JP4189915B2 - Intermediate transfer member, method for producing the same, and image forming apparatus using the same - Google Patents

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus using an electrophotographic system such as a copying machine, a printer, a facsimile, and the like, and more specifically, an intermediate transfer with primary and secondary transfer processes through an intermediate transfer body such as an intermediate transfer drum and a belt. The present invention relates to an intermediate transfer apparatus and an image forming apparatus using a method, and further relates to an image forming apparatus capable of obtaining high image quality by simultaneously using a small particle size and spherical toner. Furthermore, the present invention relates to a method for producing an intermediate transfer member.

  In recent years, electrophotographic image forming apparatuses capable of copying and printing full-color images have been put into practical use. As a transfer method for transferring a full-color image to a transfer material, an intermediate transfer member double transfer method (image of a photoconductor, etc.) is used. Each color image of yellow (Y), magenta (M), cyan (C), and black (Bk) formed for each color on the support is sequentially superimposed and transferred onto the intermediate transfer member, and the transferred full color A method of collectively transferring the toner images to a transfer material (also simply referred to as an intermediate transfer method) is advantageous in that it is paper-free and allows front copy.

  The intermediate transfer member includes (1) an image system in which the intermediate transfer member is formed of a dielectric, or at least a surface of the intermediate transfer member to which toner is transferred is formed of a dielectric, and (2) intermediate transfer The system is roughly divided into two systems: an image forming system in which the body is formed of a medium resistance material. With regard to (1), since the charge derived from the transfer bias and triboelectric charge on the intermediate transfer member affects the next transfer process, a special static eliminating device for removing the charge is required, and the cost increases. Many image forming systems are used. Regarding the above (2), those that define the surface resistivity of the intermediate transfer member, the intermediate transfer member main material, the resistance control agent, and the like are known (see, for example, Patent Documents 1 to 3).

  For example, polycarbonate, polyvinylidene fluoride, ETFE (ethylene tetrafluoroethylene), polyimide, or the like is generally used as the binder resin for the intermediate transfer member (but not limited thereto). The resistance is controlled by dispersing a resistance control agent (filler) such as carbon or metal oxide on the surface, but if a large amount of filler is dispersed, the belt surface deteriorates, resulting in toner filming or toner charge change. Or the image quality is degraded, and carbon is often used as a problem that does not occur.

  Polyimide resin is a resin excellent in heat resistance, mechanical properties, chemical resistance, radiation resistance, etc., so various molding materials such as films and sheets, paints such as enamel for electric wires, electronic materials, flexible printed circuit boards, Widely used in applications such as heat-resistant substrates, semiconductor encapsulating materials, adhesives, and organic-inorganic composites. Attempts have been made to achieve the purpose of improving physical properties by adding insulating fine particles to the polyimide resin. For example, improving heat resistance and reducing the coefficient of thermal expansion (see Patent Document 4), improving slipperiness and running durability (see Patent Documents 5 and 6), printability, heat resistance, and moisture-resistant adhesion Giving is disclosed (for example, see Patent Document 7).

  As a method for producing a polyimide resin, generally, a method in which a solvent-soluble polyamic acid is first synthesized and heated to 300 ° C. or higher to form a polyimide is generally used. Therefore, in order to disperse the insulating fine particles in the polyimide resin, it is necessary to disperse the insulating fine particles in the polyamic acid solution. As a dispersion method, insulating fine particles are added to a polyamic acid solution and dispersed by a dispersing machine such as a sand mill or a ball mill, or insulating fine particles are added to a polyamic acid varnish in a semi-liquid state, and a three-roll roll is used. A direct dispersion method of kneading and dispersing is conceivable. However, since the affinity between the insulating fine particles and the polyamic acid is very poor, when they are mixed, the insulating fine particles are aggregated and it is difficult to uniformly disperse them. The fact that the polyamic acid solution is very viscous also makes uniform dispersion difficult.

  Therefore, a method of synthesizing polyamic acid in an insulating fine particle dispersion, that is, a method of preparing a polyamic acid solution by reacting a diamine compound and an acid anhydride compound in an organic polar solvent in which insulating fine particles are dispersed in advance is proposed. (See Patent Document 6). However, even in this method, the insulating particles have a strong cohesion force, so that the insulating particles aggregate.

  The thus-aggregated insulating fine particles have a particle size of 10 μm or more and become a kind of foreign matter. For example, when formed into a film shape, the surface of the film becomes rough, the gloss is lost, and the appearance of the film is impaired. It adversely affects mechanical properties such as tensile strength and electrical properties such as electrical insulation.

  Similarly, the main method for dispersing carbon black in a polyamic acid solution is as follows: (1) A method of adding carbon black to a polyamic acid solution and dispersing it with a dispersing machine such as a sand mill or a ball mill; There are known a method in which carbon black is added to the polyamic acid varnish in this state and kneaded and dispersed with a three roll, and (3) a method in which the polyamic acid is synthesized in a carbon black dispersion. However, in any of these methods, the compatibility between the carbon black and the polyamic acid is very poor, so that when the two are mixed, the carbon black aggregates and it is impossible to perform uniform dispersion. . As a result, carbon black is agglomerated even in the resulting polyimide film or coating, and thus problems such as roughening of the film surface, loss of gloss, and difficulty in controlling the electric resistance value occur.

JP-A-63-311263 JP-A-56-164368 JP-A 64-74571 JP 63-172741 A JP-A-3-170548 JP-A-6-145378 Japanese Patent Laid-Open No. 1-1121364

  As described above, conventionally, when carbon is added to an insulating resin to control the middle resistance, the (volume / surface) resistance uniformity of the intermediate transfer body after molding is not sufficient due to poor carbon dispersibility. As a result, there is a problem that variation in transferability occurs.

  The present invention has been made in consideration of the above-described circumstances, and provides an intermediate transfer member having sufficiently improved resistance uniformity, a method for manufacturing the intermediate transfer member, and an image forming apparatus in which image quality is improved by the intermediate transfer member. There is. Further, regarding the film forming liquid composition, the polyamic acid-containing fine particle dispersion composition in which the fine particles such as insulating fine particles and carbon black are improved in compatibility with the polyimide, and the fine particles are uniformly dispersed in the polyamic acid solution, and the production method thereof And it aims at providing the fine particle dispersion composition which can be used effectively as a raw material intermediate in this manufacturing method.

In order to solve the above problems, the invention according to claim 1 is configured such that a plurality of visible color developed images sequentially formed on an image carrier by toner are sequentially superimposed on an endless transfer intermediate body. In an intermediate transfer body in an intermediate transfer apparatus that performs primary transfer and secondary transfer of a primary transfer image on the intermediate transfer body to a transfer material at once, it can be dispersed and / or dissolved in a water-soluble organic solvent without a dispersant. a layer formed from the deposition solution containing surface modified carbon black, the value of the hydrophilic functional group content / specific surface area of the carbon black is Ri range near the 5~30μmol / m ^2, and surface The modified carbon black is characterized in that the intermediate transfer member is obtained by oxidizing carbon black with hypohalous acid or a salt thereof .
According to a second aspect of the present invention, a plurality of visible color development images sequentially formed on an image carrier by toner are sequentially superimposed on an intermediate transfer member that travels endlessly to perform primary transfer. In the intermediate transfer device in the intermediate transfer apparatus for performing the secondary transfer of the primary transfer image on the transfer material in a lump, surface modified carbon black that can be dispersed and / or dissolved in a water-soluble organic solvent without a dispersant is included. A layer formed from a film-forming solution, the value of hydrophilic functional group amount / specific surface area of the carbon black is in the range of 5 to 30 μmol / m ² , and a resin is present on the surface of the surface-modified carbon black. The intermediate transfer member is encapsulated.
In the invention according to claim 3, the type of the encapsulating resin is any one of acrylic acid-butyl acrylate-methyl methacrylate copolymer, styrene-maleic ester-maleic anhydride copolymer, and polyvinylpyrrolidone. The intermediate transfer member according to claim 2 is characterized.
According to a fourth aspect of the present invention, a plurality of visible color developed images sequentially formed on an image carrier by toner are sequentially superimposed and temporarily transferred onto an intermediate transfer member running endlessly, and the intermediate transfer member In the intermediate transfer device in the intermediate transfer apparatus for performing the secondary transfer of the primary transfer image on the transfer material in a lump, surface modified carbon black that can be dispersed and / or dissolved in a water-soluble organic solvent without a dispersant is included. A layer formed from a film-forming solution, the value of hydrophilic functional group amount / specific surface area of the carbon black is in the range of 5 to 30 μmol / m ² , and the surface-modified carbon black is hypohalogenated A film-forming solution composition for forming an intermediate transfer member obtained by oxidizing carbon black with an acid or a salt thereof is characterized.
According to a fifth aspect of the present invention, a plurality of visible color development images sequentially formed on an image carrier by toner are sequentially superimposed and temporarily transferred onto an intermediate transfer member running endlessly, and the intermediate transfer member In the intermediate transfer device in the intermediate transfer apparatus for performing the secondary transfer of the primary transfer image on the transfer material in a lump, surface modified carbon black that can be dispersed and / or dissolved in a water-soluble organic solvent without a dispersant is included. A layer formed from a film-forming solution, the value of hydrophilic functional group amount / specific surface area of the carbon black is in the range of 5 to 30 μmol / m ² , and a resin is present on the surface of the surface-modified carbon black. An encapsulated film forming solution composition for forming an intermediate transfer member is characterized.
In the invention described in claim 6, the type of the encapsulating resin is any one of acrylic acid-butyl acrylate-methyl methacrylate copolymer, styrene-maleic ester-maleic anhydride copolymer, and polyvinylpyrrolidone. A film forming solution composition for forming an intermediate transfer member according to claim 5 is characterized.
The invention according to claim 7 includes at least a charging device that forms an electrostatic latent image on an image carrier, a developing device that forms a toner image on the image carrier using a developer corresponding to each color, and An intermediate transfer device that sequentially superimposes a toner image on an intermediate transfer member that travels endlessly and performs primary transfer, and then secondary-transfers the primary transfer image on the intermediate transfer member collectively to a transfer material; and An image forming apparatus having a fixing device that heats or pressurizes the toner image to fix the toner image on the transfer material, wherein the intermediate transfer device is an intermediate transfer according to any one of claims 1 to 3. An image forming apparatus using a body is characterized.

According to the present invention, the intermediate transfer member has a layer formed because it includes a surface-modified carbon black that can be dispersed and / or dissolved in a water-soluble organic solvent without a dispersant, and the hydrophilicity of the carbon black When the value of the functional group amount / specific surface area is in the range of 5 to 30 μmol / m ² , it is possible to provide an intermediate transfer member excellent in resistance uniformity.

  The surface-modified carbon black was obtained by oxidizing acidic carbon black or channel carbon black, and the oxidation method was obtained by oxidizing carbon black with hypohalous acid or a salt thereof. The surface-modified carbon black has a hydrophilic functional group of 1.5 mmol / g or more, the resin is graft polymerized on the surface of the carbon black, or the resin is encapsulated. An intermediate with excellent resistance uniformity, because the type of acrylated resin is any one of acrylic acid-butyl acrylate-methyl methacrylate copolymer, styrene-maleic ester-maleic anhydride copolymer, and polyvinylpyrrolidone. A transfer body can be provided.

  Furthermore, an intermediate transfer body having good mechanical properties is provided by using a resin contained in a film forming solution for forming an intermediate transfer body, which is a single resin or a combination of polyimide resin, modified polyimide resin, and polyamideimide resin. It becomes possible to do.

  Furthermore, when the particle diameter of the surface-modified carbon black of the present invention is 10 nm to 300 nm, it is possible to provide an intermediate transfer member with better mechanical properties.

Furthermore, the surface (rear surface) resistance of the intermediate transfer member of the present invention is 10 ⁸ to 10 ¹² Ω / □, thereby providing an intermediate transfer member excellent in image quality.

  Furthermore, since the layer structure of the intermediate transfer member is a single layer structure, it is possible to provide an intermediate transfer member that is easy to manufacture and inexpensive.

  Furthermore, since the layer structure of the intermediate transfer member is a multilayer structure, an intermediate transfer member having excellent surface characteristics can be provided.

  Furthermore, since the intermediate transfer member has a seamless belt shape, an intermediate transfer member excellent in layout flexibility can be provided.

  Further, the intermediate transfer member having excellent resistance uniformity can be provided by the film forming solution composition for forming the intermediate transfer member of the present invention.

Further, a charging device for forming an electrostatic latent image on the image carrier of the present invention, a developing device for forming a toner image using a developer corresponding to each color on the image carrier, and the toner image in an endless manner. An intermediate transfer device that sequentially superimposes and temporarily transfers the primary transfer image on the traveling intermediate transfer member, and collectively transfers the primary transfer image on the intermediate transfer member onto the transfer material, and heats or heats the toner image on the transfer material. An image forming apparatus having a fixing device that pressurizes and fixes a toner image on the transfer material, wherein the intermediate transfer device uses the intermediate transfer member according to any one of claims 1 to 4 . It is possible to provide an image forming apparatus excellent in image quality.

As described above, the intermediate transfer member of the present invention is excellent in resistance uniformity, and when used in an image forming apparatus, a stable image with little density unevenness can be obtained over a long period of time.
In addition, the film-forming liquid composition for forming an intermediate transfer body is excellent in carbon black dispersion stability, and the molded transfer body has high resistance uniformity, and can be molded by various molding methods. It is possible and has an effect of excellent long-term storage stability.

Hereinafter, the present invention will be described in more detail.
Description of Intermediate Transfer Device An intermediate transfer belt will be described as a representative example of an intermediate transfer member.
FIG. 1 is a schematic configuration diagram of a revolver type color electrophotographic apparatus using one photosensitive drum.

  In FIG. 1, an intermediate transfer unit 500 includes an intermediate transfer belt 501 that is an intermediate transfer body stretched around a plurality of rollers. Around the intermediate transfer belt 501, a secondary transfer bias roller 605 that is a secondary transfer charge applying unit of the secondary transfer unit 600, a belt cleaning blade 504 that is an intermediate transfer member cleaning unit, and a lubricant for a lubricant application unit. A lubricant application brush 505 or the like that is an application member is disposed so as to face each other.

  A position detection mark is provided on the outer peripheral surface or the inner peripheral surface of the intermediate transfer belt 501. However, on the outer peripheral surface side of the intermediate transfer belt 501, it is necessary to devise provision of position detection marks so as to avoid the passing area of the belt cleaning blade 504, which may be difficult to arrange. A position detection mark is provided on the inner peripheral surface side of the intermediate transfer belt 501. In the example of FIG. 1, the optical sensor 514 serving as a mark detection sensor is provided at a position between the primary transfer bias roller 507 and the drive roller 508 where the intermediate transfer belt 501 is bridged.

  The intermediate transfer belt 501 includes a primary transfer bias roller 507, a belt driving roller 508, a belt tension roller 509, a secondary transfer counter roller 510, a cleaning counter roller 511, and a feedback current detection roller 512, which are primary transfer charge applying units. It is stretched around. Each roller is formed of a conductive material, and each roller other than the primary transfer bias roller 507 is grounded. The primary transfer bias roller 507 is applied with a transfer bias controlled to a predetermined current or voltage according to the number of superimposed toner images by a primary transfer power source 801 controlled at a constant current or voltage. ing.

  The intermediate transfer belt 501 is driven in the arrow direction by a belt driving roller 508 that is driven to rotate in the arrow direction by a drive motor (not shown). The intermediate transfer belt 501 is a semiconductor or an insulator and has a single layer or a multilayer structure. In addition, the intermediate transfer belt is set to have a width larger than the maximum sheet passing size in order to overlap the toner images formed on the photosensitive drum 200.

  A secondary transfer bias roller 605 serving as a secondary transfer unit is attached to and separated from a belt outer peripheral surface of the intermediate transfer belt 501 in a portion stretched around the secondary transfer counter roller 510 by a contact / separation mechanism, which will be described later. It is configured to be able to contact and separate. The secondary transfer bias roller 605 is disposed so as to sandwich the recording paper P between the portion of the intermediate transfer belt 501 stretched around the secondary transfer counter roller 510 and is subjected to constant current control. A transfer bias having a predetermined current is applied by the transfer power source 802.

  The registration roller 610 feeds the transfer sheet P, which is a transfer material, between the secondary transfer bias roller 605 and the intermediate transfer belt 501 stretched around the secondary transfer counter roller 510 at a predetermined timing. The secondary transfer bias roller 605 is in contact with a cleaning blade 608 as a cleaning unit. The cleaning blade 608 is for removing the adhering matter adhering to the surface of the secondary transfer bias roller 605 for cleaning.

  In the color copying machine having such a configuration, when an image forming cycle is started, the photosensitive drum 200 is rotated in a counterclockwise direction indicated by an arrow by a drive motor (not shown), and Bk toner is placed on the photosensitive drum 200. Image formation, C toner image formation, M toner image formation, and Y toner image formation are performed. The intermediate transfer belt 501 is rotated clockwise by the belt driving roller 508 as indicated by an arrow. As the intermediate transfer belt 501 rotates, the primary transfer of the Bk toner image, the C toner image, the M toner image, and the Y toner image is performed by the transfer bias by the voltage applied to the primary transfer bias roller 507. Finally, the respective toner images are formed on the intermediate transfer belt 501 in the order of Bk, C, M, and Y.

  For example, the Bk toner image formation is performed as follows. In FIG. 1, a charging charger 203 uniformly charges the surface of the photosensitive drum 200 to a predetermined potential with a negative charge by corona discharge. The timing is determined based on the belt mark detection signal, and raster exposure with laser light is performed based on the Bk color image signal by a writing optical unit (not shown). When this raster image is exposed, the charge proportional to the exposure light amount disappears in the exposed portion of the surface of the photosensitive drum 200 that is initially uniformly charged, and a Bk electrostatic latent image is formed. When the negatively charged Bk toner on the developing roller of the Bk developing device 231K comes into contact with this Bk electrostatic latent image, the toner does not adhere to the remaining portion of the photosensitive drum 200, and the charge is not charged. The toner is attracted to the nonexposed portion, that is, the exposed portion, and a Bk toner image similar to the electrostatic latent image is formed.

  The Bk toner image formed on the photosensitive drum 200 in this manner is primarily transferred onto the belt outer peripheral surface of the intermediate transfer belt 501 that is rotating at a constant speed while being in contact with the photosensitive drum 200. Some untransferred residual toner remaining on the surface of the photoreceptor drum 200 after the primary transfer is cleaned by the photoreceptor cleaning device 201 in preparation for reuse of the photoreceptor drum 200. On the photosensitive drum 200 side, the process proceeds to the Y image forming process after the Bk image forming process, and reading of the Y image data by the color scanner starts at a predetermined timing, and the photosensitive drum is written by laser beam writing with the Y image data. A Y electrostatic latent image is formed on the surface of 200.

