JPH10268540A - Electrophotographic photoreceptor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a photoreceptive layer from peeling off and to stably form an image of improved quality and density for a long period by giving an adhesion strength equal to or exceeding a specified range to an organic photoreceptive layer and the base body of a photoreceptor. SOLUTION: An electrostatic charging means 2, an image exposing means 20, a developing means 30, a toner transfer means 45 and a means 50 for removing foreign matter such as paper powder, etc., are arranged in this order around the photoreceptor drum 1, and the means 20 is arranged at the lowermost part. And, the transfer means 45 and the fixing means 60 are installed so that the transfer material 47 may be supplied by a transfer material supply means to a part between the transfer means 45 and the photoreceptor drum 1 and also the transfer material 47 may be ejected to the outside through the fixing, means 60. And as for the electrophotographic photoreceptor, the organic photoreceptive layer and the base body of the photoreceptor are provided with the adhesion strength >=3N/10 mm which is obtained by measuring in the circumferential direction of the drum based on an adhesive tape/adhesive sheet inspection method of JIS Z0237-1980. Thus, even in the case of using the photoreceptor in an image forming device in which a positioning roller 48 for a non-contact transfer roller is directly brought into contact with the photoreceptive layer of the photoreceptor drum 1, the photoreceptive layer is prevented from peeling off.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organic photoreceptor used for an electrophotographic image forming apparatus, for example, an analog PPC, an optical printer, a facsimile, a digital PPC, and more particularly, to a non-contact transfer roller. The present invention relates to a photosensitive member used for an image forming apparatus having the positioning rollers.

[0002]

2. Description of the Related Art In electrophotographic image formation, a photosensitive member is charged and exposed to form an electrostatic latent image, and the electrostatic latent image on the photosensitive member is developed with a developer containing charged toner to form a toner image. An image is formed by forming the toner image, transferring the toner image to a transfer material such as paper, and fixing the transferred toner image.

As the electrophotographic photoreceptor, a selenium photoreceptor,
a- Various types of photoreceptors such as silicon photoreceptors and organic photoreceptors are known, but in terms of manufacturing cost, easy disposal and environmental friendliness, and adaptability to small copiers, fax machines and printers. In this respect, the organic photoreceptor is superior.

A corona charger is generally used for main charging of the photoreceptor. However, in a negative corona, since a discharge product such as ozone is remarkably generated, a positive charge type organic photoreceptor having less discharge product is used. The use of the body is desired. In an optical printer or the like, it is necessary to perform reversal development, and a positively charged toner is generally used for this purpose.

However, when transferring the positively charged toner on the surface of the photoreceptor to transfer paper, it is necessary to perform negative charging from the back surface of the transfer paper. If a negative corona charger is used, discharge products such as ozone are generated. Due to the problem of occurrence, the use of a chargeable transfer roller is desired.

The transfer method using a transfer roller includes a contact type in which the transfer roller is brought into contact with the photosensitive member and a non-contact type in which the transfer roller is separated from the photosensitive member. In the latter non-contact type, the transfer roller is used. It is necessary to accurately position the photoconductor on the photoconductor. For this purpose, the photoconductor and the transfer roller are engaged via a positioning roller.

However, since a local force is applied to the organic photoreceptor by the roller, the roller contact portion of the organic photoreceptor often peels off, and the peeled off photosensitive layer is mixed into the developer to cause an image defect. In addition, the photosensitive layer that has been peeled off may enter the main charger and cause a leak.

In order to prevent this, an elastic body is wrapped around the outer periphery of a roller contacting the photoreceptor, or the elastic body is wrapped around a portion of the photoreceptor contacting the roller to prevent peeling. I have.

[0009]

When the photosensitive member and the positioning roller are brought into contact with each other via an elastic body, the distance between the surface of the photosensitive member and the transfer roller is not constant, so that there is a disadvantage that uneven transfer is likely to occur. is there. Further, extra steps and costs are required for processing the rollers and the photosensitive member, which is not economically preferable.

Accordingly, an object of the present invention is to solve the above-mentioned drawbacks in the prior art, and to prevent the photosensitive layer from peeling off even when the photosensitive member is brought into direct contact with the positioning roller of the non-contact transfer roller. It is an object of the present invention to provide a photoreceptor capable of accurately positioning a non-contact transfer roller with respect to a photoreceptor, and as a result, capable of stably forming an image having excellent image quality and density for a long period of time.

[0011]

According to the present invention, there is provided an electrophotographic photosensitive member used in an image forming apparatus having a positioning roller for a non-contact transfer roller which is in contact with a photosensitive layer of a photosensitive drum, according to JISZ0237-1980. An electrophotographic photosensitive member is provided, wherein the organic photosensitive layer and the photosensitive member substrate have an adhesive force of 3 N / 10 mm or more as measured in the circumferential direction of the drum according to the tape / adhesive sheet test method. You.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION

[Action] In the present invention, when an organic photosensitive layer and a photosensitive body having an adhesive strength of 3 N / 10 mm width or more are measured in the drum circumferential direction in accordance with JIS Z0237-1980 adhesive tape / adhesive sheet test method, Even when used in an image forming apparatus in which a positioning roller of a non-contact transfer roller directly contacts a photosensitive layer of a photosensitive drum, peeling of the photosensitive layer can be effectively prevented. 2. It was found that the peeling of the organic photosensitive layer caused when the roller was brought into contact with the photosensitive drum was greatly affected by the circumferential adhesive strength between the organic photosensitive layer and the photosensitive substrate. As shown in the examples described below, when this adhesive force is below the above range, there is a time difference, but peeling at the roller contact portion necessarily occurs, while the circumferential adhesive force is within the above range, In the range of the life of the photoconductor, the occurrence of peeling can be suppressed to substantially zero. 3. It is considered that the stress when the roller is brought into contact with the organic photosensitive layer is concentrated on a limited portion of the interface between the photosensitive layer and the substrate. This tendency of stress concentration seems to be more pronounced as the diameter of the drum becomes smaller. The above-described method using the elastic body disperses the stress concentration, but it cannot make the distance between the photosensitive drum and the transfer roller constant. 4. In the present invention, peeling due to stress concentration is prevented by setting the circumferential adhesive force between the organic photosensitive layer and the photosensitive member substrate to the critical value or more. 5. As described above, in the present invention, an image defect due to the peeled photosensitive layer being mixed into the developer can be eliminated, and the leakage of the main charger can also be prevented. 6. In addition, the transfer roller and the photoconductor can be accurately positioned, and the transfer by roller charging is performed using a non-contact type roller, so that the contact between the toner supporting photoconductor and the transfer roller is cut off by paper. Even during non-transfer, the transfer roller is separated from the toner-supporting photoreceptor, so that the transfer roller is prevented from being stained, thereby preventing the transfer paper from being stained. This is an important effect for double-sided printing of paper. 7. Further, the use of the non-contact roller eliminates the pressing of the transfer paper against the photoreceptor, prevents the characters from dropping out, and significantly improves the image quality.

