JPH0553337A - Electrophotographic sensitive body, electrophotographic device, device unit and facsimile formed by using this photosensitive body - Google Patents

Abstract

PURPOSE:To obtain the electrophotographic sensitive body which has excellent electrophotographic characteristics and with which a good image free from fogging and black spot is obtainable and the electrophotographic device, device unit and facsimile formed by using such photosensitive body. CONSTITUTION:At the electrophotographic sensitive body having a charge generating layer and a charge transfer layer on a conductive base, the charge generating layer contains polyvinyl alcohol, alkyl aldehyde having the structure expressed by formula R-CHO (where R denotes a substd. or unsubstd. chain or cyclic alkyl group) and an acetal resin with which the structure expressed by formula Ar-CHO (where Ar denotes a substd. or unsubstd. aryl group) is obtd. by reaction of aryl aldehyde. The above-mentioned electrophotographic device, device unit and facsimile has such photosensitive body.

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 having a function-separated photosensitive layer, and more specifically, an electrophotographic photosensitive member having a charge generating layer containing a specific resin, and an electrophotographic photosensitive member having the photosensitive member. The present invention relates to a device, a device unit, and a facsimile.

[0002]

2. Description of the Related Art Hitherto, a number of so-called laminated electrophotographic photoreceptors having a charge-generating layer and a charge-transporting layer which are functionally separated have been proposed and put into practical use. These photoconductors are superior in terms of sensitivity, charge retention, surface strength, and the like (U.S.P.
3,837,851 and U.S.P. S. P. 3,871,88
2).

In the multi-layer type electrophotographic photoconductor, charge carriers generated by light absorption of the charge generation layer are injected into the charge transport layer and move to the surface of the photoconductor to neutralize the charge on the surface of the photoconductor. The result is electrostatic contrast. The role of the charge generation layer in this process is extremely important.
That is, how much and evenly the charge carriers are generated, how efficiently the generated charge carriers are injected into the charge transport layer, and how the opposite charge carriers are smoothly flowed to the support are used in the electrophotographic layer. The effect on the characteristics is very large. The charge generation layer is usually composed of an organic pigment which is a charge generation substance and a binder resin which is a binder. The weight ratio of the binder resin to the organic pigment is generally 25 to 200 wt. Not as low as%.
Therefore, it is considered that the binder resin in the charge generation layer has a very serious influence on the movement of the generated charge carriers. That is, the basic structure, functional group, molecular weight and purity of the binder resin have a great influence on electrophotographic characteristics such as sensitivity, potential characteristics and durability. However, from the viewpoint of literatures and patents, the conventional view on the binder resin of the charge generation layer is that it is merely an auxiliary agent of the organic pigment which is the charge generation substance, and dispersibility, binding property and mechanical strength. The mainstream was the recognition that it was sufficient to add For example, butyral resin is widely used as a binder resin because of good dispersibility of the pigment, but the electrophotographic characteristics of the photoconductor using this resin are such as residual potential, potential fluctuation and photomemory.
This is not always sufficient considering the demand for higher image quality in recent years. Further, by using a benzal resin produced from a substituted or unsubstituted aryl aldehyde and polyvinyl alcohol described in JP-A-62-30254, better sensitivity than butyral resin,
Residual potential and photo memory characteristics are obtained, but the dispersibility is generally poorer than that of butyral resin, and when used as a binder for the charge generation layer of a photoconductor for a laser beam printer, fog occurs on the image. There was a need for improvement. Further, even when a butyral resin and a benzal resin are mixed and used, the respective resins act independently, which may rather deteriorate the characteristics.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide an electrophotographic photoreceptor containing a novel binder resin and having excellent electrophotographic characteristics.

Another object of the present invention is to provide an electrophotographic photosensitive member which can provide a good image without fog or black spots.

A further object of the present invention is to provide an electrophotographic apparatus, an apparatus unit and a facsimile having the above electrophotographic photosensitive member.

