WO2012084773A1

WO2012084773A1 - Method for producing siloxycarboxylates

Info

Publication number: WO2012084773A1
Application number: PCT/EP2011/073177
Authority: WO
Inventors: Martin GÄRTNER; Jochen Petzoldt
Original assignee: Basf Se
Priority date: 2010-12-20
Filing date: 2011-12-19
Publication date: 2012-06-28

Abstract

The invention relates to a method for producing siloxycarboxylates, characterized by the reaction of C₂-C₁₀-monocarboxylic acid with halogen siloxanes of the general formula (I), Hal-(SiR₂-O)_x-SiR₃, where Hal is equal to or different from fluorine, chlorine, bromine or iodine, R is hydrogen, C₁-C₁₀-alkyl or C₆-C₁₄-aryl, and x is an integer from 1 to 20, forming hydrogen halide in the presence of an auxiliary base, in which the auxiliary base forms a salt with the hydrogen halide, the salt forming two immiscible liquid phases with the siloxycarboxylate or the solution of the siloxycarboxylate in a suitable solvent and being separated by liquid-liquid separation. The method allows a simple and economical production of siloxycarboxylates.

Description

Process for the preparation of siloxycarboxylates

The invention relates to a process for the preparation of silylated monocarboxylic acids by reacting monocarboxylic acids in the presence of an auxiliary base.

The silylation of carboxylic acids is known in the literature. Thus, A. Shihada et al. in Z. Naturforsch. B 1980, 35, 976-980, the reaction of acetic acid with trimethylchlorosilane in diethyl ether with the addition of diethylamine. V.F. Mironov et al. describe in Chem. Heterocycl. Compd. 1966, 2, 334-337, the silylation of, inter alia, methacrylic acid also with trimethylchlorosilane in the presence of N, N-diethylaniline as auxiliary base in diethyl ether. A disadvantage of this process is the formation of voluminous and poorly filterable hydrochloride precipitates, which lead to yield losses in the filtration. An economically attractive regeneration of the auxiliary base is complicated by the complex handling of solids.

Silylation of acrylic acid with hexamethyldisilazane is described by V.I. Rakhlin et al. in Russ. J. Org. Chem. 2004, 40. The reaction is disadvantageous because a continuous removal of the liberated ammonia is required. In addition, the process requires long reaction times at higher temperatures and provides only moderate yields.

The preparation of trimethylsilyl carboxylates is also described by C. Palermo in Synthesis 1981, 809-811. The reaction of the carboxylic acid is carried out with N-trimethylsilyl-2-oxazolidone in halogenated solvents such as carbon tetrachloride or dichloromethane. For industrial applications, this reaction route is less practicable, since the use of a halogenated solvent is problematic. In addition, the synthesis is costly, since in addition the preparation of the silylating reagent is necessary. The separation of the 2-oxazolidone from the product is carried out by complicated crystallization and filtration. The synthesis of this silylation reagent is also in Synth. Commun. 1982, 12, 225-230 of Banerji et al. disclosed. In the reaction with the carboxylic acid imidazole is obtained as a by-product, which has to be separated from the product by adding up losses of yield by filtration. Another method of preparation is described by Y.-F. Du et al. in J. Chem. Res. Synop. 2004, 3, 223-225. Therein is disclosed the reaction of sodium acetate with trimethylchlorosilane in solvents such as diethyl ether, PEG-400 or benzene. The educt used is the sodium salt of the carboxylic acid, which must first be prepared and carefully dried. As a result, sodium chloride is by-produced in the synthesis, which must be filtered off. In WO 2003/062171 A2, a process for the separation of acids which are formed as a by-product in the course of a reaction or added to a reaction mixture, for example for pH regulation, is known from the reaction mixtures by means of an auxiliary base such as 1-methylimidazole or 2-ethylpyridine. The acids form with the auxiliary base a liquid salt which is immiscible with the desired product and can therefore be separated by means of liquid-liquid phase separation. By way of example, silylations of alcohols or amines with halosilanes are described. As the acids to be separated, hydrochloric acid and acetic acid are disclosed. A method for the siloxylation of monocarboxylic acids is not disclosed.

WO 2005/061416 A1 likewise discloses a process for the separation of acids from reaction mixtures by means of an auxiliary base, wherein the auxiliary base is an alkylimidazole which has a solubility in 30% strength by weight sodium chloride solution at 25 ° C. of 10% by weight. -% or less and its hydrochloride has a melting point below 55 ° C. According to the teaching of this application, the auxiliary base is used for the separation of acids which are formed in the course of the reaction or added during the reaction, for example for pH regulation. A method for the siloxylation of monocarboxylic acids is not disclosed. WO 2010/072532 describes the silylation of monocarboxylic acids, but siloxylation is not disclosed.

The reaction of 1,5-dichlorohexamethyltrisiloxane with methacrylic acid in the presence of triethylamine as base is described by Yoshida et al. in J. Jpn. Soc. Dent. Prod. 2000, 14 (1), 8. The reaction products are also on the reaction of alkali metal methacrylates with α, ω-dichlorosiloxanes according to D.N. Andreev and N.T. Usacheva in Zhur. Obsh. Khim. 1965, 35 (4), 756 accessible. In both reactions, a complex solid-liquid separation must be carried out for product isolation, which leads to product losses.

DE 10 2007 047866 A1 describes reactions of monocarboxylic acid esters with chlorosiloxanes, as well as the synthesis of nonamethyltetrasiloxymethacrylate from trimethylsilyl methacrylate and chlorononamethyltetrasiloxane. The preparation of chlorosiloxanes from chlorotrimethylsilane and hexamethylcyclotrisiloxane and octesymethylcyclotetrasiloxane in the presence of a tetraalkylammonium salt is described in JP 2005/047852 A. The former reaction is already mentioned by T. Suzuki in Polymer, 1989, 30, 333. This reaction is also carried out with Ν, Ν-dimethylformamide as a catalyst in moderate yields (UK 1040147). EP 1 38 061 1 A1, WO 2004/056838 A1 and WO 2004/00759 A1 describe the synthesis of nonamethyltetrasiloxymethacrylate from trimethylsilyl methacrylate and hexamethylcyclotrisiloxane in the presence of an acid catalyst, but this process gives only moderate yields.

The invention is therefore based on the object to provide a process for the siloxylation of monocarboxylic acids available, which is characterized by high yields and high selectivity and is economically attractive. The object is achieved by a method for producing a Siloxycarboxylats comprising the steps of: a) reacting a C ₂ -C ₀ monocarboxylic acid with a halosiloxane the general formula (I),

Hal- (SiR ₂ -O) _x -SiR ₃ (I) wherein

Hai is fluorine, chlorine, bromine or iodine,

R is the same or different hydrogen, C is Cio-alkyl or C ₆ -C ₄ -aryl and x is an integer from 1 to 20, in the presence of an auxiliary base and optionally a solvent, wherein the auxiliary base is chosen so that it reacts with the in the reaction of monocarboxylic acid and halosilane liberated hydrogen halide forms a salt which is immiscible in the liquid phase with the siloxycarboxylate or the solution of Siloxycarboxylats in the solvent optionally present, and wherein the optionally used solvent is chosen such that it with the siloxycarboxylate is miscible and is immiscible with the liquid salt of auxiliary base and split hydrogen halide, and

Separating the liquid phase containing the siloxycarboxlate and optionally the solvent from the phase containing the salt of auxiliary base and the split-off hydrogen halide at a temperature at which both phases are liquid.

