DE1952398C3 - Process for the production of inorganic fibers - Google Patents

Description

3 4

CaO or MgO or, directly, metals such as Al or metals, non-metals. It can also Mg, adds that such processes are used, soles and even dispersions both in aqueous det, the medium common for the production of inorganic brine as well as processed in organic media which make you viscous after concentrating. Sols such as hydroxide, oxide, phosphate, SiIi sol which in special cases can be used for a 5 cat, borate, tungstate or molybdate brine Spinning process necessary property of the spinning used in commercial form and after addition have availability. Suitable high polymers are spun with pure aqueous salt solutions, Without the special measures outlined above, dispersions can also exit in the same way no spinnable solutions are obtained. can be made spinnable. The high molecular weight, Similarly, in the British patent io linear compounds are generally used in 10 30 232 described method, in the zirconium amounts of 0.001 to 5, preferably from 0.01 to Salt solutions such as acetates, lactates or oxide chlorides 2 percent by weight added.

by concentrating to 40 to 48 Vo of oxide in a higher concentration can be converted without further spinnable sol. In order for good fibers to be used, but to maintain them under certain circumstances, the sols have to be spun immediately and have an unfavorable effect on the annealing process, since they cause the. Combustion of the organic material pore-rich, inorganic solutions that can be spinnable in order to produce brittle fibers. In addition, the places, i.e. they are necessary for each individual substance, are associated with increased costs, using higher concentrations of polymer, in some cases quite complex measures,
agile, such as B. Polymerization processes at elevated temperatures, polycondensation processes, such as those occurring in concentrations below 5% in concentration, and controlled development of the spinnability are sufficient in all practically occurring cases. It has been found hydrolysis processes. Depending on the starting point, after the addition of the high-polymer compounds, the substance and property of the sol to be produced must be carried out in any further pretreatment of the various ways to be spun. 15 The solution or the sols or dispersions are omitted. Depending on the substance, spinnability is only possible in can. The previously customary process stages for a concentration range of 25 to 48%, calculated as polymerization, polycondensation, controlled Hy-oxide, are achieved. Such highly concentrated drolyse etc. are no longer necessary. It is fer solutions are disadvantageous for the spinning process, as it is advantageous that the solids concentration is difficult to degas (the freedom from gas is no longer limited to washes over the previously known methods, however, extremely high concentrations are limited for the spinning process. The solids are important), and previous filtrations due to the emergency concentration of the solutions can - calculated as agile high pressures are expensive. Oxide - between 5 and 60, preferably between The invention relates to a method of producing 5 and 40 percent by weight. This means that in many cases it is possible to work in the treatment of inorganic fibers from liquid medium below the saturation limit of the systems used by spinning solutions, brines and / or other systems, so that dispersions that decrystallize the fiber-forming systems are reliably avoided.
hold, at temperatures of from about 15 to 6O ⁰ C by the method described it is possible and, optionally, a subsequent temperature a very large variation of inorganic filaments harsh treatment at temperatures of 300 to 3000 ° C, 40 see below oxide filaments of the metals Be, Mg, which is characterized in that the fibers Ca, Sr, Ba, rare earths, Th, U, Ti, Zr, Hf, V, from a fluid solution, a sol and / or a Nb, Ta, Cr, Mo, W, Mn, Fe, Co, Ni, Zn, B, Al, Ga, dispersions are spun which, in addition to the Si, Ge, Sn, threads that fertilize mixtures or compounds desired inorganic fiber-forming systems, consist of the oxides mentioned and also dissolved linear polymer substances with a poly- 45 those which additionally contain other elements such as Li, merization degree above about 2000, whose Na, K, Rb, Cs, Re, Ru, Os, Ir, Pt, Rh, Pd, Cu, Ag , Concentration in the spinning solution 0.001 to 5 weight Au, Cd, In, Tl, Pb, P, As, Sb, Bi, S, Se or Te weight percent and below that of fiber. However, it is also possible to produce threads which are composed of inorganic substances that form carbides or nitrides of the elements mentioned. In the case of carbide threads, the production of spinnable solutions for inorganic carbon or carbonaceous materials, ganic threads, is essential. B. carbon black, graphite or soluble, to carbon number of substances applicable and allows decomposable organic compounds as a reaction also the spinning of dispersions. partner co-spun. Analogously, nitride fibers and / or fiber-forming systems can produce oxides, 55 which are obtained by spinning together nitrogen-containing carbides and / or nitrides or compounds. The conversion to carbides can be turned, but the oxides, carbides and / or nitrides and nitrides can also be formed by reaction of the. Oxide threads with carbon- or nitrogen-containing surprisingly, it was found that there are gas atmospheres. It is preferred that the spinnability is not necessary. Inorganic threads based on oxides, nitrides and / or sols are brought about by a special treatment or carbides of Be, Mg, Ca, Ti, Zr, B, Al and / or are supplied, but that only Si can be spun.

