JP2002169312A - Electrophotographic photoreceptor, coating liquid for, electric charge transferring layer and method for producing electrophotographic photoreceptor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrophotographic photoreceptor having low friction between the photoreceptor and each member of a device, superior durability and superior electrical characteristics and to provide a coating liquid for producing the photoreceptor. SOLUTION: In the electrophotographic photoreceptor obtained by successively stacking an electric charge generating layer and an electric charge transferring layer on an electrically conductive substrate, fine oxide particles and an ethylene oxide/propylene oxide compound having a fluoroalkyl group are contained in the electric charge transferring layer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an electrophotographic photosensitive member and a coating solution for a charge transport layer. More specifically, an organic electrophotographic photoreceptor having a charge generation layer and a charge transport layer laminated thereon,
The present invention relates to a charge transport layer coating solution used for forming the charge transport layer.

[0002]

2. Description of the Related Art In recent years, organic photoreceptors using non-polluting organic substances have been actively developed and widely used. Above all, so-called function-separated type photoconductors in which a carrier generation function and a carrier transport function are shared by different substances and a compound having desired characteristics can be selected from a wide range have been actively developed. However, such organic photoconductors generally have lower mechanical strength than conventional inorganic photoconductors,
There are problems such as abrasion and abrasion due to mechanical external forces such as a cleaning blade and a developing brush.

For example, in a conventional photoreceptor in which a carrier generation layer and a carrier transport layer are sequentially laminated on a support, the carrier transport layer binds a low-molecular carrier transport material with an inert polymer resin binder. Since the carrier transport layer is formed, the carrier transport layer is generally soft, and it is not always sufficient to achieve both mechanical properties and electrophotographic properties. In the case of a composition having a high sensitivity or a certain kind of resin binder, the surface of the photoreceptor is scratched or worn due to rubbing of a cleaning blade or the like when the photoreceptor is repeatedly used. Further, with a composition having a high abrasion resistance or a certain kind of resin binder, the sensitivity was low or the electrophotographic properties such as an increase in residual potential could not be satisfied.

Regarding these problems, a silicone-containing resin is used in the carrier transport layer as an agent for reducing the coefficient of friction of the surface of the photoreceptor, reducing the surface energy, and reducing the wear (Japanese Patent Application Laid-Open No. 61-1986).
Nos. 219049 and 62-205357, and fluorine-containing resins (Japanese Patent Laid-Open Nos. 50-23231, 61-116362, and 61-20463).
Nos. 3 and 61-270768). However, the electrophotographic properties such as low sensitivity, the increase in residual potential due to repeated use, and the mechanical durability such as a decrease in image quality due to wear and scratches and a decrease in sensitivity due to film wear are still insufficient. I couldn't.

A method using hydrophobic silica or hydrophobic silicone for the charge transport layer is disclosed in Japanese Patent Application Laid-Open No. 8-14662.
No. 6 discloses this. However, when using fine particles such as silica for the charge transport layer, the specific gravity of the particles is high, and the particles settle out in the coating solution, resulting in poor storage stability.
In addition, there has been a problem that coating unevenness occurs.

[0006]

SUMMARY OF THE INVENTION The present invention is a photosensitive composition having high sensitivity, excellent abrasion resistance, excellent printing durability, high durability, and lacking in potential stability due to repeated use, an increase in residual potential and a decrease in light sensitivity. Is to provide the body. Another object of the present invention is to provide a charge transport layer coating solution having excellent storage stability for producing an electrophotographic photosensitive member. Also,
Another object of the present invention is to provide a method for producing an electrophotographic photosensitive member having excellent productivity by using the above-described charge transport layer.

[0007]

Means for Solving the Problems The present inventors have conducted intensive studies in view of the above-mentioned problems, and as a result, when oxide fine particles such as silica are used for the charge transport layer, the compound having a specific structure is allowed to coexist. The inventors have found that an electrophotographic photoreceptor having improved dispersibility, excellent stability of a coating solution, and excellent abrasion resistance and electrical properties can be obtained. That is, the gist of the present invention is to provide an electrophotographic photosensitive member in which a charge generation layer and a charge transport layer are sequentially laminated on a conductive support, wherein the oxide fine particles and the general formula (I) are contained in the charge transport layer. An electrophotographic photoreceptor characterized by containing a compound represented by the formula:

