JPH03136062A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To prevent occurrence of sprinkled image unevenness and delay of potential rising at the time of electric charging after repeated uses and to reduce change of residual potential by incorporating a specified modified indium oxide in an undercoat layer. CONSTITUTION:The electrophotographic sensitive body is formed by successively laminating the undercoat layer, a charge generating layer, and a charge transfer layer on a conductive substrate, and the undercoat layer contains the modified indium oxide pretreated by an organic compound having a hydroxyl group and a heat emitting peak at 200 - 600 deg.C measured by the differential thermal analysis in an amount of >=70wt.% of a binder resin. If <70wt.%, high sensitivity cannot be obtained and if >95wt.%, chargeability is improved but photosensitivity is degraded, thus permitting occurrence of sprinkled image unevenness and potential rising delay after repeated uses to be prevented and change of residual potential to be reduced.

Description

[Detailed description of the invention] (industrial field) The present invention is directed to improving electrophotographic photoreceptors.

[Prior Art] In recent years, organic photosensitive materials, which have advantages such as low cost, productivity, and non-pollution, have become popular as photoconductors used in electrophotographic copying machines.

Organic electrophotographic photoreceptors include photoconductive resins such as polyvinylcarbazole (PVK), and PVK-TNF.
(2,4,7-dolinitrofluorenone), a pigment-dispersed type such as phthalocyanine binder, and a functionally separated type photoreceptor using a combination of a charge-generating material and a charge-transporting material, etc. is known,
In particular, functionally separated photoreceptors are attracting attention.

When such a functionally separated type high-sensitivity photoreceptor is applied to the Carlson process, it has low chargeability, poor charge retention (high dark decay), and is subject to repeated use. The deterioration of these characteristics is large, causing density unevenness and a decrease in image density on the image, and in the case of an inversion phenomenon, background smearing occurs.

Additionally, in general, high-sensitivity photoreceptors have reduced chargeability due to #exposure fatigue. This pre-exposure fatigue is mainly caused by light absorbed by the charge-generating material, so the longer the charges generated by light absorption remain in the photoconductor in a mobile state, the greater the number of charges. It is thought that the lower the chargeability becomes, the more the chargeability decreases due to pre-exposure fatigue. In other words, even if a charging operation is performed with residual t-electrode generated by light absorption, the surface charge is neutralized by the movement of the remaining carriers, so the surface charge remains until the residual charge is consumed. The potential does not rise. Therefore, the rise in surface potential is delayed by the amount of pre-exposure fatigue, and the apparent charge level 4 becomes low.

For the above-mentioned drawbacks, for example, Japanese Patent Application Laid-Open No. 47-6341.
No. 48-3544 and No. 48-12034 have cellulose nitrate resin intermediate layers, and Japanese Patent Application Laid-Open No. 48-47344.
52-25638.58-30757.58-6394
5.58-95351.58-98739 and 60-
No. 6258 discloses that the nylon resin intermediate layer is
9-6-9332 and 52-10138 disclose a maleic acid resin intermediate layer, and JP-A-58-1051 discloses a maleic acid resin intermediate layer.
No. 55 discloses a polyvinyl alcohol resin intermediate layer. Furthermore, in order to control the electrical resistance of the intermediate layer, an intermediate layer in which various conductive additives are contained in the resin has been proposed. An intermediate layer dispersed in a curable resin is disclosed in JP-A-52-82238, while a thermal polymer intermediate layer using an isocyanate-based curing agent with the addition of a quaternary ammonium salt is disclosed in JP-A-55-118045.
JP-A-58-58556 discloses a resin intermediate layer containing a resistance adjusting agent, and JP-A-58-58556 discloses a resin intermediate layer in which aluminum or tin oxide is dispersed.
No. 62 discloses a resin intermediate layer to which an organometallic compound is added, as disclosed in JP-A No. 58-93063.60-97363 and No. 6-62.
0-111255 discloses a resin intermediate layer in which conductive particles are dispersed, and JP-A-59-17557 discloses a layer in which magnetite is dispersed in a resin.
257.59-93453 and 60-32054 disclose a resin intermediate layer in which TiO, SnO, and powder are dispersed, and JP-A-57-81269 discloses an intermediate layer in which indium oxide is dispersed. ing.

