DE2059546C3 - Process for the preparation of equilibrated organopolysiloxane mixtures containing predominantly linear terminal sulfuric acid groups - Google Patents

Description

HO ₃ SO-

IO

20 dialkylcyclopolysiloxane at 15 to 70 "C.
1 L. Equilibrated organopolysiloxane mixtures of the

general formula

KO ₃ SO-

Si — O—
R.

SOjH

(n = 2 to 20, R = alkyl radical with 1 to 6 carbon atoms, where the R radicals through the radicals

- (CH ₂ J ₃ OSO ₅ SiR ₃ , - (CH ₂ J ₃ OSO ₃ H. -CH ₂ Br, - (CH ₂ ) JCl, - (CH ₂ J ₂ OR, - (CH ₂ UR ₁ , - ( CH ₂ ) ₃ OR _f ;

R _f = Perfiuoralkylrest; χ = integer can be substituted and some of the hydrocarbon radicals R by the remainder

—Ο—

Si — ΟΙ R.

SO ₃ H

can be replaced), produced by one or more of the processes of claims 1 to 10. 12. Organopolysiloxane mixtures according to An Spruch 11, characterized by the formula

"R
ι - 0 - a R. 0 - - SO ₃ H I.
Si i
Si - R. 0 - R. Si ft

Si —0 -

SO ₃ H

(where b = 0 to 20; b - 0, a = 1 to 10 ⁵ ; b Ξ> 1, a - 1 to 20, preferably 1 to 10). 13. Organopolysiloxane mixtures according to claim 11, characterized by the formula

CH ₃ -Si-

(u = 1 to 20, preferably 1 to 10).

CH ₃ OSO ₃ H il 0- -Si -
I. CH ₃

Sulfur acid derivatives of organohalosilanes have already been described many times. Such Organosilyl sulfals can be prepared by various methods, e.g. B. by the action of sulfuric acid Trimethyichlorosilane, obtained:

2 (CH ₃ I ₃ Si-Cl + H ₂ SO ₄

MCHj) ₃ Si-OSO-Si (CH ₃ ).,
O

Polysiloxanes with intramolecularly bonded sulfate groups have also already been described. Examples of such compounds can be found in US Pat. No. 3,115,512, these being polysiloxanes in addition, Haiogen or alkoxy groups bound included.

It has also long been known that organopolysiloxanes can be equilibrated with sulfuric acid. Such an equilibration process is e.g. B. in DT-PS 1034 631 described. The polysiloxanes obtained are free of sulfuric acid groups, pie equilibration is carried out with acid, such as. B. sulfuric acid or Ansolvo acid performed. It is that is not made of significance in contrast to the below-described method, a erfindungsgeniäßen> -5 homogeneous incorporation of the acids in the siloxane.

In the attempt to explain this equilibration reaction in terms of its kinetics, one has also _{postulated the occurrence of compounds with ^ SiOSO 3} H groups. It has also been suggested that compounds of the formula

atoms, where the R radicals through the radicals
- (CHJ ₃ OSO ₃ SiR ₃ , - (CH ₂ J ₃ OSO ₃ H,
-CH ₂ Br, - (CH ₂ J ₃ CI, - (CH ₂ J ₂ OR,
f, - (CH ₂ ) ₃ OR _f ;

R _r = perfluoroalkyl radical; χ = integer, can be substituted, and some of the hydrocarbon radicals R by the remainder

- O-

Si-O-R

SO ₃ H

can be replaced). which are in equilibrium with cyclic Compounds of the general formula

HO ₃ SO-

CH ₃

Si-O-CH ₃ _

SO, H

Si — ΟΙ
R.

SO ₃

(.χ = small, whole number) would be formed. However, the existence of these compounds has not been established with certainty.

moreover, these connections could only be in small amounts are present in a mixture with predominantly sulfuric acid ester-free organopolysiloxanes. In In no case could such compounds be isolated.

