JP2000338704A - Image forming method, image forming device and process cartridge - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the surface hardness, wear and scuffing resistances of a photoreceptor, to repeatedly obtain a good image, to enhance resolving power and to prevent the occurrence of moire by forming a surface protecting layer containing a siloxane resin having a structural unit with electric charge transferring performance and also having a crosslinked structure. SOLUTION: The surface protecting layer of a photoreceptor used contains a siloxane resin having a structural unit with electric charge transferring performance and also having a crosslinked structure. A crosslinkable (curable) siloxane resin for forming the above siloxane resin is produced by a known method using an organosilicon compound having a hydroxyl group or a hydrolyzable group. The structural unit with electric charge transferring performance is a group which imparts electric charge transferring ability and exhibits such a property that the partial structure itself has drift mobility of electrons or holes.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an image forming method, an image forming apparatus, and a process cartridge used as a color copying machine or a color printer.

[0002]

2. Description of the Related Art In recent years, an organic photoconductor containing an organic photoconductive substance has been widely used as an electrophotographic photoconductor. Organic photoreceptors are advantageous in that they can easily develop materials corresponding to various exposure light sources from visible light to infrared light, can select materials that do not cause environmental pollution, and have low manufacturing costs. Has low mechanical strength, and may cause deterioration or scratches on the surface of the photoreceptor when copying or printing a large number of sheets.

[0003] Such a photoreceptor is generally prepared by depositing an organic charge generating substance on a conductive support made of aluminum or an aluminum alloy, or mixing an organic charge generating substance and an organic polymer resin in a solvent. A charge generation layer is formed by applying a coating solution, and a charge transport layer is formed by applying a coating solution obtained by mixing an organic charge transport material and an organic polymer resin in a solvent. Is done.

In general, in an electrophotographic image forming apparatus, after a photosensitive member is uniformly charged, an electrostatic latent image is formed by erasing the charge imagewise by exposure, and the electrostatic latent image is formed by toner. The toner is transferred and fixed on paper or the like.

As described above, the surface of the electrophotographic photoreceptor is charged by a charger, a developing device, a transfer device, a cleaning device, and the like.
Since electrical and mechanical external forces are directly applied, durability against them is required. In particular, it is required to have mechanical durability against occurrence of abrasion and scratches on the surface of the photoreceptor due to rubbing, contamination of foreign matter, film peeling due to impact during paper jam processing, and the like. Above all, the durability against the damage and the peeling of the film due to the impact is lower than that of the inorganic photoreceptor, and the improvement is required.

Regarding mechanical durability, BPZ polycarbonate is applied to the surface of the organic photoreceptor as a binder (binder resin).
It has been reported that the use of the compound improves surface abrasion characteristics and toner filming characteristics. Japanese Patent Application Laid-Open No. Hei 6-118681 reports that a curable silicone resin containing colloidal silica is used as a surface protective layer of a photoreceptor.

However, a photoreceptor using a bisphenol Z type polycarbonate binder still lacks abrasion resistance properties and does not have sufficient durability. On the other hand, in the surface layer of the curable silicone resin containing colloidal silica, the abrasion resistance is improved, but the electrophotographic properties after repeated use are insufficient, and fogging and image blur are liable to occur. Not enough.

As a method of improving such a defect, Japanese Patent Application Laid-Open No. 9-124943 and Japanese Patent Application Laid-Open No. 9-190004
In Japanese Patent Application Laid-Open No. H11-264, a photoreceptor having a resin layer as a surface layer in which an organic silicon-modified hole transporting compound is bound in a curable organic silicon-based polymer is proposed. However, this resin layer is liable to generate fog and image blur in a high humidity environment and does not have sufficient durability. Further, such a curable organosilicon compound film has high abrasion resistance, but is easily damaged or peeled off by an external impact, and has insufficient surface strength and adhesiveness.

[0009] With the recent development of digital technology, image exposure using coherent light sources such as laser light has become the mainstream in electrophotographic image forming methods, and the generation of interference moiré suitable for these coherent light sources has occurred. It has been desired to develop an electrophotographic photoreceptor which does not have high abrasion resistance, is not scratched or peeled off by an external impact, and does not cause image blur.

In recent years, in particular, colorization has been advanced in image forming apparatuses. However, color image forming methods having high practicality can be roughly classified into transfer drum type, intermediate transfer type, and KNC type (multiple type). Development batch transfer),
There are four types of tandem type.

Of course, the above is a name from a certain point of view, and for example, there are those of the tandem type and the intermediate transfer type, and those of the type directly transferring to the recording material. But,
Among them, the tandem system, that is, a color image forming apparatus in which each color image is formed by each image forming unit and sequentially transferred, has a wide variety of usable recording materials, high full-color quality, and high speed. A full-color image is obtained. In particular, the characteristic that a full-color image can be obtained at a high speed is an advantage that cannot be seen elsewhere. However, there are still performance problems such as deterioration of image quality when used for a long time.

[0012]

SUMMARY OF THE INVENTION An object of the present invention is to provide a so-called tandem type photoconductor for forming a color image which can solve the above problems, and has a high surface hardness.
High abrasion resistance and scratch resistance, electrophotographic characteristics during repeated use are stable even under high temperature and high humidity, so good images can be repeatedly obtained, high resolution and no image blur, digital image by laser light etc. An object of the present invention is to provide an electrophotographic photoreceptor which does not generate moire even when forming a photosensitive drum, and a process cartridge and an image forming apparatus using the photoreceptor.

[0013]

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

[1] A photosensitive member in which a photosensitive layer and a surface protective layer are sequentially laminated on a conductive support, a charging unit for applying a charge to the surface of the photosensitive member, and a charging area of the photosensitive member Forming an electrostatic latent image on the surface of the photoreceptor by using the charging unit and the image exposing unit, and forming a colored toner image corresponding to the electrostatic latent image on the surface of the photoreceptor. And an image forming unit provided with transfer means for transferring a toner image formed on the photoconductor onto a recording material, and cleaning means for removing residual toner on the surface of the photoconductor. In a tandem type image forming apparatus in which a plurality of arrays are arranged and each toner image formed using a toner whose color is changed for each image forming unit is sequentially transferred to a recording material to form an image, the surface protective layer of the photoconductor is Has charge transport performance An image forming apparatus comprising a siloxane-based resin having a structural unit and having a crosslinked structure.

[2] A crosslinked structure obtained by reacting an organosilicon compound having a hydroxyl group or a hydrolyzable group with a compound containing a hydroxyl group and a structural unit having charge transportability, wherein the surface protective layer of the electrophotographic photosensitive member is The image forming apparatus according to [1], which is a layer containing a siloxane resin having the following formula:

[3] The image forming apparatus according to [1], wherein the surface protective layer contains an antioxidant.

[4] The image forming apparatus according to [3], wherein the antioxidant contains a hindered amine or a hindered phenol structural unit.

[5] Using the image forming apparatus described in [1], charge, image exposure, development,
An image forming method, comprising a step of sequentially transferring a toner image formed through the steps of transfer, separation and cleaning to a recording material.

[6] The photosensitive member used in the image forming apparatus described in [1] is combined with at least one of a charging unit, an image exposing unit, a developing unit, a transfer or separating unit, and a cleaning unit. Removable process cartridge.

