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US4774310A
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Method for making siloxane resins
Assignee: Dow Silicones UK Ltd
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Filing: 1987-06-15
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Granted: 1988-09-27
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Expires: 2007-06-15
Abstract
Abstract A method for making siloxane resins consisting essentially of tetravalent SiO 2 units and monovalent R 3 SiO 0 .5 and H a R 3-a SiO 0 .5 units wherein each R denotes an alkyl group or an aryl group having less than 9 carbon atoms and a denotes 1 or 2, comprises reacting in the presence of an acidic catalyst a siloxane resin consisting essentially of R 3 SiO 0 .5 units and SiO 2 units with (H a R 3-a Si) 2 O, where R and a are as defined above. Novel resins wherein only 0.1 to 30 percent of the monovalent units have SiH groups are also disclosed.
Inventors
- 👤 Derek W. Butler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 06:54
CPC Classifications
C; C08; C08G; C08G77/00; C08G77/04; C08G77/12
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
97 words
A method for making siloxane resins consisting essentially of tetravalent SiO 2 units and monovalent R 3 SiO 0 .5 and H a R 3-a SiO 0 .5 units, wherein each R is selected from the group consisting of alkyl and aryl groups having less than 9 carbon atoms and a denotes 1 or 2, which comprises reacting in the presence of an acidic catalyst a siloxane resin consisting essentially of R 3 SiO 0 .5 units and SiO 2 units, with (H a R 3-a Si) 2 O where R and a are as defined above.
Claim 2
Independent Claim
97 words
A method for making siloxane resins consisting essentially of tetravalent SiO 2 units and monovalent R 3 SiO 0 .5 and H a R 3-a SiO 0 .5 units, wherein each R is selected from the group consisting of alkyl and aryl groups having less than 9 carbon atoms and a denotes 1 or 2, which comprises reacting in the presence of an acidic catalyst a siloxane resin consisting essentially of R 3 SiO 0 .5 units and SiO 2 units, with (H a R 3-a Si) 2 O where R and a are as defined above.
Claim 3
Dependent Claim
36 words
A method according to claim 1 wherein the ratio of monovalent to tetravalent units in the siloxane resin consisting essentially of R 3 SiO 0 .5 units and SiO 2 units is from 0.4:1 to 2:1.
Claim 4
Dependent Claim
19 words
A method according to claim 2 wherein the ratio of monovalent to tetravalent units is from 0.4:1 to 1:1.
Claim 5
Independent Claim
18 words
A method according to claims 1, 2 or 3 wherein the acidic catalyst is trifluoro- methane sulphonic acid.
Claim 6
Dependent Claim
15 words
A method according to claim 1 when carried out in the presence of a solvent.
Claim 7
Dependent Claim
10 words
A method according to claim 1 wherein R is methyl.
Claim 8
Dependent Claim
13 words
A method according to claim 1 wherein a has a value of 1.
Claim 9
Dependent Claim
93 words
A siloxane resin consisting essentially of tetravalent SiO 2 units and monovalent R 3 SiO 0 .5 and H a R 3-a SiO 0 .5 units wherein each R is selected from the group consisting of alkyl and aryl groups having less than 9 carbons and a denotes 1 or 2, wherein the H a R 3-a SiO 0 .5 units comprise from 0.1% to 30% of the total number of monovalent units present, and the ratio of said monovalent units to said tetravalent units has a value of from 0.4:1 to 2:1.
Claim 10
Dependent Claim
93 words
A siloxane resin consisting essentially of tetravalent SiO 2 units and monovalent R 3 SiO 0 .5 and H a R 3-a SiO 0 .5 units wherein each R is selected from the group consisting of alkyl and aryl groups having less than 9 carbons and a denotes 1 or 2, wherein the H a R 3-a SiO 0 .5 units comprise from 0.1% to 30% of the total number of monovalent units present, and the ratio of said monovalent units to said tetravalent units has a value of from 0.4:1 to 2:1.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-09-27 | 1992-03-28 | 1992-09-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-09-27 | 1996-03-28 | 1996-09-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-09-27 | 2000-03-28 | 2000-09-27 | $7700.00 | Window Closed / Lapsed |