Patent GB-929134-A (GB)
Title: Coated articles
IPC: B05D7/14
Filed: 1961-08-11
Abstract: Articles are coated with outer and underlying layers formed from different resinous compositions, the underlying composition being heathardenable and comprising an interpolymer of an unsaturated carboxylic acid amide with at least one monomer having a CH2=C< group, amido hydrogen atoms of the interpolymer being replaced by the structure: <FORM:0929134/III/1> wherein R is hydrogen or a hydrocarbon radical and R1 is hydrogen or a lower alkyl radical. Such interpolymers are described in Specification 826,652 and are preferably derived by treating with formaldehyde a copolymer of acrylamide, styrene, ethyl acrylate and, optionally, acrylic or methacrylic acid.  The interpolymers may also be prepared by the method described in Specification 920,809.  The underlying coating may also contain an epoxy resin, as described in Specifications 826,653 and 842,641, ester gum, a butylated formaldehyde condensate of butenyl phenol, polyvinyl chloride, a polyamide derived from linoeic acid and ethylene diamine and a maleic anhydride modified butadiene-styrene copolymer.  The outer coating composition is preferably based on a vinyl chloride-vinyl acetate copolymer, but may also consist of other vinyl chloride polymers, polydiolefins, melamine-formaldehyde condensation products, phenolic resins, epoxy resins, alkyd resins, cellulosic resins and shellac.  Both coating compositions are used in the form of solutions in organic solvents applied by spraying or roller-coating.  After the application of the underlying coating it is baked, e.g. at 400 DEG F., and the outer coating is then applied.  The process is used in coating sheet metal, particularly the interior surfaces of beverage containers. Specification 788,397 also is referred to.ALSO:Coating compositions comprise (1) an interpolymer of an unsaturated carboxylic acid amide with at least one monomer having a <FORM:0929134/IV(a)/1> group, amido hydrogen atoms of the interpolymer being replaced by the structure <FORM:0929134/IV(a)/2> wherein R is hydrogen or a hydrocarbon radical and R1 is hydrogen or a lower alkyl radical, and (2) other resinous substances.  The interpolymers may be made by the methods described in Specifications 826,653 and 920,809.  Preferred interpolymers are derived from a mixture of acrylamide, styrene, ethyl acrylate and, optionally, acrylic or methacrylic acid. There are described compositions of such interpolymers with: (a) ester gum, (b) a condensation product of epichlorohydrin and bisphenol, (c) a mixture of epoxy resin and ester gum, (d) a mixture of a butylated formaldehyde condensation product of butenylphenol, polyvinyl chloride and an epoxy resin, (e) a mixture of an epoxy resin and the condensation product of linoleic acid and ethylene diamine, (f) polyvinyl chloride, with or without ester gum, and (g) a maleic anhydride modified butadiene-styrene copolymer.  These compositions are used in the form of solutions in solvents and solvent mixtures comprising butanol, methyl isobutyl ketone, diethylene glycol monobutyl ether, toluene, xylol, and mixed aromatic hydrocarbons. Specifications 788,397 and 842,641 also are referred to.