| 摘要 |
1288590 Coating TOKYO SHIBAURA DENKI KK 16 Dec 1969 [17 Dec 1968] 61302/ 69 Heading B2E [Also in Division C3] Electrical insulators extending between metal parts of different potential are coated, e.g. by spraying or brushing, with insulating coating compositions comprising (1) a coating material which is hydrophilic and does not hinder ion migration, (2) a cation exchange resin, (3) an anion exchange resin and (4) a solvent for (1), to prevent deterioration of to restore the insulating characteristics of the insulator. The coating material may be a natural resin, e.g. shellac, rosin or copal; a cellulose derivative, e.g. cellulose acetate, cellulose acetate/butyrate or ethyl cellulose; or a synthetic resin, e.g. polyvinyl chloride, polyvinyl acetate or an alkyd, silicone or acrylic resin. Specified cation exchange resins are sulphonic acid, carboxyl and phenol group containing resins; and specified anion exchange resins are quaternary ammonium and amine group containing resins. The compositions may also contain conventional drying, setting and dispersing agents, plasticisers and pigments. In examples insulating plates of phenolic resin laminations carrying copper electrodes bolted thereon are sprayed with compositions comprising styrene/ divinyl benzene ion exchange resins having carboxylic and amine groups, ethyl acetate, butyl acetate, isobutanol and toluene and as coating material (A) acrylic resin, (B) nitrocellulose, rosin, diol/phthalate/fatty acid alkyd resin and phthalate ester plasticiser, and (C) vinyl acetate/vinyl chloride copolymer; and insulating plates carrying silver-plated copper terminals are brushed with compositions comprising the above ion exchange resins and solvents, dimethyl ketone, glycol monoethyl ether and as coating material (D) cellulose triacetate and rosin and (E) acrylic resin and rosin. |
