Inorganic hollow fibers

Abstract

The invention relates to inorganic hollow fibers, to a spinning mass and to a method for producing the same as well as to the use thereof for material transports, for the exchange of gases and in separation procedures. The hollow fibers according to the invention are obtainable by processing a spinning mass to a hollow fiber according to general methods, by curing said fiber thermally, via radiation induction or via chemical induction, and by removing the organic components via pyrolysis. The spinning mass is obtained by hydrolytic polycondensation of hydrolyzable compounds of silicon, aluminum, titanium and zirconium and optionally of co-condensable compounds of the elements Li, Na, Mg, Ca, Sr, Ba, Zn, Sn or Pb. The hydrolytic polycondensation is performed by adding water or moisture. If desired, monomers or oligomers which may undergo co-polymerization or (poly)addition, curing catalysts, pore generating additives or compounds of the elements Li, Na, Mg, Ca, Sr, Ba, Zn, Sn and Pb which are soluble in the reaction medium are added to the spinning mass.

We claim:  
     
         1 . Inorganic hollow fiber, obtainable by processing of a spin mass to a hollow fiber according to general methods, by optionally drying the hollow fiber, by curing the optionally dried fiber thermally and/or via radiation induction and/or chemically induced by polymerization and/or polyaddition, and by removal of the organic components from the cured hollow fiber via pyrolysis, wherein the spinning mass is obtained  
       a) by hydrolytic polycondensation of 
 one or more compounds of the general formula I and/or of precondensates derived therefrom,  
 SiX a R′ 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,  
 and one or more compounds of the general formulae II and/or III which is/are optionally in the form of (a) complex(es) and/or of precondensates derived thereof,  
 M 1 R o   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 o  and R are equal or different, R o  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 optionally  
 one or more compounds of the general formula IV and/or of precondensates derived therefrom,  
 X a SiR 4-a   (IV)  
 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,  
 X=hydrogen, halogen, hydroxy, alkoxy, acyloxy, alkylcarbonyl, alkoxycarbonyl, or NR″ 2  
 wherein R″=hydrogen, alkyl, aryl, or alkylaryl,  
 
 a=1, 2 or 3,  
 and/or  
 one or more co-condensable compounds of the elements Li, Na, Mg, Ca, Sr, Ba, Zn, Sn or Pb,  
 wherein the hydrolytic polycondensation has been carried out by adding water or moisture and optionally in the presence of a solvent and/or of a condensation catalyst, and wherein the molar ratio of the compound of formula I to the sum of compounds of formulae II and III, based on the monomers, is between 99:1 and 1:99,  
 and, if desired  
 b) by addition of  
 one or more monomers and/or oligomers which are co-polymerizable and/or can be subjected to a (poly)addition,  
 and/or one or more curing catalysts,  
 and/or one or more pore generating additives  
 and/or one or more compounds of the elements Li, Na, Mg, Ca, Sr, Ba, Zn, Sn and Pb which are soluble in the reaction medium.  
 
     
     
         2 . Hollow fiber according to  claim 1 , obtainable by use of compounds of general formula I which are compounds of general formula I′ and/or of precondensates derived thereof,  
       
         
           
           
               
               
           
         
       
       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 1 =alkylene, arylene, arylenealkylene or arylenealkylene having from 0 to 20 carbon atoms each, wherein said radicals may contain oxygen atoms and/or sulfur atoms and/or ester and/or carbonyl and/or carboxy and/or amide and/or amino groups,  
 R 2 =alkylene, arylene, arylenealkylene or arylenealkylene having from 0 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 3  hydrogen, R 2 —R 1 —R 4 —SiX x R 3-x , carboxyl, 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 4 =—(CHR 6 —CHR 6 ) n —, wherein n is 0 or 1, —CHR 6 —CHR 6 —S—R 5 —, —CO—S—R 5 —, —CHR 6 —CHR 6 —NR 6 —R 5 —, —Y—CS—NH—R 5 —, —S—R 5 —Y—CO—NH—R 5 —, —CO—O—R 5 , Y—CO—C 2 H 3 (COOH)—R 5 —, —Y—CO—C 2 H 3 (OH)—R 5 — or —CO—NR 6 —R 5 —,  
 R 5 =alkylene, arylene, arylenealkylene or arylenealkylene having from 1 to 20 carbon atoms each, wherein said radicals may contain oxygen atoms and/or sulfur atoms and/or ester and/or carbonyl and/or carboxy and/or amide and/or amino groups,  
 R 6 =hydrogen, alkyl or aryl having from 1 to 10 carbon atoms,  
 R 7 =hydrogen, 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,  
 X=hydrogen, halogen, hydroxy, alkoxy, acyloxy, alkylcarbonyl, alkoxycarbonyl or NR″ 2 , 
 wherein R″ is hydrogen, alkyl, alkylaryl or aryl,  
 
