JPH04229872A - Sensitizer for electrophotography - Google Patents

Abstract

PURPOSE:To provide such a sensitizer that is high in sensitivity, remarkably less in a drop in chargeability by pre-exposure fatigue, in addition no deterioration in charging characteristic even after repetition of charge and exposure, and little in a rise of residual potential besides conspicuous functional effect. CONSTITUTION:An undercoating layer contained with metallic oxide grains surface-treated by a silane compound and binding resin is provided on a conductive base body, then a charge generating layer and a charge conveying layer are provided successively, that is constitution for this sensitizer for an electrophotography.

Description

[Detailed description of the invention]

0001

FIELD OF THE INVENTION The present invention relates to an electrophotographic photoreceptor comprising a photosensitive layer consisting of a substrate, an undercoat layer, a charge generation layer, and a charge transport layer, and particularly relates to an electrophotographic photoreceptor with an improved undercoat layer. .

0002

2. Description of the Related Art In recent years, organic photosensitive materials, which have advantages such as low cost, productivity, and non-pollution, have become popular as photoreceptors used in electrophotographic copying machines. Organic electrophotographic photoreceptors include photoconductive resins such as polyvinylcarbazole (PVK), and PVK-TNF.
(2,4,7-trinitrofluorenone), a pigment-dispersed type such as phthalocyanine binder, and a functionally separated type photoreceptor that uses a combination of a charge-generating substance and a charge-transporting substance, etc. is known, and in particular, functionally separated photoreceptors are attracting attention. When such a functionally separated high-sensitivity photoreceptor is applied to the Carlson process, it has low chargeability, poor charge retention (high dark decay), and deterioration of these characteristics such as increased residual potential due to repeated use. The major disadvantages are that density unevenness and fogging occur on images, and in the case of reversal development, scumming occurs.

In order to improve the electrical properties of the photoreceptor, improve the adhesion between the photosensitive layer and the support, improve the coatability of the photosensitive layer, or protect the support from defects, for example, Showa 4
7-6341, 48-3544 and 48-12034
The issue has a cellulose nitrate resin intermediate layer, published in Japanese Patent Application Laid-open No. 48-4
7344, 52-25638, 58-30757, 58
-63945, 58-95351, 58-98739 and 60-66258 have a nylon resin intermediate layer,
JP-A-49-69332 and JP-A-52-10138 disclose maleic acid resin intermediate layers, and JP-A-58-105 discloses maleic acid resin intermediate layers.
No. 155 discloses a polyvinyl alcohol resin intermediate layer. In addition, intermediate layers have been proposed in which various conductive additives are contained in a resin in order to control the electrical resistance of the intermediate layer. For example, JP-A No. 51-65942 uses an intermediate layer in which carbon or chalcogen-based substances are dispersed in a curable resin, and JP-A No. 52-82238 uses an isocyanate-based curing agent with the addition of a quaternary ammonium salt. JP-A-58-5855 discloses a thermopolymer intermediate layer containing a resistance modifier in JP-A-58-118045.
No. 6 has a resin intermediate layer in which aluminum or tin oxide is dispersed, and JP-A-58-93062 has a resin intermediate layer to which an organometallic compound is added.
, 60-97363 and 60-111255 disclose a resin intermediate layer in which conductive particles are dispersed, as disclosed in JP-A-59-175.
In No. 57, a layer in which magnetite is dispersed in a resin is further disclosed in JP-A No. 59-84257, 59-93453 and 6
No. 0-32054 has a resin intermediate layer in which TiO2 and SnO2 powder are dispersed, and Japanese Patent Application Laid-open No. 64-68762, 64-
68763, 64-73352, 64-73353, JP-A-1-118849, and JP-A-1-118848 contain borides of calcium, magnesium, aluminum, etc.
An intermediate layer of resin in which nitride, fluoride, and oxide powders are dispersed is disclosed.

However, conventionally known electrophotographic photoreceptors are still insufficient in terms of deterioration in charging performance due to repeated use, particularly in terms of delay in the rise of charging potential, and furthermore, the increase in residual potential is large, and further improvements are needed. is desperately needed.

[0005]

[Problems to be Solved by the Invention] The present invention has high sensitivity, significantly reduces charging performance due to pre-exposure fatigue, and has no delay in the rise of charging potential even after repeated charging and exposure. An object of the present invention is to provide an electrophotographic photoreceptor with small potential changes.

