# US 8,541,501 B2 · Water-dispersed pressure-sensitive adhesive composition, pressure-sensitive adhesive and pressure-sensitive adhesive sheet > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,541,501 B2 - Document ID: US8541501B2 - Status: Granted - Kind: B2 - Application number: 13/643,455 - Filed: 2012-04-24 - Published: 2013-05-30 - Granted: 2013-09-24 - Earliest claimed: 2011-05-26 - Assignees: Nitto Denko Corporation - Applicants: Mika Okada; Chie Kitano - Inventors: Mika Okada; Chie Kitano - Web page: https://patentgrep.com/patent/US8541501B2 ## CPC - C09J 133/064: {containing anhydride, COOH or COOM groups, with M being metal or onium-cation} - C08L 7/00: Compositions of natural rubber - C08L 9/00: Compositions of homopolymers or copolymers of conjugated diene hydrocarbons - C08L 33/08: Homopolymers or copolymers of acrylic acid esters - C09J 7/385: {Acrylic polymers} - C09J 121/02: Latex - C09J 133/04: Homopolymers or copolymers of esters {(C09J143/04 takes precedence)} - C09J 133/08: Homopolymers or copolymers of acrylic acid esters - C09J 2301/302: the adhesive being pressure-sensitive, i.e. tacky at temperatures inferior to 30°C - C09J 2301/312: parameters being the characterizing feature - C09J 2421/00: Presence of unspecified rubber - C09J 2433/00: Presence of (meth)acrylic polymer - C09J: ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES (preparation of glue or gelatine C09H) - C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06) ## Abstract Provided is a water-dispersed pressure-sensitive adhesive composition capable of forming a pressure-sensitive adhesive that exhibits good adhesiveness to a non-polar adherend and maintains its properties at a low temperature. The water-dispersed pressure-sensitive adhesive composition according to the present invention comprises a (meth)acrylic polymer obtained by polymerizing a monomer composition containing as a primary component an alkyl (meth)acrylate having an alkyl group with 1 to 18 carbon atoms, a latex containing a rubber component that is immiscible with the (meth)acrylic polymer and has a loss tangent peak temperature of −5° C. or below when determined by a dynamic viscoelastic measurement in which shear strain is applied at a frequency of 1 Hz, and a tackifier that is miscible with the rubber component, but immiscible with the (meth)acrylic polymer. ## Claims ### Claim 1 A water-dispersed pressure-sensitive adhesive composition comprising a (meth)acrylic polymer, a latex containing a rubber component, and a tackifier, wherein: the (meth)acrylic polymer is obtained by polymerizing a monomer composition comprising as a primary component an alkyl (meth)acrylate having an alkyl group with 1 to 18 carbon atoms; the rubber component is immiscible with the (meth)acrylic polymer and has a loss tangent peak temperature of −5° C. or below when determined by a dynamic viscoelastic measurement in which shear strain is applied at a frequency of 1 Hz.; and the tackifier is miscible with the rubber component, but immiscible with the (meth)acrylic polymer. ### Claim 2 (depends on 1) The water-dispersed pressure-sensitive adhesive composition according to claim 1, wherein the ratio of the (meth)acrylic polymer to the latex to be mixed ((meth)acrylic polymer/rubber-based latex) is within a range of 95/5 to 25/75 based on their solid contents. ### Claim 3 (depends on 1) The water-dispersed pressure-sensitive adhesive composition according to claim 1, wherein the tackifier is contained in an amount within a range of 5 to 100 parts by weight relative to 100 parts by weight of solid contents of the latex. ### Claim 4 (depends on 1) The water-dispersed pressure-sensitive adhesive composition according to claim 1, wherein, when the water-dispersed pressure-sensitive adhesive composition is dried, it has a storage modulus of 1 MPa or smaller over a range of −15° C. to 25° C. when determined by a dynamic viscoelastic measurement in which shear strain is applied at a frequency of 1 