UV-crosslinked acrylic pressure-sensitive adhesive systems containing unsaturated ethers

Abstract

A new class of acrylic pressure-sensitive adhesives (PSA), containing oxirane groups [formula (VII)], were developed. PSA systems obtained from butyl acrylate, glycidyl methacrylate and acrylic acid were modified with selected unsaturated allyl, vinyl or 1-propenyl ethers [formulas (I)-(VI)] in amounts of 1.0 to 5.0 wt. %. Then they were cured (using UV lamp) in the presence of 1.0 wt. % of cationic photoinitiator Irganocure 261 at room temperature and air atmosphere for 3 min. The tack, adhesion to glass and cohesion values of the cured PSA samples were measured. The effects of the type and concentration of unsaturated ether monomers used on these properties were evaluated. It was found that vinyl and 1-propenyl ethers were the most UV reactive crosslinking monomers while allyl ethers deteriorated PSA properties. The most advantageous values of adhesion, cohesion and tack were obtained for the samples containing 2 wt. % of vinyl or 1-propenyl ether. The results of investigations showed also that increase in crosslinking time, under UV radiation, caused faster increase in cohesion of the samples modified with vinyl ethers in comparison with those modified with 1-propenyl ones.