JPH04171456A - Electrophotographic sensitized body, and copying machine and facsimile using the same sensitized body - Google Patents

Abstract

PURPOSE:To enable the coating of a protecting layer on a photosensitive layer without harming the photosensitive layer by containing polyamide resin, provided with specific unit elements, in an intermediate layer. CONSTITUTION:In an electrophotographic sensitized body provided with a photo sensitive layer, an intermediate layer and a protecting layer on a conductive base body in this order from the base body side, the intermediate layer contains polyamide resin having unit elements expressed by a formula I. In the formula I, R<1> is a hydrogen atom or a low-grade alkyl group, and R<2> is a substitutional or nonsubstitutional alkyl group, a substitional or nonsubstitutional alkenyl group, a substitutional or nonsubstitutional aromatic ring, a substitutional or nonsubstitutional complex ring, or a substitutional or nonsubstitutional cycloalkyl group having an oxygen atom or a nitrogen atom in beta, gamma, delta positions in relation to a carbonyl group in the formula I. A protecting layer of high durability can be thereby laminated on the outside of the photosensitive layer without harming the photosensitive layer.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to an electrophotographic photoreceptor, and particularly to an intermediate layer when a protective layer made of a curable acrylic resin is used.

[Prior Art] Electrophotographic photoreceptors are required to have the required sensitivity, electrical properties, and optical properties according to the electrophotographic process used. In some cases, electrical and mechanical external forces such as corona charging, toner development, transfer to paper, and cleaning processes are directly applied to the surface layer of the photoreceptor, that is, the layer that is most isolated from the substrate. Durability is required. Specifically, durability is required against surface friction and scratches caused by rubbing, as well as ozone generated during corona charging.

On the other hand, there is also a problem of toner adhesion to the surface layer due to repeated toner development and cleaning, and to solve this problem, it is desired to improve the cleaning properties of the surface layer.

In particular, in the case of positively charging photoreceptors, the layer in the photoconductive layer that is most isolated from the conductive substrate is the charge generation layer, so the surface layer is mechanically and chemically weak, so it is necessary to provide a protective layer. is very effective in terms of durability. In order to satisfy the characteristics required of the surface layer as described above, attempts have been made to provide a surface protective layer containing resin as a main component. For example, as proposed in JP-A-57-30843, a protective layer in which resistance is controlled by adding metal oxide as conductive powder has been proposed.

However, the conventional methods have problems with the dispersibility and cohesiveness of metal oxide particles in the binder resin, conductivity and transparency when used in the protective layer, and non-uniformity of the surface of the protective layer.
Development problems such as image defects due to unevenness, increased residual potential due to repeated charging, and decreased sensitivity were likely to occur.

Furthermore, when a protective layer is laminated on top of a photosensitive layer for positive charging, which has a charge transport layer and a charge generation layer laminated in this order on a substrate, there is often a problem that the sensitivity decreases significantly, and this is not practical. This had become an obstacle.

[Problems to be Solved by the Invention] An object of the present invention is to provide an electrophotographic photoreceptor that meets the above-mentioned requirements. That is, an object of the present invention is to provide an electrophotographic photoreceptor having an intermediate layer that allows a durable protective layer to be coated on the outside of the photosensitive layer without damaging the photosensitive layer. That is, the object of the present invention is to provide an electrophotographic photoreceptor coated with a protective layer that has excellent slipperiness and is resistant to surface abrasion and scratches due to rubbing due to the presence of an intermediate layer. Another object of the present invention is to provide an electrophotographic photoreceptor that does not accumulate residual potential and can maintain high image quality in repeated electrophotographic processes. Still another object of the present invention is to provide an electrophotographic photoreceptor that is free from black dot-like image defects (hereinafter referred to as black dots) and can produce fog-free images.

[Means for Solving the Problems] As a result of extensive studies by the present inventors in accordance with the above-mentioned objective, an electrophotographic photoreceptor having a photosensitive layer, an intermediate layer, and a protective layer on a conductive substrate in this order from the substrate side. Invents an electrophotographic photoreceptor characterized in that the intermediate layer contains a polyamide resin having a unit component represented by the following general formula [1], and provides an electrophotographic photoreceptor that meets the above-mentioned requirements. We were able to.

