Method for producing organopolysiloxanes

Abstract

The invention relates to a continuous method for producing block-copolymer organopolysiloxanes, in which, in a first step, chlorosilanes are reacted with alcohol to form partial alkoxylates and, in a second step, the partially alkoxylated chlorosilane obtained in the first step is continuously further reacted to form fully alkoxylated silane, which then, in a further step, is first continuously condensed with water in the presence of catalytic traces of acid and a terminally functionalised polydiorganosiloxane to a low degree of condensation and then, in the final step, is condensed by way of further condensation to the desired degree of condensation. The invention also relates to intermediates, block-copolymer organopolysiloxanes, compositions comprising the intermediates and / or block-copolymer organosiloxanes produced by way of the method, and their use.

Description

[0001] Process for the preparation of organopolysiloxanes

[0002] The invention relates to a continuous process for the preparation of block copolymeric organopolysiloxanes, in which in a first step chlorosilanes are reacted with alcohol to form partial alkoxylates, and in a second step the partially alkoxylated chlorosilane obtained in the first step is continuously reacted further to form the fully alkoxylated silane, which is then continuously condensed in a further step with water in the presence of catalytic traces of acid and a terminally functionalized polydiorganosiloxane, initially to a low degree of condensation and then, in the last step, is condensed to the desired degree of condensation by further condensation. The invention also relates to the intermediates prepared by the process, block copolymeric organopolysiloxanes, compositions comprising the intermediates and / or block copolymeric organosiloxanes and the use thereof.

[0003] The invention relates to a continuous process for the preparation of soluble, reactive organopolysiloxane block copolymers, which is particularly suitable for the controlled, gel-free condensation of very reactive chlorosilanes or chlorosilane mixtures and which takes place in several stages, all stages being carried out continuously in an uninterrupted sequence.

[0004] EP3215554 and EP3204443 describe a process for preparing organopolysiloxanes in 3 and 2 steps, respectively. Neither process demonstrates that it is also possible to prepare block copolymers. Rather, both processes are limited to the preparation of random copolymers obtained from monomeric precursors. In fact, it has also been shown that the addition of the terminally functionalized polydiorganosiloxane only at a specific point in the overall process leads to the block copolymers to be prepared according to the invention, so that the processes according to EP3215554 and EP3204443 are not arbitrarily applicable here, but unforeseenly lead to the target products of the present invention only in a specific embodiment, namely the embodiment according to the invention.

[0005] US 9076934B2 and US2015 / 0031841A1 teach processes for producing block copolymers starting from a polydiorganosiloxane and a silicone resin comprising at least 60 or at least 80 mol% units of the form RS1O3 / 2 . In US 9076934B2, this takes place in the presence of a basic catalyst. A disadvantage of this procedure is that both the polydiorganosiloxane and the resin must first be produced in separate processes in order to then react them with one another. Basic condensation catalysts, as used in US 9076934B2, are also very effective for condensation, so their use generally entails a high risk of gelling and the resulting process loses robustness. Furthermore, the functional polydiorganosiloxanes according to US2015 / 0031841A1 preferably do not have easily accessible silanol end groups, but rather other functional groups, such as amino, epoxy, carboxy, oximo or amido.

[0006] Furthermore, neither US 9076934B2 nor US2015 / 0031841A1 teach that the addition of the terminally functionalized polydiorganosiloxane only at a specific point in the overall process leads to the block copolymers to be prepared according to the invention.

[0007] It would therefore be desirable to provide a continuous, economical and sustainable process for the production of block copolymeric polyorganoalkoxysiloxanes from halogen organosilanes or mixtures of halogen organosilanes and silanol-terminated polydiorganosiloxanes, which is characterized, for example, by the fact that

[0008] - it allows the reproducible preparation of polyorganosiloxanes of constant composition from mixtures of various chlorosilanes and silanol-terminated polydiorganosiloxanes,

[0009] - it does not require any inert organic solvents, i.e. the reaction mass only contains the organic components required as reactants,

[0010] - it does not produce any waste water phase,

[0011] - it makes products with low residual acid contents < 10 ppm available,

[0012] - it allows the alkoxy content to be adjusted from high to low, so that it is suitable for producing both low-molecular and high-molecular polyorganosiloxanes up to the solid state, and thus allows the highest degrees of condensation in a robust process, and

[0013] - it has a recovery rate for the released hydrogen halide acid of > 95%.

[0014] The problem is solved by the invention. Any combination of prior art processes is not suitable for solving the problem. Otherwise, partial aspects remain unresolved, especially cocondensation does not occur to a sufficient extent.

[0015] Surprisingly, it has been found that only the process according to the invention leads to success, i.e., a combination of a reaction unit comprising a column connected to a pre-reactor, followed by a reactor, also of continuous design, as a further reaction unit. This process, when operated appropriately, allows the object of the invention to be achieved and fulfills all of the above-mentioned partial aspects.

[0016] The object is thus achieved by the process according to the invention for the continuous production of block copolymeric polyorganoalkoxysiloxanes, comprising the following steps in the given order:

[0017] (i) partially reacting at least one chlorosilane with an alcohol or a mixture of alcohols in a pre-reactor to form a reaction mixture comprising a partial alkoxylate;

[0018] (ii) transferring the reaction mixture obtained after step (i) into a first reaction unit which is connected to the pre-reactor and comprises a column having an upper and a lower end and a feed point, wherein the transfer is carried out by transferring the reaction mixture into the column via the feed point, wherein the feed point into the column is arranged such that the feed takes place in the middle third of the total length of the column;

[0019] (iii) transporting the reaction mixture transferred into the column in step (ii) within the column, which transport takes place downwards following the effect of gravity, the partial alkoxylate being brought together with another alcohol or a further mixture of alcohols, the partial alkoxylate being converted to a full alkoxylate before the reaction mixture reaches a lower part of the column which is at most 25% of the total length away from the lower end of the column, the full alkoxylate then being located in the column bottom,

[0020] (iv) reacting the full alkoxylate in the lower part of the column of the first reaction unit with another alcohol or another mixture of alcohols, water and at least one silanol-terminated polydiorganosiloxane to form a low-condensation polyorganosiloxane mixture (crude mixture) which may contain volatile components,

[0021] (v) transferring the raw mixture obtained after step (iv) into a second reaction unit which is connected to the first reaction unit and comprises a further continuous reactor, wherein the transfer into the further continuous reactor takes place, and

[0022] (vi) reacting the crude mixture converted in step (v) with a further alcohol or a further mixture of alcohols and with water to form a polyorganosiloxane mixture which has a higher condensation state than the crude mixture.

[0023] In order to avoid making the number of pages of the description of the present invention too extensive, only the preferred embodiments of the individual features are listed below.

[0024] However, the knowledgeable reader should understand this type of disclosure to mean that every combination of different levels of preference is explicitly disclosed and explicitly desired.

[0025] Preferably, in step (i), 0.1 to 0.9 mol of alcohol are used per mole of hydrolyzable chlorine of the chlorosilane. Due to these molar ratios, the chlorosilane is not completely alkoxylated, but is first converted to the partial alkoxylate.

[0026] A "partial alkoxylate" according to the present invention refers to the reaction product of a chlorosilane with an alcohol, wherein a part of the chlorine substituents of the chlorosilane have been replaced by alkoxy substituents.

[0027] A "fully alkoxylate" according to the present invention refers to the reaction product of a chlorosilane with an alcohol, wherein substantially all chlorine substituents of the chlorosilane have been replaced by alkoxy substituents.

[0028] The "degree of condensation" according to the present invention refers to the molecular weight and the number of condensable groups still present, wherein a higher degree of condensation differs from a lower degree of condensation in that the molecular weight is higher at the higher degree of condensation and the number of remaining condensable groups is lower at the higher degree of condensation.

[0029] In the process according to the invention, it is possible that some of the chlorosilane molecules, preferably all of the chlorosilane molecules, are already completely alkoxylated in step (i) and thus there is no partial conversion but already a full conversion.

[0030] The step (i ii) according to the invention preferably serves to convert those chlorosilane molecules which have not yet been completely converted into the full alkoxylate into the full alkoxylate product.

[0031] Preferably, by the end of process step (iii), at least 90 wt. % of the chlorosilane used is converted to the full akoxysilane, preferably at least 95 wt. % and in particular at least 99 wt. %.

[0032] The process according to the invention is particularly advantageous because it is a continuous process, wherein all steps are carried out continuously in an uninterrupted sequence. In this case, for example, the partial conversion (1), the transfer (11), the transport (iii), the conversion (iv), the transfer (v) and the conversion (vi) are carried out continuously.

