terborne Adhesive Tackifiers Development of Viscous Liquid Resin

ber af problems fer nnr instantaneously While solvent-assisted emulsion systems have met with a degree of success in formulating pressure sensitive adhesives, they have several disadvantages. The solvent content of these systems precludes totally solvent-free adhesives. Also. there is reported evidence that surfactants used to stabilize the emulsion can adversely affect tack properties of the final adhesive (1). .c neither immediately developed for, nor A lack of stability can alsobe a trouinstantaneously applied to a specific blesome problem in storage and hancost and problem area. Rather, it 'is an evolu4lhg'e.f these .products., Emulsion stafacing a tionary process of continual product bility can be destroyed irreversibly existing and performance improvements. when subjected to temperatures below The development of aqueous resin/ freezing or to mechanical shear. Such rubber pressure sensitive adhesives is emulsion resins are usually produced at progressing through a similar evolu50-60 percent solids content, which can sol* tionary process. The basic concept rebe a limitation in formulating solids, the volvca around the use of a latex elaswater-based adhesives. tomer for cohesive strength, tackified A second approach to waterborne by a waterborne resin. One of the eartackifying resins is the solvent-free disconliest and easiest approaches to preparpersion. Using more sophisticated disonal ing this kind of tackifying resin is that persing or homogenizing technique@, of solvent-assisted emulsions. Such along with the a emulsions are prepared by dissolving level of emulsifier, relied upon solOften, technological innovation is neither The industry, immediately developed tions.