| 摘要 |
<p>1479054 Chromating metal surfaces PYRENE CHEMICAL SERVICES Ltd 20 Sept 1974 [21 Sept 1973] 40985/74 Heading C7U A chromating composition comprises hexavalent chromium and carbon in dispersed form in which the CrO 3 :C ratio is from 0À02:1 to 1:1. The composition may also include phosphate ions and an organic resin. In an example the composition comprises 1% carbon, 1% acrylic resin, 0À5% phosphate, 0À3% CrO 3 , 0À1% zinc oxide, pH 1À8. In another example the composition includes SiO 2 , the metal surface, e.g. steel, may be pre-heated.</p> |
