JPH0345962A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To obtain stable potential characteristics against environmental conditions and good images by incorporating a polyamide resin grafted with a polymer having specified structural units in an interlayer formed between a substrate and a photosensitive layer. CONSTITUTION:The interlayer contains the polyamide resin grafted with the polymer or copolymer having the structural units represented by formula I in which R1 is H or methyl; Z is O or NH; A is 1 - 6 C alkylene; Y<+> is a group of formula II or the like; and X<-> is an anion, such as halogen ion, perchlorate ion, tetrafluoroboric acid ion, or methylsulfonic ion, thus permitting potential characteristics and obtained images to be stabilized against all the environmental conditions from low temperature and low humidity to high temperature and high humidity.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to an electrophotographic photoreceptor, and more particularly to an electrophotographic photoreceptor having an improved intermediate layer provided between a support and a photosensitive layer. .

[Conventional technology]

In general, in Carlson type electrophotographic photoreceptors, the stability of the dark area potential and bright area potential is important in forming a constant image density and fog-free image when charging and exposure are repeated. .

For this reason, we support an intermediate layer that has 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. It has been proposed to provide the photosensitive layer between the body and the photosensitive layer.

In addition, 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 the charge generation layer is generally provided as an extremely thin layer, for example, about 0.5 μm. Defects, dirt, deposits, scratches, etc. on the surface of the support cause the thickness of the charge generation layer to be non-uniform. If the thickness of the charge generation layer is not 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 generating layer and the support, which functions as a barrier layer, an adhesive layer, and covers defects on the support.

Until now, polyamide (JP-A-46-47344, JP-A-52-25) has been used as a layer between the photosensitive layer and the support.
638), polyester (JP-A-52-20836, JP-A-54-26738), polyurethane (JP-A-49-10044, JP-A-53-89435), casein (JP-A-55-103556) ), polypeptide (JP-A No. 53-48523), polyvinyl alcohol (JP-A No. 52-100240), polyvinylpyrrolidone (JP-A No. 48-30936), vinyl acetate-ethylene copolymer (JP-A No. 48-30936), 48-26141), maleic anhydride ester polymers (JP-A-52-10138), polyvinyl butyral (JP-A-57-90639, JP-A-58-106549), quaternary ammonium salt-containing polymers (JP-A-51-126149, JP-A-56-6
No. 0448), ethylcellulose (Japanese Patent Application Laid-open No. 55-14
No. 3564) and the like are known to be used.

[Problem that the invention is trying to solve] However,
In an electrophotographic photoreceptor using the above-mentioned material as an intermediate layer,
Since the resistance of the intermediate layer changes with changes in temperature and humidity, it has been 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, causing the bright area potential and residual potential to rise, causing fog in copied images and reversal development. When such a photoreceptor is used in an electrophotographic printer, there are problems in that the image density becomes low and copies with a certain image quality cannot be obtained.

Furthermore, under high temperature and high humidity conditions, the barrier function decreases due to the lower resistance of the intermediate layer, and carrier injection from the support side increases, resulting in a decrease in dark area potential. Therefore, under high temperature and high humidity conditions, the density of copied images may become lighter, and when such photoreceptors are used in electrophotographic printers that perform reversal development, black dot-like defects (black spots) may appear on images. , and that capri tends to occur.

[Purpose of the invention]

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 provide an electrophotographic photoreceptor in which a good image without defects can be obtained by forming an intermediate layer that can sufficiently cover defects on the support.

[Means for solving problems]

That is, the electrophotographic photoreceptor of the present invention is an electrophotographic photoreceptor having a photosensitive layer on a support via an intermediate layer, in which the intermediate layer is made of a polymer having a unit component represented by the following formula (1). or a special general formula (I) characterized by containing a polyamide resin grafted with a copolymer 1 In the formula, R1 represents a hydrogen atom or a methyl group, and 2 represents -O
- or -NH-, and A represents an anion such as a chlorate ion, a borofluoride ion, a methyl sulfate ion, a para-toluenesulfonate ion, a thiocyanate ion, etc. having 1 to 6 carbon atoms.

