EP3717545A1

EP3717545A1 - Method for preparing sioc-linked polyether siloxanes branched in the siloxane part

Info

Publication number: EP3717545A1
Application number: EP18752163.8A
Authority: EP
Inventors: Wilfried Knott; Horst Dudzik
Original assignee: Evonik Operations GmbH
Current assignee: Evonik Operations GmbH
Priority date: 2017-11-29
Filing date: 2018-08-15
Publication date: 2020-10-07
Also published as: CA3084463A1; EP3492513B1; EP3492513A1; CN111386300A; ES2901137T3; US11725017B2; CN111386300B; WO2019105608A1; US20200339612A1

Abstract

The invention relates to a method for preparing SiOC-linked polyether siloxanes branched in the siloxane part, starting from cyclic branched siloxanes of the D/T type, wherein in a first step the mixtures of cyclic branched siloxanes of the D/T type are reacted, optionally mixed with simple siloxane cycles, with acetic anhydride in an acid-catalysed manner to form acetoxy-group-bearing, branched siloxanes, in a second step the equilibration of the acetoxy-modified branched siloxane with trifluoromethanesulfonic acid is carried out, preferably with addition of acetic acid, and in a third step the trifluoromethanesulfonic acid acetoxysiloxane is reacted with polyetherols, optionally in the presence of bases and optionally in the presence of an inert solvent.

Description

Process for the preparation of siloxane-branched SiOC-linked polyethersiloxanes

The invention relates to a process for the preparation of siloxane-branched SiOC-linked polyether siloxanes. Furthermore, the invention also relates to preparations consisting of a SiOC-linked branched silicone polyether together with a polyetherol and a polyetherol end-capped by acetyl groups. Furthermore, the invention relates to the use of these siloxane-branched SiOC-linked polyether siloxanes as defoamers, as foam stabilizers, wetting agents, coating and leveling additives and as Dismulgatoren.

As a reference to the M, D, T, Q nomenclature used in this document to describe the building blocks of organopolysiloxanes is W. Noll, chemistry and technology of silicones, Verlag Chemie GmbH, Weinheim (1960), page 2 et seq cited.

Older processes for the preparation of branched SiOC-linked polyethersiloxanes are based essentially on chlorosilane chemistry (methyltrichlorosilane and dimethyldichlorosilane) and provide for the attachment of the polyether substituents by reacting the SiCI-group-carrying siloxanes with the respective polyetherol in the presence of suitable auxiliary bases in order to obtain the Linkage reaction liberated hydrochloric acid in the form of salts to bind. If the simple chlorosilanes originating directly from the Müller-Rochow synthesis (direct synthesis) are also favorable, the storage and handling of these corrosive educts on a production scale raises many problems, for example questions about material resistance, exhaust gas, waste, etc. What makes such legacy processes increasingly unattractive from today's perspective.

The not yet disclosed patent applications EP17156421.4, EP 17169876.4 are aimed at mixtures of cyclic-branched D / T-type siloxanes and teach their further processing into functionalized branched siloxanes and / or branched silicone oils. The further processing disclosed therein is carried out by acid equilibration of the D / T-structured siloxanes with silanes and / or siloxanes.

According to this, branched SiOC-linked polyethersiloxanes in the siloxane moiety are accessible, for example, by equilibrating mixtures of cyclic branched D / T-type siloxanes with diethoxydimethylsilane and then carrying out, for example, the metal-catalyzed replacement of the ethoxy substituents by polyalkyleneoxy radicals in the context of transesterification.

However, diethoxydimethylsilane is a costly modification agent, limiting its widespread use.

Specifically, therefore, the technical problem to be solved is to find a simple and at the same time economical process that allows the production of branched in siloxane SiOC-linked polyether siloxanes.

In addition, owing to the aspect of sustainability, owing to the synthesis task to be solved according to the invention, educts such as chlorosilanes / chlorosiloxanes and intermediates such as the mineral acid alkylhalosiloxanes, for example the well-known chlorosiloxanyl sulfates, should be deliberately avoided. In addition, the branched in siloxane SiOC-linked polyether siloxanes should have a good performance quality.

Branched and unbranched siloxanes bearing acyloxy or acetoxy groups are already known from US Pat. No. 3,595,885, the preparation of which starting from terminally halogen-substituted siloxanes by reaction with mono- and / or polybasic carboxylic acids, the salts of corresponding carboxylic acids or the anhydrides of such carboxylic acids is described. In particular, the use of carboxylic acids and their anhydrides in the equilibrated systems considered there always leads to the presence of sulfuric acid incorporated into the siloxane skeleton in the form of bridging sulfato groups, which is explained by the preferred use of the chlorosiloxanyl sulfates used there as educt. However, as known to those skilled in the art, sulfo-bridged siloxanes are reactive species which, for example, can undergo undesired secondary reactions upon storage and depending on the temperature and any moisture that may be introduced into the system with liberation of sulfuric acid.

Likewise, the non-equilibrating opening of simple unbranched siloxane cycles with acetic anhydride to short-chain, chain-terminal acetoxy-carrying siloxanes in the presence of catalysts is known from a number of publications and protective rights applications.

Thus, Borisov and Sviridova describe the opening of cyclic dimethylsiloxanes with acetic anhydride in the presence of catalytic amounts of iron (III) chloride to short-chain α, ω-acetoxysiloxanes (SN Borisov, NG Sviridova, J. Organomet Chem 1, 1968, 27-33). , Lewis et al. in the US 4066680 the production of short-chain a, w-siloxane diols, where he reacts octamethylcyclotetrasiloxane with acetic anhydride on acid-treated bleaching earths and hydrolyzed the thus obtained mixtures of short-chain a, w-acetoxysiloxanes in alkaline water.

US Pat. No. 3,346,610 also discloses access to acetoxy group-bearing short-chain siloxanes which is based on metal halide-induced acetoxy modification of strained cyclic siloxanes by reacting them with acetoxy group-containing silicone compounds. A variety of Friedel-Crafts active metal halides act as a catalyst, with zinc chloride being preferred. A particular objective of US 3346610 is the acetoxy modification of strained diorganosiloxane cycles, with deliberate avoidance of equilibration events.

The prior art thus relates to work which provide the opening of cyclic siloxanes - here sometimes strained cyclosiloxanes - with reactants containing acyloxy groups and whose objective is to obtain defined linear short-chain and siloxane species which are still to be separated by fractional distillation.

However, the molecular mass-defined, chain-pure acetoxy-modified siloxane compounds synthesized in this way are not suitable for the preparation of organomodified siloxanes, in particular polyethersiloxanes, which are used in demanding technical applications, for example in PU foam stabilization or in the defoaming of fuels, etc. to take. Agents that effectively address such a field of application are always characterized by a broad oligomer distribution comprising high, medium and low molecular weights, since the oligomers contained in them very often differentiated surfactant depending on their molecular weight and thus their diffusion behavior Tasks in different time windows of the respective process are attributable. Especially in the case of the branched organo-modified siloxanes, owing to the reactivity behavior of M, D and T units discussed above, a good oligomer distribution combined with a statistically uniform distribution of siloxane units in the individual molecules is only to be achieved if the starting material used is from D / T-type already satisfies itself a distribution function.

