Patent ID: 7714086

Claim:
A polyvinyl alcohol co-polymer, comprising the reaction product of (i) a lactone-containing co-polymer formed from vinyl alcohol monomer and carboxylic acid monomer, and (ii) an amino functional reactant, wherein: (a) the amino functional reactant opens lactone rings of the lactone-containing co-polymer; (b) the polyvinyl alcohol co-polymer comprises from about 1 mol % to about 6 mol % of the amino functional reactant which is selected from the group consisting of 3-(dimethylamino)propylamine, 3-amino-1-propanol, methoxypropylamine, aminoethoxyethanol, aminopropoxypropanol, aminopropoxypropoxyethanol, 3-amino-1,2-propanediol, aminoethylethanolamine, allylamine, 3-aminopropylsulphonate, 3-aminopropylcarboxylate and mixtures thereof; and (c) the polyvinyl alcohol co-polymer is water-soluble.