| 摘要 |
1,104,324. Capacitors. UNION CARBIDE CORPORATION. 19 July, 1965 [20 July, 1964], No. 30620/65. Heading H1M. The dielectric of a capacitor, stated to show substantially invariable electrical characteristics over a wide temperature range, comprises a solid thermoplastic polyarylene polyether containing the repeating units O-E-O-E<SP>1</SP> wherein E is a dihydric phenol residue and E<SP>1</SP> a benzenoid residue having an inert electronwithdrawing group in at least one of the positions ortho or para to the bond linking the residue to the ether oxygen, both residues being bonded to the ether oxygens through aromatic carbon atoms. E may be a mono-, di- or polynuclear phenol residue optionally bearing inert substituents such as halogen, alkyl or alkoxy. Preferably E is a bisphenol wherein the nuclei are separated by -CO-, -O- -S-, -S-S-, -SO 2 -, or divalent organic radicals. In the E<SP>1</SP> residue the electron withdrawing groups may be -SO 2 -, -CO-, -CH 2 CH-, -SO-, -N=N-, -C 2 F 4 - or phosphine oxides linking two benzene rings or nitro, phenylsulphone, alkylsulphone, cyano, -CF 3 , nitroso or hetero-nitrogen substituents. The polymers are prepared by the reaction between alkali metal salts of a dehydric phenol and a dihalobenzenoid compound in an anhydrous solvent. Mixtures of monomers may be employed. The capacitor may be of the flat, stacked type or rolled. The polymer layer may be a free film or bonded to the electrode metal e.g. by casting the film or vapour deposition of the metal, or both techniques may be employed. The capacitor may be encapsulated with the same polymer, or with wax or epoxy resin. |
