GB815793A - Improvements in or relating to coating compositions containing metal particles - Google Patents

Abstract

Metallic paints comprise plate-like particles of metal between 3 and 15 millionths of an inch thick in a suitable medium. The metal may be for example aluminium, chromium, platinum, silver, copper, gold, tin, palladium, titanium, zinc, antimony or nickel. The medium may be a conventional linseed-oil paint, an asphalt paint, cellulose nitrate, a vegetable-oil-modified alkyd resin, an epoxy resin modified with ureaformaldehyde or phenol-formaldehyde or esterified with fatty acids, or styrenated, a phenolaldehyde condensation product, an acrylic resin, an inorganic medium such as a silicone, water-glass or a titanium ester resin, a mixed organic-inorganic medium, an aqueous dispersion of latices such as butadiene-styrene copolymers, silicones, polyethylene, polytetrafluorethylene, or vinyl or vinylidene chloride or acetate. The cellulose nitrate formulations may contain modifiers such as dammai, gum elemi, dewaxed bleached shellac, maleic-modified resins, pentaerythritol-rosin esters, phthalic-modified rosin, amino resins, acrylic ester resins, polyvinyl chloride or acetate resins or alkyd resins. Suitable plasticizers mentioned are alkyl ricinoleates, blown castor oil, polyvinyl butyral, ethyl cellulose, chlorinated phthalate esters, tricresyl phosphate, trichloro ethyl phosphate, di-and poly-esters of phosphoric, sebacic and phthalic acid, e.g. di-octyl-phthalate, di-octylphosphate or tri-octyl phosphate. Ethyl cellulose alone, plus the metallic particles gives a suitable material for coating fabrics. The metallic particles may also be incorporated in inks such as printing, rotogravure or xerographic inks containing maleic-modified resins from rosin, glycerol or pentaerythritol. The metallic particles are formed by depositing a film of the required thickness on a metal-releasing layer which is then softened or dissolved by solvents, and subsequently breaking up the film by agitation with an inert liquid or by scrubbing with a wire brush so that a substantial proportion will pass a 400-mesh sieve. Examples are given of preparing a suitable metal film by vacuum deposition and by electro-deposition. In the latter instance, a series of layers can be deposited, one on top of another, if the current is reversed for a few seconds between depositions so as to facilitate separation of the layers. The metal particles may be coloured by dyes. Specification 545,962 is referred to.ALSO:Metallic paints comprise plate-like particles of metal between 3 and 15 millionths of an inch thick in a suitable medium. The metal may be, for example, aluminium, chromium, platinum, silver, copper, gold, tin, palladium, titanium, zinc, antimony or nickel. The medium may be a conventional linseed-oil paint, an asphalt paint, cellulose nitrate, a vegetable-oil-modified alkyd resin, an epoxy resin modified with urea-formaldehyde or phenol-formaldehyde or esterified with fatty acids, or styrenated, a phenolaldehyde condensation product, an acrylic resin, an inorganic medium such as a silicone, waterglass or a titanium ester resin, a mixed organic-inorganic medium, an aqueous dispersion of latices such as butadiene-styrene copolymers, silicones, polyethylene, polytetrafluorethylene, or vinyl or vinylidene chloride or acetate. The cellulose nitrate formulations may contain modifiers such as dammar, gum elemi, dewaxed bleached shellac, maleic-modified resins, pentaerythritol-rosin esters, phthalic-modified rosin, amino resins, acrylic ester resins, polyvinyl chloride or acetate resins or alkyd resins. Suitable plasticizers mentioned are alkyl ricinoleates, blown castor oil, polyvinyl butyral, ethyl cellulose, chlorinated phthalate esters, tricresyl phosphate, trichloro ethyl phosphate, di- and poly-esters of phosphoric, sebacic and phthalic acid, e.g. di-octylphthalate, di-octyl-phosphate or tri-octyl phosphate. Ethyl cellulose alone, plus the metallic particles, gives a suitable material for coating fabrics. The metallic particles may also be incorporated in inks such as printing, rotogravure or xerographic inks containing maleic-modified resins from rosin, glycerol or pentaerythritol. Examples are given of compositions including (1) cellulose nitrate, coconut alkyd resin, dibutyl phthalate, aluminium particles, pigments and solvents; (2) soya alkyd resin, melamine resin, aluminium particles, pigments and solvents; each of these is compared with similar compositions using aluminium paste; and (3) chinawood oil modified, soya oil modified, pentaerythritol phthalate alkyd resin, butanol modified urea-formaldehyde, oil-modified phenol-formaldehyde, cobalt naphthenate, pigments and solvents. Specification 545,962, [Group III], is referred to.ALSO:Metallic paints comprise plate-like particles of metal between 3 and 15 millionths of an inch thick in a suitable medium. The metal may be aluminium, chromium, platinum, silver, copper, gold, tin, palladium, titanium, zinc, antimony or nickel. The metallic particles are formed by depositing a film of the required thickness on a metal-releasing layer which is then softened or dissolved by solvents, and subsequently breaking up the film by agitation with an inert liquid or by scrubbing with a wire brush so that a substantial proportion will pass a 400-mesh sieve. The metal particles may be coloured by dyes. In an example, pieces of aluminium are hung on tungsten filaments in a chamber which is then evacuated to a pressure of less than one micron of mercury. The filaments are electrically heated and workpieces previously coated with a synthetic resin metal-releasing layer are exposed to the aluminium vapour so formed. The resultant metal film was subsequently scraped off and reduced to particles. Specification 545,962 is referred to.