Polyvinyl alcohol compositions for use in the preparation of water-soluble films

Claim 1

A composition suitable for use in the preparation of cold water-soluble films consisting essentially of (i) a resin mixture of 40 to 55 parts by weight of a low molecular weight polyvinyl alcohol containing acyl groups having 1 to 4 carbon atoms, and having a viscosity in the range between 3 and 10 cps and a degree of hydrolysis in the range between 85 and 90 mol percent; 25 to 60 parts by weight of a medium molecular weight polyvinyl alcohol containing acyl groups having 1 to 4 carbon atoms, and having a viscosity in the range between 10 and 35 cps and a degree of hydrolysis in the range between 85 and 90 mol percent; and 0 to 20 parts by weight of a copolymer made up of 90 to 98 weight percent polymerized vinyl alcohol units and 10 to 2 weight percent of polymerized ester units which in monomeric form have the formula: ##STR5## wherein A is H or --CH 3 ; A' is H or --COO Alkyl; R is H, --CH 3 or ##STR6## provided that when R is ##STR7## both A and A' are H; R' is H or --CH 3 ; and Alkyl contains 1 to 4 carbon; which copolymer has a viscosity in the range between 10 and 60 cps and a degree of hydrolysis in the range between 95 and 100 mol percent; and (ii) as a plasticizer, 10 to 30 parts by weight of a polyethylene glycol per 100 parts by weight of said resin mixture, said polyethylene glycol having an average molecular weight in the range between 285 and 420; for each of said polymers, the viscosity being determined by the Hoeppler Falling Ball Method ASTM-D 1343-56, Part 8 and the degree of hydrolysis being determined by saponification.