JPH1115183A - Electrophotographic photoreceptor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve electric characteristics and image characteristics under all the environments ranging from high temperature and high humidity to low temperature and low humidity by incorporating titanium oxide grains coated with an organic compound and a polyamide copolymer comprising specified diamine units as structural units into an undercoat layer. SOLUTION: The undercoat layer contains the titanium oxide grains surface- treated with an organosilicon compound and the polyamide copolymer comprising the diamine units as the structural units each represented by the formula in which each of A and B is, independently, an optionally substituted cyclohexyl ring; and each of R<1> and R<2> is, independently, an H atom or an alkyl or alkoxy or aryl group. The titanium oxide surface-treated with the organosilicon compound is manufactured by a process for measuring the organosilicon compound and titanium oxide and feeding them into a pulverizer or a process for dissolving the organosilicon compound in a proper solvent and adding this solution into a titanium oxide slurry and well stirring until uniformly attaching the organosilicon compound to the titanium oxide and then drying them.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an electrophotographic photosensitive member having an undercoat layer. More specifically, the present invention relates to an electrophotographic photosensitive member having good electric characteristics and image characteristics.

[0002]

2. Description of the Related Art Conventionally, inorganic photoconductive materials such as selenium, selenium-tellurium alloy, arsenic selenide, and cadmium sulfide have been widely used for electrophotographic photoreceptors. On the other hand, in recent years, studies using an organic photoconductive material which has low pollution and is easy to manufacture for a photosensitive layer have been actively conducted. In particular, a laminated photoreceptor comprising a charge generation layer and a charge transfer layer in which the function of generating light by absorbing light and the function of transporting the generated charge are separated has become mainstream. These photoconductors are widely used in fields such as copying machines and laser printers.

The basic structure of an electrophotographic photosensitive member is one in which a photosensitive layer is formed on a conductive support. Injection of charge from the support, elimination of image defects due to defects in the support, and improvement of adhesion to the photosensitive layer are performed by providing an undercoat layer between the photosensitive layer and the support in order to improve chargeability. ing. Conventionally,
As the undercoat layer, for example, polyvinyl methyl ether, poly-N-vinyl imidazole, polyethylene oxide, ethyl cellulose, methyl cellulose, ethylene-acrylic acid copolymer, polyamide, casein, gelatin, polyethylene, polyester, phenol resin, vinyl chloride- Vinyl acetate copolymer, epoxy resin, polyvinylpyrrolidone, polyvinylpyridine, polyurethane,
It is known to use resin materials such as polyglutamic acid and polyacrylic acid. Among these resin materials, soluble polyamide resins are particularly preferred (JP-A-51-114132, JP-A-52-25638, and JP-A-56-25638).
-21129). More preferably, a copolyamide having a diamine component represented by the following general formula (I ') as a constituent component has been proposed (see JP-A-4-31870).

[0004]

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(Wherein, R ¹ , R ² , R ³ , R ⁴ , R ⁵ and R ⁶ each independently represent a hydrogen atom, a methyl group or an ethyl group.) Further, an inorganic material is dispersed in a polyamide resin. As the undercoat layer, for example, a layer in which titanium oxide and tin oxide are dispersed in 8-nylon (see JP-A-62-280864) and a layer in which alumina-treated titanium oxide is dispersed in a polyamide resin have been proposed. (JP-A-2-181158)
Reference).

[0006]

When these undercoat layers are used, however, the electrical characteristics or the image characteristics have a large environmental dependency, and it is difficult to satisfy both of them. For example, in the case of using the undercoating layer described in Japanese Patent Application Laid-Open No. 62-258471, the larger the film thickness, the better the image characteristics. However, the residual potential, on the other hand, sharply increases especially in a low temperature and low humidity environment. Getting worse. On the other hand, when the thickness was reduced, the residual potential was improved, but image defects could not be sufficiently eliminated.

Therefore, when, for example, fine particles of titanium oxide having no surface treatment are dispersed as a conductive agent, the residual potential in a low-humidity environment is certainly improved, but on the contrary, image characteristics under high-temperature and constant-humidity conditions deteriorate. As a result, even if the film thickness was increased, it could not be sufficiently improved. The same applies to those in which titanium oxide subjected to alumina surface treatment is dispersed. SUMMARY OF THE INVENTION An object of the present invention is to improve the electrical characteristics and image characteristics of an electrophotographic photoreceptor in all environments from high temperature and high humidity to low temperature and low humidity.

