JP5038839B2 - Image carrier, image forming method using the same, image forming apparatus, and process cartridge for image forming apparatus - Google Patents

Description

  The present invention provides an image carrier having high durability and high image quality over a long period of time by using a photosensitive layer having high wear resistance, good electrical characteristics, and high spherical toner cleaning properties. About. The present invention also relates to an image forming method, an image forming apparatus, and a process cartridge for the image forming apparatus using those long-life, high-performance image carriers.

  In recent years, organic photoreceptors (OPC) have been widely used in copying machines, facsimile machines, laser printers, and composite machines in place of inorganic photoreceptors because of their good performance and various advantages. The reasons for this include, for example, optical characteristics such as the width of the light absorption wavelength range and the amount of absorption, electrical characteristics such as high sensitivity and stable charging characteristics, wide range of material selection, ease of manufacture, Examples include low cost and non-toxicity.

  On the other hand, the diameter of the photoconductor has recently been reduced due to the downsizing of the image forming apparatus, and the high speed of the machine and the maintenance-free movement have been added to increase the durability of the photoconductor. From this point of view, organophotoreceptors are generally soft because the surface layer is mainly composed of low-molecular charge transport materials and inert polymers, and when used repeatedly in electrophotographic processes, they are mechanically driven by development and cleaning systems. There is a drawback that wear is likely to occur due to a typical load. In addition, due to the demand for higher image quality, the cleaning blade is required to increase its rubber hardness and contact pressure for the purpose of improving the cleaning property as the particle size of the toner particles is reduced. This also promotes wear of the photoreceptor. It is a factor. Such abrasion of the photoreceptor deteriorates electrical characteristics such as sensitivity deterioration and chargeability, and causes abnormal images such as image density reduction and background stains. Further, scratches where wear is locally generated cause streak-like stain images due to poor cleaning. Under the present circumstances, the wear and scratches are rate-determined and the life of the photoconductor has been replaced.

Therefore, it is indispensable to reduce the above-mentioned wear amount in order to increase the durability of the organic photoreceptor, and this is the most pressing issue in this field.
Techniques for improving the abrasion resistance of the photosensitive layer include (1) using a curable binder for the surface layer (see, for example, Patent Document 1: Japanese Patent Laid-Open No. 56-48637), (2) Polymer type One using a charge transport material (for example, see Patent Document 2: Japanese Patent Laid-Open No. 64-1728), (3) One having an inorganic filler dispersed in a surface layer (for example, Patent Document 3: Japanese Patent Laid-Open No. 4-281461) For example). Among these techniques, those using the curable binder (1) have poor compatibility with the charge transport material, and the residual potential increases due to impurities such as polymerization initiators and unreacted residues, resulting in a decrease in image density. Tends to occur. In addition, (2) using a polymer type charge transport material and (3) dispersed inorganic filler are required for organic photoreceptors, although they can improve wear resistance to some extent. The durability has not been fully satisfied.

Furthermore, a photoreceptor containing a polyfunctional acrylate monomer cured product for improving the abrasion resistance and scratch resistance of (1) is also known (see Patent Document 4: Japanese Patent No. 3262488). However, in this photoreceptor, although there is a description that the polyfunctional acrylate monomer cured product is contained in the protective layer provided on the photosensitive layer, the protective layer may contain a charge transport material. However, when the surface layer contains a low-molecular charge transport material, there is a problem of compatibility with the cured product. In some cases, the molecular charge transport material is precipitated and the cloudiness phenomenon occurs, and the mechanical strength is also lowered.
Furthermore, since this photoconductor specifically reacts with a monomer in a state containing a polymer binder, curing does not proceed sufficiently, and there is a problem of compatibility between the cured product and the binder resin. There was a tendency for surface irregularities due to phase separation to cause poor cleaning.

As an alternative to the wear resistance technology of the photosensitive layer, a charge transport layer formed by using a coating liquid comprising a monomer having a carbon-carbon double bond, a charge transport material having a carbon-carbon double bond, and a binder resin is used. It is known to be provided (for example, see Patent Document 5: Japanese Patent No. 3194392), and this binder resin has a carbon-carbon double bond and is reactive to the charge transport agent. And those having no double bond and no reactivity. This photoconductor is remarkably compatible with wear resistance and good electrical properties, but when a non-reactive binder resin is used, the binder resin, the monomer and the charge transport agent are used. The compatibility with the cured product produced by this reaction was poor, and surface irregularities were generated during cross-linking from layer separation, and a tendency to cause poor cleaning was observed. Further, as described above, in this case, the binder resin prevents the curing of the monomer, and what is specifically described as the monomer used in the photoreceptor is a bifunctional one. The monomer has a small number of functional groups and a sufficient crosslinking density cannot be obtained, and these points have not yet been satisfactory in terms of wear resistance.
Further, even when a reactive binder is used, due to the low number of functional groups contained in the monomer and the binder resin, it is difficult to achieve both the binding amount and the crosslinking density of the charge transport material, and the electrical characteristics and The abrasion resistance was not sufficient.

In addition, a photosensitive layer containing a compound obtained by curing a hole transporting compound having two or more chain polymerizable functional groups in the same molecule is also known (for example, Patent Document 6: JP 2000-66425 A). reference).
However, in this photosensitive layer, the bulky hole transporting compound has two or more chain-polymerizable functional groups, so that distortion occurs in the cured product, resulting in high internal stress, resulting in rough surface layers and cracks over time. It may be easy to do and does not have sufficient durability.

As a photoreceptor having a different charging system, a photoreceptor having a protective layer containing a compound obtained by curing a hole transporting compound having two or more chain polymerizable functional groups and conductive fine particles is also known (for example, Patent Document 7: Japanese Patent Laid-Open No. 2001-166518).
However, since this photoreceptor performs injection charging by the contact charging member, the electrical resistance of the surface layer is lowered by containing conductive fine particles. By containing conductive fine particles, the mechanical properties of the surface of the photoreceptor are improved. However, when this photoconductor is used with a charger such as a corona charger or a contact charging roller that is generally used at present, environmental (temperature / humidity) fluctuations, ozone generated from the charger, surface layer of NOx products Due to the adhesion, the electrical resistance of the surface layer is likely to fluctuate, and abnormal images such as image flow are likely to occur.

  Further, in order to improve wear resistance and scratch resistance by combining (1) and (3), a photoreceptor in which acicular fine particles having an aspect ratio of 1:10 or more are contained in the surface protective layer (for example, Patent Document 8: Japanese Patent No. 3123733), and a photoreceptor in which acicular fine particles are contained in a polyurethane resin as a surface layer (for example, see Patent Document 9: Japanese Patent Laid-Open No. 10-20536) is known. However, in these photoreceptors, the dispersed resin does not have a charge transport function, so that the electrical characteristics are not sufficient.

Similarly, in order to improve wear resistance and scratch resistance by combining (1) and (3), the surface layer has at least a trifunctional or higher functional radical polymerizable monomer having no charge transport structure and a charge transport structure. A photoreceptor having a crosslinked resin layer obtained by curing a radically polymerizable compound is also known, and filler fine particles are dispersed in a surface layer (see, for example, Japanese Patent Application Laid-Open No. 2005-99688).
This photoreceptor has little environmental fluctuation, and good electrical characteristics and mechanical durability. However, at present, further improvement in durability is desired, and further improvement is necessary.

  On the other hand, not only high durability of the photoreceptor but also recent full-color electrophotographic apparatuses are mainly using a polymerization toner because of high image quality and environmental performance. The sharpness of the image improves as the degree of sphericity of the polymerized toner increases. On the other hand, in the toner recovery method using a cleaning blade, the toner passes through the blade. As a result, streaky abnormal images are generated.

The mechanism by which toner with high sphericity (hereinafter spherical toner) slips through the cleaning blade is because the spherical toner is easy to rotate between the cleaning blade and the photoreceptor due to its shape, and cleaning is performed compared to conventional non-spherical toner. It is considered difficult.
As a technique for improving the cleaning property of such a spherical toner, the surface layer is at least a trifunctional or higher-functional radical polymerizable monomer having no charge transport structure and a crosslinked polymer obtained by curing a radical polymerizable compound having a charge transport structure. For example, there is a technique for reducing the surface energy of the photoreceptor by adding silicone oil or fluorine fine particles to the resin layer (see, for example, Patent Document 11: JP-A-2005-107490).
This photoreceptor has good mechanical durability and spherical toner cleaning properties. However, at present, further improvement in durability and improvement in spherical toner cleaning properties are desired.

JP 56-48637 A JP-A 64-1728 JP-A-4-281461 Japanese Patent No. 3262488 Japanese Patent No. 3194392 JP 2000-66425 A JP 2001-166518 A Japanese Patent No. 3123733 Japanese Patent Laid-Open No. 10-20536 JP 2005-99688 A JP 2005-107490 A

  An object of the present invention is to provide an image having high durability and high image quality over a long period of time by using a surface layer having high wear resistance, good electrical characteristics, and high spherical toner cleaning properties. It is to provide a carrier, and to provide an image forming method, an image forming apparatus, and a process cartridge for the image forming apparatus using these long-life, high-performance image carriers.

  As a result of intensive studies, the present inventors have found that in an image carrier having at least a photosensitive layer on a conductive support, needle-like fine particles are dispersed on the surface layer of the photosensitive layer, and at least have no charge transport structure. It has been found that the above object can be achieved by forming a crosslinked resin layer obtained by curing a radical polymerizable compound having a trifunctional or higher functional radical polymerizable monomer and a charge transporting structure, thereby achieving the present invention.

That is, the said subject is solved by the following this invention.
(1) “In an image carrier having at least a photosensitive layer on a conductive support, it has a surface layer on the surface of the photosensitive layer, the surface layer has needle-like fine particles dispersed therein, and has at least a charge transporting structure. no crosslinked resin layer der formed by curing a radical polymerizable compound having three or more functional radical polymerizable monomer and a charge transport structure is, the image bearing member, wherein the needle-like fine particles, wherein the aluminum oxide der Rukoto " ,
(2) "The image carrier according to item (1), wherein the acicular fine particles are metal oxide fine particles",
( 3 ) "Image bearing according to item (1) or (2), wherein the radical polymerizable compound having a charge transporting structure used in the surface layer is monofunctional. body",
( 4 ) The above-mentioned ( 1 ), wherein the functional group of the trifunctional or higher radical polymerizable monomer having no charge transporting structure used for the surface layer is an acryloyloxy group and / or a methacryloyloxy group. ) To ( 3 ), the image carrier ”,
( 5 ) "Items (1) to ( 4 ) above, wherein the functional group of the radical polymerizable compound having a charge transporting structure used for the surface layer is an acryloyloxy group or a methacryloyloxy group" The image carrier according to any one of Items
( 6 ) "Items (1) to ( 5 ), wherein the charge transporting structure of the radically polymerizable compound having a charge transporting structure used for the outermost surface layer is a triarylamine structure." Or an image carrier according to any one of
( 7 ) "The radical polymerizable compound having a monofunctional charge transporting structure used for the surface layer is one or more polymerizable compounds represented by the following general formula (1) or (2): The image carrier according to any one of items (1) to ( 6 );

