JP2000267315A - Electrophotographic photoreceptor and image forming device using same as constituent element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a stable high-quality image free from abnormalities such as surface stain, black spots and a worm hole by disposing a photosensitive layer formed through a heat drying step after film formation and containing a polyethylene wax having a melting point not more than the drying tempera ture on a substrate. SOLUTION: A photosensitive layer is formed through a heat drying step after film formation and a polyethylene wax having a melting point not more than the drying temperature is incorporated. The polyethylene wax is appropriately selected for high density polyethylene, low density polyethylene, various modified polyethylenes and polyethylene obtained by reducing the molecular weight of a molded high molecular weight polyethylene resin by thermal decomposition. When silicone oil or the like is added, the dispersibility of the polyethylene wax and the smoothness of the film are enhanced. The polyethylene wax forms blended state with a binder resin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an electrophotographic photosensitive member having excellent durability in long-term use and an image forming apparatus using the same. Furthermore, a color image of an intermediate transfer system in which a visible color developed image formed on an electrophotographic photosensitive member is primarily transferred onto an intermediate transfer member, and the primary transfer image on the intermediate transfer member is secondarily transferred to a transfer material. It relates to a forming device.

[0002]

2. Description of the Related Art Conventionally, inorganic photoconductive materials such as selenium, α-silicon, zinc oxide and the like have been mainly used as photoconductive materials for electrophotographic photosensitive members in terms of sensitivity and durability. Inorganic materials are disadvantageous in that they are harmful substances and have high productivity due to poor productivity. For this reason, organic photoreceptors that are non-polluting, can be mass-produced by coating, and can be easily reduced in cost have been actively developed in recent years. The photosensitive layer of the organic electrophotographic photosensitive member includes a single layer type in which a charge generation material and a charge transport material are contained in a binder resin, and a function separation type in which a charge generation layer and a charge transport layer are sequentially laminated. At present, the latter function separation type is predominant. In such a photosensitive layer, a low-molecular charge transporting material is contained in a binder resin such as polycarbonate.
When the film thickness decreases, background fouling easily occurs.

In recent years, a contact charging member has been increasingly used from a conventional corona charger to reduce ozone generation. In this case, the charging member rubs the surface of the photoconductor due to the contact between the photoconductor and the charging member. Further, when the thickness of the photosensitive layer is reduced by friction, discharge breakdown easily occurs locally, and an abnormal image such as black spots is generated in the reversal development process, which is not preferable. In recent years, the size of the photoreceptor has been reduced due to the downsizing of the apparatus in response to the increase in demand for printers and the like, and the situation has become more severe with respect to durability. Therefore, studies have been made to improve the abrasion resistance of the photosensitive layer, but it has been particularly actively performed in recent years.

In the above-described photosensitive layer, the transfer efficiency is poor due to a high coefficient of friction and a large adhesive force with respect to the toner. In particular, in a character image or a line image, local transfer omission may occur, resulting in an insect-like image. is there. FIG. 8 shows an example of such an insect-like image. Hereinafter, such a phenomenon is referred to as “insect eating”. This insect biting is particularly likely to occur in the case of a transfer roller pressing method as a transfer method. In recent years, there has been a demand for higher image quality in order to reduce the particle size of the toner, and an electrophotographic photoreceptor having a high transfer efficiency and a high cleaning property has been required. further,
2. Description of the Related Art Although full-color electrophotographic apparatuses have been widely used, full-color electrophotographic apparatuses require higher image quality than monochrome machines. In particular, in a full-color electrophotographic apparatus using an intermediate transfer member, a higher transfer performance is required for the photosensitive member in order to transfer from the photosensitive member to the intermediate transfer member instead of paper. If the transfer performance of the photoreceptor is poor, an worm-like image is generated when the image is transferred to the intermediate transfer member.
When worms are eaten, color shift is caused, and a beautiful full-color image is not obtained. In order to achieve these, it is particularly desired to reduce the coefficient of friction of the photoreceptor surface and to maintain its long-term stability.

As a method for solving these problems, a method has been proposed in which a charge transport layer provided on the surface of a photoreceptor contains a silicone resin or a silicone-containing polymer (Japanese Patent Application Laid-Open Nos. 57-64243 and 57-64243). Showa 25
No. 6146, JP-A-61-95358, JP-A-61-132954, JP-A-61-21904.
No. 7). However, the method of adding a silicone resin or a silicone-containing polymer has poor abrasion resistance,
Further, there is a disadvantage that the residual potential increases. Also, studies have been made to include lubricants such as fluororesin particles, polyethylene resin particles, and polypropylene resin particles. Further, a combination of a polycarbonate resin having a specific molecular weight and the above-mentioned lubricant as disclosed in JP-A-7-295278, and a specific charge transport as disclosed in JP-A-8-160648 and JP-A-8-184976. A combination of a layer and the above lubricant has also been studied.

However, in these studies, the lubricant forms a film while maintaining a state of being finely dispersed in a solution in which the resin and the charge transport material are dissolved. In this case, from the viewpoint of electrostatic characteristics, it is necessary to make the dispersed particle size as small as possible and make the dispersibility uniform. Therefore, in order to obtain a sufficient effect, an addition amount of 10 parts by weight or more is required for 100 parts by weight of the resin. In this case, there is a problem that the residual potential increases. In particular, it is difficult to overcome this point with polyethylene resin particles and polypropylene resin particles. Furthermore, these resin particles also have a disadvantage that the polar groups are generated by corona charging or the like, so that the electrostatic characteristics are significantly deteriorated.

[0007]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems. That is, the present invention has no problems in electrostatic characteristics such as an increase in residual potential, has excellent wear resistance, and has a long life. An object of the present invention is to provide an electrophotographic photoreceptor capable of obtaining a stable high-quality image free from occurrence of abnormal images such as background stains, black spots, and insect bites, and an image forming apparatus including the electrophotographic photoreceptor as a component. Furthermore, there is no defect in electrostatic characteristics such as an increase in residual potential, and it has excellent abrasion resistance, and does not generate abnormal images such as soiling and insect erosion for a long time. The purpose is to provide.

[0008]

The present invention is characterized in that a photosensitive layer containing a polyethylene wax having a melting point equal to or lower than the drying temperature is formed on a substrate by a step of heating and drying after film formation. The above problem was solved by providing an electrophotographic photoreceptor. For example, in an electrophotographic photosensitive member in which an intermediate layer, a photosensitive layer, and a protective layer are sequentially laminated on a conductive substrate, the protective layer is formed through a step of heating and drying after film formation, and has a melting point lower than the drying temperature. An electrophotographic photosensitive member characterized by containing a polyethylene wax and a charge transporting material.

The electrophotographic photoreceptor of the present invention is an image forming apparatus having an electrophotographic photoreceptor charging means, an image exposing means, a reversal developing means, a transfer means and a cleaning means, wherein the charging means is a contact charging member. It is effective as an electrophotographic photosensitive member of a forming apparatus. Further, the electrophotographic photoreceptor of the present invention primarily transfers a visible color developed image formed on the electrophotographic photoreceptor onto an intermediate transfer member, and transfers the primary transfer image on the intermediate transfer member to a secondary transfer material. It is particularly effective also as the electrophotographic photosensitive member in an intermediate transfer type full-color image forming apparatus for transferring.

