Cationic UV-crosslinkable acrylic polymers for pressure sensitive adhesives

摘要

An ultraviolet (UV) crosslinkable acrylic pressure sensitive adhesive comprises an acrylic copolymer and a cationic photoinitiator. The acrylic copolymer comprises pendant reactive functional groups. The pressure sensitive adhesive formed from the acrylic copolymer with the pendant reactive functional groups result in high green strength and/or high temperature holding strength of the adhesive.

主权项

1. An ultra-violet curable pressure sensitive adhesive comprising an acrylic polymer and a cationic photoinitiator, wherein said acrylic polymer is prepared from the group consisting of:
(i) an acrylic monomer consisting of an acrylic or methacrylic acid derivative of the formula CH2═CH(R1)(COOR2), wherein R1 is H or CH3 and R2 is C1-20 alkyl chain; (ii) a monomer, wherein said monomer comprises a pendant reactive functional group selected from cycloaliphatic epoxide, oxetane or mixtures thereof, and contains from about 0.001 to about 0.015 equivalent per 100 g of said acrylic polymer; wherein the acrylic polymer (a) is essentially free of multi-(meth)acrylate, (b) has a Tg value less than 0° C., and (c) has a weight average molecular weight from about 50,000 to about 1,000,000 g/mol; and wherein the ultra-violet curable pressure sensitive adhesive has a viscosity range of 1,000-500,000 mPa·s at 80-180° C.