Abstract: A solvent-soluble siloxane polyimide comprising a copolymer obtained by reaction of a diamine compound mixture comprising a diaminopolysiloxane and an alicyclic diamine with an aromatic tetracarboxylic acid anhydride, followed by polyimidization reaction of the resulting polyamic acid forms a heat-resistant adhesive by adding an epoxy resin, a diamine-based curing agent and an organic solvent thereto, The formed adhesives show a distinguished heat-resistant adhesiveness when the resulting siloxane polyimide soluble in ordinary organic solvents is used as a main component of the adhesive for bonding between a base material and a copper foil of a flexible printed substrate. By further addition of a fluorinated resin to the heat-resistant adhesive, the adhesiveness can be more improved.

Abstract: (1) CF.sub.2 .dbd.CFO(CF.sub.2).sub.n COOR is allowed to react with chlorine or bromine to obtain CF.sub.2 XCFXO(CF.sub.2).sub.n COOR', (2) which is allowed to react with a Grignard reagent MgBrC.sub.6 H.sub.3 (CH.sub.3).sub.2 to convert the terminal group to --COC.sub.6 H.sub.3 (CH.sub.3).sub.2, (3) followed by reaction with diethylaminosulfur trifluoride to convert --COC.sub.6 H.sub.3 (CH.sub.3).sub.2 to --CF.sub.2 C.sub.6 H.sub.3 (CH.sub.3).sub.2, (4) followed further by oxidation of the resulting methyl group and by esterification to convert the methyl group to --CF.sub.2 C.sub.6 H.sub.3 (COOR).sub.2 and (5) followed by dechlorination or debromination to obtain CF.sub.2 .dbd.CFO(CF.sub.2).sub.n CF.sub.2 C.sub.6 H.sub.3 (COOR).sub.2. The resulting bifunctional vinyl ether compound having an aromatic ring is a novel compound and can be used as a copolymer component for fluorine-containing elastomers.