Surprisingly, it has now been found that there are predominantly linear, terminal sulfuric acid groups comprising de-equilibrated organopolysiloxane mixtures the general formula

TR

(R = above meaning, with two of the Leftovers

TR

-O-

through a rest

Si —O—

SO ₃ H

-O-

HO ₃ SO-

Si-O-R

Si-O-

SO ₃

R.
-Si-O-

SO ₃ H

(D

(11 = 2 to 20, R = alkyl radical can be replaced by 1 to 6 carbon; in = 1 to 10, preferably I or 2) and sulfuric acid can be prepared by

a) Organopolysiloxanes with structural units of the general formula

Si — ΟΙ
R.

Tl

Si-O-TR

O-

Si-O-

Si — O—
R.

(III)

(R = hydrocarbon radical, which can optionally be substituted by a radical inert towards sulfuric acid; b = O to 20, if b = O, a = 1 to IO ⁵ , if b ^ 1, a = 1 to 20) with H ₂ S preferably wherein the siloxane door pyrosulfuric acid is added ₂ O ₇ in amounts (based on siloxane) 10 ~ ⁵ to $ ■ 10 "'moles optionally at elevated up to 150 ° C temperature is reacted, or

b) the aforementioned organopolysiloxanes with H ₂ SO * in amounts of (based on siloxane bonds) 10
up to 1 mol is reacted at, if appropriate, a moderately elevated temperature and the water of reaction formed is removed azeotropically with low-boiling inert solvents or in vacuo or by a stream of inert gas, the siloxane preferably being added to the sulfuric acid, or

c) organohalopolysiloxane of the general formula

X-Si-R

Si-O-R

Si - O R O

Si —ΟΙ R

Si-X

"R

Si —ΟΙ
R.

Si-X
R.

(X = halogen, preferably —Cl or —Br), the 15 of the formula optionally also linking two Si atoms

Il

- O - S - O - groups O

may contain, with H ₂ SO ₄ in amounts (based on silyl halide) 1 to 1.1 mol, optionally at up to 15O ⁰ C elevated temperature are reacted, preferably the sulfuric acid is added to the Organohalogenpolysiioxan, and optionally after a), b) or c) the compounds obtained are reacted with dialkylcyclopolysiloxanes, if appropriate at a temperature elevated to 150.degree. The compounds HO, SO- prepared according to the invention

Si-O-

SO ₃ H

are in equilibrium with compounds of the formula

Si — O—

SO ₃

(H)

and sulfuric acid, where m has a value from 1 to; 10, preferably 1 or 2. This balance can be represented by the following scheme:

m HO ₃ SO-

Si —ΟΙ

(D

SO, H =

R. 0 - SO ₃ π + wi H ₂ SO ₄ in Si -
I. _ I.
R. (H)

It is obvious to the person skilled in the art that these products contain low equilibrium contents Dialkylcyclopolysiloxanes can be included.

Is part of the radicals R of the compound of formula 1 through the radical

-O-

Si-O-R

SO ₃ H

replaced, two of these radicals can be replaced by the radical in the corresponding products of the formula II

55

-O-

Si-O-

SO ₃ -

R -Si-O-

be replaced.

It is expressly stated that the compounds of the formulas I and II are always Mixtures of polymer homologues, which are related to the molecular weights and the structural distribution are in balance.

The values for the index π need in relation to the maximum frequency for the linear and the cyclic compounds do not match.

The cyclic polydiacylsiloxanyl sulfates have predominantly η-values from 2 to 10 and "" - values of 1 and 2.

Chain-shaped polydialkylsüoxanes with SO ₃ H groups in the a and co positions can have w values of up to several thousand.

The DT-PS Π 74509 concerns a method for Production of keiicniui migcii,! LaÜGgcn or alkoxy groups and organopolysiloxanes containing sulfate groups by reacting difunctional halogen or alkoxysilanes mi '! water and Sulfuric acid. The products produced according to the invention are halogen-free and alkoxy-free. moreover lie the products manufactured according to the invention in equilibrium with cyclic compounds from Dies meets the process products of ΡΤ-PS 1174509 not to.

The process according to the invention could not be found in DT-PS 11 57 789 either. there a process for the production of organic

609620Π67

silicon compounds are described that form the grouping

= Si - M - O - S - O—

Il ο

contain. Here the SO ₃ groups are bonded to silicon via alkylene. Balance adjustments are not possible.