Further, R2, R3 and R4 may be the same or different from each other, and may be an alkyl group such as methyl, ethyl or propyl;
Indicates the residue necessary to represent a phenyl or benzyl group. Further, these groups may have a substituent such as a hydroxyl group, a halogen atom, an alkyl group, or an alkoxy group.

The grafted polyamide resin is obtained by grafting a polymer or copolymer having a unit component represented by the general formula (1) to the polyamide resin used for the main chain by polymer reaction.

The polyamide resins constituting the main chain of the grafted polyamide used in the present invention include 6,11°12,66,
Nylon resins such as 610; and copolymerized nylon resins containing the above components; N-alkoxymethylated and N-alkylated nylon resins; and nylon resins containing aromatic components.

On the other hand, the component constituting the graft side chain is expressed by the general formula (1
) may be a single polymer or a copolymer with other copolymerizable compounds. In the case of a copolymer, the unit component composition of general formula (1) in the graft side chain is 50
It is preferably m o 1% or more, more preferably 70 m o 1% or more.

The content of the grafted portion in the grafted polyamide resin is preferably in the range of 10 to 70 wt%, particularly 15 to 50 wt%.

Further, the grafted polyamide used in the present invention may be crosslinked and used in consideration of solvent resistance to the coating material for the photosensitive layer. Crosslinking is usually carried out using an epoxy compound, a melamine compound, etc. by heat treatment after the coating film is formed. When N-alkoxymethylated nylon resin is used as the polyamide component, self-crosslinking is performed by heating using an acid catalyst such as citric acid, adipic acid, tartaric acid, maleic acid, or hypophosphorous acid without using a crosslinking agent. A crosslinked body can also be formed by.

The main chain component of the polyamide resin used in the present invention is, for example, a polymer having a structure such as 1 +N(-CH2←-C+ CH2OCH3 as a unit component), or a copolymer having two or more of these structures as a unit component. Specific examples of such main chain components are shown below.

Examples of Components of Polyamide Resin Main Chain Next, examples of grafted polyamide resins actually used in the present invention will be shown.

By containing the above-mentioned grafted polyamide resin in the intermediate layer, the electrophotographic photoreceptor of the present invention can be used in environments such as an increase in residual potential under low temperature and low humidity conditions and a decrease in dark area potential due to a decrease in barrier function under high temperature and high humidity conditions. Fluctuations can be prevented.

The grafted polyamide resin of the present invention does not exhibit much variation in volume resistivity under various environments, and when this resin is used as an intermediate layer, an electrophotographic photoreceptor with little environmental variation can be obtained. The resistance of ordinary polyamide resins can drop by three orders of magnitude when exposed to high temperature and high humidity conditions compared to normal temperature and humidity conditions, but with grafted polyamide resins there is almost no change.

The reason why the grafted polyamide resin is less susceptible to environmental changes is not clear, but the following structural factors may be considered.

(1) By attaching graft chains, it becomes easier to become amorphous or mesh than a linear polymer when forming a coating film, and it is easier to retain conductive substances such as water or ions retained inside.

(2) Water, ionic substances, etc. are easily adsorbed due to the polar groups of the graft portion.

From the above two points, the resistance does not increase even under low temperature and low humidity, and the network structure formed in the amorphous prevents excessive water molecules from getting into the coating film, so the resistance increases rapidly even under high temperature and high humidity. It is considered that there is no significant decline.

The grafted polyamide resin used in the present invention is produced by grafting a monomer corresponding to the unit component represented by the general formula (1) to the main chain polyamide resin through a polymer reaction.

Although the polyamide resin that is the main chain is not particularly limited, it is necessary that it has a structure in which the graft portion is polymerized.

Generally, it is known that the methine or methylene group in contact with the N atom of the amide bond has a considerably strong degree of activity and is likely to cause radicalization, and the polyamide resin used in the present invention also has a methine or methylene group in contact with the N atom of the amide bond. Those having a proton on the carbon atom are preferred.

