| 摘要 |
A water-reducible polyester resin for use in producing urethane coatings comprises the reaction product of (a) hexahydrophthalic anhydride, trimellit ic anhydride or phthalic anhydride; (b) 1,4-cyclohexane dimethanol or trimethylolpropane; and (c) a polyethylene glycol, a methoxy polyethylene glycol or trifunctional polyethylene glycol having a molecular weight no greater than approximately 1050; the reaction product having a functionality between approximately 2 and 2.6. Such a polyester resin may additionally contain a nonionic surfactant which is a polyoxyalkylene derivative of ethylene glycol, ethylene oxide, propylene glycol and propylene oxide having terminal hydroxy groups and a molecular weight between approximately 300 and 10,000. A urethane coating for various substrates comprises the reaction product of a blend of the two above-noted polyester resin products and an aliphatic diisocyanate such as a trimer of hexamethylene diisocyanate.</SDOA B>
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