(2) (In the formula, R1 is a hydrogen atom or a lower alkyl group, and R2 is β to the carbonyl group in general formula (I).

Indicates a substituted or unsubstituted alkyl group, substituted or unsubstituted alkenyl group, substituted or unsubstituted aromatic ring, substituted or unsubstituted heterocycle, substituted or unsubstituted cycloalkyl group having an O atom or N atom at the γ or δ position ).

Hereinafter, the content of the present invention will be explained in detail.

The electrophotographic photoreceptor of the present invention has a photoconductive layer on a conductive substrate,
This is an electrophotographic photoreceptor having an intermediate layer and a protective layer in this order from the substrate side.

Hereinafter, first, the protective layer will be explained.

In the protective layer of an electrophotographic photoreceptor, it is essential to control the resistance in view of chargeability, residual potential, sensitivity, etc. For this reason, attempts have been made in the past to control resistance by dispersing metal oxides in a binder resin in a protective layer. - When particles are dispersed in a protective layer for boat fishing, in order to prevent scattering of incident light by the dispersed particles, the particle size of the particles must be smaller than the wavelength of the incident light, that is, 0.3
It is necessary that the thickness be less than μm. Examples of the resin used in the protective layer of the present invention include resins such as polycarbonate, polyester, phenolic resin polyethylene terephthalate, acrylic resin, polystyrene, cellulose, polyethylene, polypropylene, polyurethane, epoxy, silicone, and polyvinyl chloride.

The present inventors investigated how to satisfy all the characteristics of these fine particles, including dispersibility, wear resistance, and scratch resistance. When ultrafine metal oxide particles are dispersed in resin, the dispersibility of the particles, abrasion resistance, and scratch resistance are excellent! It was found that The conductive metal oxide used in the present invention includes ultrafine particles such as zinc oxide, titanium oxide, tin oxide, antimony oxide, indium oxide, bismuth oxide, tin-doped indium oxide, antimony-doped tin oxide, and zirconium oxide. can be used. These metal oxides may be used alone or in combination of two or more. When two or more types are mixed, they may be in the form of a solid solution or fusion. The curable acrylic monomer is a compound having an acrylic functional group represented by the following general formula [1].

These acrylic monomers may be used alone or in combination with other polyesters, polycarbonates, polystyrene, cellulose, polyethylene, bopropylene, polyurethanes, acrylic resins, epoxy resins, silicones,
It may be mixed with commercially available resins such as polyvinyl chloride.

In the present invention, additives such as a coupling agent and an antioxidant may be added to the protective layer for the purpose of improving dispersibility, binding properties, and weather resistance. The protective layer is formed by applying and curing a solution in which a metal oxide is dispersed in the binder resin.

However, while a protective layer made of a resin containing a curable acrylic monomer satisfies both the dispersibility of the fine particles and the properties of wear resistance and scratch resistance, when it is formed on the photosensitive layer, it soaks the photoreceptor and causes a decrease in sensitivity. It turns out that it has the disadvantage of causing This deterioration in sensitivity was particularly noticeable in positively charging photoreceptors having a charge generation layer as an upper layer.

As a way to deal with this, the present inventors have discovered that it is beneficial to provide a specific intermediate layer between the photosensitive layer and the protective layer, and have established an optimal intermediate layer formulation. Therefore, the middle layer will be explained below.

The intermediate layer of the present invention contains a polyamide resin grafted with a polymer or copolymer having a unit component represented by the general formula [1].

This grafted polyamide resin has a main chain (or backbone polymer)
) is a grafted polyamide resin obtained by grafting a polymer or copolymer produced by a polymer reaction from a unit component represented by the general formula [1] onto a polyamide resin.

Polyamide resins constituting the main chain of the grafted polyamide used in the present invention include 6-nylon, 11-nylon, 12-nylon, 6.6-nylon, 6,10-nylon,
- Various nylons such as nylon; and copolymerized nylons containing two or more of the above components; N-alkoxymethylated, N
- Alkylated nylon; nylon containing an aromatic component, etc.