The polymer reaction for grafting involves polyamide resin as the main chain and monomer as the graft component.
A grafted polyamide resin is synthesized by dissolving it in a suitable solvent that also dissolves the monomer and adding a radical initiator such as azobisisobutylnitrile (AIBN) or benzoyl peroxide or an ionic polymerization initiator such as metallic Na. I can do it.

Further, since the grafted polyamide after synthesis often contains impurities such as initiator residues, it is preferable to add purification steps such as reprecipitation and washing.

Next, a specific synthesis example of the resin example [11] will be shown as the grafted polyamide resin used in the present invention.

Synthesis Example 6, 12.66, 610 copolymerized nylon (weight composition ratio:
6/12/66/610=2/l/2/2, weight average molecular weight 140000) 4.0g, AIBFJ O,0
004g was dissolved in 160g of methanol and heated at 40℃ for 3 hours.
The grafting reaction was carried out by heating and stirring for hours. Next, the reaction mixture solution cooled to room temperature was diluted with 200 g of methanol,
This was mixed with 2.3 kg of methyl ethyl ketone (MEK), n-
It was dropped into a mixed solvent containing 1.3 kg of hexane to obtain a white precipitate of grafted polyamide. This precipitate was collected by filtration, washed three times with 400 g of MEK on a filter paper, filtered, and dried under reduced pressure at 35°C for 6 hours to obtain 12.9 g of resin (
I got 113.

The intermediate layer of the present invention may be composed only of the above-mentioned grafted polyamide resin, or may be composed of a system in which other resins and additives are added as necessary. Examples of other resins added here include polyamides such as copolymerized nylon and N-alkoxymethylated nylon, polyesters, polyurethanes, polyureas, and phenolic resins. Examples of additives include powders such as silicone resins, surfactants, silicone leveling agents, silane coupling agents, titanate coupling agents, and the like.

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 l and the conductive support 3.

The thickness of the intermediate layer of the present invention is set in consideration of electrophotographic characteristics and defects on the support, and is 0.1 to 50.
μm1 is particularly preferably in the range of 0.5 to 5 μm. 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 a laminated structure type in which a charge generation layer and a charge transport layer are separated in function.

The charge generation layer of the laminated structure type photosensitive layer contains azo pigments such as Sudan red and Guianpuru, quinone pigments such as pyrenequinone and anthinthrone, quinocyanine pigments, perylene pigments, indigo pigments such as indigo and thioindigo, azlenium salt pigments, copper phthalocyanine, A charge generating material such as a phthalocyanine pigment such as aluminophthalocyanine is dispersed in a binder resin such as polyvinyl butyral, polystyrene, polyvinyl acetate, acrylic resin, polyvinylpyrrolidone, ethyl cellulose, cellulose acetate butyrate, and this dispersion is used as described above. It can be formed by coating on the intermediate layer. The thickness of such a charge generation layer is 5 μm or less, preferably 0.05 to 2 μm.

The charge transport layer provided on the charge generation layer is made of a polycyclic aromatic compound having a structure such as biphenylene, anthracene, pyrene, or phenanthrene in the main chain or side chain, indole,
It is formed using a coating liquid in which a charge transporting substance such as a nitrogen-containing cyclic compound such as 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 with such film-forming properties include polyester,
Examples include polycarbonate, polymethacrylate, polystyrene, and the like.

The thickness of the charge transport layer is 5 to 40 μm, especially 10 to 30 μm.
A range of m is preferred.

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 8~
The thickness is preferably 50 μm, particularly in the range of 10 to 40 μm.

Furthermore, in the present invention, an organic photoconductive polymer layer such as polyvinylcarbazole or polyvinylanthracene, a selenium filtration layer, a selenium-tellurium vapor deposited layer, an amorphous silicon layer, etc. 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 conductivity, such as aluminum, copper,
Metals such as chromium, nickel, zinc, and stainless steel molded into drums or sheets; metal foils such as aluminum and copper laminated on plastic films; and plastic films with aluminum, indium oxide, tin oxide, etc. vapor-deposited on them. Alternatively, examples include metal, plastic film, paper, etc. in which a conductive layer is provided by applying a conductive substance alone or together with a suitable binder resin.

