Process for the preparation of organic silicon compounds

Abstract

The present invention relates to a process for the preparation of organic silicon compounds, and to the use of the thus obtained compounds.

Description

[0001] Process for the production of organic silicon compounds

[0002] Description

[0003] The present invention relates to a process for the preparation of organic silicon compounds and to the use of the compounds thus obtained.

[0004] Polysiloxanes are known as components of hydraulic fluids or certain brake fluids that meet the so-called DOT 5 standard of the US Department of Traffic.

[0005] US 3814691 describes the preparation of such organosilanes by reaction of the corresponding alkyl silyl chlorides with the desired alcohols, which can be glycol ethers.

[0006] However, a disadvantage of the organosilanes obtained by this reaction is the residual content of chlorides, which can lead to corrosion in the hydraulic system, which can cause leaks under the high pressures prevailing in the system.

[0007] EP 557027 A1 describes a multi-stage process in which a polysiloxane is first reacted with an alcohol in the presence of a catalyst, the catalyst is separated and then reacted with a glycol and glycol ether.

[0008] The disadvantage of this reaction procedure is that a high proportion of high-molecular residue is formed in the first reaction step, which cannot be used in the reaction with the glycol and glycol ether.

[0009] US 2015 / 0221986 A1 describes the production of organic silicon compounds by reacting various alkoxyalkanols with, for example, hexamethylcyclotrisilazane or alkoxysilanes. A disadvantage of the production from hexamethylcyclotrisilazane is its high chlorine content, which is a result of the manufacturing process.

[0010] The objective was to provide a process for the preparation of chlorine-free organic silicon compounds, with which the products can be obtained in high yield and purity, so that the reaction mixtures can be used in their applications as soon as possible. This task was solved by a process for the preparation of organic silicon compounds of formula (III)

[0011] (III) R 1 xSi(-[-O-CH2-CH2-]nOR 3 )4-x or mixtures thereof, in which at least one alkoxyalkyl silane of the formula (la)

[0012] (la) R 1 xSi(OR 2 )4-x and / or a cyclic siloxane of formula (Ib)

[0013] (lb) -(-SiR 1 2-O-) y - with at least one alkoxyalkanol of formula (II)

[0014] (II) R 3 -O-[-CH2-CH2-O-] n-H in the presence of at least one acid or at least one base, optionally in a solvent at a temperature of 0 to 200 °C, wherein

[0015] R 1 Phenyl or Ci-C4-alkyl, preferably Ci-C4-alkyl, particularly preferably methyl, ethyl or n-butyl, very particularly preferably methyl or ethyl,

[0016] R 2 Ci-C4-alkyl, particularly preferably methyl, ethyl or n-butyl, very particularly preferably methyl or ethyl,

[0017] R 3 Ci-C4-alkyl, particularly preferably methyl, ethyl or n-butyl, x is a positive integer 1, 2 or 3, y is a positive integer 3 or 4, preferably 3, and n is a positive integer from 2 to 5, preferably from 2 to 4, particularly preferably 2 or 3 and most preferably 3.

[0018] For the starting compounds of formula (la)

[0019] (la) R 1 x Si(OR 2)4-x can be monoalkoxytrialkylsilane (x = 3), dialkoxydialkylsilane (x = 2), trialkoxymonoalkylsilane (x = 1) or mixtures thereof. If the radical R is 1 to

[0020] Phenyl, these are the corresponding monoalkoxy triphenyl silane, dialkoxy diphenyl silane or trialkoxy monophenyl silane.

[0021] For the sake of simplicity, the compounds of formula (Ia) are referred to in the text as alkoxyalkyl silanes, even if the radical R 1 a phenyl group is included.

[0022] If the compounds of formula (Ia) are used as a mixture, the organic silicon compounds of formula (III) are also obtained as a mixture. The ratio of the compounds of formula (Ia) generally corresponds to the ratio of the individual compounds of formula (III) in the mixture.

[0023] Bevorzugte Verbindungen der Formel (la) mit x = 1 sind Methyl trimethoxy silan, Methyl triethoxy silan, Methyl tri n-butoxy silan, Ethyl trimethoxy silan, Ethyl triethoxy silan, Ethyl tri n- butoxy silan, n-Propyl trimethoxy silan, n-Propyl triethoxy silan, n-Propyl tri n-butoxy silan, n- Butyl trimethoxy silan, n-Butyl triethoxy silan, n-Butyl tri n-butoxy silan, Phenyl trimethoxy silan, Phenyl triethoxy silan und Phenyl tri n-butoxy silan.

[0024] Besonders bevorzugt sind Methyl trimethoxy silan, Methyl triethoxy silan, Ethyl trimethoxy silan, Ethyl triethoxy silan, ganz besonders bevorzugt sind Methyl trimethoxy silan und Ethyl trimethoxy silan.

[0025] Bevorzugte Verbindungen der Formel (la) mit x = 2 sind Dimethyl dimethoxy silan, Dimethyl diethoxy silan, Dimethyl di n-butoxy silan, Diethyl dimethoxy silan, Diethyl diethoxy silan, Diethyl di n-butoxy silan, Di n-propyl dimethoxy silan, Di n-propyl diethoxy silan, Di n-propyl di n-butoxy silan, Di n-butyl dimethoxy silan, Di n-butyl diethoxy silan, Di n-butyl di n-butoxy silan, Diphenyl dimethoxy silan, Diphenyl diethoxy silan und Diphenyl di n-butoxy silan.

[0026] Besonders bevorzugt sind Dimethyl dimethoxy silan, Dimethyl diethoxy silan, Diethyl dimethoxy silan, Diethyl diethoxy silan, ganz besonders bevorzugt sind Dimethyl dimethoxy silan und Dimethyl diethoxy silan. Bevorzugte Verbindungen der Formel (la) mit x = 3 sind Trimethyl monomethoxy silan, Trimethyl monoethoxy silan, Trimethyl mono n-butoxy silan, Triethyl monomethoxy silan, Triethyl mo- noethoxy silan, Triethyl mono n-butoxy silan, Tri n-propyl monomethoxy silan, Tri n-propyl monoethoxy silan, Tri n-propyl mono n-butoxy silan, Tri n-butyl monomethoxy silan, Tri n-butyl monoethoxy silan, Tri n-butyl mono n-butoxy silan, Tri phenyl monomethoxy silan, Tri phenyl monoethoxy silan und Tri phenyl mono n-butoxy silan.

[0027] Besonders bevorzugt sind Trimethyl monomethoxy silan, Trimethyl monoethoxy silan, Triethyl monomethoxy silan, Triethyl monoethoxy silan, ganz besonders bevorzugt sind Trimethyl monomethoxy silan und Triethyl monomethoxy silan.

[0028] In a preferred embodiment, in the alkoxyalkylsilanes of formula (Ia) used, x = 1.

[0029] In a further, particularly preferred embodiment, in the alkoxyalkylsilanes of the formula (Ia) used, x = 2, ie pure dialkoxydialkylsilanes are used as compounds of the formula (Ia).

[0030] In a further preferred embodiment, mixtures of alkoxyalkylsilanes of the formula (Ia) are used, particularly preferably mixtures of compounds with x = 2 and additionally at least one further compound with x = 1 and / or x = 3, very particularly preferably those mixtures in which the compounds with x = 2 make up at least 50 mol% of the mixture, in particular at least 75 mol%, especially at least 85 mol%.

[0031] It may also be possible to use cyclic siloxanes of the formula (Ib) as starting compounds

[0032] (Ib) -(-SiR 12-O-)y- with y = 3 or 4, preferably 3.

