JPH07199503A - Image forming method - Google Patents

Abstract

PURPOSE:To provide an image forming method capable of enhancing abrasion resistance of the surface of photoreceptor and reducing occurrence of image quality defects. CONSTITUTION:The photoreceptor contains high-molecular charge transfer materials of formulae I-III and the like in the photosensitive layer and it is charged by a contact charging method, and then, an electrostatic image is formed on the photoreceptor and a visible image is formed by development. In formulae I-III, each of Ar1, Ar2, and Ar2' is an arylene; each of Ar3, Ar3', Ar6, and Ar6' is an aryl; each of X1-X12 is an alkylene or the like; each of R9, R9', R12 and R12' is H, an alkyl, or the like; p is 0 or 1; q is 1, 2, or 3; each of a, a', b, and b' is 1 or 2; each of s, t, u, and v is a molar ratio and each of s and u is <=1; each of t and v is <1; and s+t and u+v are 1 respectively and each of n1, n2, and n3 is a polymerization degree.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic image forming method, and more particularly to an image forming method using a photoreceptor containing a polymer charge transporting material effective for contact charging in a photosensitive layer.

[0002]

2. Description of the Related Art Conventionally, in an electrophotographic apparatus such as a plain paper copying machine (PPC), a laser printer, an LED printer, a liquid crystal printer, etc., an image forming process of charging, exposing and developing is applied to a photosensitive member such as a rotating drum type. Then form an image,
After transferring to a transfer material, it is fixed to obtain a copy. As the photoconductors used in these, inorganic photoconductors such as selenium, arsenic-selenium, cadmium sulfide, zinc oxide, and a-Si are used, but they are inexpensive and excellent in terms of manufacturability and disposal property. Research and development of photoconductors (OPCs) are also active. Among them, the so-called function-separated layered photoconductors in which a charge generation layer and a charge transport layer are laminated have electrophotographic characteristics such as sensitivity, chargeability and repeatability. , And various proposals have been made and put into practical use.

As a charging device for charging these photoconductors, a corona charging device having a thin wire electrode such as a gold-plated tungsten wire and a shield plate as main constituent members is generally and widely used. However, these corona charging devices have the following problems. 1) In order to obtain a surface potential of 500 to 700 V with the latent image holding member, it is necessary to apply a high voltage of DC voltage of 4 kV or more to the wire electrode, and in order to prevent leakage to the shield plate or the main body, the wire electrode Therefore, it is necessary to take measures such as maintaining a large distance between the shield plate and the shield plate, the size of the apparatus itself becomes large, and the use of a high voltage cable or the like becomes indispensable, which further increases the cost. 2) A considerable amount of ozone is generated with corona discharge, and nitrogen in the air is oxidized to generate nitrogen oxides (NOx),
Furthermore, this nitrogen oxide reacts with moisture in the air to generate nitric acid and the like. In particular, these discharge products adhere to or act on the surface of the photoconductor to cause alteration, deterioration, etc., and lower the resistance of the surface of the photoconductor to cause image blurring. Further, even with respect to recent environmental problems, these discharge products are considered to be unfavorable, and in order to remove them, it is indispensable to use an exhaust fan, a filter, etc., which further increases the cost. There is. Therefore, recently, instead of using a corona charging device that has many of these problems, a contact charging method, that is, a conductive member to which a voltage is applied is brought into contact with the surface of the photoconductor to directly inject the charge into the surface of the photoconductor. Various contact charging methods for obtaining a desired charging potential have been proposed (JP-A-63-149669, etc.).

[0004]

However, when the contact charging method is applied to a conventional function-separated type organic photoreceptor, 1) generally, a low molecular weight charge transport material is molecularly dispersed in a polymeric binder resin. When the charge transport layer is the outermost layer,
By repeatedly using this charge-transporting layer in a state where the charging member is in direct contact with it, the charge-transporting layer is abraded significantly, causing a decrease in charging property and a change in sensitivity. The life of the photoconductor is extremely shortened. 2) Also, the direct contact makes it easier for foreign matter to adhere to the surface of the photoconductor, stains, etc., and image defects resulting from them may appear on the copy. There are various possible causes for the above-mentioned abrasion of the photosensitive layer and adhesion of foreign matter to the surface of the photoreceptor.However, in the charge transport layer in which the low molecular weight charge transport material is dispersed in the binder resin, it is locally generated during contact charging. Since electric charge flows directly to the surface of the photoconductor, not only the surface of the photoconductor is stressed, but also the system in which not only DC voltage but AC voltage is applied accelerates the deterioration of the charge transport material and the binder resin even deeper. . Further, if the charge transport material is locally non-uniformly dispersed, these deteriorations are also non-uniform, so that the film strength of the photosensitive layer is lowered and abrasion is increased, while the non-uniform deterioration is caused by foreign matter. It is considered that it also forms nuclei to be attached. Therefore, the purpose of the present invention is to
Even if the contact charging method is applied, the abrasion resistance of the photoreceptor is excellent,
Another object of the present invention is to provide an image forming method capable of reducing the occurrence of image quality defects without foreign matter adhering to or contaminating the surface of the photoconductor.

[0005]

The inventors of the present invention have conducted extensive studies to solve the above-mentioned problems, and as a result, even in the contact charging method, a photosensitive layer containing a specific polymer charge transporting material in the photosensitive layer was used. The present invention has been completed by finding that the use of the body reduces wear of the photosensitive layer and causes less image quality defects due to the adhesion of foreign matter. That is, in the image forming method of the present invention, a photosensitive layer is provided on a conductive support, and in the photosensitive layer, at least a polymer charge transport material represented by the following general formulas (A) to (J) is selected. Using a photoreceptor containing one type, the photoreceptor is charged by a contact charging method in which a voltage is applied to a conductive member brought into contact with the surface of the photoreceptor, and then an electrostatic charge image is formed on the photoreceptor and developed. Is used to form a visible image.

