EP1828055A2

EP1828055A2 - Water-free metal oxide colloids and metal oxide polymers, method for the production thereof and use thereof

Info

Publication number: EP1828055A2
Application number: EP05814848A
Authority: EP
Inventors: Uwe Lischka; Jens RÖDER; Ulrich Wietelmann
Original assignee: Chemetall GmbH
Current assignee: Chemetall GmbH
Priority date: 2004-12-14
Filing date: 2005-12-12
Publication date: 2007-09-05
Also published as: WO2006063757A2; JP2008523230A; CN101124040A; CN101124040B; US7807723B1; WO2006063757A3

Abstract

The invention relates to water-free metal oxide colloids and/or metal oxide polymers of general formula [M(O)X3X4]n (1) in an aprotic, organic solvent or solvent mixture, wherein M = Si, Ge, Sn, Ti, Zr or Hf; and X3 and X4 = independently from each other, O1/2, H, alkoxy (-OR), wherein R represents an organo radical having 1 - 20 C-atoms, alkyl having 1 - 20 C atoms or aryl having 6 - 20 C atoms, wherein the alkyl - or aryl radicals can include one or several other halogen substituents, selected from the group of F, Cl, Br or I; and n = typical values of 10 -1.000.000.

Description

Anhydrous metal oxide colloids and metal oxide polymers, processes for their

Manufacture and use

The invention relates to anhydrous metal oxide sols or metal oxide colloids and metal oxide polymers and to processes for their preparation and their use.

Sols are colloidal solutions in which a solid or liquid substance in the finest distribution, e.g. in a liquid medium. Depending on the nature of the liquid medium, a distinction is made between organosols (these are suspensions in an organic solvent) or hydrosols (these are aqueous suspensions, for example silica sol). By coagulation (flocculation), the sols go into so-called gels, which is usually externally noticeable by a reduction in flowability, that is solidification or coacervation, noticeable.

Insoluble metal oxides, such as SiO ₂ , can be dissolved in water by addition of alkali oxides or hydroxides, resulting in so-called water glasses. These viscous solutions can be used in different ways in brine,

Gels or true suspensions (e.g., production of silica). From this, so-called silica gels can be produced, which are used for

Drying of gases and organic liquids, as a stationary phase for chromatography, as a binder in paints or for example for

Surface treatment (e.g., building protection) can be used.

Silicones (polyorganosiloxanes) are compounds in which silicon atoms are bridged via oxygen atoms, but each Si atom carries one or more organic groups. These oligo- or polymers are generally prepared from halosilanes by hydrolysis or alcoholysis and subsequent polycondensation, e.g.

^ Me ₂ SiCl ₂ + /? H ₂ O -> [Me ₂ SiO] _n + 2 n HCl f produced.

The polycondensation is carried out in the presence of acidic catalysts and requires that the water of reaction formed be removed. Upon reaching sufficiently high molecular weights, silicone polymers having rubbery properties are obtained (H.H. Moretto, M. Schulze, G. Wagner, in: Ullmann's Encyclopeidia of Industrial Chemistry, VoI A24, 57-93, 1993).

Disadvantage of all processes and syntheses described above is the fact that the dispersions, oligo- and polymers are prepared either in water or a protic solvent and / or that water or a similar proton-active substance (eg an alcohol) are released in the production, which makes the use of water-sensitive structure groups difficult or impossible.

Frequently used as substrates for heterogeneous (ie solid-supported) catalysts is a SiO ₂ -containing solid. For example, a catalyst support suitable for Ziegler's polyolefin synthesis consisting of SiO ₂ / MgCl ₂ is prepared as follows:

KW

Mg + 2 RCI MgR ₂ + MgCl ₂

+ SiCl ₄

MgCl ₂ + SiR ₄ ² > SiO ₂

This is a multi-stage, complicated process, which has the disadvantage, inter alia, that in the synthesis of dialkylmagnesium compounds in hydrocarbons MgCfe waste arises, which must be disposed of consuming; In addition, dialkylmagnesium compounds require extremely careful handling, since they can spontaneously ignite when air enters. The object of the present invention is to overcome the disadvantages of the prior art and to demonstrate anhydrous metal oxide colloids or metal oxide polymers and their synthetic routes. In particular, the use or formation of proton-active substances such as water or alcohols and the use of difficult-to-handle, especially self-ignitable substances should be avoided.