[0033] Preferred are hexamethylcyclotrisiloxane or octamethylcyclotetrasiloxane, and mixtures thereof. Hexaethylcyclotrisiloxane and octaethylcyclotetrasiloxane are conceivable, although less preferred.

[0034] In the event that the desired product is alkoxyalkyloxysilanes of the formula (III) with x = 2, in particular with R 1 = Methyl, it is a preferred embodiment of the present invention to react cyclic siloxanes of the formula (Ib) with at least one alkoxyalkanol of the formula (II).

[0035] Mixtures of alkoxyalkyl silanes of formula (Ia) and cyclic siloxanes of formula (Ib) are also possible, especially if the desired product is to consist predominantly of compounds with x = 2.

[0036] In the process according to the invention, the alkoxyalkyl silanes of formula (Ia) are preferred as starting compounds over the cyclic siloxanes of formula (Ib).

[0037] In the at least one alkoxyalkanol of formula (II)

[0038] (II) R 3 -O-[-CH2-CH2-O-] n -H is R 3 Ci-C4-alkyl, particularly preferably methyl, ethyl or n-butyl and n is a positive integer from 2 to 5, preferably from 2 to 4, particularly preferably 2 or 3 and most preferably 3.

[0039] Examples of such alkoxyalkanols, which are also referred to as glycol monoalkyl ethers, are diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol mono-n-butyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol mono-n-butyl ether, tetraethylene glycol monomethyl ether, tetraethylene glycol monoethyl ether and tetraethylene glycol mono-n-butyl ether.

[0040] Preferred alkoxyalkanols are diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol mono-n-butyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether and triethylene glycol mono-n-butyl ether,

[0041] Particularly preferred are diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, triethylene glycol monomethyl ether and triethylene glycol monoethyl ether, and very particularly preferred are triethylene glycol monomethyl ether and triethylene glycol monoethyl ether.

[0042] The alkoxyalkanols can be used individually or in a mixture; purified alkoxyalkanols usually contain minor amounts of higher and lower homologous alkoxyalkanols due to the production process. In a preferred embodiment, the proportion of alkoxyalkanols with n = 3 in the total amount of incorporated alkoxyalkanols in formula (III) is at least 75% by weight, more preferably at least 85% by weight, most preferably at least 90% by weight, and in particular at least 95% by weight.

[0043] In a further preferred embodiment, the proportion of alkoxyalkanols with n = 2 in the total amount of incorporated alkoxyalkanols in formula (III) is not more than 20% by weight, more preferably not more than 10% by weight, and most preferably not more than 5% by weight. For production reasons, the alkoxyalkanols with n = 2 may also contain alkoxyalkanols with n = 1 in minor amounts. However, their content in the alkoxyalkanols with n = 2 is preferably below 7.5% by weight, more preferably below 5% by weight, and most preferably below 2.5% by weight. Such alkoxyalkanols with n = 1 are, for example, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, and ethylene glycol mono-n-butyl ether.

[0044] In a further preferred embodiment, the proportion of alkoxyalkanols with n at least 4, preferably with n = 4, of the total amount of incorporated alkoxyalkanols in formula (III) is not more than 15% by weight, particularly preferably not more than 5% by weight, and very particularly preferably not more than 3% by weight. Due to the production process, the alkoxyalkanols with n = 4 may also contain alkoxyalkanols with n > 4 in minor amounts. However, their content in the alkoxyalkanols with n = 4 is preferably below 5% by weight, particularly preferably below 2.5% by weight, and very particularly preferably below 1% by weight.

[0045] The sum of all incorporated alkoxyalkanols with n = 2 to 5 in formula (III) is always 100 wt%.

[0046] The reaction of the reactants of formulas (Ia) and / or (Ib) with the alkoxyalkanols of formula

[0047] (II) leads to the organic silicon compounds of formula (III)

[0048] (III) R 1 xSi(-[-O-CH2-CH2-]nOR 3 )4-x where the values ​​for R 1 , R 3 , n and x essentially correspond to the values ​​of the reactants used. Due to incomplete reaction or if a mixture of alkoxyalkanols of formula (II) is used in which the individual components exhibit different reactivity, the incorporation ratios in the product of formula (III) may, in individual cases, deviate from the ratio of alkoxyalkanols of formula (II) used in the reaction. The starting compounds of formula (Ia) and / or (Ib) and (II) are mixed together in the desired ratio and reacted with one another.

[0049] The starting compounds can be completely mixed together and heated together to the desired reaction temperature. In a preferred embodiment, the starting compounds of formula (Ia) and / or (Ib) are initially introduced, and the alkoxyalkanol of formula (II) is added in several portions, for example two to four, preferably two or three, portions, or continuously over the reaction time. After complete addition of the alkoxyalkanol, the reaction mixture is heated further to complete the reaction.

[0050] In a further preferred embodiment, the alkoxyalkanol of formula (II) is initially introduced, and the starting compounds of formula (Ia) and / or (Ib) are added in several portions, for example two to four, preferably two or three, portions, or continuously over the reaction time. After complete addition of the starting compounds of formula (Ia) and / or (Ib), the reaction mixture is heated further to complete the reaction. This embodiment is particularly preferred when the starting compounds of formula (Ia) and / or (Ib) exhibit significant volatility under the reaction conditions and therefore escape significantly from the liquid reaction mixture.

[0051] The at least one alkoxyalkanol of formula (II) is used in different molar ratios depending on the starting material used

[0052] Use of (Ia) with x = 1: The alkoxyalkanol (II) is used in a molar ratio of at least 3:1, where the molar ratio refers to the ratio of free hydroxyl groups in compound (II) to silicon atoms in compound (Ia). Preferably in a ratio of at least 3.1:1, particularly preferably at least 3.2:1 to 6:1, very particularly preferably at least 3.3:1 to 5:1, in particular at least 3.5:1 to 4:1.

[0053] Use of (Ia) with x = 2 or (Ib): The alkoxyalkanol (II) is used in a molar ratio of at least 2:1, where the molar ratio refers to the ratio of free hydroxyl groups in compound (II) to silicon atoms in compound (Ia) or (Ib). Preferably in a ratio of at least 2.1:1, particularly preferably at least 2.2:1 to 5:1, very particularly preferably at least 2.3:1 to 4:1, in particular at least 2.5:1 to 3:1.

[0054] Use of (Ia) with x = 3: The alkoxyalkanol (II) is used in a molar ratio of at least 1:1, where the molar ratio refers to the ratio of free hydroxyl groups in compound (II) to silicon atoms in compound (Ia). Preferably in a ratio of at least 1.1:1, particularly preferably at least 1.2:1 to 4:1, very particularly preferably at least 1.3:1 to 3:1, in particular at least 1.5:1 to 2:1.

[0055] In general, the alkoxyalkanol (II) is used in a molar ratio of at least 1 : 1 per group to be replaced (R 2 O-) in the compound of formula (Ia), preferably at least 1.1:1, particularly preferably at least 1.2:1 to 4:1, very particularly preferably at least 1.3:1 to 3:1, in particular at least 1.5:1 to 2:1.

[0056] If mixtures of compounds (la) with different values ​​for x are used, the statistical mean value x' of the alkyl groups R 1 which results from the molar proportions of the individual compounds and their respective value for x for the number of alkyl groups in each individual compound. If the mixture also contains at least cyclic siloxane of formula (Ib), its proportion per silicon atom contained is calculated with x = 2.

