Process for preparing polyalkylene ether-modified polysiloxanes and use thereof

Patent metadata

Field	Value
Publication number	US-10752736-B2
Application number	US-201615768590-A
Country	US
Kind code	B2
Filing date	Nov 2, 2016
Priority date	Nov 5, 2015
Publication date	Aug 25, 2020
Grant date	Aug 25, 2020

Abstract

The invention relates to a process for preparing oligo- or polyalkylene ether-modified polysiloxanes by transesterification of alkoxy-functionalized polysiloxanes with OH-terminated oligo- or polyalkylene ethers in the presence of an alkanesulfonic acid as catalyst. Oligo- or polyalkylene ether-modified polydimethylsiloxanes obtainable through this process are suitable as defoamers, as wetting agents, and as additives in coating material formulations.

First claim

The invention claimed is:

1. A process for preparing polysiloxanes having at least one oligo- or polyalkylene ether group, comprising:
reacting a polysiloxane having at least one C 1 -C 6 alkoxy group bonded to a silicon atom of the polysiloxane with an OH-terminated oligo- or polyalkylene ether in the presence of a catalyst, the catalyst being an alkanesulfonic acid.

2. The process as claimed in claim 1 , wherein the OH-terminated oligo- or polyalkylene ether has the following formula (3a):
R—[O-A] k -OH  (3a)

in which
A is C 2 -C 4 alkane-1,2-diyl,
k is a number in a range from 2 to 100, and
R is a monovalent hydrocarbon radical having 1 to 20 C atoms.

3. The process as claimed in claim 1 , wherein the OH-terminated oligo- or polyalkylene ether and the polysiloxane are reacted in a proportion such that a molar ratio of OH groups in the oligo- or polyalkylene ether to the C 1 -C 6 alkoxy groups in the polysiloxane is in a range from 0.8 : 1 to 2 : 1.

4. The process as claimed in claim 1 , wherein the reaction is carried out in an aprotic organic solvent, the aprotic organic solvent being selected from aromatic hydrocarbons.

5. The process as claimed in claim 1 , wherein the reaction is carried out without an addition of a solvent, in bulk.

6. The process as claimed in claim 1 , wherein the alkanesulfonic acid is used in an amount of 0.05 to 1 wt%, based on a total weight of the reaction mixture.

7. The process as claimed in claim 1 , wherein the alkanesulfonic acid is C 1 -C 6 alkanesulfonic acid.

8. The process as claimed in claim 7 , wherein the alkanesulfonic acid is methanesulfonic acid.

9. The process as claimed in claim 1 , wherein a C 1 -C 6 alkanol which forms during the reaction is at least partly removed during the reaction by distillation from the reaction mixture.

10. The process as claimed in claim 1 , wherein the polysiloxane comprises at least one of the following features:
the polysiloxane has on average 5 to 30 silicon atoms,
the polysiloxane has 1 to 6 C 1 -C 6 alkoxy groups bonded to in each case one silicon atom of the polysiloxane,
the polysiloxane is a linear polysiloxane which carries a C 1 -C 6 alkoxy group on each of the two terminal silicon atoms,
the polysiloxane is a polydimethylsiloxane,
the at least one C 1 -C 6 alkoxy group bonded to a silicon atom of the polysiloxane is selected from methoxy and ethoxy.

11. The process as claimed in claim 1 , wherein the polysiloxane is produced by reacting a linear or cyclic polysiloxane having 2 to 6 silicon atoms with a C 1 -C 6 alkoxysilane of the formula (R 9 O) m R 10 4-m Si in which R 9 is C 1 -C 6 alkyl, R 10 is C 1 - C 6 alkyl, C 3 -C 6 cycloalkyl, phenyl, C 2 -C 6 alkenyl, or C 2 -C 6 alkynyl, and m is 1, 2, 3, or 4.

12. The process as claimed in claim 11 , wherein R 9 is methyl or ethyl and R 10 is methyl.

Assignees

• Basf Se

Inventors

• Engelbrecht Lothar
• Peter Wolfgang
• Gernandt Andreas
• Auschra Clemens
• Knischka Ralf
• Kranwetvogel Reiner

Classifications

• C08G77/14

  containing silicon bound to oxygen-containing groups · CPC title

• C08G77/18 Primary

  to alkoxy or aryloxy groups · CPC title

• C09D183/04

  Polysiloxanes · CPC title

• C08G77/38

  Polysiloxanes modified by chemical after-treatment · CPC title

• C08G77/08

  characterised by the catalysts used · CPC title