JP2000019755A - Electrophotographic photoreceptor, process cartridge, and electrophotographic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance a characteristic for an electrophotographic photoreceptor, and to take an environmental problem and safety into account. SOLUTION: In an electrophotographic photoreceptor having a photosensitive layer on a conductive carrier, a thermoplastic resin is used for a resin for forming the photosensitive layer, the resin is dissolved in a solvent, materials for the photoreceptor are dissolved or dispersed into it to prepare an applying solution for the photoreceptor, and the solution is applied to be followed by drying, so as to prepare the photosensitive layer. At least alkyldiketone is used for the solvent in this electrophotographic photoreceptor, this is a process cartridge and this is an electrophotographic device of the present invention.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic photosensitive member, a process cartridge, and an electrophotographic apparatus. More specifically, the present invention relates to an electrophotographic photosensitive member, a process cartridge, and an electronic device using a specific solvent as a solvent for dissolving a binder resin for forming a photosensitive layer. Related to photographic equipment.

[0002]

2. Description of the Related Art An electrophotographic photosensitive member is one of typical image holding members. Electrophotography is instantaneous,
In recent years, since high-quality images can be obtained, they have been widely used and applied not only in the field of copying machines but also in the field of various printers. For the photoreceptor serving as the core, inorganic materials typified by selenium, cadmium sulfide, and zinc oxide have been widely used.
Organic materials have been actively developed from the viewpoints of high productivity, ease of material design, and future potential.

[0003] These electrophotographic photoreceptors are naturally required to have various characteristics such as electrical, mechanical, and optical characteristics according to the electrophotographic process to be applied. In particular, in the case of a photoreceptor that is used repeatedly, electric and mechanical forces such as charging, exposure, development, transfer, and cleaning are repeatedly applied directly or indirectly.

In an organic photoreceptor, an organic photoconductive material is usually dissolved or dispersed in a binder resin to form a coating film and used. The coating film is formed by dissolving or dispersing the organic photoconductive material and the binder resin in a solvent, and then coating and drying. As the binder resin, materials such as vinyl polymers such as polymethyl methacrylate, polystyrene, and polyvinyl chloride and copolymers thereof, polycarbonate, polyester, polyarylate, polysulfone, phenoxy resin, epoxy resin, and silicone resin are used. I have. Among these various resins, polycarbonates and polyarylates relatively satisfy each property as an electrophotographic photosensitive member.

[0005] As a solvent to be dissolved or dispersed, water or an organic solvent is generally used, but it is selected in consideration of the solubility of a binder resin, the solubility or dispersibility of an organic photoconductive material, and the like. Solvents, cyclic ethers and the like have been frequently used.

[0006] Research and development of materials proposed so far have been mainly carried out for improving the characteristics of electrophotographic photoreceptors, and today they are reaching a certain level. It is still not enough, and further improvement is desired. On the other hand, the problem of environmental destruction of chemical substances, the safety to human body, etc. have been highlighted, and the research and development in consideration of various problems and safety have become necessary from the performance-oriented research and development.

Therefore, the present inventors have considered to provide an electrophotographic photosensitive member in consideration of the above-mentioned environmental problems and safety while improving the characteristics of the electrophotographic photosensitive member, and have a photosensitive layer on a conductive support. In an electrophotographic photoreceptor, using a thermoplastic resin to form a photosensitive layer, dissolving the resin in a solvent, and obtaining a photosensitive layer by coating and drying, the object was to use an appropriate solvent as a solvent. .

That is, in many photoreceptors, since the photoreceptor is manufactured by applying a solution or dispersion for the photosensitive layer and then drying, the residual amount of the solvent in the manufactured photoreceptor itself is almost zero. However, no effect on the human body in normal use has been reported as it is.

