US4052357A
Expired / Lapsed
US
⏱️ 0.0 years remaining
High modulus silicone rubber
Assignee: Dow Silicones Corp
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Filing: 1976-05-19
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Granted: 1977-10-04
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Expires: 1996-05-19
Abstract
Abstract A silicone rubber composition prepared from a mixture of 100 parts by weight polydiorganosiloxane gum, 25 to 75 parts by weight of a reinforcing silica filler, 5 to 20 parts by weight of a hydroxylated diorganosilicon compound having about two hydroxyl radicals per molecule and the organic radicals are 10 to 50 percent phenyl, 2 to 20 percent vinyl and the remainder methyl, fiberized blast furnace slag fibers in amounts of 20 to 80 parts by weight and 0 to 10 parts by weight of alkoxy silicon compound having at least 25 weight percent alkoxy radical provides a silicone rubber when cured which has a high modulus, improved tear strength and can be made oil resistant by adding magnesium oxide to the composition. This silicone rubber can be used for seals, gaskets and particularly where magnesium oxide is present the use can be in contact with oils.
Inventors
- 👤 James A. Marinik
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 07:45
CPC Classifications
C; C08; C08L; C08L83/00; C08L83/04; C08K; C08K5/00; C08K5/54; C08K7/00; C08K7/02; C08K7/04; C08G; C08G77/00; C08G77/04; C08G77/14; C08G77/16; C08G77/20; C08G77/22; C08G77/24; C08G77/70
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
241 words
A silicone rubber composition consisting essentially of A. 100 parts by weight of polydiorganosiloxane gum where the organic radicals are selected from methyl, phenyl, vinyl, ethyl and 3,3,3-trifluoropropyl and mixtures thereof the polydiorganosiloxane gum having at least 50 percent of the organic radicals being methyl and no more than 2 percent being vinyl, the polydiorganosiloxane gums being endblocked with hydroxyl radicals or triorganosiloxy units where the organic radicals are defined above, B. from 25 to 75 parts by weight of reinforcing silica filler, C. from 5 to 20 parts by weight of hydroxylated diorganosilicon compound which has an average of about 2 hydroxyl radicals per molecule, at least 3 weight percent silicon-bonded hydroxyl radicals based on the weight of the hydroxylated diorganosilicon compound, and the organic radicals are selected from a combination of methyl, phenyl and vinyl, there being from 10 to 50 percent phenyl radicals, from 2 to 20 percent vinyl radicals and the remainder being methyl radicals, D. from 20 to 80 parts by weight fiberized blast furnace slag fibers having an average length of from 0.0001 to 0.0005 meter and a diameter of 0.00001 to 0.00001 meter, and E. from 0 to 10 parts by weight of alkoxy silicon compound having at least 25 weight percent siliconbonded alkoxy radical selected from methoxy, ethoxy and propoxy and any remaining monovalent organic groups attached to silicon atoms being bonded through silicon-carbon bonds and being selected from methyl, ethyl and vinyl.
Claim 2
Dependent Claim
241 words
A silicone rubber composition consisting essentially of A. 100 parts by weight of polydiorganosiloxane gum where the organic radicals are selected from methyl, phenyl, vinyl, ethyl and 3,3,3-trifluoropropyl and mixtures thereof the polydiorganosiloxane gum having at least 50 percent of the organic radicals being methyl and no more than 2 percent being vinyl, the polydiorganosiloxane gums being endblocked with hydroxyl radicals or triorganosiloxy units where the organic radicals are defined above, B. from 25 to 75 parts by weight of reinforcing silica filler, C. from 5 to 20 parts by weight of hydroxylated diorganosilicon compound which has an average of about 2 hydroxyl radicals per molecule, at least 3 weight percent silicon-bonded hydroxyl radicals based on the weight of the hydroxylated diorganosilicon compound, and the organic radicals are selected from a combination of methyl, phenyl and vinyl, there being from 10 to 50 percent phenyl radicals, from 2 to 20 percent vinyl radicals and the remainder being methyl radicals, D. from 20 to 80 parts by weight fiberized blast furnace slag fibers having an average length of from 0.0001 to 0.0005 meter and a diameter of 0.00001 to 0.00001 meter, and E. from 0 to 10 parts by weight of alkoxy silicon compound having at least 25 weight percent siliconbonded alkoxy radical selected from methoxy, ethoxy and propoxy and any remaining monovalent organic groups attached to silicon atoms being bonded through silicon-carbon bonds and being selected from methyl, ethyl and vinyl.
Claim 3
Dependent Claim
22 words
The composition in accordance with claim 1 in which (E) is present in an amount of 2 to 10 parts by weight.
Claim 4
Dependent Claim
12 words
The composition in accordance with claim 2 in which (E) is methyltrimethoxysilane.
Claim 5
Dependent Claim
18 words
The composition in accordance with claim 1 where there is present a vulcanizing agent for the polydiorganosiloxane gum.
Claim 6
Dependent Claim
20 words
The composition in accordance with claim 1 in which the polydiorganosiloxane gum contains from 0.1 to 0.5 percent vinyl radicals.
Claim 7
Dependent Claim
17 words
The composition in accordance with claim 5 in which there is present a vinyl specific organic peroxide.
Claim 8
Dependent Claim
31 words
The composition in accordance with claim 1 in which there is present finely divided magnesium oxide in amounts up to 10 parts by weight per 100 parts by weight polydiorganosiloxane gum.
Claim 9
Dependent Claim
31 words
The composition in accordance with claim 6 in which there is present finely divided magnesium oxide in amounts up to 10 parts by weight per 100 parts by weight polydiorganosiloxane gum.
