JPH04240862A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To advance the electrophotographic sensitive body capable of maintaining stable potential characteristics under all the environments from low temperature and low humidity to high temperature and high humidity as the intermediate layer of the body, and forming an image while keeping expected image quality. CONSTITUTION:A powder of N-methoxymethlated-6-nylon processed in contact with a solvent of methyl ethyl ketone and methanol in a ratio for greater than 5/2 weight ratio is used as the intermediate layer 2 of the electrophotographic sensitive body.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic photoreceptor, and more particularly to an electrophotographic photoreceptor having an intermediate layer provided between a support and a photosensitive layer.

0002

[Prior Art] In general, in a Carlson type electrophotographic photoreceptor, stability of dark area potential and bright area potential is required to form a constant image density and fog-free image when charging and exposure are repeated. It has become important.

[0003] For this reason, an intermediate having functions such as improving charge injection from the support to the photosensitive layer, improving adhesion between the support and the photosensitive layer, improving coatability of the photosensitive layer, and covering defects on the support has been developed. It has been proposed to provide a layer between the support and the photosensitive layer.

[0004]Also, a layered structure in which the photosensitive layer is functionally separated into a charge generation layer and a charge transport layer has been proposed, but generally the charge generation layer is an extremely thin layer, for example, 0.0000.
Since it is provided with a thickness of about 5 μm, defects on the support surface,
Dirt, deposits, scratches, etc. cause the charge generation layer to have an uneven thickness. If the thickness of the charge generation layer is non-uniform, uneven sensitivity will occur in the photoreceptor, so it is required that the charge generation layer be made as uniform as possible.

For this reason, it has been proposed to provide an intermediate layer between the charge generation layer and the support, which functions as a barrier layer, an adhesive layer, and covers defects on the support. There is.

Up to now, polyamide (JP-A-46-47344, JP-A-52-25638) and polyester (JP-A-52-25638) have been used as a layer between the photosensitive layer and the support.
20836, JP-A-54-26738), polyurethane (JP-A-49-10044, JP-A-53-894)
No. 35), casein (JP-A-55-103556),
Polypeptide (JP-A-53-48523), polyvinyl alcohol (JP-A-52-100240), polyvinylpyrrolidone (JP-A-48-30936), vinyl acetate-ethylene copolymer (JP-A-48-26141) issue)
, maleic anhydride ester polymer (JP-A-52-101
No. 38), polyvinyl butyral (JP-A-57-906)
39, JP 58-106549), quaternary ammonium salt-containing polymers (JP 51-126149, JP 56-60448), ethyl cellulose (JP 55-143564), etc. known to be used.

In particular, alcohol-soluble nylon resins, preferably copolymerized nylon resins or alkoxymethylated nylon resins, are soluble in many solvents and have excellent film-forming properties, and have thus far been put into practical use.

[0008]

[Problems to be Solved by the Invention] However, in electrophotographic photoreceptors using the above-mentioned materials as intermediate layers, impurities contained in the materials (monomers, oligomers, residual components such as polymerization initiators, polymerization terminators, etc.) The presence of , often causes the following problems.

The resistance of the intermediate layer changes due to changes in temperature and humidity, making it difficult to always obtain stable potential characteristics and image quality in all environments, from low temperature and low humidity to high temperature and high humidity.

For example, if a photoreceptor is used repeatedly under low temperature and low humidity conditions where the resistance of the intermediate layer increases, charges remain in the intermediate layer, resulting in an increase in bright area potential and residual potential, causing fog on copied images. occured. Further, when such a photoreceptor is installed in an electrophotographic printer that performs reversal development, there are problems in that the image becomes pale and copies with a certain image quality cannot be obtained.

[0011] Furthermore, under high temperature and high humidity conditions, the barrier function decreases due to the lower resistance of the intermediate layer, and as a result, carrier injection from the support side increases, resulting in a decrease in dark area potential. As a result, the density of copied images becomes low under high temperature and high humidity conditions, and when such a photoreceptor is installed in an electrophotographic printer that performs reversal development, black dot-like defects (black spots) may appear on the image. ), and fogging is likely to occur.

