| 摘要 |
1,194,751. Coated steel sheets. FUJI IRON & STEEL CO. Ltd. Oct. 2, 1967 [Sept. 30, 1966; Oct. 26, 1966; Aug. 18, 1967], No. 44838/67. Heading C7B. [Also in Divisions B2 and B3] Steel sheet is treated by coating the surface with zinc, lead, or a zinc or lead based alloy, and applying a further coating of a higher carboxylic acid or a mixture thereof with an amine, the higher carboxylic acid or mixture thereof being solid at ambient temperature. The term "higher carboxylic acid" is defined as any carboxylic acid having eight or more carbon atoms e.g. saturated fatty acids having no less carbon atoms than caprylic acid, corresponding unsaturated fatty acids, hydroxy carboxylic acids, naphthenic acid, dicarboxylic acids, natural products such as animal oil fatty acids, hardened animal oil fatty acids, vegetable oil fatty acids, hardened vegetable oil fatty acids, petroleum acids. Examples of specific acids are given. A thin layer of metallic-soap is said to be formed by reaction of the metallic coating with the higher carboxylic acid at the interface therebetween. The treatment may form the preliminary lubricating step in a process of forming steel sheet e.g. by press forming, drawing and stretching. The metallic coating may be applied by electro-plating, chemical plating or by hot-dip plating. A layer of hydrated metal oxide e.g. hydrated chromium and/or silicon oxide may be applied to the metallic coating before application of the higher carboxylic acid to improve adherance and reduce rust formation. Amines mentioned are lauryl, cyclohexyl, di-iso-propyl, di-cyclohexyl, triethyl amines, di-amino-propane, oxazines and imidazoles. The higher carboxylic acid may be heated or dissolved in an organic solvent and applied to the steel plate by roller, spray, brush, mop, dip or flow coating or by spreading and reflowing by heating with an infrared beam or hot air. One or both sides of the steel sheet may be treated. The higher carboxylic acid coating can be removed by an alkaline degreaser or an organic solvent, and the metallic coating may if necessary be removed by an acid or strong alkaline solution after the forming operation. |
