EP2414370A1

EP2414370A1 - Method for producing hydrocarbon oxy-silicon compounds

Info

Publication number: EP2414370A1
Application number: EP10710569A
Authority: EP
Inventors: Michael Stepp; Markus Merget
Original assignee: Wacker Chemie AG
Current assignee: Wacker Chemie AG
Priority date: 2009-04-01
Filing date: 2010-03-19
Publication date: 2012-02-08
Also published as: KR20110132455A; US20120010422A1; JP2012522738A; KR101335781B1; DE102009002075A1; WO2010112350A1; CN102365289A; US8507709B2

Abstract

The invention relates to a method for producing silicon compounds (A) having hydrocarbon oxy-groups that have at least one unit of the general formula (1) HmSi (OR)n (OR' ) oR"pX4-m-n-o-p (1) by conversion of silicon compounds (B) having at least one unit of the general formula (2) Hm+nSi(OR')oR"pX4-m-n-o-p (2), having an alcohol of the general formula (3 ) ROH ( 3 ) in the presence of a catalyst (K) that is on a carrier material bonded metal selected from Ni, Pd, Pt, wherein per mol formed group OR, at maximum 1 liter of solvent is used and wherein R, R', R' ', X, m, n, o and p have the meanings listed in claim 1.

Description

Process for the preparation of Kohlenwasserstoffoxysiliciumverbindungen

The invention relates to a process for the preparation of Kohlenwasserstoffoxysiliciumverbindungen by reaction of SiH-silicon compounds with alcohols in the presence of metal catalysts on support materials.

Various processes for the preparation of alkoxysiloxanes are known from the prior art.

For example, according to JP 09040681 A, the hydrolysis of alkoxysilanes in the presence of a cation exchange resin leads to mixtures of alkoxysiloxanes having 2-5 Si atoms. Access to α, ω-dialkoxyoligosiloxanes by equilibration of linear or cyclic siloxanes with dialkoxysilanes in the presence of acids is described, for example, in JP 09012720 A. A complicated route to 1,3-dimethoxy-1,1,3,9-tetramethyldisiloxane starting from the corresponding α, ω-

Dichlorodisiloxane, ammonolysis, hydrolysis, esterification with methanol described JP 08325277 A.

The abovementioned processes have the disadvantage that mixtures of siloxanes are obtained from which the defined compounds, in particular the respective disiloxanes, have to be isolated in a laborious and lossy manner.

Silanes and siloxanes in which all or part of their valences are occupied by alkoxy groups can be prepared by reacting the corresponding SiH compounds with alcohols in the presence of basic, acidic or metal-containing catalysts to release hydrogen. The Si-bonded hydrogen atoms are against the Alkoxy radicals of the respective alcohol with the release of gaseous hydrogen exchanged. Among the catalysts there are representatives that not only accelerate the desired SiH exchange reaction, but also cause unwanted side reactions, such as equilibrations or rearrangements of the siloxane backbone. These strongly basic (eg, metal alcoholates) or acidic catalysts are not suitable for targeted reactions, in particular in the presence of base or acid-incompatible functional groups, so that alternatives were sought which make a selective reaction possible.

A selection of such methods is exemplified in the following references:

No. 2,967,171 describes the replacement of Si-bonded H by alkoxy groups by dehydrocondensation of SiH silanes and SiH siloxanes with alcohols. The catalyst used is hexachloroplatinic acid, which is why only saturated systems can be used and the carryover of chloride ions or chlorine-containing compounds into the target product can not be ruled out.

A combination of a platinum compound and an organic acid is used in EP 475440 A as a catalyst for the dehydrocondensation of SiH siloxanes with an aliphatic alcohol having at least 4 C atoms. Carryover of the organic acid into the target product can not be excluded.

DE 1248048 A describes the use of hydroxylamines as catalysts. But here is the danger of one Carryover of organic components in the target product given.

A catalytic system for the dehydrocondensation of SiH units with alcohols is described in EP 1627892. It is a mixture of a boron compound (e.g., tris (pentafluorophenyl) borane) and at least one synergistically acting metal salt. Carryover of traces of metallic or boron-containing compounds in the target products can not therefore be ruled out, which is why this route is unsuitable for the production of in particular semiconducting alkoxysiloxanes.

The dehydrocoupling of polyglycol alcohols with poly (methylhydrogen) siloxane can be carried out according to Zhang, Ruzhi; Zhang,

Zhengcheng; Amines, Khalil; West, Robert (Organosilicon Research Center, Department of Chemistry, University of Wisconsin-Madison, Madison, WI, 53706, USA) Silicon Chemistry (2005), 2 (5/6), 271-277) with Rh (PPh ₃ ) ₃ C1 and Pd ₂ (dba) 3 are catalyzed without formation of branching.

Zinc hydrides have been reported by H. Mimoun in Journal of Organic Chemistry (1999), 64 (7), 2582-2589, et al. for the hydrosilylation of aldehydes, ketones and esters described, but can also be used for the dehydrogenative silylation of

Alcohols are used. Their production from NaBH4 and

Zinc carboxylates and their handling are complex and demanding in terms of safety.

All of the abovementioned processes have the disadvantage that, when the target products are isolated, carryover of (co) catalyst traces into the target product can take place, which is why the products obtainable from these processes have only limited effect on suitable for use in applications where impurities interfere, such as as CVD precursors in the semiconductor field. Some of the catalysts are not commercially available and must be synthesized consuming and expensive. Recyclability or reusability in the process is usually not possible.

