JPH09114117A - Electrostatic image forming translucent base body, electrophotographic photoreceptor and image forming method using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress deformation in a base body and to eliminate generation of image fog by using copolymer of α-methyl styrene and methacrylate or a polymer blend of poly-α-methylstyrene and polymethacrylate for formation. SOLUTION: Formation is carried out by using copolymer of α-methylstyrene and methacrylate or a polymer blend of poly-α-methylstyrene and polymethacrylate. That is, resin consisting of the copolymer of α-methylstyrene and methacrylate or the polymer blend of poly-α-methylstyrene and polymethacrylate is used for a base body material, and as a result, heat resistance can be improved, so that deformation caused by heat in production of a photosensitive body hardly occurs and deterioration in size precision can be suppressed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transparent substrate for an electrostatic charge image forming body such as an electrophotographic photosensitive member used for image formation in a copying machine, a printer and the like, an image forming method and an image forming apparatus using the same. It is a thing.

[0002]

2. Description of the Related Art In an image forming apparatus using an electrostatic charge image developing system such as electrophotography, a type in which exposure is performed from the inside of an electrostatic charge image forming body has been attracting attention. This is because the high-quality color image can be obtained at high speed, and it is considered to be the best configuration at present to satisfy the user's need to be compact in order to save space in the office.

However, in the case of exposing from the inside of the electrostatic charge image forming body, a transparent electrostatic charge image forming body base having a large diameter capable of accommodating the exposing device therein is required. For example, when glass is used as the material of the substrate, there are problems in productivity, accuracy, lightness, cost, and impact resistance, and it seems difficult to put it into practical use.

Therefore, the applicant of the present invention previously filed Japanese Patent Application No. 7-
No. 13983, a transparent and highly accurate substrate is made of a synthetic resin that is lightweight, has excellent impact resistance, and is low in cost.
The method of making was proposed. However, it has been found that the resin has a problem in heat resistance, and that the methacrylic acid ester resin or the like may be deformed due to heat applied in a drying step during coating of the photosensitive layer. The current situation is that no specific method for solving this has been studied.

[0005]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and was obtained as a result of studying the development of a substrate for an electrostatic charge image forming body from the viewpoint of material. .

Specifically, the substrate is deformed regardless of whether the photoreceptor is prepared using the substrate for the electrostatic charge image forming body having the exposure device housed therein or the image is continuously formed for a long time. SUMMARY OF THE INVENTION It is an object of the present invention to provide a transparent substrate for an electrostatic charge image forming body, which is extremely low in image blurring and the like, an electrophotographic photoreceptor using the same, an image forming method and an apparatus.

[0007]

The object of the present invention is attained by adopting one of the following constitutions.

[1] For an electrostatic charge image-forming body characterized by being formed by a copolymer of α-methylstyrene and methacrylic acid ester or a polymer blend of poly α-methylstyrene and polymethacrylic acid ester Transparent substrate.

[2] On a transparent substrate for an electrostatic charge image-forming body formed by a copolymer of α-methylstyrene and methacrylic acid ester or a polymer blend of poly α-methylstyrene and polymethacrylic acid ester, An electrophotographic photosensitive member comprising a transparent conductive layer and a photosensitive layer.

[3] An electrophotography characterized by using a cylindrical transparent substrate formed by a centrifugal polymerization method, using α-methylstyrene monomer or oligomer and methacrylic acid ester monomer or oligomer as a polymerization component. Photoconductor.

[4] A method of forming a large number of images by uniformly charging the surface of a cylindrical electrophotographic photosensitive member and repeating the steps of image exposure, development, transfer, separation, fixing and cleaning. An image forming method comprising the step of using the electrophotographic photoreceptor described above to form an image by imagewise exposing from the surface side of the photoreceptor.

[5] In an image forming apparatus for forming a large number of images having a cylindrical electrophotographic photosensitive member, a mechanism of uniform charging, image exposure, development, transfer, separation, fixing and cleaning, [2] An image forming apparatus, which uses the electrophotographic photosensitive member described above and forms an image by imagewise exposing from the surface side of the photosensitive member.

As described above, Japanese Patent Application No. 7-13983 proposes a method of manufacturing a transparent and highly accurate substrate using a synthetic resin which is lightweight, has excellent impact resistance, and is low in cost.

Although a methacrylic acid ester resin or the like is used as the resin, it has been examined by the present inventors that, when an organic photosensitive layer or the like is applied at the time of manufacturing a photoreceptor, heat must be applied for drying and the substrate itself It deforms a little and the dimensional accuracy decreases.
It has been found that this causes image blurring and density unevenness during image formation.