  Then, after the rear end portion of the previous Bk electrostatic latent image passes and before the front end portion of the Y electrostatic latent image arrives, the revolver developing unit 230 is rotated, and the Y developing device 231Y develops. The Y electrostatic latent image is developed with Y toner. Thereafter, the development of the Y electrostatic latent image area is continued. When the trailing edge of the Y electrostatic latent image passes, the revolver developing unit is rotated in the same manner as in the case of the previous Bk developing machine 231K, and the next The C developing machine 231C is moved to the developing position. This is also completed before the leading edge of the next C electrostatic latent image reaches the developing position. Note that the C and M image forming steps are the same as the Bk and Y steps described above because the color image data reading, electrostatic latent image forming, and developing operations are the same as those described above.

  The Bk, Y, C, and M toner images sequentially formed on the photosensitive drum 200 in this way are sequentially aligned on the same surface on the intermediate transfer belt 501 and primarily transferred. As a result, a toner image having a maximum of four colors superimposed on the intermediate transfer belt 501 is formed. On the other hand, at the time when the image forming operation is started, the transfer paper P is fed from a paper feed unit such as a transfer paper cassette or a manual feed tray, and is waiting at the nip of the registration roller 610.

  When the leading edge of the toner image on the intermediate transfer belt 501 reaches the secondary transfer portion where the nip is formed by the intermediate transfer belt 501 stretched around the secondary transfer counter roller 510 and the secondary transfer bias roller 605. Then, the registration roller 610 is driven so that the leading edge of the transfer paper P coincides with the leading edge of the toner image, and the transfer paper P is conveyed along the transfer paper guide plate 601, and the transfer paper P and the toner image are transferred. Resist alignment is performed.

  In this way, when the transfer paper P passes through the secondary transfer portion, the four-color superimposed toner image on the intermediate transfer belt 501 is transferred by the transfer bias applied by the secondary transfer power source 802 to the secondary transfer bias roller 605. Are collectively transferred (secondary transfer) onto the transfer paper P. After the transfer paper P is conveyed along the transfer paper guide plate 601 and passed through a portion facing the transfer paper neutralization charger 606 composed of a static elimination needle disposed on the downstream side of the secondary transfer portion, the transfer paper P is discharged. Then, it is sent to the fixing device by the belt conveying device 210. Then, after the toner image is melted and fixed at the nip portion of the fixing roller of the fixing device (not shown), the transfer paper P is sent out of the apparatus main body by the discharge roller and is stocked face up on a copy tray (not shown).

  On the other hand, the surface of the photosensitive drum 200 after the belt transfer is cleaned by the photosensitive member cleaning device 201 and is uniformly discharged by the discharging lamp 202. Further, residual toner remaining on the outer peripheral surface of the intermediate transfer belt 501 after the toner image is secondarily transferred to the transfer paper P is cleaned by the belt cleaning blade 504. The belt cleaning blade 504 is configured to be brought into contact with and separated from the belt outer peripheral surface of the intermediate transfer belt 501 at a predetermined timing by a cleaning member separating and contacting mechanism (not shown). A toner seal member 503 that contacts and separates from the belt outer peripheral surface of the intermediate transfer belt 501 is provided on the upstream side of the belt cleaning blade 504 in the movement direction of the intermediate transfer belt 501.

  The toner seal member 503 receives the falling toner dropped from the belt cleaning blade 504 when cleaning the residual toner, and prevents the falling toner from scattering on the transfer path of the transfer paper P. The toner seal member 503 is brought into contact with and separated from the belt outer peripheral surface of the intermediate transfer belt 501 together with the belt cleaning blade 504 by the cleaning member separating and contacting mechanism.

  The lubricant 506 scraped by the lubricant application brush 505 is applied to the outer peripheral surface of the intermediate transfer belt 501 from which the residual toner has been removed in this way. The lubricant 506 is made of, for example, a solid body such as zinc stearate, and is disposed so as to come into contact with the lubricant application brush 505. Further, residual charges remaining on the outer peripheral surface of the intermediate transfer belt 501 are removed by a neutralizing bias applied by a belt neutralizing brush 502 that is in contact with the outer peripheral surface of the intermediate transfer belt 501. Here, the lubricant application brush 505 and the belt neutralizing brush 502 are brought into contact with and separated from the outer peripheral surface of the intermediate transfer belt 501 at a predetermined timing by respective contact and separation mechanisms (not shown). Yes.

  Here, at the time of repeat copy, the operation of the color scanner and the image formation on the photosensitive drum 200 are performed at a predetermined timing following the first color (M) image formation process of the first sheet and the first color of the second sheet. The process proceeds to the image forming process (Bk). Further, the intermediate transfer belt 501 has a second Bk toner in the area cleaned by the belt cleaning blade 504 on the outer peripheral surface of the belt following the batch transfer process of the first four-color superimposed toner image to the transfer paper. The image is first transferred. After that, the operation is the same as the first sheet.

  The above is a copy mode for obtaining a four-color full-color copy. In the three-color copy mode and the two-color copy mode, the same operation as described above is performed for the designated color and the number of times. Further, in the single color copy mode, only the predetermined color developer of the revolver developing unit 230 is set in the developing operation state until the predetermined number of copies are completed, and the belt cleaning blade 504 is brought into contact with the intermediate transfer belt 501. The copy operation is performed in the left state.

  In the above-described embodiment, the copying machine including only one photosensitive drum 1 has been described. However, the present invention may be configured such that, for example, a plurality of photosensitive drums as illustrated in FIG. 2 are arranged in parallel along one intermediate transfer belt. The present invention can also be applied to the tandem type image forming apparatus. FIG. 2 shows a configuration of a four-drum digital color printer including four photosensitive drums 21BK, 21Y, 21M, and 21C for forming toner images of four different colors (black, yellow, magenta, and cyan). An example is shown.

  In FIG. 2, the printer body 10 includes an image writing unit 12, an image forming unit 13, and a paper feeding unit 14 for performing color image formation by an electrophotographic method. Based on the image signal, the image processing unit converts the image into black (BK), magenta (M), yellow (Y), and cyan (C) color signals for image formation and transmits them to the image writing unit 12. To do. The image writing unit 12 is a laser scanning optical system including, for example, a laser light source, a deflector such as a rotary polygon mirror, a scanning imaging optical system, and a mirror group. Image writing corresponding to each color signal is performed on image carriers (photoconductors) 21BK, 21M, 21Y, and 21C that have a writing optical path and are provided for each color of the image forming unit 13.

  The image forming unit 13 includes photoconductors 21BK, 21M, 21Y, and 21C that are image carriers for black (BK), magenta (M), yellow (Y), and cyan (C). As each photoconductor for each color, an OPC photoconductor is usually used. Around the photoreceptors 21BK, 21M, 21Y, and 21C, there are a charging device, an exposure unit for laser light from the writing unit 12, and developing devices 20BK, 20M, 20Y for black, magenta, yellow, and cyan, respectively. 20C, primary transfer bias rollers 23BK, 23M, 23Y, and 23C as primary transfer units, cleaning devices 30BK, 30M, 30Y, and 30C, and a photosensitive member discharging device (not shown) are disposed. The developing devices 20BK, M, Y, and C use a two-component magnetic brush developing method. The intermediate transfer belt 22 is interposed between the photoconductors 21BK, 21M, 21Y, and 21C and the primary transfer bias rollers 23BK, 23M, 23Y, and 23C, and the toner images of the respective colors formed on the photoconductors. Are sequentially superimposed and transferred.

  On the other hand, the transfer paper P is fed from the paper feed unit 14 and then carried by the transfer conveyance belt 50 via the registration rollers 16. When the intermediate transfer belt 22 and the transfer conveyance belt 50 come into contact, the toner image transferred onto the intermediate transfer belt 22 is subjected to secondary transfer (collective transfer) by a secondary transfer bias roller 60 as a secondary transfer unit. ) As a result, a color image is formed on the transfer paper P. The transfer paper P on which the color image is formed is conveyed to the fixing device 15 by the transfer conveying belt 50, and after the image transferred by the fixing device 15 is fixed, it is discharged out of the printer main body.

  The residual toner that is not transferred during the secondary transfer and remains on the intermediate transfer belt 22 is removed from the intermediate transfer belt 22 by the belt cleaning device 25. A lubricant application device is disposed on the downstream side of the belt cleaning device 25. This lubricant application device includes a solid lubricant and a conductive brush that rubs the intermediate transfer belt 22 to apply the solid lubricant. The conductive brush is in constant contact with the intermediate transfer belt 22 and applies a solid lubricant to the intermediate transfer belt 22. The solid lubricant has an effect of improving the cleaning property of the intermediate transfer belt 22, preventing the occurrence of filming, and improving the durability.

  In addition to the intermediate transfer belt type image forming apparatus using the intermediate transfer belt 501 or 22 as described above, the present invention is not limited to the intermediate transfer belt 501 or 22, but a transfer conveyance belt using a transfer conveyance belt. The present invention can also be applied to a type image forming apparatus. Also, this transfer / conveyor belt type image forming apparatus can be applied to any of the above-mentioned 1-drum system and 4-drum system.

Description of Intermediate Transfer Member The intermediate transfer member of the present invention has a layer formed because it contains a surface-modified carbon black that can be dispersed and / or dissolved in a water-soluble organic solvent without a dispersant. The value of the functional functional group amount / specific surface area is in the range of 5 to 30 μmol / m ² .

First, carbon black will be described.
Carbon black is defined as an aggregate of fine spherical particles obtained by incomplete combustion of various hydrocarbons or carbon-containing compounds, and is a generic name for carbon materials that are nearly pure and have a chemical composition of 98% or more. It is.
The type is generally classified by the production method, and is roughly classified as shown in Table 1 into either thermal decomposition of raw material hydrocarbons or incomplete combustion, and is further subdivided according to the type of raw material. The contact method is a manufacturing method in which a flame is brought into contact with iron or stone, and includes a channel method and a gas black method (roller method) which is an improved method thereof. Channel black is a representative product of the contact method, and is collected by bringing a flame into contact with the bottom surface of channel steel.

  The furnace method is a method of generating carbon black by continuously pyrolyzing raw material hydrocarbons by combustion heat of fuel air, and is classified into a gas furnace method and an oil furnace method.

  The thermal method is a special production method in which natural gas is used as a raw material carbon source and combustion and thermal decomposition are repeated periodically. The feature is that carbon black having a large particle size can be obtained.

  Acetylene black is a kind of thermal process that uses acetylene as a raw material. However, the thermal decomposition of acetylene is an exothermic reaction while other raw materials are endothermic, so it is possible to omit the combustion cycle in the thermal process. Continuous operation is possible. The characteristics of acetylene black are that it develops crystallinity compared to ordinary carbon black and has a high structure, so it has excellent conductivity, and is used as a conductivity-imparting agent for dry batteries and various rubbers and plastics. Yes.

Basic characteristics of carbon:
When carbon black is blended and dispersed in rubber, resin, paint and ink vehicles, the important factors for imparting functions such as reinforcement, blackness, and conductivity are the particle size and structure, and the physicochemical properties of the particle surface. These are usually called the three major characteristics of carbon black, and various carbon blacks are produced by combining these.
The three basic characteristics of carbon black are:
1. 1. Particle diameter: Particle diameter and surface area Structure: DBP oil supply (ml / 100g) and structure index Surface chemical properties: volatiles (%) and pH
It is.

In the intermediate transfer member using carbon black as a resistance control agent, the present inventors have obtained stable resistance uniformity.
(1) Carbon black that can be dispersed and / or dissolved in a water-soluble organic solvent without a dispersant, and has a hydrophilic functional group amount / specific surface area in the range of 5 to 30 μmol / m ² ;
(2) Surface-modified carbon black obtained by oxidizing acidic carbon black,
(3) Surface modified carbon black obtained by oxidizing channel carbon black,
(4) Surface-modified carbon black obtained by oxidizing carbon black with hypohalous acid or a salt thereof,
(5) The surface-modified carbon black has a hydrophilic functional group of 1.5 mmol / g or more,
However, the inventors have found that a film-forming liquid composition having high resistance uniformity and good dispersion stability can be produced, and the present invention has been achieved.

In addition, the surface treatment of carbon black can improve properties such as dispersion stability, surface wettability, rheological properties, and electrical properties. Examples of the surface treatment method include the following.
The surface of carbon black particles has a condensed aromatic ring and can be subjected to various surface treatments described below.

1. Surface oxidation treatment When carbon black is treated with an oxidizing agent, carboxyl groups and phenolic hydroxyl groups are introduced into the condensed aromatic ring on the particle surface.

2. Surfactant dispersion Carbon black can be dispersed with a normal anionic surfactant, nonionic surfactant, cationic surfactant, amphoteric surfactant, and the like.

3. Polymer (resin) dispersion Carbon black can be dispersed by the steric hindrance repulsion of the polymer dispersant.

4). Encapsulation treatment Carbon black is coated with a resin and dispersed in a solvent. Alternatively, a resin in which carbon black is impregnated, that is, a resin in which carbon black is present on the surface layer, inside, or the whole. Its characteristics can improve properties such as dispersion stability, surface wettability, rheological properties and electrical properties. In particular, in terms of dispersion stability, the dispersibility of the graft chain in a good solvent (easily dispersible in a dispersion medium and stability after dispersion) is remarkably improved, and in terms of electrical characteristics, carbon black particles are polymer matrix. Since it is easily and uniformly dispersed in the inside, there is a feature that a constant resistance value can be obtained over a wide area.

5. Grafting treatment The carbon black grafting treatment can be classified as follows based on the grafting mechanism.
(A) Graft polymerization on the surface of carbon black A method in which a vinyl monomer is polymerized using a polymerization initiator in the presence of carbon black and the growing polymer chain generated in the system is captured on the particle surface (b) carbon black Graft polymerization from surface Method of growing graft chain from polymerization initiation group introduced to carbon black surface (c) Grafting reaction between carbon black surface and polymer Method by reaction of functional group on carbon black surface with reactive polymer.

  Among these, the method a can be most easily performed, but since a non-grafted polymer is predominantly produced, a product having a large graft ratio cannot be obtained. On the other hand, the system of b is characterized in that a polymer (graft chain) grows outward from the carbon black surface, so that a polymer having a high graft rate can be obtained. Furthermore, according to the method c, there is a great feature that the molecular weight and the number of graft chains can be controlled, and a graft ratio can be relatively large.

6). Gas-phase oxidation method This is a method for oxidizing the surface of carbon black by ozone treatment or plasma treatment. By irradiating the carbon black with plasma, a hydroxyl group or a carboxyl group can be attached to the surface of the carbon black by high energy of plasma.

  More specifically, it is as follows.

1. Surface oxidation treatment When carbon black is treated with an oxidizing agent, carboxyl groups and phenolic hydroxyl groups are introduced into the condensed aromatic ring on the particle surface. Furthermore, the condensed aromatic ring on the surface of carbon black reacts with the following various reagents, and various functional groups can be introduced onto the particle surface.

2. Surfactant dispersion Anionic surfactants, nonionic surfactants, cationic surfactants, and amphoteric surfactants having the following structures can be used.
Preferred surfactants include interfacial polyoxyethylene alkyl ether acetates, dialkyl sulfosuccinates, polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, polyoxyethylene polyoxypropylene block copolymers, and acetylene glycol surfactants. Agents. More specifically, by using polyoxyethylene alkyl ether acetate (II) and / or dialkylsulfosuccinic acid (III) having a branched alkyl chain having 5 to 7 carbon chains as an anionic surfactant. The dispersion stability of carbon black is selected.

Ｒ：炭素数６〜１４の分岐してもよいアルキル基、ｍ：３〜１２
Ｍ：アルカリ金属イオン、第４級アンモニウム、第４級ホスホニウム、アルカノールアミン

Ｒ_５、Ｒ_６：炭素数５〜７の分岐したアルキル基
Ｍ：アルカリ金属イオン、第４級アンモニウム、第４級ホスホニウム、アルカノールアミン

R: an alkyl group having 6 to 14 carbon atoms which may be branched, m: 3 to 12
M: alkali metal ion, quaternary ammonium, quaternary phosphonium, alkanolamine

R _{5, R 6:} branched alkyl group having 5-7 carbon atoms M: an alkali metal ion, quaternary ammonium, quaternary phosphonium, alkanolamine

Further, the use of lithium ions, quaternary ammonium, and quaternary phosphonium as counter ions of the surfactant of the present invention shows excellent dissolution stability of the surfactant.
Preferred nonionic surfactants include those represented by general formula (IV) which are polyoxyethylene alkylphenyl ethers and general formula (V) which are acetylene glycol surfactants.

Ｒは分岐しても良い６〜１４の炭素鎖 ｋ：５〜１２

R may be branched 6-14 carbon chain k: 5-12

ｐ、ｑは０〜４０

p and q are 0 to 40

3. Polymer (resin) dispersion In the present invention, a dispersant may be further added in order to increase the affinity between the carbon black and the organic polar solvent. Although it will not specifically limit as a dispersing agent if the objective of this invention is met, For example, a polymeric dispersing agent is mentioned. Examples of the polymer dispersant include poly (N-vinyl-2-pyrrolidone), poly (N, N′-diethylacrylazide), poly (N-vinylformamide), poly (N-vinylacetamide), poly (N— Vinylphthalamide), poly (N-vinylsuccinamide), poly (N-vinylurea), poly (N-vinylpiperidone), poly (N-vinylcaprolactam), poly (N-vinyloxazoline) and the like. A single or a plurality of polymer dispersants can be added. In addition, dispersion stabilizers such as a polymer material, a surfactant, and an inorganic salt can be used within the scope of the object of the present invention.

4). Introduction of functional groups on the surface of grafting treatment Phenolic hydroxyl groups and carboxyl groups present on the surface of carbon black can be used as scaffolds for grafting reactions as they are. It can be used for grafting reactions of various polymers.

(A) Graft polymerization on the surface When radical polymerization of a vinyl monomer is performed in the presence of carbon black, a part of the produced polymer is grafted on the particle surface.

(B) Graft polymerization from the surface a. Radical polymerization i. Peroxide and peroxyester groups
ii. An azo group b. Cationic graft polymerization i. Asylium perchlorate group
ii. Chlormethyl group
iii. Benzylium perchlorate c. Anionic graft polymerization i. Potassium carboxylate
ii. Carbon black / BuLi composite (OLi group)
iii. Amino group

(C) Graft reaction with polymer on the surface a. Reaction of reactive carbon black with polymer b. Reaction of carbon black with reactive polymer i. Reaction with living polymer
ii. Reaction with terminal isocyanate group polymer

  The polymer (resin) dispersion type, graft type, and encapsulation type are preferable.

  Following the description of the carbon black grafted as described above, a polymer made of polyamic acid or polyimide will be described from polyimide.

