Patent US2439690A successfully refreshed from Google Patents.
US3843601A
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Hydraulic elastomer
Assignee: Stauffer Chemical Co
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Filing: 1973-10-11
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Granted: 1974-10-22
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Expires: 1993-10-11
Abstract
Abstract A silicone elastomer that flows like a fluid under high pressure is described. It is made by heating a silicone fluid, having a molecular weight close to 60,000 and containing approximately 0.45 mole percent of methylvinylsiloxane units, with a vinylspecific peroxide. This elastomer is characterized by a combination of a high cross-link density and a high proportion of free chain ends. It crumbles to a powder under high shear stress, but has the unique property of flowing like a viscous fluid through a narrow orifice. It is useful in hydraulic impact absorbers and other hydraulic systems.
Inventors
- 👤 L Bruner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 21:11
CPC Classifications
C; C10; C10M; C10M3/00; C08; C08K; C08K5/00; C08K5/0008; C08K5/0025; F; F16; F16F; F16F9/00; F16F9/006; C08G; C08G77/00; C08G77/04; C08G77/14; C08G77/16; C08G77/18; C08G77/20; C08G77/42; C08G77/44; C10M2229/00; C10M2229/04; C10M2229/041; C10M2229/045; C10M2229/046; C10M2229/047; C10M2229/048; C10N; C10N2020/00; C10N2020/01; C10N2040/00; C10N2040/08
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
81 words
A SILICONE FLUID CURABLE TO A HYDRAULIC ELASTOMER, HAVING A VISCOSITY OF FROM 1000 TO 1,000,000 CENTIPOISES, COMPRISING A COPOLYMER OF DIMETHYLSILOXANE UNITS WITH 0.1 TO 0.9 MOLE PERCENT OF METHYLVINYLSILOXANE UNITS, THE MOLE PERCENT OF METHYLVINYL-SILOXANE UNITS HAVING A VALUE OF (4.8/LOG V) - C, WHERE V IS THE VISCOSITY IN CENTIPOISES AND C IS A NUMBER HAVING A VALUE OF FROM 0.53 TO 0.83, SAID COPOLYMER HAVING END GROUPS SELECTED FROM THE CLASS CONSISTING OF TRIMETHYLSILOXY, HYDROXY AND ALKOXY.
Claim 2
Dependent Claim
81 words
A SILICONE FLUID CURABLE TO A HYDRAULIC ELASTOMER, HAVING A VISCOSITY OF FROM 1000 TO 1,000,000 CENTIPOISES, COMPRISING A COPOLYMER OF DIMETHYLSILOXANE UNITS WITH 0.1 TO 0.9 MOLE PERCENT OF METHYLVINYLSILOXANE UNITS, THE MOLE PERCENT OF METHYLVINYL-SILOXANE UNITS HAVING A VALUE OF (4.8/LOG V) - C, WHERE V IS THE VISCOSITY IN CENTIPOISES AND C IS A NUMBER HAVING A VALUE OF FROM 0.53 TO 0.83, SAID COPOLYMER HAVING END GROUPS SELECTED FROM THE CLASS CONSISTING OF TRIMETHYLSILOXY, HYDROXY AND ALKOXY.
Claim 3
Dependent Claim
58 words
The silicone fluid of claim 1, wherein the copolymer is represented by the formula RO((CH3)2SiO)x(CH3(C2H3)SiO)yR wherein R is selected from the class consisting of alkyl radicals of from one to four carbon atoms, hydrogen and trimethylsilyl radicals, x is a number of from about 270 to about 2,700 and y is a number of from 0.001x to 0.009x.
Claim 4
Dependent Claim
23 words
The silicone fluid of claim 1 wherein the copolymer contains trimethylsiloxy end groups and has a viscosity of from 5000 to 30,000 centipoises.
Claim 5
Dependent Claim
16 words
The silicone fluid of claim 1 wherein the value of C is from 0.63 to 0.78.
Claim 6
Dependent Claim
25 words
The silicone fluid of claim 2 wherein the viscosity is from 10,000 to 15,000 centipoises and the mole percent of methylvinylsiloxane units is approximately 0.45.
