JPH03145652A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To improve an adhesive property and the image quality stability with a change in temp. and humidity by incorporating a resin binder consisting of a specific constituting unit into a charge generating layer. CONSTITUTION:This photosensitive body has an under coating layer of a polyamide resin and melamine resin having heterocycles, the charge generating layer having an org. pigment which generates an electric charge and a charge transfer layer contg. a charge transfer agent on a conductive base body. The charge generating layer contains the resin binder consisting of the constituting unit expressed by formula I and the resin binder consisting of the constituting unit expressed by formula II therein. The number average mol. wt. of the resin binder consisting of the constituting unit expressed by the formula I is preferably inh a 3000 to 200000 range and the number average mol. wt. of the resin binder consisting of the constituting unit expressed by the formula II is preferably in a 5000 to 100000 range. The photosensitive body has the excellent adhesive property, the stable electrophotographic characteristics in a continuous printing test and the excellent image quality stability with a change in temp. and humidity in this way.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to an electrophotographic photoreceptor.

(Prior Art) Conventionally, electrophotographic photoreceptors using photoconductive substances as photosensitive materials have been made of selenium and zinc oxide.

Inorganic photoconductive materials such as titanium oxide and cadmium oxide have been mainly used. But these.

Generally, many of them are highly toxic, and there are problems with how to dispose of them.

On the other hand, the use of organic photoconductive compounds is generally more effective than the use of inorganic photoconductive materials.

Low toxicity, transparency, flexibility, and lightness.

Surface smoothness 9 Since it is advantageous in terms of price, etc.
Recently, it has been widely studied. Among them, functionally separated electrophotographic photoreceptors, which have a charge generation layer that generates charge carriers by light absorption and a charge transport layer that transports the generated charge carriers by an electric field, have conventionally used organic photoconductive compounds. Rapid progress has been made in recent years because it is possible to significantly improve the sensitivity, which was a major drawback of photoreceptors.

When these composite photoreceptors are applied to an electrophotographic device using the Carlson method, an electrostatic latent image is formed on the surface of the photoreceptor, and then toner particles charged with the same or different signs are generated. The toner image is transferred and fixed onto another substrate 2, such as paper, to obtain a copy.

(Problem to be solved by the invention) Electrophotographic photoreceptors can be used in copiers, laser beam printers (
These devices are installed in printers such as light emission diode printers (hereinafter referred to as LBP) and light emission diode printers (hereinafter referred to as T and EDP), but recently, the printing speed of these devices has become faster and the devices themselves have become smaller. Yes, process time per print (charging-exposure-development-erase time)
It also tends to be shorter. Therefore, in terms of electrophotographic properties, the photoreceptor has fast photoresponsiveness, high sensitivity, and excellent charging properties, and in terms of image quality, it satisfies stability against environmental changes and stability for continuous printing. 9 In terms of mechanical strength, there has been an increasing demand for higher adhesion of photoreceptor coatings.

However, by repeating a series of steps such as rapid charging, exposure, development, and erasing, the charging properties of the photoreceptor change and the sensitivity decreases, resulting in the transferred image becoming unclear or the so-called There have been problems such as deterioration in image quality called fog and peeling of the film on the electrophotographic photoreceptor.

The present inventors have proposed a method for preventing changes in the chargeability of the photoreceptor, deterioration in sensitivity, and deterioration in image quality among these drawbacks (Patent Document 1-118847). When this method is used, it is possible to obtain an electrophotographic photoreceptor with good image quality, with little change in the electrophotographic apparatus even with continuous printing and environmental changes, especially changes in temperature and humidity. Although there is no practical problem with the adhesion of the film, it is expected that the printing speed of printers will become faster in the future and the number of prints per surface of the photoreceptor will increase. In this case.

From the viewpoint of the mechanical life of the photoreceptor, it is necessary to further improve the adhesion of the film. A method of improving the adhesion of the film and uniformly applying the charge generation layer to improve the image quality is a method of using phenoxy resin as a resin binder for the charge generation layer (Patent Publication No. 196766/1983). Publications No. 60-232554 and No. 61-65252.

63-33747, 63-243961, etc.), melamine resin, benzoguanamine resin, polyvinyl butyral, polyester resin.