The photoreceptor according to the present invention is JIS Z0237-
1980 Measured in the circumferential direction of the drum according to the adhesive tape / adhesive sheet test method.
It has an adhesive strength of / 10 mm width or more. The above test method is defined for a stainless steel plate and an adhesive tape, but in the test of the present invention, this is applied to a photoreceptor drum. Please refer to.

In order to achieve this adhesive strength, (1) a surface treatment of the photoreceptor substrate is performed to improve the adhesive strength:
(2) As the organic photosensitive layer, one having high adhesive strength is used:
(3) Providing a primer layer for increasing the adhesive strength between the photoreceptor substrate and the organic photosensitive layer: (4) selecting and combining the photoreceptor substrate and the organic photosensitive layer so as to obtain a predetermined adhesive force: Employ at least one of the means. Of course, these means must be employed within a range that satisfies conditions such as substantially not lowering the sensitivity of the photoreceptor, not lowering the image density, and not increasing the fog density. Hereinafter, an organic photoconductor will be described as an example.

The organic photoreceptor is preferably a single-layer organic photoreceptor in which a charge generating agent is dispersed in a resin medium. A charge transporting agent, in particular, a hole transporting agent and a charge generating agent are dispersed in a resin medium. It is most preferable that the photoreceptor is a monodispersed layer type photoreceptor.

The photoreceptor of the present invention may be a laminate type photoreceptor having a charge transport layer containing a charge transport agent and a charge generation layer containing a charge generator. In this case, the charge generation layer (CG)
L) and the charge transport layer (CTL) may be a photoconductor in which the layers are stacked in this order or in the reverse order.

Examples of the charge generating agent include selenium, selenium-tellurium, amorphous silicon, pyrylium salt,
Azo pigments, disazo pigments, ancesthrone pigments,
Phthalocyanine-based pigments, indico-based pigments, selen-based pigments, toluidine-based pigments, pyrazoline-based pigments, perylene-based pigments, quinacridone-based pigments, and the like are exemplified, and one or more of them are mixed so as to have an absorption wavelength range in a desired region. Used.

The following are particularly preferred. Examples of phthalocyanine pigments include metal-free phthalocyanine, aluminum phthalocyanine, vanadium phthalocyanine, cadmium phthalocyanine, antimony phthalocyanine, chromium phthalocyanine, copper 4-phthalocyanine, germanium phthalocyanine, iron phthalocyanine, chloroaluminum phthalocyanine, oxotitanyl phthalocyanine, chloroindium phthalocyanine, and chlorogallium. Examples include phthalocyanine, magnesium phthalocyanine, dialkyl phthalocyanine, tetramethyl phthalocyanine, tetraphenyl phthalocyanine, and the like. Also, the crystal form is α-type, β-type, γ-type, δ
Any of the types, ε type, σ type, x type, τ type, etc. can be used.

Perylene pigments, in particular, of the general formula (A):

Embedded image In the formula, each of R ₁ and R ₂ is a substituted or unsubstituted alkyl group, cycloalkyl group, aryl group, alkaryl group, or aralkyl group having 18 or less carbon atoms. What is represented by Examples of the alkyl group include an ethyl group, a propyl group, a butyl group, a 2-ethylhexyl group, and the like.
Examples of the cycloalkyl group include a cyclohexyl group and the like; examples of the aryl group include a phenyl group and a naphthyl group; examples of the alkaryl group include a tolyl group, a xylyl group, and an ethylphenyl group; and an aralkyl group. Examples thereof include a benzyl group and a phenethyl group. Examples of the substituent include an alkoxy group and a halogen atom.

Bisazo pigments, especially the following formula (B)

Embedded image In the formula, A is a hydrogen atom or a substituted or unsubstituted alkyl group, aryl group or heterocyclic group, n is zero or 1, and Cp is a coupler residue. In the 3-position of the pyrazole ring, a substituted or unsubstituted alkyl group, directly or via a vinylidene group,
An aryl group or a heterocyclic group may be bonded, wherein the alkyl group includes methyl, ethyl, propyl,
Butyl, amyl group, and the like, and the aryl group includes phenyl, naphthyl, biphenyl, anthryl, phenanthryl, and fluorenyl group.The heterocyclic group includes nitrogen, oxygen, sulfur, or a combination thereof in the ring. A monocyclic or polycyclic saturated or unsaturated heterocyclic group such as thienyl, furyl, imidazolyl, pyrrolyl, pyrimidinyl, imidazole, pyrazinyl, pyrazolinyl, pyrrolidinyl, pyranyl,
Piperidyl group, piperazinyl group, morpholyl group, pyridyl group, pyrimidyl group, pyrrolidinyl group, pyrrolinyl group,
Examples include a benzofuryl group, a benzimidazolyl group, a benzofuranyl group, an indolyl group, a quinolyl group, a carbazolyl group, and a dibenzofuranyl group. These substituents include a lower alkyl group, a lower alkoxy group, an acyloxy group, a halogen atom such as chlor, a hydroxyl group, a nitrile group, a nitro group, an amino group, an amide group, an acyloxy group, a carboxyl group, and the like. On the other hand, equation (B)
The coupler residue in the above is not particularly limited as long as it is a residue of a coupler (azo coupling component) used in this type of azo pigment, such as a substituted or unsubstituted phenol, naphthol, or hydroxyl group-containing heterocyclic ring. The substituent may be a lower alkyl group, a lower alkoxy group, an aryl group, an acyloxy group,
Halogen atoms such as chlor, hydroxyl group, nitrile group, nitro group, amino group, amide group, acyloxy group,
And a carboxyl group.

As the resin medium in which the charge generating agent is dispersed, any of various resins satisfying the above conditions can be used. For example, a styrene-based polymer, an acrylic-based polymer, and a styrene-acryl-based polymer can be used. , Ethylene-vinyl acetate copolymer, polypropylene, olefin polymers such as ionomers, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polyester, alkyd resin, polyamide, polyurethane, epoxy resin, polycarbonate,
Various polymers such as polyarylate, polysulfone, diallyl phthalate resin, silicone resin, ketone resin, polyvinyl butyral resin, polyether resin, phenol resin, and photocurable resins such as epoxy acrylate can be exemplified. These binder resins may be used alone or in combination of two or more.

As a resin having a low tendency to toner filming, polycarbonate is preferred. Polycarbonate is a polycarbonate obtained by the reaction of bisphenols and phosgene, and more specifically, the following general formula (C):

Embedded image In the formula, R ₃ and R ₄ are a hydrogen atom or a lower alkyl group, and R ₃ and R ₄ may be linked to form a cyclo ring such as a cyclohexane ring together with a bonding carbon atom. Polycarbonate derived from bisphenols and phosgene.

Examples of the starting bisphenols include:
2,2-bis (4-hydroxyphenyl) propane (bisphenol A), 2,2-bis (4-hydroxyphenyl) butane (bisphenol B), 1,1-bis (4
-Hydroxyphenyl) ethane, bis (4-, 3- or 2-hydroxyphenyl) methane (bisphenol F), 1,1-bis (4-hydroxyphenyl) cyclopentane, 1,1-bis (4-hydroxyphenyl) Cyclohexane (bisphenol Z), and the like.