 Y=—O—, —S— or —NR 6 —,  
 Z=—O— or —(CHR 6 ) m —, wherein m=1 or 2,  
 a=1, 2 or 3, wherein b=1 in case a=2 or 3,  
 b=1, 2 or 3, wherein a=1 in case b=2 or 3,  
 c=1 to 6,  
 x=1, 2 or 3, wherein a+x=2, 3 or 4.  
 
     
     
         3 . Hollow fiber according to  claim 1  or  2 , obtainable by use of compounds of general formula I which are compounds of general formula I″ and/or of precondensates derived thereof,  
       
         
           
           
               
               
           
         
       
       wherein the radicals and indices have the following meaning: 
 B=straight-chain or branched organic radical having at least one C═C double bond and from 4 to 50 carbon atoms,  
 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 3 =alkylene, arylene, arylenealkylene or alkylenearylene having from 0 to 10 carbon atoms each, wherein the said radicals may be interrupted by oxygen atoms and/or by sulfur atoms and/or by amino groups.  
 X=hydrogen, halogen, hydroxy, alkoxy, acyloxy, alkylcarbonyl, alkoxycarbonyl or NR″ 2 , 
 wherein R″ is hydrogen, alkyl, aryl or alkylaryl.  
 
 A=OS or NH 
 in case d=1 and Z=CO and  
 R 1 =alkylene, arylene, or alkylenearylene having from 1 to 10 carbon atoms each, wherein the said radicals may be interrupted by oxygen atoms and/or by sulfur atoms and/or by amino groups, and  
 R 2 =COOH or H, or  
 A=O, S, NH or COO  
 in case d=1 and Z=CHR′, with the proviso that R′=H, alkyl, aryl or alkylaryl, and  
 R 1 =alkylene, arylene or alkylenearylene having from 1 to 10 carbon atoms each, wherein the said radicals may be interrupted by oxygen atoms and/or sulfur atoms and/or amino groups, and  
 R 2 =OH, or  
 
 A=OS, NH or COO 
 in case d=0 and  
 R 1 =alkylene, arylene or alkylenearylene having from 1 to 10 carbon atoms each, wherein the said radicals may be interrupted by oxygen atoms and/or by sulfur atoms and/or by amino groups, and  
 R 2 =OH, or  
 
 A=S 
 in case d=1 and Z=CO and  
 R 1 =N and  
 R 2 =H,  
 
 a=1, 2 or 3,  
 b=0, 1 or 2, with the proviso of a+b=3,  
 c=1, 2, 3 or 4.  
 
     
     
         4 . Hollow fiber according to one or more of  claims 1  to  3 , obtainable by use of compounds of general formula I which are compounds of general formula I′″ and/or of precondensates derived thereof,  
       {X a R b Si[(R′A) c ] (4-a-b) } x B  (I′″)  
       wherein the radicals and indices have the following meaning: 
 A=O, S, PR″, POR″, NHC(O)O or NHC(O)NR″,  
 B=straight-chain or branched organic radical derived from a compound B″ having at least one (if c=1 and A=NHC(O)O or NHC(O)NR″) or at least two C═C double bounds and from 5 to 50 carbon atoms,  
 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′=alkylene, arylene or alkylenearylene,  
 R″=hydrogen, alkyl, aryl or alkylaryl,  
 X=hydrogen, halogen, hydroxy, alkoxy, acyloxy, alkylcarbonyl, alkoxycarbonyl or NR″ 2 ,  
 a=1, 2 or 3,  
 b=0, 1 or 2,  
 c=0 or 1,  
 x=an integer the maximum value of which corresponds to the number of double bonds in the compound B′ minus 1 or is equal to the number of double bonds in the compound B′ in case c=1 and A represents NHC(O)O or NHC(O)NR″, wherein the above alkyl and alkenyl radicals, respectively, are optionally substituted straight-chain, branched or cyclic radials having from 1 or, respectively, 2 to 20 carbon atoms, aryl is optionally substituted phenyl, naphthyl or biphenyl, and the above alkoxy, acyloxy, alkylcarbonyl, alkoxycarbonyl, alkylaryl, arylalkyl, arylene, alkylene, and alkylenearyl radicals are derived from the above-defined alkyl and aryl radicals.  
 
