US 7,541,397 B2
Uretonimine-modified isocyanate composition and method of forming the same
Thomas Savino, Northville, Mich. (US); and Sandra Bananto, Dearborn, Mich. (US)
Assigned to BASF Corporation, Florham Park, N.J. (US)
Filed on Mar. 10, 2006, as Appl. No. 11/276,693.
Prior Publication US 2007/0213432 A1, Sep. 13, 2007
Int. Cl. C08K 5/34 (2006.01); C08G 18/08 (2006.01)
U.S. Cl. 524—99  [524/589] 35 Claims
 
1. A method of producing a uretonimine-modified isocyanate composition, said method comprising:
providing a polyisocyanate composition having two or more isocyanate groups and comprising 4,4′-diphenylmethane diisocyanate (MDI);
reacting the polyisocyanate composition at a temperature in a range of from about 80° C. to about 130° C. and in the presence of a catalyst such that the isocyanate groups form carbodiimides available for forming uretonimine and/or uretonimine oligomers;
quenching the reaction of the polyisocyanate composition with a quenching agent to inhibit formation of carbodiimides thereby inhibiting additional formation of additional uretonimine and/or uretonimine oligomers; and
adding a color inhibitor having a pKB of greater than about 7 and having at least one hindered amine group.