[0008]

The inventors of the present invention have conducted intensive studies on an undercoating material which can satisfy the above-mentioned required characteristics. As a result, at least the undercoating material containing the surface-treated titanium oxide particles of an organosilicon compound and a specific copolymerized polyamide are contained. We have found that the undercoat layer is very effective and arrived at the present invention.
That is, the gist of the present invention is to provide an organic electrophotographic photoreceptor having at least an undercoat layer and a photosensitive layer on a conductive substrate, wherein the undercoat layer comprises at least an organosilicon compound surface-treated titanium oxide particle and the following general formula (I): An electrophotographic photoreceptor comprising a copolymerized polyamide having the diamine component shown as a constituent component.

[0009]

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Each independently represents a cyclohexyl ring which may have a substituent, and R ¹ and R ² each independently represent hydrogen, an alkyl group, an alkoxy group, or an aryl group. )

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.
In the present invention, as the conductive support, for example, a support made of a metal such as aluminum, stainless steel, copper, nickel or the like, or a film of polyester, paper, glass or the like on an insulating substrate such as aluminum, copper, palladium, tin oxide And a conductive layer made of indium oxide or the like. Above all, it is desirable that an endless pipe made of metal such as aluminum is cut into an appropriate length. The surface of the conductive support can be subjected to various treatments such as an oxidation treatment and a chemical treatment within a range that does not affect the image quality.

The surface-treated titanium oxide of an organosilicon compound can be produced by the following production method. That is, a method of coating the organic silicon compound and titanium oxide while supplying them while measuring them in a pulverizer, or adding an organic silicon compound solution dissolved in an appropriate solvent to the titanium oxide slurry so that the organic silicon compound is uniformly attached. And then dry it.

As the organosilicon compound, siloxane compounds such as dimethylpolysiloxane and methylhydrogenpolysiloxane are preferable, and methylhydrogenpolysiloxane is particularly preferable in terms of properties and solution stability. The amount of the organic silicon compound to be coated depends on the particle size of the titanium oxide, but is preferably adjusted to about 0.1 to 10% by weight based on the titanium oxide. In particular, 0.2 to 5% by weight is preferable.

The titanium oxide used preferably has a primary particle size of 100 nm or less,
m is particularly preferred. The particle size may be uniform or a composite system with different particle sizes. For example, a mixture of 0.1 μm and a combination of 0.03 μm may be used. Either crystalline or amorphous titanium oxide can be used. In the case of crystalline titanium oxide, any of anatase, rutile, and brookite may be used, but rutile is generally used. The titanium oxide coated with the organosilicon compound in the present invention may be an untreated titanium oxide or a titanium oxide coated with an inorganic substance such as alumina, silica, zirconia, or the like. As the binder resin, a copolyamide resin having a diamine component represented by the above general formula (I) as a constituent component is used.

The number average molecular weight of the copolymerized polyamide is 10,000 to 50,000, more preferably 15.0.
00 to 35,000. If the ratio is out of this range, there may be a problem in applicability and retention. Also, with the above structure,
More preferably, the amide group is at the para-position, and the other groups are a hydrogen atom, a methyl group and an ethyl group.
The copolymerized polyamide may contain other diamine components usually used, for example, 1,6-diaminohexane and the like, and also contain an aminocarboxylic acid component, for example, a caprolactam ring-opening polymerization component and the like. May be. The dicarboxylic acid component is not particularly limited and may be any of those commonly used for polyamides, for example, HOOC (CH ₂ ) ₄ COOH, HOOC (CH ₂ )
₈ COOH, HOOC (CH ₂ ) ₁₀ COOH, HOOC
And polymethylene dicarboxylic acids such as (CH ₂ ) ₁₈ COOH.

Next, the ratio of the titanium particles to the copolyamide can be arbitrarily selected, but from the viewpoint of the stability and properties of the liquid, 0.5 to 6 parts by weight to 1 part by weight of the copolyamide. Is preferable. The undercoat layer is mainly composed of an organosilicon compound titanium oxide and a copolyamide resin, but if necessary, other surface-treated titanium oxide, titanium oxide without surface treatment, an antioxidant, an additive, a conductive agent, and the like. May be added.

