JP4306684B2 - Electrophotographic photosensitive member and image forming method, image forming apparatus and process cartridge using the same - Google Patents

Description

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

  In recent years, in order to write digital signal processed data, an electrophotographic image forming method in which an electrostatic latent image is formed by exposing to light on an organic photoreceptor and an image is formed by a reversal development method has been actively performed. became.

  An electrophotographic photosensitive member used in such a system is required to be stable over a long period of use and capable of handling writing that requires high resolution. In general, organic photoreceptors (sometimes referred to as OPC) have a wider range of material selection than inorganic photoreceptors, so they can be easily applied to various exposure light sources and have excellent potential stability. It has been considered an essential technology for the required processes.

  On the other hand, organic photoreceptors are weak in strength, are susceptible to defects due to depletion and scratches in the photosensitive layer, and improvements have been demanded in terms of durability. A protective layer obtained by crosslinking a siloxane-based resin having excellent surface strength is an organic photoreceptor, and has attracted attention as a technique that can improve the durability against scratches and abrasions that have been conventionally problematic.

  In recent years, as described in Patent Document 1, a photoconductor having a resin layer containing a siloxane-based resin including a structural unit having charge transport performance has been studied. This is excellent in strength characteristics and electrical characteristics, and can greatly improve the strength characteristics, which has been a drawback of conventional organic photoreceptors, but is still insufficient in terms of durability and image quality.

On the other hand, in the electrophotographic process, it is known that an oxidizing gas such as ozone or NOx is generated at the charging or transfer / separation electrode, and this deteriorates the charge transport material in the photosensitive layer. Oxidized photoconductors cause a decrease in chargeability and a decrease in photosensitivity, resulting in image defects such as fogging and a decrease in density. However, in the conventional photoconductor, appropriate abrasion of the photosensitive layer occurs, so that the outermost surface that is most deteriorated is appropriately abraded to remove deteriorated materials and surface contaminants, thereby suppressing appearance deterioration. A photoreceptor having a resin layer containing a siloxane-based resin containing a structural unit having charge transport performance can improve electrophotographic characteristics due to the strength characteristics of the original siloxane-based resin and the presence of the structural unit having charge transport performance. And has the advantage of very low wear. However, since the amount of depletion is small, it is difficult to eliminate the influence of deteriorating substances generated by the action of an oxidizing gas such as ozone or NOx over a long period of time. Therefore, suppression of deterioration has been strongly demanded particularly in an environment where wear is unlikely to occur.
JP-A-9-190004

  As described above, the siloxane-based resin having a cross-linked structure with excellent surface strength is low in wear, so that it deteriorates due to oxidizing gas in the process of use over a long period of time, and the generated deteriorated substance accumulates, stabilizing the photoreceptor potential. Problems that reduce the image quality and image quality have been pointed out. The present invention has been made to solve this problem.

  The object of the present invention is to maintain the performance of a resin layer containing a siloxane-based resin having a crosslinked structure over a long period of time, have good charging characteristics, high sensitivity, no fluctuation in charging potential even after long-term use, and good image characteristics. It is an object of the present invention to provide a photoconductor, an image forming method using the photoconductor, an image forming apparatus, and a process cartridge.

  As a result of studying the above problems, the inventors of the present invention include a structure in which the above-described resin layer has a charge transporting performance and an antioxidant, in particular, an antioxidant having a specific structure. The present inventors have found that the deterioration of the resin layer can be effectively prevented and have reached the present invention.

  That is, the object of the present invention is achieved by adopting one of the following configurations.

1.
In an electrophotographic photosensitive member having at least a photosensitive layer and a resin layer on a conductive support, the resin layer has a structural unit containing a triarylamine having charge transport performance represented by the following general formula (1), and, the number organosilicon compound of 1 to 3 hydroxyl groups or hydrolyzable groups, obtained by reacting a compound containing the structural unit consists of a layer containing the siloxane-based resin having a crosslinked structure, the resin An electrophotographic photoreceptor, wherein the layer is provided on the uppermost layer of the photoreceptor and contains an antioxidant.

(In the formula, X is a structural unit containing a triarylamine having charge transporting performance, a group bonded to Si in the formula through a carbon atom constituting the structural unit, Z is O, S, NR , R is H or a monovalent organic group.)
2
The siloxane-based resin is a resin obtained by reacting at least a hydroxyl group or an organosilicon compound having 3 hydrolyzable groups with a compound containing a hydroxyl group-containing structural unit having charge transport performance. 2. The electrophotographic photosensitive member according to 1.

3.
3. The electrophotographic photosensitive member according to 1 or 2, wherein the antioxidant is a hindered phenol antioxidant.

4).
3. The electrophotographic photosensitive member according to 1 or 2, wherein the antioxidant is a hindered amine antioxidant.

5.
3. The electrophotographic photosensitive member according to 1 or 2, wherein the antioxidant is an organic phosphorus compound-based antioxidant.

6).
3. The electrophotographic photosensitive member according to 1 or 2, wherein the antioxidant is an organic sulfur compound-based antioxidant.

7).
3. The electrophotographic photoreceptor according to 1 or 2, wherein the resin layer is an outermost layer, and Z in the general formula (1) is an oxygen atom (O).

8).
8. An image forming method comprising the steps of charging, image exposure, development, transfer and cleaning using the electrophotographic photosensitive member according to any one of 1 to 7 above.

9.
8. An image forming apparatus using the electrophotographic photosensitive member according to any one of 1 to 7 to form an image through steps of charging, image exposure, development, transfer, and cleaning.

10.
8. An electrophotographic photosensitive member according to any one of 1 to 7 above, a charger, and an image exposure device in a process cartridge used for image formation using a photosensitive member and undergoing charging, image exposure, development, transfer, and cleaning steps. , A process cartridge manufactured by combining at least one of a developing device, a transfer device, and a cleaning device.

