DE1125660B - Process for the preparation of organopolysiloxanes containing esterified carboxyl groups - Google Patents

Description

Process for the preparation of esterified carboxyl groups containing Organopolysiloxanes The invention relates to a method of preparation of organopolysiloxanes, which, in addition to other possible functional groups, have a Contain carboxyl group that has an aliphatic hydrocarbon group 1 or Is bonded to the silicon atom 2 carbon atoms away, i.e. H. that you in the oc- or the S-position of a substituted one bonded to the silicon atom or unsubstituted ethylene or ethylidene chain.

The addition of silanes to unsaturated organic compounds in the presence of a catalyst is known. However, these reactions occurred frequently not very smooth and were often accompanied by undesirable side reactions.

It was surprising, however, that when a certain Class of silanes on acrylic acid esters in the presence of a specific solvent and a platinum catalyst, the addition is directed predominantly in the, B-position.

A number of organosilicon compounds with radicals containing carboxyl groups bonded to the silicon atom are known which can be prepared by adding unsaturated aliphatic or cyclic mono- and diesters to halogen, hydrocarbon or halogen and hydrocarbon-substituted silanes with at least one hydrogen silane compound in the presence of a peroxide catalyst. The carboxylated silanes obtained in this way can be hydrolyzed to the corresponding siloxanes. However, this addition reaction does not proceed satisfactorily in the case of aliphatic or cyclic unsaturated esters in which the position of the unsaturated bonds is such that, after the ester-silane reaction, a functional carbonyl group is less than 3 carbon atoms away from the silicon core, as would be the case, for example if one starts from acrylic acid ester. This means that this known process is limited to the preparation of silanes in which the carbalkoxy substituents are not closer to the silicon atom than the γ-carbon atom to the silicon --- SiH + CH2 = CH - COOR catalyst --- SiCH2CH2COOR (ß-isomer) (1) SiH + CH2 = CH - COOR catalyst * rnSiCHCOOR (somer) (2) CH3 The acrylic acid esters presumably did not give a satisfactory bonded chain or ring structure due to excessive homopolymerization when a peroxide catalyst was used. Since the hydrolytic instability of - and p-chloroalkylsilanes has been described in the literature, based on the results obtained so far with acrylic acid esters in the above-mentioned ester-silane addition reaction, it was justified to assume that all are in the cu or p-position to the silicon atom substituted organic substituents have the same instability.

Normally, the ester-silane addition reaction has hitherto been used Acrylic acid methyl ester used.

The emergence of the two possible products of such a reaction can be represented by the following reaction equations: Results, as known Polyacrylic acid ester through polymerization triggered by free radicals (peroxide catalyst) getting produced. On the other hand is it is also known that at the Addition of methyldichlorosilanes and trichlorosilanes to methyl acrylate in Presence of a platinum catalyst and in the absence of a solvent exclusively the o'-adducts [equation (2)] arise and that the resulting chlorosilanes are unstable in water and form resinous solids.

It is known that with esters of methacrylic acid chlorosilanes with hydrogen bonded to silicon, for example trichlorosilane or methyldichlorosilane, exclusively with the formation of ß-addition products, regardless of their presence of a solvent. However, it is preferably used in such Reactions solvent, as they cause the formation of polymethacrylic acid esters (homopolymerization) prevent and also offer a possibility that occurs during the addition to absorb exothermic heat of reaction.

In contrast, the process for preparing esterified organopolysiloxanes containing carboxyl groups by reacting silanes containing hydrogen on the silicon atom with esters of unsaturated carboxylic acids in the presence of platinum catalysts and hydrolysis or mixed hydrolysis of the silanes, according to the invention, consists in using a silane of the formula R2 EoSiX4-ab ( 3) (R2 = monovalent hydrocarbon radical; X = halogen atom or alkoxy radical; a = integer from 0 to 2 and b = integer from 1 to 3) in the presence of one or more aliphatic, aromatic or halogenated aliphatic hydrocarbons, aliphatic, cyclic or linear ethers with an acrylic acid ester of the formula (R = monovalent hydrocarbon radical and R3 = hydrogen or monovalent hydrocarbon radical) and the resulting distilled silanes are hydrolyzed or mixed hydrolyzed in a manner known per se.

The monovalent hydrocarbon radical can be, for. B. to one Alkyl or aryl radical that is either not or z. B. with halogen, nitro, amino, Ether can be substituted by keto or aldehyde groups, for example in the case of R3 act substituted or unsubstituted alkyl or aryl radicals. The addition takes place in a mixed solution of the type described, with silane ester monomers which are represented by the following general formula: [(RO O C) R1] SiRãX3-a (5) Here R, X and a have the above meaning R1 stands for an ethylene or Äthylidenrest either not or with an alkyl or aryl group or with a substituted alkyl or aryl group, e.g. B. a methyl group substituted are, R2 can e.g. B. a hydrogen atom, an alkyl, aryl or [(ROOC) Rl] group be.

In general, the process is carried out by adding the acrylic acid ester to a refluxing silane mixture in the presence of a platinum catalyst carried out in a solvent mixture.

The resulting monomeric silane ester is preferably through Separated vacuum distillation.

"Acrylic acid esters" are intended to mean substituted and unsubstituted Acrylic acid esters are understood.

As can be seen from Table II, numerous solvents have been used investigated the influence of the solvent on the ratio of B to x adducts to be investigated when using unsubstituted acrylic acid esters. It was determined, that in the process according to the invention, any inert liquid organic solvent can use in which the reactants are soluble, but that the chlorinated aliphatic saturated or unsaturated hydrocarbons, aromatic Hydrocarbons and aliphatic, cyclic and linear ethers do particularly well as Solvents are suitable for the addition reaction; However, acetonitrile inhibited the reaction Completely. However, other nitriles can likely be used in the process after of the invention, since acrylonitrile and allyl cyanide are known to interact with chlorosilanes react in the presence of a platinum catalyst. While certain solvents, such as tetrahydrofuran, result in a higher ratio of ß- to o-adducts They also cause excessive polymerization of the acrylic acid esters, making them polymerization inhibitors must use in greater concentration.

The effect of the solvent on the extent of homopolymerization of the substituted acrylic acid ester, for example the methacrylic acid ester quite noticeable. Although the use of solvents to delay the Formation of o; -addition products is not necessary, since they are only less Amount, if at all, will result in a homopolymerization of methacrylic acid ester largely held back.

The reaction is preferably carried out in the presence of a polymerization inhibitor by, and you can use any phenolic substance customary for this purpose, e.g. B.

Use hydroquinone or 2,6-di-tert-butyl-4-methylphenol. Usually The acrylic acid esters on the market already contain hydroquinone in amounts from 0.25 to 1.0 percent by weight. You can add further inhibitor to the reaction mixture in Concentrations in the range from 0.25 to 5.0 percent by weight, preferably in the range add from 1.0 to 2.0 weight percent based on total reactants.

You can use any commercially available platinum catalyst, e.g. B. platinum Use animal charcoal, asbestos or platinum black. For example, a heterogeneous Catalyst, consisting of 2 percent by weight of platinum on γ-aluminum oxide in one Concentration of 2 percent by weight, based on the initial reaction products, proved suitable. Also other concentrations in the range from 0.02 to 5 percent by weight work satisfactorily.