Furthermore, depending on the type of impurity, there is a problem that carriers may be trapped, resulting in a decrease in sensitivity. The impurities in the resin for the intermediate layer can be removed by the reprecipitation method, in which the resin is completely dissolved in a good solvent, and the resulting solution is dropped into a poor solvent to reprecipitate the resin, or by the reprecipitation method, in which the resin is completely dissolved. There is a cleaning method that uses a solvent that does not dissolve impurities and elutes them.

However, the reprecipitation method requires a large amount of solvent, and when the resin dissolved in a good solvent is dropped into a poor solvent, the precipitated resin gets tangled, resulting in insufficient washing and There are problems in that impurities remain in the resin and that the purity of the resin obtained when the washing operation is done in batches becomes uneven.

[0014] On the other hand, the washing method is a resin purification method that involves introducing and dispersing the resin in a solvent to elute impurities in the resin. However, conventionally, there has been no suitable solvent that does not dissolve alcohol-soluble nylon resins, especially copolymerized nylon resins or alkoxymethylated nylon resins, and that can efficiently elute and remove only impurities in the resins, so it has not been possible to obtain good properties. A stable intermediate layer could not be obtained.

Therefore, an object of the present invention is to provide an electrophotographic photoreceptor that can provide stable potential characteristics and images in all environments from low temperature and low humidity to high temperature and high humidity.

Another object of the present invention is to form an intermediate layer which can sufficiently cover the result on the support. An object of the present invention is to provide an electrophotographic photoreceptor that can form good images without defects.

[0017]

[Means for Solving the Problems] That is, the electrophotographic photoreceptor of the present invention has a photosensitive layer on a support via an intermediate layer, and the intermediate layer contains an alcohol and a ketone. An electrophotographic photoreceptor characterized by containing an alcohol-soluble nylon resin, preferably a copolymerized nylon resin or an alkoxymethylated nylon resin, which does not completely dissolve the target resin in a mixed solvent but has been subjected to contact treatment with the solvent. be.

Preferred alcohol-soluble nylon resins used in the present invention are 6-, 11-, 12-, and 6-
, 6-, 6, 10-, or N-alkoxymethylated nylon resins; nylon resins containing aromatic components; and the like. For example, as shown below.

[0019]

[Table 1] The resin to be treated is preferably pulverized to an appropriate size before contacting with the solvent.

The solvent used for treating the alcohol-soluble nylon resin, preferably the copolymerized nylon resin or the alkoxymethylated nylon resin used in the intermediate layer of the present invention, is a solvent that penetrates into the resin and efficiently extracts impurities. What is needed is something that will not dissolve the resin and will have a non-uniform presence of the resin in the solvent during washing.

Particularly good results were obtained when a mixed solvent containing alcohols and ketones was used as such a solvent.

This is believed to be due to the combination of the excellent permeability of alcohols to alcohol-soluble nylon resins, preferably copolymerized nylon resins or alkoxymethylated nylon resins, and the excellent extraction power of ketones. According to the method of the present invention, it is possible to wash the resin uniformly and with high purity using a small amount of solvent compared to other purification methods. Examples of ketones include acetone, methyl ethyl ketone (
MEK) methyl isobutyl ketone (MIBK), diethyl ketone, etc. Examples of alcohols include methanol, ethanol, n-butanol, isopropanol, n-propanol, and the like. Select one type or more than one type each of ketones and alcohols. Furthermore, other solvents (eg, ethers, petroleum, cellosolve esters, etc.) may be added as necessary.

[0023] The mixing ratio of alcohols and ketones is selected so that the resin swells appropriately and becomes non-uniform (completely dissolved and homogenized, and the wood powder does not harden). Solubility is not a problem, even if a portion of the resin is dissolved.

[0024] If alcohol or other substances are too large, the effect as a mixed solvent will be weakened, so alcohol is preferably 5% to 95%, particularly 20 to 80%. In processing using a solvent, for example, in cleaning, it is also possible to increase the efficiency of extracting impurities by setting the solvent temperature below the azeotropic point of the mixed solvent system. For example, for a combination of methanol and methyl ethyl ketone, methanol 5-50%,
Preferably it is 20-40% (v/v).