The object is achieved by anhydrous metal oxide colloids and / or metal oxide polymers of the general formula

[M (O) X ³ X ⁴ ] _n (1)

in an aprotic, organic solvent or solvent mixture,

wherein M = Si, Ge, Sn, Ti, Zr or Hf; and X ³ and X ⁴ = independently of one another O ₁ , H, alkoxy (-OR), where R represents an organo radical having 1 to 20 C atoms, alkyl having 1 to 20 C atoms or aryl having 6 to 20 C Are atoms, wherein the alkyl or aryl radicals may carry one or more further halogen substituents selected from the group F, Cl, Br or I; and n takes typical values between 10 and 1,000,000.

The metal oxide colloids and / or metal oxide polymers may contain metal halides M ¹ HaI _x , where M ¹ = metal selected from the group consisting of rare earth metals, Mn, Zn, Fe, Mg, Ca, Ba, Sr, Hal = halogen, selected from among Group, Cl, Br, I, and x = valency of the metal M ¹ . The molar concentration of the metal halide M ^{1 is} preferably HaI _x 0.1 to 200%, particularly preferably 0.001 to 20% of that of the metal oxide colloid or metal oxide polymer MOX ³ X ⁴ .

In a preferred embodiment, the metal oxide colloids and / or metal oxide polymers contain MO ₂ with M = Si or Ti.

In another preferred embodiment, the metal oxide colloids and / or metal oxide polymers contain one or more of the following compounds: - A -

C ₆ H ₅ SiO ₁₁₆ , HSiOi ₁ S, HaIC ₆ H ₄ SiOi ₁₅ (HaI = Cl ₁ Br, I) ₁ (H ₃ C) ₂ SiO; C ₆ H ₅ TiOi ₁₆ , HTiOi _1S , HaIC ₆ H ₄ TiOi ₁₆ (HaI = Cl ₁ Br ₁ I), (H ₃ C) ₂ TiO.

Preferably, the metal oxide colloids and / or metal oxide polymers contain one or more of the following polar, aprotic solvents: ethers (either open-chain or cyclic, mono- or polyfunctional), esters (either carboxylic esters or carbonic acid esters), ketones, amides, nitriles, halogen-free sulfur compounds or tertiary amines , Particularly preferred are the following solvents: THF, 2-MeTHF, dimethyl carbonate, acetone, propionone, propylene carbonate and diethyl ether.

The concentration of metal oxide colloid and / or metal oxide polymer is preferably from 0.001 to 2 mol / l, particularly preferably from 0.01 to 1 mol / l.

The metal oxide colloids or metal oxide polymers according to the invention can be prepared by a process in which metal halide compounds of the general formula

MHaI ¹ HaI ² X ¹ X ² (2)

with M = Si, Ge, Sn, Ti, Zr, Hf

Hal = Cl, Br, IX ¹ , X ² = independently of one another Cl, Br, I, H, alkoxy (-OR), where R is a

Organo radical having 1 - 20 carbon atoms, alkyl having 1 to 20 carbon atoms or aryl having 6 to 20 carbon atoms, wherein the alkyl or

Aryl radicals may carry one or more further halogen substituents selected from the group F, Cl, Br or I.

with halogen acceptors selected from the group of rare earth metal oxides, metal (II) oxides (such as MgO ₁ CaO, BaO, SrO, ZnO, MnO) or Fe ₂ O ₃ , are reacted in a polar, aprotic solvent.

M is always 4-valued in this formula. Preferred metal halide compounds are the tetrahalogen compounds MHaI ₄ (M and HaI = meanings see above); C ₆ H ₅ MHaI ₃ ; HMHal ₃ ; CeH ₄ HaIMHaI ₃ with CoH ₄ Hal = eg chloro, bromo or iodophenyl; or mixtures thereof. Particularly preferred metal halide compounds are: SiCl ₄ , SiBr ₄ , GeCl ₄ , SnCl ₄ , TiCl ₄ , TiBr ₄ , C ₆ H ₅ SiCl ₃ , 4-CIC ₆ H ₄ SiCl ₃ , 4-BrC ₆ H ₄ SiCl ₃ , HSiCl ₃ , or (CHs) ₂ SiCl ₂ .

As rare earth metal oxides (halogen acceptors), the compounds SE ₂ O ₃ with SE = scandium, yttrium, La, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb or Lu, in general commercial form used. Preference is given to using Nd ₂ O ₃ , Sm ₂ O ₃ or La ₂ O ₃ .

As metal (II) oxides (halogen acceptors) it is possible with preference to use MgO, ZnO or MnO.

The halogen acceptors are preferably used in pulverized form and anhydrous, that is to say with H ₂ O contents <0.5%.

