Organosilicon compounds and method of making

Novel organosilicon compounds having a perfluoroalkyl or perfluoropolyether group and at least one ethynyl group are useful as an agent for controlling hydrosilylation reaction between a --SiH group-bearing compound and a --CH.dbd.CH.sub.2 group-bearing compound.

This invention relates to novel organosilicon compounds and more 
particularly, to fluorinated organosilicon compounds having at least one 
ethynyl group and useful as an agent for controlling hydrosilylation 
reaction. It also relates to a method for preparing the organosilicon 
compounds. 
BACKGROUND OF THE INVENTION 
Silicone rubber compositions of the addition curing type undergo 
crosslinking through hydrosilylation reaction represented by the following 
scheme as elementary reaction, converting into elastomers. 
##STR1## 
To control this reaction in order to insure a pot life or shelf life, a 
typical prior art practice uses ethynyl group-bearing compounds as shown 
below. 
##STR2## 
These compounds, however, are incompatible with fluorosilicones and 
perfluoropolymers having high fluorine contents and can introduce 
separation or non-uniformity into the reaction system. 
SUMMARY OF THE INVENTION 
An object of the invention is to provide a novel and improved organosilicon 
compound which is useful as an agent for controlling a hydrosilylation 
reaction between a --SiH group-bearing compound and a --CH.dbd.CH.sub.2 
group-bearing compound. More particularly, an object is to provide a novel 
and improved organosilicon compound which is fully compatible with 
fluorosilicones and perfluoropolymers having high fluorine contents so 
that it does not separate out therefrom and is effective for controlling 
an addition reaction. 
Another object of the invention is to provide a method for preparing the 
organosilicon compound. 
In one aspect, the invention provides a fluorinated organosilicon compound 
of formula (1) which is novel. In another aspect, the invention provides a 
method for preparing a fluorinated organosilicon compound of formula (1) 
by reacting a fluorinated chlorosilane of formula (2) with an ethynyl 
group-bearing alcohol of formula (3) as shown by the following reaction 
scheme. The fluorinated organosilicon compound of formula (1) is useful as 
an agent for controlling a hydrosilylation reaction. 
##STR3## 
In the formulae, Rf is a monovalent perfluoroalkyl or perfluoropolyether 
group, R.sup.1 is a divalent organic group, R.sup.2 is a monovalent 
hydrocarbon group, R.sup.3 is a divalent hydrocarbon group, and a is equal 
to 0, 1 or 2.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
According to the invention, there are provided novel organosilicon 
compounds of the following general formula (1). 
##STR4## 
In formula (1), Rf is a monovalent perfluoroalkyl or perfluoropolyether 
group, which is exemplified by the following. 
##STR5## 
In the formulae, m is an integer of 1 to 15 and especially 3 to 10, and n 
is an integer of 1 to 8 and especially 1 to 5. 
R.sup.1 is a divalent organic group. Lower alkylene groups of 1 to 6 carbon 
atoms are preferred although R.sup.1 is not limited thereto. The lower 
alkylene group of 1 to 6 carbon atoms may be separated by or terminated 
with an oxygen atom, nitrogen atom or carbonyl group. Exemplary alkylene 
groups are shown below. 
EQU --(CH.sub.2).sub.p -- 
EQU --(CH.sub.2).sub.q --O--CH.sub.2 -- 
##STR6## 
Herein, p is an integer of 1 to 6 and especially 2 to 4, and q is an 
integer of 0 to 5 and especially 2 to 4. 
R.sup.2 is a monovalent hydrocarbon group. Illustrative, non-limiting 
examples of the monovalent hydrocarbon group include lower alkyl groups of 
1 to 6 carbon atoms such as methyl, ethyl, propyl, butyl, pentyl and 
hexyl, cycloalkyl groups such as cyclohexyl, aryl groups such as phenyl, 
and aralkyl groups such as benzyl. 
R.sup.3 is a divalent hydrocarbon group. Preferred, non-limiting examples 
of the group represented by R.sup.3 are given below. 
##STR7## 
Herein, R.sup.4 and R.sup.5 are independently monovalent hydrocarbon 
groups, for example, alkyl groups of 1 to 10 carbon atoms, such as methyl, 
ethyl, propyl, butyl, isobutyl, hexyl, octyl and decyl. 
The letter a is equal to 0, 1 or 2, indicating that the compound has at 
least one ethynyl group in one molecule. 
The organosilicon compound of formula (1) can be synthesized, for example, 
by reacting a fluorinated chlorosilane with an ethynyl group-bearing 
alcohol in the presence of an acid acceptor such as urea. 
The fluorinated chlorosilane serving as one reactant is preferably of the 
following general formula (2): 
##STR8## 
wherein Rf, R.sup.1, R.sup.2 and a are as defined above. Illustrative 
examples of the fluorinated chlorosilane are given below. 