Acyloxyorganopolysiloxanes and in particular organosiloxanes with terminal acyloxy groups are known as starting materials for subsequent reactions. For example, the acyloxy groups can be hydrolyzed in a diorganosiloxane, whereupon the hydrolyzate can be dehydrated and the dehydrated hydrolyzate polymerized to form a flowable diorganopolysiloxane. These flowable polysiloxanes are useful as starting materials for the preparation of viscous oils and rubbers which can be cured to silicone elastomers.

Organosiloxanes provided with terminal acyloxy groups can be obtained, for example, by reacting an alkylsiloxane and an organic acid and / or anhydride thereof in the presence of sulfuric acid as a catalyst. Such a process is described in US Pat. No. 2,910,496 (Bailey et al.). Although in principle organosiloxanes having terminal acyloxy groups are also obtained by this process, the disadvantage of the process is that the reaction product consists of a mixture of acyloxy-containing siloxanes and acyl-containing silanes of different composition. In particular, the teaching to this end states that alkylsiloxane copolymers composed of M, D and T units are cleaved by the process into trimethylacyloxysilane, di-acyloxydimethylsiloxane and methyltriacacylsilane. Thus, in the reaction of octamethylcyclotetrasiloxane with acetic anhydride and acetic acid, after neutralization of the sulfuric acid used as a catalyst, separation of the salts and removal of water, residual acetic acid and acetic anhydride, Bailey obtains a complex mixture and in no case an equilibrate, which he subjects to fractional distillation (see Example) , ibid.). The material identity of the resulting fractions II and IV remains unclear, so that it is difficult thereafter to obtain defined products, or to separate them in high yields from the mixture.

Referring to Bailey et al. (US 2,910,496), DE 154510 (A1) (Omietanski et al.) Teaches a process in which an acyloxy group of an acyloxysiloxane is reacted with the hydroxyl group of a polyoxyalkylene hydroxypolymer to form a siloxane-oxyalkylene block copolymer and a carboxylic acid; Carboxylic acid is removed from the reaction mixture. The described there, solvent-free guided reactions sometimes require considerable reaction times (up to 1 1, 5 hours (Example 1), very high reaction temperatures (150 to 160 ° C (Example 1) and the application of an auxiliary vacuum or stripping the reaction matrix with dry Nitrogen over the entire reaction time.

Surprisingly, it has now been found that branched SiOC-linked polyethersiloxanes can be prepared starting from cyclic-branched siloxanes of the D / T type in the siloxane moiety by reacting

in a first step, cyclic-branched D / T type siloxanes acid-catalyzed with acetic anhydride, optionally in admixture with simple siloxane cycles, to give branched siloxanes bearing acetoxy groups, and in a second step, the equilibration of the acetoxy-modified branched siloxane with trifluoromethanesulfonic performs and

in a third step, reacting the trifluoromethanesulfonic acid acetoxysiloxane with polyether alcohols, if appropriate in the presence of bases and if appropriate in the presence of an inert solvent.

Surprisingly, the inventors have found that both mixtures of cyclic branched D / T type siloxanes which consist exclusively of siloxanes having D and T units and their total fraction of the D present in the siloxane matrix can be determined by ²⁹ Si NMR spectroscopy and T units which have Si-alkoxy and / or SiOH groups, less than 2 mol%, preferably less than 1 mol%, and furthermore advantageously at least 5% by weight of siloxane cycles, preferably octamethylcyclotetrasiloxane (D ₄ ) , Dekamethylcyclopentasiloxan (Ds) and / or mixtures thereof,

as well as

Mixtures of cyclic branched siloxanes containing exclusively D and T units whose total fraction of the D and T units present in the siloxane matrix and determinable by ²⁹ Si-NMR spectroscopy, which have Si-alkoxy and / or SiOH groups, greater than 2 and less than 10 mole percent are particularly well suited for use in inventive step 1.

The cyclic-branched D / T-type siloxanes used in the first step are described by way of example both in the experimental part and also described in detail in the not yet disclosed patent applications EP17156421.4, EP 17169876.4. Both documents thus fully belong to the disclosure content of this application.

The term "inert solvent" encompasses all those solvents which do not react under the conditions of the reaction carried out here with potential reactants or at most to a negligible extent. In particular, the inert solvent is an aromatic, preferably alkylaromatic solvent and very particularly preferably toluene.

The simple siloxane cycles optionally added in the acetylation step include, in particular, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, dodecamethylcyclohexasiloxane and / or their mixtures of any desired composition, which corresponds to a preferred embodiment of the invention.

The observation that those mixtures of D- and T-units containing siloxanes are suitable for further processing according to the invention, which have an increased content of Si-alkoxy and / or SiOH groups, is for those skilled in mind that in the not yet disclosed Patent application EP 17169876.4 and in the not yet disclosed patent application EP 17195510.7 described difficulties in their equilibration unpredictable.

Thus, in the context of the present invention in the experimental part in addition to the inventive use of a cyclic-branched siloxane with a target Dl T ratio of 6: 1 and containing spectroscopically detected Si units, the Si-alkoxy or SiOH groups of 0.43 mole percent (Examples 2, 3, 4 and 5) also the inventive use of a cyclic-branched siloxane with a target Dl T ratio of 6: 1 and a content of spectroscopically detected Si units, the Si-alkoxy or SiOH groups have shown by 4.0 mole percent. (Examples 7 and 8).

Since the invention resulting, branched in siloxane SiOC-linked polyether siloxanes derived from equilibrated siloxane oligomers, the application quality is ensured.

The preparation of a single-branched, acetoxy-carrying siloxane skeleton by substitution of silicon-bonded chlorine by acetic acid and the replacement of acetoxy groups associated with salt attack by polyetheroxy radicals are described in US Pat. No. 4,380,451, ibid. Example 1 described. Here, the acetoxy-carrying siloxane is initially charged in toluene with vigorous stirring and allowed to run a mixture of a butanol-initiated polyetherol in toluene within 15 minutes, and then initiate ammonia within 45 minutes. The reaction mixture is then heated to 80 ° C., a small amount of isopropanol is added and the matrix is further saturated with ammonia over 3 hours. After cooling to room temperature, the salts are separated by filtration, and the toluene is distilled at 100 ° C and an auxiliary vacuum of 20 mbar.

However, this synthesis route, based on chlorosilanes and associated with considerable salt attack, is disadvantageous from the point of view of operational production since it is necessary to accept a considerable outlay for the filtration and associated product losses.

Surprisingly, however, in the context of this invention, it was further found that the exchange acetoxy vs.. Polyetheroxy residue on siloxanes can be successfully and quantitatively carried out without the use of an acetic acid released for neutralization of added auxiliary base, such as ammonia (Examples 3 and 4).

