| 摘要 |
PURPOSE:To obtain the titled varnish having excellent storage stability and resistance to water and solvents, by adding water, a basic compd. and a water- soluble org. solvent to a urethane resin derived from a urethane prepolymer and a polyamine compd. CONSTITUTION:A polyhydric alcohol contg. COOH groups and optionally a polyester polyol having an MW of 500-3,000 are reacted with a polyisocyanate contg. at least two isocyanate groups at its terminals in a quantity by equivalent of isocyanate group larger than that of OH group at 60-100 deg.C for 2-10hr to obtain an isocyanate group-terminated urethane polymer contg. COOH groups. The resulting polymer is reacted with a polyamine compd. contg. at least two primary or secondary amino groups in a ratio of isocyanate equivalent to amino equivalent of 1.0/0.2-1.0 to obtain a urethane resin. Water, a basic compd. in such a quantity as to give a ratio of base equivalent to COOH group equivalent of 0.25-1.5 and a water-soluble org. solvent in a quantity of 10-40wt% of the resulting varnish are added to said urethane resin, and the mixture is stirred.
|