[0006]

[Means for Solving the Problems] According to the present invention, in an electrophotographic photoreceptor in which an undercoat layer, a charge generation layer, and a charge transport layer are sequentially laminated on a conductive substrate, silane is contained in the undercoat layer. An electrophotographic photoreceptor is provided that contains metal oxide particles treated with a compound and a binder resin.

[0007] The present inventors aimed to solve the above-mentioned drawbacks by focusing on a subbing layer of an electrophotographic photoreceptor, which is formed by sequentially laminating a subbing layer, a charge generation layer, and a charge transport layer on a conductive substrate. As a result of extensive studies, it was found that by containing at least one of the metal oxides treated with a silane compound in the undercoat layer, there is no delay in the rise of the charging potential after repeated use, and the increase in residual potential is small. It was discovered that an electrophotographic photoreceptor could be obtained, and the present invention was completed.

The present invention will be explained in detail below. In the present invention, as described above, a subbing layer containing metal oxide particles treated with a silane compound dispersed in a binder resin is provided between the conductive substrate and the photosensitive layer. Metal oxide particles that can be treated with a silane compound contained in such an undercoat layer include titanium oxide, tin oxide, indium oxide, zinc oxide, aluminum oxide, magnesium oxide, calcium oxide, and surface-treated titanium oxide, tin oxide, indium oxide, zinc oxide, aluminum oxide, magnesium oxide, calcium oxide, and Beryllium, silicon oxide, antimony oxide, ferric oxide,
Examples include zirconium oxide, but titanium oxide and tin oxide are preferably used. Further, a composite metal oxide of one or more of these metal oxides can also be used.

Examples of such composite metal oxides include TiO2-ZnO, TiO2-SiO2, TiO2
-SnO2, TiO2-MgO, TiO2-ZrO2,
ZrO-ZrO2, ZnO-Sb2O3, SnO2-V
2O5, SnO2-CuO, SnO2-Sb2O4, and the like. These compounds such as TiO2-Zn
To obtain O, a solution of TiCl4 dissolved in water and ZnC
Mix a solution of l2 in water, add urea and stir,
Thereafter, the solution was heated to 95-98°C, the resulting coprecipitate was filtered, thoroughly washed with distilled water, and the precipitate was dried for 40 minutes.
A method such as firing at 0 to 600° C. for several hours may be used.

[0010] These metal oxide powders preferably have an average particle size of 1.0 μm or less, and the crystal system of the oxide is not particularly limited. Further, in order to obtain the desired electrical conductivity of the undercoat layer, two or more powders having different specific resistances can be appropriately selected and used.

Another feature of the electrophotographic photoreceptor of the present invention is that the metal oxide is treated with a silane compound to impart water repellency to the metal oxide, and at the same time improve dispersibility in the binder resin. By increasing the compatibility, the dispersion stability of the coating solution for the undercoat layer and the uniformity of the coating film are improved, and at the same time, the conductive performance is improved to the expected effect.

The silane compound used in the present invention can be appropriately selected in consideration of compatibility with the resin used, and examples thereof include the following compounds. Chlorosilanes such as methyltrichlorosilane, methyldichlorosilane, dimethyldichlorosilane, n-butyldimethylchlorosilane, dimethyloctadecylchlorosilane, phenyltrichlorosilane: tetramethoxysilane, methyltrimethoxysilane, dimethyldimethoxysilane, phenyltrimethoxysilane, diphenyldimethoxy Alkoxysilanes such as silane, octyltrimethoxysilane, tetraethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, phenyltriethoxysilane, isobutyltrimethoxysilane, 3,3,3-trifluoropropyltrimethoxysilane: hexa Silazane such as methyldisilanzane, 1,1,3,3,5,5-hexamethylcyclotrisilazane, octamethylcyclotetrasilazane, N,O-(bistrimethylsilyl)acetamide, N,N'-bis (trimethylsilyl)-N,methyl-N-trimethylsilyltrifluoroacetamide, urea, tert-butyldimethylchlorosilane, N-trimethylsilylimidazole,
Special silylating agents such as trimethylsilyltrifluoromethanesulfonate; C4F9CH2CH2Si (OCH2
)3, C8F17CH2CH2Si(
OCH3)3, C8F17CH2CH
2Si(CH3)(OCH3)2, C
7F15COOCH2CH2CH2Si(OCH3)3
, C7F15COSCH2CH2CH
2Si(OCH3)3, C7F15C
ONHCH2CH2CH2Si(OC2H5)3,
C7F15CONHCH2CH2CH2S
i(OCH3)3, C8F17SO2
NHCH2CH2CH2Si(OC2H5)3,
C8F17SO2NCH2CH2CH2Si
(OCH3)3,
｜C
H2CH2CH3 C8F17CH2C
H2SCH2CH2Si(OCH3)3,
C10F21CH2CH2SCH2CH2Si(O
CH3)3, C7F15CONHCH
2CH2NCH2CH2CH2Si(OCH3)3,

｜
COC7F15
C8F17SO2NHCH2CH2NCH
2CH2CH2Si(OCH3)3,

｜
Fluorine-containing silane compounds such as SO2C8F17.

