JP2007078970A - Electrostatic latent image carrier, and image forming apparatus, image forming method, and process cartridge - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrostatic latent image carrier etc., which are reduced in surface deterioration, suppresses the chemical deterioration of the surface due to proximity display device, are free from image quality deterioration by the repeated use of a photoreceptor, and are capable of stably outputting the high quality image excellent in wear resistance and image quality stability for a long period. <P>SOLUTION: The electrostatic latent image carrier is used in image formation using an electrostatic charger for electrostatically charging the surface of the electrostatic latent image carrier by utilizing the discharge generated by applying a voltage superposed with an AC component on a DC component, and has at least a photosensitive layer and a surface layer in this order on a support, in which the surface layer contains a polycondensation product of an organic silicon compound expressed by the following general formula (1). Here, the formula (1) is R<SB>n</SB>-Si(Z)<SB>4-n</SB>; where R denotes an organic group; Z denotes either of a hydroxyl group and a hydrolyzable group; n denotes an integer from 0 to 3. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention can suppress the chemical deterioration of the surface caused by the proximity discharge, the image quality is less deteriorated even by repeated use, is excellent in wear resistance and image stability, and can stably output a high quality image over a long period of time. The present invention relates to an electrostatic latent image carrier (hereinafter sometimes referred to as “photosensitive member” or “electrophotographic photosensitive member”), an image forming apparatus, an image forming method, and a process cartridge.

In recent years, from the viewpoints of saving space in offices and expanding business opportunities, it has been desired that image forming apparatuses (sometimes referred to as “electrophotographic apparatuses”) be made smaller and higher in image quality.
Many attempts have been made to improve the electrophotographic process in order to reduce the size of the electrophotographic apparatus. In the charging process, a charging method using proximity discharge tends to be frequently employed. This is a method of charging the surface of the photoconductor by generating a proximity discharge by bringing a charger into contact with the surface of the photoconductor or by arranging a charger near the photoconductor without contact. According to this method, it is possible to charge the surface of the photoreceptor without using a large-scale charging device, which is very effective for reducing the size of the electrophotographic apparatus.
Further, as a method for stably and uniformly charging the surface of the photoreceptor, it is recently known that a method of applying an AC voltage to a DC voltage and applying it with a charger is effective. This method has a large image area ratio, and is used in many electrophotographic apparatuses as a very effective charging method for a color output machine that requires a uniform color density over the entire output image.

  However, it has been found that the charging method using proximity discharge deteriorates the surface of the photoconductor because the discharge concentrates near the surface of the photoconductor. It is reported that the tendency is large in DC / AC superposition charging, and the layer thickness is reduced due to chemical deterioration of the surface layer material in the photoreceptor. In particular, when an organic photoreceptor is used as the electrophotographic photoreceptor, there is a concern that deterioration of the organic material due to an electrical hazard may reduce its electrical characteristics, wear durability, and the like. Compared to inorganic photoreceptors, organic photoreceptors are easier to develop for various exposure light sources from visible light to infrared light, can be selected for materials without environmental pollution, and are less expensive to manufacture. There are many advantages, and it is becoming the mainstream of electrophotographic photoreceptors used in image forming apparatuses. For this reason, development of an organic photoreceptor having durability against the proximity discharge as described above is strongly desired.

Hereinafter, the deterioration mechanism of the photoreceptor surface due to the proximity discharge will be described.
FIG. 1 shows the surface of a photosensitive member when a charging experiment is performed for about 150 hours continuously with only a charger placed in a non-contact state on the surface of the photosensitive member in order to investigate the deterioration state of the surface of the photosensitive member due to proximity discharge. It is the result of having measured the change of thickness.
The photoconductor used in the experiment is an organic photoconductor using a polycarbonate resin for the charge transport layer, and all the members that contact the photoconductor are removed, and a contactless voltage in which an alternating voltage is superimposed on a direct current voltage is applied. Charging was performed using a charging roller. As a result, it was found that the amount of film scraping on the surface of the photoconductor gradually increased and the thickness of the photoconductor gradually decreased. The mechanism for reducing the thickness of the photoreceptor is currently under investigation and is not clear. However, when the photoconductor with a reduced thickness was analyzed, carboxylic acid and the like that were considered to be the decomposition of the polycarbonate resin constituting the photoconductor were detected. Since such a substance has been detected, the following may be considered as a mechanism for reducing the thickness of the photoreceptor.

2A and 2B are explanatory views illustrating the state of the surface of the photoconductor 100 when the surface of the photoconductor 100 deteriorates due to proximity discharge, taking as an example the state where the charging roller 2a is opposed to the surface of the photoconductor with a minute gap. .
When proximity discharge is performed, energy of particles (for example, ozone, electrons, excited molecules, ions, plasma, etc.) generated by the discharge is irradiated to the charge transport layer 1a on the surface of the photoreceptor in the discharge region on the surface of the photoreceptor. This energy is resonated and absorbed by the binding energy of the molecules constituting the surface of the photoreceptor, and as shown in FIG. 2A, the charge transport layer 1a has a reduced molecular weight due to the breakage of the resin molecular chain, a decreased degree of entanglement of the polymer chain, Chemical degradation such as resin evaporation occurs. It is considered that the thickness of the charge transport layer 1a on the surface of the photoreceptor gradually decreases due to such chemical degradation of the photoreceptor due to the proximity discharge.

  As described above, film abrasion occurs due to chemical deterioration of the surface of the photoreceptor due to proximity discharge as well as wear due to mechanical rubbing that has been pointed out and improved, and this causes electrostatic damage of the photoreceptor. Decrease in capacity and surface smoothness occur. In addition, chemical degradation due to electrical discharge also causes an increase in surface energy, which may cause transfer or cleaning failure due to increased adhesion between the toner and the photoreceptor, or when a toner cleaning method using a blade is applied. In this case, since the frictional force between the blade and the photoconductor increases, adverse effects such as further increasing the wear amount of the photoconductor occur. As a result, there arises a problem that image deterioration such as cleaning failure and transfer failure due to short-term use occurs.

In addition, since it is considered that the thickness reduction of the surface of the photoreceptor due to the proximity discharge is caused by the energy of particles generated by the discharge, it is considered to occur even when a photoreceptor of other materials is used in addition to the polycarbonate resin. It is done.
The following measures have been taken so far to prevent a reduction in the thickness of the photoreceptor surface. For example, there is a photoconductor whose surface is coated with amorphous silicon carbide to improve wear resistance. In addition, it has been proposed to use a material in which an inorganic material such as alumina is dispersed in the charge transport layer on the surface of the photoreceptor to improve wear resistance (see Patent Documents 1 and 2). However, with such a configuration, durability against mechanical wear is improved, but chemical deterioration of the surface of the photoreceptor due to proximity discharge cannot be prevented.

Patent Documents 3 and 4 propose an image forming apparatus provided with means for applying zinc stearate to the surface of a photoreceptor. In these proposals, it is an object that the characteristics of the photoconductor change due to the discharge, specifically, that foreign matters are likely to adhere to the surface of the photoconductor, and zinc stearate is used to prevent the hazard due to the discharge. It has been proposed that it can be improved by applying to the surface.
Patent Document 5 proposes a technique for suppressing a reduction in the thickness of the photosensitive member due to an electrical hazard by applying zinc stearate to the surface of the photosensitive member.

  In these proposals, there are many excellent points such as suppressing the reduction in the thickness of the photosensitive member and preventing foreign matter from adhering, but there is a problem that the image is liable to be deteriorated when used under high temperature and high humidity. This is thought to be due to the fact that zinc stearate coated on the surface of the photoreceptor is chemically degraded by discharge and decomposed into lower fatty acids, and an image forming apparatus that obtains an excellent output image over a long period of time. In order to achieve this, it is necessary to have a technique for removing degraded zinc stearate.

  Therefore, it is used in an image forming apparatus that employs a proximity charging method in which an AC voltage is superimposed on a DC voltage, and can suppress chemical deterioration of the surface due to proximity discharge, and there is little image quality deterioration even after repeated use, and wear resistance and image quality are reduced. At present, there is a demand for prompt provision of an electrostatic latent image carrier that is excellent in stability and that can stably output high-quality images over a long period of time and related technology.

JP 2002-207308 A JP 2002-229227 A JP 2002-244516 A JP 2002-156877 A JP 2005-17469 A

  An object of the present invention is to solve various problems in the prior art and achieve the following objects. That is, the present invention is used in an image forming apparatus that employs a proximity charging method in which an AC voltage is superimposed on a DC voltage, can suppress chemical deterioration of the surface due to proximity discharge, and has little image quality deterioration even after repeated use. It is an object of the present invention to provide an electrostatic latent image carrier that is excellent in wear resistance and image quality stability and can stably output a high-quality image over a long period of time, as well as an image forming apparatus, an image forming method, and a process cartridge.

Means for solving the above problems are as follows. That is,
<1> The surface of the electrostatic latent image carrier is charged by using a discharge which is provided in contact with or close to the electrostatic latent image carrier and is generated by applying a voltage in which an alternating current component is superimposed on a direct current component. An electrostatic latent image carrier used for image formation using a charger, having a support, and at least a photosensitive layer and a surface layer in this order on the support,
The electrostatic latent image carrier, wherein the surface layer contains a polycondensate of an organosilicon compound represented by the following general formula (1).
_{R n -Si (Z) 4-} n ··· formula (1)
However, in said general formula (1), R represents an organic group. Z represents a hydroxyl group or a hydrolyzable group. n represents an integer of 0 to 3, and when n is 2 or 3, Rs may be the same or different from each other.
<2> The electrostatic latent image carrier according to <1>, wherein the content of the organosilicon compound in the surface layer is 30 to 70% by mass.
<3> The electrostatic latent image carrier according to any one of <1> to <2>, wherein the surface layer contains a charge transport material.
<4> The electrostatic latent image carrier according to <3>, wherein the charge transporting structure in the charge transporting material is a triarylamine structure.
<5> The electrostatic latent image carrier according to any one of <1> to <4>, wherein the content of the charge transport material in the surface layer is 30 to 200 parts by mass with respect to 100 parts by mass of the organosilicon compound. is there.
<6> The electrostatic latent image carrier according to any one of <1> to <5>, wherein the surface layer has a thickness of 1 to 10 μm.
<7> The electrostatic latent image carrier according to any one of <1> to <6>, wherein a protective substance is applied to and adhered to the surface of the electrostatic latent image carrier.
<8> The electrostatic latent image carrier according to <7>, wherein the protective substance is zinc stearate.
<9> The electrostatic latent image carrier according to any one of <1> to <8>, wherein the photosensitive layer is a single-layer type photosensitive layer.
<10> The electrostatic latent image according to any one of <1> to <8>, wherein the photosensitive layer is a laminated photosensitive layer having at least a charge generation layer and a charge transport layer in this order on a support. It is a carrier.
<11> The surface of the electrostatic latent image carrier is charged by using a discharge that is provided in contact with or close to the electrostatic latent image carrier and is generated by applying a voltage in which an alternating current component is superimposed on a direct current component. An electrostatic latent image forming step of forming an electrostatic latent image on the electrostatic latent image carrier using a charger; and a developing step of developing the electrostatic latent image with toner to form a toner image. And an image forming method including at least a transfer step of transferring the toner image to a recording medium.
In the image forming method, the latent electrostatic image bearing member is the latent electrostatic image bearing member according to any one of <1> to <10>.
<12> The electrostatic latent image carrier and the electrostatic latent image carrier are provided in contact with or close to the electrostatic latent image carrier, and the static electricity is generated by using a discharge generated by applying a voltage in which an AC component is superimposed on a DC component. An electrostatic latent image forming means for forming an electrostatic latent image on the electrostatic latent image bearing member; and developing the electrostatic latent image with toner. An image forming apparatus having at least developing means for forming a toner image and transfer means for transferring the toner image to a recording medium.
The electrostatic latent image carrier is an electrostatic latent image carrier according to any one of <1> to <10>.
<13> The electrostatic latent image carrier according to any one of <1> to <10>, and the electrostatic latent image carrier that is provided in contact with or close to the electrostatic latent image carrier, wherein an alternating current component is superimposed on a direct current component A charger for charging the surface of the latent electrostatic image bearing member using a discharge generated by applying a voltage, and at least one means selected from a developing means, a transfer means, a cleaning means, and a static elimination means. The process cartridge is detachable from the main body of the image forming apparatus.

