercoat layer was changed and the film thickness of the undercoat layer was changed. The electrophotographic photoconductor of No. 6 was produced.

(Comparative Example 7) An undercoat layer obtained by dissolving 2 parts by weight of a polyamide resin (Amilan CM8000 (manufactured by Toray Industries, Inc.) in a mixed solution of 40 parts by weight of n-butanol and 60 parts by weight of methanol was used as the undercoat layer. An electrophotographic photoreceptor of Comparative Example 7 was produced in the same manner as in Example 10 except that the layer forming coating liquid was used.

These electrophotographic photoreceptors were mounted on a modified machine (using a polyvinylidene fluoride endless belt as an intermediate transfer belt) of a color laser printer IPSiO color 5000 (manufactured by Ricoh) to output a full color image. Further, the diffuse reflectance of the surface of these photoconductors was measured using an integrating sphere unit of a spectrophotometer (manufactured by Shimadzu Corporation: UV-3100). The measurement conditions were a measurement wavelength of 950 nm and a slit width of 20 nm. After measuring the reflectance, the photosensitive layer was peeled off, and the surface roughness 10-point average roughness Rz of the undercoat layer surface was measured. Ten point average roughness measurement is J
According to ISB0601, it measured using the surface roughness measuring device (Tokyo Seimitsu Co., Ltd. make: E-MD-S75A).

Table 2 shows the film thickness of the undercoat layer of the electrophotographic photoconductor thus obtained, the diffuse reflectance and film thickness of the photoconductor surface, the surface roughness, and the image results.

[0156]

[Table 2]

Further, the relationship between the surface irregular reflectance of the electrophotographic photosensitive members of Examples 10 to 15 and the film thickness of the undercoat layer showed a very good correlation as shown in FIG. Therefore, the diffuse reflectance is 25%
In order to control in the range of up to 55%, it is possible to control the diffuse reflectance by creating a correlation diagram as shown below and controlling the film thickness of the undercoat layer with which the desired diffuse reflectance is obtained.

Example 16 Production Example of Elastic Intermediate Transfer Belt Carbon black 18 was added to 100 parts by weight of PVDF.
By immersing the cylindrical mold in a dispersion liquid in which 1 part by weight, 3 parts by weight of a dispersant and 400 parts by weight of toluene are uniformly dispersed, 10 mm / s
It was gently pulled up with ec and dried at room temperature to form a uniform PVDF film of 75 μm. Repeat the mold on which a 75 μm film is formed, immerse the cylindrical mold in the solution under the above conditions, gently pull up at 10 mm / sec, and dry at room temperature.
A 150 μm PVDF belt was formed. A cylinder in which the above 150 μm PVDF is formed in a dispersion liquid in which 100 parts by weight of a polyurethane prepolymer, 3 parts by weight of a curing agent (isocyanate), 20 parts by weight of carbon black, 3 parts by weight of a dispersant, and 500 parts by weight of MEK are uniformly dispersed. The mold was dipped, pulled up at 30 mm / sec, and naturally dried. Repeated after drying, the target is 150 μm
The urethane polymer layer was formed.

Further, 100 parts by weight of a polyurethane prepolymer for the surface layer, 3 parts by weight of a curing agent (isocyanate),
Fine PTFE powder 50 parts by weight, dispersant 4 parts by weight, ME
500 parts by weight of K were uniformly dispersed. Immerse the cylindrical mold on which the 150 μm urethane prepolymer is formed,
It was pulled up at 30 mm / sec and naturally dried. After drying, the step was repeated to form a surface layer of urethane polymer in which 5 μm of PTFE was uniformly dispersed. After drying at room temperature, crosslinking is carried out at 130 ° C. for 2 hours to obtain a resin layer;
A transfer belt having a three-layer structure of 150 μm, elastic layer; 150 μm, surface layer: 5 μm was obtained. The elastic intermediate transfer belt thus obtained and the electrophotographic photosensitive member of Example 11 were treated with IPSiO c.
Installed on the modified color 5000 (manufactured by Ricoh),
When a full-color image was output, a good image was obtained in which color misregistration was significantly suppressed as compared with the image of Example 15, and there were no abnormal images such as worm eating and color tone abnormality.