The solvent and silane are initially heated to reflux temperature of the silane. Other temperatures in the range from 20 to 50 "C, preferably from 40 up to 50 "C, are also suitable. When adding the acrylic acid ester to the silane solution the temperature increases depending on the rate of addition as the reaction begins is exothermic, but the maximum temperature is caused by the reflux temperature determined by the solution. After the acrylic acid ester has been added, the mixture can also be added Heat for 1/2 to 10 hours, preferably 1 to 2 hours.

It is preferred to use a solvent with a boiling point of at least 100 "C, the reaction being carried out in the range from 100 to 120" C, however, if solvents with a lower boiling point are used, the reaction mixture will heated to reflux. So you can start the reaction at practically any temperature in the Perform range from 50 to 250 "C.

In general, a greater dilution is used when carrying out the reaction the ratio of ß- to os-adducts is higher and when using methacrylic acid esters the extent of homopolymerization is lower. The information in Table 1 shows the Increase in the formation of ß-adducts and the decrease in the formation of o; -adducts Increasing the dilution of the reaction system using unsubstituted ones Acrylic acid ester. Solvent and acrylic acid ester are preferably used in proportion 4: 1 is used, but a ratio of 1: 1 to 10: 1 generally decreases the Formation of the unstable Cu adducts is essential. When using methacrylic acid esters the extent of homopolymerization is lower.

To purify the ß-adducts, the solvent is first distilled and fractionates the residue using an effective distillation column. If unsubstituted acrylic acid esters are used, the adduct can decompose, if you have a raw mixture of a - and ß-adduct for several hours to about 150 to 160 "C. It then remains essentially the pure ß-compound, the you can purify further in the usual way by distillation.

The monomeric chlorosilanes ß-carbethoxyethyl-trichlorosilane and ß-carbethoxyethyl-methyldichlorosilane, which one occurs in the reaction of ethyl acrylate with trichlorosilane or with methyldichlorosilane obtained can easily be obtained with ethanol to the corresponding ß-carbethoxyethyl-ethoxysilanes to esterify. In the same way you can ß-Carbmethoxyäthyl-methyldichlorosilane, the obtained by adding methyldichlorosilane to methyl acrylate with ethanol esterify, so that the mixed ester ß-Carbmethoxyäthyl-methyldiäthoxysilan forms, and in the same way are formed by the reaction of trichlorosilane or

Methyldichlorosilane substituted with ethyl methacrylate monomeric chlorosilanes, e.g. B. ß-Carbäthoxypropyl-trichlorosilan and ß-Carbäthoxypropylmethyldichlorosilan. For example, substituted chlorosilanes can be used to prepare the corresponding alkoxysilanes esterify smoothly with an alkanol. ß-Carbäthoxypropyl-triäthoxysilan can be through Produce reaction of ß-carbethoxypropyl-trichlorosilane with ethanol. Depending on the The amount of alcohol used in the reaction can be that used as the starting material Chlorosilanes are partially or fully esterified. For example, you can ß-Carbmethoxypropyl-methylchloräthoxysilan by reaction of 1 mol ß-Carbmethoxypropyl-methyldichlorosilane with 1 mole of ethanol.

The silanes are produced under the usual conditions for organic esters hydrolyzed, resulting in the siloxanes substituted with carboxylic acids. in the this is generally achieved by treating the silane with an aqueous-alcoholic alkaline solution heated to reflux. So you can also hydrolyze the silanes and distilling off the corresponding pure cyclopolysiloxanes from the hydrolyzates. The carbalkoxy and the carboxy functional Siloxanes, which are made from the silane monomers can be obtained with other siloxanes in the presence of a rearrangement catalyst copolymerize, which enables the production of numerous mixed organopolysiloxanes.

The ß-carbalkoxypropylsilanes obtained as an intermediate product can be represented by the following general formula: Here, R denotes a monovalent hydrocarbon radical, R4 a hydrogen atom, a monovalent hydrocarbon radical or a radical of the formula X is halogen or alkoxy and a is a number from 0 to 2. The preparation of these silanes does not, of course, require the presence of a solvent.

Examples of these silanes are ß-carbethoxypropyl-methyldichlorosilane, ß - Carbäthoxypropyl - tri-chlorosilane and ß-Carbäthoxypropyl-triäthoxysilan called.

The β-carbalkoxypropylsilanes can be converted into β-carboxypropylpolysiloxanes and β-carbalkoxypropylpolysiloxanes of the following formula hydrolyze and condense, where R3 is hydrogen or a monovalent hydrocarbon radical, R5 is hydrogen, a monovalent hydrocarbon radical or a radical of the formula mean, a has a value from 0 to 2 and n is an integer greater than 1, e.g. B. 3 or 5. According to the invention, not only high molecular weight organopolysiloxanes but also, for example, the cyclic trimers, cyclic tetramers, cyclic pentamers or mixtures thereof and hydrolysates of the starting monomers can be prepared. Hydrolyzates are represented by the above formula, where n = 0. These organopolysiloxanes can be cyclic and linear or crosslinked substances, depending on the number of functional groups present in the starting monomer. For example, the cyclic and linear β-carbalkoxypropylsilanes can be prepared by hydrolysis of a difunctional β-carbalkoxypropylsilane. In particular, the cyclic trimers, tetramers and pentamers of β-carbethoxypropyl-methylsiloxane can be prepared by adding either β-carbethoxypropylmethyldichlorosilane or β-carbethoxypropyl-methyldiethoxysilane to water. The hydrolysis of the bifunctional chlorosilanes is catalytically promoted by the hydrogen chloride developed in the process. If, on the other hand, difunctional alkoxysilanes are hydrolyzed, it is expedient to effect the reaction by mineral acid, e.g. B. to catalyze hydrochloric acid. The crosslinked ß-carbalkoxypropylsiloxanes are produced by hydrolysis of trifunctionally substituted silanes.

The hydrolysis can be carried out in a liquid organic compound, which reacts neither with the water nor with the starting silane, but in which the The starting silane is soluble. Can be used as a solvent for the reaction one alkanols, e.g. B.

Ethanol or propanol, aromatic hydrocarbons, e.g. B. benzene or toluene, aliphatic ethers, e.g. B. diethyl ether or diisopropyl ether, chloroalkyl hydrocarbons, z. B. tetrachlorethylene, use.

The temperature at which the hydrolysis can be carried out can be varied widely. Temperatures in the range from are preferably used about 0 to 40 "C.

In the preparation of the ß-carbalkoxypropyl-polysiloxanes one leads the hydrolysis is preferably carried out in the presence of such a large excess of water, that the concentration of any acid catalyst used is less than 6 percent by weight. With a catalyst concentration of more than 60 / o a hydrolysis of the carbalkoxy groups begins, which with further increase leads to a leads to complete hydrolysis of the carbalkoxy group to form the carboxyl group.

