Electrophotographic belt and electrophotographic image forming apparatus

Abstract

To provide an electrophotographic belt that can form good electrophotographic images over a long period, and an electrophotographic image forming apparatus including the electrophotographic belt.SOLUTION: An electrophotographic belt has a surface layer 22. The surface layer 22 includes resin A. The resin A has at least one structure selected from the group consisting of a structure represented by the formula (1) and a structure represented by the specific formula (2). The total content of a portion excluding X1 and X2 from the structure represented by the formula (1) and a portion excluding specific X3 and X4 from the specific structure represented by the formula (2) is 10 mass% or more based on the mass of the surface layer 22.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to an electrophotographic belt used in an electrophotographic image forming apparatus and an electrophotographic image forming apparatus employing the electrophotographic belt. [Background technology]

[0002] Electrophotographic image forming devices widely use the tandem method, in which a toner image is formed on a photosensitive member, and then the toner images of each color (Yellow, Magenta, Cyan, and K) are superimposed on an intermediate transfer belt, and then all of the toner images are transferred onto paper at once to obtain a full-color image.

[0003] Electrophotographic devices, which require high-speed printing and maintenance-free operation, require even more durable intermediate transfer belts. A widely adopted technology for tandem printing involves placing density-correcting toner images and color-shift measurement toner images on the intermediate transfer belt and measuring the density and color shift with a sensor to correct color density and color shift, thereby maintaining consistent color tone, gradation, and color shift even when printing multiple sheets. To achieve this correction, the light reflectance of the intermediate transfer belt surface must remain consistent over multiple print runs. However, the adhesion of external additives used in toner can cause changes in the light reflectance of the intermediate transfer belt surface over multiple print runs, resulting in poor sensor measurement accuracy for the density-correcting toner images. Patent Document 1 addresses this issue by cleaning the intermediate transfer belt (ITB) with a fur brush, where the inorganic external additives adhering to the brush polish the surface of the intermediate transfer belt (ITB), thereby improving gloss reduction due to the adhesion. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2019-040125 [Patent Document 2] Japanese Patent Application Publication No. 08-044103 Summary of the Invention [Problem to be solved by the invention]

[0005] However, after extensive research, the present inventors have found that while the method described in Patent Document 1 is effective when only inorganic particles are used in the toner, when polymer particles such as polyvinylidene fluoride (PVDF) particles or styrene acrylic particles are used as particles to adhere to the toner surface, as shown in Patent Document 2, it is difficult to maintain the light reflectivity of the surface of the intermediate transfer belt using the method described in Patent Document 1, because polymer particles do not have the abrasive power of inorganic particles.

[0006] Therefore, an object of the present disclosure is to provide an electrophotographic belt that can maintain the light reflectivity of its surface and is less susceptible to changes in color tone, gradation, and color misregistration even when a large number of sheets are printed. [Means for solving the problem]

[0007] The above object can be achieved by the present disclosure as follows: 1. An electrophotographic belt having a surface layer, The surface layer contains a resin A, The resin A has at least one structure selected from the group consisting of a structure represented by formula (1) and a structure represented by formula (2), The electrophotographic belt is characterized in that the total content of the portion obtained by excluding X1 and X2 from the structure represented by formula (1) and the portion obtained by excluding X3 and X4 from the structure represented by formula (2) is 10 mass % or more based on the mass of the surface layer. [ka] [In the formula, X1 and X2 each independently represent a hydrogen atom, a moiety having a structure represented by the following formula (3), or a moiety having a structure represented by the following formula (4), n and m each independently represent an integer of 1 or greater, and 10≦m+n≦1800. In addition, any one of all X1 and X2 in the formula is a moiety having a structure represented by the following formula (3) or a moiety having a structure represented by the following formula (4). Also, AH represents a hydrogen atom or an OH group.] [ka] [In the formula, X3 and X4 each independently represent a hydrogen atom, a moiety having a structure represented by the following formula (3), or a moiety having a structure represented by the following formula (4), p and q each independently represent an integer of 1 or greater, and 10≦p+q≦1800. In addition, any one of all X3 and X4 in the formula is a moiety having a structure represented by the following formula (3) or a moiety having a structure represented by the following formula (4). Also, AH represents a hydrogen atom or an OH group.] [ka] [In the formula, A1 represents an organic group containing an aromatic group which may have a substituent, or an aliphatic group which may have a substituent, T is an integer of 2 to 6, and * represents a site connected to the structure represented by formula (1) or formula (2) directly or via a linking group.] [ka] [In the formula, A2 represents an organic group containing an aromatic group which may have a substituent, or an aliphatic group which may have a substituent, R2 represents a hydrogen atom or a methyl group, U represents an integer of 2 to 6, and * represents a site connected to the structure represented by formula (1) or formula (2) directly or via a linking group.] [Effects of the Invention]

[0008] According to at least one aspect of the present disclosure, there is provided an electrophotographic belt capable of forming good electrophotographic images over a long period of time, and further, according to at least one aspect of the present disclosure, there is provided an electrophotographic image forming apparatus capable of stably forming high-quality electrophotographic images. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a schematic configuration diagram of an electrophotographic image forming apparatus according to the present disclosure. [Figure 2] 1 is an example showing a cross-sectional configuration of an intermediate transfer belt according to the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0010] In this specification, expressions such as "XX or more and YY or less" or "XX to YY" that represent a numerical range mean a numerical range including the lower and upper limits, which are the endpoints, unless otherwise specified. Furthermore, when a numerical range is described in stages, the upper and lower limits of each numerical range can be arbitrarily combined. Furthermore, in the present disclosure, expressions such as "at least one selected from the group consisting of XX, YY, and ZZ" mean any of XX, YY, ZZ, a combination of XX and YY, a combination of XX and ZZ, a combination of YY and ZZ, or a combination of XX, YY, and ZZ.

[0011] Unless otherwise specified, the measured values ​​shown below were measured in an environment with a temperature of 23°C and a humidity of 50% RH.

