Belt materials for electrophotographic equipment

Abstract

To provide a belt member for an electrophotographic apparatus which suppresses occurrences of wrinkles and undulation due to long-term storage and use, suppresses sliding noise of a cleaning blade, improves appearance, and improves adhesion between a surface layer and a base layer.SOLUTION: There is provided a belt member 10 for an electrophotographic device in which a surface layer 14 constituted as a cured body of a resin composition containing, with respect to 100 pts.mass of a fluororesin having a hydroxyl group, 10 pts.mass or more and 30 pts.mass or less of an isocyanate curing agent having isocyanate groups at both terminals and a molecular weight of 600 g / mol or more and 4,000 g / mol or less, or 5 pts.mass or more and 18 pts.mass or less of an isocyanate curing agent having an isocyanate group at one terminal, 5 pts.mass or more and 10 pts.mass or less of a fluorine-based surface active agent, and 1.0 pts.mass or more and 5 pts.mass or less of a silane coupling agent having an amino group or an isocyanate group is provided on the outer peripheral surface of a cylindrical base layer 12.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a belt member for an electrophotographic device, and more particularly to a belt member for an electrophotographic device such as a conveyor belt or an intermediate transfer belt. [Background technology]

[0002] Known techniques for improving the sliding properties of belt members such as conveyor belts and intermediate transfer belts of electrophotographic equipment with cleaning blades include laminating a polyimide-based paint on the surface of a polyimide-based base layer, laminating a fluorine tube, and laminating a thermosetting fluorine resin with a silicone-based slip agent added. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-094605 [Patent Document 2] Japanese Patent Application Laid-Open No. 2011-073804 [Patent Document 3] International Publication No. 2022 / 071224 Summary of the Invention [Problem to be solved by the invention]

[0004] The belt member is subjected to tensile forces from two axes. Therefore, if the belt member is stored for a long period of time or used for a long period of time, wrinkles and undulations may occur on the surface of the belt member, which may cause paper transport problems during use. Furthermore, since the belt member abuts against the cleaning blade, prolonged use is likely to result in abnormal sliding noise between the belt member and the cleaning blade. Furthermore, if the adhesion between the base layer and the surface layer of the belt member is insufficient, the surface layer may peel off.

[0005] The problem to be solved by the present invention is to provide a belt member for electrophotographic equipment which prevents wrinkles and undulations from occurring during long-term storage and use, reduces the sliding noise of a cleaning blade, improves the appearance, and improves the adhesion between the surface layer and the base layer. [Means for solving the problem]

[0006] The belt member for electrophotographic equipment according to the present invention has a cylindrical base layer and a surface layer formed on the outer peripheral surface of the base layer, the base layer containing at least one of polyimide and polyamideimide, and the surface layer is formed as a cured product of a resin composition containing a fluororesin having a hydroxyl group, an isocyanate curing agent, a fluorosurfactant, and a silane coupling agent having an amino group or an isocyanate group, the isocyanate curing agent having isocyanate groups at both ends and having a molecular weight of 600 g / mol to 4000 g / mol, and the amount of the isocyanate curing agent is 10 parts by mass to 30 parts by mass, the amount of the fluororesin is 5 parts by mass to 10 parts by mass, and the amount of the silane coupling agent is 1.0 part by mass to 5 parts by mass, relative to 100 parts by mass of the fluororesin.

[0007] Another belt member for electrophotographic devices according to the present invention has a cylindrical base layer and a surface layer formed on an outer peripheral surface of the base layer, wherein the base layer contains at least one of polyimide and polyamideimide, and the surface layer is configured as a cured product of a resin composition containing a fluororesin having a hydroxyl group, an isocyanate curing agent, a fluorosurfactant, and a silane coupling agent having an amino group or an isocyanate group, the isocyanate curing agent having an isocyanate group at one end, and the amounts of the isocyanate curing agent, the fluorosurfactant, and the silane coupling agent are 5 to 18 parts by mass, 5 to 10 parts by mass, and 1.0 to 5 parts by mass, per 100 parts by mass of the fluororesin.

[0008] The fluorine content of the fluorine-based surfactant is preferably 10% by mass or more and 30% by mass or less, and the dynamic friction coefficient and static friction coefficient after 500 cycles of abrasion testing are preferably 0.5 or less.

[0009] (1) A belt member for an electrophotographic device according to the present invention has a cylindrical base layer and a surface layer formed on the outer peripheral surface of the base layer, the base layer containing at least one of polyimide and polyamideimide, and the surface layer is formed as a cured product of a resin composition containing a fluororesin having a hydroxyl group, an isocyanate curing agent, a fluorosurfactant, and a silane coupling agent having an amino group or an isocyanate group, the isocyanate curing agent having isocyanate groups at both ends and having a molecular weight of 600 g / mol or more and 4000 g / mol or less, and the amount of the isocyanate curing agent is 10 parts by mass or more and 30 parts by mass or less, the amount of the fluororesin is 5 parts by mass or more and 10 parts by mass or less, and the amount of the silane coupling agent is 1.0 part by mass or more and 5 parts by mass or less, per 100 parts by mass of the fluororesin.