Examples of polysiloxanes produced according to the invention are: ß-carbethoxypropyl polysiloxane, ß-Carbäthoxypropyl-methylpolysiloxan, ß-Carboxypropylpolysiloxane, fl-Carboxypropyl-methylpolysiloxane, ß-Carbäthoxypropylsiloxane, namely the cyclic one Trimers, tetramers or pentamers, ß-Carbäthoxypropyl-methylsiloxan, namely the cyclic trimer, tetramer or Pentamers, ß-carboxypropylsiloxane, namely the cyclic trimer, tetramer or Pentamers, ß-carboxypropyl-methylsiloxane, namely the cyclic trimer, tetramers or pentamers, and also mixtures of cyclic trimers, tetramers and pentamers each of ß-carbethoxypropylsiloxane, ß-carbethoxypropyl-methylsiloxane, ß-carboxypropylsiloxane and B-carboxypropyl methylsiloxane.

The ß-carbalkoxypropyl-polysiloxanes and the ß-carboxypropyl-polysiloxanes described here can be found on their own as well as by methods not claimed here in connection with polyester-type thermosetting resins, used as sizing agents for fiberglass fabrics. So you can z. B. water-alcohol solutions of ß-carbalkoxypropyl-polysiloxane and the corresponding ß-carboxypropyl-p olysiloxanes for coating fiberglass fabrics use, heating the coated fabrics, the coating on it and then use polyester resins to make laminates that are hardened. A using the compositions produced according to the invention as sizes for glass fibers The laminate produced has a tensile strength in the dry state of about 30,000 kg.

The trifunctional β-carbalkoxypropyl-polysiloxanes produced according to the invention and p-carboxypropyl-polysiloxanes are also found in the fully cured state Use as covering materials. The cyclic and linear ß-carbalkoxypropyl-polysiloxanes and β-carboxypropyl polysiloxanes are useful as lubricants, and are best the linear β-carbalkoxypropyl polysiloxanes and the β-carboxypropyl polysiloxanes as well as copolymers of such siloxanes with dihydrocarbon-substituted polysiloxanes.

Such polymers and mixed polymers can be represented by the following structural formula, where R is a monovalent hydrocarbon group, R3 is a hydrogen atom or a monovalent hydrocarbon radical, R5 is a hydrogen atom, a monovalent hydrocarbon radical or a radical of the formula and x, y and z are integers, where x is at least 1, preferably at least 4, y can be any value including 0 and z is an integer with a value of at least 1 and preferably 5. These polymers and copolymers can, for example, have a molecular weight of 300 to 500,000 and contain 0.001 to 92 percent by weight of carboxypropylmethylsiloxyl units.

Linear end-blocked organopolysiloxanes of the type mentioned above can be prepared either by a mixed hydrolysis process or by equilibration. In the former case, a bifunctional ß-carbalkoxypropyl-alkoxysilane or the corresponding chlorosilane is subjected to the formula: a mixed hydrolysis and a mixed condensation.

In this formula, R denotes a monovalent hydrocarbon radical, R4 denotes a hydrogen atom, a monovalent hydrocarbon radical or a radical of the formula X is a halogen atom or an alkoxy group; in the case of a monofunctional trihydrocarbon-substituted silane of the general formula R has the same meaning as above; Hal- means halogen, e.g. B. trimethylchlorosilane. The hydrolysis and condensation are carried out as described above.

To prepare mixed polymeric organopolysiloxanes which contain dihydrocarbon-siloxane units in addition to the α-carbalkoxypropylsiloxane or the -carbalkoxypropylsiloxane units, a difunctional silane of the formula is added for example dimethylchlorosilane to the hydrolysis medium, where R and Hal have the meaning given above.

To prepare the organopolysiloxane oils according to the invention by an equilibrium process, a hydrolyzate of a difunctional ß-carbalkoxypropylsilane, which contains a mixture of linear and cyclic ß-carboxypropylsiloxanes or ß-carbalkoxypropylsiloxanes or the pure linear or cyclic substances themselves, the z. B. can be expressed by the following formula: in which R3 is a hydrogen atom or a monovalent hydrocarbon radical or a radical of the formula means and m is an integer of at least 3, in the presence of an acid catalyst with compounds containing trihydrocarbyl-substituted siloxane units (end-blocking units), for example with hexamethyldisiloxane and with or without cyclic dihydrocarbyl-substituted siloxanes, e.g. B. the cyclic tetramer of dimethylsiloxane.

Compounds which contain trihydrocarbon-substituted siloxane units and are suitable for use in the method according to the invention for controlling the polymer chain length can be represented by the following structural formula: where R is a monovalent hydrocarbon radical and z is an integer of at least 1, preferably from 1 to 8.

When performing the equilibrium procedure, one uses as Catalyst preferably sulfuric acid, although other substances can be used can. The amount of catalyst can be varied within a wide range. Using an acid catalyst in an amount of as little as 0.05 up to 1 percent by weight of the Respondents get good results.

The temperature for the equilibrium process can be in a wide range, z. B. from about 70 to 100 "C, fluctuate.

Example 1 a) Preparation of - and ß-Carbethoxyethyl-methyldichlorosilanes by adding methyldichlorosilane to ethyl acrylate. A 2-1 three-necked flask with reflux condenser, stirrer and dropping funnel, 9.0 g (2 percent by weight) of an aluminum oxide catalyst with 20 / o platinum, 4.5 g (1 percent by weight) of 2,6-di-tertiary-butyl-4-methylphenol as a polymerization inhibitor, 800 g of tetrachlorethylene (4 times the weight of ethyl acrylate used) and 253 g (2.2 mol - 100/0 excess) methyldichlorosilane loaded. The mixture was heated to reflux and stirred for one Hour and 15 minutes, 200 g (20 mol) of ethyl acrylate were added. It rose the reaction temperature to about 100 "C. After the addition of the acrylic ester is complete the mixture was heated to 100 to 1100 ° C. for 4 hours with stirring, then cooled and the catalyst is filtered off. The solvent became under reduced pressure removed and the residue is distilled through a fractionating column of 50 cm, wherein 303 g of adduct resulted (70.5 mol percent conversion, based on ethyl acrylate). The distillate consisted of two fractions: 1. A small part with a boiling range from 57 to 67 "C / 10 mm, which contained a mixture of the - and the ß-adduct, and 2. the rest of the distillate with a boiling range of 70 to 82 "C / 90 mm, which is the adduct and contained some ethyl polyacrylate.

Fractionation in a column with 20 plates gave the desired result pure ß-isomers, the formula of which was confirmed by infrared analysis.

Boiling point: 49.5 "C / 4.0 mm.

Refractive index: nB "C = 1.4389.

(C6 H12 Si O2 C12) Calculated ... C 33.5, H 5.6, Si 13.0, Cl 33.0 ° / 0; Found ... C 33.4, H 6.0, Si 12.4, Cl 32.8 ovo.

