| abstract |
A method of manufacturing a polyurethane compound comprises mixing together a polyol, a polyisocyanate compound and a catalyst and allowing the mixture to cure to form a polyurethane, and is characterised in that the catalyst is a neutral complex of a metal selected from Ti, Zr, Hf, Al, Fe, Bi or Sn and a multidentate organic ligand having: a) a number of anionic donor sites = x; b) a number of neutral donor sites, capable of forming a co-ordinate bond with the metal, = y; c) where x + y = from 5 to 8; d) x is from 2 to 4; e) the ligand molecule is of a size and conformation to enable each of the anionic donor sites and neutral donor sites to form a bond with the same metal atom. |