However, since the photoreceptor is manufactured by applying and drying a solution or dispersion for the photosensitive layer, the atmosphere at the time of manufacture becomes the solvent atmosphere of the solution or dispersion, which adversely affects human bodies involved in the manufacture. Will give. Further, even if the production atmosphere is improved by a local exhaust system or the like, if the exhausted gas phase is discharged into the atmosphere, there is a concern that the environment will be affected. Further, there is a means such as adding a recovery device to the exhaust equipment in order to take countermeasures. However, complete recovery is not easy, and the investment in the equipment is not small.

[0010]

SUMMARY OF THE INVENTION An object of the present invention is to provide an electrophotographic photoreceptor which takes into account environmental issues and safety without at least deteriorating the characteristics of the electrophotographic photoreceptor.

Another object of the present invention is to improve the abrasion resistance and lubricity of the surface layer of a photoreceptor, to provide a long-life, high-quality electrophotographic photoreceptor, a process cartridge having the electrophotographic photoreceptor, and an electrophotographic apparatus. Is to provide.

[0012]

According to the present invention, in an electrophotographic photosensitive member having a photosensitive layer on a conductive support, a thermoplastic resin is used as a resin for forming the photosensitive layer.
An electrophotographic photoreceptor in which a resin is dissolved in a solvent, and a photoreceptor coating solution obtained by dissolving or dispersing the photoreceptor material in the solvent is coated and dried to obtain a photosensitive layer. An electrophotographic photoreceptor using a diketone is provided.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION An alkyl diketone has two ketone structures in the alkyl chain. Among the ketones, monoketones such as acetone have been shown in the production of electrophotographic photoreceptors, and are used for some binder resins. Poor solubility for polyester, polycarbonate, polyarylate, etc. which are said to be suitable for resin for use, and ketones are used for some binder resins, but sufficient solubility is obtained For example, the degree of swelling, the long time required for dissolution, the necessity of heating, the solution stability after dissolution was low, and the production efficiency was not always high.

Although the solubility of the binder resin is improved, the boiling point of the diaryl ether is as high as 250 ° C. or higher, and the system obtained by applying the coating solution for the photosensitive layer and drying cannot easily be dried. Further, if the drying process is performed at a high temperature for further drying, the photoreceptor material is thermally degraded. In addition, halogen-based solvents such as chlorofluorocarbon and halon having excellent solubility have already been regulated from the viewpoint of environmental problems, and the use of methylene chloride and the like has been shown to be suppressed in the future.

Still other solvents include cyclic ethers such as dioxane. Among these organic solvents, carcinogenicity, reproductive toxicity, teratogenicity, teratogenicity, etc. have been reported by organizations advocating safety in Japan, the Americas and Europe. Since information such as mutagenicity is provided, it can be said that it is preferable to avoid future use.

As an example of the provided information,
IARC (US OSHA Hazard Communication Standard-Rules and Hazardous Chemicals List), PROP65 (California, Safe Drinking Water and Toxic Substances Enforcement Act), EU Directive (EU Hazardous Substances List Council Directive Annex), There is the Japan Society for Occupational Health. Based on these, in consideration of the improvement of the characteristics of the electrophotographic photoreceptor and the environment and safety, using a thermoplastic resin as a binder resin for forming the photosensitive layer,
In obtaining a photosensitive layer by dissolving a resin in a solvent and applying and drying the resin, it has been found that at least an alkyl diketone is used as a solvent.

Alkyl diketones are useful for ordinary thermoplastic resins forming the photosensitive layer of the electrophotographic photosensitive member, especially for polycarbonates and polyarylates which are said to be suitable for the resin for the photosensitive layer of the electrophotographic photosensitive member. In terms of solubility, it dissolves in the same manner as conventionally used halogen-based solvents and cyclic ethers, and the strength of the coating film obtained from the solution is the same or higher than before. In addition, this alkyl diketone is not a halogen compound and is naturally not listed as a substance that destroys the ozone layer. Even in the information from the above-mentioned organizations, substances that are not preferable for carcinogenicity, reproductive toxicity, mutagenicity, etc. Is not listed.

