JPS62272282A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To obtain the org. electrophotographic sensitive body which has high durability and excellent environmental capability and cleaning properties of a toner by forming a protective layer by incorporating a specific compd. to a polycarbonate resin which is a main component. CONSTITUTION:In the titled body having a laminated structure composed of a conductive substrate body, an electrostatic charge generating layer, and a protective layer, the protective layer is formed by incorporating polytetrafluoroethylene and a hydrazone derivative shown by formula I to the polycarbonate resin which is the main component. In the formula, R1 and R2 are each alkyl group or a residual group capable of forming a cyclic amino group, R3 is hydrogen atom, or a halogen atom. The compd. ratio of the hydrazone derivative contd. in the protective layer is 5-100pts.wt. per 100pts.wt. binding resin. The content of polytetrafluoroethylene contd. in the protective layer is 8-40wt%.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a laminated electrophotographic photoreceptor, in particular a layered electrophotographic photoreceptor having at least a charge generation layer, a charge transport layer and a protective layer on a conductive support. The present invention relates to an electrophotographic photoreceptor having a layer.

[Prior Art] Electrophotographic photoreceptors using inorganic photoconductors such as selenium, cadmium sulfide, and zinc oxide as photoreceptor components have been known.

On the other hand, since the discovery that certain organic compounds exhibit photoconductivity, many organic photoconductors have been developed.

Organic photoconductive polymers such as poly-N-vinylcarbazole, polyvinylanthracene, carbazole,
Low-molecular organic photoconductors such as anthracene, pyrazolines, oxadiazoles, hydrazones, polyaryl alkanes, phthalocyanine pigments, azo pigments, cyanine dyes, polycyclic iron pigments, perylene pigments, indigo dyes, thioindigo Organic pigments and dyes such as dyes or methine squaric acid dyes are known.

In particular, photoconductive organic pigments and dyes are easier to synthesize than inorganic materials, and the variety of compounds that exhibit photoconductivity in an appropriate wavelength range has been expanded, so there are many photoconductive organic pigments and dyes. Pigments and dyes have been proposed.

For example, U.S. Pat. No. 4,123,270, U.S. Pat.
1614 specification, 4251613 specification, 4251614 specification, 4256821 specification, 4260672 specification, 4268596 specification, 4278747 specification, 42936
As disclosed in No. 28, etc., electrophotographic photoreceptors are known that use a disazo pigment exhibiting photoconductivity as a charge generation substance in a photosensitive layer that is functionally separated into a charge generation layer and a charge transport layer.

These organic electrophotographic photoreceptors have problems in mechanical durability.

At present, the practical level of even the most durable organic electrophotographic photoreceptor is 30,000 to 50,000 sheets.

Therefore, it has been proposed to provide a protection layer F3 on the surface of the photoreceptor as a means of increasing durability, and the following protection layers have been proposed so far.

■Maintains low-resistance resin with a volume resistance of 1013Ω and around Cm [
For use in A molecular charge transport layer is used as a protective layer.

However, the above-mentioned protective layer is far from a practical level, and no protective layer is currently in practical use.

This is because the above-mentioned security X[ has the following problems.

■It lacks mechanical strength and does not function as a protective layer due to its woody properties.

When a general-purpose resin such as an acrylic resin, a butyral resin, an epoxy resin, or a vinyl chloride-vinyl acetate copolymer is used for the protective layer, the mechanical strength, especially the abrasion resistance, is weak.

When subjected to actual machine durability, about 5 to 10 scratches occur per 10,000 sheets, and the lifespan of the photoreceptor is limited to 5,000 to 10,000 sheets.

When engineering plastics such as polysulfone and polycarbonate are used, the abrasion resistance is better than the general-purpose resins mentioned above, and even when subjected to actual machine durability, the wear resistance was 1/10,000 sheets.
It is about 2 lbs of scraping.

The lifespan of the photoconductor is greatly improved to 30,000 to 50,000 sheets, but
Compared to the durability of amorphous silicon drums, which is said to last 50 to 1 million sheets, it is still far from sufficient.

■Cannot be controlled electrically.

When a low-resistance resin is used, not only the above-mentioned mechanical strength is insufficient, but also there are problems with environmental characteristics.

That is, in order for the protective layer to function electrophotographically, a balance between charge retention and charge transport is required.

In order to maintain a balance between charge retention and transport, the volume resistivity of the protective layer must be within the range of 1012 to 1013 Ω, cm.

If the volume resistance is smaller than 1012Ω, cm, the charge retention is poor and clear images cannot be obtained.0 Volume resistance is 101
If it is larger than 3Ω, cm, ghosts and fog will occur due to the accumulation of residual charges.