If the thickness of the undercoat layer is too small, the effect on local charging failure is not sufficient. On the other hand, if the thickness is too large, the residual potential increases, or the adhesive strength between the conductive substrate and the photosensitive layer. Cause a decrease in The thickness of the undercoat layer of the present invention is 0.1 to 10 μm, more preferably 0.3 to 5 μm.
It is desirable to use it. In order to obtain a coating solution in which the organosilicon compound-coated titanium oxide is dispersed in the copolymerized polyamide resin solution, the organosilicon compound-coated titanium oxide is added to the copolymerized polyamide resin solution, and a ball mill, a sand mill, a roll mill, a paint shaker, an attritor, What is necessary is just to process by means, such as an ultrasonic wave. The undercoat layer may be applied by any coating method as long as it can be applied to some extent, but is generally applied by dip coating, spray coating, nozzle coating, or the like.

A photosensitive layer is formed on the undercoat layer. The photosensitive layer may have a single-layer structure, but is preferably a laminated structure in which a charge generation layer and a charge transport layer are separated. When the photosensitive layer has a single-layer structure, a known material in which a photosensitive material is dispersed in a binder material is used. For example, dye-sensitized ZnO
Examples include a photosensitive layer, a CdS photosensitive layer, and a photosensitive layer in which a charge generating substance is dispersed in a charge transporting substance. When the photosensitive layer has a laminated structure, a charge generation layer and a charge transport layer are formed on the undercoat layer.

Examples of the charge generating material used in the charge generating layer include selenium and its alloys, arsenic-selenium, cadmium sulfide, zinc oxide, other inorganic photoconductive materials, phthalocyanine, azo dyes, quinacridone, polycyclic quinone, and pyrylium salts. And various organic pigments such as indigo, thioindigo, anthantrone, pyranthrone and cyanine. Among them, metals such as metal-free phthalocyanine, copper, indium chloride, gallium chloride, tin, oxytitanium, zinc, vanadium, or oxides, phthalocyanines coordinated with chloride, azo pigments such as monoazo, bisazo, trisazo, and polyazos Is preferred. Among them, particularly preferred is titanyl phthalocyanine.

The charge generation layer can be obtained by coating and drying a coating solution obtained by dissolving or dispersing fine particles of these substances and a binder polymer in a solvent. Examples of the binder include polymers and copolymers of vinyl compounds such as styrene, vinyl acetate, vinyl chloride, acrylate, methacrylate, vinyl alcohol, and ethyl vinyl ether, polyvinyl acetal, polycarbonate, polyester, polyamide, polyurethane, and cellulose ether. Phenoxy resin, silicon resin, epoxy resin and the like.

The ratio between the charge generating substance and the binder polymer is not particularly limited, but is generally 5 to 500 parts by weight, preferably 20 to 30 parts by weight, per 100 parts by weight of the charge generating substance.
0 parts by weight of binder polymer are used. Further, the charge generation layer may be a deposited film of the above-described charge generation substance. The thickness of the charge generation layer is 0.05 to 5 μm, preferably 0.1 to 5 μm.
２2 μm.

The charge transfer layer is mixed with a known polymer having excellent performance as a binder on the charge generation layer, dissolved in a suitable solvent together with the charge transfer material, and if necessary, an electron withdrawing compound. Alternatively, it can be produced by applying a coating liquid obtained by adding a plasticizer, a pigment or other additives. The thickness of the charge transfer layer is usually in the range of 10 to 50 μm, preferably 13 to 35 μm. As the charge transfer material in the charge transfer layer,
High molecular compounds such as polyvinylcarbazole, polypinylpyrene, and polyacenaphthylene, or low molecular compounds such as various pyrazoline derivatives, oxazole derivatives, hydrazone derivatives, stilbene derivatives, and arylamine derivatives can be used.

As the binder polymer, a polymer having good compatibility with the above-mentioned charge transfer material and not causing crystallization or phase separation of the charge transfer material after forming a coating film is preferable. Examples of such are styrene, vinyl acetate, vinyl chloride, acrylates, methacrylates,
Examples thereof include polymers and copolymers of vinyl compounds such as vinyl alcohol and ethyl vinyl ether, polyvinyl acetal, polycarbonate, polyester, polysulfone, polyphenylene oxide, polyurethane, cellulose ester, cellulose ether, phenoxy resin, silicon resin, epoxy resin and the like.