L.H. Sommer and J. E. Lyons (Journal of American Chemical Society 91, 7061 (1969)) describe the dehydrocondensation of optically active silanes with alcohols on heterogeneous, e.g. supported catalysts (e.g., palladium, ruthenium, and rhodium on activated carbon). Their reactions, however, were carried out only in the presence of non-polar solvents, as they had evidence that polar solvents poison the surface of the catalysts in question.

It was the task of finding a method in which these disadvantages do not occur and which can be implemented with simple, commercially available available catalysts.

The invention relates to a process for the preparation of hydrocarbyl-containing silicon compounds (A) which contain at least one unit of the general formula (1)

H _m Si (OR) _n (OR ') _o R " _p X ₄ _ _m _ _n _ _o _ _p (1)

have, by reaction of silicon compounds (B), the at least one unit of the general formula (2)

^H m + n ^{Sl (} ° ^R ' ⁾ o ^R ''p ^x 4-mnop ⁽²⁾ having an alcohol of the general formula (3)

RAW

in the presence of a catalyst (K), which is metal bound to a support material, which is selected from Ni, Pd, Pt, wherein per mol of group OR formed, at most 1 liter of solvent is used and wherein

R is a monovalent hydrocarbon radical having 1 to 18 carbon atoms, which may be substituted by OH groups, halogen atoms, silyl groups, siloxy groups, -CN,

-COOR ¹ , -OCOOR ² , -CONR ³ R ⁴ , -OCONR ⁵ R ⁶ , -NR ⁷ CONR ⁸ R ⁹ , -SO ₂ -R ¹⁰ , -OSO ₂ -R ¹¹ , -OP (OR ¹² ) (OR ¹³ ), wherein the carbon chain may be interrupted by non-adjacent - (CO), -O-, -S- or -NR ¹⁴ groups;

R ', R "each represents a monovalent hydrocarbon radical of 1 to 18 carbon atoms which may be substituted by

Halogen atoms, silyl groups, siloxy groups, -CN, -COOR ¹ , -OCOOR ² , -CONR ³ R ⁴ , -OCONR ⁵ R ⁶ , -NR ⁷ CONR ⁸ R ⁹ , -SO ₂ -R ¹⁰ , -OSO ₂ -R ¹¹ , -OP (OR ¹² ) (OR ¹³ ), wherein the carbon chain may be interrupted by non-adjacent - (CO), -O-, -S- or -NR ¹⁴ groups;

R ¹ to R ¹⁴ each having a monovalent hydrocarbon radical

1 to 18 carbon atoms, which may be substituted by halogen atoms,

X is a chemical bond via which residues are attached which contain silicon atoms, m is 0, 1, 2 or 3, n is 1, 2 or 3, m + n is 1, 2 or 3, o is 0 , 1, 2 or 3, p the values 0, 1, 2 or 3 and m + n + o + p are the values 1, 2, 3 or 4.

Surprisingly, it has been found that the reaction of an SiH compound with alcohols in the presence of Ni, Pd, Pt on support materials proceeds rapidly and spontaneously at significantly lower levels up to complete absence of nonpolar solvents even under mild conditions and quantitatively with hydrogen splitting to give the corresponding alkoxysilane. ox) leads to and thus the economy is improved by increasing the space / time yield. The further advantages of the method according to the invention lie in the fact that the insoluble heterogeneous catalyst can easily and completely be separated off by filtration, sedimentation, centrifugation or, if appropriate, by distilling off the target product and used again if required. As a result, the process according to the invention is predestined for the cost-effective production of particularly pure alkoxysiloxanes which are e.g. in the semiconductor industry as CVD precursors find use. Another advantage is the avoidance of side reactions that reduce the yield and generate waste whose disposal pollutes the environment as far as possible.

When m + n + o + p = 4, i. 4-m-n-o-p = 0, then the silicon compounds (A) and (B) are monosilanes.

If m + n + o + p = 1, 2 or 3, then in the silicon compounds (A) and (B) in the units of the general formulas (1) and (2) via the chemical bonds X radicals are attached, which are silicon atoms contain.

The hydrocarbon radical R may be linear, cyclic, branched, aromatic, saturated or unsaturated. Preferably, the hydrocarbon radical R has 1 to 6 carbon atoms, Particular preference is given to alkyl radicals, alkylaryl radicals, arylalkyl radicals and phenyl radicals. Particularly preferred alkyl radicals are methyl and ethyl. The hydrocarbon radical R preferably has no or 1 to 6 additional OH groups, in particular 1, 2 or 3 OH groups. There are only one OH group on a carbon atom.

The monovalent hydrocarbon radicals R ', R "and R - * - to RΛ ^ may be linear, cyclic, branched, aromatic, saturated or unsaturated. Preferably, the

Hydrocarbon radicals R ', R' 'and R - * - to R- ^ 1 to 6

Carbon atoms, particularly preferred are alkyl, vinyl, allyl and phenyl radicals. Particularly preferred alkyl radicals are methyl and ethyl.

The radicals attached via the chemical bonds X are preferably polyvalent hydrocarbon radicals R 1, which in the case of silicon compounds (A) comprise one or more units of the general formulas (1) or, in the case of silicon compounds (B), one or more units of the general formulas (2) preferably have no or one unit of the general formula (1) or (2). Preferably, the

Hydrocarbon radicals R 2, 3 or 4 valent. The

Hydrocarbon radicals R 1 preferably have 1 to 50, in particular 1 to 18, particularly preferably 1 to 6, for example 1, 2, 3 or 4 carbon atoms. The chemical bonds X in this case are Si-C bonds.

