JPH04356056A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To obtain such a photosensitive body that has high sensitivity even an intermediate layer which enough shields defects on the substrate is provided, and that shows no lag of rising of the electrification potential after electrification and exposure is repeated, and shows little increase in the residual potential by providing specified first and second intermediate layers. CONSTITUTION:The first intermediate layer consists of at least powder of metal oxide or titanium carbide and a binder resin with specified volume ratio of the powder and the binder resin to 1-1-3/1. The metal oxide or titanium carbide powder used is preferably indium oxide, tin oxide, and titanium carbide. The second intermediate layer is formed on the first intermediate layer and consists of at least white pigment and a binder resin. The white pigment is, for example, titanium oxide, calcium fluoride, calcium oxide, etc. By using the obtd. photosensitive material, abnormal picture images due to interference of light can be prevented even under exposure of coherent light such as in a laser printer.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to an electrophotographic photoreceptor.
More specifically, the present invention relates to improvements in electrophotographic photoreceptors in which an intermediate layer is provided between a substrate and a photoconductive layer.

0002

2. Description of the Related Art Hitherto, inorganic photoconductive substances such as selenium and selenium alloys, zinc oxide, and cadmium sulfide have been mainly used as photosensitive materials for electrophotographic photoreceptors. On the other hand, recently, organic photosensitive materials, which have the advantages of being inexpensive, highly productive, and non-polluting, have been used. Organic electrophotographic photoreceptors include polyvinylcarbazole (PV
K), photoconductive resin typified by PVK-TNF (2,
Known photoreceptors include charge transfer complex type photoreceptors typified by 4,7-trinitrofluorenone), pigment dispersion types typified by phthalocyanine binders, and functionally separated photoreceptors using a combination of a charge generation substance and a charge transport substance. In particular, functionally separated photoreceptors are attracting attention.

[0003] When such a functionally separated type high-sensitivity photoreceptor is applied to the Carlson process, it has low chargeability, poor charge retention (large darkening difference), and deterioration of these characteristics due to repeated use. This method has the disadvantage of causing density unevenness, fogging, and background smearing in the case of reverse development. In order to improve the electrical properties of such a photoreceptor, it is considered effective to provide an intermediate layer between the substrate and the photosensitive layer.

Generally, the purpose of providing such an intermediate layer is to improve adhesion, improve coatability of the photosensitive layer, protect the substrate, cover defects on the substrate, protect the photosensitive layer from electrical damage, and protect the photosensitive layer from electrical damage. Examples include improving the ability to inject charges into the photosensitive layer.

For example, JP-A-47-6341, 48-3
544 and 48-12034, cellulose nitrate resin intermediate layers are disclosed in Japanese Patent Application Laid-open Nos. 48-47344 and 52-256.
38, 58-30757, 58-63945, 58-9
Nos. 5351, 58-98739 and 60-66258 have a nylon resin intermediate layer, as disclosed in JP-A-49-69332.
JP-A-58-105155 discloses a maleic acid resin intermediate layer, and JP-A-58-105155 discloses a polyvinyl alcohol resin intermediate layer.

However, since the intermediate layer of these single resin layers has a high electrical resistance, a residual potential is generated and background smear occurs on the image, so it is necessary to make it a thin film. therefore,
Since it is insufficient to cover defects in the substrate, conventionally, surface treatment processes such as cutting and mirror polishing have been applied to the surface of the substrate in order to reduce the roughness of the surface of the substrate. However, such a step causes an increase in the cost of the electrophotographic photoreceptor.

[0007] Therefore, in order to increase the thickness of the intermediate layer and cover substrate defects, 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-55-1130451 discloses a resin intermediate layer containing a resistance modifier, and JP-A-58-58556 discloses a resin intermediate layer in which aluminum or tin oxide is dispersed. , JP-A No. 58-93062 discloses a resin intermediate layer to which an organometallic compound is added.
Nos. 0-97363 and 60-111255 have a resin intermediate layer in which conductive particles are dispersed, as disclosed in JP-A-59-17557.
In this issue, a layer in which magnetite is dispersed in a resin is further disclosed in JP-A No. 59-84257, 59-93453 and 60-
No. 32054 discloses a resin intermediate layer in which TiO2 and SnO2 powder are dispersed;
8763, 64-73352, 64-73353, JP-A-1-118849, 1-118848, borides and nitrides of calcium, magnesium, aluminum, etc.
A resin intermediate layer in which fluoride and oxide powders are dispersed is disclosed.

However, these electrophotographic photoreceptors are still insufficient in terms of the deterioration in charging performance due to repeated use, especially in terms of the delay in the rise of the charging potential, and furthermore, the increase in residual potential is large, so further improvement is required. It was wanted.

[0009]

[Problems to be Solved by the Invention] The present invention provides high sensitivity even when using an intermediate layer that can sufficiently mask defects on the substrate, and furthermore, even after repeated charging and exposure, the rising of the charging potential is suppressed. An object of the present invention is to provide an electrophotographic photoreceptor that has no lag and has a small increase in residual potential.