The polycarbonate to be used preferably has a glass transition point of 100 ° C. or more from the viewpoint of preventing toner filming. Among them, polycarbonate derived from bisphenols other than bisphenol A and bisphenol Z type polycarbonate are preferred. Excellent in workability and workability. This type of polycarbonate can be obtained, in particular, as Panlite manufactured by Teijin Chemicals Limited, PCZ manufactured by Mitsubishi Gas Chemical Company, or the like.

The above polycarbonate is excellent in preventing toner filming, but tends to have poor peeling resistance when applied to a substrate such as aluminum. In order to prevent this, it is preferable that the polyester is present in the organic photosensitive layer in an amount of 5% by weight or less, particularly 0.5 to 5% by weight. When the content of the polyester exceeds 5% by weight, toner filming tends to occur. On the other hand, when the amount of the polyester is too small, satisfactory peel resistance tends to be not obtained.

The polyester used herein is preferably a polyester derived from a dibasic acid mainly composed of an aromatic dicarboxylic acid and a diol, and is a copolymerized polyester in view of solubility in a solvent and compatibility with polycarbonate. Preferably, there is.

Examples of the aromatic dicarboxylic acid component include terephthalic acid, isophthalic acid, phthalic acid, P-β-oxyethoxybenzoic acid, naphthalene-2,6-dicarboxylic acid, diphenoxyethane-4,4′-dicarboxylic acid and the like. Examples of other dicarboxylic acids include hexahydroterephthalic acid, adipic acid, sebacic acid, succinic acid, dimer acid, maleic acid, fumaric acid, xylene dicarboxylic acid, and the like.

On the other hand, diol components include ethylene glycol, propylene glycol, 1,4-butanediol, neopentyl glycol, 1,6-hexylene glycol, diethylene glycol, triethylene glycol, cyclohexane dimethanol, bisphenol A
Alternatively, a glycol component such as an ethylene oxide adduct of bisphenol F can be used.

The aromatic dicarboxylic acid component accounts for at least 40 mol%, especially at least 60 mol%, of the dibasic acid component in view of the mechanical properties, moisture resistance, durability and electrical properties of the photosensitive layer. Desirably, the acid component of the polyester contains a combination of terephthalic acid and isophthalic acid, while satisfying the above-mentioned properties, while improving the solubility and the like, and reducing the glass transition point to the photosensitive layer substrate. It is suitable for the purpose of improving the adhesion. Of course, an aliphatic dibasic acid component other than the aromatic dicarboxylic acid may be contained within a range satisfying the above requirements, and these aliphatic dibasic acid components are useful for improving the solubility of the polyester.

The glycol component may be ethylene glycol alone or ethylene glycol and other glycols.
For example, it may be a combination with neopentyl glycol, and in the latter case, the amount ratio may be in the range of 1:10 to 10: 1 molar ratio.

The polyester used has a glass transition point (T
It is useful that g) is 90 ° C. or lower, particularly 75 ° C. or lower for improving the peeling resistance. The number average molecular weight is 1000
It is preferably in the range of 0 to 30,000 and the acid value is 2 or less from the viewpoint of mechanical properties and durability of the photosensitive layer.

The polyester may be a homopolyester or a copolyester alone or a blend of two or more thereof.

As the charge transporting agent, any known electron transporting or hole transporting agent can be used. A suitable example is as follows.

Examples of the electron transporting agent include a paradiphenoquinone derivative, a benzoquinone derivative, a naphthoquinone derivative, tetracyanoethylene, tetracyanoquinodimethane, chloranil, bromoanil, 2,4,7-trinitro-9.
-Fluorenone, 2,4,5,7-tetranitro-9-
Electron-withdrawing substances such as fluorenone, 2,4,7-trinitro-9-dicyanomethylenefluorenone, 2,4,5,7-tetranitroxanthone, 2,4,8-trinitrothioxanthone, and these electron-withdrawing substances Which have been polymerized.

Of these, naphthoquinone derivatives and paradiphenoquinone derivatives, particularly asymmetric paradiphenoquinone derivatives and naphthoquinone derivatives, are preferred because they have excellent solubility and electron transport properties.

The naphthoquinone derivative is represented by the following general formula (D)

Embedded imageWhere R^a Is an alkyl group which may have a substituent or a substituent
An aryl group which may have a substituent;^b Is a substituent
Alkyl group which may have, aryl which may have a substituent
Or a group -OR^G  Is shown. R in the above group^G Is an alkyl which may have a substituent
It shows a kill group or an aryl group which may have a substituent.

As the paradiphenoquinone derivative, the following general formula (E):

Embedded image Where R ⁵ , R ⁶ , R ⁷ And R ⁸ Is a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, an alkoxy group, or the like. R ^5, R ^6, R ⁷ and R ⁸ It preferably has a substituent of the asymmetric structure, R ⁵ , R ⁶ , R ⁷ And R ⁸ Of which,
Is preferably a lower alkyl group, and the other two are branched alkyl groups, cycloalkyl groups, aryl groups or aralkyl groups.

Suitable examples include, but are not limited to,
3,5-dimethyl-3 ′, 5′-di-tert-butyldiphenoquinone, 3,5-dimethoxy-3 ′, 5′-di-tert-butyldiphenoquinone, 3,3′-dimethyl-5,5 '-Di-t-butyldiphenoquinone, 3,5'-dimethyl-
3 ′, 5-di-tert-butyldiphenoquinone, 3,5
3 ', 5'-tetramethyldiphenoquinone, 2,6
2 ′, 6′-tetrat-butyldiphenoquinone, 3,
5,3 ′, 5′-tetraphenyldiphenoquinone, 3,
5,3 ′, 5′-Tetracyclohexyldiphenoquinone and the like can be cited, but these diphenoquinone derivatives have low interaction between molecules due to low molecular symmetry and are excellent in solubility. Preferred for.