（式中、Ｒ_１は水素原子、ハロゲン原子、置換基を有してもよいアルキル基、置換基を有してもよいアラルキル基、置換基を有してもよいアリール基、シアノ基、ニトロ基、アルコキシ基、−ＣＯＯＲ_７（Ｒ_７は水素原子、置換基を有してもよいアルキル基、置換基を有してもよいアラルキル基又は置換基を有してもよいアリール基）、ハロゲン化カルボニル基若しくはＣＯＮＲ_８Ｒ_９（Ｒ_８及びＲ_９は水素原子、ハロゲン原子、置換基を有してもよいアルキル基、置換基を有してもよいアラルキル基又は置換基を有してもよいアリール基を示し、互いに同一であっても異なっていてもよい）を表わし、Ａｒ_１、Ａｒ_２は置換もしくは未置換のアリーレン基を表わし、同一であっても異なってもよい。Ａｒ_３、Ａｒ_４は置換もしくは未置換のアリール基を表わし、同一であっても異なってもよい。Ｘは単結合、置換もしくは無置換のアルキレン基、置換もしくは無置換のシクロアルキレン基、置換もしくは無置換のアルキレンエーテル基、酸素原子、硫黄原子、ビニレン基を表わす。Ｚは置換もしくは無置換のアルキレン基、置換もしくは無置換のアルキレンエーテル基、アルキレンオキシカルボニル基を表わす。ｍ、ｎは０〜３の整数を表わす。）」、
（８）「前記表面層に用いられる１官能の電荷輸送性構造を有するラジカル重合性化合物が、下記一般式（３）の一種以上の重合性化合物であることを特徴とする前記第（１）項乃至第（７）項のいずれかに記載の像担持体；

(In the formula, R ₁ represents a hydrogen atom, a halogen atom, an alkyl group which may have a substituent, an aralkyl group which may have a substituent, an aryl group which may have a substituent, a cyano group, a nitro group, Group, alkoxy group, —COOR ₇ (R ₇ is a hydrogen atom, an alkyl group which may have a substituent, an aralkyl group which may have a substituent or an aryl group which may have a substituent), halogen Carbonyl group or CONR ₈ R ₉ (R ₈ and R ₉ may have a hydrogen atom, a halogen atom, an alkyl group which may have a substituent, an aralkyl group which may have a substituent, or a substituent. Ar ₁ and Ar ₂ each represent a substituted or unsubstituted arylene group, and may be the same or different.Ar ₃ , which may be the same or different from each other. Ar ₄ may be substituted Represents an unsubstituted aryl group, which may be the same or different, X represents a single bond, a substituted or unsubstituted alkylene group, a substituted or unsubstituted cycloalkylene group, a substituted or unsubstituted alkylene ether group, An oxygen atom, a sulfur atom, or a vinylene group, Z represents a substituted or unsubstituted alkylene group, a substituted or unsubstituted alkylene ether group, or an alkyleneoxycarbonyl group, and m and n represent an integer of 0 to 3.) "
( 8 ) The above-mentioned (1), wherein the radical polymerizable compound having a monofunctional charge transporting structure used for the surface layer is one or more polymerizable compounds of the following general formula (3). The image carrier according to any one of Items 1 to ( 7 );

（式中、ｏ、ｐ、ｑはそれぞれ０又は１の整数、Ｒａは水素原子、メチル基を表わし、Ｒｂ、Ｒｃは水素原子以外の置換基で炭素数１〜６のアルキル基を表わし、複数の場合は異なっても良い。ｓ、ｔは０〜３の整数を表わす。Ｚａは単結合、メチレン基、エチレン基、

(Wherein, o, p and q are each an integer of 0 or 1, Ra represents a hydrogen atom or a methyl group, Rb and Rc represent a substituent other than a hydrogen atom and an alkyl group having 1 to 6 carbon atoms, And s and t each represents an integer of 0 to 3. Za is a single bond, a methylene group, an ethylene group,

を表わす。）」、
（９）「前記表面層の硬化手段が加熱又は光エネルギー照射手段であることを特徴とする前記第（１）項乃至第（８）項のいずれかに記載の像担持体」、
（１０）「前記第（１）項乃至第（９）項のいずれかに記載の像担持体を用いて、少なくとも帯電、画像露光、現像、転写を繰り返し行なうことを特徴とする画像形成方法」、
（１１）「前記第（１）項乃至第（９）項のいずれかに記載の像担持体を有することを特徴とする画像形成装置」、
（１２）「前記第（１）項乃至第（９）項のいずれかに記載の像担持体と、帯電手段、現像手段、転写手段、クリーニング手段および除電手段よりなる群から選ばれた少なくとも一つの手段を有するものであって、画像形成装置本体に着脱可能としたことを特徴とする画像形成装置用プロセスカートリッジ」。

Represents. ) ",
( 9 ) "The image carrier according to any one of items (1) to ( 8 ), wherein the surface layer curing means is heating or light energy irradiation means",
( 10 ) "Image forming method characterized in that at least charging, image exposure, development and transfer are repeated using the image carrier according to any one of (1) to ( 9 )" ,
( 11 ) "An image forming apparatus comprising the image carrier according to any one of (1) to ( 9 )",
( 12 ) “At least one selected from the group consisting of the image bearing member according to any one of (1) to ( 9 ), a charging unit, a developing unit, a transfer unit, a cleaning unit, and a discharging unit. An image forming apparatus process cartridge having two means and detachable from the main body of the image forming apparatus.

  According to the present invention, needle-shaped fine particles are dispersed in the surface layer of the photosensitive layer, and at least a trifunctional or higher functional radical polymerizable monomer having no charge transport structure and a radical polymerizable compound having a charge transport structure are cured. By using the resin layer, a highly durable and high-performance image carrier having high wear resistance and good electrical characteristics can be obtained. Therefore, by using this image carrier, it is possible to provide a high-performance and highly reliable image forming process, an image forming apparatus, and a process cartridge for the image forming apparatus that can provide a good image over a long period of time.

Hereinafter, the present invention will be described in detail.
The present invention relates to a trifunctional or higher functional radical polymerizable monomer having at least a photosensitive layer on a conductive support, in which needle-like fine particles are dispersed on the surface layer of the photosensitive layer, and at least having no charge transporting structure. By forming a crosslinked resin layer obtained by curing a radically polymerizable compound having a charge transporting structure, an image carrier that achieves high wear resistance and high image quality over a long period of time can be achieved.

The reasons for this are as follows.
The image carrier of the present invention uses a tri- or higher functional radical polymerizable monomer in the surface layer, thereby developing a three-dimensional network structure and obtaining a high hardness crosslinked surface layer having a very high degree of crosslinking. High wear resistance is achieved. On the other hand, when only monofunctional and bifunctional radically polymerizable monomers are used, the cross-linking bond in the cross-linked surface layer becomes dilute, and a dramatic improvement in wear resistance cannot be achieved. When a polymer material is contained in the cross-linked surface layer, the development of the three-dimensional network structure is inhibited and the degree of cross-linking is lowered, so that sufficient wear resistance cannot be obtained as compared with the present invention. Furthermore, the compatibility between the polymer material and the cured product resulting from the reaction of the radical polymerizable composition (radical polymerizable monomer or radical polymerizable compound having a charge transporting structure) is poor, resulting in localized from phase separation. Wears and appears as a scratch on the surface.

  Further, in the formation of the cross-linked surface layer of the present invention, in addition to the trifunctional radical polymerizable monomer, a radical polymerizable compound having a charge transporting structure is contained, which is the trifunctional or higher functional radical polymerizable monomer. It is incorporated into the cross-linking during curing. On the other hand, when a low molecular charge transport material having no functional group is contained in the cross-linked surface layer, precipitation of the low molecular charge transport material and white turbidity occur due to its low compatibility, and the cross-linked surface layer The mechanical strength also decreases.

Furthermore, the crosslinked surface layer of the present invention contains acicular fine particles. As a comparison with the present invention, an actual wear mechanism of a film containing spherical fine particles described in the prior art (Patent Document 10: JP-A-2005-99688) will be described with reference to FIG.
In the region (A) where no fine particles are present, the resin portion is worn. And abrasion progresses, a resin part lose | disappears, and spherical fine particles appear on the image carrier surface. Next, in the region (B) where the spherical fine particles exist, the spherical fine particles themselves do not wear because the spherical fine particles have a higher hardness than the resin portion. The resin portion around the spherical fine particles wears out, but the spherical fine particles become a three-dimensional obstacle in the resin portions around the spherical fine particles, and the wear rate decreases. Then, the periphery of the spherical fine particles is gradually worn, and the spherical fine particles protrude as shown in (C), and the spherical fine particles themselves are dug up from the film. In this way, the resin portion is gradually worn, the spherical fine particles protrude, and the phenomenon that the spherical fine particles are discharged from the film is repeated.

On the other hand, the actual wear mechanism of the film containing acicular fine particles of the present invention will be described with reference to FIG.
The area portions (A) and (B) are the same as those in FIG. In the region (C), the peripheral portion of the acicular fine particles is gradually worn out as in FIG. 1, and the acicular fine particles protrude as shown in (C), and the acicular fine particles themselves are dug up from the film. However, compared with the spherical fine particles of FIG. 1, it is less likely to be dug because of the needle shape, and the mechanical durability is improved as compared with the crosslinked surface layer containing spherical fine particles.
Furthermore, it is effective for spherical toner cleaning properties. The spherical toner slips between the cleaning blade and the image carrier while rotating. However, in the image carrier of the present invention, the rotation is suppressed by the needle-shaped fine particles protruding on the surface of the image carrier, and as a result, the cleaning blade is It was found that the amount of toner that slips through decreases.

Next, the constituent material of the crosslinked surface layer coating solution of the present invention will be described.
[Trifunctional or higher radical polymerizable monomer having no charge transport property]
The trifunctional or higher functional radical polymerizable monomer having no charge transporting property used in the present invention is a hole transporting structure such as triarylamine, hydrazone, pyrazoline, carbazole, such as condensed polycyclic quinone, diphenoquinone, cyano group. And a monomer having no electron transport structure such as an electron-withdrawing aromatic ring having a nitro group and having three or more radical polymerizable functional groups. The radical polymerizable functional group may be any group as long as it has a carbon-carbon double bond and is capable of radical polymerization.
Examples of these radical polymerizable functional groups include 1-substituted ethylene functional groups and 1,1-substituted ethylene functional groups shown below.
(1) Examples of the 1-substituted ethylene functional group include functional groups represented by the following formula (10).
_{CH 2 = CH-X 1 -} ···· formula (10)
(In the formula, X ₁ is an arylene group such as a phenylene group or a naphthylene group which may have a substituent, an alkenylene group which may have a substituent, a —CO— group, a —COO— group. , —CON (R ₁₀ ) — group (R ₁₀ represents an alkyl group such as hydrogen, methyl group or ethyl group, an aralkyl group such as benzyl group, naphthylmethyl group or phenethyl group, or an aryl group such as phenyl group or naphthyl group. Or the —S— group.)
Specific examples of these substituents include a vinyl group, a styryl group, a 2-methyl-1,3-butadienyl group, a vinylcarbonyl group, an acryloyloxy group, an acryloylamide group, and a vinyl thioether group.
(2) Examples of the 1,1-substituted ethylene functional group include functional groups represented by the following formula (11).
_{CH 2 = CH (Y) -X} 2 - ···· formula (11)
(In the formula, Y is an aryl group such as an alkyl group which may have a substituent, an aralkyl group which may have a substituent, a phenyl group which may have a substituent, or a naphthyl group. Group, halogen atom, cyano group, nitro group, alkoxy group such as methoxy group or ethoxy group, -COOR ₁₁ group (R ₁₁ is a hydrogen atom, an alkyl such as an optionally substituted methyl group or ethyl group) Group, an aralkyl group such as benzyl which may have a substituent, a phenethyl group or the like, an aryl group such as a phenyl group or a naphthyl group which may have a substituent, or -CONR ₁₂ R ₁₃ (R ₁₂ and R ₁₃ is a hydrogen atom, which may have a substituent an alkyl group such as methyl group and ethyl group, which may have a substituent group benzyl group, naphthylmethyl group, or Ara such phenethyl group, Kill group or substituent a phenyl group which may have a represents an aryl group such as phenyl or naphthyl, which may be the same or different from each other.) Further, X ₂ and X ₁ in the formula (10) Represents the same substituent, a single bond, and an alkylene group, provided that at least one of Y and X ₂ is an oxycarbonyl group, a cyano group, an alkenylene group, and an aromatic ring.)