A so-called tandem type color image forming apparatus, that is, a photoreceptor having a photosensitive layer on a conductive support, charging means for applying a charge to the surface of the photoreceptor, and a charging area for the photoreceptor An image exposure unit that irradiates light, and an electrostatic latent image is formed on the surface of the photoconductor by the charging unit and the image exposure unit; and a colored toner image corresponding to the electrostatic latent image is formed on the surface of the photoconductor. A plurality of image forming units each including a developing unit for forming, a transfer unit for transferring a toner image formed on the photoconductor to a recording material, and a cleaning unit for removing residual toner on the surface of the photoconductor; In an image forming apparatus in which toner images formed by arranging and changing the color of each image forming unit are sequentially transferred to a recording material to form an image, the reason why the surface protective layer is charged transport as in the present invention is as follows. It has a structural unit having an ability or and good to use a photosensitive member containing a siloxane-based resin having a crosslinked structure was not clear.

As a result of intensive studies, the present inventors have found the following facts.

In the tandem system, four photoconductors are required for each color of yellow, magenta, cyan, and black, and four photoconductors are contacted with each photoconductor, for example, a developer, a cleaning blade, a transfer belt, and a separator. The two photoconductors are rubbed, and are subjected to a deterioration effect by ozone and active oxygen generated from the charger. The big problem in that case is
Usually, the four photoconductors are not evenly worn or deteriorated. In particular, as the number of repetitions increases, the performance difference due to wear and deterioration of each photoconductor increases.

However, when a highly durable silicon-based resin surface protective layer is provided as in the present invention, the amount of wear is extremely low, and the four photoconductors maintain substantially the same film thickness as the initial state. Further, deterioration due to ozone or the like is extremely small, and therefore, there is also a very small difference in characteristics among the photosensitive members over a long period of time. As a result, there is no change in the color balance even in the environment, aging, repeated use, especially under high temperature and high humidity, and thus the original high performance can be maintained for a long time.

It should be noted that the effect of the present invention can be obtained by minimizing the variation between image forming units, so that the effect is exhibited in both the intermediate transfer system and the system for directly transferring to a recording material. Not even.

The present invention will be described in more detail.

The crosslinkable (also referred to as curable) siloxane resin for forming the siloxane-based resin having a structural unit having a charge transporting property and having a crosslinked structure used in the present invention is prepared by a known method, It is produced using an organosilicon compound having a hydroxyl group or a hydrolyzable group.
The organosilicon compound has a structure of any of the following general formulas (A) to (D).

[0027]

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(In the formula, R _{1 to} R ₆ each represent an organic group in which carbon is directly bonded to silicon in the formula, and Z represents a hydroxyl group or a hydrolyzable group.) In the case of a decomposable group, examples of the hydrolyzable group include a methoxy group, an ethoxy group, a methylethylketoxime group, a diethylamino group, an acetoxy group, a propenoxy group, a propoxy group, a butoxy group and a methoxyethoxy group. 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, β- (3,4-epoxycyclohexyl) ethyl, γ-acryloxypropyl, γ
-A (meth) acryloyl group containing methacryloxypropyl, a hydroxyl group such as γ-hydroxypropyl and 2,3-dihydroxypropyloxypropyl, a vinyl group such as vinyl and propenyl, a mercapto group such as γ-mercaptopropyl, Amino-containing groups such as γ-aminopropyl, N-β (aminoethyl) -γ-aminopropyl, and γ-chloropropyl, 1,1,1-trifluorofluoropropyl, nonafluorohexyl, perfluorooctylethyl, etc. Examples include a halogen group, other nitro and cyano-substituted alkyl groups, and the like. Further, R _{1 to} R ₆ may have the same or different organic groups.

In the present invention, the organosilicon compound used as a raw material of the curable siloxane resin forming a siloxane-based resin having a structural unit having a charge transporting property and having a cross-linked structure is generally bonded to a silicon atom. When the number n of the hydrolyzable groups is 1, the polymerization reaction of the organosilicon compound is suppressed. When n is 2, 3 or 4, a polymerization reaction is likely to occur, and especially when 3 or 4, the crosslinking reaction can be advanced 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 of the curable resin, a hydrolysis condensate obtained by hydrolyzing the organosilicon compound under an acidic condition or a basic condition to form an oligomer or a polymer can also be used.

The curable siloxane resin of the present invention is, as described above, an oligomer or polymer having a siloxane bond by previously polymerizing an organosilicon compound.
Further, it means a resin capable of forming a three-dimensional network structure by polymerization or crosslinking reaction and curing. That is, it means a siloxane resin formed by promoting a siloxane bond by a hydrolysis reaction and subsequent dehydration condensation of an organosilicon compound having a siloxane bond, and resulting siloxane resin.

Further, the surface layer may be a resin layer in which colloidal silica having a hydroxyl group or a hydrolyzable group is contained in a curable siloxane resin, and silica particles are incorporated in a part of a crosslinked structure.

The definition of the charge transport performance in the present invention is as follows.
It can be expressed as that a detection current due to charge transport can be obtained by a known method capable of detecting the charge transport ability of the ordinary Time-Of-Flight method.

In the present invention, a structural unit having a charge transporting ability is one in which the partial structure itself has the property of having electron or hole drift mobility (charge transporting ability imparting group).
It is. The siloxane resin used in the present invention is a resin which has a compound used as a charge transporting substance (hereinafter also referred to as a charge transporting compound or CTM) as a partial structure or can react with this to form a partial structure. .

Examples of the charge transporting compound include hole transporting CTMs: xazole, oxadiazole, thiazole, triazole, imidazole, imidazolone, imidazoline, bisimidazolidin, styryl, hydrazone, benzidine, pyrazoline, stilbene, amine, Oxazolone, benzothiazole, benzimidazole,
Quinazoline, benzofuran, acridine, phenazine,
It has a chemical structure such as aminostilbene, poly-N-vinylcarbazole, poly-1-vinylpyrene, and poly-9-vinylanthracene.

On the other hand, electron transport type CTM includes 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 structure such as 5-dinitrobenzoic acid, pentafluorobenzoic acid, 5-nitrosalicylic acid, 3,5-dinitrosalicylic acid, phthalic acid, and melitic acid.

In the present invention, preferred charge-transporting groups include the commonly used charge-transporting compounds as described above, and the charge-transporting compound may have a partial structure by way of a carbon atom constituting the charge-transporting compound. Embedded image in the curable siloxane resin via a linking atom or a linking group of Y in the following formula via a carbon atom of the compound having
Alternatively, it is incorporated.

[0038]

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X is a charge-transporting ability-imparting group, which is a group bonded to Y in the formula via a carbon atom constituting the imparting group;
Is a divalent or higher valent atom or group excluding adjacent bonding atoms (Si and C).

However, when Y is a trivalent or higher atom, the bond of Y other than Si and C in the above formula is bonded to any constituent atom in the curable resin capable of bonding, or It has a structure (group) linked to other atoms and molecular groups.

In the compound represented by the above structural formula, an oxygen atom (O), a sulfur atom (S), and a nitrogen atom (N) are particularly preferable as the Y atom. In the case of a nitrogen atom (N), it is NR, and R represents a hydrogen atom or a monovalent organic group.

The charge transport-imparting group X is shown as a monovalent group in the above formula, but the charge transport compound to be reacted with the siloxane curable resin has two or more reactive functional groups. May be bonded as a divalent or higher valent crosslink group in the curable resin, or may simply be bonded as a pendant group.

The above-mentioned atoms, ie, O, S, and N atoms, are formed by the reaction of a hydroxyl group, a mercapto group, or an amine group introduced into a compound having a charge transporting ability with an organic silicon compound having a hydroxyl group or a hydrolyzable group. It is a linking group that is formed and incorporates a charge transport compound into the curable siloxane resin as a partial structure.