[0013] As a method for treating the surface of a metal oxide using such a silane compound, a dry treatment method or a wet treatment method is employed. The dry processing method is a method in which metal oxide particles are placed in a machine capable of high-speed stirring, such as a Henschel mixer, and the silane compound as it is or a diluted solution thereof is slowly dripped or sprayed while stirring at high speed. The wet treatment method is a method in which metal oxide particles are treated in a solution and then dried, and the silane compound may be an aqueous solution or an alcoholic solution.

The integral blend method differs from the above two methods in that it is an indirect treatment method, in which a silane compound is dispersed in an organic resin, and then a metal oxide is added and treated.
This is a method of mixing. In addition, there is a method in which a silane compound is added to disperse metal oxide particles in a binder resin.

However, the latter two methods are not preferable if there is a possibility of reaction between the silane compound and the binder resin, and the former two methods, namely, treating the silane compound with a metal oxide in advance, are not preferable. The method is valid. The amount of silane compound used is 0.0 parts by weight per 100 parts by weight of metal oxide.
The amount is 1 to 30 parts by weight, preferably 0.1 to 10 parts by weight.

The resin used for the undercoat layer includes thermoplastic resins such as polyamide, polyester, vinyl chloride-vinyl acetate copolymer, thermosetting resins, etc.
A thermosetting resin obtained by thermally polymerizing a compound containing a plurality of hydrogen groups (H group, -NH2 group, -NH group, etc.) and a compound containing a plurality of isocyanate groups and/or a compound containing a plurality of epoxy groups. etc. can also be used.

In this case, the compound containing a plurality of active hydrogen groups includes, for example, polyvinyl butyral, phenoxy resin, phenol resin, polyamide, polyester, polyethylene glycol, polypropylene glycol, polybutylene glycol, hydroxyethyl methacrylate group, etc. Examples include acrylic resins and the like. Examples of compounds containing a plurality of isocyanate groups include tolylene diisocyanate, hexamethylene diisocyanate, diphenylmethane diisocyanate, and prepolymers thereof, and examples of compounds containing a plurality of epoxy groups include bisphenol A type epoxy resins. can give.

[0018] Also, thermosetting resins obtained by thermally polymerizing oil-free alkyd resins and amino resins such as butylated melamine resins, and furthermore, polyurethanes having unsaturated bonds and unsaturated polyesters having unsaturated bonds. Photocurable resins such as resins, thioxanthone compounds, and combinations with photopolymerizable light-opening agents such as methylbenzylformate can also be used as binder resins. The weight ratio of the metal oxide to the binder resin is 1/1 to 95/5, preferably 3/2 to 10/1.

[0019] The ratio of metal oxide to binder resin is 1/1.
If it is less than 1, the effect will be small, and if it exceeds 95/5, air bubbles will remain in the undercoat layer, resulting in defects in the charge generation layer and charge transfer layer coatings, which is not preferable. The thickness of the undercoat layer is 0.3 to 30 μm, preferably 0.5 to 20 μm.
It is appropriate that If the thickness of the undercoat layer is less than 0.3 μm, the effect will be small, and if it exceeds 30 μm, residual potential will accumulate, which is not desirable.

In the present invention, in addition to the metal oxide treated with a silane compound, it is also effective to mix white powder in order to adjust the electrical resistance of the undercoat layer, improve whiteness, reduce costs, etc. be. Examples of the white powder include untreated titanium oxide, calcium carbonate, barium sulfate, barium carbonate, calcium sulfate, and the like.

The undercoat layer is made of a metal oxide treated with a silane compound and a binder resin by a conventional method such as a ball mill,
Add chemicals, solvents, additives, curing accelerators, etc. necessary for curing (crosslinking) as needed, disperse using a sand mill, attritor, etc., and apply by a conventional method, for example, by blade coating,
After being formed on a substrate by a dip coating method or the like, it is dried or hardened by a curing treatment such as drying, heating, or light. In some cases, a resin layer or a resin layer in which white pigment powder is dispersed may be further provided on the undercoat layer thus formed in order to prevent injection of free carriers from the substrate side.