Specific examples of these substituents include an α-acryloyloxy chloride group, a methacryloyloxy group, an α-cyanoethylene group, an α-cyanoacryloyloxy group, an α-cyanophenylene group, and a methacryloylamino group.
In addition, examples of the substituent further substituted with the substituent for X ₁ , X ₂ , and Y include, for example, a halogen atom, a nitro group, a cyano group, a methyl group, an alkyl group such as an ethyl group, a methoxy group, an ethoxy group, and the like And an aryloxy group such as a phenoxy group, an aryl group such as a phenyl group and a naphthyl group, and an aralkyl group such as a benzyl group and a phenethyl group.
Among these radically polymerizable functional groups, acryloyloxy group and methacryloyloxy group are particularly useful. For example, a compound having three or more acryloyloxy groups is a compound having three or more hydroxyl groups in the molecule and an acrylic group. It can be obtained by using an acid (salt), an acrylic acid halide, or an acrylic ester to cause an ester reaction or a transesterification reaction. A compound having three or more methacryloyloxy groups can be obtained in the same manner. Further, the radical polymerizable functional groups in the monomer having three or more radical polymerizable functional groups may be the same or different.

Specific examples of the trifunctional or higher functional radical polymerizable monomer having no charge transporting structure include the following, but are not limited to these compounds.
That is, examples of the radical polymerizable monomer used in the present invention include trimethylolpropane triacrylate (TMPTA), trimethylolpropane trimethacrylate, HPA-modified trimethylolpropane triacrylate, EO-modified trimethylolpropane triacrylate, and PO-modified. Trimethylolpropane triacrylate, caprolactone modified trimethylolpropane triacrylate, HPA modified trimethylolpropane trimethacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate (PETTA), glycerol triacrylate, ECH modified glycerol triacrylate, EO modified glycerol triacrylate , PO-modified glycerol triacrylate, Lith (acryloxyethyl) isocyanurate, dipentaerythritol hexaacrylate (DPHA), caprolactone-modified dipentaerythritol hexaacrylate, dipentaerythritol hydroxypentaacrylate, alkyl-modified dipentaerythritol pentaacrylate, alkyl-modified dipentaerythritol tetraacrylate, alkyl Modified dipentaerythritol triacrylate, dimethylolpropane tetraacrylate (DTMPTA), pentaerythritol ethoxytetraacrylate, EO modified phosphoric acid triacrylate, 2,2,5,5-tetrahydroxymethylcyclopentanone tetraacrylate, etc. These may be used alone or in combination of two or more.

  The trifunctional or higher functional radical polymerizable monomer having no charge transport structure used in the present invention is a ratio of molecular weight to the number of functional groups in the monomer in order to form a dense crosslink in the cross-linked surface layer. (Molecular weight / functional group number) is preferably 250 or less. Further, when this ratio is larger than 250, the crosslinked surface layer is soft and wear resistance is somewhat lowered. Therefore, among the monomers exemplified above, monomers having a modifying group such as HPA, EO, and PO are extremely long. It is not preferable to use one having a modifying group alone.

  Moreover, the component ratio of the trifunctional or higher functional radical polymerizable monomer having no charge transporting structure used for the crosslinked surface layer is 20 to 80% by weight, preferably 30 to 70% by weight, based on the total amount of the crosslinked surface layer. When the monomer component is less than 20% by weight, the three-dimensional cross-linking density of the cross-linked surface layer is small, and a drastic improvement in wear resistance is not achieved as compared with the case of using a conventional thermoplastic binder resin. On the other hand, if it exceeds 80% by weight, the content of the charge transporting compound is lowered, and the electrical characteristics are deteriorated. Since the required wear resistance and electrical characteristics differ depending on the process used, it cannot be said unconditionally, but considering the balance of both characteristics, the range of 30 to 70% by weight is most preferable.

[Radically polymerizable compound having a charge transporting structure]
The radical polymerizable compound having a charge transporting structure used in the present invention includes a hole transporting structure such as triarylamine, hydrazone, pyrazoline, carbazole, such as condensed polycyclic quinone, diphenoquinone, cyano group and nitro group. It refers to a compound having an electron transport structure such as an electron-withdrawing aromatic ring and having a radical polymerizable functional group. Examples of the radical polymerizable functional group include those shown in the above radical polymerizable monomer, and acryloyloxy group and methacryloyloxy group are particularly useful. As the charge transporting structure, a triarylamine structure is highly effective, and a monofunctional compound is preferable. Furthermore, when a compound represented by the structure of the following general formula (1) or (2) is used, electrical characteristics such as sensitivity and residual potential are favorably maintained.

（式中、Ｒ_１は水素原子、ハロゲン原子、置換基を有してもよいアルキル基、置換基を有してもよいアラルキル基、置換基を有してもよいアリール基、シアノ基、ニトロ基、アルコキシ基、−ＣＯＯＲ_７（Ｒ_７は水素原子、置換基を有してもよいアルキル基、置換基を有してもよいアラルキル基又は置換基を有してもよいアリール基）、ハロゲン化カルボニル基若しくはＣＯＮＲ_８Ｒ_９（Ｒ_８及びＲ_９は水素原子、ハロゲン原子、置換基を有してもよいアルキル基、置換基を有してもよいアラルキル基又は置換基を有してもよいアリール基を示し、互いに同一であっても異なっていてもよい）を表わし、Ａｒ_１、Ａｒ_２は置換もしくは未置換のアリーレン基を表わし、同一であっても異なってもよい。Ａｒ_３、Ａｒ_４は置換もしくは未置換のアリール基を表わし、同一であっても異なってもよい。Ｘは単結合、置換もしくは無置換のアルキレン基、置換もしくは無置換のシクロアルキレン基、置換もしくは無置換のアルキレンエーテル基、酸素原子、硫黄原子、ビニレン基を表わす。Ｚは置換もしくは無置換のアルキレン基、置換もしくは無置換のアルキレンエーテル基、アルキレンオキシカルボニル基を表わす。ｍ、ｎは０〜３の整数を表わす。）

(In the formula, R ₁ represents a hydrogen atom, a halogen atom, an alkyl group which may have a substituent, an aralkyl group which may have a substituent, an aryl group which may have a substituent, a cyano group, a nitro group, Group, alkoxy group, —COOR ₇ (R ₇ is a hydrogen atom, an alkyl group which may have a substituent, an aralkyl group which may have a substituent or an aryl group which may have a substituent), halogen Carbonyl group or CONR ₈ R ₉ (R ₈ and R ₉ may have a hydrogen atom, a halogen atom, an alkyl group which may have a substituent, an aralkyl group which may have a substituent, or a substituent. Ar ₁ and Ar ₂ each represent a substituted or unsubstituted arylene group, and may be the same or different.Ar ₃ , which may be the same or different from each other. Ar ₄ may be substituted Represents an unsubstituted aryl group, which may be the same or different, X represents a single bond, a substituted or unsubstituted alkylene group, a substituted or unsubstituted cycloalkylene group, a substituted or unsubstituted alkylene ether group, An oxygen atom, a sulfur atom, or a vinylene group, Z represents a substituted or unsubstituted alkylene group, a substituted or unsubstituted alkylene ether group, or an alkyleneoxycarbonyl group, and m and n represent an integer of 0 to 3.)

Specific examples of the substituents in the general formulas (1) and (2) are shown below.
In the general formulas (1) and (2), in the substituent of R ₁ , examples of the alkyl group include a methyl group, an ethyl group, a propyl group, and a butyl group, and examples of the aryl group include a phenyl group and a naphthyl group. The aralkyl group includes a benzyl group, a phenethyl group, and a naphthylmethyl group, and the alkoxy group includes a methoxy group, an ethoxy group, a propoxy group, and the like. These include a halogen atom, a nitro group, a cyano group, and a methyl group. Substituted with an alkyl group such as an ethyl group, an alkoxy group such as a methoxy group or an ethoxy group, an aryloxy group such as a phenoxy group, an aryl group such as a phenyl group or a naphthyl group, an aralkyl group such as a benzyl group or a phenethyl group, etc. May be.

Of the substituents for R ₁ , particularly preferred are a hydrogen atom and a methyl group.
Substituted or unsubstituted Ar ₃ and Ar ₄ are aryl groups, and examples of the aryl group include condensed polycyclic hydrocarbon groups, non-fused cyclic hydrocarbon groups, and heterocyclic groups.

  The condensed polycyclic hydrocarbon group preferably has 18 or less carbon atoms forming a ring, for example, a pentanyl group, an indenyl group, a naphthyl group, an azulenyl group, a heptaenyl group, a biphenylenyl group, an as-indacenyl group. , S-indacenyl group, fluorenyl group, acenaphthylenyl group, preadenyl group, acenaphthenyl group, phenalenyl group, phenanthryl group, anthryl group, fluoranthenyl group, acephenanthrenyl group, aceanthrylenyl group, triphenylyl group, pyrenyl group , A chrycenyl group, a naphthacenyl group, and the like.

  Examples of the non-fused cyclic hydrocarbon group include monovalent groups of monocyclic hydrocarbon compounds such as benzene, diphenyl ether, polyethylene diphenyl ether, diphenyl thioether and diphenyl sulfone, or biphenyl, polyphenyl, diphenylalkane, diphenylalkene, diphenylalkyne, Monovalent groups of non-condensed polycyclic hydrocarbon compounds such as triphenylmethane, distyrylbenzene, 1,1-diphenylcycloalkane, polyphenylalkane, and polyphenylalkene, or ring assemblies such as 9,9-diphenylfluorene And monovalent groups of hydrocarbon compounds.