According to the novel siloxycarboxylates are easily and economically produced by the hydrogen halide liberated during the reaction forms a salt with the auxiliary base, which is liquid under the reaction conditions and is immiscible with the siloxycarboxylate. In this case, the added auxiliary base surprisingly removes selectively the residual hydrogen halide and not the monocarboxylic acid from the reaction mixture. By a simple liquid-liquid phase separation, the siloxycarboxylate can be separated from this salt of the auxiliary base with the hydrogen halide. The siloxylation of the monocarboxylic acid proceeds rapidly and in high yields.

The inventive method is suitable for the conversion of C ₂ -C ₀ - monocarboxylic acids having halosiloxanes of the general formula (I). It is irrelevant whether it is a straight-chain or branched and / or saturated or mono- or polyunsaturated monocarboxylic acid. The process according to the invention is preferably suitable for saturated C ₂ -C ₈ monocarboxylic acids and monoethylenically unsaturated C ₃ -C ₈ monocarboxylic acids.

Saturated C ₂ -C ₈ -monocarboxylic acids are, for example, acetic acid, propionic acid, butyric acid, valeric acid (pentanoic acid), caproic acid (hexanoic acid), heptanoic acid and octanoic acid (caprylic acid) and also their isomers. Preference is given to C ₂ -C ₄ monocarboxylic acids such as acetic acid, propionic acid and butyric acid.

The group of monoethylenically unsaturated monocarboxylic acids having 3 to 8 carbon atoms include, for example, acrylic acid, methacrylic acid, dimethacrylic acid, ethacrylic acid, α-chloroacrylic acid, maleic acid, fumaric acid, itaconic acid, mesaconic acid, citraconic acid, glutaconic acid, aconitic acid, methylenemalonic acid, allylacetic acid, vinylacetic acid and crotonic acid. Preferred monoethylenically unsaturated monocarboxylic acids are acrylic acid, methacrylic acid, ethacrylic acid and maleic acid.

The C ₂ -C ₀ used monocarboxylic acid is used with respect to the halosiloxane either in equimolar amounts or in excess. It is preferably 1, 0 to 2.0 mol / mol, more preferably 1, 0 to 1, 5 mol / mol and in particular 1, 0 to 1, 25 mol / mol monocarboxylic acid used.

Of course, any mixtures of the aforementioned C ₂ -C ₀ monocarboxylic acids may be used in the inventive process, however, only one is preferred C ₂ -C reacted with a monocarboxylic acid ₀ halosiloxane. The halosiloxanes are those of the general formula (I)

Hal- (SiR ₂ -O) _x -SiR ₃ (I) wherein Hai is fluorine, chlorine, bromine or iodine,

R is the same or different hydrogen, C is Cio-alkyl or aryl and

x is an integer from 1 to 20. Shark is preferably chlorine or bromine. Preference is given to using one (1) halosiloxane, more preferably one (1) chlorine or bromosiloxane.

The substituents R may be identical or different and independently of one another denote hydrogen, C ₁ -C 10 -alkyl or C ₆ -C ₄ -aryl. Preferably, the substituents R are the same or different and are independently C ₁ -C ₄ -alkyl or C ₆ -C ₄ -aryl, more preferably they are identical and are C 1 -C ₄ -alkyl or phenyl.

C 1 -C 4 -alkyl in the context of the invention means straight-chain or branched hydrocarbon radicals having up to 10 carbon atoms, for example methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, 1, 1-dimethylethyl, pentyl, 2-methylbutyl, 1, 1-dimethylpropyl, 1, 2-dimethylpropyl, 2,2-dimethylpropyl, 1-ethylpropyl, hexyl, 2-methylpentyl, 3-methylpentyl, 1, 1-dimethylbutyl, 1, 2-dimethylbutyl, 1, 3-dimethylbutyl, 2,2-dimethylbutyl, 2,3-dimethylbutyl, 3,3-dimethylbutyl, 2-ethylbutyl, 1, 1, 2-trimethylpropyl, 1, 2,2-trimethylpropyl, 1-ethyl-1-methylpropyl, 1-ethyl-2-methylpropyl, heptyl, octyl, 2-ethylhexyl, 2,4,4-trimethylpentyl, 1,1,3,3-tetramethylbutyl, nonyl and decyl and their isomers. Straight-chain or branched alkyl radicals having 1 to 4 C atoms are preferred.

Aryl is understood to mean mono- to trinuclear aromatic ring systems containing 6 to 14 carbon ring members, for example phenyl, naphthyl and anthryl, preferably a mononuclear aromatic ring system, more preferably phenyl.

In the formula (I), x is an integer from 1 to 20, preferably an integer from 1 to 5, and particularly preferably 3 or 4. Typically usable halosiloxanes are, for example, CI-SiMe ₂ -O-SiMe ₃ , Cl- ( SiMe ₂ -O) ₂ -SiMe ₃ , CI- (SiMe ₂ -O) ₃ -SiMe ₃ , CI- (SiMe ₂ -O) ₄ -SiMe ₃ , CI- (SiMe ₂ -O) ₅ -SiMe ₃ , Br - (SiMe ₂ -O) ₃ -SiMe ₃ , Br- (SiMe ₂ -O) ₄ -SiMe ₃ , CI- (SiEt ₂ -O) ₃ -SiMe ₃ , CI- (SiEt ₂ -O) ₄ -SiMe ₃ , Cl- (SiMe ₂ -O) ₃ -SiEt ₃ , CI- (SiMe ₂ -O) ₄ -SiEt ₃ , CI- (SiMe ₂ -O) ₃ -SiPr ₃ , CI- (SiMe ₂ -O) ₄ - SiPr ₃ , CI- (SiMe _2- O) ₃ -Si / Pr ₃ , CI- (SiMe ₂ -O) ₄ -Si / Pr ₃ , CI- (SiMe ₂ -O) ₃ -SiBu _3, and CI- (SiMe ₂ -0) ₄ -SiBu ₃ , preferably CI- (SiMe ₂ -O) ₃ -SiMe ₃ and CI- (SiMe ₂ -O) ₄ -SiMe ₃ .

Of course, any mixtures of the genannen halosiloxanes can be used, but preferably only one of said halosiloxanes is used. Suitable auxiliary bases are in particular those compounds which are mentioned in WO 03/062171 A2 and WO 05/061416 A1.

The compounds which can be used as auxiliary bases can contain phosphorus sulfur or nitrogen atoms, for example at least one nitrogen atom, preferably one to ten nitrogen atoms, particularly preferably one to five, very particularly preferably one to three and in particular one to two nitrogen atoms. If appropriate, further heteroatoms, such as oxygen, sulfur or phosphorus atoms, can also be present. Preference is given to those compounds which contain at least one five- to six-membered heterocycle which has at least one nitrogen atom and optionally an oxygen or sulfur atom, particularly preferably those compounds which contain at least one five- to six-membered heterocycle containing one, two or three nitrogen atoms and a sulfur or an oxygen atom, most preferably those having two nitrogen atoms.