  The polyimide is generally obtained by a condensation reaction between an aromatic polyvalent carboxylic acid anhydride or a derivative thereof and an aromatic diamine. However, because it has insoluble and infusible properties due to its rigid main chain structure, a polyamic acid (or polyamic acid to polyimide precursor) soluble in an organic solvent is first synthesized from an acid anhydride and an aromatic diamine. Molding is performed by various methods at a stage, and then polyimide is obtained by dehydration cyclization (imidization) by heating or a chemical method. (See Chemical Reaction Formula 1)

（式中Ａｒ^１、Ａｒ^２は少なくとも１つの炭素６員環を含む４価の芳香族残基を示す。）

(In the formula, Ar ¹ and Ar ² represent a tetravalent aromatic residue containing at least one carbon 6-membered ring.)

  For example, when an aromatic polycarboxylic acid anhydride is specifically mentioned, ethylenetetracarboxylic dianhydride, cyclopentanetetracarboxylic dianhydride, pyromellitic dianhydride, 3,3 ′, 4,4′- Benzophenone tetracarboxylic dianhydride, 2,2 ′, 3,3′-benzophenone tetracarboxylic dianhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, 2,2 ′, 3 , 3′-biphenyltetracarboxylic dianhydride, 2,2-bis (2,3-dicarboxyphenyl) propane dianhydride, bis (3,4-dicarboxyphenyl) ether dianhydride, bis (3 4-dicarboxyphenyl) sulfone dianhydride, 1,1-bis (2,3-dicarboxyphenyl) ethane dianhydride, bis (2,3-dicarboxyphenyl) methane dianhydride, (3,4-dicarboxyphenyl) methane dianhydride, 2,2-bis (3,4-dicarboxylphenyl) -1,1,1,3,3,3-hexafluoropropane dianhydride, 2 , 3,6,7-naphthalenetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride, 1,2 , 3,4-benzenetetracarboxylic dianhydride, 3,4,9,10-perylenetetracarboxylic dianhydride, 2,3,6,7-anthracenetetracarboxylic dianhydride, 1,2,7 , 8-phenanthrenetetracarboxylic dianhydride and the like. These may be used alone or in combination of two or more.

  Examples of the aromatic diamine that can be used as a mixture include m-phenylenediamine, o-phenylenediamine, p-phenylenediamine, m-aminobenzylamine, p-aminobenzylamine, 4,4′-diaminodiphenyl ether, 3 , 3′-diaminodiphenyl ether, 3,4′-diaminodiphenyl ether, bis (3-aminophenyl) sulfide, (3-aminophenyl) (4-aminophenyl) sulfide, bis (4-aminophenyl) sulfide, bis (3 -Aminophenyl) sulfide, (3-aminophenyl) (4-aminophenyl) sulfoxide, bis (3-aminophenyl) sulfone, (3-aminophenyl) (4-aminophenyl) sulfone, bis (4-aminophenyl) Sulfone, 3,3'-diaminoben Phenone, 3,4'-diaminobenzophenone, 4,4'-diaminobenzophenone, 3,3'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, bis [4- (3-amino Phenoxy) phenyl] methane, bis [4- (4-aminophenoxy) phenyl] methane, 1,1-bis [4- (3-aminophenoxy) phenyl] ethane, 1,1-bis [4- (4-amino) Phenoxy) phenyl] -ethane, 1,2-bis [4- (3-aminophenoxy) phenyl] ethane, 1,2-bis [4- (4-aminophenoxy) phenyl] ethane, 2,2-bis [4 -(3-aminophenoxy) phenyl] propane, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 2,2- [4- (3-aminophenoxy) phenyl] butane, 2,2-bis [3- (3-aminophenoxy) phenyl] -1,1,1,3,3,3-hexafluoropropane, 2,2 -Bis [4- (4-aminophenoxy) phenyl] -1,1,1,3,3,3-hexafluoropropane, 1,3-bis (3-aminophenoxy) benzene, 1,3-bis (4 -Aminophenoxy) benzene, 1,4-bis (3-aminophenoxy) benzene, 1,4-bis (4-aminophenoxy) benzene, 4,4'-bis (3-aminophenoxy) biphenyl, 4,4 ' -Bis (4-aminophenoxy) biphenyl, bis [4- (3-aminophenoxy) phenyl] ketone, bis [4- (4-aminophenoxy) phenyl] ketone, bis [4- (3-aminophenyl) Enoxy) phenyl] sulfide, bis [4- (4-aminophenoxy) phenyl] sulfide, bis [4- (3-aminophenoxy) phenyl] sulfoxide, bis [4- (4-aminophenoxy) phenyl] sulfoxide, bis [ 4- (3-aminophenoxy) phenyl] sulfone, bis [4- (4-aminophenoxy) phenyl] sulfone, bis [4- (3-aminophenoxy) phenyl] ether, bis [4- (4-aminophenoxy) Phenyl] ether, 1,4-bis [4- (3-aminophenoxy) benzoyl] benzene, 1,3-bis [4- (3-aminophenoxy) benzoyl] benzene, 4,4′-bis [3- ( 4-Aminophenoxy) benzoyl] diphenyl ether, 4,4′-bis [3- (3-aminophenoxy) Benzoyl] diphenyl ether, 4,4′-bis [4- (4-amino-α, α-dimethylbenzyl) phenoxy] benzophenone, 4,4′-bis [4- (4-amino-α, α-dimethylbenzyl) Phenoxy] diphenylsulfone, bis [4- {4- (4-aminophenoxy) phenoxy} phenyl] sulfone, 1,4-bis [4- (4-aminophenoxy) phenoxy] -α, α-dimethylbenzyl] benzene, Examples include 1,3-bis [4- (4-aminophenoxy) -α, α-dimethylbenzyl] benzene. These are used individually or in mixture of 2 or more types.

  A polyimide precursor (polyamic acid) can be obtained by polymerizing the aromatic polyvalent carboxylic acid anhydride component and the diamine component in a substantially equimolar organic polar solvent.

The manufacturing method of a polyamic acid is demonstrated concretely.
Examples of the organic polar solvent used in the polymerization reaction of polyamic acid include sulfoxide solvents such as dimethyl sulfoxide and diethyl sulfoxide, formamide solvents such as N, N-dimethylformamide and N, N-diethylformamide, and N, N. Acetamide solvents such as dimethylacetamide and N, N-diethylacetamide, pyrrolidone solvents such as N-methyl-2-pyrrolidone and N-vinyl-2-pyrrolidone, phenol, o-, m- or p-cresol, xylenol , Phenolic solvents such as halogenated phenol and catechol, ether solvents such as tetrahydrofuran, dioxane and dioxolane, alcohol solvents such as methanol, ethanol and butanol, cellosolve such as butyl cellosolve or hexamethyl Suhoruamido, .gamma.-butyrolactone, etc. can be mentioned, it is desirable to use these as the sole or mixed solvent. The solvent is not particularly limited as long as it dissolves polyamic acid, but N, N-dimethylacetamide and N-methyl-2-pyrrolidone are particularly preferable.

  First, 1 type or multiple types of diamine is melt | dissolved in said organic solvent, or is diffused in slurry form in inert gas atmosphere, such as argon and nitrogen. When at least one aromatic polycarboxylic acid anhydride or derivative thereof is added to this solution in a solid state, an organic solvent solution state or a slurry state, a ring-opening polyaddition reaction occurs with heat generation. The viscosity of the polymerization solution is rapidly increased to obtain a high molecular weight polyamic acid solution. The reaction temperature at this time is −20 ° C. to 100 ° C., preferably 60 ° C. or less. The reaction time is 30 minutes to 12 hours.

  In this reaction, contrary to the addition procedure, first, the aromatic polycarboxylic anhydride or derivative thereof is first dissolved or diffused in an organic solvent, and the solution or slurry of the diamine solid or organic solvent in this solution. May be added. Moreover, you may make it react simultaneously, and the mixing order of an acid dianhydride component and a diamine component is not limited.

  The above aromatic polycarboxylic acid anhydride or derivative thereof and the aromatic diamine component are weighed approximately equimolarly and dissolved in the organic polar solvent. In the present invention, the order of adding the aromatic tetracarboxylic dianhydride and the aromatic diamine is not limited. You may add simultaneously. Moreover, you may mix the organic polar solvent which melt | dissolved each.

  As described above, the polyamic acid composition according to the present invention is obtained by subjecting an aromatic polyvalent carboxylic acid anhydride or a derivative thereof and an aromatic diamine component to an equimolar amount by a polymerization reaction in an organic polar solvent. A polyamic acid solution in which the product is uniformly dissolved in the organic polar solvent is obtained.

Although these polyamic acid compositions can be easily synthesized as described above, it is easy to obtain a commercially available polyimide varnish in which the polyamic acid composition is dissolved in an organic solvent. Is possible.
These include, for example, Torenice (manufactured by Toray Industries, Inc.), U-Varnish (manufactured by Ube Industries, Ltd.), Rika Coat (manufactured by Nippon Nippon Chemical Co., Ltd.), Optmer (manufactured by JSR), SE812 (manufactured by Nissan Chemical Industries), CRC8000 (manufactured by Sumitomo Bakelite) ) And the like.

Various additives can be added to the polyamic acid composition as necessary in order to improve various properties.
If a specific example is given, various surface tension regulators may be added for the purpose of improving surface flatness and leveling property. These additives are generally known as leveling agents, antifoaming agents, and coating film defect improving agents. Of these, a particularly preferred additive is a silicone-based additive. Also, non-silicone additives such as glycerin higher fatty acid esters, higher alcohol borate esters, and fluorine-containing surfactants are preferably used. These addition amounts are 0.001 to 1% (composition weight).

As the reinforcing agent, for example, one or more glass fibers, carbon fibers, aromatic polyamide fibers, silicon carbide fibers, potassium titanate fibers, and glass beads can be added.
Further, for the purpose of improving the slipperiness, one or more solid lubricants such as molybdenum disulfide, graphite, boron nitride, lead monoxide, lead powder and the like can be added.

  In addition, one or more usual additives such as an antioxidant, a heat stabilizer, an ultraviolet absorber, a lubricant, and a colorant can be added within a range not detracting from the object of the present invention.

  Among the resistance control agents for adjusting the electrical resistance value of the polyimide of the present invention, examples of the electronic conductive resistance control agent include carbon black, graphite, or metals such as copper, tin, aluminum, indium, tin oxide, Examples thereof include metal oxide fine powders such as zinc oxide, titanium oxide, indium oxide, antimony oxide, bismuth oxide, tin oxide doped with antimony, and indium oxide doped with tin. In addition, as the ion conductive resistance control agent, tetraalkyl ammonium salt, trialkyl benzyl, ammonium salt, alkyl sulfonate, alkyl benzene sulfonate, alkyl sulfate, glycerol fatty acid ester, sorbitan fatty acid ester, polyoxyethylene alkyl amine, Polyoxyethylene fatty alcohol ester, alkyl betaine, lithium perchlorate and the like. However, the present invention is not limited to these exemplary compounds.

  Among these resistance control agents, carbon black can be preferably used for the polyimide of the present invention. However, carbon black has a high cohesion between particles, and its affinity with other resins and solvents is weaker than that, so it is also difficult to uniformly mix or disperse. Therefore, in order to solve this problem, carbon black is uniformly mixed or dispersed by coating the surface of carbon black with various surfactants and resins to enhance the affinity with a solid or liquid base. Many technologies have been studied.

  As a method for improving the dispersibility of carbon black, methods of treating carbon black with a coupling agent (JP-A 63-175869, JP-A 63-158666, British Patent Nos. 1583564, 1583411) and the like have been studied. These have the problem that the dispersion of the treated carbon black into the polymerizable monomer is still incomplete and the cost is high. A method using a monomer component in the presence of carbon black (Japanese Patent Laid-Open No. 64-6965, West German Patent No. 3102823) has also been proposed. The dispersion of carbon black in the polymerizable monomer was insufficient. Further, a method of treating carbon black by reacting with an organic compound by a polymer reaction using the surface functional group of carbon black (JP-A-1-284564, JP-A-5-241378) has been studied.

  Examples of organic compounds that can be used in the present invention include vinyl acetate, styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, p-ethylstyrene, p-methoxystyrene, p-bromostyrene, and p-chlorostyrene. , Styrene compounds such as sodium p-styrenesulfonate, acrylic acid ester compounds such as methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, glycidyl acrylate, methacryl Methacrylic acid ester compounds such as methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, n-butyl methacrylate, 2-ethylhexyl methacrylate, acrylonitrile, acrylamide, N-isopropylacrylamide, N-piperylacrylamide Of N- substituted acrylamide compounds, divinyl benzene, methylene bisacrylamide, 1,3-butane diol but dimethacrylate crosslinking monomer, etc. and the like, but is not limited thereto.

  The polyamic acid thus obtained can be imidized by a heating method or a chemical method, but the heating method is a method of converting to polyimide by heating to 200 to 350 ° C., which is simple and practical. The polyimide resin can be obtained by chemical method, but the method of imidizing by chemical method is to completely heat the polyamic acid with a dehydrating cyclization reagent such as a mixture of carboxylic acid anhydride and tertiary amine and then heat it. Compared to the method of heating by imidization, the method is complicated and costly, so that the method of heating is often used.

  In order to complete imidization by heating, the intrinsic performance of the polyimide cannot be exhibited unless it is heated above the glass transition temperature of the polyimide used essentially.

In order to evaluate the degree of imidization, the imidation rate is usually measured.
Various methods for measuring the imidization rate are known, and nuclear magnetic resonance spectroscopy is calculated from the integration ratio of 1H attributed to the amide group in the vicinity of 9 to 11 ppm and 1H attributed to the aromatic ring in the vicinity of 6 to 9 ppm. (NMR method), Fourier transform infrared spectroscopy (FT-IR method), a method for quantifying moisture accompanying imide ring closure, and carboxylic acid neutralization titration method, but most commonly, Fourier transform red External spectroscopy (FT-IR method) is used.
In the Fourier transform infrared spectroscopy (FT-IR method), the imidization rate can be defined as follows.
Imidation ratio = (number of moles of imide group in the firing stage) / (number of moles of imide group when theoretically imidized at 100%) × 100

This can be determined from the absorbance ratio of the characteristic absorption of the imide group of IR. Typical examples are:
Absorbance ratio of 725 cm ⁻¹ (immobilization vibration band of imide ring C═O group) which is one of characteristic absorptions of imide and 1,015 cm ⁻¹ of characteristic absorption of benzene ring 1 which is one of characteristic absorptions of imide , 380 cm ⁻¹ (inflection vibration band of imide ring C—N group) and benzene ring characteristic absorption 1,500 cm ⁻¹ Absorbance ratio 1,720 cm ⁻¹ (imide ring C) which is one of the characteristic absorptions of imide = deformation vibration band O group) as one of the characteristic absorption of the absorbance ratio imide with characteristic absorption 1,500Cm ^-1 benzene ring 1,720 cm ^-1 and an amide group characteristic absorption 1,670cm ^-1 ( The imidization ratio can be evaluated using an absorbance ratio or the like between the amide group N—H bending vibration and the C—N stretching vibration).
Further, if it is confirmed that the amide group-derived multiple absorption band from 3000 to 3300 cm ⁻¹ disappears, the reliability of imidization completion is further increased.

  For the constituent material of the intermediate transfer member of the present invention, modified polyimide or polyamideimide represented by fluorine modification or silicone modification can also be used.

[Description of fluorine-modified polyimide]
The polyimide is generally obtained by a condensation reaction between an aromatic polyvalent carboxylic acid anhydride or a derivative thereof and an aromatic diamine. (See chemical reaction formula 2)

本発明のポリイミドは化学反応式２に示したポリイミド繰り返し単位中のＡｒ^１若しくはＡｒ^２に、−ＣＦ_３基を少なくとも一つ含有することを特徴としている。ポリイミド中に−ＣＦ_３基が導入されたことにより、ポリイミドの優れた機械特性を維持しフッ素樹脂並の離型性を得ることが出来る。ポリイミド繰り返し単位中に、−ＣＦ_３基を導入するには原料となる芳香族多価カルボン酸無水物中のＡｒ^１若しくは芳香族ジアミン中のＡｒ^２の少なくともどちらか一方に−ＣＦ_３基を有していることが必要である。

The polyimide of the present invention is characterized by containing at least one —CF ₃ group in Ar ¹ or Ar ² in the polyimide repeating unit shown in Chemical Reaction Formula 2. By introducing the -CF ₃ group into the polyimide, the excellent mechanical properties of the polyimide can be maintained, and a mold release property comparable to that of a fluororesin can be obtained. In order to introduce a —CF ₃ group into the polyimide repeating unit, at least ^one of Ar ¹ in the aromatic polyvalent carboxylic acid anhydride or Ar ² in the aromatic diamine as a raw material has —CF ₃ group. It is necessary to do.

For example, when Ar ¹ in an aromatic polycarboxylic acid anhydride is specifically mentioned, (trifluoromethyl) pyromellitic acid, bis (trifluoromethyl) pyromellitic acid, 5,5′-bis (trifluoromethyl) −3,3 ′, 4,4′-tetracarboxybiphenyl, 2,2 ′, 5,5′-tetrakis (trifluoromethyl) -3,3 ′, 4,4′-tetracarboxybiphenyl, 5,5 ′ -Bis (trifluoromethyl) -3,3 ', 4,4'-tetracarboxydiphenyl ether, 5,5'-bis (trifluoromethyl) -3,3', 4,4'-tetracarboxybenzophenone, bis [ (Trifluoromethyl) dicarboxyphenoxy] benzene, bis [(trifluoromethyl) dicarboxyphenoxy] biphenyl, bis [(trifluoromethyl) dicarboxy Enoxy] (trifluoromethyl) benzene, bis [(trifluoromethyl) dicarboxyphenoxy] bis (trifluoromethyl) biphenyl, bis [(trifluoromethyl) dicarboxyphenoxy] diphenyl ether, bis (dicarboxyphenoxy) (trifluoro Methyl) benzene, bis (dicarboxyphenoxy) bis (trifluoromethyl) benzene, bis (dicarboxyphenoxy) tetrakis (trifluoromethyl) benzene, bis (dicarboxyphenoxy) bis (trifluoromethyl) biphenyl, bis (dicarboxy) Phenoxy) tetrakis (trifluoromethyl) biphenyl, 2,2-bis (3,4-dicarboxyphenyl) hexafluoropropane, 2,2-bis [4- (3,4-dicarboxyphenoxy) Phenyl] hexafluoropropane and the like.

