Abstract: A polyurea composition containing monomeric diisocyanates in an amount of max. 0.5 wt.% and consisting of a first component containing a primary, aromatic diamine and a second component containing an isocyante-group-containing polyether urethane polymer containing monomeric diisocyantes in an amount of max. 0.5 wt.% and an aliphatic polyisocyanate with an NCO content of 8 to 25 wt.%.

Abstract: A multi-component composition contains a) a polyol component having a1) acrylate polyol and a2) at least one of polyester polyol and polyether polyol, wherein the equivalent ratio of hydroxyl groups of acrylate polyol to hydroxyl groups of the at least one of polyester polyol and polyether polyol is in the range of 0.4 to 3.8, and b) an isocyanate component containing b1) aliphatic polyisocyanate monomer, dimer and/or trimer, and b2) aliphatic polyisocyanate prepolymer, wherein the equivalent ratio of isocyanate groups of aliphatic polyisocyanate monomer, dimer and/or trimer to isocyanate groups of aliphatic polyisocyanate prepolymer is in the range of 0.5 to 2.6. The multi-component composition is suitable for use as a top coat on elastic membranes, in particular roofing membranes, to provide sufficient weathering resistance/protection.

Abstract: Carboxylic acids are converted in high yields to olefins or high purity .alpha.-olefins by contacting a mixture of carboxylic acid and a carboxylic acid anhydride in the presence of a Group VIII metal or copper-containing catalyst at a temperature of from about 100.degree. C. to about 300.degree. C.