[0006]

[Chemical 10]

(In each formula, Ar ₁ is an arylene group selected from the following groups.

[Chemical 11] Here, R ₁ represents a substituted or unsubstituted alkyl group having 1 to 24 carbon atoms, and Y is a group selected from the following groups.

[Chemical 12] In the above formula, R ₂ and R ₃ represent a linear or branched alkylene group having 1 to 10 carbon atoms, and R ₄ and R ₄ ′ represent a substituted or unsubstituted alkyl group having 1 to 24 carbon atoms. And Ar ₅ represents a substituted or unsubstituted arylene group having 6 to 14 carbon atoms. Moreover, r means the integer of 0-3. Ar ₄ and Ar ₄ ', which may be the same or different, is an arylene group selected from the following groups.

[Chemical 13] In the above formula, R ₅ represents a substituted or unsubstituted alkyl group having 1 to 24 carbon atoms.

Ar ₂ and Ar ₂ ′ may be the same or different and each is an arylene group selected from Ar ₄ and Ar ₄ ′, and Ar ₃ and Ar ₃ ′ may be the same or different. Often, it is an aryl group selected from the following groups.

[Chemical 14] Here, R ₆ , R ₇ and R _{8, which} may be the same or different, each represents a substituted or unsubstituted alkyl group having 1 to 24 carbon atoms.

Further, X ₁ , X ₂ , X ₂ ′, X ₃ , X ₄ ,
X ₄ ′, X ₅ , X ₆ and X ₆ ′ may be the same or different, and may be a linear or branched alkylene group having 1 to 10 carbon atoms or a substituted or unsubstituted C 6 to 14 carbon atom. Represents an arylene group, and T is a group selected from the following groups.

[Chemical 15] Here, Z is a group selected from the above Y. Further, p means an integer of 0 or 1, and q means an integer of 1, 2 or 3. The degree of polymerization n ₁ is 5 to 5000. )

[0010]

[Chemical 16]

[0011] (In each formula, X ₇ and X ₇ 'may be the same or different, or a benzene ring and oxygen atom is a single bond to bond directly, straight or branched having 1 to 15 carbon atoms A alkylene group or alkyleneoxy group, or a substituted or unsubstituted arylene group or aryleneoxy group having 6 to 24 carbon atoms, and one or more oxygen atoms may be present in the alkylene group chain. A plurality of groups may be bonded via one or more oxygen atoms, and X ₈ and X ₈ ′ may be the same or different and are —CO—R ₁₁ —CO— or —COO—R ₁₁ —. O
CO- or -CONH-R ₁₁ -NHCO- is shown, wherein R ₁₁ is a linear or branched alkylene group having 1 to 15 carbon atoms, or a substituted or unsubstituted arylene group having 6 to 24 carbon atoms. Alternatively, it represents an alkylene group having 2 to 25 carbon atoms in which one or more oxygen atoms may be present. X ₉ represents a linear or branched alkylene group having 2 to 30 carbon atoms or is an arylene group selected from Ar ₁ described above. R ₉ , R ₉ ′, R ₁₀ and R ₁₀ ′ may be the same or different and each is a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group having 1 to 24 carbon atoms, or 1 to 24 carbon atoms. Or an alkoxy group having 6 to 14 carbon atoms or a substituted or unsubstituted aryl group or aryloxy group having 6 to 14 carbon atoms, and a, a ′, b and b ′ each represent an integer of 1 or 2. Furthermore, the molar ratio s is a numerical value of 1 or less, t is a numerical value of less than 1, and s + t = 1.0. The degree of polymerization n ₂ is 10 to 300. )

[0012]

[Chemical 17]

(In each formula, X ₁₀ , X ₁₀ ′, X ₁₁ , X
₁₁ ′ and X ₁₂ may be the same or different, and may be a linear or branched alkylene group having 1 to 25 carbon atoms, or at least one oxygen atom may be present and at least one arylene group may be present. It represents a good alkylene group or alkyleneoxy group having 2 to 25 carbon atoms, or is an arylene group selected from the above Ar ₁ . Also, R ₁₂ and R
₁₂ 'may be the same or different and have 1 to 24 carbon atoms.
Substituted or unsubstituted alkyl group or 6 to 2 carbon atoms
4 is a substituted or unsubstituted aryl group, and Ar ₆ and Ar ₆ ′ may be the same or different and are aryl groups selected from Ar ₃ described above. Further, the molar ratio u is a numerical value of 1 or less, v is a numerical value of less than 1, and u + v = 1.0. The degree of polymerization n ₃ is 5 to 1000
Is. )

In the image forming method of the present invention, at least one kind of the polymer charge transporting material and the following structural formulas (K) to (O) are contained in the charge transporting layer or the surface protective layer constituting the outermost surface layer of the photoreceptor. It is preferable to contain at least one selected from a polycarbonate resin having a repeating unit represented by the above) or a copolymer thereof.

[Chemical 18]

The present invention will be described in detail below. The photoreceptor of the present invention may have a single-layer photosensitive layer or a laminated structure in which the functional layers are separated. 1 to 4 are vertical sectional views of a photoconductor used in the present invention. 1 and 2 show the case where the photosensitive layer has a single-layer structure. In FIG. 1, the photosensitive layer 2 is provided on the conductive support 1. In FIG. 2, an undercoat layer 3 is further provided between the conductive support 1 and the photosensitive layer 2. 3 and 4 show a case where the photosensitive layer has a laminated structure. In FIG. 3, the charge generation layer 4 and the charge transport layer 5 are sequentially provided on the conductive support 1. In FIG. 4, an undercoat layer 3 is further provided between the conductive support 1 and the charge generation layer 4. A surface protective layer may be provided on the surface of the photoreceptor having the layer structure as described above, and in this case, it is desirable that the surface protective layer contains the polymer charge transport material.