  According to the present invention, an electrophotographic photosensitive member that retains the performance of a resin layer containing a siloxane-based resin having a cross-linked structure over a long period of time, has good charging characteristics, is highly sensitive, has no charge potential fluctuation even after long-term use, and has good image characteristics And an image forming method, an image forming apparatus, and a process cartridge using the same.

  A photoreceptor having a resin layer containing a structural unit having charge transport performance and a siloxane-based resin having a crosslinked structure is a siloxane-based resin layer having a film strength characteristic and a crosslinked structure, which has been a drawback of conventional organic photoreceptors. It is possible to greatly improve the electrical characteristics, which was a problem of the above.

  On the other hand, in an electrophotographic process, it is known that an oxidizing gas such as ozone or NOx is generated at a charging, transfer / separation electrode or the like, and this deteriorates a charge transport material in a photosensitive layer. Oxidized photoconductors cause a decrease in chargeability and a decrease in photosensitivity, resulting in image defects such as fogging and a decrease in density. However, in the conventional photoconductor, moderate abrasion of the photosensitive layer occurs, and the outermost surface that is most deteriorated is appropriately abraded to remove deteriorated materials and surface contaminants, thereby suppressing appearance deterioration.

  A photoreceptor having a resin layer containing a siloxane-based resin containing a structural unit having charge transport performance can improve electrophotographic characteristics due to the strength characteristics of the original siloxane-based resin and the presence of the structural unit having charge transport performance. This has the advantage that the amount of wear is very small. However, since the amount of depletion is small, it is difficult to eliminate the influence of deteriorating substances generated by the action of an oxidizing gas such as ozone or NOx over a long period of time. Therefore, it has been strongly demanded to suppress deterioration particularly in an environment in which wear hardly occurs.

  In order to prevent such an oxidizing gas, techniques for adding various kinds of deterioration inhibitors have been studied. However, the conventional siloxane-based resin is inferior in compatibility with the deterioration preventing agent as compared with a normal organic polymer material, and there is a problem that it is difficult to obtain a uniform film. In general, it is known that a resin having a crosslinked structure such as a siloxane-based resin greatly differs in compatibility with an additive when the crosslinked structure and the crosslinking density are different. When the compatibility is lowered, the additives and unreacted charge transporting compounds are precipitated, and in the case of the layer interface or the surface layer, film blurring occurs due to a breeze-out to the photoreceptor surface. This causes a decrease in film strength and image quality. Further, when the above layer is the outermost layer, adhesion of foreign matters to the photosensitive member is promoted, and filming of toner, paper dust and the like is likely to occur.

  Therefore, when the above-described investigation was made to improve the problem of the resin layer containing the siloxane-based resin, the siloxane-based resin including a structure having a charge transporting performance and having a crosslinked structure is a conventional siloxane-based resin. Resin has good compatibility with antioxidants with relatively large molecular weights that have had problems with compatibility, so it can be effectively contained in the layer without film disturbance, and even for long-term use It has been found that deterioration caused by oxidizing gases such as ozone and NOx can be greatly suppressed. Furthermore, when the resin layer is a layer containing a siloxane-based resin having a crosslinked structure obtained by reacting an organosilicon compound having a hydroxyl group or a hydrolyzable group with a compound containing a structural unit having charge transport performance In particular, it was found that the compatibility was excellent. In particular, the resin layer of the present invention has reduced wear and no filming, and can maintain good image quality over a long period of time.

  In order to achieve the object of the present invention, the resin layer of the present invention is usually preferably provided on the uppermost layer of the photoreceptor. However, an overcoat layer may be further provided on the photosensitive member in view of other performance.

  Therefore, the resin layer of the present invention needs to 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 other functions may be contained. good.

  Next, the electrophotographic photosensitive member used in the present invention will be described in detail.

In the present invention, the siloxane resin in the siloxane resin having a structural unit having charge transport performance and having a crosslinked structure is obtained by a known method, that is, using an organosilicon compound having a hydroxyl group or a hydrolyzable group. Manufactured. The organosilicon compound is represented by the following general formulas ( B ) to (D).

(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 in the above general formula is a hydrolyzable group, the hydrolyzable group is a methoxy group, an ethoxy group, a methyl ethyl ketoxime group, a diethylamino group, an acetoxy group, a propenoxy group, a propoxy group, a butoxy group, or a methoxy group. An ethoxy group etc. are mentioned. 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-glycid Epoxy-containing groups such as xylpropyl, β- (3,4-epoxycyclohexyl) ethyl, γ-acryloxypropyl, γ-methacryloxypropyl-containing (meth) acryloyl groups, γ-hydroxypropyl, 2,3-dihydroxy Hydroxyl group such as propyloxypropyl, vinyl group such as vinyl and propenyl, mercapto group such as γ-mercaptopropyl, amino group such as γ-aminopropyl, N-β (aminoethyl) -γ-aminopropyl, γ-chloropropyl, 1,1,1-trifluoropropyl, nonafluorohexyl, perfluorooctylethyl And other halogen-containing groups such as nitro and cyano-substituted alkyl groups. In addition, R _{1 to} R ₆ may have the same or different organic groups.

In the organosilicon compound used as a raw material for the siloxane-based resin, when the number n of hydrolyzable groups bonded to a silicon atom is generally 1, the polymerization reaction of the organosilicon compound is suppressed. n is 2, 3 tends to occur polymerization reaction when the, it is possible to proceed highly crosslinked reaction, especially 3. Accordingly, by controlling these, the storage stability of the coating layer solution obtained, the hardness of the coating layer, and the like can be controlled.

  In addition, as the raw material for the siloxane-based resin, a hydrolysis condensate obtained by hydrolyzing the organosilicon compound under an acidic condition or a basic condition to be oligomerized or polymerized may be used.