The electrostatic latent image carrier of the present invention is provided in contact with or close to the electrostatic latent image carrier, and uses the discharge generated by applying a voltage in which an AC component is superimposed on a DC component. It is used for image formation using a charger that charges the surface of an electrostatic latent image carrier, and has a support, and at least a photosensitive layer and a surface layer in this order on the support,
Since the surface layer contains a polycondensate of the organosilicon compound represented by the general formula (1), a three-dimensional network structure is developed, and a high hardness surface layer having a very high degree of crosslinking is obtained. High wear resistance is achieved. Further, the surface layer produced in this way has very high electrical hazard durability due to proximity discharge, and the amount of wear reduction is small. As a result, the amount of decrease in the photoreceptor thickness is small even after long-term use, there is little fluctuation in electrical characteristics, there is little deterioration in image quality even after repeated use, excellent wear resistance and image stability, and high-quality images can be used for a long time. And stable output.

  An image forming apparatus according to the present invention includes an electrostatic latent image carrier, electrostatic latent image forming means for forming an electrostatic latent image on the electrostatic latent image carrier, and the electrostatic latent image using toner. Developing means for developing a visible image by development, transfer means for transferring the visible image to a recording medium, fixing means for fixing the transfer image transferred to the recording medium, and the electrostatic latent image carrier And the electrostatic latent image carrier is the electrostatic latent image carrier of the present invention. In the image forming apparatus of the present invention, since the electrostatic latent image carrier of the present invention is used as the electrostatic latent image carrier, chemical deterioration of the surface due to proximity discharge can be suppressed and repeated. Even when used, there is little deterioration in image quality, excellent wear resistance and stability of image quality, and high durability and high quality images can be obtained over a long period of time.

  The image forming method of the present invention includes an electrostatic latent image forming step of forming an electrostatic latent image on an electrostatic latent image carrier, and developing the electrostatic latent image with toner to form a visible image. At least a developing step, a transferring step for transferring the visible image to a recording medium, a fixing step for fixing the transferred image transferred to the recording medium, and a cleaning step for cleaning the electrostatic latent image carrier. The electrostatic latent image carrier is the electrostatic latent image carrier of the present invention. In the image forming method of the present invention, since the electrostatic latent image bearing member of the present invention is used as the electrostatic latent image bearing member, it has high scratch resistance and wear resistance, and has a surface in a high humidity environment. The resistance does not decrease, and an image with high durability and high image quality can be formed over a long period of time even in a high temperature environment seen in a high-speed process or the like.

  The process cartridge of the present invention is provided in contact with or in proximity to the electrostatic latent image carrier of the present invention and by applying a voltage in which an AC component is superimposed on a DC component. Since it has a charger for charging the surface of the latent electrostatic image bearing member using the generated discharge and at least one means selected from a developing means, a transfer means, a cleaning means, and a charge eliminating means, a proximity discharge is provided. The surface can be prevented from chemical degradation due to repeated, image quality degradation is small even after repeated use, excellent wear resistance and image stability, high quality images can be obtained stably over a long period of time, blade cleaning etc. However, the wear of the electrostatic latent image carrier is very slightly suppressed, and the cleaning property is also good.

  According to the present invention, conventional problems can be solved, used in an image forming apparatus employing a proximity charging method in which an AC voltage is superimposed on a DC voltage, and chemical deterioration of the surface due to proximity discharge can be suppressed, Electrostatic latent image carrier, image forming apparatus, image forming method, and process cartridge that are less likely to deteriorate image quality even after repeated use, have excellent wear resistance and image quality stability, and can stably output high-quality images over a long period of time Can be provided.

(Electrostatic latent image carrier)
The electrostatic latent image carrier of the present invention utilizes the discharge generated by applying a voltage in which an AC component is superimposed on a DC component provided in contact with or close to the electrostatic latent image carrier. It is used for image formation using a charger that charges the surface of a latent image carrier, and has a support, and at least a photosensitive layer and a surface layer in this order on the support, and other layers as necessary. It has.

In the first embodiment, the latent electrostatic image bearing member includes a support, a single-layer type photosensitive layer on the support, and a surface layer on the single-layer type photosensitive layer, and is further necessary. Depending on the case, it has other layers.
In the second embodiment, the latent electrostatic image bearing member includes a support, a stacked photosensitive layer having at least a charge generation layer and a charge transport layer on the support, and the stacked photosensitive layer. It has a surface layer on it, has an adhesive layer between the photosensitive layer and the surface layer, and further has other layers as necessary. In the second embodiment, the charge generation layer and the charge transport layer may be laminated in reverse.

Here, the layer configuration of the electrostatic latent image carrier will be described with reference to the drawings.
FIG. 3 is a schematic cross-sectional view showing an example of the electrostatic latent image carrier of the present invention, which has a single layer structure in which a photosensitive layer 233 having a charge generating function and a charge transporting function is provided on a support 231 at the same time. It is a photoreceptor. In FIG. 3, 239 represents a surface layer.
FIG. 4 is a schematic cross-sectional view showing another example of the electrostatic latent image carrier of the present invention. On the support 231, a charge generation layer 235 having a charge generation function and a charge transport having a charge transport material function are shown. The photosensitive member has a laminated structure in which the layer 237 is laminated. In FIG. 4, 239 represents a surface layer.

<Surface layer>
The surface layer contains a polycondensate of an organosilicon compound represented by the following general formula (1), and contains a charge transport material and, if necessary, other components.
_{R n -Si (Z) 4-} n ··· formula (1)
However, in said general formula (1), R represents an organic group. Z represents a hydroxyl group or a hydrolyzable group. n represents an integer of 0 to 3, and when n is 2 or 3, Rs may be the same or different from each other.

  In the general formula (1), Z represents a hydroxyl group or a hydrolyzable group. Examples of the hydrolyzable group include a methoxy group, an ethoxy group, a methylethylketoxime group, a diethylamino group, an acetoxy group, a propenoxy group, and a propoxy Group, butoxy group, methoxyethoxy group and the like.

In the general formula (1), R represents an organic group in which carbon is directly bonded to silicon, for example, an alkyl group such as methyl, ethyl, propyl, or butyl; an aryl group such as phenyl, tolyl, naphthyl, or biphenyl; Epoxy-containing groups such as γ-glycidoxypropyl and β- (3,4-epoxycyclohexyl) ethyl; (meth) acryloyl groups containing γ-acryloxypropyl and γ-methacryloxypropyl; γ-hydroxypropyl, 2 Hydroxyl groups such as 1,3-dihydroxypropyloxypropyl; vinyl-containing groups such as vinyl and propenyl; mercapto groups such as γ-mercaptopropyl; γ-aminopropyl, N-β (aminoethyl) -γ-aminopropyl, etc. Amino-containing group: γ-chloropropyl, 1,1,1-trifluoropropyl, nonafluorohexyl, perful B halogen-containing groups such as octyl ethyl; nitro group, a cyano-substituted alkyl group, and the like.
n represents an integer of 0 to 3. When n is 2 or 3, a plurality of R (organic groups) bonded to the same silicon atom may be the same or different.
Moreover, when manufacturing 2 or more types of organosilicon compounds shown by the said General formula (1) in manufacturing the siloxane condensate component of this invention, R of each organosilicon compound may be the same, and may differ. .

  Specific examples of the organosilicon compound represented by the general formula (1) include the following compounds. These may be used individually by 1 type and may use 2 or more types together.

  Examples of the organosilicon compound in which n is 0 in the general formula (1) include tetrachlorosilane, diethoxydichlorosilane, tetramethoxysilane, phenoxytrichlorosilane, tetraacetoxysilane, tetraethoxysilane, tetraallyloxysilane, and tetrapropoxy. Examples include silane, tetraisopropoxysilane, tetrakis (2-methoxyethoxy) silane, tetrabutoxysilane, tetraphenoxysilane, tetrakis (2-ethylbutoxy) silane, tetrakis (2-ethylhexyloxy) silane, and the like.