Examples of the electron-withdrawing compound include cyano compounds such as tetracyanoquinodimethane, dicyanoquinomethane, and aromatic esters having a dicyanoquinovinyl group;
Nitro compounds such as 4,6-trinitrofluorenone, condensed polycyclic aromatic compounds such as perylene, diphenoquinone derivatives, quinones, aldehydes, ketones, esters,
Acid anhydrides, phthalides, metal complexes of substituted and unsubstituted salicylic acids, metal salts of substituted and unsubstituted salicylic acids, metal complexes of aromatic carboxylic acids, and metal salts of aromatic carboxylic acids. Preferably, cyano compounds, nitro compounds, condensed polycyclic aromatic compounds, diphenoquinone derivatives, metal complexes of substituted and unsubstituted salicylic acids, metal salts of substituted and unsubstituted salicylic acids, metal complexes of aromatic carboxylic acids, aromatic carboxylic acids It is preferable to use a metal salt. Further, the photosensitive layer of the electrophotographic photoreceptor of the present invention contains well-known plasticizers, antioxidants, ultraviolet absorbers, and leveling agents to improve film formability, flexibility, coatability, and mechanical strength. It may be. Needless to say, the photoreceptor thus formed may have an adhesive layer, an intermediate layer, a transparent insulating layer, and the like, if necessary.

[0025]

The present invention will be described below in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these without departing from the gist thereof. Note that “parts” used in the examples indicates “parts by weight” unless otherwise specified. Preparation of Dispersion Liquid (P1) Methyl hydrogen polysiloxane surface-treated titanium oxide was first produced as titanium oxide by Ishihara Sangyo Co., Ltd., product name TTO
-55N (crystalline rutile primary particle size 0.03 to 0.0
5 μm), and the surface was uniformly coated with methyl hydrogen polysiloxane at 3% by weight.

Next, the obtained titanium oxide treated with methyl hydrogen polysiloxane and the mixed alcohol (methanol / 1-propanol = 7/3) were dispersed in a ball mill for 16 hours. The titanium oxide dispersion obtained here is described in JP-A-4-31.
870 was added to a mixed alcohol (methanol / 1-propanol = 70/30) solution of a random copolymerized polyamide having the following structure, which was produced by the production method described in Examples of JP-A-870. Finally 3/1 titanium oxide / nylon ratio
(Weight ratio) to prepare a dispersion having a solid concentration of 16% by weight,
This was designated as dispersion liquid (P).

[0027]

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Preparation of Dispersion (P2) A dispersion was prepared in exactly the same manner as the dispersion (P1) except that the treatment amount of methylhydrogenpolysiloxane was 2% by weight, to obtain a dispersion (P2). Preparation of Dispersion (P3) Product name: TTO-55S (manufactured by Ishihara Sangyo Co., Ltd.) In a cyclohexanone solution and 1 in a ball mill dispersion.
Dispersed for 6 hours. The titanium oxide dispersion obtained here is added to a mixed alcohol (methanol / 1-propanol = 70/30) solution of the copolymerized polyamide, and finally, the solid content concentration is determined using titanium oxide / nylon = 2/1 (weight ratio). A dispersion of 15% by weight was prepared, and this was designated as a dispersion (P3).

Preparation of Dispersion (Q) Using titanium oxide without surface treatment (the same as that used for the preparation of dispersion (P) described above), the dispersion preparation (P) Similarly, a dispersion having a titanium oxide / nylon ratio of 1.5 / 1 (weight ratio) and a solid content concentration of 10% by weight was prepared to obtain a dispersion (Q). Preparation of Dispersion (R) Titanium Oxide with Alumina Surface Treatment (Ishihara Sangyo Co., Ltd.)
In the same manner as for the dispersion (P) using the product name TTO-55A), a titanium oxide / nylon ratio of 2/1 (weight ratio),
A dispersion having a solid concentration of 10% by weight was prepared, and the dispersion (R) was prepared.
And

Preparation of Dispersion (S) Titanium oxide TTO-55N manufactured by Ishihara Sangyo Co., Ltd. is coated with 6% by weight of zirconia, and alumina is further coated with 9% by weight.
Using the applied titanium oxide, a dispersion having a titanium oxide / nylon ratio of 1.5 / 1 (weight ratio) and a solid concentration of 10% by weight was prepared in the same manner as the dispersion (P). S). Preparation of Dispersion (T) Dispersion (P) was prepared by using titanium oxide obtained by applying 9% by weight of silica to titanium oxide TTO-55N manufactured by Ishihara Sangyo Co., Ltd. and further applying 6% by weight of alumina thereon. A dispersion having a titanium oxide / nylon ratio of 1.5 / 1 (weight ratio) and a solid concentration of 10% by weight was prepared in exactly the same manner as in the above to prepare a dispersion (T). Preparation of Dispersion (U) A dispersion having a titanium oxide / nylon ratio of 1/1 (weight ratio) and a solid content concentration of 9% by weight was prepared by the same preparation method of titanium oxide and dispersion (Q). Then, a dispersion liquid (U) was obtained.