As the polyethylene wax used in the present invention, high-density polyethylene, low-density polyethylene, various modified polyethylenes synthesized by a conventionally known polymerization method,
Alternatively, a high-molecular-weight polyethylene resin of a molded article may be obtained by thermal decomposition to reduce the molecular weight.
Among them, a pyrolytic type or aromatic modified type polyethylene wax is preferred because of its good affinity for the resin. In particular,
Polyethylene wax whose main chain or side chain is aromatically modified is more effective because the affinity with a binder resin, particularly a generally used polycarbonate resin and a charge transport material is improved. The modification rate of polyethylene wax is
20 to 50% is good. Below this, the effect of modification is not sufficient, and above this, the coefficient of friction is reduced and the wear resistance is reduced.

When silicone oil, acrylic-silicone block copolymer, acrylic-fluorine block copolymer, silicone-based or fluorine-based surfactant, etc. are added in addition to polyethylene wax, dispersibility of polyethylene wax and film This is effective because the smoothness is improved. Among them, a silicone oil that does not adversely affect the electrostatic characteristics of the photoconductor is preferable.

The silicone oils include dimethyl silicone oil, phenylmethyl silicone oil, alkyl-modified silicone oil, fluorosilicone oil,
Polyether modified silicone oil, fatty acid ester silicone oil, amino modified silicone oil, carboxylic acid modified silicone oil, epoxy modified silicone oil, mercapto modified silicone oil, carbinol modified silicone oil, alkoxy modified silicone oil, alkyl alkoxy modified silicone oil, hydroxyl group Modified silicone oil, methyl hydrogen silicone oil,
Linear polyether-modified silicone oil and the like can be mentioned. In particular, alkyl-modified silicone oils are more effective in terms of friction coefficient durability and abrasion resistance. Also,
These may be used in combination of a plurality of types as necessary.

Further, if necessary, an antioxidant or an ultraviolet absorber may be added. Polyethylene wax easily forms a polar group by corona charging and deteriorates electrostatic characteristics. Therefore, an antioxidant prevents deterioration of electrostatic characteristics. The same applies to ultraviolet rays. As the antioxidant, a conventionally known antioxidant can be used, and particularly, a material selected from the following compound group is preferable. (1) Phenols described in JP-A-57-122444, phenol derivatives described in JP-A-60-188856, and hindered phenols described in JP-A-63-18356. (2) Paraphenylenediamines described in JP-A-57-122444, paraphenylenediamine derivatives described in JP-A-60-188956, and JP-A-63-1
Paraphenylenediamines described in No. 8356. (3) Hydroquinones described in JP-A-57-122444, hydroquinone derivatives described in JP-A-60-188856, and hydroquinones described in JP-A-63-18356. (4) Sulfur compounds described in JP-A-57-188956 and organic sulfur compounds described in JP-A-63-18356. (5) Organic phosphorus compounds described in JP-A-57-122444 and organic phosphorus compounds described in JP-A-63-18356. (6) Hydroxyanisols described in JP-A-57-122444. (7) Piperidine derivatives and oxopiperazine derivatives having a specific skeleton structure described in JP-A-63-18355. (8) Carotenes, amines, tocophenols, Ni (II) complexes, sulfides, etc. described in JP-A-60-188956.

(9) US Pat. No. 1,968,906 and J. Pat. Am. Chem. Soc. 55, 1224 (1
933) and a compound represented by the following general formula (i).

Embedded image (Wherein, R _{1 to} R ₄ each represent a hydrogen atom, a halogen atom, a hydroxy group, a substituted or unsubstituted alkyl group,
An alkenyl group, an aryl group, a cycloalkyl group, an alkoxy group, an aryloxy group, an alkylthio group, an arylthio group, a substituted amino group, an imino group, a heterocyclic group, a sulfoxide group, a sulfonyl group, an acyl group, and an azo group. )

(10) The following compounds represented by the following formulas (ii) to (ix) described in JP-A-5-181298. (A) A compound represented by the following general formula (ii).

Embedded image (Wherein, R _{1 to} R ₄ each represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted cycloalkyl group, A substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryloxy group,
Alkylthio group, arylthio group, alkylamino group,
Arylamino group, acyl group, alkylacylamino group, arylacylamino group, alkylcarbamoyl group, arylcarbamoyl group, alkylsulfonamide group, arylsulfonamide group, alkylsulfamoyl group, arylsulfamoyl group, alkylsulfonyl group , An arylsulfonyl group, an alkyloxycarbonyl group, an aryloxycarbonyl group, an alkylacyloxy group, an arylacyloxy group, a silyl group or a heterocyclic group. However, at least one of R ₁ , R ₂ , R ₃ , and R ₄ is a group having a total number of carbon atoms of 4 or more. )

(B) A compound represented by the following general formula (iii):

Embedded image (Wherein, R ₅ represents —C—C _n H _{2n + 1-m} (R ₇ ) _m , and R ₆ represents a substituted or unsubstituted alkyl group having 4 to 20 carbon atoms, an aryloxy group, an alkoxy group, a cycloalkyl And represents a group, an aryl group, an aralkyl group, or R _{5, and} may combine with R ₇ to form a ring having 5 to 10 carbon atoms, wherein R ₇ is a substituted or unsubstituted aryl group, arylthio group, aryl Oxy group, arylacylamino group, arylcarbamoyl group, arylsulfonyl group,
Represents an aryloxycarbonyl group, an arylacyloxy group, an arylamino group, an arylsulfonamide group, or an arylsulfonoxy group, n represents 1 to 5, m
Represents 1 or 2. )

(C) a compound represented by the following general formula (iv)

Embedded image (Wherein, Ar ₁ and Ar ₂ represent a substituent or an unsubstituted aryl group, an arylthio group, an aryloxy group, a benzyl group, or a phthalimide group, and R ₈ and R ₉ represent a hydrogen atom, a halogen atom, a substituted or unsubstituted group, Represents an alkyl group, an alkenyl group, an alkoxy group, an alkylthio group, an acyl group, an alkylamino group, or an alkylcarbamoyl group.)

(D) Compound represented by the following general formula (v)

Embedded image (Wherein, R _{1 to} R ₈ each represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted cycloalkyl group, Substituted or unsubstituted alkoxy group, substituted or unsubstituted aryloxy group, alkylthio group, arylthio group, alkylamino group, arylamino group, acyl group, alkylacylamino group,
Arylacylamino group, alkylcarbamoyl group, arylcarbamoyl group, alkylsulfonamide group, arylsulfonamide group, alkylsulfamoyl group,
Arylsulfamoyl group, alkylsulfonyl group, arylsulfonyl group, alkyloxycarbonyl group, aryloxycarbonyl group, alkylacyloxy group,
Represents an arylacyloxy group, a silyl group or a heterocyclic group. )

(E) A compound represented by the following general formula (vi).