Examples of the heterocyclic group include monovalent groups such as carbazole, dibenzofuran, dibenzothiophene, oxadiazole, and thiadiazole.
The aryl group represented by Ar ₃ or Ar ₄ may have a substituent as shown below, for example.
(1) Halogen atom, cyano group, nitro group and the like.
(2) an alkyl group;
_Preferably, C 1 _{-C 12} especially _C 1 -C _8, more preferably a straight or branched alkyl group of _C 1 -C _4, in the alkyl group a fluorine atom, a hydroxyl group, a cyano group, C ₁ -C ₄ alkoxy group which may have a phenyl group or a halogen _atom, C 1 -C ₄ alkyl or _C 1 -C ₄ phenyl group substituted with an alkoxy group. Specifically, methyl group, ethyl group, n-butyl group, i-propyl group, t-butyl group, s-butyl group, n-propyl group, trifluoromethyl group, 2-hydroxyethyl group, 2-ethoxyethyl Group, 2-cyanoethyl group, 2-methoxyethyl group, benzyl group, 4-chlorobenzyl group, 4-methylbenzyl group, 4-phenylbenzyl group and the like.
(3) an alkoxy group (—OR ₂ );
R ₂ represents an alkyl group defined in (2). Specifically, methoxy group, ethoxy group, n-propoxy group, i-propoxy group, t-butoxy group, n-butoxy group, s-butoxy group, i-butoxy group, 2-hydroxyethoxy group, benzyloxy group And a trifluoromethoxy group.
(4) aryloxy group;
Examples of the aryl group include a phenyl group and a naphthyl group. It _may contain an alkoxy group having C 1 -C _4, alkyl group, or a halogen atom C 1 -C ₄ as a substituent. Specific examples include a phenoxy group, a 1-naphthyloxy group, a 2-naphthyloxy group, a 4-methoxyphenoxy group, and a 4-methylphenoxy group.
(5) an alkyl mercapto group or an aryl mercapto group;
Specific examples include a methylthio group, an ethylthio group, a phenylthio group, and a p-methylphenylthio group.
(6) a substituent represented by the following formula;

（式中、Ｒ_３及びＲ_４は各々独立に水素原子、前記（２）で定義したアルキル基、またはアリール基を表わす。アリール基としては、例えばフェニル基、ビフェニル基又はナフチル基が挙げられ、これらはＣ_１〜Ｃ_４のアルコキシ基、Ｃ_１〜Ｃ_４のアルキル基またはハロゲン原子を置換基として含有してもよい。Ｒ_３及びＲ_４は共同で環を形成してもよい）
具体的には、アミノ基、ジエチルアミノ基、Ｎ−メチル−Ｎ−フェニルアミノ基、Ｎ，Ｎ−ジフェニルアミノ基、Ｎ，Ｎ−ジ（トリール）アミノ基、ジベンジルアミノ基、ピペリジノ基、モルホリノ基、ピロリジノ基等が挙げられる。
（７）メチレンジオキシ基、又はメチレンジチオ基等のアルキレンジオキシ基又はアルキレンジチオ基等が挙げられる。
（８）置換又は無置換のスチリル基、置換又は無置換のβ−フェニルスチリル基、ジフェニルアミノフェニル基、ジトリルアミノフェニル基等。

(In the formula, R ₃ and R ₄ each independently represent a hydrogen atom, an alkyl group defined in (2) above, or an aryl group. Examples of the aryl group include a phenyl group, a biphenyl group, and a naphthyl group. these may form a ring _C 1 -C ₄ alkoxy _groups, C 1 -C a alkyl group or a halogen atom ₄ which may contain as substituents .R ₃ and _{R 4} jointly)
Specifically, amino group, diethylamino group, N-methyl-N-phenylamino group, N, N-diphenylamino group, N, N-di (tolyl) amino group, dibenzylamino group, piperidino group, morpholino group And pyrrolidino group.
(7) An alkylenedioxy group or an alkylenedithio group such as a methylenedioxy group or a methylenedithio group.
(8) A substituted or unsubstituted styryl group, a substituted or unsubstituted β-phenylstyryl group, a diphenylaminophenyl group, a ditolylaminophenyl group, and the like.

On the other hand, examples of the arylene group represented by Ar ₁ and Ar ₂ include a divalent group derived from the aryl group represented by Ar ₃ and Ar ₄ .
X represents a single bond, a substituted or unsubstituted alkylene group, a substituted or unsubstituted cycloalkylene group, a substituted or unsubstituted alkylene ether group, an oxygen atom, a sulfur atom, or a vinylene group.
The substituted or unsubstituted alkylene group is a C ₁ -C ₁₂ , preferably C ₁ -C ₈ , more preferably C ₁ -C ₄ linear or branched alkylene group, and these alkylene groups include a fluorine atom, a hydroxyl group, a cyano _group, an alkoxy group of C 1 -C _4, a phenyl group or a halogen _atom, a phenyl group substituted with an alkyl group or a _C 1 -C ₄ alkoxy group C 1 -C ₄ It may be. Specifically, methylene group, ethylene group, n-butylene group, i-propylene group, t-butylene group, s-butylene group, n-propylene group, trifluoromethylene group, 2-hydroxyethylene group, 2-ethoxyethylene Group, 2-cyanoethylene group, 2-methoxyethylene group, benzylidene group, phenylethylene group, 4-chlorophenylethylene group, 4-methylphenylethylene group, 4-biphenylethylene group and the like.
The substituted or unsubstituted cycloalkylene _group, a cyclic alkylene group of C 5 -C _7, these are the cyclic alkylene group fluorine atom, a hydroxyl _group, an alkyl group of C 1 -C _4, a C 1 -C ₄ It may have an alkoxy group. Specific examples include a cyclohexylidene group, a cyclohexylene group, and a 3,3-dimethylcyclohexylidene group.
The substituted or unsubstituted alkylene ether group represents ethyleneoxy, propyleneoxy, ethylene glycol, propylene glycol, diethylene glycol, tetraethylene glycol, tripropylene glycol, alkylene ether group alkylene group is hydroxyl group, methyl group, ethyl group, etc. You may have the substituent of.
Examples of the vinylene group include substituents represented by the following general formula.

〔式中、Ｒ_５は水素、アルキル基（前記（２）で定義されるアルキル基と同じ）、アリール基（前記Ａｒ_３、Ａｒ_４で表わされるアリール基と同じ）、ａは１または２、ｂは１〜３を表わす。〕
前記Ｚは置換もしくは未置換のアルキレン基、置換もしくは無置換のアルキレンエーテル基、アルキレンオキシカルボニル基を表わす。
置換もしくは未置換のアルキレン基としは、前記Ｘのアルキレン基と同様なものが挙げられる。
置換もしくは無置換のアルキレンエーテル基としては、前記Ｘのアルキレンエーテル基が挙げられる。
アルキレンオキシカルボニル基としては、カプロラクトン変性基が挙げられる。
また、本発明の１官能の電荷輸送構造を有するラジカル重合性化合物として更に好ましくは、下記一般式（３）の構造の化合物が挙げられる。

[Wherein, R ₅ is hydrogen, an alkyl group (same as the alkyl group defined in (2) above), an aryl group (same as the aryl group represented by Ar ₃ or Ar ₄ above), a is 1 or 2, b represents 1-3. ]
Z represents a substituted or unsubstituted alkylene group, a substituted or unsubstituted alkylene ether group, or an alkyleneoxycarbonyl group.
Examples of the substituted or unsubstituted alkylene group include the same alkylene groups as those described above for X.
Examples of the substituted or unsubstituted alkylene ether group include the alkylene ether group represented by X.
Examples of the alkyleneoxycarbonyl group include a caprolactone-modified group.
Further, the radical polymerizable compound having a monofunctional charge transport structure of the present invention is more preferably a compound having a structure of the following general formula (3).

（式中、ｏ、ｐ、ｑはそれぞれ０又は１の整数、Ｒａは水素原子、メチル基を表わし、Ｒｂ、Ｒｃは水素原子以外の置換基で炭素数１〜６のアルキル基を表わし、複数の場合は異なっても良い。ｓ、ｔは０〜３の整数を表わす。Ｚａは単結合、メチレン基、エチレン基、

(Wherein, o, p and q are each an integer of 0 or 1, Ra represents a hydrogen atom or a methyl group, Rb and Rc represent a substituent other than a hydrogen atom and an alkyl group having 1 to 6 carbon atoms, And s and t each represents an integer of 0 to 3. Za is a single bond, a methylene group, an ethylene group,

を表わす。）
上記一般式（３）で表わされる化合物としては、Ｒｂ、Ｒｃの置換基として、特にメチル基、エチル基である化合物が好ましい。

Represents. )
As the compound represented by the general formula (3), compounds having a methyl group or an ethyl group as substituents for Rb and Rc are particularly preferable.

  The radically polymerizable compound having a monofunctional charge transport structure of the above general formulas (1) and (2), particularly (3) used in the present invention is polymerized by opening a carbon-carbon double bond on both sides. Therefore, in the polymer that does not become a terminal structure, is incorporated in the chain polymer, and is crosslinked by polymerization with a tri- or higher functional radical polymerizable monomer, it exists in the main chain of the polymer, and Present in the main chain-cross-linked chain (this cross-linked chain has an intermolecular cross-linked chain between one polymer and another polymer, and a main chain folded in one polymer. There is an intramolecular cross-linked chain that crosslinks the site and another site derived from the polymerized monomer at a position away from this in the main chain), but even if it exists in the main chain, Even if present in the triarylamine structure suspended from the chain moiety, It has at least three aryl groups arranged in the radial direction from and is bulky, but it is not directly bonded to the chain part and is suspended from the chain part via a carbonyl group etc. Since these triarylamine structures can be spatially arranged adjacent to each other in the polymer, there is little structural distortion in the molecule, and the surface layer of the image carrier is also fixed. In this case, it is presumed that an intramolecular structure that is relatively free from interruption of the charge transport pathway can be adopted.

[Radically polymerizable compound having a monofunctional charge transport structure]
Specific examples of the radically polymerizable compound having a monofunctional charge transporting structure of the present invention are shown below, but are not limited to the compounds having these structures.

[Radically polymerizable compound having a bifunctional charge transport structure]
Specific examples of the radical polymerizable compound having a bifunctional charge transporting structure of the present invention are shown below, but are not limited to the compounds having these structures.

[Radically polymerizable compound having a trifunctional charge transport structure]
Specific examples of the radical polymerizable compound having a trifunctional charge transporting structure of the present invention are shown below, but are not limited to the compounds having these structures. These radically polymerizable compounds themselves are conventionally known (see, for example, JP-A-2005-99688 of Patent Document 10).

[Surface layer]
The radical polymerizable compound having a charge transport structure used in the present invention is important for imparting the charge transport performance of the crosslinked surface layer, and this component is preferably 20 to 80% by weight, preferably based on the total amount of the crosslinked surface layer. Is 30 to 70% by weight. When this component is less than 20% by weight, the charge transport performance of the crosslinked surface layer cannot be maintained sufficiently, and deterioration of electrical characteristics such as a decrease in sensitivity and an increase in residual potential appears with repeated use. On the other hand, if it exceeds 80% by weight, the content of the trifunctional monomer having no charge transport structure is lowered, and the crosslink density is lowered, so that high wear resistance is not exhibited. Although the electrical characteristics and abrasion resistance required differ depending on the process used, it cannot be said unconditionally, but considering the balance of both characteristics, the range of 30 to 70% by weight is most preferable.

  The surface layer of the present invention is obtained by curing at least a trifunctional or higher-functional radical polymerizable monomer having no charge transport structure and a radical polymerizable compound having a charge transport structure. Monofunctional and bifunctional radically polymerizable monomers and radically polymerizable oligomers can be used in combination for the purpose of adjustment, stress relaxation of the cross-linked surface layer, lower surface energy, and reduction of friction coefficient. Known radical polymerizable monomers and oligomers can be used.