Example 1 An outer diameter of 30 m having a mirror-finished surface was added to the dispersion liquid (P1).
m, an aluminum cylinder having a length of 254 mm and a thickness of 1.0 mm is applied by dip coating, and its dry film thickness is 0.75 μm.
m was provided with an undercoat layer. Next, 10 parts of oxytitanium phthalocyanine showing a powder X-ray spectrum pattern by CuKα ray as shown in FIG. 1 and polyvinyl butyral (trade name # 6000, manufactured by Denki Kagaku Kogyo KK)
-C) 500 parts of 1,2-dimethoxyethane was added to 5 parts, and the mixture was pulverized and dispersed by a sand grind mill.
An aluminum cylinder provided with an undercoat layer was dip-coated on this dispersion, and its dry film thickness was 0.3 g / m2.
^The charge generation layer was provided so as to be ² (about 0.3 μm).
Next, this aluminum cylinder was mixed with 56 parts by weight of a hydrazone compound shown below.

[0032]

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14 parts by weight of the following hydrazone compound:

[0034]

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And 1.5 parts by weight of the following cyan compound

[0036]

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100 parts of the following polycarbonate resin (monomer molar ratio: 1: 1) having two repeating structural units, which is produced by the production method described in Examples of JP-A-3-221962.

[0038]

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By dip-coating a solution obtained by dissolving the compound in a mixed solvent of 1,4-dioxane and tetrahydrofuran,
The charge transfer layer was provided so that the dry film thickness was 17 μm.
The drum thus obtained is referred to as a photoconductor A1. Example 2 Same as Example 1 except that the aluminum cylinder used in Example 1 was dip-coated with the dispersion liquid (P2), and an undercoat layer was provided so that the dry film thickness was 0.75 μm. To obtain a photoreceptor. The drum thus obtained is designated as A2.

Example 3 A3 was used as the photosensitive drum obtained in exactly the same manner as in Example 2 except that the undercoating dispersion of Example 2 was changed to (P3). Comparative Example 1 The same as Example 1 except that the aluminum cylinder used in Example 1 was dip-coated with the dispersion liquid (Q), and an undercoat layer was provided so that the dry film thickness was 0.5 μm. To obtain a photoreceptor. The drum thus obtained is designated as B1. Comparative Example 2 Same as Example 1 except that the aluminum cylinder used in Example 1 was dip-coated with the dispersion liquid (Q), and an undercoat layer was provided so that the dry film thickness was 1.0 μm. To obtain a photoreceptor. The drum thus obtained is designated as B2.

Comparative Example 3 The same procedure as in Example 1 was carried out except that the aluminum cylinder used in Example 1 was dip-coated with the dispersion (Q), and an undercoat layer was provided so that the dry film thickness was 1.5 μm. In the same manner as in Example 1, a photoconductor was obtained. The drum thus obtained is designated as B3. Comparative Example 4 The same as Example 1 except that the aluminum cylinder used in Example 1 was dip-coated with the dispersion liquid (R), and an undercoat layer was provided so that the dry film thickness was 0.5 μm. To obtain a photoreceptor. The drum thus obtained is designated as B4.

Comparative Example 5 The same procedure as in Example 1 was carried out except that the aluminum cylinder used in Example 1 was dip-coated with the dispersion liquid (R), and an undercoat layer was provided so that the dry film thickness was 1.0 μm. In the same manner as in Example 1, a photoconductor was obtained. The drum thus obtained is designated as B5. Comparative Example 6 Same as Example 1 except that the aluminum cylinder used in Example 1 was dip-coated with the dispersion liquid (S), and an undercoat layer was provided so that the dry film thickness became 1.0 μm. To obtain a photoreceptor. The drum thus obtained is designated as B6.

