JPH04178652A - Electrophotographic sensitive body with photosensitive layer containing polysilane compound - Google Patents

Abstract

PURPOSE:To obtain a sensitive body having superior electrophotographic characteristics durability and repetitive characteristics by forming a photosensitive layer contg. a polysilane compd. represented by a specified formula and a high molecular resinous compd. having a specified dissolution parameter delta. CONSTITUTION:A photosensitive layer contg. a polysilane compd. represented by the formula and a high molecular resinous compd. having 8.0-10.0 dissolution parameter delta is formed to obtain a sensitive body. In the formula, R1 is 1 or 2C alkyl, R2 is 3-8C alkyl, cycloalkyl, etc., R3 is 1-4C alkyl, R4 is 1-4C alkyl, each of A and A' is 4-12C alkyl, cycloalkyl, etc., (n) and (m) show the molar ratio between monomers in the polymer, n+m=1, 0<n<=1 and 0<=m<1. The high molecular resinous compd. may be polystyrene, polymethyl methacrylate or a mixture of two or more kinds of such polymers.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of the Invention] The present invention relates to an electrophotographic photoreceptor, and more particularly to an electrophotographic photoreceptor having an organic photoconductor made of a polysilane compound, which provides improved electrophotographic properties. It is something.

[Description of prior art]

Conventionally, various organic photoconductive polymers such as polyvinylcarbazole have been proposed as photoconductive materials for use in electrophotographic photoreceptors, but these polymers have poor film formability and light weight compared to inorganic photoconductive materials. Despite its superior properties in terms of properties, it has been difficult to put it into practical use until now because it has not yet achieved sufficient film-forming properties, and due to sensitivity, durability, and environmental changes. In terms of stability, inorganic light Nl
This was because it was inferior to electrical materials. Additionally, hydrazone compounds disclosed in U.S. Pat. No. 4,150,987, etc., triarylpyrazoline compounds disclosed in U.S. Pat. No. 3,837,851, etc., and JP-A-51-948
Low-molecular organic photoconductors such as 9-styrylanthracene compounds described in JP-A No. 28, JP-A-51-94829, etc. are used as uX. By appropriately selecting the binder used, such low-molecular-weight organic photoconductors can overcome the drawbacks of film-forming properties that had been a problem in the field of organic photoconductive polymers. It cannot be said that the sensitivity is sufficient.

In recent years, studies have been conducted on the use of polysilane compounds to solve these problems.

By the way, polysilane is reported to be insoluble in solvents [The Journal of the American Chemical Society, 2291p (1924)].
Subsequently, it was reported that polysilane is soluble in solvents and can be easily formed into films [The General, Offical, American Ceramic Society, Volume 1, 50].
4pp (1978): i, began to attract attention.

In addition, polysilane has the property of a photosemiconductor in which charge can be transferred through the σ-bonds in its main chain [Physical Review, B, Yoj, 28+8pp (1987)], and its application in electrophotographic photoreceptors is also expected. It became so. However, in order to be applied to such electrophotographic photoreceptors, polysilane compounds must not only be soluble in solvents and capable of forming films, but also be capable of forming films without minute defects and with high homogeneity. becomes. Since minute defects are not tolerated in electrophotographic photoreceptors, high-quality polysilane compounds are required that have clear structures for substituents and do not cause abnormalities in film formation.

Although there have been various reports on the synthesis of polysilane compounds, there are still problems with their use in electrophotographic photoreceptors. Among low-molecular-weight polysilane compounds, a structure in which all Si groups are substituted with lI groups has been reported.
Journal of American Chemical Society
mical 5octety), ■±, (11), 38
06pp, (1972), Japanese Patent Publication No. 61-38033].

The structure described in the former publication has a structure in which the terminal group of dimethylsilane is substituted with a methyl group, and the structure described in the latter publication has a structure in which the terminal group of dimethylsilane is substituted with an alkoxy group. Also, the degree of polymerization is 2 to 6, and does not exhibit the characteristics of a polymer.

