JP2001100443A - Electrophotographic photoreceptor and device and method for forming image and process cartridge using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrophotographic photoreceptor hardly generating any defects caused by the brittleness of its inorganic photosensitive layer such as exfoliation and isolation from the support by the impact received in the case of being used and cracks by scratching and hardly generating image flowing and image blur caused by the products in the case of discharging, paper powder or the like deposited on the surface of the photoreceptor and to provide a method and a device for forming an image and a process cartridge using the photoreceptor. SOLUTION: This electrophotographic photoreceptor has at least an inorganic photosensitive layer on an electrically conductive support. Such a resin layer is formed on the inorganic photosensitive layer by application, as comprises a siloxane-based resin containing a structural unit having charge transferring ability and containing a cross-linked structure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an electrophotographic photosensitive member, an image forming apparatus using the same, an image forming method, and a process cartridge.

[0002]

2. Description of the Related Art A so-called inorganic photosensitive member in which a layer using an inorganic photosensitive material such as selenium is coated on a conductive support,
It has long been used as the mainstream of electrophotographic photoreceptors. Further, recently, an amorphous silicon photoreceptor, which is a kind of inorganic photoreceptor, has attracted attention as a highly durable photoreceptor having a very hard surface hardness.

However, a problem with the amorphous silicon photoreceptor is that when the photoreceptor is subjected to an impact due to improper handling during use, the photoreceptor may be lifted off from the substrate (support), or may be removed when scratched. Cracks, such as cracks, are likely to occur due to “fragility”, which is a problem. Further, when a large number of sheets are repeatedly used, there is a problem in that discharge products, paper dust, and the like adhere to the surface of the photoreceptor, causing image deletion and image blur. These problems have recently arisen when high durability is required and the mounted equipment is small and maintenance is performed by the user himself. It has been a problem as well.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems.

That is, an object of the present invention is to eliminate the occurrence of defects caused by "fragility" such as peeling or lifting of a photosensitive layer due to impact during use of an inorganic photosensitive member, and peeling of a film due to scratching. An object of the present invention is to solve the problem that a discharge product, paper dust, or the like adheres to the surface of a photoreceptor during repeated use, causing image deletion or image blur. Another object of the present invention is to provide an image forming apparatus, an image forming method, and a process cartridge using the inorganic photosensitive member.

[0006]

The object of the present invention is attained by adopting one of the following constitutions.

[1] In an electrophotographic photosensitive member having at least an inorganic photosensitive layer on a conductive support, the inorganic photosensitive layer has a structural unit having a charge transporting property and a crosslinked structure. An electrophotographic photoreceptor comprising a resin layer containing a siloxane-based resin.

[2] The electrophotographic photosensitive member according to [1], wherein the inorganic photosensitive layer is made of amorphous silicon.

[3] The electrophotographic photosensitive member according to [1] or [2], wherein the resin layer contains a siloxane-based resin having a crosslinked structure represented by the following general formula (1).

[0010]

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(In the formula, X represents a structural unit having charge transport performance, and Z represents an arbitrary divalent or higher linking group.) [4] The resin layer is represented by the following general formula [A] or [B]. [1] characterized by containing a compound represented by
The electrophotographic photosensitive member according to [2] or [3].

[0012]

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(Wherein, R ₁ , R ₂ , R ₃ and R ₄ each represent a hydrogen atom or an alkyl group or an aryl group, and Z represents an atomic group necessary for constituting a nitrogen-containing alicyclic ring. _1, the one in R ₂ of the set and R _3, the R ₄ pairs of respective pairs may provide a double bond incorporated into the Z.

R ₅ is a branched alkyl group, R ₆ , R ₇ and R ₈
Represents a hydrogen atom, a hydroxy group, an alkyl group or an aryl group, respectively, and R ₆ , R ₇ and R ₈ may be mutually connected to form a ring. R ₉ represents a hydrogen atom, an alkyl group or an alkylidene group. [5] In the general formula (1), Z is a divalent or higher atom excluding an adjacent bonding atom (a silicon atom Si and a carbon atom C constituting a part of the structural unit having the charge transport performance) or The electrophotographic photosensitive member according to [3] or [4], which is a base.

[6] In the general formula (1), Z is O,
The electrophotographic photoreceptor according to [5], wherein S and NR are R and R is H or a monovalent organic group.

[7] An electrophotographic photosensitive member having at least an inorganic photosensitive layer on a conductive support, wherein the inorganic photosensitive layer has a structural unit having charge transport performance and a cross-linked structure. A resin layer containing a siloxane-based resin is applied, and the resin layer is reacted with an organosilicon compound having a hydroxyl group or a hydrolyzable group, and a compound having a hydroxyl group and a structural unit having charge transport performance. An electrophotographic photosensitive member characterized by being obtained by:

[8] The resin according to any one of [1] to [7], wherein the resin layer contains organic fine particles or inorganic fine particles.
The electrophotographic photosensitive member according to any one of the above items.

[0018]

[9] Using the electrophotographic photoreceptor according to any one of [1] to [8], charging, image exposure, development, transfer,
An image forming method comprising a cleaning step.

[10] An image formed by using the electrophotographic photosensitive member according to any one of [1] to [8] and forming an image through steps of charging, image exposure, development, transfer and cleaning. Forming equipment.

[11] Using an electrophotographic photosensitive member,
In a process cartridge used for forming an image through the steps of image exposure, development, transfer, and cleaning, [1] to
[8] The electrophotographic photosensitive member according to any one of [1] and a charger,
A process cartridge which is manufactured by combining at least one of an image exposure device, a developing device, a transfer device, and a cleaning device.