That is, when the photoreceptor surface layer is formed by using an alkyl diketone as a solvent, abrasion due to repeated use can be suppressed, the service life can be extended, and environmental and safety aspects can be further improved. It was found that the photosensitive member considered was obtained. Although the mechanism by which the strength has been improved has not been sufficiently investigated, it is assumed that the resin and the solvent have good compatibility, and the polymer molecular chain of the dissolved resin in the solvent is sufficiently expanded, and the coating and drying are performed. It is expected that the film forming conditions at that time will be appropriate and that the entanglement of the molecular chains and the like will be improved.

The alkyl diketone has different physical properties depending on the number of carbon atoms and the position of the ether structure. The alkyl diketone in the present invention is represented by the formula (1).

[0020]

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In the formula, R ₁ and R _{3 each} represent an alkyl chain having 1 to 5 carbon atoms such as methyl and ethyl, and may be linear or branched. R ₂ represents an alkylene chain having 1 to 5 carbon atoms, such as methylene or ethylene, which may be linear or branched, or a single bond that directly bonds both ketone structures. Further, those having a total carbon number of 5 or 6 are particularly preferred. This preferred range is not limited by solubility, and is shown in terms of film thickness uniformity, film strength, and the like during coating and drying during photoreceptor formation.

Specific examples are shown in Table 1 below, but the present invention is not limited only to the following structures.

[0023]

[Table 1]

Hereinafter, the structure of the electrophotographic photosensitive member of the present invention will be described. The electrophotographic photoreceptor of the present invention has a single layer in which the photosensitive layer contains a charge transport material and a charge generation material in the same layer, a charge transport layer containing a charge transport material and a charge generation layer containing a charge generation material. This is applied to any of the stacked types having:

As the thermoplastic resin of the present invention, those usually used for electrophotographic photosensitive members can be used, and there is no particular limitation. For example, resins such as polycarbonate, polyarylate, polyester, polystyrene, polyvinyl butyral, polyvinyl benzal, polyamide, and polyether are exemplified. Among these, when used as a resin for the surface layer, polycarbonate and polyarylate having excellent film strength and the like are preferable.

The binder resin and solvent for forming the photosensitive layer of the present invention are not limited in the photosensitive layer to be used.
A layer used by dissolving and dispersing a material (for example, a charge generation material or a charge transport material) for forming a photoreceptor in a binder resin, for example, in a laminated photoreceptor, an undercoat layer, a charge generation layer, a charge transport layer, It is possible for the protective layer and also for a single layer type.

When polycarbonate or polyarylate is used as the surface layer as the binder resin to be used, not only good solubility can be obtained, but also
The strength of the coating film obtained after coating and drying was improved as compared with the case of using a halogen-based solvent or a cyclic ether-based solvent which has been conventionally used. The preferred mixing ratio of the solvent and the binder resin in the present invention varies depending on the purpose of use and the material used, but can be used in a range in which the binder resin is soluble.

As the charge generating material in the present invention, those which are generally known can be used.
Examples include pigments such as tellurium, pyrylium, metal phthalocyanine, metal-free phthalocyanine, anthantrone, dibenzopyrenequinone, trisazo, cyanine, disazo, monoazo, indigo, and quinacdrine. These pigments were dispersed well using a homogenizer, ultrasonic dispersion, a ball mill, a vibration mill, a sand mill attritor, a roll mill, a liquid collision type high-speed disperser, etc. together with a binder resin and a solvent in a weight of 0.3 to 4 times. Make it a dispersion. In the case of a laminated type photoreceptor, this liquid is applied and dried to obtain a charge generation layer. The thickness is preferably 5 μm or less, more preferably 0.1 to 2 μm.