(Example 17) A full-color image was output in the same manner as in Example 16 except that the electrophotographic photosensitive member of Example 13 was used. As a result, a good image free from worms and abnormal color tone was obtained.

[0161]

As is apparent from the detailed and specific description above, since the density of the photoconductor, which is the reference for the density sensor to appropriately control the toner density, can be controlled to the intermediate density. Is stable, and abnormal images such as moire and background stains are reduced, and it is possible to provide an electrophotographic photoreceptor, an image forming apparatus, and a process cartridge that can stably obtain good images. It plays.

[Brief description of drawings]

FIG. 1 is a correlation diagram showing the relationship between the surface irregular reflectance of the electrophotographic photosensitive members of Examples 1 to 7 and the film thickness of an undercoat layer.

FIG. 2 is a cross-sectional view illustrating the layer structure of the electrophotographic photosensitive member of the present invention.

FIG. 3 is a cross-sectional view illustrating another layer structure of the electrophotographic photosensitive member of the present invention.

FIG. 4 is a cross-sectional view illustrating another layer structure of the electrophotographic photosensitive member of the present invention.

FIG. 5 is a cross-sectional view illustrating another layer structure of the electrophotographic photosensitive member of the present invention.

FIG. 6 is a schematic view illustrating the process of the image forming apparatus of the present invention.

FIG. 7 is a schematic view illustrating the process of the image forming apparatus of the present invention.

FIG. 8 is a schematic view illustrating the process of the image forming apparatus of the present invention.

FIG. 9 is a correlation diagram showing the relationship between the surface irregular reflectance of the electrophotographic photosensitive members of Examples 10 to 15 and the film thickness of the undercoat layer.

[Explanation of symbols]

1 photoconductor 2 Static elimination lamp 3 Charger 4 Eraser 5 Image exposure unit 6 Development unit 7 P sensor 8 Registration roller 9 Transfer paper 10 Transfer charger 11 Separation Charger 12 separate nails 13 Charger before cleaning 14 fur brush 15 blades 16 photoconductor 17 Drive roller 18 Charger 19 Image exposure source 20 Transcription Charger 21 brush 22 Static elimination light source 23 Driven roller 24P sensor 28 Transfer roller 31 conductive support 32 Undercoat layer 33 Photosensitive layer 35 Charge generation layer 37 Charge Transport Layer 39 Protective layer 40 photoconductor 49 Paper feeder 61 Developing device 62 Primary transfer device 63 Cleaning device 74 Conveyor roller 90 Static elimination means 91 Static elimination means 110 Intermediate transfer body 120 Tandem image forming apparatus 122 Secondary Transfer Device 125 fixing device

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G03G 15/16 G03G 15/16 (72) Inventor Toshiyuki Kabata 1-3-6 Nakamagome, Ota-ku, Tokyo No. Stock Company in Ricoh (72) Inventor Michio Kimura 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Company (72) Hideo Nakamori 1-3-6 Nakamagome, Ota-ku, Tokyo Stock Company R-Ricoh F-term (reference) 2H027 DA04 DA07 DA10 DD07 DE02 DE07 DE09 EA02 EA05 EA06 EA20 EC03 EC06 EC09 EC18 ED06 ED09 ED10 2H030 AB02 AD16 BB12 BB34 BB42 BB43 BB71 2A045A27 GA23A21 A25A29 A21 A11A27A11 GA44 GA47 HA01 HB13 JA01 JB06 JC04 JC17 MC01

Claims (16)