Next, the charge transporting compound having a hydroxyl group, a mercapto group and an amine group will be described more specifically.

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, typically, a charge transporting compound represented by the following general formula that can form a siloxane-based resin layer by bonding with an organosilicon compound can be given, but is not limited to the following structure. Any compound having a charge transporting ability and a hydroxyl group may be used.

X- (R ₇ -OH) _mm ≧ 1 wherein X: a group for imparting charge transport ability, R ₇ : a bond, each substituted or unsubstituted alkylene group or arylene group, m: 1 to 5 It is an integer.

Among them, the following are typical ones. For example, a triarylamine-based compound has a triarylamine structure such as triphenylamine as a charge transporting ability-imparting group (X), and has an alkylene or arylene group extended from a carbon atom constituting X or extended from X. Is a compound having a hydroxyl group.

1. Triarylamine compounds

[0049]

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2. Hydrazine compounds

[0051]

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3. Stilbene compounds

[0053]

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4. Benzidine compound

[0055]

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5. Butadiene compound

[0057]

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6. Other compounds

[0059]

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Next, a synthesis example of a compound having a charge transporting ability having a hydroxyl group will be described.

Synthesis of Exemplified Compound T-1

[0062]

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Step (A) In a four-headed kolben equipped with a thermometer, a condenser, a stirrer and a dropping funnel, 49 g of the compound (1) and phosphorus 184 chloride were added.
g was added and dissolved by heating. 117 g of dimethylformamide was gradually added dropwise from the dropping funnel.
The mixture was kept at ９５95 ° C. and stirred for about 15 hours. Next, the reaction solution was gradually poured into a large excess of warm water, and then slowly cooled with stirring.

After the precipitated crystals were filtered and dried, they were purified by adsorption of impurities using silica gel or the like and recrystallization with acetonitrile to obtain Compound (2). Yield 30
g.

Step (B) 30 g of the compound (2) and 100 ml of ethanol were charged into a kolben and stirred. After gradually adding 1.9 g of sodium borohydride, the solution was kept at 40 to 60 ° C. and 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, the resultant was sufficiently washed with water and dried to obtain a compound (3). The yield was 30 g.

Synthesis of Exemplified Compound S-1

[0067]

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Step (A) In a 300 ml Kolben equipped with a thermometer and a stirrer, C was added.
Then, 30 g of u, 60 g of K ₂ CO ₃ , 8 g of compound (1) and 100 g of compound (2) were added, and the mixture was heated to about 180 ° C. and stirred for 20 hours. After cooling, the mixture was filtered and purified by column to obtain 7 g of compound (3).

Step (B) A 100 ml Kolben equipped with a thermometer, a dropping funnel, an argon gas introducing device and a stirrer was placed in an argon gas atmosphere, and 7 g of the compound (3), 50 ml of toluene, and 3 g of phosphoryl chloride were added thereto. While stirring at room temperature, D
2 g of MF was slowly added dropwise, and then the temperature was raised to about 80 ° C. and the mixture was stirred for 16 hours. The mixture was poured into warm water of about 70 ° C. and cooled. This was extracted with toluene, and the extract was washed with water until the pH of the water reached 7. After drying over sodium sulfate, the mixture was concentrated and purified by column to obtain 5 g of compound (4).

Step (C) 100 ml with an argon gas introducing device and a stirring device
1.0 g of t-BuOK and 60 ml of DMF were charged into the Kolben, and the atmosphere was changed to an argon gas atmosphere. Compound (4)
2.0 g and 2.2 g of the compound (5) were added, and the mixture was 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,
After concentration, column purification was performed, and 2.44 g of compound (6) was obtained.
I got

Step (D) Toluene was charged into a 100 ml colben equipped with a thermometer, a dropping funnel, an argon gas introducing device and a stirrer to make an argon gas atmosphere. To this, 15 ml of a hexane solution of n-BuLi (1.72 M) was added, and the mixture was heated to 50 ° C. To this, 2.44 g of compound (6) was added in 30 ml of toluene.
The dissolved liquid was added dropwise, and the mixture was stirred at 50 ° C. for 3 hours. After cooling to −40 ° C., 8 ml of ethylene oxide was added, the temperature was raised to −15 ° C., and the mixture was stirred for 1 hour.
Thereafter, the temperature was raised to room temperature, 5 ml of water was added, and ether 2 was added.
After extraction with 00 ml, the extract was washed with saturated saline.
After washing the washing solution to pH, it was dried over sodium sulfate, concentrated and purified by column to obtain 1.0 g of compound (7).

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 may be used as long as it has a charge transporting ability and a mercapto group.

X- (R ₈ -SH) _mm ≧ 1 wherein X is a charge-transporting group, R _{8 is a} bond, each substituted or unsubstituted alkylene or arylene group, and m is an integer of 1 to 5. It is.

Among them, the following are typical ones.

[0076]

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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, a charge transporting compound represented by the following general formula that can form a resin layer by bonding to an organosilicon compound can be typically given. However, the compound is not limited to the following structure, and may be a compound having a charge transporting ability and having an amino group.

X- (R ₉ -NR ₁₀ H) _mm ≧ 1 wherein X: charge-transporting group, R ₉ : bond, each substituted or unsubstituted alkylene or arylene group, R ₁₀ : hydrogen atom And each substituted or unsubstituted alkyl group or aryl group, and m is an integer of 1 to 5.

Among them, the following are typical ones.

[0081]

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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 remaining as a branch, a group causing a crosslinking reaction, or a compound residue containing a charge transport substance.

Raw materials for forming the curable siloxane resin: The composition ratio of the above-mentioned general formulas (A) to (D) (hereinafter referred to as (A) to (D)) is as follows: organosilicon compound: (A) +
(C) + (D) component 0.05 per mole of (B) component
It is preferable to use 1 to 1 mol. When colloidal silica (E) is added, the above (A) + (B) + C) +
It is preferable to use 1 to 30 parts by weight of (E) based on 100 parts by weight of the total weight of the component (D).

When the reactive charge transporting compound (F) capable of forming a resin layer by reacting with the organosilicon compound or colloidal silica is added, the above (A) +
It is preferable to use 1 to 500 parts by weight of (F) based on 100 parts by total weight of the components (B) + C) + (D).
On the other hand, when the amount of the components (A) and (B) is small, the siloxane-based resin layer may have 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 (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 ability of the siloxane-based resin layer is small, causing a decrease in sensitivity and an increase in residual charge. When the amount of the component (F) is large, the film strength of the siloxane resin layer tends to be weak. Is seen.

The siloxane-based resin having a structural unit having charge transporting ability and having a crosslinked structure according to the present invention is characterized in that a monomer or an oligomer having a siloxane bond in the structural unit is added with a catalyst or a crosslinking agent to form a new chemical bond. In some cases, a three-dimensional network structure may be formed, and a three-dimensional network structure may be formed from an oligomer or polymer in which a siloxane bond has been promoted in advance by a hydrolysis reaction and subsequent dehydration condensation.

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 hydroxide, etc.). Methylammonium 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 And acetylacetone complex compounds.

Further, an antioxidant having a hindered phenol, hindered amine, thioether or phosphite partial structure can be added to the resin layer in the present invention.
This is effective in improving the potential stability and image quality when the environment changes.

Here, the hindered phenol refers to compounds having a branched alkyl group at the ortho position to the hydroxyl group of the phenol compound and derivatives thereof. However, the hydroxyl group may be modified to alkoxy.

Examples of the hindered amine include compounds having an organic group represented by the following structural formula.

