Alkoxysilyl functional silicone based materials

Details Alkoxysilyl functional silicone based materials Alkoxysilyl functional silicone based materials

2002-01-30

2004-04-06

Robertson, Jeffrey B. (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...

C524S267000, C524S268000, C524S861000, C524S862000, C524S863000, C524S866000, C424S401000, C424S070120

Reexamination Certificate

active

06716908

ABSTRACT:

FIELD OF THE INVENTION
This invention relates to alkoxysilyl functional silicone based materials, methods of making them and their uses. More particularly, the invention relates to thermodynamically stable materials comprising cross-linked siloxanes having alkoxysilyl functionality and a diluent, as well as to methods of making and the uses of such materials. The methods comprise cross-linking of reactants dispersed in a diluent.
BACKGROUND OF THE INVENTION
Thermodynamically stable silicone based materials comprising cross-linked siloxanes dispersed in a diluent are known in the art. One such material, made by polymerization of certain organohydrogenpolysiloxanes along with organopolysiloxanes having aliphatic unsaturated groups while in the presence of certain low viscosity silicones, is disclosed in U.S. Pat. No. 4,987,169 to Kuwata et al. Another such material is disclosed in U.S. Pat. No. 5,760,116 to Kilgour et al. In this last instance, certain alkenyl stopped polyorganosiloxanes are hydrosilylated with ≡SiH containing “MQ” silicone resins in the presence of certain other silicones.
There are of course many variations possible in these materials and the synthesis of such materials. For example, the ≡SiH groups and the aliphatic unsaturation may be on either or even both hydrosilylation reactants, as may other functionality. Sometimes, this allows for the synthesis of the same or a very similar type material using very different reactants in the same type of reaction. For example, what could be called a variant of Kilgour is seen in EP 1 057 476 by Fry, wherein the unsaturation appears in the resin and the ≡SiH functionality appears in the other hydrosilylation reactant.
As with many other silicone based materials, it is has been found that inclusion of certain functional groups in the thermodynamically stable types discussed here can impart or enhance desirable properties. One example, where the polyether functionality is used, can be seen in U.S. Pat. No. 5,811,487 to Schulz et al. Here, the polyether functionality was introduced by hydrosilylation prior to cross-linking. It may also be of note that the cross linker may be purely hydrocarbon as was the case in this last mentioned material.
There is a continual need for new functionalized silicone based materials. New alkoxysilyl functional silicone based materials would be of great interest as they often have superior durability and/or enhance durability in formulations containing them.
Certain alkoxysilyl functional silicones and their formulations are well known in the art, notably as caulks, sealants and pressure sensitive adhesives. Such materials and methods for making them are exemplified by those disclosed in U.S. Pat. No. 5,470,923 to Krahnke et al. and U.S. Pat. No. 5,457,148 to Lucas. These prior art materials are not, however, thermodynamically stable (at least as defined herein below) and are usually much too effective in enhancing durability to be suitable for many applications in the personal care industry. In addition, use of these materials does not typically result in desirable aesthetics in many of the applications for which compositions of the present invention are designed.
The present invention provides thermodynamically stable, alkoxysilyl functional silicone based materials capable of suitably enhancing durability of personal care products while providing desirable aesthetics.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide novel, thermodynamically stable, alkoxysilyl functional silicone based materials. In this regard, the invention relates to thermodynamically stable materials comprising:
(A) a cross-linked siloxane comprising:
alkoxysilyl functionality, —X—SiR
4
n
(OR
5
)
3-n
, and
cross-links, —E
1
—Y—E
2
—, with each end of such cross-links bonded to a silicon,
wherein,
X is a divalent group that is a hydrocarbon, a siloxane or some combination of these,
R
4
and R
5
are independently monovalent hydrocarbon groups,
E
1
and E
2
are independently —CH
2
CH
2
— or —CH═CH—,
Y is a divalent group that is a hydrocarbon, a siloxane or some combination of these, and
n is 0 to 2;
and
(B) a diluent.
It is a further object of this invention to provide methods of making thermodynamically stable, alkoxysilyl functional silicone based materials. Thus, the invention further relates to a method of making a thermodynamically stable material, the method comprising cross-linking, in the presence of a hydrosilylation catalyst,
(1) an ≡SiH functional siloxane,
(2) an alpha, omega diene, diyne or ene-yne (as defined later herein),
with the provisos
that at least one of (1) and (2) has alkoxysilyl functionality, —X—SiR
4
n
(OR
5
)
3-n
,
where,
X is a divalent group that is a hydrocarbon, a siloxane or some combination of these,
R
4
and R
5
are independently monovalent hydrocarbon groups and
n is 0 to 2,
that (1) and (2) are dispersed in a diluent, and
that the weight ratio of (1)+(2)+ the product of the cross-linking of (1) and (2):diluent is 1:100 to 10:1.
The invention also relates to materials preparable, as well as those prepared by, the methods according to the present invention. In addition, the invention relates to personal care products containing the compositions of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The compositions of the present invention include thermodynamically stable materials comprising:
(A) a cross-linked siloxane comprising:
alkoxysilyl functionality, —X—SiR
4
n
(OR
5
)
3-n
, and
cross-links, —E
1
—Y—E
2
—, with each end of such cross-links (meaning at E
1
and E
2
on the side opposite from Y as shown here) bonded to a silicon,
wherein,
X is a divalent group that is a hydrocarbon (especially one having 2 to 12 carbons), a siloxane or some combination of these,
R
4
and R
5
are independently monovalent hydrocarbon groups (especially those having 1 to 30 carbons),
E
1
and E
2
are independently —CH
2
CH
2
— or —CH═CH—,
Y is a divalent group that is a hydrocarbon (especially one having 1 to 30 carbons), a siloxane or some combination of these and
is 0 to 2;
and
(B) a diluent.
(These compositions will be denoted hereinafter for convenience as those “explicitly defined”.)
In the context of this disclosure and the claims that follow, thermodynamically stable refers to a material comprising a cross-linked polymer and a diluent that is homogeneous immediately after shearing and remains as such for at least 72 hours after being sheared, where homogeneous refers to something with a constant bulk viscosity (the type measured in units of cP, mPa s or equivalent units such as in a Brookfield device and sometimes referred to as absolute viscosity as opposed to kinematic viscosity) throughout a given sample within +/−10 percent.
One method for determining such thermodynamic stability is the Dow Corning Corporation Thermodynamic Stability test (hereinafter, the “DCCTS test”), wherein a sample of material is first sheared then visually inspected for homogeneity. If the sheared material is found to be visually homogenous, then viscosity is measured using a statistically significant number of random samples of the sheared material taken immediately after the visual inspection and again 72 hours later. The material is considered thermodynamically stable if all viscosity measurements (for accuracy's sake, these are taken as, respectively, the mean of several measurements at the same point) from the initial sampling and the sampling 72 hours later are within +/−10 percent of their respective means.
Alkoxysilyl functionality is normally associated with the backbone portion of the cross-linked siloxane, but it may occur in the cross links or even in both the backbone and cross links at the same time and this disclosure and claims that follow should be interpreted to include these variations whenever possible, unless otherwise indicated. Of course in polymers made from similarly sized backbone components and cross linkers, it can be a little difficult to determine which is which in the fin

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