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US5336642A
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Canasite-apatite glass-ceramics
Assignee: Corning Inc
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Filing: 1993-09-01
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Granted: 1994-08-09
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Expires: 2013-09-01
Abstract
Abstract A glass-ceramic biomaterial having high strength and toughness, a family of glasses from which the glass-ceramic biomaterial can be produced, and a method of production. The material has a primary crystal phase of F-canasite and a secondary crystal phase of F-apatite. The glass family is SiO 2 --CaO--Na 2 O--K 2 O--P 2 O 5 --F. The method may be a single stage heat treatment, or a two stage involving an initial nucleation and a subsequent crystallization.
Inventors
- 👤 Christine C. Wolcott
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 14:00
CPC Classifications
C; C03; C03C; C03C10/00; C03C10/16
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
66 words
A glass-ceramic biomaterial having a bending strength greater than 25,000 psi (172 MPa), a fracture toughness greater than 2.3 Kpsi×in 1/2 (2.5 MPa m 1/2 ), a primary crystal phase of F-canasite, a secondary crystal phase of F-apatite, a crystal phase structure including interlocking blades of F-canasite with at least a portion of the F-apatite crystals within the interlocking F-canasite blades, and a residual glassy phase.
Claim 2
Dependent Claim
66 words
A glass-ceramic biomaterial having a bending strength greater than 25,000 psi (172 MPa), a fracture toughness greater than 2.3 Kpsi×in 1/2 (2.5 MPa m 1/2 ), a primary crystal phase of F-canasite, a secondary crystal phase of F-apatite, a crystal phase structure including interlocking blades of F-canasite with at least a portion of the F-apatite crystals within the interlocking F-canasite blades, and a residual glassy phase.
Claim 3
Dependent Claim
73 words
An SiO 2 --CaO--Na 2 O--K 2 O--P 2 O 5 --F glass capable of being thermally converted to a glass-ceramic having F-canasite as a primary crystal phase and F-apatite as a secondary crystal phase and having a composition, as calculated in weight % on an oxide basis, consisting essentially of 42-70% SiO 2 , 20-30% CaO, 6-12% Na 2 O, 3-10% K 2 O, 2-13% P 2 O 5 , and 3-11%.
Claim 4
Dependent Claim
73 words
An SiO 2 --CaO--Na 2 O--K 2 O--P 2 O 5 --F glass capable of being thermally converted to a glass-ceramic having F-canasite as a primary crystal phase and F-apatite as a secondary crystal phase and having a composition, as calculated in weight % on an oxide basis, consisting essentially of 42-70% SiO 2 , 20-30% CaO, 6-12% Na 2 O, 3-10% K 2 O, 2-13% P 2 O 5 , and 3-11%.
Claim 5
Dependent Claim
29 words
A glass in accordance with claim 2 wherein the glass, as melted, is a clear glass containing no more than about 8 weight % P 2 O 5 .
Claim 6
Dependent Claim
29 words
A glass in accordance with claim 2 wherein the glass, as melted, is an opal glass containing no more than about 8 weight % P 2 O 5 .
Claim 7
Dependent Claim
24 words
A glass in accordance with claim 2 wherein the glass, as melted, contains F-apatite crystals and 8-13 weight % P 2 O 5 .
Claim 8
Dependent Claim
24 words
A glass in accordance with claim 2 wherein the glass is self nucleated by CaF 2 , P 2 O 5 , or both.
Claim 9
Independent Claim
105 words
A method of producing a glass-ceramic biomaterial having a primary crystal phase of F-canasite, and a secondary crystal phase of F-apatite, which comprises melting a glass having a composition, as calculated in weight % on an oxide basis, consisting, essentially of 42-70% SiO 2 , 20-30% CaO, 6-12% Na 2 O, 3-10% K 2 O, 2-13% P 2 O 5 , and 3-11% F, cooling the glass below its transformation range and subjecting the glass to a treat treatment at a temperature higher than the glass transformation temperature range, but, not over 950° C., for a time sufficient to produce F-canasite and F-apatite crystal phases.
Claim 10
Independent Claim
105 words
A method of producing a glass-ceramic biomaterial having a primary crystal phase of F-canasite, and a secondary crystal phase of F-apatite, which comprises melting a glass having a composition, as calculated in weight % on an oxide basis, consisting, essentially of 42-70% SiO 2 , 20-30% CaO, 6-12% Na 2 O, 3-10% K 2 O, 2-13% P 2 O 5 , and 3-11% F, cooling the glass below its transformation range and subjecting the glass to a treat treatment at a temperature higher than the glass transformation temperature range, but, not over 950° C., for a time sufficient to produce F-canasite and F-apatite crystal phases.
Claim 11
Dependent Claim
31 words
A method in accordance with claim 7 wherein the heat treatment is in the temperature range of 685°-950° C. for a period of time ranging from four hours to one-half hour.
Claim 12
Dependent Claim
23 words
A method in accordance with claim 9 wherein the heat treatment is at a temperature of about 850° C. for about one hour.
Claim 13
Dependent Claim
25 words
A method in accordance with claim 7 wherein the heat treatment comprises an initial nucleation stage followed by a crystallization stage at a higher temperature.
Claim 14
Dependent Claim
35 words
A method in accordance with claim 10 wherein the initial nucleation stage is at a temperature in the range of 585°-635° C. and the crystallization is at a temperature in the range of 750°-950° C.
References Cited (Backward Citations)
US3981736A
Cited
US4386162A
Cited
US4397670A
Cited
US4536481A
Cited
US4775646A
Cited
US4643982A
Cited
US4652534A
Cited
US5536480A
Cited
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| 3.5 Years (Year 4) | 1997-08-08 | 1998-02-07 | 1998-08-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-08-08 | 2002-02-07 | 2002-08-09 | $3760.00 | Window Closed / Lapsed |
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