Polyurethanes for Flexible Surface Coatings and Adhesives

Abstract

Polyurethanes can be tailor-made for a wide range of flexible surface coatings, e.g., for textile substrates and leather; and for a wide variety of adhesives. Polyurethanes give unexcelled performance in almost all of these applications. A prime target of coating textiles with polyurethanes is the achievement of the quality of natural leather. A highly water vapor permeable, but water repellent textile coating has recently become possible using a direct coating process. The application of a micro porous polyurethane film on split leather by a reaction process leads to prime quality leather for shoe uppers. For many years, elastomenc polyurethanes have been the top-ranking adhesives for highly plasticized PVC articles. More recently, polyure thanes have been introduced into the market as structural adhesives, especially for the bonding of automotive body parts. A new principle of heterogeneous cross-linking of polyurethanes which has potential for one-package structural adhesives is pre sented. Aqueous polyurethane dispersions can also be tailor-made for the whole range of two-dimensional applications. They complement the high solids and the powder polyurethane coatings, as well as the solvent-free polyurethane adhesives in the fulfillment of ecological and industrial hygiene requirements.