due to the presence of small amounts of high molecular weight The high polymers that are used according to the invention

rer, made up of thread molecules, are more inorganic, apart from their linear polymers

or organic substances can be produced by the level of the degree of polymerization

can. The process is by no means characterized in terms of aqueous solvent - P - or molecular weight. First above

solutions of nitrates, sulfates, acetates, oxalates, half of a minimal degree of polymerization -

Chlorides, oxide chlorides etc. of metals, semi-> 2000 - show solutions of high polymers at

Concentrations below 5% have the property of influencing spinnability. The high polymers can be organic or inorganic in nature; their selection depends on the solvent present. For aqueous Saiziösungen, Soie or dispersions, water-soluble high polymers are used, preferably polyethylene oxide, polyacrylamide, polyacrylic acid-polyacrylamide copolymers or soluble Kurrol's salts. B. polystyrene, polyisobutylene, polymethyl methacrylate or polyisoprene can be used.
Solutions of linear polymeric substances are used in

Table 1

Preparation intrinsic viscosity poly-

fo], 35 ° C, meri-

HjO sations-

T = 12.5 dynes / cm * gradP

Spinnability of 2% Solutions cm

Polyethylene oxide

2.0

Polyethylene oxide
B.

Polyethylene oxide

4.81

5 450

17,000

9.15

68 200

more than 136 400

At a degree of polymerization of 136 (M ⁼ 9.15), even a 1.5% aqueous polyethylene oxide solution shows a spinnability of 300 cm. Are 1.5% of this Polyäthyienoxids in the solution of an inorganic or organic salt, in one

Spinning processes in the synthetic fiber industry since 15 C 7.1

long used to make synthetic fibers. Also polyethylene oxide

these solutions show the property of spinning q availability, but are the molecular weights or degrees of polymerization of the substances used there nowhere near as high as in the case of the substances used according to the invention; a sufficient one Spinnability is only achieved in the concentration range of 25 to 45%. So z. B. to Manufacture of polyacrylonitrile fibers a 25%

Solution of a polyacrylonitrile with a molecular weight of 25 sol or a dispersion contain, so also have from 35,000 to 50,000, which gives a polymerization this a spinnability of several meters. The degree from 660 to 950 corresponds to spinnability of the solution of high molecular weight amide in dimethyl form (Ulimann's Encyklopadie der Tech- Polyäthylenoxid ist auf den respective solutions nischen Chemie, Vol. 7 [1956]). If these are transferred because the salt solution substances used are 0.001 to 5% solutions in a counter, sols, emulsions or dispersions are produced for a suitable solvent, they cannot be spinned on their own. If you want similarly high but not spinnable; when the spinnability values run out with a polyethylene nozzle, only a series of droplets is produced, but no oxide can achieve a lower degree of polymerization, so coherent thread. _mu ß its concentration are correspondingly higher. The spinnability of high polymer solutions 35 B. a spinnability of 300 cm also in the concentrations as they are used according to the method of a polyethylene oxide of the polymerisation degree ren of the present invention, 6800 is achieved if the aqueous solution depends on 2.5%, which is decisive on the degree of polymerisation of the behavior.

turned away substances. To illustrate this, similar conditions also occur with aqueous

The facts are the ratios in aqueous 40 solutions of the Kurrol salts z. B. in some

and organic media in some examples it has the composition [(K, Na) PO ₃ ] _P

purifies. To measure the spinnability (Tab. 2). A 0.5% aqueous solution of this salt

a method was used which is described in the literature as ... ln »r«, » _O1 , _J.

is written and is based on the dry spinning ^{with emem} ~ ^ - ^^ of 28.13 and a polymer

based on usual procedures. The 45 degree of sation to be examined of 4650 is included in the spinnability