On the other hand, as the hole transporting substance, for example, the following substances are known, and among them, those having excellent solubility and hole transporting property are used. Pyrene, N-
Ethyl carbazole, N-isopropyl carbazole,
N-methyl-N-phenylhydrazino-3-methylidene-9-carbazole, N, N-diphenylhydrazino-
3-methylidene-9-ethylcarbazole, N, N-diphenylhydrazino-3-methylidene-10-ethylphenothiazine, N, N-diphenylhydrazino-3-methylidene-10-ethylphenoxazine, p-Diethylaminobenzaldehyde-N, N-diphenylhydrazone, p-diethylaminobenzaldehyde-α-naphthyl-N-phenylhydrazone, p-pyrrolidinobenzaldehyde-N, N-diphenylhydrazone, 1,3,3
-Trimethylindolenine-ω-aldehyde-N, N-
Hydrazone salts such as diphenylhydrazone, p-diethylbenzaldehyde-3-methylbenzthiazolinone-2-hydrazone, 2,5-bis (p-diethylaminophenyl) -1,3,4-oxadizole, 1-phenyl- 3- (p-diethylaminostyryl) -5- (p-diethylaminophenyl) pyrazolin, 1- [quinonyl (2)]-3- (p-diethylaminostyryl) -5-
(P-diethylaminophenyl) pyrazoline, 1- [pyridyl (2)]-3- (p-diethylaminostyryl)
-5- (p-diethylaminophenyl) pyrazoline, 1
-[6-Methoxy-pyridyl (2)]-3- (p-diethylaminostyryl) -5- (p-diethylaminophenyl) pyrazolin, 1- [pyridyl (3)]-3- (p
-Diethylaminostyryl) -5- (p-diethylaminophenyl) pyrazoline, 1- [repidyl (3)]-3
-(P-diethylaminostyryl) -5- (p-diethylaminophenyl) pyrazoline, 1- [pyridyl (2)]-3- (p-diethylaminostyryl) -4-
Methyl-5- (p-diethylaminophenyl) pyrazoline, 1- [pyridyl (2)]-3- (α-methyl-p-
Pyrazolines such as diethylaminostyryl) -3- (p-diethylaminophenyl) pyrazoline, 1-phenyl-3- (p-diethylaminostyryl) -4-methyl-5- (p-diethylaminophenyl) pyrazoline and spiropyrazoline; -(P-diethylaminostyryl)
-3-diethylaminobenzoxazole, 2- (p-
Oxazole compounds such as diethylaminophenyl) -4- (p-dimethylaminophenyl) -5- (2-chlorophenyl) oxazole, thiazole compounds such as 2- (p-diethylaminostyryl) -6-diethylaminobenzothiazole, Bis (4-diethylamino-
Triary such as 2-methylphenyl) phenylmethane
Methane compound, 1,1-bis (4-N, N-diethylamino-2-methylphenyl) heptane, 1,1,
2,2-tetrakis (4-N, N-dimethylamino-2
Polyarylalkanes such as -methylphenyl) ethane, N, N'-diphenyl-N, N'-bis (methylphenyl) bendiben, N, N'-diphenyl-N, N '
-Bis (ethylphenyl) benzidine, N, N'-diphenyl-N, N'-bis (propylphenyl) benzidine, N, N'-diphenyl-N, N'-bis (butylphenyl) benzidine, N, N'- Bis (isopropylphenyl) benzidine, N, N'-diphenyl-N, N '
-Bis (secondary butylphenyl) benzidine, N, N '
-Diphenyl-N, N'-bis (tertiarybutylphenyl) benzidine, N, N'-diphenyl-N, N'-bis (2,4-dimethylphenyl) benziben, N, N '
Benzidine compounds such as -diphenyl-N, N'-bis (chlorophenyl) benzidine, phenylenediamine derivatives diaminonaphthalene derivatives diaminophenanthrene derivatives triphenylamine, poly-N-vinylcarbazole,
Polyvinylpyrene, polyvinylanthracene, polyvinylalixin, poly-9-vinylphenylanthracene, pyrene-formaldehyde resin, ethylcarbazole formaldehyde resin.

As a preferable hole transporting agent, the following formula (F)

Embedded image In the formula, each of Ar ₁ , Ar ₂ , Ar ₃ and Ar ₄ is a substituted or unsubstituted aryl group, Y is a substituted or unsubstituted arylene group, and n is a number of 0 or 1. And the aromatic amines represented.

Further, as other suitable hole transporting agents, hydrazones, particularly the following formula (G):

Embedded image In the formula, each of Ar ₅ may be the same or different and is a substituted or unsubstituted aryl group.

In the monodispersed photosensitive member used in the present invention, the charge generating agent (CGM) is 0.5 to 7 per solid.
% By weight, in particular in the range from 1 to 5% by weight, in the photosensitive layer, and the charge transport agent (CTM) is in the range from 20 to 75% by weight, in particular from 25 to 60% by weight, based on solids. In the photosensitive layer.

Further, from the viewpoint of sensitivity and the wide range of applications to enable reversal development, it is preferable to use an electron transporting agent (ET) and a hole transporting agent (HT) in combination. In this case, the weight ratio of ET: HT is 10: 1 to 1:10,
In particular, it is best to be in the range of 1: 5 to 1: 1.

The composition for forming a photoreceptor used in the present invention includes:
Various additives known per se, such as antioxidants, radical scavengers, singlet quenchers, UV absorbers, softeners, surface modifiers, defoaming, as long as they do not adversely affect the electrophotographic properties. Agents, extenders, thickeners, dispersion stabilizers, waxes, acceptors, donors, and the like.

When a sterically hindered phenolic antioxidant of 0.1 to 50% by weight based on the total solid content is blended,
The durability of the photosensitive layer can be significantly improved without adversely affecting the electrophotographic properties.

As the conductive substrate on which the photosensitive layer is provided, various conductive materials can be used. For example, aluminum, copper, tin, platinum, gold, silver, vanadium, molybdenum,
Chrome, cadmium, titanium, nickel, indium,
Examples thereof include a simple metal such as stainless steel and brass, a plastic material on which the above metal is deposited or laminated, a glass coated with aluminum iodide, tin oxide, indium oxide, and the like.

In the photoreceptor used in the present invention, it is preferable to use a raw tube which has been subjected to an alumite treatment so as to have a film thickness of 1 to 50 μm in order to increase the adhesive strength of the photoreceptor.

In order to form a monodispersed layer type photoreceptor, a charge generating material, a charge transporting agent and the like and a binder resin and the like are mixed by a conventionally known method, for example, a roll mill, a ball mill, an attritor, and the like.
What is necessary is just to prepare using a paint shaker or an ultrasonic disperser, apply | coat and dry by a well-known coating means conventionally. Although the thickness of the photosensitive layer is not particularly limited, it is generally preferably in the range of 5 to 100 μm, particularly 10 to 50 μm, and it is desirable to provide the photosensitive layer as thick as possible without causing a decrease in sensitivity or an increase in residual potential.

As the solvent used for forming the coating solution, various organic solvents can be used, and alcohols such as methanol, ethanol, isopropanol and butanol,
n-hexane, octane, aliphatic hydrocarbons such as cyclohexane, benzene, toluene, aromatic hydrocarbons such as xylene, dichloromethane, dichloroethane, carbon tetrachloride, halogenated hydrocarbons such as chlorobenzene, dimethyl ether, diethyl ether, tetrahydrofuran, Various solvents such as ethers such as ethylene glycol dimethyl ether and diethylene glycol dimethyl ether; ketones such as acetone, methyl ethyl ketone and cyclohexanone; esters such as ethyl acetate and methyl acetate; dimethylformamide and dimethyl sulfoxide; Used as a mixture. In general, the solid content of the coating solution is preferably 5 to 50%.

In the case of a laminated photoreceptor, the charge generating agent (CGM) is used in an amount of 30 per solid content of the charge generating layer (CGL).
And the charge transporting agent (CTM) is present in an amount in the range of from 20 to 70% by weight, especially 30 to 80% by weight, based on the solids content of the charge transporting layer (CTL). It may be contained in an amount in the range of from about 60% by weight to about 60% by weight. The components of each coating layer correspond to the components of the monodispersed layer type.

In the case of substrate / CGL / CTL photoreceptor, CG
L should generally be in the range of 0.1 to 0.5 μm,
The CTL is preferably provided within a range of 5 to 40 μm, particularly 10 to 25 μm.

