JPH04149557A - Electrophotographic sensitive body - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention is an electrophotographic photosensitive material that can be widely used in electrophotographic application fields such as electrophotographic copying machines, laser beam printers, CRT printers, and electrophotographic plate making systems. Regarding the body.

[Conventional technology]

Inorganic photoconductive materials such as selenium, cadmium sulfide, and zinc oxide have conventionally been used as photoconductive materials for electrophotographic photoreceptors. On the other hand, organic photoconductive materials such as polyvinyl rubber, oxadiazole, and phthalocyanine have advantages over inorganic photoconductive materials, such as non-pollution and high productivity, but their low sensitivity has made it difficult to put them into practical use. For this reason, several sensitization methods have been proposed, but it is known that an effective method is to use a functionally separated photoreceptor in which a charge generation layer and a charge transport layer are laminated.

On the other hand, as a matter of course, electrophotographic photoreceptors have certain sensitivity, electrical characteristics, and
Furthermore, it is required to have optical properties. In particular, in the case of photoreceptors that can be used repeatedly, external electrical and mechanical forces such as corona charging, toner development, transfer to paper, and cleaning processes are directly applied to the surface layer of the photoreceptor.
Durability against them is required. Specifically, durability is required against a decrease in sensitivity, a decrease in potential, an increase in residual potential due to deterioration due to ozone generated during corona charging, and the occurrence of surface abrasion and scratches due to rubbing. Since the surface of the photoreceptor is coated with a resin, the performance of the resin is particularly important, and a resin with excellent durability has been desired. Recently, polyarylate resins with a bisphenol A skeleton (hereinafter referred to as bisphenol A polyarylates) have been studied as resins that satisfy these requirements as binders for the surface layer, but they have various problems. ing.

(1) The solubility of the resin is poor. Dichloromethane or 1゜2-
It shows good solubility only in some halogenated aliphatic hydrocarbons such as dichloroethane. Since these halogenated aliphatic hydrocarbons have low boiling points, when a photoreceptor is manufactured using a coating solution prepared with these solvents, the coated surface tends to whiten. In addition, process control such as the solid content of the coating liquid takes time and effort.

(2) For solvents other than halogenated aliphatic hydrocarbons, it is partially soluble in tetrahydrofuran, dioxane, cyclohexanone, or a mixed solvent thereof, but the solution gels over time, such as within a few days. It is unstable and unsuitable for producing photoreceptors.

(3) Furthermore, even if the drawbacks listed in (1) and (2) above are improved, polycarbonate resins in which only bisphenol A or bisphenol A derivatives are the main chain skeleton have the drawback that solvent cracks occur. , which often appears as cracks in the drum in electrophotographic copying machines, and has been pointed out as a drawback.

[Problems to be solved by the invention]

An object of the present invention is to provide an electrophotographic photoreceptor that solves the problems of conventional electrophotographic photoreceptors, has excellent durability such as wear resistance and scratch resistance, and is easy to manufacture. The purpose is

[Failure to solve the problem]

That is, the present invention provides an electrophotographic photoreceptor having a photosensitive layer on a conductive support, in which the photosensitive layer has the following formula [I] (wherein R3 is a hydrogen atom, a methyl group, an ethyl group, or a halogen atom). , R2 is , and X and Y are integers of 1 or more.

The polycarbonate resin having the component represented by the formula CI used in the present invention is synthesized by copolymerizing a compound having a bisphenol skeleton (formula [■]) and a compound represented by the formula [IV] using phosgene. can do.

Formula (R2 is the same as above) Formula [■] (R1 is the same as above) The ratio of the compound of formula [IIL] and the compound of formula [IV] used at this time depends on the gelation rate of the copolymer. , considering solvent crack resistance and elasticity (III):
[IV) =1:199 to 1:1 (molar ratio) is preferred.

The solubility of the polycarbonate resin having the component represented by formula [I] is preferably 1 g or more, particularly preferably 5 g or more, per 100 cc of the aromatic hydrocarbon solvent and halogenated aromatic hydrocarbon solvent. This is because if the solubility is less than Ig/100cc, for example, when a solution for a charge transport layer is prepared, the viscosity of the solution is too low to obtain an appropriate film thickness required for the charge transport layer.

