Patent US3660027A successfully refreshed from Google Patents.
US3660027A
Copy Number
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US
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High purity hot pressed boron nitride
Assignee: Union Carbide Corp
•
Filing: 1969-05-06
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Granted: 1972-05-02
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Expires: 1989-05-06
Overview & Biblio
Claims (11)
Citations (6)
Maintenance Schedule (3)
Categories & Tags (0)
Abstract
Abstract High purity boron nitride articles of manufacture having a high density and improved properties. The improved boron nitride articles have a unique acicular crystal structure, an oxygen content of less than 0.5 percent by weight, a density of at least 1.9 grams/cc., excellent hot strength, low and substantially isotropic coefficients of thermal expansion with no irreversible thermal expansion, excellent thermal shock resistance, moisture insensitivity and improved dielectric properties. These articles are produced by treating conventional hot pressed boron nitride articles with a suitable solvent to lower their boron oxide (B2O3) content, and then sintering the treated material in an inert atmosphere at a temperature of from 1,600* C. to 2,100* C. in the absence of pressure or mechanical restraint.
Inventors
👤 Victor Mandorf Jr
👤 Lionel C Montgomery
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 20:59
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/515; C04B35/58; C04B35/583
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
19 words
A process as in claim 1 wherein the solvent is selected from the group consisting of water and alcohols.
Claim 2
Dependent Claim
11 words
A process as in claim 1 wherein the solvent is methanol.
Claim 3
Dependent Claim
25 words
A process as in claim 1 wherein the solvent is water and the thickness of the hot pressed boron nitride does not exceed one-half inch.
Claim 4
Dependent Claim
17 words
A process as in claim 1 wherein the sintering temperature is from 1,800* C. to 2,100* C.
Claim 5
Dependent Claim
19 words
A process as in claim 5 wherein the solvent is selected from the group consisting of water and alcohols.
Claim 6
Dependent Claim
11 words
A process as in claim 5 wherein the solvent is methanol.
Claim 7
Dependent Claim
25 words
A process as in claim 5 wherein the solvent is water and the thickness of the hot pressed boron niTride does not exceed one-half inch.
Claim 8
Dependent Claim
17 words
A process as in claim 1 wherein the sintering temperature is from 1,950* C. to 2,050* C.
Claim 9
Dependent Claim
19 words
A process as in claim 9 wherein the solvent is selected from the group consisting of water and alcohols.
Claim 10
Dependent Claim
11 words
A process as in claim 9 wherein the solvent is methanol.
Claim 11
Dependent Claim
25 words
A process as in claim 9 wherein the solvent is water and the thickness of the hot pressed boron nitride does not exceed one-half inch.
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) 1975-05-02
1975-11-01 1976-05-02
$2000.00
Window Closed / Lapsed
7.5 Years (Year 8) 1979-05-02
1979-11-01 1980-05-02
$3760.00
Window Closed / Lapsed
11.5 Years (Year 12) 1983-05-02
1983-11-01 1984-05-02
$7700.00
Window Closed / Lapsed