[0008]

Embedded image (In the general formula (I), R ¹ represents an alkyl group substituted by a fluorine atom, R ² represents a hydrogen atom or an alkyl group,
R ³ represents a hydrogen atom or a hydrocarbon group, and Q represents a direct bond or a divalent bonding group. M represents an integer of 1 to 100. )

Another aspect of the present invention resides in a charge transport layer coating solution containing at least a charge transport material, a binder resin, oxide fine particles, and a compound represented by the above general formula (I). Another aspect of the present invention is to provide a method for producing an electrophotographic photoreceptor in which a charge generation layer and a charge transport layer are sequentially laminated on a conductive support, and dip-coating is performed using the charge transport layer coating solution. A method for producing an electrophotographic photoreceptor, wherein a charge transport layer is provided.

The electrophotographic photoreceptor of the present invention is obtained by sequentially laminating a charge generation layer and a charge transport layer on a conductive support. A blocking layer is provided between the conductive support and the charge generation layer, if necessary. The blocking layer may be an alumite layer or a resin-based undercoat layer (also referred to as an intermediate layer) or a combination of these. Is used. Further, an overcoat layer can be provided outside the photosensitive layer as necessary.

As the conductive support used in the present invention, for example, a support made of a metal such as aluminum, stainless steel, copper, nickel or the like, or a polyester film,
Aluminum, copper,
There is a device provided with a conductive layer made of palladium, tin oxide, indium oxide, or the like. Above all, a metal endless pipe cut into an appropriate length is desirable, and aluminum is most preferably used. 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.

When an undercoat layer is provided on a conductive support, the binder resin may be polyvinyl methyl ether, poly-N-vinyl imidazole, polyethylene oxide, ethyl cellulose, methyl cellulose, ethylene-acrylic acid copolymer, polyamide , Casein, gelatin, polyethylene, polyester, phenolic resin, vinyl chloride-vinyl acetate copolymer, epoxy resin, polyvinylpyrrolidone, polyvinylpyridine, polyurethane,
Resin materials such as polyglutamic acid, polyacrylic acid, and polyamide resin can be used. Among them, a polyamide resin having excellent adhesion to a supporting substrate and low solubility in a solvent used for a charge generation layer coating solution is preferred.

In order to prevent interference fringes particularly in laser exposure, the undercoat layer preferably contains fine particles of metal oxides such as alumina and titania, and organic or inorganic dyes capable of absorbing laser light. It is effective. The thickness of the undercoat layer is usually 0.1 to 10 μm, preferably 0.1 to 10 μm.
2 to 5 μm. The content ratio of the metal oxide fine particles or the pigment to the binder resin is not particularly limited, but it is preferable to use the metal oxide fine particles or the pigment in the range of 40 to 400 parts by weight with respect to 100 parts by weight of the binder when dispersing the undercoat layer. It is preferable in terms of storage stability of the liquid and applicability.

As the charge generating material used in the charge generating layer, any known materials can be used. Selenium and its alloys, arsenic-selenium, cadmium sulfide, zinc oxide, other inorganic photoconductive materials, phthalocyanine, Azo dye, quinacridone, polycyclic quinone, pyrylium salt, indigo, thioindigo, anthantrone, pyranthrone,
Various organic pigments and dyes such as cyanine can be used. Among them, metal-free phthalocyanine, copper, indium chloride, gallium chloride, tin, oxytitanium, zinc, metals such as vanadium, or oxides, chloride-coordinated phthalocyanines,
Azo pigments such as monoazo, bisazo, trisazo, and polyazos are preferred. Of these, oxytitanium phthalocyanine is more preferable from the viewpoint of sensitivity when used in an image forming apparatus equipped with an exposure device using a laser beam in the range of 550 to 850 nm, and particularly, the Bragg angle (2θ) in X-ray diffraction using CuKα radiation. ± 0.2 °) = 27.3
Most preferred is Y-type oxytitanium phthalocyanine having a characteristic peak at °.

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 transport layer is formed on the charge generation layer by a known polymer having excellent performance as a binder;
The charge transfer material, the oxide fine particles, and the compound represented by the general formula (I) are mixed and dissolved or dispersed in a suitable solvent, and if necessary, an electron-accepting compound, a plasticizer, or a pigment. It can be produced by applying a coating liquid obtained by adding other additives. The thickness of the charge transfer layer is usually 10 to 50 μm, preferably 1 to 50 μm.
Used in the range of 3 to 35 μm.

