JP2010107594A - Electrophotographic photoreceptor, and image forming method, image forming apparatus and process cartridge for image forming apparatus using the electrophotographic photoreceptor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrophotographic photoreceptor which has excellent surface hardness, water repellency, crack resistance, flaw resistance and wear resistance, has significantly improved mechanical durability as a factor of hindering the improvement of durability, has satisfactory electrical properties, and increases image quality over a long period of time, and to provide an image forming method, an image forming apparatus and a process cartridge for an image forming apparatus using the electrophotographic photoreceptor. <P>SOLUTION: In the electrophotographic photoreceptor having a conductive support, a photosensitive layer and a protective layer in this order, the protective layer includes a charge-transporting organic-inorganic hybrid material including organic components and inorganic components, and concentration of the inorganic components in the protective layer continuously increases from the photosensitive layer side to the surface side opposite to the photosensitive layer side. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention has a high durability by using a photosensitive layer having excellent surface hardness, water repellency, crack resistance, scratch resistance, wear resistance, and good electrical characteristics, and has a long period of time. The present invention relates to an electrophotographic photoreceptor that achieves high image quality. The present invention also relates to an image forming method, an image forming apparatus, and a process cartridge for an image forming apparatus using a long-life, high-performance electrophotographic photosensitive member.

  Recently, an organic-inorganic hybrid material in which an inorganic component is dispersed in an organic polymer matrix on a nanoscale in a plastic composite material has attracted attention and has been actively studied. In such an organic-inorganic hybrid material, studies have been made to draw out the excellent features of the inorganic component and to develop synergistic effects. Also in the field of electrophotographic photoreceptors, functionalized organic-inorganic hybrid materials that take advantage of the characteristics of inorganic materials are also attracting attention.

In recent years, organic photoconductors (OPCs) instead of inorganic photoconductors are often used in copiers, facsimiles, laser printers, and their multifunction devices because they have good performance and various advantages. The reasons why OPC is frequently used in this way are, for example, (1) optical characteristics such as the light absorption wavelength range and the amount of absorption, and (2) electrical characteristics such as high sensitivity and stable charging characteristics. (3) Wide range of material selection, (4) Ease of manufacturing, (5) Low cost, (6) Non-toxicity and other advantages and advantages.
Under such circumstances, as the size of the image forming apparatus is reduced, the diameter of the photoconductor is reduced, and the demand for high-speed and maintenance-free machines is added, so that the photoconductor is highly durable. ing.

However, since the surface layer of the organic photoreceptor is composed mainly of a low molecular charge transport material and an inert polymer, it is generally soft, and when used repeatedly in an electrophotographic process, it depends on a developing system and a cleaning system. There is a problem that wear is likely to occur due to a mechanical load.
Further, in order to achieve high image quality, it is necessary to improve the cleaning property as the toner particles are made smaller. As a countermeasure, it is inevitable to increase the rubber hardness of the cleaning blade to increase the contact pressure, which causes a problem that the wear of the photosensitive member is promoted.
Such wear of the photoconductor causes a problem of deteriorating electrical characteristics such as deterioration of sensitivity and chargeability, thereby causing a decrease in image density and abnormal images such as background stains.
Furthermore, there is a problem that scratches locally generated due to wear result in streak-like stain images due to poor cleaning.
The life of the photoconductor has a problem that the wear and scratches are the rate-determining factors and the photoconductor is replaced without a sufficient period of use.

  As described above, in the electrophotographic image forming method, efforts are being made to improve the durability of the organic photoreceptor, which is the main member, that is, to extend the life. Until now, the lifetime of organic photoreceptors has been deteriorated due to electrostatic factors due to repeated use, scratches on the surface caused by paper, cleaning blades, separation nails, etc. coming into contact with the photoreceptor surface, and wear depending on the mechanical strength of the photosensitive layer. It has been influenced by. In recent years, electrostatic durability has been improved by improving the photosensitive material, but regarding mechanical strength, a material that surpasses polycarbonate used as a binder for the surface layer has not been found, and it is still effective. At present, few technical means have been proposed.

  Therefore, as a technique for improving the abrasion resistance of the photosensitive layer, for example, (a) a method using a curable binder for the surface layer (see Patent Document 1), (b) a method using a polymer type charge transport material (patent) (See Reference 2), (c) a method of dispersing an inorganic filler in the surface layer (see Patent Literature 3, Patent Literature 4, Patent Literature 5, Patent Literature 6, Patent Literature 7, Patent Literature 8, and Patent Literature 9). Proposed.

However, those using the curable binder (a) have poor compatibility with the charge transport material, or the residual potential increases due to impurities such as polymerization initiators and unreacted residues, resulting in a decrease in image density. It tends to occur. In addition, those using the polymer type charge transport material (b) and those containing the inorganic filler (c) can be improved to some extent, but are required for organic photoreceptors. The durability has not been fully satisfied. In addition, in the case where the inorganic filler (c) is dispersed, since there is no direct bond between the inorganic filler and the binder, the residual potential increases due to traps present on the surface of the inorganic filler, and the image density It tends to occur easily, and light scattering of the inorganic filler is unavoidable, so it is difficult to realize high image quality.
Therefore, the techniques (a), (b), and (c) are sufficiently satisfactory for the overall durability including the electrical durability and mechanical durability required for the organic photoreceptor. There is a problem that it is not a thing.

Further, as an approach for improving the durability of the organic photoreceptor, methods for improving the mechanical strength by adding silica particles to the surface layer of the photoreceptor have been proposed (Patent Document 10, Patent Document 11, and Patent). Reference 12). In addition, hydrophobic silica particles obtained by treating the silica particles with a silane coupling agent or the like are included in the outermost surface layer of the photoconductor to increase the mechanical strength of the photoconductor and increase lubricity. A method for obtaining a durable photoconductor has been proposed (see Patent Document 13, Patent Document 14, and Patent Document 15).
However, in these methods, since it is necessary to keep the particle size of the silica particles at a certain size or more in order to provide the adhesion between the silica particles and the binder, the particle size is inevitably increased. When the particle size increases, the roughness of the surface increases. For example, there is a problem that cleaning failure occurs due to damage to the edge portion of the cleaning blade, and sufficient durability cannot be obtained.

In order to improve wear resistance and scratch resistance, a method of hydrolyzing or polycondensing alkoxysilane or the like in the presence of a polycarbonate resin has been proposed (see Patent Document 16).
Furthermore, a method for obtaining an organic-inorganic hybrid polymer material from a terminal silyl-modified polycarbonate has been proposed (see Patent Document 17). Also proposed is a method for obtaining an organic-inorganic hybrid material by hydrolyzing or polycondensing a polymer having a polycarbonate and / or polyarylate moiety as a main skeleton and a metal alkoxide group as a functional group. (See Patent Document 18).
In recent years, research on organic-inorganic hybrid materials in which inorganic components are dispersed in an organic polymer matrix on a nanoscale in plastic composite materials has been actively conducted, and the excellent characteristics of inorganic components are often extracted and synergistic effects are obtained. Consideration is being made to discover specific characteristics. On the other hand, research on gradient structural materials is being conducted. The gradient structure material is a material having an excellent function obtained by continuously changing the composition and distribution of components constituting the material. This graded structure material is a new field among new materials, and is expected to be applied to a wide range of fields such as aviation, space, electronics and medical fields.
Also in the field of electronic devices such as organic photoreceptors, functionalized organic-inorganic hybrid materials having an inclined structure utilizing the characteristics of inorganic materials are also useful.
However, when these organic-inorganic hybrid polymer materials are used in an electrophotographic photoreceptor, it is necessary to add a low-molecular charge transport material, and therefore, formation of a transparent and uniform organic-inorganic hybrid material. However, there is a problem that synergistic properties as an organic-inorganic hybrid material are poorly expressed.

  In addition, an electrophotographic photosensitive member is proposed which has at least a photosensitive layer on a support, and the uppermost layer of the photosensitive layer contains a polymer charge transport material, an inorganic filler, and acryl-modified polyorganosiloxane fine particles ( (See Patent Document 19 and Patent Document 20). These proposals describe the use of an aromatic polycarbonate resin synthesized from a diol having charge transport ability as a polymer charge transport material.

The dispersion of the inorganic filler in this manner has a certain effect of improving the wear resistance, but does not have a direct connection between the inorganic filler and the binder. In fact, it does not have satisfactory performance in terms of the above.
Furthermore, a hybrid material composed of a charge transporting polymer organic component having an alkoxide group has been proposed (see Patent Documents 21 and 22). According to these proposals, a uniform charge transporting organic-inorganic hybrid can be formed, but the molecular weight of the charge transporting polymer organic component and the amount of the inorganic component added are limited, so that it can be applied to the surface layer of the photoreceptor. There is a problem that further improvement is necessary.

JP 56-48637 A JP-A 64-1728 JP-A-4-281461 Japanese Patent Application Laid-Open No. 61-132594 JP-A-2-240655 JP 7-261440 A JP-A-5-306335 JP-A-6-32884 Japanese Patent Laid-Open No. 6-282094 JP 56-117245 A JP-A-63-91666 JP-A-1-205171 JP-A-57-176057 JP 61-117558 A Japanese Patent Laid-Open No. 3-155558 JP 2000-105474 A JP 2002-241383 A JP-A-11-209596 Japanese Patent No. 3368415 JP 2003-98710 A JP 2006-161029 A JP 2006-328224 A

  An object of the present invention is to solve the conventional problems and achieve the following objects. That is, the present invention is excellent in surface hardness, water repellency, crack resistance, scratch resistance, and abrasion resistance, greatly improves the level of mechanical durability, which is a factor inhibiting high durability, and is electrically An object of the present invention is to provide an electrophotographic photosensitive member having good characteristics and achieving high image quality over a long period of time, an image forming method using the same, an image forming apparatus, and a process cartridge for the image forming apparatus.

  As a result of intensive studies by the present inventors in order to solve the above problems, the organic component and the inorganic component are contained, and the concentration of the inorganic component in the organic component and the inorganic component is opposite from the photosensitive layer side to the photosensitive layer side. It has been found that the above object can be achieved by forming a protective layer of a photoreceptor using a charge transporting organic-inorganic hybrid material that continuously increases (has an inclined structure) toward the surface side.

The present invention is based on the above findings by the present inventors, and means for solving the above problems are as follows. That is,
<1> In the electrophotographic photoreceptor having the conductive support, the photosensitive layer, and the protective layer in this order, the protective layer contains a charge transporting organic-inorganic hybrid material containing an organic component and an inorganic component, The electrophotographic photoreceptor, wherein the concentration of the inorganic component in the protective layer continuously increases from the photosensitive layer side toward the surface side opposite to the photosensitive layer side.
The charge transporting organic-inorganic hybrid material described as the prior art has a uniform composition of the photoreceptor surface layer (protective layer), so the amount of inorganic component added is limited to achieve electrical characteristics and mechanical strength at the same time. Therefore, the merit of the organic component and the inorganic component cannot be fully exhibited.
On the other hand, in the charge transporting organic-inorganic hybrid material in the present invention, the concentration of the inorganic component continuously increases from the photosensitive layer side of the protective layer toward the surface side opposite to the photosensitive layer side (inclination). In the protective layer, there are many electrotransport organic components on the photosensitive layer side and many inorganic components with high mechanical strength on the outermost surface layer side. Therefore, excellent electrical characteristics and durability are achieved. A compatible electrophotographic photoreceptor can be obtained.
<2> The electrophotography according to <1>, wherein the charge transporting organic-inorganic hybrid material is a material formed by covalently bonding a charge transporting polymer having a metal alkoxide group and a metal alkoxide compound. Photoconductor.
In order to apply an organic-inorganic hybrid material having no charge transporting functional group as described in the prior art to an organic photoreceptor, it is necessary to add a low molecular charge transport material. Usually, since the low molecular charge transport material does not have reactivity, when forming the organic-inorganic hybrid material, the cross-linking reaction is inhibited and it is difficult to become a strong material. In some cases, the charge transport material is deposited, and the transparency of the resulting photoreceptor is lost. Since the charge transporting organic-inorganic hybrid material is a material formed by covalently bonding a charge transporting polymer having a metal alkoxide group and a metal alkoxide compound, the characteristics of the organic component and the inorganic component exist. Can be demonstrated in minutes.
<3> The above <1> to <2>, wherein the protective layer is formed by applying a solution in which the composition ratio of the charge transporting polymer having a metal alkoxide group and the metal alkoxide compound is changed a plurality of times. The electrophotographic photoreceptor according to any one of the above.
If a solution containing a charge transporting polymer having a metal alkoxide group with a changed composition ratio and a metal alkoxide compound is sequentially applied to the photosensitive layer, a charge transporting organic-inorganic hybrid material with a continuously changing composition ratio is formed. it can.
<4> The electrophotographic photoreceptor according to any one of <2> to <3>, wherein the metal element contained in the metal alkoxide group and the metal alkoxide compound is Si.
In general, the Si element is considered to contribute to the low surface energy of the material. An electrophotographic photoreceptor using an organic-inorganic hybrid material containing Si element as a surface layer (protective layer) has an excellent low surface energy.
<5> An image forming method using the electrophotographic photosensitive member according to any one of <1> to <4>, wherein an electrostatic latent image is formed on the electrophotographic photosensitive member. A step of developing the latent electrostatic image with toner to form a visible image, a transfer step of transferring the visible image to a recording medium, and fixing the transferred image transferred to the recording medium An image forming method comprising at least a fixing step.
<6> An image forming apparatus comprising the electrophotographic photosensitive member according to any one of <1> to <4>.
<7> The electrophotographic photosensitive member according to any one of <1> to <4>, and at least one unit selected from the group consisting of a charging unit, a developing unit, a transfer unit, a cleaning unit, and a charge eliminating unit. And a process cartridge for an image forming apparatus, wherein the process cartridge is detachable from the main body of the image forming apparatus.