By providing a structural unit having an electron transporting property and a siloxane-based resin layer having a crosslinked structure on the surface of the inorganic photoreceptor, the fragility peculiar to the inorganic photoreceptor, in particular, the amorphous silicon photoreceptor is improved. It has become possible to produce a photoreceptor capable of maintaining a good image with little adhesion of paper dust and toner filming substance on the body surface for a long period of time.

In general, when a protective layer is provided on the surface of a photoreceptor, potential characteristics such as an increase in residual potential and a decrease in sensitivity occur, but such a problem does not occur in the photoreceptor of the present invention. In addition, since the resin layer of the present invention contains a silicon component, the adhesiveness between the resin layer and the photosensitive layer is good, and a good photosensitive film without peeling during use or floating of the film during scratching. I have a body.

The resin layer of the present invention is a non-photosensitive layer coated on a photosensitive layer. In order to achieve the object of the present invention, it is usually preferable to provide it on the uppermost layer of the photoconductor. However, an overcoat layer may be further provided thereon in view of the other performance of the photoreceptor.

The resin layer of the present invention must contain a siloxane-based resin in an amount necessary to achieve the object of the present invention, but at the same time, a substance for imparting another function (for example, Organic / inorganic fine particles or an antioxidant described below).

The inorganic photosensitive layer in the present invention is typically a deposited photosensitive layer of amorphous silicon, crystalline silicon, amorphous selenium, zinc oxide, cadmium sulfide or the like, or a photosensitive layer coated with these particles. Refers to layers and the like. Among these, the most suitable for the present invention is a photosensitive layer of amorphous silicon.

Incidentally, the inorganic photosensitive layer in the present invention may be a laminate of two or more layers.

[0027]

Next, the resin layer used in the present invention will be described in detail.

In the present invention, the siloxane-based resin having a structural unit having a charge-transporting property and having a crosslinked structure may be prepared by a known method, that is, an organosilicon compound having a hydroxyl group or a hydrolyzable group. It is manufactured using The organosilicon compound is represented by the following general formulas (A) to (D).

[0029]

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(In the formula, R _{1 to} R ₆ represent an organic group in which carbon is directly bonded to silicon in the formula, and Y _{1 to} Y ₄ represent a hydroxyl group or a hydrolyzable group.) When Y ₁ to Y ₄ are a hydrolyzable group, the hydrolyzable group includes a methoxy group, an ethoxy group, a methylethylketoxime group, a diethylamino group, an acetoxy group, a propenoxy group, a propoxy group, a butoxy group, a methoxyethoxy group and the like. No. Examples of the organic group in which carbon is directly bonded to silicon represented by R _{1 to} R ₆ include alkyl groups such as methyl, ethyl, propyl and butyl, aryl groups such as phenyl, tolyl, naphthyl and biphenyl, and γ-glycidyl. Epoxy-containing groups such as xypropyl and β- (3,4-epoxycyclohexyl) ethyl, (meth) acryloyl-containing γ-acryloxypropyl and γ-methacryloxypropyl, γ-hydroxypropyl, 2,3-dihydroxy A hydroxyl group such as propyloxypropyl, a vinyl group such as vinyl and propenyl, a mercapto group such as γ-mercaptopropyl, an amino group such as γ-aminopropyl and N-β (aminoethyl) -γ-aminopropyl; γ-chloropropyl, 1,1,1-trifluoropropyl, nonafluorohexyl, perfluorooctylethyl And nitro and cyano-substituted alkyl groups. Further, R _{1 to} R ₆ may have the same or different organic groups.

In general, when the number n of hydrolyzable groups bonded to silicon atoms of the organosilicon compound used as a raw material of the siloxane-based resin is 1, the polymerization reaction of the organosilicon compound is suppressed. You. n is 2, 3 or 4
In the case of (3), the polymerization reaction is likely to occur.
It is possible to advance the crosslinking reaction to a high degree. Therefore, by controlling these, it is possible to control the preservability of the obtained coating layer liquid, the hardness of the coating layer, and the like.

As a raw material for the siloxane-based resin, a hydrolysis-condensation product obtained by hydrolyzing the organosilicon compound under acidic or basic conditions to form an oligomer or a polymer can also be used.

As described above, the siloxane-based resin of the present invention is obtained by reacting a monomer, oligomer, or polymer having a siloxane bond in a chemical structural unit in advance (hydrolysis reaction, reaction in which a catalyst or a crosslinking agent is added, etc.). (Included) means a resin that has formed and cured a three-dimensional network structure. That is, it means a siloxane-based resin having a cross-linked structure formed by promoting a siloxane bond by a hydrolysis reaction and subsequent dehydration condensation of an organosilicon compound having a siloxane bond to form a three-dimensional network structure.

The siloxane-based resin may contain colloidal silica having a hydroxyl group or a hydrolyzable group, and may be a resin having silica particles incorporated in a part of a crosslinked structure.

A siloxane-based resin having a structural unit having a charge transporting property and having a crosslinked structure according to the present invention is a chemical structure having a characteristic of exhibiting electron or hole drift mobility (= a structure having a charge transporting property). (Unit) in a siloxane-based resin as a partial structure.
Specifically, the siloxane-based resin having a structural unit having a charge transporting property of the present invention and having a crosslinked structure includes a compound generally used as a charge transporting substance (hereinafter, also referred to as a charge transporting compound or CTM). It has a partial structure in the siloxane-based resin.

The above-mentioned structural unit having charge transporting ability is a structural unit exhibiting the property of having electron or hole drift mobility, or a charge transporting compound residue. Another definition is Time- It can also be expressed as a structural unit or a charge-transporting compound residue from which a detection current due to charge transport can be obtained by a known method capable of detecting charge-transporting performance such as the Of-Flight method.