Next, the structure of the electrophotographic photoreceptor of the present invention will be explained in more detail. As the conductive substrate, materials exhibiting conductivity with a volume resistance of 1010 Ωcm or less, such as metals such as aluminum, nickel, chromium, nichrome, copper, silver, gold, and platinum, and metal oxides such as tin oxide and indium oxide, Film-like or cylindrical plastics, paper, etc. coated by vapor deposition or sputtering, or plates made of aluminum, aluminum alloy, nickel, stainless steel, etc., and those coated with D. I. ,I. I
．． It is possible to use pipes that have been made into blank pipes using methods such as extrusion or drawing, and then surface-treated by cutting, superfinishing, polishing, etc., and cylindrical or plate-shaped substrates made by dispersing and molding conductive powder into plastic. can.

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

As the charge generating substance, for example, C.I. Pigment Blue 25 [Color Index (CI) 2]
1180], CI Pigment Red 41 (CI
21200), Sea Eye Acid Red 52 (CI
45100), CI Basic Red 3 (CI
45210), phthalocyanine pigments having a porphyrin skeleton, azulenium salt pigments, squalic salt pigments, and azo pigments having a carbazole skeleton (JP-A-5
3-95033), an azo pigment having a stilstilbene skeleton (described in JP-A-53-138229), an azo pigment having a triphenylamine skeleton (described in JP-A-53-132547), Azo pigment having dibenzothiophene skeleton (JP-A-54-21728
(described in JP-A No. 54-22834), azo pigments having an oxadiazole skeleton (described in JP-A-54-12742), azo pigments having a fluorenone skeleton (described in JP-A-54-22834), bisstilbene skeletons. Azo pigment with (
(described in JP-A No. 54-17733), azo pigments having a distyryloxadiazole skeleton (described in JP-A-54-2
129), azo pigments having a distyrylcarbazole skeleton (described in JP-A-54-17734), triazo pigments having a carbazole skeleton (described in JP-A-54-17734),
7-195767, 57-195768), and CI Pigment Blue 16 (
Phthalocyanine pigments such as CI 74100), indigo pigments such as C.I. Butt Brown 5 (CI 73410) and C.I. Butt Dye (CI 73030), Argo Scarlet B (manufactured by Violet), Indus Thread Scarlet R (manufactured by Bayer), etc. Organic pigments such as perylene pigments can be used.

Among these charge-generating substances, azo pigments are particularly preferred, and among the azo pigments, the following disazo pigments and trisazo pigments are most preferred. Specific examples of azo pigments are shown in Table 1.

[0026]

[Table 1-(1)]

[0027]

[Table 1-(2)]

[0028]

[Table 1-(3)]

[0029]

[Table 1-(4)]

[0030]

[Table 1-(5)]

[0031]

[Table 1-(6)]

[0032]

[Table 1-(7)]

[0033]

[Table 1-(8)]

[0034]

[Table 1-(9)]

[0035]

[Table 1-(10)]

[0036]

[Table 1-(11)]

[0037]

[Table 1-(12)]

[0038]

[Table 1-(13)]

[0039]

[Table 1-(14)]

[0040]

[Table 1-(15)]

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 50 parts by weight, based on 100 parts by weight of the charge generating substance.

The charge generation layer is prepared by dispersing a charge generation substance together with a binder resin if necessary using a ball mill, attritor, sand mill, etc. using a solvent such as tetrahydrofuran, cyclohexanone, dioxane, dichloroethane, etc., and diluting the dispersion liquid appropriately. It can be formed by applying it. 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.

[0043] The charge transport layer comprises a charge transport substance and a binder resin used as necessary. A charge transport 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.

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

Examples of electron transport substances include chloranil, bromoanil, tetracyanoethylene, tetracyanoquinone dimethane, 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
Electron-accepting substances such as -trinitro-4H-indeno[1,2-b]thiophen-4-one and 1,3,7-trinitrodibenzothiophenone-5,5-dioxide can be mentioned. These charge transport substances may be used alone or in a mixture of two or more.

