# US 2013/0158221 A1 · Optical 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 2013/0158221 A1 - Document ID: US20130158221A1 - Status: Published application - Kind: A1 - Application number: 13/717,986 - Filed: 2012-12-18 - Published: 2013-06-20 - Earliest claimed: 2011-12-20 - Assignees: Nitto Denko Corporation - Inventors: Tomohide BANBA; Hiroaki KISHIOKA; Takahiro NONAKA; Masatomo NATSUI; Hiroaki FUMOTO; Shou TAKARADA; Takashi SUZUKI - Web page: https://patentgrep.com/patent/US20130158221A1 ## CPC - C09J 139/06: Homopolymers or copolymers of N-vinyl-pyrrolidones - C09J 133/06: of esters containing only carbon, hydrogen and oxygen, the oxygen atom being present only as part of the carboxyl radical - C09J 133/12: Homopolymers or copolymers of methyl methacrylate - C09J 133/14: of esters containing halogen, nitrogen, sulfur or oxygen atoms in addition to the carboxy oxygen - C09J 133/26: Homopolymers or copolymers of acrylamide or methacrylamide - 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) ## Abstract The present invention provides an optical pressure-sensitive adhesive sheet which can control the change in capacitance, which cause malfunction, when the optical pressure-sensitive adhesive sheet is applied to an optical member. The present invention provides an optical pressure-sensitive adhesive sheet including a pressure-sensitive adhesive layer, wherein a relative dielectric constant at a frequency of 1 MHz is 2 to 8, and a dielectric tangent at a frequency of 1 MHz is more than 0 and 0.2 or less. ## Claims ### Claim 1 An optical pressure-sensitive adhesive sheet comprising a pressure-sensitive adhesive layer, wherein a relative dielectric constant at a frequency of 1 MHz is 2 to 8, and a dielectric tangent at a frequency of 1 MHz is more than 0 and 0.2 or less. ### Claim 2 (depends on 1) The optical pressure-sensitive adhesive sheet according to claim 1, wherein the relative dielectric constant at a frequency of 1.0×106 Hz is 60% or more of a relative dielectric constant at a frequency of 1.0×104 Hz. ### Claim 3 (depends on 1) The optical pressure-sensitive adhesive sheet according to claim 1, wherein an absolute value of a difference between the dielectric tangent at a frequency of 1.0×106 Hz and a dielectric tangent at a frequency of 1.0×104 Hz is 0.15 or less. ### Claim 4 (depends on 1) The optical pressure-sensitive adhesive sheet according to claim 1, which has a thickness accuracy of 10% or less. ### Claim 5 (depends on 1) The optical pressure-sensitive adhesive sheet according to claim 1, wherein the pressure-sensitive adhesive layer is an acrylic pressure-sensitive adhesive layer. ### Claim 6 (depends on 5) The optical pressure-sensitive adhesive sheet according to claim 5, wherein the acrylic pressure-sensitive adhesive layer comprises, as a base polymer, an acrylic polymer formed from a component comprising, as an essential monomer component, alkyl (meth)acrylate having a straight-chain or branched alkyl group having 1 to 14 carbon atoms and/or alkoxyalkyl (meth)acrylate. ### Claim 7 (depends on 5) The optical pressure-sensitive adhesive sheet according to claim 5, wherein the acrylic pressure-sensitive adhesive layer is formed by an ultraviolet-ray polymerization method through ultraviolet irradiation to a pressure-sensitive adhesive composition. ### Claim 8 (depends on 1) The optical pressure-sensitive adhesive sheet according to claim 1, which is used for laminating members contained in a touch panel. ### Claim 9 (depends on 8) The optical pressure-sensitive adhesive sheet according to claim 8, wherein the touch panel is an electric capacity type touch panel. ### Claim 10 (depends on 1) A liquid crystal display device comprising the optical pressure-sensitive adhesive sheet according to claim 1. ### Claim 11 (depends on 1) An input device comprising the optical pressure-sensitive adhesive sheet according to claim 1. ### Claim 12 (depends on 2) The optical pressure-sensitive adhesive sheet according to claim 2, wherein an absolute value of a difference between the dielectric tangent at a frequency of 1.0×106 Hz and a dielectric tangent at a frequency of 1.0×104 Hz is 0.15 or less. ### Claim 13 (depends on 2) The optical pressure-sensitive adhesive sheet according to claim 2, which has a thickness accuracy of 10% or less. ### Claim 14 (depends on 3) The optical pressure-sensitive adhesive sheet according to claim 3, which has a thickness accuracy of 10% or less. ### Claim 15 (depends on 12) The optical pressure-sensitive adhesive sheet according to claim 12, which has a thickness accuracy of 10% or less. ### Claim 16 (depends on 2) The optical pressure-sensitive adhesive sheet according to claim 2, wherein the pressure-sensitive adhesive layer is an acrylic pressure-sensitive adhesive layer. ### Claim 17 (depends on 3) The optical pressure-sensitive adhesive sheet according to claim 3, wherein the pressure-sensitive adhesive layer is an acrylic pressure-sensitive adhesive layer. ### Claim 18 (depends on 12) The optical pressure-sensitive adhesive sheet according to claim 12, wherein the pressure-sensitive adhesive layer is an acrylic pressure-sensitive adhesive layer. ### Claim 19 (depends on 4) The optical pressure-sensitive adhesive sheet according to claim 4, wherein the pressure-sensitive adhesive layer is an acrylic pressure-sensitive adhesive layer. ### Claim 20 (depends on 13) The optical pressure-sensitive adhesive sheet according to claim 13, wherein the pressure-sensitive adhesive layer is an acrylic pressure-sensitive adhesive layer.