JP5486217B2 - Multilayer belt - Google Patents

Description

  The present invention relates to a multilayer belt, which is suitably used as an intermediate transfer belt in an electrophotographic image forming apparatus, and improves transfer efficiency to paper even when liquid toner as well as powder toner is used.

  In the image forming apparatus, an electrostatic latent image is formed on a photosensitive member such as a photosensitive drum, and toner is supplied onto the photosensitive member to form a toner image. This toner image is transferred from a photoreceptor to a recording medium such as paper via an intermediate transfer belt and fixed.

  In recent years, the types of paper used have been diversified, and a system capable of transferring high-quality images on various papers has been demanded. For example, uncoated paper with relatively large irregularities on its surface may be used. When transferring a toner image formed on an intermediate transfer belt onto paper having such a surface roughness, transfer is performed. In some cases, the efficiency may be poor, or the toner may not be transferred to the concave portion of the paper and may be whitened. In order to solve such a problem, in a multilayer belt in which at least three layers of a base layer, an elastic layer, and a surface layer are sequentially laminated from the inner peripheral surface to the outer peripheral surface, It is known to specify hardness, thickness, etc. (Patent Document 1, Patent Document 2).

  However, in recent image forming apparatuses, aiming at higher image quality and energy saving, polymerized toner with a reduced particle size has been developed as a toner, and liquid toner in which a smaller diameter toner is dispersed in a solvent. The particle size of the polymerized toner is about 3 to 6 μm, and the particle size of the liquid toner is about 1 to 3 μm, which is in the direction of miniaturization. It is possible to enter the concave and convex portions of the fiber. In this way, not only the toner is transferred to the concave and convex portions due to the undulations of the paper surface, but if the toner is not transferred to the fine concave and convex portions due to the paper fibers, white spots occur during image formation. There is a problem, and there is room for further improvement in order to prevent secondary transfer failure to paper having a surface roughness of about 10 μm, for example, as the diameter of the toner is reduced.

JP 2005-134840 A JP 2006-178232 A

  INDUSTRIAL APPLICABILITY The present invention is useful as an intermediate transfer belt, which can efficiently transfer a small particle size toner to a so-called non-coated paper having a surface roughness of more than 10 μm, and is a multilayer belt that hardly causes white spots during image formation. Offering is an issue.

  In the multilayer belt of the present invention, at least three layers of a base layer, an elastic layer, and a surface layer are sequentially laminated from the inner peripheral surface to the outer peripheral surface, and the surface layer has 1 part by mass of fluororubber with respect to 1 part by mass of the fluororesin. It has more rubber latex and a hardening | curing agent contained in the ratio of 5 mass parts or less more.

  In the multilayer belt of the present invention, at least three layers of a base layer, an elastic layer, and a surface layer are sequentially laminated from the inner peripheral surface to the outer peripheral surface, and the surface layer is cured with a water-based urethane resin containing a fluororesin and a silicon component. And an agent.

  The surface energy in the surface layer of the multilayer belt is 20 mN / m to 40 mN / m, and the surface hardness is measured with a nanoindenter, and the hardness when indented by 3 μm from the surface layer side is 0.1 MPa to 1.5 MPa. It is characterized by being.

  The elastic layer has a JIS-A hardness of 25 ° to 70 °.

  The surface layer has a thickness of 3 μm to 20 μm.

It is the perspective view in which the multilayer belt concerning one Embodiment of this invention was shown. It is sectional drawing of a multilayer belt. It is a figure for demonstrating the process of forming a base layer in the manufacturing method of the multilayer belt of this invention. It is explanatory drawing of the shape of the nozzle tip in FIG. 4, and the contact position of a nozzle and a metal mold | die. It is a figure for demonstrating the hardness measuring method from the surface layer of the multilayer belt by the nanoindentation method. It is a load-displacement curve figure obtained by the nanoindentation method about the multilayer belt obtained in Example 10 of this invention. It is a hardness-displacement curve figure obtained by the nanoindentation method about the multilayer belt obtained in Example 10 of this invention, and is a figure which shows HM hardness (mgf / micrometer < ² >) at the time of 10 mgf (100 microN) load. It is a hardness-displacement curve figure obtained by the nanoindentation method about the multilayer belt obtained in Example 10 of this invention, and is a figure which shows HM hardness (mgf / micrometer < ² >) at the time of 3 micrometer indentation. It is an optical microscope photograph (viewing field range: 130 mm x 105 mm) from the surface layer side of the multilayer belt obtained in Example 10 of the present invention, and the intersection of the crosshairs is a hardness measurement point by the nanoindentation method.

Hereinafter, embodiments of the multilayer belt of the present invention will be described.
FIG. 1 shows a multilayer belt 1 according to an embodiment of the present invention. The overall shape of the multi-layer belt 1 is a substantially cylindrical seamless belt, which is highly flexible and can be freely deformed by its own weight or the like, and thus can have various shapes. Further, as shown in FIG. 2, the cross section has a three-layer structure in which a base layer 3, an elastic layer 5, and a surface layer 7 are sequentially laminated. The multilayer belt according to the embodiment includes three layers of a base layer, an elastic layer, and a surface layer, but may have a laminated structure of three or more layers, for example, a base layer and an elastic layer or / and an elastic layer and a surface layer. Other layers may be present between them. When the multilayer belt 1 is used as an intermediate transfer belt of an image forming apparatus, the outer peripheral surface 9 is a surface to which toner or the like adheres, and the inner peripheral surface 11 is a surface that directly contacts a drive shaft or the like during rotation.

  The base layer material constituting the base layer 3 is preferably made of resin. Resins that can constitute the base layer include polyimide resins, polyamideimide resins, polyetherimide resins, silicone imide resins, urethane imide resins, polyurethane resins, polyurea resins, epoxy resins, melanin resins, unsaturated polyester resins, or vinyl ester resins. Etc. Among these, a polyimide resin, a polyamideimide resin, a polyurethane resin, or a polyurea resin is preferable, and a polyimide resin or a polyamideimide resin is particularly preferable.

  The base layer material is blended with an electronic conductive agent in order to keep the surface electrical resistivity within the above-mentioned predetermined range. Electronic conductive agents such as carbon blacks such as ketjen black, furnace black or acetylene black, conductive metal oxides such as zinc oxide, potassium titanate, antimony doped titanium oxide, tin oxide or graphite, or electronic conductivity such as carbon fiber Agent is used. Among these, it is preferable to use carbon black as the electronic conductive agent. The amount of the electronic conductive agent depends on the type of the electronic conductive agent and the type of the resin constituting the base layer, but cannot generally be said, but generally about 1 to 50 parts by mass with respect to 100 parts by mass of the resin solid content. The degree is more preferably about 3 to 40 parts by mass.

The base layer 3 in the multilayer belt of the present invention preferably has a thickness of 50 μm to 150 μm, a tensile elastic modulus of 1000 MPa or more, and a surface electrical resistivity of 10 ⁶ Ω / □ to 10 ¹² Ω / □. The reason why the thickness of the base layer is set to 50 μm or more is to obtain a good image while maintaining sufficient strength to regulate the elongation in the circumferential direction and suppressing fluctuations in the belt speed. On the other hand, the reason why the thickness is 150 μm or less is to prevent the occurrence of cracks in the base layer and to prevent the bending rigidity on the shaft during driving of the belt from becoming high, thereby realizing smooth driving. More preferably, the thickness of the base layer is 70 to 110 μm.

  In addition, by making the tensile elastic modulus of the base layer 1000 MPa or more, it is possible to suppress the belt elongation and reduce the change in belt speed, which can sufficiently cope with the recent increase in the speed of image forming apparatuses, and color. Color misregistration of images can be prevented in printers and color copiers. The tensile elastic modulus of the base layer is more preferably 2000 MPa or more, and particularly preferably 2300 MPa or more. The upper limit is not particularly limited, but is usually 8000 MPa or less.

The surface electrical resistivity of the base layer is 10 ⁶ Ω / □ to 10 ¹² Ω / □, and the volume resistivity of the elastic layer laminated on the front side of the base layer is 10 ⁶ Ω · cm to 10 ¹² Ω · cm. It is preferable that As a result, as described in detail below, even when the thickness of the elastic layer is relatively large, when used as an intermediate transfer belt, moderate conductivity that can exhibit excellent transferability in both primary transfer and secondary transfer Can be granted. The surface electrical resistivity of the base layer is set to 10 ⁶ Ω / □ or more. When the surface resistivity is less than 10 ⁶ Ω / □, the charging characteristics of the belt deteriorate, the charge of the charged toner becomes easy to move, and the toner to be transferred Disturbances occur in the image. The surface electrical resistivity of the base layer is set to 10 ¹² Ω / □ or less. If it exceeds 10 ¹² Ω / □, a large transfer voltage is required for primary transfer, transfer efficiency is deteriorated, and belt neutralization is difficult. As a result, the cleaning property of the excess toner remaining on the belt is deteriorated. The surface electrical resistivity of the base layer is particularly preferably 10 ⁷ Ω / □ to 10 ¹⁰ Ω / □.

More preferably, the base layer 3 has a tensile elastic modulus of 2300 to 3500 Mpa and a surface electrical resistivity on the inner peripheral surface side of 10 ⁹ Ω / □ (1.0 × 10 ⁹ Ω / □ to 9.9 × 10 ⁹ Ω / □>, and the thickness is about 70 to 90 μm.

  Next, the elastic layer material constituting the elastic layer 5 is preferably made of an elastomer. The elastomer may be either an ionic conductive elastomer or an electronic conductive elastomer as long as it exhibits a certain range of volume resistivity. However, since it is excellent in the uniformity of electrical resistance, it is preferably an elastomer having ionic conductivity.