As polar, aprotic solvents, ethereal compounds can be used. these can

open-chain, such as R ¹ -OR ² (with R ¹ and R ² independently of one another alkyl or aryl having 1 to 8 C atoms); or

(CH ₂ i; ⁰ "CHR

- cyclic as ^ - ^ (with n = 3 or 4 and R = H or alkyl with 1 to 8 C atoms); or

- polyfunctional as RO - (- CH ₂ -CH ₂ -O) _n -R '(with R and R ¹ independently of one another alkyl radicals having 1 to 8 C atoms and n = 1 to 100)

be used either in pure form or in a mixture. As an ethereal solvent, for example, tetrahydrofuran, tetrahydropyran, 2-methyltetrahydrofuran, dimethyl ether, diethyl ether or methyl tert-butyl ether or a mixture thereof.

Furthermore, the following aprotic, polar solvents can be used:

- Esters, e.g. Carboxylic esters (such as ethyl acetate, γ-butyrolactone, methyl benzoate), or carbonic acid esters (such as dimethyl carbonate, diethyl carbonate,

Propylene carbonate, ethylene carbonate), or mixtures thereof; or

Ketones (e.g., acetone, propionone); or

Amides (e.g., N-methylpyrrolidone, dimethylacetamide, NMPU); or

- nitriles (e.g., acetonitrile, butyronitrile); or halogen-free sulfur compounds (e.g., dimethyl sulfoxide); or

tertiary amines (e.g., triethylamine, tetramethylethylenediamine).

The polar, aprotic solvents may optionally contain one or more hydrocarbons, e.g. Alkanes (e.g., pentane, hexane, cyclohexane, methylcyclohexane, heptane or octane) or aromatics (e.g., benzene, toluene, ethylbenzene, cumene or xylene) in the weight ratio of solvent: hydrocarbon = 1: maximum 5 are added.

It has surprisingly been found that the abovementioned rare earth metal oxides, metal (II) oxides and Fe ₂ O ₃ as a suspension in polar aprotic solvents already react at temperatures of <30 ^° C. with the metal halide compounds of the formula (2) as follows:

H SE ₂ O ₃ + n - MHaI ¹ Hal ² X ¹ X ^{2 Soluble with} H 2/7 SEHal ₃ + - [M (O) X ³ X ⁴ L ₁ 4-y 4-yy = Number of substituents other than Hal

X ¹ , X ² are independent of each other: Cl, Br, I, H; Alkoxy (-OR) ₁ wherein R represents an organo radical having 1 - 20 C atoms; Alkyl having 1 to 20 carbon atoms or aryl having 6 to 20 carbon atoms, wherein the alkyl or aryl radicals one or more further halogen substituents selected from the group F, Cl, Br or I can contain, y indicates the number of substituents X, which are not halogen, and can assume the values 0, 1, or 2. If none of the substituents X ¹ , X ^{2 is} a halogen, then y = 2; if all of the substituents X ¹ , X ^{2 are} halogen, then y = 0.

In the reaction product [M (O) X ³ X ⁴ J _n , the meaning of the radicals X ³ and X ^{4 is} as follows:

In the case where X ¹ and / or X ^{2 have} the meaning halogen (Cl, Br, I) in the metal halide compound MHaI ¹ Hal ² X ¹ X ² , X ³ and X ⁴ in the product have [M (O) X ³ X ⁴ J _{n is} the meaning (O) _1/2 . For the case that X ¹ and / or X ² in the metal halide compound Mhai ¹ Hal ² X ¹ X ² is not the meaning of halogen have the (X ^1, X ² Φ Hal, but X ¹ and / or X ² are, for example, alkyl or aryl ), X ³ and X ⁴ in the product [M (O) X ³ X ⁴ ] _{n have} the same, unchanged meaning as in the metal halide compound.

For clarification, the stoichiometries are shown for three selected raw material combinations:

a) X ¹ and X ² = HaI

2 n SE ₂ O ₃ + 3/7 MHaI ₄ ^► 4 n SEHaI ₃ + 3 [MO ₂ ] _n

b) X ¹ = C ₆ H ₅ , X ² = Hal SE ₂ O ₃ + 2 /? HaI ₃ MC ₆ H ₅ ► 2 n SEHaI ₃ + 2 [M (O) _1i5 C ₆ H ₅ ] _n

c) X ^1, X ² = CH ₃ n RE ₂ O ₃ + 3 n (H ₃ C) ₂ Mhai ₂ ^► n 2 SEHaI ₃ + 3 [MO (CH ₃₎ _2] _n