##STR9## 
The ethynyl group-bearing alcohol serving as another reactant is preferably 
of the following general formula (3): 
EQU HO--R.sup.3 --C.tbd.CH (3) 
wherein R.sup.3 is as defined above. Illustrative examples of the alcohol 
are given below. 
##STR10## 
In the above reaction, the silane of formula (2) and the alcohol of formula 
(3) are preferably used in such amounts that 1 to 2 mol of the alcohol of 
formula (3) is available per mol of the chlorine atom in the silane of 
formula (2). The amount of the acid acceptor used is preferably 1 to 2 mol 
per mol of the chlorine atom in the silane of formula (2). A solventless 
system is preferred for convenience of progress to the subsequent step. 
Preferably reaction is effected in an inert gas atmosphere such as 
nitrogen and at a temperature from room temperature (20.degree. C.) to 
100.degree. C. The reaction time is usually about 4 to about 24 hours. 
The organosilicon compounds of the invention are used as an agent for 
controlling hydrosilylation reaction. Particularly for hydrosilylation 
reaction between an alkenyl group-bearing compound and an SiH 
group-bearing compound in the presence of a platinum group catalyst 
wherein either one or both of the alkenyl group-bearing compound and the 
SiH group-bearing compound contain fluorine atoms, the improved 
organosilicon compound is compatible with the relevant compounds and 
becomes an effective agent for controlling hydrosilylation reaction. 
EXAMPLE 
Examples of the invention are given below by way of illustration and not by 
way of limitation. 
Example 1 
A 100-ml, three-necked flask equipped with a stirrer, condenser, and 
thermometer was charged with 19.5 g (0.23 mol) of an ethynyl group-bearing 
compound of the following formula (4) and 19.5 g (0.21 mol) of urea, which 
were stirred. The flask was purged with nitrogen and heated to an internal 
temperature of 50.degree. C. To the flask, 50.0 g (0.089 mol) of a 
fluorinated dichlorosilane of the following formula (5) was added dropwise 
from a dropping funnel. 
##STR11## 
With the flask kept at an internal temperature of 60.degree. C., the 
contents were stirred for 16 hours. The reaction solution was cooled, 
following which the lower layer was taken out. A similar flask was charged 
with the separated product, to which 0.3 g of propylene oxide was added 
for neutralization. The contents were stirred for one hour at 40.degree. 
C. 
The stirring step was followed by stripping at a bath temperature of 
100.degree. C. and a vacuum of 1 mmHg. After cooling, filtration under 
pressure was effected in order to remove the salt. The filtrate was 
distilled in vacuum, collecting 34.4 g of the compound shown below (yield 
59%, b.p. 115.degree. C./1 mmHg). 
##STR12## 
To confirm the molecular structure of the fraction, GC-MS analysis and IR 
spectroscopy were carried out, with the following results. 
GCMS: M.sup.+ =656 
IR spectrum: FIG. 1 
.nu..sub..tbd.CH : 3320 cm.sup.-1, 640 cm.sup.-1 
.nu..sub.C.tbd.CH : 2100 cm.sup.-1 
Example 2 
A flask as used in Example 1 was charged with 4.4 g (0.052 mol) of the 
ethynyl group-bearing compound used in Example 1 and 3.0 g (0.049 mol) of 
urea. The flask was purged with nitrogen and heated to an internal 
temperature of 50.degree. C. To the flask, 17.8 g (0.0395 mol) of a 
fluorinated chlorosilane of the following formula (6) was added dropwise 
from a dropping funnel. 
##STR13## 
After 7 hours of reaction, the reaction solution was cooled, following 
which the lower layer was taken out. As in Example 1, 0.04 g of propylene 
oxide was added to the separated product for neutralization. 
Post-treatment as in Example 1 was followed by vacuum distillation to 
collect 8.4 g of the compound shown below (yield 42%, b.p. 90.degree. C./3 
mmHg). 
##STR14## 
To confirm the molecular structure of the fraction, GC-MS analysis and IR 
spectroscopy were carried out, with the following results. 
GCMS: M.sup.+ =498 
IR spectrum: FIG. 2 
.nu..sub..tbd.CH : 3320 cm.sup.-1, 640 cm.sup.-1 
.nu..sub.C.tbd.CH : 2100 cm.sup.-1 
The novel and improved organosilicon compound is useful as an agent for 
controlling hydrosilylation reaction between a --SiH group-bearing 
compound and a --CH.dbd.CH.sub.2 group-bearing compound. Since the 
organosilicon compound is fully compatible with fluorosilicones and 
perfluoropolymers having high fluorine contents, it does not separate out 
therefrom and is highly effective for controlling addition reaction. 
Japanese Patent Application No. 10-232252 is incorporated herein by 
reference. 
The invention has been described in detail with particular reference to 
preferred embodiments thereof, but it will be understood that variations 
and modifications can be effected within the spirit and scope of the 
invention.