JP2010066307A - Endless belt for electrophotographic apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an endless belt for electrophotographic apparatus, which is soft and gives excellent picture quality. <P>SOLUTION: The endless belt for electrophotographic apparatus comprises a base layer 1 and a surface layer 3 formed directly or via another layer on the outer circumference of the base layer 1. At least one layer except the base layer comprises a thermally cured product of an epoxy composition containing the following (A) and at least one of (B) and (C). They are: (A) an epoxy compound having an oxyalkylene structure; (B) a curing agent; and (C) a polymerization initiator. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an endless belt for electrophotographic equipment, and more particularly, an endless belt for electrophotographic equipment used as an intermediate transfer belt and a transport belt for electrophotographic equipment such as an electrophotographic copying machine, a printer, and a facsimile machine.

In general, in electrophotographic equipment adopting electrophotographic technology such as full color LBP (laser beam printer) and full color PPC (plain paper copier), for applications such as toner image transfer, paper transfer conveyance, and photoreceptor substrate, Endless belts (seamless belts) are frequently used. As such an endless belt, for example, a belt using a semiconductive polyamideimide film in which a conductive carbon black is contained in a polyamideimide resin as an intermediate transfer belt has been proposed (for example, Patent Document 1, Patent Document 1). 2).
Japanese Patent No. 3218199 JP 2001-354854 A

  However, the intermediate transfer belt using the polyamide-imide resin described in Patent Documents 1 and 2 has a rigid molecular structure, and has high rigidity and poor flexibility. It is hard to deform along. Therefore, it is difficult for the toner on the intermediate transfer belt to follow the irregularities on the surface of the paper, and the transfer efficiency of the toner onto the paper is poor and the image quality is poor. In particular, the worse the paper (recycled paper or the like), the greater the unevenness of the surface of the paper, and the tendency for the image quality to be inferior.

  The present invention has been made in view of such circumstances, and an object thereof is to provide an endless belt for an electrophotographic apparatus that is flexible and can obtain excellent image quality.

In order to achieve the above object, an endless belt for electrophotographic equipment of the present invention is an endless belt for electrophotographic equipment in which a surface layer is formed on the outer periphery of a base layer directly or via another layer, and the base layer At least one layer excluding is composed of a thermoset of an epoxy composition containing the following (A) and at least one of (B) and (C).
(A) An epoxy compound having an oxyalkylene structure.
(B) Curing agent.
(C) A polymerization initiator.

  That is, the present inventors have intensively studied to solve the above problems. In the course of the research, at least one layer (for example, the intermediate layer and the surface layer) excluding the base layer of the endless belt for electrophotographic equipment is mainly composed of an epoxy compound having an oxyalkylene structure, and its curing agent (thermosetting agent) and polymerization. When constituted by a thermosetting body of an epoxy composition containing at least one of an initiator (which generates an acid by heat, which opens the glycidyl ring of the epoxy compound and acts as a curing catalyst), The inventors have found that the object can be achieved and have reached the present invention. That is, the epoxy composition has conductivity and is liquid and has a relatively low viscosity. For example, even when a conductive agent is added, the epoxy composition is efficiently dispersed. Therefore, the epoxy composition is easy to make the composition uniform, the electric resistance becomes uniform, and the viscosity is low, so that the processability is also excellent. And since the epoxy compound in the said composition has a flexible oxyalkylene structure in a molecule | numerator, the endless belt for electrophotographic apparatuses becomes low hardness.

  Thus, in the endless belt for electrophotographic equipment of the present invention, at least one layer (for example, the intermediate layer and the surface layer) excluding the base layer is mainly composed of an epoxy compound having an oxyalkylene structure, and its curing agent and polymerization initiator It consists of the thermosetting body of the epoxy composition containing at least one. Therefore, the endless belt for electrophotographic equipment of the present invention has a low hardness and a uniform electric resistance, and can obtain an excellent image, and can obtain an excellent image even after a durability test.

  Next, embodiments of the present invention will be described in detail.

  As an endless belt for electrophotographic equipment of the present invention (hereinafter abbreviated as “endless belt”), for example, an intermediate layer 2 is formed on the outer periphery of a base layer (base layer) 1 as shown in FIG. One having a three-layer structure in which the surface layer 3 is formed on the surface is mentioned.

In the present invention, at least one layer excluding the base layer 1 (for example, the intermediate layer 2 and the surface layer 3) contains the following (A) and at least one of (B) and (C). This is a hardened body, and this is the greatest feature of the present invention.
(A) An epoxy compound having an oxyalkylene structure.
(B) Curing agent.
(C) A polymerization initiator.

  Examples of the main component of the material (base layer material) for forming the base layer 1 of the endless belt according to the present invention include polyamideimide (PAI) resin, polyethersulfone (PES) resin, fluorine-based resin, and polyimide resin. These may be used alone or in combination of two or more. Among these, PAI resin is preferable in that it exhibits flex resistance and uniform electrical resistance.