0010

[Means for Solving the Problems] According to the present invention, in an electrophotographic photoreceptor having a photoconductive layer provided on a substrate, a metal oxide or titanium carbide powder and a binder are provided between the substrate and the photoconductive layer. A first intermediate layer containing a resin as a main component and in which the ratio of the powder to the binder used is within the range of 1/1 to 3/1 by volume, and a white pigment is provided on the first intermediate layer. Provided is an electrophotographic photoreceptor characterized in that it includes a second intermediate layer containing a binder resin as a main component.

The present inventors have discovered that an electrophotographic photoreceptor using an intermediate layer that can sufficiently hide defects on the substrate has high sensitivity, and furthermore, even after repeated charging and exposure, there is no delay in the rise of the charging potential. As a result of intensive studies, we have developed a method that uses metal oxide or titanium carbide powder and binder resin as the main components between the substrate and the photoconductive layer.
and the ratio of the powder to the binder used is 1/1 to 3 in volume ratio.
The above object can be achieved by providing a first intermediate layer within the range of /1 and providing a second intermediate layer containing a white pigment and a binder resin as main components on the first intermediate layer. They discovered this and completed the present invention.

The present invention will be explained in detail below. As the conductive substrate, metals such as aluminum, nickel, chromium, nichrome, copper, silver, gold, platinum, and stainless steel, and metal oxides such as tin oxide, indium oxide, nickel oxide, and aluminum oxide are formed into a film by vapor deposition or sputtering. Or cylindrical plastic (polyethylene terephthalate, polybutylene terephthalate, phenolic resin, polypropylene, nylon, polystyrene, etc.)
Or coated paper, etc., or plates made of aluminum, aluminum alloy, nickel, stainless steel, etc., and those coated with D. I. ,I. I. , pipes that have been made into blank pipes by extrusion, drawing, etc., and then surface-treated by cutting, superfinishing, polishing, etc., or by electroplating the above metals, etc.
It is possible to use a film-like or cylindrical material, or a film-like or cylindrical material obtained by dispersing and molding conductive powder into plastic. Further, in some cases, the first intermediate layer and the second intermediate layer according to the present invention may be provided on the insulator, and the photoconductive layer may be formed thereon.

[0013] The first intermediate layer is composed of at least a metal oxide or titanium carbide powder and a binder resin, and the volume ratio of the powder to the binder resin is 1/1 to 3/1. It is stipulated. If the capacity ratio of the metal oxide or titanium carbide powder to the binder resin is less than 1/1, the residual potential increases and the sensitivity decreases significantly after repeated use, and
If the capacitance ratio exceeds 3/1, bubbles may occur in the photoconductive layer, which reduces the charging property of the photoconductive layer and causes a deterioration in the quality of copied images.

Indium oxide, tin oxide and titanium carbide are preferably used as the metal oxide or titanium carbide powder used in the first intermediate layer. Commercially available indium oxide, tin oxide, and titanium carbide can be used as they are, but in order to reduce costs, titanium carbide, carbon black, titanium nitride, conductive titanium oxide,
It is also effective to mix low resistance powders such as metal powders and titanium black. Furthermore, tin oxides that have been treated with antimony can also be preferably used.

Any suitable binder resin can be used. Such binder resins include thermoplastic resins such as polyamides, polyesters, vinyl chloride-vinyl acetate copolymers, and thermosetting resins such as active hydrogen (-O
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, examples of compounds containing multiple active hydrogens include polyvinyl butyral, phenoxy resin, phenol resin, polyamide, polyester, polyethylene glycol, polypropylene glycol, polybutylene glycol, and acrylates containing active hydrogen such as hydroxyethyl methacrylate groups. Examples include resins. 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.

In addition, thermosetting resins obtained by thermally polymerizing oil-free alkyd resins and amino resins, such as butylated melamine resins, and furthermore, resins having unsaturated bonds such as polyurethane having unsaturated bonds and unsaturated polyester. A photocurable resin in combination with a photopolymerization initiator such as a thioxanthone compound or methylbenzylformate can also be used as the binder resin.

[0017] Further, the film thickness of the first intermediate layer is 0.5 to 1
00 μm, preferably about 1 to 50 μm. The metal oxide or titanium carbide powder is dispersed together with a solvent and a binder resin using a conventional method such as a ball mill, sand mill, attriler, etc., and, if necessary, chemicals, solvents, additives, etc. necessary for curing (crosslinking). By adding a curing accelerator etc., blade coating, dip coating, spray coating,
It is formed on a substrate by beat coating, nozzle coating, or the like. After coating, it is dried or cured by drying, heating, light, or other curing treatments.

The second intermediate layer comprises at least a white pigment and a binder resin. Examples of the white pigment used in the second intermediate layer include titanium oxide, calcium fluoride, calcium oxide,
Examples include silicon oxide, magnesium oxide, zirconium oxide, aluminum oxide, etc., and they can be used alone or in combination of two or more.

Any suitable binder resin can be used, and the same binder resin as the first intermediate layer can be used. However, it must be selected so as not to attack the first intermediate layer or the photosensitive layer.