[0007]

That is, the present invention provides an electrophotographic photosensitive member having a charge generating layer and a charge transporting layer on a conductive support, wherein the charge generating layer is polyvinyl alcohol and the following formula (1) ) R-CHO (1) (wherein R represents a substituted or unsubstituted chain or cyclic alkyl group) and an alkylaldehyde having a structure represented by the following formula (2) Ar-CHO (2) ( In the formula, Ar represents a substituted or unsubstituted aryl group.) An electrophotographic photoreceptor containing an acetal resin obtained by the reaction of an aryl aldehyde having a structure represented by

The present invention also relates to an electrophotographic apparatus, an apparatus unit and a facsimile having the above electrophotographic photosensitive member.

In formula (1), examples of the alkyl group include groups such as methyl, ethyl, propyl, isopropyl, n-butyl and cyclohexyl. Of these, a propyl group and a cyclohexyl group are preferable.

In formula (2), examples of the aryl group include groups such as phenyl, naphthyl, anthryl, pyrenyl, phenanthryl and azulenyl.

As the substituent, a halogen atom, an alkyl group which may have a substituent (for example, groups such as methyl, ethyl, propyl, isopropyl, n-butyl, t-butyl and 2-methoxymethyl) and a substituent are mentioned. An alkyl group which may have (for example, a group such as benzyl, phenethyl, chlorobenzyl and promobenzyl), an aryl group which may have a substituent (for example, a group such as phenyl, tolyl, chlorophenyl and naphthyl), an alkoxy group ( For example, groups such as methoxy, ethoxy, and propoxy), aryloxy groups (for example, groups such as phenoxy and naphthoxy), substituted amino groups (for example, dimethylamino, diethylamino,
Groups such as piperidino, morpholino, and pyrrolidino), nitro group, and cyano group, and the substituents may be plural. Of these, a halogen atom and a nitro group are preferable.

The weight average molecular weight of the polyvinyl acetal resin having a specific structure used in the present invention is 10,000.
It is preferably 0 to 200,000, particularly 3
It is preferably from 50,000 to 80,000. Further, the acetalization degree is preferably 50 mol% or more, and particularly preferably 65 to 90 mol%.
Further, the lower the content of the residual vinyl acetate component originally possessed by polyvinyl alcohol as a raw material is, the more preferable, but the saponification degree of polyvinyl alcohol is preferably 85 mol% or more.

The reason why the electric potential characteristics of the electrophotographic photoreceptor of the present invention in which the charge generation layer containing the polyvinyl acetal resin and the charge transport layer are laminated on a conductive support is improved is not clear, but butyral resin. When both benzal resin and benzal resin are used as a mixture, they both act independently and parts with poor properties appear independently, but when both butyral and benzal groups are mixed in one molecule, the bad properties of both It is thought that the pigment is wrapped in a good balance with both groups so that the pigments are just canceled.

The acetal structure portion of the polyvinyl acetal resin used in the present invention is shown below, but it is not limited thereto.

[0015]

[Outer 1]

[0016]

[Outside 2]

Of these, Resin Examples 3, 4, 5, 6,
7, 8, 9, 12 and 17 are preferred, and Resin Examples 3, 7, 8, 12 and 17 are particularly preferred.

The polyvinyl acetal resin used in the present invention can be easily prepared by reacting polyvinyl alcohol with the above aldehyde in a mixed solvent of methanol and benzene in the presence of an acid such as hydrochloric acid and sulfuric acid at 20 to 70 ° C. Can be synthesized.

Synthesis Example (Synthesis of Resin Example 1) A mixed solution of 200 g of methanol and 200 g of chlorobenzene was placed in a 3-liter three-necked flask, and polyvinyl alcohol (polymerization degree 1000, saponification degree 98.
After adding 50 g of 5 ± 0.5 mol% (manufactured by Kuraray Co., Ltd.) and 520 g of butyraldehyde, 4.2 g of concentrated hydrochloric acid was added dropwise, and the mixture was stirred for 10 hours while maintaining the reaction temperature at 35 to 38 ° C. After the reaction, the reaction solution was poured into a solution of 3.9 g of caustic soda dissolved in 10 liters of methanol, and the precipitated resin was filtered and washed with water. Acetone / benzene = 1/1
The mixture was added dropwise to 2 liters of the mixed solution and reprecipitated for purification. The obtained resin was collected by filtration and dried under reduced pressure. The yield was 79 g.