Particularly preferred compounds are those which have a molecular weight below 1000 g / mol, very particularly preferably below 500 g / mol and in particular below 250 g / mol. Furthermore, preference is given to those compounds which can be used as bases and are selected from the compounds of the formulas (IIa) to (Nr)

(a) (b) (c)

(d) (e) (f)

(g) (h) (i)

(j) (k) (I)

(m) (n) (0)

(P) (q) (0

and oligomers or polymers containing these structures, wherein

R ¹ , R ² , R ³ , R ⁴ , R ⁵ and R ⁶ are each independently hydrogen, C ₁ - Ci ₈ alkyl, optionally by one or more oxygen and / or sulfur atoms and / or a or more substituted or unsubstituted imino groups, C ₂ - C ₈ - alkyl, C ₆ - C ₂ aryl, C ₅ - C ₂ denote cycloalkyl or a five- to six-membered, oxygen-, nitrogen- and / or sulfur-containing heterocycle or two of them together form an unsaturated, saturated or aromatic ring optionally interrupted by one or more oxygen and / or sulfur atoms and / or one or more substituted or unsubstituted imino groups, said radicals being in each case denoted by functional groups, aryl, alkyl, aryloxy , Alkyloxy, halogen, heteroatoms and / or heterocycles. Therein, C 1 -C ₈ -alkyl which is optionally substituted by functional groups, aryl, alkyl, aryloxy, alkyloxy, halogen, heteroatoms and / or heterocycles are, for example, methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, tert-butyl , Pentyl, hexyl, heptyl, octyl, 2-ethylhexyl, 2,4,4-trimethylpentyl, decyl, dodecyl, tetradecyl, hetadecyl, octadecyl, 1, 1 -

Dimethylpropyl, 1,1-dimethylbutyl, 1,1,3,3-tetramethylbutyl, benzyl, 1-phenylethyl, 2-phenylethyl, α, α-dimethylbenzyl, benzhydryl, p-tolylmethyl, 1- (p-butylphenyl) -ethyl, p-chlorobenzyl, 2,4-dichlorobenzyl, p -methoxybenzyl, m-ethoxybenzyl, 2-cyanoethyl, 2-cyanopropyl, 2-methoxycarbonethyl, 2-ethoxycarbonylethyl, 2-butoxycarbonylpropyl, 1,2-di- (methoxycarbonyl) -ethyl, 2-methoxyethyl, 2-ethoxyethyl, 2-butoxyethyl, diethoxymethyl, diethoxyethyl, 1, 3-dioxolan-2-yl, 1, 3-dioxan-2-yl, 2-methyl-1,3-dioxolan-2-yl, 4-methyl-1,3-dioxolan-2-yl, 2-isopropoxyethyl, 2-butoxypropyl, 2-octyloxyethyl, chloromethyl, 2-chloroethyl, trichloromethyl, trifluoromethyl, 1, 1-dimethyl-2-chloroethyl, 2-methoxyisopropyl, 2-ethoxyethyl, butylthiomethyl, 2-dodecylthioethyl, 2-phenylthioethyl, 2,2,2-trifluoroethyl, 2-hydroxyethyl, 2-hydroxypropyl, 3-hydroxypropyl, 4-hydroxybutyl, 6-hydroxyhexyl, 2-aminoethyl, 2-aminopropyl, 3-aminopropyl, 4-aminobutyl, 6-aminohexyl, 2-methylaminoethyl, 2-methylamine n-propyl, 3-methylaminopropyl, 4-methylaminobutyl, 6-methylaminohexyl, 2-dimethylaminoethyl, 2-dimethylaminopropyl, 3-dimethylaminopropyl, 4-dimethylaminobutyl, 6-dimethylaminohexyl, 2-hydroxy-2,2-dimethylethyl, 2-phenoxyethyl, 2- Phenoxypropyl, 3-phenoxypropyl, 4-phenoxybutyl, 6-phenoxyhexyl, 2-methoxyethyl, 2-methoxypropyl, 3-methoxypropyl, 4-methoxybutyl, 6-methoxyhexyl, 2-ethoxyethyl, 2-ethoxypropyl, 3-ethoxypropyl, 4-ethoxybutyl or 6-ethoxyhexyl and, optionally interrupted by one or more oxygen and / or sulfur atoms and / or one or more substituted or unsubstituted imino groups, C ₂ - C ₈ - alkyl, for example, 5-hydroxy-3-oxa-pentyl, 8-hydroxy-3 , 6-dioxa-octyl, 1 1 -hydroxy-3,6,9-trioxa-undecyl, 7-hydroxy-4-oxa-heptyl, 1 1-hydroxy-4,8-dioxa-undecyl, 15-hydroxy-4 , 8,12-trioxa-pentadecyl, 9-hydroxy-5-oxa-nonyl, 14-hydroxy-5, 10-oxa-tetradecyl, 5-methoxy-3-oxa-pentyl, 8-methoxy-3,6-dioxa octyl, 1-methoxy-3,6,9-trioxa undecyl, 7-methoxy-4-ox a-heptyl, 1-methoxy-4,8-dioxa-undecyl, 15-methoxy-4,8, 12-trioxa-pentadecyl, 9-methoxy-5- oxa-nonyl, 14-methoxy-5,10-oxa-tetradecyl, 5-ethoxy-3-oxa-pentyl, 8-ethoxy-3,6-dioxo-octyl, 1-ethoxy-3,6,9-trioxa -undecyl, 7-ethoxy-4-oxa-heptyl, 11-ethoxy-4,8-dioxa-undecyl, 15-ethoxy-4,8, 12-trioxa-pentadecyl, 9-ethoxy-5-oxa-nonyl or 14 Ethoxy-5,10-oxato-tetradecyl.

If two radicals form a ring, these radicals can together be 1, 3-propylene, 1, 4-butylene, 2-oxa-1, 3-propylene, 1-oxa-1, 3-propylene, 2-oxa-1, 3 -propylene, 1-oxa-1, 3-propenylene, 1-aza-1, 3-propenylene, 1-CrC ₄ -alkyl-1-aza-1, 3-propenylene, 1, 4-buta-1, 3 dienylene, 1-aza-1, 4-buta-1, 3-dienylene or 2-aza-1,4-buta-1,3-dienylene.

The number of oxygen and / or sulfur atoms and / or imino groups is not limited. As a rule, it is not more than 5 in the radical, preferably not more than 4, and very particularly preferably not more than 3. Furthermore, at least one carbon atom, preferably at least two, is usually present between two heteroatoms.

Substituted and unsubstituted imino groups can be so-propylimino, n-butylimino or te / f-butylimino example, imino, methylimino, / ^'.

