| 摘要 |
<p>1482457 Phosphatizing composition and method; electro-coating BRUGAROLAS SA and F GRUBER 22 Oct 1974 [22 Oct 1973 10 May 1974] 45649/74 Headings C7B and C7U A phosphatizing composition comprises (a) a solution of a Zn, Mn, Fe or Pb primary phosphate, (b) an organic reducing agent containing a hydroxy, amino, aldehyde, or keto-group (c) a resin which is not an organic reducing agent as under (b), (d) chromic acid or a salt thereof, ingredient (d) being present in amount sufficient to at least partially oxidize ingredient (b) with consequent production of trivalent Cr ions. In a method of treating metal, e.g. Fe, Al, or Zn, compound (a) above is treated with reducing agent (b), the resulting composition is oxidized with chromic acid, salt; the composition is applied to the metal surface and dried; application may be electrolytic using the metal as cathode, or the surface may be sprayed or immersed hot or cold. The reducing agent may be a carbohydrate, cellulose, starch, a polyalcohol, an alcohol, aldehyde, ketone or amine; it may be solubilized with H 3 PO 4 , borophosphoric acid, H 3 PO 4 and alkylvinyl- or polyvinyl-phosphoric acids. The resin may be an acrylic or urea-formaldehyde resin. Other ingredients of the composition may be:- tannic acid, acrylic acid, polycarboxylic or polyhydroxycarboxylic acids, accelerators such as fluorides, nitrates, nitrites, oxalic acid, boric acid, fluosilicates, picric acid or EDTA, organic hardeners and plasticizers, a list is given, corrosion inhibitors, e.g. borates, amines, ethoxylated amines, nitrophenols, drying agents, anti-foaming agents, and chelating agents.</p> |