  Examples of the organosilicon compound in which n is 1 in the general formula (1) include, for example, trichlorosilane, chloromethyltrichlorosilane, methyltrichlorosilane, 1,2-dibromoethyltrichlorosilane, vinyltrichlorosilane, and 1,2-dichloroethyl. Trichlorosilane, 1-chloroethyltrichlorosilane, 2-chloroethyltrichlorosilane, ethyltrichlorosilane, 3,3,3-trifluoropropyltrichlorosilane, 2-cyanoethyltrichlorosilane, allyltrichlorosilane, 3-bromopropyltrichlorosilane, Chloromethyltrimethoxysilane, 3-chloropropyltrichlorosilane, n-propyltrichlorosilane, ethoxymethyldichlorosilane, dimethoxymethylchlorosilane, trimethoxysilane, 3-cyano Propyltrichlorosilane, n-butyltrichlorosilane, isobutyltrichlorosilane, chloromethyltriethoxysilane, methyltrimethoxysilane, mercaptomethyltrimethoxysilane, pentyltrichlorosilane, trimethoxyvinylsilane, ethyltrimethoxysilane, 3,3,4 , 4,5,5,6,6,6-nonafluorohexyltrichlorosilane, 4-chlorophenylchlorosilane, phenyltrichlorosilane, cyclohexyltrichlorosilane, hexyltrichlorosilane, tris (2-chloroethoxy) silane, 3,3,3 -Trifluoropropyltrimethoxysilane, 2-cyanoethyltrimethoxysilane, triethoxychlorosilane, 3-chloropropyltrimethoxysilane, triethoxysilane, 3-mercapto Propyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 2-aminoethylaminomethyltrimethoxysilane, benzyltrichlorosilane, p-tolyltrichlorosilane, 6-trichlorosilyl-2-norbornene, 2-trichlorosilylnorbornene, methyl Triacetoxysilane, heptyltrichlorosilane, chloromethyltriethoxysilane, butyltrimethoxysilane, methyltriethoxysilane, methyltris (2-aminoethoxy) silane, β-phenethyltrichlorosilane, triacetoxyvinylsilane, 2- (4-cyclohexylethyl) ) Trichlorosilane, ethyltriacetoxysilane, 3-trifluoroacetoxypropyltrimethoxysilane, octyltrichlorosilane, triethoxyvinylsilane, Rutriethoxysilane, 3- (2-aminoethylaminopropyl) trimethoxysilane, chloromethylphenylethyltrichlorosilane, 2-phenylpropyltrichlorosilane, 4-chlorophenyltrimethoxysilane, phenyltrimethoxysilane, nonyltrichlorosilane, 2-cyanoethyl Triethoxysilane, allyltriethoxysilane, 3-allylthiopropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-bromopropyltriethoxysilane, 3-chloropropyltriethoxysilane, 3-allylaminopropyltri Methoxysilane, propyltriethoxysilane, hexyltrimethoxysilane, 3-aminopropyltriethoxysilane, methyltriisopropenoxysilane, 3-methacryloxy Propyltrimethoxysilane, decyltrichlorosilane, bis (ethylmethylketoxime) methoxymethylsilane, 3-morpholinopropyltrimethoxysilane, 3-piperazinopropyltrimethoxysilane, methyltripropoxysilane, methyltris (2-methoxyethoxy) Silane), 2- (2-aminoethylthioethyl) triethoxysilane, 3- [2- (2-aminoethylaminoethylamino) propyl] triethoxysilane, tris (1-methylvinyloxy) vinylsilane, 2- ( 3,4-epoxycyclohexylethyl) trimethoxysilane, triisopropoxyvinylsilane, tris (2-methoxyethoxy) vinylsilane, diisopropoxyethylmethylketoxime methylsilane, 3-piperidinopropyltrimethoxy Sisilane, pentyltriethoxysilane, 4-chlorophenyltriethoxysilane, phenyltriethoxysilane, bis (ethylmethylketoxime) methylisopropoxysilane, bis (ethylmethylketoxime) -2-methoxyethoxymethylsilane, 3- (2 -Methylpiperidinopropyl) trimethoxysilane, 3-cyclohexylaminopropyltrimethoxysilane, benzyltriethoxysilane, 6-triethoxysilyl-2-norbornene, 3-benzylaminopropyltrimethoxysilane, methyltris (ethylmethylketoxime) ) Silane, bis (ethylmethylketoxime) butoxymethylsilane, methyltris (N, N-diethylaminoxy) silane, tetradecyltrichlorosilane, octyltriethoxysilane, Enyltris (2-methoxyethoxy) silane, 3- (vinylbenzylaminopropyl) trimethoxysilane, N- (3-triethoxysilylpropyl) -p-nitrobenzamide, 3- (vinylbenzylaminopropyl) triethoxysilane, octadecyl Examples include trichlorosilane, dodecyltriethoxysilane, docosyltrichlorosilane, octadecyltriethoxysilane, dimethyloctadecyl-3-trimethoxylsilylpropylammonium chloride, 1,2-bis (methyldichlorosilyl) ethane, and the like.

  Examples of the organosilicon compound in which n is 2 in the general formula (1) include chloromethylmethyldichlorosilane, dimethyldichlorosilane, ethyldichlorosilane, methylvinyldichlorosilane, ethylmethyldichlorosilane, dimethoxymethylsilane, and dimethoxydimethylsilane. , Divinyldichlorosilane, methyl-3,3,3-trifluoropropyldichlorosilane, allylmethyldichlorosilane, 3-chloropropylmethyldichlorosilane, diethyldichlorosilane, methylpropyldichlorosilane, diethoxysilane, 3-cyanopropylmethyl Dichlorosilane, butylmethyldichlorosilane, bis (2-chloroethoxy) methylsilane, diethoxymethylsilane, phenyldichlorosilane, diallyldichlorosilane, dimethoxymethyl -3,3,3-trifluoropropylsilane, methylpentyldichlorosilane, 3-chloropropyldimethoxymethylsilane, chloromethyldiethoxysilane, diethoxydimethylsilane, dimethoxy-3-mercaptopropylmethylsilane, 3,3,4 , 4,5,5,6,6,6-nonafluorohexylmethyldichlorosilane, methylphenyldichlorosilane, diacetoxymethylvinylsilane, cyclohexylmethyldichlorosilane, hexylmethyldichlorosilane, diethoxymethylvinylsilane, hexylmethyldichlorosilane, Diethoxymethylvinylsilane, phenylvinyldichlorosilane, 6-methyldichlorosilyl-2-norbornene, 2-methyldichlorosilylnorbornene, 3-methacryloxypropylmethyldichloro Silane, diethoxydivinylsilane, heptylmethyldichlorosilane, dibutyldichlorosilane, diethoxydiethylsilane, dimethyldipropoxysilane, 3-aminopropyldiethoxymethylsilane, 3- (2-aminoethylaminopropyl) dimethoxymethylsilane, allyl Phenyldichlorosilane, 3-chloropropylphenyldichlorosilane, methyl-β-phenethyldichlorosilane, dimethoxymethylphenylsilane, 2- (4-cyclohexenylethyl) methyldichlorosilane, methyloctyldichlorosilane, diethoxyethylmethylketoxime methyl Silane, 2- (2-aminoethylthioethyl) diethoxymethylsilane, t-butylphenyldichlorosilane, 3-methacryloxypropyldimethoxymethylsilane, 3 (3-cyanopropylthiopropyl) dimethoxymethylsilane, 3- (2-acetoxyethylthiopropyl) dimethoxymethylsilane, dimethoxymethyl-2-piperidinoethylsilane, dimethoxymethyl-3-piperazinopropylsilane, dibutoxy Dimethylsilane, dimethoxy-3- (2-ethoxyethylthiopropyl) methylsilane, 3-dimethylaminopropyldiethoxymethylsilane, diethyl-2-trimethylsilylmethylthioethyl phosphite, diethoxymethylphenylsilane, decylmethyldichlorosilane, bis ( Ethylmethylketoxime) ethoxymethylsilane, diethoxy-3-glycidoxypropylmethylsilane, 3- (3-acetoxypropylthio) propyldimethoxymethylsilane, dimethoxymethyl 3-piperidinopropylsilane, dipropoxyethylmethylketoxime methylsilane, diphenyldichlorosilane, diphenyldifluorosilane, diphenylsilanediol, dihexyldichlorosilane, bis (ethylmethylketoxime) methylpropoxysilane, dimethoxymethyl-3- ( 4-methylpiperidinopropyl) silane, dodecylmethyldichlorosilane, dimethoxydiphenylsilane, dimethoxyphenyl-2-piperidinoethoxysilane, dimethoxymethyl-3- (3-phenoxypropylthiopropyl) silane, diacetoxydiphenylsilane, Diethoxydiphenylsilane, diethoxydodecylmethylsilane, methyloctadecyldichlorosilane, diphenylmethoxy-2-piperidinoethoxysilane, docosylmeth Examples include rudichlorosilane and diethoxymethyloctadecylsilane.

The organosilicon compound is used as a raw material for a siloxane condensate component having a three-dimensional crosslinked structure. In general, when n of the number (4-n) of hydrolyzable groups bonded to a silicon atom is 3, the polymerization reaction of the reactive organosilicon compound is suppressed. When n is 0, 1 or 2, a polymerization reaction is likely to occur. In particular, when n is 1 or 0, the crosslinking reaction can be advanced to a high degree. Therefore, by controlling these, it is possible to control the storage stability of the coating layer solution obtained, the hardness of the coating film, and the like.
In addition, a condensation catalyst may be used in order to efficiently form a siloxane-based resin layer by subjecting a reactive organosilicon compound to a condensation reaction. The condensation catalyst used here may be a catalyst that acts at least one of a catalyst that acts catalytically in the condensation reaction and a catalyst that moves the reaction equilibrium of the condensation reaction to the production system.
As the condensation catalyst, known catalysts that have been used for silicon hard coat materials such as acids, metal oxides, metal salts, and alkylaminosilane compounds can be used. Examples of the catalyst include organic carboxylic acids, nitrous acid, sulfurous acid, aluminate, carbonic acid and thiocyanic acid alkali metal salts, organic amine salts (for example, tetramethylammonium hydroxide, tetramethylammonium acetate, etc.), tin organic Acid salts (for example, stannous octoate, dibutyltin diacetate, dibutyltin dilaurate, dibutyltin mercaptide, dibutyltin thiocarboxylate, dibutyltin malate, etc.).

  30-70 mass% is preferable and, as for content in the said surface layer of the said organosilicon compound, 40-70 mass% is more preferable. When the content is less than 30% by mass, durability against proximity discharge is not sufficient, and image quality may be deteriorated due to chemical deterioration of the photoreceptor. When the content exceeds 70% by mass, excessive resin crosslinking is caused. Generation of surface cracks due to shrinkage may occur.

The surface layer preferably contains a charge transport material in order to obtain excellent electrical characteristics. The charge transporting structure in the charge transporting material is preferably a triarylamine structure. The charge transport material is not particularly limited as long as it is generally dispersible in the surface layer, and can be appropriately selected according to the purpose. For example, those listed in the charge transport layer described later Are preferably used. In addition, for the purpose of improving the mechanical strength of the surface layer, a material capable of incorporating a charge transporting structural component into the crosslinked network may be used. Specific examples include a method of incorporating a charge transporting structural component into a siloxane condensate using an organosilicon compound and a reactive charge transporting compound.
Here, the reactive charge transporting compound is not particularly limited as long as it is a charge transporting compound having a reactive group capable of chemically bonding with the organosilicon compound, and can be appropriately selected according to the purpose. For example, a charge transporting compound having a hydroxyl group, a mercapto group, an amine group, or a silyl group can be used.

