# US 2019/0317422 A1 · Charging roller and method of producing the same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0317422 A1 - Document ID: US20190317422A1 - Status: Published application - Kind: A1 - Application number: 16/382,152 - Filed: 2019-04-11 - Published: 2019-10-17 - Earliest claimed: 2018-04-16 - Assignees: Sumitomo Rubber Industries, Ltd. - Applicants: Sumitomo Rubber Industries, Ltd. - Inventors: KAZUKI NOJIRI - Web page: https://patentgrep.com/patent/US20190317422A1 ## CPC - G03G 15/0233: {Structure, details of the charging member, e.g. chemical composition, surface properties} - C08J 9/105: {containing sulfur} - C08L 23/16: Ethylene-propylene or ethylene-propylene-diene copolymers - C08L 75/08: from polyethers - C08J 2323/16: Ethene-propene or ethene-propene-diene copolymers - G03G 2215/021: by contact, friction or induction - G03G: ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY - C08J: WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H (working, e.g. shaping, of plastics B29) - C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06) ## Abstract A charging roller has a roller main body including a cylindrical inner layer having a porous structure formed of a semiconductive rubber composition constituted by ethylene propylene rubber, paraffin oil, and a carbon black having a DBP oil absorption amount of 400 cm3/100 g or more and an outer layer constituted by a nonporous and seamless semiconductive tube including a polyurethane thermoplastic elastomer having a type A durometer hardness of 93 or less, carbon black, and crosslinked PMMA particles having an average particle size of 5 to 20 μm. The production method includes a process in which a semiconductive rubber composition forming the inner layer is foamed with OBSH. ## Claims ### Claim 1 A charging roller, comprising: a roller main body including a cylindrical inner layer having a porous structure formed of a semiconductive rubber composition constituted by ethylene propylene rubber, paraffin oil, and a carbon black having a DBP oil absorption amount of 400 cm3/100 g or more, and an outer layer which is provided on the outer circumference of the inner layer and constituted by a nonporous and seamless semiconductive tube including a polyurethane thermoplastic elastomer having a type A durometer hardness according to Japanese Industrial Standards JIS K7311-1995 of 93 or less at a measurement temperature of 23° C., carbon black, and crosslinked poly(methyl methacrylate) particles having an average particle size of 5 μm or more and 20 μm or less. ### Claim 2 (depends on 1) The charging roller according to claim 1, wherein the ethylene propylene rubber is ethylene propylene diene rubber. ### Claim 3 (depends on 1) The charging roller according to claim 1, wherein the inner layer has a porous structure formed by thermal decomposition of 4,4′-oxybisbenzenesulfonyl hydrazide as a foaming agent. ### Claim 4 (depends on 1) The charging roller according to claim 1, wherein the polyurethane thermoplastic elastomer is a polyether type polyurethane thermoplastic elastomer. ### Claim 5 (depends on 1) The charging roller according to claim 1, wherein, in the polyurethane thermoplastic elastomer, the type A durometer hardness is 75 or less at a measurement temperature of 23° C. ### Claim 6 (depends on 1) The charging roller according to claim 1, wherein the carbon black contained in the outer layer has a DBP oil absorption amount of 150 cm3/100 g or more. ### Claim 7 (depends on 1) A method of producing the charging roller according to claim 1, comprising: a process in which the inner layer is foamed by thermal decomposition of 4,4′-oxybisbenzenesulfonyl hydrazide as a foaming agent contained in the semiconductive rubber composition such that it has a porous structure. ### Claim 8 (depends on 2) The charging roller according to claim 2, wherein the inner layer has a porous structure formed by thermal decomposition of 4,4′-oxybisbenzenesulfonyl hydrazide as a foaming agent. ### Claim 9 (depends on 2) The charging roller according to claim 2, wherein the polyurethane thermoplastic elastomer is a polyether type polyurethane thermoplastic elastomer. ### Claim 10 (depends on 3) The charging roller according to claim 3, wherein the polyurethane thermoplastic elastomer is a polyether type polyurethane thermoplastic elastomer. ### Claim 11 (depends on 2) The charging roller according to claim 2, wherein, in the polyurethane thermoplastic elastomer, the type A durometer hardness is 75 or less at a measurement temperature of 23° C. ### Claim 12 (depends on 3) The charging roller according to claim 3, wherein, in the polyurethane thermoplastic elastomer, the type A durometer hardness is 75 or less at a measurement temperature of 23° C. ### Claim 13 (depends on 4) The charging roller according to claim 4, wherein, in the polyurethane thermoplastic elastomer, the type A durometer hardness is 75 or less at a measurement temperature of 23° C. ### Claim 14 (depends on 2) The charging roller according to claim 2, wherein the carbon black contained in the outer layer has a DBP oil absorption amount of 150 cm3/100 g or more. ### Claim 15 (depends on 3) The charging roller according to claim 3, wherein the carbon black contained in the outer layer has a DBP oil absorption amount of 150 cm3/100 g or more. ### Claim 16 (depends on 4) The charging roller according to claim 4, wherein the carbon black contained in the outer layer has a DBP oil absorption amount of 150 cm3/100 g or more. ### Claim 17 (depends on 5) The charging roller according to claim 5, wherein the carbon black contained in the outer layer has a DBP oil absorption amount of 150 cm3/100 g or more. ### Claim 18 (depends on 2) A method of producing the charging roller according to claim 2, comprising: a process in which the inner layer is foamed by thermal decomposition of 4,4′-oxybisbenzenesulfonyl hydrazide as a foaming agent contained in the semiconductive rubber composition such that it has a porous structure. ### Claim 19 (depends on 3) A method of producing the charging roller according to claim 3, comprising: a process in which the inner layer is foamed by thermal decomposition of 4,4′-oxybisbenzenesulfonyl hydrazide as a foaming agent contained in the semiconductive rubber composition such that it has a porous structure. ### Claim 20 (depends on 4) A method of producing the charging roller according to claim 4, comprising: a process in which the inner layer is foamed by thermal decomposition of 4,4′-oxybisbenzenesulfonyl hydrazide as a foaming agent contained in the semiconductive rubber composition such that it has a porous structure.