In contrast to the products according to the invention, the products are largely stable to hydrolysis. This Organofunctional products are therefore not related to those produced according to the invention Equilibrium products.

The situation is similar with the process described in DT-PS 12 06160 for sulfonating organopolysiloxanes or organoalkoxysilanes. DT-PS 12 06 160 relates, as can be seen from column 1, times 32 ff., Compounds in which the SO ₃ group is bonded to the silicon atom via an alkyl group. The reaction with alkali bisulphite or alkali pyrosulphite thus takes place according to the rules of organic carbon and not of organosilicon chemistry.

The inventive reaction, in which the SO-j group directly linked to a silicon atom could not be derived from this teaching.

The radical R can within the polysiloxane ^ - and thus also have the same or different meanings within the same Mofeküls. Sub the radicals already mentioned are the alkyl radicals with I to 6 carbon atoms and of these in particular the methyl and ethyl radicals are preferred.

The compounds represented by the general formula I in their gross composition correspond, for example, to the following more precisely defined structure:

HO ₃ SO

Si —ΟΙ R.

Si - - R

Ο -

Si - - SO ₃ H

Si-O

SO ₃ H

"R

Si —Ο -
R.

R.
j c- b R.
I. a Si —Ο - O
I. I.
Si - O - R —Si —Rl
j: O ? - ^L "R - Si - R- SO ₃ H I.
O
ι -I I.
SO ₃ -

Si-O-

so;

(lc > t_

Q-C) -I,

'-Ψ) H ₂ SO,

öchc aes pale- h Π

enzen t A h

-. ^ * «,« ^. * «« Ι \ ΐΛ-ι IA-WIiLtM öchc aes pale- h Π fco *

by weight, the remaining valences would be sated under Aus hat / ,, W tf ^{mtn value from] to 1} ^ - ^{lst b} ^ ^l >

Formation of silicon-oxygen-sulfur bond-n rnZh + ™ " ^from ' ^{to 20} ', preferably from 1 to

mtra- or intermolecular. The IndSi has ΒείϊΐΓ '" SV? * ° ^{to L} ~

a value of O to 20, preferably O to 5. Is io vorlie en ri ^{"dividuals' the} mixtures ^{in these}

CH ₃ -Si-

o — si—

- CH ₃ J OSO ₃ H

20 59 548

CH ₃ -Si

OSO ₃ H

SO CH ₃ 0 - α HO ₃ I.
Si -
I. I.
_CH ₃

CH ₃ [Γ CH ₃

- Si —Ο —Si -

0 — Si -

OSO ₃ H

In the aforementioned specific examples, α and α 'have the same meaning, but need not have identical numerical values.

The novel equilibrated organopolysiloxane mixtures containing terminal sulfuric acid groups according to the invention of the formula I can be determined by the process a), b) set out in claim 1 or c) win.

Process a) consists in organopolysiloxanes having structural units of the general formula

TR

Si — Ο—

Si — Ο—

Ο—

Si-O-

R.
(HI)

• Ex

Si — O—
R.

where α, b and R have the meaning already described, with H ₂ S ₂ O ₇ in amounts of (based on siloxane bonds) 10 " ⁵ to 5 · 10"'mol at optionally up to 150 ° C increased temperature, preferably the Siloxane is added to the pyrosulfuric acid.

The residual valences in formula III saturate - preferably intramolecularly - with formation SiOSi bonds or are occupied by end-blocking residues

Examples of such residues, the influence of which on the constitution of the end products is negligible here are hydroxyl-, alkuay-, avyloxy-trialkylsiloxy-, Haiogen, especially chlorine or bromine residues.

Those organopolysiloxanes are preferably used which have a cyclic structure and in which a = 1.5 to 5 and b = O or hydrolysates of dialkylchlorosilanes and commercial dialkylpolysiloxanes rich in such cyclopolysiloxanes.