On the other hand, the component constituting the graft side chain is expressed by the general formula [1
] The unit component may be a single polymer or a copolymer with other copolymerizable compounds. In the case of a copolymer, the composition of the unit component of general formula [1] in the graft side chain is preferably 50 mo1% or more, more preferably 70 mo1% 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 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 is formed. When N-alkoxymethylated nylon is used as the polyamide component, it can be self-crosslinked by heating without using a crosslinking agent, using an acid catalyst such as citric acid, adipic acid, tartaric acid, maleic acid, or hypophosphorous acid. , a crosslinked product can also be formed.

The main chain component of the polyamide resin used in the present invention is, for example, a polymer having a structure such as H11 + N + CH2 + TC (CH,0C)11 as a unit component, or a polymer having two or more of these structures as a unit component. Examples include polymers. Specific examples of such main chain components are shown in the following table.

Examples of Components of Polyamide Resin Main Chain Next, Table 1 shows examples of the polyamide resins shown in graph 1 which are actually used in the present invention.

Table 1 Table 1 (Continued) Table 1 (Continued) By using the intermediate layer containing the above-mentioned grafted polyamide resin, the electrophotographic photoreceptor of the present invention exhibits an increase in residual potential at low temperatures and low humidity, and a high resistance to high temperatures. It has been improved to the extent that it is almost unaffected by environmental changes such as a decrease in dark potential due to a decrease in barrier function at high temperatures.

The grafted polyamide resin in the present invention does not cause much variation in volume resistivity under various environments. When this resin is used as an intermediate layer, an electrophotographic photoreceptor that is less affected by environmental changes can be obtained. Ordinary polyamide resins exhibit resistance that drops by three orders of magnitude when exposed to higher temperatures than room temperature, but grafted polyamide resins do not show any major changes.

The grafted polyamide resin used in the intermediate layer of the present invention can be prepared by grafting a monomer corresponding to the unit component shown in general formula [1] to the main chain polyamide resin by polymer reaction.

The polyamide resin that is the main chain is not particularly limited, but from the viewpoint of its structure, it is necessary that the graft portion is polymerized (formed).

- It is known that the methylene group in contact with the nitrogen atom in the amide bond has a considerably high degree of activity and is prone to radicalization, and the polyamide resin used in the present invention also has a main chain in contact with the nitrogen atom in the amide bond. Those having a proton on the upper carbon atom are preferred.

The polymer reaction for grafting involves dissolving the main chain polyamide resin and the grafting component in an appropriate solvent that dissolves both the polyamide resin and the monomer, and adding azobisisobutyronitrile (ATBN), benzoyl peroxide, etc. A grafted polyamide resin can be produced by adding a radical initiator or an ionic polymerization initiator such as metallic sodium.

Further, since impurities such as initiator residues often remain in the grafted polyamide after production, it is preferable to add purification steps such as reprecipitation and washing before use.

Next, a specific production example of resin example [3] in Table 1 will be shown as the grafted polyamide resin used in the intermediate layer of the present invention.

<Production example> (6-12-6, 6-6, 10) quaternary copolymerized nylon (
Weight composition ratio: 6/12/6.6 /6,10=2/
1/2/2, weight average molecular weight 140000) 11.0
g, a graft monomer CH represented by the following general formula.

7.6g of AIBN and 0.0002g of AIBN were dissolved in 120g of methanol, and the mixture was heated and stirred at 40°C for 3 hours to perform a grafting reaction. Next, the reaction mixture solution cooled to room temperature was diluted with 160 g of methanol, and this was mixed with 2.0 kg of methyl ethyl ketone (MEK) and 1.0 kg of n-hexane.
It was dropped into 2 kg of mixed solvent to obtain a white precipitate of grafted polyamide. This precipitate was collected by filtration, washed three times with 600 g of MEK on a filter paper, and then filtered for 60 minutes at 35°C.
Drying under reduced pressure was performed for hours to obtain 148 g of resin (3).

The intermediate layer of the present invention may be composed of the above-mentioned grafted polyamide alone, or may be composed of a system in which other resins, additives, and conductive substances are added as necessary.

The structure of the photoconductive layer of the electrophotographic photoreceptor of the present invention may be either a single-layer type containing both a charge-generating substance and a charge-transporting substance, or a multilayer type in which a charge-generating layer and a charge-transporting layer are laminated on a conductive substrate. That's it.

The laminated type photoreceptor will be explained below.

