Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – At least one aryl ring which is part of a fused or bridged...
Reexamination Certificate
1998-12-15
2001-07-17
Moore, Margaret G. (Department: 1712)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
At least one aryl ring which is part of a fused or bridged...
C524S862000, C524S837000, C528S015000, C528S025000, C424S401000, C424S065000
Reexamination Certificate
active
06262170
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to silicone polymers, more specifically to alkyl substituted silicone elastomers.
BACKGROUND OF THE INVENTION
Silicone compositions comprising a silicone fluid and a cross-linked silicone elastomer are known, see for example, U.S. Pat. No. 4,987,169, coassigned U.S. Pat. Nos. 5,760,116; 4,987,169. Neither U.S. '169 patent nor the U.S. '116 patent disclose dispersions of the silicone elastomer in fluids other than silicone fluids.
WO 98/18849 discloses fatty alcohol or aliphatic glycol-grafted silicone gels having enhanced oil compatibility. The grafted substituents are attached to the silicone gel via Si—O—C bonds, which are readily susceptible to hydrolysis in the presence of moisture.
What is needed in a hydrolytically stable silicone elastomer that is compatible with media, such as hydrocarbons, other than silicone fluids.
SUMMARY OF THE INVENTION
In a first aspect, the present invention is directed to a cross-linked alkyl substituted silicone elastomer, comprising the cross-linked hydrosilylation reaction product of:
(i) an alkenyl functional silicone compound;
(ii) a silylhydride functional silicone compound; and
(iii) one or more &agr;,&bgr;-ethylenically unsaturated alkenes.
The silicone elastomer is hydrolytically stable, in that the alkyl substituents are attached to the elastomer via Si—C bonds having good hydrolytic stability and can be easily and economically prepared in a single step. As used herein, the terminology “hydrolytically stable” means a tendency not to undergo changes in structure, such as, for example, cleavage of bonds, as a result of exposure to moisture.
In a second aspect, the present invention is directed to a method for making a cross-linked alkyl substituted silicone elastomer, comprising forming the hydrosilylation reaction product of:
(i) an alkenyl functional silicone compound;
(ii) a silylhydride functional silicone compound; and
(iii) one or more &agr;,&bgr;-ethylenically unsaturated alkenes.
In a third aspect, the present invention is directed to a silicone composition, comprising a liquid medium, said liquid medium comprising an organic liquid, a silicone fluid or a mixture thereof; and a silicone elastomer of the present invention dispersed in the liquid medium. The elastomer of the present invention exhibits improved compatibility with organic liquids. As used herein, the “compatibility” of an elastomer with a liquid refers to the ability to form a stable dispersion of the elastomer in organic liquid.
In a fourth aspect, the present invention is directed to an emulsion comprising an emulsion of a first liquid phase and a second liquid phase and a silicone elastomer of the present invention dispersed in the emulsion.
In a fifth aspect, the present invention is directed to a personal care composition comprising a silicone elastomer of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Silicone Elastomer
In preferred embodiment, the cross-linked alkyl substituted silicone elastomer of the present invention comprises the cross-linked hydrosilylation reaction product of, based on 100 parts by weight (“pbw”) of the combined alkenyl functional silicone compound, silylhydride functional silicone compound and &agr;,&bgr;-ethylenically unsaturated alkenes, from 10 pbw to 99.9 pbw, more preferably from 40 pbw to 99.5 pbw, even more preferably from 65 pbw to 95 pbw of the combined alkenyl functional silicone compound and silylhydride functional silicone compound and from greater than 0.1 pbw to 90 pbw, more preferably from 0.5 pbw to 60 pbw, even more preferably from 5 pbw to 35 pbw of the one or more &agr;,&bgr;-ethylenically unsaturated alkenes.
In a preferred embodiment, the alkyl substituted silicone elastomer of the present invention forms a cross-linked three dimensional network that does not dissolve in, but is capable of being swollen by a suitable liquid medium, such as for example, a low molecular weight silicone or an organic liquid. The amount of crosslinking present in the cross-linked silicone elastomer network may be characterized with respect to the degree of swelling exhibited by the network in the liquid medium. In a preferred embodiment, the cross-linked structure of the silicone elastomer is effective to allow the network to be swollen by a low molecular weight silicone fluid, as defined more fully below, from its original volume to a swollen volume that is a factor of from 1.01 to 5000, more preferably from 2 to 1000, and even more preferably from 5 to 500, times its original volume.
