| 摘要 |
1383217 Coating metals BADISCHE ANILIN-& SODA-FABRIK AG 18 May 1972 [19 May 1971] 23335/72 Heading B2E Metals are coated with at least three layers of coating compositions wherein the undercoat or at least one of the undercoats applied between the primer coat and the top coat contains, as a binder, a polymer which contains polymerised units of one or more copolymerisable olefinally unsaturated compounds having a tertiary amino group and/or the reaction product of an epoxy resin with at least one primary and/or secondary monoamine. The metal may be iron of a car body. The primer coat is, for example, an oil modified acrylate resin (based on a graft copolymer on isomerised linseed oil) on an epoxide-modifled acrylate resin, applied by electrodipping and baking. Suitable nitrogen containing polymers, which are preferably present in a copolymer in an amount of 2-30% by weight, are those containing aminoalkylamide units of the formula: where R denotes hydrogen or methyl; X denotes alkylene of 2-8 C atoms; R 1 denotes hydrogen or C 1 -C 4 alkyl and R 2 and R 3 are the same or different and denote C 1 -C 4 alkyl, and those containing aminoalkyl esters of carboxylic acids having the formula: where R denotes hydrogen or methyl R 1 and R 2 are the same or different and denote C 1 -C 4 alkyl; X denotes alkylene preferably of 2 carbon atoms or oxy-alkylene of up to 8 carbon atoms. Many examples of the above polymers are given. Other suitable N-containing monomers are the vinyl derivatives of pyridines, imidazoles, imidazolines, pyarolidones, carbazoles, pyrazoles, piperidines, and indoles. Suitable comonomers for the above N- containing compounds are lower alkylenes, vinyl aromatics, acrylic and methacrylic alkanol esters,. vinyl esters, and mixtures thereof. Many examples of these are listed. Other comonomers which may make up to 10% by wt. of the copolymer are acrylic and methacrylic polyol esters, half-esters of α, #-olefinically unsaturated dicarboxylic acids with C 1 to C 8 monoalkanols, unsaturated acids C 3 -C 5 carboxylic acids and their nitriles and amides, and acrylic acids, methacrylic acids and their amide and nitrile derivatives. Many examples are listed. Epoxy resins suitable for reaction with primary and/or secondary monoamines are the reaction products of 1 mole of bisphenol A with 2 moles of epichlorohydrin. Suitable amines are aromatic or aliphatic containing C 2 to C 17 radicals which may optionally carry hydroxyl groups. Many examples are listed. Preferably, the resin produced is modified by condensation with a carboxylic acid; many examples of such a compound are given. The. copolymer is preferably sprayed as a solution. The top coat is an automotive top coat sprayed onto the copolymer and consists, for example of a thermocurable mixture of alkyd resin and melamine resin. |