The simple mode of formation of the metal oxides according to a) is surprising for the person skilled in the art because the reverse reaction in the absence of the solvents used according to the invention is known from the literature. So in Gmelin's

Handbook of Inorg. , Chem., 8 ^th ed Sc, Y, La-Lu, Part C4a, p 152, that quartz (ie pure SiÜ ₂ ) and silicate glasses with liquid and solid rare earth chlorides at elevated temperatures according to the equation

2 SECI ₃ (S ₁ 1) + SiO ₂ (S) - ► 2 MOCI (s) + SiCl ₄ (g)

responded. Furthermore, a large number of oxide silicates and chlorosilicates (eg Yb ₃ (SiO ₄ ) ₂ Cl) could form.

In contrast, it has been found here that silicon tetrachloride reacts with rare earth oxides at room temperature in, for example, tetrahydrofuran (THF) as solvent quickly and irreversibly to the desired metal oxides:

THF

2SE ₂ O ₃ + 3 SiCI ₄ ^► 4 (SECI ₃ ) _THF + 3 SiO ₂

It is also particularly surprising that the metal oxide formed, for example SiO ₂ , is initially obtained in soluble form, presumably as a metastable, soluble polymer sol. The rare earth halides, in contrast, usually have only a low solubility in the solvents or solvent mixtures according to the invention, whereby the rare earth halide in solid form, usually as a solvate with the aprotic polar solvent used, can be separated from the metal oxide sol by solid / liquid separation.

For example, in the reaction of Nd ₂ O ₃ with SiCl ₄ in THF an NdCl ₃ • 2 THF complex is formed, which is only slightly soluble in THF (about 1 to 1, 5%, based on NdCl ₃ ) and in crystalline form Form can be separated by filtration of the desired SiO ₂ - sol.

It is often observed that the metal oxide is only dissolved for a certain time (hours to a few days) as sol, but then turns into the gel form. Since a simple separation of the solid SE-halide (eg by filtration, decantation or centrifugation) then no longer possible, a preferred embodiment of the present invention is to make the solid / liquid separation before the transition to the gel state. Instead of oxides of trivalent metals (rare earth oxides and iron oxide), other metal oxides can also be used for the oxidation of the metal halide compounds. Thus, some oxides with metals in divalent oxidation state M ¹ O with M ¹ = Mg, Ca, Ba, Sr ₁ Mn, Zn are capable of oxidizing the metal halide compounds according to the following equation:

H SE ₂ O ₃ + n - MHaI ¹ Hal ² X ¹ X ^{2 Solvent with} H 2 n SEHaI _{3 +} - [M (O) X ³ X ⁴ ] _n 4-y 4-yy = number of substituents other than Hal

X ¹ , X ² are independent of each other: Cl, Br, I, H; Alkoxy (-OR), wherein R represents an organo radical having 1 - 20 C atoms; Alkyl having 1 to 20 carbon atoms or aryl having 6 to 20 carbon atoms, wherein the alkyl or aryl radicals may contain one or more further halogen substituents selected from the group F, Cl, Br or I, y is the number of substituents X, which are not halogen, and can take the values 0, 1, or 2. If none of the substituents X ¹ , X ^{2 is} a halogen, then y = 2; if all of the substituents X ¹ , X ^{2 are} halogen, then y = 0.

The meaning of the radicals X ³ and X ⁴ in the product [M (O) X ³ X ⁴ J _n is (O) _1/2 in the case where X ¹ and / or X ^{2 is} halogen (Cl, Br, I ) in the metal halide compound MHaI ¹ HaI ² X ¹ X ² , or unchanged as in the metal halide compound for the case X ¹ , X ² Φ HaI. For clarification, the stoichiometries are shown for three selected raw material combinations:

a) X ¹ and X ² = HaI

2 n M ¹ O + n MHaI ₄ ► 2 n M ¹ HaI ₂ + [MO ₂ I _n

b) X ¹ = C ₆ H ₅ , X ² = Hal

3 n M ¹ O + 2/7 Hal ₃ MC ₆ H ₅ ► 3 n M ¹ Hal ₂ + 2 [M (O) _{1 5} C ₆ H ₅ I _n

c) X ¹ , X ² = CH ₃ nM ¹ O + 2 n (H ₃ C) ₂ MHaI ₂ > - n M ¹ Hal ₂ + 2 [MO (CH ₃ ) ₂ ] _n It makes sense to comply largely with the theoretical implementation conditions. From the stated general stoichiometries can also be deviated depending on the intended application up or down, for example, preferably up to 50%. In these cases, either unreacted Halogenakzeptor (Halogenakzeptor in excess) remains, which is usually insoluble and therefore can be easily removed by filtration; or there remains an unchanged metal halide compound (metal halide compound in excess), which is usually soluble and therefore remains as a homogeneous contaminant in the metal colloid phase. The latter is generally disadvantageous if a metal oxide polymer or metal oxide colloid with the highest possible purity is desired.

