# US 9,040,076 B2 · Switchable adhesives > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,040,076 B2 - Document ID: US9040076B2 - Status: Granted - Kind: B2 - Application number: 13/638,304 - Filed: 2011-03-31 - Published: 2013-01-17 - Granted: 2015-05-26 - Earliest claimed: 2010-03-31 - Assignees: Lumina Adhesives AB - Applicants: Mats Tunius - Inventors: Mats Tunius - Web page: https://patentgrep.com/patent/US9040076B2 ## CPC - C09J 133/06: of esters containing only carbon, hydrogen and oxygen, the oxygen atom being present only as part of the carboxyl radical - A61F 13/02: Adhesive bandages or dressings - A61F 13/0206: with absorbent fibrous layers, e.g. woven or non-woven absorbent pads or island dressings - A61F 13/0253: {characterized by the adhesive material} - A61L 15/58: Adhesives - C09J 4/00: Adhesives based on organic non-macromolecular compounds having at least one polymerisable carbon-to-carbon unsaturated bond {; adhesives, based on monomers of macromolecular compounds of groups C09J183/00 - C09J183/16} - C09J 7/20: characterised by their carriers - C09J 7/38: Pressure-sensitive adhesives [PSA] - C09J 133/08: Homopolymers or copolymers of acrylic acid esters - C09J 133/10: Homopolymers or copolymers of methacrylic acid esters - C09J 175/16: having terminal carbon-to-carbon unsaturated bonds - C09J 183/04: Polysiloxanes - A61F 2013/00655: {adhesive} - C08K 5/0025: {Crosslinking or vulcanising agents; including accelerators} - C08K 5/1345: {Carboxylic esters of phenolcarboxylic acids} - C08K 5/56: Organo-metallic compounds, i.e. organic compounds containing a metal-to-carbon bond - C08L 2312/00: Crosslinking - C09J 2301/408: additives as essential feature of the adhesive layer - C09J 2301/416: use of irradiation - C09J 2433/00: Presence of (meth)acrylic polymer - C09J 2475/00: Presence of polyurethane - C09J 2483/00: Presence of polysiloxane - Y10T 428/28: Web or sheet containing structurally defined element or component and having an adhesive outermost layer - Y10T 428/2848: Three or more layers - 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) - A61F: FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS (dental prosthetics A61C) - A61L: METHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES (preservation of bodies or disinfecting characterised by the agents employed A01N; preserving, e.g. sterilising, food or foodstuffs A23; preparations for medical, dental or toiletry purposes A61K) - C08K: Use of inorganic or non-macromolecular organic substances as compounding ingredients (paints, inks, varnishes, dyes, polishes, adhesives C09) - C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06) - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract The present invention provides switchable adhesives comprising a mixture, in proportions by weight, of 20% to 98% of an adhesive, 2% to 80% of curable molecules and 0.05% to 10% of photoinitiator in which the weight proportion of the adhesive is calculated on the basis of its dry weight and wherein the adhesive includes an internal cross-linker for cross-linking the adhesive during drying to provide a cohesive strength of between 5 and 100 N/12.7×12.7 mm measured according to FINAT test method No. 18. Preferably, the adhesive and curable molecules are mutually soluble when dry, or the curable molecules and adhesive may be uniformly dispersed in each other. Preferably the amount of adhesive in the mixture is in the range 40% to 98% by weight, more preferably 60% to 95% by weight, even more preferably 70% to 85% by weight. Preferably the proportion of curable molecules in the mixture ranges from 2% to 60% by weight, more preferably 5% to 40% by weight, even more preferably 15% to 30 by weight. Preferably, the photoinitiator is present in the mixture in the proportions 0.5% to 5% by weight, more preferably 1% to 3% by weight. Such switchable adhesives are useful in medical dressings and other removable sheet products, and may be simply prepared by stirring the adhesive, the curable molecules and the photoinitiator together at room temperature. ## Claims ### Claim 1 A switchable pressure sensitive adhesive composition comprising a mixture, in proportions by weight based on the weight of the composition, of: 20% to 98% of a base adhesive polymer constituent