# US 2022/0033587 A1 · Reactive siloxanes

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- Number: US 2022/0033587 A1
- Document ID: US20220033587A1
- Status: Published application
- Kind: A1
- Application number: 17/297,372
- Filed: 2019-11-19
- Published: 2022-02-03
- Earliest claimed: 2018-12-04
- Assignees: Evonik Operations GmbH
- Applicants: Evonik Operations GmbH
- Inventors: Wilfried Knott; Horst Dudzik; Philippe Favresse; Michael Fiedel; André Brötzmann
- Web page: https://patentgrep.com/patent/US20220033587A1

## CPC

- C08G 77/38: Polysiloxanes modified by chemical after-treatment
- C08G 77/14: containing silicon bound to oxygen-containing groups
- C08G 77/18: to alkoxy or aryloxy groups
- C08G: MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS

## Abstract

The invention describes (i) reaction systems for the production of siloxanes bearing acetoxy functions, comprising a) silanes and/or siloxanes bearing alkoxy groups and/or b) silanes and/or siloxanes bearing acetoxy groups, c) silanes and/or siloxanes bearing hydroxy groups, d) optionally simple siloxane cycles and/or DT cycles, e) a reaction medium, comprising acetic anhydride, perfluoroalkanesulfonic acid and preferably acetic acid, (ii) a process for producing linear or branched siloxanes bearing acetoxy functions and also the use of same for producing polyethersiloxanes.

## Claims

### Claim 1

A reaction system for the production of siloxanes bearing acetoxy functions, comprising
a) silanes and/or siloxanes bearing alkoxy groups and/or
b) silanes and/or siloxanes bearing acetoxy groups, and/or
c) silanes and/or siloxanes bearing hydroxy groups,
d) optionally simple siloxane cycles and/or DT cycles,
e) a reaction medium, comprising acetic anhydride, perfluoroalkanesulfonic acid.

### Claim 2 (depends on 1)

The reaction system according to claim 1 for the production of branched siloxanes bearing terminal acetoxy functions, wherein a silane and/or siloxane bearing alkoxy groups and containing at least one T and/or Q group, and/or a silane/siloxane bearing acetoxy groups and containing at least one T and/or Q group,
and/or DT cycles.

### Claim 3 (depends on 1)

The reaction system according to claim 1, wherein no silanes and/or siloxanes bearing hydroxy groups are used.

### Claim 4 (depends on 1)

The reaction system according to claim 1, wherein alkoxysilanes are used.

### Claim 5 (depends on 1)

The reaction system according to claim 1, wherein linear and/or branched alkoxysiloxanes are used,

### Claim 6 (depends on 5)

The reaction system according to claim 5, wherein the alkoxysiloxanes used result from acidic equilibration of dimethyldialkoxysilanes or methyltrialkoxysilanes with simple siloxane cycles.

### Claim 7 (depends on 1)

The reaction system according to claim 1, wherein simple siloxane cycles comprise D3 (hexamethylcyclotrisiloxane), D4 (octamethylcyclotetrasiloxane), D5 (decamethylcyclopentasiloxane) and/or D6 (dodecamethylcyclohexasiloxane).

### Claim 8 (depends on 1)

The reaction system according to claim 1, wherein hydroxy-functional silanes and/or hydroxy-functional siloxanes are used

### Claim 9 (depends on 1)

The reaction system according to claim 1, wherein
cyclic branched siloxanes of the DT type (DT cycles) are used,
i) mixtures of cyclic branched siloxanes of the D/T type which consist exclusively of siloxanes having D and T units and whose cumulative proportion of D and T units present in the siloxane matrix and having Si-alkoxy and/or SiOH groups, determinable by 29Si NMR spectroscopy, is ≤2 mole percent and which contain at least 5 percent by weight of siloxane cycles, such as prefer-aby-octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5) and/or mixtures of these or else
ii) mixtures of cyclic branched siloxanes having exclusively D and T units whose cumulative proportion of D and T units present in the siloxane matrix and having Si-alkoxy and/or SiOH groups, determinable by 29Si NMR spectroscopy, is greater than 2 and less than 10 mole percent.