The cross-linked alkyl substituted silicone elastomer of the present invention may be formed by each of several alternative methods.
In a first embodiment, the silylhydride functional silicone compound and one or more &agr;,&bgr;-ethylenically unsaturated alkenes are contacted under hydrosilylation conditions to form an alkyl substituted silylhydride functional silicone compound and the alkyl substituted silylhydride functional silicone compound is subsequently contacted under hydrosilylation conditions with the alkenyl functional silicone compound to form the a cross-linked alkyl substituted silicone elastomer of the present invention.
In a second, and preferred, embodiment, the alkenyl functional silicone compound, and silylhydride functional silicone compound and the one or more &agr;,&bgr;-ethylenically unsaturated alkenes are contacted under hydrosilylation conditions to form the a cross-linked alkyl substituted silicone elastomer of the present invention.
In a third embodiment, the alkenyl functional silicone compound, and silylhydride functional silicone compound are contacted under hydrosilylation conditions to form a silicone elastomer gel and the gel is subsequently contacted under hydrosilylation conditions with the one or more &agr;,&bgr;-ethylenically unsaturated alkenes to form the a cross-linked alkyl substituted silicone elastomer of the present invention.
In a preferred embodiment the alkenyl functional silicone compound comprises one or more compounds of the formula (I):
M
a
M
vi
b
D
c
D
vi
d
T
e
T
vi
f
Q
g
(I)
wherein:
M is R
1
R
2
R
3
SiO
1/2
;
M
vi
is R
4
R
5
R
6
SiO
1/2
;
D is R
7
R
8
SiO
2/2
;
D
vi
is R
9
R
10
SiO
2/2
;
T is R
11
SiO
3/2
;
T
vi
is R
12
SiO
3/2
; and
Q is SiO
4/2
;
R
1
, R
2
, R
3
, R
7
, R
8
and R
11
are each independently alkyl, preferably (C
1
-C
60
)alkyl, aryl or aralkyl;
R
4
, R
9
and R
12
are each independently monovalent terminally unsaturated hydrocarbon radicals;
R
5
, R
6
and R
10
are each independently monovalent terminally unsaturated hydrocarbon radicals, alkyl, aryl or aralkyl, preferably (C
1
-C
60
)alkyl, aryl or aralkyl, more preferably (C
1
-C
60
)alkyl;
a, b, c, d, e, f and g are each integers wherein: a, b, e, f, and g are each greater than or equal to 0 and less than or equal to 50, 0≦c≦2000, 0≦d≦200, and provided that: (a+b)≦(2+3e+3f+4g) and 1.5≦(b+d+f)≦200.
In a highly preferred embodiment, R
4
is a monovalent terminally unsaturated (C
2
-C
6
)hydrocarbon radical; R
5
, R
6
,R
7
and R
8
are each independently (C
1
-C
6
)alkyl; R
5
, R
6
,R
7
and R
8
are each independently (C
1
-C
6
)alkyl; b is 2; 100≦c≦2000; and a, d, e, f and g are each 0.
In a preferred embodiment, the silylhydride functional silicone compound comprises one or more compounds of the formula (II):
M
h
M
H
i
D
j
D
H
k
T
l
T
H
m
Q
n
(II);
M, D, T and Q are each defined as above
M
H
is R
13
R
14
R
15
SiO
1/2
;
D
H
is R
16
R
17
SiO
2/2
;
T
H
is R
18
SiO
3/2
;
R
1
, R
2
, R
3
,R
7
, R
8
and R
11
are each independently alkyl, aryl or aralkyl;
R
13
, R
16
and R
18
are each independently H;
R
14
, R
15
and R
17
are each independently H, alkyl, aryl or aralkyl, preferably (C
1
-C
60
)alkyl, aryl or aralkyl, more preferably (C
1
-C
60
)alkyl; and
h, i, j, k, l, m, and n are each integers wherein:
h, i, l, m and n are each greater than or equal to 0 and less than or equal to 50, 0≦j≦2000, 0≦k≦200, and provided that: (h+i)≦(2+3l&pl
Kilgour John A.
Kuo An-Li
General Electric Company
Moore Margaret G.
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