which has no bound-in curable groups that are curable by free radical polymerisation; 2% to 80% of curable molecules that are curable by free radical polymerisation, and 0.05% to 10% of photoinitiator, wherein; (a) the weight proportion of the base adhesive is calculated on the basis of its dry weight; (b) said composition includes an internal cross-linker that is curable by a mechanism other than free radical polymerisation for cross-linking the base adhesive polymer constituent during drying to provide a cohesive strength of the composition of between 5 and 100N/12.7×12.7 mm measured according to FINAT test method No. 18, and (c) the curable molecules are not bound-in to the base adhesive polymer constituent. ### Claim 2 (depends on 1) A switchable pressure sensitive adhesive composition according to claim 1 comprising a mixture, in proportions by weight based on the weight of the composition, of: 40% to 98% of said base adhesive polymer constituent; 2% to 60% of said curable molecules, and 0.5% to 5% of said photoinitiator. ### Claim 3 (depends on 1) A switchable pressure sensitive adhesive composition according to claim 1 comprising a mixture, in proportions by weight based on the weight of the composition, of: 60% to 95% of said base adhesive polymer constituent; 5% to 40% of said curable molecules, and 0.5% to 5% of said photoinitiator. ### Claim 4 (depends on 1) A switchable pressure sensitive adhesive composition according to claim 1 comprising a mixture, in proportions by weight based on the weight of the composition, of: 70% to 85% of said base adhesive polymer constituent; 15% to 30% of said curable molecules, and 1% to 3% of said photoinitiator. ### Claim 5 (depends on 1) A switchable pressure sensitive adhesive composition according to claim 1 wherein the proportion of internal cross-linker is from 0.1 to 6% in proportion by weight based on the wet base adhesive polymer constituent. ### Claim 6 (depends on 1) A switchable pressure sensitive adhesive composition as claimed in claim 1 wherein the base adhesive polymer constituent is selected from the group consisting of polyacrylates, polyurethanes and polysilicones. ### Claim 7 (depends on 1) A switchable pressure sensitive adhesive composition as claimed in claim 1 wherein the base adhesive polymer constituent is a mixture of adhesives selected from the group consisting of polyacrylates, polyurethanes and polysilicones. ### Claim 8 (depends on 1) A switchable pressure sensitive adhesive composition as claimed in claim 1 wherein the base adhesive polymer constituent is a polyacrylate. ### Claim 9 (depends on 1) A switchable pressure sensitive adhesive composition according to claim 1 wherein the curable molecules are unsaturated compounds. ### Claim 10 (depends on 9) A switchable pressure sensitive adhesive composition according to claim 9 wherein the curable molecules have more than one unsaturated site. ### Claim 11 (depends on 10) A switchable pressure sensitive adhesive composition according to claim 10 wherein the curable molecules have multiple functionalities of 3 or greater. ### Claim 12 (depends on 1) A switchable pressure sensitive adhesive composition as claimed in claim 1 wherein the curable molecules are selected from the group consisting of acrylic acid esters or methacrylic acid esters of alcohols, glycols, pentaerythritol, trimethylpropane, glycerol, aliphatic epoxides, aromatic epoxides, bisphenol A epoxides, aliphatic urethanes, silicones, polyesters and polyethers, ethoxylated or propoxylated species thereof, and mixtures thereof. ### Claim 13 (depends on 1) A switchable pressure sensitive adhesive composition as claimed in claim 1 wherein the photoinitiator is selected from the group consisting of titanocene photoinitiators; dye/co-initiator systems, thionine/triethanolamine; dye/borate salt systems; dye/peroxide systems, 1,2-diketone/co-initiator systems and camphor-quinone/tertiary amine. ### Claim 14 (depends on 1) A switchable pressure sensitive adhesive composition as claimed in claim 1 wherein the photoinitiator is reactive to visible light. ### Claim 15 (depends on 1) A switchable pressure sensitive adhesive composition as claimed in claim 1 wherein the reduction in peel force of the pressure sensitive adhesive after switching is 30 to 98%.