As the conductive support, metals such as aluminum, nickel, chromium and stainless steel, aluminum, titanium, nickel, chromium, stainless steel,
Examples thereof include a plastic film provided with a thin film of gold, vanadium, tin oxide, indium oxide, ITO or the like, paper or a plastic film coated or impregnated with a conductivity-imparting agent. These conductive supports are used in a suitable shape such as a drum shape, a sheet shape, and a plate shape, but are not limited thereto. Further, if necessary, the surface of the conductive support can be subjected to various treatments within a range that does not affect the image quality. For example, surface oxidation treatment, chemical treatment, coloring treatment, or irregular reflection treatment such as graining can be performed.

As mentioned above, an undercoat layer may be further provided between the conductive support and the photosensitive layer or the charge generating layer. This undercoat layer prevents injection of charges from the conductive support to the photosensitive layer during charging of the photosensitive layer having a single-layer structure or a laminated structure, and also makes the photosensitive layer integral with the conductive support. Shows an action as an adhesive layer for adhering and holding, or an action for preventing reflected light of the conductive support in some cases. Materials used for forming the undercoat layer include polyethylene resin, polypropylene resin, acrylic resin, methacrylic resin, polyamide resin, vinyl chloride resin, vinyl acetate resin, phenol resin, polycarbonate resin, polyurethane resin, polyimide resin, vinylidene chloride resin. , Polyvinyl acetal resin, vinyl chloride-vinyl acetate copolymer, polyvinyl alcohol resin, water-soluble polyester resin, polyacrylic acid, polyacrylamide, polyglutamic acid, nitrocellulose, starch acetate, amino starch, starch, casein, gelatin, titanyl chelate Known materials such as compounds, organic titanyl compounds such as titanyl alkoxide compounds, zirconium chelate compounds, and silane coupling agents can be used. These materials can be used alone or in combination of two or more. Further, fine particles of titanium oxide, silicon oxide, zirconium oxide, barium titanate, silicone resin or the like can be mixed with the above forming material and used. Examples of the coating method include a blade coating method, a wire bar coating method, a spray coating method, a dip coating method, a bead coating method, an air knife coating method and a curtain coating method. The thickness of the undercoat layer is generally 0.01.
10 to 10 μm, preferably 0.05 to 2 μm is suitable.

When the photosensitive layer has a laminated structure, the charge generation layer is
It can be provided by applying a dispersion liquid in which the charge generation material is dispersed in a binder resin and a solvent, onto the electric support or the undercoat layer. As the charge generation material, amorphous selenium, crystalline selenium-tellurium alloy, selenium-arsenic alloy, other selenium compounds and selenium alloys, inorganic photoconductive materials such as zinc oxide and titanium oxide, phthalocyanine-based, squalium-based Organic pigments and dyes such as anthanthrone type, perylene type, azo type, anthraquinone type, pyrene type, pyrylium salt and thiapyrylium salt are used. As the binder resin, polyvinyl butyral resin, polyvinyl formal resin, partially modified polyvinyl acetal resin, polycarbonate resin, polyester resin, acrylic resin, polyvinyl chloride resin, polystyrene resin, polyvinyl acetate resin, vinyl chloride-vinyl acetate copolymer , Silicone resin, phenol resin, poly-N-vinylcarbazole resin, and the like, but are not limited thereto. These binder resins may be used alone or in combination of two or more. As the solvent, methanol, ethanol, n-propanol, n-butanol,
Ordinary organic solvents such as benzyl alcohol, methyl cellosolve, ethyl cellosolve, acetone, methyl ethyl ketone, cyclohexanone, methyl acetate, n-butyl acetate, dioxane, tetrahydrofuran, methylene chloride and chloroform may be used alone or in combination of two or more. . The compounding ratio (weight ratio) of the charge generating material and the binder resin is preferably in the range of 10: 1 to 1:10.
As a coating method for providing the charge generation layer, a usual method such as a blade coating method, a wire bar coating method, a spray coating method, a dip coating method, a bead coating method, an air knife coating method and a curtain coating method can be mentioned. The thickness of the charge generation layer is generally 0.1 to 5 μm, preferably 0.2.
˜2.0 μm is suitable.

When the photosensitive layer has a laminated structure, the charge transport layer is
It can be provided by dissolving or swelling the charge transport material in a solvent and, if necessary, a binder resin, and coating this on the charge generating layer. As the charge transport material, at least one selected from the polymer compounds represented by the general formulas (A) to (J) is used. General formula (A)-
The polymer charge transport material represented by (E) may be two or more kinds of copolymers having these as repeating units, and the degree of polymerization n ₁ thereof is in the range of 5 to 5000. General formula (F)
And the degree of polymerization n of the polymer charge transport material represented by (G)
₂ is in the range of 10 to 300, and the general formula (H)
The degree of polymerization n ₃ of the polymer charge transport material represented by (J) is
It is in the range of 5-1000. The preferred weight average molecular weight (Mw) of these polymeric charge transport materials is from 5 × 10 ³ to
7.5 × 10 ⁵ , more preferably 5 × 10 ^{4 to} 5 × 1
It is 0 ⁵ .