[0057] For example, for a mixture of compounds (Ia) with 30 mol% x = 1 , 60 mol% x = 2 and 10 mol% x = 3, a statistical functionality of alkyl groups R 1 of x' = 0.3 * 1 + 0.6 * 2 + 0.1 * 3 = 1 .8. This results in a statistical functionality of alkoxy groups (R 2 O-) or Si-O bonds of (4 — x') = 2,2.

[0058] A mixture of compounds (la) with 40 mol% x = 1 , 40 mol% x = 2, 10 mol% x = 3 and 10 mol% hexamethylcyclotrisiloxane results in a statistical functionality of alkyl groups R 1 of x' = 0.4 * 1 + 0.4 * 2 + 0.1 * 3 + 0.1 * 3 * 2 = 2.1. Accordingly, the statistical functionality of Si-O bonds is 0.4 * 3 + 0.4 * 2 + 0.1 * 1 + 0.1 * 3 * 2 = 2.7.

[0059] The alkoxyalkanol (II) is then used in an at least equimolar ratio based on Si-O bonds, preferably in at least a 1.1-fold excess, particularly preferably in a 1.2- to 4-fold and very particularly preferably in at least a 1.3- to 3-fold excess.

[0060] A preferred embodiment of the present invention is to use the at least one alkoxyalkanol of the formula (II) in an excess and to leave it in the product after completion of the reaction. In this way, mixtures of organic silicon compounds of the formula (III) and the at least one alkoxyalkanol of the formula (II) are obtainable. These mixtures are preferably essentially composed as follows: 35 to 70 wt. % organic silicon compound of the formula (III) : 65 to 30 wt. % at least one alkoxyalkanol of the formula (II), particularly preferably 40 to 60 : 40 to 60 wt. % and very particularly preferably 45 to 55 : 55 to 45 wt. % of the compounds of the formula (III) : compounds of the formula (II).

[0061] Residual solvent and residues of acid or base may still be present in minor amounts; these residues are preferably not more than 5% by weight, particularly preferably not more than 3% by weight, very particularly preferably not more than 2% by weight and in particular not more than 1% by weight.

[0062] In one embodiment, the starting compounds are mixed together without additional solvents, which has the advantage that no solvent needs to be separated from the reaction mixture after the reaction has ended. This is particularly preferred when the viscosity of the starting compounds and the reaction mixture is sufficiently low under the conditions to ensure pumping and mixing of the liquids.

[0063] In a further preferred embodiment, the reaction is carried out in at least one solvent, preferably exactly one solvent. Preferably, the at least one solvent is selected from the group consisting of

[0064] - open-chain or cyclic ethers,

[0065] - alkanols and

[0066] - hydrocarbons.

[0067] Examples of open-chain and cyclic ethers are diethyl ether, di-n-butyl ether, tert-butyl methyl ether, tert-butyl ethyl ether, tert-amyl methyl ether, diphenyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol di-n-butyl ether, tetrahydrofuran and dioxane.

[0068] Examples of alkanols are C1- to C8-alkanols, preferred are methanol, ethanol, iso-propanol, n-propanol, n-butanol, iso-butanol, se-butanol, tert-butanol, n-hexanol, n-heptanol, 2-ethylhexanol, n-octanol, 2-propylheptanol, and n-decanol. When an alkanol is used as solvent, a preferred embodiment is to use the alkanol R 2 OH as a solvent.

[0069] Alkanols are preferred as solvents only when a metal alkoxide is used as the base. In this case, the alkanol that is also used as the metal alkoxide is preferred as the solvent. Otherwise, the use of alkanols as solvents is less preferred. Hydrocarbons are preferred as solvents; examples include those that predominantly comprise aliphatic, cycloaliphatic, or aromatic C5 to C14 hydrocarbons.

[0070] Preferred aromatic hydrocarbons are toluene, o-, m- or p-xylene, trimethylbenzene isomers, tetramethylbenzene isomers, ethylbenzene, cumene, tetrahydronaphthalene and mixtures containing them.

[0071] (Cyclo)aliphatic hydrocarbons are, for example, decalin, alkylated decalin and isomer mixtures of straight or branched alkanes and / or cycloalkanes, especially cyclopentane, cyclohexane, methylcyclohexane and cycloheptane.

[0072] Preferred alkanes are n-pentane, pentane isomer mixtures, n-hexane, hexane isomer mixtures, n-heptane, heptane isomer mixtures, n-octane, octane isomer mixtures, nonane isomer mixtures, n-decane and decane isomer mixtures.

[0073] Further examples of solvents are the SolvessoO brands from ExxonMobil Chemical, in particular Solvesso® 100 (CAS No. 64742-95-6, predominantly C9 and Cw aromatics, boiling range approximately 154 - 178 °C), 150 (boiling range approximately 182 - 207 °C) and 200 (CAS No. 64742-94-5), as well as the Shellsol® brands from Shell, Caromax® (e.g. Caromax® 18) from Petrochem Carless and Hydrosol from DHC (e.g. as Hydrosol® A 170). Hydrocarbon mixtures of paraffins, cycloparaffins and aromatics are also commercially available under the names crystal oil (for example crystal oil 30, boiling range approximately 158 - 198 °C or crystal oil 60: CAS No. 64742-82-1), white spirit (for example also CAS No. 64742-82-1) or solvent naphtha (light: boiling range approximately 155 - 180 °C, heavy: boiling range approximately 225 - 300 °C).The aromatics content of such hydrocarbon mixtures is generally more than 90% by weight, preferably more than 95% by weight, particularly preferably more than 98% by weight, and most particularly preferably more than 99% by weight. It may be advantageous to use hydrocarbon mixtures with a particularly reduced naphthalene content.

[0074] Particularly preferably, this is a hydrocarbon which, under the reaction conditions, acts as an entraining agent for water, especially when using cyclic siloxanes of the formula (Ib), or for the alkanol R 2OH, particularly when using alkoxyalkylsilanes of formula (Ia). Preferred hydrocarbons are those that form a heteroazeotrope and, after distillative removal from the reaction mixture upon cooling, form two phases, of which the hydrocarbon phase is recycled back into the reaction. Particularly preferably, the at least one solvent is selected from the group consisting of cyclohexane, methylcyclohexane, benzene, toluene, xylene, hexane, and heptane.

[0075] If a solvent is used, the concentration of the reactants and the at least one acid or base in the solution is generally 10 to 90 wt%, preferably 20 to 80, particularly preferably 30 to 70 and most particularly preferably 40 to 60 wt%.

[0076] By separating the solvent, e.g. by distillation, the concentration increases during the reaction.

[0077] Although it is possible to carry out the reaction of the starting compounds purely thermally, according to the invention the reaction is preferred in the presence of at least one acid or at least one base.

[0078] The at least one acid is preferably selected from the group consisting of

[0079] - inorganic mineral acids,

[0080] - organic carboxylic acids,

[0081] - organic sulfonic acids, preferably alkyl or arylsulfonic acids and

[0082] - acidic ion exchangers.

[0083] Inorganic mineral acids are, for example, hydrochloric acid, nitric acid, sulfuric acid, sulfurous acid, phosphoric acid and phosphorous acid, among these sulfuric acid and phosphoric acid are preferred, and sulfuric acid is particularly preferred.

[0084] Among the inorganic mineral acids, those acids that have an oxidizing effect under the reaction conditions are less preferred. It is also conceivable to select the reaction conditions in the process according to the invention so that the oxidizing effect is less pronounced, for example by lowering the reaction temperature or shortening the reaction time.

