Molecular parameters and their relation to the adhesive performance of emulsion acrylic pressure-sensitive adhesives. II. Effect of crosslinking

Acrylic emulsion pressure-sensitive adhesive (PSA) films generally have much lower shear holding power than that of their solvent-borne counterparts for the same peel and tack. This is due to their discrete microgel morphology in the film. In contrast, film cast from solution-polymerized acrylic PSA forms a continuous network as a result of crosslinking acrylic acid and aluminum acetyl acetonate (AAA) in the film following the solvent evaporation. Novel acrylic emulsion PSA was made by copolymerizing ≤1 wt % isobutoxy methyl acrylamide (IBMA) in the polymer backbone. The IBMA grafted the linear portion of the acrylic polymer with the microgels upon heating the film, which resulted in a significant increase in the shear holding power.