Abstract: This invention relates to a process for the preparation of compression molded materials comprising compressing a substrate with a binder based on polyisocyanates, wherein said binder comprises polyisocyanates, compounds containing at least two isocyanate reactive hydrogen atoms, and alkylene carbonates.

Abstract: This invention relates to formaldehyde-free, aqueous glue dispersions which contain polyisocyanates. These systems are particularly suitable for gluing veneers and surface materials on wood and wood products. The systems are prepared from polyisocyanates in combination with extenders based on flours and cold water-soluble of hydrolyzed natural starch. In this process, polyisocyanates or aqueous dispersions thereof are added while stirring to aqueous solutions or mixtures of starch and flour.The extender-containing adhesive systems are aqueous glue dispersions having increased service life which in their preferred embodiment contain about 15 to 30% by weight of polyisocyanates, preferably polyphenyl-polymethylene polyisocyanate (PMDI), 10 to 15% by weight of starch which is soluble in cold water and 14 to 25% by weight of (cereal) flour and optionally, other additives and the appropriate quantity of water adding up to 100% by weight.