Doped precipitated silica
AssigneeDegussa AG
InventorsGottlieb-Georg Lindner, Astrid Mueller
Life of this patent
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Abstract
Foreign-atom-doped precipitated silicas having a BET surface area of more than 300 m2/g and a maximum surface concentration of the foreign atoms of 0.05 mmol/m2, to a process for preparing them and to the use of the resulting precipitated silicas in papermaking.
Claims19
A foreign-atom-doped precipitated silica having a BET surface area of more than 300 m2/g and a maximum surface concentration of the foreign atoms of between 1·10−5 and 0.05 mmol/m2,
- wherein said foreign-atom is selected from the group consisting of Zr, Zn, Ti, P, Cr, V, Sc, Ga, In, Fe, Ag, Sc, Mn, Co, Ni, Cu, and combinations thereof;
- and
- wherein said foreign-atoms are on the surface of the silica as well as incorporated into the internal structures of the precipitated silica.
A process for preparing a foreign atom-doped precipitated silica having a BET surface area of more than 300 m2/g and a maximum surface concentration of the foreign atoms of between 1·10−5 and 0.05 mmol/m2, which comprises adding a solution of foreign atoms in the form of organic or inorganic salts to an aqueous sodium silicate solution during addition of sulfuric acid to said aqueous sodium silicate solution;
- wherein said foreign-atoms are selected from the group consisting of Zr, Zn, Ti, P, Cr, V, Sc, Ga, In, Fe, Ag, Sc, Mn, Co, Ni, Cu, and combinations thereof;
- and
- wherein said foreign-atoms are on the surface of the silica as well as incorporated into the internal structures of the precipitated silica.
Dependencies are inferred from the claim text.