In the case of the substrate / CTL / CGL photoreceptor, the CT
L is preferably in the range of 5 to 40 μm, especially 10 to 25 μm, while CGL has a thickness of 0.1 to 0.5 μm. Further, a protective layer known per se can be provided on the CGL.

Providing an underlayer (primer layer) between the photoreceptor substrate and the organic photosensitive layer is also useful for improving the adhesion, and examples of the primer layer include polyvinyl butyral resin. These primer layers are 0.1 to 3 μm,
In particular, the thickness is preferably 0.5 to 2 μm.

[Image Forming Apparatus] FIG. 1 shows the overall arrangement of an example of an image forming apparatus using the photosensitive member of the present invention.
Around the photosensitive drum 1, a charging unit 2, an image exposing unit 20, a developing unit 30, a toner transferring unit 45, and a foreign matter removing unit 50 such as paper dust are arranged in this order at the bottom. The transfer material 47 is supplied between the transfer unit 45 and the photosensitive drum 1 from a transfer material supply unit (not shown).
Next, the transfer material 47 is provided so as to be discharged outside through the fixing unit 60.

The image forming process by this electrophotographic apparatus is briefly described as follows. First, the surface of the photoreceptor drum 1 is charged with a positive charge by the charging means 2. Then
The charged photosensitive drum 1 is irradiated with a light image by the image exposure means 20 to form an electrostatic latent image (negative image) corresponding to the original image. This electrostatic latent image is visualized by the developing unit 30 to form a toner image. The transfer material 47 is supplied at the position of the toner transfer unit 45 so as to be in contact with the drum surface, and the toner image is transferred to the transfer material 47. The transfer paper 47 on which the toner image has been transferred is separated from the drum 1 and sent to the fixing unit 60, where the toner is fixed by passing between the support roller 61 and the heating roller 62. After the transfer of the toner, the photosensitive drum 1 comes into contact with the foreign matter removing means 50 to remove foreign matter such as paper dust. The toner remaining on the photosensitive drum after the transfer of the toner is cleaned by the developing unit 30 after passing through the charging and image exposing steps described above.

The charging means 2 is preferably a scorotron charger, and as shown in FIG. 1, a pair of shields 5 arranged opposite to each other, a grid 6 arranged at an opening on the photosensitive drum 1 side, and And a corona wire (discharge member) 7. The shield 5 is made of, for example, a resin housing 8.
The charger 2 is located below the housing 8.
Is formed with a hole 4 communicating with the inside.

As already pointed out, the charging means 2 is connected to the charging means 2 shown in FIG.
As shown by, by providing the ventilation opening 4 below the photosensitive drum 1 and at a specific portion of the charging means,
Even in a compact device, the photosensitive drum 1 is significantly less affected by ozone and NOx, and even in image formation without cleaning, toner adhesion to the corona wire 7 and grid 6 is effective. Is prevented.

Regarding the size of the hole 4 provided in the charging means 2, it is sufficient to provide the hole 4 over the entire length direction of the charging means 2 in terms of air permeability. Width (W), but at least 1 of W
It is preferable that the width is / 5 times or more.

As shown in FIG. 2, the discharge member 7 is electrically insulated from the shield and the housing.
It is connected to the. Further, the grid member 6 is electrically insulated from the housing together with the shield, and the zener diode (constant potential diode) or the varistor 1
0 is grounded.

Surface potential (Sp) of single-layer photoreceptor small-diameter drum
Is effective to form a high-density and high-contrast image while preventing leakage, while maintaining the grid potential at 600 to 1300 volts while preventing leakage. Especially 70
Suitably, it is maintained in the range of 0 to 1100 volts.

The charging potential on the surface of the photoreceptor and the potential of the grid should be in the above-mentioned ranges. For this purpose, it is preferable to apply a voltage of plus 3 KV to 7 KV to the scorotron charger.

As the grid, a parallel line or grid grid having an opening area ratio of about 70 to 98% is used.

In the image exposing means 20 of the image forming apparatus, the photoreceptor after the main charging can be carried out through an exposure device using a laser beam or a light emitting diode (LED) array known per se. As the light source 21 for exposure, a monochromatic light source such as an LED of red, yellow, green or the like can be used, or a laser light source such as a semiconductor laser beam can be used.

At this time, the light exposure amount (I _B ) is a light amount such that the residual potential (E _R ) in the bright portion is lower than the bias potential (E _B ). residual potential in a bright portion (E _R) has the formula _{(1) E R = E B} - nE in _D0 ‥‥ (1) formula, E _B is the developing bias potential, E _D0 is between the developer and the photoconductor Regarding the development sensitivity characteristics of the combination, it is preferable to set the exposure amount so as to satisfy the potential at which the fog density becomes substantially zero and n is a number of 0.4 to 2.5.

Developing means 30 used in this image forming apparatus
Is a developing device for a one-component non-magnetic toner. As shown in FIG. 1, an elastic developing roller 32 for applying a non-magnetic one-component toner to a photoconductor is provided inside a developing container 31. Sub-roller 33 for supplying toner to the roller
And an agitator 34 for stirring and charging the toner. An opening 35 is provided on the side of the developing container close to the photoreceptor, and the developing roller 32 is located in the opening 35.
3 are provided.

A toner cartridge 37 having a slit-like opening 36 at the lower end is provided above the developing container 31, and a toner supply roller 38 is provided in the opening 36. Further, a blade 39 for controlling the toner layer to a constant thickness and additionally charging the toner is provided on the toner layer sending side of the elastic developing roller 32.

The one-component toner 40 contained in the toner cartridge 37 is moved by the toner supply roller 38.
The fixed amount is supplied into the developing container 31 and is stirred and charged by the agitator 34. The charged toner is applied on the sub-roller 33 and then on the elastic developing roller 32. The thickness of the toner layer on the developing roller 32 is controlled by a blade 39 so as to have a constant layer thickness, and the toner on the developing roller 32 is strongly charged by rubbing with the blade.

The developing roller 32 is a conductive elastic roller, and contacts the photosensitive drum 1 with the developing roller 32 holding the one-component toner to form an image by reversal development. This reversal development is performed so that the charging polarity of the toner is the same as the charging polarity of the dark portion (unexposed portion) of the photoconductor, and the residual toner amount in the dark portion of the photoconductor becomes substantially zero. As a result, the reversal development is effectively performed by the same repulsive action of the toner and the dark area of the photoconductor and the suction action of the charge and the toner induced to the light area of the photoconductor, and the cleaning of the dark area of the photoconductor is also effective at the time of development. Done in It is desirable to apply a bias voltage slightly higher than the bias voltage applied to the developing roller 32 so that the toner can be smoothly transferred from the sub roller 33 to the developing roller 32.

As the elastic developing roller 32, a roller formed of a composition obtained by mixing a conductive powder with an elastomer polymer is used.

The specific volume resistance of the elastic developing roller is generally 10 ^{5 to} 10 ¹² (Ω · cm), particularly 1
0 ⁷ to frequently in the range of 10 ^10, is higher than the above range, the application of the bias voltage is difficult, whereas if lower than the above range, tends to generate a leakage due to discharge at the surface of the photosensitive member There is.