[0012] One embodiment of the present disclosure is an electrophotographic belt having a surface layer, The surface layer contains a resin A, The resin A has at least one structure selected from the group consisting of a structure represented by formula (1) and a structure represented by formula (2), The electrophotographic belt is characterized in that the total content of the portion obtained by excluding X1 and X2 from the structure represented by formula (1) and the portion obtained by excluding X3 and X4 from the structure represented by formula (2) is 10 mass % or more based on the mass of the surface layer. [ka] [In the formula, X1 and X2 each independently represent a hydrogen atom, a moiety having a structure represented by the following formula (3), or a moiety having a structure represented by the following formula (4), n and m each independently represent an integer of 1 or greater, and 10≦m+n≦1800. In addition, any one of all X1 and X2 in the formula is a moiety having a structure represented by the following formula (3) or a moiety having a structure represented by the following formula (4). Also, AH represents a hydrogen atom or an OH group.] [ka] [In the formula, X3 and X4 each independently represent a hydrogen atom, a moiety having a structure represented by the following formula (3), or a moiety having a structure represented by the following formula (4), p and q each independently represent an integer of 1 or greater, and 10≦p+q≦1800. In addition, any one of all X3 and X4 in the formula is a moiety having a structure represented by the following formula (3) or a moiety having a structure represented by the following formula (4). Also, AH represents a hydrogen atom or an OH group.] [ka] [In the formula, A1 represents an organic group containing an aromatic group which may have a substituent, or an aliphatic group which may have a substituent, T represents an integer of 2 to 6, and * represents a site connected to the structure represented by formula (1) or formula (2) directly or via a linking group.] [ka] [In the formula, A2 represents an organic group containing an aromatic group which may have a substituent, or an aliphatic group which may have a substituent, R2 represents a hydrogen atom or a methyl group, U represents an integer of 2 to 6, and * represents a site connected to the structure represented by formula (1) or formula (2) directly or via a linking group.] One embodiment of the present disclosure is the electrophotographic belt described above, wherein the surface layer contains the structure of formula (1) excluding X1 and X2 and the structure of formula (2) excluding X3 and X4 in total at 20 mass % or more.

[0013] One embodiment of the present disclosure is an electrophotographic belt having a surface layer, The surface layer is (i) a compound having two or more (meth)acryloyl groups or a compound having two or more thiol groups; (ii) at least one of trans 1,4-polyisoprene and 3,4-polyisoprene; a layer made of a cured product formed by curing the The electrophotographic belt is characterized in that the total content of units derived from trans-1,4-polyisoprene and units derived from 3,4-polyisoprene in the surface layer is 10% by mass or more.

[0014] One embodiment of the present disclosure is the electrophotographic belt described above, wherein the cured product has a total content of units derived from trans-1,4-polyisoprene and units derived from 3,4-polyisoprene of 20% by mass or more based on the mass of the surface layer.

[0015] In one embodiment of the present disclosure, the Martens hardness determined by an indentation test of the surface layer is 12.0 N / mm 2 The electrophotographic belt described above is characterized in that:

[0016] One embodiment of the present disclosure is an electrophotographic image forming apparatus including an image carrier that carries a toner image, and an intermediate transfer belt that carries and transports the toner image that has been primarily transferred from the image carrier to a transfer material for secondary transfer, wherein the intermediate transfer belt is the electrophotographic belt described above.

[0017] One embodiment of the present disclosure is the electrophotographic image forming apparatus described above, characterized in that a toner having polymeric fine particles with a particle diameter of 1.0 μm or less adhered to the surface thereof is used.

[0018] Preferred embodiments of the present disclosure will be described in detail below with reference to the drawings. However, the dimensions, materials, shapes, and relative positions of the components described in the following embodiments may be changed as appropriate depending on the configuration and various conditions of the device to which the present disclosure is applied, and are not intended to limit the scope of the present disclosure to only those.

[0019] [Electrophotographic image forming device] An electrophotographic image forming apparatus 100 shown in FIG. 1 is a schematic cross-sectional view of an electrophotographic image forming apparatus equipped with an electrophotographic member according to one embodiment of the present disclosure.

[0020] The electrophotographic image forming apparatus 100 shown in FIG. 1 is equipped with an intermediate transfer belt (electrophotographic belt) 7, which is an intermediate transfer member. Further, image forming units Py, Pm, Pc, and Pk for the respective colors of yellow (Y), magenta (M), cyan (C), and black (K) are arranged along a flat portion of the intermediate transfer belt 7 in the moving direction of the belt. In FIG. 1, 1Y, 1M, 1C, and 1K respectively represent electrophotographic photosensitive members, and 2Y, 2M, 2C, and 2K respectively represent charging rollers. Further, 3Y, 3M, 3C, and 3K respectively represent laser exposure devices, 4Y, 4M, 4C, and 4K respectively represent developing units, and 5Y, 5M, 5C, and 5K respectively represent primary transfer rollers. Since the basic configuration of each image forming unit is the same, only the yellow image forming unit Py will be described in detail.

[0021] The yellow image forming unit Py has a drum-shaped electrophotographic photosensitive member 1Y (hereinafter also referred to as "photosensitive drum" or "first image carrier") as an image carrier. The photosensitive drum 1Y is formed by laminating a charge generation layer, a charge transport layer, and a surface protection layer in this order on an aluminum cylinder as a base.

[0022] The yellow image forming unit Py also includes a charging roller 2Y as a charging means. By applying a charging bias to the charging roller 2Y, the surface of the photosensitive drum 1Y is uniformly charged.

[0023] A laser exposure device 3Y is disposed above the photosensitive drum 1Y as an image exposure means. The laser exposure device 3Y scans and exposes the uniformly charged surface of the photosensitive drum 1Y in accordance with image information, forming an electrostatic latent image of a yellow color component on the surface of the photosensitive drum 1Y.

[0024] The electrostatic latent image formed on the photosensitive drum 1Y is developed with toner, which is a developer, by a developing device 4Y serving as a developing means. The developing device 4Y includes a developing roller 4Ya, which is a developer carrier, and a regulating blade 4Yb, which is a developer amount regulating member, and contains yellow toner, which is a developer. The developing roller 4Ya, to which the yellow toner is supplied, is in light pressure contact with the photosensitive drum 1Y in the developing section, and is rotated in the forward direction with a speed difference from the photosensitive drum 1Y. The yellow toner transported to the developing section by the developing roller 4Ya adheres to the electrostatic latent image formed on the photosensitive drum 1Y by applying a developing bias to the developing roller 4Ya. As a result, a visible image (yellow toner image) is formed on the photosensitive drum 1Y.

