| 摘要 |
<p>1,202,986. Ceramic pigments. FARBENFABRIKEN BAYER A.G. 10 April, 1968 [14 April, 1967], No. 17255/68. Heading C1M. Ceramic pigments, for colouring zirconiumcontaining enamel and glaze systems, consisting of zirconium/silicon/praseodymium oxide or zirconium/silicon/vanadium oxide are produced by calcining at a temperature between 850- 1300‹ C. an aqueous mixture comprising an alkali metal zirconium silicate containing 1-4 moles of alkali metal oxide, preferably Na 2 O, per mole of zirconium silicate, a pigment member consisting of a heat decomposable praseodymium or vanadium compound in an amount of from 0À1 to 10% by weight calculated as the oxide based on the zirconium silicate present, water in a molar ratio of zirconium silicate: water of from 1 : 5-1 : 20 and ammonium sulphate, sulphuric acid or mixtures thereof in an amount of from 0.8 to 1À5, acid equivalents based on the alkali metal, and a peroxide compound in a quantity of from 0À1 to 10 parts by weight per part of the corresponding element praseodymium or vanadium. A mineralizer such as sodium chloride or fluoride may be present. The peroxide compound may be hydrogen peroxide, its aqueous solutions and derivatives preferably Na 2 O 2 , other alkali metal peroxides, alkaline earth metal peroxides, peroxysulphuric and peroxydisulphuric acids and their alkali metal and ammonium salts.</p> |
