# US 2014/0194547 A1 · Surface modification method and surface-modified elastic body > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0194547 A1 - Document ID: US20140194547A1 - Status: Published application - Kind: A1 - Application number: 14/107,746 - Filed: 2013-12-16 - Published: 2014-07-10 - Earliest claimed: 2013-01-07 - Assignees: Sumitomo Rubber Industries, Ltd. - Applicants: Sumitomo Rubber Industries, Ltd. - Inventors: Yasuhisa MINAGAWA - Web page: https://patentgrep.com/patent/US20140194547A1 ## CPC - C08J 7/18: using wave energy or particle radiation - C08F 2/50: with sensitising agents - C08F 291/00: Macromolecular compounds obtained by polymerising monomers on to macromolecular compounds according to more than one of the groups C08F251/00 - C08F289/00 - C08J 2311/00: Characterised by the use of homopolymers or copolymers of chloroprene - 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) - C08F: MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS ## Abstract The present invention aims to provide a method for surface-modifying a rubber vulcanizate or a thermoplastic elastomer, which is capable of cost-effectively imparting a variety of functions, such as sliding properties and biocompatibility, according to the applications. The present invention relates to a surface modification method for surface-modifying an object of a rubber vulcanizate or a thermoplastic elastomer, the method including: step 1 of forming polymerization initiation points A on a surface of the object; step 2 of radically polymerizing a non-functional monomer, starting from the polymerization initiation points A, to grow non-functional polymer chains; step 3 of forming polymerization initiation points B on the surface of the object where the non-functional polymer chains are formed; and step 4 of radically polymerizing a functional monomer, starting from the polymerization initiation points B, to grow functional polymer chains. ## Claims ### Claim 1 A surface modification method for surface-modifying an object of a rubber vulcanizate or a thermoplastic elastomer, the method comprising: step 1 of forming polymerization initiation points A on a surface of the object; step 2 of radically polymerizing a non-functional monomer, starting from the polymerization initiation points A, to grow non-functional polymer chains; step 3 of forming polymerization initiation points B on the surface of the object where the non-functional polymer chains are formed; and step 4 of radically polymerizing a functional monomer, starting from the polymerization initiation points B, to grow functional polymer chains. ### Claim 2 (depends on 1) The surface modification method according to claim 1, wherein the step 1 comprises adsorbing a polymerization initiator A onto the surface of the object to form the polymerization initiation points A, and the step 3 comprises adsorbing a polymerization initiator B onto the surface of the object where the non-functional polymer chains are formed, to form the polymerization initiation points B. ### Claim 3 (depends on 1) The surface modification method according to claim 1, wherein the step 1 comprises irradiating the surface of the object with LED light with a wavelength of 300 to 400 nm and forming the polymerization initiation points A from a polymerization initiator A present on the surface, and the step 3 comprises irradiating the surface of the object where the non-functional polymer chains are formed with LED light with a wavelength of 300 to 400 nm and forming the polymerization initiation points B from a polymerization initiator B present on the surface. ### Claim 4 (depends on 1) The surface modification method according to claim 1, wherein the rubber vulcanizate or thermoplastic elastomer contains an allylic carbon atom which is a carbon atom adjacent to a double bond. ### Claim 5 (depends on 2) The surface modification method according to claim 2, wherein the polymerization initiator is a benzophenone compound and/or a thioxanthone compound. ### Claim 6 (depends on 1) The surface modification method according to claim 1, wherein the step 2 and the step 4 comprise adding a reducing agent or an antioxidant in the radical polymerization of the non-functional monomer and/or the functional monomer. ### Claim 7 (depends on 6) The surface modification method according to claim 6, wherein the reducing agent or antioxidant is at least one selected from the group consisting of riboflavin, ascorbic acid, α-tocopherol, β-carotene, and uric acid. ### Claim 8 (depends on 1) The surface modification method according to claim 1, wherein the radical polymerization comprises inserting an inert gas into a reaction container and a reaction solution during or before light irradiation, and polymerizing the monomer in an atmosphere replaced with the inert gas. ### Claim 9 (depends on 1) The surface modification method according to claim 1, wherein the non-functional monomer is at least one selected from the group consisting of acrylic acid, acrylic acid esters, acrylic acid alkali metal salts, acrylic acid amine salts, methacrylic acid, methacrylic acid esters, methacrylic acid alkali metal salts, methacrylic acid amine salts, acrylonitrile, acrylamide, dimethylacrylamide, diethylacrylamide, isopropylacrylamide, hydroxyacrylamide, acryloyl morpholine, methacrylamide, dimethylmethacrylamide, diethylmethacrylamide, isopropylmethacrylamide, hydroxymethacrylamide, and