Patent ID: 7084185

Claim:
A process for preparing crosslinked acrylic pressure sensitive adhesives which comprises first preparing polyacrylates by free-radical (co)polymerization in water, organic solvent or solvents or a mixture thereof from a monomer mixture comprising: (a) 45-95% by weight of acrylic acid monomers, methacrylic acid monomers, or both, of the following structure: where R 1 =H or CH 3 and R 2 =an alkyl chain with 2-20 carbon atoms, (b) 0.5 to 25% by weight of one or more carboxylic anhydrides containing olefinic double bonds, (c) 0-30% by weight of further olefinically unsaturated monomers possessing functional groups A, concentrating the polymers thus prepared to form a concentrated polyacrylate composition having a water, solvent or water and solvent concentration of ≦2% by weight, adding to the concentrated polyacrylate composition further monomers which have at least two functional groups B and C, the groups B being groups which are capable of entering into polymer-analogous reactions with the carboxylic anhydrides, and the groups C being crosslinkable groups, reacting the functional groups B with the carboxylic anhydride, to attach the monomers containing functional groups B as side chains to the polymers, after the reaction between the functional groups B and the carboxylic anhydride, crosslinking the polymers with high-energy radiation to form a cross-linked acrylic pressure sensitive adhesive.