US3865599A
Expired / Lapsed
US
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Aluminum oxide fibers and their production
Assignee: Bayer AG
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Filing: 1972-12-18
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Granted: 1975-02-11
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Expires: 1992-12-18
Abstract
Abstract Aluminum oxide fibers of the approximate percent composition by weight: Al2O3 61-98% preferably 76-96% SiO2 1-20% preferably 3-15% P2O5 0-10% preferably 0- 5% B2O3 0-10% preferably 0- 5% MgO 0- 5% preferably 0- 1% C 0.1- 4% preferably 0.5-2.8% The fibers are produced by dry spinning a solution containing a neutral or basic aluminum salt of a monobasic lower carboxylic acid, a hydrolyzed silicic acid ester or organoalkoxysilane and polyethylene oxide having a degree of polymerization of at least about 2,000. The product is then heat treated at a temperature between about 400* and 1,800*C. Phosphorus, boron and magnesium may also be present in the solution and end up in the fiber as oxides.
Inventors
- 👤 Manfred Mansmann
- 👤 Ludwig Schmidt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 22:49
CPC Classifications
C; C08; C08K; C08K7/00; C08K7/02; C08K7/04; C08K7/10; C04; C04B; C04B35/00; C04B35/622; C04B35/62227; C04B35/62231; C04B35/62236; C04B35/6224; C04B35/62245
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
109 words
A PROCESS FOR THE PRODUCTION OF ALUMINUM OXIDE FIBER WHICH COMPRISES FORMING A SOLUTION CONTAINING A NEUTRAL OR BASIC ALUMNINU SALT OF MONOBASIC LOWER CARBOXYLIC ACID, A HYDROLYZED SILICIC ACID ESTER OR ORGANOALKOXYSILANE AND ABOUT 0.1 TO 2 PERCENT BY WEIGHT OF POLYETHYLENE OXIDE HAVING A DEGREE OF POLYMERIZATITON OF AT LEAST ABOUT 100,000 SAID SOLUTION HAVING AN ALUMINUM CONTENT CALCULATED AS AL2O3 OF ABOUT 8 TO 18 PERCENT BY WEIGHT AND SIO2 CONTENT OF ABOUT 1 TO 20 PERCENT BY WEIGHT ON TOTAL OXIDES IN SAID SOLUTION, DRY SPINNING SAID SOLUTION TO FORM A FILAMENTARY STRUCTURE, AND HEAT TREATING SAID STRUCTURE AT A TEMPERATURE UP TO ABOUT 1,800*C.
Claim 2
Dependent Claim
109 words
A PROCESS FOR THE PRODUCTION OF ALUMINUM OXIDE FIBER WHICH COMPRISES FORMING A SOLUTION CONTAINING A NEUTRAL OR BASIC ALUMNINU SALT OF MONOBASIC LOWER CARBOXYLIC ACID, A HYDROLYZED SILICIC ACID ESTER OR ORGANOALKOXYSILANE AND ABOUT 0.1 TO 2 PERCENT BY WEIGHT OF POLYETHYLENE OXIDE HAVING A DEGREE OF POLYMERIZATITON OF AT LEAST ABOUT 100,000 SAID SOLUTION HAVING AN ALUMINUM CONTENT CALCULATED AS AL2O3 OF ABOUT 8 TO 18 PERCENT BY WEIGHT AND SIO2 CONTENT OF ABOUT 1 TO 20 PERCENT BY WEIGHT ON TOTAL OXIDES IN SAID SOLUTION, DRY SPINNING SAID SOLUTION TO FORM A FILAMENTARY STRUCTURE, AND HEAT TREATING SAID STRUCTURE AT A TEMPERATURE UP TO ABOUT 1,800*C.
Claim 3
Dependent Claim
12 words
The process of claim 1, wherein the aluminum salt is aluminum formate.
Claim 4
Dependent Claim
29 words
The process of claim 1, wherein the silicic acid ester or organoalkoxysilane is at least one member selected from the group consisting of tetraethyl silicate, ethoxypolysiloxane, methyltrimethoxysilane and methyltriethoxysilane.
Claim 5
Dependent Claim
18 words
The process of claiM 3, wherein the hydrolysis is effected directly in the solution of the aluminum salt.
Claim 6
Dependent Claim
37 words
The process of claim 1, wherein the solution further contains phosphorus and boron in an amount such that their sum, expressed as P2O5 + B2O3, is about 1 to 10 percent by weight based on total oxides.
Claim 7
Dependent Claim
26 words
The process of claim 1, wherein the solution further contains magnesium in up to about 5 percent by weight expressed as MgO based on total oxides.
Claim 8
Dependent Claim
19 words
The process of claim 1, wherein the filamentary structure is heated to a temperature of at least about 800*C.
Claim 9
Dependent Claim
50 words
The process of claim 7, wherein the heating takes place at a heating rate of about 2* to 20*/min. up to about 250*C., at a heating rate of about 0.5 to 10*/min. between about 250* and 400*C., and at a heating rate of about 5 and 200*/min. above about 400*C.
Claim 10
Dependent Claim
34 words
The process of claim 8, wherein the filamentary structure is first heated to about 800* to 1,200*C. and is subsequently annealed for about 5 seconds to 5 minutes at a temperature above about 1,400*C.
Claim 11
Dependent Claim
15 words
The process of claim 7, wherein the heating is carried out under an inert gas.
Claim 12
Dependent Claim
27 words
The process of claim 7, wherein heating is carried out in an atmosphere containing oxygen up to about 1,100*C. and under an inert gas above about 1,100*C.
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) | 1978-02-10 | 1978-08-12 | 1979-02-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-02-10 | 1982-08-12 | 1983-02-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-02-10 | 1986-08-12 | 1987-02-11 | $7700.00 | Window Closed / Lapsed |