[0025] The amount of solvent to be used relative to the resin is selected so that the weight ratio of the former/latter is 1/3 or more, preferably 1/5 or more.

[0026] Furthermore, the solvent may be stirred during washing to prevent the resin from sticking and to improve the efficiency of extracting impurities. Although washing may be carried out once, higher purity can be obtained by washing twice or three times.

The intermediate layer of the present invention may be composed only of an alcohol-soluble nylon resin, preferably a copolymerized nylon resin or an alkoxymethylated nylon resin, or, if necessary, two or more alcohol-soluble nylon resins, preferably It may be composed of a mixed system of copolymerized nylon resin or alkoxymethylated nylon resin, or a system to which other resins and additives are added. Examples of other resins added here include polyester, polyurethane, polyurea, phenolic resin, and the like. Examples of additives include:
Examples include powders such as silicone resins, surfactants, silicone labeling agents, silane coupling agents, and titanate coupling agents.

The layer structure of an electrophotographic photoreceptor having such an intermediate layer is shown in FIG. The intermediate layer 2 is provided between the photosensitive layer 1 and the conductive support 3.

The thickness of the intermediate layer of the present invention is determined by taking into consideration the electrophotographic properties and defects on the support.
A range of 0.1 to 50 μm, particularly 0.5 to 5 μm is preferred. The intermediate layer can be applied by dip coating, spray coating, roll coating, or the like.

In the present invention, the photosensitive layer may be of a single layer type or of a laminated structure type in which the functions are separated into a charge generation layer and a charge transport layer.

The charge generating layer of the laminated photosensitive layer is an azo pigment such as Sudan Red or Diane Blue. Charge-generating substances such as quinone pigments such as pyrenequinone and anthanthrone, quinocyanine pigments, perylene pigments, indigo pigments such as indigo and thioinsigo, phthalocyanine pigments such as azulenium salt pigments, copper phthalocyanine, and aluminophthalocyanine, polyvinyl butyral, polystyrene, and polyacetic acid. It can be formed by dispersing it in a binder resin such as vinyl, acrylic resin, polyvinylpyrrolidone, ethyl cellulose, cellulose acetate butyrate, and coating this dispersion on the above-mentioned intermediate layer. The thickness of such a charge generation layer is 5 μm or less, preferably 0.05 to 2 μm.
It is μm.

The charge transport layer provided on the charge generation layer has biphenylene, anthracene, pyrene,
Polycyclic aromatic compounds with structures such as phenanthrene,
It is formed using a coating liquid in which a charge transport substance such as a nitrogen-containing cyclic compound such as indole, carbazole, oxadiazole, or pyrazoline, a hydrazone compound, or a styryl compound is dissolved in a resin that has film-forming properties. The reason why it is formed in this way is that the charge transport material generally has a low molecular weight and has poor film-forming properties by itself.

Examples of resins having such film-forming properties include polyester, polycarbonate, polymethacrylate, and polystyrene.

The thickness of the charge transport layer is preferably in the range of 5 to 40 μm, particularly 10 to 30 μm.

Note that the charge transport layer may be provided below the charge generation layer.

Further, a single layer type photosensitive layer can be formed by simultaneously containing the above-mentioned charge generating substance and charge transporting substance in the above-mentioned suitable binder resin. In this case, the film thickness is preferably in the range of 8 to 50 μm, particularly 10 to 40 μm.

Furthermore, in the present invention, an organic photoconductive polymer layer such as polyvinylcarbazole or polyvinylanthracene, such as a selenium vapor deposited layer, a selenium-tellurium vapor deposited layer, or an amorphous silicon layer, can also be used as the photosensitive layer.

Note that a protective layer may be provided on the photosensitive layer to improve durability.