The surface hardness (Rockwell JIS A) of the elastic developing roller is 30 to 70, especially 40 to 6
It is preferably in the range of 0, and when it is higher than the above range, it tends to be difficult to uniformly contact the toner layer on the surface of the photoreceptor or the abrasion of the photoreceptor tends to occur. If it is lower than the above range, it becomes difficult to transmit a sufficient pressure contact force, or the developing roller is liable to be worn.

Examples of the elastomer polymer include nitrile-butadiene rubber (NBR), styrene-butadiene rubber (SBR), chloroprene rubber (CR), polybutadiene (BR), polyisoprene (IIB), butyl rubber, natural rubber, ethylene- Propylene rubber (EP
R), ethylene-propylene-diene rubber (EPD)
M), polyurethane, silicone rubber, fluorine rubber, chlorinated polyethylene, chlorinated polypropylene, soft vinyl chloride resin and the like can be used. In order to adjust the surface hardness, a foam (sponge) can be used, or a plasticizer or a softener can be blended.

As the conductive powder, conductive carbon black, metal powder of tin oxide, copper, silver, aluminum, etc. doped with indium or antimony or the like can be used, but conductive carbon black is preferred. The content of the conductive powder may be any as long as the electric resistance and the hardness of the roller are in the above-mentioned ranges.

In forming the conductive rubber roller,
A compounding agent known per se, for example, a sulfur or organic vulcanizing agent, a vulcanization accelerator, a softening agent, an antioxidant, a filler, a dispersant, a plasticizer, a foaming agent, etc. Can be blended. The rubber roller after molding is heated and vulcanized or vulcanized and foamed to form an elastic developing roller having a predetermined hardness.

The present invention can be advantageously applied to an organic photosensitive drum having a relatively small diameter, for example, an organic photosensitive member having an outer diameter (D _p ) of 10 to 20 mm. D _d ) is 6.5 to 20 mm, especially 1
A roller having a diameter of 0 to 18 mm is used, and the ratio (D _d / D _p ) of the diameter of the elastic developing roller to the diameter of the organic photosensitive drum is as follows.
It is preferably in the range of 40 to 125%, especially 60 to 110%.

When the diameter of the elastic developing roller is smaller than the above range, the problem of toner scattering tends to occur. On the other hand, when the diameter is larger than the above range, the area of the developing section becomes too large, which is not preferable.

At the time of development, the elastic roller is set at 0.05 to 1 kg / dm, particularly 0.08 to 0.
The pressure roller is brought into pressure contact with a linear pressure of 5 kg / dm, and the peripheral speed of the elastic roller is 1.
The peripheral speed is preferably 2 to 3 times, particularly 1.5 to 2.5 times.

When the pressing force is lower than the above range or when the peripheral speed of the elastic developing roller is lower than the above range,
It is difficult to sufficiently improve the density of the image, and there is a tendency that cleaning in the dark area of the photoreceptor cannot be sufficiently performed. On the other hand, when the pressing force is higher than the above range or when the peripheral speed of the elastic developing roller is increased. Is larger than the above range, the shaving amount of the photoconductor increases, and the life of the photoconductor tends to be shortened.

The elastic roller has the same polarity as the charged potential of the toner and the photosensitive member potential (dark portion potential) of 0.2 to 0.5.
It is preferable to apply a bias potential of 8 times, especially 0.3 to 0.7 times. If the bias potential is lower than the above range, a sufficient image density cannot be obtained. The toner cleaning of the dark portion of the photoreceptor is not performed sufficiently, and fogging occurs. Also, the supply of toner is insufficient, and the image density tends to decrease.

Although it has already been pointed out that the bias voltage is also applied to the sub-roller in the developing device shown in FIG. 1, the bias voltage applied to the sub-roller has the same polarity as the bias voltage applied to the elastic developing roller, and furthermore, A voltage that is higher by about 0 to 200 volts than the above is preferable in order to smoothly transfer the toner from the sub roller to the elastic developing roller.

The thickness of the toner layer on the elastic developing roller is
Although regulated by a blade, it is generally preferable to form about two times the toner particle size, that is, to form about two toner layers.

In the present invention, as the transfer means 45,
A conductive elastic roller is used, and the photosensitive drum 1 and the transfer roller 45 are arranged so as to be larger than the thickness of the transfer material 47 and to be separated by a small interval enabling transfer of toner to the transfer material 47. Then, toner transfer is performed. In order to position the transfer roller 45 in the above relationship, a roller 48 larger than the transfer roller diameter is arranged so as to mesh with the photosensitive drum 1 and the transfer roller 45.

As the conductive elastic body, those described for the developing roller are generally used.
A roller formed from a conductive polyurethane rubber composition having a rubber hardness of preferably 70 °, which is cured so as to exceed 0 ° (JIS A), is used. Thereby, occurrence of image defects such as white spots is prevented, and a good and stable transfer image can be formed over a long period of time.

Polyurethane rubber has soft segments based on polyester or polyether in the polymer chain,
It exhibits rubbery elasticity due to the presence of a hard segment based on an aromatic chain linked through a urethane or urea bond.

The polyurethane rubber used for the elastic transfer roller is obtained by reacting a polyurethane prepolymer (isocyanate-terminated polymer) obtained by reacting a polyol (hydroxyl-terminated polymer) with a polyisocyanate compound with a chain extender (crosslinking agent). Obtained. At this time, a desired rubber hardness can be obtained by adjusting the reaction between the isocyanate-terminated prepolymer and the chain extender. For example, by adjusting the temperature and / or the reaction time of the chain extension (crosslinking) reaction, a polyurethane having a desired hardness can be obtained. In general, it indicates that rubber hardness increases with increasing temperature and reaction time.

As the transfer roller, a roller formed of a composition obtained by mixing a conductive powder with polyurethane is used. By blending the conductive powder with the composition of the prepolymer and the chain extender (crosslinking agent) prior to crosslinking, uniform and uniform blending and dispersion can be achieved. The volume resistance of this conductive rubber is generally 10 ^{7 to} 10 ¹⁴ Ω · cm.
, Particularly in the range of 10 ^{8 to} 10 ¹² Ω · cm.

As the conductive powder, those described for the conductive elastic developing roller are used, and the compounding amount is determined so as to obtain the above-described electric resistance and hardness.

When transferring the toner, a DC voltage having a polarity opposite to the main charging polarity of the photosensitive member is applied to the transfer roller. Even if this DC voltage is lower than the charging start voltage of the photoconductor,
Although it may be higher than the charging start voltage of the photoconductor, the latter transfer method is desirable in terms of transfer efficiency. The charging start voltage (V _TH ) of the photoreceptor by the transfer roller varies depending on the type of the photoreceptor, but in the case of the monodispersed layer type organic photoreceptor suitably used in the present invention, it is approximately 0.3 to 2 kV. In the range. A preferable applied voltage in terms of toner transfer efficiency is
1.5 times or more, especially 2 times, the charging start voltage (V _TH ) of the photoconductor
More than double.

