Styrene block copolymers (SBCs) offer cohesion, strength, and heat resistance for both pressures sensitive adhesives (PSAs) and non-pressure sensitive adhesives. The styrene phase forms a physically crosslinked network in the adhesive at room temperature. Of the SBCs, styrene isoprene styrene (SIS) is most often used in hot melt PSAs. SIS polymers are generally preferred over styrene-butadiene-styrene (SBS) polymers for hot melt adhesives because the SIS polymers provide a higher level of tack and are less likely to form gels during processing.
RESULTING PROPERTIES
A typical general purpose styrene isoprene styrene hot melt pressure sensitive adhesive is provided above. It can be used for tapes and labels and for bonding low energy surfaces such as plastic films. It has good tack and peel strength, and moderate temperature resistance.