[0010] (2) Another belt member for electrophotographic devices according to the present invention has a cylindrical base layer and a surface layer formed on the outer peripheral surface of the base layer, the base layer containing at least one of polyimide and polyamideimide, the surface layer being configured as a cured product of a resin composition containing a fluororesin having a hydroxyl group, an isocyanate curing agent, a fluorosurfactant, and a silane coupling agent having an amino group or an isocyanate group, the isocyanate curing agent having an isocyanate group at one end, and the amount of the isocyanate curing agent is 5 to 18 parts by mass, the amount of the fluororesin is 5 to 10 parts by mass, and the amount of the silane coupling agent is 1.0 to 5 parts by mass, relative to 100 parts by mass of the fluororesin.

[0011] (3) In the above (1) or (2), the fluorine content of the fluorine-based surfactant may be 10% by mass or more and 30% by mass or less.

[0012] (4) In any of the above items (1) to (3), it is preferable that the coefficient of dynamic friction and the coefficient of static friction after 500 cycles of abrasion testing are 0.5 or less. [Effects of the Invention]

[0013] According to the belt member for electrophotographic equipment of the present invention, the surface layer is formed as a cured product of a resin composition containing a fluororesin having a hydroxyl group, an isocyanate curing agent, a fluorosurfactant, and a silane coupling agent having an amino group or an isocyanate group, the isocyanate curing agent having isocyanate groups at both ends and having a molecular weight of 600 g / mol or more and 4000 g / mol or less, and the amount of the isocyanate curing agent is 10 parts by mass or more and 30 parts by mass or less, the amount of the fluororesin surfactant is 5 parts by mass or more and 10 parts by mass or less, and the amount of the silane coupling agent is 1.0 part by mass or more and 5 parts by mass or less, relative to 100 parts by mass of the fluororesin. Therefore, the generation of wrinkles and undulations during long-term storage and use is suppressed, the sliding noise of a cleaning blade is suppressed, the appearance is improved, and the adhesion between the surface layer and the base layer is improved.

[0014] In addition, according to another belt member for electrophotographic equipment of the present invention, the surface layer is formed as a cured product of a resin composition containing a fluororesin having a hydroxyl group, an isocyanate curing agent, a fluorosurfactant, and a silane coupling agent having an amino group or an isocyanate group, and the isocyanate curing agent has an isocyanate group at one end, and the amount of the isocyanate curing agent is 5 to 18 parts by mass, the amount of the fluororesin surfactant is 5 to 10 parts by mass, and the amount of the silane coupling agent is 1.0 to 5 parts by mass, relative to 100 parts by mass of the fluororesin. Therefore, the generation of wrinkles and undulations during long-term storage and use is suppressed, the sliding noise of a cleaning blade is suppressed, the appearance is improved, and the adhesion between the surface layer and the base layer is improved.

[0015] When the isocyanate curing agent has isocyanate groups at both ends and has a molecular weight of 600 g / mol or more and 4000 g / mol or less, the surface layer becomes flexible and the occurrence of wrinkles and undulations during long-term storage and use can be suppressed.

[0016] Furthermore, if the isocyanate curing agent has an isocyanate group at one end, the surface layer becomes flexible, and the occurrence of wrinkles and undulations during long-term storage and use can be suppressed.

[0017] When the fluorine content of the fluorine-based surfactant is 10% by mass or more and 30% by mass or less, the surface layer has improved slip properties, and is excellent in the effect of suppressing the sliding noise of the cleaning blade.

[0018] Furthermore, if the dynamic friction coefficient and static friction coefficient after 500 cycles of abrasion testing are 0.5 or less, the surface layer has excellent slip properties and is excellent in the effect of suppressing the sliding noise of the cleaning blade. [Brief explanation of the drawings]

[0019] [Figure 1] 1 is a perspective view showing an outline of a belt member for an electrophotographic apparatus according to one embodiment of the present invention; [Figure 2] FIG. 2 is a cross-sectional view of the belt member for the electrophotographic apparatus shown in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0020] A belt member for electrophotographic equipment (hereinafter, sometimes simply referred to as a belt member) according to the present invention will be described in detail. The belt member includes an elastic layer and a surface layer formed on the outer peripheral surface of the elastic layer. The belt member is suitable as an intermediate transfer belt, a paper transfer transport belt, a fixing belt, or other endless belt used in electrophotographic equipment such as copying machines, printers, and facsimiles that employ electrophotography.

[0021] Fig. 1 shows a belt member according to one embodiment of the present invention, and Fig. 2 shows a cross-sectional view of the belt member shown in Fig. 1.