The reaction temperature is not critical, jedocl should the temperature so that side reactions are avoided ver not exceed 150 ⁰ C. The temperature range from 10 to 70 ^° C. is preferred

The reaction is preferably carried out in such a way that the Pyroschwcfclsüurc (H ₂ S ₂ O ₇ ) and the siloxane is added dropwise. The reaction proceeds according to the principle:

CH ₃

Si-O

CH ₃

+ H ₂ S ₂ O ₇

HO ₃ SO

CH ₃

Si-O-

CH ₃ SO ₃ H i === ±

"CH ₃
Si-O

LCH ₃

SO ₃

+ H ₇ SO ₄

Instead of pyrosulfuric acid (H ₂ S ₂ O ₇ ), mixtures of SO ₃ and H ₂ SO ₄ can also be used.

If the composition of the mixture differs from the gross composition H ₂ S ₂ O ₇ and there is an excess of sulfuric acid, it is advisable to remove the water of reaction that then forms from the system by azeotropic distillation, in vacuo or by passing a stream of inert gas through.

The process b) for preparing the compounds according to the invention is characterized in that the organopolysiloxanes of the Formel.III with H ₂ SO ₄ in amounts (based on siloxane) 10 ~ ^Λ to 1 mole optionally at moderately elevated Temperatui reacted and the water of reaction formed by azeotropic removed with low-boiling inert solvents or in vacuo or by a stream of inert gas, the siloxane preferably being added to the sulfuric acid.

A suitable solvent for azeolropic distillation is, for. B. dichloromethane. The preferred temperature range is about 20 to 70 ⁰ C. Also hiei it has proved useful to provide the sulfuric acid and to add the siloxane to the sulfuric acid.

Procedure c) consists in using organohalopolysiloxanes of the general formula

X-Si-

Si —ΟΙ
R.

Si - Ο - R

Si —ΟΙ
R.

Si-X

R.
Si-O

οΐ X

with H ₂ SO ₄ in amounts of (based on silyl halide) 1 to 1.1 mol, optionally at a temperature elevated to 150 ° C., the sulfuric acid preferably being added to the organohalopolysiloxane.

In the formula, X has the meaning of a halogen and is preferably chlorine or bromine.

The organohalopolysiloxanes of the above formula can optionally each have two Linking Si atoms

O

Il

—O— S — O — groups

contain.

In procedure c), in contrast to procedure b), there are essentially none Split siloxane bonds. There is only a substitution of the end group.

When using organohalopolysiloxanes which already _{contain SO 4} groups bound intramolecularly and which are already in equilibrated form, the reaction proceeds particularly easily

Even in procedure c), the reaction temperature is not of essential importance. However, if possible, it should not be above 150 ^° C. in order to avoid the formation of by-products. A temperature range from 20 to 100 ° C. is preferred

The hydrogen halide released during the reaction can be removed from the reaction mixture by reducing the pressure or passing through inert gas will.

In this reaction, in contrast to the aforementioned, it is advisable to add sulfuric acid to the initially introduced one Add siloxane in small portions.

The according to the aforementioned process variants a). Compounds produced b) or c) can now be reacted with dialkylcyclopolysiloxanes, which causes the polysiloxane chains to be lengthened, <L h., the index π or α is increased by this process measure.

It is preferred to use starting compounds with values of a = 1 to 10, in particular 1 to 5, and 6 = 0.

t Dislk ylcyclo-

polysiloxane depends on the final value of a. The cyclic polysiloxane used is preferably a diimethylpolysiloxane with 3 to 10 dimethylsiloxy units in the ring.

The cyclopolysiloxane is converted into the Built-in siloxane containing sulfate groups.

With regard to the temperature, the equilibration reaction proceeds without adherence to specific conditions. It is stirred, preferably at temperatures below 150 ⁰ C, particularly in a range of 15 to 7O ⁰ C,

[CH ₃ HO, SO— Si — Ο—

CH,

SO ₃ H

50

55

The new, terminal sulfuric acid groups equilibrated organopolysiloxane mixtures are extremely useful equilibration analyzers for organopolysiloxanes.

So you can z. B. for the production of silicone oils and high viscosity organopolysiloxanes with terminal Hydroxyl groups can be used.

Compared to the well-known equilibration catalysts such as sulfuric acid and organosilyl sulfate, the new compounds according to the invention have the advantage that they are in the system to be equilibrated are soluble and that the equilibration reaction proceeds at such a rate that continuous Procedures are possible.