  The PAI resin can be produced, for example, by an acid chloride method, an isocyanate method, or the like.

  Examples of the acid component used for the production of the PAI resin include trimellitic acid and its anhydride or acid chloride, as well as benzene-1,2,4,5-tetracarboxylic acid (pyromellitic acid), biphenyltetracarboxylic acid. , Biphenyl sulfone tetracarboxylic acid, benzophenone tetracarboxylic acid, biphenyl ether tetracarboxylic acid, ethylene glycol bis trimellitate, propylene glycol bis trimellitate, etc., and their anhydrides, oxalic acid, adipic acid, malonic acid, sebatin Aliphatic dicarboxylic acids such as acid, azelaic acid, dodecanedicarboxylic acid, dicarboxypolybutadiene, dicarboxypoly (acrylonitrile-butadiene), dicarboxypoly (styrene-butadiene), 1,4-cyclohexanedicarboxylic acid , 1,3-cyclohexanedicarboxylic acid, 4,4'-dicyclohexylmethanedicarboxylic acid, dimer acid and other alicyclic dicarboxylic acids, terephthalic acid, isophthalic acid, diphenylsulfone dicarboxylic acid, diphenyl ether dicarboxylic acid, naphthalenedicarboxylic acid and other fragrances Group dicarboxylic acids. These may be used alone or in combination of two or more. Among these, trimellitic anhydride is preferably used in terms of reactivity, heat resistance, solubility, and the like.

  Examples of the diamine or diisocyanate used in the production of the PAI resin include aliphatic diamines such as ethylenediamine, propylenediamine, and hexamethylenediamine, and diisocyanates thereof, 1,4-cyclohexanediamine, 1,3-cyclohexanediamine, and isophorone. Diamines, alicyclic diamines such as 4,4'-dicyclohexylmethanediamine, and diisocyanates thereof, m-phenylenediamine, p-phenylenediamine, 4,4'-diaminodiphenylmethane, 4,4-diaminodiphenyl ether, 4,4 ' -Aromatic diamines such as diaminodiphenylsulfone, benzidine, o-tolidine, 2,4-tolylenediamine, 2,6-tolylenediamine, xylylenediamine, and their diisocyanates And the like. These may be used alone or in combination of two or more. Among these, 4,4'-diaminodiphenylmethane and its diisocyanate, 2,4-tolylenediamine and its diisocyanate, o-tolidine and its diisocyanate, isophoronediamine, from the viewpoint of heat resistance, mechanical properties, solubility and the like. And its diisocyanate are preferably used.

  The PAI resin preferably has a number average molecular weight (Mn) in the range of 10,000 to 50,000, particularly preferably Mn in the range of 15,000 to 40,000. That is, if the Mn of the PAI resin is too small, the tear strength is lowered and the durability is deteriorated. Conversely, if the Mn of the PAI resin is too large, the solution viscosity becomes high and the workability tends to deteriorate. .

  As the base layer material, a conductive filler may be used together with the main components such as the PAI resin.

Examples of the conductive filler include conductive powders such as carbon black and graphite, metal powders such as aluminum powder and stainless steel powder, conductive zinc oxide (c-ZnO), and conductive titanium oxide (c-TiO ₂ ). , Conductive metal oxides such as conductive iron oxide (c-Fe ₃ O ₄ ) and conductive tin oxide (c-SnO ₂ ), quaternary ammonium salts, phosphate esters, sulfonates, aliphatic polyvalent Examples thereof include ionic conductive agents such as alcohol and aliphatic alcohol sulfate salts. These may be used alone or in combination of two or more.

  Further, the base layer material may contain an organic solvent such as DMF, DMAC, toluene, acetone, NMP, or a filler, if necessary, together with the above components.

  For the base layer material, for example, a PAI resin, a conductive filler, an organic solvent, and a filler are appropriately blended as necessary and mixed with a stirring blade, and then a ring mill, a ball mill, a sand mill or the like is used. And then dispersed.

Next, a material for forming the intermediate layer 2 (material for the intermediate layer) formed on the outer peripheral surface of the base layer 1 will be described. When the intermediate layer 2 is composed of the thermosetting material of the epoxy composition described above, the intermediate layer material includes the following (A) and at least one of (B) and (C): The containing epoxy composition is used.
(A) An epoxy compound having an oxyalkylene structure.
(B) Curing agent.
(C) A polymerization initiator.

