Coating and sealing polyurethanes for building applications Available to Purchase

The following article reports on the use of PUR (polyurethane) systems for the building industry and discusses the choice of PUR raw materials available with particular reference to the surface treatment of concrete facades. One‐pack polyurethanes are used principally for impregnating concrete surfaces and solvent‐free PUR coatings can be made so elastic that cracks in concrete structural components can be bridged. Knifing polyurethane products can be used in the laying of ceramic tiles. Joint sealants can be produced either from two‐pack products or from blocked isocyanate prepolymers, which react with ketimines only in the presence of atmospheric moisture. Epoxy resin coatings are elasticised by blocked prepolymers. Statistics show that 30 per cent of plastics produced in the Federal Republic of Germany are used in the building industry. Nearly all plastics and paint binders are included in this figure. Polyurethane raw materials have also been used for many years. Apart from PUR insulating materials, polyurethanes are used in interior decoration as parquet floor varnishes, where abrasion resistance, flexibility and resistance to chemicals are required.