Binder resins that can be used as necessary in the present invention 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, polyvinyl toluene,
Thermoplastic or thermosetting resins such as poly-N-vinylcarbazole, acrylic resin, silicone resin, epoxy resin, melamine resin, urethane resin, phenol resin, and alkyd resin can be mentioned. As the solvent, tetrahydrofuran, dioxane, toluene, monochlorobenzene, dichloroethane, methylene chloride, etc. are used.

The thickness of the charge transport layer is suitably about 5 to 100 μm. Further, in the present invention, a plasticizer or a leveling agent may be added to the charge transport layer. As a plasticizer,
Those used as plasticizers for general resins such as dibutyl phthalate and dioctyl phthalate can be used as they are, and the amount used is 0 to 30% based on the binder resin.
Approximately % by weight is appropriate. 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. In the present invention, it is also possible to further provide an insulating layer or a protective layer on the photosensitive layer.

[0048]

[Examples] The present invention will be explained in more detail with reference to Examples below. Example 1 0.5 cm of 1/2 volume in a 50 cc hard glass bottle
φPSZ ball and 6g of titanium oxide (T805 manufactured by Nippon Aerosil Co., Ltd.) treated with octyltrimethoxysilane
and oil-free alkyd resin (Beccolite M640
1-50, solid content concentration 50% by weight: Dainippon Ink Chemical (
Co., Ltd.), 1.7 g of butylated melamine resin (Super Beckamine G821-60, solid content concentration 60% by weight, manufactured by Dainippon Ink Chemical Co., Ltd.) and 4.8 g of methyl ethyl ketone were added. The mixture was milled for several hours to obtain a coating solution for the undercoat layer. The above-mentioned coating solution for undercoat layer was applied with a plate onto a nickel sheet prepared by electroplating, and dried and cured for 20 minutes to form an undercoat layer having a thickness of about 12 μm. Next, a disazo pigment of the following structural formula [Chemical formula 1]
Part 3

[Chemical formula 1], 0.3 parts of polyvinyl butyral (trade name: XYHL, Union Carbide Plastics Co., Ltd.) and 60 parts of methyl ethyl ketone were dispersed in a ball mill for 120 hours, and 90 parts of cyclohexanone and 150 parts of methyl ethyl ketone were added as a diluent to this dispersion. In addition to the liquid, it was used as a coating liquid for a charge generation layer. This coating solution was applied onto the undercoat layer using a doctor blade, and dried by heating at 120°C for 20 minutes to give a film thickness of 0.3.
A charge generation layer of .mu.m was formed. Next, on the charge generation layer,

[Chemical formula 2] Polycarbonate resin (manufactured by Teijin Kasei Co., Ltd., Panlite C-
1400) 20 parts silicone oil

0.004 part methylene chloride

A charge transport layer forming liquid consisting of 173 parts was applied with a blade and dried at 130° C. for 20 minutes to form a charge transport layer having a thickness of about 20 μm, thereby producing the electrophotographic photoreceptor of Example 1.

Example 2 An electrophotographic photoreceptor of Example 2 was prepared in the same manner as in Example 1 except that the titanium oxide powder in Example 1 was replaced with tin oxide powder treated with methyltrimethoxysilane.

Example 3 An electrophotographic photoreceptor of Example 3 was prepared in the same manner as Example 1 except that the tin oxide powder in Example 2 was replaced with calcium oxide powder.

Example 4 In Example 1, C7F15CO2 (CH2
An electrophotographic photoreceptor of Example 4 was prepared in the same manner as in Example 1 except that tin oxide powder treated with )3Si(OCH3)3 was used.

Example 5 In Example 1, C8F17SO2N (CH
An electrophotographic photoreceptor of Example 5 was prepared in the same manner as in Example 1 except that tin oxide powder treated with 2CH2CH3)(CH2)3Si(OCH3)3 was used.

Example 6 In Example 1, C7F15CO2 (CH2
An electrophotographic photoreceptor of Example 6 was prepared in the same manner as in Example 1 except that titanium oxide powder treated with )3Si(OCH3)3 was used.

Example 7 In Example 1, C8F17SO2N (CH
An electrophotographic photoreceptor of Example 7 was prepared in the same manner as in Example 1 except that titanium oxide powder treated with 2CH2CH3)(CH2)3Si(OCH3)3 was used.