[0022] The belt member 10 has a cylindrical base layer 12 and a surface layer 14 formed on the outer peripheral surface of the base layer 12. The belt member 10 is configured as an endless belt.

[0023] The base layer 12 serves as the substrate of the belt member 10. The base layer 12 is formed in a cylindrical shape and has a seamless structure with no seams in the circumferential direction. The base layer 12 contains at least one of polyimide and polyamideimide. The polyimide and polyamideimide may be functionally modified. Polyimide and polyamideimide are excellent in rigidity and durability, and are therefore suitable for use as materials for the base layer 12 of the belt member 10. In particular, it is preferable to use polyimide for the base layer 12. As long as the base layer 12 contains at least one of polyimide and polyamideimide as a main component, it may contain other components such as additives. Examples of additives include conductive agents such as carbon black and graphite, fillers such as calcium carbonate, release agents, flame retardants, leveling agents, and antifoaming agents.

[0024] There are no particular limitations on the thickness of the base layer 12. The thickness of the base layer 12 is, for example, preferably 50 μm or more, and 60 μm or more, and preferably 90 μm or less, and 80 μm or less.

[0025] The surface layer 14 is formed as a cured product of a resin composition containing a fluororesin having a hydroxyl group, an isocyanate curing agent, a fluorine-based surfactant, and a silane coupling agent having an amino group or an isocyanate group.

[0026] Fluorine resin is the main component of the surface layer 14 and serves as a binder polymer. There are no particular limitations on the fluororesin, as long as it can be used as a paint. Examples of fluororesin include fluorinated ethylene vinyl ether copolymer (FEVE), polyvinylidene fluoride resin (PVDF), and polychlorotrifluoroethylene resin (PCTFE). Fluorine resins with hydroxyl groups can be cured by a urethane reaction with an isocyanate curing agent.

[0027] The isocyanate curing agent functions as a curing agent for fluororesin having a hydroxyl group. Examples of the isocyanate curing agent include monoisocyanates and polyisocyanates. The isocyanate curing agent may have isocyanate groups (functional groups) at both ends, or may have an isocyanate group (functional group) at one end. It is preferable to use an isocyanate curing agent that is effective in softening the cured body.

[0028] It is preferable that the isocyanate curing agent having isocyanate groups at both ends has a relatively large molecular weight. In particular, a larger distance between crosslinks can contribute to the flexibility of the cured body. From this perspective, the molecular weight of the isocyanate curing agent having isocyanate groups at both ends is preferably 600 g / mol or more. More preferably, it is 1000 g / mol or more, even more preferably 1500 g / mol or more, and particularly preferably 2000 g / mol or more. On the other hand, if the molecular weight of the isocyanate curing agent having isocyanate groups at both ends is too large, the sliding noise of the cleaning blade tends to increase. For this reason, the molecular weight of the isocyanate curing agent having isocyanate groups at both ends is preferably 4000 g / mol or less, more preferably 3500 g / mol or less, and even more preferably 3000 g / mol or less. The molecular weight of the isocyanate curing agent is expressed as the number average molecular weight in the case of an oligomer or polymer.

[0029] As the isocyanate curing agent having isocyanate groups at both ends, an NCO-terminated urethane prepolymer obtained by reacting a polyisocyanate with a polyol may be used.

[0030] Polyisocyanates include diphenylmethane diisocyanate (MDI), polymethylene polyphenylene polyisocyanate (polymeric MDI), crude MDI (c-MDI), which is a mixture of MDI and polymeric MDI, dicyclohexylmethane diisocyanate (hydrogenated MDI), tolylene diisocyanate (TDI), hexamethylene diisocyanate (HDI), trimethylhexamethylene diisocyanate (TMHDI), and isophorone diisocyanate ( Examples of suitable polyisocyanates include methyl methyl isocyanate (MDI), methyl toluidine diisocyanate (TODI), naphthylene diisocyanate (NDI), xylylene diisocyanate (XDI), paraphenylene diisocyanate (PDI), lysine diisocyanate methyl ester (LDI), dimethyl diisocyanate (DDI), polymers such as MDI nurate, HDI nurate, and TDI nurate, as well as modified products thereof that have been subjected to urea, biuretization, allophanation, carbodiimidization, urethanization, etc. As the polyisocyanate, aliphatic polyisocyanates such as HDI are preferred from the viewpoints of imparting flexibility and ease of reactivity.

[0031] Examples of polyols include polyester polyols, polyether polyols, polycaprolactone polyols, polycarbonate polyols, etc. As the polyol, polyether polyols are particularly preferred from the viewpoint of stability (hydrolysis resistance) in a high-temperature and high-humidity environment.

[0032] Examples of polyester polyols include polyethylene adipate (PEA), polybutylene adipate (PBA), polyhexylene adipate (PHA), and copolymers of ethylene adipate and butylene adipate (PEA / BA).