[0085] Organic carboxylic acids are C1- to C50-carboxylic acids, preferably C2- to C20-mono- or dicarboxylic acids, particularly preferably monocarboxylic acids.

[0086] In a preferred embodiment, the carboxylic acids are C1 to C10 monocarboxylic acids, preferably C2 to C8, particularly preferably C2 to C4 monocarboxylic acids. In a further preferred embodiment, the carboxylic acids are C1 to C20 fatty acids.

[0087] Individuals of the respective organic carboxylic acids are listed below under (alkali earth) metal carboxylates. The preferences mentioned there also apply to the organic carboxylic acids.

[0088] Organic sulfonic acids are, for example, methanesulfonic acid, ethanesulfonic acid, trifluoromethanesulfonic acid, cyclododecanesulfonic acid, benzenesulfonic acid, para-toluenesulfonic acid and mono- to tri-CB-C2o-alkyl-substituted benzenesulfonic acids, such as nonylbenzenesulfonic acid, dodecylbenzenesulfonic acid, tetradecylbenzenesulfonic acid, hexadecylbenzenesulfonic acid or octadecylbenzenesulfonic acid.

[0089] Organic sulfonic acids are generally preferred over inorganic mineral acids.

[0090] Acidic ion exchangers are usually those that contain carboxyl or sulfonic acid groups, preferably carboxylic acid groups, in a polymer matrix, often a polymer matrix based on polystyrene, poly(meth)acrylates, or poly(meth)acrylic acid. Among acidic ion exchangers, weakly acidic ion exchangers are preferred, especially those whose acidity is determined by carboxyl groups, especially those based on poly(meth)acrylic acid.

[0091] If carried out in the presence of at least one base, this is preferably selected from the group consisting of

[0092] - (alkaline earth) metal oxides or hydroxides, preferably alkali metal hydroxides,

[0093] - (alkali earth) metal carbonates or hydrogen carbonates

[0094] - (Earth) alkali metal hydrogensulfate

[0095] - (alkaline earth) metal phosphates, hydrogen phosphates or dihydrogen phosphates

[0096] - (Earth) alkali metal carboxylates

[0097] - Metal alcoholates, preferably metal alcoholates of the alkanol R 2 OH and

[0098] - Amines, especially tertiary amines.

[0099] Examples of (alkali earth) metal oxides and hydroxides are calcium oxide, magnesium oxide, calcium hydroxide, magnesium hydroxide, sodium hydroxide, potassium hydroxide, and lithium hydroxide. Among these, alkali metal hydroxides are preferred, particularly sodium hydroxide and potassium hydroxide, and most particularly sodium hydroxide. Examples of (alkali earth) metal carbonates and bicarbonates are calcium carbonate, magnesium carbonate, lithium carbonate, sodium carbonate, potassium carbonate, calcium bicarbonate, magnesium bicarbonate, lithium bicarbonate, sodium bicarbonate, and potassium bicarbonate.

[0100] Among these, carbonates are preferred, particularly preferred are alkali metal carbonates, particularly preferred are sodium carbonate, sodium bicarbonate and potassium carbonate, very particularly preferred are sodium carbonate and sodium bicarbonate.

[0101] Examples of (alkaline earth) metal hydrogensulfates are calcium hydrogensulfate, magnesium hydrogensulfate, lithium hydrogensulfate, sodium hydrogensulfate and potassium hydrogensulfate, especially sodium hydrogensulfate and potassium hydrogensulfate.

[0102] Examples of (alkaline earth) metal phosphates, hydrogen phosphates or dihydrogen phosphates are calcium phosphate, magnesium phosphate, lithium phosphate, sodium phosphate, potassium phosphate, calcium hydrogen phosphate, magnesium hydrogen phosphate, lithium hydrogen phosphate, sodium hydrogen phosphate, potassium hydrogen phosphate, calcium dihydrogen phosphate, magnesium dihydrogen phosphate, lithium dihydrogen phosphate, sodium dihydrogen phosphate and potassium dihydrogen phosphate.

[0103] Preferred examples of (alkaline earth) metal carboxylates are the sodium and potassium salts of C1- to C20-carboxylic acids, preferably C2- to C20-mono- or dicarboxylic acids, particularly preferably monocarboxylic acids.

[0104] In a preferred embodiment, the carboxylic acids are C1 to C10 monocarboxylic acids, preferably C2 to C8, particularly preferably C2 to C4 monocarboxylic acids.

[0105] Examples of such monocarboxylic acids are acetic acid, propionic acid, n- and iso-butyric acid, pentanoic acid, pivalic acid, hexanoic acid, octanoic acid, 2-ethylhexanoic acid, decanoic acid and 2-propylheptanoic acid.

[0106] In a further preferred embodiment, the carboxylic acids are C10 to C20 fatty acids. Examples are decanoic acid (capric acid), undecanoic acid, dodecanoic acid (lauric acid), tridecanoic acid, tetradecanoic acid (myristic acid), pentadecanoic acid, palmitic acid (hexadecanoic acid), margaric acid (heptadecanoic acid), stearic acid (octadecanoic acid), palmitoleic acid [(9Z)-hexadec-9-enoic acid], oleic acid [(9Z)-octadec-9-enoic acid], elaidic acid [(9E)-octadec-9-enoic acid], erucic acid [(13Z)-docos-13-enoic acid], linoleic acid [(9Z,12Z)-octadeca-9,12-dienoic acid], linolenic acid [(9Z,12Z,15Z)-octadeca-9,12,15-trienoic acid] and elaeostearic acid [(9Z,11 E,13E)-octadeca-9,11,13-trienoic acid), nonadecanoic acid and arachidic acid (eicosanoic acid).

[0107] In a preferred embodiment of the present invention, metal alcoholates are used as bases, preferably metal Ci- to C4-alcoholates, particularly preferably metal methanolate, ethanolate, iso-propanolate, n-propanolate, n-butanolate and tert-butanolate, very particularly preferably the metal alcoholate of the alkanol R 2 OH.

[0108] Possible alcoholates, although less preferred, are phenolates, preferably the metal salts of phenol, o-, m- or p-cresol, 2-tert.-butyl-4-methylphenol, 6-tert.-butyl-2,4-dimethylphenol, 2,6-di-tert.-butyl-4-methylphenol, 2-tert.-butylphenol, 4-tert.-butylphenol, 2,4-di-tert.-butylphenol, 2-methyl-4-tert.-butylphenol, 4-tert.-butyl-2,6-dimethylphenol, hydroquinone or hydroquinone monomethyl ether.

[0109] The metals in the metal alkoxides are preferably lithium, sodium, potassium, titanium, aluminum, zirconium, iron, cobalt, nickel and zinc, particularly preferably lithium, sodium, potassium, aluminum and titanium.

[0110] Sodium methanolate, sodium ethanolate, potassium methanolate, potassium ethanolate, potassium tert-butoxide, aluminum tri(isopropoxide), titanium tetra(n-butoxide) and titanium tetra(isopropoxide) are very particularly preferred.

[0111] Examples of tertiary amines or amines with at least one trivalent nitrogen atom that can be used are trimethylamine, triethylamine, tri-n-butylamine, tri-n-hexylamine, tri-n-octylamine, dimethylethanolamine, triethanolamine, N-methylmorpholine, N-methylpiperidine, N-methylpyrrolidine, pyridine, dimethylaminopyridine, dimethylaniline, 1,4-diazabicyclo[2.2.2]octane (triethylenediamine,

[0112] DABCO), 1,5-diazabicyclo[4.3.0]non-5-ene (DBN), 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) can be used.

