Development trends in pressure-sensitive adhesive systems

Pressure-sensitive adhesives (PSA) present an interesting class of products that offers a potential to produce a novel generation of self-adhesives with a great number at excellent properties. The term pressure-sensitive describes adhesives that are aggressively and permanently tacky in the dry form at room temperature and firmly adhere to a variety of dissimilar surfaces upon mere contact, without the need of more than finger or hand pressure. Acrylic self-adhesive polymers are nowadays synthesized from a wide selection of acrylic ester monomers, often with low levels of monomers having pendant functional groups. The three basic types of acrylic common today are solvent-borne, water-borne, and solvent-free acrylic PSAs. They can be used in the production of single- and double-sided self-adhesive tapes, foil labels, carrier-free tapes, self-adhesive bioelectrodes, and decorative PVC signs and marking films. A pressure-sensitive adhesive requires a balance of cohesive strength and viscoelastic properties. These characteristics are based on three parameters: tack, adhesion, and cohesion.