The butyralization degree of this resin was measured according to the method described in Japanese Industrial Standard K-6728 (Testing method for polyvinyl butyral), and the butyralization degree was 45 mol%.

Next, 50 g of this butyral resin was placed in a mixed solution of 250 g of methanol and 250 g of dichloromethane, 300 g of p-bromobenzaldehyde was added with stirring, and then 4 g of concentrated hydrochloric acid was added dropwise, and the reaction temperature was 45 to 50 ° C.
The mixture was kept for 30 hours and stirred for 40 hours. After the reaction, 3.7 g of caustic soda
Was added to 20 liters of methanol, the reaction solution was added, and the precipitated resin was filtered and washed with water. This was dissolved in 200 g of chloroform, added dropwise to 3 liters of methanol, and reprecipitated for purification. The obtained resin was filtered and dried under reduced pressure. The yield was 80 g.

The benzalization degree of this resin was measured by the same method as described above, and when the above-mentioned butyralization degree was subtracted, the benzalization degree was 35 mol%.

Other polyvinyl acetal resins used in the present invention are also synthesized by the same method as above. When the aldehyde is condensed with polyvinyl alcohol, either the alkyl aldehyde or the substituted aryl aldehyde may be condensed first, or may be simultaneously condensed.

In the electrophotographic photosensitive member of the present invention, the binder resin of the charge generating layer must be one that does not hinder the movement of the charge carriers generated in the layer as much as possible. For that purpose, the content% of the binder resin in the charge generation layer is preferably low, but in view of the binding property and the stability of the pigment dispersion, it is preferably 20% by weight or more based on the total weight of the layer, In particular, it is preferably 25 to 90% by weight, more preferably 28 to 50% by weight. Further, in the present invention, other known binder resins may be mixed and used.

The charge generating layer of the electrophotographic photosensitive member of the present invention comprises selenium, selenium-tellurium, cadmium sulfide, amorphous silicon, pyrylium, thiopyrylium, azurenium dye, phthalocyanine pigment, anthanthrone pigment, dibenzpyrenequinone pigment, Inorganic pigments or organic pigments selected from charge generation layers such as pyranthrone pigments, trisazo pigments, disazo pigments, monoazo pigments, isodigo pigments, quinacridone pigments, asymmetric quinocyanine pigments and quinocyanine pigments, using a suitable solvent as a binder of the present invention. It can be formed by applying a resin or a liquid in which the binder resin is dispersed in another known binder resin, and drying.

As such a solvent, ketones such as acetone, methyl ethyl ketone and cyclohexanone; N, N
Amides such as dimethylformamide and N, N-dimethylacetamide; sulfoxides such as dimethyl sulfoxide; ethers such as tetrahydrofuran, dioxane and ethylene glycol monomethyl ether;
Esters such as methyl acetate and ethyl acetate; Aliphatic halogenated hydrocarbons such as chloroform, methylene chloride, dichloroethylene, carbon tetrachloride and trichloroethylene; or aromatics such as benzene, toluene, xylene, ligroin, chlorobenzene and dichlorobenzene A compound etc. are mentioned.

Dispersion is carried out by crushing and dispersing the above solvent, charge generating substance and binder resin by a sand mill, a ball mill, a roll mill, an attritor or the like until a predetermined particle size is obtained.

The coating film after coating is preferably dried by touching at room temperature and then by heating and drying. Heat drying is 30 ~
It is preferable to carry out at 200 ° C. for 5 minutes to 2 hours. The film thickness is preferably 5 μm or less, and particularly 0.01 to 1 μm.