Examples of the epoxy compound having the oxyalkylene structure (component A) include methanediol diglycidyl ether, 1,2-ethanediol diglycidyl ether, 1,3-propanediol diglycidyl ether, and 1,4-butanediol diester. Glycidyl ether, 1,5-pentanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, 1,7-heptanediol diglycidyl ether, 1,8-octanediol diglycidyl ether, 1,9-nonanediol di Glycidyl ether, 1,10-decanediol diglycidyl ether, 1,11-undecanediol diglycidyl ether, 1,12-dodecanediol diglycidyl ether, 1,13-tridecanediol diglycidyl ether, , 14-tetradecanediol diglycidyl ether, 1,15-pentadecanediol diglycidyl ether, 1,16-hexadecanediol diglycidyl ether, polymonomethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, poly Tetramethylene glycol diglycidyl ether, polypentamethylene glycol diglycidyl ether, polyhexamethylene glycol diglycidyl ether, polyheptamethylene glycol diglycidyl ether, polyoctamethylene glycol diglycidyl ether, polynonamethylene glycol diglycidyl ether, polydecamethylene Glycol diglycidyl ether, polyundecamethylene glycol Rudiglycidyl ether, polydodecamethylene glycol diglycidyl ether, polytridecamethylene glycol diglycidyl ether, polytetradecamethylene glycol diglycidyl ether, polypentadecamethylene glycol diglycidyl ether, polyheptadecamethylene glycol diglycidyl ether, cyclohexanedi methanol diglycidyl ether, trimethylolpropane polyglycidyl ether, diethylene glycol diglycidyl ether, C ₁₂ alkyl glycidyl ether, 4-hydroxybutyl acrylate glycidyl ether, butyl glycidyl ether, 2-ethylhexyl glycidyl ether, stearyl glycidyl ether, allyl glycidyl ether, butoxy polyethylene Glycol glycidyl Examples include ethers, polyglycidyl ethers of ethylene glycol-epichlorohydrin adducts, polyglycidyl ethers of glycerin-epichlorohydrin adducts, and the like. These may be used alone or in combination of two or more. Among these, an epoxy compound that is in a liquid state within a range of 0 ° C. to 150 ° C. is preferable because of low viscosity and excellent workability.

  The specific epoxy compound (component A) preferably has a number average molecular weight (Mn) in the range of 130 to 6000, particularly preferably in the range of 400 to 3000. That is, if the number average molecular weight (Mn) of the A component is too small, it tends to be difficult to reduce the belt hardness. Conversely, if the number average molecular weight (Mn) of the A component is too large, the viscosity is high at room temperature. Or, since it becomes a wax state, there is a possibility that processability may be deteriorated.

Next, the curing agent (component B) used together with the specific epoxy compound (component A) is preferably a thermosetting agent, such as amines, acid anhydrides, polyhydric phenols, imidazoles, Bronsted. Examples thereof include acid salts, amine BF ₃ complex compounds, organic acid hydrazides, dicyandiamides, and polycarboxylic acids. These may be used alone or in combination of two or more.

  Examples of the amines include bis (4-aminocyclohexyl) methane, bis (aminomethyl) cyclohexane, m-xylylenediamine, 3,9-bis (3-aminopropyl) -2,4,8,10- Aliphatic and alicyclic amines such as tetraspiro [5,5] undecane, aromatic amines such as metaphenylenediamine, diaminodiphenylmethane, diaminodiphenylsulfone, benzyldimethylamine, 2,4,6-tris (dimethylaminomethyl) ) Tertiary amines such as phenol, 1,8-diazabicyclo- (5,4,0) -undecene-7, 1,5-azabicyclo- (4,3,0) -nonene-7, triethylene Examples include tetramine, diethylenetriamine, metaxylenediamine, ethylenediamine, and salts thereof. These may be used alone or in combination of two or more.

  Examples of the acid anhydrides include aromatic acid anhydrides such as phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, anhydrous And cyclic aliphatic acid anhydrides such as methylhexahydrophthalic acid, methylendomethylenetetrahydrophthalic anhydride, dodecenyl succinic anhydride, and trialkyltetrahydrophthalic anhydride. These may be used alone or in combination of two or more.

  Examples of the polyhydric phenols include catechol, resorcin, hydroquinone, bisphenol F, bisphenol A, bisphenol S, biphenol, phenol novolac, cresol novolac, bisphenol. Examples thereof include novolak compounds of divalent phenols such as -l A, trishydroxyphenylmethanes, aralkylpolyphenols, dicyclopentadiene polyphenols, and the like. These may be used alone or in combination of two or more.

  Examples of the imidazoles include 2-methylimidazole and 2-ethyl-4-methylimidazole. Examples of the Bronsted acid salts include aliphatic sulfonium salts, aromatic sulfonium salts, iodonium salts, and phosphonium salts. Examples of the organic acid hydrazides include adipic acid dihydrazide and phthalic acid dihydrazide. Examples of the polycarboxylic acids include adipic acid, sebacic acid, terephthalic acid, trimellitic acid, and carboxyl group-containing polyester. These may be used alone or in combination of two or more.