Conductive substances used in this conductive layer include metal powders, metal foils, and short metal fibers such as aluminum, copper, nickel, and silver; conductive metal oxides such as antimony oxide, indium oxide, and tin oxide; polypyrrole. , polyaniline, polymer electrolyte, and other polymer conductive materials; carbon fiber, carbon black, graphite powder; organic and inorganic electrolytes; or conductive powder whose surface is coated with these conductive substances.

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

The weight mixing ratio of the conductive material and the binder resin is 10:1.
~1: 10. Particularly preferred is a range of 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.

If the conductive substance is a powder, use a ball mill, roll mill,
A mixture is prepared and used in a conventional manner using a sand mill or the like.

In addition, other additives include surfactants, silane coupling agents, titanate coupling agents, silicone oil,
A silicone leveling agent or the like may also be added.

Moreover, the intermediate layer containing the grafted polyamide resin in the present invention may be used as an electrically conductive intermediate layer by containing an electrically 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.

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

The thickness of this second intermediate layer is preferably 0.1 to 5 μm.

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 is also applicable to display recording, light printing, plate making, and facsimile applications that apply electrophotographic technology. It can be widely applied to devices such as

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

〔Example〕

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 parts of silicone oil (polymethylsiloxane polyoxyalkylene copolymer, average molecular weight FFI 3000) were dispersed for 2 hours in a sand mill device using φl mm glass beads to form a conductive layer. A paint for this purpose was prepared.

Aluminum cylinder (φ30 mm x 260
The above-mentioned paint was applied by dip coating on M m ) and dried at 140° C. for 30 minutes to form a conductive layer with a thickness of 20 μm.

Next, 3 parts and 5 parts of the aforementioned resin example were dissolved in 95 parts of methanol to prepare an intermediate layer paint.

This paint was applied by dip coating onto the conductive layer and heated to 100℃ for 2 hours.
It was dried for 0 minutes to form an intermediate layer with a thickness of 0.6 μm.

Next, 3 parts of a disazo pigment having the following structural formula, 2 parts of polyvinylbenzal (benzalization rate 80%, weight average molecular weight 11000) and 35 parts of cyclohexanone were dispersed for 12 hours in a sand mill apparatus using φl mm glass beads. A dispersion liquid for a charge generation layer was prepared by adding 60 parts of methyl ethyl ketone (MEK). This dispersion was dip coated onto the above intermediate layer and dried at 80° C. for 20 minutes to form a charge generation layer with a thickness of 0.2 μm.

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

The electrophotographic photoreceptor thus manufactured was attached to a reversal development type laser printer that repeats the process of charging, exposure, development, transfer, and cleaning in a 1.5-second cycle, and the exposure amount was set to 1.7 μJ/err? under normal temperature and humidity (23℃, 50% RH) and high temperature and high humidity (30
The electrophotographic properties were evaluated in an environment of (°C, 85% RH).

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, sufficient potential contrast was obtained, and even under high temperature and high humidity conditions, the dark area Potential (VO) is stable, and defects on sunspots (black spots)
, good images with no fog were obtained.

Resin example (5) for intermediate layer paint, CILL (18
).

Electrophotographic photoreceptors were produced in the same manner as in Example 1, except that [24] was used, and Examples 2 to 5 were obtained, respectively.

When these photoreceptors were evaluated in the same manner as in Example 1, the dark potential (V[1) of all of them was stable even under high temperature and high humidity, and good images were obtained without defects on sunspots (black spots) or fog. Obtained.

The results are shown in Table 1.

N-methoxymethylated 6 nylon (
An electrophotographic photoreceptor was produced as Comparative Example 1 in the same manner as in Example 1, except that a polymer having a weight average molecular weight of 160,000 and a methoxymethyl group substitution rate of 28% was used.

When this photoreceptor was evaluated in the same manner as in Example 1, it was found that the charging ability worsened under high temperature and high humidity conditions, a decrease in dark area potential (VD) was observed, and defects on the image appeared as black spots (black spots). started to occur.

The results are shown in Table 1.

An electrophotographic photoreceptor was produced in the same manner as in Example 1, except that a polymer having the following structural formula (weight average molecular weight: 24,000) was used as a coating material for the intermediate layer of the thermoplastic resin. did.

