The effect of styrene isoprene diblock content on hot melt label pressure-sensitive adhesives properties

Abstract Styrene-isoprene-styrene (SIS) based hot melt pressure sensitive adhesives (HMPSAs) have high tack, high cohesion (at ambient temperature), and good adhesion to various substrates. In this study, we investigated the effects of styrene-isoprene diblock content in SIS copolymer on the characteristics of SIS-based HMPSAs and used them for labels. We found that styrene-isoprene (SI) diblock in a styrene-isoprene-styrene (SIS) copolymer improved adhesive properties and die cutability of self adhesive labels, which is one of the most significant properties for labels. The diblock copolymer reduces the storage modulus of adhesive compounds. As the modulus is low, it improves wettability to the surface, resulting in high tack and peel, which seems to be a predominant factor on labels. The SIS used in this study is classified into low diblock SIS and high diblock SIS.