[Problem to be Solved by the Invention] However, conventionally known electrophotographic photoreceptors are still insufficient in terms of deterioration in charging performance due to repeated use, especially in terms of delay in the rise of the 4th charge, and furthermore, changes in residual potential are still insufficient. Significant and further improvements were desired.

In order to eliminate these drawbacks, the present inventors used a layer in which indium oxide was dispersed in a resin binder made of a reaction product of a compound having active hydrogen and a compound having an isocyanate group as an undercoat layer. (Japanese Patent Application No. 63-61296), this photoreceptor has excellent characteristics with little change in chargeability and residual potential even after repeated use. In order to reduce the ratio of indium oxide to the resin binder, it is necessary to increase the ratio of indium oxide to the resin binder. As a result, subsequent research has revealed that the dispersibility of indium oxide inevitably deteriorates, resulting in the occurrence of satin-like image unevenness corresponding to the unevenness formed on the surface of the coating film of the undercoat layer.

It is an object of the present invention to provide an electrophotographic photoreceptor that does not cause satin-like image unevenness, has no delay in the rise of charging potential even after repeated use of charging and exposure, and has small changes in residual potential. With the goal.

(Means for Solving the Problems 1) The present inventors have focused on an undercoat layer of an electrophotographic photoreceptor, which is formed by sequentially laminating an undercoat layer, a charge generation layer, and a charge transfer layer on a conductive substrate. As a result of intensive studies to eliminate the above drawbacks, we found that the undercoat layer contains modified indium oxide that has been pretreated with an organic compound having a hydroxyl group and has an exothermic peak at 200 to 600°C in differential thermal analysis. It was discovered that an electrophotographic photoreceptor that does not cause satin-like image unevenness, does not have a delay in the rise of the 4th charge after repeated use, and has a small change in residual potential can be obtained, and has completed the present invention. reached.

The present invention will be explained in detail below.

Pure indium oxide can be used, as well as metal oxides such as titanium oxide, aluminum oxide, calcium oxide, magnesium oxide, tin oxide, zirconium oxide, silicon oxide, beryllium oxide, zinc oxide, yttrium oxide, and magnesium fluoride. , metal fluorides such as calcium fluoride and aluminum fluoride, metal nitrides such as boron nitride, aluminum nitride, and silicon nitride, metal carbides such as boron carbide and silicon carbide, and calcium boride;
It is also possible to use a material containing or mixed with a metal boride such as silicon boride.

Organic compounds having hydroxyl groups, ie, alcohols and polymers having hydroxyl groups, are used. Examples of the alcohol include methanol, ethanol, propatool, butanol, amyl alcohol, fusel oil, methoxybutyl alcohol, hexanol, methylpentanol, ethylbutyl alcohol, heptatool, octatool, ethylhexyl alcohol, nonyl alcohol,
Dimethyl heptatool, decanol, undecyl alcohol, trimethyl nonyl alcohol, tetradecyl alcohol, heptadecyl alcohol, cyclohexanol, methylcyclohexanol, trimethylcyclohexanol, benzyl alcohol, phenylmethyl carbinol, ethylene glycol, propylene glycol, butylene gellicol , bentanediol, hexanediol, triethylene glycol, tripropylene glycol, glycerin, heptanediol, diethylene glycol, dipropylene glycol, etc. Other compounds having hydroxyl groups include methyl cellohilb, ethyl cellosolve, butyl cellosolve, ethylene glycol Monohexyl ether, ethylene glycol monophenyl ether, methyl carpitol, ethyl carpitol, butyl carpitol, hexyl carpitol, terpene glycol ether, tetrahydrofurfuryl alcohol,
Examples include diacetone alcohol and the like. Examples of polymers having hydroxyl groups include resins containing acrylic monomers having hydroxyl groups, such as polyvinyl alcohol, polyvinyl acetal, phenoxy resins, polyesters, alkyd resins, polyalkylene gelicols, and hydroxyethyl methacrylate monomers, and vinyl acetate resins.

