| 摘要 |
PURPOSE:To obtain the titled polymer of excellent heat stability inexpensively, by reacting a polyisocyanate with a polycarboxylic acid (anhydride) in the presence of a specified non-aqueous organic liquid and a dispersant at an elevated pressure and a temperature higher than the atmospheric b.p. of the organic liquid. CONSTITUTION:Lauryl methacrylate or the like soluble in a non-aqueous organic liquid (D) is reacted with glycidyl methacrylate or the like having an affinity for a dispersed phase to obtain a dispersion stabilizer (E) comprising a random copolymer of a number-average MW >=6,000. A polyisocyanate (A) is mixed with a polycarboxylic acid anhydride (B) and/or a polycarboxylic acid (C) in such amounts that the ratio of total COOH groups to total isocyanate groups is 0.5-2.0 (by equivalent), the amount of component D is 90-20pts.wt. and the total of components A, B and C is 10-80pts. wt., in the presence of component D in which the formed particulate polymer is insoluble and which has a b.p. of 50-200 deg.C and at least 0.1wt% based on the weight of dispersed particles, component E soluble in component D. The formed mixture is reacted at 80-250 deg.C in an anhydrous condition in an inert gas atmosphere of an elevated pressure to obtain the titled non-agglomerated polymer of an average particle diameter of 0.05-2,000mum or above.
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