  As described above, the siloxane-based resin of the present invention is prepared by reacting a monomer, oligomer or polymer having a siloxane bond in the chemical structural unit in advance (including hydrolysis reaction, reaction with addition of a catalyst or a crosslinking agent, etc.) 3 It means a resin in which a dimensional network structure is formed and cured. That is, it means a siloxane-based resin having a crosslinked structure formed by promoting a siloxane bond by hydrolyzing an organosilicon compound having a siloxane bond and subsequent dehydration condensation to form a three-dimensional network structure.

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

  The siloxane-based resin having a structural unit having charge transport performance in the present invention and having a crosslinked structure is a chemical structure (= structural unit having charge transport performance) having a characteristic of drift mobility of electrons or holes. It is incorporated as a partial structure in a siloxane resin. Specifically, the siloxane-based resin having a structural unit having charge transport performance of the present invention and having a crosslinked structure is generally a compound (hereinafter also referred to as a charge transport compound or CTM) used as a charge transport material. The siloxane resin has a partial structure.

  The structural unit having charge transport performance is a structural unit having a property of drift mobility of electrons or holes, or a charge transporting compound residue, and another definition is Time-Of-Flight. It can also be expressed as a structural unit or a charge transporting compound residue from which a detection current resulting from charge transport can be obtained by a known method capable of detecting charge transport performance such as a method.

  Hereinafter, a charge transporting compound capable of forming a structural unit having charge transporting performance by reaction with an organosilicon compound in a siloxane-based resin will be described.

  For example, hole transport type CTM: xazole, oxadiazole, thiazole, triazole, imidazole, imidazolone, imidazoline, bisimidazolidine, styryl, hydrazone, benzidine, pyrazoline, stilbene compound, amine, oxazolone, benzothiazole, benzimidazole, quinazoline, Chemical structures such as benzofuran, acridine, phenazine, aminostilbene, poly-N-vinylcarbazole, poly-1-vinylpyrene, poly-9-vinylanthracene are contained as a partial structure of the siloxane-based resin.

  On the other hand, as an electron transport type CTM, succinic anhydride, maleic anhydride, phthalic anhydride, pyromellitic anhydride, meritic 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-nitro Benzalmalondinitrile, α-cyano-β- (p-cyanophenyl) -2- (p-chlorophenyl) ethylene, 2,7-dinitrofluorene, 2,4,7-trinitroph Luolenone, 2,4,5,7-tetranitrofluorenone, 9-fluorenylidene dicyanomethylenemalononitrile, polynitro-9-fluoronylidenedicyanomethylenemalonodinitrile, picric acid, o-nitrobenzoic acid, p-nitrobenzoic acid Chemical structures such as acid, 3,5-dinitrobenzoic acid, pentafluorobenzoic acid, 5-nitrosalicylic acid, 3,5-dinitrosalicylic acid, phthalic acid, merit acid and the like are contained as a partial structure of the siloxane-based resin.

  In the present invention, the structural unit having preferable charge transport performance is a residue of a charge transport compound that is usually used as described above, and the structural unit represented by the following formula through a carbon atom or silicon atom constituting the charge transport compound. It binds to a linking atom or linking group represented by Z and is contained in the siloxane-based resin through Z.

  In the above general formula, the Z atom is an oxygen atom (O), a sulfur atom (S), or a nitrogen atom (N).

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.)
The structural unit X having charge transport performance is shown as a monovalent group in the formula, but it is cured when the charge transport compound to be reacted with the siloxane resin has two or more reactive functional groups. May be bonded as a bi- or higher-valent crosslink group in the conductive resin, or may be bonded as a pendant group.

  The atoms, that is, the atoms of O, S, and N are formed by the reaction of a hydroxyl group, a mercapto group, an amine group, and an organosilicon compound having a hydroxyl group or a hydrolyzable group, respectively, introduced into the compound having a charge transporting ability. It is a linking group that incorporates a structural unit having charge transport performance as a partial structure in a siloxane-based resin.

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

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

X- (R ₇ -OH) _m
put it here,
X: a structural unit having charge transport performance,
R ₇ : single bond, substituted or unsubstituted alkylene group, arylene group,
m is an integer of 1 to 5.

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

2. Hydrazone compounds

3. Stilbene compounds

4). Benzidine compounds

5). Butadiene compounds

6). Other compounds

  Next, synthesis examples of charge transporting compounds having a hydroxyl group will be described.

  Synthesis of exemplary compound T-1

Step A
In a four-headed Kolben equipped with a thermometer, a condenser, a stirrer, and a dropping funnel, 49 g of Compound (1) and 184 g of phosphorus oxychloride were added and dissolved by heating. From the dropping funnel, 117 g of dimethylformamide was gradually added dropwise, and then the reaction solution temperature was kept at 85 to 95 ° C., followed by stirring for about 15 hours. Next, the reaction solution was gradually poured into a large excess of warm water and then slowly cooled with stirring.

The precipitated crystals were filtered and dried, and then purified by adsorption of impurities with silica gel or the like and recrystallization with acetonitrile to obtain compound (2). Yield was 30 g.
Step B
30 g of compound (2) and 100 ml of ethanol were added to Kolben and stirred. After gradually adding 1.9 g of sodium borohydride, the liquid temperature was kept at 40 to 60 ° C., and the mixture was stirred for about 2 hours. Next, the reaction solution was gradually poured into about 300 ml of water and stirred to precipitate crystals. After filtration, it was sufficiently washed with water and dried to obtain a compound (3). Yield was 30 g.
Synthesis of exemplary compound S-1