[0033] The continuous reactor within the second reaction unit can be designed as a loop reactor.

[0034] The process according to the invention is characterized in particular in that, apart from the alcohol required for the reaction, no further organic components, preferably low-molecular components, are used in the entire process, in particular no inert organic solvent.

[0035] In a particular embodiment, only one specific alcohol is used in each process step instead of a mixture of different alcohols. Particularly preferably, the alcohol is identical in all process steps.

[0036] If the silanol-terminated polydiorganosiloxane is not used at the designated point in the column, but only in the downstream continuous reactor, which can be a loop reactor, no or insufficient cocondensation of the silanol-terminated polydiorganosiloxane with the silicone resin unit formed from the silane monomers (originating from the chlorosilane) takes place, so that a two-phase mixture is obtained in which the silanol-terminated polydiorganosiloxane is found almost quantitatively as the second phase. Surprisingly, even if the silanol-terminated polydiorganosiloxane is already used in the pre-reactor together with the silane monomers resulting in the resin, there is no sufficient reaction.

[0037] The alcohol used can be of technical quality and may contain small amounts of water, but should preferably not contain more than 5% by weight. Furthermore, no water is used in the pre-reactor. Water is undesirable and even harmful in the pre-reactor. In any case, the process is tolerant of the amounts of water contained in technical alcohols up to a maximum of 5% by weight. In addition, tolerance for larger amounts of water may be given depending on the silane mixture selected. However, this is no longer generally valid.

[0038] If the product contains volatile components, it is preferably freed from the volatile components by devolatilization and is then in its final form. The devolatilization can be varied as desired, the procedures all being within the scope of the known state of the art. Examples of suitable variations are explained in more detail below. The distillate obtained during the devolatilization of the product (i.e. separation of the volatile components from the product) after the second reaction unit, i.e. for example the loop unit after the column, is referred to in the following text as the distillate of the second reaction unit and contains the volatile components from the product.

[0039] The higher space-time described in DE 10 2005 003 898

[0040] Performance through the use of a pre-reactor can also be realized in the present process according to the invention, since a large part of the hydrogen chloride produced, which limits the throughput of the first reaction unit, is already formed and removed in the pre-reactor and thus relieves the load on the subsequent column.

[0041] The alcohol used in the pre-reactor for the partial conversion of the chlorosilane is preferably the distillate from the first and / or second reaction unit, which is returned to the pre-reactor as distillate or as gas. The specification to be observed is that the residual water content is adjusted to a maximum of 5 wt.%.

[0042] In the pre-reactor and before introduction into the pre-reactor, the distillate can be mixed with additional alcohol and homogenized over a short mixing section. Pure alkoxylation in the pre-reactor without condensation within it is preferred, which is why an anhydrous or at least very low-water procedure is preferred.

[0043] Preferred alcohols are hydrocarbon compounds having an alcoholic hydroxyl group which can be used to produce alkoxysilanes or organopolysiloxanes by reacting chlorosilane with alcohols and optionally water, and whose boiling points are below that of the respective alkoxysilane or organopolysiloxane to be produced. Preference is given to alkanols and alkanols substituted by ether oxygen and each having 1 to 6 carbon atoms, such as methanol, ethanol, n- or isopropanol, beta methoxyethanol, n-butanol or n-hexanol. Particular preference is given to methanol, ethanol, isopropanol and butanol, in particular methanol and ethanol. Mixtures of different alcohols can also be used.

[0044] The hydrogen chloride produced in the process is preferably freed from the condensable components at the top of the pre-reactor and at the top of the first reaction unit, which are then recycled to the corresponding reaction unit. The hydrogen chloride is thus available as a gas for recovery.

[0045] Chlorosilanes that can already be used to produce alkoxysilanes or organopolysiloxanes by reacting chlorosilane with alcohol and, if appropriate, water are preferably used. These are, in particular, silanes of the general formula (1)

[0046] RnSiCl4-n (1) , where

[0047] R represents a hydrogen radical or an acid-stable C1-C18 hydrocarbon radical, optionally substituted by at least one heteroatom, preferably C1-C10, more preferably C1-C6, and n can have the values ​​0, 1, 2 or 3.

[0048] In a preferred embodiment of formula (1), the proviso applies that n has the value 3 in at most 50% of the silanes of formula (1) and n has the value 0 or 1 in at least 20% of the silanes of formula (1).

[0049] The heteroatoms are selected, for example, from O, S, N and P, in particular O and N.

[0050] In all formulas of this invention, the symbols have independent meanings. The silicon atom is always tetravalent.

[0051] Selected examples of hydrocarbon radicals R are alkyl radicals such as methyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl, tert. -butyl, n-pentyl, isopentyl, neo-pentyl, tert. -pentyl radical, hexyl radicals, such as the n-hexyl radical, heptyl radicals, such as the n-heptyl radical, octyl radicals, such as the n-octyl radical and iso-octyl radicals, such as the 2,2,4-trimethylpentyl radical, nonyl radicals, such as the n-nonyl radical, decyl radicals, such as the n-decyl radical, dodecyl radicals, such as the n-dodecyl radical, and octadecyl radicals, such as the n-octadecyl radical, cycloalkyl radicals, such as cyclopentyl, cyclohexyl, cycloheptyl and methylcyclohexyl radicals, aryl radicals, such as the phenyl, naphthyl, anthryl and phenanthryl radicals, alkaryl radicals, such as tolyl radicals, xylyl radicals and ethylphenyl radicals, and Aralkyl radicals, such as the benzyl radical and the ß-phenylethyl radical. Particularly preferred hydrocarbon radicals R are the methyl, n-propyl, and phenyl radicals.

[0052] The silanes of formula (1) can be used both as pure silanes and as a mixture of different silanes of formula (1) to react them with alcohol in the pre-reactor to form the partial alkoxylate. In addition, other chlorosilanes of formula (1) that are not fed into the pre-reactor for partial alkoxylation can be used in the process. They are fed directly into the first reaction unit, i.e., the column, with the feed taking place in the middle third of the column, based on the total length of the column.

[0053] This procedure can be used when different silanes of formula (1) are to be reacted with one another, which have significantly different boiling points and possibly different reactivities and these differences cannot be adequately compensated for by the partial alkoxylation in the pre-reactor. In this case, higher-boiling silanes of formula (1) are always fed into the first reaction unit, while the lower-boiling silanes of formula (1) are fed into the pre-reactor for partial alkoxylation. The partial alkoxylates formed by the partial alkoxylation from the lower-boiling silanes of formula (1) have higher boiling points than the silanes of formula (1) themselves, so that the boiling points of the different silanes are equalized in this way.This procedure is preferably used when silanes of the formula (1) are used whose boiling point is below or in the region of the boiling point of the alcohol used, so that it would be expected that they would be discharged from the column due to their low boiling point, as a result of which the product composition would not correspond to the stoichiometry used. To counteract this, the amount of low-boiling silanes can be increased in order to compensate for the loss, but this reduces economic efficiency and generates higher amounts of waste. Since the chlorosilanes of the formula (1) form cross-linked, insoluble products in the exhaust gas stream and in scrubbers by condensation, silicification of the plant can also be the result of this type of chlorosilane discharge. These problems are avoided by the procedure outlined.Since the most reactive Si-Cl bonds react first during partial alkoxylation, this step also achieves an equalization of the reactivity of different chlorosilanes of formula ( 1 ).

[0054] If the different chlorosilanes of formula (1) which are to be reacted with one another have significantly different reactivities, the reactivity can be adjusted by the same procedure in which the less reactive and higher boiling silane of formula (1) is fed into the first reaction unit, by reducing the reactivity of the more reactive and possibly lower boiling chlorosilane of formula (1) through partial alkoxylate formation. As a result, a better statistical distribution of the different silane building blocks is achieved in the resulting polyorganosiloxane. The term block copolymers organopolysiloxanes in the present case means organopolysiloxanes which contain chain-like, linear D units (R 1 2SiO2 / 2) and crosslinking T-units (R 2 SiO3 / 2), so that they predominantly have the composition according to formula ( 2 ):

[0055] (^28102 / 2) a (R2 S103 / 2) b (2 ) .

[0056] In this sense, the organopolysiloxanes according to the invention differ from statistical copolymers in which D and T units alternate arbitrarily and no preferred ordering structure in the form of discrete blocks is formed.

[0057] Although the formation of block structures is not entirely impossible in statistical copolymers, it only occurs to the extent limited by the statistical probability. Block formation is of such minor importance that it has no significant influence on the properties of the resulting polyorganosiloxanes.