The charge transport layer of the electrophotographic photosensitive member of the present invention is laminated on or below the charge generation layer and has a function of receiving charge carriers from the charge generation layer in the presence of an electric field and transporting them. .. The charge transporting layer is formed by dissolving a charge transporting material in a solvent together with a suitable binder resin as necessary, and coating and drying the film. The film thickness is preferably 5 to 40 μm, and particularly 15 to 30 μm. Preferably.

The charge transport material includes an electron transport material and a hole transport material. Examples of the electron transporting substance include 2,
Examples include electron-withdrawing substances such as 4,7-trinitrofluorenone, 2,4,5,7-tetranitrofluorenone, chloranil and tetracyanoquinodimethane, and polymers obtained by polymerizing these electron-withdrawing substances. As the hole-transporting substance, polycyclic aromatic compounds such as pyrene and anthracene; carbazole-based, indole-based, imidazole-based, oxazole-based, thiazole-based, oxadiazole-based, pyrazole-based, pyrazoline-based, thiadiazole-based and triazole-based compounds A heterocyclic compound such as p-diethylaminobenzaldehyde-N, N-diphenylhydrazone and N, N-diphenylhydrazino-3-methylidene-9-ethylcarbazole; a-phenyl-4'-N, N -Diphenylaminostilbene and 5- [ - (di -p- tolylamino) benzylidene] -5H- dibenzo [a, d] styryl compounds such as cycloheptene; benzidine compounds; triarylmethane compounds; triphenylamine or,
Examples thereof include polymers having groups consisting of these compounds in the main chain or side chains (for example, poly-N-vinylcarbazole and polyvinylanthracene). In addition to these organic charge transport materials, inorganic materials such as selenium, selenium-tellurium, amorphous silicon and cadmium sulfide can also be used. Further, these charge transport materials may be used alone or in combination of two or more kinds. When the charge transport material has no film forming property, a suitable binder can be used. Specifically, acrylic resin, polyarylate, polyester, polycarbonate, polystyrene,
Examples thereof include insulating resins such as acrylonitrile-styrene copolymer, polyacrylamide, polyamide and chlorinated rubber, and organic photoconductive polymers such as poly-N-vinylcarbazole and polyvinylanthracene.

Examples of the conductive support used in the present invention include metals or alloys such as aluminum, aluminum alloys, copper, zinc, stainless steel, vanadium, molybdenum, chromium, titanium, nickel, indium, gold and platinum. .. In addition, a support or conductive particles (for example, carbon black and silver particles) obtained by forming a film of such a metal or alloy on plastics (for example, polyethylene, polypropylene, polyvinyl chloride, polyethylene terephthalate and acrylic resin) by vacuum deposition is used. A support coated on a plastic or metal substrate with a suitable binder resin, or a support obtained by impregnating plastic or paper with conductive particles can be used.

The support may be in the form of a sheet, a drum, a belt, or the like, but is preferably of any shape most suitable for the electrophotographic apparatus to which it is applied.

In the present invention, an undercoat layer having a barrier function and an adhesive function may be provided between the conductive support and the photoconductor. Examples of the material of the undercoat layer include casein, polyvinyl alcohol, nitrocellulose and polyamide (nylon 6, nylon 66, nylon 610, copolymerized nylon and alkoxymethylated nylon), polyurethane and aluminum oxide. The thickness of the undercoat layer is preferably 5 μm or less, particularly 0.1 to 3
μm is preferred.

Further, in the present invention, a resin layer or a resin layer containing conductive particles may be provided as a protective layer on the photosensitive layer.

The various layers described above can be applied by any coating method such as a dip coating method, a spray coating method, a spinner coating method, a beat coating method, a Meyer bar coating method, a blade coating method, a roller coating method or a curtain coating method. It can be applied.

The electrophotographic photoreceptor of the present invention using the above-mentioned specific acetal resin as the binder resin of the charge generation layer has more excellent sensitivity and is stable only in the light potential and the dark potential upon repeated use. However, it has an advantage that the photo-memory property can be effectively improved. Note that a photomemory is a phenomenon in which a portion which is irradiated with light before charging has a lower potential than a portion which is not irradiated with light during charging, and as a result, a white (or black) portion is removed from an image.