Examples of the groups represented by the respective symbols in the general formulas (A) to (J) include the following. R ₁ in Ar ₁ represents an alkyl group having 1 to 24 carbon atoms, Ar ₁ R ₄ of (group Y) in, R ₄ ', Ar ₂ and Ar
R _{5 in 2} ′, Ar ₃ and R ₆ , R ₇ in Ar ₃ ′,
R ₈ , and further R ₉ , R ₉ ′, R ₁₀ , R ₁₀ ′, R ₁₂ and R ₁₂ ′ are, for example, methyl group, ethyl group, propyl group, butyl group, hexyl group, octyl group, decyl group, stearyl. Examples thereof include linear or branched alkyl groups such as groups. R ₉ , R ₉ ′, R ₁₀ , R ₁₀ ′, R ₁₂ and R ₁₂ ′ which may represent an aryl group having 6 to 24 carbon atoms.
Examples thereof include a phenyl group, a naphthyl group, a biphenylyl group, an anthryl group, an acenaphthenyl group and a pyrenyl group. R ₂ and R ₃ in Ar ₁ (group Y) showing an alkylene group having 1 to 30 carbon atoms, R _{11 in} groups X ₈ and X ₈ ′, and further X ₁ , X ₂ , X ₂ ′ and X ₃ , X ₄ ,
X ₄ ′, X ₅ , X ₆ , X ₆ ′, X ₇ , X ₇ ′, X ₉ , X
Examples of ₁₀ , X ₁₀ ′ X ₁₁ , X ₁₁ ′ and X ₁₂ include methylene group, ethylene group, propylene group, butylene group, hexylene group, octylene group, decylene group, octadecylene group and 2,2-propylene group. A straight chain or branched alkylene group may be mentioned. 6 from the base X ₈ and X ₈ of an arylene group of up to 24 carbon 'R ₁₁ in, Ar ₁ Ar ₅ in (group Y) in further _{X 1, X 2, X 2} ', X 3, X
Examples of ₄ , X ₄ ′, X ₅ , X ₆ , X ₆ ′, X ₇ and X ₇ ′ include a phenylene group, a biphenylene group, a naphthylene group, an anthraquinonylene group, a fluorenylene group and a pyrenylene group. Examples of X ₇ and X ₇ ′ that may represent an alkyleneoxy group having 1 to 15 carbon atoms or an aryleneoxy group having 6 to 24 carbon atoms include, for example, a methyleneoxy group, an ethyleneoxy group, a tetramethyleneoxy group, phenoxy and the like. Group, biphenyloxy group, naphthyloxy group and the like.

The above alkyl group may have a substituent, and examples of the substituent include a fluorine atom, a chlorine atom,
Halogen atom such as bromine atom, halogenated alkyl group, hydroxy group, methoxy group, ethoxy group, propoxy group,
Alkoxy group such as butoxy group, aryloxy group such as phenoxy group, arylalkoxy group such as benzyloxy group,
Alkylthio group such as methylthio group, ethylthio group, acyl group such as acetyl group and benzoyl group, nitro group, amino group, ethylamino group, anilino group, primary or tertiary amino group such as dimethylamino group, carboxy group , An alkoxycarbonyl group such as an ethoxycarbonyl group, an aryloxycarbonyl group such as a phenyloxycarbonyl group, a carbamoyl group, and a cyano group. Further, the aryl group or the arylene group also has, for example, an alkyl group such as a methyl group, an ethyl group, a propyl group and a butyl group, an aralkyl group such as a benzyl group and a phenethyl group, and the above-described substituents. Good. Of the above symbols, for example, X ₃ is particularly preferably a group selected from the following groups.

[Chemical 19] In the above formula, R ₁₃ represents a substituted or unsubstituted alkyl group having 1 to 24 carbon atoms.

X₇And X₇′ Is a carbon number of 1-10
Ruylene group or alkyleneoxy group or 6 to 20 carbon atoms
Is preferably an arylene group or an aryleneoxy group,
Further, one or more oxygen atoms are present in the alkylene group chain.
Or an arylene group containing two or more oxygen atoms
You may combine several pieces. Examples of these are -CH₂C
H₂OCH₂CH₂-,-(OCH₂CH₂)₂-,-
(OCH₂CH₂)₃-, -C₆H_FourOC₆H_Four-,-
OC₆H_FourOC₆H_FourAnd the like are preferable. Also, X_Ten, X
_Ten’X₁₁, X₁₁'And X₁₂Is an alkane having 1 to 10 carbon atoms
A xylene group is preferable, and at least one oxygen atom is present.
And the number of carbon atoms in which one or more arylene groups may be present
2 to 25 alkylene groups or alkyleneoxy groups
You may. Examples of these include the above X₇and
X₇', In addition to -CH₂OCH₂-, -CH₂CH₂O
CH₂-, -CH₂CH₂CH₂OCH₂CH₂-,-
CH₂CH₂O (CH₂)_FourOCH₂CH₂-, -CH
₂CH₂CH (CH₃) OCH₂CH₂-,-(CH₂
CH₂O)₂CH₂CH₂-, -CH₂CH₂OC₆H
_FourOCH₂CH₂And the like are preferable. The above group X₈S
X₈R in '₁₁Is the number of carbon atoms with one or more oxygen atoms
2 to 25 alkylene groups may be used, and examples thereof include
Include the above alkylene groups and the like. Also, halogen
R that may represent an atom₉, R₉′, R_TenAnd R_Ten′
Is a fluorine atom, a chlorine atom, or bromine as described above.
An atom etc. are mentioned. R which may represent an alkoxy group
₉, R₉′, R_TenAnd R_TenAs', as described above
Methoxy group, ethoxy group, propoxy group, butoxy group
Etc.

Next, among the polymer charge transport materials represented by the above general formulas (A) to (J), specific examples preferably used are listed below. In the formula, n is n ₁ ,
It means the degree of polymerization corresponding to n ₂ and n ₃ . The polymer charge transport material represented by the general formula (A) is shown below.

[Chemical 20]

The polymer charge transport material represented by the general formula (B) is shown below.

[Chemical 21]

The polymer charge transport material represented by the general formula (C) is shown below.

[Chemical formula 22]

[0026]

[Chemical formula 23]

The polymer charge transport material represented by the general formula (D) is shown below.

[Chemical formula 24]

[0028]

[Chemical 25]

The polymer charge transport material represented by the general formula (E) is shown below.