The charge transporting compound capable of forming a structural unit having charge transporting ability by reacting with an organosilicon compound in a siloxane resin will be described below.

For example, examples of the hole transport type CTM include oxazole, oxadiazole, thiazole, triazole, imidazole, imidazolone, imidazoline, bisimidazolidine, styryl, hydrazone, benzidine and the like.
Pyrazoline, stilbene compound, amine, oxazolone, benzothiazole, benzimidazole, quinazoline, benzofuran, acridine, phenazine, aminostilbene, poly-N-vinylcarbazole, poly-1-
It has a chemical structure such as vinylpyrene and poly-9-vinylanthracene.

On the other hand, electron transport type CTMs include succinic anhydride, maleic anhydride, phthalic anhydride, pyromellitic anhydride, melitic anhydride, tetracyanoethylene, tetracyanoquinodimethane, nitrobenzene, dinitrobenzene, trinitrobenzene. , Tetranitrobenzene, nitrobenzonitrile, picryl chloride, quinone chlorimide, chloranil, bromanyl, benzoquinone, naphthoquinone, diphenoquinone, tropoquinone, anthraquinone, 1-chloroanthraquinone, dinitroanthraquinone, 4-nitrobenzophenone, 4,4'-dinitrobenzophenone , 4-nitrobenzalmalonedinitrile, α-cyano-β- (p-cyanophenyl) -2-
(P-chlorophenyl) ethylene, 2,7-dinitrofluorene, 2,4,7-trinitrofluorenone, 2,
4,5,7-tetranitrofluorenone, 9-fluorenylidenedicyanomethylenemalononitrile, polynitro-9-fluoronylidenedicyanomethylenemalonodinitrile, picric acid, o-nitrobenzoic acid, p-nitrobenzoic acid, 3, It has a chemical structure such as 5-dinitrobenzoic acid, pentafluorobenzoic acid, 5-nitrosalicylic acid, 3,5-dinitrosalicylic acid, phthalic acid, and melitic acid.

In the present invention, the structural unit having a preferable charge transporting performance is a residue of a commonly used charge transporting compound as described above, and has the following structure via a carbon atom or a silicon atom constituting the charge transporting compound. It is bonded to the linking atom or linking group represented by Z in the formula, and is contained in the siloxane-based resin via Z.

[0041]

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(In the formula, X represents a structural unit having charge transporting ability, and Z represents any divalent or higher valent linking group.) Preferably, Z in the general formula (1) is an adjacent bonding atom (silicon atom) A divalent or higher valent atom or group excluding Si and a carbon atom C) constituting a part of the structural unit having the charge transporting performance.

However, when Z is an atom having three or more valences, S in the formula
The bond of Z other than i and C is bonded to any constituent atom in the resin capable of bonding or has a structure (group) connected to another atom or molecular group.

In the above general formula, an oxygen atom (O), a sulfur atom (S), and a nitrogen atom (N) are particularly preferable as the Z atom, and the group is a substituted or unsubstituted alkylene group or an arylene group. Is good.

Here, when Z is a nitrogen atom (N), the linking group is represented by -NR- (R is a hydrogen atom or a monovalent organic group).

Although the structural unit X having charge transporting performance is shown as a monovalent group in the formula, the charge transporting compound to be reacted with the siloxane resin has two or more reactive functional groups. In this case, the resin may be joined as a divalent or higher crosslink group in the curable resin, or may be joined simply as a pendant group.

The above-mentioned atoms, ie, the atoms of O, S and N are hydroxyl groups introduced into the compound having the charge transporting performance, respectively.
A linking group formed by the reaction of a mercapto group or an amine group with an organic silicon compound having a hydroxyl group or a hydrolyzable group, and incorporating a structural unit having a charge transporting property into a siloxane-based resin as a partial structure.

Next, the charge transporting compound having a hydroxyl group, a mercapto group, an amine group and an organic silicon-containing group in the present invention will be described.

The charge transporting compound having a hydroxyl group is
It is a charge transport substance having a commonly used structure and a compound having a hydroxyl group. That is, typically, a charge transporting compound represented by the following general formula that can form a resin layer by bonding to a curable organosilicon compound can be exemplified, but is not limited to the following structure. Any compound may be used as long as it has charge transport performance and has a hydroxyl group.

X- (R ₇ -OH) _m wherein X: a structural unit having charge transporting ability, R ₇ : a single bond, a substituted or unsubstituted alkylene group, an arylene group, m: an integer of 1 to 5 is there.

Among them, the following are typical ones. For example, a triarylamine-based compound has a triarylamine structure such as triphenylamine as a structural unit having charge transporting property = X,
A compound having a hydroxyl group via a carbon atom constituting or via an alkylene or arylene group extended from X is preferably used.

1. Triarylamine compounds

[0053]

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[0054]

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[0055]

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[0056]

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2. Hydrazine compounds

[0058]

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[0059]

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[0060]

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3. Stilbene compounds

[0062]

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[0063]

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[0064]

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4. Benzidine compound

[0066]

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[0067]

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5. Butadiene compound

[0069]

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6. Other compounds

[0071]

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Next, specific examples of the charge transporting compound having a mercapto group are shown below.

The charge transporting compound having a mercapto group is a charge transporting substance having a commonly used structure and a compound having a mercapto group. That is, typically, a charge transporting compound represented by the following general formula that can form a resin layer by bonding to a curable organosilicon compound can be exemplified, but is not limited to the following structure. Any compound having charge transport performance and a mercapto group may be used.