Even a low resistance resin with an IQ of 72 to 1013 Ω, cm at normal temperature and humidity has a volume resistivity of 10) 3 Ω, cm or more under low humidity, causing ghosting and fogging.

In addition, under high humidity, the volume resistance becomes less than 1012 Ω, cm, causing image blurring and blurring.

Similarly, in a protective layer containing conductive powder, it is impossible to maintain a volume resistivity of 10 12 to 10 13 Ω, cm under all environments.

[Problems to be Solved by the Invention] An object of the present invention is to solve all the problems of the protective layers that have been proposed in the past, and to provide a highly durable organic electrophotographic photoreceptor with excellent environmental characteristics. be.

A further object of the present invention is to provide an electrophotographic photoreceptor with excellent toner cleaning properties.

[Means and effects for solving the problems] The present invention provides a conductive support, Tl! An electrophotographic photoreceptor having an XΔ layer structure consisting of a charge generation layer, a charge transport layer, and a protective layer, characterized in that the protective layer is mainly composed of a polycarbonate resin and contains polytetrafluoroethylene and a hydrazone derivative of the following general formula. It consists of an electrophotographic photoreceptor.

(In the formula, R1 and R2 represent a residue forming an alkyl group or a cyclic amine group, and R3 represents a hydrogen atom or a halogen atom).

In order to solve the above-mentioned problems and significantly improve durability, one way is to increase the hardness of the surface layer, but it is better to reduce the coefficient of friction and perform cleaning with the minimum necessary pressure. That is far more effective.

By reducing the frictional force, surface scrapes and scratches are significantly reduced, and image black spots and image blurring caused by adhesion of toner, talc, etc. are also greatly improved.

Specifically, in one aspect of the present invention, polytetrafluoroethylene is incorporated into the protective layer in order to obtain the dull surface properties. In addition, in order to satisfy charge transport and mechanical strength, a polycarbonate resin was used as a binder for the protective layer, and the hydrazone derivative represented by the general formula (1) was contained therein. .

The polycarbonate resin used in the protective layer is derived from a dioxy compound.

Aromatic polycarbonate is superior in terms of film-forming properties and mechanical strength, and its raw material, the dioxy compound, is
Examples include the following compounds.

CH.

CH.

CH3CH engineering 0H.

CH, CH3 (C) Iλ) D C) I engineering C
H3CH, -CH-CH3CH.

HO()0 ((n0L HO+0sha0sha0■, Ho()o-@)-01sha0H1 no(toso%on, Hoshasoyo()oHCH3
(J.

CH, CH! CH.

(C) Iλ) Yu C00C now H5 H3 CH□ Oh.

CH, CH3 Representative examples are listed below as specific examples of the hydrazone derivative represented by the general formula (1) contained in the protective layer of the present invention.

These compounds can be used alone or in combination of two or more.

The proportion of the hydrazone derivative in the protective layer is 5 to 5 parts by weight based on 100 parts by weight of the binder resin.
o parts by weight.

If the amount of the hydrazone derivative is less than 5 parts by weight, the electrophotographic properties will be lowered.

The content of polytetrafluoroethylene in the protective layer is 8~
40fi amount%. If the content of polytetrafluoroethylene is less than 8% by weight, the abrasion resistance of the drum will not be sufficient.The content of polytetrafluoroethylene is 40%!
When the amount is 1% or more, problems arise such as a decrease in mechanical strength and a decrease in incident light and scattering.

The thickness of the protective layer is 2 to Log. If the number of passes is less than 2, there will be problems with scratches and abrasion, and if it is more than 10, there will be problems of reduced sensitivity and reduced resolution due to the reduction and scattering of incident light.

To explain the electrophotographic photoreceptor of the present invention in more detail, first, the conductive support is made of metal such as aluminum, brass, or stainless steel, or polyethylene terephthalate,
Polymer materials such as polybutylene terephthalate, phenolic resin, polypropylene, nylon, polystyrene,
It is used by molding a material such as hard paper into a cylindrical shape, or by making it into a film or foil. In the case of an insulator, it is necessary to conduct conductive treatment, which can be done by impregnating it with a conductive substance, laminating metal foil, or vapor-depositing metal.

It is preferable to provide an undercoat layer on the conductive layer for the purpose of adhesion or prevention of carrier injection from the conductive layer.

Examples of resins for this purpose include water-soluble resins such as polyvinyl alcohol, polyvinyl methyl ether, polyvinyl pyridine, polyacrylic acids, methyl cellulose, ethyl cellulose, polyglutamic acid, casein, gelatin, and starch, polyamide, phenolic resin, polyvinyl formal, and polyurethane. Stomer, alkyd resin,
Ethylene-vinyl acetate copolymer, vinylpyrrolidone-
Examples include resins such as vinyl acetate copolymers.

