Pressure-sensitive adhesive products - by coating flexible carriers with solvent-free hot melt adhesives

摘要

The thermoplastic pressure-sensitive adhesive consists of (A) 10 to 110 pts. of thermoplastic polymer (B) 10-90 pts. adhesive resin with lower softening pt. or resin mixt. with softening pt. 100 degrees C and (C) 10 to 90 pts. filler. The composition is heated to 121-204 degrees C and applied as a fluid liquid melt to at least one side of a flexible carrier. Pref. compsns. contain (A) 35 pts. thermoplastic styrene-isoprene block copolymer, (B) 30 pts. polyterpene resin and 47.5 pts. hydrocarbon resin, with a combined softening pt. of 65 degrees C and (C) 47.5 pts. calcium carbonate. They can be applied by usual equipment, e.g. hot knife over-roll coater or extrusion coater, at high speeds of 152-305 m/min. Use of solvents or prolonged mastication to reduce viscosity is eliminated and expensive equipment e.g. for drying or multiple calendering is not required.