Patent GB-599277-A (GB)
Title: Composition of vinyl co-polymers
IPC: C09D127/06
Filed: 1945-07-20
Abstract: A coating composition comprises an organic solvent with either a copolymer containing by weight 70-96.5 per cent vinyl chloride, 2-20 per cent vinyl alcohol and 1.25-25 per cent vinyl acetate or a copolymer containing 80-95 per cent vinyl chloride, 1.5 to 10 per cent vinyl acetate, 0.2-10 per cent maleic acid and 1.0-15 per cent vinyl alcohol, preferably together with a film-forming ingredient. Suitable solvents include esters, ketones, alcohols, ether alcohols, glycols and polyglycol ethers, to which may be added hydrocarbon thinners.  In one type of coating composition, the three component copolymer may be the sole resinous constituent with plasticizers such as castor, linseed or tung oil or castor oil derivatives such as butyl acetyl ricinoleate and the methyl, ethyl and butyl esters of acetylated polymerized ricinoleic acids.  In a second type of coating the copolymers are blended with thermoplastic resins such as polyvinyl chloride, polyvinyl acetate, copolymers of vinyl chloride with vinyl acetate, ethyl or butyl acrylate or vinylidene chloride, polybutyl acrylate or methacrylate, hydrolysed polyvinyl acetate, polyvinyl acetals, polyterpenes and natural resins. Heat-hardening coatings are produced by blending the copolymers of vinyl chloride, vinyl acetate and vinyl alcohol with phenolformaldehyde resins, drying oil-modified phenolformaldehyde resins, urea-formaldehyde and melamine - formaldehyde resins and alkydmodified aminoplasts. Glyoxal may be added together with the phenol-formaldehyde resins. Heat-hardening coatings are also produced by baking the copolymer with a resinous material containing free carboxyl groups, e.g. copolymers of styrene with maleic anhydride or copolymers of vinyl chloride, vinyl acetate and maleic acid.  Alternatively the copolymers may be mixed with non-resinous ingredients with which they react, hardening being effected by baking or air-drying. Such ingredients include copper sulphate, copper chromate, potassium dichromate, zinc chromate, chromium acetate, chlorine and chlorine-releasing compounds such as sulphur chloride, glyoxal, mixtures of glyoxal tetraethyl acetal or phosphoric acid, and furfural.  Rubber accelerators such as aniline, diphenyl or triphenyl guanidine, dibenzylamine, p-benzoquinone dioxime and dibenzoparaquinone dioxime may also be used as insolubilising agents as well as dibasic acids such as maleic or succinic acids. Other compounds which undergo chemical change on heating or air-drying may be added and include high boiling plasticisers containing vinyl or allyl groups which polymerize on heating, and synthetic rubbers such as butadieneacrylonitrile copolymers which vulcanize on baking. Modified or unmodified alkyd resins which may contain stabilizing pigments, e.g. lead sulphate and stabilizing resins, e.g. ureaformaldehyde or phenol diethanolamine phthalate resins, may also be added.  Solutions of these three-component copolymers, or the copolymers themselves, may be emulsified in water with the aid of agents such as partially hydrolysed polyvinyl acetate.  The four-component copolymer may be obtained by hydrolysis or alcoholysis of a copolymer of vinyl chloride, vinyl acetate and maleic acid.  To compensate for esterification of carboxyl groups during alcoholysis, the maleate ester group may be later hydrolysed.  The insolubility of these copolymers may be increased by adding melamine- or phenol-formaldehyde resins and the coating may later be baked. Glyoxal may also be added to the phenolic resin. Plasticisers such as castor oil, triethylene glycol dioctoate, di(2-ethylhexyl) phthalate, dibutoxy ethyl phthalate, tricresyl phosphate and tri(2-ethylhexyl) phosphate may be included in these coatings as well as heat stabilizers such as basic lead sulphate, litharge, and lead and calcium stearates.  Both compositions may include paraffin waxes and terpene resins such as polymerized pinene and limonene, and pigments, e.g. titanium dioxide and carbon black and cobalt and lead driers may also be added.