GB662749A - Improvements in or relating to a composition for and method of protecting electrical equipment - Google Patents

Abstract

An insulating and moisture-proofing composition comprises 40-50 per cent polyvinyl chloride, 25-35 per cent pitch and 15-35 per cent plasticizer. Specified plasticizers are chlorinated aromatic hydrocarbons such as chlorinated diphenyl and dibenzyl, and phosphoric, phthalic, sebacic and adipic esters, particularly methylcyclohexyl adipate. 0.1-1 per cent of a fungicide may be added, specified are phenylmercurynitrate, o - phenylphenol, pentachlorphenol, iron dithiocarbamate, tetramethyl thiuram disulphide, and the copper salt of hydroxyquinoline. The composition is prepared by incorporating finely-divided polyvinyl chloride in a solution of pitch in plasticizer, and may be used for the protection of electrical equipment by application to articles, preferably pre-heated to 50-60 DEG C., directly, in strip form, or coated on a tape of glass fibre or polyvinyl chloride, followed by baking at a temperature not exceeding 80 DEG C.ALSO:Elements of electrical equipment are protected against the action of moisture, and the growth of micro-organisms by coating them with a composition comprising 40-50 per cent of polyvinyl chloride, 25-35 per cent of pitch, and 15 to 35 per cent of a plasticizer, such as a chlorinated aromatic hydrocarbon, or an ester of phosphoric, adipic, sebacic or phthalic acid 0.1-1 per cent of a fungicide may also be included, such as phenyl mercury nitrate, orthophenylphenol, pentachlorophenol, iron lithiocarbamate, tetramethyl thiuram disulphide, and the copper salt of hydroxyquinoline. Articles coated with the composition are baked at a temperature not exceeding 80 DEG C. to harden the coating, and a waterproof varnish, particularly a varnish having an organo-silicon base, is then applied. Surface waterproofing can also be obtained by exposure of the coated article to the vapours of organo-silicon compounds.