  The amount of the curing agent (component B) is preferably in the range of 1 to 200 parts, particularly preferably 100 parts by weight (hereinafter abbreviated as “part”) of the specific epoxy compound (component A). 2 to 150 parts. That is, if the blending amount of the B component is too small, each layer may not be sufficiently cured by heat, and conversely if the blending amount of the B component is too large, the unreacted component of the B component may bleed. It is.

  Next, as the polymerization initiator (component C) used together with the specific epoxy compound (component A), an acid is generated by heat, and the acid opens the glycidyl ring of the specific epoxy compound (component A). Those that act as a curing catalyst are preferred, and examples thereof include aromatic sulfonium salts, aromatic iodonium salts, and cationic polymerization initiators. These may be used alone or in combination of two or more.

  Examples of the cationic polymerization initiator include cationic or protonic acid catalysts such as phosphorus hexafluoride compounds, antimony hexafluoride compounds, boron trifluoride ether complex compounds, and boron trifluoride. These may be used alone or in combination of two or more.

  The amount of the polymerization initiator (component C) is preferably in the range of 0.01 to 20 parts, particularly preferably 0.1 to 10 parts, relative to 100 parts of the specific epoxy compound (component A). It is a range. That is, if the amount of the C component is too small, there is a risk that the thermosetting of each layer will not be sufficiently performed. Conversely, if the amount of the C component is too large, the unreacted component of the C component may bleed. It is.

  In addition to the above-mentioned components A to C, the epoxy composition includes conductive materials such as carbon black, graphite, potassium titanate, iron oxide, and ionic conductive agents (quaternary ammonium salts, borates, surfactants, etc.). An agent may be appropriately added as necessary. Among these conductive agents, ionic conductive agents are preferable from the viewpoint of uniform electrical resistance. In addition, a curing accelerator such as tertiary amines (benzyldimethylamine, etc.), a filler, a colorant and the like may be appropriately added to the epoxy composition as necessary.

  The blending amount of the ionic conductive agent is preferably in the range of 0.01 to 10 parts, particularly preferably in the range of 0.1 to 5 parts, with respect to 100 parts of the specific epoxy compound (component A).

  The said epoxy composition can be prepared by mix | blending an ionic conductive agent etc. suitably with the said AC component as needed, and mixing these each components with a stirrer etc. which have a stirring blade.

  Examples of the intermediate layer material other than the epoxy composition include a thermoplastic resin and a rubber elastic layer material.

  Examples of the thermoplastic resin include fluorine resins such as polyvinylidene fluoride (PVDF), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), and ethylene-tetrafluoroethylene copolymer (ETFE), and polyethylene-based resins. Resin, polystyrene resin, acrylic resin, polycarbonate (PC) resin, polyamide resin, EVA (ethylene-vinyl acetate copolymer) resin, EEA (ethylene-ethyl acrylate copolymer) resin, etc. It is done. These may be used alone or in combination of two or more. Among these, it is preferable to use a fluorine-based resin such as PVDF from the viewpoint of excellent flame retardancy.

  Further, as the rubber elastic layer material, for example, a vulcanization accelerator, a solvent, a processing aid, an anti-aging agent and the like can be used together with a rubber material and a vulcanizing agent as necessary. Note that the conductive elastic filler as described above may be blended in the rubber elastic layer material.

  Examples of the rubber material include chlorinated polyethylene rubber (CPE) and chloroprene rubber (CR) from the viewpoint of flame retardancy. Among these, the optimum material is selected according to the electrical characteristics, elasticity, and durability required for each intermediate transfer belt.

  Next, the forming material (surface layer material) of the surface layer 3 formed on the outer peripheral surface of the intermediate layer 2 will be described. When the surface layer 3 is composed of the thermosetting material of the epoxy composition described above, the surface layer material is a material obtained by adding a surface modifier to the above-described epoxy composition.

  Examples of the surface modifier include fluorine compounds and silicone oil. These may be used alone or in combination of two or more.

  The blending ratio of the surface modifier is preferably in the range of 1 to 40 parts, particularly preferably in the range of 2 to 30 parts, with respect to 100 parts of the epoxy compound (component A) having the oxyalkylene structure.

  Examples of the material for the surface layer other than the epoxy composition include silicone resins, fluorine resins, urethane resins, acrylic resins, polyamide resins, and the like. These may be used alone or in combination of two or more. Among these, liquid or solvent-soluble types are preferably used in consideration of normal workability. In addition, for the purpose of preventing dirt, improving the strength of the coating film, or improving the adhesion, a modified resin material may be used, for example, a modified acrylic resin. As this modified acrylic resin, those having the molecular structure of the acrylic resin as a base and modified with other resins or resin components are preferable. For example, a silicone-modified acrylic resin is preferably used.