[0033] Examples of polyether polyols include polypropylene glycol (PPG), polytetramethylene glycol (PTMG), ethylene oxide modified polyols of these, and polyethylene glycol (PEG).

[0034] Polycarbonate polyols (polycarbonate diols) are obtained by polymerizing alkylene diols as monomers with low molecular weight carbonate compounds. Examples of alkylene diols used as monomers include 1,6-hexanediol, 1,5-pentanediol, 1,4-butanediol, and cyclohexanedimethanol.

[0035] In the resin composition, the content of the isocyanate curing agent having isocyanate groups at both ends is 10 parts by mass or more and 30 parts by mass or less per 100 parts by mass of the fluororesin. If the content of the isocyanate curing agent having isocyanate groups at both ends is less than 10 parts by mass per 100 parts by mass of the fluororesin, the flexibility will be insufficient, and wrinkles and undulations will occur in the surface layer 14 after long-term storage and use. From this perspective, the content of the isocyanate curing agent having isocyanate groups at both ends is more preferably 15 parts by mass or more. On the other hand, if the amount of the isocyanate curing agent having isocyanate groups at both ends is too large, the sliding noise of the cleaning blade will increase. For this reason, the content of the isocyanate curing agent having isocyanate groups at both ends is 30 parts by mass or less per 100 parts by mass of the fluororesin. From this perspective, the content of the isocyanate curing agent having isocyanate groups at both ends is more preferably 25 parts by mass or less, and even more preferably 20 parts by mass or less.

[0036] An isocyanate curing agent having an isocyanate group at one end does not form a crosslinked structure with a fluororesin having a hydroxyl group, and therefore can contribute to the flexibility of the cured body by undergoing a urethane reaction. From this perspective, the molecular weight of an isocyanate curing agent having an isocyanate group at one end is not particularly limited.

[0037] The isocyanate curing agent having an isocyanate group at one end may be an aliphatic or aromatic monoisocyanate.

[0038] In the resin composition, the content of the isocyanate curing agent having an isocyanate group at one end is 5 parts by mass or more and 18 parts by mass or less per 100 parts by mass of the fluororesin. If the content of the isocyanate curing agent having an isocyanate group at one end is less than 5 parts by mass per 100 parts by mass of the fluororesin, the flexibility is insufficient, and wrinkles and undulations occur in the surface layer 14 after long-term storage and use. From this perspective, the content of the isocyanate curing agent is more preferably 7 parts by mass or more. On the other hand, if the content of the isocyanate curing agent having an isocyanate group at one end is too high, the sliding noise of the cleaning blade increases. For this reason, the content of the isocyanate curing agent having an isocyanate group at one end is 18 parts by mass or less per 100 parts by mass of the fluororesin. From this perspective, the content of the isocyanate curing agent having an isocyanate group at one end is more preferably 15 parts by mass or less.

[0039] The fluorosurfactant improves the surface slipperiness of the surface layer 14. The fluorosurfactant is composed of a compound having a fluorine-containing group. The fluorine-containing group is preferably present on the side chain of the compound. Examples of such compounds include polymers having a fluorine-containing group, acrylic fluorine copolymers, acrylic fluorine-acrylic copolymers, acrylic fluorine-acrylic silicone-acrylic copolymers, polyfluoropolyethers, and polyfluoropolyether alcohols. The polymer is not particularly limited, but is preferably a (meth)acrylic polymer from the viewpoint of compatibility with the fluorine paint containing the above-mentioned fluororesin.

[0040] The fluorine-containing group may be an organic group containing fluorine. The fluorine-containing organic group may be a fluoroalkyl group having 1 to 20 carbon atoms. The fluoroalkyl group may be a perfluoroalkyl group in which all hydrogen atoms of the alkyl group have been substituted with fluorine atoms, or a fluoroalkyl group in which some hydrogen atoms of the alkyl group have been substituted with fluorine atoms. Of these, perfluoroalkyl groups are preferred from the viewpoint of their tendency to be unevenly distributed on the surface of the surface layer 14.

[0041] Examples of the fluoroalkyl group having 1 to 20 carbon atoms include a trifluoromethyl group, a pentafluoroethyl group, a heptafluoropropyl group, a nonafluorobutyl group, a perfluorohexyl group, a trifluoroethyl group, a pentafluoropropyl group, and a heptafluorobutyl group.

[0042] The (meth)acrylic polymer refers to a copolymer of (meth)acrylate, a copolymer of (meth)acrylamide, a copolymer of (meth)acrylate and (meth)acrylamide, etc. For example, a copolymer having a fluorine-containing organic group can be obtained by copolymerizing a (meth)acrylate having a fluorine-containing organic group with a (meth)acrylate having a fluorine-free organic group.