The structure of the laminated photosensitive layer includes one in which a charge generation layer and a charge transport layer are laminated in this order on a conductive substrate, and one in which a charge transport layer and a charge generation layer are laminated in this order on a conductive substrate.

If the support used in the present invention has conductivity,
Any type of material may be used, such as a drum or sheet made of metal such as aluminum, copper, chromium, nickel, zinc, or stainless steel; a material made by laminating metal foil such as aluminum or copper onto a plastic film; Examples include plastic films on which indium oxide, tin oxide, etc. are vapor-deposited, and metals, plastic films, and paper on which conductive layers are provided by coating a conductive substance alone or together with a binder resin.

The charge transport layer of the laminated photoreceptor is made of a polycyclic aromatic compound having a structure such as biphenylene, anthracene, pyrene, or phenanthrene in the main chain or side chain, or a nitrogen-containing cyclic compound such as indole, carbazole, oxadiazole, or pyrazoline. It is formed using a coating liquid in which a charge transporting substance such as hydrazone compound, styryl compound, etc. is dissolved in a resin having film-forming properties.

Examples of resins with such film-forming properties include polyester,
Examples include polycarbonate, polystyrene, polymethacrylate, and the like. The thickness of the charge transport layer is 5 to 40
μM, preferably 10 to 30 μm.

The charge-generating layer of the laminated photoreceptor is made of charge-generating substances such as quinone pigments such as Sudan red and Diane blue, indigo pigments such as quinicyanine pigments, penylene pigments, indigo and thioindigo, and phthalocyanine pigments, polyvinyl butyral, polystyrene, and polyester. The pigment is formed by dispersing it in a binder resin such as vinyl acetate or acrylic resin and coating this dispersion, or by vacuum depositing the pigment.

The thickness of such a charge generation layer is 5 μm or less, preferably 0.05 to 3 L1. It is m.

In the present invention, a subbing layer having barrier and adhesive functions may be provided between the conductive layer and the photosensitive layer. The subbing layer can be formed from casein, polyvinyl alcohol, nitrocellulose, ethylene-acrylic acid copolymer, alcohol-soluble amide, polyurethane, gelatin, and the like. The thickness of the undercoat layer is suitably 0.1 parts w to 3 μm.

As described above, the electrophotographic photoreceptor of the present invention has a resin layer made of a polymer or copolymer resin grafted polyamide represented by the general formula [1] as an intermediate layer on the photosensitive layer, and further has fine particles on the resin layer. This is an electrophotographic photoreceptor on which a dispersed protective layer is formed.

According to the present invention, it was possible to form a homogeneous protective layer with high hardness and good dispersibility of conductive particles on the outside of the photosensitive layer without damaging the photosensitive layer. As a result, there are almost no image defects such as unevenness, fogging, and black spots, and it has excellent wear resistance.
It has become possible to provide an electrophotographic photoreceptor that has excellent scratch resistance and high sensitivity.

Further, in the present invention, since there is no deterioration of the photoreceptor due to charging failure, it is possible to provide a photoreceptor without image defects even after repeated durability tests.

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 can also be used in displays, recording, light printing, plate making, etc. that apply electrophotographic technology. It can also be widely applied to devices such as facsimiles.

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

Yaho■ Nialuminum cylinder (outer diameter 30mm x length 260mm)
mm), 10 parts of alcohol-soluble copolymerized nylon resin (average molecular weight 29,000), methoxymethylated 6
Nylon resin (average molecular weight 36,000, methoxylation rate
%) dissolved in a mixed solvent of 260 parts of methanol and 40 parts of butanol was dip coated to provide a 1 part m thick subbing layer.

Next, 10 parts of a styryl compound having the following structural formula and 10 parts of polycarbonate (weight average molecular weight [51000)] were added to 20 parts of dichloromethane.
part, dissolved in a mixed solvent of 40 parts of monochlorobenzene,
This solution was applied by dip coating onto the above-mentioned subbing layer and dried at 120° C. for 60 minutes to form a charge transport layer having a thickness of 18 μm.