The thickness of the undercoat layer is approximately 0.3 to 2 l. A conductive support is thus formed.

A charge generation layer is provided on the conductive support.

The charge generation layer is made of azo pigments such as Sudan Red, Guianpuru, and Jenas Green B, Algol Yellow,
Quinone pigments such as pyrenequinone, indanthrene brilliant violet) RRP, quinocyanine pigments, perylene pigments, indigo pigments such as indigo and thioindigo,
Charge-generating substances such as bisbenzimidazole pigments such as India Fast Orange Toner, phthalocyanine pigments such as copper phthalocyanine, quinacridone pigments, and pyrylium dyes are used in polyester, polystyrene, polyvinyl acetate, acrylic resin, polyvinyl butyral, polyvinyl pyrrolidone, polycarbonate, and PVK. , polymethyl methacrylate, vinyl chloride acetate copolymer, methyl cellulose,
It is formed by being dispersed in a binder resin such as hydroxypropyl methylcellulose or cellulose esters.

The thickness of the charge generation layer is approximately 0.05 to 2.0 μl.

In this way, a charge generation layer is formed.

A charge transport layer is formed on the charge generation layer.

The charge transport layer contains polycyclic aromatic compounds such as anthracene, pyrene, phenanthrene, coronene, etc., or indole, carbazole, oxazole, inoxazole, thiazole, imidazole, pyrazole, oxadiazole, pyrazoline, thiadiazole, triazole, etc. in the main chain or side chain. It is formed by dissolving a charge transporting substance such as a compound having a nitrogen-containing cyclic compound or a hydrazone compound in a resin that has film-forming properties. This is because the charge transport material generally has a low molecular weight and has poor film-forming properties by itself. Such resins include polycarbonate, polyarylate, polystyrene, polymethacrylate esters, styrene-methyl methacrylate copolymer, polyester, and styrene-methyl methacrylate copolymer.
7crylonitrile copolymer, polysulfone, and the like.

The thickness of the charge transport layer is approximately 5 to 20 IL.

Next, the above-mentioned protective layer of the present invention is laminated on the charge transport layer.

Example 1 Copolymerized nylon resin (trade name AMILAN CM8000, manufactured by Tsukushishi ■) 4 parts (weight parts, the same applies hereinafter) and 8-nylon resin (trade name Torezin EF) were placed in a 108φ mirror cylinder.
A solution consisting of 60 parts of methyl alcohol and 30 parts of butyl alcohol was applied to 4 parts of 30T (manufactured by Teikoku Kagaku) by dip coating, and a 0.5JL thick polyamide layer (subbing layer) was formed by heating and drying at 50°C for 10 minutes. Formed.

Next, 10 parts of didisazo pigment having the following structure, 5 parts of butyral resin (trade name BL-3, manufactured by Sekisui Chemical ■), and 30 parts of cyclohexanone (T) (F2O part) were dispersed for 200 hours in a sand mill using 1φ glass beads. After diluting this dispersion with cyclohexanone/THF=171, it was dip coated onto the above-mentioned undercoat layer and dried by heating at 80°C for 10 minutes to form a charge generation layer with a coating weight of 0.1 g/m2. did.

Next, 10 parts of p-diethylaminobenzaldehyde-N-β-naphthyl-N-phenylhydrazone as a charge transport substance and 12 parts of styrene-methyl methacrylate copolymer (trade name MS-200, manufactured by Seitetsu Kagaku ■) were dissolved in 70 parts of toluene. and coated on the charge generation layer to form ao'
c. Dry for 10 minutes to form a charge transport layer with a thickness of 16 pL.

Dissolve in 45 parts of dichloromethane and 45 parts of monochlorobenzene.

This polymethyl methacrylate solution was added to 3 parts of polytetrafluoroethylene (trade name: Lubron L2, manufactured by Daikin Industries, Ltd.) and dispersed in a ball mill for 48 hours. After separating the pole, specific example (2) of the hydrazone derivative
Add 5 parts of the compound. 1 monochlorobenzene in this liquid
17 parts were processed and spray coated onto the charge transport layer, and 1
Hot air drying was performed at 10° C. for 60 minutes to form a protective layer with a thickness of 5 JL.

Example 2 In the charge transport layer, 10 parts of p-diethylaminobenzaldehyde-N-diphenylhydrazone and 12 parts of polystyrene (trade name Styron 666, manufactured by Asahi Dow) were used, and in the protective layer, specific examples of the hydrazone derivatives ( 9), 5 parts of the compound, 10 parts of polycarbonate (trade name Panlite L1250, manufactured by Teijin Ltd.), polytetrafluoroethylene (trade name Lubron L5, Daikin Industries ■)
An electrophotographic photoreceptor was obtained in the same manner as in Example 1, except that 3 parts of the sample were used.