In other words, due to its low molecular weight, it does not have film-forming ability as it is, making it difficult to use industrially. A high molecular weight polysilane compound that has I in all Si groups! Structures with substituted groups have recently been reported [Nikkei New Materials, August 1
5th issue, page 46 (2988)). However, because it involves a special reaction intermediate, it is expected that the synthesis yield will decrease, making industrial mass production difficult.6 In addition, the method for synthesizing polysilane compounds was
Of Organometallic Chemistry+, 198pp
, C27 (1980) or The Middle School Office
Polymer Science, Polymer Chemistry Edition, Vol. 22゜159-170pp (19
84). However, all of the reported synthesis methods involve only a condensation reaction of the polysilane main chain;
There is no mention of terminal groups, and in all synthetic methods, unreacted chloro groups and byproducts are produced due to side reactions, making it difficult to consistently obtain the desired polysilane compound.

Examples of using the above-mentioned borinlane compounds as photoconductors have also been reported (U.S. Pat. Nos. 4,61.8, 5).
51, US Pat. No. 4,772,525, and JP-A-62-269964), the influence of unreacted chloro groups and by-products due to side reactions is presumed.

In U.S. Pat.
～・5oov is fine, but the surface potential is abnormally high -1,0
OOV is used. This is thought to be because, at a normal potential, structural defects in polysilane cause defects in the electrophotographic photoreceptor, which eliminates the spot-like abnormal phenomenon in the image knee.

In addition, in JP-A-62-269964, an electrophotographic photoreceptor was prepared using the above polysilane compound and its photosensitivity was measured, but the photosensitivity was slow, and conventionally known selenium photoreceptors and organic It has no advantages over photoreceptors.

Furthermore, the film quality of these polysilanes was poor in solubility and abrasion resistance, and when used as an electrophotographic photoreceptor, the durability was extremely poor.

Many problems still remain in using polysilane for such electronic materials, and the reality is that industrially usable polysilane has not yet been provided as a leading electric material.

[Purpose of the invention]

An object of the present invention is to solve the above-mentioned problems and provide an electrophotographic photoreceptor with excellent electrophotographic properties, durability, and repeatability.

[Structure and effects of the invention]

An object of the present invention is to provide an electrophotographic photoreceptor having a photosensitive layer on a conductive support, in which the photosensitive layer has the following general formula [1].
This is achieved by comprising a layer containing a polysilane compound represented by and a polymer resin compound having a solubility parameter δ of 8.0 to 10.0.

R, Rx A --(-Si-Chi1-Hi+"-A'...
(1) R2R4 [However, in the formula, R is an alkyl group having 1 or 2 carbon atoms, R
1 is an alkyl group having 3 to 8 carbon atoms, a cycloalkyl group,
Aryl group or aralkyl group, R5 is an alkyl group having 1 to 4 carbon atoms, R4 is an alkyl group having 1 to 4 carbon atoms, A and A' are an alkyl group having 4 to 12 carbon atoms, and a cycloalkyl group, respectively. , an aryl group or an aralkyl group, and both may be the same or different.

n and m are molar ratios indicating the proportion of the number of each monomer to the total monomers in the polymer, n + rn =
1, and Q<, 1≦1.05m<l. ] Since conventionally known polysilanes are obtained by synthesizing a polymer by removing halogen from a dichlorosilane monomer using an Na catalyst, halogen residues remain at the ends. If the end of polysilane is a halogen group, it becomes a trap for the movement of one charge in the photoreceptor,
Causes residual potential. When repeatedly charged and exposed, the residual potential increases and the bright area potential increases.
It was found that the durability was poor. Furthermore, if a CZ group remains at the end, it is decomposed by moisture or the like and generates HCI gas, which corrodes the conductive portion of the substrate in the photoreceptor, resulting in image defects due to poor conduction.

The present inventors have discovered that an electrophotographic photoreceptor with high sensitivity and high durability can be formed by shielding the terminal group of polysilane with an alkyl group, cycloalkyl group, aryl group, or aralkyl group. This point can be considered as follows. That is, if active CZ groups remain in the terminal groups of polysilane, carrier charges generated during exposure as a photoreceptor are trapped in the CA groups, generating a residual potential.

Therefore, by eliminating the Cl group from the terminal group of polysilane and shielding it with organic W or a substituent group, traps in the photoreceptor can be reduced and the residual potential during exposure can be significantly reduced. Further, the potential is stable even after repeated charging and exposure.

However, these polysilane films have insufficient solubility and abrasion resistance, and when used on electrophotographic photoreceptors that come into contact with developers, paper, and cleaning materials, polysilane films alone have insufficient durability. Become.

