Laminates having a polyurethane adhesive

Claim 2

A LAMINATE OF THE GROUP CONSISTING OF SARAN ADHESIVELY BONDED TO SARAN, SARAN ADHERED TO TREATED POLYYETHYLENE AND TREATED POLYETHYLENE ADHERED TO TREATED POLYETHYLENE THE ADHESIVE IS A WATER SOLUBLE SALT OF A SUBSTANTIALLY LINEAR THERMOPLASTIC POLYURETHANE CONTAINING 0.5 TO 2.5% BY WEIGHT OF NITROGEN DERIVED FROM TETRIARY AMINE GROUPS AND FROM 2 TO 8% OF NITROGEN DERIVED FROM ISOCYANATE GROUPS, SAID POLYURETHANE BEING PREPARED BY (A) REACTING AN EXCESS OF AN ISOCYA NATE WITH A MIXTURE OF DIOLS CONSISTING OF POLYETHER DIOLS HAVING A MOLECULAR WEIGHT OF FROM 425 TO 4,000 AND TERIARY AMINE DIOLS SELECTED FROM THE GROUP CONSISTING OF N-PHENYL DIALKANOL AMINE AND N-LOWER ALKYL DIALKANOL AMINES TO OBTAIN A REACTION PRODUCT HAVING FREE ISOCYANATE GROUPS GREATER THAN 0.1 MILLIEQUIVALENTS OF NCO PER GRAM OF SOLUTION AT 50% SOLIDS, (B) CHAIN EXTENDING THE REACTION PRODUCT WITH A CHAIN EXTENDER SELECTED FROM THE GROUP CONSISTING OF ALKANOL AMINES AND ALKYLENE DIAMINES TO OBTAIN A CHAIN EXTENDED POLYURETHANE POLYMER CONTAINING FROM 0.07 TO 0.1 MILLIEQUIVALENTS OF NCO PER GRAM OF SOLUTION AT 50% SOLIDS, (C) REACTING THE FREE ISOCYANATE GROUPS WITH A MATERIAL SELECTED FROM THE GROUP CONSISTING OF WATER MISCIBLE ALCOHOLS, ACIDS AND WATER, AND ADDING AN AMOUNT OF A WATER MISCIBLE ACID BEING ADDED SUFFICIENT TO FORM THE ACID SALTS WITH THE TERTIARY AMINE GROUPS PRESENT ON THE POLYURETHANE.

Claim 3

A laminate of the group consisting of saran adhesively bonded to saran, saran adhered to treated polyethylene and treated polyethylene adhered to treated polyethylene wherein the adhesive is a water soluble salt of a substantially linear thermoplastic polyurethane containing 0.5 to 2.5% by weight of nitrogen derived from tertiary amine groups and from 2 to 8% of nitrogen derived from isocyanate groups, said polyurethane being prepared by (a) reacting an excess of an isocyanate with a mixture of diols consisting of polyether diols having a molecular weight of from 425 to 4,000 and tertiary amine diols selected from the group consisting of N-phenyl dialkanol amine and N-lower alkyl dialkanol amines to obtain a reaction product having free isocyanate groups greater than 0.1 milliequivalents of NCO per gram of solution at 50% solids, (b) chain extending the reaction product with a chain extender selected from the group consisting of alkanol amines and alkylene diamines to obtain a chain extended polyurethane polymer containing from 0.07 to 0.1 milliequivalents of NCO per gram of solution at 50% solids, (c) reacting the free isocyanate groups with a material selected from the group consisting of water miscible alcohols, acids and water, and adding an amount of a water miscible acid being added sufficient to form the acid salts with the tertiary amine groups present on the polyurethane.

Claim 4

A laminate of the group consisting of saran adhesively bonded to saran, saran adhered to treated polyethylene and treated polyethylene adhered to treated polyethylene wherein the adhesive is a water soluble salt of a substantially linear thermoplastic polyurethane containing 0.5 to 2.5% by weight of nitrogen derived from tertiary amine groups and from 2 to 8% of nitrogen derived from isocyanate groups, said polyurethane being prepared by (a) reacting an excess of an isocyanate with a mixture of diols consisting of polyether diols having a molecular weight of from 425 to 4,000 and tertiary amine diols selected from the group consisting of N-phenyl dialkanol amine and N-lower alkyl dialkanol amines to obtain a reaction product having free isocyanate groups greater than 0.1 milliequivalents of NCO per gram of solution at 50% solids, (b) chain extending the reaction product with a chain extender selected from the group consisting of alkanol amines and alkylene diamines to obtain a chain extended polyurethane polymer containing from 0.07 to 0.1 milliequivalents of NCO per gram of solution at 50% solids, (c) reacting the free isocyanate groups with a material selected from the group consisting of water miscible alcohols, acids and water, and adding an amount of a water miscible acid being added sufficient to form the acid salts with the tertiary amine groups present on the polyurethane.

Claim 5

A laminate as in claim 1 wherein the polyether diol is polypropylene glycol, the N-lower alkyl dialkanol amine is N-methyl diethanol amine and the acid is a non-toxic organic carboxylic acid.

Claim 6

A laminate as in claim 1 wherein the polyurethane is reacted with an excess of a water soluble alcohol and the acid is a non-toxic organic carboxylic acid.

Claim 7

A laminite as in claim 3 wherein the isocyanate reactant is isopropyl alcohol.

Claim 8

A laminate as in claim 1 wherein the percentage of isocyanate derived nitrogen is 3 to 5% by weight of the tertiary nitrogen is 0.75 to 1.5% by weight.