  As the elastomer having ionic conductivity, a known ionic conductive rubber can be used, and an elastomer to which an ionic conductive agent is added may be used. Examples of the ion conductive rubber include rubber materials having a polar group in the composition, and specific examples include acrylonitrile butadiene rubber, epihalohydrin rubber (particularly epichlorohydrin rubber), chloroprene rubber, acrylic rubber, polyurethane elastomer, and the like. Examples of the ionic conductive agent include tetraethylammonium, tetrabutylammonium, dodecyltrimethylammonium (for example, lauryltrimethylammonium), octadecyltrimethylammonium (for example, stearyltrimethylammonium), hexadecyltrimethylammonium, benzyltrimethylammonium, and modified aliphatic dimethyl. Perchlorate such as ethylammonium, chlorate, hydrochloride, bromate, iodate, borofluoride, sulfate, alkyl sulfate, carboxylate, sulfonate, etc .; lithium, sodium, Perchlorates, chlorates, hydrochlorides, bromates, iodates, borofluorides, sulfates, alkyl sulfates, calcium sulfates of alkali metals or alkaline earth metals such as potassium, calcium, and magnesium Down salt, door. Examples include trifluoromethyl sulfate, sulfonate, and bistrifluoromethanesulfonylimide salt. These may be used alone or in combination of two or more.

  Especially, it is preferable that the elastic layer material contains polyurethane elastomer as a main component in a proportion of 50 to 100% by mass. As the polyurethane elastomer, a terminal isocyanate prepolymer obtained from a polyol mainly composed of polypropylene glycol and / or a hydroxyl-terminated liquid rubber and an aromatic diisocyanate is used as a main agent, and this is an aromatic diamine or / and a polyol as a curing agent. It is more preferable to use a polyurethane elastomer obtained by curing. This is because low hardness is easily achieved and flame retardancy is easily imparted, and it can be manufactured at a relatively low cost.

  As the polyol, for reasons of physical properties, a phosphorus-containing polyol or a hydroxyl group-terminated liquid rubber is more preferable, and one kind or a mixture of two or more kinds can be used. Examples of hydroxyl-terminated liquid rubber include hydroxyl-terminated liquid polybutadiene, hydroxyl-terminated liquid polyisoprene, hydroxyl-terminated liquid styrene-butadiene rubber, hydroxyl-terminated liquid acrylonitrile-butadiene rubber, liquid poly (oxypropylene) glycol, and liquid poly (oxytetramethylene). Glycol, liquid polyolefin glycol, hydroxyl-terminated liquid silicone rubber, or the like is used. Among them, hydroxyl-terminated liquid polybutadiene is preferably used from the viewpoint of balance of physical properties.

  The terminal isocyanate prepolymer is a mixture of two reactants, a reaction product of polypropylene glycol and aromatic diisocyanate, and a reaction product of polyol and aromatic diisocyanate mainly composed of a hydroxyl group-terminated liquid rubber. Is preferred. Thereby, the variation in electrical resistance can be further reduced. In addition, terminal isocyanate prepolymers are (1) only those composed of a reaction product of polypropylene glycol and aromatic diisocyanate, and (2) those composed of a reaction product of polyol and aromatic diisocyanate mainly composed of hydroxyl group-terminated liquid rubber. Only (3) a mixture of polypropylene glycol and a polyol mainly composed of a hydroxyl group-terminated liquid rubber may be reacted with an aromatic diisocyanate.

  In order to reduce the JISA hardness of the elastic layer to 70 ° or less when the polyurethane elastomer is used as the elastic layer material, a long-chain linear polyol is introduced into the terminal isocyanate prepolymer, Techniques such as reducing the proportion of both terminal amine compounds that undergo a crosslinking and curing reaction with respect to the polymer can be used.

  The elastic layer material preferably contains a bistrifluoromethanesulfonylimide salt, preferably lithium-bistrifluoromethanesulfonylimide, which is an ionic conductive agent for the purpose of adjusting the volume resistivity.

  The elastic layer material may be supplementarily provided with conductivity by an electronic conductive agent within a range in which variation in electric resistance does not occur. Thereby, the environmental dependence of electrical resistance can be reduced. The addition amount of the electronic conductive agent may be appropriately selected. The volume resistivity of the elastic layer supplementarily applied with the electronic conductive agent under the conditions of an applied voltage of 250 V, a temperature of 23 ° C., and a relative humidity of 55% is defined as R. When the volume resistivity of the elastic layer containing no electronic conductive agent under the conditions is R1, and Log (R) −Log (R1) = Log (R2), 0.1 ≦ Log (R2) ≦ 5 About, preferably 0.2 ≦ Log (R2) ≦ 3, more preferably about 0.3 ≦ Log (R2) ≦ 2, it is preferable to supplement the electronic conductive agent. When an electronic conductive agent is blended in the elastic layer material, carbon black such as ketjen black, furnace black or acetylene black, zinc oxide, potassium titanate, antimony-doped titanium oxide, tin oxide or graphite as in the case of the base layer. An electronic conductive agent such as conductive metal oxide or carbon fiber is used.

  The elastic layer material can be blended with various polyols, additives for adjusting the molecular weight, antifoaming agents, leveling agents, curing agents, and the like that improve processability when processed into a belt shape. Among these, it is preferable to add a flame retardant compound. Examples of the flame retardant compound include flame retardants such as phosphorus compounds, halogen compounds, phosphate ester compounds, red phosphorus compounds, magnesium hydroxide compounds, aluminum hydroxide compounds, and flame retardant polymer graft polyols. It is done. It is particularly preferable to use a flame retardant compound having reactivity such as a phosphorus compound or a halogen compound. By blending such a flame retardant compound having reactivity, flame retardancy can be imparted, and problems such as photoreceptor contamination and toner adhesion due to bleeding can be reduced. On the other hand, when the multilayer belt of the present invention is incorporated in an image forming apparatus and used, in order to avoid problems such as contamination of other members such as a photoreceptor due to long-term use, there is a plastic layer in the elastic layer material. It is preferable not to add a material that easily permeates, such as an agent.

The elastic layer 5 preferably has a thickness of 100 to 1500 μm, a JIS A hardness of 70 ° or less, and a volume resistivity of 10 ⁶ Ω · cm to 10 ¹² Ω · cm. When the thickness of the elastic layer is less than 100 μm, the nip width at the time of transfer cannot be sufficiently obtained, and when paper with large irregularities is used as a recording medium, white spots may occur in the concave portions of the paper. On the other hand, when the thickness of the elastic layer exceeds 1500 μm, the mass of the belt becomes too large, and the mechanical burden applied during driving becomes too large. More preferably, the thickness of the elastic layer is 200 to 1200 μm.

  Further, the elastic layer has a JIS A hardness of 70 ° or less, preferably 25 ° to 50 °. When the JIS A hardness exceeds 70 °, the nip width at the time of transfer cannot be sufficiently obtained, and when paper with large irregularities is used as a recording medium, white spots may occur in the concave portions of the paper. On the other hand, if the hardness is too low, the shape retaining property of the elastic layer is deteriorated, so the lower limit is preferably about 25 °.

In addition, the volume resistivity of the elastic layer is set to 10 ⁶ Ω · cm or more. If the elastic layer is less than 10 ⁶ Ω · cm, the charging characteristics of the belt are deteriorated, and the charge of the charged toner is easily moved and transferred. This is because the toner image is disturbed. The reason why the volume resistivity of the elastic layer is set to 10 ¹² Ω · cm or less is that, if it exceeds 10 ¹² Ω · cm, a large transfer voltage is required for primary transfer and transfer efficiency is deteriorated. The volume resistivity of the elastic layer is more preferably 10 ⁶ Ω · cm to ¹⁰ 10 Ω · cm, and particularly preferably 10 ⁷ Ω · cm to 10 ⁹ Ω · cm.

Assuming that the volume resistivity of the elastic layer and the surface electrical resistivity on the inner peripheral surface side of the base layer are within the above-mentioned fixed ranges, not only secondary transfer to a recording medium but also a photoconductor Transferability is also very good in the primary transfer from the image carrier to the intermediate transfer belt. In addition, by suppressing the hardness of the elastic layer slightly low, the nip width between the belt and the recording medium at the time of secondary transfer is widened, and even if paper with large irregularities is used as the recording medium, white spots in the concave portions of the paper are not generated. Occurrence can be further suppressed. Preferably, the elastic layer 5 JIS A hardness of 25 ° to 70 °, and the volume resistivity of the ^{10 8 Ω · cm (1.0 ×} 10 8 Ω · cm~9.9 × 10 8 Ω · cm), The thickness is 200 to 600 μm.

  Next, as a surface layer material constituting the surface layer 7, (1) a combination of rubber latex and a curing agent containing 1 to 5 parts by mass of fluororubber with respect to 1 part by mass of the fluororesin, or ( 2) A combination of a water-based urethane resin containing a fluororesin and a silicon component and a curing agent may be mentioned.

  (1) will be described. The rubber latex is a fluororubber latex containing fluororubber and a vulcanizing agent and, if desired, usual additives such as fillers, colorants, acid acceptors, vulcanization accelerators, co-vulcanizing agents or paint additives. , A fluororesin is blended.

  The fluororesin includes polyvinylidene fluoride (PVdF), polychlorotrifluoroethylene (CTFE), polytetrafluoroethylene (PTFE), tetrafluoroethylene (TFE) and at least one other ethylenic copolymerizable therewith. And a copolymer with an unsaturated monomer. Other ethylenically unsaturated monomers copolymerizable with TFE include, for example, olefins such as ethylene or propylene, halogenated compounds such as hexafluoropropylene (HFP), vinylidene fluoride, chlorotrifluoroethylene, and vinyl fluoride. Examples thereof include olefins, perfluoroalkyl vinyl ethers (PFVE), etc. Specific examples of copolymers of these with TFE include ethylene / tetrafluoroethylene copolymer (ETFE), tetrafluoroethylene (TFE) / hexa. Fluoropropylene copolymer (FEP), tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer (PFA), tetrafluoroethylene / hexafluoroethylene / perfluoroalkyl vinyl ether copolymer (EPA) Etc., and the like.