Furthermore, the molecular weight of such a copolymer is such that the viscosity average molecular weight (Mv) is 1 when considering durability, that is, abrasion resistance, scratch resistance, and viscosity during manufacturing, that is, productivity.
,000 to 150,000, particularly preferably 5,000 to 100,000.

Even if one type of the component represented by the general formula [■] is used,
Two or more types may be used.

Among the components represented by the general formula [I], particularly preferred components in the present invention are those represented by the general formula [I].

The above-mentioned copolymer used in the present invention can be used as a binder resin in a photosensitive layer, or in a laminated photosensitive layer in which a charge generation layer and a charge transport layer are functionally separated, in a charge generation layer and/or a charge transport layer. Preferably, it is used as a binder resin.

When producing the electrophotographic photoreceptor of the present invention, examples of the conductive support include metals such as aluminum and stainless steel, paper,
A cylindrical cylinder or film, such as plastic, is used. A subbing layer having barrier and adhesive functions can be provided on these substrates.

The undercoat layer is formed to improve adhesion of the photosensitive layer, improve coating properties, protect the substrate, cover defects on the substrate, improve charge injection from the substrate, protect the photosensitive layer from electrical breakdown, etc. . Known materials for the undercoat layer include polyvinyl alcohol, poly-N-vinylimidazole, polyethylene oxide, ethyl cellulose, methyl cellulose, ethylene-acrylic acid copolymer, casein, polyamide, copolymerized nylon, glue, gelatin, and the like. These are each dissolved in a suitable solvent and applied onto the substrate.

The film thickness is about 0.2 to 2 μm.

Examples of the charge generating substance in the electrophotographic photoreceptor of the present invention include selenium-tellurium, pyrylium, thiopyrylium dyes, phthalocyanine pigments, anthoanthrone pigments, dibenzpyrenequinone pigments, pyrantorosi pigments, trisazo pigments, disazo pigments, azo pigments, and indigo pigments. Pigments, quinacridone pigments, asymmetric quinocyanine, quinocyanine or JP-A-1988. Examples of the charge transport material include amorphous silicon described in Japanese Patent Publication No. 143645.
Pyrene, N-ethylcarbazole, N-isopropylcarbazole, N-methyl-N-phenylhydrazino-3
-Methylidene-9-ethylcarbazole, N,N-diphenylhydrazino-3methylidene-9-ethylcarbazole, N,N-diphenylhydrazino-3-methylidene-10ethylphenothiazine, N,N-diphenylhydrazino 3-Methylidene-10-ditylphenoxazine, p-diethylaminobenzaldehyde-N, N-diphenylhydrazone, p-diethylaminobenzaldehyde-N-α-naphthyl-N-phenylhydrazone, p-
Hydrazones such as pyrrolidinobenzaldehyde-NN-diphenylhydrazone, 1,33-trimethylindolenine-ω-aldehyde N, N-diphenylhydrazone, p-diethylbenzaldehyde-3-methylbenzthiazolinone-2-hydrazone, 2゜5-bis(p-diethylaminophenyl')-1,3,4=oxadiazole, 1-phenyl-3-(p-diethylaminostyryl)
-5-(p-diethylaminophenyl)pyrazoline, 1
-[quinolyl(2)]-3-(p-diethylaminostyryl)-5-(p-diethylaminophenyl)pyrazoline, 1-[pyridyl(2))-3-(p-diethylaminostyryl)-5-(p- diethylaminophenyl)pyrazoline, 1-[6-medoxypyridyl(2)]-3
-(p-diethylaminostyryl) -5-(p-diethylaminophenyl)pyrazoline, 1-[pyridyl(3
)] -3-(p-diethylaminostyryl)-5-(
p-diethylaminophenyl)pyrazoline, 1-[lepidyl (2)) -3-(pdiethylaminostyryl)-
5-(p-diethylaminophenyl)pyrazoline, 1-
[Pyridyl (2)]-3-(p-diethylaminostyryl)-4-methyl-5-(p-diethylaminophenyl)pyrazoline, ■-[Pyridyl (2)'1-3- (α
-methyl-p-diethylaminostyryl)-5-(p-
diethylaminophenyl) pyrazoline, ■-phenyl-3-(p-diethylaminostyryl) = 4-methyl-5
Pyrazolines such as -(p-diethylaminophenyl)pyrazoline, 1-phenyl-3-(α-benzyl p-diethylaminostyryl> -s-cp-diethylaminophenyl)pyrazoline, spiropyrazoline, 2-(p-
diethylaminostyryl)-6-dinithylaminobenzoxazole, 2-(p-diethylaminophenyl)-
Oxazole compounds such as 4-(p-dimethylaminophenyl)-5-(2talolophenyl)oxazole, 2
-(p-diethylaminostyryl)-6-dinithylaminobenzothiazole and other thiazole compounds, bis(4
Triarylmethane compounds such as -diethylamino-2-methylphenyl)-phenylmethane, 1,1-bis(
4-N.