As a result of extensive studies to suppress deformation of the transparent substrate during heating, a copolymer of α-methylstyrene and a methacrylic acid ester as a resin, or poly α-
By using a resin formed of a polymer blend of methyl styrene and polymethacrylic acid ester as the base material, heat resistance can be improved, deformation due to heat during the production of the photoconductor does not easily occur, and the dimensional accuracy is reduced. I was able to reduce it. Incidentally, the ester of methacrylic acid ester means an alkyl or aryl ester having 1 to 10 carbon atoms, typically methyl, ethyl,
Represents butyl ester or phenyl ester. Further, additives such as glass fiber and inorganic filler may be added to the resin.

The centrifugal polymerization method, which is a typical method of manufacturing a cylindrical transparent substrate for an image forming apparatus according to the present invention, will be described in detail. As shown in FIG. 1, FIG. 2 shows an example of the manufacturing apparatus.

In the manufacturing apparatus of FIG. 2, C1 is a cylindrical mold, and the inner surface is polished to form a highly accurate cylindrical surface. C2 is a heating member that heats from the outside of the mold C1. C3 is a mold holding member, which sandwiches the mold C1 from the left and right, and in the sandwiched state, the mold C1
The liquid inside does not leak. C4 is an injection port for injecting the polymerizable liquid material. C5 is a thermometer, and the temperature inside the mold C1 is measured. This apparatus has a structure in which the axis of the mold C1 is adjusted to be horizontal, a polymerizable liquid material is injected, and then the mold C1 is rotated at a high speed. After the molding, the cylindrical substrate is taken out by moving one of the mold holding members C3 in the direction of arrow B.

In the manufacturing process shown in FIG. 1, first, a polymerizable liquid material, for example, a monomer for copolymerizing α-methylstyrene and a methacrylic acid ester is synthesized, and a catalyst is added in order to rapidly polymerize the same. Pour into C1. This is rotated for each mold and heated appropriately to promote uniform polymerization. After the completion of the polymerization, for example, annealing treatment such as extremely gentle temperature reduction is performed, followed by cooling to a temperature close to room temperature, taking out the obtained substrate from the mold, cutting and, if necessary, finishing process to obtain a cylindrical shape for an image forming apparatus. The base is completed.

The cylindrical substrate obtained by such a manufacturing process has no internal strain, a hardness comparable to that of aluminum, a light transmittance of 80% or more, and an impact resistance of about 15 times that of glass.

The centrifugal polymerization method of the present invention does not leave die scratches on the surface of the cylindrical substrate as compared with the extrusion method which is a molding method which is widely used at present, and in particular, the inner surface is a natural one obtained by centrifugal force. The surface is molded to form an extremely smooth inner surface such as a glass surface. In addition, the strength is higher than that of the cylindrical substrate obtained by the extrusion method, and it has excellent mechanical strength and heat deformation temperature without any directionality. Furthermore, since there is no uneven light refraction when light is transmitted from a place where internal stress is small, it is used as a cylindrical substrate for an electrostatic charge image forming body (photoreceptor), and an image exposure light source is installed inside it. Even when applied to a forming apparatus, the image exposure is not distorted and the image performance is not deteriorated.

Next, the case where the cylindrical substrate of the present invention is used for an electrostatic charge image forming body will be described. The cylindrical substrate of the present invention has a smooth surface, and in particular, when a copolymer of methyl methacrylate is used, it has excellent transparency and high strength. It is suitable for an image forming apparatus that employs a mechanism for performing exposure from the inside.

A typical example is an electrophotographic photoreceptor having a conductive layer and a photoconductor photosensitive layer provided on the surface of a cylindrical transparent substrate,
In order to provide the conductive layer and the photoconductor photosensitive layer, conventionally used methods can be widely used.

That is, as a method for forming the transparent conductive layer, aluminum, SnO ₂ , ITO (indium tin oxide) or the like is deposited or sputtered with a metal or a metal oxide, or SnO ₂ , ITO or alumina conductive fine particles are used. A typical example is the formation of a coating film of a conductive resin with a mixture of a resin and a resin.

In order to form the photosensitive layer, an inorganic photoconductor layer may be formed by vapor deposition or the like, but an organic photoconductor layer, especially a function separation type containing both a charge transport substance and a charge generating substance, In particular, it is desirable to form an organic photoconductor of the type in which each of them is separately laminated. Further, it is desirable to apply an intermediate layer on the transparent conductive layer before forming the photosensitive layer, and these are typically a resin such as polyamide or a curable type composed of an organometallic compound and a silane coupling agent. is there.