Embedded image (Wherein, R _{1 to} R ₈ each represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted cycloalkyl group, A substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryloxy group,
Alkylthio group, arylthio group, alkylamino group,
Arylamino group, acyl group, alkylacylamino group, arylacylamino group, alkylcarbamoyl group, arylcarbamoyl group, alkylsulfonamide group, arylsulfonamide group, alkylsulfamoyl group, arylsulfamoyl group, alkylsulfonyl group , An arylsulfonyl group, an alkyloxycarbonyl group, an aryloxycarbonyl group, an alkylacyloxy group, an arylacyloxy group, a silyl group or a heterocyclic group. )

(F) A compound represented by the following general formula (vii).

Embedded image (Wherein, R _{1 to} R ₇ each represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted cycloalkyl group, Substituted or unsubstituted alkoxy group, substituted or unsubstituted aryloxy group, alkylthio group, arylthio group, alkylamino group, arylamino group, acyl group, alkylacylamino group,
Arylacylamino group, alkylcarbamoyl group, arylcarbamoyl group, alkylsulfonamide group, arylsulfonamide group, alkylsulfamoyl group,
Arylsulfamoyl group, alkylsulfonyl group, arylsulfonyl group, alkyloxycarbonyl group, aryloxycarbonyl group, alkylacyloxy group,
Represents an arylacyloxy group, a silyl group or a heterocyclic group. )

(G) A compound represented by the following general formula (viii).

Embedded image (Wherein, R _{1 to} R ₅ each represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted cycloalkyl group, Substituted or unsubstituted alkoxy group, substituted or unsubstituted aryloxy group, alkylthio group, arylthio group, alkylamino group, arylamino group, acyl group, alkylacylamino group,
Arylacylamino group, alkylcarbamoyl group, arylcarbamoyl group, alkylsulfonamide group, arylsulfonamide group, alkylsulfamoyl group,
Arylsulfamoyl group, alkylsulfonyl group, arylsulfonyl group, alkyloxycarbonyl group, aryloxycarbonyl group, alkylacyloxy group,
Represents an arylacyloxy group, a silyl group or a heterocyclic group. )

(H) A compound represented by the following general formula (ix).

Embedded image (Wherein, R _{1 to} R ₈ each represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted cycloalkyl group, Substituted or unsubstituted alkoxy group, substituted or unsubstituted aryloxy group, alkylthio group, arylthio group, alkylamino group, arylamino group, acyl group, alkylacylamino group,
Arylacylamino group, alkylcarbamoyl group, arylcarbamoyl group, alkylsulfonamide group, arylsulfonamide group, alkylsulfamoyl group,
Arylsulfamoyl group, alkylsulfonyl group, arylsulfonyl group, alkyloxycarbonyl group, aryloxycarbonyl group, alkylacyloxy group,
Represents an arylacyloxy group, a silyl group or a heterocyclic group. Specific examples of the compounds (i) to (ix) are described in JP-A-5-181298. The amount of these antioxidants used is 0 to 100 parts by weight of the binder resin.
About 5 parts by weight is appropriate. Moreover, you may use together two or more as needed.

Examples of ultraviolet absorbers include benzophenone-based, benzoate-based, benzotriazole-based, hydroxybenzophenone-based, and triazine-based compounds.
Further, there may be mentioned a polymer type polymer obtained by copolymerizing MMA, styrene, or the like with these skeletons. Specifically, triazoles include 2- (5-methyl-2-
Hydroxyphenyl) benzotriazole, 2- [2-
Hydroxy-3,5-bis (α, α-dimethylbenzyl) phenyl] -benzotriazole, 2- (3,5-
Di-tert-butyl-2-hydroxyphenyl) benzotriazole, 2- (3-tert-butyl-5-methyl-2-hydroxyphenyl) -5-chlorobenzotriazole, 2- (3,5-di-tert- Butyl-2
-Hydroxyphenyl) -5-chlorobenzotriazole, 2- (3,5-di-tert-amyl-2-hydroxyphenyl) benzotriazole, 2- (2-hydroxy-5-tert-octylphenyl) benzotriazole, -[2-hydroxy-3- (3,4,5,6
-Tetra-hydrophthalimido-methyl) -5-methylphenyl] benzotriazole. Benzophenones include 2-hydroxy-4-methoxybenzophenone,
2-hydroxy-4-n-octoxybenzophenone,
2,2 ', 4,4'-tetrahydroxybenzophenone, 2,4-dihydroxybenzophenone, 2,2'-
Dihydroxy-4,4'-dimethoxybenzophenone,
2,2'-dihydroxy-4-methoxybenzophenone, 2-hydroxy-4-octadecyloxybenzophenone, 4-dodecyloxy-2-hydroxybenzophenone. Commercially available benzoate compounds and triazine compounds are also used. Commercially available products include those found in Magazine Polyfile, March 1997, pp. 22-29. These ultraviolet absorbers and light stabilizers may be used alone or as a mixture of two or more. The use amount thereof is suitably about 0 to 5 parts by weight based on 100 parts by weight of the binder resin.

Further, a hindered amine compound may be added as a light stabilizer. As the hindered amine light stabilizer, for example, 2,2,6,6-tetramethyl-4-
Piperidyl benzoate, N- (2,2,6,6-tetramethyl-4-piperidyl) dodecylsuccinimide,
1-[(3,5-di-tert-butyl-4-hydroxyphenyl) propionyloxyethyl] -2,2,6,6-tetramethyl-4-piperidyl- (3,5-di-tert-butyl-4- (Hydroxyphenyl) propionate, bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis (1,2,2,6,6-pentamethyl-
4-piperidyl) sebacate, bis (1,2,2,6)
6-pentamethyl-4-piperidyl) -2-butyl-2
-(3,5-di-tert-butyl-4-hydroxybenzyl)
Malonate, N, N'-bis (2,2,6,6-tetramethyl-4-piperidyl) hexamethylenediamine, tetra (2,2,6,6-tetramethyl-4-piperidyl) butanetetracarboxylate, Tetra (1, 2,
2,6,6-pentamethyl-4-piperidyl) butanetetracarboxylate, bis (2,2,6,6-tetramethyl-4-piperidyl) di (tridecyl) butanetetracarboxylate, bis (1,2,2 2,6,6-pentamethyl-4-piperidyl) di (tridecyl) butanetetracarboxylate, 3,9-bis [1,1-dimethyl-2- {tris (2,2,6,6-tetramethyl- 4-piperidyloxycarbonyloxy) butylcarbonyloxy} ethyl] -2,4,8,10-tetraoxaspiro [5,5] undecane, 3,9-bis [1,
1-dimethyl-2- {tris (1,2,2,6,6-pentamethyl-4-piperidyloxycarbonyloxy)
Butylcarbonyloxy} ethyl] -2,4,8,10
-Tetraoxaspiro [5,5] undecane, 1,5
8,12-tetrakis [4,6-bis {N- (2,2,
6,6-tetramethyl-4-piperidyl) butylamino} -1,3,5-triazin-2-yl] -1,5.
8,12-tetraazadodecane, 1- (2-hydroxyethyl) -2,2,6,6-tetramethyl-4-piperidinol / dimethyl succinate condensate, 2-tert-octylamino-4,6-dichloro -S-triazine / N, N '
-Bis (2,2,6,6-tetramethyl-4-piperidyl) hexamethyldiamine condensate, N, N'-bis (2,2,6,6-tetramethyl-4-piperidyl) hexamethylenediamine / And dibromoethane condensates. The aromatic modification is also effective for this oxidation. Further, it is preferable to use contact charging instead of corona charging for the charger.