[0043] The (meth)acrylic polymer may contain a copolymerizable unmodified (meth)acrylate or unmodified (meth)acrylamide as a copolymerization component. Examples of unmodified (meth)acrylates include alkyl (meth)acrylates and hydroxyalkyl (meth)acrylates. Examples of alkyl (meth)acrylates include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate. Examples of hydroxyalkyl (meth)acrylates include hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, and hydroxybutyl (meth)acrylate. Of these, methyl (meth)acrylate is preferred from the viewpoint of copolymerization reactivity, etc.

[0044] Examples of copolymerizable unmodified (meth)acrylamides include (meth)acrylamide, alkyl(meth)acrylamide, and hydroxyalkyl(meth)acrylamide. Examples of alkyl(meth)acrylamides include methyl(meth)acrylamide, ethyl(meth)acrylamide, propyl(meth)acrylamide, butyl(meth)acrylamide, and 2-ethylhexyl(meth)acrylamide. Examples of hydroxyalkyl(meth)acrylamides include hydroxyethyl(meth)acrylamide, hydroxypropyl(meth)acrylamide, and hydroxybutyl(meth)acrylamide. Among these, methyl(meth)acrylamide is preferred from the viewpoint of copolymerization reactivity, etc.

[0045] The fluorine content of the fluorosurfactant is preferably 10% by mass or more, from the viewpoint that the fluorosurfactant is likely to be unevenly distributed on the surface of surface layer 14 and is excellent in the effect of improving the surface slipperiness, and is more preferably 15% by mass or more. Furthermore, the fluorine content of the fluorosurfactant is preferably 30% by mass or less, from the viewpoint that the effect of improving the appearance of surface layer 14 is excellent, and is more preferably 25% by mass or less. The fluorine content of the fluorosurfactant can be measured by GC-MS analysis, NMR analysis, etc.

[0046] In the resin composition, the content of the fluororesin surfactant is 5 parts by mass or more and 10 parts by mass or less per 100 parts by mass of the fluororesin. If the content of the fluororesin surfactant is less than 5 parts by mass per 100 parts by mass of the fluororesin, the effect of improving the surface slipperiness will be insufficient, and the sliding noise of the cleaning blade will increase. From this perspective, the content of the fluororesin surfactant is more preferably 7 parts by mass or more. On the other hand, if the content of the fluororesin surfactant is more than 10 parts by mass per 100 parts by mass of the fluororesin, defects will occur on the coating surface, deteriorating the surface appearance of the surface layer 14. From this perspective, the content of the fluororesin surfactant is more preferably 8 parts by mass or less.

[0047] The silane coupling agent improves the adhesion between the base layer 12 and the surface layer 14. The silane coupling agent has an amino group or an isocyanate group to form a bond with both the materials of the base layer 12 and the surface layer 14.

[0048] Examples of silane coupling agents (amine-based) having an amino group include N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N-(1,3-dimethyl-butylidene)propylamine, N-phenyl-3-aminopropyltrimethoxysilane, and N-(vinylbenzyl)-2-aminoethyl-3-aminopropyltrimethoxysilane.

[0049] In the resin composition, the content of the silane coupling agent is 1.0 part by mass or more and 5 parts by mass or less per 100 parts by mass of the fluororesin. If the content of the silane coupling agent is less than 1.0 part by mass per 100 parts by mass of the fluororesin, the adhesion between the base layer 12 and the surface layer 14 will be insufficient. From this perspective, the content of the silane coupling agent is more preferably 2 parts by mass or more. On the other hand, if the content of the silane coupling agent is more than 5 parts by mass per 100 parts by mass of the fluororesin, wrinkles and undulations will occur in the surface layer 14 after long-term storage and use. From this perspective, the content of the silane coupling agent is more preferably 3 parts by mass or less.

[0050] The resin composition constituting the surface layer 14 may contain other components such as additives as appropriate in addition to the fluororesin, isocyanate curing agent, fluorine-based surfactant, and silane coupling agent. Examples of the additives include conductive agents, fillers, release agents, flame retardants, leveling agents, and antifoaming agents.

[0051] Furthermore, the surface layer 14 is preferably formed as a cured product of the resin composition described above, so that the dynamic and static friction coefficients after a 500-cycle abrasion test are 0.5 or less. The dynamic and static friction coefficients can be adjusted by selecting a fluorochemical surfactant and adjusting its content, or by selecting an isocyanate curing agent and adjusting its content. The dynamic and static friction coefficients of the surface layer 14 can be measured using a friction and wear meter.

[0052] The thickness of the surface layer 14 is not particularly limited, but by making it relatively thin, the occurrence of wrinkles and undulations in the surface layer 14 during long-term storage and use is more likely to be suppressed. From this perspective, the thickness of the surface layer 14 is preferably 60 μm or less, and more preferably 50 μm or less. Furthermore, from the perspective of more easily exerting the effects of the surface layer 14, the thickness of the surface layer 14 is preferably 20 μm or more, and more preferably 30 μm or more.