[0020] The ratio of the white pigment to the binder resin used is 1/1 to 95/5, preferably 3/2 to 10/1 by weight.
It is. If the ratio of white pigment to binder resin is less than 1/1, the effect will be small, and if it exceeds 95/5, air bubbles will remain in the intermediate layer, causing defects in the coating film of the photoconductive layer, so it is preferable. do not have. Also, the film thickness of the second intermediate layer is 0.3
It is appropriate to set the thickness to 10 μm, preferably 0.5 to 5 μm. If the film thickness is less than 0.3 μm, the effectiveness will be small, and if it exceeds 10 μm, residual potential will accumulate, which is not desirable.

The white pigment is dispersed together with a solvent and a binder resin by a conventional method such as a ball mill, a sand mill, an attriler, etc., and if necessary, chemicals, solvents, additives, and curing accelerators necessary for curing (crosslinking) are added. It is formed on the substrate by a conventional method such as blade coating, dip coating, spray coating, beat coating, and nozzle coating. After coating, it is dried or cured by drying, heating, light, or other curing treatments.

[0022] Further, as the photoconductive layer used in the present invention,
(1) A charge transfer complex formed by a combination of an electron-donating compound and an electron-accepting compound (USP 34842)
37), (2) an organic photoconductor sensitized by adding a dye (described in Japanese Patent Publication No. 48-25658),
(3) Pigment dispersed in a hole- or electron-active matrix (JP-A-47-30328, JP-A-47-1
8545), (4) a charge generation layer and a charge transport layer separated in function (JP-A-49-1055)
37), (5) those whose main component is a eutectic complex consisting of a dye and a resin (described in JP-A-47-10785), (6) organic pigments or inorganic charges in the charge transfer complex. Added generated material (Japanese Patent Application Laid-Open No. 49-916
It may be formed of any conventionally known organic photoconductor such as those described in Japanese Patent No. 48).

However, among these, the laminated photoreceptor of type (4) is particularly advantageous because it has high sensitivity and can be made from a variety of materials depending on the function.

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 or trisazo pigments are most preferred. Specific examples of azo pigments are shown in Table 1.

[0027]

[Table 1-(1)]

[0028]

[Table 1-(2)]

[0029]

[Table 1-(3)]

[0030]

[Table 1-(4)]

[0031]

[Table 1-(5)]

[0032]

[Table 1-(6)]

[0033]

[Table 1-(7)]

[0034]

[Table 1-(8)]

[0035]

[Table 1-(9)]

[0036]

[Table 1-(10)]

[0037]

[Table 1-(11)]

[0038]

[Table 1-(12)]

[0039]

[Table 1-(13)]

[0040]

[Table 1-(14)]

[0041]

[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.

[0044] 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 and applying and drying the solution. Charge transport materials include hole transport materials and electron transport materials.

As the hole transport substance, poly-N-vinylcarbazole and its derivatives, poly-γ-carbazolylethyl glutamate and its derivatives, pyrene-formaldehyde condensate and its derivatives, polyvinylpyrene, polyvinylphenanthrene, oxazole derivatives are used. ,
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 the electron transport substance 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 may 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.

[Example] 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. Example 1 1 cm of 1/2 volume in a 9 cm φ hard glass pot
Medium PSZ ball and indium oxide (manufactured by Mitsubishi Metals Co., Ltd.)
50g of fine powder, 7.8g of oil-free alkyd resin (Beccalite M6401-50, manufactured by Dainippon Ink Chemical Co., Ltd.) with a solid content of 50% by weight, and a butylated melamine resin (Super Beckamine) with a solid content of 60% by weight. G82
1-60 (manufactured by Dainippon Ink Chemical Co., Ltd.) and 50.9 gr of methyl ethyl ketone were added thereto and milled for 24 hours to obtain a 50% by weight first intermediate layer coating solution. Note that the resin used for the first intermediate layer has a specific gravity of 1.4, and the specific gravity of indium oxide is 7.2, so the indium oxide/resin capacity ratio of the first intermediate layer is 1.5/1. Become. The first intermediate layer coating solution was applied with a blade onto a nickel sheet prepared by electroplating, and dried and cured at 130° C. for 60 minutes to form a first intermediate layer having a thickness of 25 μm.

Next, in a hard glass pot with a diameter of 9 cm, 1 cm alumina sintered balls and titanium oxide (C
R-EL, manufactured by Ishihara Sangyo Co., Ltd.) 60 gr of fine powder and 12 gr of oil-free alkyd resin (Beccolite M6401-50, Dainippon Ink Chemical Co., Ltd.) with a solid content concentration of 50% by weight and a solid content concentration of 60 wt. % of butylated melamine resin (Super Beckamine G821-60, manufactured by Dainippon Ink Chemical Co., Ltd.) with 7 gr and 50 % of methyl ethyl ketone.
gr and milled for 24 hours to obtain a second intermediate layer coating solution. This second intermediate layer coating solution was coated on the first intermediate layer with a blade, and dried and cured at 130°C for 20 minutes to a thickness of 2 μm.
A second intermediate layer of m was formed.

