Effect of crosslinking agent on performance of acrylic emulsion pressure-sensitive adhesive for protective films

Polyacrylate emulsion pressure sensitive adhesives (PSAs) for protective films were prepared via pre-emulsified semi-continuous polymerization in the presence of polymerizable emulsifier. The effects of amounts of multifunctional vinyl based internal cross linker M, aziridine cross linker SC-100 and epoxy cross linker GA-240 on the tack, 180° peel strength, growing rate of 180° peel strength and hydrothermal ageing behaviour were discussed. The experiment results showed that the 180° peel strength and growing rate of 180° peel strength was decreased and the resistance to hydrothermal ageing was improved with increasing of the amounts of cross linker M, SC-100 and GA-240. There was little change in tack with increasing of the amount of cross linker M. Tack was decreased with increasing of the amounts of cross linker SC-100 and GA-240. Cross linker GA-240 was better than SC-100 to improve the hydrothermal aging property and to inhibit the growth peel strength. 180° peel strength to use GA-240 was higher than that to use SC-100 when the amount was same. The adhesion to PVC profiles was good and there was no adhesive residue during peeling after hydrothermal ageing when the amount of cross linker M was 0.2% of monomer amount and the amount of cross linker GA-240 or SC-100 was 0.3% or 0.5% of emulsion PSA amount, respectively.