The result of further experiments with various solvents is shown in Table II. b) Purification of ß-Carbäthoxyäthyl-methyldichlorosilane by decomposition of x-Carbäthoxyäthyl-methyldichlorosilane in the heat 641 g (about 360 / o os and 740 / o ß) of a mixture of os- and ß-carbethoxyethyl-methyldichlorosilane were in a ll- Given a distillation flask equipped with a fractionating column of 50 cm. The flask was heated to 160 "C for 3 hours. 187.5 g of end product with a boiling point of 82 to 93" C / 740 mm Hg were collected. Distillation under reduced pressure gave an additional 8.0 g. Distillation of the residue under reduced pressure gave 381 g of distillate with a boiling point of 43 to 49 "C / 4mmHg, a refractive index n205 ° C of 1.4370 to 1.4389 and consisted of 6.4% o- and 93.6 ° The residue of 6870 g corresponds to the calculated 16.6% loss of isomeric c) Preparation of the cyclic trimers, tetramers and pentamers of β-carbethoxyethylmethylsiloxane by vacuum hydrolysis of β-carbethoxyethylethylmethyl A 2-1 three-necked flask equipped with a reflux condenser, stirrer and dropping funnel was charged with 400 ml of dry tetrachlorethylene and 180 g of 0.84 mol of β-carbethoxyethyl methyldichlorosilane. A vacuum of 50 to 60 mm Hg was then created in the system using a water jet pump 15.1 g (0.84 mol) of distilled water were added with stirring over the course of half an hour. After a further half hour, a further 2 mol of water were added and the contents of the flask were brought to 50 to 60.degree heated. The mixture was cooled, transferred to a separatory funnel and the tetrachlorethylene layer was washed with water and dilute sodium carbonate until it was neutral. The solvent was then distilled off under reduced pressure, resulting in a yield of 132.5 g (99 percent by weight) found (e2050C = 1.4450).

45 g of this hydrolyzate was placed in a Vigreaux column under reduced pressure distilled from 3 cm.

The following fractions were obtained: I. Boiling point: 205 to 210 ° C./0.8 mm Hg; n250 C = 1.4376 (yield 7.0 g).

II. Boiling point: 195 to 210 "C / 0.5 mm Hg; nD25 ° C = 1.4410 (yield 14.0 g).

III. Boiling point: 210 to 220 "C / 0.5 mm Hg; n2050 C = 1.4422 (yield 6.0 g).

(The substance gelled at 420 ° C.) The infrared spectrum of the fraction I showed strong absorption involving the CO 0 C2 H5, SiCH3 and Si - 0 - Si groups corresponded. The Si - 0 - Si is essentially based on the tetramer, but in traces back to the trimer. The Si - OH residue could be detected. In the case of the cyclic The following analytical data were obtained from tetramers (for C6H12SiO3): Molecular weight: Computed ... 640; found ... 721.

Saponification Number: Calculated ... 350; found ... 265.8.

Silicon: calculated. . . 17.50 / o; found ... 19.1 ° / 0.

In the fractions II and III could by infrared analysis cyclic Pentameres can be detected.

Example 2 a) Preparation of α- and ß-Carbethoxyethyl-trichlorosilanes by adding trichlorosilane to ethyl acrylate A 3-liter pressure vessel Steel was treated with 187 g (1.1 mol) tetrachlorosilane, 298 g (4.4 mol) trichlorosilane, 800 g of tetrachlorethylene, 18.4 g of an oc-aluminum oxide catalyst with 2 percent by weight Platinum and 9.0 g of 2,6-di-tertiary-butyl-4-methylphenol charged. The jar stiffened sealed and the contents heated to 70 "C while rocking. Then 400 g (4.0 mol) of ethyl acrylate pressed in for one hour and the contents Heated for a further 11/2 hours to 120 to 1400 C, cooled and placed in a 3-1 still convicted. The solvent and low boiling substances were removed by distillation removed at reduced pressure. The jB isomer was obtained in a yield of 67 mol percent, based on the ethyl acrylate, the product being 5 percent by weight «Isomers and 5 percent by weight polyacrylic acid ethyl ester was contaminated (boiling point: 81 "C / 4.0mm - 84" C / 3.4mm -73.0 ° C / 1.3mm; n750C = 1.4440 to 1.4453). The formula and the weight percentages of both impurities were confirmed by infrared analysis. The pure β-isomer was separated off and distilled again.

The compound gave the following analytical data: (Cs H9SiO2CI3) Calculated ... C 25.5, H 3.9, Si 11.9, Cl 45.20 / 0; found ... C 25.0, H 3.6, Si 12.0, C145.0%.

Boiling point: 45 ° C / 0.40 mm.

Refractive index: n250 C = 1.4457. b) By hydrolysis according to the information of Example 1, c) the corresponding polysiloxane was obtained.

Example 3 a) Preparation of ß-carbethoxyethyl dichlorosilane by Addition of dichlorosilane to ethyl acrylate. A 3 l stainless steel pressure vessel Steel was with 18.4g y-aluminum oxide catalyst with 2 weight percent platinum, 9.0 g of 2,6-di-tertiary-butyl-4-methylphenol, 202 g (2.0 mol) of dichlorosilane and 800 ml Tetrachlorethylene charged. 400 g (4.0 mol) of ethyl acrylate were obtained for 1 hour and 45 minutes pressed in continuously and the temperature of the reaction mixture increased to 100 ° C held. Thereafter, the contents were rocked to 110 to 120 ° C for 21 / hours heated, cooled and distilled in a 3-1 still flask. Slightly boiling Ingredients and solvent were stripped off under reduced pressure. distillation of the residue through a fractionating column under reduced pressure gave a Yield of 20 percent by weight of distillable adduct, mainly from the desired compound and some ethyl polyacrylate existed what by the infrared analysis was confirmed (boiling point: 56 to 60 ° C / 0.1 mm; n2050C = 1.4345 to 1.4365). The pure ß-isomer was obtained by another distillation. b) The corresponding one was obtained by hydrolysis as described in Example 1, c) Polysiloxane.

Example 4 a) Preparation of α- and ß-Carbmethoxyäthyl-methyldichlorosilane by addition of methyldichlorosilane to methyl acrylate in the absence of one Solvent One 500 ml, three neck, round bottom flask with reflux condenser, stirrer and dropping funnel was filled with 127 g (1 mol) of methyldichlorosilane and 4.0 g of γ-alumina catalyst loaded with 2 weight percent platinum. The mixture was heated to reflux and him 86 g (1 mol) of methyl acrylate with a content of 1.2 g of 2,6-di-tertiary-butyl-4-methylphenol added with stirring over 11/2 hours. Thereafter, heating was carried out for a further hour. The solids were filtered off and the filtrate packed over a glass ring Column distilled under reduced pressure. Two fractions were obtained: 1. Boiling point: 39 to 45 ° C / 1.5 to 2.0 mm (8.5 weight percent yield).

2. Boiling point: 45 to 51 "C / 2.0 mm (56 weight percent yield, based on methyl acrylate).

The first compound was identified as ß-carbmethoxyethyl-methyldichlorosilane by infrared analysis identified. The hydrolysis product of this compound was found to be [CH3OOC (CH2) 2SiCH3O] x identified.

The second compound was identified as o; -Carbmethoxyäthyl-methyldichlorosilane by means of infrared analysis identified. On hydrolysis with diethyl ether and ice, this compound gave methylpolysiloxane, what was proven by microscopic examination. b) Manufacture of - and fl-Carbmethoxyäthylmethyldichlorosilan by addition of methyldichlorosilane to acrylic acid methyl ester in tetrachlorethylene as solvent A 500 ml round bottom flask with reflux condenser, The dropping funnel and stirrer were filled with 67 g (0.56 mol) of methyldichlorosilane, 4.0 g of 2% platinum γ-alumina catalyst, 1.2 g of 2,6-di-tertiary-butyl-4-methylphenol and charged 50 g of tetrachlorethylene. The contents were heated to reflux (41 "C) and him 50 g (0.56 mol) of methyl acrylate dropwise over 11/2 hours added with stirring.

