# US 2013/0158199 A1 · Pressure-sensitive adhesive compositions, pressure-sensitive adhesive layers, and pressure-sensitive adhesive sheets > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2013/0158199 A1 - Document ID: US20130158199A1 - Status: Published application - Kind: A1 - Application number: 13/719,917 - Filed: 2012-12-19 - Published: 2013-06-20 - Earliest claimed: 2011-12-20 - Assignees: Nitto Denko Corporation - Inventors: Toru ISEKI; Keisuke HIRANO - Web page: https://patentgrep.com/patent/US20130158199A1 ## CPC - C09J 133/14: of esters containing halogen, nitrogen, sulfur or oxygen atoms in addition to the carboxy oxygen - C09J 7/385: {Acrylic polymers} - C09J 133/066: {containing -OH groups} - C08K 5/0091: {Complexes with metal-heteroatom-bonds} - C08K 5/07: Aldehydes; Ketones - C08K 5/29: Compounds containing {one or more} carbon-to-nitrogen double bonds - C08K 5/34924: {containing cyanurate groups; Tautomers thereof} - C09J 2301/408: additives as essential feature of the adhesive layer - 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) - C08K: Use of inorganic or non-macromolecular organic substances as compounding ingredients (paints, inks, varnishes, dyes, polishes, adhesives C09) ## Abstract Provided are a pressure-sensitive adhesive composition that is produced with no tin compound, has a sufficiently long pot life, and can be rapidly crosslinked in the process of forming a pressure-sensitive adhesive layer; and a pressure-sensitive adhesive layer and a pressure-sensitive adhesive sheet each produced using such a pressure-sensitive adhesive composition. A pressure-sensitive adhesive composition, comprising: 100 parts by weight of an acrylic polymer (A) having an active hydrogen-containing functional group; 0.1 parts by weight to 10 parts by weight of an isocyanate crosslinking agent (B); 0.002 parts by weight to 0.5 parts by weight of a catalyst (C) having an iron active center; and a compound (D) capable of undergoing keto-enol tautomerism, wherein the weight ratio (D/C) of the compound (D) capable of undergoing keto-enol tautomerism to the catalyst (C) having an iron active center is from 3 to 70. ## Claims ### Claim 1 A pressure-sensitive adhesive composition, comprising: 100 parts by weight of an acrylic polymer (A) having an active hydrogen-containing functional group; 0.1 parts by weight to 10 parts by weight of an isocyanate crosslinking agent (B); 0.002 parts by weight to 0.5 parts by weight of a catalyst (C) having an iron active center; and a compound (D) capable of undergoing keto-enol tautomerism, wherein the weight ratio (D/C) of the compound (D) capable of undergoing keto-enol tautomerism to the catalyst (C) having an iron active center is from 3 to 70. ### Claim 2 (depends on 1) The pressure-sensitive adhesive composition according to claim 1, wherein the acrylic polymer (A) having an active hydrogen-containing functional group comprises, as monomer components, 70% by weight to 99.9% by weight of an alkyl(meth)acrylate having an alkyl group of 4 to 12 carbon atoms and 0.1% by weight to 30% by weight of a monomer having an active hydrogen-containing functional group. ### Claim 3 (depends on 1) The pressure-sensitive adhesive composition according to claim 1, wherein the catalyst (C) having an iron active center is an iron chelate compound. ### Claim 4 (depends on 1) The pressure-sensitive adhesive composition according to claim 1, wherein the compound (D) capable of undergoing keto-enol tautomerism is a β-diketone. ### Claim 5 (depends on 1) The pressure-sensitive adhesive composition according to claim 1, which has a gel fraction of 80% or more after crosslinked. ### Claim 6 (depends on 1) A pressure-sensitive adhesive layer comprising a product of crosslinking of the pressure-sensitive adhesive composition according to claim 1. ### Claim 7 (depends on 6) A pressure-sensitive adhesive sheet comprising a support and the pressure-sensitive adhesive layer according to claim 6 formed on the support. ### Claim 8 (depends on 5) A pressure-sensitive adhesive layer comprising a product of crosslinking of the pressure-sensitive adhesive composition according to claim 5. ### Claim 9 (depends on 8) A pressure-sensitive adhesive sheet comprising a support and the pressure-sensitive adhesive layer according to claim 8 formed on the support. ### Claim 10 (depends on 1) The pressure-sensitive adhesive composition according to claim 1, wherein the viscosity of the pressure-sensitive adhesive composition is 2.0 Pa·s or less. ### Claim 11 (depends on 1) The pressure-sensitive adhesive composition according to claim 1, wherein the viscosity of the pressure-sensitive adhesive composition is 2.0 Pa·s or less 48 hours after the preparation of the pressure-sensitive adhesive composition. ### Claim 12 (depends on 1) The pressure-sensitive adhesive composition according to claim 1, which has a gel fraction of 80% or more after crosslinking with a crosslinking agent, and wherein there is no change in the gel fraction during the time period starting immediately after preparation and ending three days after preparation.