[0025] The intermediate transfer belt 7 is stretched over a drive roller 71, a tension roller 72, and a driven roller 73, and is moved (rotationally driven) in the direction of the arrow in the figure while in contact with the photosensitive drum 1Y. A cross-sectional view of the intermediate transfer belt is shown in Figure 2. Here, 21 is a base layer and 22 is a surface protection layer.

[0026] The yellow toner image formed on the photosensitive drum (first image carrier) that has reached the primary transfer section Ty is primarily transferred onto the intermediate transfer belt 7 by the primary transfer body (primary transfer roller 5Y) that is arranged opposite the photosensitive drum 1Y via the intermediate transfer belt 7.

[0027] Similarly, the above image forming operation is performed in each of the magenta (M), cyan (C), and black (K) units Pm, Pc, and Pk as the intermediate transfer belt 7 moves, and toner images of four colors (yellow, magenta, cyan, and black) are layered on the intermediate transfer belt 7. The four color toner layers are transported as the intermediate transfer belt 7 moves, and at the secondary transfer portion T', secondary transfer roller 8, which serves as secondary transfer means, transfers them all at once onto a transfer material S (hereinafter also referred to as the "second image carrier") that is transported at a predetermined timing. In this type of secondary transfer, a transfer voltage of several kV is usually applied to ensure a sufficient transfer rate.

[0028] The transfer material S is supplied to a conveying path from a cassette 12 storing the transfer material S by a pickup roller 13. The transfer material S supplied to the conveying path is conveyed to a secondary transfer portion T' in synchronization with the four-color toner image transferred to the intermediate transfer belt 7 by a conveying roller pair 14 and a registration roller pair 15.

[0029] The toner image transferred to the transfer material S is fixed by a fixing device 9 to become, for example, a full-color image. The fixing device 9 has a fixing roller 91 equipped with a heating means and a pressure roller 92, and fixes the unfixed toner image on the transfer material S by applying heat and pressure. Thereafter, the transfer material S is discharged outside the apparatus by a pair of conveying rollers 16, a pair of discharging rollers 17, etc.

[0030] As explained above, the electrical transfer process of the toner image is repeated from the photosensitive member to the intermediate transfer belt and from the intermediate transfer belt to the transfer material. Furthermore, by repeating recording onto a large number of transfer materials, the electrical transfer process is further repeated. Reference numeral 11 denotes a cleaning member.

[0031] [Color Correction / Color Misalignment Correction] Color tone correction and color misregistration correction are performed by forming an image for detecting color tone or an image for detecting color misregistration on the electrophotographic belt and reading it via a sensor on the electrophotographic belt.In this case, the reflectance of the electrophotographic belt itself is also read as background, so if the reflectance of the electrophotographic belt changes too much, it becomes difficult to determine whether the change is due to a change in the reflectance of the electrophotographic belt or a change in the toner image, and there is a possibility that correction cannot be performed accurately.

[0032] [Electrophotographic belt] The electrophotographic belt of the present disclosure has a base layer and a surface layer on the base layer. That is, the electrophotographic belt of the present disclosure is an electrophotographic belt having a surface layer, The surface layer contains a resin A, The resin A has at least one structure selected from the group consisting of a structure represented by formula (1) and a structure represented by formula (2), The electrophotographic belt is characterized in that the total content of the portion obtained by excluding X1 and X2 from the structure represented by formula (1) and the portion obtained by excluding X3 and X4 from the structure represented by formula (2) is 10 mass % or more based on the mass of the surface layer. [ka] [In the formula, X1 and X2 each independently represent a hydrogen atom, a moiety having a structure represented by the following formula (3), or a moiety having a structure represented by the following formula (4), n and m each independently represent an integer of 1 or greater, and 10≦m+n≦1800. In addition, any one of all X1 and X2 in the formula is a moiety having a structure represented by the following formula (3) or a moiety having a structure represented by the following formula (4). Also, AH represents a hydrogen atom or an OH group.] [ka] [In the formula, X3 and X4 each independently represent a hydrogen atom, a moiety having a structure represented by the following formula (3), or a moiety having a structure represented by the following formula (4), p and q each independently represent an integer of 1 or greater, and 10≦p+q≦1800. In addition, any one of all X3 and X4 in the formula is a moiety having a structure represented by the following formula (3) or a moiety having a structure represented by the following formula (4). Also, AH represents a hydrogen atom or an OH group.] [ka] [In the formula, A1 represents an organic group containing an aromatic group which may have a substituent, or an aliphatic group which may have a substituent, T represents an integer of 2 to 6, and * represents a site connected to the structure represented by formula (1) or formula (2) directly or via a linking group.] [ka] [In the formula, A2 represents an organic group containing an aromatic group which may have a substituent, or an aliphatic group which may have a substituent, R2 represents a hydrogen atom or a methyl group, U represents an integer of 2 to 6, and * represents a site connected to the structure represented by formula (1) or formula (2) directly or via a linking group.]

[0033] The material of the base layer is not particularly limited, and well-known materials can be used depending on the application of the electrophotographic member, as will be described in detail later. The surface layer contains a resin A having at least one structure selected from the group consisting of a structure represented by formula (1) and a structure represented by formula (2). The resin A includes a resin obtained by polymerizing a (meth)acrylate monomer or a resin obtained by polymerizing a polyfunctional thiol. The inclusion of such a resin improves the adhesion and mechanical strength between the surface layer and the base layer.