Hz. ### Claim 5 (depends on 1) The water-dispersed pressure-sensitive adhesive composition according to claim 1, wherein the rubber component contained in the latex is at least one kind selected from a group consisting of natural rubber, synthetic polyisoprene rubber, polybutadiene rubber, acrylonitrile-butadiene rubber and styrene-butadiene rubber. ### Claim 6 (depends on 1) The water-dispersed pressure-sensitive adhesive composition according to claim 1, wherein the tackifier has a softening point of 80° C. to 150° C. ### Claim 7 (depends on 1) A pressure-sensitive adhesive formed of the water-dispersed pressure-sensitive adhesive composition according to claim 1. ### Claim 8 (depends on 1) A pressure-sensitive adhesive sheet comprising a pressure-sensitive adhesive layer formed of the water-dispersed pressure-sensitive adhesive composition according to claim 1. ### Claim 9 (depends on 2) The water-dispersed pressure-sensitive adhesive composition according to claim 2, wherein the tackifier is contained in an amount within a range of 5 to 100 parts by weight relative to 100 parts by weight of solid contents of the latex. ### Claim 10 (depends on 2) The water-dispersed pressure-sensitive adhesive composition according to claim 2, wherein, when the water-dispersed pressure-sensitive adhesive composition is dried, it has a storage modulus of 1 MPa or smaller over a range of −15° C. to 25° C. when determined by a dynamic viscoelastic measurement in which shear strain is applied at a frequency of 1 Hz. ### Claim 11 (depends on 2) The water-dispersed pressure-sensitive adhesive composition according to claim 2, wherein the rubber component contained in the latex is at least one kind selected from a group consisting of natural rubber, synthetic polyisoprene rubber, polybutadiene rubber, acrylonitrile-butadiene rubber and styrene-butadiene rubber. ### Claim 12 (depends on 2) The water-dispersed pressure-sensitive adhesive composition according to claim 2, wherein the tackifier has a softening point of 80° C. to 150° C. ### Claim 13 (depends on 2) A pressure-sensitive adhesive formed of the water-dispersed pressure-sensitive adhesive composition according to claim 2. ### Claim 14 (depends on 2) A pressure-sensitive adhesive sheet comprising a pressure-sensitive adhesive layer formed of the water-dispersed pressure-sensitive adhesive composition according to claim 2. ### Claim 15 (depends on 3) The water-dispersed pressure-sensitive adhesive composition according to claim 3, wherein, when the water-dispersed pressure-sensitive adhesive composition is dried, it has a storage modulus of 1 MPa or smaller over a range of −15° C. to 25° C. when determined by a dynamic viscoelastic measurement in which shear strain is applied at a frequency of 1 Hz. ### Claim 16 (depends on 3) The water-dispersed pressure-sensitive adhesive composition according to claim 3, wherein the rubber component contained in the latex is at least one kind selected from a group consisting of natural rubber, synthetic polyisoprene rubber, polybutadiene rubber, acrylonitrile-butadiene rubber and styrene-butadiene rubber. ### Claim 17 (depends on 3) The water-dispersed pressure-sensitive adhesive composition according to claim 3, wherein the tackifier has a softening point of 80° C. to 150° C. ### Claim 18 (depends on 3) A pressure-sensitive adhesive formed of the water-dispersed pressure-sensitive adhesive composition according to claim 3. ### Claim 19 (depends on 3) A pressure-sensitive adhesive sheet comprising a pressure-sensitive adhesive layer formed of the water-dispersed pressure-sensitive adhesive composition according to claim 3. ### Claim 20 (depends on 4) The water-dispersed pressure-sensitive adhesive composition according to claim 4, wherein the rubber component contained in the latex is at least one kind selected from a group consisting of natural rubber, synthetic polyisoprene rubber, polybutadiene rubber, acrylonitrile-butadiene rubber and styrene-butadiene rubber.