Thermoplastic adhesives containing polyethylene, isobutylene rubber, tackifier resinand ethylene-vinyl acetate copolymer

Claim 1

A SOLVEN-FREE THERMOPLASTIC ADHESIVE CEMENT, DRYSUBSTANTIALLY TACK-FREE AND SOLID AT ROOM TEMPERATURE BUT SOFTENABLE BY HEAT TO FLUID CONDITION, SAID ADHESIVE COMPRISING AN INTIMATE MIXTURE OF FROM ABOUT 15% TO ABOUT 60% BY WEIGHT OF RESINOUS POLYETHLENE HAVING A MOLECULAR WEIGHT OF FROM ABOUT 7,000 TO ABOUT 21,000, FROM ABOUT 10% TO ABOUT 35% BY WEIGHT OF HIGH MOLECULAR WEIGHT ISOBUTYLENE POLYMERIC MATERIAL FROM THE GROUP CONSISTING OF SULPHUR VULCANIZABLE RUBBER COPOLYMERS OF ISOBUTYLENE AND A DIOLEFIN IN APPROXIMATELY THE PROPORTIONS OF 98:2 AND RUBBERY POLYISOBUTYLENE HAVING A MOLECULAR WEIGHT OF THE ORDER FROM 100,000 FROM ABOUT 20% TO ABOUT 60% BY WEIGHT OF AN ESSENTIALLY HYDROCARBON RESIN HAVING A SOFTENING POINT OF AT LEAST ABOUT 85*C. POSSESSING IN HEAT SOFTENED CONDITION SUBSTANTIAL SOLVENT POWER TOWARD SAID POLYETHYLENE, SAID RESIN BEING SELECTED FROM THE GROUP CONSISTING OF POLYBETA-PINENE RESIN HAVING A SOFTENING POINT OF 85*C. TO 125*C., POLYALPHA-PINENE RESIN HAVING A SOFTENING POINT OF 85*C. TO 125*C., THE RESIN SEPARATED FROM UTAH RESIN-BEARING COAL CONSISTING ESSENTIALLY OF CARBON AND HYDROGEN AND HAVING AN AVERAGE MOLECULAR WEIGHT OF ABOUT 1000, A REFRACTIVE INDEX OF 1.544, A SPECIFIC GRAVITY OF 1.03 TO 1.06 AND A MELTING POINT OF FROM 165* TO 180*C. AND THE RESINOUS POLYMERIZATION PRODUCT OBTAINED BY CATALYTIC POLYMERIZATION OF A MIXTURE OF UNSATURATED MONOMERS DERIVED FROM DEEP CRACKING PETROLEUM AND HAVING A SOFTENING POINT (B.R.) OF APPROXIMATELY 100*C., A SPECIFIC GRAVITY OF 25*C. OF .970 TO .975, A REFRACTIVE INDEX AT 20*C. OF 1.5116, AN ACID NUMBER LESS THAN ONE, AN IODINE VALUE (WIJS) OF 120, A BROMIDE NUMBER OF 7.3 AND A MOLECULAR WEIGHT OF APPROXIMATELY 1100, AND FROM ABOUT 10% TO ABOUT 40% BY WEIGHT OF A COPOLYMER OF ETHYLENE AND VINYL ACETATE IN THE RANGE OF FROM ABOUT 0.5 TO ABOUT 10 MOLS OF ETHYLENE TO 1 MOL OF VINYL ACETATE, SAID COPOLYMER OF ETHYLENE AND VINYL ACETATE HAVING A MELTING POINT OF FROM ABOUT 90* TO 125*C.