Next, 3 parts of the disazo pigment of the following structural formula 1

[
Chemical formula 1] and 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 as a diluent, 90 parts of cyclohexanone and 150 parts of methyl ethyl ketone were added to this dispersion. In addition, it was used as a coating liquid for charge generation layer. This coating solution was applied onto the above intermediate 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.

[0052] A compound of the following structural formula 2 is provided on the charge generation layer.
18 parts

[Chemical formula 2] Polycarbonate resin (Panlite C-1400,
20 parts Silicone oil (manufactured by Teijin Chemical Co., Ltd.)
KF-50, manufactured by Shin-Etsu Silicone Co., Ltd.) 0
．． 004 parts methylene chloride

A charge transport layer coating solution 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 20 μm, thereby producing an electrophotographic photoreceptor of Example 1.

Example 2 1 cm of 1/2 volume in a 9 cm φ hard glass pot
Medium PSZ ball and indium oxide (manufactured by Mitsubishi Metals Co., Ltd.)
50g of fine powder and copolyamide resin (Aramin CM
-8000 (manufactured by Toray Industries, Inc.) was mixed with 5.1 gr, 42.1 gr of methanol, and 18.1 gr of butanol, and milled for 24 hours to obtain a 50% by weight first intermediate layer coating solution. Note that the resin used for the first intermediate layer has a specific gravity of 1.1,
Or, since the specific gravity of indium oxide is 7.2, the capacity ratio of indium oxide/resin in the first intermediate layer is 1.5/1.
becomes. The above first intermediate layer coating solution was applied with a blade onto a nickel sheet prepared by electroplating, and
After drying for 0 minutes, a first intermediate layer having a thickness of 25 μm was formed.

Next, in a hard glass pot with a diameter of 9 cm, 1 cm alumina sintered balls and titanium oxide (C
R-EL, manufactured by Ishihara Sangyo Co., Ltd.) 60 gr of fine powder and 12 gr of oil-free alkyd resin (Beccolite M6401-50, Dainippon Ink Chemical Co., Ltd.) with a solid content concentration of 50% by weight and a solid content concentration of 60 wt. % of butylated melamine resin (Super Beckamine G821-60, manufactured by Dainippon Ink Chemical Co., Ltd.) with 7 gr and 50 % of methyl ethyl ketone.
gr and milled for 24 hours to obtain a second intermediate layer coating solution. This second intermediate layer coating solution was applied with a blade onto the first intermediate layer, and dried and cured at 130°C for 20 minutes to a thickness of 2.
A second intermediate layer of .mu.m was formed.

Next, in a 15 cm φ glass pot, 1/2 of the volume of 1 cm φ PSZ sintered balls, 300 g of a 2.7% by weight cyclohexanone solution of polyester resin (manufactured by Toyobo Co., Ltd., Byron 200), and the above azo pigment No. No. 39 was added and milling was carried out for 72 hours. Further, 500 g of methyl ethyl ketone was added and milled for another 24 hours to obtain a charge generation layer coating solution. This coating solution was applied onto the intermediate layer with a blade and dried by heating at 120° C. for 20 minutes to form a charge generation layer having a thickness of 0.3 μm.

(Charge transfer layer coating liquid) Compound of the following structural formula 3

9th part

[Chemical formula 3] Polycarbonate (product name Panlite C1400:
Teijin Chemical Co., Ltd.) 10 parts Silicone oil (
Product name KF50: Manufactured by Shin-Etsu Silicone Co., Ltd.) 0
．． 0002 parts Tetrahydrofuran

A charge transport layer coating solution of 80 parts was applied with a blade and dried at 130° C. for 20 minutes to form a charge transport layer with a thickness of 20 μm, thereby producing an electrophotographic photoreceptor of Example 2.

Example 3 The titanium oxide powder used in the second intermediate layer of Example 1 was replaced with calcium oxide (manufactured by Furuuchi Chemical Co., Ltd.: purity 99.99%).
An electrophotographic photoreceptor was produced in the same manner as in Example 1 except that powder was used instead.

Example 4 The titanium oxide powder used in the second intermediate layer of Example 1 was replaced with calcium fluoride (manufactured by Furuuchi Chemical Co., Ltd.: purity 99.99%).
) An electrophotographic photoreceptor was prepared in the same manner as in Example 1 except that powder was used instead.

Example 5 A photoreceptor was prepared in the same manner as in Example 2, except that the titanium oxide in the second intermediate layer was replaced with calcium oxide (manufactured by Furuuchi Chemical Co., Ltd., purity 99.99%).

Example 6 A photoreceptor was prepared in the same manner as in Example 2, except that the titanium oxide in the second intermediate layer was replaced with calcium fluoride (Furuuchi Chemical Co., Ltd., purity 99.99%). .

Example 7 In Example 1, the indium oxide in the first intermediate layer was replaced with tin oxide (S-1, manufactured by Mitsubishi Metals), and the tin oxide (specific gravity: 6.9)/resin capacity ratio was changed to 1. A photoreceptor was prepared in the same manner as in Example 1 except that the oil-free alkyd resin was changed to 8.2 gr and the butylated melamine resin was changed to 4.5 gr in order to achieve a ratio of 5/1.