[0090]

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(In the formula, R ₁₁ represents a hydrogen atom or a monovalent organic group, R ₁₂ , R ₁₃ , R ₁₄ and R ₁₅ represent an alkyl group, and R ₁₆ represents a hydrogen atom, a hydroxyl group or a monovalent organic group. Examples of the antioxidant having a hindered phenol partial structure include compounds described in JP-A-1-118137 (P7 to P14), but the present invention is not limited thereto.

Examples of the antioxidant having a hindered amine partial structure include, for example, JP-A-1-118138 (P.
7 to P9), but the present invention is not limited thereto.

The addition amount of the antioxidant is preferably 0.01 to 50% by weight, and more preferably 0.1 to 50% by weight based on the weight of the surface protective layer.
Most preferred is 25% by weight.

Examples of the compounds preferably used as the antioxidant used in the present invention include those having a hindered amine structural unit or a hindered phenol structural unit, those having both of them, organic phosphorus compounds and organic sulfur compounds. There is. The following are examples of these specific examples.

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

[0096]

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[0097]

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[0098]

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[0099]

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[0100]

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[0101]

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[0102]

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[0103]

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[0104]

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[0105]

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[0106]

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[0107]

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

[0109]

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[0110]

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[0111]

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(3) 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.

[0113]

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[0114]

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

[0116]

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Examples of the 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 higher hindered phenol type,
"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 higher, hindered amine type, "Sumilyzer-TPS", "Sumilyzer TP-D" or higher, thioether type, "Mark 2112", "Mark PEP.
8 "," Mark PEP 24G "," Mark PEP 3 "
6 "," Mark 329K "," Mark HP.10 "or more phosphites.

The layer structure of the electrophotographic photoreceptor of the present invention is not particularly limited, but may be a charge generation layer, a charge transport layer, or a charge generation / charge transport layer (a single layer having both functions of charge generation and charge transport). It is preferable to adopt a structure in which a photosensitive layer such as a photosensitive layer) and a resin layer of the present invention are provided thereon. Further, each of the charge generation layer, the charge transport layer, or the charge generation / charge transport layer may be composed of a plurality of layers.

Examples of the charge generating substance (CGM) contained in the photosensitive layer of the present invention include phthalocyanine pigments, polycyclic quinone pigments, azo pigments, perylene pigments, indigo pigments,
Quinacridone pigments, azurenium pigments, squarylium dyes, cyanine dyes, pyrylium dyes, thiopyrylium dyes, xanthene dyes, triphenylmethane dyes, styryl dyes, and the like.
In M), a layer is formed alone or together with a suitable binder resin.

The charge transport material (C) contained in the photosensitive layer
TM) includes, for example, oxazole derivatives, oxadiazole derivatives, thiazole derivatives, thiadiazole derivatives, triazole derivatives, imidazole derivatives, imidazolone derivatives, imidazoline derivatives, bisimidazolidine derivatives, styryl compounds, hydrazone compounds, benzidine compounds, pyrazoline derivatives, stilbenes Compound,
Amine derivatives, oxazolone derivatives, benzothiazole derivatives, benzimidazole derivatives, quinazoline derivatives, benzofuran derivatives, acridine derivatives, phenazine derivatives, aminostilbene derivatives, poly-N-vinylcarbazole, poly-1-vinylpyrene, poly-9-vinylanthracene, etc. These charge transport materials (CTM) are usually used to form a layer together with a binder.

The binder resin contained in the charge generating layer (CGL) and the charge transport layer (CTL) in the case of the photosensitive layer having a single layer structure and the charge transporting layer (CTL) in the case of a multilayer structure includes 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 Resins, epoxy resins, silicone-alkyd resins, phenol resins, polysilane resins, polyvinyl carbazole, and the like.

In the present invention, the ratio between the charge generating substance and the binder resin in the charge generating layer is 1: 5 to 5: 1 by weight.
Is preferred. The thickness of the charge generation layer is preferably 5 μm or less, and 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 applying and drying the solution. The mixing ratio of the charge transport material and the binder resin is preferably from 3: 1 to 1: 3 by weight.

The thickness of the charge transport layer is usually from 5 to 50 μm, particularly preferably from 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 10 μm.
m or less, and preferably smaller than the total thickness of the charge transport layer provided below the charge transport layer.

The siloxane-based resin layer having a crosslinked structure of the present invention may also serve as the charge transport layer, but is preferably a charge transport layer, a charge generation layer, or a photosensitive layer such as a single layer type charge generation / transport layer. It is good to provide as another layer on these. In this case, it is more preferable to provide an adhesive layer between the photosensitive layer and the resin layer of the present invention.

Next, the conductive support of the electrophotographic photoreceptor of the present invention includes: 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 electroconductive support of the electrophotographic photoreceptor of the present invention may have a surface on which a sealed alumite film is formed.

The alumite membrane treatment is usually carried out 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 best results. . In the case of anodizing 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 solution temperature is around 20 ° C., and the electrolysis voltage is about 20 V. It is not limited.

The average thickness of the anodic oxide film is usually 2
It is preferable that the film is formed to have a thickness of 0 μm or less, particularly 10 μm or less.

A specific example of the processing method is described in JP-A No. 2-7 / 1990.
No. 070, 3-212648 and 5-80565
And JP-A-9-15886.

The shape of the support may be a drum shape, a sheet shape, or a belt shape, and is preferably a shape optimized for the applied electrophotographic apparatus.

The solvent or dispersion medium used in the production of the photoreceptor of the present invention includes n-butylamine, diethylamine, ethylenediamine, isopropanolamine, triethanolamine, triethylenediamine, N, N-dimethylformamide, acetone, methylethylketone,
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, dioxolan, dioxane,
Methanol, ethanol, butanol, isopropanol, ethyl acetate, butyl acetate, dimethyl sulfoxide,
Methyl cellosolve and the like. Although the present invention is not limited to these, dichloromethane, 1,2-dichloroethane, methyl ethyl ketone and the like are preferably used. In addition, these solvents can be used alone or as a mixed solvent of two or more kinds.

The coating method for producing the electrophotographic photosensitive member of the present invention includes dip coating, spray coating,
A coating processing method such as a circular amount control type coating is used. The coating process on the surface layer side of the photosensitive layer does not dissolve the lower layer film as much as possible, and in order to achieve a uniform coating process, a coating process such as a spray coating or a circular amount control type (a typical example is a circular slide hopper type). Preferably, a method is used. 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-58-18.
No. 9061 discloses this in detail.

The photoreceptor of the present invention is preferably heated and dried at a temperature of 50 ° C. or higher, preferably 60 to 200 ° C., after the surface protective layer is formed by coating. By this heating and drying, the residual coating solvent can be reduced, and the resin layer having a crosslinked structure can be sufficiently crosslinked and cured.

In the present invention, it is preferable to provide an intermediate layer having a barrier function 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, and phenol resin polyamides (nylon 6, nylon 66, nylon 610, copolymer nylon, alkoxymethyl). And an intermediate layer using polyurethane, gelatin, and aluminum oxide, or a hardening intermediate layer using a metal alkoxide, an organic metal chelate, or a silane coupling agent as described in JP-A-9-68870. The thickness of the intermediate layer is preferably from 0.1 to 10 μm, particularly preferably from 0.1 to 10 μm.
5 μm is preferred.

In the present invention, a coating for compensating for surface defects of the support is provided between the support and the intermediate layer, and interference fringes, which is a problem particularly when image input is a laser beam, are performed. A conductive layer for the purpose of preventing generation and the like can be provided. This conductive layer is made of carbon black,
It can be formed by applying and drying a solution in which conductive powder such as metal particles or metal oxide particles is dispersed in a suitable binder resin. The thickness of the conductive layer is preferably 5 to 40 μm, particularly preferably 10 to 30 μm.

