Patent US4047965A successfully refreshed from Google Patents.
US4047965A
Expired / Lapsed
US
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Non-frangible alumina-silica fibers
Assignee: 3M Co
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Filing: 1976-05-04
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Granted: 1977-09-13
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Expires: 1996-05-04
Abstract
Abstract Transparent, smooth, fracture resistant, discreet, refractory oxide fibers of homogeneous chemical composition comprising 96 to 100 weight percent of a mixture or chemical combination of 67 to 77 parts by weight alumina and 23 to 33 parts by weight silica, said fibers having a predominant polycrystalline phase of mullite, transitional alumina, or a mixture of both, said refractory fibers being made by fiberizing a viscous liquid of oxide precursors comprising a silica sol and a water dispersible alumina sol or water soluble or dispersible organic aluminum salt, and drying, collecting, and calcining the resulting green fibers.
Inventors
- 👤 Karl A. Karst
- 👤 Harold G. Sowman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 17:17
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/622; C04B35/62227; C04B35/62231; C04B35/6224; C04B35/62245; C04B35/626; C04B35/62605; C04B35/62645; C04B35/62675; C04B2235/00; C04B2235/02; C04B2235/30; C04B2235/32; C04B2235/3201; C04B2235/3203; C04B2235/3205; C04B2235/3206; C04B2235/3208; C04B2235/3213; C04B2235/3215; C04B2235/3224; C04B2235/3225; C04B2235/3227; C04B2235/3231; C04B2235/3232; C04B2235/3239; C04B2235/3241; C04B2235/3244; C04B2235/3262; C04B2235/327; C04B2235/3272; C04B2235/3275; C04B2235/3279; C04B2235/3281; C04B2235/3284; C04B2235/3293; C04B2235/3294; C04B2235/44; C04B2235/443; C04B2235/447; C04B2235/448; C04B2235/449; C04B2235/50; C04B2235/52; C04B2235/5208; C04B2235/526; C04B2235/5264; C04B2235/54; C04B2235/5409; C04B2235/60; C04B2235/602; C04B2235/6025; C04B2235/70; C04B2235/72; C04B2235/721; C04B2235/80; C04B2235/96; C04B2235/9646; C04B2235/9653; C04B2235/9661
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
62 words
Transparent, smooth, fracture resistant, discrete, refractory oxide fibers uniformly round in cross section and of homogenous chemical composition comprising 96 to 100 weight percent of a mixture or chemical combination of 67 to 77 parts by weight alumina and 23 to 33 parts by weight silica, and fibers having a predominant polycrystalline phase of mullite, transitional alumina, or a mixture of both.
Claim 2
Dependent Claim
62 words
Transparent, smooth, fracture resistant, discrete, refractory oxide fibers uniformly round in cross section and of homogenous chemical composition comprising 96 to 100 weight percent of a mixture or chemical combination of 67 to 77 parts by weight alumina and 23 to 33 parts by weight silica, and fibers having a predominant polycrystalline phase of mullite, transitional alumina, or a mixture of both.
Claim 3
Dependent Claim
11 words
Fibers according to claim 1, wherein said polycrystalline phase is mullite.
Claim 4
Dependent Claim
30 words
Fibers according to claim 1, wherein said polycrystalline phase is mullite, the crystallites of which have an average size greater than 500 Angstroms, as determined by x-ray powder diffraction analysis.
Claim 5
Dependent Claim
35 words
Fibers according to claim 1, wherein said polycrystalline phase is transitional alumina and is in admixture with silica, said admixture being transformable at 1200 to 1400° C to a polycrystalline phase which is predominantly mullite.
Claim 6
Dependent Claim
90 words
Fibers according to claim 1, further comprising up to 4 total weight percent additive inorganic oxides selected from the group consisting of glass formers, intermediate glass formers, and non-glass formers, each said glass former being present in an amount up to 2 weight percent, each said intermediate glass former and non-glass former being present in an amount less than 1 weight percent or present in the amount of 1 to 2 weight percent provided an amount of 0.5 to 2 total weight percent of said glass formers is also present.
Claim 7
Dependent Claim
44 words
Fibers according to claim 1, further comprising up to 2 weight percent each of boria or phosphorus pentoxide, or both, the balance being a mixture or chemical combination of 70 to 75 parts by weight alumina and 25 to 30 parts by weight silica.
Claim 8
Dependent Claim
51 words
Fibers according to claim 1, further comprising from 0.5 up to 1 weight percent of boria of phosphorus pentoxide, or both, the balance being 99 to 99.5 weight percent of a mixture or chemical combination of 70 to 75 parts by weight alumina and 25 to 30 parts by weight silica.
Claim 9
Dependent Claim
47 words
Fibers according to claim 1, wherein said alumina and silica are present as 3Al 2 O 3 .2SiO 2 in the amount of 99 weight percent, said fibers further comprising 0.5 weight percent B 2 O 3 , and 0.5 weight percent P 2 O 5 .
Claim 10
Dependent Claim
13 words
Fibers according to claim 1 having a friability index of at least 0.2.
Claim 11
Dependent Claim
16 words
Fibers according to claim 1 having a surface area of less than 1 m 2 /g.