The polyethylene wax is contained in at least the layer forming the outermost surface of the electrophotographic photosensitive member, that is, a photosensitive layer when the electrophotographic photosensitive member has a single layer structure, a charge transport layer when the electrophotographic photosensitive member has a laminated structure, When a protective layer is formed, the protective layer contains at least polyethylene wax. Further, the melting point of the polyethylene wax is lower than the drying temperature at the time of forming the layer containing the wax. By using the polyethylene wax having such a melting point, the polyethylene wax dispersed in the solution is melted at the time of drying to form domains in the film, as if a binder resin, a charge transport material and polyethylene were blended. To form In the conventional particle dispersion form, a residual potential is easily generated because charges are trapped between the particles themselves and between the particles. However, according to the present invention, the above-described configuration reduces the accumulation of residual charges. Further, due to such a configuration, the coefficient of friction on the surface of the photoreceptor is reduced, and the durability thereof is also improved. Therefore, wear resistance is improved. The amount of the polyethylene wax added is preferably 0.5 to 15 parts by weight based on 100 parts by weight of the solid content of the resin. More preferably, 2
10 to 10 parts by weight is good. Below this, a sufficient effect cannot be obtained, and above this, the residual potential is undesirably high.

Hereinafter, the constitution of the electrophotographic photosensitive member of the present invention will be described.
A specific description will be given based on the drawings. Hereinafter, the photoreceptor used in the present invention will be described with reference to the drawings. FIG. 5 is a cross-sectional view showing one configuration example of the photoconductor of the present invention. Photoconductor 512
Is at least an intermediate layer 513 on the conductive support 511.
And a photosensitive layer 515. FIG. 6 is a sectional view showing another configuration example of the photoconductor of the present invention. The intermediate layer 513 and the charge generation layer 51 are formed on the conductive support 511.
7. A configuration in which a charge transport layer 519 is laminated. 7 includes an intermediate layer 513, a charge generation layer 517, and a charge transport layer 51 on a conductive support 511.
9, a configuration in which a protective layer 520 is laminated.

The photosensitive layer 515, the charge transporting layer 519, and the protective layer 520 can be formed by dissolving or dispersing the charge transporting substance and the binder resin in a suitable solvent, and applying and drying this. Examples of the method of applying the coating solution for the photosensitive layer 515, the charge transport layer 519, and the protective layer 520 include dip coating, spray coating, bead coating, nozzle coating, spinner coating, ring coating, Meyer bar coating, roller coating, and curtain coating. Etc. can be used.

The intermediate layer of the photoreceptor preferably contains titanium oxide. Titanium oxide has little absorption in visible light and near infrared light and is white, which is desirable for increasing the sensitivity of the photoreceptor. Further, since the refractive index is relatively large, moire generated when writing an image with coherent light such as laser light can be effectively prevented. In addition, a binder resin is contained together with titanium oxide in the intermediate layer.
Thermoplastic resins such as polyvinyl alcohol, casein, sodium polyacrylate, copolymerized nylon, and methoxymethylated nylon; and thermosetting resins such as polyurethane, melamine, epoxy, alkyd, phenol, butyral, and unsaturated polyester resins.

Titanium oxide contained in the intermediate layer of the present invention
(P) and the binder resin (R) have a ratio P / R of 0.
It is preferably in the range of 9/1 to 2/1. Middle class
When the P / R ratio is less than 0.9 / 1, the characteristics of the intermediate layer are bound.
Depends on the characteristics of the resin, especially changes and repetitions of temperature and humidity
The use of this material greatly changes the photoconductor characteristics. Also,
When the P / R ratio exceeds 2/1, there are many voids in the intermediate layer.
And the adhesion to the charge generation layer is reduced, and
If the air pressure exceeds / 1, air will accumulate,
This causes bubbles during coating and drying of the layer,
turn into. For the intermediate layer, in addition to titanium oxide,
Aluminum oxide, silicon oxide, etc.
Rica, zirconium oxide, tin oxide, indium oxide, etc.
A metal oxide fine powder pigment may be added. Further, the present invention
Silane coupling agent, titanium cup
Ring agent, chromium coupling agent, titanyl chelation
Compound, zirconium chelate compound, titanyl alcohol
Sid compounds and organic titanyl compounds can also be used.
You. These intermediate layers are appropriately dissolved as in the photosensitive layer described above.
It can be formed using a medium, dispersion, and coating method. this
In addition, the intermediate layer of the present invention includes Al₂O₃By anodizing
Provided, organic substances such as polyparaxylylene and SiO
₂, SnO₂, TiO₂, ITO, CeO ₂Inorganic substances such as
Can be favorably used by a vacuum thin film forming method.
The thickness of the intermediate layer is suitably from 0 to 10 μm.

As the charge generating substance used in the photosensitive layer and the charge generating layer, in addition to metal-free phthalocyanine and titanyl phthalocyanine pigment, monoazo pigment, bisazo pigment,
Azo pigments such as untargeted disazo pigments, trisazo pigments, and tetraazo pigments, pyrrolopyrrole pigments, anthraquinone pigments, perylene pigments, polycyclic quinone pigments, indigo pigments, squarium pigments, pyrene pigments, diphenylmethane pigments, azine pigments, quinoline pigments And perinone-based pigments and other known materials can be used. In the present invention, the use of phthalocyanine-based pigments has a remarkable effect. Each of them can be used in combination.

As the binder resin used for the charge generation layer, butyral resin is most preferably used, but is not limited thereto. In addition, the following resins can be used alone or in combination. Polyamide, polyurethane, epoxy resin, polyketone, polycarbonate, silicone resin, acrylic resin, polyvinyl formal, polyvinyl ketone, polystyrene,
Poly-vinyl carbazole, polyacrylamide, polyvinyl benzal, polyester, phenoxy resin, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, polyamide, polyvinyl pyridine, cellulose resin, casein, polyvinyl alcohol, polyvinyl pyrrolidone and the like. The amount of the binder resin is suitably from 10 to 500 parts by weight, preferably from 25 to 300 parts by weight, per 100 parts by weight of the charge generating substance. As the solvent used here, isopropanol, acetone, methyl ethyl ketone, cyclohexanone, tetrahydrofuran, dioxane, ethyl cellosolve, ethyl acetate, methyl acetate, dichloromethane, dichloroethane, monochlorobenzene, cyclohexane,
Examples include toluene, xylene, and ligroin. The charge generation layer is formed by dispersing these components in an appropriate solvent using a ball mill, an attritor, a sand mill, ultrasonic waves, or the like, applying the resultant on an intermediate layer, and drying. The thickness of the charge generation layer is 0.01 to 5 μm, preferably 0.1 to 2 μm.

The charge transport material includes a hole transport material and an electron transport material. Examples of the electron transporting substance include chloranil, bromanil, tetracyanoethylene, tetracyanoquinodimethane, 2,4,7-trinitro-9-fluorenone, 2,4,5,7-tetranitro-9-fluorenone, 2,4 , 5,7-tetranitroxanthone,
2,4,8-trinitrothioxanthone, 2,6,8-
Examples thereof include electron accepting substances such as trinitro-4H-indeno [1,2-b] thiophen-4-one, 1,3,7-trinitrodibenzothiophene-5,5-dioxide, and benzoquinone derivatives.