Liquid is ejected from a nozzle under pressure, a product with a degree of polymerization squeezes and measured the length of the uninterrupted thread of liquid, to the point where it cuts into individual Drops disintegrate (Kolloid-Zeitschrift 61 [1932],

of 8000 and a ^ - ^ value of 39.13 shows as

0.5% solution has a spinnability of 300 cm. P. 258). In the present measurements, the 50 r. .... ... _t in _V r . _nncnl . .. "■

Solutions under a pressure of 0.5 atü from a ^The viscosity value -f- was on 0.05%, aqueous

Nozzle with a diameter of 400 microns and a nozzle channel length of 17 mm.
2% aqueous solutions of polyethylene oxide can

table

gen solutions at 25 ° C, pH = 7 with the addition of 0.1% NaCl at a shear stress of. τ = 0.98 dynes / cm ² measured, where c is the concentration

nen means depending on the level of the molecular weight or 55 tration in grams per 100 ml of solvent. Degree of polymerization achieve different values of spinnability. The solution of a polyethylene oxide A with a degree of polymerization P of 5450
reaches only 30 cm, the solution of a polyethylene oxide B (P = 17,000) reaches 130 cm, polyethylene 60 ^ ^{ra parate}
oxide C (P = 68 200) 225 cm and the spinnability
of a polyethylene oxide D with P = 136 400 is already well over 300 cm. Polyethylene oxide is preferred with a degree of polymerization greater than 5000

used. For a more precise characterization of the sub-65

punching is also given the intrinsic viscosity [»;], measured in H ₂ O at 35 ° C with a shear stress of τ = 12.5 dyn / cm ² (Tab. 1).

0.05% solution. 25 ^C C, pH = 7; + 0.1VoNaCl, τ = 0.98ανη'ςπι *

Degree of polymerization P.

Spinnability 0.5% solution in H ₂ O

[(FCNa) PO ₁₁ I ₇ , [(ICNa) PO,! ,,

28.13
39.13

4,650 8,000

30th

300

Those Kurrol salts whose - ^ - value is greater than 15 are preferably used for the process according to the invention.

For aqueous systems, polyacrylamides or polyacrylamide-polyacrylic acid copolymers with an acrylic acid content of 0 to 100 Vo or their lithium, sodium, potassium, ammonium or substituted ammonium salts, preferably those with a viscosity value of -5 ^ over 4, are suitable

(measured at a shear stress τ = 0.98 dyn / cm ^z, 25 ⁰ C, pH = 7, O, O5 ° / cent solution having a NaCl content of 0.1 Ve). So has z. B. a polyacrylamide-polyacrylic acid copolymer, which consists of 85 Vo of polyacrylamide and has a degree of polymerization of 14 080, as a 1.7% aqueous solution a spinnability of 300 cm. A higher molecular weight product with a degree of polymerization of 70,400 has already than 0.25 ⁰ / o solution in water, a comparison ao spinnability of 300 cm. The viscosity value - ^ (determined in H ₂ O, 25 ° C., pH = 7, 0.05% solution with 0.1% NaCl at τ = 0.98 dyn / cm ² ) of this product is 35. The ratio of acrylamide to as acrylic acid in the copolymers can assume any values between 0: 1 and 1: 0. A copolymer with 2.5% acrylamide (97.5% acrylic acid) as a 0.8% solution also has a spinnability of 210 cm. A similarly good spinnability is also achieved if the carboxyl groups of the copolymer are neutralized by salt formation. Suitable salts are the Li, Na, K, NH ₁ or substituted ammonium salts.

_{The following phenomena can be observed in 3} % solutions of polystyrene in CH 3 Cl ₂ : The spinnability of a 3% solution becomes clear at degrees of polymerization above about 10,000 and increases with the degree of polymerization. In the case of particularly high molecular weight products, such as B. the polystyrene F, with a degree of polymerization of 125,000, a spinnability of at least 300 cm can be achieved with a 0.15% solution in CH ₂ Cl ₂ (Tab. 3).

Table 3 Poly-
meri-
station
Degree concentration
Weight percent
in CH ₂ Cl ₂ Spinning
availability
cm preparation 1038 3 1 Polystyrene A 20 200 3 10 Polystyrene B 25,000 3 20th Polystyrene C 27 900 3 50 Polystyrene D 34 600 3 110 Polystyrene E. 125,000 0.15 300 Polystyrene F

Similar relationships exist with other high polymers, such as. B. Solutions of polyisobutylene in trichlorethylene (Tab. 4), which is used with a degree of polymerization above about 5000.