methacryloyl morpholine. ### Claim 10 (depends on 1) The surface modification method according to claim 1, wherein the functional monomer is a fluoro group-containing monomer. ### Claim 11 (depends on 10) The surface modification method according to claim 10, wherein the fluoro group-containing monomer is a fluoroalkyl group-containing monomer. ### Claim 12 (depends on 11) The surface modification method according to claim 11, wherein the fluoroalkyl group-containing monomer is at least one selected from the group consisting of 3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11,12,12,12-heneicosafluorododecyl acrylate (H2C═CHCO2CH2CH2 (CF2)9CF3), 3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,10-heptadecafluorodecyl acrylate (H2C═CHCO2CH2CH2(CF2)7CF3), 3-(perfluorobutyl)-2-hydroxypropyl acrylate (F(CF2)4CH2CH(OH)CH2OCOCH═CH2), 3-perfluorohexyl-2-hydroxypropyl acrylate (F(CF2)6CH2CH(OH)CH2OCOCH═CH2), 3-(perfluoro-3-methylbutyl)-2-hydroxypropyl acrylate ((CF3)2CF(CF2)2CH2CH(OH)CH2OCOCH═CH2), and 3-(perfluoro-5-methylhexyl)-2-hydroxypropyl acrylate ((CF3)2CF(CF2)4CH2CH(OH)CH2OCOCH═CH2). ### Claim 13 (depends on 11) The surface modification method according to claim 11, wherein the fluoroalkyl group-containing monomer is a compound represented by the following formula (3), (4), (5), or (6): wherein R31 represents a hydrogen atom, a methyl group, an ethyl group, or a propyl group; R32 represents —O— or —NH—; R41 represents a methylene group, an ethylene group, or a propylene group; R51 represents a ketone group or is absent; w1 represents an integer of 1 to 100; and z represents an integer of 1 to 6, wherein R31 represents a hydrogen atom, a methyl group, an ethyl group, or a propyl group; w2 represents an integer of 4 to 10; and z represents an integer of 1 to 6, wherein R31 represents a hydrogen atom, a methyl group, an ethyl group, or a propyl group; w3 and w4 each independently represent an integer of 1 to 6; and z represents an integer of 1 to 6, wherein R31 represents a hydrogen atom, a methyl group, an ethyl group, or a propyl group; w3 and w4 each independently represent an integer of 1 to 6; z represents an integer of 1 to 6; and α represents an integer of 0 to 2. ### Claim 14 (depends on 10) The surface modification method according to claim 10, wherein the fluoro group-containing monomer is a fluoroalkylene oxide group-containing monomer or a fluorobenzyl group-containing monomer. ### Claim 15 (depends on 10) The surface modification method according to claim 10, wherein the fluoro group-containing monomer is at least one selected from the group consisting of [1H,1H-perfluoro(2,5-dimethyl-3,6-dioxanonanoyl)]acrylate, [1H,1H-perfluoro(2,5-dimethyl-3,6-dioxanonanoyl)]methacrylate, pentafluorobenzyl acrylate, pentafluorobenzyl methacrylate, and 2,3,5,6-tetrafluorophenyl methacrylate. ### Claim 16 (depends on 1) The surface modification method according to claim 1, wherein the functional monomer is a zwitterionic monomer that has a carboxybetaine group, a sulfobetaine group or a phosphobetaine group in a side chain thereof. ### Claim 17 (depends on 1) The surface modification method according to claim 1, wherein the functional monomer is at least one selected from the group consisting of 2-(meth)acryloyloxyethyl phosphorylcholine, 2-(meth)acryloyloxyethyl carboxybetaine, and 2-(meth)acryloyloxyethyl sulfobetaine. ### Claim 18 (depends on 1) The surface modification method according to claim 1, wherein the functional monomer is silver acrylate and/or silver methacrylate. ### Claim 19 (depends on 1) The surface modification method according to claim 1, wherein the (liquid) nonfunctional monomer, the (liquid) functional monomer, or a solution thereof contains a polymerization inhibitor, and is polymerized in the presence of the polymerization inhibitor. ### Claim 20 (depends on 19) The surface modification method according to claim 19, wherein the polymerization inhibitor is 4-methylphenol. ### Claim 21 (depends on 1) The surface modification method according to claim 1, wherein total polymer chains comprising the non-functional polymer chains and the functional polymer chains each have a length of 10 to 50000 nm. ### Claim 22 (depends on 1) The surface modification method according to claim 1, wherein a ratio between a length of the non-functional polymer chain and a length of the functional polymer chain is 50:50 to 99.9:0.01. ### Claim 23 (depends on 1) A surface-modified elastic body, which is obtained by the surface modification method according to claim 1. ### Claim 24 (depends on 1) A surface-modified elastic body, which is required to have sliding properties, low friction, or low water resistance, in the presence of water or in a dry state, and which is obtained by the surface modification method according to claim 1. ### Claim 25 (depends on 1) A surface-modified elastic body, comprising a three-dimensional solid at least partially having a surface modified by the surface modification method according to claim 1. ### Claim 26 (depends on 23) The surface-modified elastic body according to claim 23, which is a polymer brush. ### Claim 27 (depends on 1) A gasket for syringes, at least partially having a surface modified by the surface modification method according to claim 1. ### Claim 28 (depends on 1) A tire, at least partially having a groove surface modified by the surface modification method according to claim 1.