Examples of the hole transport material include poly-N-vinylcarbazole and its derivatives, poly-γ-carbazolylethylglutamate and its derivatives, pyrene-formaldehyde condensate and its derivatives, polybylpyrene, polyvinylphenanthrene, polysilane and oxazole Derivatives, oxadiazole derivatives, imidazole derivatives, monoarylamine derivatives, diarylamine derivatives, triarylamine derivatives, stilbene derivatives,
α-phenylstilbene derivative, benzidine derivative, diarylmethane derivative, triarylmethane derivative, 9
-Known materials such as styryl anthracene derivatives, pyrazoline derivatives, divinylbenzene derivatives, hydrazone derivatives, indene derivatives, butadiene derivatives, pyrene derivatives, bisstilbene derivatives, enamine derivatives, and other polymerized hole transport substances.

Examples of the binder resin used in the charge transport layer include polystyrene, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyester, polyvinyl chloride, and vinyl chloride-acetic acid. Vinyl copolymer, polyvinyl acetate, polyvinylidene chloride, polyarylate, phenoxy resin, polycarbonate, cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral, polyvinyl formal, polyvinyl toluene, poly-N-vinyl carbazole, acrylic resin, silicone resin, Epoxy resin, melamine resin, urethane resin, phenol resin, alkyd resin, JP-A-5-158250 and JP-A-6-5
Thermoplastic or thermosetting resins such as various polycarbonate copolymers described in JP-A-1544.

The amount of the charge transporting material is 20 to 300 parts by weight, preferably 40 to 15 parts by weight, per 100 parts by weight of the binder resin.
0 parts by weight is suitable. The charge transport layer has a thickness of 5 to 5.
Preferably, the thickness is about 50 μm. The drying temperature is selected from the boiling point of the solvent to be used and the temperature and time so that the residual solvent does not affect the electrostatic characteristics.

As the conductive support, a volume resistance of 10 ¹⁰
What shows conductivity of Ωcm or less, for example, aluminum, nickel, chromium, nichrome, copper, gold, silver, metals such as platinum, tin oxide, metal oxides such as indium oxide, by vapor deposition or sputtering, by film Or cylindrical plastic or paper-coated or aluminum, aluminum alloy, nickel, stainless steel, etc. plates and extruding, drawing, etc. after forming into a tube, cutting, super finishing, polishing, etc. Surface-treated tubes and the like can be used. Further, an endless nickel belt and an endless stainless belt disclosed in JP-A-52-36016 can also be used as the conductive support.

In addition to the above, a support obtained by dispersing a conductive powder on a suitable binder resin on the above support and applying the same can also be used as the conductive support of the present invention. Examples of the conductive powder include carbon black, acetylene black, metal powders such as aluminum, nickel, iron, nichrome, copper, zinc, and silver, and metal oxides such as conductive titanium oxide, conductive tin oxide, and ITO. And powder. The binder resins used simultaneously include polystyrene, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyester, polyvinyl chloride, and vinyl chloride-vinyl acetate copolymer. , Polyvinyl acetate, polyvinylidene chloride, polyarylate resin, phenoxy resin, polycarbonate,
Cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral, polyvinyl formal, polyvinyl toluene, poly-N-vinyl carbazole, acrylic resin,
Thermoplastic, thermosetting or photocurable resins such as silicone resin, epoxy resin, melamine resin, urethane resin, phenolic resin, and alkyd resin. Such a conductive layer can be provided by dispersing the conductive powder and the binder resin in an appropriate solvent, for example, tetrahydrofuran, dichloromethane, 2-butanone, toluene, or the like, and applying the dispersion. Further, a conductive layer is provided on a suitable cylindrical substrate by a heat-shrinkable tube in which the conductive powder is contained in a material such as polyvinyl chloride, polypropylene, polyester, polystyrene, polyvinylidene chloride, polyethylene, chloride rubber, and Teflon. Any of these can be favorably used as the conductive support of the present invention.

Next, an image forming apparatus of the present invention and an image forming method using the image forming apparatus will be described with reference to the drawings. As shown in FIG. 1, a charging member 1 that contacts an outer peripheral surface of a drum-shaped electrophotographic photosensitive member 12 that rotates in the direction of arrow A
As a result, the photoconductor 12 is charged to a predetermined positive or negative voltage. A positive or negative DC voltage is applied to the charging member 1. DC voltage applied to the charging member 1 is -2000V-
+ 2000V is preferred. A pulsating voltage may be applied to the charging member 1 by superimposing an AC voltage in addition to the DC voltage. The AC voltage superimposed on the DC voltage preferably has a peak-to-peak voltage of 4000 V or less. However, when the AC voltage is superimposed, the charging member and the electrophotographic photosensitive member may vibrate to generate an abnormal sound. A desired voltage may be applied to the charging member 1 instantaneously, but the applied voltage may be gradually increased to protect the photoconductor.

The charging member 1 may rotate in the same direction as the photosensitive member 12 or in the opposite direction, or may slide on the outer peripheral surface of the photosensitive member without rotating. Further, the charging member may have a function of cleaning residual toner on the photoconductor 12. In this case, the cleaning means 1
There is no need to provide 0. The charged photoconductor 12 is then subjected to optical image exposure 6 (slit exposure or laser beam scanning exposure) by an image exposure means (not shown). At the time of this exposure scanning, the exposure is interrupted for the non-image portion of the original surface,
A reverse bias development is performed by applying a developing bias slightly lower than the surface potential to the image portion having a low potential due to the exposure,
As a result, an electrostatic latent image corresponding to the original image including the non-image portion is sequentially formed. The electrostatic latent image is then developed with toner by a developing unit 7, and the toner image is synchronized between the photosensitive member 12 and the transfer member 8 by a transfer member 8 from a paper feeding unit (not shown). The recording material 9 is sequentially transferred onto the surface of the recording material 9 fed and fed. The recording material 9 to which the image has been transferred is separated from the photoreceptor surface, introduced into an image fixing means (not shown), subjected to image fixing, and printed out of the apparatus as a copy. The surface of the photoreceptor 12 after the image transfer is removed by the cleaning unit 10 to remove the untransferred toner, and the surface of the photoreceptor 12 is restored to a normal surface.

As the electrophotographic apparatus, a plurality of the above-mentioned components such as the photosensitive member and the developing means are integrally connected as an apparatus unit, and this unit is configured to be detachable from the apparatus body. May be. For example, as shown in FIG. 2, at least the photoreceptor 12, the charging member 1, and the developing means 7 are contained in a container 20 to form one electrophotographic apparatus unit, and this apparatus unit is formed by using guide means such as rails of the apparatus body. It may be configured to be detachable. The cleaning means 10 may or may not be provided in the container 20. As shown in FIG. 3, at least the photosensitive member 12 and the charging member 1 are housed in a first container 21 to form a first electrophotographic unit, and at least the developing means 7 is housed in a second container 22 so as to form a second electrophotographic unit. The first device unit and the second device unit may be configured to be detachable as an electrophotographic unit. The cleaning means 10 may or may not be provided in the container 21. 2 and 3, the transfer member 23 is used as a transfer charging unit. The transfer member 23 having the same configuration as the charging member 1 can be used. The transfer member 23 used as a transfer charging unit has a voltage of 400 V to 2000
It is desirable to apply a DC voltage of V. 24 is a fixing means.