[0113] Preferred compounds are tri-n-butylamine, pyridine, dimethylaminopyridine, 1,4-diazabicyclo[2.2.2]octane (triethylenediamine, DABCO), 1,5-diazabicyclo[4.3.0]non-5-ene (DBN), and 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU). The at least one acid or at least one base is generally used in amounts of 5 to 30 mol%, based on silicon atoms in compounds (Ia) and (Ib), preferably 10 to 25 mol%.

[0114] The reaction temperature is from 0 (zero) to 200 °C, preferably from 40 to 190, more preferably from 50 to 180, most preferably from 60 to 170 and in particular from 70 to 160 °C. In a preferred embodiment, the reaction temperature is increased during the course of the reaction, for example by up to 80 °C, preferably by up to 60 and more preferably by up to 50 °C. This is particularly preferred when the minor component of the starting compounds has been converted to at least 50, preferably to at least 70 and more preferably to at least 80%, so that the conversion is completed by increasing the temperature.

[0115] It may be expedient to carry out the reaction at superatmospheric pressure, for example up to 20, preferably up to 15, and particularly preferably up to 10 bar superatmospheric pressure. This is particularly preferred if at least one of the starting compounds has a boiling point that is approximately 30, preferably 20 °C, below the reaction temperature.

[0116] If the boiling points of the starting compounds are sufficiently far away from the desired reaction temperature, the reaction is preferably carried out at normal pressure.

[0117] To remove volatile constituents formed during the reaction and optionally used solvent, a negative pressure of at least 100 mbar below ambient pressure can preferably be applied, particularly preferably at least 200 mbar, very particularly preferably at least 500 mbar below ambient pressure, preferably the negative pressure is increased in the course of the reaction and separation of the volatile constituents to a final pressure of 200 mbar, preferably 100, particularly preferably 50 and very particularly preferably 20 mbar.

[0118] Separated solvent, which may contain volatile acids or bases, can then be reused for the next reaction.

[0119] In a preferred embodiment, volatile components formed during the reaction and any optionally used solvent are removed by stripping with an inert gas, preferably by passing it through the reaction mixture. Gases that are inert under the reaction conditions can be, for example, nitrogen, argon, carbon dioxide, or oxygen-depleted air with an oxygen content of less than 10 vol%, preferably less than 8, particularly preferably less than 5 vol%, preferably nitrogen or argon, particularly preferably nitrogen.

[0120] The inert gas can be introduced through dip tubes, ring lines, nozzles or frits.

[0121] Furthermore, it may be useful to add at least one antioxidant, preferably at least one phenolic compound, to the reaction mixture. One of the effects of the antioxidant is to increase the reaction yield.

[0122] Examples of phenolic compounds are alkylphenols, for example o-, m- or p-cresol (methylphenol), 2-tert.-butyl-4-methylphenol, 6-tert.-butyl-2,4-dimethylphenol, 2,6-di-tert.-butyl-4-methylphenol, 2-tert.-butylphenol, 4-tert.-butylphenol, 2,4-di-tert.-butylphenol, 2-methyl-4-tert.-butylphenol, 4-tert.-butyl-2,6-dimethylphenol, or 2,2'-methylene-bis-(6-tert.-butyl-4-methylphenol), 4,4'-oxydiphenyl, 3,4-methylenedioxydiphenol (sesamol), 3,4-dimethylphenol, hydroquinone, pyrocatechol (1,2-dihydroxybenzene), 2-(1'-Methylcyclohex-1'-yl)-4,6-dimethylphenol, 2- or 4-(1'-phenyl-eth-1'-yl)-phenol, 2-tert-butyl-6-methylphenol, 2,4,6-tris-tert-butylphenol, 2,6-di-tert-butylphenol, 2,4-di-tert-butylphenol, 4-tert-butylphenol, nonylphenol [11066-49-2], octylphenol [140-66-9], 2,6-dimethylphenol, bisphenol A, bisphenol F, bisphenol B, bisphenol C, bisphenol S, 3,3',5,5'-tetrabromobisphenol A, 2,6-di-tert-butyl-p-cresol, Koresin® from BASF SE, 3,5-Di-tert-Butyl-4-hydroxybenzoesäuremethylester, 4-tert- Butylbrenzcatechin, 2-Hydroxybenzylalkohol, 2-Methoxy-4-methylphenol, 2,3,6- Trimethylphenol, 2,4,5-Trimethylphenol, 2,4,6-Trimethylphenol, 2-lsopropylphenol, 4- Isopropylphenol, 6-lsopropyl-m-Kresol, n-Octadecyl-D-(3,5-di-tert-butyl-4- hydroxyphenyl)propionat, 1 , 1 ,3-T ris-(2-methyl-4-hydroxy-5-tert-butylphenyl)butan, 1 ,3,5- Trimethyl-2,4,6-tris-(3,5-di-tert-butyl-4-hydroxybenzyl)benzol, 1 ,3,5,-Tris-(3,5-di-tert-butyl-4- hydroxybenzyl)isocyanurat, 1 ,3,5,-T ris-(3,5-di-tert-butyl-4-hydroxyphenyl)-propionyloxyethyl- isocyanurat, 1 ,3,5-Tris-(2,6-dimethyl-3-hydroxy-4-tert-butylbenzyl)-isocyanurat oder Pentaeryth- rit-tetrakis-[D-(3,5,-di-tert-butyl-4-hydroxyphenyl)-propionat], 2,6-Di-te / f-butyl-4- dimethylaminomethyl-phenol, 6- / so.-Butyl-2,4-dinitrophenol, 6-se / c-Butyl-2,4-dinitrophenol, Irganox® 565, 1141 , 1192, 1222 und 1425 der Firma BASF SE, 3-(3',5'-Di-tert.-butyl-4'- hydroxyphenyl)propionsäureoctadecylester, 3-(3',5'-Di-fert.-butyl-4'-hydroxyphenyl)propionic acid hexadecyl ester, 3-(3',5'-Di-fert.-butyl-4'-hydroxyphenyl)propionic acid octyl ester, 3-thia-1,5-pentanediol-bis-[(3',5'-di-fert.-butyl-4'-hydroxyphenyl)propionate], 4,8-Dioxa-1,11-undecanediol-bis-[(3',5'-di-te / f-butyl-4'-hydroxyphenyl)propionate], 4,8-Dioxa-1,11-undecanediol-bis-[(3'-te / f-butyl-4'-hydroxy-5'-methylphenyl)propionate], 1 ,9-Nonanediol-bis-[(3',5'-di-ferrobutyl-4'-hydroxyphenyl)propionate], 1,7-Heptanediamine-bis[3-(3',5'-di-tert.-butyl-4'-hydroxyphenyl)propionamide], 1,1-Methanediamine-bis[3-(3',5'-di-tert.-butyl-4'-hydroxyphenyl)propionamide], 3-(3',5'-di-tert.-butyl-4'-hydroxyphenyl)propionic acid hydrazide, 3-(3',5'-di-methyl-4'-hydroxyphenyl)propionic acid hydrazide, Bis(3-tert.-butyl-5-ethyl-2-hydroxy-phen-1-yl)methane, Bis(3,5-di-tert.-butyl-4-hydroxy-phen-1-yl)methane, Bis[3-(1'-methylcyclohex-T-yl)-5-methyl-2-hydroxy-phen-1-yl]methane, Bis(3-tert.- Butyl-2-hydroxy-5-methyl-phen-1-yl)methane, 1,1-Bis(5-ferf.-Butyl-4-hydroxy-2-methyl-phen-1- yl)ethan, Bis(5-ferf.-Butyl-4-hydroxy-2-methyl-phen-1-yl)sulfid, Bis(3-tert.-Butyl-2-hydroxy-5- methyl-phen-1-yl)sulfid, 1,1-Bis(3,4-Dimethyl-2-hydroxy-phen-1-yl)-2-methylpropan, 1 , 1 -Bis(5- ferf.-Butyl-3-methyl-2-hydroxy-phen-1-yl)-butan, 1 ,3,5-Tris[T-(3",5"-di-ferf.-Butyl-4"-hydroxy- phen-1"-yl)-meth-T-yl]-2,4,6-trimethylbenzol, 1 ,1 ,4-Tris(5'-ferf.-Butyl-4'-hydroxy-2'-methyl-phen- T-yl)butan, Aminophenole, wie z.B. para-Aminophenol, 3-Diethylaminophenol, Nitrosophenole, wie z.B. para-Nitrosophenol, p-Nitroso-o-Kresol, Alkoxyphenole, beispielsweise 2- Methoxyphenol (Guajacol, Brenzcatechinmonomethylether), 2-Ethoxyphenol, 2- Isopropoxyphenol, 4-Methoxyphenol (Hydrochinonmonomethylether), Mono- oder Di-tert.-Butyl- 4-methoxyphenol, 3,5-Di-tert-butyl-4-hydroxyanisol, 3-Hydroxy-4-methoxybenzylalkohol, 2,5- Dimethoxy-4-hydroxybenzylalkohol (Syringaalkohol), 4-Hydroxy-3-methoxybenzaldehyd (Vanillin),4-Hydroxy-3-ethoxybenzaldehyde (ethylvanillin), 3-Hydroxy-4-methoxybenzaldehyde (isovanillin), 1-(4-Hydroxy-3-methoxy-phenyl)ethanone (acetovanillon), eugenol, dihydroeugenol, isoeugenol, tocopherols, such as α-, β-, γ-, δ- and ε-tocopherol, tocol, α-tocopherol hydroquinone, as well as 2,3-dihydro-2,2-dimethyl-7-hydroxybenzofuran (2,2-dimethyl-7-hydroxycoumaran), Trolox®, gallic acid, ferulic acid, cinnamic acid and their derivatives, hydroquinone or hydroquinone monomethyl ether, 2,5-di-tert-butylhydroquinone, 2-methyl-p-hydroquinone,