[0058] In contrast, the "block copolymer organopolysiloxanes" according to the invention are those in which the D units are predominantly bonded to one another in the form of oligomeric or polymeric chains, with chain lengths of at least 4 D units in direct and uninterrupted sequence. Depending on the chain length of the silanol-terminated polydiorganosiloxane used, the chain lengths can increase up to 400, wherein they are preferably in the range from 4 to 200, particularly preferably in the range from 4 to 100, in particular from 4 to 75. These are linear blocks of the polyorganosiloxanes according to the invention.

[0059] The non-linear T-units in turn also form blocks of uninterrupted sequences of at least 4, preferably at least 6, particularly preferably at least 8, in particular at least 10 T-units, wherein the non-linear blocks can in turn be cross-linked with one another.

[0060] From what has been said, the meaning of the indices a and b follows.

[0061] The residues R 1 and R 2 independently of each other a residue R, which has already been defined above.

[0062] In addition to the units (R 1 2SiO2 / 2) a and (R 2 SiC>3 / 2)b, the polyorganosiloxanes according to the invention can have units of formula (3) in the non-linear blocks of T units

[0063] R 2 cR 3 dSiO (4-cd) / 2 (3) , where

[0064] R 2 has the meaning given above,

[0065] R 3means a condensable radical of the form -OR, where R has the meaning given above and c means the number 1 and c + d can take the values ​​1, 2 or 3, whereby d means the values ​​0, 1 or 2.

[0066] A "condensable residue" is characterized in particular by the fact that the siloxane can enter into a condensation reaction, preferably with (partial) elimination of the condensable residue.

[0067] Overall, the polyorganosiloxanes according to the invention comprise 5 - 75 mol% D units (R 1 2SiO2 / 2) arranged in linear blocks, preferably 5-60 mol%, particularly preferably 5-50 mol%, in particular 5-40 mol%. Overall, the polyorganosiloxanes according to the invention comprise 25-95 mol% T units (R 2SiO3 / 2 ) optionally in a mixture with units of the formula (3) which are arranged in non-linear blocks, preferably 40 - 95 mol-%, particularly preferably 50 - 95 mol-%, in particular 60 - 95 mol-%.

[0068] In principle, it is possible that statistically distributed D units are also present, provided that corresponding chlorosilanes of the formula (R-^SiCl^) were used in the chlorosilane mixture that was dosed into the pre-reactor. Since this arrangement of D units can also be achieved by other processes according to the state of the art, it is not relevant here for differentiation from the existing state of the art and is also not preferred.

[0069] Suitable silanol-terminated or silanol-functionalized polydiorganosiloxanes are those of the formula (4):

[0070] HO- (R 2 2SiO2 / 2) e-OH (4 ) , where R 2represents a radical R and e represents a number in the range from 4 to 2000, preferably from 5 to 1800, in particular from 5 to 1500, particularly preferably from 5 to 1000. The silanol-functional polydiorganosiloxanes having an average chain length e of from 8 to 100 have proven particularly suitable.

[0071] About the units (R 1 2SiO2 / 2) a and (R 2 SiO3 / 2) b In addition, further siloxane units may also be present, as described below, however, the predominant presence and the described arrangement and characteristics of the units (R 1 2SiO2 / 2) a and (R 2SiC>3 / 2) b is a prerequisite that must be met for the inventiveness of the polyorganosiloxane in question. "Predominantly" means that at least 70 mol% of the total amount of siloxane units that lead to the formation of the polyorganosiloxanes according to the invention are found in a designated block copolymer arrangement, preferably at least 75 mol%, in particular at least 80%, very particularly at least 85%.

[0072] The pre-reactor can, for example, consist of a stirred tank, a tubular reactor, or a loop reactor with or without forced circulation. In the case of a pure alkoxylation reaction, forced circulation is not harmful, but it is also not necessary, since the hydrogen chloride formed during the reaction is sufficient to ensure adequate circulation and mixing. If additional water is added, forced circulation is preferred, and a pre-reactor with a high mixing tendency, such as a loop reactor, is particularly preferred.

[0073] A liquid chlorosilane or chlorosilane mixture of chlorosilanes of the formula (I) is preferably added to the pre-reactor, with a maximum of 80 mol% of the Si-bonded chlorine units being reacted with alcoholic hydroxy groups in the pre-reactor.

[0074] Hydrogen chloride gas produced in the pre-reactor is preferably diverted and recycled after removal of the brine-condensable components. The condensed components are, for example, returned to the pre-reactor.

[0075] The pre-reactor is preferably operated at a temperature below the boiling point of the chlorosilane or chlorosilane mixture used.

[0076] The partially converted reaction mixture is transferred to a column in the first reaction unit, the feed into the column taking place at the level of the middle third of the column, preferably in the upper region of the middle third of the column. This can be done, for example, by means of an overflow device. In the first reaction unit, the reaction mixture from the pre-reactor is further mixed and reacted, initially only with alcohol, in particular with alcohol which preferably flows countercurrently in the column from bottom to top, wherein the same alcohol or the same alcohol mixture is preferably used for this purpose which was already used in the pre-reactor. The reaction mixture reacts by splitting off further silicon-bonded chlorine atoms and replacing them with an alkoxy group which results from the alcohol used by splitting off a hydrogen.The hydrogen radical released from the alcohol and the chlorine radical released from silicon react to form a molecule of hydrogen chloride. In this way, the reaction mixture from the pre-reactor produces an almost completely alkoxylated product on its way to the lower part of the column, the so-called column bottom, which preferably comprises a maximum of the lower 25% of the column height.

[0077] In the column bottom, this almost complete alkoxylate encounters further alcohol, water, and the silanol-terminated polydiorganosiloxane of formula (4). Furthermore, a catalytic amount of hydrochloric acid is present in the column bottom, preferably an amount of 5 to 2000 ppm based on the mass of siloxane present in the column bottom, particularly preferably 5-1500 ppm, in particular 5-1000 ppm.

[0078] A liquid crude product is formed from the mixture present in the column bottom.

[0079] The hydrogen chloride gas produced in the column is preferably removed from the reactor and recycled after removal of condensable components. The components condensable with cooling brine are transferred to the pre-reactor after ensuring that the water quantity meets the requirements already described. If necessary, another chlorosilane or a chlorosilane mixture of chlorosilanes of formula (I) is added directly to the first reaction unit, which is also reacted with the partially reacted reaction mixture of the pre-reactor, alcohol, water, and silanol-terminated polydiorganosiloxane according to formula (4).

[0080] Preferably, the temperature of the column of the first reaction unit does not exceed 120°C. Particularly preferably, the temperature in the column does not exceed 100°C.

[0081] The liquid organopolysiloxane crude product from the first reaction unit has a low condensation level combined with a high alkoxy content and, as a pure isolated product, a low viscosity.

[0082] The alkoxy content of the pure devolatized organopolysiloxanes after the first reaction unit is > 20 wt%, preferably > 22 wt%, in particular > 25 wt%.

[0083] The viscosity of the isolated, devolatized organopolysiloxanes after the first reaction unit is < 600 mPas, especially < 500 mPas, especially < 400 mPas, each at 25°C.

[0084] The amount of silicon-bonded chlorine in the organopolysiloxane reaction product from the first reaction unit is less than 100 ppm, preferably less than 75 ppm, in particular less than 50 ppm, particularly preferably less than 30 ppm.

[0085] The reaction mixture containing the liquid organopolysiloxane from the first reaction unit is transferred to a second reaction unit comprising a continuous reactor, e.g., a loop reactor. In this second continuous reaction unit, the reaction mixture from the first reaction unit is further mixed with additional alcohol, hydrogen chloride, and water and condensed to the desired condensation stage. The mixture in the second continuous reaction unit preferably contains water in amounts of 4 to 17 parts by weight, particularly preferably 5 to 14 parts by weight, alcohol in amounts of 40 to 120 parts by weight, particularly preferably 50 to 100 parts by weight, and hydrogen chloride in amounts of 0.02 to 0.2 parts by weight, particularly preferably 0.04 to 0.15 parts by weight, in each case based on 100 parts by weight of pure devolatized organopolysiloxanes from the first reaction unit.

[0086] In this case, further alkoxy- and / or hydroxy-functional organopolysiloxanes or alkoxy- and / or hydroxy-functional silanes can be added to the second reaction unit. The further alkoxy- and / or hydroxy-functional organopolysiloxanes or alkoxy- and / or hydroxy-functional silanes are preferably liquid or they are in the alcohol or alcohol mixture used to prepare the partial alkoxylate in the

[0087] Pre-reactor served , soluble .

