Adhesive product

Abstract

Abstract Heat-activated temporary pressure-sensitive adhesives are prepared which are activated through heating and on activation take on all of the characteristics of conventional pressuresensitive adhesives which characteristics they maintain over substantial periods of time after cooling back to their initial temperature prior to the heat activation. The pressure-sensitive adhesives after activation are pressure sensitive in character exhibiting internal strength and the other characteristics of good pressure-sensitive adhesives and in this way they differ substantially from thermoplastic or hot melt adhesives which generally have substantial loss in internal strength becoming stringy and leggy in character when heated to a temperature at which they will bond to other surfaces. The temperature-activated pressure-sensitive adhesives obtain their temperature activation characteristics through the presence of an organic polymer or polymers having in balance at room temperature, prior to heat activation, an ordered or crystalline phase and a disordered or amorphous phase and having a first-order transition temperature or melting point of 35* C. or higher and a second-order transition temperature or glass temperature of 5* C. or lower. The organic polymer or polymers have little to no tack at room temperature and remain in this state until activated by heating and on activation becoming aggressively tacky, exhibiting good pressure-sensitive adhesive characteristics and maintaining such aggressive tackiness and good pressure-sensitive adhesive characteristics for an extended period of time after cooling back to room temperature after which period of time the organic polymer or polymers return to a state of little or no tack.

Inventors

• 👤 Charles H Beede

Bibliographic Details