On the other hand, the support used in the present invention may be any material as long as it has electrical conductivity, such as a drum or sheet made of metal such as aluminum, copper, chromium, nickel, zinc, or stainless steel. conductive materials, laminated metal foils such as aluminum or copper on plastic films, vapor-deposited materials such as aluminum, indium oxide, tin oxide, etc. on plastic films, or conductive materials coated alone or with a suitable binder resin. Examples include layered metal, plastic film, and paper.

[0040] As the conductive substance used for this conductive layer, metal powder such as aluminum, copper, nickel, silver, etc.
Metal foils and short metal fibers; conductive metal oxides such as antimony oxide, indium oxide, and tin oxide; polymer conductive materials such as polypyrrole, polyaniline, and polymer electrolytes;
Examples include carbon fiber, carbon black, graphite powder; organic and inorganic electrolytes; and conductive powder whose surface is coated with these conductive substances.

Binder resins used for the conductive layer include polyamide, polyester, acrylic resin,
Polyamino acid ester, polyvinyl acetate, polycarbonate, polyvinyl formal, polyvinyl butyral,
Examples include thermoplastic resins such as polyvinyl alkyl ether, polyalkylene ether, and polyurethane elastomer, and thermosetting resins such as thermosetting polyurethane, phenol resin, and epoxy resin.

The weight mixing ratio of the conductive substance and the binder resin is preferably in the range of 10:1 to 1:10, particularly 5:1 to 1:5. This mixing ratio is determined in consideration of the resistance value, surface properties, coating suitability, etc. of the conductive layer.

When the conductive substance is a powder, a ball mill,
A mixture is prepared and used in a conventional manner using a roll mill, sand mill, etc.

[0044] Other additives such as surfactants, silane coupling agents, titanate coupling agents, silicone oil, and silicone leveling agents may also be added.

Furthermore, the intermediate layer containing an alcohol-soluble nylon resin, preferably a copolymerized nylon resin or an alkoxymethylated nylon resin in the present invention may be used as a conductive intermediate layer by containing a conductive substance. . Examples of the conductive substance in this case, the mixing ratio of the conductive substance and the resin, the preparation method, and examples of other additives that may be added are the same as in the case of the conductive layer described above.

Note that the support provided with this conductive intermediate layer does not need to be conductive itself.

Furthermore, in order to control barrier properties, a second intermediate layer containing resin as a main component may be provided on this conductive intermediate layer.

[0048] Examples of the resin material used for the second intermediate layer include polyamide, polyester, polyurethane, polyurea, and phenol resin.

[0049] The thickness of this second intermediate layer is 0.1 to 5μ.
m is preferred.

The electrophotographic photoreceptor of the present invention can be applied to general electrophotographic devices such as copying machines, laser printers, LED printers, and liquid crystal shutter printers, but it can also be applied to displays, recording, light printing, etc. that apply electrophotographic technology. It can also be widely applied to devices such as plate making and facsimile machines.

The present invention will be explained in more detail below with reference to specific examples.

[0052]

[Example] 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
A conductive layer paint was prepared by dispersing for 2 hours in a sand mill using 1 mm glass beads.

[0053] Aluminum cylinder (outer diameter 30mm x
The above paint was applied by dip coating on the 140 mm length).
It was dried at ℃ for 30 minutes to form a conductive layer with a thickness of 20 μm.

Next, as a cleaning step for N-methoxymethylated nylon 6, N-methoxymethylated nylon 6
100 parts by weight (Product name: Toreshin EF
30T (manufactured by Teikoku Kagaku Sangyo) to methyl ethyl ketone (MEK)
) 1000 parts by weight
methanol
The mixture was poured into 400 parts by weight of a mixed solvent.

After washing with stirring for 3 hours, the solvent and resin are separated on a Nutsche.

[0056] Re-resin methyl ethyl ketone (MEK)
1000 parts by weight methanol

The mixture was poured into 400 parts by weight of a mixed solvent and washed with stirring for 3 hours, after which the solvent was separated using a Nutsche filter. The resin was air-dried for 5 hours and then heat-dried at 80° C. for 4 hours.

Next, to prepare an intermediate layer paint, 10 parts by weight of the washed N-methoxymethylated nylon 6.1 was dissolved in 45 parts by weight of methanol and 45 parts by weight of n-butanol to prepare an intermediate layer paint.