The metal oxide colloids and / or metal oxide polymers according to the invention are used, for example. in the surface treatment of solids, that is to say - for coating materials of all kinds, in particular metals,

Ceramics, glasses, plastics, electroactive materials or the like having an MOX ³ X ⁴ layer, optionally doped by the metal cation introduced by the halogen acceptor, or by direct evaporation to produce heterogeneous catalysts (MOX ³ X ⁴ -containing solids) of the metal colloid or precipitation / drying of the metal colloid. Such catalysts are used for polymer synthesis, for example for the production of polyolefins such as polyethylene, polypropylene or copolymers and copolymers or polyesters such as polyethylene terephthalate (PET), polyethylene naphthenate (PEN),

Polybutylene terephthalate (PBT)) used.

Furthermore, the colloid solutions can be used as gelling agents for organic or inorganic preparations. After removal of the solvent and depending on the state of aggregation of the remaining MOX ³ X ⁴ product, the following uses continue to exist: - As a heat transfer oil, lubricant, or anti-foaming agent (applies to oily products), wherein M is preferably Si or as

- Material (applies to rubber-elastic or resinous products).

The object of the invention will be explained in more detail with reference to the following examples:

Example 1: Preparation of SiO ₂ -SoI from SiCl ₄ ZNd ₂ O ₃ in THF

In an inertized, ie dried and filled with argon 0.5-1 jacketed reactor with reflux condenser and dropping funnel 25.2 g (75 mmol) of neodymium oxide (99% from Aldrich) in 14O g of THF was suspended. While stirring, 20.5 g (120 mmol) of silicon tetrachloride at internal temperatures between 25 and 30 ⁰ C were added within 30 minutes.

The reaction was clearly exothermic and a light blue suspension formed. After completion of the dropwise addition was stirred for 1.5 hours at about 30 ⁰ C and then cooled to 20 ⁰ C.

Then the suspension was drained onto a G3 glass frit and the crystalline filter residue washed once with 48 g of THF. The residue was vacuum dried at 25 ⁰ C, and (g 50.8, 90% of theory) as NdCI ₃ • 2 THF identified. Filtrate and wash filtrate were combined.

Weighing: 123 g clear, almost colorless

Analysis (mmol / g):

Si = 0.89; Nd = O ₁ H; Cl = 0.35

Based on silicon, this corresponds to a yield of 91%. Small amounts of by-product NdCl _{3 were} dissolved in the product solution. In the ²⁹ Si NMR spectrum, a broad signal at δ = 112.8 ppm was registered (for comparison: SiCl ₄ has a shift of δ = -18.5 ppm). By gas chromatography, no volatile by-products could be detected in significant amounts (THF = 99.8 Fl%).

The initially slightly mobile solution solidified after about 2 days of storage at room temperature to a solid gel.

Example 2: Preparation of TiO ₂ -SoI from TiCl ₄ ZNd ₂ O ₃ in THF

In an inertized 250 ml three-necked flask, 12.4 g (37.2 mmol) of neodymium oxide were suspended in 76 g of THF and cooled to ⁰ ° C. by means of an ice bath. Then, within half an hour, 11.4 g (61 mmol) of TiCl _{4 were added} by syringe technique with good stirring (very vigorous exothermic reaction).

Stirring was continued for 20 minutes at ⁰ ° C., then for 2 hours at room temperature and then filtered. The filter residue was washed with 20 ml of THF. There was obtained 16.7 g of a dove blue crystallizate identified as NdCb • 2 THF complex.

The yellow-greenish filtrate (83 g) was analyzed as follows:

Ti = 0.62 mmol / g Nd = 0.061 mmol / g Cl = 0.25 mmol / g

This corresponds to a titanium related yield of 84%. The TiO ₂ -SoI is doped with NdCb, which has a solubility of approximately 1.5% by weight in the system.