[0088] The additional alkoxy- and / or hydroxy-functional organopolysiloxanes are those consisting of repeating units of the formula ( 5 ) :

[0089] RpSl (OR 4 ) qO (4-pq) / 2 (5) , where in the units of the formula ( 5 )

[0090] R has the meaning given above,

[0091] R 4identical or different monovalent Ci-Ce-alkyl radicals or hydrogen, p and q in the units of formula (5) can have the values ​​0, 1, 2 or 3, with the proviso that p + q < 3 and p in at least 20%, preferably in at least 30% and particularly preferably in at least 40% of all repeat units of formula (5) has the value 1. The further additional alkoxysilanes have the general

[0092] Formula ( 6 ) on :

[0093] R 5 o Si (OR 4 ) 4-o ( 6) , where

[0094] R 5 is a hydrocarbon radical optionally substituted with heteroatoms, wherein no nitrogen atoms are contained therein, R 4 has the meaning given above and o means a number with the value 0 , 1 , 2 or 3 .

[0095] There are a number of patents that describe the condensation of alkoxysilanes and chlorosilanes to form organopolysiloxanes in continuous processes, possibly also in a loop. However, in these processes, either polar (e.g., DE 954198) or nonpolar solvents (see DE 19800023, EP3016994) are always used. In contrast, in the present process according to the invention, the further hydrolysis and condensation of alkoxy-functional liquid organopolysiloxanes from the first reaction unit is carried out without the addition of further polar or nonpolar solvents, using only the alcohol or alcohol mixture used as reactant to form organopolysiloxanes of any desired degree of condensation.

[0096] It has been found to be particularly advantageous that the silanol - terminated polydiorganosiloxane is dosed into the column bottom within the first reaction unit .

[0097] If the silanol-terminated polyorganosiloxane of the formula (4) is not metered into the column bottom as described, but into the second continuous reaction unit, which may comprise a loop reactor, for example, there is insufficient condensation between the polydiorganosiloxane of the formula (4) and the crude product from the column bottom, and a physical mixture of an optionally equilibrated form of the polydiorganosiloxane of the formula (4) and the condensed crude product from the column bottom is obtained. If the polydiorganosiloxane of the formula (4) is added directly to the chlorosilane mixture which is metered into the pre-reactor, or if it is metered separately to the partial alkyl oxylate from the pre-reactor in a part of the column which is above the part of the column described as the column bottom, gel particles gradually form and are deposited in the column. Furthermore, an inhomogeneous bottom product is obtained.

[0098] Description:

[0099] The implementation of the process according to the invention is described below using an apparatus as an example (without being limited thereto) that was also used in the following examples. The system comprises a pre-reactor, a column with a circulation evaporator, and a loop. The pre-reactor is also a loop reactor with a centrifugal pump that can be controlled by valves and circulates the liquid contents with maximum turbulence.

[0100] The chlorosilane and the distillate from the second reaction unit are metered into the lower side of the pre-reactor, comprising a loop reactor. Alcohol, if desired, is added to the distillate and homogenized over a short mixing section. The contents of the pre-reactor are transferred to the first reaction unit via an overflow device.

[0101] The pre-reactor has an outlet at the top for the resulting hydrogen chloride gas. This gas is freed of condensable components by means of a water cooler and then a brine cooler, with the condensable components being returned directly to the pre-reactor. The hydrogen chloride gas obtained after the cooler can be recovered.

[0102] This first reaction unit consists of a circulation evaporator and a column mounted on top. The column of the first reaction unit has a water-driven cooler at the top, followed by a brine-driven cooler. The distillates obtained there are fed back into the column. The hydrogen chloride gas obtained downstream of the cooler can be recovered.

[0103] The second reaction unit consists of a loop or a stirred batch reactor with continuous feed and discharge. Another variant is discontinuous post-condensation in a batch reactor.

[0104] From the circulating evaporator of the first reaction unit, as much reaction mixture as is obtained by the reaction is continuously discharged by means of a centrifugal pump. The reaction mixture from the circulating evaporator of the first reaction unit is mixed with additional water, optionally ethanol, and catalytic amounts of hydrochloric acid or chlorosilane, and metered into the loop of the second reaction unit. Product is removed from the second reaction unit as it is formed.

[0105] The organopolysiloxanes obtained from the first reaction unit, comprising a column, can be obtained as pure, stable products by conventional processing measures, comprising the steps of filtration, distillation and blending, or can be formulated with other components to give preparations. Components used to produce preparations include, in addition to other silicon-containing components, organic monomers or organic polymers, water, solvents, auxiliaries such as emulsifiers, stabilizers, pH adjusters or other additives, fillers, pigments and building materials, although this list is to be understood as being merely exemplary and not restrictive.

[0106] These organopolysiloxanes are intermediates in the overall process, so that in the following text they are referred to as silicone resin intermediates for better differentiation and linguistic resolution. This choice of term is purely rhetorical and does not imply any restriction in terms of content. The silicone resin intermediates from the first reaction unit are those composed of repeating units of formula (7):

[0107] R 6 xSi (OR 7 ) yO(4-xy) / 2 (7) , where in the units of formula (7)

[0108] R 6 a residue R,

[0109] R 7 the meaning of R 4x in the units of formula (7) has the value 1 or 2 and y in the units of formula (7) can have the value 0, 1, 2 or 3, with the proviso that x + y < 4 and x has the value 1 in at least 30%, preferably in at least 40% and particularly preferably in at least 50%, in particular in 70 ± 5% of all repeat units of formula (7) and has the value 2 in at least 5%, in particular in at least 10%, particularly preferably in at least 15%, in particular in 30 ± 5%, where the repeat units of formula (7) in which x has the value 2 contain at most one radical of the formula OR 7may have, so that in these repeating units y = 0 or 1, wherein these repeating units are bonded to one another in addition to chain segments in an uninterrupted sequence of at least 4 repeating units, wherein the silicone resin intermediates from repeating units of the formula (7) are characterized in particular in that they contain at least 15% by weight of radicals OR 7 contain, preferably at least 18% by weight, particularly preferably at least 20% by weight, in particular at least 22% by weight, wherein in the silicone resin intermediates from repeating units of the formula (7) the unit OR 7 at most 10 percent by weight, preferably at most 9 percent by weight, particularly preferably at most 8 percent by weight, in particular at most 7 percent by weight, hydroxyl groups.

[0110] Although silanol groups do not necessarily have to be present in the silicone resin intermediates consisting of repeating units of the formula (7), they are usually present due to the reaction conditions chosen, in particular the presence of water and acid. If x = 1 and y = 3, so that x + y = 4, there is no repeating unit of a polyorganosiloxane, but rather a monomeric trialkoxysilane. In the intermediate from the first reaction unit, the degree of condensation is chosen to be so low that the formation of such monomers is accepted. This does not represent a restriction for the condensation reaction in the second reaction unit, in which these monomers are incorporated into the polyorganosiloxane end product after the second reaction unit.Since it is linguistically incorrect to speak of repeating units of a polyorganosiloxane in this case of the monomers, it is pointed out here that such monomers are also meant as repeating units according to formula ( 7 ).

[0111] The silicone resin intermediates preferably have average molecular weights in the range from 600 to 3000 g / mol (weight average) with a polydispersity of at most 8. They preferably have an average molecular weight of 650 - 2900 g / mol with a polydispersity of 7, particularly preferably they have an average molecular weight of 700 - 2800 g / mol with a polydispersity of 6, in particular they have an average molecular weight of 700 - 2600 g / mol with a polydispersity of 5. As pure products they are in particular liquid, their viscosities preferably being in the range from 10 to 600 mPas, more preferably from 25 to 550 mPas and particularly preferably from 30 to 500 mPas at 25 ° C and standard pressure.The organopolysiloxanes obtained from the second reaction unit, for example comprising a loop reactor, can be obtained as pure, stable products by customary workup measures comprising the steps of filtration, distillation and blending, or can be formulated with other components to give preparations. The organopolysiloxanes from the second reaction unit, as isolated pure products, are liquid, highly viscous or solid, depending on the degree of condensation to which they are condensed. The degree of condensation obtained depends on the reaction conditions selected in the second reaction unit. In particular, the degree of condensation is determined by the amount of water, acid and temperature, as well as the type of acid selected and the dosing sequence and the dosing rate selected in the second reaction unit.In principle, any combination of these parameters is conceivable, and their choice influences the result to be achieved. Since the process in all its variability is the subject of the invention, no possible combinations are excluded here, except for those which are obviously absurd because it is obvious from the already known prior art that they do not lead to the production of soluble or meltable and thus further processable organopolysiloxanes. What is surprising about the present process is the fact, in contrast to the prior art, that the variability of the process and the resulting product diversity can be realized without the use of polar or non-polar organic solvents, apart from the alcohol or alcohol mixture already used in the pre-reactor.