Table 4

preparation Poly- concentration Spinning men- Weight percent availability station in trichloro Degree ethylene cm

Polyisobutylene A 6,900 3

Polyisobutylene B 23 600 3

Polyisobutylene C 49,000 3

Polyisobutylene D 85 500 1.5

20th

<> 0

300

The 3% solution of a polymethacrylic acid methyl ester _{with a degree of polymerization of 3600 in CH 2} Cl ₂ shows a spinnability of 10 cm, with a degree of polymerization of 15,000 as a 2% solution in CH ₂ Cl ₂ already 300 cm. Likewise, 3% solutions of the polyisoprene ζ are. B. spinnable in toluene or Trichloräthylcn (degree of polymerization P = 25,000). According to the invention, therefore, methyl polymethacrylate preferably with a degree of polymerization above about 2000 and polyisoprene preferably with a degree of polymerization above about 10,000 can be used.

Polyethylene oxide, which can be spun in aqueous solution, shows this property even in organic solvents, e.g. B. CH ₂ Ci ₂ . Here, too, an increase in spinnability with the degree of polymerization is observed. The effectiveness in CH ₂ Cl ₂ is even higher than in water. The polyethylene oxide with a degree of polymerisation of 6800 achieves a spinnability of 300 cm even as a 0.2% solution.

The inventive production of the thread-pulling systems can also be produced with other high polymers that have a chain structure, such as. B. other than the already mentioned vinyl polymers and copolymers, diolefin polymers, substituted polyethers and thioethers, polyesters, polyamides, polypeptides, polysaccharides, polysiloxanes, phosphorus nitrile chlorides (PNC1 ₂ ) "or extremely high molecular weight polyphosphates, such as the Kurrol salts of the general formula

[(K, M) PO ₃ ] p

in which M = Li, Na, NH ₄ , Rb, Cs or a substituted ammonium ion and P has a value greater than 2000, as well as mixtures of the aforementioned polymers.

The limits for the occurrence of the spinnability can be shifted depending on the nature of the Hochpoly meren and the solvent used. In any case, however, one observes with such substances in the range of high intrinsic viscosities [η] or high degrees of polymerization a ver spinnability in solutions of very low concentration, which can be transferred to salt solutions, sols or dispersions. On the other hand, by using polymeric substances with low polymeri

As sationgrad as it is in most commercially available] Products are present, no 'spinnability is caused in dilute solutions, similar to wi' this was not possible with a polyethylene oxide below a degree of polymerization of 2000,

In the production of the spinning solutions, this is done drive that the salt solutions, the sol or the dis persion with a concentrated solution of high polymer is added until sufficient Vei

609 608/11

spinnability occurs, which ranges between 0.01 such as CO ₂ , NO ₂ , NH ₃ , H ₂ S, HF, HCl, HBr or HJ

and 2% polymer, based on the total solution, can be used.

the case is. The salts can also be used directly in the sol-gel conversion

Solution of the high polymer can be solved. The thread can be accelerated by the change in pH.

the concentration of the. Salt and thus the oxide 5 den. So is z. B. an ammoniacal solution of a

content can be varied within wide limits. Silicic acid sol, which is mixed with polyethylene oxide

In the case of a high oxide content, a lower high poly was good flowable, while the same solution was im

mer concentration required, with a low oxide-neutral area forms a viscoelastic gel,

content, larger amounts must be used. When the ammoniacal solution is spun, it sinks

The amount depends however on the nature of the io by evaporating NH ₃ the pH value in the thread

Solution off; in general, more viscous extinguishers need to wipe off quickly, so that it gels. When spinning

Solutions are less highly polymeric than low-viscosity ones. of thermally easily decomposable compounds such as

The spinning solutions obtained in this way are acetates, oxalates, organic salts, nitrates,

exhibit a number of desirable properties nitrites, carbonates and sulfites being preferred

on. In addition to the good spinnability, NH _{3 was} fed into the spinning shaft before 15, which means

Above all, the relatively low viscosity and the associated rapid drying, solidification, and sometimes also

bound easy handling. The viscosity of this already decomposes into hydroxide or oxide

