N-Alkyl polyurethane/vinyl polymer mixtures

Claim 1

A moulding composition comprising: (a) at least one aromatic N-alkyl polyurethane corresponding to the following general formula: ##STR5## wherein R 1 represents methyl or ethyl; R 2 , r 3 , r 4 and R 5 , which may be the same or different, each represents an alkyl radical having such a number of carbon atoms that the total number of carbon atoms in each of the alkylene bridges formed by R 2 , R 3 and an intervening carbon atom, and by R 4 , R 5 and an intervening carbon atom, is from 3 to 6; X, y, x 1 and Y 1 , which may be the same or different, each represents hydrogen, methyl, chlorine or bromine; n = 0 or 1; m = 0 or 1; and u is such that the average molecular weight of the polyurethane is from 10,000 to 100,000; or corresponding to the following general formula: ##STR6## wherein R 1 , R 2 , R 3 , X, Y, n and u are as defined in connection with general formula (a 1 ) above; and (b) at least one elastomeric polymer based on butadiene and/or a alkyl acrylate which may be graft-polymerised with at least one radically polymersible monomer; and, optionally, (c) a homo- or co-polymer of the monomers of component (b); component (a) constituting from 80 to 20%, by weight, of the composition, and the sum of components (b) and (c) constitutes from 20 to 80%, by weight, of the composition, the sum of components (b) and (c) being made up of from 25 to 100%, by weight, of component (b) and from 75 to 0% by weight, of component (c).