Method of using phenoxy resin in combination (Japanese Patent Application Laid-Open No. 63-855
No. 62, No. 63-187248.

63-271451, etc.) have been proposed. Although these methods are effective in improving adhesion, they are unsatisfactory in terms of photographic properties.

That is, when the continuous printing test is pressed, the charging potential (VO) decreases,
An increase in residual potential (VB), a decrease in sensitivity, etc. occur, and a decrease in density and fog occur.

Additionally, the performance of the photoreceptor changes significantly due to environmental changes, particularly environmental humidity, and due to a decrease in charging potential. black spots, white spots,
This has the problem that image defects such as fogging are likely to occur.

An object of the present invention is to obtain an electrophotographic photoreceptor having stable characteristics and excellent image quality stability against changes in temperature and humidity.

(Means for Solving the Problems) The present invention provides an undercoat layer comprising a polyamide resin having a heterocycle and a melamine resin on a conductive substrate.

In an electrophotographic photoreceptor having a charge generation layer containing an organic pigment that generates a charge and a charge transport layer containing a charge transport agent, the charge generation layer is provided with a resin binder comprising a structural unit represented by formula (I). and an electrophotographic photoreceptor comprising a resin binder comprising a structural unit represented by formula (I[).

The electrophotographic photoreceptor according to the present invention will be described in detail below.

First, in the present invention, the conductive substrate is a conductive body such as a conductive-treated paper or plastic film, a plastic film laminated with metal foil such as aluminum, a metal plate, or a metal drum.

The electrophotographic photoreceptor of the present invention has an undercoat layer made of a polyamide resin having a heterocyclic ring and a melamine resin between the conductive substrate and the charge generation layer from the viewpoint of stability of image quality.

The polyamide resin having a heterocycle is already a known resin 1, for example, M1276, MX1963°MX1964.
．． MX1965. MX1966゜MX1967, MX1
968. It is commercially available as MX1969°MX1970 (all manufactured by Nippon Rilsan ■).

The melamine resin is a well-known resin, such as Methine 2000. Methine 8000. Methine 27, methine 24
5 (manufactured by Hitachi Chemical Co., Ltd.).

For the undercoat layer, to speed up the curing time of the film.

A curing agent such as trimellitic anhydride, trimellitic acid, pyromellitic anhydride, pyromellitic acid, etc. may be added as necessary. When a curing agent is used, the amount used is preferably 10 weight lees based on the total amount of the polyamide resin having a heterocycle and the melamine resin. If the weight exceeds 10 weight φ, moisture resistance tends to decrease.

The undercoat layer can be formed by dipping coating, spray coating, roll coating, or applicator coating on a conductive substrate with a solution prepared by dissolving the resin and a curing agent used as necessary in an appropriate solvent. Construction method.

It can be formed by coating using a coating method such as a wire bar coating method and drying. What is the thickness of the undercoat layer?

0.01-5.0μm, preferably 0.05-2.0μm
It is m. When the thickness is less than 0.01 μm, it becomes difficult to form a uniform charge generation layer, and black spots and white spots tend to occur, resulting in a deterioration in image quality.

It was. If it exceeds 5.0 μm, the accumulation of residual potential increases, and as the number of sheets printed increases, there is a tendency for print density to decrease and fog to occur.

In the present invention, an azoxybenzene-based organic pigment is used as the organic pigment that generates charges that are deposited in the charge generation layer.

Pigments known to generate charges, such as disazo-based, trisazo-based, benzimidazole-based, polycyclic quinoline-based, indigoid-based, quinacridone-based, phthalocyanine-based, perylene-based, methine-based pigments, can be used. These pigments are disclosed in, for example, JP-A No. 9-47-37543, JP-A No. 47-37544, JP-A-Sho 9-47-37543;
No. 18543, No. 47-18544, No. 48-439
No. 42, No. 48-70538, No. 49-1231,
It is described in 49-105536, 50-75214, and 50-92738. Among these pigments, phthalocyanine pigments are preferred in terms of the balance of various electrophotographic properties. It was a cabinet. Among the phthalocyanine pigments, τ, τ', η and η' type gold metal phthalocyanines described in JP-A-58-182640 and European Patent Application Publication No. 92,255 are particularly preferred.