[Chemical formula 26]

The polymer charge transport material represented by the general formula (F) is shown below.

[Chemical 27]

[0031]

[Chemical 28]

[0032]

[Chemical 29]

The polymer charge transport material represented by the general formula (G) is shown below.

[Chemical 30]

[0034]

[Chemical 31]

[0035]

[Chemical 32]

The polymer charge transport material represented by the general formula (H) is shown below.

[Chemical 33]

[0037]

[Chemical 34]

[0038]

[Chemical 35]

The polymer charge transport material represented by the general formula (I) is shown below.

[Chemical 36]

The polymer charge transport material represented by the general formula (J) is shown below.

[Chemical 37]

[0041]

[Chemical 38]

As the solvent used when the charge transport layer is provided, aromatic hydrocarbons such as benzene, toluene and xylene, halogenated aromatic hydrocarbons such as chlorobenzene, ketones such as acetone and 2-butanone, and methylene. Ordinary organic solvents such as halogenated aliphatic hydrocarbons such as chloride, chloroform and ethylene chloride, cyclic or linear ethers such as tetrahydrofuran and ethyl ether can be used alone or in combination of two or more. Further, if necessary, particularly when the charge transport layer is the outermost surface layer, the repeating units represented by the structural formulas (K) to (O) are used as the binder resin for the purpose of improving wear resistance. At least one selected from the polycarbonate resins or copolymers thereof can be mixed with the polymer charge transport material and used, but the invention is not limited thereto. When a binder resin is used, the viscosity average molecular weight (Mv) of the polycarbonate resin is preferably 3 × 10 ³ to
It is 5 × 10 ⁵ . The compounding ratio (weight ratio) of the polymer charge transport material and the polycarbonate resin is preferably 5: 1 to 1: 1. Examples of the application method include a blade coating method, a wire bar coating method, a spray coating method, a dip coating method, a bead coating method, an air knife coating method and a curtain coating method. The thickness of the charge transport layer is generally 5 to 50 μm, preferably 10 to 30 μm.
m is suitable.

When the photosensitive layer in the photoreceptor has a single layer structure,
The photosensitive layer can be provided by applying a dispersion liquid comprising a charge generating material, a charge transporting material, a solvent and, if necessary, a binder resin on the conductive support or the undercoat layer.
As the charge generating material, the charge transporting material, the solvent and the binder resin, the same materials as described above are used, and the photosensitive layer is formed by the same coating method as described above. In this case, the compounding ratio of the charge generating material and the polymer charge transporting material is 1:10 to 1 by weight.
A range of 0: 1 is suitable.

In the image forming method of the present invention, an antioxidant is added to the photosensitive layer for the purpose of preventing deterioration of the photoreceptor due to ozone, oxidizing gas, light or heat generated in the copying machine.
Additives such as a light stabilizer and a heat stabilizer can be added. For example, as the antioxidant, hindered phenol, hindered amine, paraphenylenediamine, arylalkane, hydroquinone, spirocumalone, spiroindanone and their derivatives, organic sulfur compounds,
Examples thereof include organic phosphorus compounds. Examples of light stabilizers include
Examples thereof include derivatives such as benzophenone, benzotriazole, dithiocarbamate and tetramethylpiperidine. In addition, at least one electron-accepting substance can be contained in the photosensitive layer for the purpose of improving sensitivity, reducing residual potential, and reducing fatigue during repeated use. Examples of such an electron acceptor include succinic anhydride, maleic anhydride, dibromomaleic anhydride, phthalic anhydride,
Tetrabromophthalic anhydride, tetracyanoethylene, tetracyanoquinodimethane, o-dinitrobenzene, m-
Dinitrobenzene, chloranil, dinitroanthraquinone, trinitrofluorenone, picric acid, o-nitrobenzoic acid, p-nitrobenzoic acid, phthalic acid and the like can be used. Among these, fluorenone-based, quinone-based, and benzene derivatives having an electron-withdrawing substituent such as chlorine atom, cyano group, and nitro group are particularly preferable. In the present invention,
Additives may be contained in the photosensitive layer mainly for the purpose of obtaining good surface properties. As this type of additive, those known as modifiers for paints can be used. For example, alkyl-modified silicone oil such as dimethyl silicone oil and aromatic-modified silicone oil such as methylphenyl silicone oil are preferable examples. These additives may be contained within the range of 1 to 10,000 ppm, preferably 5 to 2,000 ppm, based on the solid content of the photosensitive layer or the charge transport layer.

Furthermore, on the surface of the photoreceptor of the present invention, a surface protective layer containing the above-mentioned high molecular charge transport material is provided with a conventional low molecular charge transport material in which a charge transport layer is molecularly dispersed in a binder resin. It can also be provided on top. As a solvent, various additives and a coating method used when providing the surface protective layer, the same ones as those for the charge transport layer can be used. At this time, for the purpose of improving the wear resistance of the surface protective layer, it is desirable to use the polymer charge transport material in combination with the polycarbonate resin represented by the structural formulas (K) to (O) or the copolymer thereof. . The thickness of the surface protective layer is generally 1 to 10 μm, preferably 2 to 5 μm.