[0112] Liquid to viscous products are preferably obtained when the mixture contains water in amounts of 4 to 10 parts by weight, based on 100 parts by weight of pure de-volatilized organopolysiloxanes from the first reaction unit. Viscous to solid products are preferably obtained when the mixture contains water in amounts of 10 to 17 parts by weight, based on 100 parts by weight of pure de-volatilized organopolysiloxanes from the first reaction unit.

[0113] Preferably, water is partially demineralized water, fully demineralized water, distilled or (multiply) redistilled water and water for medical or pharmaceutical purposes, particularly preferably partially demineralized water and fully demineralized water.

[0114] The water used according to the invention preferably has a conductivity at 25 ° C and 1010 hPa of preferably less than 50 pS / cm. The water used according to the invention is preferably air-saturated, clear and colorless.

[0115] The alcohol is preferably the same alcohol used in the first reaction unit, i.e., methanol or ethanol. The ethanol can contain the usual denaturants, such as methyl ethyl ketone, petroleum ether, or cyclohexane, with methyl ethyl ketone being preferred.

[0116] Hydrogen chloride can be added as hydrochloric acid or in the form of a precursor such as chlorosilane, acid chloride or linear phosphonitrile chloride, with hydrochloric acid solution and in particular aqueous hydrochloric acid solution being preferred.

[0117] Preferably, the components are briefly mixed individually and then added to the loop. In a closed loop, the components can also be added individually upstream of the circulation pump.

[0118] The closed loop is preferably operated at an absolute pressure of 1 to 5 bar, temperatures of 5 to 10 °K below the boiling temperature, an average residence time of 10 to 150 min and with laminar to turbulent flow.

[0119] Preferably, the stirred batch reactor with continuous feed and discharge is operated at an absolute pressure of 1 bar, the boiling temperature of the mixture, and an average residence time of 20 to 100 minutes. The average residence time is calculated from the reaction volume divided by the withdrawal rate of the reaction product.

[0120] Components which can be used to produce preparations comprising the organopolysiloxanes from the second reaction unit include, in addition to other liquid or solid silicon-containing components, organic monomers or organic polymers, water, solvents, auxiliaries such as emulsifiers, stabilizers, pH adjusters or other additives, whereby this list is to be understood only as an example and not as limiting.

[0121] The organopolysiloxanes from the second reaction unit are those that are composed of repeating units of the formula (8):

[0122] R 6 fSi (OR 7 ) g O (4-fg) / 2 (8) where in the units of formula (8)

[0123] R 6 and R 7the meanings already given above, f and g in the units of formula (8) can have the values ​​0, 1, 2 or 3, with the proviso that f + g < 3 and f has the value 1 in at least 30%, preferably in at least 40% and particularly preferably in at least 50%, in particular in 70 ± 5% of all repeating units of formula (7) and has the value 2 in at least 5%, in particular in at least 10%, particularly preferably in at least 15%, in particular in 30 ± 5%, where these repeating units are bonded to one another in an uninterrupted sequence of at least 4 repeating units in addition to chain segments, g averaged over all repeating units of the general formula (8) has an average value of 0.05 to 1.7, preferably from 0.06 to 1.6 and particularly preferably from 0.08 to 1.5, where the silicone resin intermediates from Repeating units of formula (8) are particularly characterized bythat they contain not more than 20% by weight of residues OR, 7 contain, preferably at most 18% by weight, particularly preferably at most 16% by weight, in particular at most 14% by weight, wherein in the organopolysiloxanes from repeating units of the formula (8) the unit OR 7 at most 10% by weight, preferably at most 9% by weight, particularly preferably at most 8% by weight, in particular at most 7% by weight, of hydroxyl groups.

[0124] Silanol groups do not necessarily have to be present in the organopolysiloxanes made up of repeating units of formula (8). In the organopolysiloxanes made up of repeating units of formula (8), at least 5% by weight fewer OR 7contained as in the corresponding silicone resin intermediates of repeating units of the formula (7), preferably at least 7%, particularly preferably at least 10% by weight, in particular at least 12% by weight, where 100% by weight of the radicals OR 7 in this case the total number of residues OR 7 from the silicone resin intermediates consisting of repeating units of formula (7).

[0125] The organopolysiloxanes comprising repeating units of formula (8) preferably have average molecular weights in the range from 1000 to 50,000 g / mol (weight average) with a polydispersity of at most 20. They preferably have an average molecular weight of 1250-30,000 g / mol with a polydispersity of 18, particularly preferably they have an average molecular weight of 1500-20,000 g / mol with a polydispersity of 15, in particular they have an average molecular weight of 1500-15,000 g / mol with a polydispersity of 13. The average molecular weight of the organopolysiloxanes comprising repeating units of formula (8) is at least 1.1 times the average molecular weight of the silicone resin intermediates comprising repeating units of formula (8), preferably at least 1.2 times. particularly preferably at least 1.3 times, in particular at least 1.4 times.Since the organopolysiloxanes composed of repeating units of formula (8) can be liquid, highly viscous, or solid, they can cover a very wide viscosity range. Liquid organopolysiloxanes preferably have a viscosity of > 600 mPas, particularly preferably > 750 mPas, and especially preferably > 1000 mPas at 25°C and standard pressure.

[0126] The organopolysiloxanes obtained from the second reaction unit, comprising a loop reactor, can be obtained as pure, stable products by conventional processing measures, including the steps of filtration, distillation, and blending, or can be formulated with other components to form preparations. Components used to produce preparations include, in addition to other silicon-containing components, organic monomers or organic polymers, water, solvents, auxiliaries such as emulsifiers, stabilizers, pH adjusters or other additives, fillers, pigments, and building materials; this list is intended only as examples and not as limiting.

[0127] The silicone resin intermediates prepared by the process according to the invention from repeating units of the formula (7) or the organopolysiloxanes from repeating units of the formula (8) or the preparations obtainable therefrom are well suited for use in corrosion-protective preparations.

[0128] A further subject matter of the invention is thus directed to a preparation comprising at least one silicone resin intermediate comprising repeating units of the formula (7) and / or at least one block copolymeric polyorganoalkoxysiloxane comprising repeating units of the formula (8) and at least one auxiliary substance.

[0129] The auxiliary substance is selected, for example, from emulsifiers, biocides, water, fillers, pigments as well as pigment wetting and dispersing agents.

[0130] A further object of the invention is directed to the use of the silicone resin intermediate comprising repeating units of the formula (7), the block copolymeric polyorganoalkoxysiloxane comprising repeating units of the formula (8) or the preparation according to the invention as corrosion protection.

[0131] In particular, they are suitable for use for the purpose of corrosion protection at high temperatures.

[0132] In addition to the purpose of high-temperature-resistant corrosion protection, the silicone resin intermediates made from repeating units of the formula (7) or the organopolysiloxanes made from repeating units of the formula (8) or the preparations obtainable therefrom, which are produced by the process according to the invention, can also be used for the corrosion protection of reinforcing steel in reinforced concrete, it being possible for the silicone resin intermediates made from repeating units of the formula (7) or the organopolysiloxanes made from repeating units of the formula (8) or the preparations obtainable therefrom to be used both in pure form and in preparations. Corrosion-inhibiting effects in reinforced concrete are achieved both when the silicone resin intermediates made from repeating units of the formula (7) or the organopolysiloxanes made from repeating units of the formula (8) or the preparations obtainable therefrom, which are produced by the process according to the invention, are usedthe preparations obtainable therefrom which contain them are introduced into the concrete mixture before it is shaped and cured, as well as when the compounds according to the invention or preparations which contain them are applied to the surface of the concrete after the concrete has cured.

[0133] The silicone resin intermediates comprising repeating units of formula (7) or the organopolysiloxanes comprising repeating units of formula (8) or the preparations obtainable therefrom can be used as binders for the production of artificial stones for indoor and outdoor use.