In the present invention, in the differential thermal analysis, 20
Modified indium oxide having an exothermic peak at 0 to 60°C, preferably 260 to 350°C, can be produced by heating and dispersing indium oxide and carboxylic acid ester in a ball mill, sand mill, etc., heating and stirring, heating and ultrasonic treatment. It can be obtained by a method of heating and kneading.

The modified indium oxide thus obtained has excellent dispersibility in the resin binder, as is clear from the examples below, so it can be uniformly dispersed even if the ratio to the resin binder is small. To provide an electrophotographic photoreceptor having excellent durability, which does not cause satin-like image unevenness as described above, and shows very little decrease in charging potential or increase in residual potential due to repeated use.

On the other hand, even unmodified indium oxide or modified indium oxide has a temperature of 200 to 60 in differential thermal analysis.
Those that do not have an exothermic peak in the range of 0° C. have problems such as poor dispersibility in resin binders and increased residual potential, making it impossible to achieve the intended purpose of the present invention.

Further, in the present invention, it is preferable that the undercoat layer contains a resin binder. Examples of the binder resin include polystyrene, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, Polyester, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, polyvinylidene chloride, polyarylate resin, phenoxy resin, polycarbonate, cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral, polyvinyl formal,
polyvinyltoluene, poly-N-vinylcarbazole,
Examples include thermoplastic or thermosetting resins such as acrylic resins, silicone resins, epoxy resins, melamine resins, urethane resins, phenolic resins, and alkyd resins.

Particularly preferably active hydrogen (-〇H group, -NH, group, >N
It is desirable to use a reaction product of a compound having a plurality of H groups, -5H groups, -COOI (hydrogen groups, etc.) and a compound having an isocyanate group (-N-C-0 group).

Active hydrogen? Examples of compounds having a number of functional groups include polyvinyl acetal, phenoxy resin, polyamide, polyester, alkyd resin, polyalkylene gelicol, acrylic copolymer containing active hydrogen such as hydroxyethyl methacrylate group, and vinyl alcohol group-containing compound. Examples include vinyl acetate copolymers.

In addition, as compounds containing isocyanate groups, R such as methyl isocyanate, ethyl isocyanate, propyl isocyanate, butyl isocyanate, phenyl isocyanate, tolyl isocyanate, naphthyl isocyanate, nitrophenyl isocyanate, vinyl isocyanate, etc. -N
Compounds represented by =C=O, tolylene diisocyanate, hexamethylene diisocyanate, O-4yl diisocyanate, diphenylmethane diisocyanate, naphthylene diisocyanate, tolylene diisocyanate dimer, etc. 0=C=N-R-N engineering C Diisocyanate compound represented by 0, triphenylmethane triisocyanate, tris-(P-isocyanate phenyl)
Examples include triisocyanate compounds such as diophosphate, and polyfunctional incyanate compounds produced by adding a plurality of diisocyanates and/or triisocyanates.

A compound having an active hydrogen and a compound having an incyanate group generally react with each other by heating.

The heating temperature is 30°C to 250°C, and in order to control these reactions, a conventionally known amine type, ①.

It is possible to use catalysts based on 8-diazabisiglo(5+ 41 01 undecene-7 (DBU)) and metals.

Specific examples of such catalysts include, for example, tetramethylbutanediamine (TMBDA), 1°4-diaza-bicyclo[2,2,2]octane (DABCO), dibutyltin dilaurate (DBTDL), tin octoate,
N-ethylmorpholine, triethylamine, N, N,
N', N'-tetramethyl-1,3-prandiamine,
Cobalt naphthenate, stannous chloride, tetra-n-butyltin, stannic chloride, trimethyltin hydroxide,
Examples include dimethyldichlorotin, phenolic salts of DBU, and the like.

