US4071609A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for preparing particulate zinc oxide shapes of high surface area and improved strength
Assignee: Manufacturers Hanover Trust Co
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Filing: 1975-07-09
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Granted: 1978-01-31
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Expires: 1995-07-09
Abstract
Abstract Particulate zinc oxide shaped of high surface area and improved crushing strength are prepared without extraneous binder by a process including forming normal surface area zinc oxide into shapes without binder, converting at least a portion of the zinc oxide to basic zinc carbonate by exposing the shapes in the presence of moisture, to a carbon dioxide-containing atmosphere and effecting substantially complete decomposition of the basic zinc carbonate. Conditions of bulk density, moisture content and temperature are controlled.
Inventors
- 👤 Victor S. Robinson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 06:22
CPC Classifications
B; B01; B01D; B01D53/00; B01D53/34; B01D53/46; B01D53/48; C; C01; C01G; C01G9/00; C01G9/02
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
89 words
A process for producing high surface area and high crush strength particulate zinc oxide shapes, said process comprising: a. forming normal zinc oxide having a specific surface area less than 10 square meters per gram into pre-determined shapes without the addition of extraneous binding material; b. exposing said normal zinc oxide shapes to a carbon dioxide-containing atmosphere including water vapor; c. converting at least about 45% of said zinc oxide into basic zinc carbonate; and d. decomposing substantially all of said basic zinc carbonate into particulate zinc oxide shapes.
Claim 2
Dependent Claim
89 words
A process for producing high surface area and high crush strength particulate zinc oxide shapes, said process comprising: a. forming normal zinc oxide having a specific surface area less than 10 square meters per gram into pre-determined shapes without the addition of extraneous binding material; b. exposing said normal zinc oxide shapes to a carbon dioxide-containing atmosphere including water vapor; c. converting at least about 45% of said zinc oxide into basic zinc carbonate; and d. decomposing substantially all of said basic zinc carbonate into particulate zinc oxide shapes.
Claim 3
Dependent Claim
18 words
The process according to claim 1 wherein said normal zinc oxide shapes contain up to about 30% water.
Claim 4
Dependent Claim
26 words
The process according to claim 1 wherein said normal zinc oxide shapes have a bulk density between about 45 and about 85 lb. per cubic foot.
Claim 5
Dependent Claim
36 words
The process according to claim 1 wherein said normal zinc oxide shapes are exposed to said carbon dioxide-containing atmosphere at temperatures between about 50° and about 90° C for between about 1 and about 4 hours.
Claim 6
Dependent Claim
18 words
The process according to claim 1 wherein said carbon dioxide-containing atmosphere comprises at least about 60% carbon dioxide.
Claim 7
Dependent Claim
28 words
The process according to claim 1 wherein said carbon dioxide-containing atmosphere comprises between about 90 and 100% carbon dioxide and between about 0 and about 10% water vapor.
Claim 8
Dependent Claim
22 words
The process according to claim 1 wherein said basic zinc carbonate is decomposed at a temperature between about 200° and 500° C.
Claim 9
Dependent Claim
23 words
The process according to claim 1 wherein said basic zinc carbonate is decomposed at a temperature between about 250° and about 350° C.
Claim 10
Dependent Claim
33 words
The process of claim 1 wherein said particulate zinc oxide shapes have a crushing strength between about five and about thirty times greater than the crushing strength of the predetermined zinc oxide shapes.
References Cited (Backward Citations)
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US2727808A
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US3441370A
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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) | 1981-01-30 | 1981-08-01 | 1982-01-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-01-30 | 1985-08-01 | 1986-01-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-01-30 | 1989-08-01 | 1990-01-31 | $7700.00 | Window Closed / Lapsed |