Method for producing a UV transparent pressure sensitive adhesive

摘要

UV-transparent pressure-sensitive adhesives are obtained by polymerising an acrylic monomer mixture containing UV-crosslinking functional groups and then mixing the resulting copolymer with 2-20 wt% silicate filler with a maximum particle diameter of 50 nm. A method for the production of UV-transparent, pressure-sensitive adhesives (I) with an average mol. wt. (M w) of less than 300000 and a UV-transparency of more than 95% at 300 nm. This method involves (a) polymerising a monomer composition comprising (a1) 75-99.8 wt% (meth)acrylate ester of formula CH 2=C(R 1)COOR 2 in which R 1H or methyl; R 21-20C alkyl , (a2) 0-10 wt% (meth)acrylic acid, (a3) 0.2-5 wt% olefinically-unsaturated monomers with at least one UV-crosslinking functional group and (a4) 0-20 wt% unsaturated monomers with at least one functional group, and (b) mixing the resulting copolymer (before or after stage (a)) with 2-20 wt% silicate filler with a maximum particle diameter of 50 nm.