GB817074A - Insulating material - Google Patents

Abstract

A heat-conducting electrical-insulating material consists of metal powder, e.g. copper or aluminium, embedded in a matrix of rubber, the particles of the metal powder each being coated with an electrically-insulating resin. According to an example, the material comprises 75 per cent by weight copper powder of 100 B.S.S. mesh, coated with 5 per cent silicone resin and embedded in a matrix of silicone rubber (20 per cent). A finely-divided ceramic material such as silica, calcium carbonate, aluminium oxide, china clay, or mica may be incorporated into the resin solution to produce a material for withstanding considerable mechanical pressure. In preparation the metal powder is mixed with a solution of the resin until the majority of the solvent has evaporated, the mixture is spread out in thin layers for the remainder of the solvent to evaporate, is lightly ground and then incorporated with the rubber, after which a vulcanizing catalyst may be added.ALSO:A heat-conducting electrical-insulating material consists of metal powder, e.g. copper or aluminium, embedded in a matrix of rubber, the particles of the metal powder each being coated with an electrically-insulating resin. According to an example, the material comprises 75 per cent. by weight copper powder of 100 B.S.S. mesh, coated with 5 per cent. silicone resin and embedded in a matrix of silicone rubber (20 per cent.). A finely-divided ceramic material such as silica, calcium carbonate, aluminium hydroxide, china clay or mica may be incorporated into the resin solution to produce a material for withstanding considerable mechanical pressure. In preparation the metal powder is mixed with a solution of the resin until the majority of the solvent has evaporated, the mixture is spread out in thin layers for the remainder of the solvent to evaporate, is lightly ground and then incorporated with the rubber after which a vulcanizing catalyst may be added.