  According to the present invention, the conventional problems can be solved and the object can be achieved, the surface hardness, the water repellency, the crack resistance, the scratch resistance, the wear resistance, and the factors impeding the high durability. The electrophotographic photosensitive member that significantly improves the mechanical durability level, has good electrical characteristics, and realizes high image quality over a long period of time, and an image forming method and an image forming apparatus using the same In addition, a process cartridge for an image forming apparatus can be provided.

  Hereinafter, the present invention will be described in detail.

(Electrophotographic photoreceptor)
The electrophotographic photoreceptor of the present invention comprises a conductive support, a photosensitive layer, and a protective layer in this order, and further comprises other layers as necessary.

-Protective layer-
The protective layer contains a charge transporting organic-inorganic hybrid material containing an organic component and an inorganic component, and the concentration of the inorganic component in the protective layer is a surface side opposite to the photosensitive layer side from the photosensitive layer side. As it goes to, it grows continuously.
In general, organic-inorganic hybrid materials are roughly classified into types in which constituent components are bonded by a mild interaction such as hydrogen bonding and types in which they are covalently bonded. Comparing the two, the organic compound and inorganic component bonded by covalent bond increases the interfacial strength and can be dispersed more microscopically, in order to discover the characteristics of the material to the maximum, In the present invention, the organic-inorganic hybrid material produced by the latter method is used for the surface layer (protective layer) of the organic photoreceptor.
In this specification, the concentration of the inorganic component in the protective layer continuously increases from the photosensitive layer side toward the surface side opposite to the photosensitive layer side. It does not only indicate that the concentration of the inorganic component gradually increases toward the surface side opposite to the side, but may include a portion where the concentration is locally the same.

--Organic-inorganic hybrid material--
First, a method for forming an organic-inorganic hybrid material having an inclined structure will be described.
There is no restriction | limiting in particular as a formation method of the said organic-inorganic hybrid material, Although it can select suitably according to the objective, For example, forming by the following method is preferable.
That is, a polymer having at least one functional group in the molecule and having a charge transporting structural unit (polymer for hybrid material), and a metal alkoxide having a functional group that reacts with the functional group to form a bond. To obtain a charge transporting polymer introduced with a metal alkoxide group, and then the obtained charge transporting polymer introduced with a metal alkoxide group and the metal alkoxide compound are hydrolyzed by a sol-gel method. It is a method of forming an organic-inorganic hybrid material crosslinked to a three-dimensional structure by decomposition and polycondensation.
Further, a protective layer containing an organic-inorganic hybrid material having a gradient structure is formed by applying a solution in which the composition ratio of the charge transporting polymer having a metal alkoxide group and the metal alkoxide compound is changed a plurality of times. be able to.
The organic-inorganic hybrid material thus formed includes an organic component and an inorganic component. The organic component is an organic component contained in the charge transporting polymer and the metal alkoxide compound, and the inorganic component is an inorganic component contained in the charge transporting polymer and the metal alkoxide compound. The concentration of the inorganic component is measured by the concentration of the metal element component.

  Next, the constituent material of the organic-inorganic hybrid material will be described.

--- Charge transporting polymer ---
As described above, the charge transporting polymer having a metal alkoxide group includes a polymer having at least one functional group in the molecule and having a charge transporting structural unit (polymer for hybrid materials), and It can be obtained by reacting with a metal alkoxide having a functional group that reacts with a functional group to form a bond.

Examples of the polymer for hybrid materials include a polymer organic component including a polycarbonate structure having at least a charge transport function, and a metal alkoxide compound (hereinafter referred to as a metal) having a functional group reactive with the functional group in the polymer organic component. It is obtained by reacting and bonding. That is, the polymer for hybrid materials preferably has at least one, preferably two or more functional groups in the molecule.
Such a functional group is not particularly limited as long as it can react with the functional group of the metal alkoxide, and can be appropriately selected according to the purpose. For example, a hydroxyl group, an amino group, a carboxyl group, a thiol group Alkenyl group, alkynyl group, acid halogen group, acid ester group, formyl group, halogen group, epoxy group, and isocyanate group. Among them, a functional group having active hydrogen such as a hydroxyl group, an amino group, or a carboxyl group is preferable, and a hydroxyl group is particularly preferable.

There is no restriction | limiting in particular as said polymer organic component, According to the objective, it can select suitably, For example, the polysynthetic organic component which consists of a structural unit represented by the following general formula (I)-(III) is mentioned. It is done.

(In the formula, R ¹ represents a hydrogen atom, an alkyl group, or an aryl group. Ar ¹ represents an aryl group, and Ar ² and Ar ³ represent an arylene group.)

(In the formula, Ar ² , Ar ³ and Ar ⁴ represent an arylene group. R ¹⁷ and R ¹⁸ represent the same or different acyl group, alkyl group and aryl group.)

(In the formula, R ¹⁷ and R ¹⁸ represent the same or different acyl group, alkyl group, and aryl group.)

  In addition to the structural unit represented by any one of the general formulas (I), (II), and (III), the polymer organic component includes a structural unit represented by the following general formula (IV) You may go out.

Wherein X is an aliphatic divalent group, a cycloaliphatic divalent group, an aromatic divalent group, a divalent group formed by linking these, and any of the following formulas (1) or (2) Represents.)
(In the formulas (1) and (2), R ² , R ³ , R ⁴ and R ⁵ are each independently an alkyl group, an aryl group or a halogen atom, and a and b are each independently An integer of 0 to 4, c and d are each independently an integer of 0 to 3, Y is a single bond, a linear alkylene group having 2 to 12 carbon atoms, -O-,- S -, - SO -, - SO 2 -, - CO-, and any one of the following formulas (3) to (11),
In formulas (3) to (11), Z ¹ and Z ² represent an aliphatic divalent group or an arylene group, and R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ , R ^{12 represents} each independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, or an aryl group, and R ⁶ and R ⁷ are bonded to form 6 carbon atoms. may form a 12 carbocyclic or heterocyclic ring, also, R ^6, R ⁷ may form a carbocyclic or heterocyclic ring in cooperation with ^{R 2, R 3, R 13} , R 14 is a single Represents a bond or an alkylene group having 1 to 4 carbon atoms, R ¹⁵ and R ¹⁶ each independently represents an alkyl group or aryl group having 1 to 5 carbon atoms, e is an integer of 0 to 4 and f is 0 to 20 And g represents an integer of 0 to 2,000. )

There is no restriction | limiting in particular as a manufacturing method of the said polymer organic component, According to the objective, it can select suitably, For example, it can obtain by the reaction method of well-known bisphenol and a carbonic acid derivative.
Examples of the reaction method of the bisphenols and the carbonic acid derivative include transesterification of diol and bisaryl carbonate, solution or interfacial polymerization with carbonyl compounds such as phosgene, or bischloro derived from diol. Examples thereof include a method using chloroformate such as formate. This will be specifically described below.

  In the case of the method using the halogenated carbonyl compound, trichloromethyl chloroformate which is a dimer of phosgene or bis (trichloromethyl) carbonate which is a trimer of phosgene is also useful as the carbonyl halide compound instead of phosgene. Also useful are carbonyl halide compounds derived from halogens other than chlorine, such as carbonyl bromide and carbonyl iodide. These known production methods are described in, for example, a polycarbonate resin handbook (editor: Shinichi Honma, published by Nikkan Kogyo Shimbun).

  In the case of producing a polymer organic component containing a polycarbonate structure having a charge transport function (abbreviated as “polycarbonate resin”) by the above method, charges represented by the following general formulas (V), (VI), (VII) A diol represented by the following general formula (VIII) can be used in combination with one or more diols having a transport ability to form a copolymer with improved mechanical properties and the like.

(In the formula, R ¹ represents a hydrogen atom, an alkyl group, or an aryl group. Ar ¹ represents an aryl group, and Ar ² and Ar ³ represent an arylene group.)

(In the formula, Ar ² , Ar ³ and Ar ⁴ represent an arylene group. R ¹⁷ and R ¹⁸ represent the same or different acyl group, alkyl group and aryl group.)

(In the formula, R ¹⁷ and R ¹⁸ represent the same or different acyl group, alkyl group, and aryl group.)

(Wherein X represents an aliphatic divalent group, a cycloaliphatic divalent group, an aromatic divalent group, a divalent group formed by linking these, and the following formula (1) or (2) Represents either one.)

(In the formulas (1) and (2), R ² , R ³ , R ⁴ and R ⁵ are each independently an alkyl group, an aryl group or a halogen atom, and a and b are each independently An integer of 0 to 4, c and d are each independently an integer of 0 to 3, Y is a single bond, a linear alkylene group having 2 to 12 carbon atoms, -O-,- S -, - SO -, - SO 2 -, - CO-, and any one of the following formulas (3) to (11),

In formulas (3) to (11), Z ¹ and Z ² represent an aliphatic divalent group or an arylene group, and R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ , R ^{12 represents} each independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, or an aryl group, and R ⁶ and R ⁷ are bonded to form 6 carbon atoms. may form a 12 carbocyclic or heterocyclic ring, also, R ^6, R ⁷ may form a carbocyclic or heterocyclic ring in cooperation with ^{R 2, R 3, R 13} , R 14 is a single Represents a bond or an alkylene group having 1 to 4 carbon atoms, R ¹⁵ and R ¹⁶ each independently represents an alkyl group or aryl group having 1 to 5 carbon atoms, e is an integer of 0 to 4 and f is 0 to 20 And g represents an integer of 0 to 2,000. ). )

The ratio of the diol having the charge transport function represented by the general formulas (V), (VI), and (VII) and the diol represented by (VIII) can be selected from a wide range depending on desired characteristics.
When the organic-inorganic hybrid material described below is used, the composition ratio of the structural unit (polymer organic component) represented by any one of the general formulas (I), (II), and (III) is k. When the composition ratio of the structural unit (polymer organic component) represented by the general formula (IV) is j, the ratio of k to the total composition ratio (k + j) is represented by the following formula: 0 <k / (k + j) It is preferable to satisfy ≦ 1.
When the above formula is satisfied, the obtained polymer has a good balance between electrical properties and mechanical strength and is excellent in overall performance.

The number average molecular weight (Mn) of the polymer organic component is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 400 to 40,000, and 1,000 to 10,000. More preferred.
When the number average molecular weight is less than 400, the obtained hybrid material lacks polymer characteristics, and when it exceeds 40,000, the number of metal alkoxide groups bonded to the polymer organic component is reduced, and the resulting hybrid material is obtained. Cannot fully extract the properties of inorganic materials.

Various copolymers such as a random copolymer, an alternating copolymer, a block copolymer, a random alternating copolymer, and a random block copolymer can be obtained by selecting an appropriate polymerization operation.
For example, the diol having the charge transporting ability represented by the general formulas (V), (VI), and (VII) and the diol represented by the general formula (VIII) are uniformly mixed from the beginning to perform a condensation reaction with phosgene. A random copolymer comprising the structural unit represented by any one of the general formulas (I), (II), and (III) and the structural unit represented by the general formula (IV). can get.

  Alternatively, a random block copolymer can be obtained by adding several kinds of diols during the reaction. Further, condensation of bischloroformate derived from the diol represented by the general formula (VIII) and the diol having a charge transporting ability represented by the general formulas (V), (VI), and (VII) By carrying out the reaction, an alternating copolymer composed of repeating units represented by the following general formulas (IX), (X) and (XI) can be obtained.

(In the formula, R ¹ , Ar ¹ , Ar ² , Ar ³ , and X are the same as defined above, and n represents the degree of polymerization and represents an integer of 2 to 5,000.)

(In the formula, Ar ² , Ar ³ , Ar ⁴ , R ¹⁷ , R ¹⁸ and X are the same as defined above, and n represents the degree of polymerization and represents an integer of 2 to 5,000.)

(Wherein, R ¹⁷ , R ¹⁸ and X are the same as defined above, n represents the degree of polymerization and represents an integer of 2 to 5,000.)