Claim 12
Dependent Claim
8 words
Fibers according to claim 1 which are continuous.
Claim 13
Dependent Claim
9 words
Yarn comprising fibers of claim 1 which are continuous.
Claim 14
Dependent Claim
23 words
Fibers according to claim 1 which are nonporous, free of shot, free of alpha alumina, and containing less than 0.1 weight percent carbon.
Claim 15
Dependent Claim
12 words
Fibers according to claim 1 with uniform diameters up to 25 micrometers.
Claim 16
Dependent Claim
17 words
Fibers according to claim 1 which are straight, and having uniform diameters of 7 to 15 micrometers.
Claim 17
Dependent Claim
131 words
Transparent, smooth, discrete, continuous, refractory, ceramic oxide fibers of homogeneous chemical composition comprising 99 to 99.5 weight percent of a mixture or chemical combination of 70 to 75 parts by weight alumina and 25 to 30 parts by weight silica, 0.5 to 1 weight percent of boria or phosphorus pentoxide, or both, and less than 0.1 weight percent carbon, said fibers being free of alpha alumina and having a polycrystalline phase of predominantly transitional alumina in admixture with silica which admixture is transformable upon firing said fibers at 1200° to 1400° C to mullite crystallites, said fibers having a friability index of at least 0.5 and a surface area less than 1 m 2 /g, said fibers being straight and uniformly round with a uniform diameter of 7 to 15 micrometers.
Claim 18
Dependent Claim
131 words
Transparent, smooth, discrete, continuous, refractory, ceramic oxide fibers of homogeneous chemical composition comprising 99 to 99.5 weight percent of a mixture or chemical combination of 70 to 75 parts by weight alumina and 25 to 30 parts by weight silica, 0.5 to 1 weight percent of boria or phosphorus pentoxide, or both, and less than 0.1 weight percent carbon, said fibers being free of alpha alumina and having a polycrystalline phase of predominantly transitional alumina in admixture with silica which admixture is transformable upon firing said fibers at 1200° to 1400° C to mullite crystallites, said fibers having a friability index of at least 0.5 and a surface area less than 1 m 2 /g, said fibers being straight and uniformly round with a uniform diameter of 7 to 15 micrometers.
Claim 19
Dependent Claim
7 words
Yarn comprising the fibers of claim 16.
Claim 20
Dependent Claim
8 words
Woven fabric comprising the fibers of claim 16.
Claim 21
Dependent Claim
15 words
A composite comprising a plastic, elastomeric, metallic, or ceramic matrix and fibers of claim 1.
Claim 22
Dependent Claim
68 words
A method for forming the refractory fibers of claim 1, which comprises fiberizing a viscous liquid of oxide precursors comprising a silica sol and a water dispersible alumina sol of water soluble or dispersible organic aluminum salt, said liquid having equivalent alumina and silica contents within or along the boundary lines A-B-C-D of FIG. 1 of the accompanying drawing, and drying, collecting, and calcining the resulting green fibers.
Claim 23
Dependent Claim
99 words
A method for forming the yarn of claim 17, which comprises continuously extruding through a plurality of stationary orifices a viscous aqueous dispersion comprising colloidal silica and a water soluble organic aluminum salt calcinable to alumina, said dispersion having equivalent alumina and silica contents within or along the boundary lines A-B-C-D of FIG. 1 of the accompanying drawing, continuously drawing in air the resulting continuous green fibers, continuously collecting said green fibers together as a strand, and continuously firing said strand in air in a relaxed, loose, unrestrained configuration to calcine it and convert it into said refractory yarn.
Claim 24
Dependent Claim
79 words
Transparent, smooth, fracture resistant, discrete, refractory oxide fibers uniformly round in cross-section and of homogeneous chemical composition comprising 96 to 100 weight percent of a mixture or chemical combination of 67 to 77 parts by weight alumina and 23 to 33 parts by weight silica, said fibers having a predominant polycrystalline phase of mullite, transitional alumina, or a mixture of both, a friability index of at least 0.2 and a surface area of less than 1 m 2 /g.
Claim 25
Dependent Claim
79 words
Transparent, smooth, fracture resistant, discrete, refractory oxide fibers uniformly round in cross-section and of homogeneous chemical composition comprising 96 to 100 weight percent of a mixture or chemical combination of 67 to 77 parts by weight alumina and 23 to 33 parts by weight silica, said fibers having a predominant polycrystalline phase of mullite, transitional alumina, or a mixture of both, a friability index of at least 0.2 and a surface area of less than 1 m 2 /g.
Claim 26
Dependent Claim
22 words
Fibers according to claim 1 wherein said homogeneous chemical composition consists essentially of said mixture or chemical combination of alumina and silica.
References Cited (Backward Citations)
US3503765A
Cited
US3585153A
Cited
US3795524A
Cited
US3853688A
Cited
US3865599A
Cited
US3950478A
Cited
US3947534A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-09-12 | 1981-03-14 | 1981-09-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-09-12 | 1985-03-14 | 1985-09-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-09-12 | 1989-03-14 | 1989-09-13 | $7700.00 | Window Closed / Lapsed |