[0058] This paint is dip-coated on the conductive layer, and
It was dried at 100° C. for 20 minutes to form an intermediate layer with a thickness of 0.6 μm.

Next, the following structural formula

[0060]

After dispersing 3 parts of the disazo pigment of [Chemical 1], 2 parts of polyvinyl benzal (benzalization rate 80%, weight average molecular weight 11000) and 35 parts of cyclohexanone for 12 hours in a sand mill apparatus using φ1 mm glass beads, methyl ethyl ketone (MEK) was dispersed for 12 hours. ) to prepare a dispersion for a charge generation layer. This dispersion is dip coated onto the above intermediate layer,
It was dried at 80° C. for 20 minutes to form a charge generation layer with a thickness of 0.2 μm.

Next, the following structural formula

[0062]

10 parts of the styryl compound of formula 2 and 10 parts of polycarbonate (weight average molecular weight 46,000) are dissolved in a mixed solvent of 20 parts of dichloromethane and 40 parts of monochlorobenzene, and this solution is dip coated on the above charge generation layer, It was dried at 120° C. for 60 minutes to form a charge transport layer with a thickness of 18 μm.

The electrophotographic photoreceptor thus produced was attached to a reversal development type laser printer in which the process of charging, exposure, development, transfer and cleaning was repeated in a 1.5 second cycle, and the exposure amount was set at 1.7 μJ/. cm2, and the electrophotographic properties were evaluated under normal temperature and normal humidity (23°C, 50% RH) and high temperature and high humidity (30°C, 85% RH) environments.

As a result, as shown in Table 1, in the photoreceptor of Example 1, the difference between the dark area potential (VD) and the light area potential (VL) was large, and sufficient potential contrast was obtained. The dark potential (VD) was stable even under low conditions, and good images without black dot defects (black spots) or fog were obtained. Examples 2 to 5 Electrophotographic photoreceptors were produced in the same manner as in Example 1, except that the mixed solvents shown in Table 1 were used to wash the N-methoxymethylated 6-nylon used in the intermediate layer. and Examples 2 to 5, respectively.

When these photoreceptors were evaluated in the same manner as in Example 1, all of them showed low dark potential (VD) even under high temperature and high humidity.
) was stable, and a good image was obtained without defects on black spots (black spots) or fog.

The results are shown in Table 2.

[0067]

[Table 2] Comparative Example 1 Unrefined N-methoxymethylated 6- as intermediate layer paint
An electrophotographic photoreceptor was produced as Comparative Example 1 in the same manner as in Example 1 except that nylon was used.

When this photoreceptor was evaluated in the same manner as in Example 1, the bright area potential (VL) was high at room temperature and humidity (23° C., 50% RH), and a decrease in sensitivity was observed, as well as a decrease in potential contrast. ing. Furthermore, under high temperature and high humidity conditions, the charging ability deteriorated, a decrease in dark area potential (VD) was observed, and defects on black spots (black spots) began to appear on the image. The results are shown in Table 2. Comparative Example 2 100 parts by weight of N-methoxymethylated nylon 6 was used as an intermediate layer paint, dissolved in 400 parts by weight of methanol, and dropped into 1000 parts by weight of methyl ethyl ketone to purify the resin by reprecipitation. An electrophotographic photoreceptor was produced in the same manner as in Example 1, and was used as Comparative Example 2, except that after the solvent was separated at 100° C., the product was vacuum-dried at 80° C. overnight and used as a comparison product.

When this photoreceptor was evaluated in the same manner as in Example 1, it was found that under high temperature and high humidity conditions, the charging ability deteriorated, the dark area potential (VD) decreased, and defects (black spots) appeared on the image. Black spots) now occur. The results are shown in Table 3. Comparative Example 3 As a paint for the intermediate layer, 10 parts by weight of N-methoxymethylated 6-nylon was heated under reflux at 70°C for 5 hours with 100 parts by weight of methyl ethyl ketone and then heat-washed, which was used as a comparative purified product. An electrophotographic photoreceptor was produced in the same manner as in Example 1, and Comparative Example 3 was prepared.