  Examples of the silicone-modified acrylic resin include a silicone graft acrylic resin. The silicone graft acrylic resin is preferably a resin obtained by graft polymerization of a silicone resin to an acrylic resin (main chain). Specific examples of the silicone-grafted acrylic resin include Saimak US-350 manufactured by Toagosei Co., Ltd.

  In addition, as the material for the surface layer, the resin material is subjected to resin crosslinking using a resin crosslinking agent such as isocyanate resin, amino resin, phenol resin, xylene resin, or a photosensitive monomer or polymer. An ultraviolet curable material mixed with a photopolymerization initiator may be used.

  The surface layer material can be prepared, for example, by appropriately blending a modified acrylic resin and an organic solvent such as DMF, toluene, and acetone and mixing with a stirring blade. In order to form each layer with high accuracy, it is preferable to use different types of organic solvents as materials for forming adjacent layers. That is, it is preferable to use different types of organic solvents for the surface layer material and organic solvents for the intermediate layer material.

  The endless belt of the present invention is not limited to the three-layer structure shown in FIG. 1, and may have a two-layer structure in which the surface layer 3 is directly formed on the surface of the base layer 1, for example. Further, the intermediate layer 2 between the base layer 1 and the surface layer 3 is not limited to one layer, and may be two or more layers. However, it is necessary that at least one layer excluding the base layer 1 is made of a thermoset of an epoxy composition containing the component A and at least one of the component B and the component C.

  Next, the method for producing the endless belt of the present invention will be specifically described.

(1) An endless belt (see FIG. 1) having a three-layer structure in which an intermediate layer 2 is formed on the outer peripheral surface of a base layer 1 and a surface layer 3 is formed on the outer peripheral surface thereof. A process for producing an endless belt comprising a thermoset of an epoxy composition.

(Preparation of base layer material)
Prepare a reaction vessel equipped with a stirrer, nitrogen introduction tube, thermometer, and cooling tube, mix a predetermined amount of MDI and acid components such as trimellitic anhydride, N-methyl-2-pyrrolidone (NMP), N , N-dimethylformamide (DMF), N, N-dimethylacetamide (DMAC), γ-butyrolactone, etc. are charged with a polar solvent and stirred for a predetermined time (preferably 1 hour) under a nitrogen stream with a predetermined temperature (preferably Is raised to 130 ° C., reacted at a predetermined temperature (preferably 130 ° C.) for a predetermined time (preferably about 5 hours), and then the reaction is stopped to prepare a solvent for PAI resin. Next, a conductive filler such as carbon black, an organic solvent such as NMP, and a filler are appropriately blended in the solvent of the PAI resin as necessary, and mixed with a stirring blade, followed by a ring mill, a ball mill. The base layer material is prepared by dispersing using a sand mill or the like.

(Preparation of intermediate layer material)
It can prepare according to the manufacturing method of the above-mentioned epoxy composition. That is, the intermediate layer material is prepared by blending the components A to C and mixing these components with a stirrer having a stirring blade.

(Preparation of surface layer material)
A surface-layer material is prepared by appropriately blending a modified acrylic resin and an organic solvent such as DMF and mixing with a stirring blade.

(Production of endless belt)
First, a mold (cylindrical base) is prepared, and the base layer material is spray coated on the surface to form the base layer 1 on the surface of the mold. This is heated and heated for a predetermined time (preferably 2 hours) from room temperature (25 ° C.) to 250 ° C. Next, the intermediate layer material is spray coated on the surface of the base layer 1 and dried at 100 to 300 ° C. for 0.5 to 6 hours to form the intermediate layer 2. Subsequently, the surface layer material is spray coated on the surface of the intermediate layer 2 and dried at 100 to 300 ° C. for 0.5 to 6 hours. Thereafter, by blowing air between the base layer 1 and the mold (cylindrical base body), the cylindrical base body is extracted, an intermediate layer (elastic layer) 2 is formed on the surface of the base layer 1, and a surface layer is formed on the outer peripheral surface thereof. An endless belt (see FIG. 1) having a three-layer structure in which 3 is formed is produced. In addition, the formation method of the said surface layer 3 is not limited to the said spray coating method, For example, you may form by the dipping method etc.

(2) An endless belt (see FIG. 1) having a three-layer structure in which an intermediate layer 2 is formed on the outer peripheral surface of the base layer 1 and a surface layer 3 is formed on the outer peripheral surface. A process for producing an endless belt comprising a thermoset of the composition.

(Preparation of base layer material)
A base layer material is prepared according to the method for producing an endless belt described in (1) above.

(Preparation of intermediate layer material)
Along with rubber materials such as chloroprene rubber (CR) and vulcanizing agents, vulcanization accelerators, solvents, processing aids, anti-aging agents, conductive agents, etc. are blended as necessary, and these are mixed using a Banbury mixer. An intermediate layer material is prepared by kneading.