X- (R ₈ -SH) _m wherein X is a structural unit having charge transporting ability, R _{8 is a} single bond, a substituted or unsubstituted alkylene or arylene group, and m is an integer of 1 to 5 .

Among them, the following are typical ones.

[0076]

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[0077]

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Further, the charge transporting compound having an amino group will be described.

The charge transporting compound having an amino group is a charge transporting substance having a commonly used structure and a compound having an amino group. That is, typically, a charge transporting compound represented by the following general formula that can form a resin layer by bonding to a curable organosilicon compound can be exemplified, but is not limited to the following structure. Any compound having charge transporting performance and having an amino group may be used.

X- (R ₉ -NR ₁₀ H) _m wherein X: a structural unit having charge transporting ability, R ₉ : a single bond, a substituted or unsubstituted alkylene, a substituted or unsubstituted arylene group, R ₁₀ : A hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, m: an integer of 1 to 5.

Among them, the following are typical ones.

[0082]

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[0083]

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Among the charge transporting compounds having an amino group, in the case of a primary amine compound (—NH ₂ ), two hydrogen atoms may react with an organosilicon compound and be linked to a siloxane structure. In the case of a secondary amine compound (—NHR ₁₀ ), one hydrogen atom reacts with the organosilicon compound, and R ₁₀ may be a group that remains as a branch or a group that causes a cross-linking reaction, and includes a charge transport material. It may be a compound residue.

Further, the charge transporting compound having a silicon atom-containing group will be described.

The charge transporting compound having a silicon atom-containing group is a charge transporting substance having the following structure. This compound can also combine with the curable organosilicon compound to form a resin layer.

X-(-Z-Si (R ₁₁ ) _3-a (R ₁₂ ) _a ) _n (wherein X is a group containing a structural unit having charge transport performance, R ₁₁ is a hydrogen atom, R ₁₂ represents a hydrolyzable group or a hydroxyl group, Z represents a substituted or unsubstituted alkylene group or an arylene group, a represents an integer of 1 to 3, and n represents Represents an integer.) Among them, typical ones are as follows.

[0088]

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[0089]

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[0090]

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Raw material for forming the siloxane-based resin: The composition ratio of the above-mentioned general formulas (A) to (D) (hereinafter referred to as (A) to (D)) is: organosilicon compound: (A) + (B) component 1
It is preferable to use 0.05 to 1 mol of the component (C) + (D) based on the mol.

When colloidal silica (E) is added, 1 to 30 parts by weight of (E) is used based on 100 parts by weight of the total of the components (A) + (B) + (C) + (D). Is preferred.

The amount of the reactive charge transporting compound (F) capable of forming a resin layer by reacting with the above-mentioned organosilicon compound or colloidal silica is as follows: (A) + (B)
It is preferable to use 1 to 500 parts by weight of (F) based on 100 parts by total weight of + (C) + (D) components. (A)
When the amount of the + (B) component is small, the siloxane-based resin layer has too low a crosslinking density and insufficient hardness. On the other hand, if the amount of the component (A) + (B) is too large, the crosslinking density is too high and the hardness is sufficient, but the resin layer becomes brittle. Excess or deficiency of the colloidal silica component of the component (E) has the same tendency as that of the component (A) + (B). On the other hand, when the amount of the component (F) is small, the charge transporting performance of the siloxane-based resin layer is low, causing a decrease in sensitivity and an increase in residual charge. There is a tendency.

The siloxane-based resin having a structural unit having charge transporting ability and having a crosslinked structure according to the present invention is obtained by adding a catalyst or a crosslinking agent to a monomer, oligomer or polymer having a siloxane bond in the structural unit in advance. A bond may be formed to form a three-dimensional network structure, or a siloxane bond may be promoted by a hydrolysis reaction and subsequent dehydration condensation to form a three-dimensional network structure from monomers, oligomers, and polymers.

Generally, a three-dimensional network structure can be formed by a condensation reaction of a composition containing an alkoxysilane or a composition containing an alkoxysilane and colloidal silica.

Examples of the catalyst for forming the three-dimensional network structure include alkali metal salts of organic carboxylic acids, nitrous acid, sulfurous acid, aluminate, carbonic acid and thiocyanic acid, and organic amine salts (tetramethylammonium hydroxide, tetramethylammonium). Ammonium acetate), tin organic acid salts (stannas octoate, dibutyltin diacetate, dibutyltin dilaurate, dibutyltin mercaptide, dibutyltin thiocarboxylate, dibutyltin malate, etc.), octenoic acid, naphthenate of aluminum and zinc, An acetylacetone complex compound is exemplified.

Next, the electrophotographic photoreceptor of the present invention preferably contains an antioxidant. Antioxidants are typically used to prevent or suppress the action of oxygen under the conditions of light, heat, discharge, etc., on auto-oxidizing substances present in or on the electrophotographic photoreceptor. It is a substance having the property of Specifically, the following compounds may be mentioned.

(1) Radical chain inhibitor • Phenol antioxidant Hindered phenol • Amine antioxidant Hindered amine diallyldiamine diallylamine • Hydroquinone antioxidant (2) Peroxide decomposer • Sulfur Antioxidants Thioethers Phosphoric acid antioxidants Phosphite esters Hindered phenols are compounds having a bulky organic group at the ortho position of the phenolic OH group or the alkoxylated group of the phenolic OH, A hindered amine is a compound having a bulky organic group near an N atom. As the bulky organic group, there is a branched alkyl group, and for example, a t-butyl group is preferable.

Among the above antioxidants, the radical chain inhibitor (1) is preferable, and a hindered phenol or hindered amine antioxidant is particularly preferable.