As the charge transporting material, those commonly used can be used. For example, triarylamine compounds, hydrazine compounds, stilbene compounds, pyrazoline compounds, oxazole compounds, triallylmethane compounds, thiazole compounds and the like can be used. No. These compounds are dissolved in a solvent together with a binder resin to form a solution. In the case of a laminated photoreceptor, a charge transport layer is obtained by applying and drying this liquid. The thickness is preferably from 5 to 40 μm, more preferably from 15 to 30 μm.

When the photosensitive layer is a single layer type, the photosensitive layer can be formed by applying a solution in which the above-described charge generating material or charge transporting material is dissolved in the above-described binder resin in a solvent, and drying. . The thickness is preferably from 5 to 40 μm, more preferably from 15 to 30 μm.

The protective layer can be obtained by applying and drying a solution obtained by dissolving the above-mentioned binder resin in a solvent. If necessary, a conductive material for controlling the resistance value of the protective layer of the electrophotographic photosensitive member, a lubricating material for providing lubricity, and the like can be added. In the case of a photoreceptor having no protective layer, an antioxidant or a lubricant may be used for the surface layer as necessary.

Further, in the present invention, a support and a photosensitive layer,
Alternatively, an intermediate layer having an adhesive function and a charge barrier function can be provided between the conductive layer and the photosensitive layer, if necessary. Examples of the material for the intermediate layer include polyamide, polyvinyl alcohol, polyethylene oxide, ethyl cellulose, casein, polyurethane, and polyether urethane. These are dissolved in a solvent, applied and dried. The thickness of the intermediate layer is preferably from 0.05 to 5 μm, and particularly preferably from 0.2 to 1 μm.

There is no particular limitation on the method of coating the photoreceptor, and the photoreceptor can be used by a commonly known means such as a dip coating method, a spray coating method, and a bar coating method.

FIG. 1 shows a schematic configuration of an electrophotographic apparatus having a process cartridge having the electrophotographic photosensitive member of the present invention. In FIG. 1, reference numeral 1 denotes a drum-shaped electrophotographic photosensitive member of the present invention, which is driven to rotate around an axis 2 at a predetermined peripheral speed in a direction indicated by an arrow. The photoreceptor 1 receives a uniform charge of a predetermined positive or negative potential on the peripheral surface thereof by the primary charging means 3 during the rotation process, and then receives a charge from an image exposure means (not shown) such as slit exposure or laser beam scanning exposure. It receives image exposure light 4. Thus, an electrostatic latent image is sequentially formed on the peripheral surface of the photoconductor 1.

The formed electrostatic latent image is then transferred to developing means 5
The toner-developed image developed by the toner image is transferred from a paper supply unit (not shown) between the photoconductor 1 and the transfer unit 6 in synchronization with the rotation of the photoconductor 1 and fed to a transfer material 7 fed therefrom. The image is sequentially transferred by the transfer unit 6.

The transfer material 7 having undergone the image transfer is separated from the surface of the photoreceptor, introduced into the image fixing means 8 and subjected to image fixing, thereby being printed out of the apparatus as a copy. The surface of the photoreceptor 1 after the image transfer is cleaned and cleaned by removing the untransferred toner by a cleaning unit 9, and further subjected to a charge removal process by a pre-exposure light 10 from a pre-exposure unit (not shown). Used for image formation. When the primary charging unit 3 is a contact charging unit using a charging roller or the like, the pre-exposure is not necessarily required.

In the present invention, a plurality of components such as the above-described electrophotographic photosensitive member 1, primary charging means 3, developing means 5, and cleaning means 9 are integrally connected as a process cartridge. The process cartridge may be configured to be detachable from a main body of an electrophotographic apparatus such as a copying machine or a laser beam printer. For example, at least one of the primary charging unit 3, the developing unit 5, and the cleaning unit 9 is integrally supported together with the photoreceptor 1 to form a cartridge, which can be attached to and detached from the apparatus main body using a guide unit such as a rail 12 of the apparatus main body. Process cartridge 1
It can be 1.