### Claim 10

A process for producing linear or branched siloxanes bearing acetoxy functions, wherein
a) silanes and/or siloxanes bearing alkoxy groups, and/or
b) silanes and/or siloxanes bearing acetoxy groups, and/or
c) silanes and/or siloxanes bearing hydroxy groups,
d) optionally simple siloxane cycles and/or DT cycles,
are reacted with acetic anhydride, perfluoroalkanesulfonic acid.

### Claim 11 (depends on 10)

The process according to claim 10 for producing branched siloxanes bearing terminal acetoxy functions, wherein the component a) used is a branched silicone equilibrate bearing terminal alkoxy groups.

### Claim 12 (depends on 10)

The process according to claim 10 for producing branched siloxanes bearing terminal acetoxy functions, wherein all components a) and/or b) and also optionally c) and possibly d) are initially charged and reacted together with acetic anhydride, perfluoroalkanesulfonic acid (especially trifluoromethanesulfonic acid).

### Claim 13 (depends on 10)

The process according to claim 10 for producing α,ω-diacetoxypolydimethylsiloxanes, wherein component c) is reacted, alone and/or optionally together with simple siloxane cycles, with acetic anhydride, perfluoroalkanesulfonic acid (especially trifluoromethanesulfonic acid).

### Claim 14 (depends on 10)

The process according to claim 10, wherein it is conducted using a reaction system comprising
a) silanes and/or siloxanes bearing alkoxy groups and/or
b) silanes and/or siloxanes bearing acetoxy groups, and/or
c) silanes and/or siloxanes bearing hydroxy groups,
d) optionally simple siloxane cycles and/or DT cycles,
e) a reaction medium, comprising acetic anhydride and preferably acetic acid.

### Claim 15 (depends on 10)

The trifluoromethanesulfonic acid-acidified, end-equilibrated linear siloxanes bearing α,ω-acetoxy groups and having total cycles contents, defined as the sum total of the content fractions of the cyclic siloxanes comprising D4, D5 and D6, based on the siloxane matrix and determined by gas chromatography after their derivatization to give the corresponding linear α,ω-isopropoxysiloxanes, of less than 13, preferably less than 12 percent by weight, produced by a process according to claim 10.

### Claim 16 (depends on 10)

The trifluoromethanesulfonic acid-acidified, end-equilibrated branched siloxanes bearing acetoxy groups, preferably produced by a process according to claim 10, wherein they have total cycles contents, defined as the sum total of the content fractions of the cyclic siloxanes comprising D4, D5 and D6, based on the siloxane matrix and determined by gas chromatography after their derivatization to give the corresponding branched isopropoxysiloxanes, of less than 8 percent by weight.

### Claim 17 (depends on 1)

A product comprising the siloxanes bearing acetoxy groups, produced using a reaction system as defined in claim 1 wherein the product comprises polyurethane foam stabilizers, defoamers, paint and dispersing additives and/or demulsifiers.

### Claim 18 (depends on 1)

The reaction system according claim 1, wherein alkoxysilanes are selected from dimethyldialkoxysilanes, methyltrialkoxysilanes and/or alkyl orthosilicates Si(OR)4, where R=alkyl radical, branched alkyl radical or cycloalkyl radical, having 1 to 10.

### Claim 19 (depends on 1)

The reaction system according claim 1, wherein alkoxysilanes are selected from dimethyldialkoxysilanes, methyltrialkoxysilanes and/or alkyl orthosilicates Si(OR)4, where R==ethyl-.

### Claim 20 (depends on 1)

The reaction system according to claim 1, wherein the reaction system comprises linear and/or branched alkoxysiloxanes and have the formula:
where m=1 to 300,
or
CH3SiDaDbDc(OR)3
or
SiDaDbDcDd(OR)4
where a, b, c and d are each independently 1 to 100 and
R=alkyl radical, branched alkyl radical, cycloalkyl radical having 1 to 10.