Thus, another object and another preferred embodiment of this invention is the salt-free exchange of acetoxy groups attached to branched siloxane moieties by polyetheroxy groups by subjecting the branched siloxane bearing trifluoromethanesulfonic acid acetoxy group optionally in the presence of bases in a solvent together with the polyetherol Stirring brings to a reaction and then in the course of a distillation, the resulting and optionally present in the system already present acetic acid and residues used Acetanhydrids optionally together with portions of the solvent used. This corresponds to a preferred embodiment of the invention for the replacement of the siloxane-bound acetoxy groups by the reaction with polyether alcohols.

Preference is given to those solvents which are inert in the sense of the desired substitution reaction (exchange acetoxy vs. polyetheroxy radical) and preferably form a thermally separable azeotrope with the resulting acetic acid which may already be present in the system. This corresponds to a further preferred embodiment of the invention, wherein the use of an aromatic, preferably alkylaromatic solvent is preferred.

Among the acetic acid binary azeotroping solvents, toluene is most preferred. The use of toluene therefore corresponds to a preferred embodiment of the invention. The boiling points of toluene and acetic acid are with 1 10.6 and 1 18.5 ° C and the boiling point of the binary Azeotrope at 105.4 ° C indicated. The azeotrope has a composition of 72 weight percent toluene and 28 weight percent acetic acid (Source: Handbook of Chemistry and Physics, 58th Edition, page D2, CRC Press (1977-1978), West Palm Beach).

The associated with the azeotrope, thermal excitation of acetic acid ensures the complete exchange of bonded to the siloxane acetoxy against Polyetheroxyreste and therefore corresponds to a particularly preferred embodiment of the invention.

In this case, it is also very particularly preferred to apply an auxiliary vacuum since it minimizes the thermal stress on the resulting SiOC-linked, branched polyethersiloxane (Examples 3 and 5).

If the mixture obtained according to the invention after the second step, comprising a siloxane-branched, acetoxy-bearing, equilibrated siloxane and optionally unreacted acetic anhydride and the catalyst acid therein, are reacted with a polyetherol in the third step without adding a base, then depending on the selected stoichiometry of the reactants, the temperature and the reaction time, in addition to the SiOC-linked branched silicone polyether also changing proportions of an acetyl group end-capped polyether. This corresponds to a preferred embodiment of the invention.

If, on the other hand, an auxiliary base such as, for example, sodium bicarbonate is introduced into the polyetherol and then charged with the mixture resulting from the second step comprising an siloxane-branched, equilibrated siloxane containing acetoxy groups in addition to unreacted acetic anhydride and the catalyst acid present therein, the early neutralization of the Acid to that no esterification of hydroxy-functional polyether observed (Example 4). This corresponds to a preferred embodiment of the invention.

Particularly preferred according to the invention, the replacement of the siloxane-bound acetoxy groups in the presence of a base, in particular in the presence of sodium bicarbonate, ammonia or an organic amine.

If, however, the neutralization of the acid present in the reaction system occurs at a later time, especially after the thermal removal of acetic acid, residual acetic anhydride and any solvent used, the polyetherol in the system is closed in small proportions with acetyl end groups. Experience shows that the longer exposure time of the acid present in the system often leads to somewhat more discolored products (Example 3).

In this case, after distillative removal of the acetic acid, the preparation obtained according to the invention consists of a SiOC-linked branched silicone polyether together with a polyetherol and an acetyl-terminated polyetherol. Such reduced hydroxy functionality formulations may be of interest in particular applications and are also an object of the present invention. This invention-typical by-product can be detected by accompanying ¹³ C-NMR and ¹ H-NMR spectroscopy, since in particular the shift of the polyether-esterified carboxylate carbon with d about 171, 5 ppm is characteristic.

Surprisingly, however, it was also found that the solvent-free transformation trifluoromethanesulfonsaurer branched, acetoxy containing siloxanes to siloxane branched, SiOC-linked polyether siloxanes very quickly (within 1 hour) and also at very moderate temperatures (T = 50 ° C) quantitatively succeeds (Example 4 ).

If the replacement of the siloxane-bound acetoxy groups by the reaction with polyether alcohols is solvent-free, there is thus a further preferred embodiment of the invention.

Thus, another object and another preferred embodiment of this invention is the salt-free replacement of branched siloxane scaffolds by polyetheroxy groups by reacting the branched siloxane bearing trifluoromethanesulfonic acid acetoxy groups with the polyetherol to release acetic acid.

The advantages of this salt-free process step according to the invention are evident to the person skilled in the art since filtration steps in production processes are always time-consuming, lossy and, in addition, disposal-relevant.

In the context of the present invention, it has been found that the acetoxy functionalization of the DT cycles can in principle be catalyzed both by the use of homogeneous and heterogeneous acids. It has also been found that both certain Lewis and Bronsted acids are suitable for this purpose. In particular, anhydrous iron (III) chloride, Filtrol ^® (strongly acidic bleaching earth and acid-treated bleaching earth), concentrated sulfuric acid, and most preferably trifluoromethanesulfonic acid to catalyze the acetylation step can be used. This corresponds to a preferred embodiment of the invention.

In terms of their effectiveness, however, the acidic catalysts differ greatly.

It has been found that the trifluoromethanesulfonic acid not only facilitates the incorporation of acetoxy functions into the branched siloxane, but also ensures complete equilibration of the thus obtained acetoxy group-bearing, branched siloxane. In addition to other analytical methods such as gel permeation chromatography (GPC), a simple hand test is already suitable for practically evaluating the equilibration quality achieved, in which a volume of from 0.2 to 0.4 ml of the branched test piece is applied to a black bakelite lid. trifluoromethanesulfonsauren acetoxysiloxane applies and allowed to cure in air.

Fully equilibrated, branched acetoxysiloxanes then form a solid white gel over less than 1 minute, the presence of which stands out well against the background of the black bakelite lid (Example 2 and Example 7). Incompletely equilibrated, branched acetoxysiloxanes, on the other hand, always only give samples with partial gel content and residual liquid.

Are the resulting from the Acetoxyfunktionalisierung the DT cycles, branched subjected Acetoxysiloxane this sensitive assay, it is clear that anhydrous iron (III) chloride, Filtrol ^® (strongly acidic bleaching earth and acid-treated bleaching earth) and concentrated Although sulfuric acid catalyze the Acetoxyfunktionalisierung, but do not lead to fully equilibrated, branched acetoxysiloxanes.

If desired, the incompletely equilibrated acetoxysiloxanes can then be subjected to equilibration with trifluoromethanesulfonic acid.

Further, trifluoromethanesulfonic acid is particularly preferred in that they no tendency to product discoloration as iron (III) chloride has not and as the solid acid Filtrol ^® must be necessarily separated by filtration from the intermediate product.

Rather, trifluoromethanesulfonic acid should remain in the branched siloxane intermediate product carrying acetoxy groups (see Inventive Example 1 and Inventive Example 2).