The electrophotographic photoreceptor of the present invention can be used not only in electronic copying machines, but also in laser beam printers and CRTs.
It can also be widely used in electrophotographic application fields such as printers, LDE printers, liquid crystal printers, and laser plate making.

FIG. 1 shows a schematic structural example of a transfer type electrophotographic apparatus using the electrophotographic photosensitive member of the present invention.

In the figure, reference numeral 1 denotes a drum type photosensitive member as an image bearing member, which is rotationally driven around a shaft 1a in a direction of an arrow at a predetermined peripheral speed. In the course of its rotation, the photosensitive member 1 is uniformly charged with a predetermined positive or negative potential on its peripheral surface by the charging means 2, and then at the exposure section 3 an optical image exposure L (slit exposure Laser beam operation exposure). As a result, electrostatic latent images corresponding to the exposed images are sequentially formed on the peripheral surface of the photoconductor.

The electrostatic latent image is then toner-developed by the developing means 4, and the toner development is synchronized by the transfer means 5 between the photoconductor 1 and the transfer means 5 from a paper feeding portion (not shown) between the photoconductor 1 and the rotation. The images are sequentially transferred onto the surface of the transfer material P that has been taken and fed.

The transfer material P which has received the image transfer is separated from the surface of the photoconductor and is introduced into the image fixing means 8 where it is subjected to the image fixing and printed out as a copy.

After the image transfer, the surface of the photosensitive member 1 is cleaned by the cleaning means 6 to remove the residual toner after transfer, and is further discharged by the pre-exposure means 7 to be repeatedly used for image formation.

As the uniform charging means 2 for the photoconductor 1, a corona charging device is generally widely used. In addition, the transfer device 5
Corona transfer means are also widely used. The electrophotographic apparatus is configured by integrally combining a plurality of components, such as the above-described photoconductor, developing unit, and cleaning unit, as an apparatus unit, and this unit is configured to be detachable from the apparatus main body. May be. For example, at least one of a charging unit, a developing unit, and a cleaning unit is integrally supported with a photoconductor to form a unit, which is a detachable single unit in the apparatus main body, and a guide unit such as a rail of the apparatus main body is used. It may be detachable. At this time, the above-mentioned apparatus unit may be provided with a charging unit and / or a developing unit.

When the electrophotographic apparatus is used as a copying machine or a printer, the optical image exposure L irradiates the photoconductor with the reflected light or the transmitted light from the original, or the original is read by a sensor and converted into a signal. In accordance with this signal, the laser beam is scanned, the LED array is driven, or the liquid crystal shutter array is driven to irradiate the photoconductor with light.

When used as a printer for a facsimile, the optical image exposure L becomes an exposure for printing the received data. FIG. 2 is a block diagram showing an example of this case.

The controller 11 controls the image reading section 10 and the printer 19. The entire controller 11 is CP
It is controlled by U17. The read data from the image reading unit is transmitted to the partner station through the transmission circuit 13. The data received from the partner station is sent to the printer 19 through the receiving circuit 12. Predetermined image data is stored in the image memory. The printer controller 18 controls the printer 19. 14 is a telephone.

The image received from the circuit 15 (image information from a remote terminal connected via a line) is demodulated by the receiving circuit 12, and then the CPU 17 performs a composite process of the image information and sequentially stores it in the image memory 16. Is stored. Then, when at least one page of image is stored in the memory 16,
The image of that page is recorded. CPU 17 is a memory 1
The image information of one page is read out from 6 and the combined image information of one page is sent to the printer controller 18. The printer controller 18 is the one from the CPU 17.
When the image information of the page is received, the printer 19 is controlled to record the image information of the page.

The CPU 17 is receiving the next page while the printer 19 is recording.

The image is received and recorded as described above.

The present invention will be described in more detail with reference to the following examples.