The mixture was then heated to 100-105 ° C for an additional hour. The solids were filtered off and the solvent under reduced pressure distilled off. The residue was distilled through a column packed with glass rings, a yield of 66.5 g of mixed product (boiling point: 42 ° C / 1.7 mm - 51 ° C / 0.5 mm; n25 ° C = 1.4386 to 1.4425) showed that on the basis of the infrared analysis it was 500/0 consisted of o- and 500 / o of ß-adduct.

A similar approach using 200 g of tetrachlorethylene 50 g each of methyl acrylate yielded 600 /, β- and 400 /, adduct (see Table III). Another distillation resulted in analytically pure samples of both chlorosilanes obtain.

The pure compounds gave the following analytical data: A.

CH3OOC (CH2) 2SiCH3Cl - (Cg H10 Si O2 Cl2) Calculated ... C 29.9, H'4.97, S13.95, C135,301 ,; found C29.5, H 5.20, Si14.4, C135.3%.

Boiling point: 60.50C / 9.0mm.

Refractive index: n2D50C = 1.4389.

B.

(C5 Hlo Si ° 2 C12) Calculated ... C 29.9, H 4.97, Si 13.95, Cl 35.3 %; Found ... C 30.3, H 5.1, Si 14.4, Cl 34.70 / 0.

Boiling point: 73 to 74 "C / 7.0 mm.

Refractive index: n2050 C = 1.4420. c) Production of ß-Carbmethoxyäthyl-methyldiäthoxysilan by esterification of / 1-carbmethoxyethyl-methyldichlorosilane A l-l three-necked round bottom flask using a stirrer, reflux condenser and dropping funnel, 100 g (0.55 mol) of β-carbmethoxyethyl methyldichlorosilane were added charged and created a vacuum of about 20 mm. Then was stirred while half an hour 50.6 g (0.1 mol) of absolute ethanol was added. Finally were a further 2 mol of ethanol were added and the solution was stirred for 2 hours. Then became the solution is heated to reflux for 1/4 hour and excess ethyl alcohol is added distilled off under reduced pressure. The residue was packed over a glass ring Distilled column, 34g (28.5 percent by weight) of B-carbmethoxyethyl-methyldiethoxysilane with a boiling point of 65 to 66 "C14.0 mm. nZD5" C = 1.4091.

(CgH29SiO4) Calculated ... C 49.2, H 9.1, Si 12.720 / ,, C47.2, H 9.1, Ski 144 0/0.

Infrared analysis confirmed the formula for the adduct.

Example 5 a) Preparation of ß-carbethoxyethyl-phenyldichlorosilane by adding phenyldichlorosilane to ethyl acrylate. A three-necked flask with a stirrer, reflux condenser and dropping funnel, 97.4 g (0.55 mol) of phenyldichlorosilane, 200 g of tetrachlorethylene, 14 g of 2,6-di-tertiary-butyl-4-methylphenol and 2.5 g of platinum-γ-aluminum oxide catalyst (20 /, Pt) charged. The mixture was refluxed and heated for one hour 50 g (0.5 mol) of ethyl acrylate are added dropwise, then another 21/2 Heated to reflux for hours, cooled, filtered and passed through at reduced pressure a fractionating column of 50 cm distilled. One obtained at 106 ° C / 0.25 mm boiling fraction (n2050C = 1.5120) in a yield of 72.5 g mol percent, based on ethyl acrylate. The formula of the compound was obtained by infrared analysis determined.

The following analytical data were obtained.

(C11 Hl4SiO2Cla) Calculated ... C 47.6, H 5.1, Si 10.5, Cl 25.20%; Found ... C 47.7, H 5.1, Si 10.1, Cl 25.6%. b) Production of cyclic, ß-Carbäthoxyäthylphenylsiloxanen by hydrolysis of ß-carbethoxyethyl-phenyldichlorosilane 90 g of ß-carbethoxyethyl-phenyldichlorosilane, dissolved in 100 ml of crushed ice, were stirred vigorously over the course of 15 minutes mixed in 500 ml of isopropyl ether and 200g of crushed ice. The mixture was Stirred for a further 1.5 hours, then the ether layer separated off with water, bicarbonate solution and washed again with water until neutral. The ethereal solution was evaporated in vacuo to give 34.5 g of hydrolyzate.

Then the hydrolyzate was subjected to molecular distillation, 23.0 g of distillable material with a boiling point of 200 to 350 ° C (1 to 5 p) gave; n25oC = 1.5406.

The infrared spectrum showed strong COOC2H5-, SiC «Hs- and Si - 0 - Si absorption. The material consisted essentially of a mixture of cyclic Trimer and tetramer, especially trimer. No Si — OH group could be detected will.

Saponification Number: Calculated ... 265; found ... 250.

Calculated ... C 57.4, H 6.64, Si 13.3%; found ... C 59.8, H5.9, Si 13.80 / 0.

Table I Effect of dilution with a solvent on the ratio of fi to adduct in the addition reaction of methyldichlorosilane to acrylic acid ethyl ester in tetrachlorethylene (Pt-AlaO3 catalyst) Percentage Parts Conversion Weight Weight Acrylic zenite percent solvent per part acid ester in per polyester Acrylic carbonic pollution acid ester functional *** Silane ° *) ß **) 0.0 72.0 22.5 74.5 3.3 0.5 68.6 25.4 72.6 2.0 1.0 70.0 19.0 78.5 2.5 2.0 70.6 9.4 87.4 3.2 4.0 66.3 neg. 97.9 2.1 4.0 ***) 70.5 1.7 95.0 3.3 ***) Polyester contamination: a polymer of ethyl acrylate. Infrared spectrum suggests a dimer.

****) approach using 2.0 moles of each reactant, while all other approaches use 0.5 moles of each reactant were carried out.

Table II Effect of various solvents on the ratio of ß- to adduct in the addition reaction of methyldichlorosilane on ethyl acrylate (Pt-A12 O 3 catalyst) Percentage Parts Implementation Weight Weight Acrylic percent solvent acid ester per part acrylic in carbonic acid ester acid ester functional acid ester Silane a *) ß **) 1 acetonitrile 0 - - - 1 trichloro ethylene 68.0 20.5 77.5 2.0 1 tetrachlor carbon 68.9 26.6 69.0 4.4 1 chloroform 70.0 27.8 69.5 2.7 1 benzene 76.0 32.0 65.0 3.0 1 tetrahydro furan 77.6 8.3 66.5 25.5 1 n-heptane 74.5 22.0 76.7 1.3 1 n-heptane ***) 60.0 26.5 71.4 2.1 4 toluene ***) 66.0 12.9 85.7 1.4 No solution medium 72.0 22.2 74.5 3.3 ***) Approaches with 2 moles of each reactant. All other runs were carried out with 0.5 moles of each reactant under the same conditions.