Example 8 In Example 2, the indium oxide in the first intermediate layer was replaced with tin oxide (S-1, manufactured by Mitsubishi Metals), and the tin oxide (specific gravity: 6.9)/resin capacity ratio was changed to 1. To make the ratio 5/1, 5.3 gr of copolyamide resin and 38 gr of methanol were used.
A photoreceptor was prepared in the same manner as in Example 2 except that the amount of butanol was 16.6 gr.

Example 9 In Example 7, the titanium oxide powder used for the second intermediate layer was replaced with calcium oxide (manufactured by Furuuchi Chemical Co., Ltd., purity 99.99).
%) A photoreceptor was prepared in the same manner as in Example 7 except that powder was used instead.

Example 10 In Example 7, the titanium oxide powder used for the second intermediate layer was replaced with calcium fluoride (manufactured by Furuuchi Chemical Co., Ltd., purity 99.9).
A photoreceptor was prepared in the same manner as in Example 7 except that powder (9%) was used instead.

Example 11 A photoreceptor was prepared in the same manner as in Example 8, except that the titanium oxide in the second intermediate layer was replaced with calcium oxide (manufactured by Furuuchi Chemical Co., Ltd., purity 99.99%). .

Example 12 A photoreceptor was prepared in the same manner as in Example 8, except that the titanium oxide in the second intermediate layer was replaced with calcium fluoride (manufactured by Furuuchi Chemical Co., Ltd., purity 99.99%). did.

Example 13 In Example 1, the indium oxide of the first intermediate layer was changed to Sn.
Instead of O2・Sb (T-1, manufactured by Mitsubishi Metals), SnO2
・In order to make the Sb (specific gravity 6.6)/resin volume ratio 1.5/1, the oil-free alkyd resin was 8.5 gr, the butylated melamine resin was 4.7 gr, and the methyl ethyl ketone was 51.0 gr. A photoreceptor was prepared in the same manner as in Example 1.

Example 14 In Example 2, the indium oxide of the first intermediate layer was replaced with Sn.
Instead of O2・Sb (T-1, manufactured by Mitsubishi Metals), SnO2
- Example except that in order to make the Sb (specific gravity 6.6)/resin volume ratio 1.5/1, the copolyamide resin was 5.6gr, methanol was 38.9gr, and butanol was 16.7gr. A photoreceptor was prepared in the same manner as in Example 2.

Example 15 In Example 13, the titanium oxide powder used for the second intermediate layer was replaced with calcium oxide (manufactured by Furuuchi Chemical Co., Ltd., purity 99.9).
A photoreceptor was prepared in the same manner as in Example 13 except that powder (9%) was used instead.

Example 16 In Example 13, the titanium oxide powder used for the second intermediate layer was replaced with calcium fluoride (manufactured by Furuuchi Chemical Co., Ltd., purity 99.
A photoreceptor was prepared in the same manner as in Example 13 except that powder (99%) was used instead.

Example 17 A photoreceptor was produced in the same manner as in Example 14, except that the titanium oxide in the second intermediate layer was replaced with calcium oxide (manufactured by Furuuchi Chemical Co., Ltd., purity 99.99%). .

Example 18 A photoreceptor was prepared in the same manner as in Example 14, except that the titanium oxide in the second intermediate layer was replaced with calcium fluoride (manufactured by Furuuchi Chemical Co., Ltd., purity 99.99%). did.

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

Comparative Example 2 An electrophotographic photoreceptor of Comparative Example 2 was prepared in the same manner as in Example 1 except that the second intermediate layer was not provided.

Comparative Example 3 A comparative example was carried out in the same manner as in Example 1, except that the first intermediate layer was not provided, the second intermediate layer was made to have a film thickness of 25 μm, and was dried and cured at 130° C. for 60 minutes. An electrophotographic photoreceptor of No. 3 was prepared.

Comparative Example 4 Electrophotography was carried out in the same manner as in Example 3, except that the first intermediate layer was not provided, the second intermediate layer had a thickness of 25 μm, and was dried and cured at 130° C. for 60 minutes. A photoreceptor was created.

Comparative Example 5 Electrophotography was carried out in the same manner as in Example 4, except that the first intermediate layer was not provided, the second intermediate layer had a thickness of 25 μm, and was dried and cured at 130° C. for 60 minutes. A photoreceptor was created.

Each of the electrophotographic photoreceptors prepared as described above was tested using an electrostatic copying paper tester (Kawaguchi Electric Seisakusho SP-428).
Using a -6 KV corona discharge for 20 seconds to charge the sample, the surface potential (V2) was measured 2 seconds after the start of charging. In addition, after charging is completed, the voltage is attenuated in a dark place for 20 seconds, and the potential retention rate (Vk) (=potential after 20 seconds of dark decay/charging 20
The potential after 2 seconds was determined. In addition, after 20 seconds of dark decay, a 2856°K tungsten lamp was turned on at 150lux.
The surface potential Vr (residual potential) after sec irradiation was measured. Next, after charging the surface potential to -800V again,
Exposure was performed using the tungsten lamp at 5 lux, and the exposure amount S required for the surface potential to attenuate to -400V was measured.