The new compounds also allow equilibration reactions, which lead to products of higher viscosity.

The catalysts used with particular success are those process products which after their production have been implemented chain-lengthening with dialkylcyclopolysiloxanes.

The new compounds according to the invention are also suitable as impregnating agents for water-repellent Finishing of glass, ceramics, textiles or paper. One benefit of these connections is their excellent surface adhesion. When used as an impregnating agent, one can use the terminal Sulfuric acid groups or the small amount of sulfuric acid present in equilibrium by neutralization with appropriate bases, such as calcium hydroxide, calcium oxide, zinc oxide, Bind alkali or alkaline earth carbonates or amines.

The inventive method for the preparation of the novel compounds are based on the the following examples are explained in more detail.

example 1

This example describes the procedure characterized in claim 1 under a).

_{1 mol of H 2} S ₂ C ₇ is placed in a three-necked flask with a stirrer. 1 mol of octamethylcyclotetrasiloxane is added dropwise at 15 ° C. with water cooling. The resulting reaction product, which is obtained without weight loss, is only slightly cloudy. No sulfuric acid phase was deposited.

The viscosity of the product is at 2O ⁰ C 276 cps. The acid value determined by hydrolysis is 8.35 x 10 " ³ eq acid / g substance. The theoretical acid value of the compound

Ties split. Side reactions hardly occur. The "obtained" j-Dimethoxypolydimethylsiloxan can be at a bath temperature to 300 ⁰ C and a vacuum distilling to 10 ^-2 Torr without residue. The content of individual individuals

CH ₃ O

CH ₃

Si — ΟΙ
CH ₃

CH ;,

and CH ₃

^L 4-Si-O- .. CH ₃ J _x

can be determined by gas chromatography. In the Table I shows the area proportions of the individual linear • ur.d cyclic siloxanes in the registration curve of the. Gas chromatograph indicated:

Table 1

cyclic

0.5
2.9
0.5

Number of Si atoms Area share,% in the siloxane linear 1 0.8 2 5.6 3 20.8 4th 17.0 5 18.1 6th 12.1 7th 8.3 8th 5.8 9 3.1 10 2.0 12th 0.7 13th 0.5 Example 2

is 8.43x10 " ³ eq acid / g substance.

The presence of an equilibrium mixture according to reaction equation (1) in column 8 leaves prove themselves by mixing the reaction product with dichloromethane: The insoluble one separates and thus sulfuric acid that can be removed from the equilibrium as the second phase.

The constitution of the reaction product, in particular the establishment of equilibrium with respect to the polymer distribution, is determined by reaction with methanol / triethylamine. All SiOS bonds are thereby formed with the formation of SiOCH ₃ - This example shows the reaction of the reaction product obtained according to Example 1 with cyclic polysiloxane.

The reaction product obtained in Example 1 is added to octamethylcyclotetrasiloxane at room temperature so that there are 22 Si atoms per sulfur atom in the reaction mixture. The reaction mass becomes more viscous and is homogeneous or very slightly cloudy.

The acid value determined by hydrolysis is 1.165 · 10 ^-3 να1 acid / g substance. The theoretical acid value for the compound

HO ₃ SO-

CH ₃ Si — O—

CH,

SO ₃ H

is 1.162 · ΙΟ " ³ val'g substance.

609 620/167

After methoxylation it can be determined by gas chromatography that only »Also contain 4.8% Octanuihylcyclotetrasiloxan and, which corresponds well to the expectations for an equilibratable, single-chain dimethylsifoxane system. Short-chain (VJ-dimethoxypolydimethylsiloxane with 3 to 13 dimethylsiloxy units are each present in an amount less than 0.75%. You stir presumably from those in equilibrium

TCH ₃ 3-13 SO ₃ - Si — Ο
ι LcH ₃ _

here. A flat relative maximum in compounds with 4 to 5 Si units shows that these ring sizes are preferred in some ways.

The addition of octamelhylcyelotctrasiloxane is continued until the silicon-sulfur ratio is reached has risen to 60.