As the oxide fine particles used in the present invention, silica, titania, alumina, tin oxide, zinc oxide, and the like are used. Considering that the specific gravity is small and that it is used as an electrophotographic photoreceptor, it is better that the electric conductivity is small.Specifically, the energy gap is sufficiently large for the charge transporting agent and the charge generating agent. Generation and injection of charge between charge transport layers,
Considering that it does not become a trap during the transportation stage, silica is considered to be the best. However, the dispersibility and electrical characteristics of other oxides can be changed by some treatments typified by surface treatment and the like, and if there is a method for realizing the desired physical properties, it can be sufficiently used.

The size of the oxide fine particles is preferably at least 0.01 μm, more preferably at least 0.02 μm in terms of volume average particle size. Further, it is preferably 10 μm or less,
The following is more preferred, and the thickness is particularly preferably 0.1 μm or less.
The content of these oxide fine particles in the charge transport layer is 0.1 to 20 parts by weight per 100 parts by weight of the binder resin.
It is preferably 1 part by weight, more preferably 1 to 10 parts by weight.

Next, when the compound represented by the following general formula (I) used in the present invention coexists with oxide fine particles, the dispersibility of the oxide fine particles is improved in the coating solution and the binder resin. It is estimated that it has the effect of As a result, the storage stability of the coating solution is excellent, and since it can be applied evenly by dip coating, the productivity is improved, and further, an electrophotographic photoreceptor excellent in both durability and electric characteristics can be obtained. Conceivable.

[0021]

Embedded image (In the general formula (I), R ¹ represents an alkyl group substituted by a fluorine atom, R ² represents a hydrogen atom or an alkyl group,
R ³ represents a hydrogen atom or a hydrocarbon group, and Q represents a direct bond or a divalent bonding group. M represents an integer of 1 to 100. )

In the general formula (I), Q represents a direct bond or a divalent linking group. In order to make the affinity with the binder and other components of the charge transport layer as a dispersant appropriate, It is preferable that the polarities are not so high. Specifically, a divalent hydrocarbon group, —SR ⁴ —, and —O—R ⁴ — (where R ⁴ represents a divalent hydrocarbon group) And the like.
In this case, the divalent hydrocarbon group may be substituted with a halogen atom, an alkoxy group, or an alkylthio group.

Preferred examples of the divalent linking group represented by Q include a phenylene group, a naphthylene group, —CH ₂ —C ₆ H ₄ —CH ₂ —, and —S—C ₆ H ₄ — , -O
—C ₆ H ₄ — and —C ₆ H ₄ —C ₆ H ₄ —. Of these, a phenylene group is more preferred, and a p-phenylene group is most preferred.

In the general formula (I), R ¹ represents an alkyl group substituted by a fluorine atom. The alkyl group preferably has 1 to 20 carbon atoms, and more preferably 3 to 10 carbon atoms. The number of fluorine atoms substituted by the alkyl group is preferably 3 or more, more preferably 5 or more, and it is preferable that all hydrogen atoms are substituted by fluorine atoms, that is, a perfluoro form. Further, although it may have a substituent other than a fluorine atom, the R ¹ portion is considered to preferably have as low an affinity as possible with the binder or other components of the charge transport layer. Carbonyl group,
Hydrogen-bonding substituents such as amino groups are not preferred.
Therefore, a chlorine atom, a bromine atom, a trimethylsilyl group, an alkylthio group and the like are preferable. However, those having no substituent other than a fluorine atom are more preferable.

In the general formula (I), R ² represents a hydrogen atom or an alkyl group. From the viewpoint of production, R ² is preferably a hydrogen atom or an alkyl group having 4 or less carbon atoms, and more preferably a hydrogen atom or a methyl group. Further, in the repeating structural unit having an R ^2, R ₂ in each structural unit may be different, for example,
As described below, a structural unit having a hydrogen atom and a methyl group may be mixed as R ² .

[0026]

Embedded image

In the general formula (I), m represents an integer of 1 to 100, but if the number of repeating alkyleneoxy structural units is too large, it will not be compatible with the binder resin at all, so m is preferably 50 or less. It is more preferably at most 30.