[0053] The belt member 10 can be manufactured as follows. First, the base layer 12 is formed. The base layer 12 is formed by coating the outer surface of a cylindrical or columnar mold with a base layer material in the form of a paint using an appropriate solvent or the like, and then drying. If necessary, a heat treatment may be performed. Coating methods include dip coating, dispenser coating (nozzle coating), roll coating, and ring coating. Next, a resin composition for the surface layer is coated on the surface of the formed base layer 12 and cured to form the surface layer 14. If necessary, heat treatment can be performed to accelerate the curing of the resin composition. The resin composition can be coated using the same methods as those listed above for forming the base layer 12. Finally, the mold is removed to obtain the belt member 10 having the surface layer 14 formed on the outer surface of the base layer 12.

[0054] According to the belt member 10 having the above-described configuration, the surface layer 14 is formed as a cured product of a resin composition containing a fluororesin having a hydroxyl group, an isocyanate curing agent, a fluorosurfactant, and a silane coupling agent having an amino group or an isocyanate group, and each component is blended in a specific amount, which prevents the occurrence of wrinkles and swells during long-term storage and use, reduces the sliding noise of the cleaning blade, improves the appearance, and improves the adhesion between the surface layer 14 and the base layer 12.

[0055] In the resin composition, the isocyanate curing agent contributes to the flexibility of the surface layer 14, thereby making it possible to prevent wrinkles and undulations from occurring during long-term storage and use. When the isocyanate curing agent has isocyanate groups at both ends and a molecular weight of 600 g / mol or more and 4000 g / mol or less, the surface layer 14 becomes flexible, making it possible to prevent wrinkles and undulations from occurring during long-term storage and use. Furthermore, when the isocyanate curing agent has an isocyanate group at one end, the surface layer 14 becomes flexible, making it possible to prevent wrinkles and undulations from occurring during long-term storage and use.

[0056] In the resin composition, the fluorosurfactant contributes to the smoothness of the surface, thereby enhancing the effect of suppressing the sliding noise of the cleaning blade. When the fluorine content of the fluorosurfactant is 10% by mass or more and 30% by mass or less, the smoothness of the surface layer 14 is improved, resulting in an excellent effect of suppressing the sliding noise of the cleaning blade. Although softening the surface layer 14 may deteriorate the smoothness of the surface, the resin composition contains a fluorosurfactant that improves the smoothness of the surface, so that the deterioration of the smoothness of the surface due to softening of the surface layer 14 is suppressed.

[0057] In the resin composition, the silane coupling agent contributes to the adhesion between the surface layer 14 and the base layer 12. There is a risk that the silane coupling agent may deteriorate the flexibility of the surface layer 14, but since the resin composition contains an isocyanate curing agent that softens the surface layer 14, the deterioration of flexibility caused by the silane coupling agent is suppressed, and the occurrence of wrinkles and swells during long-term storage and use can be suppressed. [Example]

[0058] The present invention will be described in detail below using examples and comparative examples, but the present invention is not limited to the following examples.

[0059] <Synthesis of fluorosurfactants> The raw materials and methyl isobutyl ketone (MIBK) with the composition shown in Table 1 were charged into a 0.5 L flask so that the solid content was 50%. After bubbling nitrogen for 5 minutes while stirring the contents of the flask, the temperature of the internal liquid was maintained at 100°C and the polymerization reaction was allowed to proceed for 10 hours. After that, MIBK was added to the flask so that the solid content was 30%, and a fluorosurfactant was added. <1> ~ <5> A copolymer solution was obtained.

[0060] The following raw materials were used to synthesize the fluorosurfactants. The fluorine concentration (F concentration) is calculated from the amount of each raw material used. MMA: Methyl methacrylate (Tokyo Chemical Industry Co., Ltd.) (molecular weight: 100.12) BMA: Butyl methacrylate (Tokyo Chemical Industry Co., Ltd.) (molecular weight: 128.17) 2-(perfluorohexyl)ethyl acrylate (manufactured by Daikin Chemicals Co., Ltd.) (molecular weight: 418.15) Initiator (radical polymerization initiator): 1,1'-azobis(cyclohexane-1-carbonitrile) (Fujifilm Wako Pure Chemical Industries, Ltd.) (molecular weight: 244.34)

[0061] [Table 1]

[0062] <Isocyanate curing agent <5> Synthesis of> A four-necked flask equipped with a stirrer, thermometer, reflux condenser, nitrogen inlet, and dropping funnel was purged with nitrogen and charged with 60 g of HDI (hexamethylene diisocyanate) (Tokyo Chemical Industry Co., Ltd.) and 62.5 g of divalent polyether polyol (Asahi Glass Co., Ltd. "Preminol G-5000", number average molecular weight 5000) (isocyanate group / hydroxyl group equivalent ratio 30 / 1). The mixture was stirred under a nitrogen atmosphere and the temperature inside the reactor was maintained at 160°C for 3 hours. The temperature of the reaction liquid was then lowered, and unreacted HDI was removed using a thin-film evaporator. The resulting polymer with both ends terminated with isocyanate (isocyanate curing agent) was then purged with 60 g of HDI (hexamethylene diisocyanate) (Tokyo Chemical Industry Co., Ltd.) and 62.5 g of divalent polyether polyol (Asahi Glass Co., Ltd. "Preminol G-5000", number average molecular weight 5000) (isocyanate group / hydroxyl group equivalent ratio 30 / 1). The mixture was stirred under a nitrogen atmosphere and the temperature inside the reactor was maintained at 160°C for 3 hours. The temperature of the reaction liquid was then lowered, and unreacted HDI was removed using a thin-film evaporator. <5> The number average molecular weight of ) is 5000.