First, the image forming process and each mechanism will be described with reference to FIG.

FIG. 1 is a sectional view of a color image forming apparatus 100 showing an embodiment of the present invention.

This embodiment is an apparatus having a drum-type intermediate transfer means. A color image as a developer is superimposed on a transfer means 10 to form a color image and then transferred to a recording material (transfer paper P). Is performed.

The transfer means 10 includes four image forming units 20Y, 20M, 20C, 2
The yellow (Y), magenta (M), cyan (C), and black (K) toner images formed by 0K are sequentially superimposed and carried. The transfer means 10 is a drum-shaped transfer body 10, and a conductive rubber layer 12 (500 to 5000 μm in thickness, electric resistance 10 ⁸ to 10 μm as an elastic layer) is formed on an aluminum base 11 which is a cylindrical metal base. ¹⁴ Ω ・ c
m, and a release film 13 (a Teflon layer having a thickness of 20 to 200 μm and an electric resistance of 10 ¹⁰ to 10 ¹⁶ Ω · cm for separation) provided thereon. Around the transfer body 10, four image forming units 20Y, 20M, 20C, and 20K, and a transfer paper transfer unit 3
0, cleaning means 16 are provided respectively. or,
The transfer body 10 is moved by the shaft 101 to the color image forming apparatus 1
00 is rotatably supported.

The four image forming units 20Y,
20M, 20C, 20K are frame bodies 26Y, 26M, respectively.
26C, 26K, the frame bodies 26Y, 26M,
26C and 26K are provided so as to be movable in the color image forming apparatus 100, and each image forming unit is moved to an image transfer position or a non-image transfer position with respect to the drum-shaped transfer body 10 according to a used color. For moving 27Y, 2
7M, 27C, 27K are frame bodies 26Y, 26M, 26, respectively.
C, 26K.

The four image forming units 20Y and 20
M, 20C, and 20K are photosensitive drums 21Y, 21M,
Charging means 22Y, 2 rotating around 21C and 21K;
2M, 22C, 22K and exposure means 23Y, 23M, 2
3C, 23K and rotating developing means 24Y, 24M, 2
4C, 24K, and photosensitive drums 21Y, 21M, 2
Cleaning means 25 for cleaning 1C and 21K
Y, 25M, 25C, and 25K.

The image forming units 20Y, 20M, 2
0C and 20K have the same configuration except that the color of the toner image formed on the transfer body 10 is different. The image forming unit 20Y will be described in detail with reference to FIG.

Image forming unit 2 provided in frame 26Y
0Y is provided around the photosensitive drum 21Y as an image forming body.
Image forming body charging means 22Y (hereinafter simply charging means 22Y,
Alternatively, a charging unit 22Y), an exposing unit 23Y, a developing unit 24Y, and an image forming body cleaning unit 25Y (hereinafter, simply referred to as a cleaning unit 25Y or a cleaning blade 25Y) are arranged.
This is to form a yellow (Y) toner image on 1Y. In the present embodiment, at least the photosensitive drum 21Y, the charging unit 22Y, the developing unit 24Y, and the cleaning unit 25 in the image forming unit 20Y.
Y is provided so as to be integrated.

The charging means 22Y is a means for applying a uniform potential to the photosensitive drum 21Y. In the present embodiment, the charging means 22Y is a roller-shaped charger which is driven and rotated while being in contact with the photosensitive drum 21Y. 22Y is used.

The exposure means 23Y includes a roller-shaped charger 22.
Photoconductor drum 21Y given a uniform potential by Y
Above, means for performing exposure based on an image signal (yellow) to form an electrostatic latent image corresponding to the yellow image, and the exposure means 23Y includes a photosensitive drum 21Y.
An LED having light emitting elements arranged in an array in the axial direction and an imaging element (trade name: Selfoc lens), a laser optical system, or the like is used.

The developing means 24Y is a means for containing a yellow toner as a developer and reversing the electrostatic latent image formed on the photosensitive drum 21Y to form a yellow toner image. In the developing unit 24Y of the present embodiment,
The yellow toner contained in the developing unit 24Y is
After being stirred by the stirring member 241Y, the toner supply roller 242 having an elastic (sponge) surface that rotates in the direction of the arrow.
By Y, it is supplied to the developing sleeve 243Y. At this time, the developing sleeve 243Y is formed by the thin layer forming member 244Y.
The upper yellow toner is made into a uniform thin layer. Developing means 24
In the developing operation of Y, a developing bias to which a direct current or a further alternating current is applied is applied to the developing sleeve 243Y rotating in the direction of the arrow, so that jumping development by one component housed in the developing means 24Y is performed, and grounding is performed. A non-contact reversal development is performed by applying a bias in which a DC component and an AC component having the same polarity as the toner are superimposed on the photosensitive drum 21Y. The developing sleeve 243
The abutting rollers provided at both ends outside the Y image area come into contact with the photosensitive drum 21Y, so that the developing sleeve 2
43Y and the photosensitive drum 21Y are kept in non-contact.
In addition, contact development can be used instead of non-contact development.

In the yellow toner image formed on the photosensitive drum 21Y, the abutting rollers rotate while contacting the positioning portion of the transfer member 10, and the transfer member 10 to which a bias voltage having a polarity opposite to that of the toner is applied. Are sequentially transferred onto the transfer body 10.

After the yellow toner image is transferred to the transfer member 10, the cleaning means 25Y
This is a means for removing the yellow toner remaining on Y from the photoreceptor drum 10. In the present embodiment, the cleaning means 25Y slides on the photoreceptor drum 21Y to remove the residual toner. Is going.

Thus, the image forming unit 20Y
Accordingly, the yellow toner image corresponding to the image signal (yellow) formed by the charging, exposing, and developing processes is transferred onto the transfer body 10.

Then, as shown in FIG. 1, the other image forming units 20M, 20C, and 20K similarly have magenta toner images corresponding to image signals (magenta) on the photosensitive drums 21M, 21C, and 21K, respectively. Cyan toner image corresponding to image signal (cyan), image signal (K)
Are formed in parallel processing in synchronization with each other. By such an operation, the toner images formed on the photosensitive drums 21Y, 21M, 21C, 21K of the image forming units 20Y, 20M, 20C, 20K are sequentially transferred by applying a transfer bias of 1-2 kV. The toner image is transferred onto the body 10 and superimposed. When all the toner images are superimposed, a color toner image is formed on the transfer body 10.

On the other hand, a paper feed cassette CA as a transfer material storage means is provided below the transfer body 10, and the transfer paper P, which is the transfer material stored in the paper feed cassette CA, is supplied to the paper feed roller r1. By the operation, the sheet is unloaded from the sheet cassette CA and sent to the timing roller pair r2. The timing roller pair r2 sends out the transfer paper P in synchronization with the color toner image formed on the transfer body 10.

The transferred transfer paper P is transferred with the color toner image formed on the transfer body 10 by the transfer paper transfer means 30 at the transfer position. This transfer paper transfer means 30
Grounded roller 31, transfer belt 32, paper charger 3
3, a transfer electrode 34, and a paper separating AC static eliminator 35.