The charging member 1 may take any shape such as a roller shape, a brush shape, a blade shape, a flat plate shape and the like. The roller-shaped charging member 1 has an elastic layer, a conductive layer, and a resistance layer around a rod-shaped conductive core material. As the conductive core material,
A metal such as iron, copper, or stainless steel, or a conductive resin such as a carbon-dispersed resin or a metal-particle-dispersed resin can be used, and a rod-shaped or plate-shaped shape can be used. The elastic layer is a layer rich in elasticity and hardness,
1.5 mm or more, further 2 mm or more, especially 3 mm to 13
mm (film thickness) is preferred. Materials used for the elastic layer include, for example, chloroprene rubber, isoprene rubber, EPD
Preferred are M rubber, polyurethane, epoxy rubber, butyl rubber and the like.

The conductive layer is a layer having a high electric conductivity, and has a volume resistivity of 10 ⁷ Ω · cm or less, and more preferably 10 ⁶ Ω · cm.
Hereinafter, those having a range of 10 ⁻² Ω · cm to 10 ⁶ Ω · cm are particularly preferable. The thickness of the conductive layer is desirably a thin layer for transmitting the flexibility of the lower elastic layer to the upper resistive layer, and is preferably 3 mm or less, more preferably 2 mm or less, and particularly preferably 20 μm or less.
A range of 1 mm is preferred. As a material used for the conductive layer, a metal deposition film, a conductive particle-dispersed resin, a conductive resin, or the like can be used. Examples of the metal deposition film include a film obtained by vapor deposition of a metal such as aluminum, indium, nickel, copper, and iron. Examples of the conductive particle-dispersed resin include those in which conductive particles such as carbon, aluminum, nickel, and titanium oxide are dispersed in a resin such as urethane, polyester, vinyl acetate-vinyl chloride copolymer, and polymethyl methacrylate. Can be Examples of the conductive resin include quaternary ammonium salt-containing polymethyl methacrylate, polyvinyl aniline, polyvinyl pyrrole, polydiacetylene, polyethylene imine, and the like.

The resistance layer is formed so as to have a higher resistance than the conductive layer, and has a volume resistivity of 10 ⁶ to 10 ¹² Ω ·.
cm, more preferably 10 ⁷ to 10 ¹¹ Ω · cm, and a semiconductive resin, a conductive particle-dispersed insulating resin, or the like can be used. Examples of the semiconductive resin include resins such as ethyl cellulose, nitrocellulose, methoxymethylated nylon, ethoxymethylated nylon, copolymerized nylon, polyvinylpyrrolidone, and casein, and a mixture of these resins. As the conductive particle-dispersed insulating resin, for example, carbon, aluminum, indium oxide, a small amount of conductive particles dispersed in an insulating resin such as urethane, polyester, vinyl acetate-vinyl chloride copolymer, polymethacrylic acid, etc. One in which the resistance is adjusted is exemplified. The thickness of the resistance layer is preferably 1 μm to 500 μm, particularly preferably 50 μm to 200 μm from the viewpoint of chargeability.

The flat charging member is formed by providing an elastic layer and a resistance layer on a metal plate. The brush-shaped charging member is formed by providing conductive fibers radially around a conductive core material via an adhesive layer, or by providing conductive fibers on one surface of a metal flat plate via an adhesive layer. The conductive fiber is a fiber having a high electric conductivity, and has a volume resistivity of 10 ³ Ω · cm or less, further 10 ⁶ Ω · cm or less, and particularly 10 ⁻² Ω · cm to 10 ⁶ Ω.
・ Cm range is preferred. In addition, it is desirable that the thickness of one conductive fiber be thin in order to maintain flexibility.
1-100 μm in diameter, further 5-50 μm, especially 8-3
A range of 0 μm is preferred. The length of the conductive fiber is 2 to 10
mm, more preferably 3 to 8 mm. As the material for forming the conductive fiber, for example, the above-described conductive particle-dispersed resin, conductive resin, or the like can be used. Further, carbon fibers can also be used for the conductive fibers.

FIG. 4 is a schematic diagram of a full-color image apparatus using an intermediate transfer member. The latent image formed on the photoreceptor 51 is first visualized by the developing unit 55-1 for the first color, and then transferred to the intermediate transfer body at a contact portion with the intermediate transfer body 61. This transfer is called primary transfer. After the primary transfer, the untransferred toner on the photoreceptor is cleaned by the cleaning members 58 and 59, and after the charge elimination step by the charge elimination lamp 60, the image forming step for the second color is started. For full color,
This process is repeated for three or four colors to form a full-color image on the intermediate transfer member. The image formed on the intermediate transfer member is
Next, it is collectively transferred onto the transfer paper 62. This transfer is called secondary transfer. Here, the transfer bias is applied by the transfer roller 63. The transfer paper is then output as a full-color image through a fixing process. In this apparatus, the photoconductor transfers a toner image to an intermediate transfer body instead of paper.
The intermediate transfer member is made of a material having a relatively good releasability in order to transfer the received toner image to paper in secondary transfer in the next step. For this reason, if the surface characteristics of the photoreceptor are poor, a so-called insect-eating image in which a part of the image is not transferred and remains on the photoreceptor during the primary transfer is generated. Specifically, it is likely to occur when the friction coefficient of the photoconductor is as large as 0.3 or more. In the present invention, by using the photoconductor having the above-described configuration, the friction coefficient on the surface of the photoconductor is reduced, the amount of wear is suppressed, and the friction coefficient does not change with time.

[0046]

Example 1 70 parts by weight of titanium oxide (CREL: manufactured by Ishihara Sangyo), 15 parts by weight of an alkyd resin [Beccolite M6401-50-S (solid content: 50%): manufactured by Dainippon Ink and Chemicals, Inc.], melamine resin [Super Vicamine L-121-60 (solid content 60%): manufactured by Dainippon Ink and Chemicals, Inc.] 10 parts by weight,
A mixture comprising 100 parts by weight of methyl ethyl ketone was dispersed in a ball mill for 72 hours to prepare a coating liquid for an intermediate layer, which was applied on an aluminum drum having a diameter of 30 mm.
After drying at 30 ° C. for 20 minutes, an intermediate layer having a thickness of 3 μm was formed. Next, 19 parts by weight of a triazo pigment represented by the following structural formula (1),
1 part by weight of a disazo pigment of the following structural formula (2) and 4 parts by weight of polyvinyl butyral (BM-2: manufactured by Sekisui Chemical Co., Ltd.) are added to a resin solution dissolved in 150 parts by weight of cyclohexanone, and dispersed by a ball mill for 72 hours. went. After completion of the dispersion, 210 parts by weight of cyclohexanone was added and the mixture was dispersed for 3 hours to prepare a coating liquid for a charge generation layer. This was applied on the intermediate layer and dried at 130 ° C. for 10 minutes to form a film having a thickness of 0.2 μm.
m of the charge generation layer was formed. Next, 3 parts by weight of polyethylene wax (400P; Mitsui Chemicals; melting point: 126 ° C) and 80 parts by weight of tetrahydrofuran were dispersed in a ball mill for 48 hours. This dispersion has the following structural formulas (1) to
8 parts by weight of the charge transporting substance shown in (3) and 10 parts by weight of polycarbonate (Z type viscosity average molecular weight of 40,000) were dissolved to prepare a coating liquid for a charge transporting layer. This was applied on the charge generation layer and dried at 135 ° C. for 20 minutes to form a film having a thickness of 30
A μm charge transport layer was formed, and an electrophotographic photosensitive member constituting the electrophotographic image forming apparatus of the present invention was prepared.