The charge generation layer is formed by dispersing a charge generation material (CGM) in a binder resin as needed. Examples of CGM include metal or metal-free phthalocyanine compounds, azo compounds such as bisazo compounds and trisazo compounds, squarium compounds, azurenium compounds, perylene compounds, indico compounds, quinacridone compounds, polycyclic quinone compounds, cyanine dyes, xanthene dyes, Examples include, but are not limited to, charge transfer complexes comprising poly-N-vinylcarbazole and trinitrofluorenone. These may be used as a mixture of two or more as necessary. However, in order to achieve the object of the present invention at the highest level, one of perylene compounds, one of imidazole perylene compounds and one of metal phthalocyanine compounds, titanyl phthalocyanine (TiOP
c) is preferred.

Examples of the binder resin that can be used in the charge generating layer include polystyrene resin, polyethylene resin, polypropylene resin, polyacrylic resin, polymethacrylic resin, polyvinyl chloride resin, polyvinyl acetate resin, polyvinyl butyral resin, and poly (vinyl butyral) resin. Epoxy resin, polyurethane resin, polyphenol resin, polyester resin, polyalkyd resin, polycarbonate resin, polysilicone resin, polymelamine resin, and copolymer resin containing two or more of the repeating units of these resins, for example, vinyl chloride-acetic acid. Vinyl copolymer resin, vinyl chloride-vinyl acetate-maleic anhydride copolymer resin, and high molecular organic semiconductors such as poly-N-vinylcarbazole,
And the like, but are not limited thereto. Among the above, as a preferred binder when an imidazole perylene compound is used as CGM, a polyvinyl butyral resin is used. As a preferred binder when using TiOPc, a polysilicone resin and a polyvinyl butyral resin, or a mixture of both are used. No.

The charge transport layer is composed of a charge transport material (CTM) alone or with a binder resin. C
Examples of TM include carbazole derivative, oxazole derivative, oxadiazole derivative, thiazole derivative, thiadiazole derivative, triazole derivative, imidazole derivative, imidazolone derivative, imidazolidine derivative, bisimidazolidine derivative, styryl compound,
Hydrazone compounds, pyrazoline derivatives, oxazolone derivatives, benzimidazole derivatives, quinazoline derivatives,
Benzofuran derivatives, acridine derivatives, phenazine derivatives, aminostilbene derivatives, triarylamine derivatives, phenylenediamine derivatives, stilbene derivatives,
Examples include, but are not limited to, benzidine derivatives, poly-N-vinylcarbazole, poly-1-vinylpyrene, poly-9-vinylanthracene, and the like. These may be used alone or in combination of two or more.

Examples of the binder resin usable in the charge transport layer include polycarbonate resin, polyacrylate resin, polyester resin, polystyrene resin,
Examples thereof include, but are not limited to, styrene-acrylonitrile copolymer resin, polymethacrylate resin, and styrene-methacrylate copolymer resin.

Further, in order to reduce fatigue deterioration after repeated use or to improve durability, a conventionally known antioxidant, ultraviolet absorber, electron-accepting substance, surface may be used in any of the layers of the photoreceptor. If necessary, an appropriate amount of a modifier, a plasticizer or the like, an environment dependency reducing agent, etc. may be added and used.

In order to improve durability, a non-photosensitive layer such as a protective layer may be provided in addition to the photosensitive layer, if necessary.

The substrate is a cross-linking agent for an electrostatic image forming body,
By using a conductivity-imparting agent, a colorant and the like mixed with the polymerizable liquid material, more preferable physical properties can be realized. For example, by adding a crosslinking agent, heat resistance, solvent resistance,
The improvement in strength makes it possible to prevent electrostatic stains such as dust by the conductivity-imparting agent and replace the conductive layer. These are effective when external force or heat is applied during use or when an electrostatic charge image forming body is prepared by applying a solution onto a substrate.

Next, an embodiment of the image forming apparatus of the present invention will be described.
The color image forming apparatus of FIG. 3 will be described. FIG.
FIG. 3 is a cross-sectional configuration diagram of a color image forming apparatus showing an example of an image forming apparatus to which the electrophotographic photosensitive member manufactured using the cylindrical transparent substrate of the present invention described above is applied.