The transferred transfer paper P is stretched on rollers 31 and is conveyed to a transfer position by a transfer belt 32 which rotates in the direction of the arrow in synchronization with the peripheral speed of the transfer body 10. The transfer belt 32 is a belt having a high resistance of 10 ⁶ to 10 ¹⁰ Ω · cm. At this time, the transfer paper P is charged to the same polarity as the toner by the paper charger 33 as the transfer material charging means, is attracted to the transfer belt 32, and is fed to the transfer position. By charging the paper with the same polarity as that of the toner, it is possible to prevent the toner from being attracted to the color toner image on the transfer body 10 and prevent the color toner image from being disturbed. Also,
As the transfer material charging unit, a current-carrying roller or a brush charger that can be brought into contact with or separated from the transfer belt 32 can be used.

At the transfer position, the color toner image on the transfer body 10 is transferred onto the transfer paper P by the transfer electrode. By the transfer electrode 34, corona discharge is performed on the back surface of the transfer paper P so as to have a potential of 1.5 to 3 kV, which is a voltage having a polarity opposite to that of the toner higher than the bias of the transfer body 10.

Transfer paper P to which color toner image has been transferred
Is further conveyed by a transfer belt 32, discharged by a paper separation AC static eliminator 35 for separating a transfer material, separated from the transfer belt 32, and conveyed to a fixing unit 40. In the fixing unit 40, the color toner image is heated and pressed by the heating roller 41 and the pressure roller 42, and the color toner image is deposited and fixed on the transfer paper P.
3, the sheet is discharged onto a tray provided at the upper part of the color image forming apparatus.

On the other hand, the transfer member 10 on which the color toner image has been transferred to the transfer sheet P is rubbed on the transfer member 10 by the cleaning blade 161 which is the transfer member cleaning means 16, and remains on the transfer member 10. Remove toner
Be cleaned. Further, a blade is slid on the transfer belt 32 as a transfer belt cleaning unit 36,
The transfer belt 32 after the paper separation is cleaned.

FIG. 3 is a cross-sectional view of an image forming unit having a slightly different structure from that of FIG. 2 in which the developing means and the photosensitive drum are detachable from the image forming unit and can be replaced.

This embodiment will be described by taking the configuration of the image forming unit 20C as an example.

Frame 2 Constituting Image Forming Unit 20C
6C is provided on a guide member 111 provided in the color image forming apparatus. A moving member 27C having a cam structure is provided so as to contact a part of the frame 26C.
And the image forming unit 20C is stopped at a predetermined image forming position together with the frame 26C. In the frame 26C, a charging unit 2 is provided around a photosensitive drum 21C as an image forming body.
2C, an exposing unit 23C, and a second frame 261C detachably mounted on the frame 26C so as to be replaceable are provided with a developing unit 24C, a developer supply unit 241C, and a developer stirring unit 242C. Are provided, and the developing means 24C is disposed so as to face the periphery of the photosensitive drum 21C.

Further, in the second frame 261C, a cyan (C) toner composed of the one-component developer T is incorporated, and the remaining amount of the developer is detected to detect the remaining amount of the one-component developer T. Means A is provided in developing means 24C.

A cyan (C) toner image is formed on the photosensitive drum 21C by the image forming process.
After the cyan (C) toner image is transferred from the photoconductor drum 21C to the transfer body 10 in the same manner as described above, the periphery of the photoconductor drum 21C is cleaned by a cleaning unit 25C.

FIG. 4 shows an image forming apparatus for directly transferring a recording material (transfer paper P) on a drum without using an intermediate transfer member.
FIG. 5 shows an image forming apparatus for directly transferring a recording material on a transfer belt. The image forming procedure in FIGS. 4 and 5 is almost the same as that in FIGS. 1 to 3, except that the image is directly transferred to the recording material instead of the intermediate transfer body.

An image forming apparatus for directly transferring a recording material on a transfer belt shown in FIG. 5 will be described. Four photoconductors are arranged in parallel, and yellow (Y), magenta (M), cyan (C),
This is an example of color image formation by a tandem color image forming apparatus that sequentially transfers four color black (K) toner images.

According to FIG. 5, the photosensitive drum 21Y (21
M, 21C, 21K), scorotron charger (charging means) 24Y (24M, 24C, 24K), exposure optical system (exposure means), developing device (developing means) 22Y (22M,
2C, 22K) and a cleaning device (cleaning means) 25Y (25M, 25C, 25K).
The M, C, and K image forming units 20Y (20M, 20
C, 20K), a recording material (recording paper P) is supplied to each toner image formed by the Y, M, C, and K toner image forming units at a proper timing, and a transfer unit 34Y ( 34M, 34C, and 34K) to form a superimposed color toner image.

The recording material is conveyed on a conveyance belt 115, and is provided with a paper separation AC neutralizer 161 as recording material separating means.
And the separation claw 210, which is a separation member provided on the conveyance section 160 at a predetermined interval, is separated from the conveyance belt.

Further, after passing through the transport section 160, it is transported to a fixing device (fixing means) 40 composed of a heating roller 41 and a pressure roller 42, and is formed by the fixing roller 41 and the pressure roller 42. The recording paper P is nipped at the nip portion T, and heat and pressure are applied to the recording paper P to
After the upper superposed toner image is fixed, it is discharged out of the apparatus.

[0170]

Next, embodiments of the present invention will be described specifically.
The configuration of the present invention is not limited to this.

A photoreceptor was prepared as described below.

Example 1 The following intermediate layer composition solution was prepared and applied on a cleaned cylindrical aluminum substrate by a dip coating method to form an intermediate layer having a thickness of 0.3 μm.

<Intermediate layer (UCL) composition liquid> Polyamide resin (Amilan CM-8000: manufactured by Toray Industries, Inc.) 60 g methanol 1600 ml Next, the following coating composition liquid was mixed, and the mixture was mixed with a sand mill to obtain 10 parts.
After time dispersion, a charge generation layer coating solution was prepared. This coating solution was applied by a dip coating method to form a charge generation layer having a thickness of 0.2 μm.

<Charge Generating Layer (CGL) Composition Solution> Y-type titanyl phthalocyanine 60 g silicone resin solution 700 g (KR5240, 15% xylene-butanol solution: manufactured by Shin-Etsu Chemical Co., Ltd.) 2-butanone 2000 ml The following coating composition solution was mixed and dissolved. Thus, a charge transport layer coating solution was prepared. This coating solution was applied on the charge generation layer by a dip coating method to form a charge transport layer having a thickness of 20 μm.

<Charge Transport Layer (CTL) Composition Liquid> Charge transport substance (D1) 200 g Bisphenol Z-type polycarbonate 300 g (Iupilon Z300: manufactured by Mitsubishi Gas Chemical Company) 1,2-dichloroethane 2000 ml The following coating composition liquid was mixed and dissolved. Thus, a surface protective layer coating composition was prepared.

[0176]

Embedded image

<Surface Protective Layer (OCL) Composition> Molecular sieve 4A was added to 10 parts by weight of a polysiloxane resin composed of 80 mol% of methylsiloxane units and 20 mol% of methyl-phenylsiloxane units, and allowed to stand for 15 hours for dehydration. Processed. This resin is dissolved in 10 parts by weight of toluene,
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 0.3 parts of hindered amine (2-1)
The resulting solution was applied as a surface protective layer having a dry film thickness of 2 μm, and was heated and cured at 120 ° C. for 1 hour to prepare a photoreceptor 1 of Example 1.

Example 2 A photoreceptor 2 was prepared in the same manner as in Example 1 except that dihydroxymethyltriphenylamine in the protective layer was replaced with 4- [2- (triethoxysilyl) ethyl] triphenylamine. .

Example 3 A photoconductor 3 was prepared in the same manner as in Example 1, except that the hindered amine in the protective layer was changed to hindered phenol (1-32).