Next, typical examples of Ar ² in the aromatic diamine include diaminobenzotrifluoride, bis (trifluoromethyl) phenylenediamine, diaminotetra (trifluoromethyl) benzene, diamino (pentafluoroethyl) benzene, 2, 2'-bis (trifluoromethyl) benzidine, 3,3'-bis (trifluoromethyl) benzidine, 2,2'-bis (trifluoromethyl) -4,4'-diaminodiphenyl ether, 3,3'-bis (Trifluoromethyl) -4,4′-diaminodiphenyl ether, 3,3 ′, 5,5′-tetrakis (trifluoromethyl) -4,4′-diaminodiphenyl ether, 3,3′-bis (trifluoromethyl) -4,4'-diaminobenzophenone, bis (aminophenoxy) di (trifluoromethyl) ben Bis (aminophenoxy) tetrakis (trifluoromethyl) benzene, bis [(trifluoromethyl) aminophenoxy] benzene, bis [(trifluoromethyl) aminophenoxy] biphenyl, bis {[(trifluoromethyl) aminophenoxy] Phenyl} hexafluoropropane, 2,2′-bistrifluoromethyl-4,4′-diaminobiphenyl, 2,2-bis {4- (p-aminophenoxy) phenyl} hexafluoropropane, 2,2-bis {4 -(M-aminophenoxy) phenyl} hexafluoropropane, 2,2-bis {4- (o-aminophenoxy) phenyl} hexafluoropropane, 2- {4- (p-aminophenoxy) phenyl} -2- { 4- (m-aminophenoxy) phenyl} hexafluoropropane, 2- {4- (m-aminophenoxy) phenyl} -2- {4- (o-aminophenoxy) phenyl} hexafluoropropane, 2- {4- (o-aminophenoxy) phenyl} -2- {4- (p -Aminophenoxy) phenyl} hexafluoropropane and the like.

  The fluorine-containing polyimide used in the intermediate transfer member of the present invention uses at least the above-described fluorine-containing aromatic polyvalent carboxylic acid anhydride or derivative thereof and an aromatic diamine as raw materials, but does not contain fluorine. Carboxylic anhydride or a derivative thereof and an aromatic diamine can also be mixed and used.

  For example, examples of the most typical tetracarboxylic dianhydrides as aromatic polycarboxylic anhydrides include ethylene tetracarboxylic dianhydride, cyclopentane tetracarboxylic dianhydride, pyromellitic dianhydride, 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride, 2,2 ′, 3,3′-benzophenone tetracarboxylic dianhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic acid Dianhydride, 2,2 ′, 3,3′-biphenyltetracarboxylic dianhydride, 2,2-bis (2,3-dicarboxyphenyl) propane dianhydride, bis (3,4-dicarboxyphenyl) ) Ether dianhydride, bis (3,4-dicarboxyphenyl) sulfone dianhydride, 1,1-bis (2,3-dicarboxyphenyl) ethane dianhydride, bis (2,3-di Ruboxyphenyl) methane dianhydride, bis (3,4-dicarboxyphenyl) methane dianhydride, 2,2-bis (3,4-dicarboxylphenyl) -1,1,1,3,3,3 -Hexafluoropropane dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 1,2,5,6-naphthalenetetra Carboxylic dianhydride, 1,2,3,4-benzenetetracarboxylic dianhydride, 3,4,9,10-perylenetetracarboxylic dianhydride, 2,3,6,7-anthracenetetracarboxylic acid A dianhydride, 1,2,7,8-phenanthrenetetracarboxylic dianhydride etc. are mentioned. These may be used alone or in combination of two or more.

  Examples of the aromatic diamine that can be used as a mixture include m-phenylenediamine, o-phenylenediamine, p-phenylenediamine, m-aminobenzylamine, p-aminobenzylamine, 4,4′-diaminodiphenyl ether, 3 , 3′-diaminodiphenyl ether, 3,4′-diaminodiphenyl ether, bis (3-aminophenyl) sulfide, (3-aminophenyl) (4-aminophenyl) sulfide, bis (4-aminophenyl) sulfide, bis (3 -Aminophenyl) sulfide, (3-aminophenyl) (4-aminophenyl) sulfoxide, bis (3-aminophenyl) sulfone, (3-aminophenyl) (4-aminophenyl) sulfone, bis (4-aminophenyl) Sulfone, 3,3'-diaminoben Phenone, 3,4'-diaminobenzophenone, 4,4'-diaminobenzophenone, 3,3'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, bis [4- (3-amino Phenoxy) phenyl] methane, bis [4- (4-aminophenoxy) phenyl] methane, 1,1-bis [4- (3-aminophenoxy) phenyl] ethane, 1,1-bis [4- (4-amino) Phenoxy) phenyl] -ethane, 1,2-bis [4- (3-aminophenoxy) phenyl] ethane, 1,2-bis [4- (4-aminophenoxy) phenyl] ethane, 2,2-bis [4 -(3-aminophenoxy) phenyl] propane, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 2,2- [4- (3-aminophenoxy) phenyl] butane, 2,2-bis [3- (3-aminophenoxy) phenyl] -1,1,1,3,3,3-hexafluoropropane, 2,2 -Bis [4- (4-aminophenoxy) phenyl] -1,1,1,3,3,3-hexafluoropropane, 1,3-bis (3-aminophenoxy) benzene, 1,3-bis (4 -Aminophenoxy) benzene, 1,4-bis (3-aminophenoxy) benzene, 1,4-bis (4-aminophenoxy) benzene, 4,4'-bis (3-aminophenoxy) biphenyl, 4,4 ' -Bis (4-aminophenoxy) biphenyl, bis [4- (3-aminophenoxy) phenyl] ketone, bis [4- (4-aminophenoxy) phenyl] ketone, bis [4- (3-aminophenyl) Enoxy) phenyl] sulfide, bis [4- (4-aminophenoxy) phenyl] sulfide, bis [4- (3-aminophenoxy) phenyl] sulfoxide, bis [4- (4-aminophenoxy) phenyl] sulfoxide, bis [ 4- (3-aminophenoxy) phenyl] sulfone, bis [4- (4-aminophenoxy) phenyl] sulfone, bis [4- (3-aminophenoxy) phenyl] ether, bis [4- (4-aminophenoxy) Phenyl] ether, 1,4-bis [4- (3-aminophenoxy) benzoyl] benzene, 1,3-bis [4- (3-aminophenoxy) benzoyl] benzene, 4,4′-bis [3- ( 4-Aminophenoxy) benzoyl] diphenyl ether, 4,4′-bis [3- (3-aminophenoxy) Benzoyl] diphenyl ether, 4,4′-bis [4- (4-amino-α, α-dimethylbenzyl) phenoxy] benzophenone, 4,4′-bis [4- (4-amino-α, α-dimethylbenzyl) Phenoxy] diphenylsulfone, bis [4- {4- (4-aminophenoxy) phenoxy} phenyl] sulfone, 1,4-bis [4- (4-aminophenoxy) phenoxy} -α, α-dimethylbenzyl] benzene, Examples include 1,3-bis [4- (4-aminophenoxy) -α, α-dimethylbenzyl] benzene. These are used individually or in mixture of 2 or more types.

  The fluorine-containing polyimide used on at least the surface of the intermediate transfer member of the present invention can be produced by a known method using the compounds listed above. For example, these are dissolved in an aprotic polar solvent such as N-methyl-2-pyrrolidone, dimethylformamide, dimethylacetamide, dimethylsulfoxide, dimethylimidazoline, hexamethylphosphoramide, and the mixture is heated and stirred at room temperature or a temperature of 40 to 80 ° C. By doing so, the polyamic acid which is a precursor of a polyimide can be obtained.

  Polyamide acid is used for amide solvents such as NMP (N-methylpyrrolidone), DMF (N, N-dimethylformamide), DMAc (N, N-dimethylacetamide), polyamic acids such as γ-butyrolactone, and polyimide resins. It can be used as a polyimide varnish having a necessary solid content and viscosity by dissolving in a solvent such as dipole solvent, ethyl lactate, methoxymethyl propionate, propylene glycol monomethyl ether acetate and the like.

  From the viewpoint of better balance of varnish viscosity and ease of use, the amount of solvent added is in the range of 250 to 2000 parts by weight (solid content concentration of about 5 to 30% by weight) with respect to 100 parts by weight of fluorine-containing polyimide. It is preferable to do this. Using this varnish, if necessary, prepare a film-forming solution by dissolving it in a predetermined organic solvent, and cast it on a metal plate or glass plate by a suitable casting means such as a doctor blade or a doctor knife, A film of fluorine-containing polyimide can be obtained by imidization by heating to a predetermined temperature. In order to fully imidize, it is good to heat at 100-400 degreeC, Preferably it is 200-350 degreeC.

（式中、Ｘは４価の芳香族環若しくは脂肪族環基、Ｒ_１、Ｒ_６は２価の有機基、Ｒ_２〜Ｒ_５はアルケニル基、アルキル基、フェニル基、又は置換フェニル基を示し、ｎは５以上の整数を表す） (Description of Si-modified PI)
The polyimide-modified silicone resin used on at least the surface of the intermediate transfer member of the present invention can be represented by the following general formula (8).

(Wherein X represents a tetravalent aromatic ring or aliphatic ring group, R ₁ and R ₆ represent a divalent organic group, R _{2 to} R ₅ represent an alkenyl group, an alkyl group, a phenyl group, or a substituted phenyl group. N represents an integer of 5 or more)

  Generally, polyimide is known as a high-strength and rigid resin. However, the introduction of a siloxane structure into the main chain gives flexibility and further improves the releasability. Accordingly, it is possible to satisfy the wear resistance and toner releasability of the intermediate transfer member by including the above material on at least the surface.

The structure of the polyimide modified silicone resin, R ₂ to R ₅ is preferably a methyl group. The side chain of the siloxane structure can reduce the surface characteristics, especially the friction coefficient. In the case of an intermediate transfer member, there are many contact members as described above. Is preferably in the range of 0.2 to 0.4. In the polyimide-modified silicone resin, this can be achieved by using a dimethylsiloxane monomer component in which methyl groups are introduced into R _{2 to} R ₅ as siloxane units.

  Such a polyimide-modified silicone resin can be produced using a mixture of siloxane diamine, aromatic diamine, and tetracarboxylic dianhydride as a raw material.

As a siloxane diamine compound,
_{H 2 N-R 1 - (} - SiR 2 R 3 -O-) n-SiR 4 R 5 -R 6 -NH 2

(R ₁ and R ₆ represent a divalent organic group, R _{2 to} R ₅ represent an alkyl group, a phenyl group, or a substituted phenyl group, and n represents an integer of 5 to 50)
Are represented by the general formula, specifically, bis (3-aminopropyl) tetramethyldisiloxane, bis (10-aminodecamethylene) tetramethyldisiloxane, dimethylsiloxane tetramer having aminopropyl end groups, 8 And bis (3-aminophenoxymethyl) tetramethyldisiloxane.

  The aromatic diamine used in the polyimide-modified silicone resin of the present invention is, for example, a biphenyl diamine compound, a diphenyl ether diamine compound, a benzophenone diamine compound, a diphenylsulfone diamine compound, a diphenylmethane diamine compound, or 2,2-bis (phenyl). Diphenylalkane diamine compounds such as propane, 2,2-bis (phenyl) hexafluoropropane diamine compounds, diphenylene sulfone diamine compounds, di (phenoxy) benzene diamine compounds, di (phenyl) benzene diamine compounds, Two or more aromatic rings (such as benzene rings) such as di (phenoxyphenyl) hexafluoropropane-based diamine compounds and bis (phenoxyphenyl) propane-based diamine compounds, especially Can be mentioned aromatic diamine containing mainly aromatic diamine compounds having 5 carbon atoms, they alone, or can be used as a mixture.

  Examples of the aromatic diamine include diphenyl ether diamine compounds such as 1,4-diaminodiphenyl ether and 1,3-diaminodiphenyl ether, 1,3-di (4-aminophenoxy) benzene, 1,4-bis (4- Di (phenoxy) benzene-based diamine compounds such as aminophenoxy) benzene, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 2,2-bis [4- (3-aminophenoxy) phenyl] propane And bis (phenoxyphenyl) propane-based diamine-based compounds.

  Next, specific examples of the tetracarboxylic dianhydride used in the present invention include pyromellitic dianhydride, 3,3 ′, 4,4′-diphenylsulfone tetracarboxylic dianhydride as the tetracarboxylic dianhydride. 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, 2,3 ′, 3,4′-biphenyltetracarboxylic Acid dianhydride, bis (3,4-dicarboxyphenyl) ether dianhydride, 4,4′-bis (3,4-dicarboxyphenoxy) diphenylsulfone dianhydride, ethylene glycol bistrimellitate dianhydride, 2,2-bis [4- (3,4-dicarboxyphenoxy) phenyl] propane dianhydride, 4,4′-diphenylsulfonetetracarboxylic dianhydride, 3,3 , 4,4'-biphenyltetracarboxylic dianhydride, 2,3 ', 3,4'-biphenyltetracarboxylic dianhydride, and the like.

  The polyimide-modified silicone resin used in the present invention can be produced by a known method using the compounds listed above. For example, these are heated in an organic solvent in the presence of a catalyst such as tributylamine, triethylamine, or triphenyl phosphite as necessary, and a polyimide is obtained directly. Tetracarboxylic dianhydride and diamine are reacted in an organic solvent. After obtaining polyamic acid which is a precursor of polyimide, a method of obtaining polyimide by adding a dehydration catalyst such as p-toluenesulfonic acid as necessary and imidizing by heating, or this polyamic acid, acetic anhydride Dehydrating ring closure agents such as acid anhydrides such as propionic anhydride and benzoic anhydride, carbodiimide compounds such as dicyclohexylcarbodiimide, and a method of chemically ring-closing by adding a ring closure catalyst such as pyridine, isoquinoline, imidazole, triethylamine, etc. There is.

The polyimide-modified silicone resin of the present invention can be used by appropriately adding a crosslinking agent capable of crosslinking the silicone polymer. As a crosslinking agent, it does not specifically limit and a conventionally well-known thing is used. For example, peroxides such as benzoyl peroxide, 2,4-dichlorobenzoyl peroxide, dicumyl peroxide, t-butylcumyl peroxide, 1,1-bis (t-butylperoxy) 3,3,5-trimethylcyclohexane A crosslinking agent is mentioned. These may be used alone or in combination of two or more. Of these, benzoyl peroxide is preferably used from the viewpoint of crosslinkability.
The addition amount of the crosslinking agent is preferably 0.5 to 10 parts by weight with respect to 100 parts by weight of the polyimide-modified silicone resin. When the addition amount is less than 0.5 parts by weight, the crosslinkability is not sufficient, and when it exceeds 10 parts by weight, the excess crosslinking agent adversely affects the releasability of the intermediate transfer member.

[Polyamideimide]
Polyamideimide is a resin having a rigid imide group and an amide group imparting flexibility in the molecular skeleton, and a general polyamideimide used in the present invention can be used.

As a method of synthesizing polyamideimide resin,
1. Isocyanate process: a process for producing a trivalent carboxylic acid derivative having an acid anhydride group and an aromatic isocyanate in a solvent (for example, Japanese Examined Patent Publication No. 44-19274)
2. Acid chloride method to trivalent carboxylic acid derivative halide having an acid anhydride group, most typically a method of producing from a derivative chloride and a diamine in a solvent (for example, Japanese Examined Patent Publication No. Sho 42-15637)
Is used. Each manufacturing method will be described.

（両式中Ｒは水素、炭素数１〜１０のアルキル基又はフェニル基を示し、Ｙは−ＣＨ_２−、−ＣＯ−、−ＳＯ_２−又は−Ｏ−を示す） 1. Isocyanate method As the derivative of the trivalent carboxylic acid having an acid anhydride group, for example, compounds represented by the general formulas (9) and (10) can be used.

(In both formulas, R represents hydrogen, an alkyl group having 1 to 10 carbon atoms, or a phenyl group, and Y represents —CH ₂ —, —CO—, —SO ₂ —, or —O—).

Any of these can be used, but most typically trimellitic anhydride is used.
These trivalent carboxylic acid derivatives having an acid anhydride group may be used alone or in combination depending on the purpose.

  Next, examples of the aromatic polyisocyanate used in the polyamideimide of the present invention include 4,4′-diphenylmethane diisocyanate, tolylene diisocyanate, xylylene diisocyanate, 4,4′-diphenyl ether diisocyanate, and 4,4 ′-[2 , 2-bis (4-phenoxyphenyl) propane] diisocyanate, biphenyl-4,4′-diisocyanate, biphenyl-3,3′-diisocyanate, biphenyl-3,4′-diisocyanate, 3,3′-dimethylbiphenyl-4 , 4′-diisocyanate, 2,2′-dimethylbiphenyl-4,4′-diisocyanate, 3,3′-diethylbiphenyl-4,4′-diisocyanate, 2,2′-diethylbiphenyl-4,4′-diisocyanate , 3, 3'- Methoxy-biphenyl-4,4'-diisocyanate, 2,2'-dimethoxy-biphenyl-4,4'-diisocyanate, naphthalene-1,5-diisocyanate, it can be used 2,6-diisocyanate. These can be used alone or in combination.

  If necessary, as this part, hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, isophorone diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, transcyclohexane-1,4-diisocyanate, hydrogenated m-xyl Aliphatic isocyanates such as range isocyanate and lysine diisocyanate, alicyclic isocyanates, and trifunctional or higher polyisocyanates can also be used.

  In this method, polyamideimide is produced while generating carbon dioxide gas without passing through a polyamic acid. An example using trimellitic anhydride and aromatic isocyanate is shown in Chemical Reaction Formula 3. (In the formula, Ar represents an aromatic group.)

2. Acid chloride method As the derivative halide of a trivalent carboxylic acid having an acid anhydride group, for example, compounds represented by the general formulas (12) and (13) can be used.

（両式中Ｘはハロゲン元素を示し、Ｙは−ＣＨ_２−、−ＣＯ−、−ＳＯ_２−又は−Ｏ−を示す）

(In both formulas, X represents a halogen element, and Y represents —CH ₂ —, —CO—, —SO ₂ — or —O—).

  The halogen element is preferably chloride, and specific examples include terephthalic acid, isophthalic acid, 4,4′-biphenyldicarboxylic acid, 4,4′-biphenyletherdicarboxylic acid, 4,4′-biphenylsulfonedicarboxylic acid, 4′-benzophenone dicarboxylic acid, pyromellitic acid, trimellitic acid, 3,3 ′, 4,4′-benzophenone tetracarboxylic acid, 3,3 ′, 4,4′-biphenylsulfone tetracarboxylic acid, 3,3 Polyvalents such as', 4,4'-biphenyltetracarboxylic acid, adipic acid, sebacic acid, maleic acid, fumaric acid, dimer acid, stilbene dicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid Examples include acid chlorides of carboxylic acids.

  The diamine is not particularly limited, and any of an aromatic diamine, an aliphatic diamine, and an alicyclic diamine is used, and an aromatic diamine is preferably used.