Claim 10
Independent Claim
277 words
A method of making a silicone rubber composition consisting essentially of I. mixing A. 100 parts by weight of polydiorganosiloxane gum where the organic radicals are selected from methyl, phenyl, vinyl, ethyl and 3,3,3-trifluoropropyl and mixtures thereof, the polydiorganosiloxane gum having at least 50 percent of the organic radicals being methyl and no more than 2 percent being vinyl, the polydiorganosiloxane gum being endblocked with hydroxyl radicals or triorganosiloxy units where the organic radicals are defined above, B. from 25 to 75 parts by weight of reinforcing silica filler, C. from 5 to 20 parts by weight of hydroxylated diorganosilicon compound which has an average of about 2 hydroxyl radicals per molecule, at least 3 weight percent silicon-bonded hydroxyl radicals based on the weight of the weight of the hydroxylated diorganosilicon compound, and the organic radicals are selected from a combination of methyl, phenyl and vinyl, there being from 10 to 50 percent phenyl radicals, from 2 to 20 percent vinyl radicals and the remainder being methyl radicals, D. from 20 to 80 parts by weight fiberized blast furnace slag fibers having an average length of from 0.0001 to 0.0005 meter and a diameter of 0.000001 to 0.00001 meter, and E. from 0 to 10 parts by weight of alkoxy silicon compound having at least 25 weight percent silicon-bonded alkoxy radical selected from methoxy, ethoxy and propoxy and any remaining monovalent organic groups attached to silicon atoms being bonded through silicon-carbon bonds and being selected from methyl, ethyl and vinyl, to obtain a mixture and, Ii heating the mixture from (I) under reduced pressure for at least 30 minutes at a temperature from 100° to 200° C.
Claim 11
Independent Claim
277 words
A method of making a silicone rubber composition consisting essentially of I. mixing A. 100 parts by weight of polydiorganosiloxane gum where the organic radicals are selected from methyl, phenyl, vinyl, ethyl and 3,3,3-trifluoropropyl and mixtures thereof, the polydiorganosiloxane gum having at least 50 percent of the organic radicals being methyl and no more than 2 percent being vinyl, the polydiorganosiloxane gum being endblocked with hydroxyl radicals or triorganosiloxy units where the organic radicals are defined above, B. from 25 to 75 parts by weight of reinforcing silica filler, C. from 5 to 20 parts by weight of hydroxylated diorganosilicon compound which has an average of about 2 hydroxyl radicals per molecule, at least 3 weight percent silicon-bonded hydroxyl radicals based on the weight of the weight of the hydroxylated diorganosilicon compound, and the organic radicals are selected from a combination of methyl, phenyl and vinyl, there being from 10 to 50 percent phenyl radicals, from 2 to 20 percent vinyl radicals and the remainder being methyl radicals, D. from 20 to 80 parts by weight fiberized blast furnace slag fibers having an average length of from 0.0001 to 0.0005 meter and a diameter of 0.000001 to 0.00001 meter, and E. from 0 to 10 parts by weight of alkoxy silicon compound having at least 25 weight percent silicon-bonded alkoxy radical selected from methoxy, ethoxy and propoxy and any remaining monovalent organic groups attached to silicon atoms being bonded through silicon-carbon bonds and being selected from methyl, ethyl and vinyl, to obtain a mixture and, Ii heating the mixture from (I) under reduced pressure for at least 30 minutes at a temperature from 100° to 200° C.
Claim 12
Dependent Claim
35 words
The method in accordance with claim 9 in which there is mixed with (A), (B), (C) and (D) from 0.01 to 1 part by weight ammonium carbonate per 100 parts by weight of polydiorganosiloxane gum.
Claim 13
Dependent Claim
38 words
The method in accordance with claim 10 in which there is also mixed with (A), (B), (C) and (D) magnesium oxide in an amount of up to 10 parts by weight per 100 parts by weight of polydiorganosiloxane.
Claim 14
Dependent Claim
46 words
The method in accordance with claim 10 in which magnesium oxide is mixed with the resulting product of (II) which has been cooled below 100° C. and is present in amounts of up to 10 parts by weight per 100 parts by weight of the polydiorganosiloxane.
Claim 15
Dependent Claim
46 words
The method in accordance with claim 11 in which the resulting product from (II) is cooled below 100° C., the polydiorganosiloxane gum of (A) contains from 0.1 to 0.5 percent vinyl radicals, and a vinyl specific organic peroxide is mixed with the cooled product of (II).
Claim 16
Dependent Claim
28 words
The method in accordance with claim 13 in which the resulting product is heated above the activation temperature of the organic peroxide and a silicone rubber is obtained.
Claim 17
Dependent Claim
10 words
A silicone rubber prepared by the method of claim 14.
Claim 18
Dependent Claim
36 words
The method in accordance with claim 12 in which the polydiorganosiloxane gum of (A) contains from 0.1 to 0.5 percent vinyl radicals, and a vinyl specific organic peroxide is mixed with the cooled product of (II).
Claim 19
Dependent Claim
28 words
The method in accordance with claim 16 in which the resulting product is heated above the activation temperature of the organic peroxide and a silicone rubber is obtained.
Claim 20
Dependent Claim
10 words
A silicone rubber prepared by the method of claim 17.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-10-03 | 1981-04-04 | 1981-10-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-10-03 | 1985-04-04 | 1985-10-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-10-03 | 1989-04-04 | 1989-10-04 | $7700.00 | Window Closed / Lapsed |