In this case, conversely, the bischloroformate derived from the diol having the charge transporting ability represented by the general formulas (V), (VI) and (VII) and the diol represented by the general formula (VIII) Similarly, an alternating copolymer composed of repeating units represented by the general formulas (IX), (X), and (XI) can also be obtained by the condensation reaction.
In the condensation reaction of these bischloroformates and diols, a random alternating copolymer can be obtained by using a plurality of bischloroformates and diols.

  In addition, when an interfacial polymerization method is applied using a carbonyl halide compound or chloroformate, an alkaline aqueous solution of diol and a solution that is substantially insoluble in water and dissolves the polycarbonate resin are used. The reaction is carried out in the presence of a carbonic acid derivative and a catalyst between the phases. At this time, a polycarbonate resin having a narrow molecular weight distribution can be obtained in a short time by emulsifying the reaction catalyst by high-speed stirring or addition of an emulsifying substance.

As the base used in the alkaline aqueous solution, hydroxide or carbonate of alkali metal or alkaline earth metal is used. For example, hydroxide such as sodium hydroxide, potassium hydroxide, calcium hydroxide, sodium carbonate, potassium carbonate And carbonates such as calcium carbonate and sodium hydrogen carbonate. These bases may be used individually by 1 type, and may use 2 or more types together.
Among these, sodium hydroxide or potassium hydroxide is preferable. The water used is preferably distilled water or ion exchange water.

The organic solvent used as the solution for dissolving the polycarbonate resin is not particularly limited and can be appropriately selected depending on the purpose. For example, dichloromethane, 1,2-dichloroethane, 1,2-dichloroethylene, trichloroethane, Examples thereof include aliphatic halogenated hydrocarbons such as tetrachloroethane and dichloropropane, or a mixture thereof. Furthermore, an organic solvent in which an aromatic hydrocarbon such as toluene, xylene, or ethylbenzene, or an aliphatic hydrocarbon such as hexane or cyclohexane is mixed with these organic solvents may be used.
Among these, aliphatic halogenated hydrocarbons and aromatic halogenated hydrocarbons are preferable, and dichloromethane and chlorobenzene are more preferable.

There is no restriction | limiting in particular as a polycarbonate production | generation catalyst used at the time of manufacture of a polycarbonate resin, According to the objective, it can select suitably, For example, a tertiary amine, a quaternary ammonium salt, a tertiary phosphine, a quaternary phosphonium salt, Examples thereof include nitrogen-containing heterocyclic compounds and salts thereof, imino ethers and salts thereof, and compounds having an amide group.
Specific examples of such a polycarbonate production catalyst include trimethylamine, triethylamine, tri-n-propylamine, tri-n-hexylamine, N, N, N ′, N′-tetramethyl-1,4-tetramethylenediamine. 4-pyrrolidinopyridine, N, N′-dimethylpiperazine, N-ethylpiperidine, benzyltrimethylammonium chloride, benzyltriethylammonium chloride, tetramethylammonium chloride, tetraethylammonium bromide, phenyltriethylammonium chloride, triethylphosphine, triphenylphosphine , Diphenylbutylphosphine, tetra (hydroxymethyl) phosphonium chloride, benzyltriethylphosphonium chloride, benzyltriphenylphosphine Nium chloride, 4-methylpyridine, 1-methylimidazole, 1,2-dimethylimidazole, 3-methylpyridazine, 4,6-dimethylpyrimidine, 1-cyclohexyl-3,5-dimethylpyrazole, 2,3,5,6 -Tetramethylpyrazine etc. are mentioned.

The polycarbonate-forming catalyst is preferably a tertiary amine, more preferably a tertiary amine having 3 to 30 carbon atoms, and particularly preferably triethylamine. These polycarbonate formation catalysts may be used individually by 1 type, and may use 2 or more types together.
These polycarbonate formation catalysts can be added before or after adding a carbonic acid derivative such as phosgene or bischloroformate to the reaction system.

  Further, an antioxidant such as hydrosulfite may be added to prevent oxidation of the diol in the alkaline aqueous solution. The reaction temperature is usually 0 to 40 ° C., the reaction time is several minutes to 5 hours, and the pH during the reaction is preferably maintained at 10 or more.

On the other hand, when the solution polymerization method is applied, a polycarbonate resin is obtained by dissolving a diol in a solvent, adding a deoxidizing agent, and adding a bischloroformate or phosgene multimer thereto.
Examples of the deoxidizer in this case include tertiary amines such as trimethylamine, triethylamine, and tripropylamine, and pyridine.
The solvent used for the reaction is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include halogenated hydrocarbons such as dichloromethane, dichloroethane, trichloroethane, tetrachloroethane, trichloroethylene, chloroform, and tetrahydrofuran. Cyclic ether solvents such as dioxane and pyridine are preferred.
The reaction temperature at this time is 0 to 40 ° C., and the reaction time is several minutes to 5 hours.

A polycarbonate resin can also be produced by a transesterification method. In this case, a diol and bisallyl carbonate are mixed in the presence of an inert gas and reacted at 120 to 350 ° C. under reduced pressure. The degree of vacuum is changed step by step, and finally the phenols produced to 1 mmHg or less are distilled out of the system. The reaction time is about 1 to 4 hours.
Moreover, you may add antioxidant as needed.
The bisallyl carbonate is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include diphenyl carbonate, di-p-tolyl carbonate, phenyl-p-tolyl carbonate, di-p-chlorophenyl carbonate, and di- A naphthyl carbonate etc. are mentioned.

  A polymer organic component comprising a polycarbonate resin having at least one, preferably two or more functional groups in a molecule obtained by the various methods, and a functional group having reactivity with the functional groups in the polymer organic component. By reacting and bonding the metal alkoxide, a polymer for a hybrid material having a metal alkoxide group bonded to the polymer organic component can be obtained. Below, the metal alkoxide provided with the functional group is shown concretely.

There is no restriction | limiting in particular as said metal alkoxide, Although it can select suitably according to the objective, For example, the compound shown by the following general formula (a) is preferable.
R ₁ A _m M (R′X) _n (a)

(In formula (a), R ₁ represents an alkyl group having 1 to 12 carbon atoms, preferably 1 to 5 carbon atoms, A represents an alkoxy group having 1 to 8 carbon atoms, preferably 1 to 4 carbon atoms, and M represents , Si, Ti, Zr, Fe, Cu, Sn, B, Al, Ge, Ce, and Ta, preferably a metal element selected from any of the group consisting of Si, Ti, and Zr R ′ represents an alkylene group or alkylidene group having 1 to 4 carbon atoms, preferably 2 to 4 carbon atoms, and X consists of an isocyanate group, an epoxy group, a carboxyl group, an acid halogen group, and an acid anhydride group. Represents a functional group selected from any one of the groups, l represents an integer of 0 to 3, and m and n independently represent an integer of 1 to 3).

As described above, the metal element in the structural unit having a metal oxide bond is preferably at least one selected from the group consisting of Si, Ti and Zr.
Among these, Si is more preferable. When it is Si, it is easy to synthesize a polymer for a hybrid material, and the resulting polymer for a hybrid material has chemical stability. In addition, the obtained polymer for hybrid material has appropriate reactivity (temperature, time, etc.). For example, the polymer can be easily hydrolyzed and polycondensed (sol-gel reaction) to form an organic-inorganic hybrid. A material is obtained, and the cured polymer can have electrical, mechanical, physical and other properties useful for organic electronic devices, particularly electrophotographic photoreceptors.
Moreover, there is no restriction | limiting in particular as a raw material of the said metal alkoxide, For example, it can select widely like the following example and can also use it properly according to the objective.

  Examples of the metal alkoxide represented by the formula (a) include monoisocyanate trialkoxymetals, monoisocyanate dialkoxymetals, monoisocyanate monoalkoxymetals, diisocyanate alkoxymetals, triisocyanate alkoxymetals, and functionalized epoxy groups. Examples thereof include metal alkoxides having a group, alkylalkoxysilanes having an epoxy group as a functional group, metal alkoxides having an acid halide as a functional group, and alkoxysilanes having an amino group or a mercapto group as a functional group. Hereinafter, such metal alkoxides are specifically exemplified.

  Examples of monoisocyanate trialkoxymetals include 3-isocyanatopropyltriethoxysilane, 3-isocyanatopropyltrimethoxysilane, 2-isocyanateethyltriethoxysilane, 2-isocyanateethyltripropoxyzirconium, 2-isocyanateethyltributoxytin, and the like. Can be mentioned.

  Monoisocyanate dialkoxymetals include 3-isocyanatepropylethyldiethoxysilane, 3-isocyanatepropylethyldiisopropoxytitanium, 2-isocyanateethylethyldipropoxyzirconium, 2-isocyanateethylmethyldibutoxytin, and isocyanatemethyldimethoxyaluminum. Etc.

  Examples of monoisocyanate monoalkoxymetals include 3-isocyanatepropyldiethylethoxysilane, 3-isocyanatopropyldimethylisopropoxytitanium, 2-isocyanatoethyldiethylpropoxyzirconium, 2-isocyanatoethyldimethylbutoxytin, and isocyanatomethylmethylmethoxyaluminum. It is done.

Examples of the diisocyanate alkoxymetals include di (3-isocyanatopropyl) diethoxysilane, di (3-isocyanatopropyl) methylisopropoxytitanium, and the like.
Moreover, ethoxysilane triisocyanate etc. are mentioned as triisocyanate alkoxymetals.

Examples of the metal alkoxide having an epoxy group as a functional group include γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, and γ-glycidoxypropyldimethylethoxy. Silane, γ-glycidoxypropylmethyldiethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3,4-epoxybutyltrimethoxysilane, γ-glycidoxypropyltriisopropoxytitanium, γ -Glycidoxypropylmethyl diisopropoxy titanium, γ-glycidoxypropyl dimethyl isopropoxy titanium, 3,4-epoxybutyl tripropoxyzirconium, 3,4-epoxybutylmethyl dipropoxyzirconium, 3,4-epoxybutyl Methyl propoxy zirconium, beta-(3,4-epoxycyclohexyl) ethyl triethoxy tin, and the like.

  Alkyl alkoxysilanes having an alkoxy group as a functional group include methyltrimethoxysilane, ethyltriethoxysilane, isopropyltriisopropoxysilane, dimethyldimethoxysilane, diethyldiethoxysilane, diisopropyldiisopropoxysilane, trimethylmethoxysilane, and triethyl. Examples thereof include ethoxysilane and triisopropylisopropoxysilane.

  Examples of the metal alkoxide having an acid anhydride as a functional group include 3- (triethoxysilyl) -2-methylpropyl succinic anhydride.

  Examples of the metal alkoxide having an acid halide as a functional group include 2- (4-chlorosulfonylphenyl) ethyltriethoxysilane.

  Other examples of alkoxysilanes having amino groups or mercapto groups as functional groups include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, and 3-mercaptopropyltriethoxysilane. Is mentioned.

Furthermore, examples of the metal alkoxide include compounds represented by the following general formula (b).
AoM (b)

(In the formula (b), Ao represents an alkoxy group having 1 to 8 carbon atoms, preferably 1 to 4 carbon atoms, and M represents Si, Ti, Zr, Fe, Cu, Sn, B, Al, Ge, Ce, And represents a metal element selected from any of the group consisting of Si, Ti, and Zr.

  As described above, the metal element in the structural unit having a metal oxide bond is preferably at least one selected from the group consisting of Si, Ti and Zr. In particular, the metal element is more preferably Si. The reason is the same as the reason why Si is preferable for the general formula (a).

  Specific examples of the compound represented by the general formula (b) include tetraalkoxysilanes such as tetramethoxysilane, tetraethoxysilane, and tetrabutoxysilane; tetrapropoxytitanium, tetraisopropoxytitanium, tetraisopropoxyzirconium, tetrapropoxy Examples thereof include metal alkoxides such as zirconium, tetrabutoxytin, tetraisopropoxytin, and triisopropoxyaluminum.

  As said metal alkoxide, it may be used individually by 1 type and may use 2 or more types together. Alternatively, a metal alkoxide in which two or more kinds of metal elements are contained in one molecule or an oligomer type metal alkoxide having two or more repeating units in one molecule may be used.

As a polymer for a hybrid material containing a structural unit having a charge transport function as described above, a polymer organic component composed of a polycarbonate resin having at least one, preferably two or more functional groups in the molecule, and a polymer It is obtained by reacting a metal alkoxide having a functional group having reactivity with a functional group in the organic component.
In the reaction, a catalyst can also be used. Specific examples of the reaction between the polymer organic component and the metal alkoxide will be described below.

Specific examples of the reaction between the polymer organic component and the metal alkoxide include, for example, a polymer organic component composed of a polycarbonate resin having a functional group having an active hydrogen such as a hydroxyl group, an amino group, a carboxyl group, and a thiol group; It is preferable to react a metal alkoxide having a functional group such as an isocyanate group, an epoxy group, a carboxyl group, an acid halide group, or an acid anhydride group in a solvent in an inert gas atmosphere.
There is no restriction | limiting in particular as a solvent to be used, What is necessary is just to dissolve both the said polymer and metal alkoxide well.