[0051]

【Example】

50 parts of titanium oxide powder coated with tin oxide containing 1.10% antimony oxide (parts by weight, the same applies hereinafter), 25 parts of resol type phenol resin, 20 parts of methyl cellosolve,
5 parts of methanol and 0.002 parts of silicone oil (polydimethylsiloxane-polyoxyalkylene copolymer, weight average molecular weight of 3,000) are dispersed for 2.5 hours in a sand mill using φ1 mm glass beads to coat the conductive layer. A liquid was prepared. The coating liquid is applied on an aluminum support with a Meyer bar and dried at 140 ° C. for 35 minutes to give a film thickness of 3
A 0 μm conductive layer was formed.

On this, a solution prepared by dissolving 5 parts of methoxymethylated nylon (weight average molecular weight 32,000) and 10 parts of alcohol-soluble copolymer nylon (weight average molecular weight 29,000) in 95 parts of methanol was applied with a Meyer bar. Then, an undercoat layer having a film thickness after drying of 1 μm was formed.

Next, 5 parts of a phthalocyanine pigment having the following structure was added to a solution prepared by dissolving 3 parts of the polyvinyl acetal resin of Resin Example 5 (acetalization degree: 80 mol%, weight average molecular weight: 40,000) in 90 parts of cyclohexanone, and added thereto. Disperse with a lighter for 10 hours. This dispersion was applied onto the previously formed undercoat layer with a Meyer bar so that the film thickness after drying was 0.3 μm, and dried at 90 ° C. to form a charge generation layer.

[0054]

[Outside 3]

Next, 5 parts of a styryl compound having the following structure was added:

[0056]

[Outside 4] Polycarbonate resin (Brand name Panlite L-125
0, Teijin Kasei Co., Ltd., number average molecular weight 100,000)
5 parts of chlorobenzene was dissolved in 70 parts of chlorobenzene, and this was coated on the charge generation layer with a Meyer bar so that the film thickness after drying was 18 μm, and dried to form a charge transport layer.

The obtained photoconductor is applied to an electrostatic copying paper test device (M
Using ode1 SP-428, manufactured by Kawaguchi Electric Co., Ltd., corona charging was performed at -5 KV by a static method, and after holding in the dark for 10 seconds, exposure was performed with 5 illuminances to examine charging characteristics. The charging characteristics include the surface potential V ₀ of the photoconductor,
Exposure amount E1 / 2 required to attenuate the potential when it is dark-decayed for 10 seconds in a dark place, that is, the sensitivity and the residual potential V
_{The r} was measured. Further, after the photosensitive charging means and exposed for 3 minutes at an illuminance 600 lux, 'was measured _0, V' surface potential V of the photoreceptor again the method described above was left 1 min in the dark ₀ and the V
_The photomemory property was evaluated by the difference from ₀ , that is, | V ₀ −V ′ ₀ |.

The photoconductor is charged-exposure-developing-transfer-
The cleaning process is repeated in a cycle of 1.5 seconds. It is affixed to the cylinder for the photosensitive drum of the laser beam printer of the reversal phenomenon type, and it is used at room temperature and normal humidity (23 ° C, 50%
RH) and high-temperature high-humidity (30 ° C., 85% RH) images were actually printed, and fogging and black-spot defects (black spots) on the obtained images were visually evaluated.

Furthermore, the charge generation layer dispersion liquid was left at room temperature, and the dispersion state of the pigment after 6, 12, 24, 48, and 192 hours was visually observed.

The results are shown in Table 1.

(Comparative Example 1) Example 1 was repeated except that a commercially available butyral resin (trade name BM-2, manufactured by Sekisui Chemical Co., Ltd.) was used in place of the polyvinyl acetal resin Example 5 used in Example 1. An electrophotographic photoreceptor was prepared in exactly the same manner and evaluated.

The results are shown in Table 1.

Comparative Example 2 Instead of the polyvinyl acetal resin Example 5 used in Example 1, a benzal resin having the following structure (degree of benzalization 80 mol%, weight average molecular weight 5) was used.
10,000) was used and an electrophotographic photosensitive member was prepared and evaluated in the same manner as in Example 1.

[0064]

[Outside 5]

The results are shown in Table 1.

