摘要:
Pyrogenically prepared, structurally modified titanium dioxides or pyrogenically prepared, structurally modified titanium-dioxide mixed oxides are prepared by the titanium dioxides being treated with a ball mill and optionally being subsequently ground. They may be employed in sunscreen formulations.
摘要:
Pulverulent materials which contain surface-modified and structure-modified pyrogenically prepared metalloid or metallic oxide for the purposes of improvement.
摘要:
Metal oxide particles having a metal oxide core and a silicon dioxide coating have a low structure. The particle are produced by a base dissolved in water being added under agitation to a dispersion comprising a metal oxide, at least one compound of the type XnSi(OR)4−n, and water, the reaction product being separated out, optionally washed with water and dried. The metal oxide particles coated with silicon dioxide may be used in sun screening agents and in chemical-mechanical-polishing (CMP) applications.
摘要:
Iron oxide-silicon dioxide-titanium dioxide mixed oxide is produced by burning vaporizable compounds of iron, silicon and titanium together in a hydrogen/oxygen flame. The mixed oxides may be used as UV absorbers in cosmetics.
摘要:
Microporous and mesoporous metal silicates are prepared by the hydrothermal reaction of a silicon and metal source in the presence of a template. The choice of raw materials influences the purity and hence the catalytic activity of the products. A pyrogenic mixed oxide is used as the silicon and metal source. Prepared products have the composition (SiO2)1-x(AmOn)x, where A is Ti, Al, B, V or Zr and x is 0.005 to 0.1. Shaped objects of the microporous and mesoporous metal silicates are obtained directly by using a shaped object of the pyrogenic mixed oxide. The products obtained are used as oxidation catalysts.
摘要:
Oximes are prepared by reacting carbonyl compounds, hydrogen peroxide and ammonia in the presence of a catalyst system comprising a catalyst comprising titanium, silicon and oxygen and a cocatalyst comprising an acidic solid comprising an organic or inorganic support material, where either the support material itself has Lewis-acid or Brönsted acid properties, or Lewis-acid or Brönsted-acid functional groups are applied to the support material.
摘要:
Titanium-containing molecular sieves are prepared by adding an aqueous template solution to a mixture of tetraalkyl orthosilicate and tetraalkyl orthotitanate, crystallizing the reaction mixture in an autoclave and separating the solid obtained optionally, the solid is washed and calcined. The titanium-containing molecular sieves can be used as catalysts, inter alia in the epoxidation of olefins.
摘要:
Microporous and mesoporous metal silicates are prepared by the hydrothermal reaction of a silicon and metal source in the presence of a template. The choice of raw materials influences the purity and hence the catalytic activity of the products. A pyrogenic mixed oxide is used as the silicon and metal source. Prepared products have the composition (SiO.sub.2).sub.1-x (A.sub.m O.sub.n).sub.x, where A is Ti, Al, B, V or Zr and x is 0.005 to 0.1. Shaped objects of the microporous and mesoporous metal silicates are obtained directly by using a shaped object of the pyrogenic mixed oxide. The products obtained are used as oxidation catalysts.