Low surface energy adhesive

摘要

Adhesives suitable for use with low surface energy materials are described. The adhesive contain an acrylic copolymer, a high glass transition temperature tackifier and a low glass transition temperature tackifier. The acrylic copolymer is the reaction product of a first alkyl(meth)acrylate having at least 5 carbon atoms in the alkyl group, a second alkyl(meth)acrylate having 1 to 4 carbon atoms in the alkyl group, and a vinyl carboxylic acid. Both tackifiers have a Tg greater than the Tg of the acrylic copolymer. The high glass transition temperature tackifier has a Tg of at least 20° C. and the low glass transition temperature tackifier has a Tg of less than 0° C.

主权项

1. An adhesive comprising:
a) an acrylic copolymer comprising the reaction product of i) a first alkyl (meth)acrylate, wherein the alkyl group of the first alkyl (meth)acrylate comprises at least 5 carbon atoms; ii) a second alkyl(meth)acrylate, wherein the alkyl group of the second alkyl (meth)acrylate comprises 1 to 4 carbon atoms; and iii) a vinyl carboxylic acid; and b) a high Tg tackifier having a glass transition temperature of at least 20° C.; and c) a low Tg tackifier having a glass transition temperature of no greater than 0° C.,wherein the glass transition temperatures of the high Tg tackifier and the low Tg tackifier are greater than the glass transition temperature of the acrylic copolymer,wherein the weight ratio of the first alkyl (meth)acrylate to the second alkyl (meth)acrylate is between 3:1 and 1:3, and the acrylic copolymer comprises at least 3% by weight and no greater than 8% by weight of the vinyl carboxylic acid; and wherein the adhesive comprises 35 to 45% by weight of the high Tg tackifier and 2 to 13% by weight of the low Tg tackifier, based on the total weight of the acrylic copolymer, the high Tg tackifier and the low Tg tackifier.