By gas chromatography, no significant amounts of volatile by-products, in particular no pointing to a decomposition of THF indicating components such as butanol could be detected. Further examples according to the invention can be found in the following table:

Examples 3 to 13:

Tab. 1: Preparation of metal oxide sols

Ex. Metal oxide metal halide solvent reaction conditions No. compound

Type Quantity Type Quantity Type Quantity (mmol) (g) (g)

3 Nd ₂ O ₃ 50 PhSiCl ₃ 100 THF 92 1 hour 30 ⁰ C, then reflux for 2 hours

4 La ₂ O ₃ 100 SiCl ₄ 158 248 THF stirring 25 ⁰ C, then 3 h refluxing

5 La ₂ O ₃ 50 SiCl ₄ 78.9 THF / 160 4 h 25-35 ⁰ C toluene

6 La ₂ O ₃ 50 SiCl ₄ 78.5 DMC 171 1 h approx. 25 ⁰ C, then reflux for 1.5 h

7 Sm ₂ O ₃ 19.4 SiCl ₄ 29.4 THF 90 3 h Reflux

8 ZnO 50 SiCl ₄ 25 THF 31 1 hr 20 - 50 ⁰ C

9 MnO 79 SiCI ₄ 44 THF 90 2 hr 25-40 ° C

MgO 10 28 SiCl ₄ 18 Et ₂ O 105 1 hr 20 - 30 ⁰ C, 2 h refluxing

11 MgO 50 SiCl ₄ 25 THF 27 1 h 30-65 ⁰ C

12 MgO 157 PhSiCl ₃ 100 THF 191 1 h 20 - 30 ⁰ C, 1 h Reflux

13 La ₂ O ₃ 30 SiBr ₄ 45 2- 140 1 h Reflux MeTHF

Tab. 2: Test results of metal oxide sol preparation

Example Solution Analysis (mmol / g) Composition Observations No. Appearance Amount Metal Si Halide Metal oxide Metal colloid Halide

(g) (wt%) (wt%)

3 yellowish greenish 149 ¹⁾ 0.05 (Nd) 0.63 0.18 (Cl) SiPhOi ₁ S NdCl ₃ (1, 3) (8,2)

4 yellow, clear 370 ¹⁾ 0.005 (La) 0.31 0.18 (Cl) SiO ₂ (1, 9) LaCI ₃ (O ₁ I) Gelation on storage

5 yellowish 260 0.07 (La) 0.25 0.30 (Cl) SiO ₂ (1, 5) LaCl ₃ (0.15)

6 colorless, clear 79 nn 0.34 0.04 (Cl) SiO ₂ 2.0 ./. gelled after about 2 weeks

7 light yellow, 147 0.06 (Sm) 0.10 0.26 (Cl) SiO ₂ (0.6) LaCl ₃ (1, 5) Gelation slightly turbid

8 colorless, clear 25 0.75 (Zn) 0.85 1, 73 (Cl) SiO ₂ (4.9) ZnCl ₂ (10)

9 light brown111 0.005 0.44 0.12 (Cl) SiO ₂ (2.5) MnCl ₂ (O ₁ I) Lich, clear (Mn)

10 colorless, 163 0.03 (Mg) 0.07 0.07 (Cl) SiO ₂ (0.4) MgCl ₂ (0.3) slightly cloudy

11 colorless, clear 23 0.65 (Mg) 0.27 1, 35 (Cl) SiO ₂ (1.5) MgCl ₂ (6.2)

12 yellowgreen / clear 220 ¹⁾ 0.50 (Mg) 0.45 0.95 (Cl) SiPhOi s MgCl ₂ (4.8) Precipitation (6.0)

13 colorless 144 ¹ »0.21 (La) 0.19 0.65 (Br) SiO ₂ (1, 1) LaBr ₃ (8.0)

¹⁾ incl. Amount of washing solvent nn = undetectable

In contrast to example 1, in example 3 an organosilane (phenyltrichlorosilane) was used instead of SiCl ₄ as halogenating agent. After filtration, a clear, readily mobile solution containing a Si polymer of the general formula [SiPhOi, s] _{n was obtained} . Even after prolonged storage, the product solution did not change, ie no gelation occurred.

In Examples 4 and 7, instead of Nd ₂ O _3, other SE oxides (La ₂ O ₃ , Sm ₂ O ₃ ) were used. In both cases, the filtrates went into gel state after solidification after a few days. If a mixture of THF / toluene is used as the reaction solvent instead of pure THF, no gelation was observed in the combination of raw materials selected in Example 5.

On the other hand, when using dimethyl carbonate (DMC), gelling occurred after a longer useful life (Example 7). Examples 8 to 12 deal with halogen acceptors other than rare earth metal oxides: zinc oxide (Example 8), manganese oxide (Example 9), magnesium oxide (Examples 10 to 12). Finally, Example 13 shows that bromine compounds, in this case silicon tetrabromide, can be used instead of chlorine-based metal halide compounds.