In general, a metal alkoxide solution or a metal alkoxide is gradually added to a polymer solution as it is, and then reacted at room temperature or while gently warming.
The functional group amount in the metal alkoxide with respect to the functional group in the polymer organic component is preferably 1/10 to 10/1 equivalent ratio.
After completion of the reaction, the reaction solution may be used as it is, and may be transferred to the next step sol-gel reaction shown below, or the reaction solution may be concentrated or poured into a large amount of poor solvent to precipitate the reaction product. After performing treatments such as washing, purification, and drying, a sol-gel reaction may be performed using this.

--- Metal alkoxide compound ---
There is no restriction | limiting in particular as said metal alkoxide compound, Although it can select suitably according to the objective, Especially, the compound represented by a following formula (c) is preferable.
A _p M (c)

(In the formula (c), A represents an alkoxy group having 1 to 8 carbon atoms, preferably 1 to 4 carbon atoms, and M represents Si, Ti, Zr, Fe, Cu, Sn, B, Al, Ge, Ce, A metal element selected from any one of the group consisting of Ta, W, etc., preferably any one of the group consisting of Si, Ti, Zr, and p represents an integer of 2-6.)

  Specifically, tetraalkoxysilanes such as tetramethoxysilane, tetraethoxysilane, tetraisopropoxysilane, and tetrabutoxysilane, tetraalkoxy titaniums such as tetra n-propoxy titanium, tetraisopropoxy titanium, tetrabutoxy titanium, tetra Tetraalkoxyzirconium such as n-propoxyzirconium, tetraisopropoxyzirconium, tetrabutoxyzirconium, and dimethoxycopper, diethoxybarium, trimethoxyboron, triethoxygallium, tributoxyaluminum, tetraethoxygermanium, tetrabutoxylead, pentan -Metal alkoxides, such as propoxy tantalum and hexaethoxy tungsten.

  Among these, as the metal alkoxide compound, in the formula (c), M is preferably Si. This is because Si alkoxide is the most general-purpose and easy to apply.

Another example of the metal alkoxide compound is preferably a compound represented by the following formula (d).
R _k A _l M (R ″ _m X) _n (d)

(In the formula (d), R represents hydrogen and an alkyl group having 1 to 12 carbon atoms, preferably 1 to 5 alkyl groups or a phenyl group, and A represents 1 to 8 carbon atoms, preferably 1 to 4 carbon atoms. Represents an alkoxy group, and M is one of the group consisting of Si, Ti, Zr, Fe, Cu, Sn, B, Al, Ge, Ce, Ta and W, preferably the group consisting of Si, Ti, Zr Represents a metal element selected from any of the above, R ″ represents an alkylene group or alkylidene group having 1 to 4 carbon atoms, preferably 2 to 4 carbon atoms, and X represents an isocyanate group, an epoxy group, a carboxyl group, or an acid halide group. , An acid anhydride group, an amino group, a thiol group, a vinyl group, a methacryl group, a halogen group and the like, k represents an integer of 0 to 5, l represents an integer of 1 to 5, m Represents an integer of 0 to 1, and n is an integer of 0 to 5 Show.)

  The compound represented by the formula (d) is exemplified by Si, specifically, trimethoxysilane, triethoxysilane, tri-n-propoxysilane, dimethoxysilane, diethoxysilane, diisopropoxysilane. , Monomethoxysilane, monoethoxysilane, monobutoxysilane, methyldimethoxysilane, ethyldiethoxysilane, dimethylmethoxysilane, diisopropylisopropoxysilane, methyltrimethoxysilane, ethyltriethoxysilane, n-propyltrin-propoxysilane, Butyltributoxysilane, dimethyldimethoxysilane, diethyldiethoxysilane, diisopropyldiisopropoxysilane, dibutyldibutoxysilane, trimethylmethoxysilane, triethylethoxylane, tri-n-propyl n-propyl Pokishishiran, tributyl-butoxy silane, phenyl trimethoxysilane, diphenyl diethoxy silane, (alkyl) alkoxysilanes such as triphenyl silane;

  3-isocyanatopropyltriethoxysilane, 2-isocyanatoethyltri-n-propoxysilane, 3-isocyanatopropylmethyldimethoxysilane, 2-isocyanatoethylethyldibutoxysilane, 3-isocyanatopropyldimethylisopropoxysilane, 2-isocyanatoethyldiethylbutoxy (Alkyl) alkoxysilanes having an isocyanate group such as silane, di (3-isocyanatopropyl) diethoxysilane, di (3-isocyanatopropyl) methylethoxysilane, ethoxysilane triisocyanate;

  3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyldimethylethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3,4-epoxy (Alkyl) alkoxysilanes having an epoxy group such as butyltrimethoxysilane;

  (Alkyl) alkoxysilanes having a carboxyl group such as carboxymethyltriethoxysilane, carboxymethylethyldiethoxysilane, carboxyethyldimethylmethoxysilane and the like;

  Alkoxysilanes having acid anhydride groups such as 3- (triethoxysilyl) -2-methylpropyl succinic anhydride;

  Alkoxysilanes having acid halide groups such as 2- (4-chlorosulfonylphenyl) ethyltriethoxysilane;

  3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-2- (aminoethyl) -3-aminopropyltriethoxysilane, N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane, (Alkyl) alkoxysilane having an amino group such as N-phenyl-3-aminopropyltrimethoxysilane;

  (Alkyl) alkoxysilanes having a thiol group such as 3-mercaptopropyltrimethoxysilane, 2-mercaptoethyltriethoxysilane, 3-mercaptopropylmethyldimethoxysilane and the like;

  (Alkyl) alkoxysilanes having a vinyl group such as vinyltrimethoxysilane, vinyltriethoxysilane, vinylmethyldiethoxysilane;

  (Alkyl) alkoxysilanes having a methacrylic group such as 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-methacryloxypropylmethyldimethylsilane;

  And (alkyl) alkoxysilane having a halogen group such as triethoxyfluorosilane, 3-chloropropyltrimethoxysilane, 3-bromopropyltriethoxysilane, 2-chloroethylmethyldimethoxysilane, and the like.

  As the compound represented by the formula (d), not only Si according to the above example but also other metals such as Ti, Zr, Fe, Cu, Sn, B, Al, Ge, Ce, Ta, and W may be used. A compound having a similar structure can be exemplified.

These metal alkoxide compounds may be used alone or in combination of two or more. In addition, Mg [Al (iso-OC ₃ H ₇ ) ₄ ] ₂ , Ba [Zr ₂ (OC ₂ H ₅ ) ₉ ] ₂ , (C ₃ H ₇ O) ₂ Zr [Al (OC ₃ H ₇ ) ₄ ] oligomer type having two or more repeating units per molecule, such as a metal alkoxide compound and tetramethoxysilane oligomer and tetraethoxysilane oligomer appears to contain two or more metal elements in one molecule of _2, etc. Metal alkoxide compounds may be used. Further, the alkoxy group may be an acetoxy group.

The charge transporting organic-inorganic hybrid material having a tilted structure can be obtained by hydrolyzing and polycondensing a charge transporting polymer having a metal alkoxide group and a metal alkoxide compound by a sol-gel reaction.
At this time, the composition ratio between the charge transporting polymer having a metal alkoxide group and the metal alkoxide compound is not particularly limited and may be appropriately selected depending on the intended purpose. For example, the charge transporting property having a metal alkoxide group The mass ratio of the polymer to the metal alkoxide compound is 1:99 to 99: 1, preferably 10:90 to 90:10.
When the mass ratio of the charge transporting polymer having a metal alkoxide group to the metal alkoxide compound is 10:90 to 90:10, the toughness of the organic material possessed by the charge transporting polymer, the electrical characteristics, and the metal alkoxide It is possible to obtain a protective layer of an electrophotographic photosensitive member that is well balanced with the mechanical strength of the inorganic material possessed by the compound and has both excellent electrical characteristics and durability.

Hydrolysis and polycondensation by the sol-gel method means that a polymer having a metal alkoxide group in the molecule is reacted with water to convert the alkoxy group to a hydroxyl group, and then this hydroxyl group is simultaneously polycondensed. As a result, a polymer having a hydroxy metal group (for example, —Si (OH) ₃ ) and a hydroxy metal compound undergo a dehydration reaction or a dealcoholization reaction with an adjacent molecule, and three-dimensionally through an inorganic covalent bond. Refers to the reaction of cross-linking.
As water used for the hydrolysis reaction, an amount necessary for converting all alkoxy groups to hydroxyl groups may be added, or moisture in the reaction system may be used or moisture in the atmosphere may be absorbed. You may do it.
The reaction conditions are preferably about 0.5 to 24 hours under a temperature condition of room temperature to 100 ° C.
At that time, an acidic catalyst such as hydrochloric acid, sulfuric acid, acetic acid, benzenesulfonic acid, p-toluenesulfonic acid, or a basic catalyst such as sodium hydroxide, potassium hydroxide, ammonia, triethylamine, or piperidine may be used.
The obtained reaction solution can be used as it is as a coating solution for a photoreceptor.
As described above, the charge transporting organic-inorganic hybrid material having an inclined structure used in the electrophotographic photoreceptor of the present invention has been described. An embodiment in which this is applied to a protective layer (surface layer) will be described below. .

The protective layer (surface layer) is formed by applying a solution having a different composition ratio between the charge transporting polymer having a metal alkoxide group and a metal alkoxide compound as a coating solution, and curing the coating. The
As said coating liquid, it dilutes with a solvent as needed, and is apply | coated.
The solvent used at this time is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include alcohols such as methanol, ethanol, propanol and butanol, and ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone. Systems, ester systems such as ethyl acetate and butyl acetate, ether systems such as tetrahydrofuran, dioxane and propyl ether, halogen systems such as dichloromethane, dichloroethane, trichloroethane and chlorobenzene, aromatic systems such as benzene, toluene and xylene, methyl cellosolve and ethyl Cellosolve such as cellosolve and cellosolve acetate can be used.
These solvent may be used individually by 1 type, and may use 2 or more types together.
Further, the dilution rate of the coating solution with these solvents is not particularly limited, and can be selected according to the solubility of the coating solution composition, the coating method, and the desired film thickness. .
The application method is not particularly limited, and examples thereof include a dip coating method, spray coating, bead coating, and ring coating.

Among them, the spray method is an effective means, and the following method can be mentioned as the optimum method.
One is a method in which protective layer coating liquids having different ratios of a charge transporting polymer having a plurality of metal alkoxide groups and a metal alkoxide compound are sequentially laminated by a spray method before the lower layer is dried. In this case, it is desirable to prepare as many spray heads as the number of coating liquids and perform coating continuously.
Another one is a method in which a coating solution for a protective layer having a different ratio between a charge transporting polymer having a plurality of metal alkoxide groups and a metal alkoxide compound is sequentially laminated by spraying after the lower layer is dried by touch It is. In this case, it is desirable to prepare as many spray heads as the number of coating liquids and perform coating continuously.

  Before applying the coating liquid having the charge transporting polymer having a metal alkoxide group and the metal alkoxide compound, a small amount of an acidic catalyst is added, and the temperature is about 0.5 to 24 hours at room temperature to 100 ° C. It is preferable to carry out the hydrolysis reaction. Under such reaction conditions, the charge transporting polymer having the metal alkoxide group and the metal alkoxide compound are easily crosslinked.

After applying the coating liquid, a sol-gel crosslinking reaction is performed, and a heat treatment is performed when a protective layer made of a charge transporting organic-inorganic hybrid material is formed.
The conditions for the heat treatment are preferably about 5 minutes to 24 hours under a temperature condition of 50 to 250 ° C.
If it is less than 50 degreeC, reaction rate is slow and reaction does not complete | finish completely. When the temperature is higher than 250 ° C., the reaction proceeds non-uniformly and a large strain is generated in the surface layer.
In order to advance the curing reaction uniformly, it is also effective to complete the reaction by heating at a relatively low temperature of less than 100 ° C. and then heating to 100 ° C. or more.
Since the thickness of the protective layer varies depending on the layer structure of the photoreceptor having the protective layer, it will be described later together with the layer structure.

  The protective layer prepared by crosslinking and curing is preferably insoluble in an organic solvent. A film that is not sufficiently cured is soluble in an organic solvent and has a low crosslink density, so that the mechanical durability is also low.

-Conductive support-
There is no restriction | limiting in particular as an electroconductive support body, Although it can select suitably according to the objective, What shows electroconductivity with a volume resistance of 10 < ¹⁰ > ohm * cm or less is preferable. As such a conductive support, for example, a metal such as aluminum, nickel, chromium, nichrome, copper, gold, silver, platinum, or a metal oxide such as tin oxide or indium oxide is deposited or sputtered to form a film or Cylindrical plastic, paper coated, or aluminum, aluminum alloy, nickel, stainless steel, etc., and extruding them into a tube by a method such as drawing, then applying surface treatments such as cutting, superfinishing, and polishing. Can be used.
Further, endless nickel belts and endless stainless steel belts disclosed in JP-A-52-36016 can also be used as the conductive support.