  Aromatic diamines include m-phenylenediamine, p-phenylenediamine, oxydianiline, methylenediamine, hexafluoroisopropylidenediamine, diamino-m-xylylene, diamino-p-xylylene, 1,4-naphthalenediamine, 1, 5-naphthalenediamine, 2,6-naphthalenediamine, 2,7-naphthalenediamine, 2,2′-bis- (4-aminophenyl) propane, 2,2′-bis- (4-aminophenyl) hexafluoro Propane, 4,4'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl sulfone, 3,3'-diaminodiphenyl ether, 3,4-diaminobiphenyl, 4,4'-diaminobenzophenone 3,4-diaminodiphenyl ether , Isopropylidenedianiline, 3,3′-diaminobenzophenone, o-tolidine, 2,4-tolylenediamine, 1,3-bis- (3-aminophenoxy) benzene, 1,4-bis- (4- Aminophenoxy) benzene, 1,3-bis- (4-aminophenoxy) benzene, 2,2-bis- [4- (4-aminophenoxy) phenyl] propane, bis- [4- (4-aminophenoxy) phenyl ] Sulfone, bis- [4- (3-aminophenoxy) phenyl] sulfone, 4,4′-bis- (4-aminophenoxy) biphenyl, 2,2′-bis- [4- (4-aminophenoxy) phenyl Hexafluoropropane, 4,4′-diaminodiphenyl sulfide, 3,3′-diaminodiphenyl sulfide and the like.

  Also, siloxane compounds having amino groups at both ends as diamines, such as 1,3-bis (3-aminopropyl) -1,1,3,3-tetramethyldisiloxane, α, ω-bis (3-amino Propyl) polydimethylsiloxane, 1,3-bis (3-aminophenoxymethyl) -1,1,3,3-tetramethyldisiloxane, α, ω-bis (3-aminophenoxymethyl) polydimethylsiloxane, 1, 3, -bis (2- (3-aminophenoxy) ethyl) -1,1,3,3-tetramethyldisiloxane, α, ω-bis (2- (3-aminophenoxy) ethyl) polydimethylsiloxane, , 3-Bis (3- (3-aminophenoxy) propyl) -1,1,3,3-tetramethyldisiloxane, α, ω-bis (3- (3-aminophenoxy) propyl ) Silicone-modified polyamideimide can be obtained by using polydimethylsiloxane or the like.

  In order to obtain the polyamideimide resin of the present invention by the acid chloride method, the trivalent carboxylic acid derivative halide having an acid anhydride group and the diamine are dissolved in an organic polar solvent, as in the production of the polyimide resin. The reaction is carried out at a low temperature (0 to 30 ° C.) to form a polyamic acid (polyamic acid).

  Examples of the organic polar solvent used include sulfoxide solvents such as dimethyl sulfoxide and diethyl sulfoxide, formamide solvents such as N, N-dimethylformamide and N, N-diethylformamide, N, N-dimethylacetamide, N, Acetamide solvents such as N-diethylacetamide, N-methyl-2-pyrrolidone, pyrrolidone solvents such as N-vinyl-2-pyrrolidone, phenol, o-, m- or p-cresol, xylenol, halogenated phenol, catechol Phenol solvents such as tetrahydrofuran, ether solvents such as tetrahydrofuran, dioxane and dioxolane, alcohol solvents such as methanol, ethanol and butanol, cellosolves such as butyl cellosolve or hexamethylphosphoramide, γ-butyro Etc. can be mentioned lactone, to use them as sole or mixed solvent desirable. The solvent is not particularly limited as long as it dissolves polyamic acid, but N, N-dimethylacetamide and N-methyl-2-pyrrolidone are particularly preferable.

  Thereafter, the polyamic acid is imidized to form polyamideimide. Examples of the imidization method include a method of dehydrating and cyclizing by heating and a method of chemically cyclizing using a dehydrating and ring-closing catalyst. When dehydrating and ring-closing by heating, the reaction temperature is 150 to 400 ° C., preferably 180 to 350 ° C., and the time is 30 seconds to 10 hours, preferably 5 minutes to 5 hours. When a dehydration ring closure catalyst is used, the reaction temperature is 0 to 180 ° C., preferably 10 to 80 ° C., and the reaction time is several tens of minutes to several days, preferably 2 to 12 hours. Examples of the dehydration ring closure catalyst include acid anhydrides such as acetic acid, propionic acid, butyric acid, and benzoic acid.

(Film forming liquid composition)
The present invention relates to a polymer or block-type polymer comprising an acidic carbon black having a volatile content in the range of 3.5 to 8.0% by weight and a polyamic acid or polyimide having a weight average molecular weight in the range of 3000 to 300,000. It contains carbon black and binder resin dispersed in a water-soluble organic solvent using a coalescent as a dispersant, and the content ratio of the acidic carbon black to the dispersant is in the range of 3: 1 to 10: 1 by weight. Is a film forming liquid composition for forming an intermediate transfer member.

In the film-forming liquid composition for forming an intermediate transfer member using carbon black as a resistance control agent, the present inventors have made extensive studies on a film-forming liquid composition that obtains stable resistance uniformity.
(1) Carbon black that can be dispersed and / or dissolved in a water-soluble organic solvent without a dispersant, and has a hydrophilic functional group amount / specific surface area in the range of 5 to 30 μmol / m ^2. ,
(2) Surface-modified carbon black obtained by oxidizing acidic carbon black,
(3) Surface modified carbon black obtained by oxidizing channel carbon black,
(4) Surface-modified carbon black obtained by oxidizing carbon black with hypohalous acid or a salt thereof,
(5) The surface-modified carbon black has a hydrophilic functional group of 1.5 mmol / g or more,
As a result, it was found that a film-forming liquid composition having high resistance uniformity and good dispersion stability can be produced, and the present invention has been achieved.

The carbon black dispersion according to the present invention comprises at least a water-soluble organic solvent and a surface-modified carbon black. The surface-modified carbon black can be dispersed and / or dissolved in a water-soluble organic solvent without a dispersant. It is possible and the value of the hydrophilic functional group amount / specific surface area is in the range of 5 to 30 μmol / m ² .

  The surface-modified carbon black in the present invention is obtained by modifying the surface of the carbon black by introducing a large amount of hydrophilic functional groups into the carbon black, thereby maintaining the hydrophilicity of the carbon black itself. For this reason, the surface-modified carbon black has a particle size (preferably the minimum particle size) in which the carbon black can be dispersed, as if the water-soluble dye is dissolved in water as a single molecule. It is thought to disperse in water without. Such surface-modified carbon black is usually referred to as self-dispersing carbon black. In the present invention, such carbon black is used.

  By using the carbon black dispersion according to the present invention, an ink composition can be prepared without a dispersant. As a result, even if the concentration of carbon black is increased, the viscosity of the film forming liquid composition does not change greatly, and a high concentration of carbon black can be stably dispersed in the film forming liquid composition. Therefore, high resistance uniformity can be realized. Furthermore, the carbon black dispersion according to the present invention is a carbon black that does not satisfy the requirements according to the present invention by using carbon black having a specific hydrophilic functional group amount / specific surface area value and having a specific surface modification. As compared with the above, there is an advantage that the dispersibility can be improved.

In the present invention, the surface-modified carbon black refers to a carboxyl group, a carbonyl group, a hydroxyl group, a sulfone group, a phosphoric acid group, and a hydrophilic functional group such as a quaternary ammonium salt and a salt thereof directly or an alkyl group, an alkyl group. It means what is bonded to the surface of carbon black as a pigment through an ether group or an aryl group.
In the present invention, “dispersed and / or dissolved in water without a dispersant” means that carbon black is stably present in a particle size (preferably the minimum particle size) that can be dispersed in water without using a dispersant. Means the state. The dispersible particle diameter means a particle diameter that does not further reduce the particle even when the dispersion time is increased.

The surface-modified carbon black contained in the carbon black dispersion according to the present invention has a value obtained by dividing the amount of hydrophilic functional groups (μmol / g) by the specific surface area (m ² / g) of carbon black, that is, the amount of hydrophilic functional groups. / The value of the specific surface area is in the range of 5 to 30 μmol / m ² , preferably in the range of 7.5 to 15 μmol / m ² . Moreover, when the said carbon black dispersion liquid is used as a film-forming liquid composition, it is especially preferable that said value is in the range of 7.5 to 15 μmol / m ² . An ink composition using a carbon black dispersion liquid containing surface-modified carbon black having a value in this range can achieve higher resistance uniformity and better dispersion stability and storage stability.

  Here, the amount of hydrophilic functional group is determined by quantifying the amount of a hydrophilic functional group such as a carboxyl group, a carbonyl group, or a hydroxyl group, and is generally a vacuum pyrolysis gas method for measuring the volatile content of carbon black. Can be obtained. The vacuum pyrolysis gas method is a method described in Journal of Chemical Society of Japan, Vol. 88, No. 3 (1967), pages 69 to 74, and specifically, the following method.

  That is, the amount of the hydrophilic functional group in the surface-modified carbon black is measured by using a vacuum thermal analyzer having an electric furnace and a gas chromatograph as shown in FIG. Here, the gas chromatograph is of an intermediate cell type, the column is packed with silica gel in the first stage, the molecular sieve 13X in the second stage, and argon is used as the carrier gas. 0.1 to 0.5 g of carbon black as a sample is weighed and placed in a quartz tube, loaded into an electric furnace, and evacuated at 120 ° C. for 2 hours to remove adsorbed moisture and air as a pretreatment. Next, the temperature controller of the electric furnace is set to 200 ° C. and kept for 1 hour, and the generated gas is collected during that time and analyzed by a gas chromatograph. Immediately after that, the generated gas for 1 hour set at 300 ° C. was collected and analyzed, and thereafter, each one at 400 ° C., 500 ° C., 600 ° C., 700 ° C., 800 ° C., 900 ° C., and 1000 ° C. Collect the evolved gas over time and analyze its composition. The generated gas is mainly carbon monoxide and carbon dioxide. The amount of hydrophilic functional groups in the surface-modified carbon black is calculated from the composition data in the generated gas under each temperature condition obtained in this way.

  In the present invention, the amount of hydrophilic functional groups in the surface-modified carbon black is preferably 1.5 mmol / g or more. Such a value of the hydrophilic functional group amount is advantageous in that the carbon black dispersion liquid can ensure good dispersion stability and storage stability.

In the present invention, the specific surface area (m ² / g) is obtained by adsorbing gas on carbon black and calculating the surface area of carbon black from the amount of adsorption and the molecular cross section in the adsorbed state (known as nitrogen adsorption method). ). In the present invention, the specific surface area of the carbon black includes the specific surface area based on the surface-modified carbon black and the carbon black of any aspect of the surface-unmodified carbon black used as the raw material. Shall. In addition, the specific surface area of the surface-modified carbon black and the specific surface area of the unmodified carbon black are substantially the same, and are estimated to show substantially the same value.

  As the carbon black used in the present invention, any carbon black can be used as long as it is generally available. Specifically, when classified according to pH, acidic carbon black, neutral carbon black, or Any of the basic carbon blacks can be used. Further, when classified according to the production method, any of furnace carbon black, channel carbon black, acetylene carbon black, or thermal carbon black can be used.

  According to a preferred embodiment of the present invention, the surface-modified carbon black is preferably obtained by oxidizing acidic carbon black in the classification of the carbon black. Usually, when carbon black is oxidized, the step of pulverizing the raw material carbon black and the step of oxidizing the pulverized carbon black are performed continuously or almost simultaneously. At this time, the oxidizing agent is used in both steps. Necessary. Since acidic carbon black has many hydrophilic groups such as carboxyl groups on its surface, it is easily compatible with aqueous media and pulverized easily. Therefore, an oxidant can be eliminated during pulverization, so that the amount of oxidant used for the oxidation treatment can be reduced.

As a result, in the present invention, the hydrophilic functional group amount / specific surface area value of the surface-modified carbon black can be easily controlled within a range of, for example, 5 to 30 μmol / m ² . Further, according to the present invention, since the amount of the oxidizing agent can be reduced, the target carbon black dispersion can be produced at a relatively low cost.

  Specific examples of acidic carbon black suitably used in the present invention include # 50, MA8, MA100 (manufactured by Mitsubishi Chemical Corporation), etc .; Color Black FW1, Color Black FW18, Color Black S170, Special Black 250 ( As mentioned above, Raven 3500, Raven 1080, Raven C (above Colombian Carbon), etc .; and Monarch 1300, Regal 400R (Cabot), etc.

  According to a further preferred aspect of the present invention, the surface-modified carbon black is preferably obtained by oxidizing channel carbon black in the classification of the acidic carbon black. By using channel carbon black, it is possible to obtain a carbon black dispersion liquid having higher dispersion stability and resistance uniformity than in the prior art. Here, the channel carbon black means a color carbon black produced by the channel method. The channel method is a method for producing carbon black by combusting a source gas in air and causing a flame to collide with a metal surface called a channel. Natural gas is the most common raw material gas, but steam such as cleaning oil or naphthalene oil can also be used.

  The reason why a carbon black dispersion with higher dispersion stability and resistance uniformity can be obtained by using channel carbon black is presumed as follows. That is, in general, when obtaining surface-modified carbon black, the step of pulverizing the raw material carbon black and the step of oxidizing the pulverized carbon black are performed successively or almost simultaneously. In the process, an oxidizing agent is required. Channel carbon black generally has a high volatile content, which is caused by a large amount of hydrophilic groups on the surface. For this reason, channel carbon black is easy to adapt to an aqueous medium even if untreated, and is easy to grind. Therefore, no oxidizing agent is required during grinding, and the amount of oxidizing agent used in the oxidation treatment should be reduced. Can do. As a result, a carbon black dispersion having higher dispersion stability and resistance uniformity can be obtained.

  In addition, since channel carbon black has many smaller particle diameters and smaller particle diameter distributions than furnace carbon black, when the transfer body is molded, the density of carbon black particles on the surface of the transfer body may be increased. it can. Therefore, it is considered that dispersion stability and resistance uniformity can be enhanced by using channel carbon black.

  Channel carbon blacks are generally classified according to their blackness by high-grade blackness channel black (HCC), intermediate blackness channel black (MCC), standard blackness channel black (RCC), and regular color channel channel (RCC). ). Moreover, it can classify | categorize into a long flow channel (LFC; Long Flow Channel), a medium flow channel (MFC), etc. according to the film-forming liquid characteristic. Any of these classifications can be used in the present invention.

  Specific examples of channel carbon black preferably used in the present invention include color black FW200, color black FW1, color black FW18, special black 74, special black 6, special black 5, color black S170, color black S160, print Tex U, Printex V (trade name; manufactured by Degussa) and the like.

  According to the present invention, the carbon black dispersion includes a step of pulverizing carbon black in an aqueous medium having a surface tension of 50 mN / m or less, and oxidizing the carbon black in an aqueous medium to introduce a hydrophilic functional group. By this, it can manufacture by the method of including the process of obtaining the carbon black dispersion liquid containing surface-modified carbon black.

That is, the method for producing a carbon black dispersion according to the present invention includes a step of pulverizing carbon black with an aqueous medium having a surface tension of 50 mN / m or less. Usually, the oxidation treatment of carbon black is performed continuously or almost simultaneously with the step of pulverizing the raw material carbon black and the step of oxidizing the pulverized carbon black, and an oxidant is required in both steps. On the other hand, in an aqueous medium having a surface tension of 50 mN / m or less, it easily penetrates into the carbon black aggregate, and as a result, the carbon black is easily pulverized, and no oxidizing agent is required during pulverization. For this reason, the oxidizing agent used for the oxidation treatment of carbon black is used only in the step of oxidizing the pulverized carbon black, and the amount of oxidizing agent used and the amount of hydrophilic functional group are in a relationship of approximately 1: 1. It becomes. For this reason, it becomes easy to control the value of the hydrophilic functional group amount / specific surface area of the surface-modified carbon black within a range of, for example, 5 to 30 μmol / m ² . Further, since the total amount of the oxidizing agent can be reduced because it is used only in the step of oxidizing the oxidizing agent, the target carbon black dispersion can be produced at a relatively low cost.

  In the method for producing a carbon black dispersion in the present invention, the main solvent of the aqueous medium is water. As the water, pure water such as ion exchange water, ultrafiltration water, reverse osmosis water, distilled water, or ultrapure water can be used. In addition, the use of water sterilized by ultraviolet irradiation or addition of hydrogen peroxide is preferable because generation of mold and bacteria can be prevented when the carbon black dispersion is stored for a long period of time. As the aqueous medium in the present invention, in addition to water as a main solvent, a water-soluble organic solvent and a surfactant, for example, those described later can be included.

  In the method for producing a carbon black dispersion according to the present invention, a water-soluble organic solvent or a surfactant that adds a low surface tension to the aqueous medium is added to reduce the surface tension of the aqueous medium in the pulverization step to 50 mN / m or less. can do.

  For example, lower alcohols such as ethanol and propanol, cellosolves such as ethylene glycol monomethyl ether and ethylene glycol monoethyl ether, carbitols such as diethylene glycol monomethyl ether and diethylene glycol monoethyl ether, or nonionic, anionic and cationic surfactants Etc. can be added to water to adjust the surface tension of the aqueous medium at the temperature of the pulverization step to 50 mN / m or less. The surfactant used here is used only for the purpose of facilitating the penetration of the aqueous medium into the carbon black aggregate. In other words, it is usually necessary to select a surfactant that imparts dispersibility to the pigment, but in the present invention, only penetrability needs to be considered, and a combination having no adsorptivity may be used. it can.

  In addition, the method for producing a carbon black dispersion according to the present invention includes the step of obtaining the carbon black dispersion containing the surface-modified carbon black by oxidizing the carbon black in an aqueous medium to introduce a hydrophilic functional group. Comprising.

  In the present invention, the oxidation of carbon black can be performed by a generally known oxidation treatment. Specifically, for example, it can be obtained by a method using nitric acid, ozone, hydrogen peroxide solution, nitrogen oxide, hypohalite or the like as an oxidant under wet or dry conditions, or a method by plasma treatment. it can.

  In a preferred embodiment of the present invention, the oxidation of carbon black is preferably performed using hypohalous acid and / or a salt thereof. Here, examples of hypohalous acid or a salt thereof include sodium hypochlorite, potassium hypochlorite, sodium hypobromite, potassium hypobromite and the like. Among these, sodium hypochlorite is preferable from the viewpoint of reactivity and cost. Therefore, the surface-modified carbon black in the present invention is preferably obtained by oxidizing carbon black using hypohalous acid and / or a salt thereof.

In the method for producing a carbon black dispersion according to the present invention, in order to adjust the value of the hydrophilic functional group amount / specific surface area of the surface-modified carbon black contained in the carbon black dispersion to a range of 5 to 30 μmol / m ^2. It is preferable to adjust the amount ratio of carbon black and oxidizing agent, pulverization and / or oxidation time, and the like. For example, when acidic carbon black is treated with sodium hypochlorite as an oxidizing agent, sodium hypochlorite in an amount 5 to 20 times that of carbon black as a raw material is used for 10 to 15 hours, 95 to 105. The target surface-modified carbon black can be obtained by stirring at ° C.

  When oxidation is performed using hypohalous acid or a salt thereof, for example, carbon black and a hypohalite (for example, sodium hypochlorite) having an effective halogen concentration of 10 to 30% are added in an appropriate amount. The oxidation can be carried out by charging in water and stirring for 5 hours or more, preferably about 10 to 15 hours, 50 ° C. or more, preferably 95 to 105 ° C. In that case, it is preferable to pulverize carbon black before making it react or to make it react simultaneously, grind | pulverizing.