Claims

claims

1. Anhydrous metal oxide colloids and / or metal oxide polymers of the general formula

[M (O) X ³ X ⁴ ] _n (1)

in an aprotic, organic solvent or solvent mixture,

wherein M = Si, Ge, Sn, Ti, Zr or Hf; and X ³ and X ⁴ independently of one another O1 _/ 2, H, alkoxy (-OR) wherein R is an organic radical having 1 - 20 carbon atoms represents, alkyl having 1 to 20 carbon atoms or aryl having 6 to 20 carbon Atoms, wherein the alkyl or aryl radicals may carry one or more further halogen substituents selected from the group F, Cl, Br or I; and n takes typical values between 10 and 1,000,000.

2. Metal oxide colloids and / or metal oxide polymers according to claim 1, characterized in that the metal oxide colloids and / or metal oxide polymers contain metal halides M ¹ Hal _x , where M '= metal selected from the group of rare earth metals, Mn, Zn, Fe, Mg, Ca, Ba, Sr is, Hal = halogen, selected from the group, Cl, Br, I, and x = valency of the metal M is ¹ .

3. Metal oxide colloids and / or metal oxide polymers according to claim 2, characterized in that the molar concentration of the metal halide M ¹ HaI _x 0.1 to 200% of that of the metal oxide colloid MOX ³ X ⁴ .

4. Metal oxide colloids and / or metal oxide polymers according to any one of claims 1 to 3, characterized in that the metal oxide colloids and / or metal oxide polymers further metal salts in concentrations of 0.001 to 20 wt -.% Contain.

5. Metal oxide colloids and / or metal oxide polymers according to any one of claims 1 to 4, characterized in that the metal oxide colloids and / or metal oxide polymers MO ₂ with M = Si or Ti.

6. Metalloxidkolloide and / or metal oxide polymers according to one of claims 1 to 4, characterized in that the metal oxide colloids and / or

Metal oxide polymers contain compounds of the following empirical formulas: C ₆ H ₅ SiOi, ₅ , HSiOi, ₅ , HalC ₆ H ₄ SiOi, ₅ (Hal = Cl, Br, I), (H ₃ C) ₂ SiO; C ₆ H ₅ TiOi, ₅ , HTϊO - ,, 5, HaIC ₆ H ₄ TiO ₁₁₅ (Hal = Cl, Br, I), (H ₃ C) ₂ TiO.

7. metal oxide colloids and / or metal oxide polymers according to one of claims 1 to 6, characterized in that the metal oxide colloids and / or

Metal oxide polymers include one or more of the following polar, aprotic solvents: ethers (either open-chain or cyclic, mono- or polyfunctional), esters (either carboxylic esters or carbonic acid esters), ketones, amides, nitriles, halogen-free sulfur compounds, tertiary amines, or hydrocarbons.

8. metal oxide colloids and / or metal oxide polymers according to claim 7, characterized in that is used as the solvent THF, 2-MeTHF, dimethyl carbonate, acetone, propionone, propylene carbonate and / or diethyl ether.

9. Metal oxide colloids and / or metal oxide polymers according to any one of claims 1 to 8, characterized in that the concentration of metal oxide colloid and / or metal oxide polymer is 0.001 to 2 mol / l.

10. Metal oxide colloids and / or metal oxide polymers according to claim 9, characterized in that the concentration of metal oxide colloid and / or metal oxide polymer is from 0.01 to 1 mol / l.

11.The process for the preparation of anhydrous metal oxide colloids or metal oxide polymers of the general formula

[M (O) X ³ X ⁴ ] _n (1) in an aprotic organic solvent or solvent mixture,

in the metal halide compounds of the general formula

MHaI ¹ HaI ² X ¹ X ² (2)

with M = Si ₁ Ge ₁ Sn ₁ Ti ₁ Zr ₁ Hf Hal = Cl ₁ Br ₁ I

X ¹ , X ² = independently of one another Cl, Br ₁ I ₁ H ₁ alkoxy (-OR), where R represents an organo radical having 1 to 20 C atoms, alkyl having 1 to 20 C atoms or aryl having 6 to 20 C -Atomen, wherein the alkyl or aryl radicals may carry one or more further halogen substituents selected from the group F ₁ Cl, Br or I ₁ with halogen acceptors selected from the group of rare earth metal oxides SE ₂ O ₃ (with SE = Sc, Y, La , Pr ₁ Nd ₁ Pm, Sm ₁ Eu ₁ Gd ₁ Tb ₁ Dy ₁ Ho ₁ Er ₁ Tm ₁ Yb or Lu) ₁ metal (II) oxide or Fe ₂ O ₃ ,

be reacted in a polar, aprotic solvent.