Furthermore, functional groups are carboxy, carboxamide, hydroxy, di- (CC ₄ -alkyl) -amino, CC ₄ -alkyloxycarbonyl, cyano or CC ₄ -alkyloxy, optionally substituted by functional groups, aryl, alkyl, aryloxy, alkyloxy, halogen, heteroaryl roatome and / or heterocycles substituted C ₆ - C ₂ -aryl, for example phenyl, tolyl, xylyl, α-naphthyl, ß-naphthyl, 4-diphenylyl, chlorophenyl, dichlorophenyl, trichlorophenyl, difluorophenyl, methylphenyl, dimethylphenyl, trimethylphenyl, ethylphenyl, diethylphenyl, / ^' so-propylphenyl, tert-butylphenyl, dodecylphenyl, methoxyphenyl, dimethoxyphenyl, ethoxyphenyl, hexyloxyphenyl, methylnaphthyl, isopropylnaphthyl, chloronaphthyl,

Ethoxynaphthyl, 2,6-dimethylphenyl, 2,4,6-trimethylphenyl, 2,6-dimethoxyphenyl, 2,6-dichlorophenyl, 4-bromophenyl, 2- or 4-nitrophenyl, 2,4- or 2,6-dinitrophenyl, 4- dimethylaminophenyl, 4-acetylphenyl, methoxyethylphenyl or ethoxymethylphenyl, optionally roatome by functional groups, aryl, alkyl, aryloxy, alkyloxy, halogen, hetero- and / or heterocycles substituted C ₅ - Ci ₂ cycloalkyl, for example,

Cyclopentyl, cyclohexyl, cyclooctyl, cyclododecyl, methylcyclopentyl, dimethylcyclopentyl, methylcyclohexyl, dimethylcyclohexyl, diethylcyclohexyl, butylcyclohexyl,

Methoxycyclohexyl, dimethoxycyclohexyl, diethoxycyclohexyl, butylthiocyclohexyl, Chlorocyclohexyl, dichlorocyclohexyl, dichlorocyclopentyl and a saturated or unsaturated bicyclic system such as norbornyl or norbornenyl, a five- to six-membered, oxygen, nitrogen and / or sulfur-containing heterocycle such as furyl, thiophenyl, pyrryl, pyridyl, indolyl, benzoxazolyl, dioxolyl, dioxy , Benzimidazolyl, benzthiazolyl, dimethylpyridyl, methylquinolyl,

Dimethylpyrryl, methoxyfuryl, dimethoxypyridyl, difluoropyridyl, methylthiophenyl,

Isopropylthiophenyl or tert-butylthiophenyl and C 1 -C ₄ -alkyl, methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl or tert-butyl.

Preferably, R ¹ , R ² , R ³ , R ⁴ , R ⁵ and R ^{6 are} independently hydrogen, methyl, ethyl, n-butyl, 2-hydroxyethyl, 2-cyanoethyl, 2- (methoxycarbonyl) -ethyl, 2- ( Ethoxycarbonyl) -ethyl, 2- (n-butoxycarbonyl) -ethyl, dimethylamino, diethylamino and chloro.

Particularly preferred pyridines (IIa) are those in which one of the radicals R ¹ to R ^{5 is} methyl, ethyl or chlorine and all others are hydrogen, or R ^{3 are} dimethylamino and all others are hydrogen or are all hydrogen or R ^{2 is} carboxy or carboxy - amide and all others are hydrogen or R ¹ and R ² or R ² and R ^{3 are} 1, 4-buta-1, 3-dienylene and all others are hydrogen.

Particularly preferred pyridazines (IIb) are those in which one of the radicals R ¹ to R ^{4 is} methyl or ethyl and all others are hydrogen or all hydrogen.

Particularly preferred pyrimidines (IIc) are those in which R ² to R ^{4 is} hydrogen or methyl and R ^{1 is} hydrogen, methyl or ethyl, or R ² and R ^{4 are} methyl, R ^{3 is} hydrogen and R ^{1 is} hydrogen, methyl or ethyl. Particularly preferred pyrazines (lld) are those in which R ¹ to R ^{4 are} all methyl or all hydrogen.

Particularly preferred imidazoles (IIe) are those in which R ¹ is independently selected from methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-octyl, 2-hydroxyethyl or 2-cyanoethyl and

R ² to R ⁴ independently of one another denote hydrogen, methyl or ethyl. Particularly preferred 1 H-pyrazoles (IIf) are those in which independently of one another R ¹ is hydrogen, methyl or ethyl,

R ² , R ³ and R ⁴ are hydrogen or methyl

are selected.

Particularly preferred 3H-pyrazoles (IIg) are those in which, independently of one another, R ¹ is hydrogen, methyl or ethyl,

R ² , R ³ and R ⁴ are hydrogen or methyl

are selected.

Particularly preferred 4H-pyrazoles (IIh) are those in which, independently of one another, R ¹ to R ⁴ are hydrogen or methyl,

are selected.

Particularly preferred 1-pyrazolines (III) are those in which, independently of one another, R ¹ to R ⁶ are hydrogen or methyl

are selected.

Particularly preferred 2-pyrazolines (IIj) are those in which independently of one another R ¹ is hydrogen, methyl, ethyl or phenyl and

R ² to R ⁶ are hydrogen or methyl

are selected.

Particularly preferred 3-pyrazolines (IIk) are those in which independently of one another R ¹ or R ² is hydrogen, methyl, ethyl or phenyl and

R ³ to R ⁶ are hydrogen or methyl are selected.

Particularly preferred imidazolines (III) are those in which, independently of one another, R ¹ or R ² is hydrogen, methyl, ethyl, n-butyl or phenyl and R ³ or R ⁴ are hydrogen, methyl or ethyl and R ⁵ or R ⁶ is hydrogen or methyl are selected.

Particularly preferred imidazolines (Ilm) are those in which, independently of one another, R ¹ or R ^{2 are selected} from hydrogen, methyl or ethyl and R ³ to R ⁶ are selected from hydrogen or methyl.

Particularly preferred imidazolines (IIn) are those in which, independently of one another, R ¹ , R ² or R ^{3 are selected} from hydrogen, methyl or ethyl and R ⁴ to R ⁶ are selected from hydrogen or methyl.

Particularly preferred thiazoles (Mo) or oxazoles (Up) are those in which independently of one another

R ¹ is hydrogen, methyl, ethyl or phenyl and

R ² or R ³ are selected from hydrogen or methyl.

