Plural resin coated metal article

摘要

Copolymers used in coating compositions, are formed by copolymerizing methyl methacrylate with ethyl acrylate, butyl methacrylate, dimethyl itaconate, dibutyl itaconate, octyl methacrylate, a mixture of decyl and octyl methacrylate, lauryl methacrylate or hexyl methacrylate in aqueous suspensions containing tertiary dodecyl mercaptan and sodium polyacrylate, polyacrylamide, or sodium polymethacrylate. A suitable coating composition comprises solutions of copolymer of methyl methacrylate and lauryl methacrylate in toluene and methyl ethyl ketone, titanium dioxide, alkyl ammonium montmorillonite, dicyclohexyl phthalate, butyl benzyl phthalate nitrocellulose, "Cellosolve" (Registered Trade Mark) acetate, butyl acetate, toluene, xylene and a silicone solution in toluene. Specifications 826,652 and 920,809 are referred to.ALSO:Metal and glass articles, e.g. phosphatized steel panels, car bodies and containers, are coated with (1) a primer composition comprising a heat-hardenable resinous composition containing an interpolymer of an unsaturated carboxylic acid amide with at least one monomer having a CH2=C< group, said interpolymer having amido hydrogen atoms replaced by the structure: wherein R is hydrogen or a saturated lower aliphatic hydrocarbon radical having 1-8 carbon atoms, and R1 is hydrogen or a lower alkyl radical having 1-8 carbon atoms and then with (2) a polymethyl methacrylate lacquer. The coatings may be applied by spraying and then baked. Preferred types of interpolymers are described in Specifications 826,652, 920,809 and the parent Specification. Other compounds which may be present in the primer composition include alkyd esins, epoxy resins, vinyl halide resins, nitrocellulose, cellulose acetate butyrate, cellulose acetate propionate, cellulose nitrate, adducts of a hydroxyl-containing polymer and a carboxylic acid anhydride and melamine- or urea-formaldehyde resins. The top coat may be a copolymer of methyl methacrylate and ethyl acrylate, butyl methacrylate, dimethyl itaconate, dibutyl itaconate, octyl methacrylate, a mixture of decyl and octyl methacrylate, lauryl methacrylate or hexyl methacrylate. Other compounds which may be present in primer or top coating compositions include titanium dioxide, alkyl ammonium montmorillonite, dicyclohexyl and butyl beuryl phthalate, iron oxide, barium sulphate, aluminium silicate, talc, lamp black, lithopone, mica and "Cellosolve" (Registered Trade Mark) acetate.