The bonded via chemical bonds X radicals are preferably monovalent or polyvalent hydrocarbon radicals R ^^ ^1, which contain Si-C bonds embedded silicon atoms. The silicon compounds (A) and (B) can be made Residues R ^ S ⁱ and one or more units of the general formulas (1) and (2) exist. Preferably, the hydrocarbon radicals R ^ S ^{i are} 2, 3 or 4 valent. The radicals R ^ S ⁱ preferably 1 to 50, especially 1 to 18 have, particularly preferably 1 to 6, for example 1, 2, 3 or 4

Carbon atoms on. The radicals RpS ⁱ preferably have 1 to 10, particularly preferably 1 to 6, for example 1, 2, 3 or 4 silicon atoms. The chemical bonds X in this case are Si-C bonds.

The bonded via chemical bonds X radicals are preferably mono- or polyhydric (poly) silane group R ^ ¹ containing Si-Si bonds embedded silicon atoms. The

Silicon compounds (A) and (B) can be selected from radicals R ^ ¹ and one or more units of the general formulas (1) or

(2) exist. Preferably, the hydrocarbon radicals R ^ are ¹

2, 3 or 4-valued. The radicals R ¹ have preferably 1 to 50, in particular 1 to 18, more preferably 1 to 6, for example 1, 2, 3 or 4 silicon atoms. The radicals R ¹ have preferably 1 to 10, more preferably 1 to 6, for example 1, 2, 3 or 4 silicon atoms. The chemical bonds X in this case are Si-Si bonds.

The bonded via chemical bonds X radicals are preferably mono- or polyhydric (poly) siloxane groups R ^ S ⁱ containing Si-O-Si bonds embedded silicon atoms. The (poly) siloxane radicals R ^ ⁱ S may be prepared by

Units of the general formulas (4), (5), (6) and / or (7)

⁽ X ' ⁾ b ⁽ R'" ⁾ _c Si ⁽ 4 ⁾ , (X ') d ( ^R '") e ^sio l / 2 (5),

(X ') f (R'") _g Si0 _2/2 (6), X'SiO _{_3/2} (7; t be attached to the units of the general formulas (1) or (2), wherein

X 'is a group -O-, R' '' has the meanings of R '', b is 1, 2, 3 or 4 c is 0, 1, 2 or 3, b + c is 4, d the values 1, 2 or 3 e have the values 0, 1 or 2, d + e the value 3, f the values 1 or 2 g the values 0 or 1 and d + e the value 2.

The chemical bonds X together with X 'form in this

Case Si-O-Si bonds.

The (poly) siloxane groups R ^ S ⁱ can still preferably up to 1,000 more units of the general formulas (8), (9), (10) and (11)

R "_'3 Si0 _1/2 (8),

R '"2 ^si0 2/2 (9),

R '' _SiO3 / 2 (10) SiO _{_4/2} (H) contain, where

R '' 'has the above meanings.

The silicon compounds (A) and (B) may consist of radicals R ^ ^Si and one or more units of the general formulas (1) or (2). The radicals R 1, Si preferably have 1 to 1000, in particular 1 to 200, particularly preferably 1 to 10, for example, 1, 2, 3 or 4 units of the general formulas (4) to (11).

The silicon compounds (A) and (B) may be linear, cyclic or branched.

If the hydrocarbon radical R has further OH groups, two or more silicon compounds (A) may be linked via R radicals or crosslinked.

Preference is given to preparing silicon compounds (A) of the general formulas (12) to (15)

(RO) _h -SiR " ₄ _ _h (12),

RO- [SiR '' 2 ^~ O-] _Z -R (13),

[RO-SiR " _2- O] _y Si-R" ₄ _ _y < ¹⁴ ) '

[R ^v R "2 ^SiO l / 2] a [(R {0-CH ₂ CH (R ^IV)} _r O) R" SiO ₂ / k ₂ 1

[SiR " ₂ O _2/2 ] ₁ [SiHR" O _2/2 ] _m (15),

in which

R * V are hydrogen atoms or methyl radicals, R ^{v are} methyl, ethyl, vinyl, allyl or phenyl radicals, h are the values 1 or 2, z are values from 1 to 20, y are the values 1, 2, 3 or 4, a values from 0 to 2, r values from 0 to 20, k values from 1 to 20,

1 values from 0 to 200, m values from 0 to 100 and a + k + l + m mean values of at least 4 and

R and R "have the above meanings.

In mixtures of the silicon compounds (A) of the general formulas (13) and (15), z, a, r, k, 1, m may represent mean values and thus also be numbers with decimal places.

In the general formula (15), units [(R (O-CH 2 CH (R ^IV )} _r O) R "SiO 2 / 2I ^ may occur in which the radicals R ^IV exclusively hydrogen atoms or methyl radicals, or in which Radicals R * ^, mixed hydrogen atoms or methyl radicals mean that all hydrogen atom / methyl radical ratios of 0-100% hydrogen atoms are possible.

