PITUITOUS SILICONE FLUID COMPOSITION
A fluid composition comprises A) a branched organopolysiloxane and B) a carrier fluid. Component A) comprises the reaction product of a) a cyclic siloxane and b) a polyorganosiloxane, in the presence of a hydrosilylation catalyst. Component a) has at least two silicon-bonded alkenyl groups per molecule, and component b) has at least two silicon-bonded hydrogen atoms per molecule. The fluid composition has a viscosity of at least 100 mPa·s at 23° C. and exhibits pituitous rheological properties. The pituitous rheological properties are generally determined from a plot of normal force (in Pascals) vs a perpendicular shear rate in (sec −1 ). Also disclosed is a personal care composition that comprises the fluid composition. When formulated into a personal care composition, the fluid composition generally provides enhanced sensory and film-forming properties based on its pituitous rheological properties.
1 . A method of making a fluid composition comprising:
A) forming a branched organopolysiloxane by reacting
a) a cyclic siloxane having at least two silicon-bonded alkenyl groups per molecule, and
b) a polyorganosiloxane having at least two silicon-bonded hydrogen atoms per molecule,
in the presence of a hydrosilylation catalyst; and
B) causing the combination of the branched organopolysiloxane formed in (A) with a carrier fluid;
wherein the fluid composition has a viscosity of at least 100 mPa·s at 23° C. and exhibits pituitous rheological properties.
2 . The method as set forth in claim 1 , wherein the molar ratio of silicon-bonded alkenyl groups of component a) to silicon-bonded hydrogen atoms of component b), prior to reaction to form component A), is from about 0.5/1 to about 2.5/1.
3 . The method as set forth in claim 1 , wherein component a) has the formula:
[R 1 R 2 SiO] g
where each R 1 is an independently selected substituted or unsubstituted hydrocarbyl group;
each R 2 is R 1 or an alkenyl group, with the proviso that at least two R 2 groups are alkenyl groups in one molecule; and “g” is ≧3.
4 . The method as set forth in claim 3 , wherein:
i) each R 1 is an independently selected C 1 -C 6 alkyl group; or
ii) each R 2 is an independently selected C 2 -C 12 alkenyl group; or
iii) “g” is from 3-10.
5 . The method as set forth in claim 3 , wherein “g” is from 3-6.
6 . The method as set forth in claim 1 , wherein component b) comprises siloxy units of the formula:
(R 2 HSiO 1/2 ) v (R 2 SiO 2/2 ) x
where each R is independently selected substituted or unsubstituted hydrocarbyl group; “v” is ≧2; and “x” is ≧50.
7 . The method as set forth in claim 6 , wherein:
i) each R is an independently selected C 1 -C 6 alkyl group; and/or
ii) “v” is 2; or
iii) “x” is ≧100.
8 . The method as set forth in claim 1 , wherein the silicon-bonded hydrogen atoms of component b) are terminal.
9 . The method as set forth in claim 1 , wherein component A) is present in an amount of from about 0.1 to about 50 wt % based on 100 parts by weight of the fluid composition.
10 . The method as set forth in claim 1 , wherein component B) is selected from the group of silicones, organic solvents, organic oils, and combinations thereof.
11 . The method as set forth in claim 1 , wherein component B) is present in an amount of from about 50 to about 99.9 wt % based on 100 parts by weight of the fluid composition.
12 . A method of making of making a fluid composition comprising: combining
A) about 0.1 to about 50 wt % of a branched organopolysiloxane formed by reacting;
a) a cyclic siloxane having the formula
[R 1 R 2 SiO] g
where each R 1 is an independently selected C 1 -C 6 alkyl group, each R 2 is R 1 or a C 2 -C 12 alkenyl group, with the proviso that at least two R 2 groups are alkenyl groups in one molecule, and “g” is from 3-8, and
b) a polyorganosiloxane comprising siloxy units of the formula
(R 2 HSiO 1/2 ) v (R 2 SiO 2/2 ) x
where each R is an independently selected C 1 -C 6 alkyl group, “v” is ≧2, and “x” is ≧50,
in the presence of a hydrosilylation catalyst,
wherein the molar ratio of silicon-bonded alkenyl groups of component a) to silicon-bonded hydrogen atoms of component b), prior to reaction to form component A), is from about 0.5/1 to about 2.5/1; with
B) about 50 to about 99.9 wt % of a carrier fluid selected from the group of silicones, organic solvents, organic oils, and combinations thereof;
wherein the fluid composition has a viscosity of at least 100 mPa·s at 23° C. and exhibits pituitous rheological properties.
13 . The method as set forth in claim 12 , wherein:
i) each R and R 1 is a methyl group, each R 2 is a vinyl group, “g” is 4, “v” is 2, and “x” is from 150 to 10,000;
ii) the carrier fluid comprises a silicone; and
iii) the molar ratio of silicone-bonded alkenyl groups of component a) to silicon bonded-hydrogen atoms of component b), prior to reaction to form component A), is from about 0.9/1 to about 2.2/1.
14 . The method as set forth in claim 1 , wherein rheological properties of the fluid composition are determined from a plot of normal force (in Pascals) vs a perpendicular shear rate (in sec −1 ) and the plot has an average slope that is >3.6.
15 . A personal care composition comprising the fluid composition formed by the method as set forth in claim 1 .