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 fog appeared on the entire surface of the image. became.

The results are shown in Table 1.

5 parts of Resin Example (12) was dissolved in 95 parts of methanol to prepare a paint for the intermediate layer.

Apply this paint to an aluminum cylinder (φ30mm
360 mm) and dried at 100° C. for 15 minutes to form an intermediate layer with a thickness of 1.2 μm.

Next, 4 parts of a disazo pigment having the following structural formula, 2 parts of polyvinyl butyral (butyral conversion rate: 68%, weight average molecular weight: 24,000), and 34 parts of cyclohexanone were dispersed for 12 hours using a sand mill device using φ1 mm glass beads. A dispersion liquid for a charge generation layer was prepared by adding 60 parts of tetrahydrofuran (THF). This dispersion was dip coated onto each of the above intermediate layers and dried at 80°C for 15 minutes, resulting in a film thickness of 0.15 μm.
A charge generation layer of m was formed.

Next, 10 parts of the styryl compound used in Example 1 and 10 parts of polycarbonate (weight average molecular weight f163000) were dissolved in a mixed solvent of 15 parts of dichloromethane and 45 parts of monochlorobenzene, and this solution was applied onto the above charge generation layer. Dip coating, drying at 120℃ for 60 minutes, film thickness 25μ
A charge transport layer of m was formed.

The electrophotographic photoreceptor thus produced was attached to a copying machine in which a process of charging, exposure (exposure amount: 2.21 ux-sec), development, transfer, and cleaning was repeated in a 0.6 second cycle.

This photoreceptor was exposed to low temperature and low humidity (15°C, 15% R
When the electrophotographic characteristics were evaluated in the environment of H), Table 2
As shown in FIG. 2, this photoreceptor had a large difference between the dark area potential (VD) and the light 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 of resins as medium-temperature layer paints (14), [19],
(25).

Electrophotographic photoreceptors were produced in the same manner as in Example 6, except that [32] was used in each case, and Examples 7 to 10 were obtained, respectively.

When these photoreceptors were evaluated in the same manner as in Example 6, it was found that all of the photoreceptors had a large difference between the dark area potential ("vo") and the bright area potential (VL), and that sufficient potential contrast was obtained and continuous Even after producing 100 images, very stable images were obtained with almost no rise in bright area potential (VL).

The results are shown in Table 2.

Alcohol-soluble copolymerized nylon (
Example 6 except that weight average molecular weight 78000) was used.
An electrophotographic photoreceptor was produced in the same manner as Comparative Example 3.

When this photoreceptor was evaluated in the same manner as in Example 6, the bright area potential (Vt) increased after 1000 continuous sheets were printed, and fog appeared on the image.

The results are shown in Table 2.

Table 30 parts of conductive titanium oxide powder coated with tin oxide containing 10% antimony oxide, 20 parts of rutile type titanium oxide powder, 20 parts of the above resin example [8], 20 parts of methanol
A conductive intermediate layer coating material was prepared by dispersing 10 parts of 2-proper tool for 1 hour in a sand mill using 1 mm diameter glass beads.

The above paint was applied by dip coating onto an aluminum cylinder (φ60 mm x 260 mm) and dried at 160'C for 30 minutes to form an intermediate layer with a thickness of 16 μm.

Next, 5 parts of alcohol-soluble copolymerized nylon (weight average molecular weight 75,000) was dissolved in 95 parts of methanol, and after dip coating on the above intermediate layer, it was dried at 80 ° C. for 10 minutes.
A second intermediate layer having a thickness of 0.3 μm was formed.

Next, 2 parts of a disazo pigment with the following structural formula, 1 part of polyvinyl butyral (butyralization rate 72%, weight average molecular weight 18000) and 30 parts of cyclohexanone were mixed in a sand mill apparatus using φ1 mm glass beads. After dispersing for 20 hours, 65 parts of methyl ethyl ketone (MEK) was added to prepare a dispersion liquid for a charge generation layer. This dispersion was dip coated onto the second intermediate layer and dried at 80° C. for 20 minutes to form a charge generation layer with a thickness of 0.2 μm.

