Patent US3849181A successfully refreshed from Google Patents.
US3849181A
Expired / Lapsed
US
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Product and process
Assignee: EIDP Inc
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Filing: 1972-06-30
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Granted: 1974-11-19
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Expires: 1992-06-30
Abstract
Abstract High-strength fiber is prepared by coating a small grain, small diameter polycrystalline refractory oxide fiber with a specified amount of a glass-forming oxide or its precursor, and heating the coated fiber at a temperature sufficient to decompose the precursor to the oxide and/or to vitrify the oxide coating into an adherent, optically uniform, thin layer. The coating significantly increases the tensile strength of the fiber, while the fiber retains a substantial percentage of its original modulus. The fibers are especially suitable for reinforcement uses.
Inventors
- 👤 James Ralph Green
- 👤 Raymond Frank Tietz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 15:13
CPC Classifications
C; C04; C04B; C04B41/00; C04B41/80; C04B41/81; C04B14/00; C04B14/38; C04B14/46; C04B20/00; C04B20/10; C04B20/1055; C04B35/00; C04B35/01; C04B35/10; C04B35/622; C04B35/62227; C04B35/62231; C04B35/62236; C04B35/6224; C04B35/62245; C04B41/45; C04B41/4584; F; F02; F02B; F02B75/00; F02B75/02; F02B2075/022; F02B2075/027; Y; Y10; Y10T; Y10T428/00; Y10T428/29; Y10T428/2913; Y10T428/2933; Y10T428/294; Y10T428/296; Y10T428/2973; Y10T428/2978
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
92 words
A HIGH STRENGTH POLYCRYSTALLINE REFRACTORY OXIDE FIBER HAVING A DIAMETER BETWEEN ABOUT 3 AND 250 MICRONS AND COMPRISED OF GRAINS HAVING A MEDIAN GRAIN DIAMETER OF LESS THAN ABOUT 3 MICRONS AND LESS THAN ABOUT 10 PERCENT OF SAID FIBER DIAMETER, SAID FIBER HAVING ADHERED THERETO A VIRIFIED COATING CONSISTING ESSENTIALLY OF A GLASS-FORMING OXIDE, IN THE FORM OF AN OPTICALLY UNIFORM LAYER, THE APPARENT THICKNESS OF SAID COATING BEING LESS THAN ABOUT 1 MICRON, LESS THAN ABOUT 5 PERCENT OF SAID FIBER DIAMETER AND LESS THAN 1/2 SAID MEDIAN GRAIN DIAMETER.
Claim 2
Dependent Claim
92 words
A HIGH STRENGTH POLYCRYSTALLINE REFRACTORY OXIDE FIBER HAVING A DIAMETER BETWEEN ABOUT 3 AND 250 MICRONS AND COMPRISED OF GRAINS HAVING A MEDIAN GRAIN DIAMETER OF LESS THAN ABOUT 3 MICRONS AND LESS THAN ABOUT 10 PERCENT OF SAID FIBER DIAMETER, SAID FIBER HAVING ADHERED THERETO A VIRIFIED COATING CONSISTING ESSENTIALLY OF A GLASS-FORMING OXIDE, IN THE FORM OF AN OPTICALLY UNIFORM LAYER, THE APPARENT THICKNESS OF SAID COATING BEING LESS THAN ABOUT 1 MICRON, LESS THAN ABOUT 5 PERCENT OF SAID FIBER DIAMETER AND LESS THAN 1/2 SAID MEDIAN GRAIN DIAMETER.
Claim 3
Dependent Claim
26 words
The fiber of claim 1 wherein the refractory oxide fiber is at least 60 percent alumina by weight, based on the total weight of said fiber.
Claim 4
Dependent Claim
24 words
The fiber of claim 2 wherein the vitrified coating is at least 50% SiO2 by weight, based on the total weight of said coating.
Claim 5
Dependent Claim
21 words
The fiber of claim 3 wherein the apparent thickness of said coating is between about 0.01 micron and about 0.1 micron.
Claim 6
Dependent Claim
19 words
The fiber of claim 4 wherein the porosity of the refractory oxide fiber is less than about 20 percent.
Claim 7
Dependent Claim
55 words
The fiber of claim 5 wherein the refractory oxide fiber has a porosity of less than 10 percent, a crystallinity of greater than 85 percent, and a grain size distribution wherein substantially none of the grains is larger than about 3 microns and at least 30 percent by weight are smaller than about 0.5 micron.
Claim 8
Dependent Claim
14 words
The fiber of claim 1 wherein said median grain diameter is about 0.5 micron.
Claim 9
Dependent Claim
13 words
The fiber of claim 1 wherein the vitrified coating is substantially 100% SiO2.
Claim 10
Dependent Claim
20 words
The fiber of claim 8 wherein the apparent thickness of said coating is between about 0.01 micron and 1 micron.
Claim 11
Dependent Claim
15 words
The fiber of claim 9 wherein the refractory oxide fiber is substantially 100 percent alumina.
Claim 12
Dependent Claim
64 words
percent, plurality of the fibers of claim 10 in the form of a continuous yarn, each refractory oxide fiber having a porosity of less than 10 percent, a crystallinity of greater than 85 %, and a grain size distribution wherein substantially none of the grains is larger than about 3 microns and at least 30 percent by weight are smaller than about 0.5 micron.
Claim 13
Dependent Claim
142 words
Process for strengthening a yarn of polycrystalline refractory oxide fibers which comprises: applying a coating to the surface of each fiber by advancing the yarn continuously through a fluid composition comprised of a precursor of a glass-forming oxide, said fiber having a diameter between about 3 and 250 microns and comprised of grains having a median grain diameter of less than about 3 microns and less than about 10 percent of said diameter of said fiber, and advancing the coated yarn to and through a heat zone, thereby heating each fiber to a temperature sufficient to convert said precursor to said oxide and to vitrify said coating, the amount of precursor applied to the yarn being sufficient to provide said vitrified coating in an apparent thickness of less than about 1 micron and less than about 5 percent of said fiber diameter.
Claim 14
Dependent Claim
142 words
Process for strengthening a yarn of polycrystalline refractory oxide fibers which comprises: applying a coating to the surface of each fiber by advancing the yarn continuously through a fluid composition comprised of a precursor of a glass-forming oxide, said fiber having a diameter between about 3 and 250 microns and comprised of grains having a median grain diameter of less than about 3 microns and less than about 10 percent of said diameter of said fiber, and advancing the coated yarn to and through a heat zone, thereby heating each fiber to a temperature sufficient to convert said precursor to said oxide and to vitrify said coating, the amount of precursor applied to the yarn being sufficient to provide said vitrified coating in an apparent thickness of less than about 1 micron and less than about 5 percent of said fiber diameter.
Claim 15
Dependent Claim
20 words
Process of claim 12 wherein said glass-forming oxide is silica, said precursor being applied in the liquid or vapor state.
Claim 16
Dependent Claim
12 words
Process of claim 13 wherein said precursor of silica is silicon tetrachloride.
Claim 17
Dependent Claim
22 words
Process of claim 14 wherein said heating is at a temperature of at least about 1,350*C. for less than about 30 seconds.
Claim 18
Dependent Claim
23 words
Process of claim 15 wherein said heating is at a temperature of between about 1,500* and 1,900*C. for about 0.1 to 5.0 seconds.
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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) | 1977-11-18 | 1978-05-20 | 1978-11-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-11-18 | 1982-05-20 | 1982-11-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-11-18 | 1986-05-20 | 1986-11-19 | $7700.00 | Window Closed / Lapsed |