Next, 4 parts of a disazo pigment with the following structural formula, polyvinyl butyral (degree of butyralization 68%, weight average molecular weight 280
00) and 30 parts of cyclohexanone were mixed and dispersed in a sand mill for 24 hours, and then 60 parts of tetrahydrofuran (THF) was added to prepare a dispersion for a charge generation layer. This dispersion was spray coated onto the charge transport layer and dried at 80° C. for 20 minutes to form a charge generation layer with a thickness of 0.20 μm.

Next, as a coating solution for the intermediate layer, 2 parts and 5 parts of the polymer shown in Table 1 above were dissolved in 95 parts of methanol to prepare an intermediate layer coating.

This paint was spray coated on the charge generation layer to a film thickness of 1
．． A 5 μm intermediate layer was formed.

Next, 60 parts of an acrylic monomer represented by a curable acrylic represented by the following structural formula, 30 parts of fractional tin oxide ultrafine particles (average particle size 400), and 2-2 as a photoinitiator.
0.1 part of methylruthioxanthone and 300 parts of toluene were mixed and dispersed in a sand mill for 48 hours. Using this mixture, first form a film on the intermediate layer by spray coating,
After drying, use a high-pressure mercury lamp at a light intensity of 8 mW/am2 for 20
A protective layer was obtained by irradiating with ultraviolet rays for seconds.

The electrophotographic photoreceptor produced in this manner was installed in a normal development type copying machine that repeats the process of charging, exposure, development, transfer, and cleaning in a 1.5 second cycle, and the electrophotographic characteristics were evaluated at room temperature. Furthermore, the image printing durability was repeated 10,000 times. As a result, as shown in Table 2, the sensitivity and residual potential were stable, and images without unevenness or black spots could be obtained. Furthermore, a stable image could be maintained even after repeated image display 10,000 times.

Tojo Properties 2 A photoreceptor was prepared and evaluated in the same manner as in Example 1, except that the resin in the coating solution for the intermediate layer in Example 1 was changed to the polymer resin (3) shown in Table 1. was carried out. The results are shown in Table 2.

Example 3 A photoreceptor was prepared and evaluated in the same manner as in Example 1, except that the resin in the coating solution for the intermediate layer in Example 1 was changed to the polymer (6) shown in Table 1. Ta.

The results are shown in Table 2.

Example 4 A photoreceptor was prepared and evaluated in the same manner as in Example 1, except that the resin in the coating solution for the intermediate layer in Example 1 was changed to the polymer (10) shown in Table 1. Ta.

Example 5 A photoreceptor was prepared and evaluated in the same manner as in Example 3, except that the curable acrylic monomer for forming the protective layer was changed to one having the following structural formula. The results are shown in Table 2.

Example 6 A subbing layer was provided on an aluminum cylinder in the same manner as in Example 1. Next, 10 parts of a charge transport material having the following structural formula and 1 part of polycarbonate (weight average molecular weight 28,000)
0 parts, 20 parts of dichloromethane, 40 parts of monochlorobenzene
This solution was applied onto the undercoat layer by dip coating and dried at 120° C. for 60 minutes to form a charge transport layer with a thickness of 18 μm. Next, 4 parts of a disazo pigment with the following structural formula [Et: ethyl group], 2 parts of polyvinyl benzal (benzal conversion rate: 80%, weight average molecular weight: 12,000), and 30 parts of cyclohexane.
After 20 hours of dispersion using a sand mill, 60 parts of methyl ethyl ketone was added to prepare a dispersion for a charge generation layer. This dispersion was spray-coated onto the charge transport layer at 80°C.
C. for 15 minutes to form a charge generation layer of 0.15 .mu.m.

An intermediate layer and a protective layer were formed on this charge generation layer in the same manner as in Example 5 to obtain a photoreceptor.

The electrophotographic photoreceptor manufactured in this way was installed in a reversal development type laser printer that repeats the process of charging, laser exposure, development, transfer, and cleaning in a 1.5 second cycle, and the electrophotographic properties were evaluated. 1000
Durable image printing was performed 0 times. The result is the second
As shown in the table, the sensitivity and residual potential were stable, and images without unevenness or black spots could be obtained.

Examples 7 and 8 Polymer resin (12) exemplified in Table 1 as paint for intermediate layer
Electrophotographic photoreceptors were prepared in the same manner as in Example 6, except that the modified polyamide resins of (20) and (20) were used, and named as Examples 7 and 8, respectively.