  Examples of the pulverization method include pulverizing carbon black together with beads such as glass, zirconia, alumina, stainless steel, or magnetism using a ball mill, an attritor, a colloid mill, or a sand mill. In addition, when carbon black is easily crushed, the carbon black may be pulverized by a rotary homogenizer or an ultrasonic homogenizer.

  After carbon black is pulverized and oxidized, beads and coarse particles are separated and removed from the resulting liquid, followed by purification such as ultrafiltration to remove by-products and excess ions, and carbon black dispersion Get. If necessary, concentration with a separation membrane, filtration using a metal filter or membrane filter, classification by centrifugation, etc. may be performed, and neutralization with a hydroxide or amine of an alkali metal salt. May be performed.

On the other hand, the disperser used in the present invention may be any commonly used disperser, and examples thereof include a ball mill, a roll mill, and a sand mill.
Among them, a high-speed sand mill is preferable, and examples thereof include a super mill, a sand grinder, a bead mill, an agitator mill, a glen mill, a dyno mill, a pearl mill, and a cobol mill (all are trade names).

  In the present invention, as a method of obtaining a pigment having a desired particle size distribution, the pulverizing media size of the disperser is reduced, the pulverizing media filling rate is increased, the processing time is increased, the discharge speed is decreased, and the pulverization is performed. A method such as classification with a post-filter or a centrifuge is used. Or the combination of those methods is mentioned.

  As a method for measuring the amount of unadsorbed resin according to the present invention, the pigment content and the resin content adsorbed on the pigment are precipitated using an ultracentrifuge or the like, and the amount of residual resin contained in the supernatant is determined. A TOC (Total Organic Carbon, total organic carbon meter), a weight method (a method of evaporating a supernatant to dryness and measuring a resin amount), or the like is preferably used.

[Transfer structure]
The semiconductive belt of the present invention is a semiconductive belt having a polyimide resin layer in which carbon black is uniformly dispersed as a conductive fine powder on at least a surface layer. You may have. As carbon black, the primary particle diameter of carbon black is generally 10 nm to 1 μm, but when mixed in a dispersion or resin, aggregation may occur when carbon black is dispersed. In this invention, it is preferable that the particle diameter of the carbon black currently disperse | distributed in a polyimide resin as a semiconductive belt is 10-300 nm. When the thickness exceeds 300 nm, carbon black having a large particle size present in the surface layer during the manufacturing process of the semiconductive belt becomes a protrusion on the surface of the belt, resulting in deterioration of surface accuracy, non-uniform resistance, and further the electric power of the semiconductive belt. May cause a decrease in resistance due to mechanical loading. On the other hand, if the thickness is less than 10 nm, the amount added is too large to obtain a desired resistance value, and the mechanical properties of the intermediate transfer member deteriorate.

[Carbon black]
The polyimide resin composition of the present invention contains carbon black as a conductive substance.
As carbon black, channel black or furnace black is preferable. About furnace black, what used the oxidation process improves the dispersibility to a solvent, Therefore The thing which performed the oxidation process suitably is preferable. Furthermore, the furnace black subjected to the oxidation treatment is given a functional group containing oxygen (carboxyl group, ketone group, lactone group, hydroxyl group, etc.) on the surface by the treatment, so the affinity with the polar solvent is good, In addition, the carbon black surface is less susceptible to oxidative degradation due to an electrical load or the like. When such carbon black is used for a semiconductive belt, formation of a conductive path is difficult to occur, and resistance reduction can be prevented.

  Examples of the carbon black used in the present invention include furnace black, ketjen black, channel black and the like, and a single type or a plurality of types of carbon black may be used in combination. In the present invention, it is preferable to contain at least one carbon black having a volatile content of 1.0% or more.

  Such carbon blacks include Degussa Color Black FW200, Color Black FW2, Color Black FW2V, Color Black FW1, Color Black FW18, Special Black 6, Color Black S170, Color Black S160, Special Black 5, Special Black 4, Special Black 4A, Printex 150T, Printex U, Printex V, Printex 140U, Printex 140V, Special Black 550, Special Black 350, Special Black 250, Special Black 100, Mitsubishi Chemical Corporation MA7, MA77 , MA8, MA11, MA100, MA100R, MA230, MA220, MONARCH700, MONARC manufactured by Cabot Corporation 800, MONARCH880, MONARCH900, MONARCH1000, MONARCH1300, MONARCH1400, MOGUL-L, REGAL400R, and the like VULCAN XC-72R.

  The carbon black used in the present invention has an average particle diameter of 5 to 100 nm, preferably 10 to 70 nm. Those having an average particle diameter of less than 5 nm are substantially difficult to obtain. When the average particle diameter exceeds 100 nm, the surface roughness, mechanical strength and electrical properties of the polyimide resin composition containing the carbon black This is because it is difficult to obtain a practically satisfactory one from the viewpoint of resistance controllability.

  The said average particle diameter shows the average particle diameter based on the primary particle diameter measured with the electron microscope etc. In addition, the carbon black may have its electric resistance controlled by grafting the particle surface with a polymer such as styrene or methyl methacrylate, or by coating an insulating material, and the carbon black particle surface may be oxidized. May be.

[Polyimide resin]
The polyimide resin composition of the present invention can be obtained by heating the polyamic acid solution containing the carbon black to perform solvent removal and imide conversion reaction. The polyimide resin used for this invention can use a well-known thing, and is obtained by superposing | polymerizing a dianhydride and diamine in a solvent. Among them, the aromatic polyimide resin is preferable because the obtained belt has good mechanical strength, heat resistance, and dimensional stability.

  As the solvent used in the present invention, an organic polar solvent is preferable, and N, N-dialkylamides are particularly useful. Examples of low molecular weight solvents include N, N-dimethylformamide and N, N-dimethylacetamide. . They can be easily removed from the polyamic acid and the polyamic acid molded article by evaporation, displacement or diffusion. Other organic polar solvents include N, N-diethylformamide, N, N-diethylacetamide, N, N-dimethylmethoxyacetamide, dimethyl sulfoxide, hexamethylphosphortriamide, N-methyl-2-pyrrolidone, pyridine. , Tetramethylene sulfone, dimethyltetramethylene sulfone and the like. These may be used alone or in combination.

  Furthermore, phenols such as cresol, phenol and xylenol, benzonitrile, dioxane, butyrolactone, xylene, cyclohexane, hexane, benzene, toluene and the like can be mixed alone or in combination with the organic polar solvent. However, in order to prevent lowering the molecular weight due to hydrolysis of the produced polyamic acid, it is preferable to avoid mixing water during the polymerization reaction.

  In the present invention, a dispersant can be further added to increase the affinity between the carbon black and the organic polar solvent. Although it will not specifically limit as a dispersing agent if the objective of this invention is met, For example, a polymeric dispersing agent is mentioned. Examples of the polymer dispersant include poly (N-vinyl-2-pyrrolidone), poly (N, N′-diethylacrylazide), poly (N-vinylformamide), poly (N-vinylacetamide), poly (N— Vinylphthalamide), poly (N-vinylsuccinamide), poly (N-vinylurea), poly (N-vinylpiperidone), poly (N-vinylcaprolactam), poly (N-vinyloxazoline) and the like. A single or a plurality of polymer dispersants can be added.

  In addition to this, within the scope of the object of the present invention, a polymer material, a surfactant, and a dispersion stabilizer for inorganic salt damage can be used.

  As the acid dianhydride component, pyromellitic dianhydride, 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride 2,3,3 ′, 4-biphenyltetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 2,2′-bis (3,4-dicarboxyphenyl) propane dianhydride, bis (3,4-dicarboxyphenyl) sulfone dianhydride Perylene-3,4,9,10-tetracarboxylic dianhydride, bis (3,4-dicarboxyphenyl) ether dianhydride, ethylenetetracarboxylic dianhydride and the like.

Examples of the diamine include 4,4'-diaminodiphenyl ether, 4,4'-diaminodiphenylmethane, 3,3'-diaminodiphenylmethane, 3,3'-dichlorobenzidine, 4,4'-diaminodiphenyl sulfide, 3,3'- Diaminodiphenylsulfone, 1,5-diaminonaphthalene, m-phenylenediamine, p-phenylenediamine, 3,3′-dimethyl-4,4′-biphenyldiamine, benzidine, 3,3′-dimethylbenzidine, 3,3 ′ -Dimethoxybenzidine, 4,4'-diaminodiphenylsulfone, 4,4'-diaminodiphenylsulfide, 4,4'-diaminodiphenylpropane, 2,4-bis (β-amino-t-butyl) toluene, bis (P-β-amino-t-butylphenyl) ether, bis (p-β-methyl-δ-aminophenyl) Nyl) benzene, bis-p- (1,1-dimethyl-5-amino-pentyl) benzene, 1-isopropyl-2,4-m-phenylenediamine, m-xylylenediamine, p-xylylenediamine, di ( p-aminocyclohexyl) methane, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, decamethylenediamine, diaminopropyltetramethylene, 3-methylheptamethylenediamine, 4,4-dimethylheptamethylenediamine, 2 , 11-diaminododecane, 1,2-bis-3-aminopropoxyethane, 2,2-dimethylpropylenediamine, 3-methoxyhexamethylenediamine, 2,5-dimethylheptamethylenediamine, 3-methylheptamethylenediamine, 5-methylno Methylenediamine, 2,11-diaminododecane, 2,17-diaminoeicosadecane, 1,4-diaminocyclohexane, 1,10-diamino-1,10-dimethyldecane, 1,12-diaminooctadecane, 2,2- Bis [4- (4-aminophenoxy) phenyl] propane, piperazine, H ₂ N (CH ₂ ) ₃ O (CH ₂ ) ₂ OCH ₂ NH ₂ , H ₂ N (CH ₂ ) ₃ S (CH ₂ ) ₃ NH ₂ , H ₂ N (CH ₂ ) ₃ N (CH ₂ ) ₂ (CH ₂ ) ₃ NH _{2 and the} like.

  In order to prepare a carbon black-dispersed polyamic acid solution from these raw materials, diamine and acid dianhydride are dissolved in an organic polar solvent, and carbon black is added to the polyamic acid solution obtained after the polymerization reaction and mixed. Examples thereof include a stirring method, a method in which carbon black is uniformly dispersed in an organic polar solvent in advance to prepare a carbon black dispersion, and then a diamine and an acid dianhydride are dissolved therein to conduct a polymerization reaction.

[Film forming solution manufacturing method]
Hereinafter, an example of a method for producing the polyimide resin composition and the seamless belt of the present invention will be described.
First, carbon black and an appropriate polymer dispersant are added and dispersed in the organic polar solvent to prepare a carbon black dispersion.
As a dispersion method, a known method can be applied, and examples thereof include a ball mill, a sand mill, a basket mill, and ultrasonic dispersion.
Next, the acid dianhydride and diamine are dissolved in the carbon black dispersion, mixed and stirred to advance the polymerization reaction, thereby obtaining a polyamic acid solution.

  Regarding the blending amount of each raw material, it is necessary to experimentally examine a composition suitable for the intended use of the finally obtained polyimide resin composition. For example, the amount of carbon black added to obtain a highly antistatic seamless belt having a common logarithmic value of surface resistivity of 8 to 13 (log Ω / □) is about 10 to 40% by weight based on the polyimide resin solid content. Preferably, 13 to 30% by weight is more preferable. If it is less than 10% by weight, it is necessary to use highly conductive carbon black in order to develop the resistance region. If such highly conductive carbon black is added in a low addition amount, stable resistance can be produced with good reproducibility. May be difficult to do. On the other hand, if it exceeds 40% by weight, the inherent high mechanical properties of the polyimide resin are impaired, brittleness is developed, and the belt end face may be cracked when the belt is driven by a plurality of drive rollers or the like.

  The monomer concentration (concentration of acid dianhydride component and diamine component in the solvent) of the polyamic acid solution is set according to various conditions, but is preferably 5 to 30% by weight. The polymerization reaction is performed in a nitrogen atmosphere, the reaction temperature is preferably set to 80 ° C. or less, and the reaction time is preferably about 0.5 to 10 hours. The polyamic acid solution can be adjusted in viscosity because the solution viscosity increases as the polymerization reaction proceeds. The viscosity can be adjusted by lowering the monomer concentration by adding a solvent or the like. The viscosity of the polyamic acid solution in the present invention is usually 1 to 1000 Pa · s.

The polyamic acid solution thus obtained is heated to remove the solvent and undergo an imide conversion reaction to obtain the polyimide resin composition of the present invention.
The heating temperature for removing the solvent is not particularly limited as long as the applied solvent can be evaporated, and can be appropriately set. In order to prevent generation of microvoids due to rapid evaporation of the solvent in the polyamic acid solution, it is preferably 230 ° C. or lower, and preferably 80 ° C. or higher from the viewpoint of shortening the heating time. The heating time is appropriately set according to the heating temperature, and is usually about 10 to 60 minutes.
Next, heating is performed to complete the imide conversion reaction and remove ring-closing water. Usually, the heating temperature at this time is not lower than the solvent evaporation temperature and not higher than 450 ° C., preferably 250 to 400 ° C., and the heating time is 10 to 60 minutes.

[Transfer production method]
In order to make the polyimide resin composition into molded products having various shapes, known molding methods are used. For example, in order to obtain a thin film such as a film or a belt, a film is formed by applying the polyamic acid solution to a flat plate such as a glass plate or a copper plate, an endless belt or a cylindrical mold, and then the solvent is removed by heating. By performing imide conversion reaction and ring-closing water removal, a film or belt made of a polyimide resin composition can be obtained. In order to obtain a seamless belt, after casting or applying a polyamic acid solution to the inner surface of a cylindrical mold, a method of rotating the mold, a method of running a bullet-shaped traveling body by its own weight or gas pressure, or a cylindrical mold After the mold is immersed in the polyamic acid solution, a film is formed by a method such as lifting and molding with a cyclic mold, etc., and then the solvent is removed by heating, the imide conversion reaction, and the ring-closing water are removed. Can be selected as appropriate.
The highly antistatic seamless belt of the present invention can be multilayered by laminating, but at least the outermost surface is made of the polyimide resin composition.

[Carbon black graft polymer]
The carbon black graft polymer refers to fine particles in which a polymer part is grafted on a carbon black part. The carbon black graft polymer is obtained by grafting a polymer to primary particles or several aggregates of carbon black. Addition reactions that can be used for “grafting” include electrophilic addition reactions, radical addition reactions, nucleophilic addition reactions, and cycloaddition reactions.

  Carbon black usually has a particle size of several nm to several hundred nm. However, since carbon black has a large cohesion force between particles, it is usually handled as an aggregate having a particle diameter of several microns or more. In addition, the cohesive strength between carbon blacks is significantly greater than the affinity between carbon black and other substances such as resin-based materials, and it is very difficult to disperse carbon black in resin-based materials etc. in submicrons. A stable resistance value cannot be obtained.

  On the other hand, in the carbon black graft polymer, the polymer portion can effectively enter between the carbon black particles, and the cohesive force between the carbon blacks can be weakened. Furthermore, when the polymer portion has an affinity with the resin material, etc., the carbon black graft polymer can be dispersed in the resin material, etc. in submicrons. However, even if the polymer portion has a high affinity with the resin-based material or the like, if the polymer portion is not effectively grafted to the carbon black portion, the characteristics will not be stable. As a result, the carbon black portion of the carbon black graft polymer becomes low in content when carbon black graft polymer is used to obtain a certain level of affinity. The conductivity of black is significantly impaired.

The carbon black graft polymer according to the present invention can be obtained by reacting a carbon black reactive polymer with carbon black.
The polymer having reactivity with carbon black may be any polymer having a reactive group reactive with the surface functional group of carbon black, for example, and the reactive group is present on the surface of carbon black. The reactive group is not particularly limited as long as it can react with the functional group and contribute to the grafting of the polymer onto carbon black, and various reactive groups can be used.

  Here, in order to make the grafting more reliable and stable, it is desired that the polymer portion is bonded to the carbon black through a covalent bond, in particular, an ester bond, a thioester bond, an amide bond, an amino bond, An at least one bond selected from the group consisting of an ether bond, a thioether bond, a carbonyl bond, a thiocarbonyl bond and a sulfonyl bond, and at least one bond selected from the group consisting of an ester bond, a thioester bond and an amide bond It is desirable to be.

  Considering such points, the reactive group is preferably at least one or more selected from the group consisting of an epoxy group, a thioepoxy group, an aziridine group and an oxazoline group. Although the reactive group with respect to carbon black is not necessarily limited to these, when the polymer which has groups other than these reactive groups is used, the kind of carbon black which can be used may restrict | limit. The reason why it is preferable that the polymer has the reactive group is that carbon black and the polymer are added with very high grafting efficiency even under mild conditions regardless of the type and state of carbon black that can be used. It is to react. In particular, when carbon black has a carboxyl group as a surface functional group as described above, the carboxyl group undergoes an irreversible addition reaction in a high yield by thermal reaction with an epoxy group, thioepoxy group, aziridine group or oxazoline group. The addition reaction is desirable because the above-described covalent bond is formed between the carbon black portion and the polymer portion.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. In the following, “parts” as a blending ratio represents “parts by weight”.

1. Surface-modified carbon black (adjustment of carbon black dispersion)

[Carbon black dispersion 1]
100 g of color black FW18 (trade name; manufactured by Degussa) (specific surface area 260 m ² / g), which is commercially available acidic carbon black, was mixed with 500 g of water, and pulverized with a ball mill using zirconia beads. 1500 g of sodium hypochlorite (effective chlorine concentration: 12%) was added dropwise to the pulverized stock solution, and the mixture was boiled for 10 hours for wet oxidation. The obtained dispersion stock solution was filtered with glass fiber filter paper GA-100 (trade name, manufactured by Advantech Toyo Co., Ltd.) and further washed with water. The obtained wet cake was redispersed in 5 kg of water, and desalted and purified by a reverse osmosis membrane until the electric conductivity reached 20 μS / cm. Further drying was carried out to prepare a carbon black dispersion 1 having a pigment concentration of 15% by weight with n-methyl-2-pyrrolidone. The amount of the hydrophilic functional group of the obtained surface-modified carbon black was 2340 μmol / g as measured by the above-described vacuum pyrolysis gas method, and this value was divided by the specific surface area of color black FW18 (that is, hydrophilic The functional functional group amount / specific surface area value) was 9.0 μmol / m ² .

[Carbon black dispersion 2]
Color black S170 (trade name; manufactured by Degusa) (specific surface area 200 m ² / g), which is a commercially available acidic carbon black, was mixed with 1 kg of water and pulverized with a ball mill using zirconia beads. 1400 g of sodium hypochlorite (effective chlorine concentration 12%) was added dropwise to this pulverized stock solution, reacted for 5 hours while pulverizing with a ball mill, and further boiled for 4 hours with stirring to perform wet oxidation. The obtained dispersion stock solution was filtered with glass fiber filter paper GA-100 (trade name, manufactured by Advantech Toyo Co., Ltd.) and further washed with water. The obtained wet cake was redispersed in 5 kg of water, and desalted and purified by a reverse osmosis membrane until the electric conductivity reached 20 μS / cm. Further, it was dried to prepare a carbon black dispersion 2 having a pigment concentration of 15% by weight with n-methyl-2-pyrrolidone. The amount of the hydrophilic functional group of the obtained surface-modified carbon black was 2100 μmol / g as measured by the above method, and the value obtained by dividing this value by the specific surface area of the color black S170 was 10.5 μmol / m ² . there were.

