摘要 |
The present invention is directed to carboxyl-containing monomers for use in preparing a polyurethane polymers, the carboxyl-containing monomers being the reaction product of a low molecular weight polyol compound and an acid anhydride in the presence of 5-500 ppm phosphoric acid, the carboxyl-containing monomer having a viscosity in the range of 3,000 to 100,000 centipoise, and having oligomer content of less than about 30 mg KOH/g. The present invention is also directed to methods of making the above carboxyl-containing monomers, as well as prepolymers and urethane polymers containing the above carboxyl-containing monomers.
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