Further, two or more kinds may be used in combination, for example, a combination of the hindered phenol antioxidant (1) and the thioether antioxidant (2) may be used.

In the present invention, those having the above hindered amine structure in the molecule are more preferable for improving image quality such as prevention of image blur and black spots. In another embodiment, the hindered phenol structural unit and the hindered amine structure are preferred. Those containing units in the molecule are likewise preferred.

The hindered phenol-based and hindered amine-based antioxidants preferably used in the present invention include compounds having the following general formulas [A] and [B] as structural units.

[0103]

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In the formula, R ₁ , R ₂ , R ₃ and R ₄ each represent a hydrogen atom or an alkyl group or an aryl group, and Z represents an atomic group necessary for constituting a nitrogen-containing alicyclic ring. Also, in each set of R ₁ , R ₂ and R ₃ , R ₄ , one of them may be incorporated into Z to provide a double bond.

Further, R ₅ is a branched alkyl group, R ₆ and R ₇
And R ₈ each represent a hydrogen atom, a hydroxy group, an alkyl group or an aryl group, and R ₆ , R ₇ and R ₈ may be mutually connected to form a ring.

R ₉ represents a hydrogen atom, an alkyl group or an alkylidene group.

The above R ₁ , R ₂ , R ₃ and R ₄ are preferably an alkyl group having 1 to 40 carbon atoms, and the alkyl group may have a substituent. Aryl groups, alkoxy groups, carboxylic acid groups, amide groups, halogen atoms and the like are optional.

Z is an atomic group necessary for constituting a nitrogen-containing alicyclic ring, and is preferably an atomic group constituting a 5- or 6-membered ring.

Preferred ring structures include piperidine, piperazine, morpholine, pyrrolidine, imidazolidine,
Oxazolidine, thiazolidine, selenazolidine, pyrroline, imidazoline, isoindoline, tetrahydroisoquinoline, tetrahydropyridine, dihydropyridine, dihydroisoquinoline, oxazoline, thiazoline, selenazoline, pyrrole and the like, and particularly preferably piperidine, piperazine, morpholine and pyrrolidine. Each ring.

R ₅ and R ₆ are tert-carbon having 3 to 40 carbon atoms.
-Or a sec-alkyl group is preferred.

R ₇ and R ₈ are preferably alkyl groups having 1 to 40 carbon atoms, and aryl groups include phenyl, naphthyl and pyridyl. Also R
_{When 6} and R ₇ are rings, a chroman ring is preferred.

It represents an alkyl group or an alkylidene group represented by R ₉ and preferably has 1 to 40 carbon atoms, and particularly preferably has 1 to 18 carbon atoms.

The following (1) hindered phenol or (2) hindered amine, (3) hindered amine
The content of the structural antioxidant such as hindered phenol type, (4) organic phosphorus type, and (5) organic sulfur type in the resin is 0.0
Preferred is 1 to 25% by weight. If the content is more than 25% by weight, the charge transporting performance in the resin layer is reduced, the residual potential is likely to increase, and the film strength may be reduced. More preferably, the content is 0.1 to 10% by weight.

The antioxidant may be contained in the lower charge generation layer, charge transport layer, intermediate layer and the like, if necessary. The amount of the antioxidant added to these layers is preferably 0.01 to 25% by weight based on each layer.

The antioxidants used in the present invention include:
There is no particular limitation as long as it meets the above conditions,
Specific examples are described below.

(1) Examples of compounds having a hindered phenol structural unit

[0117]

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[0118]

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[0119]

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[0120]

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[0121]

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[0122]

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[0123]

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[0124]

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[0125]

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[0126]

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[0127]

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[0128]

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(2) Examples of compounds having hindered amine structural units

[0130]

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[0131]

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[0132]

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[0133]

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[0134]

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[0135]

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[0136]

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[0137]

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[0138]

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[0139]

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[0140]

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[0141]

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[0142]

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(3) Examples of compounds having a hindered amine structural unit and a hindered phenol structural unit

[0144]

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[0145]

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[0146]

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(4) Examples of Organic Phosphorus Compounds The following are typical examples of compounds represented by the general formula RO-P (OR) -OR. Here, R represents a hydrogen atom, a substituted or unsubstituted alkyl group, alkenyl group or aryl group.

[0148]

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[0149]

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(5) Organic Sulfur Compounds For example, the following are typical compounds represented by the general formula RSR. Here, R represents a hydrogen atom, a substituted or unsubstituted alkyl group, alkenyl group or aryl group.

[0151]

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Examples of commercially available antioxidants include the following compounds, for example, “Irganox 107
6, Irganox 1010, Irganox 1098, Irganox 245, Irganox 1330, Irganox 3114, Irganox 1076, 3,5-di-t-butyl-4 −
Hydroxybiphenyl or more hindered phenols,
"Sanol LS2626", "Sanol LS765"
"Sanol LS2626", "Sanol LS770",
“Sanol LS744”, “Tinuvin 144”, “Tinuvin 622LD”, “Mark LA57”, “Mark LA”
67 "," Mark LA62 "," Mark LA68 ",
"Mark LA63" or more is a hindered amine type.

Next, the configuration of the present invention will be described.

Examples of the conductive support of the electrophotographic photoreceptor of the present invention include: 1) a metal plate such as an aluminum plate or a stainless steel plate; 2) a support such as paper or a plastic film;
A thin metal layer such as aluminum, palladium, or gold provided by lamination or vapor deposition. 3) On a support such as paper or plastic film,
Examples thereof include those in which a layer of a conductive compound such as a conductive polymer, indium oxide, or tin oxide is provided by coating or vapor deposition.

