US3821070A
Expired / Lapsed
US
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Producing novel silicon dioxide fibers
Assignee: Bayer AG
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Filing: 1971-08-09
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Granted: 1974-06-28
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Expires: 1991-08-09
Abstract
Abstract Silicon dioxide fibers are produced by dry spinning a hydrolysis solution containing poly-lower alkylene oxide, especially polyethylene oxide of high molecular weight, the product preferably being post-heat treated to a temperature of about 200* to 1,500*C at a controlled rate of heating either in an oxygen containing or in an inert atmosphere to produce novel fibers as characterized by physical properties and amorphous Xray diagram. The hydrolysis is effected with less than about 3 moles of water per mole of alkoxy group contained in a tetraalkoxysilane or alkoxypolysiloxane and in the presence of a small amount of hydrochloric acid and a lower alkanol solubilizing agent.
Inventors
- 👤 M Mansmann
- 👤 G Winter
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 06:55
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/622; C04B35/62227; C04B35/62231; C04B35/6224; C01; C01B; C01B33/00; C01B33/113; C03; C03C; C03C13/00; C03C13/005; Y; Y10; Y10S; Y10S264/00; Y10S264/19; Y10S65/00; Y10S65/901; Y10T; Y10T428/00; Y10T428/29; Y10T428/2913; Y10T428/2918
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
18 words
A process according to claim 1, wherein the alkoxy groups of said siloxane are methyl or ethyl groups.
Claim 2
Dependent Claim
31 words
A process according to claim 1, wherein the hydrolysis of said tetraalkoxysilane or of said alkoxypolysiloxane is effected in the presence of said alkanol which contains, up to four carbon atoms.
Claim 3
Dependent Claim
24 words
A process according to claim 3, wherein the hydrolysis is effected with less than about 3 moles of water per mole of alkoxy group.
Claim 4
Dependent Claim
38 words
A process according to claim 1, wherein the heat treatment is carried out at a rate of heating of about 10* to 200* C/hour up to 400* C and of about 100* - 1,000* C/hour above 400* C.
Claim 5
Dependent Claim
17 words
A process according to claim 1, wherein the heat treatment is carried out under an inert gas.
Claim 6
Dependent Claim
88 words
A process according to claim 5, wherein the poly-lower alkylene oxide has a degree of polymerization of at least about 100,000, the hydrolysis of the alkoxy groups of said siloxane is effected with less than about 3 moles of water per mole of alkoxy group in the presence of about 10 to 40 percent of methanol or ethanol and less than about 0.1 percent of hydrochloric acid, and the solution being extruded contains about 15 to 30 percent of SiO2, all percentages being by weight of the solutions.
Claim 7
Dependent Claim
51 words
An amorphous silicon dioxide fiber having a tensile strength in excess of about 70 kp/mm2, a Young''s-modulus of more than about 6,000 kp/mm2, a specific surface area of less than 1 m2/g, and consisting essentially of only silicon dioxide and of between about 0.1 and 15 percent by weight of carbon.
Claim 8
Dependent Claim
77 words
An amorphous silica gel fiber having a tensile strength of about 30 to 80 kp/mm2, a Young''s-modulus below about 6,000 kp/mm2, a specific surface area of less than 1 m2/g, and a density of about 1.70 to 2.17, and comprising by weight about 70 to 100 percent of silicon dioxide, about 0 to 20 percent of water, about 0 to 20 percent of alkoxy groups and less than about 2 percent of acid radicals other than silicate.
Claim 9
Dependent Claim
17 words
A silica gel fiber according to claim 9 having a Young''s-modulus of less than about 2,500 kp/mm2.
Claim 10
Dependent Claim
24 words
A process according to claim 1, wherein said poly-lower alkylene oxide is polyethylene oxide of a degree of polymerization of at least about 100,000.
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) | 1977-06-27 | 1977-12-27 | 1978-06-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-27 | 1981-12-27 | 1982-06-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-27 | 1985-12-27 | 1986-06-28 | $7700.00 | Window Closed / Lapsed |