US4950435A
Expired / Lapsed
US
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Process for producing aluminum nitride sintered body
Assignee: Tokuyama Corp
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Filing: 1987-07-08
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Granted: 1990-08-21
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Expires: 2007-07-08
Abstract
Abstract A process for producing a sintered body of aluminum nitride, which comprises mixing an aluminum nitride powder with (A) an alkaline earth metal aluminate, or both of (A-1) an oxide or oxide-forming compound of aluminum, and (A-2) an oxide or oxide-forming compound of an alkaline earth metal, and (B) an oxide or oxide-forming compound of yttrium or an element of the lanthanide series, and firing the resulting mixture.
Inventors
- 👤 Hitofumi Taniguchi
- 👤 Nobuyuki Kuramoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 11:59
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/515; C04B35/58; C04B35/581
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
99 words
A process for producing a sintered body of aluminum nitride, which consists essentially of an aluminum nitride powder with (A) an alkaline earth metal aluminate, and (B) an oxide or oxide-forming compound of yttrium or an element of the lantanide series, the amount of component (A) being 0.3 to 10% by weight based on the total weight of the aluminum nitride powder and components (A) and (B), and the amount of component (B) being 0.2 to 5% by weight based on the total weight of the aluminum nitride powder and components (A) and (B), and firing the resulting mixture.
Claim 2
Dependent Claim
99 words
A process for producing a sintered body of aluminum nitride, which consists essentially of an aluminum nitride powder with (A) an alkaline earth metal aluminate, and (B) an oxide or oxide-forming compound of yttrium or an element of the lantanide series, the amount of component (A) being 0.3 to 10% by weight based on the total weight of the aluminum nitride powder and components (A) and (B), and the amount of component (B) being 0.2 to 5% by weight based on the total weight of the aluminum nitride powder and components (A) and (B), and firing the resulting mixture.
Claim 3
Dependent Claim
22 words
The process of claim 1 wherein the weight ratio of the component (A) to the component (B) is from 0.2 to 15.
Claim 4
Dependent Claim
19 words
The process of claim 1 wherein the firing is carried out at a temperature of 1600° to 2400° C.
Claim 5
Dependent Claim
17 words
The process of claim 1 wherein the firing is carried out for 10 minutes to 30 hours.
Claim 6
Dependent Claim
18 words
The process of claim 1 wherein the firing is carried out in vacuum or in a non-oxidizing atmosphere.
Claim 7
Dependent Claim
39 words
The process of claim 1 wherein the firing is carried out at a temperature of 1600° to 2400° C., and from 1100° C. to 1600° C., the temperature is elevated at a rate of 1° C. to 40° C./min.
Claim 8
Dependent Claim
45 words
The process of claim 1 wherein the alkaline earth metal aluminate (A) has the composition represented by the formula mMO.Al.sub.2 O.sub.3.nH.sub.2 O wherein M is an alkaline earth metal, m is a number of at least 0.3, and n is 0 or a positive number.
Claim 9
Dependent Claim
17 words
The process of claim 1 wherein the alkaline earth metal aluminate is calcium, strontium or barium aluminate.
Claim 10
Dependent Claim
46 words
The process of claim 1 wherein the oxide of yttrium or an element of the lanthanide series is an oxide of an element selected from the group consisting of Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu.
Claim 11
Dependent Claim
46 words
The process of claim 1 wherein the oxide-forming compound of yttrium or an element of the lanthanide series is a carbonate, oxalate, nitrate, nitrite, bicarbonate, sulfate, sulfite, chlorate or acetate of an element selected from the group consisting of yttrium and elements of the lanthanide series.
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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) | 1993-08-20 | 1994-02-19 | 1994-08-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-08-20 | 1998-02-19 | 1998-08-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-08-20 | 2002-02-19 | 2002-08-21 | $7700.00 | Window Closed / Lapsed |