N-diethylami, nor 2-methylphenyl)hebutane, 1,1,2.2-tetrakis-(4,-N.

Examples include polyarylalkanes such as N-dimethylamino-2-methylphenyl)ethane.

The electrophotographic photoreceptor of the present invention may be of a so-called single-layer type in which the photosensitive layer contains the above-mentioned charge generating substance and charge transporting substance in the same layer, or may contain a charge generating layer containing a charge generating substance and a charge transporting substance. A so-called functionally separated type in which charge transport layers are laminated may also be used. In the case of a functionally separated type, the charge generation layer is prepared by using a homogenizer, an ultrasonic wave, a ball mill, a vibrating ball mill, a sand mill, an attritor, a roll mill, etc., together with the above-mentioned charge generation substance, a binder resin in an amount of 0.3 to 4 times, and a solvent. It is well dispersed and formed by coating and drying.

Its thickness is about 0.1 to 1 μm.

The charge transport layer is applied by dissolving the charge transport material and the binder resin. The mixing ratio of the charge transport material and the binder resin is about 2:1 to 1:2. Particularly useful solvents are toluene, xylene or monochlorobenzene.

The method of applying this solution is, for example, dip coating method,
Spray coating method, spinner coating method,
Curtain coating methods are known. Dip coating is the best way to mass-produce electrophotographic photoreceptors efficiently and accurately, and this is made possible by using the polyarylate of the present invention. After coating, air blow drying or stationary drying is performed at 10°C to 200°C, preferably 20°C to 150°C, for 5 minutes to 5 hours, preferably 10 minutes to 2 hours, to obtain a charge transport layer of 5 to 20 μm. .

The charge transport layer used in the present invention can contain various additives. Such additives include diphenyl, diphenyl chloride, o-terphenyl, p-terphenyl, dibutyl phthalate, dimethyl glycol phthalate, dioctyl phthalate, triphenyl phosphoric acid, methylnaphthalene, benzophenone, chlorinated paraffin, dilaurylthiopropionate. , 3,5-dinitrosalicylic acid and the like.

Next, the present invention will be explained according to examples.

Example 1 50 parts of conductive titanium oxide powder coated with tin oxide containing 10% antimony oxide, 25 parts of phenolic resin,
20 parts of methyl cellosolve, 5 parts of methanol, and 0.002 part of silicone oil (polydimethylsiloxane polyoxyalkylene copolymer, average molecular weight 3000) were added to φ
The mixture was dispersed for 2 hours in a sand mill using a 1 mrn glass heater to obtain a coating material for a conductive layer. This paint was applied onto an aluminum sheet with a wire bar and dried at 140° C. for 30 minutes to form a conductive layer with a thickness of 20 μm.

Next, 5 parts of N-methoxymethylated nylon was dissolved in 95 parts of methanol to form a paint for the intermediate layer.

This paint was applied onto the conductive layer using a wire bar and dried at 100° C. for 20 minutes to form a 0.6 μm intermediate layer.

