Polyurethane based thermoreactive hot-melt adhesives
AssigneeE. I. Du Pont de Nemours and Company
InventorsSilke Hellwig, Olaf Kleineberg, Heinz-Peter Pfeiffer
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Abstract
A thermally curable hot-melt adhesive composition, comprises (A) a prepolymer having isocyanate groups, a number average molecular mass Mn of 700 to 6000 and wherein 50 to 100%, preferably 70-95%, of the reactive isocyanate groups of the prepolymer are blocked, the prepolymer being the reaction product of one or more at least semi-crystalline straight-chain polyesters; one or more amorphous or liquid straight-chain polyesters, optionally one or more polyethers, and one or more diisocyanates; and (B) at least one reactive component selected from the group consisting of diamines, epoxide adducts of diamines, and polyalcohols.
Claims10
A thermally curable hot-melt adhesive composition, comprising
- (A) a prepolymer having isocyanate groups, a number average molecular mass Mn of 700 to 6000 and wherein 50 to 100% of the reactive isocyanate groups of the prepolymer are blocked, said prepolymer being the reaction product of
- (1) at least one straight-chain polyester which is at least semi-crystalline with
- (2) at least one straight-chain polyester selected from the group consisting of amorphous polyesters and liquid polyesters,
- (3) optionally at least one polyether, and
- (4) at least one diisocyanate;
- and
- (B) at least one reactive component selected from the group consisting of diamines, epoxide adducts of diamines, and polyalcohols.
Dependencies are inferred from the claim text.