[0034] The content of resin A in the surface layer is not particularly limited, but in order to impart excellent strength to the surface layer and to impart excellent toner releasability to the outer surface of the surface layer, it is preferable that the content be 20 to 90% by mass relative to the mass of the total solid content of the surface layer. Examples of the (meth)acrylic monomer include the following (i) acrylate, (ii) methacrylate, (iii) urethane acrylate, and (iv) urethane methacrylate. As the polymerizable monomer, those commercially available as paints can also be used. (i) At least one acrylate selected from the group consisting of pentaerythritol triacrylate, pentaerythritol tetraacrylate, ditrimethylolpropane tetraacrylate, dipentaerythritol hexaacrylate, alkyl acrylate, benzyl acrylate, phenyl acrylate, ethylene glycol diacrylate, and bisphenol A diacrylate. (ii) At least one methacrylate selected from the group consisting of pentaerythritol trimethacrylate, pentaerythritol tetramethacrylate, ditrimethylolpropane tetramethacrylate, dipentaerythritol hexamethacrylate, alkyl methacrylate, benzyl methacrylate, phenyl methacrylate, ethylene glycol dimethacrylate, and bisphenol A dimethacrylate. (iii) At least one acrylate selected from the group consisting of polyether-based urethane acrylates and polyester-based urethane acrylates. (iv) At least one methacrylate selected from the group consisting of polyether-based urethane methacrylates and polyester-based urethane methacrylates. Examples of polyfunctional thiols include secondary thiols such as pentaerythritol tetrakis(3-mercaptobutyrate), 1,4-bis(3-mercaptobutyryloxy)butane, 1,3,5-tris(2-(3-sulfanylbutanoyloxy)ethyl)-1,3,5-triazinane-2,4,6-trione, and trimethylolpropane tris(3-mercaptobutyrate); and 3-(3-mercaptopropoxy)-2,2-bis-(3-mercaptopropoxymethyl)-propan-1-ol and trimethylolpropane. Examples of primary thiols include dipropanethiol, 2,2-bis[(3-sulfanylpropoxy)methyl]butan-1-ol, and pentaerythritol tetrapropanethiol, 3-{3-(3-mercapto-propoxy)-2,2-bis-[(3-mercaptopropoxy)methyl]propoxy}-propan-1-ol.

[0035] In addition, in order to form a (meth)acrylic resin from such a polymerizable monomer, there is a method in which a photopolymerization initiator is added and polymerization is carried out by electron beam or ultraviolet light.

[0036] Examples of the photopolymerization initiator include radical-generating photopolymerization initiators such as benzophenone, thioxanthone, benzyl dimethyl ketal, α-hydroxyketone, α-hydroxyalkylphenone, α-aminoketone, α-aminoalkylphenone, monoacylphosphine oxide, bisacylphosphine oxide, hydroxybenzophenone, aminobenzophenone, titanocene, oxime ester, and oxyphenylacetic acid ester.

[0037] [Surface layer] The surface layer of an electrophotographic belt generally requires low adhesion and slipperiness. Fluorine and silicone materials have been used to achieve this. Organic fluorine and silicone materials have low surface free energy, making them capable of achieving low adhesion and slipperiness. However, in recent years, significant restrictions on organic fluorine materials have been discussed in some countries. Silicone materials also sometimes contain cyclic siloxanes such as D4, D5, and D6 as unreacted raw materials, but cyclic siloxanes are also restricted in some countries. Therefore, there is a demand for materials that can achieve low adhesion and slipperiness without relying on organic fluorine or silicone materials.

[0038] [Polyisoprene] In this disclosure, polyisoprene with a specific structure is used in the surface layer of an electrophotographic belt. Polyisoprene typically exists in various isomers, but attempts have been made to provide elastic intermediate transfer belts (ITBs) by using polyisoprene, which contains 90% or more cis isomers and has properties similar to natural rubber, in the surface layer of an intermediate transfer belt. For such an elastic layer to be usable as a belt, the elastic layer made of polyisoprene must have a thickness of 100 μm or more. This disclosure does not involve the use of polyisoprene in such an elastic layer, but rather the use of polyisoprene as a surface layer.

[0039] [Base layer] The material of the base layer may be any known material for electrophotographic materials and is not particularly limited. For example, resins with excellent mechanical strength, such as nylon, polyphenyl sulfide, polyimide, polyamideimide, polyether ether ketone, and polyurethane elastomer, are used. The thickness of the base layer is not particularly limited, but is preferably 20 μm to 500 μm, more preferably 40 μm to 300 μm, from the viewpoints of strength, flexibility, and heat capacity. Furthermore, conductive fillers such as carbon black and ionic conductive agents may be added to the resin to impart semiconductivity. [Example]

[0040] The present disclosure will be described in more detail below using examples and comparative examples. The present disclosure is not limited in any way by the following examples, as long as it does not deviate from the gist of the disclosure. In the following description of the examples, "parts" are based on mass unless otherwise specified.

[0041] [Example 1] (Example of manufacturing base layer α) Using a twin-screw kneader, 85% by mass of nylon 12 (Rilsamid AMN P20 TL, manufactured by Arkema) and 15% by mass of acetylene black (Denka Black, manufactured by Denka) were melt-kneaded to prepare raw material α-1. Raw material α-1 was fed into an extruder and connected to a circular die to obtain a seamless belt α as the base layer α.

[0042] (Example of manufacturing surface layer paint A1) The following four compounds were mixed for 6 hours using a mix rotor in a darkened state to obtain a surface layer coating material A1. Tokyo Chemical Industry Co., Ltd. Trimethylolpropane tris(3-mercaptopropionate) 60 parts by mass Sigma-Aldrich trans-1,4-polyisoprene (99% by mass, Mw 50,000, 1% by mass is 1,2-cis polyisoprene) 40 parts by mass Tokyo Chemical Industry Co., Ltd. 1-hydroxycyclohexyl phenyl ketone 6 parts by mass Kishida Chemical Toluene 100 parts by mass

[0043] (Manufacturing example of electrophotographic belt 1) The surface layer coating material A1 was applied to the seamless belt α, and the solvent was dried for 10 minutes at 80° C. Thereafter, UV irradiation was performed with an integrated light amount of 2000 mJ at a wavelength of 365 nm, thereby obtaining a seamless belt α1 as an electrophotographic belt 1.

[0044] [Example 2] (Example of manufacturing base layer β) Using a twin-screw kneader, 85% by mass of polyphenyl sulfide (Toray, E2180), 17% by mass of acetylene black (Denka, Denka Black), and a graft copolymer of ethylene-glycidyl methacrylate copolymer / styrene-acrylonitrile copolymer (NOF, Modiper A4400) were melt-kneaded to produce raw material β-1. Raw material β-1 was fed into an extruder and connected to a circular die to obtain seamless belt β as base layer β.