For the introduction of the acetoxy groups, trifluoromethanesulfonic acid is preferably present in concentrations of from 0.05 to 0.2 percent by weight (% by weight), more preferably in concentrations of from 0.07 to 0.15 percent by weight (% by weight), based on the total mass of the reaction mixture used. This corresponds to a preferred embodiment of the invention.

The inventors have further found that completely by-equilibrated, branched acetoxysiloxanes can be produced very rapidly and advantageously by catalysing the cyclic-branched D / T-type trifluoromethanesulfonic acid siloxanes catalyzed with acetic anhydride, optionally in admixture with simple siloxane cycles with the addition of acetic acid Reacting acetoxy-bearing, branched siloxanes, which corresponds to a very particularly preferred embodiment of the invention.

Acetic acid is preferred in amounts of 0.4 to 3.5 weight percent, preferably 0.5 to 3 weight percent, preferably 0.8 to 1, 8 weight percent, more preferably in amounts of 1, 0 to 1, 5 weight percent based on the reaction matrix consisting of acetic anhydride, cyclic-branched D / T-type siloxanes and optionally simple siloxane cycles, which corresponds to a very particularly preferred embodiment of the invention.

In the context of a broad investigation, the inventors have found that the addition of acetic acid in addition to achieving the Acetoxyfunktionalisierung to ensure a perfect Äquilibrierergebnisses after a very short reaction time is used (see Example 9). In addition to the above-described Bakelitdeckeltest (manual test) is defined as an indicator for the reaching of the Äquilibriergleichgewichtes the gas chromatographic Gesamtcylengehalt than the sum of Ü ₄ -, Ds, D6 contents based on the siloxane matrix and determined after derivatization of the branched Acetoxysiloxane to the corresponding branched isopropoxysiloxanes used. The derivatization to the branched isopropoxysiloxanes is hereby chosen deliberately in order to prevent any thermally induced cleavage reaction of the branched acetoxysiloxanes which takes place under the conditions of the gas chromatographic analysis (for the cleavage reaction see, inter alia, J. Pola et al., Collect. Czech Chem. Commun. 1974 39 (5), 1169-1176 and W. Simmler, Houben-Weyl, Methods of Organic Chemistry, Vol. VI / 2, 4 ^th Edition, O-metal derivative of Organic hydroxy compounds S. 162 ff) ). According to the invention, this total cycle content should preferably be less than 8 Percent by weight, preferably less than 7 percent by weight, of the branched isopropoxysiloxane siloxane matrix.

Thus, anhydrous ferric chloride, Filtrol® (strong acid bleaching earth) and concentrated sulfuric acid as catalysts address only the first step of the process of the invention, while trifluoromethanesulfonic acid as catalyst densifies the first and second steps advantageously into one process step, that is, both the acetylation the cyclic-branched D / T-type siloxanes as well as the equilibration of the acetoxysiloxane catalyzes. In addition, the trifluoromethanesulfonic acid, as explained, can be used for reworking incompletely equilibrated acetoxysiloxanes.

It therefore corresponds to a preferred embodiment of the invention that when using trifluoromethanesulfonic acid as catalyst, the first step of the process according to the invention, ie the acid-catalyzed reaction of mixtures of cyclic branched D / T-type siloxanes optionally in admixture with simple Siloxan cycles with acetic anhydride and the preferred with the addition of acetic acid to branched siloxanes carrying acetoxy groups, and the second step, ie the equilibration of the acetoxy-modified branched siloxanes, be compacted into a single process step.

In the concluding (ie third) step of the process according to the invention, the replacement of the acetoxy groups by the reaction of the trifluoromethanesulfonic acid acetoxysiloxane with polyether oils is carried out.

In this case, the polyetheroils which can be used according to the invention are preferably those of the formula (I)

A [-O- (CH ₂ -CHR'-O-) m- (CH ₂ -CH ₂ -O-) n- (CH ₂ -CH (CH ₃ ) -O-) oZ], (I)

With

A is either hydrogen or a saturated or unsaturated organic radical having at least one carbon atom, preferably an organic radical of an organic starting compound having at least one carbon atom for preparing the compound, particularly preferably a methyl, ethyl, propyl, butyl, vinyl or allyl group is

R 'independently of one another is a saturated alkyl group having 2-18 C atoms or an aromatic radical, or preferably an ethyl group or a phenyl radical,

Z is either hydrogen, a linear or branched, saturated or unsaturated hydrocarbon radical having 1-18 C atoms, preferably a methyl, ethyl, propyl, butyl, vinyl or allyl group, or

the radical of an organic acid of the formula -C (= O) -ZE, where ZE is an organic radical, preferably a linear or branched, saturated or olefinically unsaturated hydrocarbon radical having 1 to 17 C atoms, preferably a methyl group, or an aromatic hydrocarbon radical with 6 to 20 C atoms, preferably a phenyl radical, or the radical of the formula is -C (= O) -O-ZC, where ZC is an organic radical, preferably a linear or branched, saturated or olefinically unsaturated hydrocarbon radical having 1 to 18 C atoms, preferably a methyl, ethyl group, or an aromatic hydrocarbon radical having 6 to 20 C atoms, preferably a phenyl radical,

m is 0 to 50, preferably 0 to 30, more preferably 0 to 20

n is 0 up to 250, preferably 3 up to 220, more preferably 5 up to 200

o is 0 up to 250, preferably 3 up to 220, more preferably 5 up to 200

a is 1 to 8, preferably greater than 1 to 6, particularly preferably 1, 2, 3 or 4,

with the proviso that the sum of m, n and o is equal to or greater than 1 and with the proviso that at least A or Z represent hydrogen.

Preference is given to using compounds of the formula (I) which have exclusively hydrogen atoms, oxygen atoms and carbon atoms.

The index numbers reproduced here and the value ranges of the specified indices can be understood as mean values (weight average) of the possible statistical distribution of the actual structures present and / or their mixtures. This also applies to as such per se exactly reproduced structural formulas, such as for formula (I).

The units denoted by m, n and o can optionally be mixed randomly or else in blocks in the chain. Statistical distributions can be constructed block by block with an arbitrary number of blocks and an arbitrary sequence or a randomized distribution, they can also be of alternating construction or also form a gradient over the chain, in particular they can also form all mixed forms in which optionally groups of different Distributions can follow one another. Special designs may cause statistical distributions to be constrained by execution. For all areas that are not affected by the restriction, the statistical distribution does not change.

In the context of the present invention, the radical A is preferably understood as meaning radicals of substances which form the beginning of the compound of the formula (I) to be prepared, which is obtained by the addition of alkylene oxides. The starting compound is preferably selected from the group of alcohols, polyethers or phenols. The starting compound containing the group A is preferably a monohydric or polyhydric polyether alcohol and / or monohydric or polyhydric alcohol, or any desired mixtures thereof. In the event that multiple starting compounds A were used as a mixture, the index a may also be subject to a statistical distribution. In addition, Z can also be the remainder of a starting compound Z-OH.