Step A
A 300 ml Kolben equipped with a thermometer and a stirrer was charged with 30 g of Cu, 60 g of K ₂ CO ₃ , 8 g of compound (1) and 100 g of compound (2), heated to about 180 ° C. and stirred for 20 hours. . After cooling, the mixture was filtered, and 7 g of compound (3) was obtained by column purification.
Step B
100 ml Kolben equipped with a thermometer, a dropping funnel, an argon gas introducing device and a stirring device was placed in an argon gas atmosphere, and 7 g of compound (3), 50 ml of toluene and 3 g of phosphoryl chloride were added thereto. While stirring at room temperature, 2 g of DMF was slowly added dropwise, and then the temperature was raised to about 80 ° C. and stirred for 16 hours. After cooling to about 70 ° C. warm water, it was cooled. This was extracted with toluene, and the extract was washed with water until the pH of water reached 7. After drying over sodium sulfate and concentrating, column purification gave 5 g of compound (4).
Step C
A 100 ml Kolben equipped with an argon gas introducing device and a stirring device was charged with 1.0 g of t-BuOK and 60 ml of DMF to make an argon gas atmosphere. To this, 2.0 g of compound (4) and 2.2 g of compound (5) were added and stirred at room temperature for 1 hour. This was poured into a large excess of water, extracted with toluene, the extract was washed with water, dried over sodium sulfate, concentrated and purified by column to obtain 2.44 g of compound (6).
Step D
Toluene was put into a 100 ml Kolben equipped with a thermometer, a dropping funnel, an argon gas introducing device and a stirring device to make an argon gas atmosphere. To this was added 15 ml of a hexane solution (1.72M) of n-BuLi, and the mixture was heated to 50 ° C. A solution prepared by dissolving 2.44 g of compound (6) in 30 ml of toluene was added dropwise thereto, and the mixture was kept at 50 ° C. and stirred for 3 hours. After cooling this to -40 degreeC, 8 ml of ethylene oxide was added, and it heated up to -15 degreeC and stirred for 1 hour. Thereafter, the temperature was raised to room temperature, 5 ml of water was added, the mixture was extracted with 200 ml of ether, and the extract was washed with saturated saline. After washing until the washing solution reached pH, it was dried over sodium sulfate, concentrated and column purified to obtain 1.0 g of Compound (7).

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

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

X- (R ₈ -SH) _m
put it here,
X: a structural unit having charge transport performance,
R ₈ : single bond, substituted or unsubstituted alkylene, arylene group,
m is an integer of 1 to 5.

  Among them, typical ones are as follows.

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

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

X- (R ₉ -NR ₁₀ H) _m
put it here,
X: a structural unit having charge transport performance,
R ₉ : single bond, substituted, unsubstituted alkylene, substituted, unsubstituted arylene group,
R ₁₀ : a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group,
m is an integer of 1 to 5.

  Among them, typical ones are as follows.

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 the 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 remaining as a branch or a group causing a crosslinking reaction, and includes a charge transport material. It may be a compound residue.

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

  Moreover, when adding colloidal silica (E), it is preferable to use 1-30 mass parts of (E) with respect to 100 mass of total mass of the said (A) + (B) + (C) + (D) component. .

  The amount of the reactive charge transporting compound (F) that can form a resin layer by reacting with the organosilicon compound or colloidal silica is as follows: (A) + (B) + (C) + (D) It is preferable to use 1 to 500 parts by mass of (F) with respect to 100 parts by mass of the components. When the component (A) + (B) is used beyond the above range, when the component (A) + (B) is small, the crosslinking density of the siloxane resin layer is too small and the hardness is insufficient. On the other hand, if there are too many components (A) + (B), the crosslinking density is too high and the hardness is sufficient, but a brittle resin layer is obtained. A tendency similar to that of the components (A) + (B) is also observed in the excess or deficiency of the colloidal silica component of the component (E). On the other hand, when the amount of the component (F) is small, the charge transport capability of the siloxane resin layer is small, resulting in a decrease in sensitivity and an increase in residual power. When the amount of the component (F) is large, the film strength of the siloxane resin layer tends to be weak. Be looked at.

  The siloxane-based resin having a structural unit with charge transport performance and having a crosslinked structure according to the present invention forms a new chemical bond by adding a catalyst or a crosslinking agent to a monomer, oligomer or polymer having a siloxane bond in the structural unit in advance. In some cases, a three-dimensional network structure may be formed, or a three-dimensional network structure may be formed from a monomer, an ologomer, and a polymer by promoting a siloxane bond by hydrolysis and subsequent dehydration condensation.

  In general, a three-dimensional network structure can be formed by a condensation reaction of a composition having alkoxysilane or a composition having alkoxysilane and colloidal silica.

  The catalyst for forming the three-dimensional network structure includes organic carboxylic acid, nitrous acid, sulfurous acid, aluminate, carbonic acid and thiocyanic acid alkali metal salts, organic amine salts (tetramethylammonium hydroxide, tetramethylammonium acetate). , Tin organic acid salt (stannas octoate, dibutyltin diacetate, dibutyltin dilaurate, dibutyltin mercaptide, dibutyltin thiocarboxylate, dibutyltin malate, etc.), aluminum, zinc octenoic acid, naphthenate, acetylacetone complex Etc.

  Next, representative examples of the antioxidant of the present invention are those in which oxygen is oxidized under the conditions of light, heat, discharge, etc., against an auto-oxidizing substance present in the electrophotographic photoreceptor or on the surface of the photoreceptor. It is a substance that has the property of preventing or suppressing its action. Specifically, the following compound groups can be mentioned.

(1) Radical chain inhibitor ・ Phenolic antioxidant
Hindered phenols and amine antioxidants
Hindered amine
Diallyldiamine
Diallylamine type ・ Hydroquinone type antioxidant (2) Peroxide decomposition agent ・ Sulfur type antioxidant
Thioethers ・ Phosphoric antioxidants
Phosphorous acid 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, and hindered amines are bulky organic compounds near the N atom. A compound having a group. The bulky organic group includes a branched alkyl group, for example, a t-butyl group is preferable.

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

  Two or more types may be used in combination, for example, a combination of (1) a hindered phenol antioxidant and (2) a thioether antioxidant.

