Patent GB-476042-A (GB)
Title: Improvements in and relating to coating compositions and the coating of surfaces
IPC: C08L89/00
Filed: 1936-03-27
Abstract: A coating-composition comprises a suspension of finely divided graphite in a solution of an emulsoid colloid and an acid of chromium or a salt of an acid of chromium.  The finely divided graphite employed is preferably colloidal or semi-colloidal. Specified emulsoid colloids are gelatine, albumen and isinglass, and alkali metal bichromates are mentioned as suitable salts of an acid of chromium.  Fillers, such as the oxides or hydroxides of zinc, manganese, aluminium, beryllium and magnesium, or the finely divided metals themselves, may be added.  When the applied and dried coating is subjected to the action of actinic light, a hardening and stabilizing of the emulsoid colloid takes place. The film of coating-composition may also be hardened by heating, e.g. to 100 DEG C., with or without exposure to light.  The coating-composition may be applied to electrically nonconducting materials to prepare them for electroplating, and parts of electrical insulators may be coated therewith where, otherwise, metallized surfaces would be used. Switch blades and electrical contacts generally may be coated with the composition to inhibit oxidation.  Electrical resistance elements may be made by applying one or more coats of the composition to a paper or other suitable base.  Metals, such as nickel, silver, steel, and readily oxidizable metals or alloys may be coated with the composition to render them resistant to oxidation and corrosion. Furring or corrosion of boilers or of electric immersion heaters may be prevented or minimized by an application of the coating-composition.  The composition may be applied, e.g. to screws, pistons and steel rams, either as a lubricant, or to render them suitable for retaining a lubricating film.  Fabrics may be made electrically conductive by impregnation with the composition, and a similar treatment of asbestos gaskets prevents their adherence to metal surfaces.  Improved heat transference in the cylinder head of an internal-combustion engine may be obtained by coating the interior of the head with the composition.  The insides of moulds for moulding thermoplastic materials, such as ebonite and phenolformaldehyde resins, may be coated with the composition to prevent flaking. According to the Provisional Specification, finely divided materials, such as carbon other than graphite, and metallic colloids, may be used in addition to or in substitution for the finely divided graphite.ALSO:The insides of moulds for moulding thermoplastic materials, such as ebonite and phenolformaldehyde resins, are coated to prevent flaking with a composition comprising a suspension of finely-divided graphite in a solution of an emulsoid colloid and an acid of chromium or a salt of an acid of chromium.  The film of coating may be hardened by the action of actinic light or by heating with or without exposure to light.  According to the Provisional Specification, finely divided materials, such as carbon other than graphite, and metallic colloids, may be used in addition to or in substitution for the finely-divided graphite.