| 摘要 |
<p>1,177,001. Zirconium-vanadium pigments. FARBENFABRIKEN BAYER A.G. 5 Jan., 1967 [18 Jan., 1966], No. 722/67. Heading C1M. A zirconium-vanadium blue pigment is obtained by calcining at 850-1150‹ C. a mixture containing zirconium oxide, silica and vanadium oxide, optionally in the presence of a mineralizer, obtained by a process in which (i) zirconium silicate is decomposed with alkali above 800‹ C., the molar ratio of alkali metal to zirconium silicate being greater than 1, (ii) the product is mixed with water in a molar ratio water: zirconium silicate >5:1, and (iii) the resulting suspension is immediately mixed with an inorganic mineral acid, preferably H2SO4' in a ratio of more than 0À5 gm. equivalents acid per gm. atom alkali metal, oxides of vanadium or precursors thereof being added before, during or following the acid addition in an amount of 0À01-0À10 mols V2O5 per mol ZrSiO4. The alkali is preferably Na2CO3 but may also be NaOH, KOH, K2CO3 or Li2CO3. Vanadium is added preferably as V2O5 or NH4VO3 or alternatively as its oxychloride, oxyfluoride or trichloride. Fluorides, particularly sodium or potassium fluoride or zirconium oxyfluoride, may be added as mineralizers. Silica and reaction salts, such as sodium sulphate, produced in the process are not separated from the pigment herein.</p> |