  In the present invention, it is more preferable that those having the hindered amine structure in the molecule are good for image quality improvement such as image blur prevention and black spot countermeasures, and in another aspect, the hindered phenol structural unit and the hindered amine structural unit are composed of molecules. Those contained therein are also preferred.

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

In the formula, R ₁ , R ₂ , R ₃ and R ₄ each represents a hydrogen atom, an alkyl group or an aryl group, and Z represents an atomic group necessary for constituting a nitrogen-containing alicyclic ring. Further, _one of R ₁ and R ₂ and R ₃ and R ₄ may be incorporated into Z to give a double bond.

Furthermore, R ₅ represents a branched alkyl group, R ₆ , R ₇ and R ₈ each represents a hydrogen atom, a hydroxy group, an alkyl group or an aryl group, and R ₆ , R ₇ and R ₈ are linked to each other to form a ring. It may be formed.

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

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. Examples of the substituent include an aryl group, Arbitrary things, such as an alkoxy group, a carboxylic acid group, an amide group, a halogen atom, are mentioned.

  Z is an atomic group necessary for constituting a nitrogen-containing alicyclic ring, preferably an atomic group constituting a 5-membered ring or a 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, etc. Examples of each ring include piperidine, piperazine, morpholine, and pyrrolidine.

R ₅ and R ₆ are preferably a tert- or sec-alkyl group having 3 to 40 carbon atoms.

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

An alkyl group or an alkylidene group represented by R ₉ is preferable, and those having 1 to 40 carbon atoms are preferable, and those having 1 to 18 carbon atoms are particularly preferable.

  The content of the hindered phenol-based or hindered amine-based antioxidant in the resin is preferably 0.01 to 25% by mass. If the content is more than 25% by mass, the charge transport ability in the resin layer is lowered, the residual potential is likely to increase, and the film strength may be lowered. More preferably, the content is 0.1 to 10% by mass.

  The antioxidant may be contained in the lower charge generation layer, charge transport layer, intermediate layer or the like as required. The amount of the antioxidant added to these layers is preferably 0.01 to 25% by mass with respect to each layer.

The antioxidant used in the present invention is not particularly limited as long as it satisfies the above conditions, but specific examples are listed below.
(1) Examples of compounds having hindered phenol structural units

(2) Examples of compounds having hindered amine structural units

(3) Compound examples having a hindered amine structural unit and a hindered phenol structural unit

(4) Examples of organophosphorus compounds For example, the following are typical compounds represented by the general formula RO-P (OR) -OR. Here, R represents a hydrogen atom, each substituted or unsubstituted alkyl group, alkenyl group or aryl group.

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

  Examples of the antioxidants that have been commercialized include the following compounds such as “Irganox 1076”, “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 LA67”, “Mark LA62”, “Mark LA68”, “Mark LA63” and more are hindered amines.

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

  The layer structure of the electrophotographic photoreceptor of the present invention is not particularly limited, but a photosensitive layer such as a charge generation layer, a charge transport layer, or a charge generation / charge transport layer and the resin layer of the present invention are coated thereon. As described above, it is preferable to adopt the configuration.

  The charge generating material (CGM) contained in the photosensitive layer of the present invention is formed alone or together with a suitable binder resin. Typical examples of charge generation materials include pyrylium dyes, thiopyrylium dyes, phthalocyanine pigments, anthanthrone pigments, dibenzpyrenequinone pigments, pyranthrone pigments, azo pigments, trisazo pigments, disazo pigments. Pigments, indigo pigments, quinacridone pigments, cyanine pigments, and the like.

  Examples of the charge transport material (CTM) contained in the photosensitive layer include oxazole derivatives, oxadiazole derivatives, thiazole derivatives, thiadiazole derivatives, triazole derivatives, imidazole derivatives, imidazolone derivatives, imidazoline derivatives, bisimidazolidine derivatives, and styryl compounds. , Hydrazone compound, benzidine compound, pyrazoline derivative, stilbene compound, amine derivative, oxazolone derivative, benzothiazole derivative, benzimidazole derivative, quinazoline derivative, benzofuran derivative, acridine derivative, phenazine derivative, aminostilbene derivative, poly-N-vinylcarbazole, Poly-1-vinylpyrene, poly-9-vinylanthracene, etc. are mentioned. These charge transport materials (CTM) are usually combined with a binder. Formation is performed.

  As the binder resin contained in the single layer photosensitive layer, and the charge generation layer (CGL) and charge transport layer (CTL) in the case of a laminated configuration, polycarbonate resin, polyester resin, polystyrene resin, methacrylic resin, acrylic resin, Polyvinyl chloride resin, polyvinylidene chloride resin, polyvinyl butyral resin, polyvinyl acetate resin, styrene-butadiene resin, vinylidene chloride-acrylonitrile copolymer resin, vinyl chloride-maleic anhydride copolymer resin, urethane resin, silicone resin, epoxy Examples thereof include resins, silicon-alkyd resins, phenol resins, polysilane resins, and polyvinyl carbazole.

  In the present invention, the ratio of the charge generation material to the binder resin in the charge generation layer is preferably 1: 5 to 5: 1 by mass ratio. The thickness of the charge generation layer is preferably 5 μm or less, particularly preferably 0.05 to 2 μm.

  The charge transport layer is formed by dissolving the charge transport material and the binder resin in an appropriate solvent, and coating and drying the solution. The mixing ratio of the charge transport material and the binder resin is preferably 3: 1 to 1: 3 by mass ratio.

  The thickness of the charge transport layer is preferably 5 to 50 μm, particularly 10 to 40 μm. When a plurality of charge transport layers are provided, the thickness of the upper layer of the charge transport layer is preferably 10 μm or less and smaller than the total thickness of the charge transport layer provided under the upper layer of the charge transport layer. It is preferable.