[0123] 2.3-Dimethylhydrochinon, Trimethylhydrochinon, 4-Methylbrenzcatechin, tert-Butylhydrochinon, 3-Methylbrenzcatechin, Benzochinon, 2-Methyl-p-hydrochinon, 2,3-Dimethylhydrochinon, Trimethylhydrochinon, 3-Methylbrenzcatechin, 4-Methylbrenzcatechin, tert-Butylhydrochinon, 4- Ethoxyphenol, 4-Butoxyphenol, Hydrochinonmonobenzylether, p-Phenoxyphenol, 2- Methylhydrochinon, 2,5-Di-tert.-Butylhydrochinon, Tetramethyl-p-benzochinon, Diethyl-1 ,4- cyclohexandion-2,5-dicarboxylat, Phenyl-p-benzochinon, 2,5-Dimethyl-3-benzyl-p-benzochinon, 2-lsopropyl-5-methyl-p-benzochinon (Thymochinon), 2,6-Diisopropyl-p-benzochinon, 2,5- Dimethyl-3-hydroxy-p-benzochinon, 2,5-Dihydroxy-p-benzochinon, Embelin, Tetrahydroxy-p- benzochinon, 2,5-Dimethoxy-1,4-benzochinon, 2-Amino-5-methyl-p-benzochinon, 2,5- Bisphenylamino-1 ,4-benzochinon, 5,8-Dihydroxy-1 ,4-naphthochinon, 2-Anilino- 1 ,4,naphthochinon, Anthrachinon, N,N-Dimethylindoanilin, N,N-Diphenyl-p-benzochinondiimin,

[0124] 1,4-Benzoquinone dioxime, coerulignon, 3,3'-di-tert-butyl-5,5'-dimethyldiphenoquinone, p-rosolic acid (aurin), 2,6-di-tert-butyl-4-benzylidenebenzoquinone, 2,5-di-tert-amylhydroquinone, 3-ethyl-1,5-dimethyl-1H-pyrazol-4-ol. When the desired conversion has been reached or nearly reached and a solvent has been used, it can be separated from the reaction mixture, preferably by distillation or rectification, optionally assisted by stripping with an inert gas. This can preferably be achieved by increasing the temperature of the reaction mixture and / or reducing the pressure, preferably by a combination of these two measures. This increase in temperature generally completes the conversion.

[0125] A single-stage distillation can be carried out either from the reactor or by passing through a suitable device such as a rotary evaporator, thin film evaporator, falling film evaporator, wiped blade evaporator, Sambay evaporator, etc. and combinations thereof.

[0126] Rectification is preferably carried out in distillation columns mounted above the reactor, such as tray columns, which can be equipped with internals, valves, side draws, etc. if desired. The distillation column(s) used can be realized in a conventional design (see, for example, Sattler, Thermal Separation Processes, 2nd edition 1995, Weinheim, p. 135ff; Perry's Chemical Engineers Handbook, 7th edition 1997, New York, Section 13). The distillation columns used can contain separating internals, such as separating trays, e.g., perforated trays, bubble-cap trays, or valve trays, structured packings, e.g., sheet metal or fabric packings, or random packings. As a rule, up to 20, preferably up to 10, theoretical trays are sufficient.

[0127] A particular embodiment of the present invention is to carry out the reaction in the form of a reactive distillation.

[0128] The reaction of the starting compounds takes place to a significant extent or even completely on the separating internals of the separation column. Since the alkanol R formed as a product 2 Since OH is generally the lowest-boiling component in the reaction system, it is immediately removed from the reaction equilibrium by distillation immediately after formation, allowing the reaction to proceed under relatively mild conditions. The number of theoretical plates is chosen such that the other low-boiling compounds, usually the alkoxyalkylsilane of formula (Ia) and the cyclic siloxane of formula (Ib), remain in the reaction mixture.

[0129] In one embodiment of reactive distillation, the separating internals are coated with an acid or base to promote the reaction. This has the advantage that no significant reaction takes place unless the reaction mixture is in direct contact with the separating internals. This also suppresses side or subsequent reactions promoted by the presence of acid or base.

[0130] In order to increase the contact of the reactants with the separating internals, a portion of the distillation receiver is taken and added to the internals as reflux, optionally supplemented with fresh, unreacted alkoxyalkanol of formula (II).

[0131] In another embodiment of reactive distillation, the at least one acid or at least one base is added to the separating internals together with the reflux. This has the advantage that the acid or base is also present in the distillation receiver, and the reaction takes place not only at the separating internals but also in the receiver, which increases the space-time yield.

[0132] As a rule, the at least one alkoxyalkanol of formula (II) and the product of formula (III) are the highest boiling components in the reaction mixture, whereas the reactants of formulas (Ia) and / or (Ib) and the resulting alkanol R 2 OH are lower boiling. During the reaction, the reactants of formulas (Ia) and / or (Ib) should be available for the reaction, i.e. kept in the reaction mixture, whereas the resulting alkanol R 2OH is preferentially separated from the reaction mixture. Therefore, a preferred embodiment is to select reaction conditions and components such that the alkanol R 2 OH is the lowest boiling compound in the system and the boiling points of the reactants of formulas (Ia) and / or (Ib) are between those of R 2 OH and alkoxyalkanol of formula (II) and product of formula (III).

