| 摘要 |
<p>1,168,568. Basic lead sulphate/carbonate pigments. OSKAR NEYNABER & CO. A.G. 29 March, 1967 [6 April, 1966], No. 14277/67. Heading C4A. Mixed pigments of basic lead carbonate and basic lead sulphate are produced by adding H 2 SO 4 and CO 2 to an aqueous lead monoxide slurry in amounts less than the stoichiometric equivalents of the monoxide, separating washing and drying the coprecipitate, and thereafter submitting it to a heating step at 150-300‹ C. in the presence of one or more decomposition catalysts. The catalysts may be C 1 -C 6 carboxylic acids, e.g. acetic or propionic acids, or lead salts thereof. Preferred mixtures contain 50-90% by wt. basic lead sulphate.</p> |