The viscosity of this product is 134 60OcP (at 20 C. Octamethylcyclotetrasiloxane is gas diroiriatographic only about 5% detectable in the mixture.

A ί /, ΐΊ-dihydroxypolydimethylsiloxane can be obtained by hydrolysis of the process product, that is used to manufacture a cold-curing elastomer system particularly suitable.

45

x—

C ₂ H 3.21 C ₂ H ₅ I.
Si—
I. Si-X
I. C ₂ H. C ₂ H ₅ S. 0—

manufactured. In the formula, X denotes the radical -Cl

- SO
Or —y- ⁴ -. The sulfate content of the product is 6TgMoI. An acid value of 4.104 · 10 ^-3 eq / g substance can be determined by hydrolysis.

According to the invention, 58 g of this siloxane are gradually admixed with 3 g of foO% sulfuric acid at room temperature. This corresponds to a ratio of 1.02 mol sulfuric acid / eq Cl. After all the sulfuric acid has been added, the mixture is ^{heated to 50 °} C. for a few hours. The released hydrogen chloride is finally driven off completely by heating to 100 ° C. for half an hour and subsequent vacuum treatment at 30 ° C. and 20 Torr.

1.7 g of a lower phase separate out. The upper phase (69.8 g) has an acid value of 6.297 · 10 ~ " ³ eq / g substance and a chlorine content of 0.006 · 10 ^r eq / g substance.

HO ₃ SO-

Si-OC ₂ H ₅

SO ₃ H

3.21

an acid value of 6.58 · 10 ^{3 can be} calculated. The compound was methoxylated as in Example 2 and the polymer distribution was determined by gas chromatography. The values are given in Table 11:

³⁰ Table II

Example 3

This example describes the procedure characterized in claim 1 under c).

From diethyldichlorosilane is corresponding to the ^ ÜSA.-Patent 31 15 512 with the full 4 ° Inadequate amounts of water and sulfuric acid hydrolyze an equilibrated chlorpolysiloxanyl Sulphate of the formula

Number of Si-Atorae
in the siloxane

Area,%
linear

0.44
11.12
29.55
19.85
10.80

4.49

1.64

cyclic

4.5

2.18

2.16

1.36

1.03

The content of higher and non-identifiable by-products is 10.87%.

Example 4

This example also describes reaction c) of claim 1.
400 g of a siloxane of the formula

"CH ₃

Si-O

CH ₃

"CH
I. 3 - CH ₃ - X b O — Si -
ι a _ a Si —O- I.
CH ₃ -

CH ₃

Si-O

CH ₃

CH ₃
Si-X

, -. CH ₃

where a = 6.17 and 6 = 3, X is the remainder -Cl or and its sulfate content is 54g / MoI (at

the definition of the molecular weight remains the bridging one Function of the sulphate residue not taken into account, SO *

the rest

is thus the end-limiting remainder

) believed to be stirred at ⁰ C and then for 20 hours at 50 ⁰ C with 64 g of sulfuric acid 1 -hour WLO. Smaller amounts of dean are repeatedly added to the product and this is ^{distilled off again at 70 °} C. and 9 Torr to remove the water.

The result is a very viscous mass with an acid value of 3.44 · 10 ^-3 eq / g substance, of which 0.03 · 10 ^-3 eq Cl / g. This means that the amount of residual chlorine remaining in the product is negligible. A product of the formula

CH ₃
Si-O- CH ₃ j

HO ₃ SO

CH ₃
Si — O -

16.17

ift.17

"CH ₃

Si —O -

O-

Si -ΟΙ CH ₃ SO ₃ H

c-3

"CH ₃

Si — Ο -
CH ₃

SO ₃ H

6, Π

CH ₃
Si-OO

CH ₃ -Si-CH ₃ "
O

6.1 TJ

CH ₃ Si-O-CH ₃ J

6.17

(1 -c) ■ 3

has a theoretical acid value of 3.36 x 10 " ³ eq acid / g substance.