Furthermore, in order to find out the repeated fatigue characteristics, the applied voltage and light intensity were adjusted using the above device so that the current flowing through the photoreceptor was -9.6 μA and the surface potential of the photoreceptor was -800V. Meanwhile, charging and exposure were alternately repeated for 15 minutes, and the characteristics after fatigue were measured in the same manner as above. The results are shown in Table 2.

[0080]

[Table 2]

Examples 19 to 21 In Example 1, the indium oxide/resin capacity ratio of the first intermediate layer was set to 1.1/1, 2.0/1, and 2.0/1, respectively.
Photoreceptors of Examples 19 to 21 were prepared in the same manner as in Example 1 except that 9/1 was used.

Examples 22 to 24 In Example 3, the indium oxide/resin capacity ratio of the first intermediate layer was set to 1.1/1, 2.0/1, and 2.0/1, respectively.
Photoreceptors of Examples 22 to 24 were prepared in the same manner as in Example 3 except that 9/1 was used.

Examples 25 to 27 In Example 4, the indium oxide/resin capacity ratio of the first intermediate layer was set to 1.1/1, 2.0/1, and 2.0/1, respectively.
Example 25 was carried out in the same manner as in Example 4 except that 9/1 was replaced.
~27 photoreceptors were made.

Examples 28 to 30 In Example 7, the tin oxide/resin capacity ratio of the first intermediate layer was 1.1/1, 2.0/1, and 2.9/1, respectively.
Examples 28 to 30 were carried out in the same manner as in Example 7 except that
A photoreceptor was created.

Examples 31 to 33 In Example 9, the tin oxide/resin capacity ratio of the first intermediate layer was 1.1/1, 2.0/1, and 2.9/1, respectively.
Examples 31 to 33 were carried out in the same manner as in Example 9 except that
A photoreceptor was created.

Examples 34 to 36 In Example 10, the tin oxide/resin capacity ratio of the first intermediate layer was changed to 1.1/1, 2.0/1, and 2.9/1, respectively.
Example 34-
Thirty-six photoreceptors were made.

Examples 37 to 39 In Example 13, the SnO2/Sb/resin capacity ratio of the first intermediate layer was 1.1/1, 2.0/1 and 2, respectively.
．． Photoreceptors of Examples 37 to 39 were produced in the same manner as Example 13 except that 9/1 was used.

Examples 40 to 42 In Example 15, the SnO2/Sb/resin capacity ratio of the first intermediate layer was 1.1/1, 2.0/1 and 2, respectively.
．． Photoreceptors of Examples 40 to 42 were prepared in the same manner as in Example 15 except that 9/1 was used.

Examples 43 to 45 In Example 16, the SnO2/Sb/resin capacity ratio of the first intermediate layer was 1.1/1, 2.0/1 and 2, respectively.
．． Photoreceptors of Examples 43 to 45 were prepared in the same manner as in Example 16 except that 9/1 was used.

Comparative Examples 6 to 7 Comparisons were made in the same manner as in Example 1, except that the indium oxide/resin capacity ratio of the first intermediate layer was 0.6/1 and 3.7/1. Photoreceptors of Examples 6-7 were prepared.

Comparative Examples 8 to 9 Comparisons were made in the same manner as in Example 3, except that the indium oxide/resin capacity ratio of the first intermediate layer was 0.6/1 and 3.7/1. Photoreceptors of Examples 8-9 were prepared.

Comparative Examples 10 to 11 Comparisons were made in the same manner as in Example 4, except that the indium oxide/resin capacity ratio of the first intermediate layer was 0.6/1 and 3.7/1. Photoreceptors of Examples 10-11 were prepared.

Comparative Examples 12 to 13 Comparisons were made in the same manner as in Example 7, except that the tin oxide/resin capacity ratio of the first intermediate layer was 0.6/1 and 3.7/1. Photoreceptors of Examples 12-13 were made.

Comparative Examples 14 to 15 Comparisons were made in the same manner as in Example 9, except that the tin oxide/resin capacity ratio of the first intermediate layer was 0.6/1 and 3.7/1. Photoreceptors of Examples 14-15 were made.

Comparative Examples 16 to 17 Comparisons were made in the same manner as in Example 10, except that the tin oxide/resin capacity ratio of the first intermediate layer was 0.6/1 and 3.7/1. Photoreceptors of Examples 16-17 were made.

Comparative Examples 18 to 19 The same procedure as in Example 13 was carried out except that the SnO2/Sb/resin capacity ratio of the first intermediate layer was 0.6/1 and 3.7/1. Photoreceptors of Comparative Examples 18 to 19 were prepared.

Comparative Examples 20 to 21 The same procedure as in Example 15 was carried out except that the SnO2/Sb/resin capacity ratio of the first intermediate layer was 0.6/1 and 3.7/1. Photoreceptors of Comparative Examples 20 and 21 were prepared.

Comparative Examples 22 to 23 The same procedure as in Example 16 was carried out except that the SnO2/Sb/resin capacity ratio of the first intermediate layer was 0.6/1 and 3.7/1. A photoreceptor was created.