     
     
         5 . Hollow fiber according to one or more of  claims 1  to  4 , obtainable by use of compounds of general formula I which are compounds of general formula I″″ and/or of precondensates derived thereof,  
       Y a SiX x R 4-a-x   (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,  
 X=hydrogen, halogen, hydroxy, alkoxy, acyloxy, alkylcarbonyl, alkoxycarbonyl or NR″ 2 , 
 wherein R″ is hydrogen, alkyl, aryl or alkylaryl,  
 
 Y=an organic radical having from 1 to 30, preferably from 1 to 20 carbon atoms and from 1 to 5, preferably from 1 to 4 mercapto groups.  
 a=1, 2 or 3,  
 x=1, 2 or 3, with the proviso that a+x=2, 3 or 4.  
 
     
     
         6 . Hollow fiber according to one or more of  claims 1  to  5 , obtainable by using a spinning mass which contains one or more organic compounds having one or more mercapto groups.  
     
     
         7 . Hollow fiber according to one or more of  claims 1  to  6 , obtainable by using a spinning mass which contains one or more organic compounds having one or more substituted and/or unsubstituted amino groups.  
     
     
         8 . Hollow fiber according to one or more of  claims 1  to  7 , obtainable by using a spinning mass which contains one or more salts and/or one or more liquids and/or one or more blowing agents and/or one or more porous fillers as additives in order to generate pores.  
     
     
         9 . Hollow fiber according to one or more of  claims 1  to  8 , obtainable by eluting and/or removing via thermal treatment the pore generating additives after curing.  
     
     
         10 . Spinning mass for the preparation of inorganic hollow fibers, obtainable by  
       a) by hydrolytic polycondensation of 
 one or more compounds of the general formula I and/or of precondensates derived from said compounds,  
 SiX a R′ 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,  
 
 and one or more compounds of the general formulae II and/or III which is/are optionally in the form of (a) complex(es) and/or of precondensates derived thereof,  
 M 1 R o   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 o  and R are equal or different, R o  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 optionally  
 one or more compounds of the general formula IV and/or of precondensates derived therefrom,  
 X a SiR 4-a   (IV)  
 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,  
 X=hydrogen, halogen, hydroxy, alkoxy, acyloxy, alkylcarbonyl, alkoxycarbonyl or NR″ 2 , 
 wherein R″=hydrogen, alkyl, aryl or alkylaryl,  
 
 a=1, 2 or 3,  
 and/or  
 one or more co-condensable compounds of the elements Li, Na, Mg, Ca, Sr, Ba, Zn, Sn or Pb,  
 wherein the hydrolytic polycondensation has been carried out by adding water or moisture and, optionally, in the presence of a solvent and/or of a condensation catalyst and wherein the molar ratio of the compound of formula I to the sum of the compounds of formulae II and III is between 99:1 and 1:99, based on the monomers,  
 and, if desired,  
 b) by addition of  
 one or more monomers and/or oligomers which are co-polymerizable and/or can be subjected to a (poly)addition,  
 and/or one or more curing catalysts,  
 and/or one or more pore generating additives,  
 and/or one or more compounds of the elements Li, Na, Mg, Ca, Sr, Ba, Zn, Sn and Pb which are soluble in the reaction medium.  
 