[0045] (Production example of 3,4-polyisoprene) The following two compounds were placed in a flask: Toluene (Kishida Chemical) 13ml Isoprene (Tokyo Chemical Industry Co., Ltd.) 2ml Next, a condenser was attached, and the mixture was stirred in a water-ethanol-dry ice bath while maintaining the temperature at -30°C. The following two compounds were then added. The reaction was allowed to proceed at -30°C, and the nitrogen substitution was removed to terminate the reaction. 3,4-polyisoprene (80% by mass, 20% by mass being 1,2-cis polyisoprene) was obtained by evaporating the solvent. Note that 3,4-polyisoprene with different weight-average molecular weights (Mw) was obtained by controlling the reaction time from 10 minutes to 2 hours. Tris(2,2'-BIPYRIDINE)IRON(II)DICHLORIDE (Matrix) 5 μl Methylaluminoxane 10 wt% toluene solution (Sigma-Aldrich) 50 μl

[0046] (Example of manufacturing surface layer paint A2) Surface layer paint A2 was obtained in the same manner as surface layer paint A1, except that the compounds used in surface layer paint A1 were changed to the following compounds and parts by mass. Tokyo Chemical Industry Co., Ltd. Trimethylolpropane tris(3-mercaptopropionate) 75 parts by mass 3,4-Polyisoprene (80% by mass, Mw 5,000, 20% by mass is 1,2-cis polyisoprene) 25 parts by mass Tokyo Chemical Industry Co., Ltd. 1-hydroxycyclohexyl phenyl ketone 6 parts by mass Kishida Chemical Toluene 100 parts by mass

[0047] (Manufacturing example of electrophotographic belt 2) The surface layer coating material A2 was applied to the seamless belt β, and the solvent was dried for 10 minutes at 80° C. Thereafter, UV irradiation was performed at a wavelength of 365 nm with an integrated light amount of 2000 mJ, thereby obtaining a seamless belt β2 as the electrophotographic belt 2.

[0048] [Example 3] (Example of manufacturing surface layer paint A3) Surface layer paint A3 was obtained in the same manner as surface layer paint A1, except that the compounds used in surface layer paint A1 were changed to the following compounds and parts by mass. Toagosei hexafunctional acrylate (Aronix M-405) 90 parts by weight 10 parts by mass of trans-1,4 polyisoprene (99% by mass, Mw 50,000, 1% by mass is 1,2-cis polyisoprene) manufactured by Sigma-Aldrich Tokyo Chemical Industry Co., Ltd. 1-hydroxycyclohexyl phenyl ketone 6 parts by mass Kishida Chemical Toluene 100 parts by mass

[0049] (Manufacturing example of electrophotographic belt 3) The surface layer coating material A3 was applied to the seamless belt β, and the solvent was dried for 10 minutes at 80° C. Thereafter, UV irradiation was performed at a wavelength of 365 nm with an integrated light amount of 2000 mJ, thereby obtaining a seamless belt β3 as an electrophotographic belt 3.

[0050] [Example 4] (Example of manufacturing surface layer paint A4) Surface layer paint A4 was obtained in the same manner as surface layer paint A1, except that the compounds used in surface layer paint A1 were changed to the following compounds and parts by mass. Toagosei trifunctional acrylate (Aronix M-309) 75 parts by weight 25 parts by mass of 3,4-polyisoprene (80% by mass, Mw 50,000, 20% by mass is 1,2-cis polyisoprene) Tokyo Chemical Industry Co., Ltd. 1-hydroxycyclohexyl phenyl ketone 6 parts by mass Kishida Chemical Toluene 100 parts by mass

[0051] (Manufacturing example of electrophotographic belt 4) The surface layer coating material A4 was applied to the seamless belt α, and the solvent was dried for 10 minutes at 80° C. Thereafter, UV irradiation was performed with an integrated light amount of 2000 mJ at a wavelength of 365 nm, thereby obtaining a seamless belt α4 as an electrophotographic belt 4.

[0052] [Example 5] (Example of manufacturing surface layer paint A5) Surface layer paint A5 was prepared in the same manner as surface layer paint A1, except that the compounds used in surface layer paint A1 were changed to the following compounds and parts by mass. Toagosei trifunctional acrylate (Aronix M-306) 87.5 parts by weight 3,4-Polyisoprene (80% by mass, Mw 20,000, 20% by mass is 1,2-cis polyisoprene) 12.5 parts by mass Tokyo Chemical Industry Co., Ltd. 1-hydroxycyclohexyl phenyl ketone 6 parts by mass Kishida Chemical Toluene 100 parts by mass

[0053] (Manufacturing example of electrophotographic belt 5) The surface layer coating material A5 was applied to the seamless belt α, and the solvent was dried for 10 minutes at 80° C. Thereafter, UV irradiation was performed with an integrated light amount of 2000 mJ at a wavelength of 365 nm, thereby obtaining a seamless belt α5 as an electrophotographic belt 5.

[0054] [Example 6] (Example of manufacturing surface layer paint A6) Surface layer paint A6 was obtained in the same manner as surface layer paint A1, except that the compounds used in surface layer paint A1 were changed to the following compounds and parts by mass. Toagosei tetrafunctional acrylate (Aronix M-408) 88 parts by weight 3,4-Polyisoprene (80% by mass, Mw 10,000, 20% by mass is 1,2-cis polyisoprene) 10 parts by mass Sigma-Aldrich trans-1,4-polyisoprene 2 parts by mass Tokyo Chemical Industry Co., Ltd. 1-hydroxycyclohexyl phenyl ketone 6 parts by mass Kishida Chemical Toluene 100 parts by mass

[0055] (Manufacturing example of electrophotographic belt 6) The surface layer coating material A6 was applied to the seamless belt β, and the solvent was dried for 10 minutes at 80° C. Thereafter, UV irradiation was performed at a wavelength of 365 nm with an integrated light amount of 2000 mJ, thereby obtaining a seamless belt β6 as an electrophotographic belt 6.

[0056] [Example 7] (Example of manufacturing base layer γ) The following three compounds were melt-kneaded using a twin-screw kneader to prepare raw material γ-1. BASF Elastollan ET155D 99 parts by mass Sigma-Aldrich Poly(ethylene oxide) Mw 150,000 1 part by mass Tokyo Chemical Industry Co., Ltd. Lithium perchlorate 0.1 parts by mass Raw materials γ-1 and α-1 were each fed into separate extruders, connected to a cylindrical die for co-extrusion, and co-extruded so that the layer derived from raw material γ-1 was the outer layer and the layer derived from raw material α-1 was the inner layer, thereby obtaining a seamless belt γ as the base layer γ.