Example 4 A photoconductor 4 of Example 4 was prepared in the same manner as in Example 1, except that the following intermediate layer was used.

<Intermediate layer (UCL) composition liquid> Zirconium chelate compound ZC-540 (manufactured by Matsumoto Pharmaceutical Co., Ltd.) 200 g Silane coupling agent KBM-903 (manufactured by Shin-Etsu Chemical Co., Ltd.) 100 g Methanol 700 ml Ethanol 300 ml After drying at 150 ° C. for 30 minutes, an intermediate layer having a thickness of 1.0 μm was formed.

Example 5 The following dispersion was prepared and applied on a cylindrical aluminum substrate obtained by drawing to form a conductive layer having a dry film thickness of 15 μm.

<Conductive Layer (PCL) Composition Solution> Phenol resin 160 g Conductive titanium oxide 200 g Methyl cellosolve 100 ml The following intermediate layer coating solution was prepared. This coating solution was applied onto the conductive layer by a dip coating method to form an intermediate layer having a thickness of 1.0 μm.

<Intermediate layer (UCL) composition liquid> Polyamide resin (Amilan CM-8000: manufactured by Toray Industries, Inc.) 60 g Methanol 1600 ml 1-butanol 400 ml The following coating composition liquids were mixed and dispersed using a sand mill for 10 hours to generate electric charge. A layer coating solution was prepared. This coating solution was applied on the intermediate layer by a dip coating method to form a 0.2 μm-thick charge generation layer.

<Charge Generating Layer (CGL) Composition Solution> Y-type titanyl phthalocyanine 60 g Silicone resin solution 700 g (KR5240, 15% xylene-butanol solution: manufactured by Shin-Etsu Chemical Co., Ltd.) 2-butanone 2000 ml The following coating composition solution was mixed and dissolved. Thus, a charge transport layer coating solution was prepared. This coating solution was applied on the charge generation layer by a dip coating method to form a charge transport layer having a thickness of 20 μm.

<Charge Transport Layer (CTL) Composition> Charge transport substance (D1) 200 g Bisphenol Z-type polycarbonate 300 g (Iupilon Z300: manufactured by Mitsubishi Gas Chemical Company) 1,2-dichloroethane 2000 ml <Surface protective layer (OCL) composition The molecular sieve 4A was added to 10 parts by weight of a polysiloxane resin composed of 80 mol% of a methylsiloxane unit and 20 mol% of a methyl-phenylsiloxane unit on the CTL, and 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 0.3 parts by weight of hindered amine (2-1) were added and mixed, and this solution was applied as a protective layer having a dry film thickness of 2 μm. Then, heat curing was performed at 120 ° C. for 1 hour to prepare a photoreceptor 5 of Example 5.

Example 6 The photoconductor of Example 6 was prepared in the same manner as in Example 5 except that dihydroxymethyltriphenylamine in the protective layer was replaced with 4- [2- (triethoxysilyl) ethyl] triphenylamine. No. 6 was produced.

Example 7 A photoconductor 7 of Example 7 was produced in the same manner as in Example 5, except that the hindered amine in the protective layer was changed to hindered phenol (1-32).

Example 8 10 parts by weight of a 1% by weight silanol-containing methylpolysiloxane resin consisting of 80% by mole of methylsiloxane units and 20% by mole of dimethylsiloxane units on the photoreceptor coated to the CTL of Example 1 Was dissolved in 10 parts by weight of toluene, molecular sieve 4A was added, and the mixture was allowed to stand for 15 hours to be dehydrated. 5 parts by weight of methyltrimethoxysilane and 0.2 parts by weight of dibutyltin acetate were added thereto to form a uniform solution. 100 parts by weight of this composition were added to 200 parts of toluene.
Parts by weight and 4- [N, N-bis (3,4-dimethylphenyl) amino]-[2- (triethoxysilyl) ethyl]
40 parts by weight of benzene and hindered amine (2-10)
0.3 parts by weight were added and mixed.
m, and heat-cured at 140 ° C. for 4 hours to prepare a photoreceptor 8 of Example 8.

Example 9 10 parts by weight of a 1% by weight silanol-containing methylpolysiloxane resin consisting of 80% by mole of methylsiloxane units and 20% by mole of dimethylsiloxane units on the photoreceptor coated to the CTL of Example 5 Was dissolved in 10 parts by weight of toluene, molecular sieve 4A was added, and the mixture was allowed to stand for 15 hours to be dehydrated. 5 parts by weight of methyltrimethoxysilane and 0.2 parts by weight of dibutyltin acetate were added thereto to form a uniform solution. 100 parts by weight of this composition were added to 200 parts of toluene.
Parts by weight and 4- [N, N-bis (3,4-dimethylphenyl) amino]-[2- (triethoxysilyl) ethyl]
40 parts by weight of benzene and hindered amine (2-10)
0.3 parts by weight were added and mixed.
m, and cured by heating at 140 ° C. for 4 hours to produce a photoreceptor of Example 9.

Example 10 A photoconductor 10 of Example 10 was produced in the same manner as in Example 5, except that the conductive layer was replaced with the following composition.

<Conductive Layer (PCL) Composition> Phenol Resin 160 g Conductive Barium Sulfate 200 g Methyl Cellosolve 100 ml Silicone Resin Particles (Average Particle Size 2 μm) 3 g Example 11 A conductive aluminum substrate was replaced with alumite that had been subjected to a sealing treatment. The photoreceptor 11 of Example 11 was produced in the same manner as in Example 1.

Example 12 The polysiloxane resin in Example 11 was obtained by adding 30 mol% of a methylsiloxane unit, 40 mol% of an ethylsiloxane unit,
A photoreceptor 12 of Example 12 was produced in exactly the same manner except that the polysiloxane resin was composed of 20 mol% of dimethylsiloxane units and 10 mol% of diethylsiloxane units (including 2% by weight of silanol groups).

Example 13 The polysiloxane resin in Example 1 was prepared by adding 30 mol% of a methylsiloxane unit, 30 mol% of a phenylsiloxane unit,
A photoreceptor 13 of Example 13 was produced in exactly the same manner except that a polysiloxane resin (containing 2% by weight of silanol groups) composed of 20 mol% of dimethylsiloxane units and 20 mol% of diethylsiloxane units was used.

Example 14 Dihydroxymethyltriphenylamine (Exemplified Compound T-1) in Example 1 was replaced with Exemplified Compound H of the hydrazone type.
A photoreceptor 14 of Example 14 was made in exactly the same manner except that -1 was used.

Example 15 Dihydroxymethyltriphenylamine (Exemplified Compound T-1) in Example 1 was replaced with a stilbene-type Exemplified Compound S
A photoreceptor 15 of Example 15 was produced in exactly the same manner except that the value was changed to -1.

Example 16 The dihydroxymethyltriphenylamine (exemplary compound T-1) in Example 1 was replaced with a benzidine-type exemplified compound B
A photoconductor 16 of Example 16 was produced in the same manner except that the photoconductor 16 was changed to e-1.

Example 17 Dihydroxymethyltriphenylamine (Exemplified Compound T-1) in Example 1 was replaced with Exemplified Compound B of butadiene type.
A photoreceptor 17 of Example 17 was made in exactly the same manner except that u-1 was used.

Example 18 A photoreceptor 18 of Example 18 was prepared in exactly the same manner as in Example 1 except that dihydroxymethyltriphenylamine (Exemplified Compound T-1) was replaced with Exemplified Compound So-1.

