Manufacture of polyisocyanates containing uretdione groups

摘要

Use of phosphine (I) comprising tertiary alkyl residue that are bound directly with one or two phosphorus atom to form uretdione (isocyanate dimerization), is claimed. An independent claim is included for a method for dimerization of isocyanate comprising reacting at least one organic isocyanate, a catalyst comprising (I) showing one or two directly phosphorus bound, tertiary alkyl residue and optionally a solvent and an additive.