Patent ID: 6720366
Filing Date: 2004-04-13
Classification: B22C,C08G,C08L

Abstract:
A two-component polyurethane-based binder system for casting molding materials consisting essentially of:(a) a phenolic resin component consisting essentially of at least (i) one phenolic resin exhibiting free phenolic and free alcoholic OH-groups and (ii) a solvent for the phenolic resin, said phenolic resin being the condensation product of a phenol with a formaldehyde component prepared in the presence of catalytic concentrations of zinc ions; and (b) a polyisocyanate component consisting essentially of (i) at least one polyisocyanate capable of reacting with said phenolic resin exhibiting free phenolic and free alcoholic OH-groups to form a resin therewith and (ii) a solvent for said polyisocyanate; wherein said solvent (b) (ii) for said polyisocyanate is comprised at least in part of a fatty acid methyl ester, wherein said fatty acid methyl ester is a methyl monoester of one or more fatty acids with a carbon chain of twelve or more carbon atoms, and wherein said solvent (b) (ii) for said polyisocyanate contains more fatty acid methyl ester than high-boiling aromatic hydrocarbon.