[0047]

Embedded image

Example 2 The polyethylene wax of Example 1 was used in a pyrolysis type (NL50).
0; Mitsui Chemicals; melting point: 105 ° C.), except that Example 1 was used. Example 3 The polyethylene wax of Example 1 was replaced with an aromatic modified polyethylene wax (1140H; Mitsui Chemicals, melting point: 102 ° C.)
Other than replacing with the above, the same as Example 1. Example 4 In addition to Example 1, a hindered phenol compound (A
O-20 (Asahi Denka) was the same as Example 1 except that 0.2 part by weight was added. Example 5 In addition to Example 1, a benzotriazole-based compound (LA
-31; Asahi Denka) except that 0.2 part by weight was added. Example 6 In addition to Example 1, a hindered phenol compound (A
O-20; Asahi Denka) and 0.1 part by weight of a thioether compound (AO-23; Asahi Denka) were the same as Example 1 except that 0.1 part by weight was added. Example 7 Example 3 was the same as Example 3 except that 0.005 parts by weight of methylphenyl silicone oil (KF50; Shin-Etsu Chemical) was further added. Example 8 An alkyl-modified silicone oil (F
Z3340; Nippon Unicar) was the same as Example 3 except that 0.005 parts by weight was added.

Comparative Example 1 Example 1 was the same as Example 1 except that no polyethylene wax was added.

Comparative Example 2 70 parts by weight of titanium oxide (CREL: manufactured by Ishihara Sangyo), 15 parts by weight of alkyd resin [Beccolite M6401-50-S (solid content: 50%): manufactured by Dainippon Ink and Chemicals, Inc.], melamine resin [ Super Beckamine L-121-60 (solid content: 60%): manufactured by Dainippon Ink and Chemicals, Inc.] 10 parts by weight,
A mixture consisting of 100 parts by weight of methyl ethyl ketone was dispersed in a ball mill for 72 hours to prepare a coating liquid for an intermediate layer, which was applied on an aluminum drum having a diameter of 80 mm and a length of 359 mm, and dried at 130 ° C. for 20 minutes. 3μ thick
m intermediate layers were prepared. Next, 19 parts by weight of the triazo pigment of the structural formula (1) and the disazo pigment 1 of the structural formula (2) were used.
4 parts by weight of polyvinyl butyral (BM-2: manufactured by Sekisui Chemical Co., Ltd.) was added to a resin solution dissolved in 150 parts by weight of cyclohexanone, and dispersed in a ball mill for 72 hours. After the dispersion was completed, 210 parts by weight of cyclohexanone was added and the mixture was dispersed for 3 hours to prepare a charge generation layer coating liquid. This was applied on the intermediate layer and dried at 130 ° C. for 10 minutes to form a 0.2 μm-thick charge generation layer. Next, polyethylene wax (400P; Mitsui Chemicals; melting point 1)
(26 ° C.) 3 parts by weight and 60 parts by weight of methylene chloride were dispersed in a ball mill for 48 hours. To this dispersion, 8 parts by weight of the charge transporting material represented by the above structural formula (3), 10 parts by weight of polycarbonate (Z type; viscosity average molecular weight of 40,000), and 0.05 parts of silicone oil (KF50; Shin-Etsu Chemical) were added.
02 parts by weight were dissolved to prepare a charge transport layer coating solution.
This was applied on the charge generation layer and dried at 100 ° C. for 30 minutes to form a charge transport layer having a thickness of 30 μm, thereby producing an electrophotographic photosensitive member provided in the electrophotographic image forming apparatus of the present invention. Each of the electrophotographic photoreceptors produced above was mounted on a Ricoh copier MF-200, and the change in the photoreceptor friction coefficient and the abrasion film thickness when the 30,000 sheets of the test chart were output; The results of the images are shown in Table 1. The measurement of the coefficient of friction was performed as follows. A belt-shaped measuring member, which is obtained by cutting medium-thick high-quality paper so that the paper cutting direction is in the longitudinal direction, is brought into contact with a quarter of the outer periphery of the cylindrical photoreceptor surface, and a load (100 g) is applied to one (lower end) thereof. ,
After connecting the force gauge to the other side, the force gauge is moved at a constant speed, and the value of the force gauge when the belt starts moving is read and calculated by the following equation.

Μs = 2 / π × In (F / W) where μs: coefficient of static friction F: force gauge reading (g) W: load (100 g)

[0051]

[Table 1]

Example 9 70 parts by weight of titanium oxide (CREL: manufactured by Ishihara Sangyo), 15 parts by weight of alkyd resin (Beccolite M6401-50-S (solid content: 50%): manufactured by Dainippon Ink and Chemicals, Inc.), melamine resin [ Super Beckamine L-121-60 (solid content: 60%): manufactured by Dainippon Ink and Chemicals, Inc.] 10 parts by weight,
A mixture consisting of 100 parts by weight of methyl ethyl ketone was dispersed in a ball mill for 72 hours to prepare a coating liquid for an intermediate layer, which was applied on an aluminum drum having a diameter of 30 mm,
After drying at 130 ° C. for 20 minutes, an intermediate layer having a thickness of 3 μm was prepared. Next, 19 parts by weight of the trisazo pigment of the structural formula (1), 1 part by weight of the disazo pigment of the structural formula (2), and 4 parts by weight of polyvinyl butyral (BM-2, manufactured by Sekisui Chemical Co., Ltd.) were added to 150 parts by weight of cyclohexanone. It was added to the dissolved resin solution and dispersed for 72 hours in a ball mill. After completion of the dispersion, 210 parts by weight of cyclohexanone was added and the mixture was dispersed for 3 hours to prepare a coating liquid for a charge generation layer. This was applied on the intermediate layer and dried at 130 ° C. for 10 minutes to form a 0.2 μm-thick charge generation layer.