In addition, when a charge transporting structural component is incorporated into the crosslinked structure or not, if the charge transporting structure is a triarylamine structure, a surface layer having excellent charge transporting performance is formed. This is preferable.
As content in the said surface layer of the said charge transport material, 30-200 mass parts is preferable with respect to 100 mass parts of said organosilicon compounds, and 50-150 mass parts is more preferable. If the content is less than 30 parts by mass, desired electrical characteristics may not be obtained. If the content exceeds 200 parts by mass, desired electrical characteristics may be easily obtained, but mechanical durability may be reduced. .

  If necessary, the surface layer may further contain a leveling agent such as dimethyl silicone oil or methylphenyl silicone oil, or a commonly used plasticizer such as dibutyl phthalate or dioctyl phthalate.

As a method of forming a siloxane-based resin layer by polycondensation of the organosilicon compound, a method of preparing a coating solution using a solvent that dissolves the composition is generally used. At this time, it is preferable that the coating liquid has low viscosity and fluidity. The solvent is not particularly limited and may be appropriately selected depending on the intended purpose. For example, alcohols such as methanol, ethanol, propanol, butanol, methyl cellosolve, ethyl cellosolve or derivatives thereof; methyl ethyl ketone, acetone, etc. Ketones; esters such as ethyl acetate and butyl acetate;
As the coating method, generally known methods for forming a surface layer of an electrophotographic photosensitive member can be used, and examples thereof include a dip coating method, spray coating, bead coating, and ring coating method.
1-10 micrometers is preferable, as for the thickness of the said surface layer, 1.5-8 micrometers is more preferable, and 2-5 micrometers is more preferable. If the thickness is less than 1 μm, the photosensitive layer may be exposed in a short time due to film disappearance due to abrasion, and a protective effect for a long period of time may not be obtained. A reduction in image definition due to diffusion may occur.

<Multi-layer type photosensitive layer>
The multilayer photosensitive layer has at least a charge generation layer and a charge transport layer in this order, and further includes an intermediate layer and other layers as necessary.

-Charge generation layer-
The charge generation layer includes at least a charge generation material, and includes a binder resin and, if necessary, other components.
As the charge generating substance, inorganic materials and organic materials can be used.
Examples of the inorganic material include crystalline selenium, amorphous-selenium, selenium-tellurium, selenium-tellurium-halogen, selenium-arsenic compound, and amorphous-silicon. In the amorphous-silicon, those obtained by terminating dangling bonds with hydrogen atoms or halogen atoms, or those doped with boron atoms, phosphorus atoms or the like are preferably used.
The organic material is not particularly limited and can be appropriately selected from known materials according to the purpose. Examples thereof include phthalocyanine pigments such as metal phthalocyanine and metal-free phthalocyanine, azulenium salt pigments, methine squaric acid. Pigment, azo pigment having carbazole skeleton, azo pigment having triphenylamine skeleton, azo pigment having diphenylamine skeleton, azo pigment having dibenzothiophene skeleton, azo pigment having fluorenone skeleton, azo pigment having oxadiazole skeleton, bis Azo pigments having a stilbene skeleton, azo pigments having a distyryl oxadiazole skeleton, azo pigments having a distyryl carbazole skeleton, perylene pigments, anthraquinone or polycyclic quinone pigments, quinoneimine pigments, diphenylmethane and triphenyl Enirumetan pigments, benzoquinone and naphthoquinone pigments, cyanine and azomethine pigments, indigoid pigments, and bisbenzimidazole pigments. These may be used individually by 1 type and may use 2 or more types together.

There is no restriction | limiting in particular as said binder resin, According to the objective, it can select suitably, For example, a polyamide resin, a polyurethane resin, an epoxy resin, a polyketone resin, a polycarbonate resin, a silicone resin, an acrylic resin, a polyvinyl butyral resin, polyvinyl Formal resin, polyvinyl ketone resin, polystyrene resin, poly-N-vinyl carbazole resin, polyacrylamide resin, and the like can be given. These may be used individually by 1 type and may use 2 or more types together.
In addition to the binder resin described above, the charge generation layer binder resin may be a polymer charge transport material having a charge transport function, such as (1) an arylamine skeleton, a benzidine skeleton, a hydrazone skeleton, a carbazole skeleton, or a stilbene. Polymer materials such as polycarbonate, polyester, polyurethane, polyether, polysiloxane, and acrylic resin having a skeleton and a pyrazoline skeleton, and (2) a polymer material having a polysilane skeleton can be used.

  Specific examples of the above (1) include JP-A-01-001728, JP-A-01-009964, JP-A-01-013061, JP-A-01-019049, JP-A-01-241559. JP, 04-011627, JP 04-175337, JP 04-183719, JP 04-22514, JP 04-230767, JP 04-320420, JP 05-232727, JP 05-310904, JP 06-234836, JP 06-234837, JP 06-234838, JP 06-234839, JP JP 06-234840, JP 06-234841 A, JP 06-239049 A JP-A 06-236050, JP-A 06-236051, JP-A 06-295077, JP-A 07-056374, JP-A 08-176293, JP 08-208820, JP 08-21640 A, JP 08-253568 A, JP 08-269183 A, JP 09-062019 A, JP 09-038883 A, JP 09-71642 A, JP JP 09-87376, JP 09-104746, JP 09-110974, JP 09-110976, JP 09-157378, JP 09-221544, JP 09-09. No. 227669, JP 09-235367 A, JP 09-241369 JP-A 09-268226, JP-A 09-272735, JP-A 09-302084, JP-A 09-302085, JP-A 09-328539, and the like. Materials.

Specific examples of the above (2) include, for example, those described in JP-A-63-285552, JP-A-05-19497, JP-A-05-70595, JP-A-10-73944, and the like. Examples are polysilylene polymers.
The content of the binder resin is preferably 0 to 500 parts by mass and more preferably 10 to 300 parts by mass with respect to 100 parts by mass of the charge generation material. The binder resin may be added either before or after dispersion.

The charge generation layer may contain a low molecular charge transport material.
The low molecular charge transport material includes a hole transport material and an electron transport material.
Examples of the electron transporting material include chloroanil, bromoanil, tetracyanoethylene, tetracyanoquinodimethane, 2,4,7-trinitro-9-fluorenone, 2,4,5,7-tetranitro-9-fluorenone, 2 , 4,5,7-tetranitroxanthone, 2,4,8-trinitrothioxanthone, 2,6,8-trinitro-4H-indeno [1,2-b] thiophen-4-one, 1,3,7 -Trinitrodibenzothiophene-5,5-dioxide, diphenoquinone derivatives and the like. These may be used individually by 1 type and may use 2 or more types together.

  Examples of the hole transport material include oxazole derivatives, oxadiazole derivatives, imidazole derivatives, monoarylamine derivatives, diarylamine derivatives, triarylamine derivatives, stilbene derivatives, α-phenylstilbene derivatives, benzidine derivatives, diarylmethane derivatives. , Triarylmethane derivatives, 9-styrylanthracene derivatives, pyrazoline derivatives, divinylbenzene derivatives, hydrazone derivatives, indene derivatives, butadiene derivatives, pyrene derivatives, and the like, and other known materials. These may be used individually by 1 type and may use 2 or more types together.

As a method for forming the charge generation layer, a vacuum thin film preparation method and a casting method from a solution dispersion system can be mentioned.
As the vacuum thin film production method, for example, 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.
As the casting method, the inorganic or organic charge generating material, and optionally binder resin, tetrahydrofuran, dioxane, dioxolane, toluene, dichloromethane, monochlorobenzene, dichloroethane, cyclohexanone, cyclopentanone, anisole, xylene, methyl ethyl ketone It can be formed by dispersing with a ball mill, attritor, sand mill, bead mill or the like using a solvent such as acetone, ethyl acetate, butyl acetate, etc., and applying the solution after diluting the dispersion appropriately. Moreover, leveling agents, such as a dimethyl silicone oil and a methylphenyl silicone oil, can be added as needed. The application can be performed by dip coating, spray coating, bead coating, ring coating, or the like.

  The thickness of the charge generation layer is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 0.01 to 5 μm, and more preferably 0.05 to 2 μm.

-Charge transport layer-
The charge transport layer is a layer intended to hold a charged charge and to couple the charge generated and separated in the charge generation layer by exposure to the charged charge held by movement. In order to achieve the purpose of holding the charged charge, it is required that the electric resistance is high. Further, in order to achieve the purpose of obtaining a high surface potential with the charged charge that has been held, it is required that the dielectric constant is small and the charge mobility is good.

  The charge transport layer includes at least a charge transport material, and includes a binder resin and, if necessary, other components.

Examples of the charge transport material include a hole transport material, an electron transport material, and a polymer charge transport material.
Examples of the electron transporting material (electron accepting material) include chloranil, 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] thiophene-4-one, 1,3,7-trinitrodibenzothiophene-5,5-dioxide, and the like. These may be used individually by 1 type and may use 2 or more types together.

Examples of the hole transport material (electron donating material) include oxazole derivatives, oxadiazole derivatives, imidazole derivatives, triphenylamine derivatives, 9- (p-diethylaminostyrylanthracene), 1,1-bis- (4 -Dibenzylaminophenyl) propane, styrylanthracene, styrylpyrazoline, phenylhydrazones, α-phenylstilbene derivatives, thiazole derivatives, triazole derivatives, phenazine derivatives, acridine derivatives, benzofuran derivatives, benzimidazole derivatives, thiophene derivatives, etc. It is done.
These may be used individually by 1 type and may use 2 or more types together.

Examples of the polymer charge transport material include those having the following structure.
Examples of (a) a polymer having a carbazole ring include, for example, poly-N-vinylcarbazole, JP-A-50-82056, JP-A-54-9632, JP-A-54-11737, JP-A-5-11737. Examples thereof include compounds described in JP-A-4-175337, JP-A-4-183719, and JP-A-6-234841.
(B) Examples of the polymer having a hydrazone structure include, for example, JP-A-57-78402, JP-A-61-20953, JP-A-61-296358, JP-A-1-134456, Compounds described in Kaihei 1-179164, JP-A-3-180851, JP-A-3-180852, JP-A-3-50555, JP-A-5-310904, and JP-A-6-234840 Etc. are exemplified.
(C) Examples of the polysilylene polymer include, for example, JP-A-63-285552, JP-A-1-88461, JP-A-4-264130, JP-A-4-264131, and JP-A-4-264132. Examples thereof include compounds described in JP-A-4-264133 and JP-A-4-289867.
(D) As a polymer having a triarylamine structure, for example, N, N-bis (4-methylphenyl) -4-aminopolystyrene, JP-A-1-134457, JP-A-2-282264, Examples thereof include compounds described in Kaihei 2-304456, JP-A-4-133605, JP-A-4-133066, JP-A-5-40350, and JP-A-5-202135.
(E) As other polymers, for example, a formaldehyde condensation polymer of nitropyrene, JP-A-51-73888, JP-A-56-15049, JP-A-6-234363, JP-A-6-234837 And the compounds described in Japanese Patent Publication No.

