| abstract |
The new copolymers based on maleic anhydride and alpha , beta -unsaturated compounds contain, as bivalent structural units, A: 20 to 95 mole % of the structural element <IMAGE> B: 0 to 40 mole % of the structural element <IMAGE> C: and 0 to 40 mole % of the structural element <IMAGE> the sum of the mole percents of (A), (B) and (C) being 100, and wherein R1 and R2 are identical or different and denote hydrogen, alkyl, optionally substituted aryl or the ester group <IMAGE> in which R4 represents alkyl with 1 to 20 carbon atoms, R3 denotes an alkyl, cycloalkyl or optionally substituted aryl radical with 1 to 20 carbon atoms and X and Y are identical or different and represent the group -O-R5 in which R5 denotes hydrogen, a cation or alkyl with 1 to 40 carbon atoms, or X and Y represent the group -NHR3 in which R3 has the abovementioned meaning, at least one of the radicals X and Y representing the group -O-R5, and at least one of the radicals in the radicals X and Y containing at least 18 carbon atoms. The new copolymers can be prepared by reacting alternating copolymers of maleic anhydride and alpha , beta -unsaturated compounds with monoalcohols and monoamines. They can be used as paraffin inhibitors. |