Fluorinated polyacrylates and polyacrylamides having a controlled cross-linking degree, and process for preparing same

Claim 1

Acrylic or methacrylic polymers, having a controlled cross-linking degree, prepared by radicalic polymerization of a monomer mixture comprising: (a) from 1% to 99% by moles of a monomer of the monoacrylate or monoacrylamide type, consisting of a perfluoropolyoxyalkylene chain and having one of the following general formulas: ##STR4## wherein: m, n and q are integers from 0 to 50, and m+n+q is not lower than 2, the oxyfluororalkylene unites being statistically distributed along the chain; A is a perfluoroalkyl end groups of the type CF.sub.3 --, CF.sub.3 --O--CF(CF.sub.3)--, C.sub.3 F.sub.7 --; Z is --CX(Y)O--(CH 2 --CH 2 O) p -- or --CH 2 NR'--; X is a hydrogen atom or a fluorine atom; Y is CF 3 or it may be also H if also X is H; R and R', like or different from each other, may be H or CH 3 ; p=0-3; C.sub.3 F.sub.7 O(C.sub.3 F.sub.6 O).sub.r CF.sub.2 --Z--CO--CR═CH.sub.2 (a. 2) wherein Z and R have the above defined meanings and r is an integer of at least 2; F(CH.sub.2 CF.sub.2 CF.sub.2 O).sub.s CH.sub.2 CF.sub.2 --Z--CO--CR═CH.sub.2 (a. 3) wherein s is an integer comprised between 1 and 50 and Z and R have the meanings above defined; (b) from 99% to 1% by moles of a monomer of the diacrylate or diacrylamide type, consisting of a perfluoropolyoxyalkylene chain and having one of the following formulas: CH.sub.2 ═CR--CO--Z--CF.sub.2 O(C.sub.2 F.sub.4 O).sub.m --(CF.sub.2 O).sub.n --CF.sub.2 --Z--CO--CR═CH.sub.2 (b. 1) in which the units --C 2 F 4 O-- and --CF 2 O-- are statistically distributed along the chain, Z and R being the same as defined hereinbefore, and m and n being integers from 1 to 50; CH.sub.2 ═CR--CO--Z--CF.sub.2 O (C.sub.3 F.sub.6 O).sub.r (C.sub.2 F.sub.4 O).sub.s (CFXO).sub.t CF.sub.2 --Z--CO--CR═CF.sub.2 (b. 2) wherein r, s and t are integers from 1 to 50 and Z and R have the meanings as above defined: CH.sub.2 ═CR--CO--Z--CF.sub.2 CH.sub.2 (OCF.sub.2 CF.sub.2 CH.sub.2).sub.s --OR'.sub.f --O--(CH.sub.2 CF.sub.2 CF.sub.2 O).sub.v CH.sub.2 CF.sub.2 --Z--CO--CR═CH.sub.2 (b. 3) wherein s and v are integers from 1 to 50 and Z and R have the meanings as above defined, R' f being a perfluoroalkylene radical of 1-6 carbon atoms.