The monomers used in the alkoxylation reaction are preferably ethylene oxide, propylene oxide, butylene oxide and / or styrene oxide, as well as any desired mixtures of these epoxides. The different monomers can be used in pure form or mixed. Also, the metering of another epoxide to an epoxide already present in the reaction mixture can be carried out continuously over time, so that an increasing concentration gradient of the continuously added Epoxides is created. The resulting polyoxyalkylenes are thus subject to a statistical distribution in the final product, with restrictions by the dosage can be determined. In the case mentioned here of the continuous addition of another epoxide to an epoxide already present in the reaction mixture, a structure gradient can then be expected over the chain length. The relationships between dosage and product structure are known in the art.

In the process according to the invention, the compounds of the formula (I) used are preferably those which have a weight average molecular weight of from 76 to 10,000 g / mol, preferably from 100 to 8,000 g / mol and more preferably from 200 to 6,000 g / mol.

As compounds of the formula (I) it is possible with preference to use those compounds which are prepared from a compound of the formula (II)

A [-OH] a (II)

have emerged, wherein the radical A is derived from compounds selected from the group of mono- or polyhydric monomeric, oligomeric or polymeric alcohols, phenols, carbohydrates or carbohydrate derivatives, with particular preference being given to those compounds in which the radical A of one or several alcohols from the group of butanol, 1-hexenol, octanol, dodecanol, stearyl alcohol, vinyloxybutanol, 2-ethylhexanol, cyclohexanol, benzyl alcohol, ethylene glycol, propylene glycol, di-, tri- or polyethylene glycol, 1, 2-propylene glycol, di- and polypropylene glycol , 1, 4-butanediol, 1, 6-hexanediol, trimethylolpropane, glycerol, pentaerythritol, sorbitol, allyl alcohol, vinyl alcohol or derived from natural compounds, hydroxyl-bearing compounds.

Particularly preferred compounds are those which are liquid at a pressure of 101325 Pa and a temperature of 23 ° C. Among them, butyl diglycol, dipropylene glycol and propylene glycol are most preferred.

Compounds of the formula (I) which can be used according to the invention as polyetherois and processes for their preparation are described, for example, in US Pat. In EP 0075703, US 3775452 and EP 1031603. Suitable methods use, for example, basic catalysts such as alkali metal hydroxides and alkali metal. Especially widespread and known for many years is the use of KOH. Typically, a usually low molecular weight, that is, having a molecular weight of less than 200 g / mol, hydroxy-functional starters such as butanol, allyl alcohol, propylene glycol or glycerol in the presence of the alkaline catalyst with an alkylene oxide such as ethylene oxide, propylene oxide, butylene oxide or a mixture of different Alkylene oxides reacted to a polyoxyalkylene polyether. The strongly alkaline reaction conditions in this so-called living polymerization promote various side reactions. The compounds of formula (II) may also be prepared by double metal cyanide catalysis. Polyethers prepared by double metal cyanide catalysis generally have a particularly low level of unsaturated end groups of less than or equal to 0.02 meq / gram of polyether compound (meq / g), preferably less than or equal to 0.015 meq / g, more preferably less than or equal to 0.01 meq / g (method of determination ASTM D2849-69), contain significantly fewer monols and usually have a low polydispersity of less than 1.5. The polydispersity (PD) can be determined by a method known per se to those skilled in the art, by both the number average molecular weight (Mn) as well as by gel permeation chromatography (GPC) the weight-average molecular weight (Mw) can be determined. The polydispersity results as PD = Mw / Mn. The preparation of such polyethers z. For example, in US-A 5158922 and EP-A 0654302 described.

Regardless of the preparation route, preference is given to compounds of the formula (I) which preferably have a polydispersity Mw / Mn of from 1.0 to 1.5, preferably having a polydispersity of from 1.0 to 1.3.

Depending on the alkylene oxide terminus, the polyetheroic compounds to be used according to the invention may have a primary or secondary OH function. In view of the later achieved hydrolytic resistance of the obtained SiOC-linked polyether siloxanes, the use of those polyether oils which have a secondary alcohol function is preferred within the scope of the inventive teaching.

The inventive replacement of the acetoxy groups by reaction with polyethers to SiOC-linked polyethersiloxanes can be carried out in the presence of solvents or preferably without solvent by intimate mixing of the reactants with stirring at reaction temperatures of preferably 20 ° C to 60 ° C.

The molar ratio of the reactants is in particular dimensioned such that at least 1 mol of OH functionality bound to the polyether is used per mole of acetoxy group of the branched siloxane. Preference is given to 1 to 2 moles of OH functionality bonded to the polyether, preferably from 1.1 to 1.6 moles of OH functionality bound to the polyether, more preferably 1.2 to 1.4 moles of OH functionality bonded to the polyether per mole of the branched alkoxy group Siloxane used.

The SiOC-linked, branched polyether siloxanes used in a variety of surface-active applications are often characterized as containing polyether radicals of different composition and / or molecular weight. Thus, a possible embodiment of the method according to the invention is the acetoxy-containing, equilibrated branched siloxane to implement in the third step with a mixture of different types Polyetheroie. A person skilled in the art is familiar with the sometimes different reaction behavior of the polyetheroie employed, so that the aim is to induce a special interfacial activity, make some orienting hand tests with polyetherol mixtures and then evaluate these products in each case in terms of performance, in order to achieve an optimum result.

The replacement of the acetoxy groups by reaction with polyether alcohols is carried out according to the invention preferably in the course of 30 minutes to 3 hours.

The invention furthermore relates to a preparation prepared by the process according to the invention as described above, containing at least one SiOC-linked, branched silicone polyether, a polyetherol and a polyether end-capped with an acetyl group, with the proviso that the polyether radical present in the silicone polyether is chemically identical is with the polyether radical of the polyetherol and with the polyether radical of the polyetherol end-capped with an acetyl group, and that the proportion of the SiOC-linked branched silicone polyether is at least 50% by mass, based on the total preparation. Another object of the invention is the use of this preparation, prepared by the novel process as described above, as defoamers, as foam stabilizers, wetting agents, coating and leveling additives and as Dismulgatoren.

Examples

The following examples serve those skilled in the art alone to illustrate this invention and do not limit the claimed process. The determination of the water content according to the invention is carried out in principle with the Karl Fischer method based on DIN 51777, DGF E-Ill 10 and DGF C-III 13a. ²⁹ Si NMR spectroscopy was used in all examples for reaction tracking.

The ²⁹ Si NMR samples are resolved in this invention at a measurement frequency of 79.49 MHz in a Bruker Avance III spectrometer equipped with a 10 mm gap width 287430 probe head, dissolved in CDCl 3 at 22 ° C. and against tetramethylsilane ( TMS) was measured as an external standard [5 ( ²⁹ Si) = 0.0 ppm].

The DT cycles used in the examples are prepared by the methods of European patent application EP 17195510.7, EP 17169876.4, not yet disclosed, and European patent application EP 3 321 304 A1, respectively.