  The fluororubber is not particularly limited. For example, a vinylidene fluoride copolymer that contains vinylidene fluoride as a comonomer, a tetrafluoroethylene copolymer that contains tetrafluoroethylene as a comonomer, or an ethylene / hexafluoropropylene copolymer. Examples thereof include coalescence and phosphazene rubber. Examples of the vinylidene fluoride copolymer include vinylidene fluoride / hexafluoropropylene copolymer, vinylidene fluoride / tetrafluoroethylene / hexafluoropropylene copolymer, and vinylidene fluoride / chlorotrifluoroethylene copolymer. Can be mentioned. Examples of the tetrafluoroethylene copolymer include a tetrafluoroethylene / propylene copolymer and a tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer.

As the vulcanizing agent, a commonly used fluororubber vulcanizing agent can be used. Examples of preferred vulcanizing agents are shown below.
(1) Polyamine vulcanizing agent As polyamine, ethyleneamine, propylamine, butylamine, triethylenetetramine, tetraethylenepentamine, ethylenediamine, triethylenediamine, ethanolamine, 3,9-bis (3-aminopropyl) -2 , 4,8,10-tetraoxa-2-spiro [5.5] -undecane and the like, and salts thereof, aromatic amines such as diaminodiphenylmethane, xylylenediamine, phenylenediamine, diaminodiphenylsulfone, and diaminodiphenyl ether; Its salts, modified polyamines, polyamidoamines, and the general formula:

(In the formula, R represents a methyl group or an ethyl group, X represents a single bond, —C ₂ H ₄ NH—, —CONH— or —C ₂ H ₄ NH—C ₂ H ₄ NH—NH—, n Is 2 or 3.>
An aminosilane compound represented by the formula, a portion thereof or a complete hydrolyzate is preferred.
(2) Polyol-based vulcanizing agent Examples of the polyol include compounds having at least two hydroxyl groups, particularly phenolic hydroxyl groups in the molecule, and polymer compounds having vulcanization performance. For example, phenol derivatives such as bisphenol A, bisphenol AF, and hydroquinone, and salts thereof, polyhydroxy compounds having two enol-type hydroxyl groups in the molecule, such as phenol resin, and salts thereof, Rf (CH ₂ OH) ₂ (however, Rf is a perfluoroalkyl polyether group.
(3) Polythiol-based vulcanizing agent The polythiol is preferably triazine thiol, 1,6-hexanedithiol, 4,4'-dimethylmercaptodiphenyl, 1,5-naphthalenedithiol, etc. The blending amount of the vulcanizing agent is fluorine. The amount is preferably 0.1 to 20 parts by weight, more preferably 0.5 to 5 parts by weight with respect to 100 parts by weight of rubber. The blending amount of the agent is preferably 3 parts by mass or less, and it is preferable to use a vulcanizing agent that is soluble in the organic solvent when the medium is an organic solvent and soluble in water when the medium is water. .

Vulcanizing aids can also be used to accelerate vulcanization. The compounding quantity of a vulcanization auxiliary is 0-10 mass parts with respect to 100 mass parts of fluororubber, Preferably it is 0.1-5 mass parts. Vulcanizing aids include trimethylbenzylammonium chloride, triethylbenzylammonium chloride, dimethyldecylbenzylammonium chloride, triethylbenzylammonium chloride, myristylbenzyldimethylammonium chloride, dodecyltrimethylammonium chloride, dimethyltetradecylbenzylammonium chloride, trimethyltetradecylammonium chloride. Chloride, coconut trimethylammonium chloride, stearyltrimethylammonium chloride, distearyldimethylammonium chloride, tetrabutylammonium hydroxide, 1,4-phenylenedimethylenebistrimethylammonium dichloride, 1,4-phenylenedimethylenebistriethyl Nmo pyridinium dichloride, alkyl and aralkyl quaternary ammonium salts such as ethylene bis-triethylammonium dibromide;
8-methyl-1,8-diaza-bicyclo [5.4.0] -7-undecenium chloride, 8-methyl-1,8-diaza-bicyclo [5.4.0] -7-undecenium Iodide, 8-methyl-1,8-diaza-bicyclo [5.4.0] -7-undecenium hydroxide, 8-methyl-1,8-diaza-bicyclo [5.4.0] -7 Undecenium-methyl sulfate, 8-methyl-1,8-diaza-bicyclo [5.4.0] -7-undecenium bromide, 8-propyl-1,3-diaza-bicyclo [5.4.0] -7-undecenium bromide, 8-dodecyl-1,8-diaza-bicyclo [5.4.0] -7-undecenium chloride, 8-dodecyl-1,8-diaza-bicyclo [5.4. 0] -7-Undeceni Muhydrooxide, 8-eicosyl-1,8-diaza-bicyclo [5.4.0] -7-undecenium chloride, 8-tetracosyl-1,8-diaza-bicyclo [5.4.0] -7 -Undecenium chloride, 8-benzyl-1,8-diaza-bicyclo [5.4.0] -7-undecenium chloride, 8-benzyl-1,8-diaza-bicyclo [5.4.0] -7-undecenium hydroxide, 8-phenethyl-1,8-diaza-bicyclo [5.4.0] -7-undecenium chloride, 8- (3-phenylpropyl) -1,8-diaza- Quaternary ammonium salts such as quaternary 1,8-diaza-bicyclo [5.4.0] -7-undecenium salts such as bicyclo [5.4.0] -7-undecenium chloride;
Trimethylamine, triethylamine, tri-n-propylamine, tri-n-butylamine, triisobutylamine, methyldiethylamine, dimethylethylamine, dimethyln-propylamine, dimethyln-butylamine, dimethylisobutylamine, dimethylisopropylamine, dimethyl-sec-butylamine, Dimethyl-tert-butylamine, triallylamine, diallylmethylamine, allyldimethylamine, benzyldimethylamine, benzyldiethylamine, N-allylpiperidine, N-ethylpiperidine, N-butylpiperidine, N-methylpyrrolidine, N-cyclohexylpyrrolidine, N -Tertiary amino such as n-butylpyrrolidine, N-ethylpyrrolidine, N-benzylpyrrolidine, 2,4,6-trimethylpyridine And quaternary phosphonium salts such as triphenylphosphine benzyl chloride salt. In the case where the medium is an organic solvent, it is preferable to use an organic solvent, and in the case of water, a medium soluble in water is used.

  Examples of the filler include carbon black, white carbon, calcium carbonate, barium sulfate, talc, and calcium silicate. Examples of the colorant include inorganic pigments and composite oxide pigments. Examples of the acid acceptor include double salts such as magnesium oxide, lead oxide, zinc oxide, lead carbonate, zinc carbonate, and hydrotalcite. Usually, the amount of the acid acceptor may be appropriately adjusted according to the activity thereof, and for example, 1 to 40 parts by mass can be added to 100 parts by mass of the fluororubber.

  In preparing the rubber latex, for example, an organic solvent, water, or the like is used as a medium of a substance that dissolves or disperses the fluororesin, fluororubber, vulcanizing agent, and other additives. From the viewpoint of environmental problems, it is particularly preferable to use water as the medium.

  Examples of the organic solvent include ketones such as methyl ethyl ketone and methyl isobutyl ketone; esters such as butyl acetate and isopentyl acetate; ethers such as diethylene glycol dimethyl ether; hydrocarbons such as toluene and xylene; N, N-dimethylacetamide, N -Amides such as methyl-2-pyrrolidone; and alcohols such as methanol and ethanol. The medium is preferably used in a proportion of 30 to 90% by mass based on the mass of the entire composition.

  When water is used as a medium, a dispersant is used to disperse fluororubber or fluororesin in water. Dispersing agents include anionic surfactants such as lauryl sulfate, perfluoroalkyl carboxylate, and ω-hydroperfluoroalkyl carboxylate; nonionic surfactants such as polyethylene glycol derivatives and polyethylene glycol / polypropylene glycol derivatives Agents: alkyl polyethylene glycol ether, alkylphenyl polyethylene glycol ether, alkyl polyethylene glycol ester, ethylene glycol / propylene glycol copolymer, polyethylene glycol alkyl ester and the like. The dispersant is preferably used in a proportion of 0.1 to 10% by mass based on the mass of the entire composition. A stabilizer can be added to the rubber latex. As the stabilizer, an organic acid having 1 to 12 carbon atoms, preferably an organic acid having 1 to 4 carbon atoms is used. More preferable organic acids are monocarboxylic acids such as formic acid, acetic acid and propionic acid, and dicarboxylic acids such as oxalic acid, malonic acid and succinic acid.

  In the rubber latex, the fluororubber may be contained in an amount of more than 1 part by mass and 5 parts by mass or less, preferably 1.1 parts by mass to 4 parts by mass with respect to 1 part by mass of the fluororesin. The surface free energy in the surface layer can be adjusted to a desired value. When the fluororubber content is equal to or less than 1 part by mass of the fluororesin, the mixing ratio of the fluororesin increases and the surface free energy tends to be too small. On the other hand, when more than 5 parts by mass of fluororubber is contained, the effect of mixing the fluororesin does not appear, and the surface free energy on the surface layer tends to be too large.