There is no particular restriction on the proportion of modified indium oxide used in the undercoat layer, but the content of modified indium oxide is preferably 70% by weight or more, preferably about 80 to 90% by weight based on the resin binder. If the amount is less than 70% by weight, high sensitivity cannot be obtained, and charging performance decreases with repeated use. In addition, the content of modified indium oxide is 9
If it exceeds 5% by weight, the charging property will be good, but the photosensitivity will be lowered.

In addition, the film thickness of the subbing layer is 0.2 to 20 μm, preferably 0.
．． A suitable thickness is 5 to 5 μm. Undercoat layer thickness is 0
．． If the thickness is less than 2 .mu.m, the effect will be small, and if it exceeds 20 .mu.m, residual potential will accumulate, which is not desirable.

In the present invention, in order to form the undercoat layer, a liquid in which the components are dissolved or dispersed may be applied onto the conductive support and dried and hardened.

As the conductive support, materials exhibiting conductivity of 10''Ω or less, such as metals such as aluminum, nickel, chromium, nichrome, copper, silver, gold, and platinum, tin oxide, and indium oxide. A film or cylindrical plastic, paper, etc. coated with a metal oxide such as by vapor deposition or sputtering, a film or cylindrical plastic in which the metal or conductive carbon is dispersed, or Plates of aluminum, aluminum alloy, nickel, stainless steel, etc., and pipes made of them, made into blank pipes by extrusion, drawing, etc., and then surface-treated by cutting, superfinishing, polishing, etc. can be used.

Next, the photosensitive layer will be described.

The charge generation layer is a layer mainly composed of a charge generation substance, and a binder resin may be used as necessary.

Binder resins include polyamide, polyurethane,
Polyester, epoxy resin, polyketone, polycarbonate, silicone resin, acrylic resin, polyvinyl butyral, polyvinyl formal, polyvinyl ketone,
Polystyrene, poly-N-vinylcarbazole, polyacrylamide, etc. are used.

Examples of the charge generating substance include CI Pigment Blue 25 (color index [CI] 21180),
CI Pigment Red 41 (Cr 21200)
, Sea Acid Red 52 (CI45100), Sea Eye Basic Red 3 (CI45210), and
Phthalocyanine pigments having a porphyrin skeleton, azulenium salt pigments, squalic salt pigments, azo pigments having a carbazole skeleton (described in JP-A-53-138229), azo pigments having a triphenylamine skeleton (
(described in JP-A No. 53-95033), an azo pigment having a stilstilbene skeleton (described in JP-A-53-132547)
Azo pigments having a dibenzothiophene skeleton (described in JP-A No. 54-21728), azo pigments having an oxadiazole skeleton (described in JP-A No. 54-127)
42), an azo pigment having a fluorenone skeleton (described in JP-A No. 54-22834), an azo pigment having a bisstilbene skeleton (described in JP-A-54-17733)
(described in JP-A-54-2129), an azo pigment having a distyryloxadiazole skeleton (described in JP-A-54-2129),
Azo pigments having a distyrylcarbazole skeleton (described in JP-A No. 54-17734), triazo pigments having a carbazole skeleton (described in JP-A-57-195767).

In addition, phthalocyanine pigments such as CI Pigment Blue 16 (CI74100), CI Bat Brown 5 (described in CI 57-195768), etc.
CI73410), Sea Eye Bat Die (CI730)
Organic pigments such as indigo pigments such as No. 30), perylene pigments such as Argo Scarlet B (manufactured by Violet) and Indus Thread Scarlet R (manufactured by Bayer) can be used.

Among these charge generating substances, azo pigments are particularly suitable.

These charge generating substances may be used alone or in combination of two or more.

The binder resin is suitably used in an amount of 0 to 100 parts by weight, preferably 0 to 100 parts by weight, based on 100 parts by weight of the charge generating substance.
~50 parts by weight.