τ, τ, η, and η' type gold metal phthalocyanines have high sensitivity even to long wavelengths and are effective as electrophotographic photoreceptors for printers equipped with diode lasers. In addition to these, any organic pigment that generates charge carriers upon irradiation with light can be used.

The charge generation layer according to the present invention contains, as a resin binder, a 10 resin consisting of structural units represented by the above formulas (I) and (II) as an essential component.

The resin binder consisting of the structural unit represented by formula +11 is already a known brominated bisphenol type resin.

For example, YPB-40AM40. It is commercially available as YPB-43C (manufactured by Tobu Kasei Corporation). formula f
The number average molecular weight of the resin binder consisting of the structural unit represented by I) is preferably in the range of 3,000 to 200,000. a, ooo If there are no drops, the resin strength of the charge generation layer tends to be poor.If it exceeds 200,000, the workability during formation of the charge generation layer tends to deteriorate.

The resin binder consisting of the structural unit represented by the formula (I[) may be a known bisphenol-containing polyester resin, such as Vylon 290. They are commercially available as Nokuiron 29C8 and Byron 29XS (manufactured by Toyobo Co., Ltd.). - The resin represented by Monka (II) has a hydroxyl group at the linear end.

The number average molecular weight of the resin consisting of the structural unit represented by formula (I[) is preferably in the range of 5,000 to 100.000. If it is less than 5.000, the resin strength of the charge generation layer tends to be poor, and if it exceeds 100,000, the workability during formation of the charge generation layer tends to be poor.

The charge generation layer according to the present invention includes a resin binder made of the structural unit represented by the formula (I) and a resin binder made of the structural unit represented by the formula (II), and further includes a resin binder made of the structural unit represented by the formula (II). It is preferable to contain an alkyl etherified benzoguanamine resin capable of reacting with the hydroxyl group of the resin binder consisting of the structural unit represented by the formula (If) or the resin binder consisting of the structural unit represented by the formula (If).

Already known alkyl etherified benzoguanamine resins can be used, but alkyl etherification is possible when the number of formaldehyde bonds per triazine nucleus is 1.5 to 3.0 and the number of methylol groups is 2.0 or less. Benzoguanamine resin is a good choice. It is more preferable that the number of methylol groups is 0.8 or less, and it is particularly preferable that tL<, 0.6 or less.

If the number of bound formaldehydes per triazine nucleus exceeds 3.0, the reactivity decreases, and if it is less than 1.5, the storage stability of the resin tends to deteriorate and the cured coating film tends to become brittle. -1, If the number of methylol groups per triazine nucleus exceeds 2.0, the storage stability of the resin tends to be poor and the cured coating film tends to become brittle.

The alkyl etherified benzoguanamine resin used in the present invention can be produced, for example, by subjecting benzoguanamine to an addition reaction with formaldehyde in an alcohol such as butanol or methanol, or in water, followed by alkyl etherification and condensation reaction under acidic conditions. . Finally, the solvent may be removed to obtain the desired solid content.

In the above reactions, excluding the addition reaction step, hydrochloric acid and sulfuric acid.

An acidic catalyst such as phosphoric acid, p-toluenesulfonic acid, phthalic acid, oxalic acid, or formic acid is added, and the mixture is heated under acidic conditions (preferably p,
It is preferable to carry out H4-6). The reaction temperature is preferably the reflux temperature of the alcohol. For example, butanol is 9.
It is desirable to set the temperature to 5 to 150°C.

3 In addition, it is preferable to use 1.5 to 6 moles of formaldehyde and 1.5 to 6 moles of alcohol per 1 mole of benzoguanamine.

The amount of the resin binder in the charge generation layer is preferably 5 to 200 parts by weight, more preferably 10 to 10 oi*i parts, based on 100 parts by weight of the organic pigment that generates charges.

If it is less than 5 parts by weight, the adhesion will be poor, and the film of the 'vL charge-generating layer will tend to be non-uniform, leading to poor image quality. 200
Beyond the weight section.

Sensitivity tends to decrease and residual potential increases.

The former (formula (■)) vs. the latter (formula (If)) (former/latter)
It is preferable to mix it so that it becomes 278-4/6. When the amount of the resin of formula 9 (I[) increases below 2/8, the sensitivity tends to decrease. When the ratio exceeds 4/6 and the amount of resin of Formula 9 (I) increases, the charge generation layer film tends to become brittle and have poor adhesion.