  As the solvent or dispersion medium used in the present invention, n-butylamine, diethylamine, ethylenediamine, isopropanolamine, triethanolamine, triethylenediamine, N, N-dimethylformamide, acetone, methyl ethyl ketone, methyl isopropyl ketone, cyclohexanone, benzene, toluene , Xylene, chloroform, dichloromethane, 1,2-dichloroethane, 1,2-dichloropropane, 1,1,2-trichloroethane, 1,1,1-trichloroethane, trichloroethylene, tetrachloroethane, tetrahydrofuran, dioxolane, dioxane, methanol, ethanol , Butanol, isopropanol, ethyl acetate, butyl acetate, dimethyl sulfoxide, methyl cellosolve and the like. Although this invention is not limited to these, Dichloromethane, 1, 2- dichloroethane, methyl ethyl ketone, etc. are used preferably. These solvents may be used alone or as a mixed solvent of two or more.

Next, as the conductive support of the electrophotographic photosensitive member of the present invention,
1) Metal plate such as aluminum plate and stainless steel plate,
2) A thin metal layer such as aluminum, palladium or gold provided on a support such as paper or plastic film by lamination or vapor deposition,
3) What provided the layer of conductive compounds, such as a conductive polymer, an indium oxide, a tin oxide, by application | coating or vapor deposition on support bodies, such as paper or a plastic film, etc. are mentioned.

  As a material for the conductive support used in the present invention, a material obtained by molding a metal material such as aluminum, copper, brass, steel, stainless steel, or other plastic material into a belt shape or a drum shape is mainly used. Among them, aluminum excellent in cost, workability, and the like is preferably used, and a thin cylindrical aluminum base tube that is usually extruded or pultruded is often used.

  As the conductive support used in the present invention, one having an alumite film that has been sealed on the surface thereof may be used. The alumite treatment is usually performed in an acidic bath such as chromic acid, sulfuric acid, oxalic acid, phosphoric acid, boric acid, sulfamic acid, etc., but anodizing treatment in sulfuric acid gives the most preferable result. In the case of anodizing in sulfuric acid, the sulfuric acid concentration is preferably 100 to 200 g / l, the aluminum ion concentration is 1 to 10 g / l, the liquid temperature is about 20 ° C., and the applied voltage is preferably about 20 V. It is not limited. The average film thickness of the anodized film is usually 20 μm or less, particularly preferably 10 μm or less.

  Next, as a coating processing method for producing the electrophotographic photosensitive member of the present invention, coating processing methods such as dip coating, spray coating, and circular amount regulation type coating are used. In order to prevent the lower layer film from being dissolved as much as possible, and in order to achieve uniform coating processing, it is preferable to use a coating processing method such as spray coating or circular amount regulation type (a circular slide hopper type is a typical example). The spray coating is described in detail in, for example, JP-A-3-90250 and JP-A-3-269238, and the circular amount-regulating coating is described in detail in, for example, JP-A-58-189061. Yes.

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

  Examples of the material for the intermediate layer include casein, polyvinyl alcohol, nitrocellulose, ethylene-acrylic acid copolymer, polyvinyl butyral, phenol resin polyamides (nylon 6, nylon 66, nylon 610, copolymer nylon, alkoxymethylated nylon, etc. ), An intermediate layer using polyurethane, gelatin and aluminum oxide, or a curable intermediate layer using a metal alkoxide, an organometallic chelate, a silane coupling agent, as disclosed in JP-A-9-68870, and the like. The film thickness of the intermediate layer is preferably from 0.1 to 10 μm, particularly preferably from 0.1 to 5 μm.

  The support may be in the form of a drum, sheet or belt, as long as it is suitable for the electrophotographic apparatus to be applied.

  The electrophotographic photosensitive member of the present invention can be applied to general electrophotographic apparatuses such as copying machines, laser printers, LED printers, and liquid crystal shutter printers, and further displays, recordings, and light printings using electrophotographic technology. It can be widely applied to apparatuses such as plate making and facsimile.

  FIG. 1 shows a cross-sectional view of a color image forming apparatus as an example of an image forming apparatus equipped with the electrophotographic photosensitive member of the present invention. However, the present invention is not limited to color image formation, and can also be applied to monochrome image formation.

  In FIG. 1, reference numeral 10 denotes a photosensitive drum (photosensitive member) which is an image bearing member. An organic photosensitive layer is coated on the drum, and the resin layer of the present invention is coated thereon. Is driven and rotated. Reference numeral 12 denotes a scorotron charger, which gives a uniform charge to the circumferential surface of the photosensitive drum 10 by corona discharge. Prior to the charging by the charger 12, in order to eliminate the history of the photoconductor in the previous image formation, exposure by the exposure unit 11 using a light emitting diode or the like may be performed to neutralize the peripheral surface of the photoconductor.

  After uniform charging of the photoreceptor, the image exposure unit 13 performs image exposure based on the image signal. The image exposure unit 13 in this figure uses a laser diode (not shown) as an exposure light source. Scanning on the photosensitive drum is performed by light whose optical path is bent by the reflection mirror 132 through the rotating polygon mirror 131, the fθ lens, and the like, and an electrostatic latent image is formed.

  The electrostatic latent image is then developed by the developing device 14. At the periphery of the photosensitive drum 10, there are provided developing devices 14 each containing a developer composed of toner such as yellow (Y), magenta (M), cyan (C), and black (K) and a carrier. The development of the first color is performed by a developing sleeve 141 that contains a magnet and rotates while holding the developer. The developer is composed of, for example, a carrier in which ferrite is used as a core and an insulating resin is coated around it, and a toner containing polyester as a main material and a pigment according to color, a charge control agent, silica, titanium oxide and the like. The developer is regulated to a layer thickness of 100 to 600 μm on the developing sleeve 141 by a layer forming means (not shown) and is transported to the developing area for development. At this time, normally, development is performed by applying a direct current and / or alternating current bias voltage between the photosensitive drum 10 and the developing sleeve 141.