Claim 7
Dependent Claim
30 words
The silicone fluid of claim 1 which contains in addition 0.1 to 1.5 percent of a curing agent selected from the class consisting of tertiary alkyl peroxides and diperoxy ketals.
Claim 8
Dependent Claim
18 words
The silicone fluid of claim 6 wherein the amount of curing agent is from 0.3 to 0.8 percent.
Claim 9
Dependent Claim
15 words
The silicone fluid of claim 6 wherein the curing agent is a tertiary alkyl peroxide.
Claim 10
Dependent Claim
13 words
The silicone fluid of claim 8 wherein the curing agent is dicumyl peroxide.
Claim 11
Dependent Claim
12 words
The silicone fluid of claim 8 wherein the curing agent is bis-(t-butylperoxyisopropyl)-ethane.
Claim 12
Dependent Claim
12 words
The silicone fluid of claim 8 wherein the curing agent is bis-(t-butylperoxyisopropyl)-benzene.
Claim 13
Dependent Claim
25 words
The silicone fluid of claim 11 wherein the curing agent has an ultraviolet absorbance at 240 nanometers that is no greater than at 260 nanometers.
Claim 14
Dependent Claim
14 words
The silicone fluid of claim 6 wherein the curing agent is a diperoxy ketal.
Claim 15
Dependent Claim
12 words
The silicone fluid of claim 13 wherein the curing agent is 1,1-di-t-butylperoxy-3,3,5-trimethylcyclohexane.
Claim 16
Dependent Claim
61 words
A process for curing the silicone fluid of claim 1 to a hydraulic elastomer which comprises heating said fluid with 0.1 to 1.5 percent of a curing agent selected from the class consisting of tertiary alkyl peroxides and diperoxy ketals at a temperature from 130*C. to 210* C. for a time equal to at least one half-life of the curing agent.
Claim 17
Dependent Claim
20 words
The process of claim 15 wherein the curing time is equal to at least 5 half-lives of the curing agent.
Claim 18
Dependent Claim
30 words
The process of claim 15 wherein the curing agent is a tertiary alkyl peroxide, the curing temperature is at least 150*C., and the curing time is at least 1 minute.
Claim 19
Dependent Claim
29 words
The process of claim 14 wherein the curing agent is a diperoxy ketal, the curing temperature is at least 130*C. and the curing time is at least 1 minute.
Claim 20
Dependent Claim
87 words
A hydraulic elastomer composed of a polydimethylsiloxane cross-linked by three-carbon bridges, in which the cross-link density is from 0.25 to 0.50 cross-links per 100 silicon atoms, and in which there are from 0.074 to 0.74 free chain ends per 100 silicon atoms, said free ends having an average of from 50 to 100 silicon atoms each, said elastomer being characterized by a Shore A hardness of from 9 to 15, and being further characterized by its ability to absorb energy by flowing under pressure like a fluid.
Claim 21
Dependent Claim
87 words
A hydraulic elastomer composed of a polydimethylsiloxane cross-linked by three-carbon bridges, in which the cross-link density is from 0.25 to 0.50 cross-links per 100 silicon atoms, and in which there are from 0.074 to 0.74 free chain ends per 100 silicon atoms, said free ends having an average of from 50 to 100 silicon atoms each, said elastomer being characterized by a Shore A hardness of from 9 to 15, and being further characterized by its ability to absorb energy by flowing under pressure like a fluid.
Claim 22
Dependent Claim
30 words
The hydraulic elastomer of claim 19 in which there are from 0.18 to 0.34 free ends per 100 silicon atoms, and the Shore A hardness is from 11 to 14.
Claim 23
Dependent Claim
21 words
The hydraulic elastomer of claim 19 in the form of fine particles which are predominantly less than 1 millimeter in diameter.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-10-21 | 1978-04-22 | 1978-10-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-10-21 | 1982-04-22 | 1982-10-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-10-21 | 1986-04-22 | 1986-10-22 | $7700.00 | Window Closed / Lapsed |