Therefore, as a result of intensive studies, it was found that a polymer resin having a solubility parameter similar to the value of solubility parameter 6 of polysilane is well compatible with the polysilane, and when a compatible film is used as an electrophotographic photoreceptor. It was discovered that the material has both excellent electrophotographic properties and sufficient durability.

The above "solubility parameter δ" is based on Yuji Harasaki's Basic Science of Coatings, pp. 54 to 57 (1977).
It is calculated using the F edors calculation formula described in ``Nenmaki Shoten Publishing''.

Specifically, the values of the solubility parameter δ of polysilanes are concentrated in the range of 8 to 10, and these polysilanes are compatible with many polymeric resin compounds having similar values and can form films. becomes. These resins include polystyrene, polymethyl methacrylate, polyL'yl acetate, polycarbonate, etc., all of which have a solubility parameter 6 value in the range of 8 to 10. Two or more types of these resins may be mixed depending on the case, and the types are not limited to these. Solvents that dissolve these polysilanes and resins having a specific solubility parameter of 6 are determined by the following solubility parameters:
Aromatic hydrocarbons such as toluene, benzene, and xylene, halogenated hydrocarbons such as dichloromethane, dichloroethane, chloroform, and carbon tetrachloride, and their tetrahydrofuran and dioxane are used.

j! of the electrophotographic photoreceptor of the present invention. The structure may be either a laminated type photoreceptor or a single layer type photoreceptor.

The laminated photoreceptor consists of at least a charge generation layer and a charge transport layer. The charge generation layer in this case is formed by vapor depositing a charge generation substance or by dispersing the charge generation substance in a binder resin, applying the resulting dispersion, and drying. The charge generating substances include selenium-tellurium, pyrylium, thiopyrylium dyes, phthalocyanine pigments, anthanthrone pigments, dibenzpyrenequinone pigments, vilanthrone pigments, trisazo pigments, disazo pigments, azo pigments, indigo pigments, quinacridone pigments, Asymmetric quinocyanine, quinocyanine, etc. can be used.

! The binder resin for dispersing the generated substances can be selected from a wide variety of insulating resins or organic photoconductive polymers, including polyvinyl butyral, polyvinylbenzal, polyarylate, polycarbonate, polyester,
Preferred are phenoxy resins, cellulose resins, acrylic resins, polyurethane and polysilane compounds, and how much should they be used? The content in the load-generating layer is 80% by weight or less, preferably 40% by weight or less.

The solvent used is preferably selected from those that dissolve the resin described above but do not dissolve the charge transport layer or undercoat layer described below.

Specifically, ethers such as tetrahydrofuran and 1,4-dioxane, ketones such as cyclohexanone and methyl ethyl ketone, amides such as N,N-dimethylformamide, esters such as methyl #acid and ethyl acetate, toluene, and xylene. , chlorine includes aromatics such as benzene, alcohols such as methanol, ethanol, and 2-propanol, and aliphatic halogenated hydrocarbons such as chloroform, methylene chloride, dichloroethylene, carbon tetrachloride, and trichloroethylene.

The charge generation layer is prepared by thoroughly dispersing the above charge generation substance together with 0.3 to 4 times the amount of binder resin and a solvent using a method such as a homogenizer, ultrasonic wave, ball mill, vibrating ball mill, sand mill, attritor, roll mill, etc. Coating-drying and forming. Its thickness is about 0.1 to 1 μm.

Coating methods include dip coating, spray coating, spinner coating, bead coating,
This can be carried out using a coating method such as a wire bar coating method, a blade coating method, a roller coating method, or a curtain coating method. For drying, it is preferable to dry to the touch at room temperature and then heat dry. Heat drying can be performed at 30 to 200° C. for a period of 5 minutes to 2 hours, either stationary or with ventilation.

The charge transport layer is made of the above-mentioned specific polysilane compound,
and a polymeric resin compound having a solubility parameter δΦ value of 8°0 to 10.0. Examples of the polysilane compound used include the following.

(Left below) Ω%- Part ``C, 11゜I3 CHI (012) +.+Si -3-T-(C1(
z)+. crucian carp.

Island C113 (CH2) 5-3iMo, (1□) SCI (3
CI((C1(s) t CtI (Q(3) z O12 Four Island I 01, C)+3 CH3 Island You C)13 σ3 CI'13 CHx Island CH:+ (Oh)i (Jl:+ ((Jz ) 3 ″(Siji↑纂Sitov
(CH2) sc&+] i し+3 [2I3 C)13 (C)12) 3 Note) 2.Neither X nor Y in the above structural formula indicates the kaede-polymerization position. And n is X/(X0Y), and m is Y
/ (X+Y), respectively.