The material of the conductive support used in the present invention is mainly aluminum, copper, brass, steel,
A belt-shaped or drum-shaped metal material such as stainless steel or another plastic material is used. Among them, aluminum excellent in cost, workability and the like is preferably used, and a thin-walled cylindrical aluminum tube usually formed by extrusion or drawing is often used.

The conductive support used in the present invention may have a surface on which a sealed alumite film is formed. The alumite treatment is usually performed in an acidic bath such as chromic acid, sulfuric acid, oxalic acid, phosphoric acid, boric acid, and sulfamic acid, but anodizing treatment in sulfuric acid gives the most preferable result. In the case of anodic oxidation treatment in sulfuric acid, it is preferable that the sulfuric acid concentration is 100 to 200 g / l, the aluminum ion concentration is 1 to 10 g / l, the liquid temperature is around 20 ° C., and the applied voltage is about 20 V. It is not limited. The average thickness of the anodic oxide coating is usually 2
It is preferably 0 μm or less, particularly preferably 10 μm or less.

Next, as a method of coating the resin layer of the present invention, a coating method such as dip coating, spray coating, and circular amount control type coating is used.

[0158] The spray coating is described in detail in, for example, JP-A-3-90250 and JP-A-3-269238, and the circular amount control type coating is described in, for example, JP-A-58-189061. Has been described.

In the present invention, an intermediate layer having a barrier function can be provided between the conductive support and the photosensitive layer.

The shape of the support may be a drum shape, a sheet shape, or a belt shape, and may be any shape suitable for the electrophotographic apparatus to be applied.

The electrophotographic photoreceptor of the present invention can be applied to general electrophotographic devices such as copiers, laser printers, LED printers, and liquid crystal shutter printers. It can be widely applied to devices such as light printing, plate making, and facsimile.

FIG. 1 is a sectional view of an image forming apparatus according to one embodiment of the present invention.

In the present invention, reference numeral 4 denotes a photosensitive drum,
An aluminum silicon drum photosensitive layer and a resin surface protective layer of the present invention are formed on the outer peripheral surface of an aluminum drum base, and are rotated at a predetermined speed in the direction of the arrow. In the embodiment, the photosensitive drum 4 has an outer diameter of 60 mm.

In FIG. 1, exposure light is emitted from the semiconductor laser light source 1 based on information read by a document reading device (not shown). This is distributed by a polygon mirror 2 in the direction perpendicular to the plane of the paper of FIG. 1, and is radiated on the photoreceptor surface via an fθ lens 3 for correcting image distortion to form an electrostatic latent image. The photoreceptor is uniformly charged in advance by the charger 5 and starts rotating clockwise in synchronization with the timing of image exposure.

The electrostatic latent image on the surface of the photoreceptor is developed by the developing device 6 and the formed toner image is transferred to the image support (recording material) 8 conveyed at a proper timing by the operation of the transfer device 7. Is done. Further, the photosensitive drum 4 and the recording material 8
Are separated by a separator (separation pole) 9, and the toner image is transferred and carried on the recording material 8, guided to a fixing device 10 and fixed.

The untransferred toner remaining on the photoreceptor surface is
It is cleaned by a cleaning device 11 of a cleaning blade type, and the remaining charge is removed by a pre-charging exposure (PCL) 12, and is uniformly charged again by the charger 5 for the next image formation.

Incidentally, the recording material is typically plain paper,
There is no particular limitation as long as an unfixed image after development can be transferred, and a PET base for OHP and the like are of course included.

The cleaning blade 13 has a thickness of 1 mm.
A rubber-like elastic body of about 30 mm is used, and urethane rubber is most often used as a material. Since this is used while being pressed against the photoconductor, heat is easily transmitted, and it is desirable to keep the photoconductor away from the photoconductor when the image forming operation is not performed.

In recent years, in the field of electrophotography and the like in which an electrostatic latent image is formed on a photoreceptor and this latent image is developed to obtain a visible image, it is easy to improve image quality, convert, edit, etc., and obtain a high quality image. Research and development of an image forming method employing a digital method capable of forming are being actively conducted.

As a scanning optical system that modulates light with a digital image signal from a computer or a copy original used in the image forming method and apparatus, an acousto-optic modulator is interposed in a laser optical system, and the acousto-optic modulator uses the acousto-optic modulator. There is a device that modulates and a device that directly modulates laser intensity using a semiconductor laser. A spot image is formed on a uniformly charged photoconductor from these scanning optical systems to form a dot-shaped image.

The beam emitted from the above-described scanning optical system has a round or elliptical luminance distribution approximating a normal distribution with a skirt spreading left and right. One or both of the scanning direction and the sub-scanning direction has a very small circular or elliptical shape of 20 to 100 μm.

Further, the image forming apparatus includes a photosensitive drum 4
And a process cartridge including at least one of the charger 5, the developing device 6, the cleaning device 11, the transfer device 7, and the like.

FIG. 2 is a sectional view (a) and a perspective view (b) of an example of a process cartridge to be mounted on the image forming apparatus of the present invention. This process cartridge 15
Is loaded into the apparatus by a guide rail or the like from the side of the image forming apparatus, that is, a direction perpendicular to the direction in which the recording material is conveyed.

Although the above-described electrophotographic image forming apparatus is an apparatus for forming a monochrome image, it goes without saying that the present invention can be similarly applied to a color image forming apparatus.

When the image forming apparatus is used as a copying machine or a printer, the image exposure is performed by irradiating the photosensitive member with reflected light or transmitted light from the original, or by reading the original with a sensor and converting it into a signal. Scanning of a laser beam, driving of an LED array, or driving of a liquid crystal shutter array is performed by irradiating the photosensitive member with light. When used as a facsimile printer, image exposure is performed for printing received data.

