Repulpable EVA Hot Melt Packaging Adhesives Using Polybutenes, 1995 Polymers, Laminations & Coatings Conference Proceedings

Martin R. Spatz

Amoco Corporation

Amoco Research Center

Polybutenes, a series of viscous liquid polymers used to plasticize and tackify a variety of adhesive base resins, have been shown to lower the blend density of ethylene-vinyl acetate (EVA) based hot melt packaging adhesives. Lower blend density is beneficial in applications where repulpability is important because it improves the ability of paper mills to remove the hot melt adhesive from the repulping process using the density difference method. In a basic hot melt formulation consisting of EVA base resin, wax, tackifying resin and antioxidant, various molecular weight grades of polybutene were used to partially replace the tackifying resin. This resulted in lower blend densities and improved hot melt removal efficiencies in laboratory tests which simulate the repulping process. Polybutene also had the benefit of improving low temperature flexibility without increasing open time.