Patent ID: 7850881

Claim:
A method for the preparation of inorganic microporous or meso porous hollow fibers, comprising SiO 2 and at least one oxide of aluminum, boron, titanium, and zirconium, comprising the steps of: (a) spinning a spinning mass, which comprises a liquid or solid polycondensate resin of at least one hydrolytically condensed silicon compound of formula I and at least one hydrolytically condensed compounds of formulae II and/or III, to a hollow fiber by extruding the spinning mass through an annular die; (b) curing said hollow fiber thermally and/or via radiation induction and/or via chemical induction by polymerization and/or by polyaddition; and (c) converting the hollow fiber into an intermediate product containing carbon, by way of thermal cracking under inert gas, and subsequently, (d) removing the organic components from the cured hollow fiber via pyrolysis in an oxidizing atmosphere, wherein formula I comprises SiX a R 1 b R (4-a-b) (I) wherein the radicals and indices have the following meaning: R =alkyl, alkenyl, aryl, alkylaryl or arylalkyl having from 1 to 20 carbon atoms each, wherein said radicals may contain oxygen and/or sulfur atoms and/or ester and/or carbonyl and/or carboxy and/or amide and/or amino groups, R′ =organic radical having from 1 to 50 carbon atoms and containing at least one group which can undergo a polymerization or a polyaddition, X=hydrogen, halogen, hydroxy, alkoxy, acyloxy, alkylcarbonyl, alkoxycarbonyl or NR″ 2 , wherein R″=hydrogen, alkyl or aryl, a=1, 2 or 3, b=1, 2 or 3, with the proviso that a+b=2, 3 or 4; formulae II and/or III comprises M 1 R° 3 (II) M 2 X y R Z (III) wherein M 1 is aluminum or boron and M 2 is titanium or zirconium, the radicals X, R° and R are equal or different, R° is halogen, hydroxy, alkoxy or acyloxy, y is an integer of from 1 to 4, z is 0, 1, 2, or 3 under the proviso that y+z=4, and X and R are defined as in formula I; and wherein the lumen of the annular die includes a gas and/or liquid carrying inner die.