  Examples of the monofunctional radical monomer include 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, tetrahydrofurfuryl acrylate, 2-ethylhexyl carbitol acrylate, 3-methoxybutyl acrylate, benzyl acrylate, and cyclohexyl acrylate. , Isoamyl acrylate, isobutyl acrylate, methoxytriethylene glycol acrylate, phenoxytetraethylene glycol acrylate, cetyl acrylate, isostearyl acrylate, stearyl acrylate, styrene monomer, and the like.

  Examples of the bifunctional radical polymerizable monomer include 1,3-butanediol diacrylate, 1,4-butanediol diacrylate, 1,4-butanediol dimethacrylate, 1,6-hexanediol diacrylate, 1, Examples include 6-hexanediol dimethacrylate, diethylene glycol diacrylate, neopentyl glycol diacrylate, EO-modified bisphenol A diacrylate, EO-modified bisphenol F diacrylate, and neopentyl glycol diacrylate.

  Examples of the functional monomer include those substituted with a fluorine atom such as octafluoropentyl acrylate, 2-perfluorooctylethyl acrylate, 2-perfluorooctylethyl methacrylate, 2-perfluoroisononylethyl acrylate, No. 60503, JP-B-6-45770, siloxane repeating units: 20-70 acryloyl polydimethylsiloxane ethyl, methacryloyl polydimethylsiloxane ethyl, acryloyl polydimethylsiloxane propyl, acryloyl polydimethylsiloxane butyl, diacryloyl polydimethylsiloxane Examples include vinyl monomers having a polysiloxane group such as diethyl, acrylates and methacrylates.

  Examples of the radical polymerizable oligomer include epoxy acrylate, urethane acrylate, and polyester acrylate oligomers. However, when a large amount of monofunctional and bifunctional radically polymerizable monomers and radically polymerizable oligomers are contained, the three-dimensional cross-linking density of the cross-linked surface layer is substantially reduced, resulting in a decrease in wear resistance. For this reason, the content of these monomers and oligomers is limited to 50 parts by weight or less, preferably 30 parts by weight or less, with respect to 100 parts by weight of the tri- or higher functional radical polymerizable monomer.

  Further, the surface layer of the present invention is obtained by curing at least a trifunctional or higher functional radical polymerizable monomer having no charge transport structure and a radical polymerizable compound having a charge transport structure. In order to make the process proceed efficiently, a polymerization initiator may be used in the crosslinked surface layer.

  Examples of the thermal polymerization initiator include 2,5-dimethylhexane-2,5-dihydroperoxide, dicumyl peroxide, benzoyl peroxide, t-butylcumyl peroxide, 2,5-dimethyl-2,5-di ( Peroxybenzoyl) hexyne-3, di-t-butyl peroxide, t-butyl hydroperoxide, cumene hydroperoxide, peroxide initiators such as lauroyl peroxide, azobisisobutylnitrile, azobiscyclohexanecarbonitrile Azo initiators such as methyl azobisisobutyrate, azobisisobutylamidine hydrochloride, 4,4′-azobis-4-cyanovaleric acid.

Examples of the photopolymerization initiator include diethoxyacetophenone, 2,2-dimethoxy-1,2-diphenylethane-1-one, 1-hydroxy-cyclohexyl-phenyl-ketone, 4- (2-hydroxyethoxy) phenyl- (2 -Hydroxy-2-propyl) ketone, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) butanone-1, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 2- Acetophenone-based or ketal-based photopolymerization initiators such as methyl-2-morpholino (4-methylthiophenyl) propan-1-one, 1-phenyl-1,2-propanedione-2- (o-ethoxycarbonyl) oxime, Benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isobutyl ether Benzoin ether photopolymerization initiators such as benzoin isopropyl ether, benzophenone, 4-hydroxybenzophenone, methyl o-benzoylbenzoate, 2-benzoylnaphthalene, 4-benzoylbiphenyl, 4-benzoylphenyl ether, acrylated benzophenone, Benzophenone photopolymerization initiators such as 1,4-benzoylbenzene, thioxanthones such as 2-isopropylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2,4-dichlorothioxanthone Examples of photopolymerization initiators and other photopolymerization initiators include ethyl anthraquinone, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoic acid. Phenylethoxyphosphine oxide, bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide, bis (2,4-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide, methylphenylglyoxyester, 9,10 -Phenanthrene, an acridine type compound, a triazine type compound, an imidazole type compound is mentioned. Moreover, what has a photopolymerization acceleration effect can also be used individually or in combination with the said photoinitiator. Examples thereof include triethanolamine, methyldiethanolamine, ethyl 4-dimethylaminobenzoate, isoamyl 4-dimethylaminobenzoate, (2-dimethylamino) ethyl benzoate, 4,4′-dimethylaminobenzophenone, and the like.
These polymerization initiators may be used alone or in combination of two or more. The content of the polymerization initiator is 0.5 to 40 parts by weight, preferably 1 to 20 parts by weight with respect to 100 parts by weight of the total content having radical polymerizability.

  Furthermore, the coating liquid of the present invention can contain additives such as various plasticizers (for the purpose of stress relaxation and adhesion improvement), leveling agents, and low molecular charge transport materials having no radical reactivity as required. As these additives, known additives can be used, and as plasticizers, those used in general resins such as dibutyl phthalate and dioctyl phthalate can be used, and the amount used is the total solid content of the coating liquid. To 20% by weight or less, preferably 10% or less. As leveling agents, silicone oils such as dimethyl silicone oil and methylphenyl silicone oil, polymers or oligomers having a perfluoroalkyl group in the side chain can be used, and the amount used is based on the total solid content of the coating liquid. 3% by weight or less is appropriate.

[Acicular fine particles]
The acicular fine particles in the present invention are fine particles having an aspect ratio of 2 or more. Examples include carbon nanotubes, titanium oxide, zinc oxide, tin oxide, silicon oxide, zirconium oxide, potassium titanate, indium oxide, aluminum oxide and the like. In particular, metal oxide fine particles are preferable in terms of wear resistance and electrostatic characteristics. Furthermore, aluminum oxide is good in terms of image stability.
The fine particles preferably have a minor axis length of 0.5 μm or less and a major axis length of 10 μm or less. The aspect ratio is preferably in the range of 2 to 500.
The shape of the acicular fine particles is evaluated by direct observation with an electron microscope such as SEM or TEM. Next, a specific observation example by SEM is shown.
The fine particle powder is fixed on an aluminum sample stage with a conductive carbon double-sided tape and coated with platinum-palladium to prepare a sample. Thereafter, a sample is set in a SEM (S-4200) manufactured by Hitachi Electronics, and observation is performed at an acceleration voltage of 5 kV and a magnification of 10,000 to 100,000. The shape is evaluated from the observed image.
The larger the amount of acicular fine particles added to the surface layer, the better the wear resistance. However, if the amount is too large, the residual potential increases, the write light transmittance of the protective layer decreases, and side effects may occur. is there. Therefore, it is about 50% by weight or less, preferably about 30% by weight or less based on the total solid content.

Furthermore, these needle-shaped fine particles can be surface-treated with at least one kind of surface treatment agent, which is preferable from the viewpoint of dispersibility of the needle-shaped fine particles. Decreasing dispersibility of acicular fine particles not only increases residual potential, but also decreases transparency of the coating film, causes coating film defects, and decreases wear resistance. There is a possibility that it will develop into a big problem. As the surface treatment agent, a conventionally used surface treatment agent can be used, but a surface treatment agent capable of maintaining the insulating properties of the acicular fine particles is preferable. For example, a titanate coupling agent, an aluminum coupling agent, a zircoaluminate coupling agent, a higher fatty acid, etc., or a mixing treatment of these with a silane coupling agent, Al ₂ O ₃ , TiO ₂ , ZrO ₂ , Silicone, aluminum stearate, or the like, or a mixed treatment thereof is more preferable from the viewpoint of dispersibility of the needle-shaped fine particles and image blur. The treatment with the silane coupling agent is strongly influenced by image blur, but the influence may be suppressed by performing a mixing treatment of the surface treatment agent and the silane coupling agent. These acicular fine particle materials may be used alone or in combination of two or more.

[Formation of crosslinked surface layer]
The crosslinked surface layer of the present invention is applied and cured with a coating solution containing at least a trifunctional or higher functional radical polymerizable monomer having no charge transport structure, a radical polymerizable compound having a charge transport structure, and needle-shaped fine particles. It is formed by. When the radically polymerizable monomer is a liquid, such a coating liquid can be applied by dissolving other components in the liquid, but if necessary, it is diluted with a solvent and applied. Solvents used at this time include alcohols such as methanol, ethanol, propanol and butanol, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone, esters such as ethyl acetate and butyl acetate, tetrahydrofuran, dioxane and propyl ether. And ethers such as dichloromethane, dichloroethane, trichloroethane, and chlorobenzene, aromatics such as benzene, toluene, and xylene, and cellosolves such as methyl cellosolve, ethyl cellosolve, and cellosolve acetate. These solvents may be used alone or in combination of two or more. The dilution ratio with the solvent varies depending on the solubility of the composition, the coating method, and the target film thickness, and is arbitrary. The coating can be performed using a dip coating method, spray coating, bead coating, ring coating method or the like.

In the present invention, after applying such a coating solution, energy is applied from the outside and cured to form a crosslinked surface layer. The external energy used at this time includes heat, light, and radiation. The heat energy is applied by heating from the coating surface side or the support side using a gas such as air or nitrogen, steam, various heat media, infrared rays, or electromagnetic waves. The heating temperature is preferably 100 ° C. or higher and 170 ° C. or lower. If the heating temperature is lower than 100 ° C., the reaction rate is slow and the reaction is not completely completed. At a temperature higher than 170 ° C., the reaction proceeds non-uniformly and a large strain is generated in the crosslinked 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. As the energy of light, UV irradiation light sources such as high-pressure mercury lamps and metal halide lamps, which mainly have an emission wavelength in ultraviolet light, can be used, but a visible light source can also be selected according to the absorption wavelength of radically polymerizable substances and photopolymerization initiators. Is possible. Irradiation light amount is 50 mW / cm ² or more, preferably 1000 mW / cm ² or less, it takes time for the curing reaction is less than 50 mW / cm ^2. If it is higher than 1000 mW / cm ^2, the progress of the reaction becomes non-uniform and the cross-linked surface layer becomes very rough. Examples of radiation energy include those using electron beams. Among these energies, those using heat and light energy are useful because of the ease of reaction rate control and the simplicity of the apparatus.

  Since the film thickness of the crosslinked surface layer of the present invention varies depending on the layer structure of the image carrier in which the crosslinked surface layer is used, it will be described later together with the layer structure.

  In the composition contained in the crosslinked surface layer coating solution, it is possible to contain a binder resin as long as the smoothness, electrical characteristics, or durability of the image carrier surface is not impaired. However, when a polymer material such as a binder resin is included in the coating liquid, it is in phase with the polymer formed by the curing reaction of the radical polymerizable composition (radical polymerizable monomer and radical polymerizable compound having a charge transporting structure). Phase separation occurs due to poor solubility, and the surface of the crosslinked surface layer becomes uneven. Therefore, it is preferable not to use a binder resin.