Next, the characteristics of each electrophotographic photoreceptor produced as described above were measured using an electrostatic copying paper tester (SP-428 manufactured by Kawaguchi Electric Seisakusho) in the same manner as in Example 1. Ta. The results are shown in Table 3.

[0100]

[Table 3-(1)]

[0101]

[Table 3-(2)]

Example 46 In Example 1, indium oxide in the first intermediate layer was replaced with titanium carbide (manufactured by Nippon Shinkinzoku Co., Ltd.), and the volume ratio of titanium carbide (specific gravity 4.9)/resin was changed to 2/1. A photoreceptor was prepared in the same manner as in Example 1, except that 8.6 gr of oil-free alkyd resin, 4.8 gr of butylated melamine resin, and 51 gr of methyl ethyl ketone were used.

Example 47 In Example 2, indium oxide in the first intermediate layer was replaced with titanium carbide (manufactured by Nippon Shinkinzoku Co., Ltd.), and the titanium oxide (specific gravity 4.9)/resin volume ratio was changed to 2/1. 5.6g of copolyamide resin, 39g of methanol,
A photoreceptor was prepared in the same manner as in Example 2, except that the amount of butanol was 16.7 gr.

Comparative Example 24 An electrophotographic photoreceptor of Comparative Example 24 was prepared in the same manner as in Example 46 except that the second intermediate layer was not provided.

Examples 48 to 49 Same as Example 46 except that the actual ratio of titanium carbide/resin in the first intermediate layer was changed to 1.3/1 and 2.7/1, respectively. Electrophotographic photoreceptors of Examples 48 to 49 were prepared respectively.

Comparative Examples 25 to 26 The same procedure as in Example 46 was carried out except that the actual ratio of titanium carbide/resin in the first intermediate layer was changed to 0.7/1 and 3.6/1, respectively. Electrophotographic photoreceptors of Comparative Examples 25 and 26 were prepared respectively.

Examples 50 to 51 Same as Example 47 except that the titanium carbide/resin capacity ratio of the first intermediate layer was changed to 1.3/1 and 2.7/1, respectively. Similarly, Examples 50 to 51, respectively.
An electrophotographic photoreceptor was prepared.

Comparative Examples 27 to 28 Same as Example 47 except that the titanium carbide/resin capacity ratio of the first intermediate layer was changed to 0.7/1 and 3.6/1, respectively. Similarly, Examples 27 to 28, respectively.
An electrophotographic photoreceptor was prepared.

Example 52 Example 46 was carried out in the same manner as in Example 46, except that the titanium oxide in the second intermediate layer of Example 46 was replaced with calcium fluoride (manufactured by Furuuchi Chemical Co., Ltd.: purity 99.99%) powder. 52 electrophotographic photoreceptors were produced.

Example 53 Example 47 was carried out in the same manner as in Example 47, except that the titanium oxide in the second intermediate layer of Example 47 was replaced with calcium fluoride (manufactured by Furuuchi Chemical Co., Ltd.: purity 99.99%) powder. 53 electrophotographic photoreceptors were produced.

Comparative Example 29 The electronics of Comparative Example 29 were prepared in the same manner as in Example 52, except that the first intermediate layer was not provided, the second intermediate layer had a film thickness of 25 μm, and was dried and cured at 130° C. for 60 minutes. A photographic photoreceptor was created.

Examples 54 to 55 The same procedure as in Example 52 was carried out except that the titanium carbide/resin capacity ratio of the first intermediate layer was changed to 1.3/1 and 2.7/1, respectively. Electrophotographic photoreceptors of Examples 54 and 55 were prepared.

Comparative Examples 30 to 31 The same procedure as in Example 52 was carried out except that the titanium carbide/resin capacity ratio of the first intermediate layer was changed to 0.7/1 and 3.6/1, respectively. Electrophotographic photoreceptors of Comparative Examples 30 to 31 were prepared.

Example 56 Example 46 was carried out in the same manner as in Example 46, except that the titanium oxide in the second intermediate layer of Example 46 was replaced with magnesium oxide (manufactured by Kojundo Kagaku Co., Ltd.: purity 99.99%) powder. 56 electrophotographic photoreceptors were produced.

Example 57 Example 47 was carried out in the same manner as in Example 47 except that the titanium oxide in the second intermediate layer of Example 47 was replaced with magnesium oxide (manufactured by Kojundo Kagaku Co., Ltd.: purity 99.99%) powder. 57 electrophotographic photoreceptors were produced.

Comparative Example 32 Comparative Example 32 was prepared in the same manner as in Example 56, except that the first intermediate layer was not provided in Example 56, the thickness of the second intermediate layer was 25 μm, and the film was dried and cured at 130° C. for 60 minutes. An electrophotographic photoreceptor was created.

Examples 58 to 59 The same procedure as in Example 55 was carried out except that in Example 56, the titanium carbide/resin capacity ratio of the first intermediate layer was changed to 1.3/1 and 2.7/1, respectively. Electrophotographic photoreceptors of Examples 58 to 59 were prepared.

