| 摘要 |
1,272,201. Resin-treatment of fabrics. UPJOHN CO. 2 Jan., 1970 [17 Jan., 1969], No. 302/70. Heading D1P. [Also in Divisions C2 and C3] Woven fabrics are impregnated with cyclic polymides prepared by reacting a polyisocyanate with a polycarboxylic derivative containing at least two carboxylic moieties one of which is an intramolecular anhydride group, the remainder being free carboxy groups, or inter- or intra-molecular anhydride groups, in the presence of a catalyst being MOH(I) # M # and/or R-N-CONHR<SP>1</SP> (II), wherein R and R<SP>1</SP> each represent C 1-12 optionally substituted hydrocarbyl, and MOH is such as to react with the polyisocyanate to form a urethane which decomposes with the elimination of CO 2 at # 150‹C. M may be H; C 4-12 tert-alkyl; Ar-Hg-; Ar 3 Pb-; Ar 3 Si-; or Ar 3 C-; Armeans a C 6-12 aryl radical. An example describes the preparation of a polyimide from 4,4' - methylenebis (phenylisocyanate) and benzophenone - 33,4,4'-tetracarboxylic acid dianhydride. |