In addition, the alkyl etherified benzoguanamine 14 resin is 5 parts by weight based on the total amount of the resin binder consisting of the structural units represented by formula (I) and the resin binder consisting of the structural units represented by % (n). It is preferable to use tL< 70 parts by weight, and it is more preferable to use 10 to 30 parts by weight. If the amount is less than 5 parts by weight, the charge generation layer may swell or dissolve in the coating liquid for the charge transport layer;
The film of the charge generation layer tends to be non-uniform, resulting in poor image quality. If it exceeds 70 parts by weight, the dispersibility of the charge generation layer coating solution tends to be poor.

It is also commonly used in charge generation layers in electrophotographic photoreceptors. A plasticizer, fluidity imparting agent, and pinhole control agent can be used as necessary.

Examples of the plasticizer include halogenated paraffin, dimethylnaphthalene, and dibutyl phthalate. As a fluidity imparting agent, Modaflow (Monsanto Chemical Company m
), Acronal 4F (manufactured by Basf), etc.
Examples of pinhole control agents include Citeha, benzoin, and 1-dimethyl phthalate. Each of these is preferably used in an amount of 5 weight percent or less relative to the charge-generating organic pigment.

A method for forming a charge generation layer is to prepare a solution in advance in which an organic pigment that generates a charge, a resin binder, a curing agent used as necessary, an additive used as necessary, etc. are uniformly mixed in a solvent. Dip coating, spray coating, roll coating, or applicator coating on an undercoat layer formed on a conductive substrate.

Coating using a coating method such as wire bar coating method.

Can be dried and formed.

In this case, the solvents used include acetone, methyl ethyl ketone, methyl isobutyl ketone, tetrahydrofuran, toluene, ethyl acetate, cellosolve, xylene,
Methanol, methylene chloride.

1.1.2-) There are solvents such as dichloroethane, isopropyl alcohol, isobutyl alcohol, n-butyl alcohol, and trichloroethane.

The thickness of the charge generation layer is usually 0.001 to 10 μm.

Preferably, the thickness is 0.1 to 5 μm. This thickness is o, oo
When it is less than i, it becomes difficult to uniformly form a charge generation layer, and when it exceeds 10 μm, electrophotographic properties tend to deteriorate.

A charge transport layer is provided on the charge generation layer formed as described above. The charge transport layer contains a charge transport material, a resin binder, and other additives.

Charge transport substances used in the charge transport layer include fluorene, fluorenone, 2,7-sinitro-9-fluorenone, 4H-indeno(I,2,6)thiophene-4-
1, 3,7-sinitrodibenzothiophene-5-oxide, 1-bromopyrene, 2-phenylpyrene, carbazole, 3-phenylcarbazole, 2-phenylindole, 2-phenylnaphthalene, oxazole, oxadiazole, oxatriazole , triphenylamine.

imidazole, chrysene, tetrafen, acridene,
Various hydrazones, styryl compounds, poly-N-vinylcarbazole, halogenated poly'JN-vinylcarbazole, 1-phenyl-3-(4-diethylaminostyryl)-5-(4-diethyl-fluoraminophenyl)pyrazoline, Polyvinyl fin 7.2
-phenyl-4-(4-diethylaminophenyl)-5
-Phenyloxazole, polyhinyl indoquinoxaline, 1,1-bis(p-diethylaminophenyl)-
4,4-diphenyl-1,3-butadiene, polyvinylbenzothiophene, polyvinylanthracene, polyvinylacridine.

Examples include polyvinylpyrazoline and derivatives thereof.

As the resin binder for the charge transport layer, silicone resin,
Polyamide resin, polyurethane resin, polyester resin, epoxy resin, polycarbonate resin, polystyrene resin, polymethyl methacrylate resin, polyacrylamide resin, polybutadiene resin, polyisoprene resin, phenolic resin.

Melamine resin, ethyl cellulose resin, nitrocellulose resin, polyvinyl alcohol resin, tamilvinyl formal fat, polychloropre/resin.