  In the cross-linked surface layer of the present invention, it is necessary to contain a bulky charge transporting structure in order to maintain electrical characteristics and to increase the cross-linking density in order to increase the strength. In such curing after application of the crosslinked surface layer, if very high energy is applied from the outside and the reaction proceeds rapidly, curing proceeds unevenly and the unevenness of the crosslinked film surface becomes severe. For this reason, the thing using the heat | fever which can control reaction rate according to heating conditions, light irradiation intensity | strength, and the amount of polymerization initiators, or the external energy of light is preferable.

In the case of using the crosslinked surface layer forming material of the present invention, examples of the coating method include, for example, an acrylate monomer having three acryloyloxy groups and a triarylamine compound having one acryloyloxy group as a coating solution. When these are used, their use ratio is 7: 3 to 3: 7, and 3-20% by weight of a polymerization initiator is added to the total amount of these acrylate compounds, and a solvent is added to prepare a coating solution. To do. For example, in the case where the charge transport layer which is the lower layer of the cross-linked surface layer uses a triarylamine donor as the charge transport material and polycarbonate as the binder resin, and the cross-linked surface layer is formed by spray coating, the above coating solution As the solvent, tetrahydrofuran, 2-butanone, ethyl acetate and the like are preferable, and the use ratio thereof is 3 to 10 times the total amount of the acrylate compound.
The cured surface crosslinked layer 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.
Next, the prepared coating solution is applied by spraying or the like onto a photosensitive layer in which an undercoat layer, a charge generation layer, and the charge transport layer are sequentially laminated on a support such as an aluminum cylinder. Thereafter, it is dried at a relatively low temperature for a short time (25 to 80 ° C., 1 to 10 minutes) and cured by UV irradiation or heating.
For UV irradiation, uses a metal halide lamp, illuminance 50 mW / cm ² or more, preferably 1000 mW / cm ² or less, for example, the case of irradiation with UV light of 700 mW / cm ^2, for example upon curing, by rotating the drum All the surfaces may be uniformly irradiated for about 20 seconds. At this time, the drum temperature is controlled so as not to exceed 50 ° C.
In the case of thermosetting, the heating temperature is preferably 100 to 170 ° C. For example, when a blowing oven is used as a heating means and the heating temperature is set to 150 ° C, the heating time is 20 minutes to 3 hours.
After the curing is completed, the image bearing member of the present invention is obtained by heating at 100 to 150 ° C. for 10 to 30 minutes to reduce the residual solvent.

Hereinafter, the present invention will be described according to the layer structure.
[Layer structure of image carrier]
The image carrier used in the present invention will be described with reference to the drawings.
FIG. 3 is a cross-sectional view showing an image carrier of the present invention, which is an image carrier having a single layer structure in which a photosensitive layer having a charge generation function and a charge transport function at the same time is provided on a conductive support. FIG. 3A shows the case where the cross-linked surface layer is the entire photosensitive layer, and FIG. 3B shows the case where the cross-linked surface layer is the surface portion of the photosensitive layer.
FIG. 4 shows an image carrier having a stacked structure in which a charge generation layer having a charge generation function and a charge transport layer having a charge transport material function are stacked on a conductive support. FIG. 4A shows the case where the cross-linked surface layer is the entire charge transport layer, and FIG. 4B shows the case where the cross-linked surface layer is the surface portion of the charge transport layer.

[Conductive support]
Examples of the conductive support include those having a volume resistance of 10 ¹⁰ Ω · cm or less, such as metals such as aluminum, nickel, chromium, nichrome, copper, gold, silver, and platinum, tin oxide, and indium oxide. After metal oxide is deposited or sputtered, film or cylindrical plastic, paper coated, or aluminum, aluminum alloy, nickel, stainless steel, etc. Pipes that have been subjected to surface treatment such as cutting, super-finishing, 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, those obtained by dispersing and coating conductive powder in an appropriate binder resin on the support can also be used as the conductive support of the present invention.

  Examples of the conductive powder include carbon black, acetylene black, metal powder such as aluminum, nickel, iron, nichrome, copper, zinc and silver, or metal oxide powder such as conductive tin oxide and ITO. Can be mentioned. The binder resin used at the same time 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 coating these conductive powder and binder resin in a suitable solvent such as tetrahydrofuran, dichloromethane, methyl ethyl ketone, and toluene.

  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 of the present invention.

[Photosensitive layer]
Next, the photosensitive layer will be described. The photosensitive layer may have a laminated structure or a single layer structure.
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 a layer having a charge generation function and a charge transport function at the same time.
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 a layer mainly composed of a charge generation material having a charge generation function, and a binder resin can be used in combination as necessary. As the charge generation material, inorganic materials and organic materials can be used.
Inorganic materials include crystalline selenium, amorphous selenium, selenium-tellurium, selenium-tellurium-halogen, selenium-arsenic compounds, and amorphous silicon. In amorphous silicon, dangling bonds that are terminated with hydrogen atoms or halogen atoms, or those that are doped with boron atoms, phosphorus atoms, or the like are preferably used.
On the other hand, a known material can be used as the organic material. For example, phthalocyanine pigments such as metal phthalocyanine and metal-free phthalocyanine, azulenium salt pigments, squaric acid methine pigments, azo pigments having carbazole skeleton, azo pigments having triphenylamine skeleton, azo pigments having diphenylamine skeleton, dibenzothiophene skeleton Azo pigments having a fluorenone skeleton, azo pigments having an oxadiazole skeleton, azo pigments having a bis-stilbene skeleton, azo pigments having a distyryl oxadiazole skeleton, azo pigments having a 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.

  As a binder resin used as necessary for the charge generation layer, polyamide, polyurethane, epoxy resin, polyketone, polycarbonate, silicone resin, acrylic resin, polyvinyl butyral, polyvinyl formal, polyvinyl ketone, polystyrene, poly-N-vinylcarbazole, Examples include polyacrylamide. These binder resins can be used alone or as a mixture of two or more. In addition to the binder resin described above as a binder resin for the charge generation layer, a polymer charge transport material having a charge transport function, such as an arylamine skeleton, benzidine skeleton, hydrazone skeleton, carbazole skeleton, stilbene skeleton, pyrazoline skeleton, etc. Polymer materials such as polycarbonate, polyester, polyurethane, polyether, 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. No. 1, JP-A 09-104746, JP 09-110974, JP 09-110976, JP 09-157378, JP 09-221544, JP 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 No. 63-285552, JP-A No. 05-19497, JP-A No. 05-70595, JP-A No. 10-73944, and the like. Illustrated.

The charge generation layer may contain a low molecular charge transport material.
Low molecular charge transport materials that can be used in the charge generation layer include hole transport materials and electron transport materials.
Examples of the electron transporting material include chloroanil, bromanyl, 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-tri Examples thereof include electron-accepting substances such as nitrodibenzothiophene-5,5-dioxide and diphenoquinone derivatives. These electron transport materials can be used alone or as a mixture of two or more.

  Examples of the hole transporting material include the electron donating materials shown below and are used favorably. As hole transport materials, oxazole derivatives, oxadiazole derivatives, imidazole derivatives, monoarylamine derivatives, diarylamine derivatives, triarylamine derivatives, stilbene derivatives, α-phenylstilbene derivatives, benzidine derivatives, diarylmethane derivatives, triaryls Other known materials such as methane derivatives, 9-styrylanthracene derivatives, pyrazoline derivatives, divinylbenzene derivatives, hydrazone derivatives, indene derivatives, butadiene derivatives, pyrene derivatives, bisstilbene derivatives, enamine derivatives, and the like can be given. These hole transport materials can be used alone or as a mixture of two or more.

Methods for forming the charge generation layer include a vacuum thin film preparation method and a casting method from a solution dispersion system.
As the former method, a vacuum deposition method, a glow discharge decomposition method, an ion plating method, a sputtering method, a reactive sputtering method, a CVD method, or the like is used, and the above-described inorganic materials and organic materials can be satisfactorily formed.
In addition, in order to provide a charge generation layer by the casting method described later, if necessary, the inorganic or organic charge generation material together with a binder resin, tetrahydrofuran, dioxane, dioxolane, toluene, dichloromethane, monochlorobenzene, dichloroethane, cyclohexanone, cyclohexane. Can be formed by dispersing with a ball mill, attritor, sand mill, bead mill, etc. using a solvent such as pentanone, anisole, xylene, methyl ethyl ketone, acetone, ethyl acetate, butyl acetate, etc. . Moreover, leveling agents, such as a dimethyl silicone oil and a methylphenyl silicone oil, can be added as needed. The coating can be performed using a dip coating method, spray coating, bead coating, ring coating method or the like.
The thickness of the charge generation layer provided as described above is suitably about 0.01 to 5 μm, preferably 0.05 to 2 μm.

(About charge transport layer)
The charge transport layer is a layer having a charge transport function, and the crosslinked surface layer having the charge transport structure of the present invention is useful as a charge transport layer. When the cross-linked surface layer is the entire charge transport layer, the radical polymerizable composition (radical polymerizable monomer having no charge transport structure) of the present invention is formed on the charge generation layer as described in the above cross-linked surface layer preparation method. And a radically polymerizable compound having a charge transporting structure; the same shall apply hereinafter) and a coating liquid containing needle-shaped fine particles, and if necessary, after drying, a curing reaction is initiated by external energy to form a crosslinked surface layer. The At this time, the film thickness of the crosslinked surface layer is 10 to 30 μm, preferably 10 to 25 μm. If it is thinner than 10 μm, a sufficient charging potential cannot be maintained, and if it is thicker than 30 μm, peeling from the lower layer tends to occur due to volume shrinkage during curing.
In addition, when the cross-linked surface layer is formed on the surface portion of the charge transport layer and the charge transport layer has a laminated structure, the lower layer portion of the charge transport layer uses a charge transport material having a charge transport function and a binder resin as an appropriate solvent. Dissolved or dispersed, formed on the charge generation layer by coating and drying, and coated thereon with a coating solution containing the radical polymerizable composition of the present invention and needle-shaped fine particles, and external energy. Crosslink and cure.

  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 surface layer is applied, and is particularly useful.

As the binder resin, 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, melamine resin, urethane resin And thermoplastic or thermosetting resins such as phenol resins and alkyd resins.
The amount of the charge transport material is appropriately 20 to 300 parts by weight, preferably 40 to 150 parts by weight, based on 100 parts by weight of the binder resin. However, when a polymer charge transport material is used, it can be used alone or in combination with a binder resin.
As the solvent used for coating the lower layer portion of the charge transport layer, the same solvent as that for the charge generation layer can be used, but a solvent that dissolves the charge transport material and the binder resin well is suitable. These solvents may be used alone or in combination of two or more. In addition, the same coating method as that for the charge generation layer can be used to form the lower layer portion of the charge transport layer.

If necessary, a plasticizer and a leveling agent can be added.
As a plasticizer that can be used in combination with the lower layer portion of the charge transport layer, those used as plasticizers for general resins such as dibutyl phthalate and dioctyl phthalate can be used as they are, and the amount used is 100 parts by weight of the binder resin. On the other hand, about 0 to 30 parts by weight is appropriate.
As a leveling agent that can be used in combination with the lower layer portion of 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 to 1 part by weight is appropriate for 100 parts by weight of the binder resin.
The thickness of the lower layer portion of the charge transport layer is appropriately about 5 to 40 μm, preferably about 10 to 30 μm.