Example 8 6 g of titanium oxide treated with decyltrimethoxysilane
and butyral resin (BL-1) with a solid content concentration of 9% by weight.
9.5g of methyl ethyl ketone solution (manufactured by Sekisui Kagaku Co., Ltd.)
were milled for 24 hours using the same dispersion method as in Example 1, and then 3.6 g of a 7% by weight solution of tolylene diisocyanate in methyl ethyl ketone was added and stirred for about 5 minutes to prepare the undercoat layer coating solution. And so. The above coating solution was applied with a blade onto the same nickel sheet as in Example 1, and dried and cured at 120°C for 30 minutes to a thickness of about 2.
A subbing layer of μm was formed. Next, an electrophotographic photoreceptor was prepared on this subbing layer in the same manner as in Example 1, except that the charge generation layer coating liquid and the charge transfer layer coating liquid were replaced with those shown below. [Charge generation layer coating liquid] 1 cm of 1/2 volume in a 15 cm φ glass pot
φ alumina sintered balls, 300 g of a 2.7% by weight cyclohexanone solution of polyester resin (manufactured by Toyobo Co., Ltd., Vylon 200), and the azo pigment No. 72 by adding 39
Time milled. Further, 500 g of methyl ethyl ketone was added and milled for another 24 hours to obtain a charge generation layer coating solution. [Charge transfer layer coating liquid]

[Chemical formula 3] Polycarbonate (product name Panlite C1400: Teijin Kasei Ltd.) 10 parts silicone oil (product name KF50: Shin-Etsu Silicone Ltd.)
0.0002 parts THF
80 copies

Comparative Example 1 An electrophotographic photoreceptor of Comparative Example 1 was prepared in the same manner as in Example 1 except that the subbing layer was not provided.

Comparative Example 2 Comparative Example 2 was carried out in the same manner as in Example 1, except that the titanium oxide powder in Example 1 was replaced with fine titanium oxide powder (Tiepeke R680 manufactured by Ishihara Sangyo Co., Ltd.) that was not treated with a silane compound.
An electrophotographic photoreceptor was prepared.

Comparative Example 3 Electrons in Comparative Example 3 were prepared in the same manner as in Example 2, except that the tin oxide powder treated with methyltrimethoxysilane was replaced with a tin oxide powder not treated with a silane compound. It was used as a photographic photoreceptor.

Comparative Example 4 Electrophotography of Comparative Example 4 was carried out in the same manner as in Example 3, except that the calcium oxide powder treated with methyltrimethoxysilane was replaced with calcium oxide powder not treated with a silane compound. It was used as a photoreceptor.

Comparative Example 5 Electrophotographic exposure of Comparative Example 5 was carried out in the same manner as in Example 8, except that the titanium oxide powder treated with decyltrimethoxysilane was replaced with titanium oxide that was not treated with a silane compound. created a body.

The photoreceptor characteristics of these photoreceptors were measured using an electrostatic paper analyzer SP- manufactured by Kawaguchi Electric Co., Ltd.
Measurement was carried out using 428 under the following conditions. Charging 20sec (applied voltage -6KV) Dark decay 20sec Exposure 30sec (exposure intensity 5lux) Charging 2
The value after sec is V1, and the voltage after 30 seconds of exposure is V30.
The amount of exposure required to reduce the surface potential of −800 V to 1/2 was defined as E1/2. The fatigue conditions are as follows: the current flows through the photoreceptor, and the applied voltage and light intensity are adjusted so that the current becomes -9.6μA and the surface potential of the photoreceptor becomes -800V.
Fatigued for 5 minutes. Thereafter, the post-fatigue characteristics of the photoreceptor were measured under the same conditions as the initial characteristics. The results are shown in Table 2.

[0062]

[Table 2]

[0063]

Effects of the Invention The electrophotographic photoreceptor of the present invention has the above-mentioned structure, and since the undercoat layer contains at least one metal oxide treated with a silane compound, it has high sensitivity and The deterioration in chargeability due to pre-exposure fatigue is extremely small, the chargeability does not deteriorate even after repeated charging and exposure, and the increase in residual potential is small, so it has remarkable effects. Further, according to the electrophotographic photoreceptor of the present invention, it is possible to prevent abnormal images from occurring due to optical interference even in exposure using coherent light from a laser printer or the like.

Claims (2)

[Claims] 1. An electrophotographic photoreceptor comprising an undercoat layer, a charge generation layer, and a charge transport layer sequentially laminated on a conductive substrate, wherein the undercoat layer includes a metal oxide surface-treated with a silane compound. An electrophotographic photoreceptor characterized by containing particles and a binder resin. 2. The electrophotographic photoreceptor according to claim 1, wherein the silane compound is a fluorine-containing silane compound.