[Carbon black dispersion 3]
100 g of MA8 (trade name; manufactured by Mitsubishi Chemical Corporation) (specific surface area of 137 m ² / g), which is commercially available acidic carbon black, was mixed with 500 g of water and pulverized by a ball mill using zirconia beads. To this crushed stock solution, 500 g of sodium hypochlorite (effective chlorine concentration: 12%) was dropped, and the mixture was boiled for 10 hours for wet oxidation. The obtained dispersion stock solution was filtered with glass fiber filter paper GA-100 (trade name, manufactured by Advantech Toyo Co., Ltd.) and further washed with water. The obtained wet cake was redispersed in 5 kg of water, and desalted and purified by a reverse osmosis membrane until the electric conductivity reached 20 μS / cm. Furthermore, it dried and the carbon black dispersion liquid 3 whose pigment concentration is 15 weight% with n-methyl-2-pyrrolidone was prepared. The amount of the hydrophilic functional group of the obtained surface-modified carbon black measured by the above method was 1230 μmol / g, and the value obtained by dividing this value by the specific surface area of MA8 was 9.0 μmol / m ² . .

[Carbon black dispersion 4]
100 g of color black FW200 (trade name; manufactured by Degussa) (specific surface area 460 m ² / g), which is a commercially available channel carbon black, was mixed with 500 g of water and pulverized by a ball mill using zirconia beads. 1000 g of sodium hypochlorite (effective chlorine concentration 12%) was added dropwise to the pulverized stock solution, and the mixture was boiled for 10 hours for wet oxidation. The obtained dispersion stock solution was filtered with glass fiber filter paper GA-100 (trade name, manufactured by Advantech Toyo Co., Ltd.) and further washed with water. The obtained wet cake was redispersed in 5 kg of water, and desalted and purified by a reverse osmosis membrane until the electric conductivity reached 20 μS / cm. Furthermore, it dried and the carbon black dispersion liquid 4 whose pigment concentration is 15 weight% with n-methyl-2-pyrrolidone was prepared. The amount of the hydrophilic functional group of the obtained surface-modified carbon black was 2600 μmol / g as measured by the above method, and the value obtained by dividing this value by the specific surface area of FW200 was 5.7 μmol / m ² .

[Carbon black dispersion 5]
100 g of special black 4 (trade name; manufactured by Degussa) (specific surface area 180 m ² / g), which is a commercially available channel carbon black, was mixed with 500 g of water and pulverized by a ball mill using zirconia beads. 1100 g of sodium hypochlorite (effective chlorine concentration 12%) was added dropwise to the pulverized stock solution, and the mixture was boiled for 10 hours for wet oxidation. The obtained dispersion stock solution was filtered with glass fiber filter paper GA-100 (trade name, manufactured by Advantech Toyo Co., Ltd.) and further washed with water. The obtained wet cake was redispersed in 5 kg of water, and desalted and purified by a reverse osmosis membrane until the electric conductivity reached 20 μS / cm. Furthermore, it dried and the carbon black dispersion liquid 5 whose pigment concentration is 15 weight% with n-methyl-2-pyrrolidone was prepared. The amount of the hydrophilic functional group of the obtained surface-modified carbon black was 2500 μmol / g as measured by the above method, and the value obtained by dividing this value by the specific surface area of Special Black 4 was 13.9 μmol / m ^2. It was.

[Carbon Black Dispersion 6] (Comparative Example)
5 g of color black FW18, which is acidic carbon black described in Carbon Black Dispersion 1, was added to 95 g of n-methyl-2-pyrrolidone and sufficiently stirred with a homomixer. Next, when left standing for several minutes, the carbon black aggregated and settled. The amount of the hydrophilic functional group of the obtained carbon black was 130 μmol / g as measured by the above method, and the value obtained by dividing this value by the specific surface area of the color black FW18 was 0.50 μmol / m ² .

[Carbon Black Dispersion 7] (Comparative Example)
100 g of color black S170, which is acidic carbon black described in the carbon black dispersion 2, was mixed with 500 g of water and pulverized by a ball mill using zirconia beads. 350 g of sodium hypochlorite (effective chlorine concentration: 12%) was added dropwise to the pulverized stock solution, and the mixture was boiled for 10 hours for wet oxidation. The obtained dispersion stock solution was filtered with glass fiber filter paper GA-100 (trade name, manufactured by Advantech Toyo Co., Ltd.) and further washed with water. The obtained wet cake was redispersed in 5 kg of water, and desalted and purified by a reverse osmosis membrane until the electric conductivity reached 20 μS / cm. Furthermore, it dried and the carbon black dispersion liquid 7 whose pigment concentration is 15 weight% with n-methyl-2-pyrrolidone was prepared. The amount of the hydrophilic functional group of the obtained surface-modified carbon black was 960 μmol / g as measured by the above method, and the value obtained by dividing this value by the specific surface area of the color black S170 was 4.80 μmol / m ² . there were.

[Carbon Black Dispersion 8] (Comparative Example)
MA8 which is acidic carbon black described in the carbon black dispersion 3 was mixed with 500 g of water and pulverized by a ball mill using zirconia beads. 70 g of sodium hypochlorite (effective chlorine concentration 12%) was added dropwise to the pulverized stock solution, and the mixture was boiled for 6 hours for wet oxidation. The obtained dispersion stock solution was filtered with glass fiber filter paper GA-100 (trade name, manufactured by Advantech Toyo Co., Ltd.) and further washed with water. The obtained wet cake is redispersed in 5 kg of water, desalted and purified with a reverse osmosis membrane until the conductivity becomes 2 mS / cm, and further concentrated until the pigment concentration becomes 15% by weight to obtain a carbon black dispersion. 8 was prepared. The amount of hydrophilic functional group of the obtained surface-modified carbon black was 620 μmol / g as measured by the above method, and the value obtained by dividing this value by the specific surface area of MA8 was 4.53 μmol / m ² . .

[Carbon Black Dispersion 9] (Comparative Example)
100 g of color black FW18, which is acidic carbon black described in the carbon black dispersion 1, was mixed with 500 g of water and pulverized by a ball mill using zirconia beads. To this crushed stock solution, 3840 g of sodium hypochlorite (effective chlorine concentration 12%) was added dropwise and boiled for 10 hours for wet oxidation. The obtained dispersion stock solution was filtered with glass fiber filter paper GA-100 (trade name, manufactured by Advantech Toyo Co., Ltd.) and further washed with water. The obtained wet cake was redispersed in 5 kg of water, and desalted and purified by a reverse osmosis membrane until the electric conductivity reached 20 μS / cm. Furthermore, it dried and the carbon black dispersion liquid 9 whose pigment concentration is 15 weight% with n-methyl-2-pyrrolidone was prepared. The amount of the hydrophilic functional group of the obtained surface-modified carbon black was 7900 μmol / g as measured by the above method, and the value obtained by dividing this value by the specific surface area of the color black FW18 was 30.38 μmol / m ² . there were.

[Carbon Black Dispersion 10] (Comparative Example)
100 g of color black S170 which is acidic carbon black described in the carbon black dispersion 2 was mixed with 1 kg of water and pulverized by a ball mill using zirconia beads. To this pulverized stock solution, 2420 g of sodium hypochlorite (effective chlorine concentration 12%) was dropped, reacted for 5 hours while pulverizing with a ball mill, and further boiled for 4 hours with stirring to perform wet oxidation. The obtained dispersion stock solution was filtered with glass fiber filter paper GA-100 (trade name, manufactured by Advantech Toyo Co., Ltd.) and further washed with water. The obtained wet cake was redispersed in 5 kg of water, and desalted and purified by a reverse osmosis membrane until the electric conductivity reached 20 μS / cm. Furthermore, it dried and the carbon black dispersion liquid 10 whose pigment concentration is 15 weight% with n-methyl-2-pyrrolidone was prepared. The obtained pigment dispersion was acidified with hydrochloric acid water and subjected to membrane purification again, and then concentrated, dried, and finely pulverized to obtain oxidized carbon black powder. The amount of the hydrophilic functional group of the obtained surface-modified carbon black was 6400 μmol / g as measured by the above method, and the value obtained by dividing this value by the specific surface area of the color black S170 was 32.00 μmol / m ² . there were.

[Carbon Black Dispersion 11] (Comparative Example)
MA8 which is acidic carbon black described in the carbon black dispersion 3 was mixed with 1 kg of water and pulverized by a ball mill using zirconia beads. To this crushed stock solution, 870 g of sodium hypochlorite (effective chlorine concentration 12%) was added dropwise, reacted for 5 hours while pulverizing with a ball mill, and further boiled for 4 hours with stirring to perform wet oxidation. The obtained dispersion stock solution was filtered with glass fiber filter paper GA-100 (trade name, manufactured by Advantech Toyo Co., Ltd.) and further washed with water. The obtained wet cake was redispersed in 5 kg of water, and desalted and purified by a reverse osmosis membrane until the electric conductivity reached 20 μS / cm. Further drying was performed to prepare a carbon black dispersion 11 having a pigment concentration of 15% by weight with n-methyl-2-pyrrolidone. The obtained pigment dispersion was acidified with hydrochloric acid water and subjected to membrane purification again, and then concentrated, dried, and finely pulverized to obtain oxidized carbon black powder. The amount of hydrophilic functional groups of the obtained oxidized carbon black was 4320 μmol / g as measured by the above method, and the value obtained by dividing this value by the specific surface area of MA8 was 31.53 μmol / m ² .

[Carbon Black Dispersion 12] (Comparative Example)
100 g of color black FW200, which is channel carbon black described in the carbon black dispersion 4, 150 g of a water-soluble resin dispersant 150 g, trade name of Johnson Polymer Co., Ltd., 6 g of sodium hydroxide, n-methyl- 250 g of 2-pyrrolidone was mixed and dispersed for 10 hours by a ball mill using zirconia beads. The obtained dispersion stock solution is filtered through a stainless steel filter having a pore size of about 5 μm, diluted with n-methyl-2-pyrrolidone to a pigment concentration of 15% by weight, and dispersed with a water-soluble resin. Was prepared.

(Example 1)
After mixing the following components, the mixture was stirred with an ultrasonic homogenizer for 1 hour to obtain a film-forming solution (A).
(Creation of film forming solution)
Carbon black dispersion liquid 1 25 parts N-methylpyrrolidone 8 parts Polyimide resin (Ube Industries U-Varnish S) 33 parts (solid content 6 parts)
Polyimide resin (Ube Industries U-Varnish A) 33 parts (solid content 6 parts)
Silicone leveling agent 0.001 part

(Example 2)
After mixing the following components, the mixture was stirred for 1 hour with an ultrasonic homogenizer to obtain a film-forming solution (B).
(Creation of film forming solution)
Carbon black dispersion 2 25 parts N-methylpyrrolidone 8 parts Polyimide resin (U-Varnish S manufactured by Ube Industries) 33 parts (solid content 6 parts)
Polyimide resin (Ube Industries U-Varnish A) 33 parts (solid content 6 parts)
Silicone leveling agent 0.001 part

(Example 3)
After mixing the following components, the mixture was stirred for 1 hour with an ultrasonic homogenizer to obtain a film-forming solution (C).
(Creation of film forming solution)
Carbon black dispersion liquid 3 25 parts N-methylpyrrolidone 8 parts Polyimide resin (Ube Industries U-Varnish S) 33 parts (solid content 6 parts)
Polyimide resin (Ube Industries U-Varnish A) 33 parts (solid content 6 parts)
Silicone leveling agent 0.001 part

Example 4
After mixing the following components, the mixture was stirred for 1 hour with an ultrasonic homogenizer to obtain a film-forming solution (D).
(Creation of film forming solution)
Carbon black dispersion 4 25 parts N-methylpyrrolidone 8 parts Polyimide resin (U-Varnish S manufactured by Ube Industries) 33 parts (solid content 6 parts)
Polyimide resin (Ube Industries U-Varnish A) 33 parts (solid content 6 parts)
Silicone leveling agent 0.001 part

(Example 5)
The following components were mixed, and then stirred for 1 hour with an ultrasonic homogenizer to obtain a film-forming solution (E).
(Creation of film forming solution)
Carbon black dispersion 5 25 parts N-methylpyrrolidone 8 parts Polyimide resin (U-Varnish S manufactured by Ube Industries) 33 parts (solid content 6 parts)
Polyimide resin (Ube Industries U-Varnish A) 33 parts (solid content 6 parts)
Silicone leveling agent 0.001 part

(Comparative Example 1)
After mixing the following components, the mixture was stirred for 1 hour with an ultrasonic homogenizer to obtain a film-forming solution (F).
(Creation of film forming solution)
Carbon black dispersion 6 25 parts N-methylpyrrolidone 8 parts Polyimide resin (U-Varnish S manufactured by Ube Industries) 33 parts (solid content 6 parts)
Polyimide resin (Ube Industries U-Varnish A) 33 parts (solid content 6 parts)
Silicone leveling agent 0.001 part

(Comparative Example 2)
The following components were mixed, and then stirred for 1 hour with an ultrasonic homogenizer to obtain a film-forming solution (G).
(Creation of film forming solution)
Carbon black dispersion 7 25 parts N-methylpyrrolidone 8 parts Polyimide resin (U-Varnish S manufactured by Ube Industries) 33 parts (solid content 6 parts)
Polyimide resin (Ube Industries U-Varnish A) 33 parts (solid content 6 parts)
Silicone leveling agent 0.001 part

(Comparative Example 3)
The following components were mixed and then stirred for 1 hour with an ultrasonic homogenizer to obtain a film-forming solution (H).
(Creation of film forming solution)
Carbon black dispersion liquid 8 25 parts N-methylpyrrolidone 8 parts Polyimide resin (Ube Industries U-Varnish S) 33 parts (solid content 6 parts)
Polyimide resin (Ube Industries U-Varnish A) 33 parts (solid content 6 parts)
Silicone leveling agent 0.001 part

(Comparative Example 4)
The following components were mixed, and then stirred for 1 hour with an ultrasonic homogenizer to obtain a film-forming solution (I).
(Creation of film forming solution)
Carbon black dispersion 9 25 parts N-methylpyrrolidone 8 parts Polyimide resin (U-Varnish S manufactured by Ube Industries) 33 parts (solid content 6 parts)
Polyimide resin (Ube Industries U-Varnish A) 33 parts (solid content 6 parts)
Silicone leveling agent 0.001 part

(Comparative Example 5)
After mixing the following components, the mixture was stirred for 1 hour with an ultrasonic homogenizer to obtain a film-forming solution (J).
(Creation of film forming solution)
Carbon black dispersion 10 25 parts N-methylpyrrolidone 8 parts Polyimide resin (U-Varnish S manufactured by Ube Industries) 33 parts (solid content 6 parts)
Polyimide resin (Ube Industries U-Varnish A) 33 parts (solid content 6 parts)
Silicone leveling agent 0.001 part

(Comparative Example 6)
The following components were mixed and then stirred for 1 hour with an ultrasonic homogenizer to obtain a film-forming solution (K).
(Creation of film forming solution)
Carbon black dispersion 11 25 parts N-methylpyrrolidone 8 parts Polyimide resin (U-Varnish S manufactured by Ube Industries) 33 parts (solid content 6 parts)
Polyimide resin (Ube Industries U-Varnish A) 33 parts (solid content 6 parts)
Silicone leveling agent 0.001 part

(Comparative Example 7)
The following components were mixed, and then stirred for 1 hour with an ultrasonic homogenizer to obtain a film-forming solution (L).
(Creation of film forming solution)
Carbon black dispersion liquid 12 25 parts N-methylpyrrolidone 8 parts Polyimide resin (Ube Industries U-Varnish S) 33 parts (solid content 6 parts)
Polyimide resin (Ube Industries U-Varnish A) 33 parts (solid content 6 parts)
Silicone leveling agent 0.001 part

2. Grafted carbon black (Reference Example 1)
75 parts of AA-6 (manufactured by Toa Gosei Co., Ltd., polymethyl methacrylate macromer), 15 parts of styrene monomer (St), 10 parts of isopropenyloxazoline (IPO), and azoisobutyronitrile (AIBN) 3 as an initiator A part was dissolved in 100 parts of propylene glycol monomethyl ether acetate (PGM-Ac) to obtain a polymerizable monomer composition (1). 50 parts of PGM-Ac was charged into a separable flask equipped with a stirrer, N2 introduction tube, thermometer, and dropping funnel, and the temperature was raised to 80C. The monomer composition (1) was charged into a dropping funnel, dropped at 80 ° C. over 3 hours, further polymerized at the same temperature for 2 hours, heated to 120 ° C., and aged for 2 hours. It cooled and the polymer solution (1) (nonvolatile content 40%) was obtained.

(Reference Example 2)
The same procedure as in Reference Example 1 was performed except that AA-714 (manufactured by Toa Gosei Co., Ltd., methyl methacrylate / hydroxyethyl methacrylate copolymer macromer) was used instead of AA-6 in Reference Example 1, and a polymer solution ( 2) (nonvolatile content 40%) was obtained.

(Reference Example 3)
With respect to 250 parts of the polymer solution (2) obtained in Reference Example 2, 8.9 parts of methacryloyl isocyanate (molecular weight 111.1) was diluted to 13.35 parts of PGM-Ac for 30 minutes at room temperature. The solution was added dropwise to obtain a polymer solution (3) having a double bond (nonvolatile content: 40%).

(Synthesis Example 1)
In a separable flask equipped with a thermometer, a stirring blade and a cooling tube, 30 parts of carbon black dispersion 1 (solid), 22.5 parts of the polymer solution (1) obtained in Reference Example 1, PGM-Ac97. Each 5 parts was charged and dispersed. Subsequently, 800 parts of sirconia beads were charged into the flask. While stirring at a rotation speed of 300 rpm, the grafting reaction was performed at 100 ° C. for 2 hours. Subsequently, the reaction contents and zirconia beads were separated to obtain a carbon black graft polymer dispersion 1.

(Synthesis Example 2)
In Synthesis Example 1, carbon black dispersion 2 (solid) instead of carbon black dispersion 1 (solid), polymer solution (1) 25 parts instead of 22.5 parts, PGM-Ac 97.5 parts instead of A carbon black graft polymer dispersion 2 was obtained in the same manner as in Synthesis Example 1 except that the amount was 90 parts.

(Synthesis Example 3)
A carbon black graft polymer dispersion 3 was obtained by repeating the same operation as in Synthesis Example 1 except that the carbon black dispersion 3 (solid) was used instead of the carbon black dispersion 1 (solid) in Synthesis Example 1. .