Polyvinyl butyral resin, alkyl vinyl-fluorine resin M combination, cycloalkyl vinyl-fluorine co-8 polymer, vinyl acetate resin, polyacrylonitrile resin,
Examples include urea resin, acrylonitrile-styrene copolymer, maleic anhydride-styrene copolymer, ethylene-vinyl acetate copolymer, vinyl chloride-vinyl acetate copolymer, and blends thereof. Heat and/or photocurable resins can also be used. In any case, any resin may be used as long as it is electrically insulating and can form a film under normal conditions.

There are no particular restrictions. The amount of these resin binders used is preferably 400 parts by weight or less per 100 parts by weight of the charge transport material in order to avoid deterioration of electrophotographic properties. Due to characteristics 5
It is preferable that the amount is 0 parts by weight or more.

It was. In the charge transport layer, additives 9 similar to those in the charge generation layer, such as a plasticizer, a fluidity imparting agent, a pinhole control agent, etc., can be used as necessary. Preferably, each additive is present in an amount of 5 parts by weight or less based on the charge transport material.

To form the charge transport layer, the charge transport material, resin binder, and additives are uniformly dissolved in the same solvent used to create the charge generation layer, and then this solution is applied onto the charge generation layer by dip coating. , spray coating method.

It can be formed by coating using a coating method such as a roll coating method, an applicator coating method, or a wire coating method, and then drying.

The thickness of the charge transport layer is 5 to 50 μm, and preferably tL< is 8 to 30
It is μm. If it is less than 5 μm, the initial potential will be low and 5 μm.
If it exceeds 0 μm, sensitivity tends to decrease.

For the electrophotographic photoreceptor of the present invention, an undercoat layer, a charge generation layer, and a charge transport layer may be sequentially laminated on a conductive substrate, and a protective layer may be further formed thereon. The thickness of the protective layer is
o, oi to 10 μm, preferably 0.1 to 3 μm. If it is less than 0.01 μm, it will have little effect as a protective layer;
Durability is poor, and if it exceeds 10 μm, sensitivity tends to be poor and residual potential increases.

When printing using the electrophotographic photoreceptor of the present invention,
After being charged and exposed in the same manner as in the past, development is performed, and the image is transferred onto plain paper and fixed.

(Example) Next, the present invention will be explained in detail with reference to Examples, but the present invention is not limited thereto. Each material used in the examples below is listed below. Abbreviations are shown in parentheses.

(I) Charge-generating organic pigment τ-type metal-free phthalocyanine (τ-H2PC) (manufactured by Toyo Ink) (2)! Cargo-transporting substance butadiene derivative: 1.1-bis(p-diethylaminophenyl)-4,4 -diphenyl-1,3-butadiene (
PBD) (3) Resin binder (A) Resin binder for undercoat layer Polyamide resin having heterocycle: M1276 (M1276) 100% solids [manufactured by Nippon Rilsan ■] MX1965 (MX1965) 100% solids 1- [Nippon Rilsan ■] [Manufactured by ■] MX1970 (MX1970) Solid content 100 yen [Made by Nippon Rilsan ■] Compound 1 ton 1 ton Melamine resin: Methine 2000 (ML2000) Solid content 50% [Made by Hitachi Chemical ■] Alcohol-soluble nylon resin: CM8000 ( CM8000) Solid content ioo 悌 [manufactured by Toshi ■] (Bi is a resin for the generation layer Resin consisting of the structural unit expressed by the Pine Dani construction formula (I): YPB
-40AM40 (YPB-40) Solid content 40%
[Manufactured by Tobu Kasei ■] Resin consisting of structural units represented by 4 formula (II): Bi-oy290 (V290) Solid content 100% [Manufactured by Toyobo ■] Phenoxy resin: YP-50 (YP-50) Solid content 100 % [Tobu Kasei ■
] Polyvinyl butyral resin: 22-fathom 4000-1 (now 400-1) solid content 100% [manufactured by Denki Kagaku Kogyo ■] Polyester resin: Vylon 200 (V2O3) solid content ioo% [manufactured by Toyobo ■] Hexamethoxy Melamine resin: Sumimaru M-100 (SM-100) solid content 97%
[Manufactured by Sumitomo Chemical ■] Alkyl etherified benzoguanamine resin Nibutyl etherified benzoguanamine resin (BGA-1) Solid content 60% [Produced as follows] Alkyl etherified benzoguanamine resin Nibutyl etherified benzoguanamine resin (BGA-2) Solid content 60
[Produced as follows] (Production of BGA-1) In a flask equipped with a stirrer and a reflux condenser.