The content of the compound represented by formula (I) in the charge transport layer is preferably at least 0.001 part by weight, more preferably at least 0.01 part by weight, based on 100 parts by weight of the binder. Preferably, it is particularly preferably at least 0.03 parts by weight. Further, it is preferably at most 10 parts by weight, more preferably at most 5 parts by weight, particularly preferably at most 1 part by weight. If the content is significantly lower than the above range, the dispersibility of the oxide fine particles tends to deteriorate, and if it is extremely high, the strength of the charge transport layer tends to decrease.

Examples of the charge transfer material in the charge transport layer include high molecular compounds such as polyvinyl carbazole, polyvinyl pyrene, and polyacenaphthylene, and low charge compounds such as various pyrazoline derivatives, oxazole derivatives, hydrazone derivatives, stilbene derivatives, and arylamine derivatives. Molecular compounds can be used. Among them, compounds represented by the following general formula (II) are preferable in terms of sensitivity and other electrical characteristics. In particular,
The compound represented by the general formula (II) is preferable since oxytitanium phthalocyanine is used as the charge generating substance, since the electrical characteristics are significantly improved.

[0030]

Embedded image(In the general formula (II), Ar¹Is an optionally substituted
Benzene ring, an optionally substituted naphthalene ring, or
Represents a biphenyl ring which may be substituted; ^Two~ A
r^FiveEach independently represents an optionally substituted aromatic ring
Represent. )

In the general formula (II), Ar ¹ represents an optionally substituted benzene ring, an optionally substituted naphthalene ring, or an optionally substituted biphenyl ring. An optionally substituted biphenyl ring is preferred. As the substituent, a halogen atom, an alkyl group having 4 or less carbon atoms, an alkoxy group having 3 or less carbon atoms, an alkylthio group having 3 or less carbon atoms, a cyano group, and a nitro group are preferable. Atoms are more preferred. However, an unsubstituted aromatic ring is most preferred.

Ar ^{2 to} Ar ⁵ each independently represent an optionally substituted aromatic ring, and the aromatic ring may be any of an aromatic hydrocarbon and an aromatic heterocyclic ring. Is a benzene ring, a naphthalene ring, a phenanthrene ring,
Anthracene ring, pyridine ring, pyrrole ring, furan ring,
A thiophene ring, a benzofuran ring, a benzothiophene ring and the like. Of these, a benzene ring, a naphthalene ring and a thiophene ring are preferred.

The substituent on the aromatic ring may be a halogen atom, an alkyl group having 4 or less carbon atoms, an alkoxy group having 3 or less carbon atoms, an alkylthio group having 3 or less carbon atoms, a cyano group, a nitro group, or The following general formula (III)
The substituent represented by is preferred.

[0034]

Embedded image

(In the general formula (III), Ar ⁶ represents a phenyl group which may be substituted with a halogen atom or an alkyl group. R ⁵ and R ⁷ each independently represent a hydrogen atom or a methyl group. n represents 1, 2 or 3.) In the general formula (III), Ar ⁶ represents a phenyl group which may be substituted with a halogen atom or an alkyl group, but is preferably an unsubstituted phenyl group. R ⁵ and R ⁶ represent a hydrogen atom or a methyl group, and a hydrogen atom is preferable. n represents 1, 2 or 3, but 2 is preferred. In addition, among the charge transfer agent compounds represented by the general formula (II), compounds represented by the following general formula (IV) are particularly effective.

[0036]

Embedded image

In the general formula (4), R ⁶ , R ⁷ , Ar ⁶ and n have the same meanings as described above. R ⁷ and R ¹⁰ are each independently a hydrogen atom or a methyl group.

The binder used in the charge transport layer is preferably a polymer which has good compatibility with the above-mentioned charge transfer material and does not crystallize or phase-separate the charge transfer material after forming the coating film. Examples thereof 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, polysulfone, and polyphenylene oxide. , Polyurethane, cellulose ester, cellulose ether, phenoxy resin, silicon resin, epoxy resin and the like. Also,
The binder used for the charge transport layer preferably has high strength and is at least partially compatible with the above-mentioned polysiloxane compound. In this respect, polycarbonate, polyarylate or a mixture thereof is preferably used.