Example 19 A photoconductor 19 of Example 19 was prepared in exactly the same manner as in Example 1 except that dihydroxymethyltriphenylamine (Exemplified Compound T-1) was changed to Exemplified Compound V-1.

Example 20 A photoconductor 20 of Example 20 was prepared in exactly the same manner as in Example 1 except that dihydroxymethyltriphenylamine (Exemplified Compound T-1) was replaced with Exemplified Compound W-1.

Example 21 The same procedure as in Example 4 was repeated except that 5 parts by weight of colloidal silica was added to the protective layer.
Was prepared.

Example 22 The same procedure as in Example 1 was repeated except that 12 parts by weight of colloidal silica was added to the protective layer.
2 was produced.

Example 23 A CTL was manufactured in the same manner as in Example 1.

Further, a commercially available curable siloxane resin K
Example 2-60 parts by weight of P-854 (manufactured by Shin-Etsu Chemical Co., Ltd.) and 60 parts by weight of isopropanol were added and uniformly dissolved.
6 parts by weight of dihydroxymethyltriphenylamine (exemplified compound T-1) were added and mixed in the same manner as in Example 1, and this solution was applied so as to form a protective layer having a dry film thickness of 1 μm.
-Drying was performed for 1 hour to prepare a photoconductor 23 of Example 23.

Example 24 Instead of the siloxane resin KP-854 of Example 23, X
Photoconductor 24 of Example 24 was made in exactly the same manner except that -40-2239 (manufactured by Shin-Etsu Chemical Co., Ltd.) was used.

Example 25 Instead of the siloxane resin KP-854 of Example 23, X
Photoconductor 25 of Example 25 was made in exactly the same manner except that -40-2269 (manufactured by Shin-Etsu Chemical Co., Ltd.) was used.

Example 26 A commercially available primer PC-7J (manufactured by Shin-Etsu Chemical Co., Ltd.) was diluted twice with toluene on the CTL of Example 1, and 100 μl after coating.
C. for 30 minutes to form an adhesive layer having a dry film thickness of 0.3 .mu.m.

Further, molecular sieve 4A was added to 10 parts by weight of a polysiloxane resin (containing 1% by weight of silanol group) composed of 80% by mole of methylsiloxane unit and 20% by mole of methyl-phenylsiloxane unit, and
It was left to stand for 5 hours to perform a dehydration treatment. 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.

To this, 6 parts by weight of dihydroxymethyltriphenylamine (Exemplified Compound T-1) was added and mixed, and this solution was applied as a protective layer having a dry film thickness of 1 μm.
Drying was carried out at 0 ° C. for 1 hour to prepare a photoreceptor 26 of Example 26.

Comparative Example 1 A photoreceptor was prepared in the same manner as in Example 1 except that a charge transporting layer having a thickness of 22 μm was formed on the charge generating layer and then dried at 120 ° C. for 1 hour. Produced.

Comparative Example 2 A photoconductor of Comparative Example 2 was prepared in the same manner as in Example 1, except that dihydroxymethyltriphenylamine in the protective layer was replaced with triphenylamine.

<Evaluation> Evaluation was performed by mounting each of the above photoreceptors on the digital copying machine shown in FIG.
In an environment of 0 ° C. and 80% RH, initial and 50,000 image evaluations were performed using A4 paper.

In Examples 1 to 26 of the present invention, no fogging occurred in the initial and 50,000 sheets under any of the environmental conditions, and the density of the black solid portion was 1.2 or more in reflection density. In addition, an image having excellent color balance was obtained. Also, 5
The difference in the abrasion amount of each photoconductor at the end of 10,000 sheets was as small as 0.1 μm or less. Further, scars on the surface of the photoreceptor were scarcely observed, and the resolving power was good. Image defects due to scratches and image blur were not seen on the halftone image,
The adhesion between the surface protective layer (OCL) and the charge transport layer (CTL) was also good.

The color balance at the end of 500,000 copies was measured by separating the black image with a Macbeth densitometer. Although there was no problem in the case of the present invention, the comparative example had a cyan density 0.3 to 1.0 higher than that of the example, was somewhat cyan-based blackish, and was out of balance.

Table 1 below shows the evaluation results under the environment of 30 ° C. and 80% RH.

[0218]

[Table 1]

[0219]

According to the present invention, a so-called tandem type photoreceptor for color image formation, having high surface hardness, high abrasion resistance and high scratch resistance, and exhibiting electrophotographic characteristics even under high temperature and high humidity when repeatedly used. It is possible to provide an electrophotographic photoreceptor capable of repeatedly obtaining a stable and favorable image, having a high resolution and no image blur, and free from moire even when forming a digital image by a laser beam or the like. Further, a process cartridge and an image forming apparatus using the photosensitive member can be provided.

[Brief description of the drawings]

FIG. 1 is a cross-sectional configuration diagram of a color image forming apparatus of the present invention.

FIG. 2 is a cross-sectional configuration diagram of an image forming unit of the present invention.

FIG. 3 is a sectional view illustrating another example of the image forming unit of the present invention.

FIG. 4 is a cross-sectional configuration diagram of another color image forming apparatus of the present invention.

FIG. 5 is a cross-sectional configuration diagram of another color image forming apparatus of the present invention.

[Explanation of symbols]

10 Transfer Body (Transfer Unit) 20Y, 20M, 20C, 20K Image Forming Unit 21Y, 21M, 21C, 21K Photoconductor Drum (Image Forming Unit) 22Y, 22M, 22C, 22K Charging Unit 23Y, 23M, 23C, 23K Exposure Unit 24Y, 24M, 24C, 24K Developing unit 25Y, 25M, 25C, 25K Cleaning unit 26Y, 26M, 26C, 26K Frame 27Y, 27M, 27C, 27K Moving member

Claims (6)

[Claims] 1. A photoreceptor comprising a photosensitive layer and a surface protective layer sequentially laminated on a conductive support, charging means for applying a charge to the surface of the photoreceptor, and a charging area of the photoreceptor. Image exposure means for irradiating light, while forming an electrostatic latent image on the surface of the photoreceptor by these charging means and image exposure means,
Developing means for forming a colored toner image corresponding to the electrostatic latent image on the surface of the photoconductor, and transfer means for transferring the toner image formed on the photoconductor to a recording material; A plurality of image forming units provided with a cleaning unit for removing residual toner are arranged, and each toner image formed by using a toner whose color is changed for each image forming unit is sequentially transferred to a recording material to form an image. Wherein the surface protective layer of the photoreceptor has a structural unit having charge transport performance and contains a siloxane-based resin having a crosslinked structure. 2. A crosslinked structure obtained by reacting an organic silicon compound having a hydroxyl group or a hydrolyzable group with a compound containing a hydroxyl group and a structural unit having charge transport performance, wherein the surface protective layer of the electrophotographic photoreceptor has a hydroxyl group or a hydrolyzable group. The image forming apparatus according to claim 1, wherein the image forming apparatus is a layer containing a siloxane resin. 3. The image forming apparatus according to claim 1, wherein the surface protective layer contains an antioxidant. 4. The image forming apparatus according to claim 3, wherein the antioxidant contains a hindered amine or a hindered phenol structural unit. 5. An image forming apparatus according to claim 1, wherein the toner images formed through the steps of charging, image exposing, developing, transferring, separating and cleaning are sequentially transferred to a recording material for each image forming unit. An image forming method comprising the steps of: 6. A photosensitive member used in the image forming apparatus according to claim 1, and at least one of a charging unit, an image exposing unit, a developing unit, a transfer or separation unit, and a cleaning unit.
Detachable process cartridge made by combining the two.