  In the present invention, for example, “Daiel Latex” manufactured by Daikin Industries, Ltd. may be used. For example, “Daiel Latex GLS-213F” is a fluororubber latex containing 25% by mass of the above-described fluororubber and 25% by mass of a fluororesin and containing a colorant. “Daiel Latex GLS-213CR” is an uncolored fluororubber latex composed of 25% by mass of the above-mentioned fluororubber and 25% by mass of a fluororesin. Furthermore, “DAIEL Latex GL-252” consists of 50% by mass of the above-mentioned fluororubber and is commercially available as a fluororubber latex containing a colorant. In the present invention, it is preferable to adjust the content ratio of the fluororesin and the fluororubber by appropriately mixing the product numbers.

  Next, (2) will be described. Even when the surface layer material constituting the surface layer 7 is made of a water-based urethane resin containing a fluororesin and a silicon component and a curing agent, the surface free energy in the surface layer can be adjusted to a desired value. The polyurethane resin contained in the water-based urethane resin is obtained by addition reaction of a polyol (a compound containing two or more hydroxyl groups) and a polyisocyanate (a compound containing two or more isocyanate groups). Examples of the polyol include aliphatic, alicyclic and aromatic polyhydric alcohols having two or more hydroxyl groups in the molecule. Specific examples include polyester polyol, polyether polyol, polycarbonate polyol, polycaprolactone polyol, polythioether polyol, polyacetal polyol, polytetramethylene glycol, polybutadiene polyol, polyisoprene polyol, hydrogenated polybutadiene polyol, castor oil polyol, and the like. . These may be used singly or in combination of two or more.

  Examples of the polyisocyanate include diphenylmethane diisocyanate, polymethylene polyphenylene polyisocyanate, tolylene diisocyanate, polytolylene polyisocyanate, xylene diisocyanate, and naphthalene diisocyanate; aliphatic polyisocyanates such as hexamethylene diisocyanate; dicyclohexylmethane diisocyanate, Cycloaliphatic polyisocyanates such as isophorone diisocyanate and hydrogenated xylylene diisocyanate can be used. In addition, polyisocyanate obtained by modifying the polyisocyanate with carbodiimide, polyisocyanate obtained by modifying the polyisocyanate with isocyanurate, and the like can also be used. These may be used singly or in combination of two or more.

  In order to make a polyurethane resin into an aqueous composition, it is necessary to make the polyurethane resin into an aqueous emulsion or an aqueous solution. An aqueous emulsion or aqueous solution of a polyurethane resin is obtained by adding a polyol and an excess polyisocyanate to synthesize a urethane prepolymer having an isocyanate group at the molecular end, and then using a surfactant to form the urethane prepolymer. Can be obtained by emulsifying dispersion or solubilization in water.

  The molar ratio of polyol: polyisocyanate in the addition reaction is preferably 1: 1.1 to 10, more preferably 1: 1.3 to 5. When the polyol: polyisocyanate molar ratio is less than 1: 1.1, sequential addition polymerization is likely to occur, and a high molecular weight product is formed. When the molar ratio is greater than 1:10, the residual amount of free isocyanate increases, and the stability during storage may decrease.

  There is no restriction | limiting in particular as surfactant, A nonionic surfactant, a cationic surfactant, and an amphoteric surfactant can be used conveniently. The emulsification dispersion or solubilization may be performed using a known emulsification apparatus.

  When preparing an aqueous emulsion or aqueous solution of a polyurethane resin, a urethane prepolymer is synthesized using a compound having an active hydrogen atom that reacts with an isocyanate group and a salt-forming group in addition to a polyol and a polyisocyanate, The obtained urethane prepolymer may be emulsified or solubilized in water using a salt forming agent.

  Examples of the compound having an active hydrogen atom that reacts with an isocyanate group and a salt-forming group include hydroxy acid, aminocarboxylic acid, aminosulfonic acid, hydroxysulfonic acid, and the like, and a salt-forming agent for the compound is a metal hydroxide. Ammonia, a tertiary amine compound, and the like. In addition, examples of the compound having an active hydrogen atom and a salt-forming group that react with other isocyanate groups different from the above include amino alcohols, amines, and the like, and salt-forming agents for them include organic acids, inorganic acids, Examples thereof include compounds having a reactive halogen atom.

  Furthermore, examples of the compound having an active hydrogen atom and a salt-forming group that react with another isocyanate group different from the above include alcohols having a halogen atom, and as a salt-forming agent therefor, tertiary amines, sulfides, A phosphine etc. are mentioned. In this method, a surfactant may be used in combination. The salt forming agent is usually added in an equivalent amount.

  Also, when preparing an aqueous emulsion or aqueous solution of a polyurethane resin, a urethane prepolymer using the above polyol and polyisocyanate, and further polyoxyethylene monoalkyl ether and / or polyoxyethylene polyoxypropylene monoalkyl ether is used. A polymer may be synthesized and the resulting urethane prepolymer may be emulsified or solubilized in water. In this method, a surfactant may be used in combination.

  The urethane prepolymer in the aqueous emulsion or solubilized liquid is made to have a high molecular weight by reaction with water, or a polyvalent amine compound is added to the obtained aqueous emulsion or solubilized liquid to obtain a polyvalent By making it high molecular weight by reaction with an amine compound, it can be set as the aqueous emulsion or aqueous solution of a polyurethane resin.

  In the water-based urethane resin used in the present invention, the composition ratio of the polyurethane resin aqueous emulsion or aqueous solution is preferably 20 to 60% by mass, more preferably 30 to 50% by mass in terms of solid content.

  Examples of the fluororesin contained in the aqueous urethane resin used in the present invention include the same compounds as the fluororesin contained in the rubber latex.

  The silicon component contained in the water-based urethane resin used in the present invention may have any form. Examples of the silicon component include water-soluble or water-dispersed silicon compounds having siloxane units. In addition, reactive silicon such as amino modification, epoxy modification, carboxy modification, carbinol modification, acrylic modification, methacryl modification, mercapto modification, and phenol modification, polyether modification, methyl styryl modification, alkyl modification, hydrophilization, non-reacting special modification It is also possible to use conductive silicon. Furthermore, it may be contained as a silicone oil such as dimethyl silicone oil or methylphenyl silicone oil. Such a silicon component is preferably contained in the water-based urethane resin in a proportion of 0.5 to 10% by mass.

  In the water-based urethane resin used in the present invention, a silicon component may be included in the form of a silicon-modified polyurethane resin. The silicone-modified polyurethane resin is a copolymer in which a structure having a urethane bond in the main chain and a partial siloxane bond is incorporated in a block form and / or a graft form. In this case, any ratio of the siloxane bond unit to the structural unit of the main chain can be used.

  The silicon-modified urethane resin is a silicon-modified polyol obtained by reacting an organosilicon compound and a polyol and / or a silicon-modified isocyanate obtained by reacting an organosilicon compound and an isocyanate (even a silicon-modified polyisocyanate prepolymer). (1) silicon-modified polyol and isocyanate, (2) polyol and silicon-modified isocyanate, and (3) silicon-modified polyol and silicon-modified isocyanate. Here, the organosilicon compound used for silicon modification is preferably a polyorganosiloxane having at least one active hydrogen group or alkoxy group and having a main chain of polydimethylsiloxane.

  The surface layer 7 has a thickness after drying of 3 to 20 μm, preferably 5 to 15 μm. The reason why the thickness of the surface layer is set to 3 μm or more is to prevent the surface layer from being worn away during use and reducing the detachability of the toner particles. The reason why the thickness is set to 20 μm or less is to reduce the manufacturing cost by reducing the time and labor required for forming the surface layer.

  While pursuing transfer performance to a recording medium when the multilayer belt is used as an intermediate transfer belt, the present inventor has transfer efficiency for efficiently transferring the toner on the intermediate transfer belt to paper, and has unevenness. It has been found that it is necessary to satisfy both of the two performances, that is, the embedding ratio in paper that allows toner to adhere to the back of the paper fiber. When transferring the toner from the intermediate transfer belt to the paper, the charged toner is moved to the paper side by electrostatic force, and when intensive studies were made to improve the transfer efficiency, at least the base layer, the elastic layer, and the surface layer were transferred. In the multilayer belt in which the three layers are laminated, the surface layer has a rubber latex and a curing agent containing more than 1 part by mass of fluororubber with respect to 1 part by mass of the fluororesin and 5 parts by mass or less, or , Having a water-based urethane resin containing a fluororesin and a silicon component and a curing agent, or having a surface energy of 20 mN / m to 40 mN / m on the surface layer, and measured by a nanoindentation method The surface hardness of the surface layer is 3 μm from the surface layer side, and the hardness is 0.1 MPa to 1.5 MPa. Improvement that can improve the filling rate to the paper along with found that possible filling rate to transfer efficiency and paper in both good.

  The surface free energy of the surface layer is a reference for efficiently moving the toner to easily separate the toner from the belt. However, if the surface free energy is lower than 20 mN / m, the adhesion force of the toner to the surface layer is too small, and image misalignment, etc. In the case of exceeding 40 mN / m, the adhesion force of the toner to the surface layer is increased, the separation of the toner is deteriorated, and the transfer efficiency to the paper is deteriorated. Even if the surface free energy is lower than 20 mN / m or exceeds 40 mN / m, the detailed reason is unknown, but the embedding rate in paper is lowered. The multilayer belt of the present invention has a surface free energy of 20 to 40 mN / m so that the toner is well separated and exhibits excellent transfer efficiency, and also follows the unevenness of the paper to be transferred, and is excellent in paper. It shows the filling rate.