Particularly preferred 1, 2,4-triazoles (IIQ) are those in which independently of one another R ¹ or R ² is hydrogen, methyl, ethyl or phenyl and R ^{3 are selected} from hydrogen, methyl or phenyl. Particularly preferred 1, 2,3-triazoles (Nr) are those in which independently of one another R ^{1 is selected} from hydrogen, methyl or ethyl and R ² or R ³ are selected from hydrogen or methyl or

R ² and R ^{3 are} 1, 4-buta-1, 3-dienylene and all others are hydrogen. Among these, pyridines and imidazoles are preferred. Very particular preference is given as bases to 3-chloropyridine, 4-dimethylaminopyridine, 2-ethyl-4-aminopyridine, 2-methylpyridine (α-picoline), 3-methylpyridine (β-picoline), 4-methylpyridine (γ-picoline), 2 -Ethylpyridine, 2-ethyl-6-methylpyridine, quinoline, isoquinoline, 1-CrC ₄ -alkylimidazole, 1-methylimidazole, 1, 2-dimethylimidazole, 1-n-butylimidazole, 1, 4,5-trimethylimidazole, 1, 4- Dimethylimidazole, imidazole, 2-methylimidazole, 1-butyl-2-methylimidazole, 4-methylimidazole, 1-n-pentylimidazole, 1-n-hexylimidazole, 1-n-octylimidazole, 1- (2'-aminoethyl) -imidazole, 2 - ethyl 4-methylimidazole, 1-vinylimidazole, 2-ethylimidazole, 1- (2'-cyanoethyl) -imidazole and benzotriazole.

Particularly preferred are 1-n-butylimidazole, 1-methylimidazole, 2-methylpyridine and 2-ethylpyridine.

Also suitable are tertiary amines of the formula (III)

NR ^a R ^b R ^c (III) wherein

R ^a, R ^b and R ^c are each independently Ci - Ci ₈ alkyl, optionally substituted by one or more oxygen and / or sulfur atoms and / or one or more substituted or unsubstituted imino groups, C ₂ - C ₈ alkyl, C ₆ - Ci ₂ -aryl or C ₅ - Ci ₂ -cycloalkyl or a five- to six-membered, oxygen, nitrogen and / or sulfur atoms containing heterocycle or two of them together an unsaturated, saturated or aromatic and optionally by one or more oxygen form - and / or sulfur atoms and / or one or more substituted or unsubstituted imino groups interrupted ring, wherein said radicals each- because they may be substituted by functional groups, aryl, alkyl, aryloxy, alkyloxy, halogen, heteroatoms and / or heterocycles,

with the proviso that

- At least two of the three radicals R ^a , R ^b and R ^{c are} different and

- The radicals R ^a , R ^b and R ^c together have at least 8, preferably at least 10, more preferably at least 12 and most preferably at least 13 carbon atoms.

Preferably, R ^a, R ^b and R ^c are each independently Ci - Ci ₈ alkyl, C ₆ - C ₂ -aryl or C ₅ - Ci ₂ cycloalkyl, and more preferably Ci - Ci ₈ alkyl, where the radicals mentioned may each be may be substituted by functional groups, aryl, alkyl, aryloxy, alkyloxy, halogen, heteroatoms and / or heterocycles.

Examples of the respective groups are already listed above.

Preferred meanings for the radicals R ^a , R ^b and R ^c are methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, n-pentyl (n-amyl), 2-pentyl ( sec-amyl), 3-pentyl, 2,2-dimethyl-prop-1-yl (neo-pentyl), n-hexyl, n-heptyl, n-octyl, iso-octyl, 2-ethylhexyl, 1, 1 - Dimethylpropyl, 1, 1-dimethylbutyl, benzyl, 1-phenylethyl, 2-phenylethyl, α, α-dimethylbenzyl, phenyl, tolyl, xylyl, α-naphthyl, β-naphthyl, cyclopentyl or cyclohexyl.

If two of the radicals R ^a , R ^b and R ^{c form} a chain, this may be, for example, 1,4-butylene or 1,5-pentylene. Examples of the tertiary amines of the formula (III) are diethyl-n-butylamine, diethyl-tert-butylamine, diethyl-n-pentylamine, diethyl-hexylamine, diethyl-octylamine, diethyl (2-ethylhexyl) -amine, di-n propyl-butylamine, di-n-propyl-n-pentylamine, di-n-propyl-hexylamine, di-n-propyl-octylamine, di-n-propyl- (2-ethylhexyl) -amine, di-iso-propyl -ethylamine, di-isopropyl-n-propylamine, di-iso-propyl-butylamine, di-iso-propyl-pentylamine, di-iso-propyl-hexylamine, di-iso-propyl-octylamine, di-iso-propyl - (2-ethylhexyl) amine, di-n-butyl-ethylamine, di-n-butyl-n-propylamine, di-n-butyl-n-pentylamine, di-n-butyl-hexylamine, di-n-butyl - octylamine, di-n-butyl- (2-ethylhexyl) -amine, Nn-butylpyrrolidine, N-sec-butylpyrrolidine, N-tert-butylpyrrolidine, Nn-pentyl-pyrrolidine, Ν, Ν-dimethylcyclohexylamine , N, N-diethylcyclohexylamine, N, N-di-n-butylcyclohexylamine, Nn-propyl-piperidine, N-iso-propyl-piperidine, Nn-butyl-piperidine, N-sec-butyl-piperidine, N-tert-butyl -piperidine, Nn-pentyl-piperidine, Nn-butylmorpholine, N-sec-butylmorpholine, N-tert-butylmorpholine, Nn-pentylmorpholine, N-benzyl-N-ethyl-aniline, N-benzyl-Nn-propyl-aniline, N-benzyl-N-isopropyl-aniline, N- Benzyl-Nn-butyl-aniline, N, N-dimethyl-p-toluidine, N, N-diethyl-p-toluidine, N, N-di-n-butyl-p-toluidine, diethylbenzylamine, di-n-propylbenzylamine, Di-n-butylbenzylamine, diethylphenylamine, di-n-propylphenylamine and di-n-butylphenylamine. Preferred tertiary amines (III) are di-iso-propyl-ethylamine, diethyl-tert-butylamine, di-isopropyl-butylamine, di-n-butyl-n-pentylamine, N, N-di-n-butylcyclohexylamine and tertiary Amines of pentyl isomers. Particularly preferred tertiary amines are di-n-butyl-n-pentylamine and tertiary amines of pentyl isomers.

A tertiary amine, which is likewise preferred and can be used according to the invention, but in contrast to the above-mentioned three identical radicals, is triallylamine.

Tertiary amines, preferably of the formula (III), are generally preferred over heterocyclic compounds, for example of the formulas (IIa) to (Nr), if the basicity of the latter auxiliary bases is not sufficient for the reaction, for example for eliminations.

Preference is given to those auxiliary bases whose salts of auxiliary bases and acids have a melting temperature at which no significant decomposition of the siloxycarboxylate occurs during the separation of the salt as the liquid phase, i. less than 10 mol% per hour, preferably less than 5 mol% / h, more preferably less than 2 mol% / h, and most preferably less than 1 mol% / h.

The melting points of the salts of the particularly preferred auxiliary bases are generally below 160 ° C., more preferably below 100 ° C. and most preferably below 80 ° C.

Among the auxiliary bases, very particular preference is given to those whose salts have an E _T (30) value of> 35, preferably of> 40, particularly preferably of> 42. The E _T (30) value is a measure of polarity and is reviewed by C. Reichardt of Reichardt, Christian Solvent Effects in Organic Chemistry Weinheim: VCH, 1979. XI, (Monographs in Modern Chemistry; 3), ISBN 3-527-25793-4 page 241.

A preferred base which fulfills the task e.g. is satisfied, is 1-methylimidazole.