[0057] (Example of manufacturing surface layer paint A7) Surface layer paint A7 was prepared in the same manner as surface layer paint A1, except that the compounds used in surface layer paint A1 were changed to the following compounds and parts by mass. 90 parts by weight of Shin-Nakamura Chemical Urethane Acrylate (UA-290TM) 10 parts by mass of trans-1,4-polyisoprene (99% by mass, Mw 50,000, 1% by mass is 1,2-cis polyisoprene) manufactured by Sigma-Aldrich Tokyo Chemical Industry Co., Ltd. 1-hydroxycyclohexyl phenyl ketone 6 parts by mass Kishida Chemical Toluene 100 parts by mass

[0058] (Manufacturing example of electrophotographic belt 7) The surface layer coating material A7 was applied to the seamless belt γ, and the solvent was dried for 10 minutes at 80° C. Thereafter, UV irradiation was performed with an integrated light amount of 2000 mJ at a wavelength of 365 nm, thereby obtaining a seamless belt γ7 as an electrophotographic belt 7.

[0059] [Comparative Example 1] (Example of manufacturing surface layer paint B1) Surface layer paint B1 was obtained in the same manner as surface layer paint A1, except that the compounds used in surface layer paint A1 were changed to the following compounds and parts by mass. Tokyo Chemical Industry Co., Ltd. Trimethylolpropane tris(3-mercaptopropionate) 85 parts by mass Sigma-Aldrich cis-1,4-polyisoprene (97% by mass, Mw 40,000, 3% by mass is 1,2-cis-polyisoprene) 15 parts by mass Tokyo Chemical Industry Co., Ltd. 1-hydroxycyclohexyl phenyl ketone 6 parts by mass Kishida Chemical Toluene 100 parts by mass

[0060] (Manufacturing example of electrophotographic belt 11) The surface layer coating material B1 was applied to the seamless belt α, and the solvent was dried for 10 minutes at 80° C. Thereafter, UV irradiation was performed at a wavelength of 365 nm with an integrated light amount of 2000 mJ, thereby obtaining a seamless belt α11 as an electrophotographic belt 11.

[0061] Comparative Example 2 (Example of manufacturing surface layer paint B2) Surface layer paint B2 was obtained in the same manner as surface layer paint A1, except that the compounds used in surface layer paint A1 were changed to the following compounds and parts by mass. Toagosei trifunctional acrylate (Aronix M-306) 89 parts by weight Sigma-Aldrich cis-1,4-polyisoprene (97% by mass, Mw 40,000, 3% by mass is 1,2-cis-polyisoprene) 21 parts by mass Tokyo Chemical Industry Co., Ltd. 1-hydroxycyclohexyl phenyl ketone 6 parts by mass Kishida Chemical Toluene 100 parts by mass

[0062] (Manufacturing example of electrophotographic belt 12) The surface layer coating material B2 was applied to the seamless belt β, and the solvent was dried for 10 minutes at 80° C. Thereafter, UV irradiation was performed at a wavelength of 365 nm with an integrated light amount of 2000 mJ, thereby obtaining a seamless belt β12 as the electrophotographic belt 12.

[0063] Comparative Example 3 (Example of manufacturing surface layer paint B3) Surface layer paint B3 was obtained in the same manner as surface layer paint A1, except that the compounds used in surface layer paint A1 were changed to the following compounds and parts by mass. Tokyo Chemical Industry Co., Ltd. Trimethylolpropane tris(3-mercaptopropionate) 87 parts by mass Sigma-Aldrich cis-1,4-polyisoprene (97% by mass, Mw 40,000, 3% by mass is 1,2-cis-polyisoprene) 5 parts by mass Sigma-Aldrich trans-1,4-polyisoprene (99% by mass, Mw 50,000, 1% by mass is 1,2-cis-polyisoprene) 8 parts by mass Tokyo Chemical Industry Co., Ltd. 1-hydroxycyclohexyl phenyl ketone 6 parts by mass Kishida Chemical Toluene 100 parts by mass

[0064] (Manufacturing example of electrophotographic belt 13) The surface layer coating material B3 was applied to the seamless belt β, and the solvent was dried for 10 minutes at 80° C. Thereafter, UV irradiation was performed at a wavelength of 365 nm with an integrated light amount of 2000 mJ, thereby obtaining a seamless belt β13 as the electrophotographic belt 13.

[0065] Comparative Example 4 (Example of manufacturing surface layer paint B4) Surface layer paint B4 was obtained in the same manner as surface layer paint A1, except that the compounds used in surface layer paint A1 were changed to the following compounds and parts by mass. Toagosei trifunctional acrylate (Aronix M-306) 90 parts by weight 3,4-Polyisoprene (80% by mass, 20% by mass is 1,2-cis polyisoprene) 5 parts by mass Sigma-Aldrich trans-1,4-polyisoprene (99% by mass, Mw 50,000, 1% by mass is 1,2-cis polyisoprene) 5 parts by mass Tokyo Chemical Industry Co., Ltd. 1-hydroxycyclohexyl phenyl ketone 6 parts by mass Kishida Chemical Toluene 100 parts by mass

[0066] (Manufacturing example of electrophotographic belt 14) The surface layer paint B4 was applied to the seamless belt β, and the solvent was dried for 10 minutes at 80° C. Thereafter, UV irradiation was performed with an integrated light amount of 2000 mJ at a wavelength of 365 nm, thereby obtaining a seamless belt β14 as an electrophotographic belt 14.

[0067] Comparative Example 5 (Example of manufacturing surface layer paint B5) Surface layer paint B5 was obtained in the same manner as surface layer paint A1, except that the compounds used in surface layer paint A1 were changed to the following compounds and parts by mass. Toagosei trifunctional acrylate (Aronix M-306) 92 parts by weight Sigma-Aldrich trans-1,4-polyisoprene (99% by mass, Mw 50,000, 1% by mass is 1,2-cis-polyisoprene) 8 parts by mass Tokyo Chemical Industry Co., Ltd. 1-hydroxycyclohexyl phenyl ketone 6 parts by mass Kishida Chemical Toluene 100 parts by mass

[0068] (Manufacturing example of electrophotographic belt 15) The surface layer paint B5 was applied to the seamless belt β, and the solvent was dried for 10 minutes at 80° C. Thereafter, UV irradiation was performed with an integrated light amount of 2000 mJ at a wavelength of 365 nm, thereby obtaining a seamless belt β15 as an electrophotographic belt 15.