Next, 3 parts of a disazo pigment having the following structural formula, 2 parts of polyvinylbenzal (benzal conversion rate: 80%, weight average molecular weight: 11,000), and 35 parts of cyclohexanone were dispersed for 12 hours using a sand mill device using φ1 mm glass beads. 60 parts of methyl ethyl ketone was added to obtain a charge generation layer dispersion. This dispersion was applied onto the above-mentioned intermediate layer using a wire bar.
It was dried at 0° C. for 20 minutes to obtain a charge generation layer with a thickness of 0.2 μm.

Next, 10 parts of the styryl compound having the structural formula and 10 parts of the copolymer shown below were dissolved in a mixed solvent of 20 parts of dichloromethane and 40 parts of monochlorobenzene, and this solution was applied onto the charge generation layer described above using a wire bar. and dried at 120℃ for 60 minutes to obtain a film thickness of 18
A charge transport layer of .mu.m was formed.

Hv = 2.5 x 10' Next, using this photoreceptor, abrasion resistance and electrophotographic properties were measured. For abrasion resistance, an ablation tester Nα101 taper type manufactured by Yasuda Seiki was used, and commercially available copy paper was used as the abrasive material. Further, electrophotographic properties were obtained by measuring photodischarge properties using 10 crn' conductive glass. Furthermore, finger oil was applied to this surface layer, and after 24 hours, the presence or absence of solvent cracks was observed using a microscope. These results are listed in Table 1.

Example 2 A photoreceptor was prepared in exactly the same manner as in Example 1, except that a charge transport layer was formed using a copolymer having the following composition, and various measurements were performed.

Hv = 3. OX 10’ The results obtained are listed in Table 1.

Example 3 A photoreceptor was prepared in exactly the same manner as in Example 1, except that a charge transport layer was formed using a copolymer having the following composition, and various measurements were performed.

Hv = 9.6 x 10' The results obtained are listed in Table 1.

Example 4 A photoreceptor was prepared in exactly the same manner as in Example 1, except that a charge transport layer was formed using a copolymer having the following composition, and various measurements were performed.

Hv = 4. OX 10″ The results obtained are listed in Table 1.

Example 5 A photoreceptor was prepared in exactly the same manner as in Example 1, except that a charge transport layer was formed using a copolymer having the following composition, and various measurements were performed.

Hv = 3I) X 10' The results obtained are listed in Table 1.

Comparative Example 1 A photoreceptor was prepared in exactly the same manner as in Example 1, except that the charge transport layer was formed using polycarbo Z (weight average molecular weight: 4.6×10″), and various measurements were performed.

The results obtained are shown in Table 1.

[Table] [Effects of the Invention] The electrophotographic photoreceptor of the present invention has excellent durability, abrasion resistance, and abrasion resistance, has low symmetry, has excellent solubility, and does not gel. It is easy to manufacture and is extremely advantageous industrially.

Claims (2)

[Claims] (1) In an electrophotographic photoreceptor having a photosensitive layer on a conductive support, the photosensitive layer has the following formula [I] Formula [I] ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (In the formula, R_1 is a hydrogen atom , represents a methyl group, an ethyl group, or a halogen atom, and R_2 has ▲ mathematical formulas, chemical formulas, tables, etc. ▼, ▲ mathematical formulas, chemical formulas, tables, etc. ▼, ▲
There are mathematical formulas, chemical formulas, tables, etc. ▼, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼, ▲ Mathematical formulas, chemical formulas,
There are tables, etc. ▼, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼
, ▲There are mathematical formulas, chemical formulas, tables, etc.▼,▲Mathematical formulas, chemical formulas,
There are tables, etc. ▼, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼
, or ▲There are mathematical formulas, chemical formulas, tables, etc.▼ where X and Y are integers of 1 or more. ) An electrophotographic photoreceptor comprising a copolymer having the following components. (2) A patent claim in which the formula [I] is the following formula [II] Formula [II] ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (wherein R_1, X and Y are the same as above) The electrophotographic photoreceptor according to range (1).