Abstract: A stimuli-responsive polymer derivative utilizing keto-enol tautomerization. Also disclosed are a simple process for producing an N-acyl(meth)acrylamide derivative which can be used as a monomer for the stimuli-responsive polymer, a process for the production of an intermediate thereof, and an intermediate thus produced.

Abstract: The invention provides water-soluble or water-swellable copolymers obtained by free-radical copolymerization of A) acryloyldimethyltaurine and/or acryloyldimethyltaurates, B) optionally, one or more other olefinically unsaturated, optionally crosslinking, comonomers containing at least one oxygen, nitrogen, sulfur or phosphorus atom and possessing a molecular weight of less than 500 g/mol, and C) one or more at least monofunctional, fluorine-containing components capable of free-radical polymerization, the copolymerization D) taking place in the presence or absence of at least one polymeric additive having number-average molecular weights of from 200 g/mol to 109 g/mol. The water-soluble or water-swellable copolymers of the present invention are useful in paper processing, laundry detergents, textile processing, petroleum extraction and formulating cosmetics.