| 摘要 |
<p>1512975 Pigment BAYER AG 24 Oct 1975 [26 Oct 1974] 43782/75 Headings C1A and C1N A temperature-stable inorganic pigment based on pseudo-brookite-titanium dioxide having a composition Fe 2 TiO 5 xTiO 2 where x is less than 15 is prepared by adding at least one compound of at least one metal selected from Li, Na, K, Mg, Zn, Ca, Al, Cu, V, Cr, Mn, Co and Ni in the oxide form, in a quantity sufficient to provide 0À1-10% by weight of metal based on the pigment to a suspension of finely divided iron oxide and/or iron oxide hydroxide and/or iron hydroxide and/or iron carbonate and finely-divided titanium dioxide and/or titanium-dioxide hydrate, separating the aqueous phase of the mixed suspension, and calcining the residue at 600-1100‹C The doping elements may be added in the form of a salt, oxide or hydroxide or in elemental form as a solid or a solution or a suspension. In a preferred embodiment, an aqueous titanium hydroxide suspension is introduced into an aqueous iron (II) sulphate solution, and the iron is precipitated as iron hydroxide with NaOH solution, and the sodium sulphate thus formed may be used as the doping agent.</p> |