  In addition, the conductor support may be coated by dispersing conductive powder in an appropriate binder resin.

There is no restriction | limiting in particular as this electroconductive powder, According to the objective, it can select suitably, For example, metals, such as carbon black, acetylene black, and aluminum, nickel, iron, nichrome, copper, zinc, silver, etc. Examples thereof include powder, or metal oxide powder such as conductive tin oxide and ITO.
The binder resin used simultaneously is polystyrene, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyester, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer. , Polyvinyl acetate, polyvinylidene chloride, polyarylate resin, phenoxy resin, polycarbonate, cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral, polyvinyl formal, polyvinyl toluene, poly-N-vinyl carbazole, acrylic resin, silicone resin, epoxy resin, Examples thereof include thermoplastic, thermosetting resins, and photocurable resins such as melamine resin, urethane resin, phenol resin, and alkyd resin.
Such a conductive layer can be provided by dispersing and applying the conductive powder and the binder resin in a suitable solvent such as tetrahydrofuran, dichloromethane, methyl ethyl ketone, toluene and the like.

  Furthermore, it is electrically conductive by a heat-shrinkable tube in which the conductive powder is contained in a material such as polyvinyl chloride, polypropylene, polyester, polystyrene, polyvinylidene chloride, polyethylene, chlorinated rubber, Teflon (registered trademark) on a suitable cylindrical substrate. Those provided with a conductive layer can also be used favorably as the conductive support.

-Photosensitive layer-
Next, the photosensitive layer will be described.
There is no restriction | limiting in particular as said photosensitive layer, According to the objective, it can select suitably, A laminated structure or a single layer structure may be sufficient.

  In the case of a laminated structure, the photosensitive layer is composed of a charge generation layer having a charge generation function and a charge transport layer having a charge transport function. In the case of a single layer structure, the photosensitive layer is composed of a layer having both a charge generation function and a charge transport function.

  Hereinafter, each of the photosensitive layer having a laminated structure and the photosensitive layer having a single layer structure will be described.

<Photosensitive layer with a laminated structure>
<< Charge generation layer >>
The charge generation layer is not particularly limited as long as it is a layer mainly composed of a charge generation material having a charge generation function, and may contain a binder resin as necessary. As the charge generation material, inorganic materials and organic materials can be used.

Examples of the inorganic material include crystalline selenium, amorphous selenium, selenium-tellurium, selenium-tellurium-halogen, selenium-arsenic compounds, and amorphous silicon.
As the amorphous silicon, those in which dangling bonds are terminated with hydrogen atoms or halogen atoms, or those in which boron atoms or phosphorus atoms are doped are preferably used.

  On the other hand, there is no restriction | limiting in particular as said organic type material, According to the objective, it can select suitably, A well-known material can be used. For example, phthalocyanine pigments such as metal phthalocyanine and metal-free phthalocyanine, azulenium salt pigments, squaric acid methine pigments, azo pigments having a carbazole skeleton, azo pigments having a triphenylamine skeleton, azo pigments having a diphenylamine skeleton, dibenzothiophene skeleton Azo pigments having fluorenone skeleton, azo pigments having oxadiazole skeleton, azo pigments having bis-stilbene skeleton, azo pigments having distyryl oxadiazole skeleton, azo pigments having distyrylcarbazole skeleton, perylene Pigments, anthraquinone or polycyclic quinone pigments, quinoneimine pigments, diphenylmethane and triphenylmethane pigments, benzoquinone and naphthoquinone pigments, cyanine and azomethine pigments, Goido based pigments, and bisbenzimidazole pigments. These charge generation materials can be used alone or as a mixture of two or more.

The binder resin used as necessary for the charge generation layer is not particularly limited and may be appropriately selected according to the purpose. Polyamide, polyurethane, epoxy resin, polyketone, polycarbonate, silicone resin, acrylic resin, polyvinyl Examples include butyral, polyvinyl formal, polyvinyl ketone, polystyrene, poly-N-vinyl carbazole, and polyacrylamide.
These binder resins may be used alone or in combination of two or more.
In addition to the binder resin, a polymer charge transport material having a charge transport function, for example, polycarbonate, polyester, polyurethane, polysiloxane having arylamine skeleton, benzidine skeleton, hydrazone skeleton, carbazole skeleton, stilbene skeleton, pyrazoline skeleton, etc. Polymer materials such as ether, polysiloxane, and acrylic resin, polymer materials having a polysilane skeleton, and the like can be used.

  Specific examples of the former include JP-A-01-001728, JP-A-01-009964, JP-A-01-013061, JP-A-01-019049, JP-A-01-241559, Japanese Unexamined Patent Publication Nos. 04-011627, 04-175337, 04-183719, 04-2225014, 04-230767, 04-320420, 05 -232727, JP-A 05-310904, JP-A 06-234836, JP-A 06-234837, JP-A 06-234838, JP-A 06-234839, JP-A 06-234840. No. 1, JP-A 06-234841, JP-A 06-239049, Japanese Unexamined Patent Publication Nos. 06-236050, 06-236051, 06-295077, 07-0756374, 08-176293, 08-208820, 08 No. -21640, JP 08-253568, JP 08-269183, JP 09-062019, JP 09-043883, JP 09-71642, JP 09-87376. JP-A 09-104746, JP-A 09-110974, JP-A 09-110976, JP-A 09-157378, JP-A 09-221544, JP-A 09-227669. JP 09-235367 A, JP 09-241369 A Charge transporting polymer materials described in JP 09-268226 A, JP 09-272735 A, JP 09-302084 A, JP 09-302085 A, JP 09-328539 A, etc. Can be mentioned.

  Specific examples of the latter include polysilylene polymers described in, for example, JP-A-63-285552, JP-A-05-19497, JP-A-05-70595, and JP-A-10-73944. Is exemplified.

  The charge generation layer may contain a low molecular charge transport material.

  Examples of the low molecular charge transport material that can be used in the charge generation layer include a hole transport material and an electron transport material.

  The electron transport material is not particularly limited and may be appropriately selected depending on the intended purpose. For example, chloroanil, bromilyl, tetracyanoethylene, tetracyanoquinodimethane, 2,4,7-trinitro-9-fluorenone 2,4,5,7-tetranitro-9-fluorenone, 2,4,5,7-tetranitroxanthone, 2,4,8-trinitrothioxanthone, 2,6,8-trinitro-4H-indeno [1 , 2-b] thiophen-4-one, 1,3,7-trinitrodibenzothiophene-5,5-dioxide, and diphenoquinone derivatives. These electron transport materials may be used alone or in combination of two or more.

  The hole transport material is not particularly limited and may be appropriately selected depending on the purpose, but an electron donating material is preferable. Such hole transport materials include oxazole derivatives, oxadiazole derivatives, imidazole derivatives, monoarylamine derivatives, diarylamine derivatives, triarylamine derivatives, stilbene derivatives, α-phenylstilbene derivatives, benzidine derivatives, diarylmethane derivatives. , Triarylmethane derivatives, 9-styrylanthracene derivatives, pyrazoline derivatives, divinylbenzene derivatives, hydrazone derivatives, indene derivatives, butadiene derivatives, pyrene derivatives, and the like, and other known materials such as bisstilbene derivatives and enamine derivatives. These hole transport materials may be used alone or in combination of two or more.

  There is no restriction | limiting in particular as a method of forming the said charge generation layer, According to the objective, it can select suitably, For example, the vacuum thin film preparation method and the casting method from a solution dispersion system are mentioned largely.

  Examples of the former method include a vacuum deposition method, a glow discharge decomposition method, an ion plating method, a sputtering method, a reactive sputtering method, a CVD method, and the like, and the inorganic material and the organic material can be favorably formed.

In order to provide a charge generation layer by a casting method described later, the inorganic or organic charge generation material, together with a binder resin if necessary, tetrahydrofuran, dioxane, dioxolane, toluene, dichloromethane, monochlorobenzene, dichloroethane, cyclohexanone, Formed by dispersing with a ball mill, attritor, sand mill, bead mill, etc. using a solvent such as cyclopentanone, anisole, xylene, methyl ethyl ketone, acetone, ethyl acetate, butyl acetate, etc. it can.
Moreover, leveling agents, such as a dimethyl silicone oil and a methylphenyl silicone oil, can be added as needed.
The application method is not particularly limited, and examples thereof include a dip coating method, spray coating, bead coating, and ring coating.

The thickness of the charge generation layer provided as described above is preferably 0.01 to 5 μm, and more preferably 0.05 to 2 μm.
If the film thickness is less than 0.01 μm, the sensitivity of the photoreceptor may be lowered, and if it exceeds 5 μm, the charge of the photoreceptor may be reduced by repeated use.

<< Charge transport layer >>
The charge transport layer is a layer having a charge transport function. A protective layer of charge transporting organic-inorganic hybrid material having a gradient structure is formed on the charge transport layer, and the charge transport layer dissolves or disperses a charge transport material having a charge transport function and a binder resin in an appropriate solvent. A plurality of coating liquids containing a metal-alkoxide compound and a charge-transporting polymer having a metal alkoxide group in which the composition ratio of the present invention is changed. Apply twice and heat and cure by sol-gel crosslinking.

  As the charge transport material, the electron transport material, hole transport material and polymer charge transport material described in the charge generation layer can be used. As described above, the use of the polymer charge transport material can reduce the solubility of the lower layer when the protective layer is applied, and is particularly useful.

  The binder resin is not particularly limited and may be appropriately selected depending on the intended purpose.For example, polystyrene, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, Polyester, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, polyvinylidene chloride, polyarylate resin, phenoxy resin, polycarbonate, cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral, polyvinyl formal, polyvinyl toluene, poly- Examples thereof include thermoplastic or thermosetting resins such as N-vinylcarbazole, acrylic resin, silicone resin, epoxy resin, melamine resin, urethane resin, phenol resin, alkyd resin.

  As content of the said charge transport material, it is 20-300 mass parts with respect to 100 mass parts of binder resin, and 40-150 mass parts is preferable. However, when a polymer charge transport material is used, the polymer charge transport material may be used alone or in combination with a binder resin.

  As the solvent used for coating the charge transport layer, the same solvent as the charge generation layer can be used, but a solvent that dissolves the charge transport material and the binder resin well is preferable. These solvents may be used alone or in combination of two or more. The charge transport layer can be formed by the same coating method as that for the charge generation layer.

  If necessary, a plasticizer and a leveling agent can be added.

  As the plasticizer that can be used in combination with the charge transport layer, those used as general resin plasticizers such as dibutyl phthalate and dioctyl phthalate can be used as they are, and the amount used is 0 with respect to 100 parts by mass of the binder resin. About 30 mass parts is preferable.

  As the leveling agent that can be used in combination with the charge transport layer, silicone oils such as dimethyl silicone oil and methylphenyl silicone oil, and polymers or oligomers having a perfluoroalkyl group in the side chain are used. About 0-1 mass part is preferable with respect to 100 mass parts of resin.

  As a film thickness of the said charge transport layer, it is about 5-40 micrometers, and 10-30 micrometers is preferable.

  As a film thickness of the said protective layer, it is 1-20 micrometers, and 2-10 micrometers is preferable. When the thickness is less than 1 μm, the durability varies due to uneven film thickness, and when the thickness is more than 20 μm, the entire thickness of the charge transport layer is increased and the reproducibility of the image is deteriorated due to the diffusion of charges.

<Photosensitive layer having a single layer structure>
The photosensitive layer having a single layer structure is a layer having a charge generation function and a charge transport function at the same time.
The protective layer is formed as a surface layer of a photoreceptor on a photosensitive layer having a single layer structure. In this case, the photosensitive layer can be formed by dissolving or dispersing a charge generation material having a charge generation function, a charge transport material having a charge transport function, and a binder resin in an appropriate solvent, and applying and drying the solution.
Moreover, a plasticizer, a leveling agent, etc. can also be added as needed. As the charge generation material dispersion method, the charge generation material, the charge transport material, the plasticizer, and the leveling agent may be the same as those already described in the charge generation layer and the charge transport layer.
As the binder resin, in addition to the binder resin mentioned in the section of the charge transport layer, a binder resin mentioned in the charge generation layer may be mixed and used.
In addition, the above-described polymer charge transport materials can also be used, which is useful in that contamination of the lower photosensitive layer composition into the surface layer can be reduced. The film thickness of the lower layer portion of the photosensitive layer is about 5 to 30 μm, and preferably 10 to 25 μm.

The composition ratio of the charge transporting polymer having the metal alkoxide group and the metal alkoxide compound is changed on the photosensitive layer by applying a coating solution containing the charge transporting polymer having the metal alkoxide group and the metal alkoxide compound. Cross-linking protection including a compound (organic-inorganic hybrid material) in which a charge-transporting polymer having a metal alkoxide group and a metal alkoxide compound are cross-linked Form a layer.
At this time, as a film thickness of a crosslinked protective layer, it is 1-20 micrometers, and 2-10 micrometers is preferable. When the thickness is less than 1 μm, the durability varies due to the film thickness unevenness. If it is thicker than 20 μm, the bright part potential may be increased.