(Preparation of surface layer material)
It can prepare according to the manufacturing method of the above-mentioned epoxy composition. That is, the surface component material (coating liquid) is prepared by blending the components A to C and mixing these components with a stirrer having a stirring blade.

(Production of endless belt)
The base layer 1 is formed according to the method for producing an endless belt (1). That is, first, a mold (cylindrical base body) is prepared, and the base layer material is spray coated on the surface to form the base layer 1 on the surface of the mold. This is heated and heated for a predetermined time (preferably 2 hours) from room temperature (25 ° C.) to 250 ° C. Next, the intermediate layer material is spray coated on the surface of the base layer 1 and dried at 100 to 300 ° C. for 0.5 to 6 hours. Next, the surface layer material is spray-coated on the surface of the intermediate layer 2 and dried at 100 to 300 ° C. for 0.5 to 6 hours to form the surface layer 3. Thereafter, by blowing air between the base layer 1 and the mold (cylindrical base body), the cylindrical base body is extracted, an intermediate layer (elastic layer) 2 is formed on the surface of the base layer 1, and a surface layer is formed on the outer peripheral surface thereof. An endless belt (see FIG. 1) having a three-layer structure in which 3 is formed is produced.

(3) An endless belt (see FIG. 1) having a three-layer structure in which the intermediate layer 2 is formed on the outer peripheral surface of the base layer 1 and the surface layer 3 is formed on the outer peripheral surface. However, the manufacturing method of the endless belt which consists of a thermosetting body of the above-mentioned epoxy composition.

(Preparation of base layer material)
A base layer material is prepared according to the method for producing an endless belt described in (1) above.

(Preparation of intermediate layer material)
An intermediate layer material (epoxy composition) is prepared in accordance with the method for producing an endless belt described in (1) above.

(Preparation of surface layer material)
A surface layer material (epoxy composition) is prepared in accordance with the method for producing an endless belt described in (2) above.

(Production of endless belt)
The base layer 1 and the intermediate layer 2 are formed in accordance with the method for producing an endless belt (1). Next, the surface layer material is spray-coated on the surface of the intermediate layer 2 and dried at 100 to 300 ° C. for 0.5 to 6 hours to form the surface layer 3. Thereafter, by blowing air between the base layer 1 and the mold (cylindrical base body), the cylindrical base body is extracted, an intermediate layer (elastic layer) 2 is formed on the surface of the base layer 1, and a surface layer is formed on the outer peripheral surface thereof. An endless belt (see FIG. 1) having a three-layer structure in which 3 is formed is produced.

(4) A process for producing an endless belt having a two-layer structure in which a surface layer 3 is directly formed on the outer peripheral surface of a base layer 1, wherein the surface layer 3 is made of a thermoset of the above-described epoxy composition.

(Preparation of base layer material)
A base layer material is prepared according to the method for producing an endless belt described in (1) above.

(Preparation of surface layer material)
A surface layer material (epoxy composition) is prepared in accordance with the method for producing an endless belt described in (2) above.

(Production of endless belt)
The base layer 1 is formed according to the method for producing an endless belt (1). Next, the surface layer material is spray coated on the surface of the base layer 1 and dried at 100 to 300 ° C. for 0.5 to 6 hours to form the surface layer 3. Thereafter, by blowing air between the base layer 1 and a mold (cylindrical base body) or the like, the cylindrical base body is extracted, and an endless belt having a two-layer structure in which the surface layer 3 is formed on the surface of the base layer 1 is manufactured.

  Although the thickness of each layer of the endless belt of the present invention is appropriately set according to the use of the belt, the thickness of the base layer 1 is usually in the range of 30 to 300 μm, and preferably in the range of 50 to 200 μm. The thickness of the intermediate layer 2 is preferably in the range of 30 to 5000 μm, particularly preferably in the range of 50 to 200 μm. The thickness of the surface layer 3 is preferably in the range of 0.1 to 30 μm, particularly preferably in the range of 0.5 to 20 μm. The endless belt of the present invention preferably has an inner peripheral length of 500 to 2500 mm and a width of about 150 to 600 mm. That is, if the size is set within the above range, the size is appropriate for use in an electrophotographic copying machine.

  In the endless belt of the present invention, the elastic modulus of the base layer 1 is preferably in the range of 1000 to 10000 MPa, particularly preferably in the range of 3000 to 8000 MPa, from the viewpoint of durability.

  Next, examples will be described together with comparative examples. However, the present invention is not limited to these examples.

  First, prior to the examples and comparative examples, the following materials were prepared.

