# US 11,897,977 B2 · Photolabile barbiturate compounds > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,897,977 B2 - Document ID: US11897977B2 - Status: Granted - Kind: B2 - Application number: 16/965,688 - Filed: 2019-01-16 - Published: 2021-02-11 - Granted: 2024-02-13 - Earliest claimed: 2018-01-31 - Assignees: 3M Innovative Properties Company - Applicants: 3M Innovative Properties Company - Inventors: William H. Moser; Erik M. Townsend; Zachary J. Thompson; Mary M. Caruso Dailey; Michael A. Kropp - Web page: https://patentgrep.com/patent/US11897977B2 ## CPC - C08F 2/50: with sensitising agents - C07D 239/62: Barbituric acids - C07D 405/12: linked by a chain containing hetero atoms as chain links - C08F 2/48: by ultraviolet or visible light - C08F 220/1802: {C2-(meth)acrylate, e.g. ethyl (meth)acrylate} - C08L 33/10: Homopolymers or copolymers of methacrylic acid esters - C08F: MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS - C07D: HETEROCYCLIC COMPOUNDS (macromolecular compounds C08) - C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06) ## Abstract The present disclosure provides a redox initiator system for initiating polymerization comprising an oxidizing agent, a photolabile reducing agent derived from a barbiturate, and a transition metal complex that participates in a redox cycle. On exposure to actinic radiation, such as UV, the photolabile compound photolyzes, releasing the reducing agent and initiating the redox-initiated polymerization. ## Claims ### Claim 1 A polymerizable composition comprising a polymerizable component, and a redox initiation system comprising: a) a transition metal complex that participates in a redox cycle; b) an oxidizing agent; c) a photolabile reducing agent of the formula: wherein R1, R2 and R3 are each independently H, C1-18 hydrocarbyl; and a) RPhoto is a photolabile group; and optionally a quaternary ammonium halide. ### Claim 2 (depends on 1) The polymerizable composition of claim 1, wherein the photolabile group Rphoto is selected from phenacyl groups, 2-alkylphenacyl groups, ethylene-bridged phenacyl groups, p-hydroxyphenacyl groups, benzoin groups, o- or p-nitrobenzyl groups, o-nitro-2-phenethyloxycarbonyl groups, coumarin-4-yl methyl groups, benzyl groups, o- or p-hydroxylbenzyl groups, o- or p-hydroxynapthyl groups, 2,5-dihydroxyl benzyl groups, 9-phenylthioxanthyl, 9-phenylxanthyl groups, anthraquinon-2-yl groups, 8-halo-7-hydroxyquinoline-2-yl methyl groups, and pivaloylglycol groups. ### Claim 3 (depends on 1) The polymerizable composition of claim 1 wherein the transition metal complex is of the formula: [MLp]n+A−, wherein M is a transition metal that participates in a redox cycle, L is a ligand, A- is an anion, n is the formal charge on the transition metal having a whole number value of 1 to 7, and p is the number of ligands on the transition metal having a number value of 1 to 9. ### Claim 4 (depends on 3) The polymerizable composition of claim 3 wherein M is selected from Cu, Fe, Ru, Cr, Mo, Pd, Ni, Pt, Mn, Rh, Re, Co, V, Au, Nb and Ag. ### Claim 5 (depends on 1) The polymerizable composition of claim 1 wherein the redox initiator system is present in the composition in amounts, from 0.05 to about 10 parts by weight, based on 100 parts by weight of the polymerizable component of the polymerizable composition. ### Claim 6 (depends on 1) The polymerizable composition of claim 1 wherein further comprising a secondary reducing agent selected from tertiary amines; aromatic sulfinic salts; thioureas; and mixtures thereof. ### Claim 7 (depends on 1) The polymerizable composition of claim 1 wherein the oxidizing agent of the redox initiator system is selected from persulfuric acid and salts thereof; peroxides, hydroperoxides; transition metals, perboric acid and salts thereof, permanganic acid and salts thereof, perphosphoric acid and salts thereof, and mixtures thereof. ### Claim 8 (depends on 1) The polymerizable composition of claim 1 comprising more than one oxidizing agent. ### Claim 9 (depends on 1) The polymerizable composition of claim 1 wherein the polymerizable component comprises: i) 85 to 100 parts by weight of an (meth)acrylic acid ester; ii) 0 to 15 parts by weight of an acid functional ethylenically unsaturated monomer; iii) 0 to 10 parts by weight of a non-acid functional, ethylenically unsaturated polar monomer; iv) 0 to 5 parts vinyl monomer; and v) 0.1 to 5 parts of a multifunctional (meth)acrylate; vi) 0.1 to 10 parts by weight of the redox initiator system, based on 100 parts by weight of i) to v). ### Claim 10 (depends on 9) The polymerizable composition of claim 9 further comprising 0.01 to 5 parts of a multifunctional (meth)acrylate. ### Claim 11 (depends on 1) The polymerizable composition of claim 1 wherein the polymerizable component comprises: i) up to 100 parts by weight of an (meth)acrylic acid ester; ii) 0 to 15 parts by weight of an acid functional ethylenically unsaturated monomer; iii) 0 to 15 parts by weight of a non-acid functional, ethylenically unsaturated polar monomer; iv) 0 to 5 parts vinyl monomer; v) 0 to 100 parts of a multifunctional (meth)acrylate, relative to 100 parts i)-iv); and vii) the redox initiator system (including the transition metal complex, oxidant and photolabile reductant) in amounts from about 0.1 weight percent to about 5.0 weight percent, relative to 100 parts total monomer i)-v). ### Claim 12 (depends on 1) The polymerizable composition of claim 1 further comprising 1-35 parts by weight of a toughening agent, relative to 100 parts by weight of the polymerizable component of the polymerizable composition. ### Claim 13 (depends on 1) The polymerizable composition of claim 1 wherein the transition metal complex is Cu(II) naphthenate. ### Claim 14 (depends on 1) The polymerizable composition of claim 1, wherein the polymerizable ethylenically unsaturated component comprises a reactive oligomer having pendent polymerizable groups, and wherein the reactive oligomer comprises: a) greater than 50 parts by weight of (meth)acrylate ester monomer units; b) 0.5 to 10 parts by weight of monomer units having a pendent, free-radically polymerizable functional groups, c) 0 to 20 parts by weight of other polar monomer units, wherein the sum of the monomer units is 100 parts by weight. ### Claim 15 (depends on 1) A multilayer article comprising the polymerizable composition of claim 1 on a substrate. ### Claim 16 (depends on 15) The multilayer article of claim 15 wherein the substrate is a release liner. ### Claim 17 (depends on 15) The multilayer article of claim 15 wherein the substrate is a tape backing.