The charge generation layer contains a charge generation substance, along with a binder resin if necessary, tetrahydrofuran, cyclohexanone,
It can be formed by dispersing using a ball mill, attritor, sand mill, etc. using a solvent such as dioxane or dichloroethane, diluting the dispersion liquid appropriately, and applying the dispersion. Application can be performed using a dip coating method, a spray coating method, a bead coating method, or the like.

The thickness of the charge generation layer is suitably about 0.01 to 5 .mu.m, preferably 0.1 to 2 .mu.m.

The charge transfer layer consists of a charge transfer substance and an optional binder resin.

A charge transfer layer can be formed by dissolving or dispersing the above-mentioned substances in a suitable solvent, applying the solution and drying it.

Charge transport materials include hole transport materials and electron transport materials.

As hole transport substances, poly-N-vinylcarbazole and its derivatives, poly-γ-carbazolylethyl glutamate and its derivatives, pyrene-formaldehyde condensate and its derivatives, polyvinylpyrene, polyvinylphenanthrene, oxazole conductor, oxadi Azole derivatives, imidazole derivatives, triphenylamine derivatives, 9-(p-diethylaminostyryl)anthracene, 1,1-bis-(4-dibenzylaminophenyl)propane, styrylanthracene, styrylpyrazoline, phenylhydrazones, α- Examples include electron-donating substances such as phenylstilbene derivatives.

Examples of the electron transport substance include gloluanil, bromoanil, tetracyanoethylene, tetracyanoquinone dimentane, 2,4.7-hlinitro-9-fluorenone, 2,4,5.7-tetranitro-9-fluorenone, 2 , 4,5.7-titranitroxanthone, 2,4.
8-trinitrothioxanthone, 2,6.8-trinitro-4H-indeno[1,2-b]thiophene-4-
Examples include electron-accepting substances such as 1,3,7-dolinitrodibenzothiophenone-5,5-dioxide and the like.

These charge transfer layers may be used alone or in combination of two or more.

In addition, the binder resin used as necessary in the subbing layer, charge generation layer, and charge transfer layer of the present invention includes:
polystyrene, styrene-acrylonitrile copolymer,
Styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyester, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, polyvinylidene chloride, polyarylate resin, phenoxy resin, polycarbonate, cellulose acetate Thermoplastic or thermosetting resins such as resins, ethyl cellulose resins, polyvinyl butyral, polyvinyl formal, polyvinyltoluene, poly-N-vinylcarbazole, acrylic resins, silicone resins, epoxy resins, melamine resins, urethane resins, phenolic resins, alkyd resins, etc. can be mentioned.

Solvents used when coating each layer include tetrahydrofuran, dioxane, toluene, monochlorobenzene,
Dichloroethane, methylene chloride, etc. are used.

The appropriate thickness of the charge transfer layer is about 5 to 100 μm.

Furthermore, in the present invention, a plasticizer or a leveling agent may be added to the charge transfer layer. As the plasticizer, those used as plasticizers for general resins, such as dibutyl phthalate and dioctyl phthalate, can be used as they are, and the appropriate amount to be used is about 0 to 30% by weight based on the binder resin. As the leveling agent, silicone oils such as dimethyl silicone oil and methylphenyl silicone oil are used, and the appropriate amount thereof is about 0 to 1% by weight based on the binder resin.

Also, on the charge transfer layer, ozone lI! is applied during mechanical abrasion and charging. It is also possible to provide a protective layer or a coating layer to protect against lff, and furthermore, a known adhesive layer can be provided to improve the adhesion between the conductive substrate and the undercoat layer.

(Effect 1) The electrophotographic photoreceptor of the present invention has the above-mentioned structure, and the undercoat layer contains modified indium oxide that has an exothermic peak at 200 to 600°C in differential thermal analysis and has been pretreated with an organic compound having a hydroxyl group. As a result of this, there is no image unevenness, and the deterioration in charging properties due to exposure fatigue is extremely small. Also, the charging properties do not deteriorate even after repeated charging and exposure, and the increase in residual potential is small. It has an effect.