Examples of the electron-accepting compound optionally contained in the charge transporting layer include cyano compounds such as tetracyanoquinodimethane, dicyanoquinomethane, aromatic esters having a dicyanoquinovinyl group, 2,4,4 and the like. Metal complexes of nitro compounds such as 6-trinitrofluorenone, condensed polycyclic aromatic compounds such as perylene, diphenoquinone derivatives, quinones, aldehydes, ketones, esters, acid anhydrides, phthalides, substituted and unsubstituted salicylic acids , Substituted and unsubstituted metal salts of salicylic acid, 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 complexes It is preferred to use metal salts of carboxylic acids. Further, the photosensitive layer of the electrophotographic photoreceptor of the present invention may contain a well-known plasticizer, antioxidant, and ultraviolet absorber in order to improve film formability, flexibility, applicability, and mechanical strength. good

When an overcoat layer is further provided on the charge transport layer, examples of the binder resin include polyvinyl methyl ether, poly-N-vinyl imidazole, polyethylene oxide, ethyl cellulose, methyl cellulose, ethylene-acrylic acid copolymer, polyamide, Casein, gelatin, polyethylene, polyester, phenolic resin, vinyl chloride-vinyl acetate copolymer, epoxy resin, polyvinylpyrrolidone, polyvinylpyridine, polyurethane, polyglutamic acid, polyacrylic acid, polyamide resin, silicone resin, and fluorine resin are used. Preferably, polyurethane, silicone resin and fluorine resin are used. The thickness of the overcoat layer is usually 0.01 to 100 μm, preferably 1 to 10 μm.

[0042]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, which should not be construed as limiting the scope of the present invention. Comparative Example 1 [Preparation of charge generation layer] To 10 parts of β-type oxytitanium phthalocyanine and 5 parts of polyvinyl butyral (trade name # 6000-C, manufactured by Denki Kagaku Kogyo Co., Ltd.), 500 parts of 1,2-dimethoxyethane was added. Pulverization and dispersion treatment were performed with a sand grind mill. This dispersion was prepared by depositing aluminum on a polyester film having a thickness of 75 μm and used as a conductive support, and the weight after drying was 0.4 g / m ^2.
(Approximately 0.4 .mu.m) by a wire bar and dried to form a charge generation layer.

[Preparation of charge transport layer] 60 parts of a charge transfer agent (compound of the following A), 8 parts of a phenol compound (compound of the following B) as an antioxidant, a cyano compound (compound of the following C), and a polycarbonate resin 100 And a mixed solvent of tetrahydrofuran and toluene. To this, silica fine particles (SEAHOSTAR manufactured by Nippon Shokubai)
-KEP-50, average particle size 0.4 µm) 5 parts by weight and 100 parts by weight of tetrahydrofuran are mixed with a paint shaker 3
Dispersion containing silica fine particles obtained by dispersion over time (P1)
With a weight ratio of polycarbonate resin / silica fine particles of 1
00/6, and finally the solid concentration is 2
The solution was adjusted to be 0% by weight. This coating solution was applied on the above-mentioned charge generation layer with an applicator, dried at room temperature for 20 minutes, and further dried at 125 ° C. for 20 minutes to provide a charge transport layer so that the dry film pressure became 25 μm. . The electrophotographic photosensitive member thus obtained is designated as PCP1.

[0044]

Embedded image

Example 1 An electrophotographic photosensitive member was produced in the same manner as in Comparative Example 1, except that the following dispersion (S1) was used in place of the dispersion (P1) containing silica fine particles. The electrophotographic photosensitive member thus obtained is designated as PCS1. S1: 5 parts by weight of silica fine particles (SEAHOSTAR-KEP-50, manufactured by Nippon Shokubai, average particle size 0.4 μm), an EO-PO-compound modified with the following fluorinated alkyl group (compound of the following D)
A dispersion containing silica fine particles obtained by dispersing 0.05 parts by weight and 100 parts by weight of tetrahydrofuran for 3 hours using a paint shaker.

[0046]

Embedded image

Example 2 An electrophotographic photosensitive member was produced in the same manner as in Comparative Example 1, except that the following dispersion (S2) was used in place of the silica fine particle-containing dispersion (P1). The electrophotographic photosensitive member thus obtained is designated as PCS2. S2: 5 parts by weight of silica fine particles (SEAHOSTAR-KEP-50, manufactured by Nippon Shokubai, average particle size 0.4 μm), an EO-PO-compound modified with the following fluorinated alkyl group (compound of the above D)
A dispersion containing silica fine particles obtained by dispersing 0.25 parts by weight and 100 parts by weight of tetrahydrofuran for 3 hours using a paint shaker.

