| 摘要 |
1,222,630. Polyimides; curing epoxy resins. RHONE-POULENC S.A. 15 Dec., 1969 [16 Dec., 1968], No. 61095/69. Headings C3B and C3R. [Also in Division C2] As curing agents for epoxy resins, use is made of the dianhydrides of the tetracarboxylic acids of the formula in which R denotes a hydrogen atom or a benzoyl group (see Division C2). The dianhydrides are also useful in the manufacture of polyimides containing units of the formula in which Y denotes a divalent aliphatic, cycloaliphatic, aromatic or heterocyclic radical other than a methylene group. Such polyimides may be made in known manner by reacting one of the dianhydrides with a diamine of the formula H 2 N-Y-NH 2 . A number of diamines are specified, as also are a number of additional instances of the radical Y. Examples describe the reaction of the dianhydrides with 4,4<SP>1</SP>-diaminodiphenyl ether. |