[0069] Comparative Example 6 (Example of manufacturing surface layer paint B6) Surface layer paint B6 was prepared in the same manner as surface layer paint A1, except that the compounds used in surface layer paint A1 were changed to the following compounds and parts by mass. Toagosei trifunctional acrylate (Aronix M-306) 90 parts by weight 10 parts by mass of 3,4-polyisoprene (80% by mass, Mw 20,000, 20% by mass is 1,2-cis polyisoprene) Tokyo Chemical Industry Co., Ltd. 1-hydroxycyclohexyl phenyl ketone 6 parts by mass Kishida Chemical Toluene 100 parts by mass

[0070] (Manufacturing example of electrophotographic belt 16) The surface layer paint B6 was applied to the seamless belt β, and the solvent was dried for 10 minutes at 80° C. Thereafter, UV irradiation was performed with an integrated light amount of 2000 mJ at a wavelength of 365 nm, thereby obtaining a seamless belt β16 as an electrophotographic belt 16.

[0071] The formulations of Examples 1 to 7 and Comparative Examples 1 to 6 are shown in Table 1. [Table 1] (10) [ka] (11) [ka] (12) [ka]

[0072] (Evaluation of raw material polyisoprene) The weight-average molecular weight Mw of polyisoprene can be measured using a commercially available device in accordance with JIS K 7252-2. In the present disclosure, the measurement was performed under the following measurement conditions, but is not limited to these. Apparatus: Showa Denko GPC Column: Showa Denko KF800 series Liquid: THF (for high performance liquid chromatography) manufactured by Kishida Chemical Standard particles: Agilent Easyial series

[0073] (Physical properties of electrophotographic belts) The Martens hardness of the outer surface of the surface layer can be evaluated by the following method. The obtained electrophotographic belt is cut into a sheet measuring 20 mm in length and 20 mm in width, and the Martens hardness and elastic deformation power can be measured by nanoindentation. Using a commercially available device conforming to ISO 14577, the Martens hardness and elastic deformation power can be calculated from the obtained load-displacement curve according to the indentation test procedure specified in ISO 14577. In the present disclosure, a nanoindenter device conforming to the above ISO standard (PICODENTOR HM500 manufactured by FISCHER) was used. In the present disclosure, measurements were performed using the above measuring device and the following measurement conditions, but are not limited to these. Measurement environment: 23°C, 40% Indenter: Vickers indenter Measurement load: 260μN ·Number of measurement points: 3 points average The measurement results are shown in Table 2. The Martens hardness determined by an indentation test of the surface layer is 12.0 N / mm 2 It is preferable that this is equal to or greater than this.

[0074] (Evaluation of electrophotographic belts) A copier (product name: iR ADVANCE C5560F, manufactured by Canon Inc.) was used as the electrophotographic device, and the electrophotographic belts of the example and comparative examples were installed as intermediate transfer belts. A toner having polymeric fine particles with a particle diameter of 1.0 μm or less adhered to its surface is preferably used. In this example, a toner having styrene acrylic particles with a particle diameter of 1.0 μm or less adhered to its surface, prepared with reference to Patent Document 2, was used to print a standard image according to JIS X 9201-2001, and the L*, a*, and b* of each of the 16 color patch images were measured using an X-Rite portable spectrophotometer. After printing 10,000 sheets of A4-sized paper, the copier was turned off for 12 hours, and then another 10,000 sheets were printed. This process was repeated, and L*, a*, and b* were measured every 1,000 sheets, until 100,000 sheets were printed. The color difference (ΔE76) was calculated by calculating the difference between the L*, a*, and b* values ​​of the 1,000th image and the L*, a*, and b* values ​​of the 1,000th image, squaring each value, and taking the square root of the sum. If the color difference on the 100,000th image was 2.0 or more, it was evaluated as ×, if it was 1.0 or more but less than 2.0, it was evaluated as ○, and if it was less than 1.0, it was evaluated as ⊚. The evaluation results are shown in Table 2.

[0075] [Table 2]

[0076] (Color difference evaluation results) In the Examples, even after printing 100,000 sheets, there was little color difference, i.e., little color variation. While the reasons for this are largely unknown, it is believed that in the Examples, the use of a specific structure of polyisoprene as the raw material for the surface layer resulted in the action of methyl groups, resulting in low adhesion. This is because, when the electrophotographic belt was observed with an optical microscope after printing 100,000 sheets, it was confirmed that in the Examples, the styrene acrylic particles used in the toner adhered to the electrophotographic belt, but in the Comparative Examples, a large amount of styrene acrylic particles adhered. Due to this difference in adhesion, in the Examples, noise was less likely to be introduced when detecting the toner image for density correction placed on the belt, allowing for accurate correction, which is believed to have suppressed color variation.

