| 摘要 |
Polyester of formula (-CO-R')a-CO.O-R-O-)n (R' is is phenylene in which the H-atoms may be halogen-substituted, or opt. satd. 1-10C alkylene; a is zero or 1, n is an integer 30-300, pref. 50-225, and R is an org. residue consisting up to 99 mole-% of a chlorinated phenylene residue or two chlorinated phenylene residue, a methylene group or a sulphone group oor an oxygen atom optionally being placed between the chlorinated phenylene residues; and the rest (up make to a total of 100 mole-%) corresponding to the formula:- O - C6H4YC6H4- (where Y is -O-, -CO-, -S-, -SO2- or an optionally alkyl- or phenyl- substd. methylene residue. The carbonyl- or carboxyl- groups of the polyester may be in p- or m- position on the phenylene residue R'. Polyesters are suitable for use as electrically insulating foils, films, coatings, impregnations. The polyester is produced by reaction of e.g. 2,2-bis-(4-hydroxyphenyl)-propane, terephthalic acid dichloride, isophthalic acid dichloride and 2,2-bis-(3,5-dichloride and 2,2-bis-(3,5-dichloro-4-hydroxyphenyl)-propane. |