Table III Effect of dilution with solvent on the ratio of ß- to adduct in the addition reaction of methyldichlorosilane to methyl acrylate in tetrachlorethylene as solvent (Pt-Al2 O3 catalyst) Parts Percentage Weight Solvent conversion percent per part of acrylic acid ester Acrylic acid ester in carbofunctional Silane a *) ß **) ° 64 88 12 1 56 50 50 4 65 41 59 Example 6 a) Preparation of ß-carbethoxypropyl-methyldichioresilane by addition of methyldichlorosilane to methyl methacrylate in the absence of a solvent 0 / according to Pt-AlaO3 and 1 percent by weight (4.6 g) 2.6 - di-tertiary - butyl - 4 - methylphenol. The solution was heated to reflux with stirring; then 2.0 mol of ethyl methacrylate were added over a period of 2 hours, the reaction temperature rising from 40 to 99 ° C. The mixture was then refluxed for a further 2 hours and then cooled under an inert gas 60 cm distilled.

The yield was 53.50% adduct with a low content of ethyl polymethacrylate.

Hydrolyzable Chlorine: Found ... 29.6; calculated ... 9 b) Manufacture of ß-carbethoxypropyl-methyldichioresilane by addition of methyldichlorosilane of methacrylic acid ethyl ester in a solvent A flushed with nitrogen 3 l three-necked flask with stirrer, thermometer, reflux condenser and dropping funnel was with 2.0 mol (230 g) of methyldichlorosilane, 912 g (4 times the weight of the Acrylic acid ester) tetrachlorethylene, 20 /, 2 ° / Oigem Pt-Al2O3 (9.2 g), 1 weight percent Charged 4.6 g of 2,6-di-tertiary-butyl-4-methylphenol. The solution was stirred heated to moderate reflux, there were 2.0 mol (228 g) of ethyl methacrylate added over 2 hours, during which the reaction temperature rose from 70 "C to 100" C. The mixture was then refluxed for an additional 2 hours and then under a nitrogen atmosphere chilled. The crude product was reduced through a 50 cm fractionating column Fractional printing. The yield was 66.00 / 0. Infrared analysis showed that mainly the ß-adduct was obtained. A sample was chemically analyzed.

Found C 37.1 ± 0.5 ° / 0, H 6.4 ± 0.3 ° / 0, Si 12.6 ± 0.6 ° / 0, C1 30.4 t 0.6 0 / ,; calcd C 36.70 / 0, H 6.10 / ,, Si 12.20 / ,, C1 30.90 / 0.

Physical properties of ß-carbethoxypropylmethyl dichlorosilane.

Boiling point: 150 to 170 "C / 19 mm.

Refractive index: n2050 C = 1.4420.

Color: water clear. c) Preparation of ß-carbethoxypropyl-methylsiloxane A 2-1 three-necked flask with reflux condenser, stirrer and dropping funnel was charged with 100 g (0.436 mol) of ß-carbethoxypropyl-methyldichlorosilane (n25 = 1.4410) and 200 ml of dry tetrachlorethylene. Under the vacuum of the water jet pump and with vigorous stirring, 8.8 ml of water were added over the course of 10 minutes. After stirring for a further 7 minutes, 50 ml of water were added and the mixture was stirred under vacuum for a further 30 minutes. The layers were separated and the solvent layer washed neutral with water and dilute bicarbonate solution. The tetrachlorethylene was removed in a rotating scraper under reduced pressure to give 73.3 g (97 mole percent of theory) of water-clear oil. The residue was subjected to molecular distillation. 95 percent by weight of the original batch was obtained, which contained approximately equal amounts of trimer and tetramer: Calculation index n2D50C = 1.4418.

(C7H14SiO3) 3 Calculated C 48.3, H 8.1, Ski16.10 /, (322 saponification number, 523 molecular weight); found C47.8, In 8.2, Ski 15.90 / 0 (321 saponification number, 553-155 molecular weight). d) Preparation of ß-carboxypropyl-methylsiloxane 32 g (0.184 mol) of cyclic trimer and cyclic tetramer of ß-carbethoxypropyl-methylsiloxane, 25 g, were concentrated in a 500 ml three-necked flask with magnetic stirrer, thermometer and a 50 cm fractionating column with distillation head Hydrochloric acid is added to 100 ml of H2O and 100 ml of diethylene glycol diethyl ether. The contents were refluxed for 4 hours while the ethanol-water azeotrope was collected. The vapor temperature rose to 100 ° C. after 3 hours. The contents were evaporated to dryness, with 27 g of crude product remaining. This was dissolved in about 1N dilute sodium hydroxide solution and the solution was extracted twice with 200 ml of diethyl ether each time 1 nH Cl acidified and extracted twice with 200 cm3 of diethyl ether. The ether was dried over calcium sulfate. It was removed under reduced pressure, leaving 24 g of clear, viscous resin. The infrared analysis gave the formula (Cg Hlo Si 03) 3.4 Calculated C41.1, H 6.85, Si 19.20 / ,, 384 acid number; found C42.3, H 7.0, Si - 397 acid number. e) Production of a dimethylsiloxane oil with a molecular weight of 1000 and a content of 16 percent by weight carboxypropyl-methylsiloxyl units 38.4 g of linear dodecamethylpentasiloxane, 45.6 g of cyclic tetramer of dimethylsiloxane and 19.2 g of hydrolyzate of linear and cyclic β-carboxypropyl-methylsiloxane a content of 16 g or an equivalent weight of 80 β-carboxypropylmethylsiloxyl units were introduced into a 500 ml three-necked round bottom flask which was provided with a stirrer. The flask and contents were heated to 80 "C in an oil bath and the sulfuric acid added. The mixture was equilibrated at 80" C for 3 hours. The reaction product was allowed to cool to room temperature and 100 ml of water were added. The mixture was stirred and the siloxane extracted with ether. The ether solution was washed with distilled water until the wash water reacted neutrally to reagent paper. The ether was evaporated and 100 ml of benzene was added.

The benzene and any remaining water was vacuumed at 80 "C during an hour away. The viscosity at 25 "C was 117 cSt. F) Preparation of a Dimethylsiloxane oil with a molecular weight of 5000 and a content of 5 percent by weight 0-carboxypropyl-methylsiloxyl units In a 500 ml three-necked round bottom flask with a stirrer were 7.68 linear dodecamethylpentasiloxane, 6.6 g hydrolyzate of linear and cyclic ß-carboxypropyl-methylsiloxane with a content of 5 g of gß-carboxypropyl-methylsiloxyl units, determined on the basis of the equivalent weight, and 87.32 g of cyclic tetramer of Dimethylsiloxane mixed and heated to 800 C in an oil bath with stirring. For this 0.25 g of concentrated sulfuric acid was added and to terminate the equilibrium reaction heated and stirred for a further 3 hours. The vessel was cooled to room temperature and 100 ml of distilled water are added with stirring. Then the mixture was with Diethyl ether extracted and the ether solution until neutral reaction against pn reagent paper washed with distilled water. Then the ether was evaporated and 150 ml of toluene admitted. The toluene and remaining water were then evaporated in vacuo. 92.4 g of water-clear oil with a viscosity of 130 cSt at 25 ° C. were isolated. g) Preparation of a dimethylsiloxane oil with a molecular weight of about 5000 and a content of 25 percent by weight of fl-carboxypropyl-siloxyl units in one 500 ml three-necked round bottom flask with stirrer was 7.68 g of dodecamethylpentasiloxane, 67.32 g cyclic tetramer of dimethylsiloxane and 28.0 g hydrolyzate of linear and cyclic ß-carboxypropyl-methylsiloxane, containing 25 g ß-carboxypropyl-methylsiloxyl units, determined on the basis of the equivalent weight, mixed and placed on the steam bath Stirring heated to 80 to 90 ° C. 0.25 g of concentrated sulfuric acid were added and heated and stirred for a further 3 hours. Now the vessel was at room temperature cooled and 100 ml of distilled water added with stirring. Then was the siloxane dissolved in diethyl ether, and the ethereal solution with distilled water washed until the washing water reacts neutrally. Then the ether was evaporated and 150 ml of toluene are added. The toluene and all remaining water were then im Vacuum evaporated. 97.0 g of thick water-white oil were isolated.