The variety of silicon compounds (A) obtainable by the process according to the invention are intended to reflect the following examples: (tBuO) HSi (OEt) ₂ , MeO-Si (n-Bu) 3, (MeOSiMe ₂ ) ₂ -CH-CH- (SiMe ₂ OMe ) ₂ , (MeO) 3 Si-O-CH ₂ CH ₂ -O-Si (OMe) 3, (EtO) 3 Si-O-CH ₂ CH (CH ₃ ) -O-Si (OEt) 3, PhO-SiPh ( OMe) ₂ , n-cyclohexyl-O-SiMe (OEt) ₂ , HO-CH ₂ CH ₂ -O-SiMe ₂ (O-CH ₂ CH ₂ -O-CH ₂ CH ₂ -O-CH ₂ CH ₂ -OMe ), HO-CH ₂ -SiMe ₂ -O-SiMe ₂ -CH ₂ -O-SiMe ₂ -O-SiMe ₂ -O-CH ₂ -SiMe ₂ -O-SiMe ₂ -CH ₂ -OH, Me-CH ₂ CH ₂ O-CH ₂ CH ₂ O-CH ₂ CH ₂ O-CH ₂ CH ₂ O-SiMe ₂ O-SiMe ₂ O-SiMe ₂ O-SiMe ₂ O-SiMe ₂ -CH = CH ₂ , tBuOSi (OEt) ₂ -CH ₂ -Si (OEt) ₂ H, (EtO) 3 Si-O-CH ₂ CH (CH ₃ ) -O-Si (OEt) 3 MeO-SiMe ₂ -O-SiMe ₂ -OMe, (MeO-SiMeO ) ₄ , (EtO-SiMeO) ₅ , (Me ₂ SiO) ₃ (SKtBuO) MeO), (MeO-SiMe ₂ -O) ₄ Si, (MeO-SiMe ₂ -O) ₃ SiMe, (PhO-SiMe ₂ - O) ₃ SiPh,

Me ₃ Si-O-SiMe ₂ -O-CH ₂ CH ₂ -O-CH ₂ CH ₂ -O-CH ₂ CH ₂ -CH ₂ CH ₂ OMe, MeO-SiMe ₂ O- (SiMe ₂ O) 55-SiMe ₂ -OMe, Me ₃ SiO- (SiHMeO) 35- (Si (OEt) MeO) ₂₀ -SiMe ₃ , Me ₃ SiO- (SiMe ₂ O) ₂₂₀ ( ^Si (O-iPr) MeO) 5-SiMe ₃

H ₂ C = CH-CH ₂ -O-CH ₂ CH ₂ -O-SiMe ₂ O- (SiMe ₂ O) 140 (SiHMeO) 5 SiMe ₂ -O- CH ₂ CH ₂ -O-CH ₂ -CH = CH ₂

(EtO) ₃ Si-O- (SiMe ₂ O) 495-Si (OEt) 3

[Me ₃ Si0i / _2] 4 [SiMeO _{_3/2]} 7 _f 5 [SiMe (OEt) O1 / 2] 4 [SiMeHO ₂ Z _2] 1

[(EtO) ₃ SiO ₁ Z ₂ ] 6 [(EtO) ₂ SiO ₂ Z ₂ ] 4, 6t ^HSi (OEt) O _2/2 ] 1.4 [HSiO _3/2 ] ₂ , ₂

[SiO ₄₇₂ ] IH ₂ C = CH-SiMe ₂ O- (SiMe ₂ O) ₄₄₀ (Si [0- (CH ₂ CH ₂ O) ₃ -Me] MeO) ₁₄ -SiMe ₂ -CH = CH ₂

Me ₃ SiO- (SiMe (CH = CH ₂ ) O) 4 _^ 9- (SiMe ₂ O) ₁₂ - (Si [O- (CH ₂ ) 9-CH = CH ₂ ] MeO) g _^ 5-SiMe ₃

Me ₃ S iO- (S iMeCH ₂ CH ₂ CF ₃ O) ₁ 5/2 (S i [on-dodecyl] MeO) 7 - S iMe ₃ H ₂ C = CH- S iMe ₂ O-

(SiMe (OCH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OMeIO) g (Si (OEt) MeO) ₂ -SiMe ₂ -CH = CH ₂

A special feature of the process according to the invention is that the part of the silicon compounds (B) not affected by the dehydrocondensation reaction with the alcohol of the general formula (3) is as a rule not or only insignificantly changed by the conversion to silicon compounds (A). Possible changes to the molecular skeleton are essentially limited to secondary side reactions, such as condensation reactions of silanol groups, which are formed by hydrolysis reactions. The water required for this purpose can be introduced, for example, into the reaction by the reaction components. Accordingly, only the units of the general formula (2) contained in silicon compounds (B), depending on the stoichiometry and Reaction conditions completely or partially converted into units of the general formula (1). The

Accordingly, silicon compounds (A) differ essentially from the silicon compounds (B) from the units of the general formula (1) formed from the units of the general formula (2) in the process according to the invention.

Examples of silicon compounds (B) are:

HSi (n-Bu) ₃ , H ₂ Si (OEt) ₂ , (HSiMe ₂ J ₂ -CH-CH- (SiMe ₂ H) ₂ , HSi (OMe) ₃ , HSi (OEt) ₃ , HSiPh (OMe) ₂ , HSiMe (OEt) ₂ , HSiMe ₂ (O-CH ₂ CH ₂ -O-CH ₂ CH ₂ -

0-CH ₂ CH ₂ -OMe),

H-SiMe ₂ O-SiMe ₂ O-SiMe ₂ O-SiMe ₂ O-SiMe ₂ -CH = CH ₂ ,

HSi (OEt) ₂ -CH ₂ -Si (OEt) ₂ H, HSi (OEt) ₂ -O-CH ₂ CH (CH ₃ ) -O-Si (OEt) ₂ H

H-SiMe ₂ -O-SiMe ₂ -H, (H-SiMeO) ₄ , (H-SiMeO) ₅ , (Me ₂ SiO) ₃ (SiHMeO), (H-SiMe ₂ -O) ₄ Si, (H- SiMe ₂ -O) ₃ SiMe, (H-SiMe ₂ -O) ₃ SiPh,