  In addition to the above, the polymer charge transporting material includes, for example, a polycarbonate resin having a triarylamine structure, a polyurethane resin having a triarylamine structure, a polyester resin having a triarylamine structure, and a triarylamine structure. And a polyether resin. Examples of the polymer charge transporting material include JP-A 64-1728, JP-A 64-13061, JP-A 64-19049, JP-A-4-11627, JP-A 4-116627. JP 2225014, JP 4-230767, JP 4-320420, JP 5-232727, JP 7-56374, JP 9-127713, JP 9-222740. And compounds described in JP-A-9-265197, JP-A-9-211877, JP-A-9-30495, and the like.

  Examples of the polymer having an electron donating group include not only the above-mentioned polymer but also a copolymer with a known monomer, a block polymer, a graft polymer, a star polymer, It is also possible to use a crosslinked polymer having an electron donating group as disclosed in JP-A-109406.

Examples of the binder resin include polycarbonate resin, polyester resin, methacrylic resin, acrylic resin, polyethylene resin, polyvinyl chloride resin, polyvinyl acetate resin, polystyrene resin, phenol resin, epoxy resin, polyurethane resin, polyvinylidene chloride resin, Alkyd resins, silicone resins, polyvinyl carbazole resins, polyvinyl butyral resins, polyvinyl formal resins, polyacrylate resins, polyacrylamide resins, phenoxy resins, and the like are used. These may be used individually by 1 type and may use 2 or more types together.
The charge transport layer may also contain a copolymer of a crosslinkable binder resin and a crosslinkable charge transport material.

  The charge transport layer can be formed by dissolving or dispersing these charge transport materials and a binder resin in an appropriate solvent, and applying and drying them. In addition to the charge transport material and the binder resin, an appropriate amount of additives such as a plasticizer, an antioxidant, and a leveling agent may be added to the charge transport layer as necessary.

As the solvent used for coating the charge transport layer, the same solvent as the charge generation layer can be used, but a solvent that dissolves the charge transport material and the binder resin well is suitable. These solvents may be used alone or in combination of two or more. The charge transport layer can be formed by the same coating method as that for the charge generation layer 35.
If necessary, a plasticizer and a leveling agent can be added.
As said plasticizer, what is used as a plasticizer of general resins, such as dibutyl phthalate and dioctyl phthalate, can be used as it is, and the usage-amount is 0-30 with respect to 100 mass parts of said binder resins. Part by mass is preferred.
Examples of the leveling agent include silicone oils such as dimethyl silicone oil and methylphenyl silicone oil, and polymers or oligomers having a perfluoroalkyl group in the side chain. The amount used is 100 parts by mass of a binder resin. 0 to 1 part by mass is preferable.
The thickness of the charge transport layer is not particularly limited and may be appropriately selected according to the purpose. However, it is preferably 30 μm or less, more preferably 25 μm or less from the viewpoint of resolution and responsiveness. About a lower limit, although it changes with systems (especially charging potential etc.) to be used, 5 micrometers or more are preferable.

<Single layer type photosensitive layer>
The single-layer type photosensitive layer includes a charge generation material, a charge transport material, a binder resin, and other components as necessary.
The aforementioned materials can be used as the charge generation material, charge transport material, and binder resin.

When a single-layer type photosensitive layer is provided by a casting method, in many cases, such a single-layer type photosensitive layer is prepared by dissolving or dispersing a charge generating substance, a low molecular weight molecule, and a polymer charge transporting substance in an appropriate solvent, It can be formed by drying. In addition, a plasticizer can be added to the single-layer type photosensitive layer as necessary. Furthermore, as the binder resin that can be used as necessary, the binder resins mentioned above for the charge transport layer can be used as they are. In addition, the same binder resin as the charge generation layer may be mixed and used.
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. The polymer charge transporting material can also be used, which is useful in that contamination of the lower photosensitive layer composition into the surface layer can be reduced.

There is no restriction | limiting in particular in the thickness of the said single layer type photosensitive layer, According to the objective, it can select suitably, 5-25 micrometers is preferable and 10-25 micrometers is more preferable.
The charge generation material contained in the single-layer type photosensitive layer is preferably 1 to 30% by mass with respect to the total amount of the photosensitive layer. The binder resin contained in the lower layer portion of the photosensitive layer is preferably 20 to 80% by mass of the total amount. The charge transport material is preferably 10 to 70 parts by mass with respect to 100 parts by mass of the binder resin.

<Support>
There is no restriction | limiting in particular as said support body, Although it can select suitably according to the objective, The thing which shows the electroconductivity whose volume resistance is 10 < ¹⁰ > ohm * cm or less is suitable.
The material, shape, and size of the support are not particularly limited, and any of a plate shape, a drum shape, or a belt shape can be used. For example, aluminum, nickel, chromium, nichrome, copper, gold, and the like can be used. Metals such as silver and platinum, metal oxides such as tin oxide and indium oxide by vapor deposition or sputtering, film or cylindrical plastic, paper coated, or plates made of aluminum, aluminum alloy, nickel, stainless steel, etc. And after making them into a raw pipe by a method such as extruding and drawing, pipes subjected to surface treatment such as cutting, superfinishing, polishing, etc. can be used. Further, an endless nickel belt and an endless stainless steel belt disclosed in JP-A-52-36016 can also be used as a support.

In addition to the above, it is also possible to use a conductive layer formed by dispersing conductive powder on an appropriate binder resin and coating the support.
Examples of the material of the conductive powder include carbon black, acetylene black, metal powder such as aluminum, nickel, iron, nichrome, copper, zinc, and silver, or metal oxide such as conductive tin oxide and ITO. Examples thereof include powder. Examples of the binder resin include polystyrene resin, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyester resin, polyvinyl chloride resin, vinyl chloride-vinyl acetate copolymer. Polymer, polyvinyl acetate resin, polyvinylidene chloride resin, polyarylate resin, phenoxy resin, polycarbonate, cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral resin, polyvinyl formal resin, polyvinyl toluene resin, poly-N-vinyl carbazole resin, acrylic resin , Silicone resin, epoxy resin, melamine resin, urethane resin, phenol resin, alkyd resin and the like.
The conductive layer can be formed by applying a coating solution obtained by dissolving or dispersing the conductive powder and a binder resin in a solvent on a support. Examples of the solvent include tetrahydrofuran, dichloromethane, methyl ethyl ketone, toluene, and the like.

  In addition, the conductive powder is contained in the cylindrical substrate in polyvinyl chloride resin, polypropylene resin, polyester resin, polystyrene resin, polyvinylidene chloride resin, polyethylene resin, chlorinated rubber, polytetrafluoroethylene fluororesin, or the like. It is also preferable to provide a conductive layer with a heat shrinkable tube.

-Undercoat layer-
An undercoat layer may be provided between the support and the photosensitive layer as necessary. The undercoat layer generally contains a resin as a main component, but these resins are resins having a high solvent resistance with respect to a general organic solvent in consideration of applying a photosensitive layer thereon with a solvent. It is preferable. Examples of the resin include water-soluble resins such as polyvinyl alcohol, casein, and sodium polyacrylate, alcohol-soluble resins such as copolymer nylon and methoxymethylated nylon, polyurethane resins, melamine resins, phenol resins, alkyd-melamine resins, Examples thereof include a curable resin that forms a three-dimensional network structure, such as an epoxy resin.

In addition, 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. Good.
The undercoat layer can be formed using the same solvent and coating method as the photosensitive layer. Furthermore, a silane coupling agent, a titanium coupling agent, a chromium coupling agent, or the like can be used as the undercoat layer of the present invention. For the undercoat layer, an anodized layer of Al ₂ O ₃ , an organic material such as polyparaxylylene (parylene), or an inorganic material such as SiO ₂ , SnO ₂ , TiO ₂ , ITO, or CeO ₂ is vacuumed. Those provided by the thin film manufacturing method can also be used favorably. In addition, known ones can be used.
There is no restriction | limiting in particular in the thickness of the said undercoat layer, According to the objective, it can select suitably, 0-5 micrometers is preferable.

In the electrostatic latent image carrier of the present invention, the surface layer, photosensitive layer, charge generation layer, charge transport layer are used for the purpose of preventing the decrease in sensitivity and the increase in residual potential, in order to improve the environmental resistance. An antioxidant may be added to each layer such as the undercoat layer.
Examples of the antioxidant include phenolic compounds, paraphenylenediamines, organic sulfur compounds, and organic phosphorus compounds.
Examples of the phenol compound include 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-t-butylphenol), 2,2'-methylene-bis- (4-ethyl- 6-t-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-hydroxy Ben ) Benzene, tetrakis- [methylene-3- (3 ′, 5′-di-t-butyl-4′-hydroxyphenyl) propionate] methane, bis [3,3′-bis (4′-hydroxy-3 ′) -T-butylphenyl) butyric acid] cricol ester, tocopherols and the like.
Examples of the paraphenylenediamines include N-phenyl-N′-isopropyl-p-phenylenediamine, N, N′-di-sec-butyl-p-phenylenediamine, N-phenyl-N-sec-butyl- Examples include p-phenylenediamine, N, N′-di-isopropyl-p-phenylenediamine, N, N′-dimethyl-N, N′-di-t-butyl-p-phenylenediamine, and the like.
Examples of the hydroquinones include 2,5-di-t-octyl hydroquinone, 2,6-didodecyl hydroquinone, 2-dodecyl hydroquinone, 2-dodecyl-5-chlorohydroquinone, 2-t-octyl-5-methyl. Examples include hydroquinone and 2- (2-octadecenyl) -5-methylhydroquinone.
Examples of the organic sulfur compounds include dilauryl-3,3′-thiodipropionate, distearyl-3,3′-thiodipropionate, ditetradecyl-3,3′-thiodipropionate, and the like. .
Examples of the organic phosphorus compounds include 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, oils and fats, and commercially available products can be easily obtained.
The addition amount of the antioxidant is preferably 0.01 to 10% by mass with respect to the total mass of the layer to be added.