Solutions can be between 1 and 100 poise, follows.

but preferably 1 to 10 poise, so that it is during the subsequent annealing treatment

below the values that are otherwise used for spinning 20 the residues of the solution remaining in the thread

processes needed. The spinning solutions are therefore easily split off by means of and all volatile components,

filterable, easy to degas and can easily Organic constituents can be removed by air oxidation

pump through the supply lines. removed. By suitable choice of the sintering

As the spinning process comes wet and dry conditions, you have it in your hand, on the one hand porous

spinning process in question. In the wet spinning process 25 threads, ζ. B. for catalysts and catalyst carriers

the threads are spun in a suitable precipitation bath and, on the other hand, dense fibers, e.g. for reinforcement

and tempered after coagulation has taken place. The purposes to establish.

Dry spinning can be carried out in a centrifugal spinning machine.

machine done. Here the threads of the peri-play are explained in more detail:

phery of a rotating spinning vessel thrown out 30

change, pass through a drying zone and are then Example 1 MeO threads recorded. This method is suitable e.g. B. for

the production of staple fibers, which are then continuously In 125 g of a 2% solution of a polyacrylic acid

Lich or discontinuous temperature treatment / lnnr \

are fed. However, a con- ₃₅ rotyacrylamid copolymer \ -f = 35, Oj is preferred with

conventional dry spinning process used. The 60 Vo acrylamide became 100 e Me (CH ₅ O,)., · 4 H _n O

Solutions are essentially dissolved when the room is heated. It would start a spinnable one

temperature from a solution provided with many nozzles, the 8.5 Vo MgO and 1.14%> of the polyacrylic

Spinning head spun, the threads run through an acid-polyacrylamide copolymer containing. The Lö-

Spinning chute, which could be tempered in its lower part without the application of pressure from a spinning

ture can have up to several hundred degrees, vessel, the nozzles with a diameter of

where it was 400 microns to a diameter of 50 to 1 micron. The strings

can be warped and wound up afterwards. were through a shaft heated to 200 ° C,

However, the threads can also be rinsed immediately after leaving the ammonia-containing dry air

of the spinning shaft through the high-temperature zone 45 was directed and collected.

be performed. At the beginning there is one that was then in the ΝΗ, stream to 300 ⁰ C.

Temperature from 300 to 400 ⁰ C; the final temperature and then ^{heated to 2000 0} C in air, with white

depends largely on the sintering behavior and the polycrystalline MgO threads Melting point of the resulting compound, they

must be used for high-melting substances such. B. 50 Example 2 CeO ₂ threads ZrO ₂ or ThO _{2 be} correspondingly higher than i _72g Ce (NO,), · 6 HO, 37.3 g H ₂ O and 40.7 {lower melting compounds, such as. B. TiO ₂ , a 2.7% Polyäthvlenoxidlösung (M = 9.15; SnO ₂ and the like, where one stirred at temperatures of 800 to were stirred to a clear solution. The spinning 1100 ° C. _{Solution; The 044} % polyethylene oxide and 26.0% Ce "0 _; While the threads run through the spinning shaft, 55, as indicated in Example 1, most of the solvent is already removed. The threads in the ammonia stream 800 ⁰ C unt removed. the first thin liquid thread is thereby then in the N ₀ stream at 1100 ⁰ C heated to concentrates and goes through a thick liquid to characterized in CeO transferred filaments. gel state. in this state, the threads can still Contains 10 to 40% of the solvent, 60 bis ρ ie 1 3 Al. ₂ O _{3 threads}

The gel formation of the thread can be accelerated 50 g of a commercially available aluminum hydroxide gel (see above

If you add a gas to the spinning solution, the said DH-SoI from Giulini) were in 1001

has a dissolving effect on the substance to be spun, dispersed as methanol, whereby de

eg SO ₂ on AlPO or Al (OH) ,, which after dispersing agent a weight decrease to 1461

however, quickly re-entered from thread 65 after spinning. 50 g of this dispersion were with a

emerges and with regression of the now 2% solution of polyethylene oxide ([>?] = 9.15) ii

insoluble substance that causes gel formation. Mixed in methanol and a spinnable dispersion

Other gases with a dissolving effect can be obtained in the same way, which contain 6.0 Va A1 “O. and 1 per cent. polyoxyethylene

The dispersion was spun and the filaments were converted into Al ₂ O ₃ filaments by annealing.