[0077] The disclosure of this embodiment includes the following configuration. (Configuration 1) 1. An electrophotographic belt having a surface layer, The surface layer contains a resin A, The resin A has at least one structure selected from the group consisting of a structure represented by formula (1) and a structure represented by formula (2), an electrophotographic belt, wherein the total content of the portion obtained by excluding X1 and X2 from the structure represented by formula (1) and the portion obtained by excluding X3 and X4 from the structure represented by formula (2) is 10% by mass or more based on the mass of the surface layer. [ka] [In the formula, X1 and X2 each independently represent a hydrogen atom, a moiety having a structure represented by the following formula (3), or a moiety having a structure represented by the following formula (4), n and m each independently represent an integer of 1 or greater, and 10≦m+n≦1800. In addition, any one of all X1 and X2 in the formula is a moiety having a structure represented by the following formula (3) or a moiety having a structure represented by the following formula (4). Also, AH represents a hydrogen atom or an OH group.] [ka] [In the formula, X3 and X4 each independently represent a hydrogen atom, a moiety having a structure represented by the following formula (3), or a moiety having a structure represented by the following formula (4), p and q each independently represent an integer of 1 or greater, and 10≦p+q≦1800. In addition, any one of all X3 and X4 in the formula is a moiety having a structure represented by the following formula (3) or a moiety having a structure represented by the following formula (4). Also, AH represents a hydrogen atom or an OH group.] [ka] [In the formula, A1 represents an organic group containing an aromatic group which may have a substituent, or an aliphatic group which may have a substituent, T represents an integer of 2 to 6, and * represents a site connected to the structure represented by formula (1) or formula (2) directly or via a linking group.] [ka] [In the formula, A2 represents an organic group containing an aromatic group which may have a substituent, or an aliphatic group which may have a substituent, R2 represents a hydrogen atom or a methyl group, U represents an integer of 2 to 6, and * represents a site connected to the structure represented by formula (1) or formula (2) directly or via a linking group.] (Configuration 2) 2. The electrophotographic belt according to claim 1, wherein the total content of the structure of formula (1) excluding X1 and X2 and the structure of formula (2) excluding X3 and X4 in the surface layer is 20% by mass or more. (Configuration 3) 1. An electrophotographic belt having a surface layer, The surface layer is (i) a compound having two or more (meth)acryloyl groups or a compound having two or more thiol groups; (ii) at least one of trans 1,4-polyisoprene and 3,4-polyisoprene; a layer made of a cured product formed by curing the The electrophotographic belt is characterized in that the total content of units derived from trans-1,4-polyisoprene and units derived from 3,4-polyisoprene in the surface layer is 10% by mass or more. (Configuration 4) The electrophotographic belt according to Configuration 3, wherein the cured product has a total content of units derived from trans-1,4-polyisoprene and units derived from 3,4-polyisoprene of 20% by mass or more based on the mass of the surface layer. (Configuration 5) The Martens hardness determined by an indentation test of the surface layer is 12.0 N / mm 2 The electrophotographic belt according to any one of the first to fourth aspects described above. (Configuration 6) 6. An electrophotographic image forming apparatus comprising: an image carrier that carries a toner image; and an intermediate transfer belt that carries and transports the toner image, which has been primarily transferred from the image carrier, to a transfer material for secondary transfer, wherein the intermediate transfer belt is the electrophotographic belt according to any one of Configurations 1 to 5. (Configuration 7) 7. The electrophotographic image forming apparatus according to Configuration 6, wherein the toner has polymeric fine particles with a particle diameter of 1.0 μm or less adhered to the surface thereof. [Explanation of symbols]

[0078] Py: yellow image forming unit, Pm: magenta image forming unit, Pc: cyan image forming unit, Pk: black image forming unit, 1Y: yellow photosensitive drum, 1M: magenta photosensitive drum, 1C: cyan photosensitive drum, 1K: black photosensitive drum, 4Y: yellow developing unit, 4M: magenta developing unit, 4C: cyan developing unit, 4K: black developing unit, 5Y, 5M, 5C, 5K: primary transfer roller, Ty, Tm, Tc, Tk: primary transfer section, 73: driven roller, 100: electrophotographic image forming apparatus, 2Y, 2M, 2C, 2K: charging roller, 3Y, 3M, 3C, 3K: laser exposure device, 11: cleaning member, 12: cassette, 15: pair of registration rollers, 7: intermediate transfer belt, 8: secondary transfer roller, 9: fixing unit, 91: fixing roller, 92: pressure roller, S: transfer material

Claims

1. 1. An electrophotographic belt having a surface layer, The surface layer contains a resin A, The resin A has at least one structure selected from the group consisting of a structure represented by formula (1) and a structure represented by formula (2), an electrophotographic belt, wherein a total content of a portion obtained by excluding X1 and X2 from the structure represented by formula (1) and a portion obtained by excluding X3 and X4 from the structure represented by formula (2) is 10% by mass or more based on the mass of the surface layer. 【Chemistry 1】 [In the formula, X1 and X2 each independently represent a hydrogen atom, a moiety having a structure represented by the following formula (3), or a moiety having a structure represented by the following formula (4): n and m each independently represent an integer of 1 or more, and 10≦m+n≦1800. In addition, any one of all of X1 and X2 in the formula is a moiety having a structure represented by the following formula (3) or a moiety having a structure represented by the following formula (4). Furthermore, AH represents a hydrogen atom or an OH group. 【Chemistry 2】 [In the formula, X3 and X4 each independently represent a hydrogen atom, a moiety having a structure represented by the following formula (3), or a moiety having a structure represented by the following formula (4): p and q each independently represent an integer of 1 or more, and 10≦p+q≦1800. In addition, any one of all of X3 and X4 in the formula is a moiety having a structure represented by the following formula (3) or a moiety having a structure represented by the following formula (4). Furthermore, AH represents a hydrogen atom or an OH group. 【Transformation 3】 [In the formula, A1 represents an organic group containing an aromatic group which may have a substituent or an aliphatic group which may have a substituent, T is an integer of 2 to 6, and * represents a site connected to the structure represented by formula (1) or formula (2) directly or via a linking group.] 【Chemistry 4】 [In the formula, A2 represents an organic group containing an aromatic group which may have a substituent or an aliphatic group which may have a substituent, R2 represents a hydrogen atom or a methyl group, U represents an integer of 2 to 6, and * represents a site connected to the structure represented by formula (1) or formula (2) directly or via a linking group.]

2. 2. The electrophotographic belt according to claim 1, wherein the total content of the structure of formula (1) excluding X1 and X2 and the structure of formula (2) excluding X3 and X4 in the surface layer is 20% by mass or more.

3. 1. An electrophotographic belt having a surface layer, The surface layer is (i) a compound having two or more (meth)acryloyl groups or a compound having two or more thiol groups; (ii) at least one of trans 1,4-polyisoprene and 3,4-polyisoprene; a layer made of a cured product formed by curing the The electrophotographic belt is characterized in that the total content of units derived from trans 1,4-polyisoprene and units derived from 3,4-polyisoprene in the surface layer is 10% by mass or more.

4. 4. The electrophotographic belt according to claim 3, wherein the cured product has a total content of units derived from trans 1,4-polyisoprene and units derived from 3,4-polyisoprene of 20% by mass or more based on the mass of the surface layer.

5. The Martens hardness of the surface layer determined by an indentation test is 12.0 N / mm ２ 2. The electrophotographic belt according to claim 1, wherein the electrophotographic belt is a belt having the above structure.

6. 6. An electrophotographic image forming apparatus comprising: an image carrier that carries a toner image; and an intermediate transfer belt that carries and transports the toner image, which has been primarily transferred from the image carrier, to a transfer material for secondary transfer, wherein the intermediate transfer belt is the electrophotographic belt according to claim 1.

7. 7. An electrophotographic image forming apparatus according to claim 6, wherein the toner has polymeric fine particles with a particle diameter of 1.0 [mu]m or less adhered to the surface thereof.

Images