Me ₃ Si-O-SiMe ₂ -H,

H-SiMe ₂ O- (SiMe ₂ O) ₃₅ -SiMe ₂ -H, Me ₃ SiO- (SiHMeO) 55-SiMe ₃ ,

Me ₃ SiO- (SiMe ₂ O) ₂₂₀ (SiHMeO) 5-SiMe ₃

H-SiMe ₂ O- (SiMe ₂ O) ₁₄₀ (SiHMeO) 5-SiMe ₂ -H HSi (OEt) 2 "O- (SiMe ₂ O) ₄ 95 ~ Si (OEt) ₂ -H

[Me ₃ Si0 _1/2] 4 [SiMeO _3/2] _lf 5 [SiMe (OEt) _O1 / _2] ₂ [SiMeHO _{_2/2]} ₆

[HSi (OEt) ₂ O _1/2 J ₆ [HSi (OEt) O _2/2 ] 5

H ₂ C = CH-SiMe ₂ O- (SiMe ₂ O) ₄₄₀ (SiHMeO) ₁₄ -SiMe ₂ -CH = CH ₂

Me ₃ SiO- (SiMe (CH = _CH2) 0) _{4 ^} 9- (SiMe ₂ O) ₁₂ - (SiHMeO) g _^ 5-SiMe ₃ Me ₃ SiO- (SiMeCH ₂ CH ₂ CF ₃ O) _15/2 (SiHMeO) 7-SiMe ₃

H ₂ C = CH-SiMe ₂ O- (SiMe (OCH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OMeIO) ₆

(SiHMeO) ₂ -SiMe ₂ -CH = CH ₂

Numbers with decimal places in the examples of silicon compounds (A) and (B) represent average values of mixtures of silicon compounds (A) or (B). Examples of alcohols of the general formula (3) are: methanol, ethanol, 2-propanol, 1-propanol, 1-butanol, 2-butanol, 2-methyl-2-propanol, 2-methyl-1-propanol, 1-pentanol , 1-hexanol, 1, 2-ethanediol, 1-methyl-l, 2-ethanediol, 2, 5-dimethyl-2, 5-hexanediol, 2-butene-l, 4-diol, 2-butyne-l, 4 -diol, 3-hexyne-2,5-diol, hydroxypivalic acid neopentyl glycol ester, neopentyl glycol, poly-THF-1000® (BASF) (= H [OCH ₂ CH ₂ CH ₂ CH ₂ I _n OH), 1-ethynyl-1-cyclohexanol , 2-methyl-3-butyn-2-ol, 4-ethyl-1-octyn-3-ol, 2-chloroethanol, propargyl alcohol, t-amyl alcohol, N- (2-

Hydroxyethyl) -2-pyrrolidone, 1,4-butanediol, 2,4-butanediol, 2-ethylhexanol, furfuryl alcohol, glycerol, 1,3-propanediol, 10-undecen-1-ol, 1-dodecanol, 1-octadecanol, allyl alcohol , Allyl PEG-OH with an average of 3 PEG units, 2-hydroxy-1-ethyl methacrylate, ethyl lactate, HO-CH ₂ -SiMe ₂ -O-

SiMe ₂ -CH ₂ -OH, HO-CH ₂ CH ₂ CH ₂ -SiMe ₂ -O-SiMe ₂ -CH ₂ CH ₂ CH ₂ -OH.

As catalysts (K), the fixed metals Ni, Pd, Pt are used in the process according to the invention on support materials.

Suitable carrier materials are, in principle, all inorganic or organic polymers previously used for this purpose according to the prior art, such as, for example, SiO ₂ , Al ₂ O 3, clays, activated carbons, zeolites or organic resins.

The catalyst support material is preferably activated carbon or Al ₂ O 3, it being possible to use as catalysts (K)

Palladium / activated carbon, palladium / Al ₂ θ3 and nickel / activated carbon, especially palladium / activated carbon is preferred. The catalysts used are commercially available products or can be prepared by conventional methods in organometallic chemistry. The concentration of the metal bound on the carrier material is preferably in the range of at least 0.01, more preferably at least 0.1 wt .-%, in particular at least 1 and at most 30 wt .-%, particularly preferably at most 10 wt .-% and in particular at most 6 wt .-%. Catalysts (K) with higher metal concentrations can bleed out and contaminate the silicon compound (A) with metallic constituents (this is especially true if the silicon compound (A) can not be distilled), for catalysts (K) with lower metal concentrations due to the reduced specific activity higher proportions by weight of catalyst necessary, which can make the work-up consuming and / or losses by adsorption of silicon compounds (A) on the catalyst (K) may occur.

The catalysts (K) may contain certain amounts of water. The drier the catalysts are, the more reactive they are usually in particular in air or in contact with organic materials. In order to suppress the resulting undesirable reactions, which can lead to auto-ignition, in particular in the handling of the pure catalysts (K), the solid catalysts are sometimes prepared with a certain water content. The proportion of water may come from the preparation of the catalyst (K) or deliberately added. In the process according to the invention, preference is given to using catalysts (K) with a water content which does not lead to any undesirable side reactions, but which is sufficient to ensure safe handling of the catalyst (K). The water content is preferably at least 0.1% by weight, particularly preferably at least 1, in the case of catalysts (K) with activated carbon as support material

Wt .-%, in particular at least 10 wt .-% and at most 90 wt .-%, particularly preferably at most 70 wt .-%, in particular at most 60 wt .-%. The catalysts (K) can be introduced directly as a solid or suspended in one of the two reactants silicon compound (B) or alcohol of the general formula (3), or the target product component (A) or a suitable solvent in the reaction.

Preferably, the catalyst (K) bound to a support material is removed after completion of the reaction or at the end of the process according to the invention by filtering, decanting or centrifuging and optionally reused or recycled.

