ABSTRACT
Hot-melt pressure-sensitive adhesives have become very popular and have gained importance in all areas of adhesive usage in the last decade because of their superior application properties and due to environmental concerns about solvent-based adhesives [1,2] . These are 100% solid thermoplastic compounds that contain neither solvent nor an aqueous carrier for the active adhesive components [3] (See Vol. l,Chapt.4, Sect.2.1.2; Chapt.5, Sect.2.5, and Vol.2, Chapt.l). Hot-melt PSAs are widely used for spreading over the substrate in the melted state, followed by solidifying after cooling [4], and in those manufacturing processes that require quick and strong bonding. These adhesives are solids at room temperature, but they liquefy when heated to the application temperature. When applied, hot-melts bond and cool rapidly. The increasing usage of hot-melt PSAs is also due to their being environmentally friendly adhesives and because they are economical, quick bonding and do not include any solvent [5]. Previously, hot-melt PSAs using synthetic polymers, a mixture of natural waxes, rosin, pitch and other naturally occurring substances, were used, either alone or in mixtures, to produce sealing compounds for a variety of applications [6].