(Example 1 Next, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to the following Examples.

[Modified indium oxide-A]

Indium oxide fine powder (average particle size 0.01 to 0.03 μm
) and 5 parts by weight of butanol were placed in a glass container equipped with a reflux condenser and stirred for 1 hour while boiling.
Subsequently, ultrasonication was performed for 30 minutes. The obtained dispersion was filtered and dried under vacuum heating at 100° C. to obtain about 1 part by weight of slightly brownish modified indium oxide-A. (It had an exothermic peak at 295-315°C in differential thermal analysis.) [Modified indium oxide-B] 1 part by weight of indium oxide lamb fine powder and 1 part by weight of cyclohexanol
0 parts by weight were placed in a glass container equipped with a reflux condenser and stirred for 1 hour while boiling, and the resulting dispersion was filtered and dried in the same manner as the above-mentioned modified indium oxide-A to give a slightly brownish modified indium oxide. Indium-B was obtained.

[Modified indium oxide-C]

1 weight of indium oxide fine powder and 10 parts by weight of methanol are placed in a glass container equipped with a reflux condenser, stirred for 1 hour while boiling, and the resulting dispersion is filtered and dried in the same manner as the modified indium oxide-A. A modified indium oxide-C with a brownish color was obtained. (Differential thermal analysis showed exothermic peaks at 260°C and 315°C.)
Modified Indium Oxide-D] 1 weight of indium oxide fine powder and 5 parts by weight of a methyl chloride solution of polyvinyl butyral (trade name Kosurek BL-1; manufactured by Sekisui Kagaku Co., Ltd.) with a solid content concentration of 1.3% by weight were attached to a reflux condenser. The mixture was placed in a heated glass container, stirred for 1 hour while boiling, and then subjected to ultrasonication for 30 minutes.

The resulting dispersion was filtered and dried in the same manner as the modified indium oxide-A, to obtain about 1 part by weight of modified indium oxide-D with a greenish-brown tinge.

[Modified Indium Oxide-El] 1 weight of indium oxide fine powder and 5 parts by weight of an aqueous solution of polyvinyl alcohol (product name #2000; manufactured by Kanto Kagaku Co., Ltd.) with a solid content concentration of 1.3% are placed in a glass container equipped with a reflux condenser. The mixture was stirred for 1 hour while being kept at about 90°C, and then subjected to ultrasonication for 30 minutes. The resulting dispersion was filtered, washed with deionized water, and dried under vacuum heating at 100°C to obtain about 1 part by weight of a modified indira oxide with a greenish-brown color.
I got it.

[Modified Indium Oxide-F] 1 weight of indium oxide fine powder and 5 parts by weight of methylene chloride were placed in a glass container equipped with a reflux condenser, stirred for 1 hour while boiling, and subjected to ultrasonication for 30 minutes.

The resulting dispersion was filtered and dried in the same manner as the modified indium oxide-A, to obtain a pale yellow modified indium oxide-F. (Differential thermal analysis showed an exothermic peak as low as 250°C.) Example 1 [Undercoat layer coating liquid] 1/2 of the volume of O2 was placed in a 9CIIIφ hard glass pot.
゜Put a 5 cmφYTZ (partially stabilized zirconia) ball, 24 g of the modified indium oxide-A fine powder, and 64 g of a cyclohexane solution of butyral resin (Sekisui Kagaku Co., Ltd., S-LEC BL-1) with a solid content concentration of 6.3% by weight. Milled for 3 days.

Next, 41 g of a 2% by weight methyl ethyl ketone solution of an isocyanate curing agent (manufactured by Dainippon Ink & Chemicals, Parnock D750) was added and stirred for about 5 minutes to obtain a subbing layer coating solution.

The above subbing layer coating solution was spray coated onto an 80φ thick aluminum drum and dried and cured at 130°C for 1 hour to form a subbing layer with a thickness of about 2 μm. The following charge generation layer coating solution was dip coated and dried by heating at 120° C. for about 20 minutes to form a charge generation layer with a thickness of about 0.1 μm.

