Polyvinyl butyral sheet

Plasticized polyvinyl butyral sheet containing an effective amount of chemically bound ionomeric groups capable of producing thermally reversible cross-links, said ionomeric groups having 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.

A sheet containing plasticized polyvinyl butyral thermally reversibly cross-linked through ionomeric bonds.

Plasticized polyvinyl butyral sheet comprising first and second polyvinyl butyral components, one component present in minor weight amount (based on the weight of polyvinyl butyral) containing chemically bound ionomeric groups.

Plasticized polyvinyl butyral sheet comprising first and second polyvinyl butyral components each having a hydroxyl content of about 15 to about 30% by weight calculated as vinyl alcohol, one of said components present in minor weight amount (based on the weight of polyvinyl butyral) containing ionomeric groups chemically bound to adjacent precursor vinyl alcohol groups.

Plasticized polyvinyl butyral sheet containing first and second polyvinyl butyral components, one of said components present in minor weight amount (based on the weight of polyvinyl butyral) containing chemically bound ionomeric groups of the formula R-XYZ-M where 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.

Plasticized polyvinyl butyral sheet comprising plasticizer admixed with 70 to 90 weight % of a first polyvinyl butyral and 30% to 10 weight % of a second polyvinyl butyral containing chemically bound ionomeric groups, said percentages always totaling 100 weight %.