Benzoguanamine 1879 (1 mol), n-butanol 2229 (3 mol) and 80% paraformaltehyde 9
Weigh out 3.75 g (2.5 mol).

The temperature was raised to 90°C and addition reaction was carried out for 1 hour. Thereafter, dilute nitric acid was added to adjust the pH to 5.0, and heating was performed again. Dehydration was performed for 3 hours while refluxing. Thereafter, desolvation was started at the same temperature, and when the temperature reached 130°C, the end point of desolvation was determined. After this, make Tsurpets so that the remaining amount after heating is 60%.
Diluted with 100%. The viscosity at this time is S (Gardna/25
°C).

(Production of BGA-2) Using the same equipment as in Production Example 1, benzoguanamine 187
9 (I mol), 296 g (4 mol) of n-butanol, and 187 g (5 mol) of 80% paraformaldehyde were weighed out, heated to 90° C., and subjected to an addition reaction for 2 hours. Thereafter, dilute nitric acid was added to adjust the pH to 5.0. Heat again,
Nine reactions were allowed to proceed while performing reflux dehydration. Finished in 3 hours.

Thereafter, desolvation was started at the same temperature, and the time when the temperature reached 145°C was defined as the end point of desolvation. Thereafter, the mixture was diluted with Tsurpets-100 so that the residual amount after heating was 60. The viscosity at this time was C (Gardna 725°C).

The number of bound formaldehydes and the number of methylol groups per triazine nucleus of BGA-1 and BGA-2 are expressed as lH-NM.
I asked R. The number average molecular weight was calculated by gel permeation chromatography using a standard polystyrene calibration curve (Table 1).

Table 1 (C) Resin binder for charge transport layer Polycarbonate resin Newpilon 8-3000 (UP3000) Solid content 10
0φ [Mitsubishi Gas Chemical ■] Comparative Example 1 IOG 0M8000 was completely dissolved in 190 g of ethyl alcohol.

25 Apply this solution to an aluminum plate (conductive substrate thickness 0.1 mm)
It was coated on top with an applicator and dried at 120° C. for 20 minutes to form an undercoat layer with a thickness of 0.3 μm.

Then 2.59 T-H2Pc, 3.6 g Y
P-50゜93g of tetrahydrofuran was milled in a ball mill (
The mixture was kneaded for 8 hours using a 3-inch pot mill (manufactured by Nippon Kagaku Tougyo). The obtained pigment dispersion was applied onto the undercoat layer using an applicator, and dried at 120°C for 30 minutes to give a film thickness of 0.
A charge generation layer of 3 μm was formed.

Next, a, og of PBD and 7.0 g of UP3000 were mixed in methylene chloride and 1,1,2-trichloroethane in 1:1.
Completely dissolved in 90 g of mixed solvent. This solution was applied onto the charge generation layer having the undercoat layer using an applicator and dried at 120° C. for 30 minutes to form a charge transport layer having a thickness of 18 μm, thereby forming an electrophotographic photoreceptor.

Comparative Example 2 Using the materials and procedures shown in Comparative Example 1, an undercoat layer with a thickness of 0.6 μm was formed on an aluminum plate (conductive substrate thickness: o, i mm).

26 Next, 2.5 g + 7) T-H2PO, 2.5 g (
D+ 4000-1 and 959 tetrahydrone runs were kneaded for 8 hours using a ball mill (3-inch Bottmiln manufactured by Nippon Kagaku Tou Co., Ltd.). The obtained pigment dispersion was applied onto the undercoat layer using an applicator and dried at 120° C. for 30 minutes to form a charge generation layer having a thickness of 0.3 μm.

Comparative Example 3 Using the materials and procedures shown in Comparative Example 1, an undercoat layer with a thickness of 0.4 μm was formed on an aluminum plate (conductive substrate thickness: 0.1 mm).