  The content of the charge generation material contained in the photosensitive layer having the single layer structure is preferably 1 to 30% by mass with respect to the total amount of the photosensitive layer, and the content of the binder resin contained in the lower layer portion of the photosensitive layer is as follows: 20 to 80% by mass of the total amount of the photosensitive layer is preferable, and the content of the charge transport material is preferably 10 to 70 parts by mass with respect to the total amount of the photosensitive layer.

-Other layers-
There is no restriction | limiting in particular as said other layer, According to the objective, it can select suitably, For example, an undercoat layer etc. are mentioned.

--Undercoat layer--
In the photoreceptor, an undercoat layer can be provided between the conductive support and the photosensitive layer. In general, the undercoat layer is mainly composed of a resin. However, considering that the photosensitive layer is coated with a solvent on these resins, the resin may be a resin having high solvent resistance with respect to a general organic solvent. preferable.
Such a resin is not particularly limited and may be appropriately selected depending on the purpose. Water-soluble resins such as polyvinyl alcohol, casein and sodium polyacrylate, alcohol-soluble such as copolymer nylon and methoxymethylated nylon Examples thereof include curable resins that form a three-dimensional network structure such as resins, polyurethanes, melamine resins, phenol resins, alkyd-melamine resins, and epoxy resins. Further, a metal oxide fine powder pigment exemplified by titanium oxide, silica, alumina, zirconium oxide, tin oxide, indium oxide and the like may be added to the undercoat layer in order to prevent moire and reduce residual potential.

These undercoat layers can be formed using the same solvent and coating method as described for the photosensitive layer.
Furthermore, a silane coupling agent, a titanium coupling agent, a chromium coupling agent, or the like can be used as the undercoat layer.
In addition, the undercoat layer is formed by anodizing Al ₂ O ₃ , organic materials such as polyparaxylylene (parylene), and inorganic materials such as SiO ₂ , SnO ₂ , TiO ₂ , ITO, and CeO _2. Can also be used favorably. In addition, known ones can be used. The thickness of the undercoat layer is 0 to 5 μm.

<Addition of antioxidant to each layer>
In order to improve environmental resistance, an antioxidant is added to each layer such as the cross-linked surface layer, charge generation layer, charge transport layer, subbing layer, and intermediate layer, especially for the purpose of preventing sensitivity drop and increase in residual potential. can do.

  There is no restriction | limiting in particular as said antioxidant, According to the objective, it can select suitably, For example, the following are mentioned.

<< Phenolic compound >>
2,6-di-t-butyl-p-cresol, butylated hydroxyanisole, 2,6-di-t-butyl-4-ethylphenol, stearyl-β- (3,5-di-t-butyl-4 -Hydroxyphenyl) propionate, 2,2'-methylene-bis- (4-methyl-6-tert-butylphenol), 2,2'-methylene-bis- (4-ethyl-6-tert-butylphenol), 4, 4'-thiobis- (3-methyl-6-tert-butylphenol), 4,4'-butylidenebis- (3-methyl-6-tert-butylphenol), 1,1,3-tris- (2-methyl-4 -Hydroxy-5-t-butylphenyl) butane, 1,3,5-trimethyl-2,4,6-tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene, tetrakis- [methylene- -(3 ', 5'-di-t-butyl-4'-hydroxyphenyl) propionate] methane, bis [3,3'-bis (4'-hydroxy-3'-t-butylphenyl) butyric acid] Examples include cholesteric esters and tocopherols.

<< Paraphenylenediamines >>
N-phenyl-N'-isopropyl-p-phenylenediamine, N, N'-di-sec-butyl-p-phenylenediamine, N-phenyl-N-sec-butyl-p-phenylenediamine, N, N'- Examples include di-isopropyl-p-phenylenediamine and N, N′-dimethyl-N, N′-di-t-butyl-p-phenylenediamine.

<< Hydroquinones >>
2,5-di-t-octylhydroquinone, 2,6-didodecylhydroquinone, 2-dodecylhydroquinone, 2-dodecyl-5-chlorohydroquinone, 2-t-octyl-5-methylhydroquinone, 2- (2-octadecenyl) ) -5-methylhydroquinone and the like.

<< Organic sulfur compounds >>
Examples include dilauryl-3,3′-thiodipropionate, distearyl-3,3′-thiodipropionate, and ditetradecyl-3,3′-thiodipropionate.

<< Organic phosphorus compounds >>
Examples include triphenylphosphine, tri (nonylphenyl) phosphine, tri (dinonylphenyl) phosphine, tricresylphosphine, and tri (2,4-dibutylphenoxy) phosphine.

  These compounds are known as antioxidants such as rubbers, plastics and fats and oils, and commercially available products can be easily obtained.

  As addition amount of the said antioxidant, it is 0.01-10 mass% with respect to the total mass of the layer to add.

  Hereinafter, the electrophotographic photoreceptor will be described together with its layer structure.

<Layer structure of electrophotographic photoreceptor>
The layer structure of the electrophotographic photoreceptor will be described with reference to the drawings.

FIG. 1 is a cross-sectional view showing the electrophotographic photosensitive member. A single-layer photosensitive member having a single-layered photosensitive layer 22 having a charge generating function and a charge transporting function on a conductive support 23 is shown. It is shown. Further, a protective layer 21 containing an organic-inorganic hybrid material having an inclined structure is disposed on the photosensitive layer 22, and the protective layer 21 forms a surface layer of the photoreceptor.
In the figure, 26 indicates the photosensitive layer side of the protective layer, and 27 indicates the surface side opposite to the photosensitive layer side.

FIG. 2 shows a photosensitive member having a photosensitive layer 32 having a laminated structure in which a charge generation layer 34 having a charge generation function and a charge transport layer 35 having a charge transport material function are stacked on a conductive support 33. Has been. On the charge transport layer 35, a protective layer 31 containing an organic-inorganic hybrid material having an inclined structure is disposed, and the protective layer 31 forms a surface layer of the photoreceptor.
In the figure, 36 indicates the photosensitive layer side of the protective layer, and 37 indicates the surface side opposite to the photosensitive layer side.

(Image forming method, image forming apparatus, and image forming process cartridge)
Next, the image forming method and the image forming apparatus of the present invention will be described in detail.

-Image forming method-
The image forming method includes an electrostatic latent image forming step, a pre-development step, a transfer step, and a fixing step, and further includes other steps as necessary. In addition, the electrostatic latent image forming process, the pre-development process, the transfer process, and the fixing process are repeatedly performed.

  As an image forming method, a photoreceptor having a smooth charge transporting cross-linked surface layer is used. For example, after at least a process of forming an electrostatic latent image (charging, exposure) and development on the photoreceptor, an image holding member ( The toner image is transferred onto a transfer sheet), fixed, and the surface of the photoreceptor is cleaned.

  In some cases, an image forming method or the like in which an electrostatic latent image is directly transferred to a transfer member and developed does not necessarily have the above-described process arranged on a photosensitive member.

--Electrostatic latent image forming step and electrostatic latent image forming means--
The electrostatic latent image forming step is a step of forming an electrostatic latent image on the electrophotographic photosensitive member.
The material, shape, structure, size, etc. of the electrophotographic photosensitive member (photosensitive member) are not particularly limited, and can be appropriately selected from known ones. The shape is preferably a drum shape. Examples of the material include inorganic photoreceptors such as amorphous silicon and selenium, and organic photoreceptors such as polysilane and phthalopolymethine. Among these, amorphous silicon or the like is preferable in terms of long life.
The formation of the electrostatic latent image can be performed, for example, by uniformly charging the surface of the electrophotographic photosensitive member and then performing imagewise exposure, and can be performed by the electrostatic latent image forming unit. it can. The electrostatic latent image forming means includes at least a charger that uniformly charges the surface of the electrophotographic photosensitive member and an exposure device that exposes the surface of the electrophotographic photosensitive member imagewise.
The charging can be performed, for example, by applying a voltage to the surface of the electrophotographic photosensitive member using the charger.
The charger is not particularly limited and may be appropriately selected depending on the purpose. For example, a known contact charging device including a conductive or semiconductive roll, brush, film, rubber blade, etc. And non-contact chargers using corona discharge such as corotrons and corotrons.
The exposure can be performed, for example, by exposing the surface of the electrophotographic photosensitive member imagewise using the exposure device.
The exposure device is not particularly limited as long as the surface of the electrophotographic photosensitive member charged by the charger can be exposed like an image to be formed, and can be appropriately selected according to the purpose. However, various exposure devices such as a copying optical system, a rod lens array system, a laser optical system, and a liquid crystal shutter optical system can be used.
In the present invention, an optical backside system that performs imagewise exposure from the backside of the electrophotographic photosensitive member may be employed.

--Development process and development means--
The developing step is a step of developing the electrostatic latent image using the developer to form a visible image.
The visible image can be formed, for example, by developing the electrostatic latent image using the developer of the present invention, and can be performed by the developing unit.
The developing unit is not particularly limited as long as it can be developed using, for example, the developer, and can be appropriately selected from known ones. For example, the developer is accommodated and the electrostatic latent is stored. Suitable examples include those having at least a developer capable of applying the developer to the image in a contact or non-contact manner, and more preferably a developer equipped with the developer-containing container.
The developing unit may be a dry developing type, a wet developing type, a single color developing unit, or a multi-color developing unit. Well, for example, a developer having a stirrer for charging the developer by frictional stirring and a rotatable magnet roller is preferable.
In the developing device, for example, the toner and the carrier are mixed and agitated, and the toner is charged by friction at that time, and held on the surface of the rotating magnet roller in a raised state to form a magnetic brush. . Since the magnet roller is disposed in the vicinity of the electrophotographic photosensitive member (photosensitive member), a part of the toner constituting the magnetic brush formed on the surface of the magnet roller is caused by an electric attractive force. It moves to the surface of the electrophotographic photosensitive member (photosensitive member). As a result, the electrostatic latent image is developed with the toner, and a visible image is formed with the toner on the surface of the electrophotographic photosensitive member (photosensitive member).

--- Transfer process and transfer means--
The transfer step is a step of transferring the visible image onto a recording medium. After the primary transfer of the visible image onto the intermediate transfer member using an intermediate transfer member, the visible image is transferred onto the recording medium. A primary transfer step of forming a composite transfer image by transferring a visible image onto an intermediate transfer body using two or more colors, preferably full color toner as the toner, and a composite transfer image; A mode including a secondary transfer step of transferring the transfer image onto the recording medium is more preferable.
The transfer can be performed, for example, by charging the electrophotographic photosensitive member (photosensitive member) with respect to the visible image using a transfer charger, and can be performed by the transfer unit. The transfer means includes a primary transfer means for transferring a visible image onto an intermediate transfer member to form a composite transfer image, and a secondary transfer means for transferring the composite transfer image onto a recording medium. Embodiments are preferred.
The intermediate transfer member is not particularly limited and may be appropriately selected from known transfer members according to the purpose. For example, a transfer belt and the like are preferable.
The transfer means (the primary transfer means and the secondary transfer means) includes a transfer device that peels and charges the visible image formed on the electrophotographic photosensitive member (photosensitive member) to the recording medium side. It is preferable to have at least. There may be one transfer means or two or more transfer means.
Examples of the transfer device include a corona transfer device using corona discharge, a transfer belt, a transfer roller, a pressure transfer roller, and an adhesive transfer device.
The recording medium is typically plain paper, but is not particularly limited as long as it can transfer an unfixed image after development, and can be appropriately selected according to the purpose. PET for OHP A base or the like can also be used.

The fixing step is a step of fixing the visible image transferred to the recording medium using a fixing device, and may be performed each time the toner of each color is transferred to the recording medium, or for the toner of each color. You may perform this simultaneously in the state which laminated | stacked this.
There is no restriction | limiting in particular as said fixing device, Although it can select suitably according to the objective, A well-known heating-pressing means is suitable. Examples of the heating and pressing means include a combination of a heating roller and a pressure roller, a combination of a heating roller, a pressure roller, and an endless belt.
The heating in the heating and pressing means is usually preferably 80 to 200 ° C.
In the present invention, for example, a known optical fixing device may be used together with or in place of the fixing step and the fixing unit depending on the purpose.

The neutralization step is a step of performing neutralization by applying a neutralization bias to the electrophotographic photosensitive member, and can be suitably performed by a neutralization unit.
The neutralization means is not particularly limited, and may be appropriately selected from known neutralizers as long as it can apply a neutralization bias to the electrophotographic photosensitive member. For example, a neutralization lamp is preferably used. Can be mentioned.

The cleaning step is a step of removing the toner remaining on the electrophotographic photosensitive member, and can be suitably performed by a cleaning unit.
The cleaning means is not particularly limited, and may be selected from known cleaners as long as the electrophotographic toner remaining on the electrophotographic photosensitive member can be removed. For example, a magnetic brush cleaner Suitable examples include electrostatic brush cleaners, magnetic roller cleaners, blade cleaners, brush cleaners, web cleaners, and the like.