Next, the image forming method of the present invention will be described. FIG. 5 shows an example of the image forming apparatus,
The image forming method is carried out as follows. That is,
The surface of the cylindrical photoreceptor 10 is charged by applying a voltage from a power source 11 to a conductive member (contact charger) 12.
Next, an optical system for irradiating the original image, laser, LED
And the like is exposed to light from the image input device 13 to form an electrostatic charge image. The formed electrostatic charge image is visualized with toner by the developing device 14 and converted into a toner image. In this case, a magnetic brush method can be used for development. The toner image is then transferred to the sheet 16 by the pressure transfer device or the electrostatic transfer device 15, and is fixed by the fixing device 17. On the other hand, the toner remaining on the surface of the photoconductor 10 after the transfer is removed by the cleaner mechanism 18 using a blade, and the electric charge slightly remaining on the surface of the photoconductor 10 is erased by the neutralization photometer 19. As a method of charging the photoconductor using a conductive member, as described above, a voltage is applied to the conductive member, but the applied voltage is an AC voltage instead of a DC voltage rather than only a DC voltage because of the uniformity. Those in which are superimposed are preferable. As for the voltage range, the DC voltage is preferably positive or negative 50 to 2000 V, and particularly preferably 100 to 15 V.
00V is preferable. The AC voltage to be superimposed has a peak-to-peak voltage of 400 to 1800V, preferably 800 to 1600V,
Particularly, 1200 to 1600V is preferable. If the peak-to-peak voltage exceeds 1800 V, uniform charging cannot be obtained, as compared with the case where no AC voltage is superimposed. The frequency of the alternating voltage is preferably 100 to 2000 Hz.

In the present invention, the shape of the conductive member for contact charging may be any of a brush shape, a blade shape, a pin electrode shape or a roller shape, and among them, it is preferable to use the roller shape member. The roller-shaped member is usually composed of a resistance layer, an elastic layer supporting the resistance layer, and a core material from the outside. Further, if necessary, a protective layer can be provided outside the resistance layer. The material of the core material has conductivity, and iron, copper, brass, stainless steel, aluminum, nickel, etc. are generally used. In addition, a resin molded product in which conductive particles and the like are dispersed can be used. The material of the elastic layer has conductivity or semiconductivity, and is generally a rubber material in which conductive particles or semiconductive particles are dispersed. As a rubber material, EPD
M, polybutadiene, natural rubber, polyisobutylene, S
BR, CR, NBR, silicone rubber, urethane rubber,
Epichlorohydrin rubber, SBS, thermoplastic elastomer, norbornene rubber, fluorosilicone rubber, ethylene oxide rubber and the like are used. The conductive particles or semi-conductive particles, carbon black, zinc, aluminum, copper, iron, nickel, chromium, metal such as titanium,
_{ZnO-Al 2 O 3, SnO} 2 -Sb 2 O 3, In 2 O
_{3 -SnO 2, ZnO-TiO 2} , MgO-Al
₂ O ₃ , FeO-TiO ₂ , TiO ₂ , SnO ₂ , Sb
A metal oxide such as ₂ O ₃ , In ₂ O ₃ , ZnO, or MgO can be used. You may use these materials individually or in mixture of 2 or more types. When two or more kinds are mixed and used, one of them may be in the form of fine particles, and fine particles of fluororesin can be used.

The resistance layer and the protective layer are made of a binder resin in which conductive particles or semiconductive particles are dispersed to adjust the resistance, and the resistivity is 10 ³ to 10 ¹⁴ Ωcm.
Preferably 10 ⁵ to 10 ¹² Ωcm, further 10 ⁷ to 1
0 ¹² Ωcm is preferred. As the binder resin, acrylic resin, cellulose resin, polyamide resin, methoxymethylated nylon, ethoxymethylated nylon, polyurethane resin, polycarbonate resin, polyester resin, polyarylate resin, PET, polythiophene resin, polyvinyl chloride resin, PFA, FEP, polyolefin resin such as polyethylene resin, styrene-butadiene resin and the like are used. As the conductive particles or the semiconductive particles, the same carbon black, metal or metal oxide as that of the elastic layer is used. The resistance layer and / or the protective layer have a thickness of 0.01 to 1000 μm, preferably 0.1 to 5 μm.
00 μm, more preferably 0.5 to 100 μm. If necessary, antioxidants such as hindered phenol and hindered amine, fillers such as clay and kaolin, and lubricants such as silicone oil can be added. Examples of means for forming these layers include a blade coating method, a wire bar coating method, a spray coating method, a dip coating method, a bead coating method, an air knife coating method, a curtain coating method, a vacuum vapor deposition method and a plasma coating method. be able to.

[0049]

EXAMPLES The present invention will now be described in more detail with reference to examples, but the present invention is not limited to these examples. The following "parts" mean "parts by weight". Example 1 Zirconium compound (trade name: Organix ZC54
0, manufactured by Matsumoto Pharmaceutical Co., Ltd.) and 1 part of a silane compound (trade name: A1110, manufactured by Nippon Unicar Co., Ltd.), 40 parts of i-propanol and 20 parts of butanol are applied onto an aluminum pipe by a dip coating method,
Film thickness 0.1μm after heating and drying at 150 ° C for 10 minutes
An undercoat layer was formed. Next, 1 part of x-type metal-free phthalocyanine crystal was mixed with 1 part of polyvinyl butyral resin (trade name: S-REC BM-S, manufactured by Sekisui Chemical Co., Ltd.) and 100 parts of cyclohexanone, and treated with glass beads in a sand mill for 1 hour to be dispersed. Then, the obtained coating liquid was applied onto the above-mentioned subbing layer by a dip coating method, and dried by heating at 100 ° C. for 10 minutes to form a charge generation layer having a film thickness of 0.15 μm. Next, E-2 (weight average molecular weight: Mw = 170,000) 3 described above was used as the polymer charge transport material.
Part of the solution was dissolved in a mixed solvent of 15 parts of monochlorobenzene and 15 parts of tetrahydrofuran, the resulting coating solution was applied onto the charge generation layer by a dip coating method, and dried by heating at 115 ° C. for 1 hour to transport a charge having a film thickness of 20 μm. Layers were formed. The photoconductor was manufactured as described above.