[0133] In this case, it is a particularly preferred embodiment to carry out the reaction in a reactor with a rectification column whose separation efficiency is sufficient to separate the alkanol R 2 OH as low boilers at the top of the column, whereas the higher than R 2OH-boiling components in the reaction mixture, especially the reactants of formulas (Ia) and / or (Ib), are recycled as column reflux into the reaction mixture. The reaction mixture also contains a solvent, which can preferably also be recycled as reflux into the reaction mixture or together with the alkanol R 2 OH can be removed as the overhead product. If the solvent and alkanol or the water formed form a two-phase mixture after condensation, the solvent phase can be recycled back into the reaction mixture after phase separation. This embodiment is particularly preferred when dimethoxydimethylsilane (boiling point 81 °C) or dimethoxydiethylsilane is used as the alkoxyalkylsilane of formula (Ia). In this case, methanol with a boiling point of 65 °C at atmospheric pressure is released, which can be separated from dimethoxydimethylsilane by rectification or at least depleted.

[0134] This embodiment is particularly preferred when the alkoxyalkyl silane of the formula

[0135] (la) Diethoxydimethylsilane (boiling point 113-114 °C) or diethoxydiethylsilane (boiling point approx. 159 °C) is used. In this case, ethanol with a boiling point of 78 °C at atmospheric pressure is released, which can be separated or at least depleted from both diethoxydimethylsilane and diethoxydiethylsilane by rectification.

[0136] This embodiment is particularly preferred when the cyclic siloxane of the formula

[0137] (lb) Hexamethyl cyclotrisiloxane (boiling point 134 °C) or octamethyl cyclotetrasiloxane (boiling point 175-176 °C) is used. In this case, water with a boiling point of 100 °C at atmospheric pressure is released, which can be separated or at least depleted by rectification.

[0138] After completion of the reaction, unreacted reactants of formulas (Ia) and / or (Ib) as well as any solvent present are then removed from the reaction mixture by distillation.

[0139] After separation of the solvent, the reaction mixture is purified.

[0140] Once the desired conversion has been achieved and no solvent has been used, the reaction is usually stopped by cooling, and the reaction mixture is purified. The reaction mixture is left at a temperature where its viscosity is sufficiently low for purification.

[0141] By means of the purification, the at least one acid or base after completion of the reaction as well as any solvent still present are separated by at least one of the purification steps selected from the group consisting of

[0142] - Filtration,

[0143] - Membrane filtration,

[0144] - reverse osmosis,

[0145] - sorption on at least one inorganic metal oxide or activated carbon and

[0146] - Contact with at least one acidic, basic, or mixed ion exchanger. The first three techniques are known to those skilled in the art.

[0147] Sorption can occur on inorganic materials, such as silica gel, silicates, aluminum oxide, zeolites, diatomaceous earth, mixed aluminum / silicon oxides, and calcium carbonates and oxides, or on activated carbon or charcoal.

[0148] Basic materials are preferred for the separation of acids and vice versa.

[0149] The separation of acids is preferably carried out by passing the reaction mixture through basic ion exchangers, the separation of bases by passing the reaction mixture through acidic ion exchangers.

[0150] After purification, the reaction mixture is essentially free of acids, bases and solvents and can be used as or in functional fluids, preferably hydraulic or brake fluids, as well as for water capture.

[0151] Depending on the intended use, it may be necessary to add other typical additives to the reaction mixture. Examples include corrosion inhibitors, antifoam agents, pH stabilizers, or antioxidants.

[0152] An advantage of the process described according to the invention is that the reaction mixtures can be obtained under gentle conditions. In particular, the reaction mixtures are free of halides, especially chlorides, so that the reaction mixtures exhibit lower corrosiveness than the corresponding compounds obtained from the corresponding alkylchlorosilanes. The content of halides, especially chlorides, in the reaction mixtures thus obtained is generally not more than 100 ppm by weight, preferably not more than 75, more preferably not more than 50, most preferably not more than 25, in particular not more than 15, and even not more than 10 ppm by weight.

[0153] Examples

[0154] General work instruction (Example 1)

[0155] 40 ml of cyclohexane was added to a three-necked flask equipped with a water separator, reflux condenser, thermometer, and nitrogen inlet. Triethylene glycol monomethyl ether (50.0 g, 0.30 mol, 2.0 equiv), dimethoxydimethylsilane (18.3 g, 0.15 mol, 1.0 equiv), and sodium methoxide (0.40 g, 7.5 mmol, 5 mol%) were then added. The mixture was stirred at room temperature for 5 minutes and then heated to reflux for 6.5 hours. After cooling to room temperature, the crude product was purified by vacuum distillation (22 to 160°C, 0.24 mbar).

[0156] The product fraction (21.0 g, 57 mmol, 37% isolated yield) was obtained as a colorless liquid at 142 °C at 0.24 mbar. The structure was confirmed by NMR and high-resolution mass spectrometry (HRMS).

[0157] HRMS expected 402.2518 [M+NH4] + found 402,2514

[0158] 1H-NMR (500 MHz, CDCI3): ö = 0.02 (s, 6 H), 3.25 (s, 6 H), 3.42 (m, 4 H), 3.46 (t, J = 5.3 Hz, 4

[0159] H), 3.50-3.60 (m, 12 H), 3.71 (t, J = 5.3 Hz, 4 H),

[0160] 13 C-NMR (125 MHz, CDCI3): ö = -3.5, 55.6, 61.4, 70.1, 70.20, 70.23, 71.5, 72.0, 2 9 Si NMR (99 MHz, CDCI3): ö = -1.85

[0161] Example 2 - Variation of the starting material

[0162] Analogously to Example 1, the starting materials listed in the table were reacted with triethylene glycol monomethyl ether (MTG-OH) in a molar ratio of 2:1 at the specified temperature for the specified time.

[0163] The yield was determined in the reaction mixture by 1 H-NMR was determined, assuming that only product and unreacted triethylene glycol monomethyl ether were present in the reaction mixture.

[0164] D3: Hexamethylcyclotrisiloxane

[0165] D4: Octamethylcyclotetrasiloxane

[0166] Example 3 - Variation of the catalyst

[0167] Analogously to Example 1, diethoxydimethylsilane was reacted with 2.0 equivalents of triethylene glycol monomethyl ether in the presence of the catalysts listed in the table in the stated amount at 126 °C for the stated time.

[0168] The yield was determined as in Example 2 in the reaction mixture by 1 H NMR determined. No. Catalyst amount t [h] Yield a - 5.5 34% b NaOEt 5 mol% 5.5 55% c Ti(O / 7Bu)45 mol% 5.5 51% d NaHCO35 mol% 12 63% e p-TosOH 5 mol% 5.5 64% f MSA 5 mol% 5.5 69% g AI(O / Pr)35 mol% 5.5 65% h K2CO35 mol% 5.5 67%

[0169] ' KHSO4 5 mol ' % 5 ' 5 60.6% j Na-phenolate 5 mol-% 5.5 54 .8 % k NaHSCM 5 mol ' % 5 ' 5 56.0%

[0170] 1 NaHCO DMAP 5 / 5 mol ' % 5 ' 562.9% m ion exchanger 5 wt% 5.5 58.0% n H3CCOONa 5 mol-% 5.5 61.3%

[0171] 0 DMAP 5 mol% 5.5 53% p-TosOH: para-toluenesulfonic acid

[0172] MSA: Methylsulfonic acid

[0173] DMAP: 4-(Dimethylamino)pyridine ion exchanger: Amberlite® CG50 (weakly acidic)

[0174] Example 4 - Variation of the alkoxyalkanol

[0175] Analogously to Example 1, diethoxydimethylsilane was reacted with 2.0 equivalents of the listed alkoxyalkanol in the presence of 5 mol% sodium ethanolate at 135 °C for 2.5 hours, then a vacuum of 100 mbar was applied for a further hour.