On the other hand, the upper limit of the voltage applied to the transfer roller is determined by the surface potential of the photosensitive layer after static elimination (the residual potential before the main charge). That is, the applied voltage should be set so that the absolute value of the residual potential before main charging is 50 V or less, preferably 20 V or less.

As the positioning roller for the transfer roller, a plastic roller having high mechanical accuracy and excellent abrasion resistance is used. For example, a roller made of polytetrafluoroethylene, polyoxymethylene, high molecular weight nylon, or polyacetal is used. Is used.

Generally, the transfer roller has a diameter of 7 to 16 mm.
It is suitable that the diameter of the photosensitive drum is 0.6 to 1.0 times the diameter of the photosensitive drum. On the other hand, the positioning roller has a diameter of 7 to 17 mm and is 0.6 to 1.0 times the diameter of the photosensitive drum. Those having a diameter of 1.1 times are suitable.

In this image forming apparatus, since the developing means 30 also serves to clean the toner remaining on the photoreceptor, no so-called cleaning mechanism is provided, and the toner remaining on the photoreceptor is used again for development. However, since the photosensitive drum contacts a transfer material such as paper,
Foreign matter such as paper dust tends to adhere to the photoreceptor surface, and it is necessary to provide foreign matter removing means 50 to remove the foreign matter.

As the foreign matter removing means 50, a fur brush is used, and at least a part of the brush fibers is made of a conductive material such as a metal, so that the photosensitive member can be simultaneously neutralized.

In this image forming apparatus, the fixing operation of the toner can be performed by using a means known per se and under the conditions known per se.

[Non-Magnetic One-Component Toner] As the non-magnetic one-component toner, a colored toner having a visible property and a fixing property is used, and generally, a colored pigment is contained in a binder resin. And particles having a particle diameter of 1 to 30 μm, particularly 5 to 25 μm, in which a charge control agent, a releasing agent for fixing, and the like are dispersed.

As the binder resin which is the toner component, a thermoplastic resin or a thermosetting resin which is uncured or an initial condensate is used. Suitable examples thereof include styrene-based polymers, acrylic-based polymers, styrene-acryl-based polymers,
Polyester resin, polyamide resin, olefin resin such as ionomer, chlorine-containing polymer such as vinyl chloride resin, modified or unmodified polyurethane, modified or unmodified epoxy resin, modified or unmodified silicone resin, modified or unmodified Unmodified phenol resin, petroleum resin, and modified or unmodified alkyd resin. These resins can be freely selected and used in accordance with a fixing method, development conditions, and the like.

Styrene-based polymers, acrylic-based polymers, or styrene-acryl-based polymers are particularly preferred as binder resins for toners. These resins are prepared by the polymerization method. However, there is an advantage that the toner can be easily manufactured by the pulverization and classification method, and the fixing property can be easily controlled. These polymers generally have a weight average molecular weight of 30,000 to 200,000, especially 50,000 to 150,000, and those having a molecular weight distribution (Mw / Mn) in the range of 5 to 100 are suitable. Further, from the viewpoint of offset prevention, those having a plurality of peaks in the molecular weight distribution are also useful.

Another preferred example of the binder resin for toner is a low melting point aromatic polyester resin. The polyester is derived from an acid component and an alkylene oxide adduct of bisphenols or an alcohol component. 3 to 30 equivalent% of the acid component or the alcohol component is a trivalent or higher valent acid component or an alcohol component, and the remainder is 2%. It is a monovalent acid component or alcohol component, and contains an alkylene oxide adduct unit of a bisphenol in an amount of 30 to 80% by weight based on the whole.

The divalent acid components include terephthalic acid, isophthalic acid, P-β-oxyethoxybenzoic acid, diphenoxyethane-4,4′-dicarboxylic acid, 5-sodium sulfoisophthalic acid, hexahydroterephthalic acid,
Naphthalenedicarboxylic acid, adipic acid, sebacic acid and the like can be mentioned, while as the trivalent polybasic acid, trimellitic acid, pyromellitic acid, butanetricarboxylic acid,
Hexanetricarboxylic acid and the like can be mentioned. Examples of the dihydric alcohol component include ethylene glycol, propylene glycol, 1,4-butanediol, neopentyl glycol, 1,6-hexylene glycol, diethylene glycol, triethylene glycol, and cyclohexane dimethanol. Examples of the alcohol component include glycerin, trimethylolpropane, pentaerythritol and sorbitol. Examples of the alkylene oxide adducts of bisphenols include ethylene oxide or propylene oxide adducts such as bisphenol A, bisphenol F, and bisphenol B. The polyester used preferably has an acid value of 20 or less, especially 10 or less.

As the coloring agent to be contained in the resin, for example, the following inorganic or organic pigments and dyes are used alone or in combination of two or more, but are not limited thereto. Carbon black such as furnace black and channel black; titanium dioxide such as rutile type or anatase type; phthalocyanine blue; phthalocyanine green; cadmium yellow; molybrene orange; pyrazolone red; The pigment is used in an amount of 1 to 20 parts by weight, particularly 5 to 12 parts by weight, per 100 parts by weight of the fixing resin medium.

As the releasing agent for heat fixing, various waxes, low molecular weight olefin resins and the like are used. The olefin resin has a number average molecular weight (Mn) of 1000 to 10
000, especially those in the range of 2000 to 6000. As the olefin-based resin, polypropylene, polyethylene, and a propylene-ethylene copolymer are used, and polypropylene is particularly preferable. The heat-fixing release agent is used in an amount of 1 to 10 parts by weight, especially 2 to 5 parts by weight, per 100 parts by weight of the fixing resin medium.

Examples of the charge control agent include any charge control agent known per se, for example, oil-soluble dyes such as nigrosine base (CI50415), oil black (CI20150) and spiron black, and 1: 1 or 2: A type 1 metal complex dye, a metal salt of salicylic acid or a derivative thereof, a metal salt of naphthenic acid, a fatty acid, a soap, a resin acid soap and the like are used. The charge control agent is
It is used in an amount of 0.5 to 10 parts by weight, particularly 0.5 to 3 parts by weight, per 100 parts by weight of the fixing resin medium.

As the toner particles, it is preferable to use a toner having a uniform particle size distribution such that particles having an average particle diameter of 1/2 or less are 20% by weight or less of the whole. The particle shape may be an irregular shape produced by a melt kneading / pulverization method, a spherical shape produced by a dispersion or suspension polymerization method, or a shape obtained by melting and spheroidizing the irregular toner in a hot air flow. .

In the case of the pulverization classification method, each of the toner components is
After pre-mixing with a mixer such as a Henschel mixer, the mixture is kneaded using a kneading device such as a twin screw extruder, and the kneaded composition is cooled, pulverized and classified to obtain a toner. Of course, the above-mentioned irregular shaped toner can be melted in a hot air stream to form a spherical toner.