This product had a viscosity of 2280 cP at 25 "C. H) Production a trimethylsiloxyl endblocked dimethylsiloxane oil of molecular weight 1000 and a content of 16 percent by weight ß-carboxypropyl-methylsiloxyl units In A l-l three-necked flask with a stirrer was 33.6 g of carboxypropyl-methylsiloxyl units in a hydrolyzate of linear and cyclic β-carb oxypropyl-methylsiloxane, 94.7 g cyclic tetramer of dimethylsiloxane and 80.6 g dodecamethylpentasiloxane filled in and heated in an oil bath with stirring to 80 "C. 0.5 g concentrated Sulfuric acid was added and stirring was continued for 3 hours. Then 100 ml were distilled Water is added and the mixture is used to dilute the sulfuric acid and to wash it out Stirred for 1 hour.

Furthermore, the siloxane was dissolved in diethyl ether and distilled with Washed water until the wash water reacted neutral to px reagent paper. The ether was then evaporated and 200 ml of toluene were added. The toluene and remaining water were evaporated in vacuo for 3 hours at 100 "C, whereby 192 g of oil were isolated. i) Preparation of a molecular weight dimethylsiloxane oil of 5000, which contains 5 percent by weight of carbethoxypropyl methylsiloxyl units and end-blocked with trimethylsiloxyl units. A 500 ml round bottom flask with a stirrer was made with 7.68 g dodecamethylpentasiloxane, 87.32 g cyclic tetramer of dimethylsiloxane and 5.00 g of cyclic tetramerem of p-carbethoxypropylmethylsiloxane and charged heated to 90 ° C. with stirring on an oil bath. 0.5 g concentrated sulfuric acid were added and the equilibrium reaction was carried out for 3 hours at 80 ° C. with stirring long carried out. The organopolysiloxane oil was cooled to room temperature and to inactivate the catalyst, add 200 ml of dilute bicarbonate solution. The siloxane was dissolved in diethyl ether and washed with distilled water, until the wash water reacted neutrally. Then the ether was on a steam room driven off and added 100 ml of toluene. The toluene and all remaining water were removed by vacuum evaporation at 90 to 100 "C.

There were 45 g of water-clear oil with a viscosity of 186 cSt 25 "C isolated. K) Production of a dimethylsiloxane oil with a molecular weight of 5000 and a content of 25 percent by weight ß-carbethoxypropyl-methylsiloxyl units, which is end-blocked with trimethylsiloxyl units In a 500 ml round bottom flask with Stirrer were 7.68 g of dodecamethylpentasiloxane, 67.32 g of cyclic tetramer of Dimethylsiloxane and 25.0 g of cyclic tetramer of, B-carbethoxypropylmethylsiloxane filled in and heated to 900 C with stirring on a steam bath. 0.5 g 96 above concentrated sulfuric acid was added and the mixture was heated and stirred for an additional 3 hours. The oil was then cooled to room temperature and used to neutralize the catalyst 100 ml of saturated sodium bicarbonate solution were added. Then the oil was made with diethyl ether undressed and washed with distilled water until the wash waters against pH reagent paper reacted neutrally. The ether was then distilled off and 100 ml of toluene were added. Finally, the toluene and any remaining water were removed in vacuo for 2 hours Heating to 95 "C removed. A water-clear oil with a viscosity of 83 cSt isolated at 25 ° C.

1) Production of a dimethylsiloxane oil having a molecular weight of 10,000 and a content of 5 percent by weight of fl-carbethoxypropyl-methylsiloxyl units 3.84 g of dodecamethylpentasiloxane, 5.0 g of cyclic tetramer of fl-carbethoxypropylmethylsiloxane and 91.16 g of cyclic Filled with tetrameres of dimethylsiloxane. The jar was taking on a steam bath Stirring heated to 80 to 90 ° C. and the sulfuric acid was added. It was further Heated and stirred for 3 hours. The vessel was now cooled to room temperature and 100 ml of saturated sodium bicarbonate solution were added to neutralize the acid. The oil was extracted with diethyl ether and the solution until neutral Wash waters washed with water. Then the toluene and any remaining water removed in vacuo for 2 hours at 100 ° C. 92 g of water-clear oil were also added a viscosity of about 133 cSt at 25 "C.

Example 7 a) Preparation of β-carbethoxypropyl-methyldiethoxysilane by esterification of-carbethoxypropylmethyldichlorosilane under reduced pressure 57.3 g (0.26 mol) of fl-carbethoxypropyl-methyldichlorosilane were placed in a 600 ml three-necked flask with dropping funnel, stirrer and reflux condenser and an approach for a water jet pump filled. From the dropping funnel, with stirring and under reduced pressure 23.0 g (0.5 mol) of ethanol were added over 2 hours without external cooling. It was The mixture was stirred for a further 1 hour and a 20% excess of ethanol (4.6 g) was slowly added. After stirring for a further half hour under reduced pressure, the mixture was heated and during a vessel temperature of 700 ° C. was maintained during the distillation. After cooling it was the clear yellow product is distilled through a column of 30 cm packed with glass rings, a yield of 77.6% was obtained. b) Production of ß-Carbäthoxypropyl-methyldiäthoxysilan by esterification of fl-carbethoxypropylmethyldichlorosilane at atmospheric pressure 94.0 g (0.41 mol) of β-carbethoxypropyl-methyldichlorosilane were placed in a 500 ml three-necked flask filled with stirrer, thermometer, reflux condenser and dropping funnel. While 3/4 hours were allowed with gentle warming to maintain the rate of the reaction 37.7 g (0.82 mol) of ethanol and then another 200% of the excess of 7.6 g were added. After the addition, the mixture was heated to 90 ° C. for 3 hours in order to remove hydrogen chloride. The vessel was then cooled to room temperature under nitrogen with anhydrous N H3 neutralized, diluted with diethyl ether and filtered. The raw ester was transferred to a 100 ml distillation vessel and placed in a 60 cm column with Alumina was filled, distilled. An overall yield of 74.6 was obtained ° lo.

Physical properties of fl-carbethoxypropyl-methyldiethoxysilane.