12. The method according to claim 1 1, characterized in that the tetrahalogen compounds MHaI ₄ are used as metal halide compounds.

13. The method according to claim 11, characterized in that as metal halide compounds, the following compounds are used: C ₆ H ₅ MHaI ₃ , HMHaI ₃ , C ₆ H ₄ HaIMHaI ₃ , (H ₃ C) ₂ MCICH ₂ Hal, (CH) ₂ MHaI ₂ ,

(CH ₃ ) ₃ MHal or mixtures thereof.

14. The method according to any one of claims 1 1 to 13, characterized in that as metal halide compounds, the following compounds are used: SiCl ₄ , SiBr ₄ , GeCl ₄ , SnCl ₄ , TiCl ₄ , TiBr ₄ , C ₆ H ₅ SiCl ₃ , 4- CIC ₆ H ₄ SiCl ₃ , 4-BrC ₆ H ₄ SiCl ₃ , HSiCl ₃ or (CH ₃ ) ₂ SiCl ₂ .

15. The method according to any one of claims 11 to 14, characterized in that as rare earth metal oxides Nd ₂ O ₃ , Sm ₂ θ3 or La ₂ O ₃ are used.

16. The method according to any one of claims 11 to 14, characterized in that are used as metal (II) oxides MgO, CaO, BaO, SrO, ZnO or MnO.

17. The method according to any one of claims 11 to 16, characterized in that the halogen acceptors are used in powdered form and with H ₂ O contents <0.5%.

18. The method according to any one of claims 11 to 17, characterized in that as polar, aprotic solvent one or more ethereal

Compounds may be used, which may be open-chain, such as

R ¹ -OR ² (with R ¹ and R ² independently of one another alkyl or aryl with 1 to 8

(CH ₂ I CHR

C-atoms); or may be cyclic, such as ^v - (with n = 3 or 4 and R = H or alkyl with 1 to 8 C atoms); or polyfunctional, such as RO- (OH ₂ -CH ₂ -O) _n -R ¹ (with R and R ¹ independently of one another alkyl radicals having 1 to 8 C atoms and n = 1 to 100) and either in pure form or be used in mixture.

19. The method according to any one of claims 1 1 to 18, characterized in that one or more of the following aprotic, polar solvents are used: esters, (carboxylic acid esters such as ethyl acetate, γ-butyrolactone,

Methyl benzoate, or carbonic acid esters such as dimethyl carbonate, diethyl carbonate, propylene carbonate, ethylene carbonate), or mixtures thereof; or ketones (such as acetone, propionone); or amides (such as N-methylpyrrolidone, dimethylacetamide, NMPU); or nitriles (such as acetonitrile, butyronitrile); or halogen-free sulfur compounds (such as dimethyl sulfoxide); or tertiary

Amines (such as triethylamine, tetramethylethylenediamine).

20. The method according to any one of claims 11 to 19, characterized in that the polar, aprotic solvent one or more hydrocarbons such as alkanes or aromatics in a weight ratio solvent: hydrocarbon = 1: maximum 5 are added.

21. The method according to claim 20, characterized in that is used as the hydrocarbon pentane, hexane, cyclohexane, methylcyclohexane, heptane octane, benzene, toluene, ethylbenzene, cumene or XyIoI.

22. Use of the metal oxide colloids and / or metal oxide polymers according to any one of claims 1 to 10 in the surface treatment of solids.

23. Use according to claim 22 for coating materials of all kinds, in particular of metals, ceramics, glasses, plastics, electroactive materials or the like with a MOX ³ X ⁴ layer, which is optionally doped by the introduced by the halogen acceptor metal cation.

24. Use according to claim 22 for the preparation of heterogeneous catalysts (MOX ³ X ⁴ -containing solids) by direct evaporation of the metal colloid or precipitation / drying of the metal colloid.

25. Use of the solids according to claim 24 as catalysts for polymer synthesis, for example for the preparation of polyolefins, copolymers and polyesters and polyesters.

26. Use of the metal oxide colloids and / or metal oxide polymers according to any one of claims 1 to 10 as a gelling agent for organic or inorganic preparations, as a heat transfer oil, as a lubricant, as an antifoaming agent or as a material.