When the electrophotographic apparatus is a copying machine or a printer, the image exposure light 4 is reflected and transmitted from the original, or the original is read by a sensor and converted into a signal. Laser beam scanning,
Light emitted by driving the LED array, driving the liquid crystal shutter array, and the like.

The electrophotographic photosensitive member of the present invention can be used not only for an electrophotographic copying machine but also for a laser beam printer,
It can be widely used in electrophotographic applications such as RT printers, LED printers, liquid crystal printers, and laser plate making.

[0040]

The present invention will be described below in more detail with reference to examples. In the examples, "parts" represents parts by weight.

(Example 1) φ30 mm, length 357 mm
A coating composed of the following materials was applied by dip coating on the aluminum cylinder described above, and thermally cured at 140 ° C. for 30 minutes to form a conductive layer having a thickness of 15 μm.

Conductive pigment: SnO ₂ coated barium sulfate 10 parts Resistance adjusting pigment: titanium oxide 2 parts Binder resin: phenol resin 6 parts Leveling material: silicone oil 0.001 part Solvent: methanol / methoxypropanol 2/8 20 Department

Next, a solution prepared by dissolving 3 parts of N-methoxymethylated nylon and 3 parts of copolymer nylon in a mixed solvent of 65 parts of methanol / 30 parts of n-butanol was applied onto the conductive layer by dip coating. By drying, an intermediate layer having a thickness of 0.5 μm was formed.

Next, in the CuKα characteristic X-ray diffraction, the black angles (2θ ± 0.2 °) of 9.0 °, 14.2 °, 2 °
A sand mill using 4 parts of oxytitanium phthalocyanine having strong peaks at 3.9 ° and 27.1 °, 2 parts of polyvinyl butyral (trade name: Eslec BM2, manufactured by Sekisui Chemical) and 60 parts of cyclohexanone using φ1 mm glass beads. After dispersion for 4 hours, 100 parts of ethyl acetate was added to prepare a charge generation layer dispersion. This dispersion was applied on the intermediate layer by a dip coating method, and dried to form a charge generation layer having a thickness of 0.1 μm.

Next, 9 parts of an amine compound having the following structural formula:

[0046]

Embedded image 1 part of amine compound of the following structural formula

[0047]

Embedded image

Polycarbonate Z as binder resin
Using 12 parts of a mold (Iupilon Z200, manufactured by Mitsubishi Gas Chemical Co., Ltd., viscosity average molecular weight 20,000) as a solvent, 80 parts of an alkyl diketone represented by the structural formula 1-1 in Table 1 was dissolved, and a coating liquid for a charge transport layer I got The coating solution was applied by a dip coating method and dried at 120 ° C. for 1 hour to form a charge transport layer having a thickness of 27 μm.

Next, the evaluation will be described. The apparatus used was a copying machine GP210 manufactured by Canon Inc. Humidity 5 at 23 ° C
Under an environment of 5% RH, the dark area potential was set to -700 V, and the light area potential was measured to determine the sensitivity. Further, 10,000 sheets were copied in the intermittent mode in which the A4 size plain paper was stopped once for each copy, and the light portion potential after repeated use was measured. Further, the wear amount of the photoconductor film thickness was measured. Table 2 shows the results.

Example 2 A photoreceptor was prepared and evaluated in the same manner as in Example 1 except that the solvent used in the preparation of the coating solution for the charge transport layer was changed to the structural formula 1-2 in Table 1. Table 2 shows the results.

Example 3 A photoconductor was prepared and evaluated in the same manner as in Example 1 except that the solvent used in the preparation of the coating solution for the charge transport layer was changed to the structural formula 1-3 shown in Table 1. Table 2 shows the results.

Example 4 A photoreceptor was prepared and evaluated in the same manner as in Example 1, except that a polycarbonate represented by the following structural formula was used as a binder resin in preparing a coating solution for a charge transport layer. Table 2 shows the results.