The reference numeral 10 designates a photosensitive member which is a drum-shaped electrostatic charge image forming member, and is provided on the outer periphery of a cylindrical substrate formed of a highly transparent copolymer resin of α-methylstyrene and methyl methacrylic acid ester. A functionally separated organic photosensitive layer comprising a transparent conductive layer, an intermediate layer, a charge generation layer and a charge transfer layer is formed. 110Y, 110M, 110C, and 110K are scorotron-type corona charging devices used in the image forming process of each color of yellow (Y), magenta (M), cyan (C), and black (K). In order to hold a charge of a predetermined potential on the photosensitive layer, a charging operation is performed by corona discharge,
A uniform electric potential is applied to.

12Y, 12M, 12C and 12K are
FL (phosphor emission), EL (electroluminescence), PL (plasma discharge), LED (light emitting diode), and lamp and optical shutter functions in which light emitting elements arranged in the axial direction of the photoconductor 10 are arranged in a line in an array. LISA (Opto-Magnetic Effect Optical Shutter Array) in which elements with
PLZT (transmissive piezoelectric element shutter array), LCS
An image of each color read by a separate image reading device with an exposure optical system that is an image exposure device configured as a unit with an exposure element such as a (liquid crystal shutter) and a SELFOC lens as a unity-magnification imaging element. The signals are sequentially taken out from the memory and the exposure optical systems 12Y, 12M, 1
It is input as an electric signal to 2C and 12K, respectively. The exposure optical systems 12Y, 12M, 12C and 1
Each of the 2K is attached to a cylindrical holding member 20 and accommodated inside the base of the photoconductor 10.

13Y, 13M, 13C and 13K are developing devices which are non-contact developing devices for accommodating yellow (Y), magenta (M), cyan (C) and black (K) developers. The developing sleeve 1 rotates in the same direction with a predetermined gap from the peripheral surface of the photoconductor 10.
30Y, 130M, 130C and 130K.

The developing devices 13Y, 13M, 13C and 13K are the corona charging devices 110Y and 110 described above.
Optical system 1 for charging and exposing by M, 110C and 110K
The electrostatic latent image formed on the photoconductor 10 by image exposure with 2Y, 12M, 12C and 12K is reversely developed in a non-contact state by applying a developing bias voltage.

The image of the original is temporarily read as an image signal for each color of Y, M, C and K from an image read by an image pickup device or an image edited by a computer in an image reading apparatus separate from this apparatus. Stored and stored in memory.

When the image recording is started, the photoconductor driving motor is started to rotate the photoconductor 10 in the clockwise direction, and at the same time, the photoconductor 10 is charged by the corona charging device 110Y.
Application of electric potential is started.

After a potential is applied to the photoconductor 10, the exposure optical system 12Y starts exposure by an electric signal corresponding to a first color signal, that is, a yellow (Y) image signal, and the drum is rotationally scanned to expose it. An electrostatic latent image corresponding to the yellow (Y) image of the original image is formed on the photosensitive layer on the surface.

The latent image is reversal-developed by the developing device 13Y with the developer on the developing sleeve in a non-contact state, and a yellow (Y) toner image is formed according to the rotation of the photosensitive drum 10.

Then, the photosensitive drum 10 is further covered with the corona charging device 110M on the yellow (Y) toner image.
Is applied with a potential by the charging action of the exposure optical system 12M, the exposure is performed by an electric signal corresponding to the second color signal of the exposure optical system 12M, that is, the image signal of magenta (M), and the non-contact reverse development by the developing device 13M causes A magenta (M) toner image is sequentially formed on the yellow (Y) toner image.

By the same process, the corona charging device 11
0C, the exposure optical system 12C and the developing device 13C further convert a cyan (C) toner image corresponding to the third color signal into a fourth color signal by the corona charging device 110K, the exposure optical system 12K and the developing device 13K. Corresponding black (K) toner images are sequentially superposed and formed, and a color toner image is formed on the peripheral surface of the photosensitive drum 10 within one rotation.

These exposure optical systems 12Y, 12M, 12C
The exposure of the organic photosensitive layer of the photoconductor drum 10 by (1) and (12K) is performed from the inside of the substrate through the transparent substrate described above. Therefore, the exposure of the image corresponding to the second, third, and fourth color signals is performed without any influence of the toner image previously formed, and is equivalent to the image corresponding to the first color signal. It is possible to form an electrostatic latent image. In order to stabilize the temperature inside the photoconductor drum and prevent the temperature rise due to the heat generated by the exposure optical systems 12Y, 12M, 12C and 12K, a material having good thermal conductivity is used for the holding member 20,
When the temperature is low, a heater is used, and when the temperature is high, heat is radiated to the outside through a heat pipe. Also, the developing device 13
When developing by Y, 13M, 13C and 13K, the developing sleeves 130Y, 130M and 13 are used.
A developing bias in which direct current or further alternating current is applied to 0C and 130K is applied, and jumping development is performed by the one-component or two-component developer accommodated in the developing device, and the photoconductor 10 having the transparent conductive layer grounded. On the other hand, a non-contact reversal development in which a DC bias having the same polarity as that of the toner is applied to attach the toner to the exposed portion is performed.