Further, examples of the polymer resin compound include polystyrene, polymethyl methacrylate, polyvinyl acetate, polycarbonate, and the like. The mixing ratio of the polysilane compound and the polymer resin compound is preferably such that the borinolane ratio is 20% to 80%. If the ratio of the poly/ran compound is less than 20%, the charge transport function will be insufficient, and if it exceeds 80%, the abrasion resistance will be insufficient. The preferred proportion of the polysilane compound is 40% to 70%.

Examples of solvents used to dissolve the polysilane compound and the polymeric resin compound include henzene, toluene, xylene, dichloromethane, dichloroethane, chloroform, carbon tetrachloride, tetrahydrofuran, dioxane, and the like.

As a coating method for forming a charge transport layer using the obtained liquid, the same means as in the case of forming the charge generation layer described above can be adopted. The thickness of the charge transport layer is preferably 5
p m to 35 μm.

In the case of a single-layer photoreceptor, the charge generating substance described above is dispersed in the polysilane compound and polymer resin compound described above,
It is formed by applying and drying the resulting dispersion. The mixing ratio of each substance in the dispersion liquid is preferably 3 to 7 parts by weight of the polysilane compound and 3 to 7 parts by weight of the polymer resin compound to 1 to 10 parts by weight of the generated substance. A single-layer photoreceptor can be obtained as follows.

First, we need a charge-generating substance! Disperse together with the mollusc and the polymeric resin compound using a dispersing machine such as a ball mill, sand mill, or attritor.

Next, a polysilane compound and, if necessary, a polysilane compound! A solvent is added to create a polysilane solution in which a charge generating substance is dispersed. This solution is coated on the substrate and dried (7) to obtain a single layer type photoreceptor. In this case, the film thickness is preferably 5 μm to 35 μm.

Examples of the conductive support used in the present invention include aluminum, aluminum alloy, copper, zinc, stainless steel, titanium, nickel, indium, gold, and platinum. In addition, plastics (e.g., polyethylene, polypropylene, polyvinyl chloride, polyethylene terephthalate, acrylic resin, etc.) coated with these metals or alloys by vacuum deposition, and conductive particles (
For example, a support made of carbon blank, silver particles, etc.) coated on a plastic or metal substrate together with a suitable binder resin, or a support made of plastic or paper impregnated with conductive particles can be used.

In the electrophotographic photoreceptor of the present invention, a subbing layer having barrier and adhesive functions may be provided between the conductive support and the photosensitive layer.

The undercoat layer can be formed of casein, polyvinyl alcohol, nitrocellulose, polyamide (nylon 6, nylon 66, nylon 6102 copolymerized low iron, alkoxymethylated nylon, etc.), polyurethane, aluminum oxide, and the like.

The thickness of the subbing layer is 5 μm or less, preferably 0.1 to 3 μm.
is appropriate.

The electrophotographic photoreceptor of the present invention can be used not only in electrophotographic copying machines, but also in a wide range of electrophotographic applications such as laser beam printers, CRT printers, LED printers, liquid crystal printers, and laser plate making.

[Examples] Hereinafter, the present invention will be explained in more detail according to Examples and Comparative Examples.

""-1- An aluminum substrate was prepared. Next, chloroaluminum phthalocyanine was added to IO heavy part (1M lower part) and 5 parts of polyvinyl butyral were added to 90 parts of MEK, dispersed in a ball mill for 2 hours, coated on an aluminum substrate with a wire bar, and after drying, A charge generation layer of 1/m'' was provided.

Next, it has the following structural formula (A) and has a number average molecular weight of 2300.
5 parts of a polysilane compound with a number average molecular weight of 9800
0 and the value of the solubility parameter δ is 9.37 (value of the solubility parameter δ: 9.0), 5 parts of polystyrene (value of the solubility parameter δ: 9.0) is dissolved in toluene (value of the solubility parameter δ: 8.9), and the obtained liquid was applied onto the charge generation layer using a wire bar and dried to form a polysilane-containing layer having a thickness of 18 μm, thereby obtaining photoreceptor body 1.