Example 2 Instead of E-2 as the polymer charge transport material, the above-mentioned C- was used.
Example 1 except that 5 (Mw = 180,000) was used.
A photoconductor was manufactured in the same manner as in. Example 3 As the polymer charge transporting material, the above-mentioned D- was used instead of E-2.
Example 1 except that 3 (Mw = 170,000) was used.
A photoconductor was manufactured in the same manner as in. Example 4 Instead of E-2 as the polymer charge transport material, the above B- was used.
A photoconductor was produced in the same manner as in Example 1 except that 2 parts of 2 (Mw = 250,000) was used. Example 5 Instead of E-2 as the polymer charge transport material, the above-mentioned A-
2 (Mw = 170,000) 2 parts and the polycarbonate resin represented by the structural formula (L) (viscosity average molecular weight: Mv =
A photoconductor was produced in the same manner as in Example 1 except that 1 part of 5 × 10 ⁴ ) was used. Example 6 Instead of E-2 as the polymer charge transport material, the above-mentioned F-
3 (Mw = 180,000) (2 parts) was used, and the polycarbonate resin represented by the structural formula (M) (M
A photoconductor was manufactured in the same manner as in Example 1 except that 1 part of v = 3 × 10 ⁴ ) was used.

Comparative Example 1 2 parts of a benzidine compound represented by the following chemical formula as a charge transporting material and 3 parts of a polycarbonate resin (Mv = 4 × 10 ⁴ ) represented by the structural formula (K) as a binder resin were mixed with monochlorobenzene. 10 parts and tetrahydrofuran 10
A photoconductor was manufactured in the same manner as in Example 1 except that the charge transport layer was formed using a coating solution dissolved in a part of the mixed solvent.

[Chemical Formula 39]

Example 7 The above-mentioned H-5 (Mw = 24) was used as the polymer charge transport material.
20,000) 2 parts was dissolved in a mixed solvent of 15 parts of monochlorobenzene and 15 parts of tetrahydrofuran, and the obtained coating solution was applied onto the charge transport layer of Comparative Example 1 by a dip coating method and heated at 115 ° C. for 1 hour. Dry film thickness 5μ
A photoconductor was produced in the same manner as in Comparative Example 1 except that the surface protective layer of m was formed. Example 8 The above-mentioned J- was used instead of H-5 as the polymer charge transport material.
A photoconductor was produced in the same manner as in Example 7, except that 3 parts of 4 (Mw = 180,000) was used.

Comparative Example 2 3 parts of a hydrazone compound represented by the following chemical formula as a charge transport material in place of the benzidine compound of Comparative Example 1 and a polycarbonate resin represented by the structural formula (L) as a binder resin (Mv = A photoconductor was produced in the same manner as in Comparative Example 1 except that the charge transport layer was formed by using 3 parts of 5 × 10 ⁴ ).

[Chemical 40]

Example 9 I-4 (Mw = 24) was used as the polymer charge transport material.
20,000) 2 parts were dissolved in a mixed solvent of 15 parts of monochlorobenzene and 15 parts of tetrahydrofuran, and the obtained coating solution was applied onto the charge transport layer of Comparative Example 2 by a dip coating method and heated at 115 ° C. for 1 hour. Dry film thickness 5μ
A photoconductor was produced in the same manner as in Comparative Example 2 except that the surface protective layer of m was formed. Example 10 Instead of I-4 as the polymer charge transport material, the above-mentioned G-
Example 7 except that 5 (Mw = 180,000) was used.
A photoconductor was manufactured in the same manner as in.

Each of the photoconductors thus manufactured and the following conductive members were connected to a laser beam printer (XP-11
It is mounted on a modified machine (Fuji Xerox Co., Ltd.), a DC voltage of -550V and an AC voltage of 1000V (peak-to-peak voltage) are applied as a bias, repeated printing is performed 50,000 times, and the image quality after 50,000 times is evaluated. At the same time, the amount of wear of the outermost surface layer of the photoconductor was measured. The results are shown in Table 1. As the conductive member, a stainless steel rod having a diameter of 6 mm was used as a core material, and a conductive EPD having a resistance of 10 ⁶ Ωcm was used as an elastic layer.
A conductive roll having a diameter of 12 mm was formed by using M rubber and epichlorohydrin rubber having a resistance of 10 ⁹ Ωcm as a resistance layer.

[Table 1]

Further, each photoconductor is provided with a laser beam printer (XP having a charging means using a normal scorotron.
-11, manufactured by Fuji Xerox Co., Ltd.) and evaluated and measured in the same manner as above. The results are shown in Table 2.

[Table 2]

[0057]

According to the image forming method of the present invention, a conventional charge transporting material is added to a molecule by incorporating the polymer charge transporting material represented by the general formulas (A) to (J) into the photosensitive layer. Compared with the dispersed photosensitive layer, in the contact charging method, it is possible to reduce image quality defects due to abrasion of the photosensitive layer and adhesion of foreign matters, and it is possible to significantly improve the life of the photosensitive member.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a photoreceptor having a single-layer photosensitive layer according to the present invention.

FIG. 2 is another cross-sectional view of a photoreceptor having a single-layer photosensitive layer according to the present invention.

FIG. 3 is a cross-sectional view of a photoreceptor having a laminated structure of photosensitive layers according to the present invention.

FIG. 4 is another cross-sectional view of a photoreceptor having a laminated structure of photosensitive layers according to the present invention.

FIG. 5 shows a schematic view of an image forming apparatus for carrying out the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Conductive support, 2 ... Photosensitive layer, 3 ... Undercoat layer, 4 ... Charge generation layer, 5 ... Charge transport layer, 10 ... Photoconductor, 12 ... Conductive member.

Front Page Continuation (72) Inventor Sadao Okano 1600 Takematsu, Minamiashigara City, Kanagawa Prefecture, Fuji Xerox Co., Ltd. (72) Inventor Katsumi Nukata 1600 Takematsu, Minamiashigara City, Kanagawa Prefecture, Fuji Xerox Co., Ltd. (72) Inventor Imai Akira 1600 Takematsu, Minamiashigara-shi, Kanagawa Fuji Xerox Co., Ltd. (72) Inventor Ryosaku Igarashi 1600 Takematsu, Minamiashigara-shi, Kanagawa Prefecture Fuji Xerox Co., Ltd.