Example 3 An electrophotographic photosensitive member was produced in the same manner as in Comparative Example 1, except that the following dispersion (S3) was used in place of the dispersion containing silica fine particles (P1). The electrophotographic photosensitive member thus obtained is designated as PCS3. S1: 5 parts by weight of silica fine particles (SEAHOSTAR-KEP-50, average particle size: 0.4 μm, manufactured by Nippon Shokubai), an EO-PO-compound modified with the following fluorinated alkyl group (compound of the above D)
A dispersion containing silica fine particles obtained by dispersing 0.5 part by weight and 100 parts by weight of tetrahydrofuran for 3 hours using a paint shaker.

Comparative Example 2 An electrophotographic photosensitive member was prepared in the same manner as in Comparative Example 1, except that the dispersion liquid containing silica fine particles (P1) was not added. The electrophotographic photoreceptor obtained in this way was
Let it be 2.

[Evaluation of Dispersibility of Silica Fine Particles] The particle size distribution of silica in each of the above silica dispersions was measured with a Microtrac particle size distribution meter (manufactured by Nikkiso Co., Ltd.). The particle size distribution was compared with the average particle size of 10%, 50%, and 90% of the Gaussian distribution. In addition, the zeta potential indicating the dispersibility of particles
It was measured with a NETIC SONIC analyzer (manufactured by MATEC). At this time, the measurement was performed with the polarity of the silica particles being positive. The results are shown in Table 1.

[0051]

[Table 1]

A comparison between P1 and S1, S2, and S3 to which a dispersant has been added shows that the viscosities differ greatly when the solutions are prepared at the same solid content concentration. In P1, it is considered that the particles added in the solution are agglomerated and thickened, while in S1, the particles are favorably dispersed by the dispersant, and the viscosity is almost increased compared to the liquid without added particles. I can't. S2, S
3, it was found that the viscosity was slightly thicker than that of S1, but the viscosity was lower than that of P1. It is considered that it is important to prepare particles with good dispersibility and low viscosity since controlling the viscosity of the coating liquid has a very significant effect on productivity.

Further, since P1 has a large particle size distribution and a large amount of aggregates, and the width of D10 and D90 is large, it can be seen that silica is not sharply dispersed. On the other hand, S1 has a sharp distribution curve because the particle size width of silica is small and the distribution on the large particle size side is small.
However, when the amount of the additive is increased as in S2, the particle size width becomes wider again, and when it becomes S3, the particle size width becomes smaller.
Since the value of 0 is large and the value of D10 is also large, it is considered that many aggregates are contained. This is reflected in the value of the zeta potential, indicating that the dispersibility is not very good at P1 due to the small potential, and the dispersion is apparently dispersible immediately after the preparation of the solution. In the liquid state after 7 days, the amount of sediment was very large.

On the other hand, the dispersant-added system S1 was a liquid having a large zeta potential, a large repulsion between particles, and a good dispersion stability. No precipitate was found for S2 even after 7 days. S3 had good dispersibility at the beginning. Next, the electrophotographic photosensitive members produced in Comparative Examples 1 and 2 and Examples 1, 2, and 3 were subjected to photosensitive member characteristic measurement [Model EPA81 manufactured by Kawaguchi Electric Co., Ltd.]
00], and charged so that the current flowing into the aluminum surface was 25 μA, and then exposure and static elimination were performed. The chargeability (Vo) at that time, the rate of decrease in potential after 2 seconds from the start of charging (Dark decay DD), half-exposure (E1 / 2)
Reference potential: -450 V) and residual potential (Vr) were measured. The surface condition was visually determined after the preparation of the electrophotographic photosensitive member. Table 2 shows the results.