[Epoxy compound A (component A)]
Polytetramethylene glycol diglycidyl ether (number average molecular weight: 950) (Epogosei PT, manufactured by Yokkaichi Chemical Co., Ltd.)
[Epoxy compound B (component A)]
Polypropylene glycol diglycidyl ether (number average molecular weight: 718) (manufactured by Nagase ChemteX, EX-931)
[Epoxy compound C (component A)]
1,6-hexanediol diglycidyl ether (number average molecular weight: 230) (manufactured by Nagase ChemteX Corporation, Denacol-EX-212)

[Epoxy compound a]
Bisphenol A type epoxy compound (DIC Corporation, Epicron 840)
[Epoxy compound b]
Polybutylene glycidyl ether (Daicel Chemical Industries, Epolide PB3600)

[Polymerization initiator (component C)]
Aromatic sulfonium salt (manufactured by Sanshin Chemical Co., Ltd., Sun-Aid SI60L)

[Curing agent A (amine curing agent) (component B)]
Ethylenediamine [made by Wako Pure Chemical Industries, ethylenediamine (reagent)]
[Curing agent B (acid anhydride) (component B)]
3or4-methylhexahydrophthalic anhydride (manufactured by Hitachi Chemical Co., Ltd., HN-5500)

[Surface modifier]
Epoxy-modified silicone oil (manufactured by Chisso Corporation, FM-0521, Mn: 5000, one end type)

  Next, an epoxy composition was prepared as follows using each of the above materials.

[Preparation of Epoxy Compositions A to F, a to d]
The components shown in Table 1 below were blended in the proportions shown in the same table, and these were mixed with a stirrer having stirring blades to prepare an epoxy composition.

  Next, an endless belt was produced using the epoxy composition.

[Example 1]
(Preparation of base layer material)
In a reaction vessel equipped with a stirrer, a nitrogen introducing tube, a thermometer, and a cooling tube, 50 parts of MDI (manufactured by Nippon Polyurethane Industry Co., Ltd., Millionate MT, Mn: 250.06), 38 parts of trimellitic anhydride, and NMP solvent 164 The mixture was heated to 130 ° C. over 1 hour with stirring under a nitrogen stream, reacted for about 5 hours at 130 ° C., and then the reaction was stopped, and a PAI-NMP solution (PAI: 30% by weight) was added. Prepared. Next, 3 parts of carbon black (manufactured by Cabot Japan, Show Black N220) was mixed with this PAI-NMP solution, mixed with a stirring blade, and then dispersed with a ball mill to prepare a base layer material.

(Preparation of intermediate layer material)
The previously prepared epoxy composition A (see Table 1) was used.

(Preparation of surface layer material)
100 parts of silicone graft acrylic resin (Saimak US-350, manufactured by Toagosei Co., Ltd.) and 500 parts of toluene solvent were blended and mixed with a stirring blade to prepare a surface layer material.

(Production of endless belt)
First, a mold (cylindrical base body) was prepared, and the base layer material was spray coated on the surface to form a base layer on the surface of the mold. This was heated and heated for 2 hours from normal temperature (25 ° C.) to 250 ° C. Next, the intermediate layer material was spray coated on the surface of the base layer, and this was heat-treated at 120 ° C. for 1 hour to form an intermediate layer. Subsequently, the surface layer material was spray coated on the surface of the intermediate layer, and this was heat-treated at 120 ° C. for 1 hour. After that, by blowing air between the base layer and the mold (cylindrical base body), the cylindrical base body is extracted, and an intermediate layer (elastic layer) (thickness: 100 μm) is formed on the surface of the base layer (thickness: 100 μm). Further, an endless belt (see FIG. 1) having a three-layer structure in which a surface layer (thickness: 5 μm) was formed on the outer peripheral surface was produced.

[Examples 2 to 5, Comparative Examples 1 to 4]
As the intermediate layer material, the epoxy compositions shown in Table 1 and Table 2 below were used in place of the epoxy composition A of Example 1. Then, an endless belt was produced in the same manner as in Example 1 except that this intermediate layer material was used.

Example 6
(Preparation of base layer material)
A base layer material was prepared in the same manner as the base layer material of Example 1.

(Preparation of intermediate layer material)
100 parts of chloroprene rubber (Denka Chloroprene A-30, manufactured by Denki Kagaku Kogyo Co., Ltd.), 1.5 parts of vulcanizing agent (manufactured by Sanshin Chemical Industry Co., Ltd., Sunseller 22C), carbon black (Ketjen Black International Co., Ltd., Ketjen) EC) 2 parts were kneaded and then dissolved in MEK solvent to prepare an intermediate layer material.

(Preparation of surface material)
The previously prepared epoxy composition F (see Table 1) was used.