Claims (3)

[Claims] 1. An image forming method of forming an electrostatic image on a photoreceptor after charging the photoreceptor and forming a visible image by development, wherein a photosensitive layer is provided on a conductive support, and the photosensitive layer is formed. A photoreceptor containing at least one selected from the polymer charge transport materials represented by the following general formulas (A) to (J) is used, and a voltage is applied to a conductive member brought into contact with the photoreceptor surface. An image forming method characterized in that a photoreceptor is charged by a contact charging method applied. [Chemical 1] (In each formula, Ar ₁ is an arylene group selected from the following groups. Here, R ₁ represents a substituted or unsubstituted alkyl group having 1 to 24 carbon atoms, and Y is a single bond in which two benzene rings are directly bonded or a group selected from the following groups. [Chemical 3] In the above formula, R ₂ and R ₃ represent a linear or branched alkylene group having 1 to 10 carbon atoms, and R ₄ and R ₄ ′ represent a substituted or unsubstituted alkyl group having 1 to 24 carbon atoms. And Ar ₅ represents a substituted or unsubstituted arylene group having 6 to 14 carbon atoms. Moreover, r means the integer of 0-3. Ar ₄ and Ar ₄ ', which may be the same or different, is an arylene group selected from the following groups. [Chemical 4] In the above formula, R ₅ represents a substituted or unsubstituted alkyl group having 1 to 24 carbon atoms. Ar ₂ and Ar ₂ ′, which may be the same or different, are arylene groups selected from Ar ₄ and Ar ₄ ′ described above, and Ar ₃ and A
r ₃ ′, which may be the same or different, is an aryl group selected from the following groups. [Chemical 5] Here, R ₆ , R ₇ and R _{8, which} may be the same or different, each represents a substituted or unsubstituted alkyl group having 1 to 24 carbon atoms. In addition, X ₁ , X ₂ , X ₂ ′, X ₃ , X ₄ ,
X ₄ ′, X ₅ , X ₆ and X ₆ ′ may be the same or different, and may be a linear or branched alkylene group having 1 to 10 carbon atoms or a substituted or unsubstituted C 6 to 14 carbon atom. Represents an arylene group, and T is a group selected from the following groups. [Chemical 6] Here, Z is a group selected from the above Y. Further, p means an integer of 0 or 1, and q means an integer of 1, 2 or 3. The degree of polymerization n ₁ is 5 to 5000. ) [Chemical 7] (In each formula, X ₇ and X ₇ ′, which may be the same or different, are a single bond in which a benzene ring and an oxygen atom are directly bonded to each other, or a linear or branched alkylene having 1 to 15 carbon atoms. Group or alkyleneoxy group, or a substituted or unsubstituted arylene group or aryleneoxy group having 6 to 24 carbon atoms, one or more oxygen atoms may be present in the alkylene group chain, and the arylene group is 1 A plurality of oxygen atoms may be bonded to each other.
X ₈ and X ₈ ′ may be the same or different, and
CO—R ₁₁ —CO—, —COO—R ₁₁ —OCO— or —CONH—R ₁₁ —NHCO—, where R
₁₁ is a linear or branched alkylene group having 1 to 15 carbon atoms, a substituted or unsubstituted arylene group having 6 to 24 carbon atoms, or a carbon number of 2 to 25 in which one or more oxygen atoms may be present. Indicates an alkylene group. X ₉ has 2 to 3 carbon atoms
0 is a linear or branched alkylene group or is an arylene group selected from the above Ar ₁ . R ₉ , R ₉ ′, R ₁₀ and R ₁₀ ′ may be the same or different and each is a hydrogen atom, a halogen atom, or a carbon number of 1 to 1.
24 substituted or unsubstituted alkyl groups, 1 to 2 carbon atoms
4 is an alkoxy group or a substituted or unsubstituted aryl group or aryloxy group having 6 to 14 carbon atoms,
a, a ′, b and b ′ each represent an integer of 1 or 2. Furthermore, the molar ratio s is a numerical value of 1 or less,
t is a numerical value less than 1, and s + t = 1.0. The degree of polymerization n ₂ is 10 to 300. ) [Chemical 8] (In each formula, X ₁₀ , X ₁₀ ′, X ₁₁ , X ₁₁ ′ and X
₁₂ may be the same or different, and is a straight-chain or branched alkylene group having 1 to 25 carbon atoms, or 2 or more carbon atoms in which at least one oxygen atom may be present and at least one arylene group may be present. 25 are alkylene groups or alkyleneoxy groups, or an arylene group selected from the above Ar ₁ . R ₁₂ and R ₁₂ ′ may be the same or different and each represents a substituted or unsubstituted alkyl group having 1 to 24 carbon atoms or a substituted or unsubstituted aryl group having 6 to 24 carbon atoms, and Ar ₆ And Ar ₆ ′
Are the same or different and are aryl groups selected from the above Ar ₃ . Further, the molar ratio u is a numerical value of 1 or less, v is a numerical value of less than 1, and u + v =
Set to 1.0. The degree of polymerization n ₃ is 5 to 1000. ) 2. The image according to claim 1, wherein the photoreceptor has a photosensitive layer and a surface protective layer sequentially provided on a conductive support, and the surface protective layer contains at least one kind of the polymer charge transport material. Forming method. 3. A charge transporting layer or a surface protective layer constituting the outermost surface layer of the photoreceptor, and at least one of the polymer charge transporting materials and repeating units represented by the following structural formulas (K) to (O). The image forming method according to claim 1, further comprising a polycarbonate resin having a unit or at least one selected from a copolymer thereof. [Chemical 9]