When this photoreceptor was evaluated in the same manner as in Example 1, it was found that the charging ability deteriorated under high temperature and high humidity conditions, and the dark area potential (
A decrease in VD was observed, and fog appeared over the entire image. The results are shown in Table 3.

[0071]

[Table 3] Example 6 A paint for an intermediate layer similar to that in Example 1 was prepared.

[0072] This paint was dip-coated onto a marminium cylinder (outer diameter 30 mm x length 360 mm) and heated at 100°C.
It was dried for 15 minutes to form an intermediate layer with a thickness of 1.2 μm.

Next, the following structural formula

[0074]

After dispersing 4 parts of the disazo pigment of [Chemical 3], 2 parts of polyvinyl butyral (butyralization rate: 68%, weight average molecular weight: 24,000) and 34 parts of cyclohexanone for 42 hours in a sand mill device using φ1 mm glass beads, methyl ethyl ketone (MEK) was dispersed. A dispersion liquid for a charge generation layer was prepared by adding 60 parts. This dispersion was dip coated onto each of the above intermediate layers and dried at 80°C for 15 minutes to give a film thickness of 0.15 μm.
A charge generation layer was formed.

Next, styryl compound 1 used in Example 1
0 parts and polycarbonate (weight average molecular weight 6300
0) Dissolve 10 parts in a mixed solvent of 15 parts of dichloromethane and 45 parts of monochlorobenzene, apply this solution by dip coating onto the above charge generation layer, and dry at 120°C for 60 minutes.
A charge transport layer having a thickness of 25 μm was formed.

The electrophotographic photoreceptor thus produced was charged, exposed (exposure amount: 2.2 lux·sec), developed, and
It was installed in a copying machine that repeated the transfer-cleaning process in 0.6 second cycles.

[0077] This photoreceptor was exposed to low temperature and low humidity (15°C,
When the electrophotographic characteristics were evaluated in an environment of 15% RH), as shown in Table 2, this photoreceptor had a
) and the bright area potential (VL), and sufficient potential contrast was obtained. Furthermore, when 1000 images were continuously produced, very stable images were obtained without any rise in bright area potential (VL). Examples 7 to 10 Electrophotographic photoreceptors were produced in the same manner as in Example 6, except that Examples 2 to 5 were used as intermediate layer coatings, respectively, to give Examples 7 to 10, respectively.

When these photoreceptors were evaluated in the same manner as in Example 6, the difference between the dark area potential (VD) and the light area potential (VL) was large for each photoreceptor, and sufficient potential contrast was obtained. Even when 1000 images were continuously produced, very stable images were obtained with almost no increase in bright area potential (VL). The results are shown in Table 4. Comparative Example 4 An electrophotographic photoreceptor was produced in the same manner as in Example 6, except that Comparative Examples 2 and 3 were used as the intermediate layer paint, and Comparative Example 4
and 5.

When this photoreceptor was evaluated in the same manner as in Example 6, the bright area potential (VL
) increased, causing fog to appear on the image. The results are shown in Table 4.

[0080]

[Table 4] Example 11 6,12,66,610-quaternary copolymerized nylon (resin) 100 parts by weight [Product name: CM-8000 (
(manufactured by Toray Industries, Inc.)] n-butanol
200
Part by weight Methanol

200 parts by weight methyl ethyl ketone

After pouring into a mixed solvent of 1000 parts by weight and washing with stirring for 2 hours, the solvent was separated using a Nutsche. The obtained washed resin was air-dried for 5 hours and then heated at 80°C for 4 hours.
Heat dried for an hour. Next, 10 parts by weight of this copolymerized nylon was mixed with 5 parts by weight of n-butanol.
0 parts by weight and 40 parts by weight of methanol to prepare an intermediate layer paint. This coating solution was applied by dip coating onto the conductive layer used in Example 1 to form an intermediate layer with a thickness of 1.2 μm.