  In the multilayer belt of the present invention, the embedding rate in paper is improved by keeping the surface free energy as described above and the hardness at the time of 3 μm indentation from the surface side measured by the nanoindentation method within a certain range. I found something that could be done. Hardness measurement by the nanoindentation method is a method of measuring the relationship between the load and the indentation depth (displacement amount) while pushing a small diamond indenter into the thin film, and calculating the hardness from the measured value. The amount of displacement can be measured with nanometer accuracy, and is generally used as a physical property specification in a thin metal layer such as copper or zinc or an inorganic compound layer such as silicon oxide. It is considered that the hardness at the time of indentation of 3 μm into a multilayer belt having a laminated structure of a thin surface layer laminated on an elastic layer is a standard for the ease of capturing toner particles on the surface and the ease of separation. Further, it is considered to be a standard for embedding in a transfer material such as paper. In examining the hardness at the time of indentation of 3 μm from the surface layer side, the present inventors made 0.1 MPa to 1.5 MPa, preferably 0.3 MPa to 0.5 MPa, so that the filling ratio in paper It has been found that if the hardness at 3 μm indentation is lower than 0.1 MPa, the force for capturing the toner increases, so it is difficult to separate from the belt surface, and transfer efficiency and embedding are reduced. In addition, if the pressure is higher than 1.5 MPa, it is impossible to improve both the transfer efficiency and the embedding rate in paper at the same time.

  Excellent surface transfer performance when the multilayer belt of the present invention is used as an intermediate transfer belt by combining the surface layer with fluorine resin, etc., and also having the surface energy and hardness when pressed in by 3 μm. As a result, a high-quality image can be obtained. When the multilayer belt of the present invention is used as the intermediate transfer belt, it shows a transfer efficiency of 80% or more and a filling ratio of 80% or more in paper.

The tensile modulus of elasticity in the surface layer 7 is not particularly specified, but is preferably in the range of 0.1 to 100 MPa, and the surface electrical resistivity is 10 ⁷ Ω / □ to 10 ¹⁴ Ω / □. It should be of a range.

Next, the manufacturing method of a multilayer belt is demonstrated.
The base layer material is continuously supplied from the nozzle to the outer surface of the mold while rotating the cylindrical mold, and at the same time, the nozzle is moved in the direction of the rotation axis of the mold, and the material is uniformly applied and cured. A preferred embodiment is a production method in which the base layer is formed by forming the base layer, then the elastic layer is formed on the base layer by the same method, and then the surface layer is coated on the elastic layer.

  In this manufacturing method, in order to improve mold releasability, a mold release agent made of silicone oil or the like may be applied to the mold surface, or the mold may be coated with ceramics. Examples of the ceramic include silica, alumina, zirconia, silicon nitride coated by a sol-gel method; alumina, zirconia coated by a thermal spray method; or aluminum nitride coated by a sputtering method.

  As shown in FIG. 3, the base layer material 32 is continuously supplied from the nozzle 31 while rotating the cylindrical mold 33 in the circumferential direction, and at the same time, the nozzle 31 is moved in the direction of the rotation axis of the mold. . Thereby, the supplied base layer material 32 is wound spirally. By adjusting the moving speed of the nozzle 31 and the rotating speed of the mold 33, the liquid material 32 wound in a spiral shape is bonded at adjacent portions to form a uniform coating layer. After this coating step, the liquid material applied by a conventional method is cured to form a base layer.

  As shown in FIG. 4, the nozzle 31 for applying the base layer material 32 to the mold 33 has a liquid discharge port in a tubular shape, its tip is inclined, and its wall thickness is about 0.3 to 3.0 mm. More preferably, it is about 0.5 to 2.0 mm. The inner diameter of the nozzle (liquid discharge port) is set to 0.5 to 5 mm, preferably about 1 to 3 mm. The center of the liquid discharge port of the nozzle 31 is in contact with the outer surface of the mold 33 and the mold rotates. It is set to move in the axial direction, and the liquid discharge port of the nozzle 31 and the material applied to the mold 33 are in contact with each other.

  The nozzle moving speed V (mm / second) and the rotational speed R (rotation / second) of the mold are (V / R) <1.5, preferably 0.85 <(V / R) <1.5. Set to satisfy the relationship. By performing application under the conditions in the above range, it is possible to prevent the occurrence of stripes and irregularities due to the liquid stirring effect in the vicinity of the liquid discharge port of the nozzle.

  In consideration of cost reduction, it is preferable that the coating time is short. The coating time can be shortened by increasing the number of rotations of the mold, but there is an upper limit to the number of rotations of the mold because it is necessary to prevent the liquid from splashing due to centrifugal force. Therefore, the liquid discharge port of the nozzle is tubular and the wall thickness is set to about 0.3 to 3.0 mm, more preferably about 0.5 to 2.0 mm, so that the application time is shortened so that the stripe pattern and the unevenness do not occur. I have to. The elastic layer can be formed on the base layer in exactly the same way as the method for forming the base layer.

  After forming the elastic layer on the base layer, a primer may be applied to the surface of the elastic layer in order to improve the adhesion between the elastic layer and the surface layer. Examples of methods for coating the surface layer material on the elastic layer include roll coater or bar coat coating, spray coating, electrostatic coating, dip coating, and the like. Painting is preferred.

  According to such a manufacturing method, there is an advantage that the accuracy of the thickness of each layer is good and the material loss is small. Furthermore, there is an advantage that a belt whose thickness varies in the axial direction can be obtained by adjusting the amount of material supplied from the nozzle, the moving speed of the nozzle in the rotational axis direction, and the like. Further, when the base layer material or the elastic layer material is a two-liquid mixed type material, it is possible to use an apparatus that can mix two liquids at a desired ratio and supply them to the nozzle, thereby improving the efficiency of the production process. Can be achieved.

  Other methods for producing the multilayer belt of the present invention include, for example, (1) a method of centrifugal molding in the order of the surface layer, the elastic layer, and the base layer, and (2) centrifugal molding in the order of the elastic layer and the base layer, followed by demolding. Then, a method of applying a surface layer, (3) a method of centrifugally forming only the base layer, removing the mold, and then applying an elastic layer and a surface layer in order, (4) laminate extrusion using a base layer material and an elastic layer material A belt in which a base layer and an elastic layer are laminated by the above method, and a surface layer is applied on the elastic layer. (5) A single-layer belt consisting only of the base layer is produced by extrusion, and a cylindrical layer is formed on the base layer. By continuously supplying the elastic layer material from the nozzle to the outer surface of the mold while rotating the mold, and simultaneously moving the nozzle in the direction of the rotation axis of the mold, and uniformly curing the material after curing Form an elastic layer and apply a surface layer on the elastic layer Law, and a method of co-extruding the three layers with (6) the base layer material and the elastic layer material and the surface layer material.

  The multilayer belt of the present invention can be suitably used as an intermediate transfer belt in an electrophotographic image forming apparatus such as a laser beam printer, a copying machine, or a facsimile. In particular, it is preferably used as an intermediate transfer belt of an electrophotographic color printer or a color copier.

  The image forming apparatus may be either a dry development type image forming apparatus using powder toner or a wet development type image forming apparatus using liquid toner.

  In Examples described later, “LP-S7000R” manufactured by Seiko Epson Corporation was used as a page printer, and the following toners were used as toners.

(Toner preparation)
(Production of master batch)
70 parts by mass of “Crosslinked Polyester Resin ES-803” manufactured by Sanyo Chemical Industries, Ltd. and 30 parts by mass of “ECR-101” manufactured by Dainichi Seika Kogyo Co., Ltd. are mixed as a pigment, A masterbatch in which the pigment was dispersed was prepared by kneading with Kneedex 100 ".

  After roughly pulverizing this masterbatch with a feather mill, 124 mass parts of “crosslinked polyester resin ES-803” manufactured by Sanyo Chemical Industries, Ltd. and 273 mass of “linear polyester resin ES-8022” manufactured by Sanyo Chemical Industries, Ltd. Part, 83 parts by mass of the above-mentioned master batch, 15 parts by mass of “Purified Carnauba WAX type # 1” manufactured by Nippon Wax as a release agent, and 5 parts by mass of “Bontron W-81” manufactured by Orient Chemical as a charge control agent These were mixed and diluted and kneaded with a twin-screw extruder manufactured by Toshiba Machine. Further, the diluted kneaded material was coarsely pulverized with a feather mill, pulverized with an airflow collision pulverizer, and recovered with an airflow classifier to produce toner base particles having a volume average particle diameter of 8.1 μm after classification. .

  To 100 parts by mass of the toner base particles, 0.5 part by mass of hydrophobic silica (RX200 manufactured by Nippon Aerosil Co., Ltd., particle size: 12 nm) was added and mixed and stirred with a Henschel mixer to obtain a magenta toner. At this time, the blending amount of the release agent in the magenta toner was 3% by mass. Then, when the cross section of the toner was observed with a transmission electron microscope for the dispersion state of the release agent, it was found that the release agent was uniformly dispersed, the equivalent diameter of the dispersed particles of the release agent, the maximum diameter being 1200 nm, arithmetic The average diameter was 780 nm. The magenta toner had a Tg of 59.7 ° C. and a Tm of 111.5 ° C.

  EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention, each physical property of the multilayer belt produced by the Example and the comparative example was measured as follows.

  (1) Surface free energy: A small piece of a multilayer belt was cut out, and the contact angle when water, iodomethane and bromonaphthalene were dropped on the surface layer was measured. For the measurement, “FTA125” manufactured by First Ten Angstroms (USA) was used, and calculation was performed using the KITAZAKI formula.

(2) Surface hardness of multilayer belt: Measured using a microhardness measuring device (nanoindenter). As shown in FIG. 5, this device comprises a transducer a and a diamond Berkovich indenter with an equilateral triangle at the tip. The displacement amount (indentation depth) is measured with an accuracy of nm by applying a load of mgf order to the surface of the multilayer belt. As a commercially available product, “ENT-2100” (triangular pyramid indenter, 115 degrees between ridges) manufactured by Elionix can be used. This apparatus measures the reaction force (mgf / μm ² ) from the measurement surface, and in the present invention, it measures hardness HM (Martens hardness) when pressed by 3 μm, and hardness HM (Martens hardness) when loaded with 10 mgf. . In each example described later, it is an average value of 5-point measurement. Further, the standard deviation at this time is a value that is smaller by one digit or more than the measurement result, and indicates the significance of the measurement. Note that 1 mgf / μm ² = 10 MPa and 1 mgf = 10 μN.

