Ionomeric polyvinyl butyral

Polyvinyl butyral containing about 15 to about 30% by weight hydroxyl groups calculated as vinyl alcohol and chemically bound neutralized ionomeric groups of the formula R--XYZ--M where R is aromatic, aliphatic or heterocyclic aldehyde, acid, acid chloride or isocyanate, provided that when R is aliphatic it has the configuration (CH.sub.2).sub.n where n is an integer from 1 to 200;

• X and Y, which can be the same or different, are substituents on the aromatic and heterocyclic forms of R and are H or C.sub.1 to C.sub.5 alkyl;
• Z is So.sub.3.sup.-, COO.sup.- or PO.sub.4.sup.-3 and M is a cation selected from alkali metals, alkaline earth metals and transition metals selected from zinc, copper and manganese said ionomeric groups being present in amount sufficient to be capable of providing thermally reversible ionic cross-links.

Polyvinyl butyral thermally reversibly cross-linked through ionomeric bonds and containing about 15 to about 30% by weight hydroxyl groups calculated as vinyl alcohol.

Polyvinyl butyral containing chemically combined, neutralized ionomeric groups and about 15 to about 30% by weight hydroxyl groups calculated as vinyl alcohol, said polyvinyl butyral having been polymerized an situ with but after formation of modified polyvinyl alcohol containing up to about 10 mole % ionic sulfonated benzal groups.

Partial polyvinyl butyral containing 65 to 95 weight percent vinyl butyral units, 15 to 30 weight percent hydroxyl groups calculated as vinyl alcohol and neutralized ionomeric groups chemically bound onto the chain backbone.