[0134] Apart from the purpose of corrosion protection on metals, the silicone resin intermediates prepared by the process according to the invention from repeating units of the formula (7) or the organopolysiloxanes from repeating units of the formula (8) or the preparations obtainable therefrom can also be used to manipulate further properties of preparations which contain the silicone resin intermediates prepared by the process according to the invention from repeating units of the formula (7) or the organopolysiloxanes from repeating units of the formula (8) or the preparations obtainable therefrom or of solids or films which are obtained from preparations which contain the silicone resin intermediates prepared by the process according to the invention from repeating units of the formula (7) or the organopolysiloxanes from repeating units of the formula (8) or the preparations obtainable therefrom, such as e.g.:

[0135] Control of electrical conductivity and electrical resistance

[0136] Control of the leveling properties of a preparation Control of the gloss of a wet or cured film or object

[0137] Increased weathering resistance

[0138] Increasing chemical resistance

[0139] Increasing the color stability Reducing the tendency to chalking Reducing or increasing the static and sliding friction on solids or films obtained from preparations containing silicone resin intermediates according to the invention from repeating units of the formula (7) or the organopolysiloxanes from repeating units of the formula (8) or the preparations obtainable therefrom

[0140] Stabilization or destabilization of foam in the preparation containing silicone resin intermediates according to the invention comprising repeating units of formula (7) or the organopolysiloxanes comprising repeating units of formula (8) or the preparations obtainable therefrom

[0141] Improving the adhesion of the preparation which contains the silicone resin intermediates produced by the process according to the invention from repeating units of the formula (7) or the organopolysiloxanes produced from repeating units of the formula (8) or the preparations obtainable therefrom to substrates on or between which the preparation which contains the silicone resin intermediates produced by the process according to the invention from repeating units of the formula (7) or the organopolysiloxanes produced from repeating units of the formula (8) or the preparations obtainable therefrom is applied, Control of the filler and pigment wetting and dispersing behavior, Control of the rheological properties of the preparation which contains the silicone resin intermediates produced by the process according to the invention from repeating units of the formula (7) or the organopolysiloxanes produced from repeating units of the formula (8) orthe preparations obtainable therefrom, control of the mechanical properties, such as flexibility, scratch resistance, elasticity, extensibility, bending ability, tear behavior, rebound behavior, hardness, density, tear resistance, compression set, behavior at different temperatures, coefficient of expansion, abrasion resistance as well as other properties such as thermal conductivity, flammability, gas permeability, resistance to water vapor, hot air, chemicals, weathering and radiation, sterilizability, of solids or films available which contain the silicone resin intermediates prepared by the process according to the invention from repeating units of the formula (7) or the organopolysiloxanes from repeating units of the formula (8) or the preparations obtainable therefrom or preparations containing them, control of the electrical properties, such asDielectric loss factor, dielectric strength, dielectric constant, tracking resistance, arc resistance, surface resistance, specific dielectric resistance, flexibility, scratch resistance, elasticity, extensibility, bendability, tear behavior, rebound behavior, hardness, density, tear resistance, compression set, behavior at different temperatures of solids or films obtainable from the preparation which contains the silicone resin intermediates prepared by the process according to the invention from repeating units of the formula (7) or the organopolysiloxanes from repeating units of the formula (8) or the preparations obtainable therefrom.

[0142] A further subject matter of the invention is thus directed to a use of the silicone resin intermediate comprising repeating units of the formula (7), the block copolymeric polyorganoalkoxysiloxane comprising repeating units of the formula (8) or the preparation according to the invention for producing artificial stones or for controlling the electrical conductivity and electrical resistance, controlling the flow properties of a preparation, controlling the gloss of a moist or cured film or an object, increasing weathering resistance, increasing chemical resistance, increasing color stability, reducing the tendency to chalking, reducing or increasing static and sliding friction, stabilizing or destabilizing foam, improving adhesion, controlling filler and pigment wetting and dispersing behavior, controlling rheological properties,Control of mechanical properties as well as other properties such as thermal conductivity, flammability, gas permeability, resistance to water vapor, hot air, chemicals, weathering and radiation, sterilizability, electrical properties, control of flexibility, scratch resistance, elasticity, extensibility, bending ability, tear behavior, rebound behavior, hardness, density, tear resistance, compression set, behavior at different temperatures, control of transparency, heat resistance, yellowing tendency and weathering resistance.

[0143] Examples of applications in which the preparation according to the invention can be used to manipulate the properties described above are the production of coating materials and impregnations and coatings and coverings obtainable therefrom on substrates such as metal, glass, wood, mineral substrates, synthetic and natural fibers for the production of textiles, carpets, floor coverings or other goods producible from fibers, leather, plastics such as films, molded parts. The silicone resin intermediates according to the invention consisting of repeating units of the formula (7) or the organopolysiloxanes consisting of repeating units of the formula (8) or.The preparations obtainable therefrom can, with appropriate selection of the preparation components, also be used as additives for the purposes of defoaming, promoting flow, hydrophobizing, hydrophilizing, filler and pigment dispersing, filler and pigment wetting, substrate wetting, promoting surface smoothness, and reducing the adhesion and sliding resistance on the surface of the cured composition obtainable from the additized preparation. The silicone resin intermediates produced by the process according to the invention from repeating units of the formula (7) or the organopolysiloxanes from repeating units of the formula (8) or the preparations obtainable therefrom can be incorporated into elastomer compositions in liquid or in cured solid form.It can be used for the purpose of strengthening or improving other performance properties such as controlling transparency, heat resistance, yellowing tendency, weathering resistance.

[0144] A further subject matter of the invention is therefore directed to a use of the silicone resin intermediate comprising repeating units of the formula (7), of the block copolymeric polyorganoalkoxysiloxane comprising repeating units of the formula (8) or of the preparation according to the invention for producing coating materials and impregnations and coatings and coverings obtainable therefrom on substrates such as metal, glass, wood, mineral substrate, synthetic and natural fibers for producing textiles, carpets, floor coverings or other goods producible from fibers, leather, plastics such as films, molded parts.

[0145] All symbols in the above formulas have their meanings independent of one another. In all formulas, the silicon atom is tetravalent.

[0146] Examples:

[0147] The process according to the invention is described below using examples, without, however, limiting the present invention to these examples or the contents disclosed therein. All percentages are by weight. Unless otherwise stated, all manipulations are carried out at room temperature of approximately 23°C and under atmospheric pressure (1,013 bar). The apparatus used is commercially available laboratory equipment such as is commercially available from numerous equipment manufacturers.

[0148] Ph means a phenyl residue = CeHs-

[0149] Me stands for one methyl radical = CH3- . Me2 stands for two methyl radicals.

[0150] In this text, substances are characterized by data obtained by instrumental analysis. The underlying measurements are either performed according to publicly available standards or determined using specially developed procedures. To ensure the clarity of the teachings presented, the methods used are listed here:

[0151] Viscosity:

[0152] Unless otherwise stated, viscosities are determined by rotational viscometric measurement in accordance with DIN EN ISO 3219. Unless otherwise stated, all viscosity data apply at 25 °C and a standard pressure of 1013 mbar.

[0153] Molecule compositions:

[0154] The molecular compositions are determined by nuclear magnetic resonance spectroscopy (for terminology see ASTM E 386 : High-resolution nuclear magnetic resonance spectroscopy (NMR): Terms and Symbols ), where the 1H-core and the 29 Si nucleus is measured. Description 1H-NMR measurement

[0155] Solvent: CDC 13.99.8%d

[0156] Sample concentration: approximately 50 mg / 1 ml CDC13 in 5 mm NMR

[0157] tube

[0158] Measurement without addition of TMS, spectra referencing of residual CHCI3 in CDC13 to 7.24 ppm

[0159] Spectrometer: Bruker Avance I 500 or Bruker Avance HD 500 Probe head: 5 mm BBO probe head or SMART probe head (Fa.

[0160] Bruker)

[0161] Measurement parameters:

[0162] Pulprog = zg30 TD = 64k

[0163] NS = 64 or 128 (depending on the sensitivity of the probe head)

[0164] SW = 20.6 ppm

[0165] AQ = 3.17 s

[0166] Dl = 5 s

[0167] SFO1 = 500, 13 MHz

[0168] 01 = 6.175 ppm

[0169] Processing parameters:

[0170] ST = 32k

[0171] WDW = EM

[0172] LB = 0.3 Hz

[0173] Depending on the type of spectrometer used, individual adjustments of the measurement parameters may be necessary.

[0174] Description 29 Si-NMR measurement

[0175] Solvent: CeDe 99.8%d / CC14 1:1 v / v with 1 wt% Cr(acac) 3 as relaxation reagent Sample concentration: approximately 2 g / 1.5 ml solvent in 10 mm NMR-

[0176] tube

[0177] Spectrometer: Bruker Avance 300

[0178] Probe head: 10 mm 1H / 13C / 15N / 29Si glass-free QNP probe head

[0179] (Bruker)

[0180] Measurement parameters:

[0181] Pulprog = zgig60

[0182] TD = 64k

[0183] NS = 1024 (depending on the sensitivity of the probe head)

[0184] SW = 200 ppm

[0185] AQ = 2.75 s

[0186] Dl = 4 s

[0187] SFO1 = 300, 13 MHz

[0188] 01 = -50 ppm

[0189] Processing parameters:

[0190] SI = 64k

[0191] WDW = EM

[0192] LB = 0.3 Hz

[0193] Depending on the type of spectrometer used, individual adjustments of the measurement parameters may be necessary.