<Protective substances>
For the purpose of improving cleaning properties by reducing the surface energy of the electrostatic latent image carrier and protecting it from electrical and mechanical hazards, a protective substance may be applied and adhered to the surface of the electrostatic latent image carrier. it can.

  The protective substance is not particularly limited as long as it can be uniformly applied to the surface of the electrostatic latent image carrier, and various materials can be used. For example, wax, silicone oil, fatty acid salt, and the like can be used. Can be mentioned. Among these, fatty acid salts are particularly preferred because they can be uniformly applied to the surface of the photoreceptor without causing a deterioration in the electrical characteristics of the electrophotographic photoreceptor. Examples of the fatty acid include undecylic acid, lauric acid, tridecylic acid, myristic acid, palmitic acid, pendadecylic acid, stearic acid, heptadecylic acid, arachidic acid, montanic acid, oleic acid, arachidonic acid, caprylic acid, capric acid, capron An acid etc. are mentioned. Examples of the metal salt in the fatty acid salt include salts with metals such as zinc, iron, copper, magnesium, aluminum, and calcium.

  It is preferable to use a lamellar crystal powder such as zinc stearate as the protective substance. The lamellar crystal has a layered structure in which amphiphilic molecules are self-organized, and when a shearing force is applied, the crystal is broken and slips easily along the layer. This action is effective for lowering the coefficient of friction. Even from the viewpoint of protecting the photoreceptor surface from electric discharge, the lamellar crystals that uniformly cover the photoreceptor surface by receiving shearing force have a small amount of protection. Since the surface of the photoreceptor can be effectively covered with a substance, it is desirable as a protective substance.

  The method for applying the protective substance is not particularly limited and may be appropriately selected depending on the purpose. For example, a method in which a protective substance is previously applied to a member such as a cleaning member that contacts the photosensitive member, There is a method in which the coating member is integrated with the process cartridge. Among these, it is preferable to provide a dedicated application member because a stable amount can be applied over a long period of time.

  The electrostatic latent image carrier of the present invention can be used not only for electrophotographic copying machines but also widely for electrophotographic application fields such as laser beam printers, CRT printers, LED printers, liquid crystal printers, and laser plate making. In particular, it is suitably used for the image forming method, image forming apparatus, and process cartridge of the present invention described below.

(Image forming method and image forming apparatus)
The image forming apparatus of the present invention includes at least an electrostatic latent image carrier, an electrostatic latent image forming unit, a developing unit, a transfer unit, and a fixing unit, and further appropriately selected as necessary. It has other means, for example, static elimination means, cleaning means, recycling means, control means and the like.
The image forming method of the present invention includes at least an electrostatic latent image forming step, a developing step, a transfer step, and a fixing step, and other steps appropriately selected as necessary, for example, a static elimination step, a cleaning step. A recycling process, a control process, and the like.

  The image forming method of the present invention can be preferably carried out by the image forming apparatus of the present invention, the electrostatic latent image forming step can be performed by the electrostatic latent image forming means, and the developing step is the developing The transfer step can be performed by the transfer unit, the fixing step can be performed by the fixing unit, and the other steps can be performed by the other unit.

-Electrostatic latent image forming step and electrostatic latent image forming means-
The electrostatic latent image forming step is a step of forming an electrostatic latent image on the electrostatic latent image carrier.
The electrostatic latent image carrier of the present invention is used as the electrostatic latent image carrier.

  The formation of the electrostatic latent image can be performed, for example, by uniformly charging the surface of the electrostatic latent image carrier and then performing imagewise exposure, and is performed by the electrostatic latent image forming unit. be able to. The electrostatic latent image forming means includes, for example, at least a charger that uniformly charges the surface of the electrostatic latent image carrier and an exposure device that exposes the surface of the electrostatic latent image carrier imagewise. Prepare.

The charging can be performed, for example, by applying a voltage to the surface of the electrostatic latent image carrier using the charger.
As the charger, a charger that is provided in contact or close to the surface and charges the surface of the electrostatic latent image carrier using a discharge generated by applying a voltage in which an AC component is superimposed on a DC component is used. .

The exposure can be performed, for example, by exposing the surface of the latent electrostatic image bearing member imagewise using the exposure device.
The exposure device is not particularly limited as long as it can expose the surface of the electrostatic latent image carrier charged by the charger so as to form an image to be formed, and is appropriately selected according to the purpose. For example, various exposure devices such as a copying optical system, a rod lens array system, a laser optical system, and a liquid crystal shutter optical system can be used.
In the present invention, a back light system in which imagewise exposure is performed from the back side of the electrostatic latent image carrier may be employed.

-Development process and development means-
The developing step is a step of developing the electrostatic latent image using the toner or the developer to form a visible image.
The visible image can be formed, for example, by developing the electrostatic latent image using the toner or the developer, and can be performed by the developing unit.
The developing unit is not particularly limited as long as it can be developed using, for example, the toner or the developer, and can be appropriately selected from known ones. For example, the toner or developer is accommodated. Preferred examples include those having at least a developing unit capable of bringing the toner or developer into contact or non-contact with the electrostatic latent image.

  The developing unit may be a dry developing type, a wet developing type, a single color developing unit, or a multi-color developing unit. For example, a toner having a stirrer for charging the toner or the developer by frictional stirring and a rotatable magnet roller is preferable.

  In the developing device, for example, the toner and the carrier are mixed and agitated, and the toner is charged by friction at that time, and held on the surface of the rotating magnet roller in a raised state to form a magnetic brush. . Since the magnet roller is disposed in the vicinity of the electrostatic latent image carrier (photoconductor), a part of the toner constituting the magnetic brush formed on the surface of the magnet roller is electrically attracted. It moves to the surface of the electrostatic latent image carrier (photoconductor) by force. As a result, the electrostatic latent image is developed with the toner, and a visible image is formed with the toner on the surface of the electrostatic latent image carrier (photoconductor).

  The developer accommodated in the developing device may be a one-component developer or a two-component developer.

-Transfer process and transfer means-
The transfer step is a step of transferring the visible image onto a recording medium. The intermediate recording medium is used to primarily transfer the visible image onto the intermediate recording medium, and then the visible image is transferred onto the recording medium. A primary transfer step of forming a composite transfer image by transferring a visible image onto an intermediate recording medium using two or more colors, preferably a full color toner as the toner, and a composite transfer image; A mode including a secondary transfer step of transferring the transfer image onto the recording medium is more preferable.
The transfer can be performed, for example, by charging the latent electrostatic image bearing member (photoconductor) of the visible image using a transfer charger, and can be performed by the transfer unit. The transfer unit includes a primary transfer unit that transfers a visible image onto an intermediate recording medium to form a composite transfer image, and a secondary transfer unit that transfers the composite transfer image onto a recording medium. Embodiments are preferred.
The intermediate recording medium is not particularly limited and may be appropriately selected from known recording media according to the purpose. For example, a transfer belt or the like is preferable.

The transfer means (the primary transfer means and the secondary transfer means) is a transfer for peeling and charging the visible image formed on the electrostatic latent image carrier (photoconductor) to the recording medium side. It is preferable to have at least a vessel. There may be one transfer means or two or more transfer means.
Examples of the transfer device include a corona transfer device using corona discharge, a transfer belt, a transfer roller, a pressure transfer roller, and an adhesive transfer device.
The recording medium is typically plain paper, but is not particularly limited as long as it can transfer an unfixed image after development, and can be appropriately selected according to the purpose. PET for OHP A base or the like can also be used.

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

The neutralization step is a step of performing neutralization by applying a neutralization bias to the electrostatic latent image carrier, and can be suitably performed by a neutralization unit.
The neutralization means is not particularly limited, and may be appropriately selected from known neutralizers as long as it can apply a neutralization bias to the electrostatic latent image carrier. Preferably mentioned.

The cleaning step is a step of removing the electrophotographic toner remaining on the electrostatic latent image carrier, and can be suitably performed by a cleaning unit.
The cleaning means is not particularly limited as long as it can remove the electrophotographic toner remaining on the electrostatic latent image carrier, and can be appropriately selected from known cleaners. Suitable examples include brush cleaners, electrostatic brush cleaners, magnetic roller cleaners, blade cleaners, brush cleaners, web cleaners, and the like.

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

The control means is a process for controlling the respective steps, and can be suitably performed by the control means.
The control means is not particularly limited as long as the movement of each means can be controlled, and can be appropriately selected according to the purpose. Examples thereof include devices such as a sequencer and a computer.

  Now, an embodiment of an image forming apparatus to which the present invention is applied will be described. However, these are just examples, and the present invention is not limited to these. FIG. 5 shows an example of an image forming apparatus having a configuration common to the embodiments described later. This image forming apparatus includes the electrostatic latent image carrier of the present invention.

In FIG. 5, an electrostatic latent image carrier (electrophotographic photosensitive member) 1 is rotationally driven by a driving device (not shown), and its surface is charged to a predetermined polarity by a charging roller 2a of a charging device 2 of a proximity charging system. . The surface of the charged electrophotographic photosensitive member 1 is exposed by the exposure device 3 to form an electrostatic latent image corresponding to the image information. The electrostatic latent image is developed with toner as a developer supplied from the developing device 4 to the surface of the electrophotographic photosensitive member 1 to be visualized as a toner image.
On the other hand, transfer paper as a recording medium is fed toward the electrophotographic photosensitive member 1 from a paper supply unit (not shown). A toner image on the electrophotographic photosensitive member 1 is transferred onto the transfer paper on the transfer paper by a transfer device 5 disposed opposite to the electrophotographic photosensitive member 1. The transfer paper onto which the toner image has been transferred is separated from the electrophotographic photosensitive member 1 and then conveyed to the fixing device 6 along the transfer material conveyance path 10 to fix the toner image. The transfer residual toner as the residual toner remaining on the electrophotographic photosensitive member 1 after the toner image is transferred to the transfer paper is removed from the electrophotographic photosensitive member 1 by the cleaning device 7 provided with the cleaning blade 8. . Further, the residual charge on the surface of the electrophotographic photosensitive member after the transfer residual toner is removed is removed by the static eliminator 9. In this way, the electrophotographic photoreceptor 1 is repeatedly used.
In FIG. 5, 30 shows a protective substance coating apparatus. This apparatus includes a fur brush 31 for supplying and applying a protective substance to the surface of the photoreceptor, a protective substance 32, and a pressurizing means 33 for pressing the protective substance against the fur brush with an arbitrary pressure. By using this protective substance coating apparatus, a certain amount of protective substance can be efficiently supplied to the photoreceptor surface through the fur brush.
In the image forming apparatus, the electrostatic latent image carrier, the charging member, the developing device, and the cleaning device are integrally configured, and may be configured as a process cartridge that is detachable from the image forming apparatus main body.

