Chapter 12 - Release coatings for pressure sensitive adhesives

Abstract

This chapter presents the effect of the release material chemistry, surface and interfacial composition, and the rheology on release performance in addition to the potential chemical interactions between the pressure sensitive adhesives (PSA) and release coating. The requirements for a release coating include (1) a release force desired for the intended application, (2) the release force must be stable under the environmental (temperature and humidity) conditions that the PSA product will experience, and (3) the release material should be well anchored to the backing so that it does not transfer to the PSA, thereby decreasing the subsequent PSA adhesion. The types of polymers that are used as release coatings include silicone networks, silicone containing copolymers, and polymers with long alkyl or fluoroalkyl side chains, fluoropolymers, and polyolefins. These polymers have surface energies that are less than the surface energies of commonly used PSAs, an important feature of release materials. The chapter provides an example of a perfluoropolyether molecule, with the level of ether linkage, type of curable functional group, and overall molecular weight being variable.