[0053]

Embedded image

Example 5 A photoreceptor was prepared and evaluated in the same manner as in Example 1 except that a polycarbonate represented by the following structural formula was used as a binder resin in preparing a coating solution for a charge transport layer. Table 2 shows the results.

[0055]

Embedded image

Example 6 The preparation of the coating solution for the charge transport layer was carried out in the same manner as in Example 1, except that 7 parts of the polycarbonate Z type was used as the binder resin and 5 parts of the polycarbonate represented by the following structural formula. A photoreceptor was prepared and evaluated. Table 2 shows the results.

[0057]

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Example 7 A photoreceptor was prepared in the same manner as in Example 1 except that polyarylate A type (U-100, manufactured by Unitika Ltd.) was used as the binder resin in preparing the coating solution for the charge transport layer. Was prepared and evaluated. Table 2 shows the results.
Shown in

Example 8 A photoreceptor was prepared and evaluated in the same manner as in Example 1, except that a polyarylate represented by the following structural formula was used as a binder resin in preparing a coating solution for a charge transport layer. Table 2 shows the results.

[0060]

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Example 9 A photoconductor was prepared and evaluated in the same manner as in Example 8, except that the solvent used in the preparation of the coating solution for the charge transport layer was changed to the structural formula 1-6 shown in Table 1. Table 2 shows the results.

Example 10 In the preparation of the coating solution for the charge transport layer, the solvent was changed to the structural formula 1-7 in Table 1 except that
A photoconductor was prepared and evaluated in the same manner as in Example 8. Table 2 shows the results.

Example 11 In the preparation of the coating solution for the charge transport layer, the solvent was changed to the structural formula 1-8 in Table 1 except that
A photoconductor was prepared and evaluated in the same manner as in Example 8. Table 2 shows the results.

Example 12 A photoconductor was prepared in the same manner as in Example 1, except that a polyester resin (Vylon 200, manufactured by Toyobo Co., Ltd.) was used as the binder resin in preparing the coating solution for the charge transport layer. evaluated. Table 2 shows the results.

Example 13 A photosensitive material was prepared in the same manner as in Example 1 except that a styrene-methacrylate resin (MS-200, manufactured by Nippon Steel Chemical Co., Ltd.) was used as a binder resin in preparing a coating solution for a charge transport layer. The body was prepared and evaluated.
Table 2 shows the results.

Comparative Example 1 Example 1 was repeated except that acetone was used as the solvent in preparing the coating solution for the charge transport layer.
A photoconductor was prepared and evaluated in the same manner as in the above. Table 2 shows the results.

Comparative Example 2 A photoconductor was prepared and evaluated in the same manner as in Example 1, except that methyl isobutyl ketone was used as a solvent in preparing a coating solution for a charge transport layer. Table 2 shows the results.

(Comparative Example 3) In the preparation of the coating solution for the charge transport layer, except that 1,4-dioxane was used as the solvent,
A photoconductor was prepared and evaluated in the same manner as in Example 1. Table 2 shows the results.

Comparative Example 4 Example 8 was repeated except that acetone was used as the solvent in preparing the coating solution for the charge transport layer.
A photoconductor was prepared and evaluated in the same manner as in the above. Table 2 shows the results.

(Comparative Example 5) In the preparation of the coating solution for the charge transport layer, except that 1,4-dioxane was used as the solvent,
A photoconductor was prepared and evaluated in the same manner as in Example 8. Table 2 shows the results.

Comparative Example 6 A photoconductor was prepared and evaluated in the same manner as in Example 8, except that tetrahydrofuran was used as the solvent in preparing the coating solution for the charge transport layer. Table 2 shows the results.

[0072]

[Table 2]

As shown in Table 2, in the example using the alkyl diketone, the solubility of the binder resin was higher than in the example using the monoketone such as acetone or methyl isobutyl ketone, so that a uniform coating film was formed. did it. Further, the binder resin showed almost the same solubility as that of the example using the cyclic ether, and the same initial sensitivity and sensitivity after the durable use were obtained.