When these photoreceptors were evaluated in the same manner as in Example 6, the sensitivity and residual potential were stable, and the images were good with no defects.

The results are shown in Table 2.

Comparative Example 1 A photoreceptor was prepared in the same manner as in Example 1, except that the intermediate layer and protective layer of Example 1 were omitted, and the same evaluation was performed. As a result, as shown in Table 2, the initial electrophotographic properties were good, but after 300 sheets, the charge generation layer on the surface was scraped off and good images could no longer be obtained.

Comparative Example 2 A photoreceptor was prepared and evaluated in the same manner as in Example 1 except that the intermediate layer of Example 1 was omitted.

As a result, as shown in Table 2, the initial electrophotographic sensitivity was extremely low.

Comparative Example 3 The intermediate layer of Example 1 was made of a polycarbonate cap with an average molecular weight of 11
35000) A photoreceptor was prepared and evaluated in the same manner as in Example 1, except that a 1.0 μm film was spray-coated. As a result, as shown in Table 2, the initial residual potential was very high (fogging occurred in the background of the image).

Comparative Example 4 A photoreceptor was prepared and evaluated in the same manner as in Example 6 except that the intermediate layer in Example 6 was omitted.

As a result, as shown in Table 2, the initial electrophotographic sensitivity was extremely low.

[Effects of the Invention] The electrophotographic photoreceptor of the present invention has the aforementioned intermediate layer interposed between the photosensitive layer and the protective layer, thereby laminating a highly durable protective layer on the outside of the photosensitive layer without damaging it. be able to. That is, materials useful for forming a protective layer with excellent slip properties can be selected more freely than before.

Moreover, by using the electrophotographic photoreceptor having the intermediate layer of the present invention, high image quality can be continuously achieved even in continuous durability tests with almost no accumulation of residual potential even after repeated image formation.

[Brief explanation of drawings]

FIG. 1 is a schematic sectional view of a transfer copying machine equipped with the electrophotographic photoreceptor of the present invention, and FIG. 2 is a block diagram of a facsimile system using the electrophotographic photoreceptor of the invention as a printer. [Main symbols in the diagram] 1... Drum-type photoreceptor 12... Charging means 13... Exposure section 14... Developing means 15... Transfer means 16... Cleaning means 18...・Image fixing means L...Light image exposure P...Transfer material agent Patent attorney Tsumi Yamashita Figure 1 Figure 2

Claims (6)

[Claims] (1) In an electrophotographic photoreceptor having a photosensitive layer, an intermediate layer, and a protective layer on a conductive substrate in this order from the substrate side, the intermediate layer is made of a polyamide resin having a unit component represented by the following general formula [1]. Electrophotographic photoreceptor characterized by containing: ▲There are mathematical formulas, chemical formulas, tables, etc.▼General formula [1] (In the formula, R^1 is a hydrogen atom or a lower alkyl group, R^2 is the general formula (1) ) Substituted or unsubstituted alkyl groups, substituted or unsubstituted alkenyl groups, substituted or unsubstituted aromatic rings having O or N atoms at the β, γ, δ positions with respect to the carbonyl group in
substituted or unsubstituted heterocycle, substituted or unsubstituted cycloalkyl group). (2) The electrophotographic photoreceptor according to item 1, wherein the photosensitive layer is a positively charging photosensitive layer formed by laminating a charge transport layer and a charge generation layer in this order from the substrate side. (3) An electrophotographic apparatus comprising an electrophotographic photoreceptor, a latent image forming means, a means for developing the formed latent image, and a means for transferring the developed image to a transfer material, wherein the electrophotographic photoreceptor is the one according to claim 1. An electrophotographic device characterized by being as described in . (4) A facsimile machine comprising an electrophotographic apparatus including the electrophotographic photoreceptor according to claim 1 and a receiving means for receiving image information from a remote terminal. (5) An electrophotographic apparatus comprising the electrophotographic photoreceptor according to claim 1, a latent image forming means, a means for developing the formed latent image, and a means for transferring the developed image onto a transfer material. (6) The electrophotographic photoreceptor according to claim 1, an electrophotographic apparatus comprising a latent image forming means and a means for transferring a developed image to a transfer material, and a receiving means for receiving image information from a remote terminal. A facsimile machine featuring