Claims (10)

Patent claims: •1. Process for the production of predominantly linear, terminal sulfuric acid groups equilibrated organopolysiloxane mixtures of the general formula HO, SO— Si-O-R SO ₃ H (D (ii = 1 to 20, R = alkyl radical with 1 to 6 carbon atoms, the R radicals being replaced by the radicals - (CH ₂ ) ₃ OSO., SiR ₃ , - (CHj) ₃ OSO ₃ H, -CH ₂ Br,. - (CHJjCl, - (CHJ ₂ OR, - (CH ₂ ) j0R _r ; R _f = perfluorocyl radical; χ - integer can be substituted and where ei α part of the hydrocarbon radicals R by the remainder -O- Si — O— SO ₃ H can be replaced), which are in equilibrium with cyclic compounds of the general formula (H) (R = the above meaning, with two of the radicals R.
ι SO ₃ π I.
Si — O— R. Q Si — ΟΙ R. SO, H 45 with a remainder [R -O- Si-O- SO ₃ Γ R
Si-OR can be replaced; 1 « = 1 to 10, preferably Γ or 2) and sulfuric acid, characterized in that one a) Organopolysiloxanes with structural units of the general formula R. a ι "R R.
I. b ί
Si — 0— Si — 0— Si — 0— R. R. _R I.
Si —0— O - R.
ι R.
I. 0 - a ι 0- - R.
I. —X I. k I.
Si -
I. I.
Si -
I. S. "R -0 - I.
Si
I. I.
Si —Ο
ι I.
R. I.
_R Si I.
_U R I.
R. ι R. ; i - ο (III) (R = hydrocarbon residue, which can optionally be substituted with a residue inert towards sulfuric acid; b = O bus 20; if b - O, a - 1 to 10 ⁵ , if b S 1, α = 1 to 20) with H ₂ S ₂ O _{7 is} reacted in amounts of (based on siloxane bonds) 10 " ^s to 5 · 10"'mol at a temperature which is optionally up to 150 ° C., the siloxane preferably being added to the pyrosulfuric acid, or b) the aforementioned organopolysiloxanes are reacted with H ₂ SO ₄ in amounts of (based on siloxane bonds) 10 ~ ^y to 1 mol at, if appropriate, a moderately elevated temperature and the water of reaction formed is removed azeotropically with low-boiling inert solvents or in vacuo or by means of an inert gas stream, preferably the siloxane is added to the sulfuric acid, or c) organohalopolysiloxanes of the general formula Si-X
R. (X = halogen, preferably —Cl or —Br), optionally linking two Si atoms - O — S — O — groups _ό , Il ο may contain, with H ₂ SO ₄ in amounts (based on silyl halide) 1 to 1.1 mol, optionally at up to 150 ⁰ C elevated temperature are reacted, preferably the sulfuric acid is added to the Organohalogenpolysiloxan, and optionally after a), b) or c) the compounds obtained are reacted with dialkylcyclopolysilcxanes, if appropriate at a temperature elevated to 150.degree. 2. The method according to claim 1, characterized It means that, in process variant a), anopolysiloxanes of the formula III in which the index a = 1.5 to 5 and h = 0 are used. 3. A process according to claim 1 and 2, characterized in that ₂ O ₇ (based on siloxane used) in the process variant a) from 0.5 to 5 × 10 ^-2 mol of H ₂ S. 4. The method according to claim 1 to 3, characterized in that "indicates that the process variant a) carried out at temperatures of 10 to 70 ° C. 5. The method according to claim 1, characterized in that in process variant b), CH ₂ Cl _{2 is} used as the low-boiling solvent. 6 The method of claim 1 or 5, characterized celcennzeichnet in that the process variant b) 20 to 70 ⁰ C is carried out. 7. The method according to claim 1, characterized in that that the process variant c) is stirred through at 20 to 100.degree. 8. The method according to claim 1 or 7, characterized. ^ Indicates that one becomes free Hydrogen halide by reducing the pressure and / or passing inert gas through from the reaction mixture removed. 9. The method according to claim 1, characterized in that the compounds prepared according to process variants a), b) or c) with dimethylcyclopolysiloxanes with 3 to 10 dimethylsiloxy units implements. 10. The method of claim 1 or 9 characterized ^ • indicates that the implementation with the