[0176]

EXAMPLES The present invention will be described below in detail with reference to examples, but embodiments of the present invention are not limited thereto.

Each of the photoreceptors was prepared in the following manner. One of them was used for a photoreceptor surface strength test, and the other was used for characteristic evaluation.

Production of Photoreceptor 1 <Photosensitive Layer> An amorphous silicon photosensitive layer was formed on an aluminum drum support by glow discharge.

First, a clean support having a smooth surface was placed in a reaction (vacuum) tank of a glow discharge device. The inside of the reaction vessel was evacuated to a high vacuum of about 10 ⁻⁶ Torr, the support was heated to 200 ° C., and high-purity Ar gas was introduced.
A high frequency power having a frequency of 13.56 MHz and a current density of 0.004 W / cm ² was applied under a back pressure of 5 Torr, and 1
Preliminary discharge was performed for 5 minutes.

Next, a reaction gas consisting of SiH ₄ and CH ₄ was introduced, and (Ar + S) having a flow ratio of 3: 1: 0.5 to 0.05 was introduced.
i-H ₄ + CH ₄ ) Glow discharge decomposition of mixed gas and B ₂ H ₆ gas to prevent carrier injection a-Si:
H-layer, and a-S responsible for the potential holding and charge transport functions
An i: H layer was formed at a deposition rate of 350 ° / min.

The carbon content in the a-Si: H layer was 15 atomic% as a result of Auger electron spectroscopy.
The reaction vessel is once evacuated, CH ₄ is not supplied, the discharge decomposition of SiH ₄ and B ₂ H _6, boron-doped a-Si: After the formation of the H photosensitive layer, the CH ₄ and Oyobi B ₂ H ₆ again Supplied. This time, a flow ratio of 5: 1: _{4 to} 0.5 (Ar + SiH ₄ + C
H ₄ ) The mixed gas is decomposed by glow discharge, and boron-doped a-
An Si: H surface modification layer was further provided to form an electrophotographic photosensitive layer.

The optical energy gap of this a-Si: H surface modified layer was 2.5 to 2.0 eV. The analysis also revealed that the carbon composition was 50 to 20 atom%.

<Resin Layer (Surface Protective Layer)> A polysiloxane resin 1 comprising 80 mol% of methylsiloxane units and 20 mol% of methyl-phenylsiloxane units on the photosensitive layer.
Molecular sieve 4A was added to 0 parts by weight, and the mixture was allowed to stand for 15 hours to be dehydrated. This resin was dissolved in 10 parts by weight of toluene, and 5 parts by weight of methyltrimethoxysilane and 0.2 parts by weight of dibutyltin acetate were added thereto to form a uniform solution. 6 parts by weight of dihydroxymethyltriphenylamine (Exemplified Compound T-1) and hindered amine (2-
1) 0.3 parts by weight were added and mixed.

This solution was applied as a protective layer having a dry film thickness of 2 μm, and was heated and cured at 120 ° C. for 1 hour to produce a photoreceptor 1.

Production of Photoreceptor 2 Photoreceptor 2 was produced in exactly the same manner as in production of photoreceptor 1, except that the hindered amine in the surface protective layer was changed to hindered phenol (1-32).

Production of Photoreceptor 3 Photoreceptor 3 was produced in exactly the same manner as in production of photoreceptor 1, except that hindered amine in the surface protective layer was not used.

Production of Photoreceptor 4 Photoreceptor 4 was produced in exactly the same manner as in production of photoreceptor 1, except that a coating solution having the following composition was applied as a surface protective layer and heated.

4-2- (Trimethoxysilyl) methyltriphenylamine 5 parts by weight Dimethyldimethoxysilane 2 parts by weight Methyltrimethoxysilane 5 parts by weight 0.1 parts by weight of dibutyltin diacetate 38 parts by weight of 1-butanol On the photosensitive layer By dip coating and curing at 140 ° C. for 4 hours, a 2 μm surface protective layer was provided.

Production of Photoreceptor 5 On photoreceptor 1, a coating solution having the following composition was applied as a surface protective layer, and heated to form a protective layer. Except that, the photoconductor 5 was manufactured in the same manner.

4- (Trimethoxysilyl) methyltriphenylamine 5 parts by weight Dimethyldimethoxysilane 2 parts by weight Methyltrimethoxysilane 5 parts by weight 0.1 parts by weight of dibutyltin diacetate 1 part by weight of hindered amine (2-1) 1 -Butanol 38 parts by weight Dip coating on the photosensitive layer and curing at 140 ° C. for 4 hours to provide a 2 μm surface protective layer.

Production of Photoconductor 6 Monochrome Analog Copier U-BIX 500 manufactured by Konica Corporation
The same surface protective layer as in Example 1 was provided on the hard selenium photoconductor for No. 0 to prepare photoconductor 6.

Production of Photoreceptor 7 (Comparative) Photoreceptor 7 was produced in the same manner as in Photoreceptor 1 except that charge transporting compound T-1 in the surface protective layer was omitted.

Production of Photoreceptor 8 (for Comparison) On the same photosensitive layer as that of Photoreceptor 1, the following surface protective layer was provided to produce Photoreceptor 8.

<Surface Protective Layer> Bisphenol Z polycarbonate (Iupilon Z-300) 5 parts by weight The film thickness was 4 μm.

Production of Photoreceptor 9 (for comparison) Except for the surface protective layer in the production of Photoreceptor 1,
It was produced in the same manner as the photoreceptor 1.