Example 4 TiO ₂ threads

Pure TiCl ₄ was added dropwise to water until a solution was formed which contained 36.8% TiO ₂ . 80 g of this solution were mixed with 3.92 g of a percent polyethylene oxide solution ([η] = 7.1) and 14.23 g of H ₂ O. The finished spinning solution, which contained 30 _{% TiO 2} and 0.04% polyethylene oxide, was spun in the manner described and the spun threads were converted into TiO ₂ threads by annealing.

Example 5 SiO ₂ threads with carbon black

_{100 g of 30% SiO 2} sol and 78.1 g of 2% polyethylene oxide solution ([??] = 9.15) were added to 45 g of a carbon black dispersion with 40% carbon and the pH was 10.0 _{by introducing NH 3} set. The spinning solution obtained in this way contained 13.5% SiO ₂ , 8.1% carbon as a carbon black dispersion and 0.7% polyethylene oxide. Therefrom black, carbon black-containing SiO ₂ filaments obtained by spinning and annealing at 900 ⁰ C, which could be converted by calcination under inert conditions in SiC. ^a 5

Example 6 Al ₂ O _s threads containing boron

3.2 g of tri-2-ethylhexyl borate, 8.4 g of H ₂ O, 0.5 g of dinaphthyl methanesulphonate and 1.3 g of ammonium lignosulphonate as an emulsifying aid were used to produce, with the addition of 4.5 g of 2% strength polyethylene oxide solution (W = 9.15 ) and 12.2 g of 8.5% aluminum oxalate solution prepares a spinnable emulsion. The filaments obtained therefrom were converted into Al ₂ O ₃ filaments containing boron oxide and having the composition Al ₂ O ₃ · 0.39 B ₂ O ₃ by annealing in air.

Example 7 TiO ₂ threads

100 g of ethanol were _{mixed with 100 g of TiCl 4 while} hot. 100 g of a warm 0.3% solution of polyethylene oxide ([η] = 9.15) in ethanol were added to 50 g of this ethanolic TiCl ₄ solution and 70 g of excess ethanol were stripped off in vacuo. The remaining spinning solution contained 13.1% TiO ₂ and 0.38% polyethylene oxide. It was spun in a heated to 100 ⁰ C, gassed with air shaft and the threads of air to burn up TiÖ ₂ -F'äden. Some of the threads were converted into titanium carbide by reacting them in a methane gas atmosphere at 1500 ° C.

Example 8 TiO ₂ threads

A polycondensed titanium ester with the composition Ti ₁₀ O ₉ (OC ₄ Hg) _{22 was} produced from titanium tetrabutylate by hydrolytic condensation. 20 g of this polymeric butyl titanate were mixed with 60 g of a 1% strength solution of a polystyrene with a degree of polymerization of 125,000 in CH ₂ Cl ₂ , and a spinnable solution containing 25% polymer butyl tuanate and 0.75% polystyrene was obtained. The filaments were converted into TiO ₂ by annealing.

Example 9 TiO ₂ threads

20 g of the polymeric butyl titanate from Example 8 were processed with 60 g of 2% polyisobutylene solution (degree of polymerisation 85,500) in trichlorethylene to form a spinning solution with 25% polymeric butyl titanate and 1.5% polyisobutylene, spun and burned _{to TiO 2.}

Example 10 TiO ₂ threads

20 g of the polymeric butyl titanate from Example 8 were mixed with 60 g of a 4.7% strength solution of a polymethyl methacrylate (degree of polymerization 15,000) in CH ₂ Cl ₂ . The "spinning solution" contained 25% polymeric butyl titanate and 3.5% polymethyl methacrylate. It was spun and the filaments were annealed _{to give TiO 2.}