In particular, with respect to the abrasion loss of the photosensitive layer in repeated use, it was confirmed that the abrasion loss was reduced by about 10 to 20% in the case of using the alkyl diketone of the present invention.
That is, the system using the alkyl diketone of the present invention has the same solubility, applicability, and sensitivity as those of the conventionally used solvent system, and achieves improved abrasion resistance.

(Example 14) φ30 mm, length 357 m
A conductive layer was formed on an aluminum cylinder of m in the same manner as in Example 1. Next, an intermediate layer was formed on this conductive layer in the same manner as in Example 1.

Next, an azo pigment represented by the following structural formula
Department,

[0077]

Embedded image

As a solvent, 2 parts of polyvinyl butyral (trade name: Esrec BLS, manufactured by Sekisui Chemical) and 80 parts of the solvent represented by the structural formula 1-2 in Table 1 were dispersed in a sand mill using 1 mmφ glass beads for 4 hours. After that, 50 parts of a solvent represented by Structural Formula 1-2 in Table 1 was further added to prepare a dispersion for a charge generation layer. This dispersion is applied on the intermediate layer by a dip coating method and dried to obtain a film thickness of 0.1.
A 3 μm charge generation layer was formed.

Further, the same amount of the same amine compound shown in Example 1 was taken, and the same amount of the same polycarbonate Z type was taken.
It was dissolved in 80 parts of 1,4-dioxane as a solvent to prepare a charge transport layer coating solution. This is applied by dip coating,
By drying, a charge transport layer having a thickness of 20 μm was formed. The obtained photoreceptor was evaluated for sensitivity in the same manner as in Example 1. Table 3 shows the results.

Example 15 A photoreceptor was formed and evaluated in the same manner as in Example 14, except that the solvent of the coating solution for the charge generation layer was represented by Structural Formula 1-6 in Table 1. Table 3 shows the results.

Example 16 A photoconductor was formed and evaluated in the same manner as in Example 14, except that the solvent of the coating solution for the charge generation layer was represented by Structural Formula 1-8 in Table 1. Table 3 shows the results.

Example 17 A photoreceptor was formed and evaluated in the same manner as in Example 14 except that polyvinyl benzal represented by the following structural formula was used as a binder resin of a coating solution for a charge generation layer. Table 3 shows the results.

[0083]

Embedded image

Example 18 Polymethyl methacrylate (MB) was used as the binder resin of the coating solution for the charge generation layer.
-3002, manufactured by Mitsubishi Rayon Co., Ltd.)
A photoconductor was formed and evaluated in the same manner as in Example 14. Table 3 shows the results.

Comparative Example 7 A photoreceptor was formed and evaluated in the same manner as in Example 14, except that 1,4 dioxane was used as a solvent for the coating solution for the charge generation layer. Table 3 shows the results.

Comparative Example 8 A photoreceptor was formed and evaluated in the same manner as in Example 14, except that the same polyvinyl benzal as in Example 17 was used as the binder resin of the coating solution for the charge generation layer. Table 3 shows the results.

Comparative Example 9 Polymethyl methacrylate (MB-MB) was used as the binder resin of the coating solution for the charge generation layer.
A photosensitive member was formed and evaluated in the same manner as in Example 14 except that 3002 (manufactured by Mitsubishi Rayon Co., Ltd.) was used. Table 3 shows the results.