In this way, the color toner image formed on the peripheral surface of the photosensitive drum is sent from the paper feeding cassette 15 by the sending roller 15a in the transfer device 14a, and is sent to the timing roller 16 by the pair of carrying rollers 15b and 15c. The sheet is conveyed, and is driven by the timing roller 16 to be transferred onto a transfer sheet P that is a transfer material that is fed in synchronization with the toner image on the photoconductor 10.

The transfer paper P on which the toner image has been transferred is separated from the drum peripheral surface by being subjected to the removal of charge in the static eliminator 14b, and then the transport driving roller 14c and the driven roller 14d.
The fixing device 17 is provided by the conveyance belt 14e stretched between
In the fixing device 17, the fixing roller 17 is conveyed to
a, the toner is fused and fixed on the transfer paper P by being heated and pressure-bonded between the pressure roller 17b and the fixing outlet roller pair 17d.
Is discharged from the fixing device 17 by the
The sheet is conveyed by 8a and discharged onto the sheet discharge tray 200 at the upper part of the apparatus via the sheet discharge roller 18. With the above-described photosensitive drum 10 having the photosensitive layer provided on the cylindrical substrate of the present invention, a clear and excellent image was obtained.

On the other hand, the photoconductor 10 from which the transfer paper is separated is cleaned by the cleaning blade 19a in the cleaning device 19.
Thus, the surface of the photoconductor 10 is rubbed to remove and clean residual toner, and the toner image of the original image is continuously formed or is temporarily stopped to form a new toner image of the original image. The waste toner scraped off by the cleaning blade 19a is removed by the toner transport screw 19b.
It is discharged to a waste toner container (not shown).

Since the photoconductor 10 has the exposure optical system housed therein, even if the diameter of the drum is relatively small,
A plurality of corona charging devices 110 described above are provided on the outer peripheral surface thereof.
Y, 110M, 110C and 110K, developing device 13
Y, 13M, 13C, 13K, etc. can be provided, and the volume of the apparatus can be made compact by using a small-diameter drum having an outer diameter of 30 mm to 150 mm.

[0048]

The present invention will be described in detail below with reference to examples, but the embodiments of the present invention are not limited thereto.

1 Preparation of Cylindrical Transparent Substrate A mixture in which the compounding ratio of α-methylstyrene monomer and methyl methacrylate monomer was changed as shown in “Table 1” below,
Azobisisobutyronitrile was added as a catalyst for accelerating the polymerization, and the mixture was heated at 50 ° C. for 3 hours for prepolymerization to obtain a syrup-like polymerizable liquid material having a viscosity of 100 cp. This syrup-like polymerizable liquid material is poured into a cylindrical mold having an inner diameter of 80 mm and a length of 800 mm, and the whole cylindrical mold is rotated and brought into close contact with the inner wall of the mold by centrifugal force, while the entire mold is steamed. Polymerization was performed by heat treatment at 60 ° C. for 9 hours. The obtained substrate was subjected to an annealing treatment for cooling it to room temperature at a rate of 0.2 ° C./minute, and then taken out from the mold. The end portions of the obtained base body were cut to obtain two cylindrical base bodies having an outer diameter of 80 mm and a length of 360 mm. Furthermore, if necessary, the outer peripheral surface was cut with a cutting tool to obtain a cylindrical substrate of the present invention.

[0050]

[Table 1]

The ITO-dispersed resin as a conductive layer was dip-coated on the outer peripheral surfaces of the two cylindrical transparent substrates thus obtained to obtain two cylindrical substrates having a transmittance of 85% for light having a wavelength of 780 nm. It was

2 Formation of Photosensitive Layer (Undercoat Layer) A1 Titanium chelate compound TC-750 (Matsumoto Pharmaceutical Co., Ltd.) 20 parts by weight B1 Silane coupling agent KBM-503 (Shin-Etsu Chemical Co., Ltd.) 13 parts by weight 2- 100 parts by weight of propanol was mixed to obtain a subbing liquid. This is dip-coated on a cylindrical transparent substrate having the conductive layer, dried at 100 ° C. for 90 minutes,
An undercoat layer having a thickness of 1.0 μm was obtained.

