| 摘要 |
<p>Degreased metal articles are primed by applying a dispersion of a fully polymerised polyamide in a butadiene-styrene copolymer, a butadiene-acrylonitrile copolymer, or a cyclorubber which copolymer or cyclorubber is polymerised only to the extent that it is a liquid or is soluble in an organic solvent, and completing the polymerisation of the copolymer or cyclorubber by heating. Suitable polyamides are polyhexamethyleneadipamide, polycaprolactam, polyamides prepared by the condensation of hexamethylene diamine and sebacic acid, or mixtures thereof, and the preferred polyamide is polyundecanamide. The metal article may be the super-structure of cars, rail and industrial vehicles, household machines. The dispersion may be applied by spraying, dipping or electrostatically. The primed metal may be coated with an undercoat and a top coat of paint. In the Examples, degreasing involves treatment of the metal article with trichloroethylene and caustic soda, and in (2) a degreased motor vehicle body superstructure is coated electrostatically with a butadiene-styrene polymer dissolved in a mixture of aromatic and aliphatic hydrocarbons before a dispersion of polyundecanamide in butadiene-styrene copolymer applied electrostatically; in (5) a metal panel is degreased, roughened and dried before treatment.</p> |