[0088]

[Table 3]

As shown in Table 3, the same characteristics were obtained when the present invention was used for the charge generation layer, and the advantages of using an alkyl diketone, such as environmental friendliness and safety, were given. Can be

Example 19 First, a photoreceptor similar to the photoreceptor prepared in Example 1 was prepared, and then a protective layer was provided as follows. Polycarbonate Z type (Iupilon Z80
0, 4 parts of Mitsubishi Gas Chemical Co., Ltd., 95 parts of a solvent represented by Structural Formula 1-6 in Table 1 and 1 part of Teflon powder (Rublon L2, manufactured by Daikin Industries, Ltd.) at 1 mm.
The mixture was dispersed for 2 hours with a sand mill disperser using φ glass beads. Further, the solution was diluted with 30 parts of a solvent represented by Structural Formula 1-1 in Table 1 to prepare a coating solution for a protective layer.
This coating solution was applied to the surface of the above-mentioned photoreceptor by a spray coating method, and dried to form a 5 μm protective layer. The evaluation was performed by the method described in Example 1. Table 4 shows the results.

Example 20 A photoconductor was formed and evaluated in the same manner as in Example 19, except that the binder resin for the protective layer was the same as the polyarylate used in Example 8. Table 4 shows the results.

Comparative Example 10 A photoconductor was formed and evaluated in the same manner as in Example 19, except that 1,4-dioxane was used as the dispersing solvent and trichloroethane was used as the diluting solvent. Shown in

[0093]

[Table 4]

As shown in Table 4, when the present invention was used for the protective layer, coating properties and sensitivity equivalent to those of the comparative example were obtained. Alkyl diketone is a solvent reported to have a small adverse effect on the human body and the like, and can have a small adverse effect on persons involved in the production of the photoreceptor, and requires only a small amount of equipment to deal with it. In particular, in the case of the spray coating method, in order to improve the uniformity of coating, it is necessary to lower the concentration of the coating solution as compared with the case of the dip coating method, and a large amount of solvent is required. Furthermore, because of the composition of the coating method, the coating liquid and the solvent are liable to be scattered, so that the influence on the human body and the equipment for dealing with it are regarded as more important.

[0095]

According to the present invention, a thermoplastic resin is used as a resin for forming a photosensitive layer, and the resin is dissolved in a solvent, and the photosensitive layer is obtained by coating and drying. By using the electrophotographic photosensitive member, it is possible to provide an electrophotographic photosensitive member, a process cartridge, and an electrophotographic apparatus in consideration of environmental issues and safety without at least reducing the characteristics of the electrophotographic photosensitive member.

[Brief description of the drawings]

FIG. 1 is a diagram showing an example of a schematic configuration of an electrophotographic apparatus having a process cartridge having an electrophotographic photosensitive member of the present invention.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Miyako Nagata 3-30-2 Shimomaruko, Ota-ku, Tokyo F-term in Canon Inc. (reference) 2H068 AA03 AA13 BB23 BB25 BB27 EA13 EA14 FA27 FA30 FC01 FC05 FC08 FC11 FC15

Claims (7)

[Claims] 1. An electrophotographic photoreceptor having a photosensitive layer on a conductive support, wherein a thermoplastic resin is used as a resin for forming the photosensitive layer, and the resin is dissolved in a solvent. An electrophotographic photoreceptor in which the photosensitive layer is obtained by applying and drying a coating solution for a photoreceptor obtained by dissolving or dispersing a material, wherein at least an alkyl diketone is used as the solvent. Photoconductor. 2. The electrophotographic photoreceptor according to claim 1, which contains at least polyester as a resin for forming a photosensitive layer. 3. The electrophotographic photoreceptor according to claim 1, which contains at least polycarbonate as a resin for forming a photosensitive layer. 4. The electrophotographic photoreceptor according to claim 1, which contains at least polyarylate as a resin for forming a photosensitive layer. 5. An electrophotographic photoreceptor wherein at least a surface layer of the photoreceptor has the structure described in claim 1. 6. An electrophotographic apparatus main body which integrally supports at least one means selected from the group consisting of the electrophotographic photosensitive member according to claim 1, a charging means, a developing means and a cleaning means. A process cartridge which is detachably mounted on a process cartridge. 7. An electrophotographic apparatus comprising the electrophotographic photosensitive member according to claim 1, a charging unit, an image exposing unit, a developing unit, and a transferring unit.