Comparative Example 7 The procedure of Example 1 was repeated except that the aluminum cylinder used in Example 1 was dip-coated with the dispersion liquid (T), and an undercoat layer was provided so that the dry film thickness was 1.0 μm. In the same manner as in Example 1, a photoconductor was obtained. The drum thus obtained is designated as B7. Comparative Example 8 A photoconductor B8 was obtained in the same manner as in Example 1, except that the undercoat layer was not provided. Comparative Example 9 Same as Example 1 except that the aluminum cylinder used in Example 1 was dip-coated with the dispersion liquid (U), and an undercoat layer was provided so that the dry film thickness was 0.75 μm. To obtain a photoreceptor. The drum thus obtained is designated as B9.

Evaluation Next, these photoreceptors were commercialized using a laser printer (HE
LASER JET made by WLETT PACKARD
4 Plus), a white background image was obtained under each environment, and image evaluation was performed. The results are shown in Table 1.
In the photoconductors A1, A2, and A3 of the examples, good images were obtained in any environment of temperature / humidity of 5 ° C./10%, 25 ° C./50° C., and 35 ° C./85%. As for the photosensitive member of Comparative Example, only B9 provided a good image under each environment.

In the photosensitive member B1 of Comparative Example 1, many minute black spots appeared on the white background image under any environmental conditions. In the photosensitive members B2 and B3 of Comparative Examples 2 and 3, the temperature / humidity was 35 ° C. /
Many minute black spots appeared on the white background image under the environmental condition of 85%. In the photoconductors B4 and B5 of Comparative Examples 4 and 5, a large number of minute black spots appeared on the white background image under the environmental conditions of temperature / humidity of 25 ° C./50% and 35 ° C./85%. In the photoconductors B6 and B7 of Comparative Examples 6 and 7, many small black spots appeared on the white background image under the environmental condition of the temperature / humidity of 35 ° C./85%. In the photoconductor B8 of Comparative Example 8, the temperature / humidity was particularly 5 ° C./15%, 25
Under the environment of ° C./50%, many minute black spots appeared on a white background image.

[0046]

[Table 1]

Next, these electrophotographic photoreceptors were mounted on a photoreceptor characteristic measuring instrument, charged to a surface potential of -700 V, and then irradiated with 780 nm light. The potential holding ratio after being charged to 700 V and left for 5 seconds and the residual potential after removing the 660 nm LED light were measured. Table 2 shows the results.

[0048]

[Table 2]

The photoconductors A1, A2 and A3 of the present invention have a temperature / humidity of 5 ° C./10%, 25 ° C./50%, 35 ° C./85.
% Environment, the half-exposure amount is equivalent to that of the photoconductor B8 having no undercoat layer, and the potential holding ratio is
Slightly better, the rise in the residual potential is small and almost equal. Under each environment, the photoreceptor B9, which has good image characteristics, has a 10% increase in residual potential at 5 ° C. as compared with the photoreceptor of the example, and has a problem in characteristics at low temperature and low humidity.

From the above results, it can be determined that the electrophotographic photoreceptor of the present invention has very excellent performance. Further, the P3 coating solution (treated with dimethylpolysiloxane) in the example cannot be obtained as a good dispersion unless the high boiling point cyclohexanone-based solvent is mixed, and the storage stability is poor. The coating solution of siloxane or titanium silicate can be dispersed only with a low-boiling alcohol solvent, and has excellent storage stability.

[0051]

The electrophotographic photoreceptor using the undercoat layer according to the present invention has good electric and image characteristics in all environments from high temperature and high humidity to low temperature and low humidity, and has good chargeability and the photosensitive layer and the conductive substrate. Adhesion with is improved and excellent. In particular, in the case of methyl hydrogen siloxane treatment, the storage stability of the coating solution is also good.

Claims (4)

[Claims] An electrophotographic photoreceptor having at least an undercoat layer and a photosensitive layer on a conductive substrate, wherein the undercoat layer is coated with titanium oxide particles coated with an organosilicon compound; An electrophotographic photoreceptor comprising a copolyamide having the diamine component shown as a constituent component. Embedded image Each independently represents a cyclohexyl ring which may have a substituent, and R ¹ and R ² each independently represent hydrogen, an alkyl group, an alkoxy group, or an aryl group. ) 2. The titania particles having an average primary particle diameter of 1
The electrophotographic photoreceptor according to claim 1, having a thickness of not more than 00 nm (as measured from a TEM photograph). 3. The electrophotographic photoreceptor according to claim 1, wherein the organosilicon compound is methyl hydrogen polysiloxane. 4. The electrophotographic photoreceptor according to claim 1, wherein the charge generation layer contains a phthalocyanine compound.