[0055]

[Table 2]

Next, Comparative Examples 1 and 2, and Examples 1, 2, and 3
0.1 mg / toner on the electrophotographic photoreceptor
It applied to the sample at an angle of 45 degrees with those of the same material of the urethane rubber cleaning blade to uniformly placed face contacting so that the cm ² was cut into 1cm wide, weighted 20
0 g, velocity 5 mm / sec, stroke 20 mm The dynamic friction coefficient when urethane rubber was moved 0 times, 25 times, 50 times, 75 times, and 100 times was determined by a fully automatic dynamic friction wear test manufactured by Kyowa Interface Chemical Co., Ltd. It was measured by DFPM-SS. The photoreceptor was cut into a circle having a diameter of 10 cm, and a wear test was performed using a Taber abrasion tester (manufactured by Toyo Seiki Co., Ltd.). The test conditions were determined by comparing the amount of wear after 1000 rotations with no load (self-weight of the worn wheel) using a worn wheel CS-10F in an atmosphere of 23 ° C. and 50% RH under no load (self-weight of the worn wheel). . The results are shown in Table 3.

[0057]

[Table 3]

[0058]

According to the present invention, it is possible to provide an electrophotographic photoreceptor having reduced friction between the photoreceptor and each member of the apparatus, improved durability, and excellent electric characteristics.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G03G 5/06 371 G03G 5/06 371 (72) Inventor Ringo 1000 Kamoshida-cho, Aoba-ku, Yokohama-shi, Kanagawa-ken Mitsubishi Chemical Corporation Yokohama Research Laboratory F-term (reference) 2H068 AA13 AA14 AA19 AA20 AA21 AA35 BA13 BA39 BA61 BB25 BB27 CA06 EA16 EA36 FA03

Claims (11)

[Claims] 1. An electrophotographic photoreceptor comprising a charge generating layer and a charge transporting layer sequentially laminated on a conductive support, wherein the charge transporting layer has oxide fine particles and a compound represented by the following general formula (I). An electrophotographic photoreceptor comprising a compound. Embedded image (In the general formula (I), R ¹ represents an alkyl group substituted by a fluorine atom, R ² represents a hydrogen atom or an alkyl group,
R ³ represents a hydrogen atom or a hydrocarbon group, and Q represents a direct bond or a divalent bonding group. M represents an integer of 1 to 100. ) 2. The oxide fine particles have a volume average particle diameter of 0.1 μm.
2. The electrophotographic photoreceptor according to claim 1, which has a length of not less than m and not more than 10 μm. 3. The electrophotographic photoreceptor according to claim 1, wherein the oxide fine particles are silicon oxide fine particles. 4. The electrophotographic photoreceptor according to claim 1, wherein the binder of the charge transport layer is polycarbonate or polyarylate. 5. The charge transport layer according to claim 1, wherein said charge transport layer is represented by the following general formula (II):
6. An electron according to claim 1, comprising a charge transport material to be used.
Photoreceptor. Embedded image(In the general formula (II), Ar¹Is an optionally substituted
Benzene ring, an optionally substituted naphthalene ring, or
Represents a biphenyl ring which may be substituted; ^Two~ A
r^FiveEach independently represents an optionally substituted aromatic ring
Represent. ) 6. The electrophotographic photoreceptor according to claim 1, wherein the charge generation layer contains oxytitanium phthalocyanine. 7. The electrophotographic photosensitive member according to claim 1, wherein the charge transport layer is an outermost layer. 8. A coating solution for a charge transport layer containing at least a charge transport material, a binder resin, oxide fine particles, and a compound represented by the following general formula (I). Embedded image (In the general formula (I), R ¹ represents an alkyl group substituted by a fluorine atom, R ² represents a hydrogen atom or an alkyl group,
R ³ represents a hydrogen atom or a hydrocarbon group, and Q represents a direct bond or a divalent bonding group. M represents an integer of 1 to 100. ) 9. The charge transport material is 10 to 100 parts by weight, the oxide fine particles is 0.1 to 20 parts by weight, and the compound represented by the general formula (I) is 100 parts by weight of the binder resin. The coating solution for a charge transport layer according to claim 8, wherein the amount is 0.01 to 10 parts by weight. 10. The coating solution has a viscosity of 50 to 1000 cps.
The coating solution for a charge transport layer according to claim 8 or 9, wherein 11. A method for producing an electrophotographic photoreceptor comprising a charge generation layer and a charge transport layer sequentially laminated on a conductive support, wherein the charge transport layer is coated with the charge transport layer coating solution according to claim 8. A method for producing an electrophotographic photoreceptor, wherein a charge transport layer is provided by coating.