1-Methylimidazole is also effective as a nucleophilic catalyst [Julian Chojnowski, Marek Cypryk, Witold Fortuniak, Heteroatom. Chemistry, 1991, 2, 63-70]. Chojnowski et al. have found that 1-methylimidazole accelerates the phosphorylation of f-butanol by a factor of 33 and the silylation of pentamethyldisiloxanol by a factor of 930 compared to triethylamine. Instead of 1-methylimidazole, for example, 1-butylimidazole can be used. The hydrochloride of 1-butylimidazole is already liquid at room temperature, so that 1-butylimidazole can be used as the auxiliary base and catalyst for reactions which handle materials which are already decomposable at temperatures above room temperature. Also liquid at room temperature is the acetate and formate of 1-methylimidazole.

Likewise, it is possible to use all derivatives of imidazole whose salts have an E _T (30) value of> 35, preferably of> 40, more preferably of> 42, and which have a melting temperature during which the salt is separated off as the liquid phase no significant decomposition of the siloxycarboxylate occurs. The polar salts of these imidazoles form two immiscible phases as noted above with less polar organic media. Another exceptionally preferred base that fulfills the task is 2-ethylpyridine.

Pyridine itself and derivatives of pyridine are the expert as nucleophilic catalysts known [Jerry March, "Advanced Organic Chemistry, ^3rd Edition, John Wiley & Sons, New York 1985, pp 294, 334, 347].

It has also been found that the hydrochloride of 2-ethylpyridine has a melting point of about 55 ° C and is immiscible with the nonpolar organic siloxycarboxylates or solvents. Thus, 2-ethylpyridine can at the same time serve as auxiliary base and nucleophilic catalyst and be separated off from organic media as liquid hydrochloride by a process-technically simple liquid-liquid phase separation.

It is likewise possible to use all derivatives of pyridine whose salts have an E _T (30) value of> 35, preferably of> 40, more preferably of> 42, and a

Have melting temperature at which in the course of the separation of the salt as a liquid phase, no significant decomposition of the desired product occurs. The polar salts of these pyridines form two immiscible phases with less polar organic media.

Preferred auxiliary bases are also alkylimidazoles of the formula (IV)

in which R 'and R "can each independently be hydrogen or linear or branched C 1 -C ₆ -alkyl, with the proviso that R' and R" have in total at least 1 carbon atom and in total not more than 6 carbon atoms, preferably in total 1 have up to 4 carbon atoms, more preferably have a total of 1 to 2 carbon atoms and most preferably have in total 2 carbon atoms.

Examples of R 'and R "are hydrogen, methyl, ethyl, ^/' so-propyl, n-propyl, n-butyl, iso- butyl, s / (-. Butyl, te / f-butyl and n-hexyl Preferred radicals R 'and R "are hydrogen, methyl and ethyl.

Examples of compounds of formula (IV) are n-propylimidazole, n-butylimidazole, iso- butylimidazole, 2'-Methylbutylimidazol, / ^{'so-Pentylimidazo,} n-Pentylimidazol, iso- Hexylimidazo, n-hexylimidazole, ^/' so-Octylimidazol and n-Octylimidazol.

Preferred compounds (IV) are n-propylimidazole, n-butylimidazole and iso- butylimidazole, particularly preferred are n-butylimidazole and / ^{'so-butylimidazole} and most preferably is n-butylimidazole. According to the invention, auxiliary bases are those compounds which form a salt with the hydrogen halide formed during the reaction, which forms two immiscible phases at the reaction temperature with the siloxycaroxylate or the solution of the siloxycarboxylate in a suitable solvent and is separated off. Preference is given to those auxiliary bases which do not participate in the reaction as a reactant. Further preferably, this auxiliary base can act as a nucleophilic catalyst in the reaction, so that the addition of a further base, for example the bases cited in the literature diethylamine or triethylamine, is not required. As described above, the auxiliary base forms a salt with the hydrogen halide formed during the reaction. These are, depending on the halosilane used, hydrogen fluoride (HF), hydrogen chloride (HCl), hydrogen bromide (HBr) or hydrogen iodide (HI) or, in the case of mixed halosiloxanes of the formula (I), mixtures of the hydrogen halides mentioned. In the process according to the invention, hydrogen chloride (HCl) or hydrogen bromide (HBr) is preferably formed.

Furthermore, the auxiliary base is suitable for binding other acids which are added, for example, during the pH-adjusting reaction, for example nitric acid, nitrous acid, carbonic acid, sulfuric acid, phosphoric acid or sulfonic acids, such as methanesulfonic acid, ethanesulfonic acid, benzenesulfonic acid or p-toluenesulfonic acid. The reaction mixture contains beside the used C ₂ -C ₀ monocarboxylic acid no further acids, as is per mol separated is hydrogen halide, at least one mole of auxiliary base used as a rule, preferably 1, 0 to 1, 5 mol / mol, particularly preferably 1, 0 to 1.3 mol / mol and especially 1.0-0.1, 25 mol / mol. If other acids are added, for example for pH regulation, the amount of auxiliary base must be adjusted accordingly.

In general, the residence time of the auxiliary base in the reaction mixture is a few minutes to several hours, preferably 5 to 120 minutes, more preferably 10 to 60 minutes and most preferably 10 to 30 minutes.

Typically, the auxiliary base is used together with the to siloxylierenden C ₂ -C ₀ - submitted monocarboxylic acid, and then the halosiloxane added completely or continuously.

The salt of the auxiliary base with the hydrogen halide formed during the reaction forms two immiscible phases with the siloxycarboxylate or a solution of the siloxycarboxylate in a suitable solvent. Immiscible means that two separate phases are formed by a phase interface.

When the pure siloxycarboxylate is miscible with the salt of the auxiliary base and the hydrogen halide wholly or to a greater extent, a solvent may also be added to the siloxycarboxylate to achieve segregation or solubility reduction. This is useful, for example, if the solubility of the salt in the siloxycarboxylate or vice versa is 20% by weight or more, preferably 15% by weight or more, particularly preferably 10% by weight or more and very particularly preferably 5% by weight. % or more. The solubility is determined under the conditions of the respective separation. The solubility is preferably determined at a temperature which is above the melting point of the salt and preferably 10 ° C., particularly preferably 20 ° C., below the lowest of the following temperatures: boiling point of the siloxycarboxylate, boiling point of the solvent and temperature of the significant decomposition of the Siloxycarboxylates.

The solvent is suitable if the mixture of siloxycarboxylate and solvent is able to dissolve the salt or the salt, the siloxycarboxylate or a mixture of siloxycarboxylate and solvent less than the amounts indicated above. Suitable solvents are, for example, benzene, toluene, o-, m- or p-xylene, cyclohexane, cyclopentane, pentane, hexane, heptane, octane, petroleum ether, acetone, isobutyl methyl ketone, diethyl ketone, diethyl ether, tert-butyl methyl ether, tert-butyl ethyl ether . Tetrahydrofuran, dioxane, ethyl acetate, methyl acetate, dimethylformamide, dimethyl sulfoxide, acetonitrile, chloroform, dichloromethane, methyl chloroform or mixtures thereof.

