Process for preparing siloxanols from metal salts of silanols

Patent metadata

Field	Value
Publication number	US-10196408-B2
Application number	US-201615545810-A
Country	US
Kind code	B2
Filing date	Nov 15, 2016
Priority date	Dec 9, 2015
Publication date	Feb 5, 2019
Grant date	Feb 5, 2019

Abstract

Siloxanes which are liquid at 25° C. and 1 bar, have 2% to 12% by weight of silanol groups and are of the formula (1):

M a D b T c Q d M′ e D′ f T′ g   (1),
are prepared by reacting metal salts of silanols of the formula (2):

R 1 Si(OH) 4−l−m (O − Z r+ /r ) m   (2)
or condensation products thereof with silanes of the formula (3):

R′ n SiX 4−n   (3)
in a ratio which is calculated by:

mol of organosiliconate of the general formula (2): mol of silane of the general formula (3)= x *(4− n )/ m,
where x=0.8 to 1.2.

First claim

The invention claimed is:

1. A process for preparing siloxanes which are liquid at 25° C. and 1 bar, have 2% to 12% by weight of silanol groups, and are of the formula (1):
M a D b T c Q d M′ e D′ f T′ g   (1),

comprising reacting metal salts of silanols of the formula (2):
R 1 Si(OH) 4−l−m (O − Z r+ 1/r ) m   (2)

or condensation products thereof, with silanes of the formula (3):
R′ n SiX 4-n   (3)

in a ratio which is calculated by the following equation:
mol of organosiliconate of the formula (2): mol of silane of the formula (3)= x *(4 −n )/ m,

where x=0.95 to 1.05,
M is a (R 3 SiO 1/2 ) unit,
D is a (R 2 SiO 2/2 ) unit,
T is a (RSiO 3/2 ) unit,
Q is a (SiO 4/2 ) unit,
M′ is a (R′ 3 SiO 1/2 ) unit,
D′ is a (R′ 2 SiO 2/2 ) unit,
T′ is a (R′SiO 3/2 ) unit,
R is an organic radical bonded to silicon via carbon,
R′ is hydrogen, an unsubstituted or substituted alkoxy radical, or a hydrocarbyl radical which is unsubstituted or substituted by halogen atoms or epoxy, thiol, nitrile, (poly)ether, carboxyalkyl, alkoxy or silyl groups and has 1 to 20 carbon atoms,
and the following relations apply:
a=0 to 0.2*(a+b+c+d+e+f+g),
b=0 to 0.2*(a+b+c+d+e+f+g),
c=0.3 to 0.9*(a+b+c+d+e+f+g),
d=0 to 0.2*(a+b+c+d+e+f+g),
e=0.05 to 0.6*(a+b+c+d+e+f+g),
f=0 to 0.6*(a+b+c+d+e+f+g),
g=0 to 0.1*(a+b+c+d+e+f+g),
and (a+b+c+d+e+f+g)=1

l has values of 0.8 to 1.3,
m is 0.3 to 0.7,
r has values of 1, 2, 3 or 4,
n has values of 1, 2 or 3,
Z is a metal cation, and
X denotes hydrolysable radicals which are selected from halogen radicals and carboxyalkyl radicals.

2. The process of claim 1 , wherein R is a hydrocarbyl radical having 1 to 8 carbon atoms.

3. The process of claim 1 , in which R′ is a hydrocarbyl radical having 1 to 8 carbon atoms.

4. The process of claim 1 , wherein Z is an alkali metal, alkaline earth metal, aluminium, zinc, or iron.

5. The process of claim 1 , wherein X is a halogen radical or a carboxyalkyl radical having 2 to 10 carbon atoms.

6. The process of claim 1 , wherein the reaction is conducted in a solvent comprising an aprotic polar or nonpolar organic solvent.

7. A siloxane which is liquid at 25° C. and 1 bar, contains from 2 to 12 weight percent of silanol groups, and has the formula (1) of claim 1 .

8. The siloxane of claim 7 , wherein R is a hydrocarbyl radical having 1 to 8 carbon atoms.

9. The siloxane of claim 7 , wherein R′ is a hydrocarbyl radical having 1 to 8 carbon atoms.

10. The siloxane of claim 7 , wherein the alkoxy content of the siloxane is not more than 0.2 percent by weight.

Assignees

• Wacker Chemie Ag

Inventors

• Stepp Michael

Classifications

• C07F7/1804

  Compounds having Si-O-C linkages (Si-O-acyl linkages C07F7/1896) · CPC title

• C08G77/06 Primary

  Preparatory processes · CPC title

• C07F7/188 Primary

  by reactions involving the formation of Si-O linkages · CPC title

• C08G77/16

  to hydroxy groups · CPC title

• C08G77/24

  halogen-containing groups · CPC title