US4310678A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Liquid copolymeric organopolysiloxanes comprising SiO2 and method therefor
Assignee: Dow Silicones Corp
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Filing: 1980-12-02
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Granted: 1982-01-12
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Expires: 2000-12-02
Abstract
Abstract Copolymeric organopolysiloxanes comprising SiO 2 are prepared by forming an acidic, homogeneous mixture of a silanol-containing resinous copolymeric siloxane comprising R 3 SiO 1/2 siloxane units and SiO 2 siloxane units, an organohydrogenpolysiloxane and an organic solvent and heating the resulting mixture to remove substantially all of the organic solvent. The copolymeric organosiloxanes contain silicon-bonded hydroxyl radicals and/or silicon-bonded hydrogen radicals in varying amounts which depends upon the acidity of the homogeneous mixture that is formed and the ratio of silicon-bonded hydrogen radicals to silicon-bonded hydroxyl radicals therein. The copolymeric organopolysiloxanes are useful as a reactive component in various types of curable silicone compositions.
Inventors
- 👤 John D. Blizzard
- 👤 Terence J. Swihart
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 14:42
CPC Classifications
C; C08; C08G; C08G77/00; C08G77/42; C08G77/44; C08L; C08L83/00; C08L83/04; C08G77/04; C08G77/12; C08G77/14; C08G77/16
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
140 words
A method for preparing a liquid copolymeric organopolysiloxane, said method comprising (A) forming a homogeneous mixture having an acid number greater than zero and comprising (a) an organic solvent solution of a resinous copolymeric siloxane containing silicon-bonded hydroxyl radicals and consisting essentially of R 3 SiO 1/2 siloxane units and SiO 4/2 siloxane units wherein the ratio of the number of said R 3 SiO 1/2 siloxane units to the number of said SiO 4/2 siloxane units has a value of from 0.6/1 to 0.9/1 and each R denotes, independently, a monovalent hydrocarbon radical and (b) a liquid organohydrogenpolysiloxane wherein each organic radical is, independently, a monovalent hydrocarbon radical, there being an average of at least one silicon-bonded hydrogen radical per molecule of said organohydrogenpolysiloxane, and (B) heating said homogeneous mixture to remove substantially all of said organic solvent therefrom.
Claim 2
Independent Claim
140 words
A method for preparing a liquid copolymeric organopolysiloxane, said method comprising (A) forming a homogeneous mixture having an acid number greater than zero and comprising (a) an organic solvent solution of a resinous copolymeric siloxane containing silicon-bonded hydroxyl radicals and consisting essentially of R 3 SiO 1/2 siloxane units and SiO 4/2 siloxane units wherein the ratio of the number of said R 3 SiO 1/2 siloxane units to the number of said SiO 4/2 siloxane units has a value of from 0.6/1 to 0.9/1 and each R denotes, independently, a monovalent hydrocarbon radical and (b) a liquid organohydrogenpolysiloxane wherein each organic radical is, independently, a monovalent hydrocarbon radical, there being an average of at least one silicon-bonded hydrogen radical per molecule of said organohydrogenpolysiloxane, and (B) heating said homogeneous mixture to remove substantially all of said organic solvent therefrom.
Claim 3
Dependent Claim
32 words
A method according to claim 1 wherein the homogeneous mixture is sufficiently acidic to provide an acid number of from 0.1 to 1 for the homogeneous mixture, extrapolated to the solvent-free state.
Claim 4
Dependent Claim
39 words
A method according to claim 2 wherein the ratio of the total number of silicon-bonded hydrogen atoms in component (b) to the total number of silicon-bonded hydroxyl radicals in component (a) has a value of at least about 2.
Claim 5
Dependent Claim
52 words
A method according to claim 1, 2 or 3 wherein the resinous copolymeric siloxane consists of (CH 3 ) 3 SiO 1/2 siloxane units and SiO 4/2 siloxane units and has a silicon-bonded hydroxy content of from 1 to 5 percent by weight and an acid number of from 0.3 to 1.4.
Claim 6
Dependent Claim
58 words
A method according to claim 4 wherein the organohydrogenpolysiloxane has the formula (R")(CH 3 ) 2 SiO{(CH 3 ) 2 SiO} a {(CH 3 )(H)SiO} b Si(CH 3 ) 2 (R") wherein each R" denotes, independently, a methyl radical or a hydrogen radical and a and b denote numbers, each having an average value of zero or more.
Claim 7
Dependent Claim
35 words
A method according to claim 5 wherein the organohydrogenpolysiloxane has the formula (CH 3 ) 3 SiO{(CH 3 )(H)SiO} b Si(CH 3 ) 3 wherein b has an average value of from 30 to 70.
Claim 8
Dependent Claim
32 words
A method according to claim 6 wherein the homogeneous mixture contains from 40 to 60 parts by weight of resinous copolymeric siloxane and from 40 to 60 parts by weight of organohydrogenpolysiloxane.
Claim 9
Dependent Claim
13 words
A copolymeric organopolysiloxane prepared by the method of claims 1, 2, or 3.
Claim 10
Dependent Claim
10 words
A copolymeric organopolysiloxane prepared by the method of claim 4.
Claim 11
Dependent Claim
10 words
A copolymeric organopolysiloxane prepared by the method of claim 5.
Claim 12
Dependent Claim
10 words
A copolymeric organopolysiloxane prepared by the method of claim 6.
Claim 13
Dependent Claim
10 words
A copolymeric organopolysiloxane prepared by the method of claim 7.
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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) | 1985-01-11 | 1985-07-13 | 1986-01-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-01-11 | 1989-07-13 | 1990-01-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-01-11 | 1993-07-13 | 1994-01-12 | $7700.00 | Window Closed / Lapsed |