The amount of the catalyst used depends on the number of present in the silicon compounds (B)

Units of the general formula (2). Preferably, the catalyst (K) in amounts of at least 10 ppm, more preferably at least 20 ppm, in particular at least 50 ppm and at most 10,000 ppm, more preferably at most 1000 ppm and in particular at most 700 ppm, calculated as a metallic element and based on the total weight of

Silicon compounds (B) used counted. The optimal concentration in terms of reaction rate or economy can be determined in simple preliminary experiments, e.g. a partial amount of silicon compound (B) with the alcohol of the general formula (3) is introduced and as much catalyst (K) is added until a clearly recognizable hydrogen evolution begins.

The amount of the alcohol of the general formula (3) used depends on the number of units of the general formula (2) present in silicon compounds (B) and the desired degree of conversion. Unless complete sales is desired, the alcohol of the general formula (3) is used in equimolar amounts or in excess of the units of the general formula (2) contained in the silicon compounds (B).

The amount of alcohol of the general formula (3) used is preferably at least 1 mol, and at most 4 mol, particularly preferably at most 3 mol and in particular at most 2 mol OH, based on 1 mol of the Si n-reacted in the silicon compounds (B) bonded H atoms in the units of the general formula (2). If incomplete turnover is desired, i. m> 0, can e.g. even lower levels of alcohol can be used.

The inventive method is preferably in a

Temperature of at least -10 ⁰ C, more preferably at least + 10 ° C, more preferably at least + 20 ° C and at most + 200 ° C, more preferably at most + 120 ° C, in particular at most + 100 ° C. If the boiling point of the lowest-boiling component is below the desired reaction temperature for the fastest possible reaction, the reaction can be carried out under an elevated pressure. In exothermic reactions, it may be useful to dissipate the heat of reaction that can not be used by cooling (jacket cooling or evaporative cooling).

The process according to the invention is preferably carried out under an absolute pressure of at least 10 hPa, particularly preferably at least 100 hPa and at most 4000 hPa, particularly preferably at most 2000 hPa. In particular, the method according to the invention is carried out at the pressure of the surrounding atmosphere. The hydrogen formed during the reaction can be completely or partially for Pressure build-up can be used. For technical reasons, it may be advantageous to allow the hydrogen formed during the reaction to escape during the reaction.

If the reactants silicon compound (B), the alcohol of the general formula (3) and the catalyst (K) are mixed, then in the process according to the invention in the abovementioned temperature range, the desired reaction usually begins spontaneously with evolution of hydrogen. For safety reasons, it may therefore be advantageous not to mix the total amount, but to submit one of the two reactants with the catalyst (K) and to meter in the other reactants in such a rate that the gas evolution can be controlled. Alternatively, the catalyst (K) may be initially charged and a mixture of both

Reactants are metered or each reactants are added separately but in parallel. If only part of the units of the general formula (2) present in silicon compound (B) or only part of the silicon compound (B) is to be reacted, silicon compound (B) is preferably initially charged with the catalyst (K) and the alcohol with the general formula (3) added. For reaction mixtures which react only slowly due to kinetic effects, e.g. because of steric hindrance, incomplete miscibility, it is also possible to include the total amount of all reactants

Catalyst (K) to mix and allow to react until the desired degree of conversion is achieved. The degree of conversion of the mixture can be determined by gas evolution, e.g. by volumetric determination of the released amount of hydrogen, or by means of the usual analytical

Methods such as hydrogen content titration, gas chromatography, infrared, Raman, NMR spectroscopy are followed on the reaction mixture. The complete conversion of the entire alcohol of the general formula (3) and / or all units of the general formula (2) in the reaction is easily recognized at the completion of gas evolution.

In principle, mixtures of different silicon compounds (B) and / or mixtures of alcohols of the general formula (3) can be used in the process according to the invention.

By the process according to the invention, by successive reaction of component (B) with various alcohols of the general formula (3) also mixed silicon compounds (A) accessible, wherein the proportion of the respective radical R in the silicon compounds (A) on the stoichiometric ratio of alcohol of general formula (3) to units of the general formula (2) can be adjusted. For example, 30% of all units of the general formula (2) can first be reacted with an alcohol 1 and subsequently the remaining 70% of the units of the general formula (2) can be reacted with an alcohol 2.

In principle, it is possible in the process according to the invention for the reaction of silicon compounds (2) with the alcohol of the general formula (3) by deactivating and / or separating off the catalyst (K), separating off the alcohol and / or the silicon compounds (B) and / or the silicon compounds (A) to break off from the reaction mixture before reaching full conversion. The separation of the solid catalyst (K) can be carried out by the methods customary for solids separation, such as filtration, sedimentation, centrifuging. The separation of the silicon compounds (A) and (B) and alcohol of the general formula (3), if they are solids, together with the catalyst (K) by the methods described or by distillation, extraction, Adsorption or reaction with a trapping reagent, for example a chlorosilane or hexamethyldisilazane for the separation of the alcohol of the general formula (3), take place.

The reaction mixture is preferably worked up after the desired conversion has been achieved with removal of the catalyst (K) and / or the other silicon compounds (A), (B) still present, and more preferably silicon compound (A) by removal of undesirable minor components, e.g. purified by heating volatile components or distillation. The reaction mixture can also be fed directly without processing their further processing or application.

Preferably, at most 0.5 liter, particularly preferably at most 0.1 liter, in particular at most 0.01 liter, in particular preferably at most 0.001 liter of solvent is used per mole of group OR formed.

