Hot melt pressure sensitive adhesive, useful for removably bonding labels, e.g. to glass bottles, comprises styrene-butadiene block copolymer mixture, tackifying resin and fatty acid

摘要

A hot melt pressure sensitive adhesive composition (I) comprises (a) 25-40% mixture of 20-90% styrene-butadiene-styrene (SBS) triblock copolymer(s) and 10-80% styrene-butadiene (SB) diblock copolymer(s), the styrene unit content of the mixture being 15-40%, (b) 45-75% compatible tackifying resin(s) of softening point 80-150[deg] C and (c) 0.5-5.5% fatty acid(s) (optionally in alkali(ne earth) metal salt form) with 10-22C hydrocarbon chains. Independent claims are included for: (1) a multilayer system consisting of an adhesive layer of (I), between a printable support layer (consisting of one or more layers of paper of polymer film) and a protective layer; (2) a self-adhesive label, obtained by conversion of the multilayer system; (3) an article covered by the label; and (4) a method for recycling the labeled article, including the stage of removing the label by immersing the article in basic aqueous solution at 60-100[deg] C.