Next, 25g of T-H2PO, 2.0g of V290°0
．． 59 BGA-2 and 959 tetrahydrofuran (
THF) was kneaded for 8 hours using a ball mill (3-inch ball mill manufactured by Nihon Kagaku Togyo Co., Ltd.). The obtained pigment dispersion was applied to an aluminum plate (conductive substrate thickness 0.1 m) using an applicator.
m) and dried at 120°C for 30 minutes to form a charge generation layer with a thickness of 0.8 μm.

Next, using the substance and operation shown in Comparative Example 1, a film thickness of 18
A charge transport layer with a thickness of μm was formed to form an electrophotographic photoreceptor.

Comparative Example 4 Using the materials and procedures shown in Comparative Example 1, an undercoat layer with a thickness of 0.5 μm was formed on an aluminum plate (conductive substrate thickness: 0.1 mm).

Next, 2.5 g of T-H2Pc, 2.0 g of V2
5M-100 of O00°0.59 and tetrahydrofuran of 959 were kneaded for 8 hours using a ball mill (3-inch bot mill manufactured by Nihon Kagaku Togyo Co., Ltd.). The obtained pigment dispersion was applied onto the undercoat layer using an applicator and heated at 120°C.
This was dried for 30 minutes to form a charge generation layer with a thickness of 0.4 μm.

Next, using the substance and operation shown in Comparative Example 1, a film thickness of 18
A charge transport layer with a thickness of μm was formed to form an electrophotographic photoreceptor.

Example 1 3.5 g of M1276.3.59 ML2000 and o
.

Using the procedure shown in Comparative Example 1, this solution was coated on an aluminum plate (conductive substrate thickness: 0.1 mm) to a thickness of 0.3 μm.
A subbing layer was formed.

Then τ-H2Pc of 2.59, YP of 1.0 g
B40.1.6g of V290, 0.990BGA-1°479 of THF and 47G of methylene chloride were kneaded for 8 hours using a ball mill (3-inch bot mill manufactured by Nippon Kagaku Togyo). The obtained pigment dispersion was applied onto the undercoat layer using an applicator, and dried at 120°C for 30 minutes until the film thickness was 0.
．． A charge generation layer of 4 μm was formed.

Next, using the substance and operation shown in Comparative Example 1, a film thickness of 18
A charge transport layer with a thickness of μm was formed to form an electrophotographic photoreceptor.

Example 2 2.5 g of MXI 965.4.59 ML2000 and 0.159 trimellitic acid were completely dissolved in 939, a 1:1 mixed solvent of methanol and methylene chloride.

9 Apply this solution to an aluminum plate (conductive substrate thickness 0.1 mm).
) with an applicator and dried at 120° C. for 20 minutes to form an undercoat layer with a thickness of 0.3 μm.

Next 3, Og of T-H2PO, 1.0g of YPB-40
°o, 4g V290.0.25g BGA-1 and 4
．． 5 g of THF and 45 g of methylene chloride were kneaded for 8 hours using a ball mill (3-inch bot mill manufactured by Nihon Kagaku Togyo Co., Ltd.). The obtained pigment dispersion was applied onto the undercoat layer using an applicator and dried at 120° C. for 30 minutes to form a charge generation layer having a thickness of 0.3 μm.

Next, 3. ug of PBD and 7.09 of UP3000 in methylene chloride and 1:1 of 1,1,2-trichloroethane.
completely dissolved in the mixed solvent 909. This solution was applied onto the charge generation layer having the undercoat layer using an applicator and dried at 120° C. for 30 minutes to form a charge transport layer having a thickness of 18 μm] to form an electrophotographic photoreceptor.

Example 3 2.5 g of MXI 970.4.59 ML20003
0- and 0.15 g of trimellitic acid were completely dissolved in a 1:1 mixed solvent of methanol and methylene chloride.

This solution was applied to an aluminum plate (conductive substrate thickness: 0.1 mm) using the materials and procedures shown in Comparative Example 1 to form a film with a thickness of 0.
．． A 7 μm undercoat layer was formed.

Next, 3.0 T-H2Pc, 1. Ota's YPB-
43° 0.4g of V290, 0.3g of BGA-1 and 909 of tetrahydrofuran were kneaded for 8 hours using a ball mill (3-inch pot mill manufactured by Nihon Kagaku Togyo).

The obtained pigment dispersion was applied onto an aluminum plate (conductive substrate thickness: 0.1 mm) using an applicator.