  When the cross-linked surface layer is the surface portion of the charge transport layer, as described in the above cross-linked surface layer preparation method, the coating liquid containing the radical polymerizable composition of the present invention on the lower layer portion of the charge transport layer After the coating and drying as necessary, the curing reaction is initiated by external energy such as heat or light to form a crosslinked surface layer. At this time, the film thickness of the crosslinked surface layer is 1 to 20 μm, preferably 2 to 10 μm. If the thickness is less than 1 μm, the durability varies due to uneven film thickness. If the thickness is more than 20 μm, the entire thickness of the charge transport layer is increased, and the reproducibility of the image is reduced due to the diffusion of charges.

<Single photosensitive layer>
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, and the crosslinked surface layer having the charge transport structure of the present invention contains a charge generation material having a charge generation function, thereby providing a single layer structure. It is useful as a photosensitive layer. As described in the method for forming a charge generation layer, the charge generation material is dispersed together with a coating liquid containing a radical polymerizable composition, applied onto the charge generation layer, dried as necessary, and then external energy. By this, the curing reaction is started and a crosslinked surface layer is formed. In addition, you may add the liquid in which the charge generation material was previously disperse | distributed with the solvent to this coating material for bridge | crosslinking surface layers. At this time, the film thickness of the crosslinked surface layer is 10 to 30 μm, preferably 10 to 25 μm. If the thickness is less than 10 μm, a sufficient charging potential cannot be maintained. If the thickness is more than 30 μm, peeling from the conductive substrate or the undercoat layer tends to occur due to volume shrinkage during curing.

  Further, when the crosslinked surface layer is a surface portion of a photosensitive layer having a single layer structure, the lower layer portion of the photosensitive layer is composed of a charge generating material having a charge generating function, a charge transporting material having a charge transport function, and a binder resin in an appropriate solvent. It can be formed by dissolving or dispersing in, coating and drying. 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 previously mentioned in the section of the charge transport layer, the 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 crosslinked surface layer can be reduced. The thickness of the lower layer portion of the photosensitive layer is suitably about 5 to 30 μm, preferably about 10 to 25 μm.

  When the cross-linked surface layer is the surface portion of the photosensitive layer having a single layer structure, the coating solution containing the radical polymerizable composition of the present invention and the charge generating material is applied onto the lower layer portion of the photosensitive layer as described above. If necessary, after drying, it is cured by external energy such as heat or light to form a crosslinked surface layer. At this time, the film thickness of the crosslinked surface layer is 1 to 20 μm, preferably 2 to 10 μm. When the thickness is less than 1 μm, the durability varies due to the film thickness unevenness.

  The charge generation material contained in the photosensitive layer having a single layer structure is preferably 1 to 30% by weight based on the total amount of the photosensitive layer, and the binder resin contained in the lower layer portion of the photosensitive layer is 20 to 80% by weight of the total amount. The transport material is preferably used in an amount of 10 to 70 parts by weight.

<About the intermediate layer>
In the image carrier of the present invention, when the cross-linked surface layer becomes the surface portion of the photosensitive layer, an intermediate layer can be provided for the purpose of suppressing mixing of the lower layer components into the cross-linked surface layer or improving the adhesion with the lower layer. It is. This intermediate layer prevents inhibition of the curing reaction and unevenness of the crosslinked surface layer caused by mixing of the lower photosensitive layer composition in the outermost surface layer containing the radical polymerizable composition. It is also possible to improve the adhesion between the lower photosensitive layer and the surface cross-linked layer.
In the intermediate layer, a binder resin is generally used as a main component. Examples of these resins include polyamide, alcohol-soluble nylon, water-soluble polyvinyl butyral, polyvinyl butyral, and polyvinyl alcohol. As a method for forming the intermediate layer, a generally used coating method is employed as described above. In addition, about 0.05-2 micrometers is suitable for the thickness of an intermediate | middle layer.

<About the undercoat layer>
In the image carrier of the present invention, 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. desirable. Examples of such resins include water-soluble resins such as polyvinyl alcohol, casein, and sodium polyacrylate, alcohol-soluble resins such as copolymer nylon and methoxymethylated nylon, polyurethane, melamine resin, phenol resin, alkyd-melamine resin, and epoxy. Examples thereof include a curable resin that forms a three-dimensional network structure such as a resin. 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 an appropriate solvent and a coating method like the above-mentioned 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 of the present invention. In addition, in the undercoat layer of the present invention, Al ₂ O ₃ is provided by anodization, organic substances such as polyparaxylylene (parylene), SiO ₂ , SnO ₂ , TiO ₂ , ITO, CeO ₂ A material provided with an inorganic material such as a vacuum thin film can also be used favorably. In addition, known ones can be used. The thickness of the undercoat layer is suitably from 0 to 5 μm.

<Addition of antioxidant to each layer>
Further, in the present invention, in order to improve environmental resistance, in order to prevent a decrease in sensitivity and an increase in residual potential, in particular, a crosslinked surface layer, a charge generation layer, a charge transport layer, an undercoat layer, an intermediate layer, etc. Antioxidants can be added to each layer.
The following are mentioned as antioxidant which can be used for this invention.

(Phenolic compounds)
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 ] Cryol ester, tocopherols and the like.

(Paraphenylenediamines)
N-phenyl-N'-isopropyl-p-phenylenediamine, N, N'-di-sec-butyl-p-phenylenediamine, N-phenyl-N-sec-butyl-p-phenylenediamine, N, N'- Di-isopropyl-p-phenylenediamine, N, N′-dimethyl-N, N′-di-t-butyl-p-phenylenediamine and the like.

(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)
Dilauryl-3,3′-thiodipropionate, distearyl-3,3′-thiodipropionate, ditetradecyl-3,3′-thiodipropionate, and the like.

(Organic phosphorus compounds)
Triphenylphosphine, tri (nonylphenyl) phosphine, tri (dinonylphenyl) phosphine, tricresylphosphine, tri (2,4-dibutylphenoxy) phosphine, and the like.
These compounds are known as antioxidants such as rubbers, plastics and fats and oils, and commercially available products can be easily obtained.
The addition amount of the antioxidant in the present invention is 0.01 to 10% by weight based on the total weight of the layer to be added.

[Image Forming Method and Image Forming Apparatus]
Next, the image forming method and the image forming apparatus of the present invention will be described in detail with reference to the drawings.
The image forming method and the image forming apparatus of the present invention use an image carrier having a smooth charge transport cross-linked surface layer. For example, at least after the image carrier is subjected to charging, image exposure, and development processes, An image forming method and an image forming apparatus including a process of transferring a toner image onto an image holding member (transfer paper), fixing, and cleaning the surface of the image carrier.
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 the image carrier.

FIG. 5 is a schematic diagram illustrating an example of an image forming apparatus. A charging charger (3) is used as means for charging the image carrier 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 image carrier (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 image carrier (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 image carrier is positively (negatively) charged and image exposure is performed, a positive (negative) electrostatic latent image is formed on the surface of the image carrier. 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 image carrier 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 image carrier (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 post-transfer image carrier. 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, static elimination means is used for the purpose of removing the latent image on the image carrier 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 processes such as document reading, paper feeding, fixing, and paper ejection that are not close to the image carrier.

The present invention is an image forming method and an image forming apparatus using the image carrier according to the present invention for such image forming means.
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. An example of the process cartridge is shown in FIG.
The process cartridge for the image forming apparatus includes an image carrier (101), and in addition, a charging unit (102), a developing unit (104), a transfer unit (106), a cleaning unit (107), and a charge eliminating unit (not shown). The apparatus (parts) includes at least one of the first and second components and is detachable from the main body of the image forming apparatus.

Referring to the image forming process by the apparatus illustrated in FIG. 6, the image carrier (101) is rotated on the surface 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 exposure image is formed, and this 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), Printed out. Next, the surface of the image bearing member after the image transfer is cleaned by the cleaning means (107), and further neutralized by the neutralizing means (not shown), and the above operation is repeated again.
The present invention provides a process cartridge for an image forming apparatus in which an image carrier having a polymer charge transport layer and a crosslinked surface layer is integrated with at least one of charging, developing, transferring, cleaning, and charge eliminating means. .
As is apparent from the above description, the image carrier 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. It can be used widely.

[Synthesis example of radical polymerizable compound having charge transporting structure]
The compound having a charge transporting structure in the present invention is synthesized, for example, by the method described in Japanese Patent No. 3164426. Moreover, this example is shown below.
(1) Synthesis of hydroxy group-substituted triarylamine compound (the following structural formula B) 113.85 g (0.3 mol) of a methoxy group-substituted triarylamine compound (the following structural formula A) and 138 g (0.92 mol) of sodium iodide To this, 240 ml of sulfolane was added and heated to 60 ° C. in a nitrogen stream. In this solution, 99 g (0.91 mol) of trimethylchlorosilane was added dropwise over 1 hour and stirred at a temperature of about 60 ° C. for 4 and a half hours to complete the reaction. About 1.5 L of toluene was added to the reaction solution, cooled to room temperature, and washed repeatedly with water and an aqueous sodium carbonate solution. Thereafter, the solvent was removed from the toluene solution and purified by column chromatography (adsorption medium: silica gel, developing solvent: toluene: ethyl acetate = 20: 1). Cyclohexane was added to the obtained pale yellow oil to precipitate crystals. In this way, 88.1 g (yield = 80.4%) of white crystals of the following structural formula B was obtained.
Melting point: 64.0-66.0 ° C

(2) Triarylamino group-substituted acrylate compound (Exemplary Compound No. 54 in Table 1)
82.9 g (0.227 mol) of the hydroxy group-substituted triarylamine compound (Structural Formula B) obtained in (1) above was dissolved in 400 ml of tetrahydrofuran, and an aqueous sodium hydroxide solution (NaOH: 12.4 g, Water: 100 ml) was added dropwise. The solution was cooled to 5 ° C., and 25.2 g (0.272 mol) of acrylic acid chloride was added dropwise over 40 minutes. Then, it stirred at 5 degreeC for 3 hours, and reaction was complete | finished. The reaction solution was poured into water and extracted with toluene. This extract was repeatedly washed with an aqueous sodium bicarbonate solution and water. Thereafter, the solvent was removed from the toluene solution and purified by column chromatography (adsorption medium: silica gel, developing solvent: toluene). N-Hexane was added to the obtained colorless oil to precipitate crystals. In this way, Exemplified Compound No. As a result, 80.73 g (yield = 84.8%) of 54 white crystals were obtained.
Melting point: 117.5-119.0 ° C

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 weight.
[ Reference Example 1]
<Formation of undercoat layer>
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.)
Titanium oxide 40 parts (CR-EL: Ishihara Sangyo)
50 parts of methyl ethyl ketone

<Formation of charge generation layer>
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 structure

ポリビニルブチラール（ＸＹＨＬ、ＵＣＣ製） ０．５部
シクロヘキサノン ２００部
メチルエチルケトン ８０部

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

<Formation of charge transport layer>
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 solution for charge transport layer 10 parts of bisphenol Z type polycarbonate 10 parts of low molecular charge transport material with the following structure

テトラヒドロフラン ８０部
１％シリコーンオイルのテトラヒドロフラン溶液 ０．２部
（ＫＦ５０−１００ＣＳ、信越化学工業製）

Tetrahydrofuran 80 parts Tetrahydrofuran solution of 1% silicone oil 0.2 parts (KF50-100CS, manufactured by Shin-Etsu Chemical Co., Ltd.)