(Charge Generating Layer) G1 Y-type titanyl phthalocyanine 4 parts by weight Silicone resin KR-5240 (Shin-Etsu Chemical Co., Ltd.) 45 parts by weight 2-butanone 100 parts by weight are mixed and dispersed in a sand mill for 10 hours to charge. A generating layer coating solution was obtained. This solution was applied onto the undercoat layer by dip coating to obtain a charge generation layer having a thickness of 0.25 μm.

(Charge Transport Layer) T1 charge transport material 8 parts by weight Bisphenol Z-type polycarbonate Z-300 (Mitsubishi Gas Chemical Co., Inc.) 12 parts by weight 2-dichloroethane 100 parts by weight are mixed and dissolved to prepare a charge transport layer coating solution. Obtained. This solution was applied onto the charge generation layer by dip coating and heat-treated at 95 ° C. for 1 hour to form a charge transport layer having a thickness of 25 μm.

[0055]

Embedded image

3 Evaluation The following tests were carried out on each of the photoconductors thus produced.

(1) Dimensional change rate After heating at 100 ° C. for 1 hour, the dimensional change rate in the diameter direction and the length direction was measured.

(2) Image Performance Each image bearing member was mounted on the internal exposure type color image forming apparatus shown in FIG.

[0059]

[Table 2]

The image performance was evaluated by evaluating the printing characteristics, the character image information was applied to the photosensitive member by LED exposure, and the quality of the character image formed on the plain paper through the regular image forming process was evaluated.

The image blur in the table means a state in which the resolution of the character image is not sufficient and the stroke cannot be sufficiently discriminated in small Kanji.

[0062]

According to the present invention, the substrate is not deformed even when it is used as a substrate for an electrostatic image forming body having an exposure device housed therein and is heated during the formation of a photosensitive layer or when image formation is continuously performed for a long time. It is possible to provide a substrate for an electrostatic charge image forming body that is extremely small and does not cause image blurring, and a photoreceptor, an image forming method and an image forming apparatus using the same.

[Brief description of the drawings]

FIG. 1 is a process drawing of a method for manufacturing a cylindrical substrate for an image forming apparatus of the present invention.

FIG. 2 is a sectional view showing an example of a manufacturing apparatus.

FIG. 3 is a cross-sectional configuration diagram of the image forming apparatus of the present invention.

[Explanation of symbols]

10 Photoreceptor (photoreceptor drum) 12Y, 12M Yellow, magenta exposure optical system (exposure device) 12C, 12K Cyan, black exposure optical system (exposure device) 13Y, 13M, 13C, 13K Yellow, magenta, cyan, black Developing device (developing device) 110Y, 110M, 110C, 110K yellow,
Magenta, cyan, and black corona charging device 15 Paper feed cassette 16 Timing roller 17 Fixing device 19 Cleaning device P Transfer paper

Claims (5)

[Claims] 1. A transparent for an electrostatic charge image-forming body, which is formed by a copolymerization polymer of α-methylstyrene and methacrylic acid ester or a polymer blend of poly α-methylstyrene and polymethacrylic acid ester. Substrate. 2. A transparent substrate for an electrostatic charge image forming body, which is formed of a copolymer of α-methylstyrene and a methacrylic acid ester or a polymer blend of poly α-methylstyrene and a polymethacrylic acid ester. An electrophotographic photoreceptor comprising a conductive layer and a photosensitive layer. 3. An electrophotographic photosensitive member characterized by using a cylindrical transparent substrate formed by centrifugal polymerization using α-methylstyrene monomer or oligomer and methacrylic acid ester monomer or oligomer as a polymerization component. . 4. A method for forming a large number of images by uniformly charging a surface of a cylindrical electrophotographic photosensitive member and repeating the steps of image exposure, development, transfer, separation, fixing and cleaning to form a large number of images. An image forming method using the electrophotographic photoconductor of claim 1 to form an image by imagewise exposing from the surface side of the photoconductor. 5. An image forming apparatus for forming a large number of images having a cylindrical electrophotographic photosensitive member, a mechanism of uniform charging, image exposure, development, transfer, separation, fixing and cleaning, and an image forming apparatus according to claim 2. An image forming apparatus using the electrophotographic photosensitive member of 1) to form an image by performing image exposure from the surface side of the photosensitive member.