The gas chromatograms are fitted on a GC 7890B GC machine from Agilent Technologies with an HP-1 column; 30m x 0.32mm ID x 0.25pm dF (Agilent Technologies # 19091Z-413E) and hydrogen as the carrier gas with the following parameters:

Detector: FID; 310 ° C

Injector: split; 290 ° C

Mode: constant flow 2 mL / min

Temperature program: 60 ° C with 8 ° C / min -150 ° C with 40 ° C / min - 300 ° C 10 min.

As an indicator for the achievement of the equilibrium equilibrium, the total cyanogen content determined by gas chromatography is defined as the sum of the D4, Ds, D6 contents based on the siloxane matrix and determined after the derivatization of the α, ω-diacetoxypolydimethylsiloxanes to the corresponding α, ω-diisopropoxypolydimethylsiloxanes , The derivatization to the α, ω-diisopropoxypolydimethylsiloxanes is hereby deliberately chosen in order to prevent a thermally induced cleavage reaction of the α, ω-diacetoxy-polydimethylsiloxanes, which optionally takes place under the conditions of the gas chromatographic analysis (for the cleavage reaction see, inter alia, J. Pola et al., Collect. Czech Chem. Commun. 1974, 39 (5), 1 169-1 176, and also W. Simmler, Houben-Weyl, Methods of Organic Chemistry, Vol. VI / 2, 4th Edition, O-Metal Derivatives of Organic Hydroxy Compounds p. 162 ff)).

The polyetheroie used have water contents of about 0.2% by mass and are used without further predrying. Toluene used has a water content of 0.03% by mass and is also used without predrying. To ensure storage stability, which is particularly important in terms of production logistics, the branched acetoxysiloxanes prepared according to the invention are not initially stored in glass bottles at 23 ° C. storage temperature over a period of 3 weeks unless they are explicitly described differently in the respective synthesis examples, before they are mixed with the polyether alcohols to give the corresponding SiOC. linked, branched siloxane-polyoxyalkylene block copolymers or to the corresponding branched isopropoxysiloxanes are reacted.

example 1

Preparation of a cyclic-branched siloxane with a desired D-I T ratio of 6: 1

In a 10-liter four-necked round bottom flask equipped with KPG stirrer and attached reflux condenser, 783 g (4.39 mol) of methyltriethoxysilane together with 978.7 g (2.64 mol) of decamethylcyclopentasiloxane are heated to 60 ° C. with stirring, with 2.98 g Trifluoromethanesulfonic acid and equilibrated for 4 hours. Then, 237 g of water and 59.3 g of ethanol are added and the reaction is heated to reflux for a further 2 hours. 159.0 g of water and 978.8 g (2.64 mol) of decamethylcyclopentasiloxane (Ds) are added and the reflux condenser is exchanged for a distillation bridge and distilled off within the following hour, the volatile components to 90 ° C. Then add to the reaction mixture 3000 ml of toluene and distilled to a sump temperature of 100 ° C on a water from the water still in the material system. The reaction mixture is allowed to cool to about 60 ° C, the acid is neutralized by adding 60.0 g of solid sodium bicarbonate and then stirred for complete neutralization for a further 30 minutes. After cooling to 25 ° C, the salts are separated using a pleated filter.

At 70 ° C and an applied auxiliary vacuum of <1 mbar, the toluene used as solvent is distilled off. The distillation bottoms is a colorless, readily mobile liquid whose ²⁹ Si NMR spectrum assigns a D / T ratio of 5.2: 1 (aimed at 6.0: 1). Based on the sum of the spectroscopically detected Si units, the D and T units, the Si-alkoxy or SiOH groups have a proportion of 0.43 mole percent. The gas chromatographic analysis of the liquid also shows a proportion of about 15 weight percent of simple siloxane cycles in the form of D ₄ , Ds and Ü6. The GPC has a broad molecular weight distribution, characterized by Mw = 55258 gmol; Mn 1693 g / mol and Mw / Mn = 32.63.

Example 2 (inventive steps 1 and 2)

Preparation of an acetoxy-terminated, branched siloxane

In a 500 ml four-necked flask with KPG stirrer, internal thermometer and attached reflux condenser, 22.8 g (0.223 mol) of acetic anhydride are mixed with 101.2 g of the DT cycles prepared in Example 1 (D / T ratio after ²⁹ minutes). NMR spectrum = 5.2: 1, M = 452.8 g / mol and a proportion of SiOH / SiOEt groups of 0.43 mol%) and 125.9 g of decamethylcyclopentasiloxane (Ds) were initially charged with stirring , 25 g (0.15 ml) of trifluoromethanesulfonic acid (0.1% by mass based on the Total batch) and heated rapidly to 150 ° C. The initially slightly cloudy reaction mixture is left under further stirring for 6 hours at this temperature.

After cooling of the approach, a colorless-clear, easily mobile liquid is isolated, their ²⁹ Si NMR spectrum, the presence of Si-acetoxy groups in a yield of about 80% based on the acetic anhydride and the complete disappearance of spectroscopically detectable levels of Si alkoxy - and SiOH groups occupied. About 0.7 ml of the liquid is applied by means of a pipette to a black bakelite lid. In less than 1 minute, a solid, white, liquid-free gel forms whose presence stands out well against the background of the black bakelite lid and demonstrates complete equilibration of the acetoxysiloxane.

Example 3 (Inventive Step 3)

Preparation of a branched, SiOC-linked polyethersiloxane in toluene with later neutralization

In a 500 ml four-necked flask with KPG stirrer, internal thermometer and attached reflux condenser, 76.1 g of a butanol-initiated polyetherol (propylene oxide content of 100%) with a molecular weight of 1935 g / mol (molecular weight determined by OH number) presented in 200 ml of toluene with stirring and treated with 20 g of the branched trifluoromethanesulfonsauren acetoxysiloxane prepared in Example 2. Then, the reaction mixture is heated to 40 ° C for 1 hour with continuous stirring. The reflux condenser is then replaced by a distillation bridge with distillate and under application of an auxiliary vacuum, the mixture is freed by distillation at 70 ° C of toluene and acetic acid.

After cooling, the distillation bottoms with 1, 9 g of sodium bicarbonate is added and the salt is allowed to stir for about 30 minutes. Then the salts are separated using a filter press on a Seitz K 300 filter disc.

Obtained is a dark yellowish, SiOC-linked branched polyether siloxane whose ²⁹ Si NMR spectrum ensures the desired structure. A supplementary ¹³ C NMR spectrum shows that about 8 mole percent of the polyetherol used in excess is in acetylated form.