Next, 8 parts by weight of the charge transporting material represented by the above structural formula (3) and 10 parts by weight of polycarbonate (Z type; viscosity average molecular weight of 40,000) are dissolved in 80 parts by weight of tetrahydrofuran, A working fluid was prepared. This was applied on the charge generation layer and dried at 120 ° C. for 20 minutes to form a charge transport layer having a thickness of 20 μm. Next, polyethylene wax (400P; Mitsui Chemicals; melting point 126 ° C) 3
Parts by weight and 80 parts by weight of tetrahydrofuran were dispersed in a ball mill for 48 hours. 8 parts by weight of the charge transport material represented by the above structural formula (3), 10 parts by weight of polycarbonate (Z type; viscosity average molecular weight of 40,000) were added to this dispersion.
0.002 of silicone oil (KF50; Shin-Etsu Chemical)
A part by weight was dissolved to prepare a coating liquid for a protective layer. This was coated on the charge transport layer and dried at 135 ° C. for 20 minutes to form a protective layer having a thickness of 10 μm, thereby preparing an electrophotographic photosensitive member provided in the electrophotographic image forming apparatus of the present invention. Example 10 Same as Example 9 except that the polyethylene wax was replaced with an aromatic modified polyethylene wax (1140H; Mitsui Chemicals, melting point: 102 ° C). Example 11 Example 10 was the same as Example 10 except that 0.005 parts by weight of an alkyl-modified silicone oil (FZ3340; Nippon Unicar) was further added. Comparative Example 3 Example 9 was the same as Example 9 except that polyethylene wax was not added to the protective layer.

Comparative Example 4 The following protective layer was laminated on the charge transporting layer produced in Example 9 to produce an electrophotographic photosensitive member. 3 parts by weight of polyethylene wax (400P; Mitsui Chemicals; melting point: 126 ° C.) and 60 parts by weight of methylene chloride were dispersed in a ball mill for 48 hours. 8 parts by weight of the charge transport material represented by the above structural formula (3), 10 parts by weight of polycarbonate (Z type; viscosity average molecular weight of 40,000), and 0.002 parts by weight of silicone oil (KF50; Shin-Etsu Chemical) Was dissolved to prepare a coating liquid for a protective layer. This was applied on the charge transport layer and dried at 100 ° C. for 30 minutes to form a protective layer having a thickness of 10 μm, thereby producing an electrophotographic photosensitive member provided in the electrophotographic image forming apparatus of the present invention. Each of the electrophotographic photoreceptors produced above was mounted on a Ricoh copier MF-200, and the change in the photoreceptor friction coefficient and the abrasion film thickness when the 30,000 sheets of the test chart were output; The results of the image are shown in Table 2.

[0055]

[Table 2]

Example 12 The same manufacturing method as that of the photoreceptor used in Example 1 was carried out, and the diameter was 80
mm using an aluminum drum, mounted on a Ricoh color copier Pretail 550, and changed the photoreceptor friction coefficient and abrasion film thickness when 10,000 color test charts were output; Table 3 shows the results of the abnormal images. Example 13 Example 12 was the same as Example 12 except that the photoconductor in Example 12 was replaced with the photoconductor used in Example 6.

Comparative Example 5 Example 12 was the same as Example 12 except that the photosensitive member used in Example 12 was replaced with the photosensitive member used in Comparative Example 1. Comparative Example 6 Example 12 was the same as Example 12, except that the photoconductor in Example 12 was replaced with the photoconductor used in Comparative Example 2.

[0058]

[Table 3]

[0059]

[Effect] 1. An electrophotographic photoreceptor which is excellent in abrasion resistance and obtains a stable high-quality image free of abnormal images such as background stains, black spots, and insect bites, and an image forming apparatus including the electrophotographic photoreceptor as a component. sponsored. 2. There is no defect in electrostatic characteristics such as increase in residual potential,
Further, a stable high-quality color image forming apparatus, particularly a full-color image forming apparatus, which is excellent in abrasion resistance and does not generate abnormal images such as background stains and insect bites over a long period of time has been provided.

[Brief description of the drawings]

FIG. 1 is a front view showing an example of the electrophotographic apparatus of the present invention.

FIG. 2 is a front view showing another example of the electrophotographic apparatus of the present invention.

FIG. 3 is a front view showing another example of the electrophotographic apparatus of the present invention.

FIG. 4 is a front view showing an example of the full-color electrophotographic apparatus of the present invention.

FIG. 5 is a cross-sectional view illustrating a layer configuration of the electrophotographic photosensitive member of the present invention.

FIG. 6 is a cross-sectional view illustrating a layer configuration of the electrophotographic photosensitive member of the present invention.

FIG. 7 is a cross-sectional view illustrating a layer configuration of the electrophotographic photosensitive member of the present invention.

FIG. 8 shows an insect-eating image.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Charging member 6 Exposure means 7 Developing means 8 Transfer member (corona type) 9 Recording material 10 Cleaning means 11 Static elimination means 12 Photoconductor 20 Container 21 Container 22 Container 23 Transfer member 24 Fixing means 51 Photoconductor 52 Charger 53 Exposure 54 Potential Sensor 55-1 First-color developing section 55-2 Second-color developing section 55-3 Third-color developing section 55-4 Fourth-color developing section 56 Developed toner density detection sensor 57 Static electricity remover before cleaning 58 Cleaning member 59 Cleaning member Reference Signs List 60 static elimination lamp 61 intermediate transfer body 62 transfer paper 63 transfer roller 511 conductive support 512 photoconductor 513 intermediate layer 515 photosensitive layer 517 charge generation layer 519 charge transport layer 520 protective layer A rotation direction W

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Tatehiko Kinoshita 1-3-6 Nakamagome, Ota-ku, Tokyo F-term in Ricoh Co., Ltd. (reference) 2H068 AA04 AA06 AA14 AA20 AA21 BA13 BB04 BB34 BB55 BB11 FB11 FC01

Claims (8)

[Claims] 1. An electrophotographic photoreceptor having at least a photosensitive layer on a conductive substrate, wherein the photosensitive layer is formed through a step of heating and drying after film formation, and a polyethylene wax having a melting point equal to or lower than the drying temperature is used. An electrophotographic photoreceptor characterized by containing. 2. An electrophotographic photoreceptor comprising at least a photosensitive layer and a protective layer sequentially laminated on a conductive substrate, wherein the protective layer is formed through a step of heating and drying after film formation, and is performed at a temperature not higher than the drying temperature. An electrophotographic photosensitive member containing a polyethylene wax having a melting point and a charge transport material. 3. The electrophotographic photoconductor according to claim 1, wherein the protective layer and / or the photosensitive layer further contains an antioxidant and / or an ultraviolet absorber. 4. The method according to claim 1, wherein the polyethylene wax comprises a main chain and / or
The electrophotographic photoreceptor according to any one of claims 1 to 3, wherein the side chain is an aromatic-modified polyethylene wax having an aromatic modification. 5. The electrophotographic photosensitive member according to claim 1, wherein the protective layer and / or the photosensitive layer contains a silicone oil. 6. An electrophotographic photosensitive member, charging means,
An image forming apparatus having at least an image exposing unit, a developing unit, a transferring unit, and a cleaning unit, wherein the electrophotographic photosensitive member is the electrophotographic photosensitive member according to claim 1. . 7. The charging device according to claim 6, wherein said charging means is a contact charging member.
An image forming apparatus according to claim 1. 8. An intermediate transfer system in which a visible color developed image formed on an electrophotographic photosensitive member is primarily transferred onto an intermediate transfer member, and the primary transfer image on the intermediate transfer member is secondarily transferred onto a transfer material. 6. A color image forming apparatus, wherein the electrophotographic photosensitive member is the electrophotographic photosensitive member according to claim 1.