[0066]

[Table 1]

50 parts of titanium oxide powder coated with tin oxide containing 2.10% antimony oxide, 25 parts of resol type phenol resin, 20 parts of methyl cellosolve, 5 parts of methanol and silicone oil (polydimethylsiloxane-polyoxy). Alkylene copolymer, weight average molecular weight 3,
000) 0.002 part was dispersed in a sand mill using φ1 mm glass beads for 2 hours to prepare a coating liquid for conductive layer. The coating liquid was applied on an aluminum support with a Meyer bar and dried at 145 ° C. for 30 minutes to form a conductive layer having a film thickness of 30 μm.

On this, a solution prepared by dissolving 5 parts of methoxymethylated nylon (weight average molecular weight 32,000) and 9 parts of alcohol-soluble copolymer nylon (weight average molecular weight 29,000) in 97 parts of methanol was applied with a Meyer bar. An undercoat layer having a film thickness after drying of 1 μm was formed.

Next, 5 parts of the pigment having the following structural formula was added to Resin Example 8 described above.
Polyvinyl acetal (acetalization degree 75 mol%,
3 parts of a weight average molecular weight of 50,000) was dissolved in 90 parts of cyclohexanone, and dispersed with an attritor for 10 hours. This dispersion was applied onto the previously formed undercoat layer with a Meyer bar so that the film thickness after drying was 0.3 μm, and dried at 70 ° C. to form a charge generation layer.

[0070]

[Outside 6]

Next, 5 parts of a hydrazone compound having the following structure

[0072]

[Outside 7] 5 parts of polycarbonate (trade name: Panlite L-1250, Teijin Kasei Co., Ltd., number average molecular weight 10,000) is dissolved in 70 parts of chlorobenzene, and this is dried to a film thickness of 18 μm on the charge generation layer. Thus, a charge transport layer was formed by coating with a Meyer bar and drying.

The photoreceptor thus obtained was evaluated in the same manner as in Example 1.

The results are shown in Table 2.

Comparative Example 3 Example 2 was repeated except that a commercially available butyral resin (trade name BM-1, manufactured by Sekisui Chemical Co., Ltd.) was used in place of the polyvinyl acetal resin Example 8 used in Example 2. An electrophotographic photoreceptor was prepared and evaluated in exactly the same manner.

The results are shown in Table 2.

(Comparative Example 4) In place of the polyvinyl acetal resin Example 8 used in Example 2, a benzal resin (degree of benzalization of 75 mol%, weight average molecular weight 45,000) was used so as to have the following structure. An electrophotographic photosensitive member was prepared and evaluated in exactly the same manner as in Example 2.

[0078]

[Outside 8]

The results are shown in Table 2.

[0080]

[Table 2]

3-9. Instead of Resin Example 5 in Example 1, Resin Example 3 (acetalization degree 73 mol%, weight average molecular weight 35,000), 4 (acetalization degree 82 mol%,
Weight average molecular weight 42,000), 6 (Acetalization degree 7
9 mol%, weight average molecular weight 60,000), 7 (degree of acetalization 65 mol%, weight average molecular weight 54,000),
10 (degree of acetalization 75 mol%, weight average molecular weight 4
5,000), 11 (degree of acetalization 80 mol%, weight average molecular weight 50,000) and 12 (degree of acetalization 8).
Each electrophotographic photosensitive member was prepared and evaluated in exactly the same manner as in Example 1 except that 2 mol% and a weight average molecular weight of 56,000) were used.

The results are shown in Table 3.

[0083]

[Table 3]

50 parts of titanium oxide powder coated with tin oxide containing 10.10% antimony oxide, 25 parts of resol type phenol resin, 20 parts of methyl cellosolve, 5 parts of methanol and silicone oil (polydimethylsiloxane-polyoxy). 0.002 parts of allylxylene copolymer, weight average molecular weight 3,000) was dispersed for 2 hours with a sand mill using φ1 mm glass beads to prepare a conductive layer coating liquid. The coating liquid was applied on an aluminum support with a Meyer bar and dried at 140 ° C. for 30 minutes to form a conductive layer having a film thickness of 30 μm.