Next, the following structural formula

[0082]

After dispersing 2 parts of the disazo pigment of [Chemical 4], 1 part of polyvinyl butyral (butyralization rate 72%, weight average molecular weight 18,000) and 30 parts of cyclohexanone in a sand mill device using φ1 mm glass beads for 20 hours, methyl ethyl ketone (MEK) was dispersed. A dispersion liquid for a charge generation layer was prepared by adding 65 parts. This dispersion is dip coated onto the second intermediate layer,
It was dried at 80° C. for 20 minutes to form a charge generation layer with a thickness of 0.2 μm.

Next, the following structural formula

[0084]

10 parts of the hydrazone compound of formula 5 and 10 parts of polycarbonate (weight average molecular weight 46,000) were mixed with 20 parts of dichloromethane.
part, dissolved in a mixed solvent of 40 parts of monochlorobenzene,
This solution was dip coated onto the above charge generation layer and heated to 120°C.
This was dried for 60 minutes to form a charge transport layer with a thickness of 23 μm.

The electrophotographic photoreceptor thus produced was charged, exposed (exposure amount: 2.8 lux·sec), developed, and
It was installed in a copying machine that repeated the transfer-cleaning process in a 0.8 second cycle.

[0086] This photoreceptor was exposed to low temperature and low humidity (10°C,
When the electrophotographic characteristics were evaluated in an environment of 10%RH), as shown in Table 3, this photoreceptor had a
) and the bright area potential (VL), and sufficient potential contrast was obtained. Furthermore, when 1000 images were continuously produced, very stable images were obtained without any rise in bright area potential (VL). Example 12 100 parts by weight of 6,66,610-quaternary copolymerized nylon [trade name: Amilan 4000 (manufactured by Toray Industries, Inc.)] was mixed with a mixed solvent consisting of 200 parts by weight of n-butanol, 200 parts by weight of ethanol, and 1000 parts by weight of methyl ethyl ketone. A conductive intermediate layer, a charge generation layer, and a charge transport layer were formed in the same manner as in Example 11 except for washing with water, and an electrophotographic photoreceptor of Example 12 was manufactured.

When this photoreceptor was evaluated in the same manner as in Example 11, the dark area potential (VD) and the light area potential (VL)
The bright area potential (V
A very stable image was obtained with almost no increase in L). The results are shown in Table 5. Comparative Examples 6 and 7 6,12,66,610-quaternary copolymerized nylon, 6,6
Electrophotographic photoreceptors were produced in the same manner as in Examples 11 and 12, except that an unwashed one made of 6,610-terpolymerized nylon resin was used, and Comparative Examples 6 and 7 were produced, respectively.
And so.

[0088] When each of these photoreceptors was evaluated in the same manner as in Example 11, it was found that in Comparative Example 4, the bright area potential (VL) increased after 1000 continuous sheets were printed, and fog appeared on the image. . The results are shown in Table 4.

[0089]

[Table 5]

[0090]

Effects of the Invention The electrophotographic photoreceptor of the present invention does not substantially dissolve in a mixed solvent containing alcohols and ketones as an intermediate layer between the support and the photosensitive layer, but remains in a non-uniform state. By providing a resin layer containing a washed alcohol-soluble nylon resin, stable potential characteristics can be maintained in all environments from low temperature and low humidity to high temperature and high humidity, and good images can be formed.

[Brief explanation of the drawing]

FIG. 1 shows a schematic cross-sectional view of the layer structure of an electrophotographic photoreceptor.

[Symbols in the diagram]

1 Photosensitive layer 2 Intermediate layer of the present invention 3 Support

Claims (2)

[Claims] Claim 1: In an electrophotographic photoreceptor having a photosensitive layer on a support via an intermediate layer, the intermediate layer does not completely dissolve in a mixed solvent containing alcohols and ketones, and is mixed with the solvent. An electrophotographic photoreceptor characterized by containing an alcohol-soluble nylon resin that has been subjected to a melting process. 2. The electrophotographic photoreceptor according to claim 1, wherein the alcohol-soluble nylon resin is a copolymerized nylon resin or an alkoxymethylated nylon.