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US 5,670,596 AGranted
Production of low molecular weight linear hydrogen siloxanes
AssigneeGeneral Electric Company
InventorsJohn S. Razzano, Patricia P. Anderson, Robert J. Perry
Life of this patent
Estimating the term…
Abstract
A batch or continuous process for the production of low molecular weight hydrogen siloxanes catalyzed by soluble phosphonitrilic halides or solid acid catalysts such as acid washed clays, zeolites and ion exchange resins.
Claims20
A process for the production of hydrogen containing siloxanes of the formula:
- M'D.sub.x.sup.H D.sub.y M'
- where
- M'=R.sub.3-i.sup.1 H.sub.i SiO.sub.1/2 with R.sup.1 being independently selected from the group of one to forty carbon atom monovalent hydrocarbon radicals and the subscript i ranges from 0 to 3;
- D.sup.H =R.sup.2 HSiO.sub.2/2 with R.sup.2 being independently selected from the group consisting of hydrogen and one to forty carbon atom monovalent hydrocarbon radicals;
- and
- D=R.sub.2.sup.3 SiO.sub.2/2 where each R.sup.3 is independently selected from the group of one to forty carbon atom monovalent hydrocarbon radicals;
- and the subscript x ranges from 1 to 20 and the subscript y ranges from 0 to 20;
- comprising:
- (a) mixing a hydrogen containing siloxane selected from the group consisting of:
- i) D.sub.z.sup.H where D.sup.H is as previously defined and z varies from 3 to 8;
- and
- ii) M'D.sub.xx.sup.H D.sub.yy M' where M', D.sup.H, and D are as previously defined and xx is greater than 20 and yy is either 0 or greater than 20;
- with
- (b) an M' rich silicone compound comprising M' where M' is as previously defined, wherein when said M' rich compound additionally comprises D, T, or Q groups, D is as previously defined,
- T=R.sup.4 SiO.sub.3/2 with R.sup.4 being independently selected from the group of one to forty carbon atom monovalent hydrocarbon radicals, and Q=SiO.sub.4/2 where the molar ratio of silicon atoms in the M' groups in said M' rich silicone compound to the sum of the silicone atoms in the M', D, T, and Q groups in said M' rich silicone compound is 0.04 or greater;
- in the presence of a catalyst selected from the group consisting of acid washed clays, zeolites, ion exchange resins and linear phosphonitrilic halides and
- (c) heating the mixture of said hydrogen containing siloxane and said M' rich silicone compound to a temperature ranging from 20.degree. C. to 200.degree. C.
14 more elements
A process for the production of hydrogen containing siloxanes of the formula:
- M'D.sub.x.sup.H D.sub.y M'
- where
- M'=R.sub.3-i.sup.1 H.sub.i SiO.sub.1/2 with R.sup.1 being independently selected from the group of one to forty carbon atom monovalent hydrocarbon radicals and the subscript i ranges from 0 to 3;
- D.sup.H =R.sub.2.sup.3 SiO.sub.2/2 with R.sup.2 being independently selected from the group consisting of hydrogen and one to forty carbon atom monovalent hydrocarbon radicals;
- and
- D=R.sub.2.sup.3 SiO.sub.2/2 where each R.sup.3 is independently selected from the group of one to forty carbon atom monovalent hydrocarbon radicals;
- and the subscript x ranges from 1 to 20 and the subscript y ranges from 0 to 20;
- consisting essentially of:
- (a) mixing a hydrogen containing siloxane selected from the group consisting of:
- (i) D.sub.z.sup.H where D.sup.H is as previously defined and z varies from 3 to 8;
- and
- (ii) M'D.sub.xx.sup.H D.sub.yy M' where M', D.sup.H, and D are as previously defined and xx is greater than 20 and yy is either 0 or greater than 20;
- with
- (b) an M' rich silicone compound comprising M' where M' is as previously defined, wherein when said M' rich compound additionally comprises D, T, or Q groups, D is as previously defined,
- T=R.sup.4 SiO.sub.3/2 with R.sup.4 being independently selected from the group of one to forty carbon atom monovalent hydrocarbon radicals, and Q=SiO.sub.4/2 where the molar ratio of silicon atoms in the M' groups in said M' rich silicone compound to the sum of the silicone atoms in the M', D, T, and Q groups in said M' rich silicone compound is 0.04 or greater;
- in the presence of a catalyst selected from the group consisting of acid washed clays, zeolites, ion exchange resins and linear phosphonitrilic halides and
- (c) heating the mixture of said hydrogen containing siloxane and said M' rich silicone compound to a temperature ranging from 20.degree. C. to 200.degree. C.
14 more elements
Dependencies are inferred from the claim text.