  (3) Tensile modulus: measured according to JISK7113. The tensile modulus of the surface layer is a sheet produced by pouring the surface layer material of each of the examples and comparative examples onto a silicon rubber mold, drying at room temperature, and curing under the same conditions as those of the examples and comparative examples. It measured using. Measured from the linear portion of the 50mm stress curve between 10mm wide chucks.

  (4) Surface resistivity: Measured with a URS probe under the conditions of an applied voltage of 250 V and a measurement time of 10 seconds using “Hiresta UPMCP-HT450 type” manufactured by Dia Instruments Co., Ltd. The measurement environment is a temperature of 23 ° C. and a relative humidity of 55%.

  (5) Volume resistivity: Measured with a URS probe using a “HIRESTA UPMCP-HT450 type” manufactured by Dia Instruments Co., Ltd. under an applied voltage of 250 V and a measurement time of 10 seconds. The measurement environment is a temperature of 23 ° C. and a relative humidity of 55%.

  (6) JIS A hardness of elastic layer; measured according to JIS K6253 (1993), and type A was used.

  (7) IRHD hardness of multilayer belt: Wallace hardness meter {needle shape is spherical (φ0.395mm)}, which converts the indentation depth into hardness using a conversion table. Is 15.6 gf, for example, a hardness of 50 corresponds to an indentation depth of 160 μm.

  (8) Tack: A force that a cylindrical surface receives from a belt when a cylinder with a diameter of 3 mm is pressed against the belt surface with a predetermined load and is moved away from the belt at a constant speed.

  (9) Tensile strength; the maximum value of stress obtained by measurement of tensile modulus (JISK7113).

  (10) Elongation: Elongation at which breakage occurs due to measurement of tensile modulus (JISK7113).

(1) Preparation of base layer-Polyamideimide varnish synthesized by a known method from trimellitic acid and diphenylmethane diisocyanate-100 parts by mass-Carbon black (furnace black)-7.0 parts by mass-Dispersant ... 0.1 parts by mass were uniformly mixed with a bead mill to prepare a base layer material.

  As the mold, an aluminum cylinder having an outer diameter of 200 mmφ coated with ceramics was used, and the nozzle was brought into contact with the mold outer surface while rotating the cylindrical mold. In this state, the base layer material was quantitatively supplied from the nozzle, and the nozzle was moved at a constant speed in the direction of the rotation axis of the mold to apply the material. At this time, the rotor rotational speed is 6 rpm, (V / R) = 1.17 (mm / rotation) (where V is the moving speed of the nozzle (mm / second), and R is the rotational speed of the mold (rotation / second). It was applied under the conditions of As the nozzle, a PTFE tube having an inner diameter of 2 mm and an outer diameter of 4 mm was used.

  As shown in FIG. 4, the tip of the nozzle 31 was cut off at 45 degrees, and the nozzle position was set so that the central part of the cut-off surface moved in the axial direction of the mold while being in contact with the outer surface of the mold 33. Next, the material was cured by gradually heating to 300 ° C. while rotating the mold and cooling to form a base layer having a thickness of 80 μm. The tensile elastic modulus was 2800 MPa, and the surface resistivity (logΩ / □) was 9.4.

(2) Production of elastic layer The elastic layer material is shown in Table 1 below. The components contained in the curing agent shown in Table 1 were first mixed at the ratio shown in Table 1, and the obtained curing agent and the main agent were mixed at the ratio shown in Table 1 to prepare an elastic layer material. This material was coated on the base layer using the same apparatus as that used for the base layer preparation to form an elastic layer. Next, the belt coated with the elastic layer material on the base layer was heated at 150 ° C. for 1 hour to cure the elastic layer. The elastic layer had a thickness of 230 μm, a JIS A hardness of 27, and a volume resistivity (log Ω · cm) of 9.5.

-Main agent: terminal prepolymer with NCO content of 6.9% obtained from polypropylene glycol and tolylene diisocyanate (manufactured by Sumika Bayer Urethane Co., Ltd.)
・ Acclaim 4220: Polypropylene glycol (manufactured by Sumika Bayer Urethane Co., Ltd.)
Ecure 300; dimethylthiotoluenediamine (manufactured by Albemarle)
Antistatic agent: “Sanconol PEO-20R” manufactured by Sanko Chemical Co., Ltd. (aqueous solution in which lithium-bis (trifluoromethanesulfonyl) imide is dissolved in polyol)
Antifoaming agent: “Floren AC326F” manufactured by Kyoeisha Chemical Co., Ltd.

(3) Preparation of surface layer Next, the surface layer of the following composition was formed on the elastic layer on the base layer obtained above, respectively, and it was set as the multilayer belt of Examples 1-8 and Comparative Example 1. Moreover, the measurement example of the surface hardness by the nanoindentation method is shown about the multilayer belt obtained in the following Example 10.

  A multilayer belt is set on the nano indenter ("ENT-2100" manufactured by Elionix Co., Ltd.) shown in FIG. 5, and the load speed is set to 15 mgf / sec so that the load change is constant. , Step interval: 20 msec, measured at a temperature of 32 ° C.

  FIG. 6 shows the relationship between the obtained displacement vs. load. FIG. 6 shows the relationship between the load (mgf) and the displacement (μm) (when the indenter is pressed against the multilayer belt surface) → (when the indenter is unloaded). From this figure, it can be seen that the displacement A when the load is 10 mgf is 2 μm.

The hardness (mgf / μm ² , HM, Martens hardness) is
HM = P / A
(P is the (maximum) load applied to the indenter, and A is the contact projection area between the indenter and the sample at that time.)
As shown in FIG. 7, a displacement (μm) vs hardness (mgf / μm ² ) curve can be obtained using this apparatus. From FIG. 7, it can be seen that the hardness (B) corresponding to the displacement A (2 μm) is obtained, and the HM hardness at a load of 10 mgf (100 μN) is 0.48 MPa. FIG. 8 shows the hardness (A) corresponding to the displacement (3 μm) in FIG. It can be seen that the hardness when pressed at 3 μm is 0.46 MPa.

  FIG. 9 shows an optical micrograph (view range: 130 mm × 105 mm) from the surface side of the multilayer belt subjected to the measurement. Note that the intersection of the crosshairs is a hardness measurement point by the nanoindentation method.

Example 1
・ “Daiel Latex GLS-213CR” manufactured by Daikin Industries, Ltd. (uncolored fluororubber latex consisting of 25% by mass of fluororubber and 25% by mass of fluororesin)
... 40% by mass
・ “Daiel Latex GL-252CR” (uncolored fluororubber latex consisting of 50% by mass of fluororubber) manufactured by Daikin Industries, Ltd. 60% by mass
・ Curing agent ("Daiel Latex GL-200" manufactured by Daikin Industries, Ltd.)
... 1.5% by mass (outer hook)
To obtain a surface layer material containing 4 parts by mass of fluoro rubber with respect to 1 part by mass of the fluororesin. The obtained surface layer material was coated on the elastic layer obtained above with an electrostatic coating gun. After drying, it was cured in an oven at 150 ° C. for 60 minutes to form a surface layer having a thickness of 10 μm, and a multilayer belt of Example 1 was produced. Although a surface layer with a film thickness of 10 μm was created with an electrostatic coating gun, the height from the base layer to the surface layer using a dial gauge and the height of the area where the surface layer was not applied (area of only the base layer and the elastic layer) When the difference in thickness was measured again (hereinafter referred to as measurement using a dial gauge), the film thickness of the surface layer was 14.8 μm. The surface free energy (mN / m) of the surface layer was 22.6. The tensile modulus (MPa) was 5.2, the tack (gf) was 90, and the hardness (IRHD) was 68.1. Further, according to the same measurement method as the nanoindentation method described above, the HM hardness at 10 mgf (100 μN) load was 0.41 MPa, and the hardness at 3 μm indentation was 0.41 MPa.

(Example 2)
・ “Daiel Latex GLS-213CR” manufactured by Daikin Industries, Ltd. (uncolored fluororubber latex consisting of 25% by mass of fluororubber and 25% by mass of fluororesin)
... 60% by mass
・ “Daiel Latex GL-252CR” (uncolored fluororubber latex consisting of 50% by mass of fluororubber) manufactured by Daikin Industries, Ltd. 40% by mass
・ Curing agent ("Daiel Latex GL-200" manufactured by Daikin Industries, Ltd.)
... 1.5% by mass (outer hook)
To obtain a surface layer material containing 2.33 parts by mass of fluoro rubber with respect to 1 part by mass of the fluororesin. The obtained surface layer material was coated on the elastic layer obtained above with an electrostatic coating gun. After drying, it was cured in an oven at 150 ° C. for 60 minutes to form a surface layer having a thickness of 10 μm, and a multilayer belt of Example 2 was produced. In addition, it was 14.2 micrometers when the film thickness was measured again using the dial gauge similarly to Example 1. The surface free energy (mN / m) of the surface layer was 28.3. The tensile modulus (MPa) was 10.7, the tack (gf) was 62, and the hardness (IRHD) was 77.9. Further, according to the same measurement method as the nanoindentation method described above, the HM hardness at 10 mgf (100 μN) load was 1.00 MPa, and the hardness at 3 μm indentation was 0.68 MPa.

