Silicone oils and solvents thickened by silicone elastomers
AssigneeDow Corning Corporation
InventorsWilliam James Schulz, Jr., Shizhong Zhahg
Life of this patent
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Abstract
Silicone gels are made by reacting an .tbd.Si--H containing polysiloxane with an alpha, omega-diene. The reaction is conducted in the presence of a platinum catalyst and in the presence of a low molecular weight silicone oil. The reaction is continued until a gel is formed by crosslinking and addition of .tbd.Si--H across double bonds in the alpha, omega-diene. The silicone gel can then be crumbled into a silicone powder using mechanical force. When additional amounts of low molecular weight silicone oil are added to the gel, and the silicone oil and the gel are subjected to shear force, a silicone paste can be formed.
Claims18
A method of thickening solvents comprising reacting (A) an .tbd.Si--H containing polysiloxane of formula R.sub.3 SiO(R'.sub.2 SiO).sub.a (R"HSiO).sub.b SiR.sub.3 and optionally an .tbd.Si--H containing polysiloxane of formula HR.sub.2 SiO(R'.sub.2 SiO).sub.c SiR.sub.2 H or formula HR.sub.2 SiO(R'.sub.2 SiO).sub.a (R"HSiO).sub.b SiR.sub.2 H where R, R', and R" are alkyl groups of 1-6 carbon atoms;
- a is 0-250;
- b is 1-250;
- and c is 0-250;
- with (B) an alpha, omega-diene as only the unsaturated hydrocarbon of formula CH.sub.2 .dbd.CH(CH.sub.2).sub.x CH.dbd.CH.sub.2 where x is 1-20;
- conducting the reaction in the presence of a platinum catalyst and (C) a solvent selected from the group consisting of (i) organic compounds, (ii) compounds containing a silicon atom, (iii) mixtures of organic compounds, (iv) mixtures of compounds containing a silicon atom, and (v) mixtures of organic compounds and compounds containing a silicon atom;
- and continuing the reaction until a gel is formed by crosslinking and addition of .tbd.Si--H across double bonds in the alpha, omega-diene.
A method of thickening silicone oils to gel-like consistency comprising reacting (A) an .tbd.Si--H containing polysiloxane of formula R.sub.3 SiO(R'.sub.2 SiO).sub.a (R"HSiO).sub.b SiR.sub.3 and optionally an .tbd.Si--H containing polysiloxane of formula HR.sub.2 SiO(R'.sub.2 SiO).sub.c SiR.sub.2 H or formula HR.sub.2 SiO(R'.sub.2 SiO).sub.a (R"HSiO).sub.b SiR.sub.2 H where R, R', and R" are alkyl groups of 1-6 carbon atoms;
- a is 0-250;
- b is 1-250;
- and c is 0-250;
- with (B) an alpha, omega-diene as the only unsaturated hydrocarbon of formula CH.sub.2 .dbd.CH(CH.sub.2).sub.x CH.dbd.CH.sub.2 where x is 1-20;
- conducting the reaction in the presence of a platinum catalyst and (C) a silicone oil of formula R.sup.1.sub.3 SiO(R.sup.1.sub.2 SiO).sub.y SiR.sup.1.sub.3 or (R.sup.1.sub.2 SiO).sub.z where R.sup.1 is an alkyl group of 1-20 carbon atoms or an aryl radical, y is 0-375, and z is 3-9;
- and continuing the reaction until a gel is formed by crosslinking and addition of .tbd.Si--H across double bonds in the alpha, omega-diene.
Dependencies are inferred from the claim text.