  In color image formation, after the first color visualization is completed, the second color image formation process is started, and uniform charging is performed again by the scorotron charger 12, and the second color latent image is converted into the image exposure unit 13. Formed by. For the third and fourth colors, the same image forming process as that for the second color is performed, and a four-color visible image is formed on the circumferential surface of the photosensitive drum 10.

  On the other hand, in the monochrome electrophotographic apparatus, the developing device 14 is composed of one type of black toner, and an image can be formed by one development.

  The recording paper P is fed to the transfer area by the rotation operation of the paper feed roller 17 at the time when the transfer timing is ready.

  In the transfer area, a transfer roller (transfer device) 18 is pressed against the peripheral surface of the photosensitive drum 10 in synchronism with the transfer timing, and the fed recording paper P is sandwiched to transfer the multicolor images all at once. Is done.

  Next, the recording paper P is neutralized by a separation brush (separator) 19 brought into a pressure contact state almost simultaneously with the transfer roller, separated by the peripheral surface of the photosensitive drum 10 and conveyed to the fixing device 20, and pressed against the heat roller 201. After the toner is welded by heating and pressurizing the roller 202, the toner is discharged to the outside of the apparatus via the discharge roller 21. The transfer roller 18 and the separation brush 19 are retracted and separated from the peripheral surface of the photosensitive drum 10 after the recording paper P has passed to prepare for the next toner image formation.

  On the other hand, the photosensitive drum 10 from which the recording paper P has been separated removes and cleans residual toner by the pressure contact of the blade 221 of the cleaning device 22, and is subjected again to charge removal by the exposure unit 11 and charging by the charger 12, and the next image. Enter the formation process. When a color image is formed on the photosensitive member in an overlapping manner, the blade 221 moves immediately after cleaning the photosensitive member surface and retracts from the peripheral surface of the photosensitive drum 10.

  Reference numeral 30 denotes a detachable process cartridge in which a photoconductor, a charger, a transfer device / separator, and a cleaning device are integrated.

  As an electrophotographic image forming apparatus, the above-described photosensitive member and components such as a developing device and a cleaning device are integrally coupled as a process cartridge, and this unit may be configured to be detachable from the apparatus main body. good. In addition, a process cartridge is formed by integrally supporting at least one of a charger, an image exposure device, a developing device, a transfer or separation device, and a cleaning device together with a photosensitive member, and a single unit that is detachable from the apparatus main body. It is good also as a structure which can be attached or detached using guide means, such as a rail of an apparatus main body.

  Process cartridges generally include an integral cartridge and a separate cartridge as described below. The integrated cartridge is a structure in which at least one of a charging device, an image exposure device, a developing device, a transfer or separation device, and a cleaning device is integrally formed with a photosensitive member, and is detachable from the apparatus main body. Is a charger, an image exposure device, a developing device, a transfer or separation device, and a cleaning device that are configured separately from the photoconductor. When integrated, it is integrated with the photoreceptor. The process cartridge in the present invention includes both types of cartridges.

  When the image forming apparatus is used as a copying machine or a printer, image exposure is performed by irradiating a photosensitive member with reflected light or transmitted light from a document, or by reading a document with a sensor and converting a laser beam in accordance with this signal. Scanning, driving the LED array, or driving the liquid crystal shutter array and irradiating the photosensitive member with light are performed.

  When used as a facsimile printer, the image exposure unit 13 performs exposure for printing received data.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated in detail, the aspect of this invention is not limited to this.

A photoreceptor was prepared as follows.
Examples 1-9
<Intermediate layer>
Polyamide resin (Amilan CM-8000: manufactured by Toray Industries, Inc.) 60 g
1600 ml of methanol
1-butanol 400ml
Were mixed and dissolved to prepare an intermediate layer coating solution. This coating solution was applied onto a cylindrical aluminum substrate by a dip coating method to form an intermediate layer having a thickness of 0.3 μm.
<Charge generation layer>
Titanyl phthalocyanine 60g
700g of silicone resin solution
(KR5240, 15% xylene-butanol solution: manufactured by Shin-Etsu Chemical Co., Ltd.)
2-butanone 2000ml
Were mixed for 10 hours using a sand mill to prepare a charge generation layer coating solution. This coating solution was applied onto the intermediate layer by a dip coating method to form a charge generation layer having a thickness of 0.2 μm.
<Charge transport layer>
Charge transport material (D1) 200g
300g of bisphenol Z-type polycarbonate
(Iupilon Z300: manufactured by Mitsubishi Gas Chemical Company)
1,2-dichloroethane 2000ml
Were mixed and dissolved to prepare a charge transport layer coating solution. This coating solution was applied onto the charge generation layer by a dip coating method to form a charge transport layer having a thickness of 20 μm.
<Protective layer>
On top of this, molecular sieve 4A was added to 10 parts by mass of polysiloxane composed of 80 mol% of methylsiloxane units and 20 mol% of methyl-phenylsiloxane units, and allowed to stand for 15 hours for dehydration treatment. This resin was dissolved in 10 parts by mass of toluene, and 5 parts by mass of methyltrimethoxysilane and 0.2 parts by mass of dibutyltin acetate were added thereto to make a uniform solution.

  To this, 6 parts by mass of dihydroxymethyltriphenylamine (Exemplary Compound T-1) and 0.3 parts by mass of the antioxidants listed in Table 1 were added and mixed. This solution was applied to a dry film thickness of 1 μm, and 120 ° C. The photoconductors of Examples 1 to 9 having the resin layer of the present invention were produced by heat curing for 1 hour.