CI'+3 □ Ctlz (CHz) 5 edition -5l sr (C) 12) 5C
)13 =-(A) □ This electrophotographic photoreceptor was statically charged to -5 using an electrostatic copying paper tester Model 5P-428 manufactured by Kawaguchi Denki ■, and corona charged with V, and then charged in the dark for 1 second. After holding
It was exposed to light at an illuminance of 2.5 lux and its charging characteristics were examined. Furthermore, the residual potential after strong exposure (illuminance: 20 lux·sec) was examined.

As for the charging characteristics, the surface potential (Vo) and the exposure amount (El/2> required to attenuate the potential (Vl) after 1 second of dark decay to 1/2) were measured.Also, the residual potential VSL
was measured.

Furthermore, the photoreceptor was used in a PPC copier NIP manufactured by Canon.
-3825 photosensitive drum solinder, 10,000 copies were made using the same machine, and after 10,000 copies were made, the fluctuation of the residual potential VSt was measured using 5P428.

These results are shown in Table 1.

Table 1 also shows the initial film thickness and the film thickness after copying 10,000 sheets.

A photoreceptor was prepared that was completely the same as in Example 1, and was designated as Comparative Photoreceptor 1, except that the IJ silane-containing layer did not contain polystyrene.

Further, the same evaluation as in Example 1 was performed, and the results are shown in Table 1.

1 day - 2 ↓ An aluminum cylinder of φ80 was prepared as a base. As an undercoat layer, polyamide resin (6-66-61,0
-1 part of 12, quaternary nylon copolymer) and 3 parts of 8 nylon resin (methoxymethylated 6 nylon) are dissolved in a solvent consisting of 50 parts of methanol and 40 parts of butanol to obtain a coating solution, and a dip coating method is used. After drying, a 0.5 μm subbing layer was formed on the substrate.

Next, 10 parts of a disazo pigment having the following structural formula (B), C/ci and 5 parts of polyvinyl butyral were mixed with 10 parts of cyclohexanone.
0 parts, dispersed in a ball mill for 2 hours, diluted appropriately with methyl ethyl ketone to obtain i55 raw layer coating solution, coated on the undercoat layer by dip coating method to a film thickness of 180 cm/m'' after drying, and charged. A generation layer was formed.

Next, it has the following structural formula (C) and has a number average molecular weight of 28
000 (f4 solution parameter 6
value: 9.37) 4 parts, and polymethyl methacrylate (number average molecular weight 98,000
, melting parameter 6 value 1.3) 1 part, 4 parts, and 16 parts, respectively, were dissolved in luene, diluted with the same solvent as appropriate, and applied as a coating solution onto the charge generation layer by dip coating. After drying, a polysilane-containing layer having a thickness of 18 μm was formed to obtain a photoreceptor.

The photoreceptors obtained contained 1 part, 4 parts, and 16 parts of polymethyl methacrylate.
The floor was set at 33rd floor and 4th floor.

Each of the obtained positive photoreceptors 2 to 4 was deposited on a Canon ■ copier N'P 3825, and the dark potential (Vd) was
The exposure amount (ρux-sec) required for the bright area potential (Ve) to become 150 V when set to 650 V was calculated (E
Δ500V), 10,000 copies were actually copied, and changes in V, , V, at that time were also determined. Furthermore, changes in the initial film thickness and the film thickness after copying 10,000 sheets were also determined, and these are shown in Table 2.

Comparison-1-EJ Photoreceptors were prepared in the same manner as in Examples 2 to 5, except that the mixed numbers of polymethyl methacrylate in the polysilane-containing layer were 0 parts, 0.5 parts, and 20 parts, respectively. Then, compare photoreceptor levels 2 and 2 in order. NQ3. It was set as floor 4.

Examples 2-4 for each of these comparative photoreceptors
The evaluation was carried out in the same manner as in the case of , and the results are shown in Table 2.

The charge generation layer was formed in the same manner as in Examples 2 to 4, and then a polysilane compound having the following structural formula (D) and a number average molecular weight of 18,000 (with a solubility parameter δ) was used. Mix 1 part, 4 parts, and 16 parts of bisphenol Z-type polycarbonate (number average molecule 122000. Solubility parameter δ value: 8.2) with 1 part of toluene/dichloromethane. The mixture was dissolved in a solvent of 100% and diluted appropriately with the same solvent, and coated as a coating solution on the charge generation layer by a dip coating method, and after drying, a polysilane-containing layer having a thickness of 25 μm was formed to obtain a photoreceptor.