[0194] HCl content

[0195] HCl content is determined by direct titration of an isopropanolic sample solution with ethanolic potassium hydroxide solution against tetrabromophenolphthalein ethyl ester.

[0196] Molecular weight distributions:

[0197] Molecular weight distributions are determined as weight average Mw and number average Mn using gel permeation chromatography (GPC or size exclusion chromatography (SEC)) with a polystyrene standard and a refractive index detector (RI detector). Unless otherwise stated, THF is used as the eluent, and DIN 55672-1 is applied. Polydispersity is the quotient Mw / Mn.

[0198] Example 1: Preparation of a block copolymer organopolysiloxane resin using a reaction column and a loop with a short-path still, wherein the polydimethylsiloxane is fed into the column bottom.

[0199] 1500 g / h of methyltrichlorosilane is continuously fed into the upper third of a reaction column. There, it reacts with the ethanol flowing countercurrently from below to form methyltriethoxysilane. The resulting amount of HCl is discharged via the top of the reaction column through a reflux condenser into the exhaust system, and the resulting condensate is continuously recycled to the upper third of the reaction column. The alkoxylate falls into the bottom of the reaction column, where 170 g / h of water, 1370 g / h of ethanol, and 150 g / h of o-dihydroxypolydimethylsiloxane with a viscosity of 70 mPas are continuously added. The reaction mixture is collected from the bottom of the reaction column in a sample vessel while maintaining a constant bottom level. A clear solution of a partial condensate in ethanol with an HCl content of 35 ppm is obtained. An ethanol content of 29 wt% was determined by 1H NMR.In the 29S1-NMR, an average composition of the partial condensate of 1 mol% methyltrimethoxysilane, 34 mol% MeSi(OEt)2O1 / 2, 38 mol% MeSi(OEt)O2 / 2, 10 mol% Me-S1O3 / 2, 1 mol% Me2Si(OEt)O1 / 2 and 16 mol% Me2SiO2 / 2 was found.

[0200] 3000 g / h of the partial condensate solution are continuously metered in with 120 g / h water and 13.8 g / h 20 wt. % hydrochloric acid in a loop with a volume of 1.5 l and turbulent flow, while heated to 70°C. The overflowing reaction mixture is evaporated in a short-path still at atmospheric pressure using a heating finger at 140°C to an ethanol content of 0.6 wt. % and an HCl content of 12 ppm. A cloudy liquid with a viscosity of 430 mPas is obtained. The 29S1 NMR showed an average composition of 1 mol . -% MeSi (OEt) 2O1 / 2 , 32 mol . -% MeSi (OEt) O2 / 2 , 50 mol . -% MeSiOs / 2 , 1 mol . -% Me2Si ( OEt ) O1 / 2 and 16 mol . -% Me2SiO2 / 2 were found .

[0201] Example 2: Preparation of a block copolymer organopolysiloxane resin using a pre-reactor, a reaction column and a batch with reflux condenser and distillate divider, wherein the polydimethylsiloxane is fed into the column bottom.

[0202] 40 kg / h of methyltrichlorosilane are continuously fed to a pre-reactor upstream of the reaction column. 15 kg / h of the ethanol / HCl condensate from the stirred distillation is fed to the pre-reactor, partially alkoxylating methyltrichlorosilane. The HCl released in this process is discharged in gaseous form from the pre-reactor via a reflux condenser into the exhaust system.

[0203] This reaction mixture containing partially alkoxylated methyltrichlorosilane is continuously transferred from the pre-reactor into the upper third of the reaction column. There it reacts with the ethanol coming in countercurrent from below to form methyltrimethoxysilane, with the remaining amounts of HCl being discharged via the top of the reaction column through a reflux condenser into the exhaust gas line and the resulting condensate being continuously recycled to the upper third of the reaction column. The alkoxylate falls into the bottom of the reaction column, where 5.7 kg / h of water, 30 kg / h of ethanol and 5.0 kg of a,o-dihydroxypolydimethylsiloxane with a viscosity of 70 mPas are continuously added. The reaction mixture is collected from the bottom of the reaction column in a sample vessel while maintaining a constant bottom level. A clear solution of a partial condensate in ethanol with an HCl content of 50 ppm is obtained. By 1H-NMR an ethanol content of 28 wt.-%. 29S1-NMR revealed an average composition of the partial condensate of 1 mol% methyltrimethoxysilane, 33 mol% MeSi(OEt)2O1 / 2, 39 mol% MeSi(OEt)O2 / 2, 10 mol% MeSiO3 / 2, 1 mol% Me2Si(OEt)O1 / 2, and 16 mol% Me2SiO2 / 2.

[0204] 306 kg of the partial condensate solution, 17.8 kg of water and 1.38 kg of 20% by weight hydrochloric acid are stirred in a stirrer for 30 minutes at 70°C and atmospheric pressure and then evaporated to a bottom temperature of 100°C and an absolute pressure of 100 mbar to an ethanol content of 0.3% by weight and an HCl content of 4 ppm. A cloudy liquid with a viscosity of 650 mPas is obtained. The 29S1 NMR showed an average composition of 0.5 mol% MeSi(OEt)2O1 / 2, 31.5 mol% MeSi(OEt)O2 / 2, 51 mol% MeSiO3 / 2, 1 mol% Me2Si(OEt)O1 / 2 and 16 mol% Me2SiO2 / 2.

[0205] Comparative Example 1: Preparation of a block copolymer organopolysiloxane resin using a reaction column, wherein the polydimethylsiloxane is fed into the upper third of the column.

[0206] 1500 g / h of methyltrichlorosilane and 150 g / h of o-dihydroxypolydimethylsiloxane with a viscosity of 70 mPas are continuously fed into the upper third of a reaction column. There, the methyltrichlorosilane reacts with the ethanol flowing countercurrently from below to form methyltriethoxysilane. The resulting HCl is discharged via the top of the reaction column through a reflux condenser into the exhaust system, and the resulting condensate is continuously recycled to the upper third of the reaction column. Gel particles gradually deposited in the lower two thirds of the column, making continuous operation impossible. The alkoxylate-siloxane mixture falls into the bottom of the reaction column, where 170 g / h of water and 1370 g / h of ethanol are continuously added. The reaction mixture is collected from the bottom of the reaction column in a sample vessel while maintaining a constant bottom level.A cloudy liquid is obtained which separates into two phases after 24 hours and was therefore not analyzed further.

[0207] Comparative Example 2: Preparation of a block copolymer organopolysiloxane resin using a reaction column and a loop with a short-path distillation still, wherein the polydimethylsiloxane is fed into the loop.

[0208] 1500 g / h of methyltrichlorosilane is continuously fed into the upper third of a reaction column. There, it reacts with the ethanol flowing countercurrently from below to form methyltriethoxysilane. The resulting HCl is discharged via the top of the reaction column through a reflux condenser into the exhaust system, and the resulting condensate is continuously recycled to the upper third of the reaction column. The alkoxylate falls into the bottom of the reaction column, where 170 g / h of water and 1370 g / h of ethanol are continuously added. The reaction mixture is collected from the bottom of the reaction column in a sample vessel while maintaining a constant bottom level. A clear solution of a partial condensate in ethanol with an HCl content of 30 ppm is obtained. An ethanol content of 49 wt.% was determined by 1H NMR. In the 29S1-NMR, an average composition of the partial condensate of 0.2 mol% methyltrimethoxysilane, 19 mol% Me-

[0209] Si (OEt ) 2O1 / 2, 58 mol% MeSi (OEt ) O2 / 2 and 22.8 mol% MeSiC>3 / 2 were found.

[0210] 2850 g / h of the partial condensate solution are continuously metered with 150 g / h of o-dihydroxypolydimethylsiloxane with a viscosity of 70 mPas, 120 g / h of water, and 13.8 g / h of 20 wt. % hydrochloric acid in a 1.5 l volume loop with turbulent flow, while being heated to 70°C. The overflowing reaction mixture is evaporated in a short-path distillation apparatus at atmospheric pressure using a 140°C heating finger to an HCl content of less than 30 ppm. A cloudy liquid is obtained, which separates into two phases after 24 hours and was therefore not analyzed further.