     
     
         11 . Method for the preparation of inorganic hollow fibers according to one or more of  claims 1  to  9 , characterized in that a spinning mass is processed to a hollow fiber according to general methods, in that the hollow fiber is optionally dried, in that the optionally dried hollow fiber is cured thermally and/or via radiation induction and/or via chemical induction by polymerization and/or by polyaddition, and in that the organic components are removed from the cured hollow fiber via pyrolysis, wherein the spinning mass is obtained by  
       a) by hydrolytic polycondensation of 
 one or more compounds of the general formula I and/or of precondensates derived therefrom,  
 SiX a R′ 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,  
 and one or more compounds of the general formulae II and/or III which is/are optionally in the form of (a) complex(es) and/or of pre-condensates derived thereof,  
 M 1 R o   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 o  and R are equal or different, R o  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 optionally  
 one or more compounds of the general formula IV and/or of precondensates derived therefrom,  
 X a SiR 4-a   (IV)  
 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,  
 X=hydrogen, halogen, hydroxy, alkoxy, acyloxy, alkylcarbonyl, alkoxycarbonyl or NR″ 2 , 
 wherein R″=hydrogen, alkyl, aryl or alkylaryl,  
 
 a=1, 2 or 3,  
 and/or  
 of one or more co-condensable compounds of the elements Li, Na, Mg, Ca, Sr, Ba, Zn, Sn or Pb,  
 wherein the hydrolytic polycondensation is carried out by adding water or moisture and, optionally, in the presence of a solvent and/or a condensation catalyst and wherein the molar ratio of the compound of formula I to the sum of compounds of formulae II and III is between 99:1 and 1:99, based on the monomers,  
 and, if desired  
 b) by addition of  
 one or more monomers and/or oligomers which are co-polymerizable and/or can be subjected to a (poly)addition,  
 and/or one or more curing catalysts,  
 and/or one or more pore generating additives,  
 and/or one or more compounds of the elements Li, Na, Mg, Ca, Sr, Ba, Zn, Sn and Pb which are soluble in the reaction medium.  
 
     
     
         12 . Inorganic hollow fiber, characterized by 1 to 99% by weight SiO 2  and 0 to 99% by weight Al 2 O 3  and/or 0 to 40% by weight B 2 O 3  and/or 0 to 50% by weight TiO 2  and/or 0 to 99% by weight ZrO 2 .  
     
     
         13 . Inorganic hollow fiber according to  claim 12 , characterized by 0 to 10% by weight LiO 2  and/or 0 to 10% by weight Na 2 O and/or 0 to 20% by weight MgO and/or 0 to 20% by weight CaO and/or 0 to 20% by weight SrO and/or 0 to 20% by weight BaO and/or 0 to 20% by weight ZnO and/or 0 to 20% by weight SnO and/or 0 to 20% by weight PbO.  
     
     
         14 . Use of the hollow fibers according to one or more of  claims 1  to  9  in separation procedures and for the exchange of gases.  
     
     
         15 . Hollow fiber according to  claim 5 , obtainable by use of silanes of general formula I″″ which are silanes of general formula V  
       [(HS—R 5 ) n R 6 —S—E—R 5 ] a SiX x R 4-a-x    (V)  
       wherein the radicals and indices have the following meaning: 
 E=—CO—NH—, —CS—NH—, —CH2—CH2— or —CH2—CH(OH)— 
 R=as defined for general formula IV;  
 R 5 =alkylene, arylene, arylenealkylene or arylenealkylene having from 0 to 20 carbon atoms each, wherein the said radicals may be interrupted by oxygen atoms and/or by sulfur atoms and/or by ester and/or by carbonyl and/or by carboxy and/or by amide and/or by amino groups;  
 R 6 =alkylene, arylene, arylenealkylene or arylenealkylene having from 0 to 20 carbon atoms each, wherein the said radicals may be interrupted by oxygen atoms and/or sulfur atoms and/or by ester and/or by carbonyl and/or by carboxy and/or by amide and/or by amino groups;  
 X=as defined for general formula IV;  
 a=as defined for general formula IV;  
 n=2, 3, 4 or 5;  
 x=as defined for general formula IV.  
 
     
     
         16 . Hollow fiber according to one or more of  claims 1  to  9  and  15 , obtainable in that the hollow fiber made from the polycondensate and cured by polymerization and/or polyaddition is first converted into a carbon-containing intermediate by thermal cracking and in that subsequently, the remaining carbon is removed from said carbon-containing intermediate in an oxidizing atmosphere.  
     
     
         17 . Method according to  claim 11 , characterized in that the hollow fiber which has been made from the polycondensate and has been cured by polymerization and/or polyaddition is first converted into a carbon-containing intermediate by thermal cracking and that subsequently, the remaining carbon is removed from said carbon-containing intermediate in an oxidizing atmosphere.