Example 3 In the charge transport layer, 1 p-diethylaminobenzaldehyde-N-β-naphthyl-N-phenylhydrazone was added.
0 parts, in the protective layer having the following repeating unit, 5 parts of the compound of the specific example (2) of the hydrazone derivative, 3 parts of polycarbonate polytetrafluoroethylene having the following structure (trade name: Lublon L2, manufactured by Daikin Industries, Ltd.) An electrophotographic photoreceptor was obtained in the same manner as in Example 1 except that .

Example 4 In the charge transport layer, 12 parts of pyrazole polysulfone (trade name P-1700, manufactured by UCC) having the following structure was used, and in the protective layer, a specific example of the hydrazone derivative (
An electrophotographic photoreceptor was obtained in the same manner as in Example 1, except that 5 parts of the compound 4) and 3 parts of the following polytetrafluoroethylene (trade name: Lublon L5F, manufactured by Daikin Industries, Ltd.) were used.

Examples 5 to 7 Electrophotographic photoreceptors were obtained in the same manner as in Example 3, except that the proportion of polytetrafluoroethylene (Luburon L2) used in the protective layer in Example 3 was changed.

Example 5 is 2 parts of polytetrafluoroethylene, Example 6
In Example 7, 5 parts of polytetrafluoroethylene was used, and 10 parts of polytetrafluoroethylene was used in Example 7.

Comparative Example 1 Butyral resin (trade name BL-S, manufactured by fJl Suikagaku ■) was used instead of the polycarbonate resin in the protective layer of Example 3.
An electrophotographic photoreceptor was obtained in the same manner as in Example 3 except that .

Comparative Examples 2 to 4 Electrophotographic photoreceptors obtained in the same manner as in Example 3 except that the proportion of polytetrafluoroethylene in the protective layer of Example 3 was changed as follows.

Comparative Example 2 did not use polytetrafluoroethylene, Comparative Example 3 used 1 part of polytetrafluoroethylene, Comparative Example 4
used 15 parts of polytetrafluoroethylene.

Comparative Example 5 An electrophotographic photoreceptor was obtained in the same manner as in Example 3, except that a pyrazoline compound having the following structure was used instead of the hydrazone derivative in the protective layer of Example 3.

Comparative Examples 6-7 Example 3 except that the thickness of the protective layer in Example 3 was changed as follows.
An electrophotographic photoreceptor obtained in the same manner as above.

Comparative Example 5 had a film thickness of 1.5 mm, and Comparative Example 6 had a film thickness of 15 mm.

For each of the electrophotographic photoreceptors of Examples and Comparative Examples obtained as described above, a copying machine manufactured by Canon Co., Ltd. (NP-7) was used.
045) was modified and evaluated. The results are shown below.

Example 1 3.5 6.3 200,000 sheets no problem Example 22.7 Q, 3 //Example 32.76
．． 3.

Example 42.9 6.3 // Example 52.
7 6.3 tt Example 62.8 5.6
tt Example 73.05. O// also occurs Comparative example 43.53.6 Image roughness Comparative example 71.8
4.0 Image gas sack content (X) Example 1 1 5 16.7 Example 2
1 5 16.7 Example 3 1
5 16.7 Example 4 1
5 16.7 Example 5 2 5
11.8 Example 6 0.5 5 25.
0 Example 7 0.5 or less 5 40.0 Comparative example 1
3 5 16.7 Comparative Example 2 10
5 0 Comparative Example 3 5
5 6.3 Comparative Example 4 0.5 or less 5 50
．． 0 Comparative Example 5 1 5 16.7 Comparative Example 6 1 1 16.7 Comparative Example 7
1 15 16.7 [Effects of the Invention] As is clear from the above description and Examples, the electrophotographic photoreceptor of the present invention has a protective layer made of a polycarbonate resin containing polytetrafluoroethylene and a hydrazone derivative. By.

It has excellent durability, and has the advantage of less toner fusion and filming due to a lower coefficient of friction.

Claims (2)

[Claims] (1) In an electrophotographic photoreceptor having a laminated structure consisting of a conductive support, a charge generation layer, a charge transport layer, and a protective layer, the protective layer is mainly composed of polycarbonate resin, polytetrafluoroethylene, and hydrazone of the following general formula. An electrophotographic photoreceptor characterized by containing a derivative. General formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (1) (In the formula, R_1 and R_2 represent residues forming an alkyl group or a cyclic amino group, and R_3 represents a hydrogen atom or a halogen atom.) (2) The electrophotographic photoreceptor according to claim 1, wherein the content of polytetrafluoroethylene in the protective layer is 8 to 40% by weight.