Polyurethane adhesives are often chosen over other adhesives when greater resistance to plasticizer migration is required or difficult to bond polymeric substrates are involved. One of the largest applications is in footwear where high bond strengths to PVC compositions are required. Polyurethane adhesives also give the formulator more freedom in “engineering” the modulus and elongation required of the adhesive film to meet specific applications.
RESULTING PROPERTIES
Heat seal adhesives are widely used because of their easy application, fast setting properties, and excellent adhesion to many different substrates. The adhesive is coated on both surfaces to be joined. After the carrier evaporates, the two surfaces are brought together under slight pressure and heat, and the adhesive bonds to itself. A typical formulation for a solvent borne, hot melt polyurethane contact adhesive is provided in the above table.
Properties of B.F. Goodrich Estane Thermoplastic Polyurethanes
Melt temperature, °C
Time, hrs, for recrystallization to amorphous form