Example 4 (Inventive Step 3)

Solvent-free production of a branched, SiOC-linked polyether siloxane with early neutralization

In a 500 ml four-necked flask with KPG stirrer, internal thermometer and attached reflux condenser, 76.1 g of a butanol-initiated polyetherol (propylene oxide content of 100%) with a molecular weight of 1935 g / mol (molecular weight determined by OH number) submitted with stirring, mixed with 0.4 g of sodium bicarbonate and then allowed to stir the salt for about 30 minutes. 20 g of the branched trifluoromethanesulfonic acid acetoxysiloxane prepared in Example 2 are added and the batch is heated to 50 ° C. with stirring for 1 hour. Then, the reflux condenser is replaced by a distillation bridge with template and under application of an auxiliary vacuum of <1 mbar (oil pump) is distilled off at a bottom temperature of 100 ° C in the course of 3 hours acetic acid. After cooling to 25 ° C., the distillation bottom is treated with 1.9 g of NaHCO 3. The bicarbonate is allowed to stir for 30 minutes and then the salts are separated using a filter press on a Seitz K 300 filter disc.

Obtained is a bright-yellowish-clear, easily mobile liquid whose associated ²⁹ Si NMR spectrum shows the structure of the desired, branched, SiOC-linked polyether siloxane. A supplementary ¹³ C-NMR spectrum shows that no proportions of the polyetherol are present in acetylated form

Example 5 (according to the invention) (step 3)

Preparation of a branched, SiOC-linked polyethersiloxane in toluene with early neutralization

In a 500 ml four-necked flask with KPG stirrer, internal thermometer and attached reflux condenser, 76.1 g of a butanol-initiated polyetherol (propylene oxide content of 100%) with a molecular weight of 1935 g / mol (molecular weight determined by OH number) presented in 200 ml of toluene with stirring and treated with 20 g of the branched trifluoromethanesulfonsauren acetoxysiloxane prepared in Example 2.

The reaction mixture is heated to 50 ° C for 30 minutes with continuous stirring. Then, in the course of a further 30 minutes, the amount of gaseous ammonia required for neutralization is first introduced into the reaction matrix. Over a further 45 minutes, a slight stream of ammonia is passed in, so that the reaction mixture shows a clearly alkaline reaction (wet indicator paper).

The precipitated salts are separated by a double-fold filter from the toluene phase.

On a rotary evaporator at 70 ° C bottom temperature and an applied auxiliary vacuum of 1 mbar, the crude product is freed from toluene by distillation.

The virtually colorless preparation of a SlOC-linked branched polyethersiloxane is isolated, whose desired structure is verified by a ²⁹ Si NMR spectrum. Accompanying ¹³ C NMR and ¹ H NMR spectroscopy further show that no shares of acetyl-end-capped polyetherol are present.

Example 6

Preparation of a cyclic-branched siloxane with a desired D / T ratio of 6: 1

In a 500 ml four-necked round bottom flask equipped with KPG stirrer and attached reflux condenser, 52.2 g (0.293 mol) of methyltriethoxysilane together with 130.3 g (0.351 mol) Dekamethylcyclopentasiloxan heated to 60 ° C with stirring, charged with 0.400 g of trifluoromethanesulfonic acid and Equilibrated for 4 hours. Then 15.8 g of water and 4.0 g of ethanol are added and the mixture is heated for a further 4 hours at reflux temperature (about 80 ° C). Add 10.6 g of water and 200 ml of decamethylcyclopentasiloxane (Ds) and replace the reflux condenser with a distillation bridge and distilled within the following hour from the volatile to 90 ° C components. The reaction mixture is left for a further 2 hours at 90 ° C, then allowed to cool to 50 ° C and added 5 ml of a 25% aqueous ammonia solution and stirred for complete neutralization for another hour.

At 100 ° C. and an applied auxiliary vacuum of <1 mbar, water and the decamethylcyclopentasiloxane (Ds) used as solvent are distilled off. After cooling of the distillation bottoms, the precipitated ammonium triflate is separated by means of a pleated filter. The filtrate is a colorless, readily mobile liquid whose ²⁹ Si NMR spectrum assigns a D / T ratio of 6.44: 1 (aimed at 6.0: 1). Based on the sum of the spectroscopically detected Si units, the D and T units carrying Si-alkoxy or SiOH groups, respectively, have a proportion of 4.0 mol%.

Example 7 (inventive steps 1 and 2)

Preparation of an acetoxy-terminated, branched siloxane

In a 500 ml four-necked flask with KPG stirrer, internal thermometer and attached reflux condenser, 22.8 g (0.223 mol) of acetic anhydride are mixed with 121.8 g of the DT cycles prepared in Example 5 (D / T ratio after ²⁹ minutes). NMR spectrum = 6.44: 1, M = 544.71 g / mol and a proportion of SiOH / SiOEt groupings of 4.0 mol%) and 106.5 g of decamethylcyclopentasiloxane (Ds) were initially charged with stirring , 25 g (0.15 ml) of trifluoromethanesulfonic acid (0.1% by mass based on the total amount) and heated rapidly to 150 ° C. The initially slightly cloudy reaction mixture is left under further stirring for 6 hours at this temperature.

After cooling of the approach, a colorless-clear, easily mobile liquid is isolated, their ²⁹ Si NMR spectrum, the presence of Si-acetoxy groups in a yield of about 80% based on the acetic anhydride and the complete disappearance of spectroscopically detectable levels of Si alkoxy - and SiOH groups occupied. About 0.7 ml of the liquid is applied by means of a pipette to a black bakelite lid. In less than 1 minute, a solid, white, liquid-free gel forms which stands out well against the background of the lid and demonstrates complete equilibration of the acetoxysiloxane.

Example 8 (Inventive Step 3)

Solvent-free production of a branched, SiOC-linked polyethersiloxane with earlier

Neutralization

In a 500 ml four-necked flask with KPG stirrer, internal thermometer and attached reflux condenser, 76.1 g of a butanol-initiated polyetherol (propylene oxide content of 100%) with a molecular weight of 1935 g / mol (molecular weight determined by OH number) submitted with stirring, mixed with 0.4 g of triisopropanolamine and then allowed to stir the amine for about 30 minutes. 20 g of the branched trifluoromethanesulfonic acid acetoxysiloxane prepared in Example 7 are added and the mixture is heated to 50 ° C. for 1 hour with stirring. Then, the reflux condenser is replaced by a distillation bridge with template and under application of an auxiliary vacuum of <1 mbar (oil pump) is distilled off at a bottom temperature of 100 ° C in the course of 3 hours acetic acid. After cooling to 25 ° C., the distillation bottom is treated with 1.9 g of NaHCO 3. The bicarbonate is allowed to stir for 30 minutes and then the salts are separated using a filter press on a Seitz K 300 filter disc.

Obtained is a bright-yellowish-clear, easily mobile liquid whose associated ²⁹ Si NMR spectrum shows the structure of the desired, branched, SiOC-linked polyether siloxane. A supplementary ¹³ C-NMR spectrum shows that no proportions of the polyetherol are present in acetylated form.

