Patent ID: 7393901

Claim:
A pressure sensitive adhesive comprising: (a) a polymer comprising: (i) 90 to 99 parts by weight of an (meth)acrylic acid ester of non-tertiary alcohol, said alcohol having from 1 to 14 carbon atoms; (ii) 1 to 10 parts by weight of an acid functional monomer; (iii) 0 to 10 parts by weight of a second, non-acid functional, polar monomer; (iv) 0 to 5 parts vinyl monomer; (v) optionally 0.01 to 1 part by weight of a multifunctional acrylate; (b) 0.001 to 1 part of a polyfunctional aziridine crosslinking agent, based on 100 parts of polymer (a) and (c) 1 to 8 parts by weight of silica nanoparticles having an average particle diameter of 20 nanometers or less, based on 100 parts of polymer.