ACRYLIC MODIFIED REACTIVE URETHANE HOT MELT ADHESIVE COMPOSITIONS

摘要

The addition to urethane prepolymers of low molecular weight polymers formed from ethylenically unsaturated monomers which do not contain active hydrogen provides a hot melt adhesive which can be readily coated at a viscosity of 3000 to 50,000 cps. at 120.degree.C Thermosel without the need for additional tackifiers or plasticizers and which has improved initial cohesive strength as well as improved strength after aging of the cured bond. In a preferred embodiment of the invention, the ethylenically unsaturated monomers are polymerized in the non-isocyanate containing components of the isocyanate terminated prepolymer.