Amorphous Polyolefins as Ingredients in Pressure-Sensitive Adhesives, 1992 Hot Melt Symposium Proceedings

The changing catalyst technology for crystalline polypropylene polymerization and the corresponding reduction in by-product amorphous polypropylene production have stimulated development of direct synthesis amorphous polymers. One effect of this development has been to expand the field of study from amorphous polypropylene homopolymers to higher performance amorphous copolymers and terpolymers. A study was undertaken to determine the relative performance of five families of direct-synthesis amorphous polyolefins in a single pressure-sensitive adhesive formulation: homopolymers; propylene copolymers with ethylene, butene, or hexene; and terpolymers. Performance of the compounds was measured by 180 degrees peel adhesion, Polyken probe tack, and room-temperature hold power. The compounds produced in the study demonstrated a wide range of adhesive properties suggesting that many areas of opportunity exist for formulating amorphous polyolefin-based pressure-sensitive adhesives. The structure of the study was designed to maximize the effectiveness of statistical analysis. This led to the construction of a mathematical model relating the physicalproperties of the amorphous polyolefins to the adhesive properties of the system.