Next, the charging device 2 used in the image forming apparatus will be described. The charging device 2 charges the electrophotographic photosensitive member using proximity discharge. As a method of charging the electrophotographic photosensitive member using proximity discharge, a contact charging method in which a rotatable roller-shaped charging member (hereinafter referred to as a charging roller) 2a is placed in contact with the electrophotographic photosensitive member, and charging is performed. There is a non-contact charging method in which a roller is disposed in a non-contact manner on an electrophotographic photosensitive member. In this embodiment, a non-contact charging method is used.
The image forming apparatus of the present invention can also be applied to a contact charging method. In the contact charging method, an elastic member that improves the contact property with the surface of the electrophotographic photosensitive member and does not apply mechanical stress to the electrophotographic photosensitive member is used. Things are preferable. However, when an elastic member having poor mechanical durability is used because it is in direct contact with the surface of the photosensitive member, the charging roller is worn or scratched, resulting in a problem that uniform charging cannot be achieved over a long period of time. For this reason, it is more advantageous for high durability to employ the non-contact charging method.

FIG. 6 is an explanatory diagram of a charging device used in an image forming apparatus employing a non-contact charging method. In the charging device 2, the charging roller 2a includes a shaft portion 21a and a roller portion 21b. In FIG. 6, reference numeral 16 denotes a high voltage power source.
The roller portion 21 b can be rotated by the rotation of the shaft portion 21 a, and a portion of the surface of the electrophotographic photosensitive member 1 that faces the image forming region 11 where an image is formed is not in contact with the electrophotographic photosensitive member 1. The length of the charging roller in the longitudinal direction (axial direction) is set slightly longer than the image forming area, and spacers 22 are provided at both ends in the longitudinal direction. By bringing these two spacers into contact with the non-image forming regions 12 at both ends of the electrophotographic photosensitive member surface, a minute gap 14 is formed between the electrophotographic photosensitive member 1 and the charging roller. The minute gap 14 is configured such that the distance at the closest portion between the charging roller and the electrophotographic photosensitive member 1 can be maintained at 1 to 100 μm. The gap 14 is preferably 10 to 80 μm, more preferably 30 to 65 μm. In the apparatus of this embodiment, the gap was set to 50 μm.
Further, the shaft portion 21a is pressed against the electrophotographic photosensitive member side by a pressing spring 15 made of a spring. Thereby, the minute gap 14 can be accurately maintained. The charging roller rotates along with the surface of the electrophotographic photosensitive member via the spacer 22.
A charging power source is connected to the charging roller 2a. As a result, the surface of the electrophotographic photosensitive member is uniformly charged by proximity discharge in a minute gap between the surface of the electrophotographic photosensitive member and the surface of the charging roller. As an applied voltage, an AC voltage is superimposed on a DC voltage. When an alternating voltage obtained by superimposing an AC voltage on a DC voltage is used as the applied voltage, the effect of variations in charging potential due to minute gap fluctuations is suppressed, and uniform charging becomes possible. In this embodiment, an alternating voltage obtained by superimposing an AC voltage that is an AC component on a DC voltage that is a DC component is used.

The charging roller 2a has a cored bar as a conductive support having a cylindrical shape and a resistance adjusting layer formed on the outer peripheral surface of the cored bar. The surface of the charging roller 2a is preferably hard. A rubber member can also be used as the roller member. However, if the member is easily deformed, such as a rubber member, it is difficult to maintain the minute gap 14 with the electrophotographic photosensitive member 1 uniformly, and depending on the image forming conditions, the charging roller 2a There is a possibility that only the central portion suddenly contacts the surface of the electrophotographic photosensitive member. The charging roller 2a is preferably a hard member with less deflection when the non-contact charging method is used.
As the charging roller 2a having a hard surface, for example, a thermoplastic resin composition in which a polymer ion conductive agent is dispersed in a resistance adjusting layer (for example, polyethylene, polypropylene, polymethyl methacrylate, polystyrene, or a copolymer thereof) In which the surface of the resistance adjustment layer is cured with a curing agent. The cured film treatment is performed, for example, by immersing the resistance adjustment layer in a treatment solution containing an isocyanate-containing compound, but may be performed by forming a cured treatment film layer on the surface of the resistance adjustment layer. Good. In the present embodiment, the charging roller 2a is formed with a diameter of 10 mm.

(Process cartridge)
The process cartridge of the present invention is provided in contact with or in proximity to the electrostatic latent image carrier of the present invention and by applying a voltage in which an AC component is superimposed on a DC component. A charger for charging the surface of the latent electrostatic image bearing member using the generated discharge, and at least one means selected from a developing means, a transfer means, a cleaning means, and a charge eliminating means, and further required Accordingly, it has other means and can be attached to and detached from the main body of the image forming apparatus.

Here, as shown in FIG. 7, the process cartridge includes a photosensitive member 101, and at least one of a charging unit 102, a developing unit 104, a transfer unit 108, a cleaning unit 107, and a charge eliminating unit (not shown). And an apparatus (part) that can be attached to and detached from the main body of the image forming apparatus.
Next, the image forming process using the process cartridge shown in FIG. 7 will be described. The photoconductor 101 is exposed to the surface by charging by the charging means 102 and exposure means (not shown) exposure 103 while rotating in the direction of the arrow. An electrostatic latent image corresponding to the image is formed. The electrostatic latent image is developed with toner by the developing unit 104, and the toner development is transferred to the recording medium 105 by the transfer unit 108 and printed out. Next, the surface of the photoconductor after the image transfer is cleaned by the cleaning unit 107 and further neutralized by a neutralizing unit (not shown), and the above operation is repeated again.

  The image forming apparatus of the present invention is configured by integrally combining the above-described electrostatic latent image carrier and components such as a developing device and a cleaning device as a process cartridge, and this unit is detachable from the apparatus main body. You may comprise. Further, at least one of a charger, an image exposure device, a developing device, a transfer or separation device, and a cleaning device is integrally supported together with a photosensitive member to form a process cartridge, and a single unit that is detachable from the apparatus main body, It is good also as a structure which can be attached or detached using guide means, such as a rail of an apparatus main body.

  In the image forming apparatus, the image forming method, and the process cartridge of the present invention, the chemical deterioration of the surface due to the proximity discharge can be suppressed, the image quality deterioration is small even by repeated use, the wear resistance and the image quality stability are excellent, and the high image quality. Since the electrostatic latent image carrier of the present invention that can output images stably over a long period of time is used, image degradation due to wear can be suppressed, and high-definition and high-quality images can be formed over a long period of time. .

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to a following example. In the following examples, “part” represents “part by mass”, and “%” represents “% by mass”.

Example 1
-Production of electrostatic latent image carrier-
An undercoat layer coating solution, a charge generation layer coating solution, and a charge transport layer coating solution having the following composition are sequentially applied onto an aluminum cylinder having a diameter of 30 mm, and dried to undercoat a thickness of 3.5 μm. A layer, a charge generation layer having a thickness of 0.2 μm, and a charge transport layer having a thickness of 18 μm were formed.

[Undercoat layer coating solution]
・ Alkyd resin (Beccosol 1307-60-EL, manufactured by Dainippon Ink & Chemicals, Inc.) ... 6 parts Melamine resin (Super Becamine G-821-60, manufactured by Dainippon Ink & Chemicals, Inc.) ... 4 parts ・ Titanium oxide ・ ・ ・ 40 parts ・ Methyl ethyl ketone ・ ・ ・ 50 parts

[Charge generation layer coating solution]
-Bisazo pigment represented by the following structural formula (A)-2.5 parts-Polyvinyl butyral (XYHL, manufactured by UCC)-0.5 part-Cyclohexanone-200 parts-Methyl ethyl ketone-80 Part

[Charge transport layer coating solution]
Bisphenol Z polycarbonate (Panlite TS-2050, manufactured by Teijin Chemicals Ltd.) 10 parts Low molecular charge transport material represented by the following structural formula (B) 7 parts Tetrahydrofuran 100 parts・ Tetrahydrofuran solution of 1% silicone oil (KF50-100CS, manufactured by Shin-Etsu Chemical Co., Ltd.) ・ ・ ・ 1 part

  Next, a surface layer coating solution having the following composition is applied onto the laminate comprising the support / undercoat layer / charge generation layer / charge transport layer using a ring coater and dried at 120 ° C. for 1 hour. And a surface layer having a thickness of 5 μm was formed. Thus, the electrostatic latent image carrier of Example 1 was produced.

[Method for preparing surface layer coating solution]
(1) A solution prepared by stirring the following formulation at 60 ° C. for 2 hours was used as solution A. • Methyltrimethoxysilane: 10 parts by mass • 1% acetic acid aqueous solution: 5 parts by mass • n-butanol ... 15 parts by mass (2) 10 parts by mass of the charge transport material represented by the following structural formula (C) and tin organic acid salt (nBu ₂ · Sn (OAc) ₂ ) After adding 0.016 parts by mass, the mixture was stirred for 3 hours at a temperature of 40 ° C. to prepare a surface layer coating solution.

(Example 2)
-Production of electrostatic latent image carrier-
An electrostatic latent image carrier was produced in the same manner as in Example 1 except that the organosilicon compound (methyltrimethoxysilane) was changed to tetraethoxysilane in Example 1.

(Example 3)
-Production of electrostatic latent image carrier-
An electrostatic latent image carrier was produced in the same manner as in Example 1 except that the organosilicon compound (methyltrimethoxysilane) was changed to dimethyldimethoxysilane in Example 1.

Example 4
-Production of electrostatic latent image carrier-
An electrostatic latent image carrier was produced in the same manner as in Example 1 except that the organosilicon compound (methyltrimethoxysilane) was changed to an organosilicon compound having the following composition in Example 1.
・ Organic silicon compound Methyltrimethoxysilane: 50 parts by mass Tetraethoxysilane: 50 parts by mass

(Example 5)
-Production of electrostatic latent image carrier-
An electrostatic latent image carrier was produced in the same manner as in Example 1 except that the organosilicon compound (methyltrimethoxysilane) was changed to an organosilicon compound having the following composition in Example 1.
・ Organic silicon compound Methyltrimethoxysilane: 50 parts by mass Phenyltrimethoxysilane: 10 parts by mass

(Example 6)
-Production of electrostatic latent image carrier-
An electrostatic latent image carrier was produced in the same manner as in Example 1 except that the organosilicon compound (methyltrimethoxysilane) was changed to an organosilicon compound having the following composition in Example 1.
・ Organic silicon compound 30 parts by mass of methyltrimethoxysilane 80 parts by mass of dimethyldimethoxysilane

(Comparative Example 1)
-Production of electrostatic latent image carrier-
In Example 1, an electrostatic latent image carrier was produced in the same manner as in Example 1 except that the surface layer was not formed.