The recycling process is a process of recycling the developer removed by the cleaning process to the developing unit, and can be suitably performed by the recycling unit.
There is no restriction | limiting in particular as said recycling means, A well-known conveyance means etc. are mentioned.

-Image forming device-
The image forming apparatus includes the electrophotographic photosensitive member.

FIG. 3 is a schematic diagram illustrating an example of an image forming apparatus. A charging charger (3) is used as a means for charging the photoconductor on average.
As the charging means, a corotron device, a scorotron device, a solid discharge element, a needle electrode device, a roller charging device, a conductive brush device, or the like is used, and a known system can be used.

Next, the image exposure unit (5) is used to form an electrostatic latent image on the uniformly charged photoreceptor (1). As the light source, all luminescent materials such as a fluorescent lamp, a tungsten lamp, a halogen lamp, a mercury lamp, a sodium lamp, a light emitting diode (LED), a semiconductor laser (LD), and an electroluminescence (EL) can be used.
Various types of filters such as a sharp cut filter, a band pass filter, a near infrared cut filter, a dichroic filter, an interference filter, and a color temperature conversion filter can be used to irradiate only light in a desired wavelength range.

  Next, the developing unit (6) is used to visualize the electrostatic latent image formed on the photoreceptor (1). Development methods include a one-component development method using a dry toner, a two-component development method, and a wet development method using a wet toner. When the photosensitive member is positively (negatively) charged and image exposure is performed, a positive (negative) electrostatic latent image is formed on the surface of the photosensitive member. A positive image can be obtained by developing this with negative (positive) toner (electrodetection fine particles), and a negative image can be obtained by developing with positive (negative) toner.

  Next, a transfer charger (10) is used to transfer the toner image visualized on the photoconductor onto the transfer body (9). In addition, a pre-transfer charger (7) may be used for better transfer. As these transfer means, a transfer charger, an electrostatic transfer method using a bias roller, a mechanical transfer method such as an adhesive transfer method and a pressure transfer method, and a magnetic transfer method can be used. As the electrostatic transfer method, the charging means can be used.

  Next, a separation charger (11) and a separation claw (12) are used as means for separating the transfer body (9) from the photoreceptor (1). As other separation means, electrostatic adsorption induction separation, side end belt separation, tip grip conveyance, curvature separation, and the like are used. As the separation charger (11), the charging means can be used.

  Next, a fur brush (14) and a cleaning blade (15) are used to clean the toner remaining on the photoreceptor after transfer. Further, a pre-cleaning charger (13) may be used in order to perform cleaning more efficiently. Other cleaning means include a web method, a magnet brush method, and the like, but each may be used alone or in combination.

  Next, a neutralizing unit is used for the purpose of removing the latent image on the photoreceptor as required. As the charge removal means, a charge removal lamp (2) and a charge removal charger are used, and the exposure light source and the charging means can be used respectively.

  In addition, known processes can be used for reading, feeding, fixing, paper discharge and the like that are not close to the photoconductor.

  The image forming means may be fixedly incorporated in a copying apparatus, facsimile, or printer, but may be incorporated in these apparatuses in the form of a process cartridge and detachable.

-Process cartridge-
The process cartridge for image formation of the present invention comprises a photoreceptor having a protective layer made of a charge transporting organic-inorganic hybrid material having an inclined structure, and a group consisting of a charging means, a developing means, a transfer means, a cleaning means, and a static elimination means. It has at least one selected means and is detachable from the image forming apparatus main body. An example of this image forming process cartridge is shown in FIG.

  The process cartridge for the image forming apparatus includes a photoconductor (101), and in addition, a charging unit (102), a developing unit (104), a transfer unit (106), a cleaning unit (107), and a discharging unit (not shown). ), And an apparatus (part) that can be attached to and detached from the image forming apparatus main body.

  Referring to the image forming process by the apparatus illustrated in FIG. 4, the surface of the photoreceptor (101) is exposed by charging by the charging means (102) and exposure by the exposure means (103) while rotating in the direction of the arrow. An electrostatic latent image corresponding to the image is formed, and the electrostatic latent image is developed with toner by the developing means (104). The toner development is transferred to the transfer body (105) by the transfer means (106), and printed. Be out. Next, the surface of the photoconductor after the image transfer is cleaned by a cleaning unit (107), and further neutralized by a neutralizing unit (not shown), and the above operation is repeated again.

  As is apparent from the above description, the electrophotographic photosensitive member of the present invention is not only used in electrophotographic copying machines, but also in electrophotographic application fields such as laser beam printers, CRT printers, LED printers, liquid crystal printers, and laser plate making. Can also be used widely.

  EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited to a following example. Note that “parts” used in the examples all represent parts by mass.

<Synthesis of Charge Transporting Polymer Having Hydroxyl Production Examples 1-4>
-Production Example 1-
In a 200 ml four-necked flask equipped with a stirrer, thermometer, silica gel tube and dropping funnel, N- {4- [2,2-bis (4-hydroxyphenyl) vinyl] phenyl} -N, N-bis ( 4-Tolyl) amine 3.87 g (0.008 mol), 2,2-bis (4-hydroxyphenyl) propane 2.74 g (0.012 mol), dehydrated pyridine 2.5 ml and dehydrated dichloromethane 40 ml were charged with nitrogen. The mixture was dissolved by stirring under a gas stream. A solution in which 1.48 g (5.0 mmol) of bis (trichloromethane) carbonate, which is a phosgene trimer, was dissolved in 20 ml of dehydrated dichloromethane in 20 minutes while maintaining the internal temperature at 3 ° C. with a water bath and stirring vigorously. The reaction was carried out for 3 hours while keeping the internal temperature at 4 ° C. After stopping the stirring, the reaction solution was washed with a 2% hydrochloric acid aqueous solution and then washed with ion-exchanged water. The obtained solution was dropped into 1.5 l of methanol to precipitate a yellow product and dried to obtain a charge transporting polymer (polymer No. 1) having a hydroxyl group shown in Table 1 below. (Production Example 1).
The obtained polymer no. When the molecular weight of 1 was measured by gel permeation chromatography (GPC), the molecular weight in terms of polystyrene was 2,200 in terms of number average molecular weight.
An infrared absorption spectrum is shown in FIG. Table 1 shows the structural units of the polymer and the results of elemental analysis.

-Production Example 2-
In a 200 ml four-necked flask equipped with a stirrer, thermometer, silica gel tube and dropping funnel, N- {4- [2,2-bis (4-hydroxyphenyl) vinyl] phenyl} -N, N-bis ( 4-Tolyl) amine 3.87 g (0.008 mol), 2,2-bis (4-hydroxyphenyl) propane 2.74 g (0.012 mol), dehydrated pyridine 2.5 ml and dehydrated dichloromethane 40 ml were charged with nitrogen. The mixture was dissolved by stirring under a gas stream. A solution in which 1.78 g (6.0 mmol) of bis (trichloromethane) carbonate, which is a phosgene trimer, was dissolved in 20 ml of dehydrated dichloromethane in 20 minutes while maintaining the internal temperature at 3 ° C. with a water bath and stirring vigorously. The reaction was carried out for 3 hours while keeping the internal temperature at 4 ° C. After stopping the stirring, the reaction solution was washed with a 2% hydrochloric acid aqueous solution and then washed with ion-exchanged water. The obtained solution was dropped into 1.5 l of methanol to precipitate a yellow product and dried to obtain a charge transporting polymer (polymer No. 2) having a hydroxyl group shown in Table 1 below. (Production Example 2).
The obtained polymer no. When the molecular weight of 2 was measured by gel permeation chromatography (GPC), the molecular weight in terms of polystyrene was 3,400 in terms of number average molecular weight.
The structural units of the polymer and the results of elemental analysis are shown in Table 1.

-Production Example 3-
In a 200 ml four-necked flask equipped with a stirrer, thermometer, silica gel tube and dropping funnel, N- {4- [2,2-bis (4-hydroxyphenyl) vinyl] phenyl} -N, N-bis ( 4-Tolyl) amine (9.96 g, 0.02 mol), dehydrated pyridine (2.5 ml), and dehydrated dichloromethane (40 ml) were added and dissolved by stirring under a nitrogen gas stream. A solution in which 1.48 g (5.0 mmol) of bis (trichloromethane) carbonate, which is a phosgene trimer, was dissolved in 20 ml of dehydrated dichloromethane in 20 minutes while maintaining the internal temperature at 3 ° C. with a water bath and stirring vigorously. The reaction was carried out for 3 hours while keeping the internal temperature at 4 ° C. After stopping the stirring, the reaction solution was washed with a 2% hydrochloric acid aqueous solution and then washed with ion-exchanged water. The obtained solution was dropped into 1.5 l of methanol to precipitate a yellow product and dried to obtain a charge transporting polymer (polymer No. 3) having a hydroxyl group shown in Table 1 below. (Production Example 3).
The obtained polymer no. When the molecular weight of No. 3 was measured by gel permeation chromatography (GPC), the molecular weight in terms of polystyrene was 2,500 in terms of number average molecular weight.
The structural units of the polymer and the results of elemental analysis are shown in Table 1.

-Production Example 4-
In a 200 ml four-necked flask equipped with a stirrer, thermometer, silica gel tube and dropping funnel, N- {4- [2,2-bis (4-hydroxyphenyl) vinyl] phenyl} -N, N-bis ( 4-Tolyl) amine (9.96 g, 0.02 mol), dehydrated pyridine (2.5 ml), and dehydrated dichloromethane (40 ml) were added and dissolved by stirring under a nitrogen gas stream. A solution in which 1.78 g (6.0 mmol) of bis (trichloromethane) carbonate, which is a phosgene trimer, was dissolved in 20 ml of dehydrated dichloromethane in 20 minutes while maintaining the internal temperature at 3 ° C. with a water bath and stirring vigorously. The reaction was carried out for 3 hours while keeping the internal temperature at 4 ° C. After stopping the stirring, the reaction solution was washed with a 2% hydrochloric acid aqueous solution and then washed with ion-exchanged water. The obtained solution was dropped into 1.5 l of methanol to precipitate a yellow product and dried to obtain a charge transporting polymer (polymer No. 4) having a hydroxyl group shown in Table 1 below. (Production Example 4).
The obtained polymer no. When the molecular weight of No. 4 was measured by gel permeation chromatography (GPC), the molecular weight in terms of polystyrene was 4,500 in terms of number average molecular weight.
The structural units of the polymer and the results of elemental analysis are shown in Table 1.

<Alkoxysilylation of charge transporting polymer having hydroxyl group Production Examples 5 to 8>
-Production Example 5-
Alkoxysilylation of the synthesized charge transporting polymer having a hydroxyl group was carried out as follows. An alkoxysilyl group was introduced into No. 1 (polymer No. 1 for hybrid materials).
Charge transporting polymer No. having a hydroxyl group 1 (3.5 g) was dissolved in 25 ml of chloroform. Next, 0.6 g of 3-isocyanatopropyltriethoxysilane (IPTES) was added to this solution, heated under reflux for 10 hours, and then cooled to room temperature. This reaction solution was dropped into methanol to precipitate the reaction product. The precipitate was filtered off, washed with methanol, and dried under reduced pressure (Production Example 5).
The measurement result by ¹ H-NMR of the obtained product is shown in FIG. As a result of the measurement, it was confirmed that alkoxysilyl groups were introduced at both ends of the product. As a result of measurement by GPC, the product had a number average molecular weight of 2,700.

-Production Example 6
Alkoxysilylation of the synthesized charge transporting polymer having a hydroxyl group was carried out as follows. An alkoxysilyl group was introduced into No. 2 (polymer No. 2 for hybrid material).
Charge transporting polymer No. having a hydroxyl group 2 (3.5 g) was dissolved in 25 ml of chloroform. Next, 0.5 g of 3-isocyanatopropyltriethoxysilane (IPTES) was added to this solution, heated under reflux for 10 hours, and then cooled to room temperature. This reaction solution was dropped into methanol to precipitate the reaction product. The precipitate was filtered off, washed with methanol, and dried under reduced pressure (Production Example 6).
The product was confirmed by introduction of alkoxysilyl groups at both ends by ¹ H-NMR. As a result of measurement by GPC, the product had a number average molecular weight of 4,000.

-Production Example 7-
Alkoxysilylation of the synthesized charge transporting polymer having a hydroxyl group was carried out as follows. An alkoxysilyl group was introduced into 3 (polymer No. 3 for hybrid material).
Charge transporting polymer No. having a hydroxyl group 3 (3.5 g) was dissolved in 25 ml of chloroform. Next, 0.6 g of 3-isocyanatopropyltriethoxysilane (IPTES) was added to this solution, heated under reflux for 10 hours, and then cooled to room temperature. This reaction solution was dropped into methanol to precipitate the reaction product. The precipitate was filtered off, washed with methanol, and dried under reduced pressure (Production Example 7).
The product was confirmed by introduction of alkoxysilyl groups at both ends by ¹ H-NMR. As a result of measurement by GPC, the product had a number average molecular weight of 3,000.