Example 11
A photoconductor was prepared in the same manner as in Example 1 except that the amount of the antioxidant in Example 1 was changed from 0.3 part by mass to 0.03 part by mass.
Comparative Example 1
A photoconductor was prepared in the same manner as in Example 1 except that the antioxidant was not used in Example 1.
Comparative Example 3
When a photoconductor was prepared in the same manner as in Example 1 except that dihydroxymethyltriphenylamine (Exemplary Compound T-1) in the protective layer was not used in Example 1, precipitation of the antioxidant was observed and an initial image was observed. Black spots occurred.
Characteristic Evaluation The evaluation was carried out by mounting the above photoreceptor on an apparatus for forming an image by a digital method.

  In other words, the Konica digital copying machine “Konica 7050” was modified and mounted on an evaluation machine with an appropriate exposure amount, the initial charging potential was set to −650 V, and A4 paper was used in an ambient temperature environment at 50,000. Copies were made repeatedly, and the fluctuations in the exposed portion potential (VL) and unexposed portion potential (VH) after 50,000 copies, the measurement of film thickness loss, and the image quality evaluation were performed.

  As a result, as shown in Table 1, the photoreceptors obtained in Examples 1 to 5, 7 to 9, and 11 are free from defects such as fogging, image blurring, image flow, filming, scratches, black spots, and the like. A high-resolution image was obtained with a solid black portion having a reflection density as high as 1.2 or higher. On the other hand, it can be seen that the photoreceptors of Comparative Examples 1 and 3 are poor in practicality because of their poor potential variation and image characteristics.

  For the measurement of the image density, the density of the solid black image was measured using a densitometer “RD-918” (manufactured by Macbeth Co., Ltd.). Ten thousand sheets of fog were visually confirmed. The presence or absence of image blur was visually evaluated.

Image density ◎: 1.2 or higher: Good
○: Less than 1.2 to 0.8: Level that does not cause a problem in practical use
X: Less than 0.8: a level causing a practical problem.

Fog ◎: No fogging
○: Occasional fogging, but no problem in practical use
×: Continuous fogging occurred.

Image blur
A: Occurrence of 5 or less of 50,000 sheets
○: Generation of 6 to 20 of 50,000 sheets
X: 21 or more out of 50,000 sheets.

The evaluation of the black spots was performed by measuring the particle diameter and number of black spots using an image analyzer “Omnikon 3000” (manufactured by Shimadzu Corporation), measuring the grain diameter and number of black spots, 0.1 mm The number of the above black spots was determined per 100 cm ² . The criteria for black spot evaluation are as shown below.

Black spot of 0.1mm or more
◎: 1 piece / 100 cm ² or less: Good
○: 2 to 3 pieces / 100 cm ² : a level with no practical problem
×: 4/100 cm ² or more: There is a problem in practical use.

  The thickness loss of the photoreceptor was determined from the difference in film thickness between the first copy and the 50,000th photosensitive layer.

  The results are shown in Table 1.

  As is clear from the results in Table 1, Examples 1 to 11 within the present invention have good characteristics, whereas Comparative Examples 1, 2, and 3 outside the present invention have potential fluctuation amounts or image evaluation. It turns out that it is inferior.

  According to the present invention, an electrophotographic photosensitive member that retains the performance of a resin layer containing a siloxane-based resin having a cross-linked structure over a long period of time, has good charging characteristics, is highly sensitive, has no fluctuation in charging potential even after long-term use, and has good image characteristics. An image forming apparatus, an image forming method, and a process cartridge using the same can be provided.

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

Explanation of symbols

10 Photosensitive drum (or photoconductor)
DESCRIPTION OF SYMBOLS 11 Exposure part using light emitting diode etc. 12 Charging device 13 Image exposure device 14 Developing device 17 Paper feed roller 18 Transfer roller (transfer device)
19 Separation brush (separator)
DESCRIPTION OF SYMBOLS 20 Fixing device 21 Paper discharge roller 22 Cleaning device 30 Detachable process cartridge in which a photoconductor, a charger, a transfer device / separator, and a cleaning device are integrated

Claims (10)

In an electrophotographic photosensitive member having at least a photosensitive layer and a resin layer on a conductive support, the resin layer has a structural unit containing a triarylamine having charge transport performance represented by the following general formula (1), and, the number organosilicon compound of 1 to 3 hydroxyl groups or hydrolyzable groups, obtained by reacting a compound containing the structural unit consists of a layer containing the siloxane-based resin having a crosslinked structure, the resin An electrophotographic photoreceptor, wherein the layer is provided on the uppermost layer of the photoreceptor and contains an antioxidant.

(In the formula, X is a structural unit containing a triarylamine having charge transporting performance, a group bonded to Si in the formula through a carbon atom constituting the structural unit, Z is O, S, NR , R is H or a monovalent organic group.) The siloxane-based resin is a resin obtained by reacting at least a hydroxyl group or an organosilicon compound having 3 hydrolyzable groups with a compound containing a hydroxyl group-containing structural unit having charge transport performance. The electrophotographic photosensitive member according to claim 1. The electrophotographic photosensitive member according to claim 1, wherein the antioxidant is a hindered phenol antioxidant. The electrophotographic photosensitive member according to claim 1, wherein the antioxidant is a hindered amine antioxidant. The electrophotographic photosensitive member according to claim 1, wherein the antioxidant is an organic phosphorus compound-based antioxidant. The electrophotographic photosensitive member according to claim 1, wherein the antioxidant is an organic sulfur compound-based antioxidant. 3. The electrophotographic photoreceptor according to claim 1, wherein the resin layer is an outermost layer, and Z in the general formula (1) is an oxygen atom (O). An image forming method comprising the steps of charging, image exposure, development, transfer, and cleaning using the electrophotographic photosensitive member according to claim 1. 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. The process cartridge used for image formation which uses a photoconductor and passes through processes of charging, image exposure, development, transfer, and cleaning, and the electrophotographic photoconductor, the charger, and the image exposure according to any one of claims 1 to 7. A process cartridge manufactured by combining at least one of a developing device, a developing device, a transfer device, and a cleaning device.

Images