(Production of endless belt)
First, a mold (cylindrical base body) was prepared, and the base layer material was spray coated on the surface to form a base layer on the surface of the mold. This was heated and heated for 2 hours from normal temperature (25 ° C.) to 250 ° C. Next, the intermediate layer material was spray coated on the surface of the base layer, and this was heat-treated at 120 ° C. for 1 hour to form an intermediate layer. Next, the surface layer material was spray-coated on the surface of the intermediate layer, and this was dried at 120 ° C. for 1 hour to form a surface layer. After that, by blowing air between the base layer and the mold (cylindrical base body), the cylindrical base body is extracted, and an intermediate layer (elastic layer) (thickness: 100 μm) is formed on the surface of the base layer (thickness: 100 μm). Further, an endless belt (see FIG. 1) having a three-layer structure in which a surface layer (thickness: 5 μm) was formed on the outer peripheral surface was produced.

Example 7
(Preparation of base layer material)
A base layer material was prepared in the same manner as the base layer material of Example 1.

(Preparation of surface material)
The previously prepared epoxy composition F (see Table 1) was used.

(Production of endless belt)
First, a mold (cylindrical base body) was prepared, and the base layer material was spray coated on the surface to form a base layer on the surface of the mold. This was heated and heated for 2 hours from normal temperature (25 ° C.) to 250 ° C. Next, the surface layer material was spray coated on the surface of the base layer, and this was dried at 120 ° C. for 1 hour to form a surface layer. Thereafter, air is blown between the base layer and the mold (cylindrical base body) to extract the cylindrical base body, and a surface layer (thickness: 20 μm) is formed on the surface of the base layer (thickness: 100 μm). An endless belt was prepared.

  Using the endless belts of Examples and Comparative Examples thus obtained, each characteristic was evaluated according to the following criteria. These results are shown in Tables 2 and 3 above.

[Hardness (Martens hardness)]
The Martens hardness (N / mm ² ) of each endless belt surface was measured using a Fischer scope H100 (Fischer). The indentation condition at the time of the measurement was to push in with a load up to 2 mN over 5 seconds, and then release the load up to 0 mN over 5 seconds.

[Bench durability test]
Two metal rollers having a diameter of 13 mm were prepared, and one metal roller was fixed on the table in a state where an endless belt (width 150 mm) was stretched between the two metal rollers. Next, the other metal roller that is not fixed to the table is placed at the end of the table, and 2 kg of weight is suspended from both ends of the metal roller (total load 4 kg), and the laboratory environment (25 ° C × 40%), the endless belt was rotated. Then, the cumulative number of revolutions until a crack was confirmed on the endless belt was measured.

[Uniformity of electrical resistance]
Volume electrical resistivity at eight locations on the inner peripheral side of the endless belt equally divided in the circumferential direction was measured according to JIS K6911, and the variation between the maximum value and the minimum value was displayed in digits. The applied voltage was 10V. In the evaluation, a case where the variation is 0.5 digits or less is indicated by ○, and a case where the variation exceeds 0.5 digits is indicated by ×.

[Real machine image evaluation]
Each endless belt was attached to a full-color PPC, and 1000 images were evaluated for evaluation, and the presence or absence of image defects such as defective cleaning and transfer to the endless belt was evaluated. In the evaluation, “◯” indicates no image defect and “x” indicates an image defect.

  From the results shown in Tables 2 and 3, all of the examples were excellent in durability, uniformity of electrical resistance, and evaluation of actual machine images. In addition, in the epoxy compositions B to F shown in Table 1, the epoxy compositions B to F were used even when the epoxy compositions in which the amount of the curing agent was changed to 1 part and 200 parts were used. The same excellent effect as the product was obtained. Similarly, in the case of using an epoxy composition in which the blending amount of the polymerization initiator was changed to 0.01 parts and 20 parts in the epoxy composition A shown in Table 1, the implementation using the epoxy composition A was performed. The same excellent effect as the product was obtained.

  On the other hand, Comparative Examples 1 to 4 were inferior in durability, and good images were not obtained.

  The endless belt of the present invention is used as an intermediate transfer belt and a conveying belt in an electrophotographic apparatus such as an electrophotographic copying machine, a printer, and a facsimile.

It is a fragmentary sectional view which shows an example of the endless belt for electrophotographic apparatuses of this invention.

Explanation of symbols

1 base layer 2 intermediate layer 3 surface layer

Claims (2)

An endless belt for an electrophotographic apparatus in which a surface layer is formed on the outer periphery of a base layer directly or via another layer, and at least one layer excluding the base layer includes the following (A), (B) and (C) An endless belt for electrophotographic equipment, comprising a thermoset of an epoxy composition containing at least one of the above.
(A) An epoxy compound having an oxyalkylene structure.
(B) Curing agent.
(C) A polymerization initiator.   A base layer, an intermediate layer formed on the outer peripheral surface of the base layer, and a surface layer formed on the outer peripheral surface of the intermediate layer, wherein at least one of the intermediate layer and the surface layer is made of a thermoset of the epoxy composition. Item 16. An endless belt for an electrophotographic apparatus according to Item 1.

Images