(Example 3)
・ “Daiel Latex GLS-213CR” manufactured by Daikin Industries, Ltd. (uncolored fluororubber latex consisting of 25% by mass of fluororubber and 25% by mass of fluororesin)
... 80% by mass
・ “Daiel Latex GL-252CR” manufactured by Daikin Industries, Ltd. (uncolored fluororubber latex consisting of 50% by mass of fluororubber) 20% by mass
・ Curing agent ("Daiel Latex GL-200" manufactured by Daikin Industries, Ltd.)
... 1.5% by mass (outer hook)
To obtain a surface layer material containing 1.5 parts by mass of fluoro rubber with respect to 1 part by mass of the fluororesin. The obtained surface layer material was coated on the elastic layer obtained above with an electrostatic coating gun. After drying, it was cured in an oven at 150 ° C. for 60 minutes to form a surface layer having a thickness of 10 μm, and a multilayer belt of Example 3 was produced. In addition, it was 15.3 micrometers when the film thickness was measured again using the dial gauge similarly to Example 1. The surface free energy (mN / m) of the surface layer was 33.4. The tensile modulus (MPa) was 19, the tack (gf) was 49, and the hardness (IRHD) was 86. Further, according to the same measurement method as the nanoindentation method described above, the HM hardness under a load of 10 mgf (100 μN) was 1.50 MPa, and the hardness when pressed in by 3 μm was 0.89 MPa.

(Example 4)
・ “Daiel Latex GLS-213CR” manufactured by Daikin Industries, Ltd. (uncolored fluororubber latex consisting of 25% by mass of fluororubber and 25% by mass of fluororesin)
... 90% by mass
・ “Daiel Latex GL-252CR” (uncolored fluororubber latex consisting of 50% by mass of fluororubber) manufactured by Daikin Industries, Ltd. 10% by mass
・ Curing agent ("Daiel Latex GL-200" manufactured by Daikin Industries, Ltd.)
... 1.5% by mass (outer hook)
To obtain a surface layer material containing 1.22 parts by mass of fluororubber with respect to 1 part by mass of the fluororesin. The obtained surface layer material was coated on the elastic layer obtained above with an electrostatic coating gun. After drying, it was cured in an oven at 150 ° C. for 60 minutes to form a surface layer having a thickness of 10 μm, and a multilayer belt of Example 4 was produced. In addition, it was 13.1 micrometers when the film thickness was measured again using the dial gauge similarly to Example 1. The surface free energy (mN / m) of the surface layer was 40. The tensile elastic modulus (MPa) was 33.1, the tack (gf) was 30, and the hardness (IRHD) was 90.4. Further, according to the same measurement method as the nanoindentation method described above, the HM hardness under a load of 10 mgf (100 μN) was 1.60 MPa, and the hardness when pressed in by 3 μm was 0.93 MPa.

(Example 5)
・ “Daiel Latex GLS-213CR” manufactured by Daikin Industries, Ltd. (uncolored fluororubber latex consisting of 25% by mass of fluororubber and 25% by mass of fluororesin)
... 40% by mass
・ “Daiel Latex GL-252CR” (uncolored fluororubber latex consisting of 50% by mass of fluororubber) manufactured by Daikin Industries, Ltd. 60% by mass
・ Curing agent ("Daiel Latex GL-200" manufactured by Daikin Industries, Ltd.)
... 5% by mass (outer)
To obtain a surface layer material containing 4 parts by mass of fluoro rubber with respect to 1 part by mass of the fluororesin. The obtained surface layer material was coated on the elastic layer obtained above with an electrostatic coating gun. After drying, it was cured in an oven at 150 ° C. for 60 minutes to form a surface layer having a thickness of 10 μm, and a multilayer belt of Example 5 was produced. In addition, when the film thickness was measured again using a dial gauge in the same manner as in Example 1, it was 16.6 μm. The surface free energy (mN / m) of the surface layer was 25.9. The tensile modulus (MPa) was 10.1, the tack (gf) was 70, and the hardness (IRHD) was 78.2. Further, according to the same measurement method as the nanoindentation method described above, the HM hardness at 10 mgf (100 μN) load was 0.78 MPa, and the hardness at 3 μm indentation was 0.64 MPa.

(Example 6)
・ “Daiel Latex GLS-213CR” manufactured by Daikin Industries, Ltd. (uncolored fluororubber latex consisting of 25% by mass of fluororubber and 25% by mass of fluororesin)
... 60% by mass
・ “Daiel Latex GL-252CR” (uncolored fluororubber latex consisting of 50% by mass of fluororubber) manufactured by Daikin Industries, Ltd. 40% by mass
・ Curing agent ("Daiel Latex GL-200" manufactured by Daikin Industries, Ltd.)
... 5% by mass (outer)
To obtain a surface layer material containing 2.33 parts by mass of fluoro rubber with respect to 1 part by mass of the fluororesin. The obtained surface layer material was coated on the elastic layer obtained above with an electrostatic coating gun. After drying, it was cured in an oven at 150 ° C. for 60 minutes to form a surface layer having a thickness of 10 μm, and a multilayer belt of Example 6 was produced. In addition, it was 14.4 micrometers when the film thickness was measured again using the dial gauge like Example 1. FIG. The surface free energy (mN / m) of the surface layer was 22. The tensile modulus (MPa) was 26.2, the tack (gf) was 38, and the hardness (IRHD) was 86.2. Further, according to a measurement method similar to the nanoindentation method described above, the HM hardness at 10 mgf (100 μN) load was 1.34 MPa, and the hardness at 3 μm indentation was 0.88 MPa.

(Example 7)
・ “Daiel Latex GLS-213CR” manufactured by Daikin Industries, Ltd. (uncolored fluororubber latex consisting of 25% by mass of fluororubber and 25% by mass of fluororesin)
... 80% by mass
・ “Daiel Latex GL-252CR” manufactured by Daikin Industries, Ltd. (uncolored fluororubber latex consisting of 50% by mass of fluororubber) 20% by mass
・ Curing agent ("Daiel Latex GL-200" manufactured by Daikin Industries, Ltd.)
... 5% by mass (outer)
To obtain a surface layer material containing 1.5 parts by mass of fluoro rubber with respect to 1 part by mass of the fluororesin. The obtained surface layer material was coated on the elastic layer obtained above with an electrostatic coating gun. After drying, it was cured in an oven at 150 ° C. for 60 minutes to form a surface layer having a thickness of 10 μm, and a multilayer belt of Example 7 was produced. In addition, it was 14.2 micrometers when the film thickness was measured again using the dial gauge similarly to Example 1. The surface free energy (mN / m) of the surface layer was 30. The tensile modulus (MPa) was 50 and the tack (gf) was 22. Hardness (IRHD) was 94.0. Further, according to the same measurement method as that of the nanoindentation method described above, the HM hardness at 10 mgf (100 μN) load was 1.75 MPa, and the hardness at 3 μm indentation was 1.00 MPa.

(Example 8)
・ “Daiel Latex GLS-213CR” manufactured by Daikin Industries, Ltd. (uncolored fluororubber latex consisting of 25% by mass of fluororubber and 25% by mass of fluororesin)
... 90% by mass
・ “Daiel Latex GL-252CR” (uncolored fluororubber latex consisting of 50% by mass of fluororubber) manufactured by Daikin Industries, Ltd. 10% by mass
・ Curing agent ("Daiel Latex GL-200" manufactured by Daikin Industries, Ltd.)
... 5% by mass (outer)
To obtain a surface layer material containing 1.22 parts by mass of fluororubber with respect to 1 part by mass of the fluororesin. The obtained surface layer material was coated on the elastic layer obtained above with an electrostatic coating gun. After drying, it was cured in an oven at 150 ° C. for 60 minutes to form a surface layer having a thickness of 10 μm, and a multilayer belt of Example 8 was produced. In addition, when the film thickness was measured again using a dial gauge in the same manner as in Example 1, it was 12.8 μm. The surface free energy (mN / m) of the surface layer was 34. The tensile modulus (MPa) was 75 and the tack (gf) was 18. Hardness (IRHD) was 97.0. Further, according to a measurement method similar to the nanoindentation method described above, the HM hardness when loaded with 10 mgf (100 μN) was 1.80 MPa, and the hardness when pressed in by 3 μm was 1.02 MPa.

(Comparative Example 1)
A multilayer belt having a polytetrafluoroethylene (PTFE) resin as a surface layer was produced and used as Comparative Example 1. In addition, when the film thickness was measured again using a dial gauge in the same manner as in Example 1, it was 12.8 μm. The surface free energy (mN / m) of the surface layer was 18. Further, according to a measurement method similar to the nanoindentation method described above, the HM hardness when loaded with 10 mgf (100 μN) was 5.11 MPa, and the hardness when pressed in by 3 μm was 2.22 MPa.

  Next, the case where the thickness of the elastic layer is changed and the surface layer is made of an aqueous urethane resin containing a fluororesin and a silicon component and a curing agent will be described with reference to Examples 9 to 11 and Comparative Example 2.

Example 9
(Formation of elastic layer)
On the same base layer as in Example 1, the components contained in the curing agent shown in Table 1 above are first mixed in the proportions shown in Table 1, and the resulting curing agent and the main agent are mixed in the proportions shown in Table 1. Then, an elastic layer material was prepared and applied in the same manner using the same apparatus as that used for the base layer preparation to form an elastic layer. Next, the belt coated with the elastic layer material on the base layer was heated at 150 ° C. for 1 hour to cure the elastic layer. The elastic layer had a thickness of 600 μm, a JIS A hardness of 27, and a volume resistivity (log Ω · cm) of 9.5.
(Formation of surface layer)
A water-based urethane paint containing a urethane resin as a binder, containing a fluororesin powder (PTFE) in an amount of 1% by mass or less and a silicon resin in a ratio of 5 to 20% by mass (urethane paint “TW805” manufactured by Nippon Atson Co., Ltd.). ) As a main agent, and a curing agent (“WHI” manufactured by Nippon Atchison Co., Ltd.) was mixed at a ratio of main agent: curing agent = 95: 5 (mass ratio) to obtain a surface layer material. The obtained surface layer material was coated on the elastic layer with an electrostatic coating gun. After drying, it was cured in an oven at 120 ° C. for 10 minutes to form a surface layer having a thickness of 8 μm, and a multilayer belt of Example 9 was produced. In addition, when the film thickness was measured again using a dial gauge in the same manner as in Example 1, it was 10.3 μm. The surface free energy (mN / m) of the surface layer was 28. The tensile modulus (MPa) was 5.9, the hardness (IRHD) 61.5, the tensile strength (MPa) 1.2, and the elongation (%) 22.2. Further, according to the same measurement method as the nanoindentation method described above, the HM hardness at 10 mgf (100 μN) load was 0.41 MPa, and the hardness at 3 μm indentation was 0.41 MPa.