In general, however, the siloxycarboxylate is immiscible with the salt of auxiliary base and hydrogen halide, so that the addition of a solvent can be dispensed with.

The particular advantage of the method according to the invention is that the separation of the salt from auxiliary base and hydrogen halide can be carried out by a simple liquid-liquid phase separation, so that eliminates a procedurally complex handling of solids.

From the salt of the auxiliary base separated from the siloxycarboxylate, the person skilled in the art can recover the free auxiliary base in a known manner and bring it back to the process.

The recovery of the free auxiliary base can be carried out, for example, by reacting the salt of the auxiliary base with a strong base, for. B. NaOH, KOH, Ca (OH) ₂ , lime, Na ₂ C0 ₃ , NaHC0 ₃ , K ₂ C0 ₃ or KHC0 ₃ , optionally in a solvent such as water, methanol, ethanol, n- or iso-propanol, n-butanol, n-pentanol, butanol or pentanol isomer mixtures or acetone releases. The auxiliary base thus liberated, if it forms its own phase, separated or, if it is miscible with the salt of the stronger base or the solution of the salt of the stronger base, are separated by distillation from the mixture. If necessary, the liberated auxiliary base can also be separated from the salt of the stronger base or the solution of the salt of the stronger base by extraction with an extractant, such as solvents, alcohols or amines.

If necessary, the auxiliary base can be washed with water or aqueous NaCl or Na ₂ SO ₄ solution and then dried, for. B. by removal of any water contained by means of an azeotropic distillation with benzene, toluene, xylene, butanol or cyclohexane.

If necessary, the auxiliary base can be distilled before being used again in the process according to the invention.

As described earlier, the auxiliary base ₂ -C suitable on the one hand to separate the hydrogen halide formed during the reaction and on the other hand as a nucleophilic catalyst in the Siloxylierung the C ₀ monocarboxylic acid. The execution of the siloxylation is not limited and can be carried out according to the invention intercepting the released hydrogen halide and the optionally added acid batchwise or continuously and in air or under a protective atmosphere.

The siloxylation can be carried out without pressure but also at overpressure or underpressure. Preferably, work is carried out at normal pressure.

The reaction temperature is selected so that the salt of the auxiliary base with the halogenated hydrogen at the respective pressure is in liquid form, so that a liquid-liquid phase separation is possible.

Monoethylenically unsaturated C ₃ -C ₈ monocarboxylic acids and their siloxylation products are polymerizable compounds. Therefore, in the case of the siloxylation of monoethylenically unsaturated C ₃ -C ₈ monocarboxylic acids, it is important to pay attention to a sufficient polymerization inhibition and therefore to work in the presence of conventional amounts of polymerization inhibitors known per se. An unwanted polymerization is safety-critical due to the released large amount of heat.

As a rule, based on the monoethylenically unsaturated monocarboxylic acid, from 1 to 10,000 ppm, preferably from 10 to 5,000 ppm, more preferably from 30 to 2,500 ppm and in particular from 50 to 1,500 ppm of a suitable stabilizer are used per single substance.

Suitable stabilizers are, for example, N-oxides (nitroxyl or N-oxyl radicals, ie compounds which have at least one> N-0 group), such as 4-hydroxy-2,6,6,6-tetramethylpiperidine-N-oxyl , 4-Oxo-2,2,6,6-tetramethylpiperidine-N-oxyl, 4-acetoxy-2, 2,6,6-tetramethylpiperidine-N-oxyl, 2,2,6,6-tetramethylpiperidine-N -oxyl, 4,4 ', 4 "-tris (2,2,6,6-tetramethyl-piperidine-N-oxyl) phosphite or 3-oxo-2,2,5,5-tetramethylpyrrolidine-N- monohydric or polyhydric phenols optionally having one or more alkyl groups, such as alkylphenols, for example o-, m- or p-cresol (methylphenol), 2-tert-butylphenol, 4-tert-butylphenol, 2,4 -Di-tert-butylphenol, 2-methyl-4-tert-butylphenol, 2-tert-butyl-4-methylphenol, 2,6-tert-butyl-4-methylphenol, 4-tert-butyl 2,6-dimethylphenol or 6-tert-butyl-2,4-dimethylphenol; quinones such as hydroquinone, hydroquinone monomethyl ether, 2-methylhydroquinone or 2,5-di-tert-butylhydroquinone; hydroxyphenols, for example catechol (1, 2) Dihydroxybenzene) or benzoquinone; Aminophenols, such as p-aminophenol; Nitrosophenols, such as p-nitrosophenol; Alkoxyphenols, such as, for example, 2-methoxyphenol (guaiacol, catechol monomethyl ether), 2-ethoxyphenol, 2-isopropoxyphenol, 4-methoxyphenol (hydroquinone monomethyl ether), mono- or di-tert-butyl Butyl-4-methoxyphenol; Tocipherols such as α-tocopherol and 2,3-dihydro-2,2-dimethyl-7-hydroxybenzofuran (2,2-dimethyl-7-hydroxycoumaran), aromatic amines such as N, N-diphenylamine or N-nitroso-diphenylamine; Phenylenediamines, such as N, N'-dialkyl-p-phenylenediamine, where the alkyl radicals may be identical or different and each independently of one another consist of 1 to 4 carbon atoms and are straight-chain or branched, such as N, N'-dimethyl-p- phenylenediamine or N, N'-diethyl-p-phenylenediamine, hydroxylamines, such as Ν, Ν-diethylhydroxylamine, imines, such as methylethylimine or methylene violet, sulfonamides, such as. For example, N-methyl-4-toluenesulfonamide or N-tert-butyl-4-toluenesulfonamide, oximes, such as Aldoxime, Ketoxime or amidoximes, such as diethyl, methylethylketoxime or salicyladoxime, phosphorus-containing compounds such as triphenylphosphine, triphenyl phosphite, triethyl phosphite, hypophosphorous acid or Alkyl ester of phosphorous acids; sulfur-containing compounds such as diphenyl sulfide or phenothiazine; Metal salts, such as copper or manganese, cerium, nickel, chromium salts, for example chlorides, sulfates, salicylates, tosylates, acrylates or acetates, such as copper acetate, copper (II) chloride, copper salicylate, cerium (III) acetate or cerium (II) ethyl hexanoate, or mixtures thereof.

Preference is given as polymerization inhibitor (mixture) at least one compound from the group of hydroquinone, hydroquinone monomethyl ether, phenothiazine, 4-hydroxy-2, 2,6,6-tetramethylpiperidine-N-oxyl, 4-oxo-2,2,6,6-tetramethylpiperidine N-oxyl, 2-tert-butylphenol, 4-tert-butylphenol, 2,4-di-tert-butylphenol, 2-tert-butyl-4-methylphenol, 6-tert-butyl-2, 4-dimethylphenol, 2,6-di-tert-butyl-4-methylphenol, 2-methyl-4-tert-butylphenol, hypophosphorous acid, copper acetate, copper (II) chloride, copper salicylate and cerium (II) acetate, used.