(Synthesis Example 4)
In Synthesis Example 1, instead of carbon black dispersion 1 (solid matter), carbon black dispersion 4 (solid matter), 22.5 parts of polymer solution (1), and polymer solution (97.5 parts of PGM-Ac) 2) A carbon black graft polymer dispersion 4 was obtained in the same manner as in Synthesis Example 1 except that 25 parts and PGM-Ac 82.5 parts were used.

(Synthesis Example 5)
In Synthesis Example 1, Synthesis Example 1 was used except that the carbon black dispersion 5 (solid) was used instead of the carbon black dispersion 1 (solid), and the polymer solution (3) was used instead of the polymer solution (1). The same operation was performed to obtain a carbon black graft polymer dispersion 5.

(Example 6)
The following components were mixed using the carbon black graft polymer dispersion 1 obtained in Synthesis Example 1, and then stirred for 1 hour with an ultrasonic homogenizer to obtain a film-forming solution (M).
(Creation of film forming solution)
Carbon black graft polymer dispersion 1 25 parts N-methylpyrrolidone 8 parts Polyimide resin (U-Varnish S manufactured by Ube Industries) 33 parts (solid content 6 parts)
Polyimide resin (Ube Industries U-Varnish A) 33 parts (solid content 6 parts)
Silicone leveling agent 0.001 part

(Example 7)
The following components were mixed using the carbon black graft polymer dispersion 2 obtained in Synthesis Example 2, and then stirred for 1 hour with an ultrasonic homogenizer to obtain a film-forming solution (N).
(Creation of film forming solution)
Carbon black graft polymer dispersion 2 25 parts N-methylpyrrolidone 8 parts Polyimide resin (U-Varnish S manufactured by Ube Industries) 33 parts (solid content 6 parts)
Polyimide resin (Ube Industries U-Varnish A) 33 parts (solid content 6 parts)
Silicone leveling agent 0.001 part

(Example 8)
The following components were mixed using the carbon black graft polymer dispersion 3 obtained in Synthesis Example 3, and then stirred for 1 hour with an ultrasonic homogenizer to obtain a film-forming solution (O).
(Creation of film forming solution)
Carbon black graft polymer dispersion 3 25 parts N-methylpyrrolidone 8 parts Polyimide resin (U-Varnish S manufactured by Ube Industries) 33 parts (solid content 6 parts)
Polyimide resin (Ube Industries U-Varnish A) 33 parts (solid content 6 parts)
Silicone leveling agent 0.001 part

Example 9
The following components were mixed using the carbon black graft polymer dispersion 4 obtained in Synthesis Example 4, and then stirred for 1 hour with an ultrasonic homogenizer to obtain a film-forming solution (P).
(Creation of film forming solution)
Carbon black graft polymer dispersion 4 25 parts N-methylpyrrolidone 8 parts Polyimide resin (U-Varnish S manufactured by Ube Industries) 33 parts (solid content 6 parts)
Polyimide resin (Ube Industries U-Varnish A) 33 parts (solid content 6 parts)
Silicone leveling agent 0.001 part

(Example 10)
The following components were mixed using the carbon black graft polymer dispersion 5 obtained in Synthesis Example 5, and then stirred for 1 hour with an ultrasonic homogenizer to obtain a film-forming solution (Q).
(Creation of film forming solution)
Carbon black graft polymer dispersion 5 25 parts N-methylpyrrolidone 8 parts Polyimide resin (U-Varnish S manufactured by Ube Industries) 33 parts (solid content 6 parts)
Polyimide resin (Ube Industries U-Varnish A) 33 parts (solid content 6 parts)
Silicone leveling agent 0.001 part

(Comparative Example 8)
In Synthesis Example 1, carbon black dispersion 6 (solid) instead of carbon black dispersion 1 (solid), 30 parts of polymer solution (1) instead of 22.5 parts, and 97.5 parts of PGM-Ac Instead, a carbon black graft polymer dispersion 6 was obtained in the same manner as in Synthesis Example 1, except that the amount was 90 parts. The following components were uniformly mixed in the carbon black graft polymer dispersion 6 and stirred for 1 hour with an ultrasonic homogenizer to obtain a film-forming solution (R).
(Creation of film forming solution)
Carbon black graft polymer dispersion 6 25 parts N-methylpyrrolidone 8 parts Polyimide resin (U-Varnish S manufactured by Ube Industries) 33 parts (solid content 6 parts)
Polyimide resin (Ube Industries U-Varnish A) 33 parts (solid content 6 parts)
Silicone leveling agent 0.001 part

(Comparative Example 9)
In Synthesis Example 1, instead of carbon black dispersion 1 (solid), carbon black dispersion 7 (solid), 22.5 parts of polymer solution (1), and polymer solution instead of 97.5 parts of PGM-Ac (2) A carbon black graft polymer dispersion 7 was obtained in the same manner as in Synthesis Example 1 except that 37.5 parts and PGM-Ac 82.5 parts were used. The following components were uniformly mixed in the carbon black graft polymer dispersion 7, and stirred for 1 hour with an ultrasonic homogenizer to obtain a film-forming solution (S).
(Creation of film forming solution)
Carbon black graft polymer dispersion 7 25 parts N-methylpyrrolidone 8 parts Polyimide resin (U-Varnish S manufactured by Ube Industries) 33 parts (solid content 6 parts)
Polyimide resin (Ube Industries U-Varnish A) 33 parts (solid content 6 parts)
Silicone leveling agent 0.001 part

(Comparative Example 10)
In Synthesis Example 1, carbon black dispersion 8 (solid) was used instead of carbon black dispersion 1 (solid), and 30 parts of polymer solution (3) was used instead of 22.5 parts of polymer solution (1). A carbon black graft polymer dispersion 8 was obtained in the same manner as in Synthesis Example 1 except that. The following components were uniformly mixed in the carbon black graft polymer dispersion 8 and stirred for 1 hour with an ultrasonic homogenizer to obtain a film-forming solution (T).
(Creation of film forming solution)
Carbon black graft polymer dispersion 8 25 parts N-methylpyrrolidone 8 parts Polyimide resin (U-Varnish S manufactured by Ube Industries) 33 parts (solid content 6 parts)
Polyimide resin (Ube Industries U-Varnish A) 33 parts (solid content 6 parts)
Silicone leveling agent 0.001 part

3. Encapsulated carbon black In the carbon black encapsulation process, it is particularly necessary to use an acrylic or polyester-based fine particle impregnated with a pigment, that is, an encapsulated carbon black in which the pigment is present in the surface layer, inside, or entirely. preferable. More specifically, carbon black fine particles produced by the method disclosed in Japanese Patent Application Laid-Open No. 2000-53898 can be mentioned. One example according to this is shown below.

Carbon black encapsulated dispersion 1
In a sealable reaction vessel equipped with a stirring blade, a cooling pipe, and a nitrogen gas introduction pipe, 20 parts by weight of methyl ethyl ketone as a polymerization solvent and an initial charge monomer and a polymerization chain transfer agent having the following composition as a polymerizable unsaturated monomer were charged, Gas replacement was sufficiently performed.
Methyl methacrylate (monomer) 12.8 parts 2-hydroxyethyl methacrylate (monomer) 1.2 parts Methacrylic acid (monomer) 2.9 parts Silicone macromer (FM-0711 manufactured by Chisso Corporation) 2 parts Styrene acrylonitrile macromer (Toa Gosei Co., Ltd. AN-6) 1 part Mercaptoethanol (polymerization chain transfer agent) 0.3 part It heated up to 65 degreeC, stirring the liquid mixture in reaction container in nitrogen atmosphere. Separately, the following dropped monomer monomer and polymerization chain transfer agent, 60 parts of methyl ethyl ketone, and 0.2 part of 2,2′-azobis (2,4-dimethylvaleronitrile) are mixed and sufficiently purged with nitrogen. The obtained mixed solution was gradually dropped into the reaction vessel over 3 hours.
Methyl methacrylate (monomer) 51 parts 2-hydroxyethyl methacrylate (monomer) 4.2 parts Methacrylic acid (monomer) 11 parts Silicone macromer (FM-0711 manufactured by Chisso Corporation) 8 parts Styrene acrylonitrile macromer (Toa Gosei ( Co., Ltd. AN-6) 4 parts Mercaptoethanol (polymerization chain transfer agent) 1.2 parts Two hours after the completion of the dropping, 0.1 part by weight of 2,2′-azobis (2,4-dimethylvaleronitrile) was added. A solution dissolved in 5 parts by weight of methyl ethyl ketone was added, and further aged at 65 ° C. for 2 hours and then at 70 ° C. for 2 hours to obtain a vinyl polymer solution.
A part of the obtained vinyl polymer solution was isolated by drying at 105 ° C. for 2 hours under reduced pressure to completely remove the solvent. The weight average molecular weight was about 10,000 and Tg was 180 ° C.

  To 3 g of the vinyl polymer obtained by drying the vinyl polymer solution obtained above under reduced pressure, 25 g of toluene and 10 g of carbon black dispersion 1 (solid) are added and completely dissolved, and 2 g of an aqueous sodium hydroxide solution is added. In addition, some acidic groups of the vinyl polymer were neutralized. Subsequently, after adding 300 g of ion-exchange water and stirring, it emulsified for 30 minutes using Nanomaker TM (made by Nanomizer) which is an emulsifier. Toluene was completely removed at 60 ° C. under reduced pressure, and the resulting emulsion was concentrated by removing a part of water, and impurities such as monomers were removed with an ultrafiltration membrane. Thereafter, the water was completely removed at 60 ° C. under reduced pressure, and the carbon black encapsulated dispersion liquid 1 (average particle size; 98 nm, carbon black solid content concentration) of vinyl-based polymer fine particles replaced with NMP and impregnated with carbon black; 10%).

Carbon black encapsulated dispersion 2
In the carbon black encapsulated dispersion 1, the same operation as described above was performed except that the carbon black dispersion 1 (solid) was replaced with carbon black 6 (solid) and the vinyl polymer 3 g was replaced with 5 g. A carbon black encapsulated dispersion 2 was obtained.

(Example 11)
The following components were uniformly mixed in the carbon black encapsulated dispersion 1, and then stirred for 1 hour with an ultrasonic homogenizer to obtain a film-forming solution (U).
(Creation of film forming solution)
Carbon black encapsulated polymer dispersion 1 25 parts N-methylpyrrolidone 8 parts Polyimide resin (Ube Industries U-Varnish S) 33 parts (solid content 6 parts)
Polyimide resin (Ube Industries U-Varnish A) 33 parts (solid content 6 parts)
Silicone leveling agent 0.001 part

(Comparative Example 11)
The following components were uniformly mixed in the carbon black encapsulated dispersion 2 and then stirred for 1 hour with an ultrasonic homogenizer to obtain a film-forming solution (V).
(Creation of film forming solution)
Carbon Black Encapsulated Polymer Dispersion 2 25 parts N-methylpyrrolidone 8 parts Polyimide resin (Ube Industries U-Varnish S) 33 parts (solid content 6 parts)
Polyimide resin (Ube Industries U-Varnish A) 33 parts (solid content 6 parts)
Silicone leveling agent 0.001 part

Evaluation of film-forming solution and intermediate transfer member Evaluation of Storage Stability of Film Formation Solution Each of the example and the comparative example was put in a sealed container and left at 50 ° C. for 1 month. The viscosity and average particle size of the film-forming solution composition before and after being allowed to stand were measured, and the storage stability was evaluated as follows. Moreover, the presence or absence of the deposit adhering to the bottom of the storage bottle was visually observed.
A: The change in viscosity and average particle size of the film-forming solution composition is ± 20% or less with respect to that before standing. No precipitate is seen.
B: Changes in viscosity and average particle diameter of the film forming liquid composition are ± 20% or less with respect to that before standing. Although a slight deposit is seen at the bottom of the bottle, there is no practical problem.
C: Change in viscosity or average particle diameter of the film forming liquid composition exceeds ± 20% of that before standing. Precipitates are suddenly generated.
The evaluation results are shown in Table 3.

2. Method for Forming Intermediate Transfer Member Each of the film forming liquids of Examples and Comparative Examples is dispensed onto the inner surface of a cylindrical mold having an inner surface of 300 mm and a length of 500 mm that is mirror-finished with a surface roughness Ra of 0.2 μm. The film was applied to a thickness of 400 μm through a film and rotated at 1800 rpm for 15 minutes to form a coating layer having a uniform film thickness. Then, while rotating at 250 rpm, hot air of 60 ° C. was applied for 30 minutes from the outside of the mold, After heating at 150 ° C. for 60 minutes, it was cooled to room temperature. After the polyamic acid belt hardened until it can be self-supported is peeled off from the inner surface of the mold by pumping air to the belt end, the surface is replaced with the outer surface of a metal cylinder having a surface roughness Ra of 1.8 μm. After the temperature was raised to 360 ° C. at a rate of temperature rise of ° C./min, the temperature was maintained at 360 ° C. for 30 minutes, and dehydration ring-closing water was removed and imide conversion was completed. Thereafter, it was cooled to room temperature to obtain a target intermediate transfer belt having a thickness of about 80 μm.

3. Surface resistivity and its variation HIRESTA IP, MCP-HT260 (manufactured by Mitsubishi Oil Chemical Co., Ltd., probe: HR-100), applied voltage 100V, one minute later, measured surface resistivity at measurement conditions 25 ° C., 60% RH did. The measurement was performed at 12 points on the outer peripheral surface of the belt, the average value was defined as the surface resistivity of the belt, and the difference between the maximum value and the minimum value was defined as the variation. Table 3 shows the measurement results.

  As shown in Table 3, from 1 to 11 of the examples, no abnormality was observed in the storage stability, and the variation of the resistance value was within one digit. On the other hand, in Comparative Examples 1 to 11, no abnormality was observed in the storage stability, but the resistance value variation was one digit or more.

1 is a schematic configuration diagram of a revolver type color electrophotographic apparatus using an intermediate transfer member of the present invention. 1 is a schematic configuration diagram of a tandem color electrophotographic apparatus using an intermediate transfer member of the present invention. It is the schematic of the vacuum pyrolysis apparatus for the amount of hydrophilic functional groups of surface modification carbon black.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electric furnace 2 Quartz sample tube 3 Manometer 4 Cooling trap 5 Vacuum pump 6 Tepler pump 7 Gas burette 8 Gas chromatograph 9 Carrier gas inlet / outlet 10 Printer main body 12 Image writing part 13 Image forming part 14 Paper feed part 15 Fixing device 16 Registration roller 20BK, 20M, 20Y, 20C Developing device 21BK, 21M, 21Y, 21C Photoconductor 22 Intermediate transfer belt 25 Belt cleaning device 50 Transfer conveyance belt 60 Secondary transfer bias roller 200 Photoconductor drum 201 Photoconductor cleaning device 203 Charge charger 230 Revolver Developing unit 500 Intermediate transfer unit 501 Intermediate transfer belt 503 Toner seal member 504 Belt cleaning blade 505 Lubricant application brush 505
507 Primary transfer bias roller 508 Drive roller 510 Secondary transfer counter roller 514 Optical sensor 600 Secondary transfer unit 605 Secondary transfer bias roller 606 Transfer paper neutralization charger 610 Registration roller 801 Primary transfer power source 802 Secondary transfer power source

Claims (7)

A plurality of visible color development images sequentially formed on the image carrier with toner are sequentially superimposed and primarily transferred onto an endless intermediate transfer member, and the primary transfer image on the intermediate transfer member is used as a transfer material. A layer formed from a film-forming solution containing surface-modified carbon black that can be dispersed and / or dissolved in a water-soluble organic solvent without a dispersant in an intermediate transfer body in an intermediate transfer apparatus that performs secondary transfer in a batch. The carbon black has a hydrophilic functional group amount / specific surface area value in the range of 5 to 30 μmol / m ² , and the surface-modified carbon black oxidizes carbon black with hypohalous acid or a salt thereof. The intermediate transfer member obtained as described above. A plurality of visible color development images sequentially formed on the image carrier with toner are sequentially superimposed and primarily transferred onto an endless intermediate transfer member, and the primary transfer image on the intermediate transfer member is used as a transfer material. A layer formed from a film-forming solution containing surface-modified carbon black that can be dispersed and / or dissolved in a water-soluble organic solvent without a dispersant in an intermediate transfer body in an intermediate transfer apparatus that performs secondary transfer in a batch. The carbon black has a hydrophilic functional group amount / specific surface area value in the range of 5 to 30 μmol / m ² , and a resin is encapsulated on the surface of the surface-modified carbon black. The intermediate transfer member.   The type of the encapsulating resin is any one of acrylic acid-butyl acrylate-methyl methacrylate copolymer, styrene-maleic ester-maleic anhydride copolymer, and polyvinylpyrrolidone. Intermediate transfer body. A plurality of visible color development images sequentially formed on the image carrier with toner are sequentially superimposed and primarily transferred onto an endless intermediate transfer member, and the primary transfer image on the intermediate transfer member is used as a transfer material. A layer formed from a film-forming solution containing surface-modified carbon black that can be dispersed and / or dissolved in a water-soluble organic solvent without a dispersant in an intermediate transfer body in an intermediate transfer apparatus that performs secondary transfer in a batch. The carbon black has a hydrophilic functional group amount / specific surface area value of 5 to 30 μmol / m. ² A film-forming liquid composition for forming an intermediate transfer member, wherein the surface-modified carbon black is obtained by oxidizing carbon black with hypohalous acid or a salt thereof. A plurality of visible color development images sequentially formed on the image carrier with toner are sequentially superimposed and primarily transferred onto an endless intermediate transfer member, and the primary transfer image on the intermediate transfer member is used as a transfer material. A layer formed from a film-forming solution containing surface-modified carbon black that can be dispersed and / or dissolved in a water-soluble organic solvent without a dispersant in an intermediate transfer body in an intermediate transfer apparatus that performs secondary transfer in a batch. The carbon black has a hydrophilic functional group amount / specific surface area value of 5 to 30 μmol / m. ² A film forming liquid composition for forming an intermediate transfer member, wherein the resin is encapsulated on the surface of the surface-modified carbon black. The type of the encapsulating resin is any one of acrylic acid-butyl acrylate-methyl methacrylate copolymer, styrene-maleic ester-maleic anhydride copolymer, and polyvinylpyrrolidone. A film-forming liquid composition for forming an intermediate transfer member. At least a charging device that forms an electrostatic latent image on the image carrier, a developing device that forms a toner image using a developer corresponding to each color on the image carrier, and an intermediate that travels the toner image endlessly An intermediate transfer device that sequentially superimposes the image on the transfer body to perform primary transfer, and secondary transfer the primary transfer image on the intermediate transfer body onto the transfer material, and the toner image on the transfer material is heated or pressurized. An image forming apparatus having a fixing device for fixing a toner image on the transfer material, wherein the intermediate transfer device
An image forming apparatus using the intermediate transfer member according to any one of claims 1 to 3.

Images