<Formation of crosslinked surface layer>
Spray coating is performed on the charge transport layer using a crosslinked surface layer coating solution having the following constitution, and light irradiation is performed under the conditions of a metal halide lamp, irradiation intensity (365 nm): 700 mW / cm 2, irradiation time: 240 seconds, and Drying was performed at 130 ° C. for 30 minutes to provide a 5.0 μm cross-linked surface layer to obtain an image carrier of the present invention.
・ Crosslinked surface layer coating solution Trifunctional or higher radical polymerizable monomer having no charge transporting structure 9 parts Trimethylolpropane triacrylate (KAYARAD TMPTA, Nippon Kayaku)
Molecular weight: 382, number of functional groups: trifunctional, molecular weight / number of functional groups = 99
9 parts of radically polymerizable compound having a charge transporting structure (Exemplary Compound No. 54)
Photoinitiator 2 parts 1-hydroxy-cyclohexyl-phenyl-ketone (Irgacure 184, manufactured by Ciba Specialty Chemicals)
Acicular titanium oxide fine particles (ST-485SA15: manufactured by Titanium Industry Co., Ltd.) 2 parts (aspect ratio: about 2 to 12)
Tetrahydrofuran 100 parts

[ Reference Example 2]
The image is the same as Reference Example 1 except that acicular titanium oxide fine particles (FTL-100: manufactured by Ishihara Sangyo Co., Ltd., aspect ratio: about 13) are used as the acicular fine particles of the crosslinked surface layer coating liquid material of Reference Example 1. A carrier was prepared.

[Example 1 ]
Needle-like aluminum oxide particles as a needle-like fine particles of cross-linked surface layer coating liquid material of Reference Example 1 (nano Serum Fiber: Arugonaido Ltd., aspect ratio: about 20 to 100) All except for using the same tooth as in Reference Example 1 Thus, an image carrier was prepared.

[ Reference Example 3 ]
The radical polymerizable compound having the charge transporting structure of the crosslinked surface layer coating solution of Reference Example 2 is exemplified as Compound No. 1. An image carrier was prepared in the same manner as in Reference Example 1 except that 182 was used.

[ Reference Example 4 ]
The radical polymerizable compound having the charge transporting structure of the crosslinked surface layer coating solution of Reference Example 2 is exemplified as Compound No. 1. An image carrier was prepared in the same manner as in Reference Example 1 except that 364.

[Comparative Example 1]
An image bearing member was produced in the same manner as in Reference Example 1 except that the acicular fine particles in the crosslinked surface layer coating solution of Reference Example 1 were not included.

[Comparative Example 2]
An image carrier was prepared in the same manner as in Reference Example 1 except that spherical aluminum oxide fine particles (AA03: manufactured by Sumitomo Chemical Co., Ltd.) were used as the needle-shaped fine particles of the crosslinked surface layer coating liquid material of Reference Example 1.

[Comparative Example 3]
An image carrier was prepared in the same manner as in Reference Example 1 except that spherical titanium oxide fine particles (CR-97: manufactured by Ishihara Sangyo Co., Ltd.) were used as the needle-shaped fine particles of the crosslinked surface layer coating solution material of Reference Example 1.

[Comparative Example 4]
An image carrier was prepared in the same manner as in Reference Example 1 except that fluorine fine particles (Lublon L2: manufactured by Daikin Industries, Ltd.) were used as the needle-shaped fine particles of the crosslinked surface layer coating liquid material of Reference Example 1.

[Comparative Example 5]
It was prepared in the same all Reference Example 1 except that as the following structure as a cross-linked surface layer coating liquid of Reference Example 1.
・ Crosslinked surface layer coating liquid Trifunctional or higher radical polymerizable monomer having no charge transporting structure 9 parts Trimethylolpropane triacrylate (KAYARAD TMPTA, Nippon Kayaku)
Molecular weight: 382, number of functional groups: trifunctional, molecular weight / number of functional groups = 99
9 parts of a radically polymerizable compound having a monofunctional charge transporting structure (Exemplary Compound No. 54)
Photoinitiator 2 parts 1-hydroxy-cyclohexyl-phenyl-ketone (Irgacure 184, manufactured by Ciba Specialty Chemicals)
Silicone oil (Shin-Etsu Chemical KF50) 5 parts Tetrahydrofuran 120 parts

[Comparative Example 6]
An image carrier was prepared in the same manner as in Reference Example 1 except that the charge transport layer thickness in Reference Example 1 was 27 μm and no cross-linked surface layer was provided.

[Real machine paper test]
The image carrier thus produced was subjected to 200,000 actual machine passing tests using RICOH Imagio Neo C455, which employs polymerized toner (spherical toner), and was subjected to wear characteristics and image evaluation (streaking by white image output). Image evaluation). The results are shown in Tables 6 and 7.
Paper used: NBS Ricoh's My Paper A4
Station used: Black Output image: 7% grid image

[Abrasion characteristics evaluation method]
For the wear characteristics, the film thickness at 20 points on the photoconductor was measured with an eddy current film thickness meter (Fisherscope MMS), and the amount of decrease in film thickness (average value) from the initial stage was determined.

[Image evaluation method]
In the image evaluation, five white images were output on A4 paper, and the images were evaluated visually.

スジ画像：○→良好、△→局部的に発生、×→画像全面に発生

Streaked image: ○ → good, △ → locally generated, x → generated over the entire image

Reference Examples 1 and 2 and Example 1 had good wear resistance and image characteristics. Reference Examples 3 and 4 are image carriers using a radically polymerizable compound having a bifunctional and trifunctional charge transport structure, but the surface of the photoreceptor is locally cracked and cleaned at 200,000 sheets. The nature was bad. Since Comparative Example 1 did not contain fine particles in the surface layer, the wear resistance was low. Comparative Examples 2 and 3 contain spherical fine particles, but an improvement in wear resistance is recognized as compared with the non-added sample, but the wear resistance is lower than that of the sample containing acicular fine particles. Further, the samples of Comparative Examples 1 to 3 were not so good in spherical toner cleaning property. In Comparative Examples 4 and 5, the spherical toner cleaning property was good, but the wear resistance was not good. Since Comparative Example 6 did not have a cross-linked surface layer, the wear resistance was poor.
From the above, needle-like fine particles are dispersed in the surface layer of the photosensitive layer of the present invention, and at least a trifunctional or higher functional radical polymerizable monomer having no charge transport structure and a radical polymerizability having a charge transport structure. It has been found that by using a crosslinked resin layer obtained by curing the compound, it is possible to provide a long-life and high-performance image carrier capable of maintaining a good image for a long period of time. In addition, it has been found that the image forming process, the image forming apparatus, and the process cartridge for the image forming apparatus using the image carrier of the present invention have high performance and high reliability.

It is the figure which showed the abrasion mechanism of the spherical fine particle containing surface layer. It is the figure which showed the abrasion mechanism of the acicular fine particle containing surface layer. 1 is an example of a cross-sectional view of an image carrier of the present invention. It is another example of sectional drawing of the image carrier of this invention. 1 is a schematic diagram illustrating an example of an image forming apparatus of the present invention. FIG. 2 is a schematic diagram illustrating an example of a process cartridge for an image forming apparatus according to the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image carrier 2 Static elimination lamp 3 Charger charger 4 Eraser 5 Image exposure part 6 Developing unit 7 Pre-transfer charger 8 Registration roller 9 Transfer paper 10 Transfer charger 11 Separation charger 12 Separation claw 13 Pre-cleaning charger 14 Fur brush 15 Cleaning blade 101 Image Carrier 102 Charging device 103 Exposure 104 Developing device 105 Transfer body 106 Transfer device 107 Cleaning blade

Claims (12)

An image carrier having at least a photosensitive layer on a conductive support, having a surface layer on the surface of the photosensitive layer, wherein the surface layer is dispersed with needle-like fine particles, and at least has no charge transport structure. or more radically polymerizable monomers and Ri crosslinked resin layer der formed by curing a radical polymerizable compound having a charge transport structure, the image bearing member, wherein the needle-like fine particles, wherein the aluminum oxide der Rukoto. The image carrier according to claim 1, wherein the acicular fine particles are metal oxide fine particles. An image bearing member according to claim 1 or 2 radical polymerizable compound having a charge transport structure used in the surface layer, characterized in that it is a mono-functional. Functional groups of trifunctional or more radical polymerizable monomer having no charge transport structure for use in the surface layer, any one of claims 1 to 3, characterized in that an acryloyloxy group and / or a methacryloyloxy group The image carrier according to 1. The functional groups of the radical polymerizable compound having a charge transport structure for use in the surface layer, acryloyloxy group or methacryloyloxy image bearing member according to any one of claims 1 to 4, characterized in that a acryloyloxy group. The charge transport structure of the radical polymerizable compound having a charge transport structure for use in the outermost surface layer, the image bearing member according to any one of claims 1 to 5, characterized in that a triaryl amine structure. Radical polymerizable compound having one functionality and a charge transporting structure used for the surface layer, according to claim 1 to 6, characterized in that a polymerizable compound of one or more of the following general formula (1) or (2) The image carrier according to any one of the above.

(In the formula, R ₁ represents a hydrogen atom, a halogen atom, an alkyl group which may have a substituent, an aralkyl group which may have a substituent, an aryl group which may have a substituent, a cyano group, a nitro group, Group, alkoxy group, —COOR ₇ (R ₇ is a hydrogen atom, an alkyl group which may have a substituent, an aralkyl group which may have a substituent or an aryl group which may have a substituent), halogen Carbonyl group or CONR ₈ R ₉ (R ₈ and R ₉ may have a hydrogen atom, a halogen atom, an alkyl group which may have a substituent, an aralkyl group which may have a substituent, or a substituent. Ar ₁ and Ar ₂ each represent a substituted or unsubstituted arylene group, and may be the same or different.Ar ₃ , which may be the same or different from each other. Ar ₄ may be substituted Represents an unsubstituted aryl group, which may be the same or different, X represents a single bond, a substituted or unsubstituted alkylene group, a substituted or unsubstituted cycloalkylene group, a substituted or unsubstituted alkylene ether group, An oxygen atom, a sulfur atom, or a vinylene group, Z represents a substituted or unsubstituted alkylene group, a substituted or unsubstituted alkylene ether group, or an alkyleneoxycarbonyl group, and m and n represent an integer of 0 to 3.) Radical polymerizable compound having one functionality and a charge transporting structure used for the surface layer, in any one of claims 1 to 7, characterized in that one or more polymerizable compounds of the following general formula (3) The image carrier as described.

(Wherein, o, p and q are each an integer of 0 or 1, Ra represents a hydrogen atom or a methyl group, Rb and Rc represent a substituent other than a hydrogen atom and an alkyl group having 1 to 6 carbon atoms, And s and t each represents an integer of 0 to 3. Za is a single bond, a methylene group, an ethylene group,

Represents. ) An image bearing member according to any one of claims 1 to 8, characterized in that the curing means of the surface layer is a heat or light energy irradiating means. Using an image bearing member according to any one of claims 1 to 9, at least charging, image exposure, development, image forming method characterized by repeating the transfer. An image forming apparatus, comprising an image bearing member according to any one of claims 1 to 9. An image bearing member according to any one of claims 1 to 9 , 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, A process cartridge for an image forming apparatus, wherein the process cartridge is removable from the apparatus main body.

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