It was dried at 120° C. for 30 minutes to form a charge generation layer with a thickness of 0.4 μm.

Next, using the substance and operation shown in Comparative Example 1, a film thickness of 18
A charge transport layer with a thickness of μm was formed to form an electrophotographic photoreceptor.

The electrophotographic photoreceptors obtained in the Comparative Examples and Examples were evaluated for adhesion, electrophotographic characteristics 9 image quality, and resistance to temperature and humidity environments, and the results are shown in Table 2.

Adhesion was determined using a goblin test. 100/100 indicates no peeling at all and good adhesion.

The electrophotographic properties were measured using an electrostatic recording paper tester (Kawaguchi Electric Co., Ltd. 5
P-428). Initial potential in Table 2■
. After setting the sample on the rotating disk of 5P-428,
Approximately -5kV while rotating at 1000 rotations/rotation speed
It shows the charging potential when the corona is left for 10 seconds, and the dark decay Vx is the potential decay when the corona is left in the dark for 30 seconds (Vx = Vso / Vo
Vx indicates the potential after 30 seconds), and the half-decreased exposure amount E50 indicates the light amount value at 1, at which the potential is halved when 10 lux of white light is subsequently irradiated. The residual potential Va indicates the potential after irradiation with white light for 60 seconds. In the durability test, a piece of electrophotographic photoreceptor (60 mm x 70 mm square) was subjected to corona charging (surface potential -1000V±100V) and static electricity removal (
The cycle (wavelength: 500 nm: exposure amount: 50 mJ/m2) was repeated 10,000 times.

The image quality was determined by cutting the pieces of the obtained electrophotographic photoreceptor into pieces with a diameter of 60 mm.
, attached to a 247 mm long aluminum tube using a 9-image evaluation machine (negatively charged 9-reversal development method).

Evaluation was performed at 25° C. and relative humidity of 65% at the initial stage and after 10,000 charging to neutralizing cycles.

The temperature and humidity environment resistance was evaluated by using the same sample and measuring device as in the above image quality test, and evaluating the image quality after the sample was left at 40° C. and 80% relative humidity for 72 hours.

As is clear from the results shown in Table 2, the electrophotographic photoreceptor of the present invention has good adhesion, chargeability, dark decay,
Excellent half-reduction exposure and residual potential. In addition, durability tests (
It shows excellent characteristics even after 10,000 charging-discharging cycles (characteristics after 10,000 charging-discharging cycles), and there is only slight deterioration in electric shock photographic characteristics. Furthermore, it is excellent in image quality and its resistance to temperature and humidity environments (property that does not cause abnormalities even under high temperature and high humidity conditions).

On the other hand, the electrophotographic photoreceptor of the comparative example has problems with the balance of adhesion and electrophotographic properties, or even if these properties are good, the durability test case or the image and its temperature-humid environment resistance case are not good. It is inferior in terms of performance balance, including problems in practical use.

(Effects of the Invention) The electrophotographic photoreceptor of the present invention has excellent adhesion and stable electrophotographic properties in continuous printing tests.

Moreover, the image quality stability against changes in temperature and humidity is excellent.

Claims (1)

[Scope of Claims] 1. An undercoat layer made of a polyamide resin having a heterocycle and a melamine resin on a conductive substrate, a charge generation layer containing an organic pigment that generates a charge, and a charge transport containing a charge transport agent. In an electrophotographic photoreceptor having a layer, the charge generation layer includes a resin binder consisting of a structural unit represented by formula (I) and formula (II) ▲ mathematical formula, chemical formula, table, etc. ▼ (
I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(II) An electrophotographic photoreceptor containing a resin binder consisting of the structural units represented by. 2. The charge generation layer further contains an alkyl etherified benzoguanamine resin capable of reacting with the hydroxyl group of the resin binder consisting of the structural unit represented by formula (I) or the resin binder consisting of the structural unit represented by formula (II). The electrophotographic photoreceptor according to claim 1, which is formed by: 3. The alkyl etherified benzoguanamine resin has a formaldehyde number of 1.5 to 3 bound per triazine nucleus.
．． The electrophotographic photoreceptor according to claim 2, which is an alkyl etherified benzoguanamine resin having 0 and 2.0 or less methylol groups.