A fine powder of a fluidity improver is externally added to the non-magnetic one-component toner particles, and used as a toner composition for developing an electrostatic latent image. As the fluidity improver, amorphous silica fine particles, alumina fine particles, titanium dioxide fine particles, acrylic resin fine particles and the like are used alone or in combination of two or more. The blending amount of the fluidity improver is the same as that of the toner 10
It is preferably in the range of 0.01 to 2.0 parts by weight with respect to 0 parts by weight.

[0106]

The present invention is further described by the following examples.

[Preparation of Photoconductor] <Photoconductor A> 5 parts by weight of X-type metal-free phthalocyanine as a charge generating agent and N, N'-bis (o, p-dimethylphenyl) -N, N as a hole transporting agent 40 parts by weight of '-diphenylbenzine, 40 parts by weight of 2-t-butylcarbonyl-3-phenyl-1,4-naphthoquinone as an electron transporting agent, 100 parts by weight of bisphenol Z-type polycarbonate as a binder and 100 parts by weight of a solvent 800 parts by weight of tetrahydrofuran was added and mixed and dispersed by a ball mill for 50 hours to prepare a coating solution for a single layer type photosensitive layer, and this coating solution was applied on an aluminum tube (φ16 mm) having an alumite layer of about 8 μm on the surface. Thereafter, the resultant was dried with hot air at 100 ° C. for 60 minutes to produce a 25 μm-thick electrophotographic single-layer photosensitive member. <Photoconductor B> 5 parts by weight of X-type metal-free phthalocyanine as a charge generating agent and 40 parts by weight of N, N'-bis (o, p-dimethylphenyl) -N, N'-diphenylbenzine as a hole transporting agent 40 parts by weight of 2-t-butylcarbonyl-3-phenyl-1,4-naphthoquinone as an electron transporting agent, 100 parts by weight of bisphenol Z-type polycarbonate as a binder, and 10 parts by weight of Toyobo polyester resin Byron 600, Further, 800 parts by weight of tetrahydrofuran as a solvent was added and mixed and dispersed by a ball mill for 50 hours to prepare a coating solution for a single-layer type photosensitive layer. The coating solution was applied on an aluminum tube (φ16 mm), and then heated at 100 ° C. for 60 hours. 2 minutes by hot air drying
A 5 μm electrophotographic single layer type photoreceptor was prepared. <Photoconductor C> 5 parts by weight of X-type metal-free phthalocyanine as a charge generating agent and 40 parts by weight of N, N′-bis (o, p-dimethylphenyl) -N, N′-diphenylbenzine as a hole transporting agent Then, 40 parts by weight of 2-t-butylcarbonyl-3-phenyl-1,4-naphthoquinone as an electron transporting agent, 100 parts by weight of bisphenol Z-type polycarbonate as a binder, and 800 parts by weight of tetrahydrofuran as a solvent were added to a ball mill. The mixture was mixed and dispersed for 50 hours to prepare a coating solution for a single-layer photosensitive layer, and this coating solution was applied on an aluminum tube (φ16 mm).
By drying with hot air at 0 ° C. for 60 minutes, a 25 μm-thick electrophotographic single-layer photosensitive member was produced.

Crosscut test JIS K 5400-197 for each photoreceptor
9 according to Nichiban Cellotape CT-24 (JIS
Z 0237-1980 pressure-sensitive adhesive tape / pressure-sensitive adhesive sheet according to a test method of 9.8 N / 24 mm). The results are shown in Table 1, and show the number of unturned out of 100 grids (1 mm square).

Adhesion Test For each photoreceptor, 100 base squares of 1 mm square were formed in the same manner as in the base square test, and the JIS Z was used.
It was measured by a 90 ° peeling method with respect to the tangential line in the circumferential direction of the drum in accordance with the test method for adhesive tapes and sheets of 0237-1980.

Peeling State of Transfer Roller Contact Area by Durability Test TC-720 manufactured by Mita Kogyo was modified for this experiment. The configuration is as shown in FIG. 1 (note that the roller is made of polyacetal and has a diameter of 10.6 mm and a width of 3 mm). A4 paper 10
An image was formed on each of the photoreceptors on 00 sheets based on a standard original (image ratio 5%). Thereafter, the peeled state of the transfer roller contact portion on the photoreceptor surface was visually confirmed, and the formed image was also confirmed. Table 1 shows the results.

Table 1 結果 Adhesive strength durability test result ── ────────────────────────────────── Photoconductor A 3.07 N / 10 mm or more good (cross cut test 100 / 100) Photoconductor B 3.41 N / 10 mm or more good (crosscut test 100/100) Photoconductor C less than 0.82 N / 10 mm Image in which the photosensitive layer at the roller contact portion is peeled off (crosscut test 0/100) Black streaks occur in the part (from the 700th sheet) ────────────────────────────────────

As described above, excellent results can be obtained without any problem even when a photosensitive drum having a specific or higher adhesive strength is used in an image forming apparatus having a roller for positioning a non-contact transfer roller in contact with a photosensitive layer. Recognize.

[0113]

According to the present invention, JI is used as an electrophotographic photosensitive member used in an image forming apparatus having a positioning roller for a non-contact transfer roller in contact with a photosensitive layer of a photosensitive drum.
S Z0237-1980 Measured in the circumferential direction of the drum in accordance with the adhesive tape / adhesive sheet test method, and using an organic photosensitive layer and a photoreceptor substrate having an adhesive force of 3 N / 10 mm or more causes disadvantages in the prior art. Is resolved,
Even when the photoconductor is brought into direct contact with the positioning roller of the non-contact transfer roller, peeling of the photoconductive layer is prevented, and the non-contact transfer roller can be accurately positioned with respect to the photoconductor, resulting in an image quality In addition, it is possible to stably form an image having excellent density over a long period of time.

[Brief description of the drawings]

FIG. 1 is an overall layout view of an example of an image forming apparatus of the present invention.

FIG. 2 is a connection diagram illustrating an example of electrical connection of a charger.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 photoconductor drum 2 charging means 3 charging opening 4 hole 5 shield 6 grid 7 corona wire 8 housing 9 high-voltage power supply 10 Zener diode or varistor 20 image exposure means 21 light source 30 developing means 31 developing container 32 elastic developing roller 33 sub-roller 34 Agitator 35 Opening 36 Slit-like opening 37 Toner cartridge 38 Toner supply roller 39 Blade 40 One-component toner 45 Toner transfer means 48 Positioning roller 50 Foreign matter removing means 60 Fixing means 61 Supporting roller 62 Heating roller

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Ichiro Yamazato 1-2-28 Tamazo, Chuo-ku, Osaka City Inside Mita Industries Co., Ltd. (72) Inventor Toru Ueno 1-2-28, Tamazo, Chuo-ku, Osaka Mita (72) Inventor Hiroshi Mishima 1-2-2, Tamazo, Chuo-ku, Osaka City Inside Mita Kogyo Co., Ltd.

Claims (1)

[Claims] 1. An electrophotographic photoreceptor used in an image forming apparatus having a positioning roller for a non-contact transfer roller in contact with a photosensitive layer of a photoreceptor drum.
1980 Measured in the circumferential direction of the drum according to the adhesive tape / adhesive sheet test method.
An electrophotographic photoreceptor having an adhesive strength of / 10 mm or more in width.