Example 9 (preferred step 2 according to the invention)

Preparation of an acetoxy-terminated, branched siloxane

In a 1000 ml four-necked flask with KPG stirrer, internal thermometer and attached reflux condenser, 49.9 g (0.489 mol) of acetic anhydride are mixed with 268.1 g of DT cycles prepared according to Example 1 (D / T ratio after ²⁹ minutes). NMR spectrum = 6, 18: 1, M = 525.42 g / mol and a proportion of SiOH / SiOEt groupings of 0.52 mol%) and 188.5 g Dekamethylcyclopentasiloxan (Ds) initially charged with stirring , 03 g (0.56 ml) of trifluoromethanesulfonic acid (0.2% by mass based on the total amount) and 7.6 g of acetic acid (1, 5% based on the mass of the reactants) and heated rapidly to 150 ° C. The initially slightly cloudy reaction mixture is left under further stirring for 6 hours at this temperature.

After cooling the approach, a colorless-clear, easily movable liquid is isolated, the ²⁹ Si NMR spectrum of the presence of Si-acetoxy groups in a yield of about 88.2% based on the acetic anhydride and the complete disappearance of spectroscopically detectable levels of Si - Alkoxy and SiOH groups occupied.

Transfer of the branched acetoxylsiloxane into the corresponding branched isopropoxysiloxane for analytical characterization

Immediately after the synthesis, 100.0 g of this trifluoromethanesulfonic acid equilibrated branched acetoxysiloxane are fitted in a 250 ml four-neck round bottom flask equipped with a KPG stirrer, internal thermometer and reflux condenser together with 23.2 g of a molecular sieve-dried isopropanol with stirring at 22 ° C mixed. The reaction mixture is then charged by introducing gaseous ammonia (NH3) to the alkaline reaction (wet universal indicator paper) and then stirred for 45 minutes at this temperature. The precipitated salts are separated by means of a pleated filter.

A colorless, clear liquid is isolated whose accompanying ²⁹ Si NMR spectrum demonstrates the quantitative conversion of the branched acetoxysiloxane into a branched isopropoxysiloxane. An aliquot of this branched isopropoxysiloxane is taken and analyzed by gas chromatography. The gas chromatogram has the following contents (in percentage by mass):

Taking into account the Isopropanolüberschusses the contents of siloxane (D _4, D s and D _Ö) are in this case calculated based solely on the siloxane.

Claims

claims

1. A process for the preparation of branched in siloxane, SiOC-linked polyether siloxanes starting from mixtures of cyclic-branched siloxanes of the D / T type, characterized in that acid-catalyzed in a first step cyclic-branched D / T-type siloxanes with acetic anhydride optionally in admixture with simple Siloxanzyklen to acetoxy group-bearing, branched siloxanes and in a second step, the equilibration of the acetoxy-modified branched siloxane with trifluoromethanesulfonic preferably with the addition of acetic acid and in a third step, the trifluoromethanesulfonic acetoxysiloxane optionally in the presence of bases and optionally in the presence of an inert solvent with Polyetheroien.

2. The method of claim 1, wherein the mixtures of cyclic-branched D / T-type siloxanes consist exclusively of D and T units containing siloxanes with the proviso that the determinable by ²⁹ Si NMR spectroscopy total fraction of in the Siloxanmatrix D and T units present which have Si-alkoxy and / or SiOH groups, less than 2 mole percent, preferably less than 1 mole percent, and further that at least 5 wt .-% siloxane, such as preferably Oktamethylcyclotetrasiloxan (D4 ), Dekamethylcyclopentasiloxan (D5) and / or mixtures thereof.

3. The method of claim 1, wherein the mixtures of cyclic-branched D / T-type siloxanes consist exclusively of D and T units containing siloxanes with the proviso that the determinable by ²⁹ Si NMR spectroscopy total fraction of in the Siloxane matrix existing D and T units which have Si-alkoxy and / or SiOH groups is greater than 2 mole percent and less than 10 mole percent.

4. The method according to any one of claims 1 to 3, wherein the optionally added in the acetylation step, simple siloxane cycles in particular Oktamethylcyclotetrasiloxan, Dekamethylcyclopentasiloxan, Dodekamethylcyclohexasiloxan and / or their random composite mixtures.

5. The method according to at least one of claims 1 to 4, characterized in that acetic acid in amounts of 0.4 to 3 weight percent, preferably 0.5 to 1, 8 weight percent, preferably 0.8 to 1, 6 weight percent, more preferably in amounts of 1, 0 to 1, 5 weight percent based on the reaction matrix consisting of acetic anhydride, cyclic branched D / T-type siloxanes and optionally simple Siloxanzyklen added.

6. The method of claim 1 to 5, wherein the replacement of the siloxane-bound acetoxy groups takes place at least in the presence of a base, in particular in the presence of sodium bicarbonate, ammonia or an organic amine.

7. The method of claim 1 to 6, wherein the replacement of the siloxane-bound acetoxy groups by the reaction with polyether alcohols using an inert solvent, preferably using an inert and at the same time with resulting and optionally already existing acetic acid azeotrope-forming solvent.

8. The method of claim 1 to 7, wherein the inert solvent is an aromatic, preferably alkylaromatic solvent and most preferably toluene.

9. The method of claim 1 to 6, wherein the replacement of the siloxane-bound acetoxy groups by the reaction with polyether alcohols is solvent-free.

10. The method of claim 1 to 9, wherein anhydrous iron (III) chloride, acid-treated bleaching earths, concentrated sulfuric acid or more preferably trifluoromethanesulfonic acid, and most preferably trifluoromethanesulfonic acid are used in the presence of acetic acid as a catalyst in the acetylation.

11. The method according to claim 1 to 10, wherein as polyetheroxy preferably those of the formula (I)

A [-O- (CH 2 -CHR'-O-) m - (CH ₂ -CH 2 -O-) n - (CH ₂ -CH (CH ₃ ) -O-) oZ] a (I)

With

m is 0 to 50, preferably 0 to 30, more preferably 0 to 20, n is 0 to 250, preferably 3 to 220, more preferably 5 to 200, o is 0 to 250, preferably 3 to to 220, more preferably 5 to 200, a is equal to 1 to 8, preferably greater than 1 to 6, particularly preferably 1, 2, 3 or 4, with the proviso that the sum of m, n and o is equal to or greater than 1 and with the

Given that at least A or Z represent hydrogen,

be used.

12. The method of claim 1 to 1 1, wherein at least 1 mol of polyether-bound OH functionality per mole of acetoxy group of the branched siloxane, preferably 1 to 2 moles of polyether-bonded OH functionality, preferably 1, 1 to 1, 6 mol Polyether-bonded OH

Functionality, particularly preferably 1, 2 to 1, 4 moles of polyether-bound OH functionality per mole of acetoxy group of the branched siloxane used.

13. A preparation prepared according to claim 1 comprising at least one SiOC-linked, branched silicone polyether, a polyetherol and one end-capped with an acetyl group

Polyethers, with the proviso that the polyether residue contained in the silicone polyether is chemically identical to the polyether radical of the polyetherol and with the polyether radical of the end-capped with an acetyl polyether and that the proportion of SiOC-linked, branched silicone polyether at least 50 percent by mass based on the total preparation.

14. Use of the preparation according to claim 13 as a defoamer, as a foam stabilizer, wetting agent, coating and leveling additive or as a demulsifier.