Solvent, e.g. aliphatic and aromatic hydrocarbons, such as n-pentane, n-heptane, isooctane,

Alkane mixtures, benzene, toluene, o-xylene, p-xylene and m-xylene; chlorinated hydrocarbons, such as dichloromethane, trichloromethane, chlorobenzene; Ethers, such as diethyl ether, diisopropyl ether, di-n-butyl ether, tetrahydrofuran, dioxane, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether,

Triethylene glycol dimethyl ether, polyethylene glycol dimethyl ether, methyl t-butyl ether; Silicone oils such as hexamethyldisiloxane, trimethylsilyl endblocked polydimethylsiloxanes with viscosities of 2-100 mPas at 20 ° C); Siloxane cycles, such as octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane; As well as solvent mixtures can in the inventive method, for example, the mediation poorly miscible or immiscible reactants or to reduce the Viscosity are used, but are preferably present only for polymers having a viscosity> 100 mPas at 20 ° C and / or alcohols having a molecular weight> 75 g / mol. With particular preference, no solvents are used in the process according to the invention.

In principle, the process can be carried out in batch, semibatch or continuous mode. In particular, in the continuous process, it is advisable to use the catalyst (K) as a fixed bed and pass over the mixture of the reactants in gaseous, liquid or dissolved form.

All the above symbols of the above formulas each have their meanings independently of each other. In all formulas, the silicon atom is tetravalent.

In the following examples, unless otherwise indicated, all amounts and percentages are by weight, all pressures are 0.10 MPa (abs.) And all temperatures are 20 ^° C.

Example Ia

Preparation of 1,3-dimethoxy-1,1,3,3-tetramethyldisiloxane In a 500 ml four-necked flask with reflux condenser, KPG stirrer and thermometer was added 2.12 g of 5% palladium on charcoal, anhydrous (commercially available from Sigma Aldrich Corp., USA) in 150 g of methanol. This mixture was heated in an oil bath to 50 ° C. Subsequently, at this temperature 212.5 g of 1, 1, 3, 3-tetramethyldisiloxane metered in with stirring within 2.5 hours. Upon addition of the first drops of the SiH-functional siloxane, spontaneous evolution of hydrogen started. After completion of the addition, the reaction was allowed to continue for 15 minutes, The black precipitate was filtered through a pressure suction filter and distilled the colorless clear filtrate through a 35cm packed column. After the forerun, which consisted mainly of methanol according to gas chromatographic analysis, distilled at 139 ° C boiling temperature 248.9 g of 1,3-dimethoxy-1, 1, 3, 3-tetramethyldisiloxane (ie 81% of theory) with a Purity of 99% according to gas chromatographic analysis. The total chlorine content was determined by means of ashing and coulometry, it was below the detection limit of 3 ppm. The product is therefore suitable for use in semiconductor applications.

Example Ib

Preparation of 1,3-dimethoxy-1,1,3,3-tetramethyldisiloxane Example 1a was repeated with the modification that

Catalyst 2.12 g of 5% palladium on charcoal containing 54.9% by weight of water (commercially available from Johnson & Matthey, UK, as Pd on Charcoal Type 87L). The target product was obtained with a yield of 85% of theory isolated by distillation. Its purity was 99.4% according to gas chromatographic analysis. The total chlorine content was determined by means of ashing and coulometry, it was below the detection limit of 3 ppm. The product is therefore also suitable for use in semiconductor applications.

Example 2

Preparation of Tetrakis (1,1-dimethyl-1-methoxysiloxy) silane In a 500 ml four-necked flask with reflux condenser, KPG stirrer and thermometer, 0.75 g of 5% palladium on charcoal, anhydrous (commercially available from Sigma). Aldrich Corp., USA) in 87.8 g of methanol. This mixture was heated in an oil bath to 50 ° C. Subsequently, at this temperature, 150 g of tetrakis (1, 1-dimethylsiloxy) silane within 3 Hours added with stirring. After adding the first drops of the SiH-functional siloxane spontaneous

Hydrogen evolution. After completion of the addition, the reaction was allowed to continue for 15 minutes, the black precipitate was filtered off through a pressure filter and the colorless, clear filtrate was distilled over a 35 cm packed column. After the forerun, which according to gas chromatographic analysis mainly consisted of methanol, distilled at 120 ° C boiling point at 12 hPa 26.7 g of pure tetrakis (1, 1-dimethyl-l-methoxysiloxy) silane.

Example 3

Preparation of tri-n-butylmethoxysilane

In a 500 ml four-necked flask with reflux condenser, KPG stirrer and thermometer, 1.2 g of 5% palladium on activated carbon, anhydrous (commercially available from Sigma-Aldrich Corp., USA) was suspended in 23.7 g of methanol. 124 g of tri-n-butylsilane (prepared by a method customary in organic chemistry from trichlorosilane and n-butylmagnesium chloride) were then added at room temperature within one hour with stirring. Upon addition of the first drops of the SiH-functional siloxane, spontaneous evolution of hydrogen started. The temperature of the reaction mixture rose to a maximum of 35 ° C. After completion of the addition, the reaction was allowed to continue until none had occurred at the connected bubble counter

Gas evolution was more noticeable, filtered off the black precipitate on a pressure suction filter and distilled the colorless clear filtrate through a 20cm Vigreux column. After the forerun, which according to gas chromatographic analysis consisted mainly of methanol, distilled at 112 ° C.