The photoreceptors obtained were made of 1 part, 4 parts, and 16 parts of polycarbonate.
It was set at 7. These photoreceptors were evaluated in the same manner as in Examples 2 to 4, and the results are shown in Table 2.

Example 5 except that the mixed numbers of polycarbonate in the borinlan-containing layer were 0 parts, 0.5 parts, and 20 parts, respectively.
Photoreceptors were obtained in the same manner as in steps 7 to 7, and comparative photoreceptors 5, 6, and 7 were used as comparative photoreceptors, respectively.

These photoreceptors were evaluated in the same manner as in Examples 2 to 4, and the results are shown in Table 2.

Mibaranuki 1- The process up to the subbing layer was carried out in the same manner as in Examples 2 to 4.

Next, 2 parts of a disazo pigment having the following structural formula (E) and 5 parts of polyvinyl acetate (number average molecular weight 3 (1000, value of melting parameter δ: 9.4) were added to 70 parts of toluene,
Dispersion was carried out in a ball mill for 4 hours, and 5 parts of the same borinlan compound used in Example 1 was added to this dispersion to prepare a coating solution.
Dry the film w-20μ on the underlayer by soaking tlAWlr cloth method.
A photoreceptor was prepared by forming a photosensitive layer of m. This photoreceptor was attached to a Canon copier NP-3825, and the V, -65 (lv)
When , the exposure lid was measured with -1.50V, and it was 3.5ffux-see.
There was no change in potential after copying 10,000 sheets, and excellent properties were exhibited.Example 8 except that the amount of polysilane compound in the photosensitive layer was changed to 1 part and 17 parts. A photoreceptor was prepared in the same manner as in Example 8, and evaluated in the same manner as in Example 8.

As a result, in the case of one part of polysilane compound, after 10,000 sheets were copied, the value of ■ varied to 1,280 V, resulting in a poor image quality of 2.

Further, when the polysilane compound was used in an amount of 17 parts, the photosensitive layer was scratched and copying became impossible after 5,000 copies were made.

[Summary of the effects of the invention] As is clear from the Examples and Comparative Examples, the polysilane compound exhibits excellent electrophotographic properties when used alone in the photosensitive layer, but when installed in an actual copying machine, the mechanical Durability is poor due to lack of strength.

However, according to the present invention, it is possible to impart sufficient mechanical strength to a polysilane-containing photoreceptor without impairing electrophotographic properties. This is the solubility parameter (SPY)
This becomes possible by making a polymeric resin compound having a value extremely close to that of a polysilane compound compatible with each other.

Claims (1)

[Scope of Claims] (1) In an electrophotographic photoreceptor having a photosensitive layer on a conductive support, the photosensitive layer is a polysilane compound represented by the following general formula [I] and has a solubility parameter δ of 8.0. An electrophotographic photoreceptor comprising a polymer resin compound having a molecular weight of 10.0 to 10.0. ▲There are mathematical formulas, chemical formulas, tables, etc.▼... [I] [However, in the formula, R_1 is an alkyl group with 1 or 2 carbon atoms,
R_2 represents an alkyl group having 3 to 8 carbon atoms, a cycloalkyl group, an aryl group, or an aralkyl group, R_3 represents an alkyl group having 1 to 4 carbon atoms, and R_4 represents an alkyl group having 1 to 4 carbon atoms, A, A' are an alkyl group, a cycloalkyl group, an aryl group, or an aralkyl group each having 4 to 12 carbon atoms, and they may be the same or different. n and m are molar ratios indicating the proportion of each monomer number to the total monomers in the polymer,
n+m=1, 0<n≦1, 0≦m<1. ] (2) The value of the solubility parameter δ is 8.0 to 10.
．． 2. The electrophotographic photoreceptor according to claim 1, wherein the polymeric resin compound having 0.0 is a mixture of one or more of polystyrene, polymethyl methacrylate, polyvinyl acetate, or polycarbonate. (3) The electrophotographic photoreceptor according to claim 1, wherein the photosensitive layer is of a laminated type, and the polysilane ratio in the polysilane-containing layer is 20 to 80%. (4) The electrophotographic photoreceptor according to claim 1, wherein the photosensitive layer is a single layer type, and the polysilane ratio in the polysilane-containing layer is 15 to 70%.