ABSTRACT
The first use of acrylic acid esters as pressure-sensitive adhesives (PSAs) is generally attributed to Walter Bauer working at the Rohm and Haas Company in 1928. Some variation is found in the literature for values reported for homopolymers of some of the most important monomers used in the manufacture of acrylic PSAs. Vinyl acetate is sufficiently different from the acrylic and methacrylic secondary comonomers that polymers containing it are often classified as “vinyl acrylics,” as distinct from “all acrylics.” Ulrich’s patent was the first to recognize the advantages of including a carboxylic acid, either acrylic, methacrylic, or itaconic acid, as a comonomer. Hydroxyl functional groups, being much less polar than the carboxylic acids, have correspondingly less impact on the properties. Cross-linking proceeds via a ring opening addition to carboxylic acid functional groups on the polymer. Polymeric emulsifiers, also called protective colloids, function by creating entropic repulsion between particles.