Next, 10 parts of a hydrazone compound having the following structural formula and 10 parts of polycarbonate (weight average molecular weight 46,000) were added to 2 parts of dichloromethane.
0 parts of monochlorobenzene and 40 parts of monochlorobenzene, and this solution was dip-coated onto the above charge generation layer.
It was dried at .degree. C. for 60 minutes to form a charge transport layer with a thickness of 23 .mu.m.

The electrophotographic photoreceptor thus produced was attached to a copying machine in which a process of charging, exposure (exposure amount: 2.81 ux-sec), development, transfer, and cleaning was repeated in a 0.8 second cycle.

This photoreceptor was exposed to low temperature and low humidity (10°C, 10% RH).
) When the electrophotographic characteristics were evaluated in an environment of Ta. Furthermore, when 1000 images were continuously produced, very stable images were obtained without any rise in bright area potential (VL).

A conductive intermediate layer, a charge generation layer, and a charge transport layer were formed in the same manner as in Example 11 except that the second intermediate layer was not provided, and the electrophotographic photoreceptor of Example 12 was manufactured. Manufactured.

When this photoreceptor was evaluated in the same manner as in Example 11,
The difference between the dark area potential (VD) and the light area potential (VL) is large,
Sufficient potential contrast is obtained and continuous 100
Even when 0 images were produced, very stable images were obtained with almost no rise in bright area potential (VL).

The results are shown in Table 3.

L motion 7 An electrophotographic photoreceptor was prepared in the same manner as in Examples 11 and 12, except that a phenol resin was used as the resin in the conductive intermediate layer paint containing conductive titanium oxide powder and rutile-type titanium oxide powder. These were prepared as Comparative Examples 4 and 5, respectively.

When this photoreceptor was evaluated in the same manner as in Example 11,
In Comparative Example 4, the bright area potential (V
L) increased, and fog appeared on the image. In addition, in Comparative Example 5 in which a charge generation layer and a charge transport layer were provided directly on the intermediate layer, the barrier properties of the intermediate layer were insufficient, and the charge injection on the support side -bX etc. was large and the dark potential (vo) was low. , the potential contrast necessary for image formation could not be obtained.

The results are shown in Table 3.

Table 3 Electrophotographic photoreceptors were produced in the same manner as in Example 1, except that Resin Examples [29] and (34) were used as intermediate layer paints, respectively, and Example 13. It was set at 14.

When these photoreceptors were evaluated in the same manner as in Example 1, the dark potential (Vo) of all of them was stable even under high temperature and high humidity.
A good image was obtained with no defects on black spots (black spots) or fog.

The results are shown in Table 4.

Table 4 [Effects of the Invention] As is clear from the above, the electrophotographic photoreceptor of the present invention has the following effects:
By containing a polyamide resin grafted with a polymer or copolymer having a unit component represented by the above-mentioned general formula (I) in the intermediate layer between the support and the photosensitive layer, it is possible to withstand temperatures ranging from low temperature and low humidity to high temperature. Stable potential characteristics and good images can be obtained in all environments including high humidity.

[Brief explanation of drawings]

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

Claims (3)

[Claims] (1) In an electrophotographic photoreceptor having a photosensitive layer on a support via an intermediate layer, the intermediate layer is grafted with a polymer or copolymer having a unit component represented by the following general formula (I). An electrophotographic photoreceptor characterized by containing a polyamide resin. General formula (I) ▲ Numerical formulas, chemical formulas, tables, etc. Indicates a group, Y^+ indicates ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ or ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼, and X^+ indicates an anion. Furthermore, R_2, R_3 and R_4 represent an alkyl group, phenyl group or benzyl group which may be the same or different, and B represents a residue necessary to form a heterocycle containing N.) (2) The electrophotographic photoreceptor according to claim 1, wherein the support comprises a support base and a conductive layer provided thereon. (3) The electrophotographic photoreceptor according to claim 1, wherein the intermediate layer contains a conductive substance, and further has a second intermediate layer containing a resin as a main component between the intermediate layer and the photosensitive layer.