[0176] The yield refers to the isolated yield, the purity was determined by NMR.

[0177] (*) Comparison (**) Example 3, No. b

[0178] (***) determined by NMR It can be seen that higher alkoxyalkanols with n=2 or n=3 give higher yields in the reaction than monoethylene glycol monomethyl ether.

[0179] Example 5 - Variation of catalyst amount and amount of alkoxyalkanol

[0180] Analogously to Example 1, diethoxydimethylsilane was reacted with the indicated equivalents of triethylene glycol monomethyl ether (MTG-OH) in the presence of 1 mol% sodium hydrogen carbonate (NaHCO3) at 126 °C for the stated time.

[0181] In some experiments, an additional 1000 ppm of an antioxidant (dissolved in triethylene glycol monomethyl ether) was added to the reaction mixture as indicated in the table.

[0182] The yield was determined as in Example 2 in the reaction mixture by 1 H-NMR determined.

[0183] Amount of MTG-OH t [h] Yield

[0184] No. [Eq] Addition , g 2 EDP 5.5 73.7% h 2 BHT 5.5 68.6%

[0185] MeHQ: hydroquinone monomethyl ether

[0186] EDP: 3-Ethyl-1,5-dimethyl-1H-pyrazole-4-ol

[0187] BHT: tert. Butyl hydroxytoluene

[0188] It can be seen that the addition of antioxidant significantly increases the yield.

Claims

Patent claims 1. Method for the preparation of organic silicon compounds of formula (III) (III) R 1 xSi(-[-O-CH2-CH2-]nOR 3 )4-x or mixtures thereof, in which at least one alkoxy alkyl silane of formula (1a) (1a) R 1 x Si(OR 2 )4-x and / or a cyclic siloxane of formula (Ib) (lb) -(-SiR 1 2-O-) y - with at least one alkoxyalkanol of formula (II) (II) R 3 -O-[-CH2-CH2-O-] n -H reacts in the presence of at least one acid or at least one base, optionally in a solvent at a temperature of 0 to 200 °C, wherein R 1 Phenyl or Ci-C4-alkyl, preferably Ci-C4-alkyl, particularly preferably methyl, ethyl or n-butyl, especially methyl or ethyl, R 2Ci-C4-alkyl, particularly preferably methyl, ethyl or n-butyl, most preferably methyl or ethyl, R 3 Ci-C4-alkyl, particularly preferably methyl, ethyl or n-butyl, x for a positive integer 1, 2 or 3, y for a positive integer 3 or 4, preferably 3, and n for a positive integer from 2 to 5, preferably from 2 to 4, particularly preferably 2 or 3 and most particularly preferably 3.

2. Method according to claim 1, characterized in that only compounds with x = 2 are used as alkoxy alkyl silanes of formula (1a).

3. Method according to claim 1 or 2, characterized in that the at least one alkoxyalkanol of formula (II) is used in a molar ratio of at least 1 : 1 per group (R) to be replaced. 2O-) in the compound of formula (a), preferably at least 1.1 : 1, particularly preferably at least 1.2 : 1 to 4 : 1, most preferably at least 1.3 : 1 to 3 : 1, in particular at least 1.5 : 1 to 2 :

1.

4. A method according to one of the preceding claims, characterized in that the at least one solvent is selected from the group consisting of - open-chain or cyclic ethers, - Alkanols and - Hydrocarbons.

5. Method according to claim 4, characterized in that the solvent is an alkanol R 2 OH is involved.

6. The method according to claim 4, characterized in that the solvent is a hydrocarbon which, under the reaction conditions, acts as an entrainer for water and / or alkanol R 2 OH works.

7. Method according to claim 6, characterized in that the hydrocarbon is cyclohexane, methylcyclohexane, benzene, toluene, xylene, hexane or heptane.

8. Method according to one of the preceding claims, characterized in that the The reaction is carried out in the presence of at least one base, selected from the group consisting of - (Earth) alkali metal oxides or hydroxides, preferably alkali metal hydroxides, - (Earth) alkali metal carbonates or hydrogen carbonates - (Earth) alkali metal hydrogen sulfates - (Earth) alkali metal phosphates, -hydrogen phosphates or -dihydrogen phosphates - (Earth) alkali metal carboxylates - Metal alcoholates, preferably metal alcoholates of the alkanol R 2 OH and - Amines.

9. A method according to any one of claims 1 to 7, characterized in that the reaction is carried out in the presence of at least one acid selected from the group consisting of - inorganic mineral acids, preferably sulfuric acid, - organic carboxylic acids, - organic sulfonic acids, preferably alkyl or arylsulfonic acids and - acidic ion exchangers.

10. Method according to one of the preceding claims, characterized in that in the The volatile components produced during the reaction, as well as any optionally used solvent, are separated by applying a vacuum of at least 100 mbar below ambient pressure, preferably increasing the vacuum during the course of the reaction.

11. Method according to one of the preceding claims, characterized in that in the The volatile components produced during the reaction, as well as any optionally used solvent, are removed by stripping with an inert gas, preferably by passing it through the reaction mixture.

12. A process according to one of the preceding claims, characterized in that the reaction is carried out in a reactor with an attached rectification column, the separation efficiency of which is sufficient to remove the alkanol R 2 OH as a low-boiling compound at the column head, and one that is higher than alkanol R 2 OH boiling components into the reaction mixture, especially the reactants of formulas (1a) and / or (1b) as column return- returns to the reaction mixture. according to claim 12, characterized in that the alkoxy alkyl silane of the Formula (1a) is selected from the group consisting of dimethoxy dimethyl silane, dimethoxy diethyl silane, diethoxy dimethyl silane, and diethoxy diethyl silane. A reaction according to any one of the preceding claims, characterized in that the at least one alkoxyalkanol of formula (II) is introduced into the reaction in several portions or continuously during the course of the reaction. A reaction according to any one of claims 1 to 13, characterized in that the starting compounds of formula (1a) and / or (1b) are introduced into the provided alkoxyalkanol of formula (II) in several portions or continuously during the course of the reaction. A reaction according to any one of the preceding claims, characterized in that the The reaction temperature is increased during the course of the reaction. This is achieved according to one of the preceding claims, characterized in that the at least one acid or base is separated after completion of the reaction by at least one of the purification steps selected from the group consisting of: - filtration, - Membrane filtration, - Reverse osmosis, - Sorption on at least one inorganic metal oxide or activated carbon and - Contact with at least one acidic, basic or mixed ion exchanger. Experienced according to one of the preceding claims, characterized in that an excess of the at least one alkoxyalkanol of formula (II) is substantially in the The reaction mixture is left in place. Use of a reaction mixture obtained according to one of the preceding claims as or in functional fluids, preferably hydraulic or brake fluids, as well as for trapping water.

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