[Claims] 1. An electrophotographic photoreceptor having an undercoating layer comprising at least a binder resin and fine particles and a photosensitive layer on a conductive support, wherein the support is an aluminum tube having a roughened surface, And the diffuse reflectance of the surface of the photoconductor is 800 n
An electrophotographic photoconductor characterized by being 50% to 65% with respect to light having any wavelength in the wavelength range of m to 1300 nm. 2. The undercoat layer has a particle size of at least 0.5 μm.
The electrophotographic photosensitive member according to claim 1, which contains particles of m to 3 μm. 3. An electrophotographic photoreceptor having an undercoat layer comprising at least a binder resin and fine particles and a photosensitive layer on a conductive support, wherein the support is a nickel seamless belt, and the surface of the photoreceptor is Diffuse reflectance of 800nm-1
2 for light of any wavelength in the wavelength range of 300 nm
An electrophotographic photoconductor characterized by being 5% to 55%. 4. The undercoat layer has a grain size of at least 0.3 μm.
The electrophotographic photosensitive member according to claim 3, wherein the electrophotographic photosensitive member contains particles of m to 3 μm. 5. The electrophotographic photosensitive member according to claim 1, wherein the fine particles contained in the undercoat layer are inorganic fine particles containing a metal oxide as a main component. 6. The electrophotographic photosensitive member according to claim 1, wherein the surface of the roughened aluminum tube is roughened by cutting. 7. An electrophotographic photoreceptor, a charging means, an exposing means,
Developing means, transfer means, means for forming a toner image for density measurement on the electrophotographic photosensitive member, optical density sensor comprising a light emitting part and a light receiving part, and the surface density of the photoconductor detected by the optical density sensor An image forming apparatus having means for controlling an image forming condition by using the information of 1.
An image forming apparatus using the electrophotographic photosensitive member according to any one of 1 to 6. 8. The image forming apparatus according to claim 7, further comprising a calibrating unit that feeds back information on the photoconductor density detected by the optical density sensor to calibrate the optical density sensor. apparatus. 9. The optical density sensor is a diffuse reflection type optical density sensor, and the light having a wavelength emitted from a light emitting portion has substantially the same wavelength as the light for measuring the reflectance of the electrophotographic photosensitive member. The image forming apparatus according to claim 7 or 8, wherein: 10. The optical density sensor is a diffuse reflection type optical density sensor, and the light having a wavelength emitted from a light emitting portion has a wavelength substantially the same as the light for measuring the reflectance of the electrophotographic photosensitive member. 9. The image forming apparatus according to claim 7, wherein the spot of the irradiated light is larger than the cutting pitch of the conductive support. 11. The image forming apparatus according to claim 7, wherein the image forming apparatus is a color image forming apparatus that sequentially forms toner images of a plurality of colors to form a color image. apparatus. 12. The image forming apparatus comprises a plurality of electrophotographic photoconductors, and the developed monochromatic toner images are sequentially superposed on the electrophotographic photoconductors to form a color image. The image forming apparatus according to claim 7 or 8. 13. The image forming apparatus primarily transfers a toner image developed on an electrophotographic photosensitive member onto an intermediate transfer member, and then secondarily transfers the toner image on the intermediate transfer member onto a recording material. An image forming apparatus having an intermediate transfer unit, wherein toner images of a plurality of colors are sequentially superposed on an intermediate transfer member to form a color image, and the color image is secondarily transferred onto a recording material collectively. The image forming apparatus according to claim 11, wherein the image forming apparatus is an image forming apparatus. 14. The image forming apparatus according to claim 13, wherein the intermediate transfer member is a seamless belt and is an elastic belt in which all layers of the belt or a part of the belt is an elastic member. 15. A process cartridge for an image forming apparatus, which comprises an electrophotographic photosensitive member, wherein the image forming apparatus is the image forming apparatus according to any one of claims 7 to 14. Process cartridge for image forming apparatus. 16. A method for producing an electrophotographic photoreceptor having an undercoat layer comprising at least a binder resin and fine particles and a photosensitive layer on a conductive support, the diffuse reflectance of the electrophotographic photoreceptor being: The film thickness is controlled by the thickness of the undercoat layer,
7. A method for manufacturing an electrophotographic photosensitive member, comprising obtaining the electrophotographic photosensitive member according to any one of items 1 to 6.