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US 7,683,004 B2Granted
Air-activated organotin catalysts for polyurethane synthesis
AssigneeE.I. du Pont de Nemours and Company
InventorsJerald Feldman, Stephan J. McLain
Life of this patent
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Abstract
This invention relates to an organotin-based catalyst system for polyurethane synthesis that is useful in coatings applications. The catalyst has low activity in the absence of oxygen. When a coating mixture comprising the catalyst is sprayed and/or applied to a substrate as a thin film in air, the catalyst is activated. For solvent-based refinish systems comprising hydroxyl and isocyanate species at high solids levels, the catalyst system therefore provides extended viscosity stability, i.e., pot life.
Claims2
A catalyst of the formula selected from the group consisting of
- R1aR2bR3cSn[CH(OH)R4]d, [R4CH(OH)]qR1sR2tSn(Sn(R5)(R6))uSnR1vR2w[CH(OH)R4]x, [R4C(O)]qR1sR2tSn(Sn(R5)(R6))uSnR1vR2w[C(O)R4]x and mixtures thereof,
- wherein R1, R2, and R3 are independently hydrogen, optionally substituted hydrocarbyl, optionally substituted aryl, halide, silyl, carboxylate, hydroxide, alkoxide group;
- R4 represents an optionally substituted hydrocarbyl or optionally substituted aryl group;
- R5 and R6 are each independently optionally substituted hydrocarbyl or alkoxide;
- a, b, and c are independently 0, 1, 2, or 3;
- d is 1 or 2;
- each q and x are independently 1 or 2
- each s, t, v and w are independently 0, 1 or 2;
- u is 0 or 1;
- q+s+t=3;
- v+w+x=3 and
- a+b+c+d=4.
9 more elements
Dependencies are inferred from the claim text.