Patent GB-916496-A (GB)
Title: Improvements in or relating to multicolour coating compositions and method for the preparation thereof
IPC: C08L77/00
Filed: 1959-04-15
Abstract: A multicolour oil-in-water emulsion coating composition comprises an aqueous solution of 0,5-20% by weight of a p  protective colloid as the continuous phase, a disperse phase comprising microscopically suspended pigment particles and a paint latex emulsion polymer of ethylenically unsaturated monomers and macroscopically suspended therein discrete particles of one or more differently coloured pigmented liquid hydrophobic organic varnish containing coating compositions, the varnish vehicles of which are mineral spirits soluble oleoresinous varnish ester-polyamide condensation products characterized by extreme thixotropy and having a molecular weight between 3000 and 9000 and formed by the reaction of (1) a polyamide of polymerized unsaturated fatty acids and an alkylene polyamine having 2-4 amine groups and (2) an oleoresinous varnish ester which is an unsaturated drying oil fatty acid ester of a polyhydric alcohol which may be modified by reaction with polycarboxylic acids. Preferred protective colloids are methyl cellulose, water-soluble ethyl cellulose, methyl-ethyl cellulose, hydroxyethyl cellulose, sodium cellulose glycollate and carboxymethyl cellulose; and water-dispersible high polymers such as sodium polyacrylate and ammonium polyacrylate.  Specified paint latex emulsion polymers are copolymers and terpolymers of monovinyl aromatic hydrocarbons, e.g. styrene and vinyl toluene, and aliphatic conjugated diolefines, e.g. butadiene, which contain not more than 67 mole per cent of the monovinyl aromatic hydrocarbon and not more than 60 mole per cent of the aliphatic conjugated diene (terpolymers may include the lower alkyl acrylates or vinyl monomers); polyvinyl acetate, vinyl acetate-vinyl alcohol copolymers, vinyl acetatedibutyl maleate copolymers, polymethyl acrylate, polyethyl acrylate and polybutadiene.  In the example, the oleoresinous varnish is prepared from soya bean oil, refined tall oil, linoleic acid, maleic anhydride, pentaerythritol and phthalic anhydride and reacted with a polyamide of dimerized fatty acid and ethylene diamine before thinning with mineral spirits; from this product a smooth paste is prepared containing additionally CaCO3 -silica pigment, molybdate orange, diatomaceous earth, lead, cobalt and manganese driers and the paste is thinned with more of the varnish vehicle plus high flash naphtha to give one liquid hydrophobic coating composition; a similar composition is prepared containing phthaloazomine blue instead of the molybdate orange; and the two liquid hydrophobic coating compositions are added to an aqueous phase containing titanium dioxide, black iron oxide, CaCO3- silica pigment, methyl cellulose, sulphonated tallow (antifoam agent), sodium orthophenyl phenate, cobalt drier and a copolymer of styrene (major amount) and butadiene, which final composition upon spraying with one pass of a spray gun gives a grey base coat with a superimposed or interspersed spatter coat of visibly large orange and blue particles.  Specification 916,497 is referred to.