US 12,269,971 B2
UV-curable acrylic copolymers
Olivier Demoulin, Grez-Doiceau (BE); Jurgen Van Holen, Ninove (BE); and Marc Van Muylder, Geraardsbergen (BE)
Assigned to HENKEL AG & CO. KGaA, Duesseldorf (DE)
Filed by HENKEL AG & CO. KGAA, Duesseldorf (DE)
Filed on Dec. 19, 2016, as Appl. No. 15/382,839.
Application 15/382,839 is a continuation of application No. PCT/EP2015/062194, filed on Jun. 2, 2015.
Claims priority of application No. 14173603 (EP), filed on Jun. 24, 2014.
Prior Publication US 2017/0096588 A1, Apr. 6, 2017
Int. Cl. C09J 151/00 (2006.01); B05D 3/06 (2006.01); C08F 8/14 (2006.01); C08F 220/18 (2006.01); C08F 265/06 (2006.01); C09D 4/06 (2006.01); C09J 4/06 (2006.01); C09J 7/22 (2018.01); C09J 7/38 (2018.01); C09J 133/06 (2006.01); C09J 133/08 (2006.01)
CPC C09J 151/003 (2013.01) [B05D 3/067 (2013.01); C08F 8/14 (2013.01); C08F 220/1808 (2020.02); C08F 265/06 (2013.01); C09D 4/06 (2013.01); C09J 4/06 (2013.01); C09J 7/22 (2018.01); C09J 7/38 (2018.01); C09J 7/385 (2018.01); C09J 133/068 (2013.01); C09J 133/08 (2013.01); C08F 220/1804 (2020.02); C09J 2301/162 (2020.08); C09J 2301/302 (2020.08); C09J 2301/416 (2020.08); C09J 2451/00 (2013.01)] 4 Claims
 
1. A method for producing a pressure sensitive adhesive, the method comprising:
(A) polymerizing a mixture, based on the total weight of the mixture, of:
(i) 40-75 wt. % of 2-ethyl hexylacrylate and/or butyl acrylate,
(ii) 5 to about 10 wt. % of methacrylic acid, and
(iii) about 20 to about 55 wt. % of methyl acrylate and/or ethyl acrylate,
in a solvent selected from the group consisting of ethyl acetate, propyl acetate, butyl acetate, isopropanol, glycol ethers, alkyl lactates, and any mixture thereof, and in the presence of a free radical agent, to form a composition comprising an acrylic copolymer and the solvent;
(B) reducing the solvent content within the composition such that the residual solvent content is less than 1 wt. %, based on the total weight of the composition;
(C) reacting the acrylic copolymer with a monomer having a UV-curable functional group, which comprises a vinyl and an epoxy group in the presence of a chain transfer catalyst, thereby forming a UV-curable acrylic copolymer having a glass transition temperature of about 0° C. to about 10° C.;
(D) adding a photoinitiator to the UV-curable acrylic copolymer; and
(E) irradiating the UV-curable acrylic copolymer with ultraviolet light to form the pressure sensitive adhesive,
wherein the pressure sensitive adhesive remains permanently tacky.