Comparative Examples 33 to 34 The same procedure as in Example 56 was carried out except that the titanium carbide/resin capacity ratio of the first intermediate layer was changed to 0.7/1 and 3.6/1, respectively. Electrophotographic photoreceptors of Comparative Examples 33 and 34 were prepared.

Example 60 Example 60 was carried out in the same manner as in Example 46, except that the titanium oxide in the second intermediate layer of Example 46 was replaced with zirconium oxide (manufactured by Furuuchi Chemical Co., Ltd.: purity 99.99%) powder. An electrophotographic photoreceptor was prepared.

Example 61 Example 60 was carried out in the same manner as in Example 47 except that the titanium oxide in the second intermediate layer of Example 47 was replaced with zirconium oxide (manufactured by Furuuchi Chemical Co., Ltd.: purity 99.99%) powder. An electrophotographic photoreceptor was prepared.

Comparative Example 35 Comparative Example 35 was prepared in the same manner as in Example 60, except that the first intermediate layer was not provided, the second intermediate layer had a thickness of 25 μm, and was dried and cured at 130° C. for 60 minutes. Electrophotographic exposure was created.

Examples 62 to 63 The same procedures as in Example 60 were repeated except that the titanium carbide/resin capacity ratio of the first intermediate layer was changed to 1.3/1 and 2.7/1, respectively. Electrophotographic photoreceptors of Examples 62 and 63 were produced.

Comparative Examples 36 to 37 The same procedure as in Example 60 was carried out except that the titanium carbide/resin capacity ratio of the first intermediate layer was changed to 0.7/1 and 3.6/1, respectively. Electrophotographic photoreceptors of Comparative Examples 36 and 37 were prepared.

Example 64 The same procedure as in Example 46 was carried out except that the titanium oxide used in the second intermediate layer in Example 46 was replaced with silicon oxide (manufactured by Kojundo Kagaku Co., Ltd.: purity 99.99%) powder. An electrophotographic photoreceptor of Example 64 was prepared.

Example 65 The same procedure as in Example 47 was carried out except that the titanium oxide used in the second intermediate layer in Example 47 was replaced with silicon oxide (manufactured by Kojundo Kagaku Co., Ltd.: purity 99.99%) powder. An electrophotographic photoreceptor of Example 65 was prepared.

Comparative Example 38 Comparative Example 38 was carried out in the same manner as in Example 64, except that the first intermediate layer was not provided, the second intermediate layer had a thickness of 25 μm, and was dried at 130° C. for 60 minutes. An electrophotographic photoreceptor was prepared.

Examples 66 to 67 The same procedure as in Example 64 was carried out except that the titanium carbide/resin capacity ratio of the first intermediate layer was changed to 1.3/1 and 3.6/1, respectively. Electrophotographic photoreceptors of Examples 66 and 67 were prepared.

Comparative Examples 39 to 40 The same procedure as in Example 64 was carried out except that the titanium carbide/resin capacity ratio of the first intermediate layer was changed to 0.7/1 and 3.6/1, respectively. Electrophotographic photoreceptors of Comparative Examples 39 to 40 were prepared.

[0129] As in Example 1, the photoreceptor characteristics of each of the electrophotographic photoreceptors prepared as described above were measured using an electrostatic copying paper tester (SP-428 manufactured by Kawaguchi Electric Seisakusho). The results are shown in Table 4.

[0130]

[Table 4-(1)]

[0131]

[Table 4-(2)]

[0132]

[Effects] The electrophotographic photoreceptor of the present invention has the above structure, and since the first intermediate layer and the second intermediate layer having a specific composition are provided between the substrate and the photoconductive layer, defects on the substrate can be prevented. An electrophotographic photoreceptor using an intermediate layer that can be sufficiently hidden has high sensitivity, and even after repeated charging and exposure, there is no delay in the rise of the charging potential, and the increase in residual potential is small. It has great effects. Further, according to the electrophotographic photoreceptor of the present invention, it is possible to prevent abnormal images from occurring due to light interference even in exposure using coherent light from a laser printer or the like.

Claims (5)

[Claims] Claim 1: An electrophotographic photoreceptor comprising a photoconductive layer provided on a substrate, the main components being a metal oxide or titanium carbide powder and a binder resin between the substrate and the photoconductive layer; A first intermediate layer is provided in which the ratio of binder resin used is within the range of 1/1 to 3/1 by volume, and a white pigment and a binder resin are provided as main components on the first intermediate layer. An electrophotographic photoreceptor comprising a second intermediate layer. 2. The electrophotographic photoreceptor according to claim 1, wherein the metal oxide or titanium carbide powder is indium oxide or tin oxide. 3. The electrophotographic photoreceptor according to claim 2, wherein the tin oxide is surface-treated with antimony. 4. The electrophotographic photoreceptor according to claim 1, wherein the white pigment is titanium oxide, calcium oxide, calcium fluoride, magnesium oxide, zirconium oxide or silicon oxide. 5. The electrophotographic photoreceptor according to claim 1, wherein the photoconductive layer comprises a charge generation layer and a charge transport layer.