[0063] Other materials for forming the surface layer are as follows: Fluorine resin: "Kanpeflon EX" manufactured by Kansai Paint Isocyanate hardener <1> : Uniroyal "Adiprene BL-16" (number average molecular weight 2000-3000) Isocyanate hardener <2> : Nippon Polyurethane "Coronate 2412" (number average molecular weight 600-2000) Isocyanate hardener <3> : Hodogaya Chemical's "Millionate 0" (molecular weight 296) Isocyanate hardener <4> DIC Burnock DB-980K (molecular weight 504) Silane coupling agent: Shin-Etsu Chemical Co., Ltd. "KBM-903"

[0064] <Preparation of Composition for Forming Surface Layer> Each component was mixed in the parts by mass shown in Tables 2 to 4 to prepare a composition for forming a surface layer.

[0065] <Production of Belt Component> A polyimide-containing coating liquid (HCI-1300 manufactured by Hitachi Chemical Co., Ltd.) was applied to the surface of a cylindrical mold by dip coating, and the mixture was heated at 120°C for 30 minutes, 150°C for 10 minutes, 200°C for 10 minutes, 250°C for 10 minutes, and 350°C for 10 minutes to form a base layer (70 μm thick). Next, a surface layer-forming composition was applied to the surface of the base layer by dipping, and the mixture was heated and cured at 160°C for 30 minutes to form a surface layer with a thickness shown in Tables 2 to 4. Next, the mold was removed to produce a belt member.

[0066] The produced belt members were evaluated for undulation, sliding noise, appearance, and adhesion, and the friction coefficient of the surface of the produced belt members was measured.

[0067] (undulation) The prepared belt member was set in a paper transport unit (Seiko Epson "WF-C20590") and left in an environment of 32.5°C x 90% RH for 5 days. After that, the belt member was rotated a quarter turn, and the height of the waviness that occurred at the point where the rotating shaft had been in contact before the rotation was evaluated as "◎" if it was 0.7 mm or less, "◯" if it was more than 0.7 mm and 0.9 mm or less, and "×" if it was more than 0.9 mm.

[0068] (sliding sound) The prepared belt member was set in a paper transport unit (Seiko Epson "WF-C20590"), and the belt member was rotated at a peripheral speed of 420 mm / sec. If no sliding noise was generated due to contact with the cleaning blade for 250 hours or more, the result was marked "◎", if sliding noise was generated between 200 hours and less than 250 hours, the result was marked "◯", and if sliding noise was generated within 200 hours, the result was marked "×".

[0069] (exterior) In the process of producing the belt member, the surface layer forming composition was applied to the base layer and subjected to a curing reaction at 160°C for 30 minutes. If defects occurred on the coating surface, the result was marked as "X", and if no defects (cracking, cracking, wrinkles, bubbles, bleeding) occurred, the result was marked as "O".

[0070] (adhesion) Fifty 1mm square cuts were made on the surface of the belt material, adhesive tape (Nitto Denko's "P-422") was attached, and when the tape was peeled off, if no peeling occurred in the surface squares, it was marked as "◎", if only one square peeled off, it was marked as "○", and if two or more squares peeled off, it was marked as "×" (cross-cut method).

[0071] (coefficient of friction) The belt member was set on the base of a friction and wear meter ("Triboster 500" manufactured by Kyowa Interface Science), and a wear test was carried out on the surface side of the belt member 500 times at a speed of 2.5 mm / s using a metal wire indenter, and the static and dynamic friction coefficients were measured after the 500th test.

[0072] [Table 2]

[0073] [Table 3]

[0074] [Table 4]

[0075] In Comparative Example 1, the content of the isocyanate curing agent in the surface layer forming composition is too low, causing undulations on the surface of the belt member. In Comparative Example 2, the content of the isocyanate curing agent in the surface layer forming composition is too high, and sliding noise is not suppressed. In Comparative Example 3, the isocyanate curing agent in the surface layer forming composition has functional groups at both ends, and its molecular weight is small, causing undulations on the surface of the belt member. In Comparative Example 4, the isocyanate curing agent in the surface layer forming composition has functional groups at both ends, and its molecular weight is large, and therefore sliding noise is not suppressed. In Comparative Example 5, the isocyanate curing agent in the surface layer forming composition has a functional group at one end, and the content of the isocyanate curing agent is too high, and therefore sliding noise is not suppressed.