[0211] As can be seen from the result, following this process, at least in a solvent-free manner, ie a solvent that does not correspond to the alcohol used for the alkoxylation reaction, it is not possible to add the polydimethylsiloxane at any point, since gel formation and two-phase nature counteract this.

Claims

Claims 1 . A process for the continuous production of block copolymeric polyorganoalkoxysiloxanes, comprising the following steps in the given order: (i) partially reacting at least one chlorosilane with an alcohol or a mixture of alcohols in a pre-reactor to form a reaction mixture comprising a partial alkoxylate; (ii) transferring the reaction mixture obtained after step (i) into a first reaction unit which is connected to the pre-reactor and comprises a column having an upper and a lower end and a feed point, wherein the transfer is carried out by transferring the reaction mixture into the column via the feed point, wherein the feed point into the column is arranged such that the feed takes place in the middle third of the total length of the column; (iii) transporting the reaction mixture transferred into the column in step (ii) within the column, which transport takes place downwards under the effect of gravity, the partial alkoxylate being brought together with a further alcohol or a further mixture of alcohols, the partial alkoxylate being converted to a full alkoxylate before the reaction mixture reaches a lower part of the column (column bottom) which is at most 25% of the total length away from the lower end of the column, the full alkoxylate subsequently being located in the column bottom; (iv) reacting the full alkoxylate in the lower part of the column of the first reaction unit with another alcohol or another mixture of alcohols, water and at least one silanol-terminated polydiorganosiloxane to form a low-condensation polyorganosiloxane mixture (crude mixture); (v) transferring the raw mixture obtained after step (iv) into a second reaction unit which is connected to the first reaction unit and comprises a further continuous reactor, wherein the transfer into the further continuous reactor takes place; and (vi) reacting the crude mixture converted in step (v) with a further alcohol or a further mixture of alcohols and with water to form a polyorganosiloxane mixture which has a higher condensation state than the crude mixture.

2. Process according to claim 1, wherein the silanol-terminated polydiorganosiloxane is metered into the column bottom in the first reaction unit for step (iv).

3. Process according to claim 1 or 2, wherein the continuous reactor within the second reaction unit is designed as a loop reactor. 4 . Process according to one of the preceding claims, with the proviso that apart from the alcohol required for the reaction, no further organic components, preferably low molecular weight components, are used in the entire process, in particular no inert organic solvent.

5. Process according to one of the preceding claims, wherein in process steps (i), (iii), (iv) and (vi) only one specific alcohol is used for the reaction, preferably the same alcohol.

6. Process according to one of the preceding claims, wherein the chlorosilane corresponds to the following general formula (1): RnSiCl4-n (1) , where R represents a hydrogen radical or an acid-stable Cl - C18 hydrocarbon radical optionally substituted by at least one heteroatom and n can have the values 0, 1, 2 or 3.

7. Process according to one of the preceding claims, wherein the block copolymeric polyorganoalkoxysiloxanes prepared contain linear D units (R 1 2SiO2 / 2) and non-linear crosslinker T- units (R 2 SiC>3 / 2), wherein the D units are predominantly bonded to one another in the form of oligomeric or polymeric chains, with chain lengths of at least 4 D units in direct and uninterrupted sequence, and / or wherein the non-linear T units form blocks of uninterrupted sequences of at least 4 T units, wherein the non-linear blocks may in turn be cross-linked with one another, wherein R 1 and R 2 are defined independently of each other as R.

8. The method according to claim 7, wherein the block copolymeric polyorganoalkoxysiloxanes additionally contain units of the general Formula ( 3 ) in the nonlinear blocks of T-units: R 2 cR3 dSiO (4-cd) / 2 (3) , where R 2 is defined as R, R 3 means a condensable radical of the form -OR , where R has the meaning given above and c means the number 1 and c + d can assume the values 1 , 2 or 3 , where d means the values 0 , 1 or 2 . 9 . Process according to one of the preceding claims, wherein the silanol-terminated polydiorganosiloxane corresponds to the following general formula (4): HO- (R 2 2SiO2 / 2) e-OH (4 ) , where R 2 represents a residue R and e represents an integer value from 4 to 2000 .

10. Process according to one of the preceding claims, wherein in the second reaction unit, additional alkoxy- and / or hydroxy-functional organopolysiloxanes and / or alkoxy- and / or hydroxy-functional silanes are additionally added, wherein the additional alkoxy- and / or hydroxy-functional organopolysiloxanes are those of repeating units of the general formula (5) and the additional alkoxy- and / or hydroxy-functional silanes are those of the general formula (6): RpSi (OR 4 ) q O ( 4-pq) / 2 (5) , where in the units of formula (5) R has the meaning given above, R 4 identical or different monovalent Ci-Ce-alkyl radicals or hydrogen, p and q in the units of formula (5) have the values 0, 1, 2 or 3, with the proviso that p + q < 3 and p has the value 1 in at least 20% of all repeating units of formula (5); R 5 o Si (OR 4 ) 4-o (6) , where R 5 is a hydrocarbon radical containing no nitrogen atoms, R 4 has the meaning given above and o means a number with a value of 0, 1, 2 or 3.

11. Silicone resin intermediate obtainable according to step (iv) of the process according to any one of the preceding claims, wherein the silicone resin intermediate is composed of repeating units of the following general formula (7): R 6 x Si (OR 7 ) Y O(4-X- Y) / 2 (7) , where in the units of formula (7) R 6 a residue R, R 7 the meaning of R 4x in the units of formula (7) has the value 1 or 2 and y in the units of formula (7) can have the value 0, 1, 2 or 3, with the proviso that x + y < 4 and x has the value 1 in at least 30% of all repeating units of formula (7) and has the value 2 in at least 5%, where the repeating units of formula (7) in which x has the value 2 contain at most one radical of the formula OR 7 may have, so that in these repeating units y = 0 or 1, wherein these repeating units are bonded to one another in addition to chain segments in an uninterrupted sequence of at least 4 repeating units, wherein in the silicone resin intermediates from repeating units of the formula (7) the unit OR 7 to a maximum of 10 wt.% hydroxy groups.

12. Block copolymeric polyorganoalkoxysiloxane obtainable by a process according to any one of claims 1-10, wherein the polyorganoalkoxysiloxane is constructed from repeating units of the general formula (8): R 6 fSi (OR 7 ) g O (4-fg) / 2 (8) where in the units of formula (8) R 6 and R 7the meanings already given above, f and g in the units of formula (8) can have the values 0, 1, 2 or 3, with the proviso that f + g < 3 and f has the value 1 in at least 30% of all repeating units of formula (7) and has the value 2 in at least 5%, where these repeating units are bonded to one another in addition to chain segments in an uninterrupted sequence of at least 4 repeating units, g averaged over all repeating units of the general formula (8) has an average value of 0.05 to 1.7, where in the organopolysiloxanes from repeating units of formula (8) the unit OR 7 not more than 10% by weight of hydroxyl groups.

13. Preparation comprising at least one silicone resin intermediate according to claim 11 and / or at least one block copolymeric polyorganoalkoxysiloxane according to claim 12 and at least one auxiliary agent.

14. Use of the silicone resin intermediate according to claim 11, the block copolymer polyorganoalkoxysiloxane according to claim 12 or the preparation according to claim 13 as corrosion protection, for the production of artificial stones or for controlling the electrical conductivity and the electrical resistance, controlling the flow properties of a preparation, controlling the gloss of a moist or cured film or an object, increasing the weathering resistance, increasing the chemical resistance, increasing the color stability, reducing the tendency to chalking, reducing or increasing the static and sliding friction, stabilizing or destabilizing foam, improving adhesion, controlling the filler and pigment wetting and dispersing behavior, controlling the rheological properties, controlling the mechanical properties and other properties such as thermal conductivity, flammability, gas permeability, resistance to water vapor,Hot air, chemicals, weathering and radiation, sterilizability, electrical properties, control of flexibility, scratch resistance, elasticity, extensibility, bendability, tear behavior, rebound behavior, hardness, density, tear resistance, compression set, behavior at different temperatures, control of transparency, heat resistance, yellowing tendency and weathering resistance, especially as corrosion protection.

15. Use of the silicone resin intermediate according to claim 11, the block copolymeric polyorganoalkoxysiloxane according to claim 12 or the preparation according to claim 13 for the production of coating materials and impregnations and coatings and coverings obtainable therefrom on substrates, such as metal, Glass, wood, mineral substrate, synthetic and natural fibers for the production of textiles, carpets, floor coverings or other goods made from fibers, leather, plastics such as films, molded parts.