Very particular preference is given to using phenothiazine and / or hydroquinone monomethyl ether (M EHQ) as the polymerization inhibitor.

To further support the stabilization, an oxygen-containing gas, preferably air or a mixture of air and nitrogen (lean air) may be present.

The addition of the educts of the siloxylation and any other auxiliary agents such as solvents or polymerization inhibitors present may be carried out as desired. In a preferred embodiment, the C ₂ -C ₀ monocarboxylic acid and the auxiliary base in each case at least partially, preferably completely in each case, charged to a suitable reactor and heated. Subsequently, the halosilane is metered in, wherein the dosage usually takes place within a few minutes to several hours, preferably 5 to 120 minutes, more preferably 10 to 60 minutes and most preferably 10 to 30 minutes continuously or in portions. Following the siloxylation as described, the liquid-liquid separation of the salt of the auxiliary base and the subsequent recovery of the auxiliary base from the separated phase. The siloxylated C ₂ -C ₀ produced by the inventive method - monocarboxylic acids may be used as comonomers in copolymers for various applications, such as for waterproofing coatings or for the production of antifouling paints. The following examples are intended to illustrate the invention without, however, limiting it.

The percentages and ppm used are by weight unless otherwise indicated. Examples

example 1

Preparation of Nonamethyltetrasiloxymethacrylate (MAD3M) 162 g (1.88 mol, 1.13 equivalents) of methacrylic acid and 136 g (1.66 mol) of 1-methylimidazole under argon were initially introduced into a 2 l double-shell plane-milling reactor. Subsequently, 546 g (purity: 97%; 1.65 mol) of 1-chlorononamethyltetrasiloxane were added within one minute, the internal temperature rising to 70 ° C. Thereafter, the jacket temperature was raised to 90 ° C and the reaction mixture stirred for one hour. Then, the two phases were separated within two hours, whereby 21 1 g of 1-methylimidazolium chloride lower phase and 624 g of upper phase were obtained. According to GC analysis, the upper phase consisted of 95% nonamethyltetrasiloxymethacrylate (MAD3M, 1.56 mol), which corresponds to a yield of 95%. Example 2

Preparation of undecamethylpentasiloxymethacrylate (MAD4M)

In a 500 ml four-necked flask, 29.3 g (0.34 mol, 1.3 equivalents) of methacrylic acid and 23.3 g (0.28 mol, 1.1 equivalents) of 1-methylimidazole were placed under argon. Thereafter, 1 14 g (purity: 94%, 0.26 mol) of 1-chloroundecamethylpentasiloxane were added within one minute, the internal temperature rising to 65 ° C. Thereafter, the flask was heated in an oil bath at 90 ° C for two hours, then the two phases were separated within two hours to obtain 39 g of 1-methylimidazolium chloride lower phase and 127 g of upper phase. The upper phase was according to GC- Analysis of 91% undecamethylpentasiloxymethacrylate (MAD4M, 0.25 mol), which corresponds to a yield of 96%.

Example 3

Preparation of Nonamethyltetrasiloxyacrylate (AD3M)

131 g (1.81 mol, 1.3 equivalents) of acrylic acid and 124 g (1.51 mol, 1.1 equivalents) of 1-methylimidazole were placed under argon in a 2 l jacketed flanged reactor. Subsequently, 500 g (purity: 95%, 1.43 mol) of 1-chlorononamethyltetrasiloxane were added within one minute, the internal temperature rising to 70.degree. Thereafter, the jacket temperature was raised to 90 ° C and the reaction mixture stirred for one hour. Then, the two phases were separated within two hours to obtain 200 g of 1-methylimidazolium chloride lower phase and 547 g of upper phase. According to GC analysis, the upper phase was 90% nonamethyltetrasiloxyacrylate (AD3M, 1.34 mol), which corresponds to a yield of 94%.

Claims

claims

1. A method for producing a Siloxycarboxylats umassend the steps of: a) reacting a C ₂ -C ₀ monocarboxylic acid with a halosiloxane the general formula (I),

Hal- (SiR ₂ -O) _x -SiR ₃ (I) wherein

Hai is fluorine, chlorine, bromine or iodine,

R is the same or different hydrogen, C is Cio-alkyl or C ₆ -C ₄ -aryl and x is an integer from 1 to 20, in the presence of an auxiliary base and optionally a solvent, wherein the auxiliary base is chosen so that it reacts with the in the reaction of monocarboxylic acid and halosilane liberated hydrogen halide forms a salt which is immiscible in the liquid phase with the siloxycarboxylate or the solution of Siloxycarboxylats in the solvent optionally present, and wherein the optionally used solvent is chosen such that it the siloxycarboxylate is miscible and is not mixed with the liquid salt of auxiliary base and split off hydrogen halide, and b) separation of the liquid phase containing the siloxycarboxlate and optionally the solvent from the phase containing the salt of the auxiliary base and the hydrogen halide split off, at a temperature at which both phases are liquid are.

2. The method according to claim 1, characterized in that the C ₂ -Ci ₀ - monocarboxylic acid is a saturated C ₂ -C ₈ monocarboxylic acid or a monoethylenically unsaturated C ₃ -C ₈ monocarboxylic acids.

3. The method according to claim 2, characterized in that the saturated C ₂ -C ₈ - monocarboxylic acid is acetic acid, propionic acid or butyric acid.

4. The method according to claim 2, characterized in that the monoethylenically unsaturated C ^ -Cs monocarboxylic acid is acrylic acid, methacrylic acid, ethacrylic acid or maleic acid.

5. The method according to any one of claims 1 to 4, characterized in that Hai is chlorine or bromine.

6. The method according to any one of claims 1 to 5, characterized in that the substituents R of the halosilane are the same and CC ₄ alkyl or phenyl.

7. The method according to any one of claims 1 to 6, characterized in that the halosiloxane CI (SiMe ₂ 0) _x -SiMe ₃ with x = 1, 2, 3, 4, or 5 ,.

8. The method according to any one of Ansprüchel to 7, characterized in that the auxiliary base simultaneously acts as a nucleophilic catalyst for the siloxylation.

9. The method according to claim 8, characterized in that the auxiliary base is 1-methylimidazole, 1-ethylimidazole, 1-n-butylimidazole, 2-methylpyridine or 2-ethylpyridine.

10. The method according to any one of claims 1 to 9, characterized in that per mole of hydrogen halide to be separated off at least one mole of auxiliary base is used.

1 1. A method according to claim 10, characterized in that the salt of the auxiliary base in the siloxycarboxylate or in the solution of Siloxycarboxylates in a suitable solvent less than 20 wt .-% is soluble.

12. The method according to any one of claims 1 to 1 1, characterized in that the C ₂ - Cio-monocarboxylic acid and the auxiliary base are at least partially presented in a reactor and then the metered addition of the halosilane.

13. The method according to any one of claims 1 to 12, characterized in that the monocarboxylic acid and the auxiliary base are at least partially presented in a reactor and then the metered addition of the halosilane.

14. The method according to any one of claims 1 to 13, characterized in that the monocarboxylic acid is used in an amount of 1 to 2 equivalents, based on the amount of the halosilane.