(Example 10)
(Formation of elastic layer)
On the same base layer as in Example 1, the components contained in the curing agent shown in Table 1 above are first mixed in the proportions shown in Table 1, and the resulting curing agent and the main agent are mixed in the proportions shown in Table 1. Then, an elastic layer material was prepared and applied in the same manner using the same apparatus as that used for the base layer preparation to form an elastic layer. Next, the belt coated with the elastic layer material on the base layer was heated at 150 ° C. for 1 hour to cure the elastic layer. The elastic layer had a thickness of 200 μm, a JIS A hardness of 27, and a volume resistivity (log Ω · cm) of 9.5.

  Next, a surface layer was formed in the same manner as in Example 9. In addition, when the film thickness was measured again using a dial gauge in the same manner as in Example 1, it was 10.9 μm. The physical property values in the surface layer were the same. In addition, according to the measurement method similar to the nanoindentation method described above, the HM hardness when loaded with 10 mgf (100 μN) was 0.48 MPa, and the hardness when pressed in by 3 μm was 0.46 MPa.

(Example 11)
(Formation of elastic layer)
On the same base layer as in Example 1, the components contained in the curing agent shown in Table 1 above are first mixed in the proportions shown in Table 1, and the resulting curing agent and the main agent are mixed in the proportions shown in Table 1. Then, an elastic layer material was prepared and applied in the same manner using the same apparatus as that used for the base layer preparation to form an elastic layer. Next, the belt coated with the elastic layer material on the base layer was heated at 150 ° C. for 1 hour to cure the elastic layer. The elastic layer had a thickness of 100 μm, a JIS A hardness of 27, and a volume resistivity (log Ω · cm) of 9.5.

  Next, a surface layer was formed in the same manner as in Example 9. In addition, when the film thickness was measured again using a dial gauge in the same manner as in Example 1, it was 12.1 μm. The physical property values in the surface layer were the same. In addition, according to the measurement method similar to the nanoindentation method described above, the HM hardness at 10 mgf (100 μN) load was 0.97 MPa, and the hardness at 3 μm indentation was 0.74 MPa.

(Comparative Example 2)
On the same base layer and elastic layer as in Example 1, a water-based urethane paint, which is self-curing urethane, was used as a surface layer material, and was coated on the elastic layer obtained above with an electrostatic coating gun. After drying, it was cured in an oven at 150 ° C. for 10 minutes to form a surface layer having a thickness of 10 μm, and a multilayer belt of Comparative Example 2 was produced. In addition, when the film thickness was measured again using a dial gauge in the same manner as in Example 1, it was 12.1 μm. The surface free energy (mN / m) of the surface layer was 48. Further, according to the same measurement method as the nanoindentation method described above, the HM hardness under a load of 10 mgf (100 μN) was 3.22 MPa, and the hardness when pressed in by 3 μm was 1.60 MPa.

(Example 12)
The obtained surface layer material obtained in Example 8 was coated on the elastic layer in the same manner as in Example 8 using an electrostatic coating gun. After drying, it was cured in an oven at 150 ° C. for 60 minutes, and when a film thickness was measured using a dial gauge in the same manner as in Example 1, a surface layer of 6 μm was formed, and a multilayer belt of Example 12 was produced.

  The surface free energy (mN / m) of the surface layer was 34. The tensile modulus (MPa) was 75 and the tack (gf) was 18. The hardness (IRHD) was 96. Further, according to the same measurement method as the nanoindentation method described above, the HM hardness when loaded with 10 mgf (100 μN) was 0.48 MPa, and the hardness when pressed in by 3 μm was 0.44 MPa.

(Example 13)
The obtained surface layer material obtained in Example 7 was coated on the elastic layer in the same manner as in Example 7 using an electrostatic coating gun. After drying, it was cured in an oven at 150 ° C. for 60 minutes, and when a film thickness was measured using a dial gauge in the same manner as in Example 1, a surface layer of 6.4 μm was formed, and a multilayer belt of Example 13 was produced.

  The surface free energy (mN / m) of the surface layer was 30. The tensile modulus (MPa) was 50 and the tack (gf) was 22. The hardness (IRHD) was 92. Further, according to the same measurement method as the nanoindentation method described above, the HM hardness under a load of 10 mgf (100 μN) was 0.56 MPa, and the hardness when pressed in by 3 μm was 0.49 MPa.

(Example 14)
The obtained surface layer material obtained in Example 3 was coated on the elastic layer in the same manner as in Example 3 using an electrostatic coating gun. After drying, it was cured in an oven at 150 ° C. for 60 minutes, and when a film thickness was measured using a dial gauge in the same manner as in Example 1, a surface layer of 7.8 μm was formed, and a multilayer belt of Example 14 was produced.

  The surface free energy (mN / m) of the surface layer was 33. The tensile modulus (MPa) was 33 and the tack (gf) was 49. The hardness (IRHD) was 86. Further, according to the same measurement method as the nanoindentation method described above, the HM hardness at 10 mgf (100 μN) load was 0.46 MPa, and the hardness at 3 μm indentation was 0.44 MPa.

(Example 15)
The obtained surface layer material obtained in Example 2 was coated on the elastic layer in the same manner as in Example 2 using an electrostatic coating gun. After drying, it was cured in an oven at 150 ° C. for 60 minutes, and when a film thickness was measured using a dial gauge in the same manner as in Example 1, a surface layer of 7.7 μm was formed, and a multilayer belt of Example 15 was produced.

  The surface free energy (mN / m) of the surface layer was 28. The tensile modulus (MPa) was 10, and the tack (gf) was 63. Further, the hardness (IRHD) was 78. Further, according to the same measurement method as the nanoindentation method described above, the HM hardness under a load of 10 mgf (100 μN) was 0.30 MPa, and the hardness when pressed in by 3 μm was 0.34 MPa.

  The multilayer belts obtained in Examples 1 to 15 and Comparative Examples 1 and 2 were incorporated into a page printer (“LP-S7000R” manufactured by Seiko Epson Corporation), and the above toner was used, and paper (Fuji Fuji) was used as a recording medium. It was printed on “J paper” manufactured by Xerox Co., Ltd., with a surface roughness of 30 to 40 μm, and the transfer efficiency and the filling ratio on paper were measured.

  The transfer efficiency is determined by measuring the toner amount (A) on the intermediate transfer belt before transfer, printing a solid black image, and transferring the toner from the intermediate transfer belt to the paper (B) ) And is calculated from the weight ratio, and the transfer efficiency is 90% or more for double circles, 80 to 90% for ◯, and 80% or less for X. The results are shown in the table below.

  As for the embedding ratio on paper, an image printed by exposing the entire surface in the same manner as the transfer efficiency was used as a solid image, and the solid image on the paper at that time was enlarged using a microscope or the like. The recesses on the paper are whitened out if they are not well embedded in the paper. Therefore, the ratio of the area of the white spots is calculated by image processing, and an image without white spots is evaluated as a filling ratio of 100%. The double circle is 95% or more, and the circles are 85 to 95. %, X indicates a filling ratio of 85% or less in paper. The results are shown in the table below.

  From the table, if the surface free energy of the surface layer in the intermediate transfer belt (multi-layer belt) and the hardness when indented by 3 μm are within the range of the present invention, the toner is transferred to paper having a surface roughness of more than 10 μm using a small particle size toner. It can also be seen that an image excellent in both transfer efficiency and paper embedding ratio can be formed.

DESCRIPTION OF SYMBOLS 1 ... Multilayer belt (intermediate transfer belt), 3 ... Base layer, 5 ... Elastic layer, 7 ... Surface layer, 9 ... Outer peripheral surface, 11 ... Inner peripheral surface, 31 ... Nozzle, 32 ... Base layer material, 33 ... Mold, a ... transducer, b ... Berkovich indenter

Claims (4)

At least three layers of a base layer, an elastic layer, and a surface layer are sequentially laminated from the inner peripheral surface toward the outer peripheral surface, and the surface layer contains more than 1 part by weight of fluoro rubber with respect to 1 part by weight of the fluororesin, and 5 parts by weight or less possess the a curing agent rubber latex, a in a proportion of surface energy in the surface layer is 20 mN / 40 mN / m, and a surface hardness measured by a nano indenter, 3 [mu] m from the surface layer side A multilayer belt having a hardness of 0.1 MPa to 1.5 MPa when pressed . Base layer, an elastic layer and a surface layer of sequentially stacked toward the outer peripheral surface at least three layers from the inner peripheral surface, wherein the surface layer, possess an aqueous urethane resin containing a fluororesin and silicon component and a curing agent, a The surface energy of the surface layer is 20 mN / m to 40 mN / m, and the surface hardness is measured with a nanoindenter, and the hardness when indented by 3 μm from the surface layer side is 0.1 MPa to 1.5 MPa. A characteristic multilayer belt. The multilayer belt according to claim 1, wherein the elastic layer has a JIS-A hardness of 25 ° to 70 °. The multilayer belt according to claim 1, wherein the surface layer has a thickness of 3 μm to 20 μm.

Images