Boiling point: 228 to 230 "C at atmospheric pressure and 125 to 1280C / 22 mm.

Refractive index: n250C = 1.4170.

Color: water-clear liquid.

Stability tests.

The diethoxy compound can be distilled at atmospheric pressure, and it turns out to be distilled from a mixture of 20 percent by weight of ethanol, 2 percent by weight sodium methylate or hydrochloric acid at atmospheric pressure stable. c) By hydrolysis according to the information in Example 6, c) the corresponding Polysiloxane obtained.

Example 8 a) Production of β-carbethoxypropyl-trichlorosilane by Addition of trichlorosilane to methacrylic acid ethyl ester in a pressure vessel with one Nitrogen-flushed 3-liter pressure vessel was filled with 500 g of trichlorosilane, 156 g of silicon tetrachloride, 700 g of tetrachlorethylene and 12.0 g of 2 0/0 Pt / Al2O3 are charged. The vessel became tightly closed and heated in an electric oven with swings. At 180 "C (14kg / cm2) 350 g of ethyl methacrylate were added over the course of one hour.

Now the heat supply was turned off and the vessel was swinging brought to room temperature overnight. The crude product weighing 1690 g was filtered and distilled through a 60 cm column packed with glass rings. The yield was 45.50 / 0. The infrared spectrum showed that a ß-adduct with a Trace of polyester was present.

Physical properties of ß-carbethoxypropyl-trichlorosilane.

Boiling point: 106 to 108 "C / 11 mm.

Refractive index: n2D5 ° C = 1.44457.

Color: water-clear liquid. b) Production of ß-carbethoxypropylsiloxane In a 1 l three-necked flask with a dropping funnel, stirrer and reflux condenser were Filled in 100 ml of diethyl ether and 100 ml of water. With vigorous stirring at reduced The pressure was 94.0 g (0.377 mol) of β-carbethoxypropyl-trichlorosilane over the course of 30 minutes admitted. The following day the mixture was freed of solids. Then became a mixture of 50 g hydrochloric acid, 200 cm8 water and 200 cm3 diethylene glycol diethyl ether added and the contents heated under reflux for 4 hours. The steam temperature rose after 3 hours to 100 "C. The contents became solids under reduced pressure freed, from which 40 g of white powder were obtained after grinding. Neutralization equivalent = 178 (theory 139).

Example 9 a) Preparation of β-carbethoxypropyl-triethoxysilane by Esterification of p-carbethoxypropyl-trichlorosilane at reduced pressure in one One-liter three-necked flask with stirrer, thermometer, dropping funnel and reflux condenser 124.8 g (0.5 mol) of β-carbethoxypropyltrichlorosilane were introduced with a vacuum. In a water jet vacuum and with stirring, 69.0 g (1.5 Mol) and a 20% excess 13.8 g of ethanol were added. It wasn't refrigerated.

The excess alcohol was added after stirring for 30 minutes, and then stirring was continued for 11/2 hours. The vessel was now on a Temperature of 80 "C. The crude product was cooled and activated by a Alumina packed column of 60 cm under reduced pressure distilled. The yield of triethoxy product was 94.0%. The infrared spectrum showed that there was no adduct or polyester present.

Physical properties of p-carbethoxypropyltriethoxysilane.

Boiling point: 243 to 244 "C at atmospheric pressure.

Refractive index: n2D5 "C = 1.4130.

Color: water-clear liquid.

Stability tests on ß-carbethoxypropyltriethoxysilane.

Thermal: The compound can be distilled at atmospheric pressure.

Boiling point: 243 to 244 "C.

Basic hydrolysis: The compound was made with 20 weight percent ethanol and 2 percent by weight sodium methylate mixed and heated to 900 C for 2 hours. It was then distilled off from the base at atmospheric pressure, with no Si-C cleavage was to be determined.

Acid hydrolysis: The compound was made with 20 weight percent ethanol and mixed with 2 percent by weight dry hydrogen chloride and distilled as above.

No Si-C cleavage was found. b) Production of p-carbethoxypropyl-polysiloxane 20 g (0.72 mol) of jB-carbethoxypropyl-triethoxysilane, 20.0 g (1.11 mol) of water and Two drops of concentrated HCl were placed in a 100 ml still and shaken for 10 minutes until a homogeneous solution was obtained. Here was developed some warmth.

The clear solution was left at room temperature for 1 hour and then 21/2 Standing in a bath at 150 ° C. for hours. 11.8 g of a very viscous, clear product were obtained Of oil in a yield of 97.501. A sample of this product showed the following properties: Saponification number: 338.

Ethoxy groups found: 27.00 /, corresponding to the carbethoxy group.

Claims (13)

Theory: 26.9 ° / ot PATENT CLAIMS: 1. Process for the preparation of esterified organopolysiloxanes containing carboxyl groups by reacting silanes containing hydrogen on the silicon atom with esters of unsaturated carboxylic acids in the presence of platinum catalysts and hydrolysis or mixed hydrolysis of the silanes, characterized in that one Silane of the formula Ra2 E SiX4 - b (R2 = monovalent hydrocarbon radical; X = halogen atom or alkoxy radical; a = integer from 0 to 2 and b = integer from 1 to 3) in the presence of one or more aliphatic, aromatic or halogenated aliphatic Hydrocarbons, of aliphatic cyclic or linear ethers with an acrylic acid ester of the formula (R = monovalent hydrocarbon radical and R3 = hydrogen or monovalent hydrocarbon radical) and the resulting distilled silanes are hydrolyzed or mixed hydrolyzed in a manner known per se. 2. Modification of the method according to claim 1, characterized in that that, prior to the hydrolysis, the silane which may be present in the resulting silane Halogen atoms esterified with an alkanol. 3. Form of embodiment of the method according to claim 1, characterized in that that the platinum catalyst used is y-aluminum oxide with 2 percent by weight of platinum on the reactants. 4. Modification of the method according to claim 1, characterized in that that the reaction is carried out in the presence of a polymerization inhibitor. 5. The method according to claim 4, characterized in that as Polymerization inhibitor uses a phenol. 6. The method according to claim 4, characterized in that the Inhibitor in an amount of 0.25 to 5.0 percent by weight, based on the reactants, used. 7. The method according to claim 1, characterized in that there is solvent and acrylic acid esters in a ratio of 1 to 10: 1. 8. The method according to claim 7, characterized in that the 4: 1 ratio applies. 9. The method according to claim 1, characterized in that the The silane and the solvent are first heated to 20 to 50 "C, then the acrylic acid ester is added and the mixture is heated to 50 to 250 ° C. 10. The method according to claim 1, characterized in that as Solvent tetrachlorethylene used. 11. The method according to claim 1, characterized in that as Silane methyldichlorosilane or phenyldichlorosilane is used. 12. Form of embodiment of the method according to claim 1, characterized in that that the resulting silanes by heating with an aqueous-alcoholic alkali solution hydrolyzed under reflux. 13. Form of embodiment of the method according to claim 1, characterized in that that the resulting silanes are hydrolyzed with water in the presence of a mineral acid, wherein the mineral acid in an amount of less than 6 percent by weight of the reaction mixture is used. References considered: U.S. Patent No. 2,721 873. Older patents considered: German Patent No. 1,057,340.