[Characteristics Evaluation] Photoreceptor Surface Strength Test 1 A diamond needle of R = 0.1 was placed on the surface of each photoreceptor with a load of 5
It was checked whether or not the protective layer was peeled off when abutting at 0 g and scratching at a speed of 10 mm / sec.

Photoreceptor Surface Strength Test 2 A 50 g iron ball was dropped from 50 cm onto the surface of each photoreceptor, and it was confirmed whether the film would float.

Image Quality / Resolution Test The above photoreceptor was converted to a monochrome analog copier UB manufactured by Konica Corporation.
IX 5000 remodeling machine,
H: 33 ° C., 80% RH).
The characteristics at the start of actual shooting and after 100 kp (100,000 copies) were compared.

The image quality evaluation was indicated based on the following criteria. The resolution is represented by the number of discriminable fine lines drawn to a width of 1 mm of the document.

◎: No problem Δ: Slight character bleeding observed with a microscope X: Character bleeding, image blurring, character blurring, density reduction, etc. can be visually identified.

Photoreceptor Potential Stability Test An actual photographing test was performed in a high-temperature and high-humidity environment (HH: 33 ° C., 80% RH). ) The potential was measured as each VH and VL.

In the morning following the test, the first charging performance in the morning was measured in the same manner. In addition, these were all displayed by the volt (V).

[Evaluation Results] Table 1 shows the results.

[0204]

[Table 1]

It is found that the photoconductors 1 to 6 in the present invention have good test results, but the photoconductors 7 to 9 out of the present invention have problems in at least one of the tests.

[0206]

According to the present invention, it is possible to eliminate the occurrence of defects caused by "fragility" such as peeling of the photosensitive layer due to impact upon use of the inorganic photoreceptor, lifting of the photosensitive layer, and cracking of the film due to scratching. In use, it is possible to solve the problem that discharge products, paper dust, and the like adhere to the surface of the photoreceptor, causing image deletion and image blur. Further, an image forming apparatus, an image forming method, and a process cartridge using the inorganic photoreceptor can be provided.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of an image forming apparatus according to one embodiment of the present invention.

FIG. 2 is a sectional view and a perspective view of a process cartridge to which the present invention is applied.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 semiconductor laser light source 2 polygon mirror 3 fθ lens 4 photoreceptor drum 5 charger 6 developing device 7 transfer device 8 image support (recording material) 9 separator (separation pole) 10 fixing device 11 cleaning device 12 pre-charge exposure (PCL) ) 13 Cleaning blade 15 Process cartridge

Claims (11)

[Claims] 1. An electrophotographic photoreceptor having at least an inorganic photosensitive layer on a conductive support, wherein the siloxane has a structural unit having charge transport performance and a crosslinked structure on the inorganic photosensitive layer. An electrophotographic photosensitive member comprising a resin layer containing a base resin. 2. The electrophotographic photosensitive member according to claim 1, wherein the inorganic photosensitive layer is made of amorphous silicon. 3. The electrophotographic photoconductor according to claim 1, wherein the resin layer contains a siloxane-based resin having a crosslinked structure represented by the following general formula (1). Embedded image (In the formula, X represents a structural unit having charge transport performance, and Z represents an arbitrary divalent or higher linking group.) 4. The electrophotographic photosensitive member according to claim 1, wherein said resin layer contains a compound represented by the following general formula [A] or [B]. Embedded image (Expressed in the formula, R _1, R _2, R ₃ and R ₄ are each a hydrogen atom or an alkyl group, an aryl group, Z is an atomic group necessary to configure the nitrogen-containing ring. The R _1, R _second set and R _3, the one in R ₄ sets of each set of which may provide a double bond incorporated into the Z .R ₅ is branched alkyl radical, R _6,
R ₇ and R ₈ each represent a hydrogen atom, a hydroxy group, an alkyl group or an aryl group, and R ₆ , R ₇ and R ₈ may be mutually connected to form a ring. R ₉ represents a hydrogen atom, an alkyl group or an alkylidene group. ) 5. In the general formula (1), Z is a divalent or higher atom excluding an adjacent bonding atom (silicon atom Si and carbon atom C constituting a part of the structural unit having the charge transporting performance). 5. The electrophotographic photoreceptor according to claim 3, wherein the electrophotographic photoreceptor is a base. 6. Z in the general formula (1) is O, S, NR
The electrophotographic photoreceptor according to claim 5, wherein R is H or a monovalent organic group. 7. An electrophotographic photosensitive member having at least an inorganic photosensitive layer on a conductive support, wherein a siloxane having a structural unit having charge transport performance and a crosslinked structure on the inorganic photosensitive layer. A resin layer containing a base resin is applied, and the resin layer is reacted with an organic silicon compound having a hydroxyl group or a hydrolyzable group, and a compound containing a structural unit having a charge transport property having a hydroxyl group. An electrophotographic photosensitive member characterized by being obtained. 8. The electrophotographic photosensitive member according to claim 1, wherein the resin layer contains organic fine particles or inorganic fine particles. 9. An image forming method, comprising the steps of charging, image exposure, development, transfer and cleaning using the electrophotographic photosensitive member according to claim 1. 10. An image forming apparatus using the electrophotographic photosensitive member according to claim 1 to form an image through steps of charging, image exposure, development, transfer and cleaning. 11. A process cartridge which uses an electrophotographic photoreceptor and is used for image formation through steps of charging, image exposure, development, transfer and cleaning.
A process cartridge, comprising: a combination of the electrophotographic photosensitive member according to any one of the above, and at least one of a charger, an image exposure device, a developing device, a transfer device, and a cleaning device.