Claims (6)

chen solution the liquid as more or less patent claims: long thread is drawn, or that when such a solution does not flow through a nozzle 1. Process for the production of inorganic a series of droplets, but a more or more fibers from liquid medium by spinning 5 less long coherent liquid favon solutions, brines and / or dispersions, which arises. This feature is included to Nordie fiber-forming systems in tempera- mally only in solutions of polymeric orgasmic temperatures of about 15 to 60 ⁰ C and, where African substances not to inorganic SaIzfalls a subsequent temperature treatment solutions or sols. One can easily even at temperatures of 300 to 3000 ⁰ C, DA io convince that, for example in a solution of Madurch that the fibers gnesiumacetat or cerium nitrate is not verspmnbar from a fluid solution, a sol and / or as little like a silicic acid, aluminum hydroeiner dispersion are spun, the except oxide or vanadium pentoxide sol. The spinnability of the desired inorganic fiber-forming solutions is tied to a very special state of dissolved linear polymeric substances with the same systems and must be adjusted by a special degree of polymerization above about 2000 positional processes, the concentration of which is contained in the spinning solution 272 the Hersung is 0.001 to 5 percent by weight and the position of silicate materials through a spinning hall) which describes the fiber-forming inorganic process from aqueous solution. The VerSubstanzen lies. ao spinnbarkeii is achieved that mixtures 2. A process for the production of inorganic silica sols and alkali silicates by adding fibers according to claim 1, characterized in that the fiber-forming systems are oxides, car-. B. B ₂ O ₃ , AJ ₂ O ₃ or ZnO with increased temperature and / or nitrides or compounds are turned into linear polymeric silicate by dehydration, the oxides, carbides and / or 25 fibrils with a molecular weight of over 5000 polymeric Nitrides are formed, whereby a spinnable sol is 3. The method according to claim 1 or 2, there is. characterized in that a spinning mixture is In the German Auslegeschrift 1249 832 is is used, in which the high polymers in a process for the production of inorganic threads a concentration of 0.01 to 2 wt .- 3 ° described, with the metal salt solutions an aliprocent available. phatic carboxylic acid with an excess of this 4. The method according to any one of claims 1 acid added, concentrated and by a heat up 3, characterized in that an inorganic treatment in the atmosphere of this carboxylic acid niche fiber-forming system is used to polymerize a viscous, spinnable solution Concentration (calculated as oxide) 5 to 35, with chain-like polymers with 40 ° / o. 1000 to 10,000 molecules per chain are created. the 5. The method according to any one of claims 1 atmosphere of the carboxylic acid and the acid over bis 4, characterized in that when firing are necessary to the deposition of a to avoid spinning thermally easily decomposable compounds second, insoluble phase. The allusions Ammonia in the spinning shaft in-40 amounts of acid in relation to the fed wild. dissolved oxide is between 2: 1, depending on the oxide 6. The method according to any one of claims 1 and 8: 1. to 5, characterized in that the gel gel- In US Patent 33 22 865 is a ver manure in the spun thread is thereby accelerated, drive described in the aqueous, inorganic that the spinning solution is mixed with the metal salt solutions to a viscosity of 1 to spinning substance dissolving gas can be concentrated to 1000 poise, the solid matter settling, which in the spinning process can again be up to 50% content, which then verdem Thread escapes. and be burned to the oxide. As salts the sulfates, chlorides, oxide chlorides, Phos-50 called phate and nitrates of Al, Be, Cr, Mg, Th, U and Zr. Salt solutions can usually only be done like that concentrate well until the solubility product is reached; further concentration is possible Hch, but then over-saturated, unstable results There are solutions for the production of inorganic fibers. Thus containing a saturated at 2O ⁰ C LOE number of processes have been disclosed; one of the solutions of MgSO ₄ -7 H ₂ O 36.5 g MgSO ₄ in 100 g oldest is the production of glass threads by H ₂ O = 8.8% MgO, and a solution of Al ₂ (SO ₄ )., spinning a glass melt. The to be used · 18H ₂ O 3 * _; 3 g A1 ₂ (SO ₄ ) ₃ = 7.94 _{% Al 2} O ₃ (chemical temperatures make high demands on the ^1960s calendar 1956). From the aforementioned to the apparatus. It is therefore endeavored to use the examples cited in the patent, however, spinning process from solutions according to the conventional method that, in order to achieve the viscosity mentioned, new methods of synthetic fiber production have to carry out concentrations of 25 to 38% of oxide. must be. This is achieved in that Prerequisite for the spinning process from solutions ⁶ 5 of hydrolyzable salts, such as. B. acetates or gen, ζ. B. aqueous systems is the spinnability of chlorides, which is assumed when concentrating the respective solution, which is expressed in the fact that ren are converted into a sol or that one alkali when pulling a glass rod out of a solic reacting substances, such as metal hydroxides,