[Charge generation layer coating liquid]

1/2 volume of lan in a 15anφ glass pot
Cyclohexanone solution 3 of XYZ balls of φ and butyral resin (trade name: XYHL) with a solid content concentration of 0.2% by weight
00g and the azo llF + 1lhl were added and the mixture was heated to 120 g.
Time milled. Furthermore, 500 g of methyl ethyl ketone was added and milled for another 24 hours to obtain a charge generation layer coating solution.

Next, the charge transfer layer coating solution shown below was applied by dip coating on the charge generation layer, and dried at 120° C. for 30 minutes to form a charge transfer layer with a thickness of about 25 μm. As a body.

(Product name KF-50: Shin-Etsu Silicone ■) Methylene chloride 900 parts by weight Example 2 In Example 1, modified indium oxide-A was replaced with modified indium oxide-B, and the charge transport layer coating liquid was changed to the following charge transport layer coating solution. A charge photographic photoreceptor of Example 2 was obtained in the same manner as in Example 1 except that the working solution was changed.

[Charge transfer layer coating liquid]

100 parts by weight of polycarbonate (product name Hashirai Ondai 1400: Teijin Kasei Silicone Oil 0.3 parts by weight (product name KF-5)
0: Shin-Etsu silicone ■) Methylene chloride
900 parts by weight Example 3 An electrophotographic photoreceptor of Example 3 was prepared in the same manner as in Example 1 except that modified indium oxide-A was replaced with modified indium oxide-C.

Example 4 The electrophotographic product of Example 4 was prepared in the same manner as in Example 1, except that modified indium oxide-A was replaced with modified indium oxide-D, and the solid content of the butyral resin was 3% by weight. A photoreceptor was created.

Example 5 An electrophotographic photoreceptor of Example 5 was prepared in the same manner as in Example 4 except that modified indium oxide-D was replaced with modified indium oxide-E.

Examples 6 to 8 In Example 1, the solid content concentration of the butyral resin (trade name, S-LEC BL-1: Sekisui Chemical ■) was 4.7% by weight, 5.4% by weight, 1.7.5% by weight. Electrophotographic photoreceptors of Examples 6, 7, and 8 were produced in the same manner as in Example 1 except for the above.

Comparative Examples 1 to 4 In Example 1, the modified indium oxide-A was replaced with unmodified indium oxide, and the solid content concentration of the butyrald resin (trade name Kosuretsu BL-1: Sekisui Kagaku ■) was changed to 4.
7% by weight, 5.4% by weight, 6°3% by weight, 7.5% by weight
Electrophotographic photoreceptors of Comparative Examples 1, 2, 3, and 4 were prepared in the same manner as in Example 1, except for the following.

Comparative Example 5 An electrophotographic photoreceptor of Comparative Example 5 was prepared in the same manner as in Example 1, except that modified indium oxide-A was replaced with modified indium oxide-F.

Regarding each photoreceptor obtained in each Example and Comparative Example
Fluctuations in chargeability (Vo), sensitivity (VL), and residual potential (■3) during repeated use were evaluated using a photoconductor potential simulation device described in Japanese Patent No. 100167.

The results are shown in Table-1.

[Evaluation conditions] ■D = surface potential after charging (drum rotation speed 80 rpm,
Charging conditions -7.5 KV) ■L: Surface potential after fi light (n light illuminance 30 Qux, slit width 10 M) ■*: Potential after static discharge (n light illuminance 350 Qux, slit width 10+m5) V'. , V'V',: Potential after repeated use for 1 hour

Claims (1)

[Claims] (1) In an electrophotographic photoreceptor having at least a subbing layer, a charge generation layer, and a charge transfer layer in the above order on a conductive support, the subbing layer is pretreated with an organic compound having a hydroxyl group, and the differential An electrophotographic photoreceptor comprising modified indium oxide having an exothermic peak at 200 to 600°C in thermal analysis.