Patent ID: 8349976

Claim:
A copolymer which comprises copolymerized units which originate from monomers of formulae a) to g) in the following relative amounts 35-55 mol % of units originating from a) 8-55 mol % of units originating from b) 8-42 mol % of units originating from c) 4-18 mol % of units originating from d) 3-16 mol % of units originating from e) 4-16 mol % of units originating from f) 3-16 mol % of units, originating from g) where all of the radicals R 1 , independently of one another, are hydrogen or a methyl group, R F is a perfluoroalkyl radical of the formula in which x is a number from 2 to 22, t is a number from 8 to 24, and n is a number from 2 to 6.