Boiling temperature at 10 hPa 134 g tributylmethoxysilane with a GC purity of 99.5 Fl .-%. Example 4

Preparation of a reaction product of H-siloxane

Polymethyl (H) siloxane with 2-ethylhexan-1-ol

In a 100 ml three-necked flask with reflux condenser, magnetic stirrer and thermometer were 20 g of a methyl-H-polysiloxane of the average formula: [Me ₃ Si0] _ / ₂ ] ₂ [MeSiHO] 55 with

0.1 g of 5% palladium on activated carbon, anhydrous (commercially available from Fluka / Aldrich). Subsequently, the mixture was heated to 70 ° C in an oil bath. While stirring, 2.1 g of 2-ethylhexan-1-ol were metered in within one minute. The mixture was stirred for 8 h at 100 ° C, then cooled and filtered. After heating the clear colorless filtrate at

100 ° C / 10 mbar gave a polysiloxane, which according to ^ H and 2 "si-NMR was assigned the following average formula: [Me ₃ SiO ₁ Z ₂ ] 2 [MeSiHO] 54 [MeSi (O-CH ₂ CH ( CH ₂ CH ₃ ) -CH ₂ CH ₂ CH ₂ CH ₃ ) O]] _, the palladium content was below the detection limit of 0.5 ppm, the total chlorine content was below the detection limit of 3 ppm.

Claims

claims

1. A process for the preparation of hydrocarbyl-containing silicon compounds (A) which contain at least one unit of the general formula (1)

H _m Si (OR) _n (OR ') _o R " _p X ₄ _ _m _ _n _ _o _ _p (1)

^H m + n ^{si (} ° ^R ' ⁾ o ^R ''p ^x 4-mnop ⁽²⁾

having an alcohol of the general formula (3)

RAW (3)

in the presence of a catalyst (K) attached to a

Supported material is metal, which is selected from Ni, Pd, Pt, wherein per mol of formed group OR at most 1 liter

Solvent is used and wherein R is a monovalent hydrocarbon radical having 1 to 18

Carbon atoms which may be substituted by OH groups, halogen atoms, silyl groups, siloxy groups, -CN,

-COOR ¹ , -OCOOR ² , -CONR ³ R ⁴ , -OCONR ⁵ R ⁶ , -NR ⁷ CONR ⁸ R ⁹ , -SO ₂ -R ¹⁰ , -OSO ₂ -R ¹¹ , -OP (OR ¹² ) (OR ¹³ ), wherein the carbon chain may be interrupted by non-adjacent - (CO), -O-, -S- or -NR ¹⁴ groups; R ', R "each represents a monovalent hydrocarbon radical of 1 to 18 carbon atoms which may be substituted by

Halogen atoms, silyl groups, siloxy groups, -CN, -COOR ¹ , -OCOOR ² , -CONR ³ R ⁴ , -OCONR ⁵ R ⁶ , -NR ⁷ CONR ⁸ R ⁹ , -SO ₂ -R ¹⁰ , -OSO ₂ -R ¹¹ , -OP (OR ¹² ) (OR ¹³ ) where the carbon chain may be interrupted by non-adjacent - (CO), -0-, -S- or -NR ¹⁴ groups; R ¹ to R ^{14 are} each a monovalent hydrocarbon radical having 1 to 18 carbon atoms which may be substituted by halogen atoms, X is a chemical bond via which radicals are attached which contain silicon atoms, m is 0, 1, 2 or 3, n den Values 1, 2 or 3, m + n the values 1, 2 or 3, o the values 0, 1, 2 or 3, p the values 0, 1, 2 or 3 and m + n + o + p the values 1 , 2, 3 or 4 mean.

2. The method of claim 1, wherein the

Hydrocarbon radical R has 1 to 6 carbon atoms and no additional OH group.

3. The method of claim 1 or 2, wherein the bound via the chemical bonds X radicals polyvalent

Hydrocarbon radicals R 1 are those which have one or more units of the general formula (1) in the case of silicon compounds (A) or one or more units of the general formula (2) in the case of silicon compounds (B).

4. The method of claim 1 or 2, wherein the bound via the chemical bonds X radicals mono- or polyhydric hydrocarbon radicals R ^ S ⁱ , which contain bonded via Si-C bonds silicon atoms.

5. The method of claim 1 or 2, wherein the bound via the chemical bonds X radicals mono- or polyvalent (poly) silane radicals R ^ ¹ , which contain silicon atoms bonded via Si-Si bonds.

6. The method of claim 1 or 2, wherein the bound via the chemical bonds X radicals mono- or polyvalent (poly) siloxane radicals RP ^ ¹ , which contain bonded Si-O-Si bonds silicon atoms.

A method according to claim 1 or 2, wherein the silicon compounds (A) selected from the general formulas (12) to (15)

(RO) _h -SiR " ₄ _ _h (12),

RO- [SiR '' 2 ^~ 0-] _Z -R (13),

[RO-SiR " _2- O] _y Si-R" ₄ _ _y < ¹⁴ ) '

[R ^v R "2 ^SiO l / 2] a [(R {0-CH ₂ CH (R ^IV)} _r 0) R" SiO ₂ / k ₂ 1 [SiR _'2 O _2/2] ₁ [SiHR " O _2/2 ] _m (15),

be prepared, wherein

R ^ V are hydrogen atoms or methyl radicals,

R ^{v is} methyl, ethyl, vinyl, allyl or phenyl, h is 1 or 2, z is 1 to 20, y is 1, 2, 3 or 4, a is 0 to 2, r is values from 0 to 20, k are values from 1 to 20, 1 values from 0 to 200, m values from 0 to 100 and a + k + l + m are values of at least 4 and R and R "have the above meanings.

8. The method of claim 1 to 7, wherein the catalyst support materials are selected from Siθ2, AI2O3,

Clays, activated carbons, zeolites and organic resins.

9. The method of claim 1 to 7, wherein the temperature is -10 ° C to + 200 ° C.

10. The method of claim 1 to 9, which is carried out as a batch, semibatch or continuous driving.