[0076] In Comparative Example 6, the content of the fluorosurfactant in the surface layer-forming composition is low, so the effect of improving the surface slipperiness is low and sliding noise is not suppressed. In Comparative Example 7, the content of the fluorosurfactant in the surface layer-forming composition is high, so defects occur on the coating surface during surface layer formation, resulting in poor appearance. In Comparative Example 8, the content of the silane coupling agent in the surface layer-forming composition is low, so the adhesion between the base layer and the surface layer is poor. In Comparative Example 9, the content of the silane coupling agent in the surface layer-forming composition is high, so undulations occur on the surface of the belt member. In Comparative Example 10, the content of the fluorosurfactant in the surface layer-forming composition is low, so the surface slipperiness is poor and sliding noise is not suppressed. In Comparative Example 11, the content of the silane coupling agent in the surface layer-forming composition is low, so the adhesion between the base layer and the surface layer is poor.

[0077] On the other hand, in the examples, the surface layer-forming composition contains a fluororesin having a hydroxyl group, an isocyanate curing agent, a fluorine-based surfactant, and a silane coupling agent having an amino group or an isocyanate group, each component being in a specific amount, and the isocyanate curing agent has isocyanate groups at both ends and a molecular weight of 600 g / mol to 4000 g / mol, or the isocyanate curing agent has an isocyanate group at one end. According to the examples, the occurrence of undulations on the surface of the belt member is suppressed, the sliding noise of the cleaning blade is suppressed, no defects are observed on the coating surface during surface layer formation, the appearance is good, and the adhesion between the surface layer and the base layer is also excellent.

[0078] Furthermore, Examples 1, 2, and 7 show that when the content of the isocyanate curing agent having isocyanate groups at both ends is 15 to 25 parts by mass per 100 parts by mass of the fluororesin, the effect of suppressing undulation on the belt member surface is superior. Furthermore, Examples 1, 8, and 9 show that when the thickness of the surface layer is 20 μm to 50 μm, the effect of suppressing undulation on the belt member surface is superior. Furthermore, Examples 1 and 10 and Comparative Examples 3 and 4 show that when the molecular weight of the isocyanate curing agent having isocyanate groups at both ends is 2000 to 4000, the effect of suppressing undulation on the belt member surface and the effect of suppressing sliding noise are superior.

[0079] Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and various modifications are possible without departing from the gist of the present invention. [Explanation of symbols]

[0080] 10 Belt member 12 Base layer 14 Surface layer

Claims

1. A cylindrical base layer and a surface layer formed on an outer peripheral surface of the base layer, the base layer contains at least one of polyimide and polyamideimide, the surface layer is formed as a cured product of a resin composition including a fluororesin having a hydroxyl group, an isocyanate curing agent, a fluorine-based surfactant, and a silane coupling agent having an amino group or an isocyanate group; the isocyanate curing agent has isocyanate groups at both ends and a molecular weight of 600 g / mol or more and 4000 g / mol or less; a content of the isocyanate curing agent of 10 parts by mass or more and 30 parts by mass or less, a content of the fluorine-based surfactant of 5 parts by mass or more and 10 parts by mass or less, and a content of the silane coupling agent of 1.0 part by mass or more and 5 parts by mass or less, relative to 100 parts by mass of the fluorine-containing resin;

2. A cylindrical base layer and a surface layer formed on an outer peripheral surface of the base layer, the base layer contains at least one of polyimide and polyamideimide, the surface layer is formed as a cured product of a resin composition including a fluororesin having a hydroxyl group, an isocyanate curing agent, a fluorine-based surfactant, and a silane coupling agent having an amino group or an isocyanate group; The isocyanate curing agent has an isocyanate group at one end, a content of the isocyanate curing agent in an amount of 5 parts by mass or more and 18 parts by mass or less, a content of the fluorine-based surfactant in an amount of 5 parts by mass or more and 10 parts by mass or less, and a content of the silane coupling agent in an amount of 1.0 part by mass or more and 5 parts by mass or less, relative to 100 parts by mass of the fluorine-containing resin;

3. 3. The belt member for an electrophotographic apparatus according to claim 1, wherein the fluorine content of the fluorine-containing surfactant is 10% by mass or more and 30% by mass or less.

4. 3. The belt member for an electrophotographic apparatus according to claim 1, wherein the dynamic friction coefficient and static friction coefficient after 500 cycles of abrasion testing are 0.5 or less.

5. the fluorine content of the fluorine-based surfactant is 10% by mass or more and 30% by mass or less, 3. The belt member for an electrophotographic apparatus according to claim 1, wherein the dynamic friction coefficient and static friction coefficient after 500 cycles of abrasion testing are 0.5 or less.

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