Onto this, a solution prepared by dissolving 5 parts of methoxymethylated nylon (weight average molecular weight 32,000) and 10 parts of alcohol-soluble copolymerized nylon (weight average molecular weight 29,000) in 95 parts of methanol was applied using a Meyer bar. An undercoat layer having a film thickness after drying of 1 μm was formed.

Next, 5 parts of the pigment having the following structural formula was added to Resin Example 9 described above.
Polyvinyl acetal (acetalization degree 81 mol%,
3 parts of a weight average molecular weight of 58,000) was added to a solution prepared by dissolving 90 parts of cyclohexanone, and dispersed by an attritor for 10 hours. This dispersion was applied onto the previously formed undercoat layer with a Meyer bar so that the film thickness after drying was 0.3 μm, and dried at 70 ° C. to form a charge generation layer.

[0087]

[Outside 9]

Next, 5 parts of a fluorene compound having the following structure

[0089]

[Outside 10] 5 parts of polycarbonate (trade name: Panlite L-1250, Teijin Kasei Co., Ltd., number average molecular weight: 100,000) is dissolved in 70 parts of chlorobenzene, and the film thickness after drying on the charge generation layer is 18 μm. Thus, a charge transport layer was formed by coating with a Meyer bar and drying.

The obtained photoreceptor was evaluated in the same manner as in Example 1. The results are shown in Table 4.

(Comparative Example 5) In place of the polyvinyl acetal resin Example 9 used in Example 10, 1.5 parts of a commercially available butyral resin (trade name BM-2, manufactured by Sekisui Chemical Co., Ltd.) and benzal having the following structure were used. 1.5 parts of resin (degree of benzalization 75 mol%, weight average molecular weight 44,000) was added to TFH9.
An electrophotographic photosensitive member was prepared and evaluated in exactly the same manner as in Example 10 except that the liquid dissolved in 0 part was used as the binder liquid for the charge generation layer.

[0092]

[Outside 11]

The results are shown in Table 4.

[0094]

[Table 4]

[0095]

As can be seen from the above results, the photoreceptor of the present invention, that is, the resin having the specific structure as the binder resin for the charge generation layer, contains butyral resin and polyvinyl acetal resin respectively, or It is superior in charging characteristics, image quality and stability of the dispersion liquid used, as compared with the photoconductor used by mixing.

Further, an electrophotographic apparatus having this photoconductor,
Similar effects can be obtained in the device unit and the facsimile.

[Brief description of drawings]

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

FIG. 2 is a diagram showing an example of a block diagram of a facsimile having the electrophotographic photosensitive member of the present invention.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazushi Inouchi 27-7 Ohamaencho, Ebetsu City, Hokkaido

Claims (6)

[Claims] 1. An electrophotographic photosensitive member having a charge generating layer and a charge transporting layer on a conductive support, wherein the charge generating layer is polyvinyl alcohol, the following formula (1) R-CHO (1) (wherein , R represents a substituted or unsubstituted chain or cyclic alkyl group) and an alkylaldehyde having a structure represented by the following formula (2) Ar-CHO (2) (wherein Ar represents a substituted or unsubstituted). An electrophotographic photoreceptor containing an acetal resin obtained by the reaction of an aryl aldehyde having a structure represented by the formula (1). 2. The electrophotographic photosensitive member according to claim 1, wherein R is a propyl group or a cyclohexyl group. 3. The electrophotographic photosensitive member according to claim 1, wherein the substituent contained in the Ar is a halogen atom or a nitro group. 4. The electrophotographic photosensitive member according to claim 1, an electrostatic latent image forming means, a means for developing the formed electrostatic latent image, and a means for transferring the developed image to a transfer material. Electrophotographic device. 5. An apparatus unit comprising the electrophotographic photosensitive member according to claim 1, integrally supporting the charging means, the developing means, and the transfer means, and being detachable from the apparatus main body. 6. A facsimile comprising an electrophotographic apparatus having the electrophotographic photosensitive member according to claim 1 and means for receiving image information from a remote terminal.