Patent ID: 8829145

Claim:
A method of manufacturing a polyurethane compound consisting of mixing together (A) a polyol, (B) a polyisocyanate compound, and (C) a catalyst, and allowing the mixture to cure to form a polyurethane, wherein the catalyst consists of a) a metal-organic compound which is a complex of i) a metal selected from the group consisting of Ti, Zr, Hf, and Al; and ii) a multidentate organic ligand, wherein said multidentate organic ligand has (a) a number of anionic donor sites=x; and (b) a number of neutral donor sites, capable of forming a co-ordinate bond with the metal, =y; where x+y=from 5 to 8 and x is from 2 to 4; said multidentate organic 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; and wherein said multidentate organic ligand is derived from a ligand-forming compound having the following formula: (HO(OC) w (CR 1 R 2 ) z ) 2 Y—(CR 3 R 4 ) x —Y((CR 1 R 2 ) z (CO) w OH) 2 (Formula I) in which: Y is selected from P and N; each R 1 , R 2 , R 2 and R 4 is independently selected from H, alkyl, aryl, substituted alkyl or substituted aryl; each z is independently 1, 2, 3 or 4; x represents the least number C atoms between the Y atoms and is 2 or 3; each w is independently 0 or 1; and wherein (a) the catalyst is first mixed with the polyol to form polyol composition, and (b) the polyol composition is then reacted by mixing with the polyisocyanate compound; and wherein the mixing is continuous.