-Production Example 8-
Alkoxysilylation of the synthesized charge transporting polymer having a hydroxyl group was carried out as follows. An alkoxysilyl group was introduced into 4 (polymer No. 4 for hybrid material).
Charge transporting polymer No. having a hydroxyl group 4 (3.5 g) was dissolved in 25 ml of chloroform. Next, 0.5 g of 3-isocyanatopropyltriethoxysilane (IPTES) was added to this solution, heated under reflux for 10 hours, and then cooled to room temperature. This reaction solution was dropped into methanol to precipitate the reaction product. The precipitate was filtered off, washed with methanol, and dried under reduced pressure (Production Example 8).
The product was confirmed by 1H-NMR to have alkoxysilyl groups introduced at both ends. As a result of measurement by GPC, the product had a number average molecular weight of 5,100.

Example 1
An undercoat layer was formed on an Al support (outer diameter 30 mmφ) by dipping so that the film thickness after drying was 3.5 μm.
・ Coating liquid for undercoat layer 6 parts alkyd resin (Beckosol 1307-60-EL, manufactured by Dainippon Ink and Chemicals, Inc.)
Melamine resin 4 parts (Super Becamine G-821-60, manufactured by Dainippon Ink & Chemicals, Inc.)
40 parts of titanium oxide
(CR-EL: Ishihara Sangyo)
50 parts of methyl ethyl ketone

On this undercoat layer, it was dip-coated in a charge generation layer coating solution containing a bisazo pigment having the following structure and dried by heating to form a charge generation layer having a thickness of 0.2 μm.
-Coating solution for charge generation layer 2.5 parts of bisazo pigment with the following structural formula

Polyvinyl butyral (XYHL, manufactured by UCC) 0.5 part Cyclohexanone 200 parts Methyl ethyl ketone 80 parts

On this charge generation layer, a charge transport layer coating solution having the following structure was dip-coated and heat-dried to obtain a charge transport layer having a thickness of 22 μm.
・ Coating liquid for charge transport 10 parts of bisphenol Z-type polycarbonate 10 parts of low molecular charge transport material with the following structure
Tetrahydrofuran 80 parts 1% Silicone oil tetrahydrofuran solution 0.2 parts (KF50-100CS, manufactured by Shin-Etsu Chemical Co., Ltd.)

Using a protective layer coating solution (No. 1 to 3) containing an organic-inorganic hybrid material having the composition shown in Table 2 on the charge transport layer, three spray heads were used. Spray coating was continuously performed in the order of 1 to 3. Here, the term “continuous” means that after the lower layer is applied, the next coating liquid is spray-coated before the touch is dried. No. The protective layer coating solutions Nos. 1 and 2 were applied in an amount corresponding to 2 μm. The protective layer coating solution No. 3 was applied in an amount equivalent to 1 μm, and heat-treated at 130 ° C. for 30 minutes to form an organic-inorganic hybrid protective layer having a total thickness of 5 μm. Thus, an electrophotographic photoreceptor of Example 1 was produced.
As the polymer in Table 2, the alkoxysilylated charge transporting polymer obtained in Production Example 5 was used, and as the TMOS, tetramethoxysilane oligomer MKC silicate MS-56 manufactured by Mitsubishi Chemical Corporation was used.

(Example 2)
In Example 1, it replaced with the alkoxysilylation charge transportable polymer obtained in Production Example 5, and the same procedure as in Example 1 was used except that the alkoxysilylated charge transportable polymer obtained in Production Example 6 was used. Thus, an electrophotographic photosensitive member of Example 2 was produced. The thickness of the protective layer was 5.0 μm.

(Example 3)
In Example 1, it replaced with the alkoxysilylation charge transportable polymer obtained in Production Example 5, and the same procedure as in Example 1 was used except that the alkoxysilylation charge transportable polymer obtained in Production Example 7 was used. Thus, an electrophotographic photosensitive member of Example 3 was produced. The thickness of the protective layer was 5.0 μm.

Example 4
In Example 1, the same procedure as in Example 1 was used except that the alkoxysilylated charge transporting polymer obtained in Production Example 8 was used instead of the alkoxysilylated charge transporting polymer obtained in Production Example 5. Thus, an electrophotographic photosensitive member of Example 4 was produced. The thickness of the protective layer was 5.0 μm.

(Comparative Example 1)
In Example 1, an electrophotographic photoreceptor of Comparative Example 1 was produced in the same manner as in Example 1 except that the protective layer coating solution containing the organic-inorganic hybrid material was not applied.

(Comparative Example 2)
Example 1 is the same as Example 1 except that a protective layer coating solution containing the No. 1 organic-inorganic hybrid material was used to form a 5 μm organic-inorganic hybrid protective layer by a single spray coating. Similarly, an electrophotographic photosensitive member of Comparative Example 2 was produced.

(Comparative Example 3)
Example 1 is the same as Example 1 except that the protective layer coating solution containing the organic-inorganic hybrid material of No. 2 was used to form a 5 μm organic-inorganic hybrid protective layer by a single spray coating. Similarly, an electrophotographic photoreceptor of Comparative Example 3 was produced.

(Comparative Example 4)
Example 1 is the same as Example 1 except that the protective layer coating solution containing the organic-inorganic hybrid material of No. 3 was used to form a 5 μm organic-inorganic hybrid protective layer by a single spray coating. Similarly, an electrophotographic photosensitive member of Comparative Example 4 was produced.

<Measurement method and evaluation>
(Measurement of surface pure water contact angle)
The surface pure water contact angle of the photoconductor was measured by AUTOMATIC CONTACT ANGLE METER (KYOWA INTERFACE SCIENCE Co. LTD). The results are shown in Table 3.

(surface hardness)
The surface hardness of the photoconductor was measured with a microhardness test system, Fischerscope H-100 (Fischer Instruments Co., Ltd.). The results are shown in Table 3.

(Si element concentration distribution)
The Si element concentration distribution was measured using a scanning electron microscope (SEM). The measurement is performed by taking a cross section of the photoconductor and measuring whether or not the Si element concentration gradually decreases (that is, whether or not there is an inclined structure) from the outermost surface side of the protective layer toward the photosensitive layer side. It was. Table 3 shows the measurement results.

HM: Universal hardness measurement condition calculated considering the edge of the tip of the Vickers indenter Test method: Load unloading repetition (1 time) test Number of tests: 5 times for each photoreceptor Indenter: Vickers indenter Maximum load: 9.8 mN
Load (unloading) time: 30 seconds Holding time: 5 seconds

(Real machine paper test)
The electrophotographic photoreceptors obtained in Examples 1 to 4 and Comparative Examples 1 to 4 were set in a modified Rigoh imagio MF2200 machine (655 nm semiconductor laser as an image exposure light source), and 50,000 sheets were passed through an actual machine. (A4, MyPaper made by NBS Ricoh Co., Ltd., charging potential at start-700 V) was carried out, and the wear characteristics, crack resistance, actual machine potential and image evaluation of the photoreceptor were performed.

<Abrasion characteristics>
The abrasion amount was measured by measuring the film thickness at 20 points on the photoreceptor after the actual paper passing test with an eddy current film thickness meter (Fisherscope MMS), and calculating the film thickness reduction amount (average value) from the initial stage. .

<Crack resistance>
The evaluation of crack resistance was performed by storing the photoreceptor after the actual paper passing test at 30 ° C. and 85% Rh for 2 weeks and visually judging the presence or absence of cracks on the surface of the photoreceptor. The results are shown in Table 4.

<Image density>
Evaluation of image density is based on the condition that a graphic pattern image with an image density of 5% is printed on every 5 consecutive sheets, and a total of 50,000 sheets are output to a copy sheet, and the graphic of the output 50,000th copy sheet is output. The pattern image was compared with the graphic pattern image on the first copy sheet by visually determining the change in image density.

<Streak image>
For the evaluation of the streak image, the paper passing test for the actual machine was completed, five white images were output on A4 paper, and the presence or absence of the streak-like image was visually evaluated.

Crack resistance: ○ → No occurrence, Δ → 1 to less than 4 locations, × → 4 or more image densities: ○ → Good, Δ → Slightly reduced image density, × → Image density decreased streak image: ○ → Good, △ → Generate locally, × → Generate all over the image

<In-machine potential>
The potential in the actual machine was measured by incorporating a surface potentiometer (Tlek MODEL 344) in the actual machine.

Since Comparative Example 1 did not have a protective layer, the surface was soft and the amount of wear was large.
Comparative Example 2 contains an organic-inorganic hybrid material having a charge transport function in the protective film. However, since the content of the inorganic component is small, the surface hardness is low and the wear resistance is inferior. Further, the surface water repellency is insufficient, and a streak image due to poor cleaning tends to occur.
In Comparative Examples 3 and 4, since the organic-inorganic hybrid material protective film has few organic components having a charge transport function, even if the mechanical strength such as hardness and abrasion resistance is high, the image density is lowered due to poor charge transport. Cheap.
On the other hand, all the photoreceptors using the organic-inorganic hybrid material having an inclined structure in the present invention as a protective layer have good abrasion resistance and stable image quality. The protective layer having an organic-inorganic hybrid material in the present invention has a larger amount of inorganic component as it gets closer to the outermost layer, and the surface hardness, mechanical strength of the inorganic component, and the water repellency of the Si-based inorganic component, etc. The closer the photosensitive layer is to the photosensitive layer, the more organic components with the charge transport function exist, and the electric charge can be smoothly transported from the photosensitive layer to the protective layer. Both are excellent.
Therefore, a long-life and high-performance electrophotographic image capable of maintaining a good image for a long period of time by using a cross-linked resin layer of a charge transporting organic-inorganic hybrid material having an inclined structure in the protective layer of the photosensitive layer in the present invention. It has been found that a photoconductor can be provided. In addition, it has been found that the image forming method, the image forming apparatus, and the process cartridge for the image forming apparatus using the photoconductor of the present invention have high performance and high reliability.

FIG. 1 is an example of a cross-sectional view of the electrophotographic photoreceptor of the present invention. FIG. 2 is another example of a cross-sectional view of the electrophotographic photoreceptor of the present invention. FIG. 3 is a schematic view showing an example of the image forming apparatus of the present invention. FIG. 4 is a schematic view showing an example of a process cartridge for an image forming apparatus according to the present invention. 5 is an infrared absorption spectrum diagram of the charge transporting polymer synthesized in Production Example 1. FIG. Figure 6 is a ¹ H-NMR spectrum of the product obtained in Preparation Example 5.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Photoconductor 2 Static elimination lamp 3 Charger charger 4 Eraser 5 Image exposure part 6 Development unit 7 Charger before transfer 8 Registration roller 9 Transfer paper (transfer body)
10 Transfer Charger 11 Separation Charger 12 Separation Claw 13 Charger Before Cleaning 14 Fur Brush 15 Cleaning Blades 21, 31 Protective Layers 22, 32 Photosensitive Layers 23, 33 Conductive Supports 26, 36 Photosensitive Layer Sides 27, 37 Surface Side 34 Charge Generation Layer 35 Charge transport layer 101 Photosensitive drum (photoconductor)
102 Charging device (charging means)
103 Exposure Unit 104 Development Device (Development Unit)
105 Transfer body 106 Transfer device (transfer means)
107 Cleaning blade

Claims (7)

In the electrophotographic photoreceptor having the conductive support, the photosensitive layer, and the protective layer in this order,
The protective layer contains a charge transporting organic-inorganic hybrid material containing an organic component and an inorganic component,
An electrophotographic photoreceptor, wherein the concentration of the inorganic component in the protective layer continuously increases from the photosensitive layer side toward the surface side opposite to the photosensitive layer side.   The electrophotographic photoreceptor according to claim 1, wherein the charge transporting organic-inorganic hybrid material is a material formed by covalently bonding a charge transporting polymer having a metal alkoxide group and a metal alkoxide compound.   The electron according to any one of claims 1 to 2, wherein the protective layer is formed by applying a solution in which the composition ratio of the charge transporting polymer having a metal alkoxide group and the metal alkoxide compound is changed a plurality of times. Photoconductor for photography.   4. The electrophotographic photoreceptor according to claim 2, wherein the metal element contained in the metal alkoxide group and the metal alkoxide compound is Si.   An image forming method using the electrophotographic photosensitive member according to claim 1, wherein an electrostatic latent image forming step of forming an electrostatic latent image on the electrophotographic photosensitive member, and the electrostatic At least a developing step of developing the latent image with toner to form a visible image, a transferring step of transferring the visible image to a recording medium, and a fixing step of fixing the transferred image transferred to the recording medium And an image forming method.   An image forming apparatus comprising the electrophotographic photosensitive member according to claim 1.   An image forming apparatus comprising: the electrophotographic photosensitive member according to claim 1; and at least one unit selected from the group consisting of a charging unit, a developing unit, a transfer unit, a cleaning unit, and a discharging unit. A process cartridge for an image forming apparatus, wherein the process cartridge is removable from a main body.