(Comparative Example 2)
-Production of electrostatic latent image carrier-
In Example 1, a surface layer coating solution having the following composition was applied on a laminate comprising a support / undercoat layer / charge generation layer / charge transport layer using a spray coater and heated at 150 ° C. for 40 minutes. An electrostatic latent image bearing member was produced in the same manner as in Example 1 except that a polyurethane crosslinked resin-based surface layer having a dry thickness of 5 μm was formed by drying.

(Preparation of surface layer coating solution)
A surface layer coating solution having NCO / OH = 1.0 and solid content = 10% by mass was prepared by the usual method with the following composition.
・ Isocyanate compound (Takenate D140, manufactured by Mitsui Takeda Chemical Co., Ltd.) 2.5 parts ・ Polyol compound (molecular weight 334.16) represented by the following structural formula (D) 1.0 part ・ The following structure Low molecular charge transport material represented by formula (B): 3.5 parts Solvent: acetone / cellosolve acetate / methyl isobutyl ketone = 4/4/1 ... 63 parts

(Example 7)
-Production of electrostatic latent image carrier-
In Example 1, an electrostatic latent image carrier was produced in the same manner as in Example 1 except that the content of the charge transport material in the surface layer was 20 parts by mass.

(Example 8)
-Production of electrostatic latent image carrier-
In Example 1, an electrostatic latent image carrier was produced in the same manner as in Example 1 except that the content of the charge transport material in the surface layer was 5 parts by mass.

Example 9
-Production of electrostatic latent image carrier-
In Example 1, an electrostatic latent image carrier was produced in the same manner as in Example 1 except that the thickness of the surface layer was 1 μm.

(Example 10)
-Production of electrostatic latent image carrier-
In Example 1, an electrostatic latent image carrier was produced in the same manner as in Example 1 except that the thickness of the surface layer was 10 μm.

  Next, using each electrostatic latent image carrier produced in the examples and comparative examples, an actual machine paper passing test was performed as follows.

<Actual paper feeding test 1: DC / AC superimposed charging method>
Using an image forming apparatus (IPCO Color CX9000, manufactured by Ricoh Co., Ltd.) having a non-contact charger that applies a voltage in which the AC component is superimposed on the DC component, an actual paper feeding test (A4 size, manufactured by NBS Ricoh Co., My Paper) The photosensitive member surface charging potential at the start of −650 V was performed, and the wear characteristics and image (S3 chart) characteristics were evaluated. The results are shown in Tables 2 and 3.

* Image density evaluation criteria: ○ → good (actual use possible), x poor (not practical use)

From the results of Table 2 and Table 3, in Examples 1 to 10 using the DC / AC superimposed charging system provided in the vicinity, the electrostatic latent image carrier having a surface layer containing a siloxane skeleton has little thickness reduction. It can be seen that it has excellent properties with little change in output image over a long period.
In Example 9, since the thickness of the surface layer was 1 μm, after 30,000 sheets, the surface layer disappeared due to wear, and generation of vertical streaks was observed.
On the other hand, when the surface layer of Comparative Example 1 was not provided, the thickness reduction amount was increased, and it was shown that defects that affect the image quality are likely to occur.
Further, the amount of decrease in thickness also changes depending on the amount of the charge transporting material, and as described in the present invention, when the charge transporting material is excessively contained, even if the surface layer has a siloxane skeleton, the thickness reduction amount is reduced. In many cases, it has been shown that the photoconductor has poor durability. On the other hand, when the amount of the charge transport material is too small, the function as the photoconductive material cannot be sufficiently exhibited, and it is difficult to obtain a good output image. Furthermore, interesting knowledge about the thickness of the surface layer was obtained. That is, even if it has a surface layer having a siloxane skeleton, if the thickness is too small, the surface layer disappears quickly due to mechanical and electrical hazards inside the actual machine, and the protective effect can hardly be seen. Indicated. On the other hand, when the thickness was too large, the charge transport function was lowered, and the exposure part potential was relatively high, suggesting that it contributes to the reduction in image density and gradation. .

<Actual paper feeding test 2: DC charging method>
Using an image forming apparatus (IPSio Color CX9000, manufactured by Ricoh Co., Ltd.) remodeled into a contact charger that applies only a DC component voltage, an actual paper passing test (A4 size, manufactured by NBS Ricoh, My Paper, start-up photosensitivity) Body surface charging potential -700 V) was performed, and wear characteristics and image (S3 chart) characteristics were evaluated. The results are shown in Tables 4 and 5.

* Image density evaluation criteria: ○ → good (actual use possible), x poor (not practical use)

  From the results of Tables 4 and 5, when the direct current charging method was adopted in the charging means provided in the vicinity, there was no significant difference in the thickness reduction amount in any of the examples and the comparative examples. . In Example 9, since the thickness of the surface layer was 1 μm, after 30,000 sheets, the surface layer disappeared due to wear, and generation of vertical streaks was observed.

  From the results of Examples and Comparative Examples adopting the DC / AC superimposed charging method, in the case where the DC / AC superimposed charging method is adopted in the charger provided in contact with or close to the photosensitive member, the surface When the layer contains a siloxane skeleton, it is possible to provide an electrophotographic photoreceptor and an image forming apparatus capable of obtaining an excellent output image over a long period of time with a small thickness reduction amount.

  An image forming method, an image forming apparatus, and a process cartridge using an electrostatic latent image carrier according to the present invention, in particular, a full-color copying machine, a full-color laser printer that employs a proximity charging method in which an AC voltage is superimposed on a DC voltage, and Widely used for full-color plain paper fax machines.

FIG. 1 is a graph showing the result of a charging test for examining deterioration of the surface of the electrostatic latent image carrier due to proximity discharge. FIG. 2A is a schematic diagram showing a state before the surface of the electrostatic latent image carrier is deteriorated due to proximity discharge. FIG. 2B is a schematic diagram illustrating a state in which the surface of the electrostatic latent image carrier has deteriorated due to proximity discharge. FIG. 3 is a schematic sectional view showing an example of the electrostatic latent image carrier of the present invention. FIG. 4 is a schematic sectional view showing another example of the electrostatic latent image carrier of the present invention. FIG. 5 is a schematic view showing an example of the image forming apparatus of the present invention. FIG. 6 is a schematic view showing an example of an image forming apparatus employing the non-contact charging method of the present invention. FIG. 7 is a schematic view showing an example of the process cartridge of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electrostatic latent image carrier 2 Charging device 2a Charging roller 3 Exposure device 4 Developing device 5 Transfer device 6 Fixing device 7 Cleaning device 8 Cleaning blade 9 Electric discharge device 11 Image forming region 12 Non-image forming region 14 Micro gap 15 Pressure spring 21a Shaft portion 21b Roller portion 22 Spacer 101 Photoconductor 102 Charging means 103 Exposure means 104 Development means 105 Recording medium 107 Cleaning means 108 Transfer means 231 Support 233 Photosensitive layer 235 Charge generation layer 237 Charge transport layer 239 Surface layer

Claims (13)

A charger that is provided in contact with or in proximity to the electrostatic latent image carrier and charges the surface of the electrostatic latent image carrier using a discharge generated by applying a voltage in which an alternating current component is superimposed on a direct current component. An electrostatic latent image carrier used in the image formation used, having a support and at least a photosensitive layer and a surface layer in this order on the support,
The electrostatic latent image carrier, wherein the surface layer contains a polycondensate of an organosilicon compound represented by the following general formula (1).
_{R n -Si (Z) 4-} n ··· formula (1)
However, in said general formula (1), R represents an organic group. Z represents a hydroxyl group or a hydrolyzable group. n represents an integer of 0 to 3, and when n is 2 or 3, Rs may be the same or different from each other.   The electrostatic latent image carrier according to claim 1, wherein the content of the organosilicon compound in the surface layer is 30 to 70% by mass.   The electrostatic latent image carrier according to claim 1, wherein the surface layer contains a charge transport material.   4. The electrostatic latent image carrier according to claim 3, wherein the charge transport structure in the charge transport material is a triarylamine structure.   5. The electrostatic latent image carrier according to claim 1, wherein the content of the charge transport material in the surface layer is 30 to 200 parts by mass with respect to 100 parts by mass of the organosilicon compound.   The electrostatic latent image carrier according to claim 1, wherein the surface layer has a thickness of 1 to 10 μm.   The electrostatic latent image carrier according to any one of claims 1 to 6, wherein a protective substance is applied and adhered to the surface of the electrostatic latent image carrier.   The electrostatic latent image carrier according to claim 7, wherein the protective substance is zinc stearate.   9. The electrostatic latent image carrier according to claim 1, wherein the photosensitive layer is a single-layer type photosensitive layer.   9. The electrostatic latent image carrier according to claim 1, wherein the photosensitive layer is a laminated photosensitive layer having at least a charge generation layer and a charge transport layer in this order on a support. A charger that is provided in contact with or in proximity to the electrostatic latent image carrier and charges the surface of the electrostatic latent image carrier using a discharge generated by applying a voltage in which an alternating current component is superimposed on a direct current component. An electrostatic latent image forming step of forming an electrostatic latent image on the electrostatic latent image carrier, a developing step of developing the electrostatic latent image with toner to form a toner image, and the toner In an image forming method including at least a transfer step of transferring an image to a recording medium,
11. The image forming method according to claim 1, wherein the electrostatic latent image carrier is the electrostatic latent image carrier according to any one of claims 1 to 10. The electrostatic latent image carrier and the electrostatic latent image using discharge generated by applying a voltage in which an alternating current component is superimposed on a direct current component, provided in contact with or close to the electrostatic latent image carrier. An electrostatic latent image forming means for forming an electrostatic latent image on the electrostatic latent image carrier; and developing the electrostatic latent image with toner to form a toner. In an image forming apparatus having at least developing means for forming an image and transfer means for transferring the toner image to a recording medium,
11. The image forming apparatus, wherein the electrostatic latent image carrier is the electrostatic latent image carrier according to claim 1. An electrostatic latent image carrier according to any one of claims 1 to 10 and a voltage that is provided in contact with or close to the electrostatic latent image carrier and in which an alternating current component is superimposed on a direct current component. An image forming apparatus comprising: a charger for charging the surface of the latent electrostatic image bearing member using the generated discharge; and at least one unit selected from a developing unit, a transfer unit, a cleaning unit, and a discharging unit. A process cartridge which is detachable from the main body.