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US3663357A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Bleaching of mechanical cellulosic pulp with ozone in the presence of a peroxygen compound
Assignee: FPInnovations
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Filing: 1970-03-18
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Granted: 1972-05-16
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Expires: 1990-03-18
Abstract
Abstract Bleaching of mechanical pulp in the form of fibers and fiber aggregates by adding a peroxygen compound to moist pulp to provide a mixture of pulp and peroxygen compound and thereafter treating said mixture with an ozone containing gaseous mixture.
Inventors
- 👤 Norman Liebergott
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 06:40
CPC Classifications
D; D21; D21C; D21C9/00; D21C9/10; D21C9/1073
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
22 words
The process of claim 1 further including the positive step of comminuting said pulp, thereby to form said fiber and fiber aggregates.
Claim 2
Dependent Claim
27 words
The process of claim 2 wherein the comminuted pulp is in the form of fiber and fiber aggregates having an average diameter of 1/4 - 1 inch.
Claim 3
Dependent Claim
16 words
The process of claim 2 wherein the peroxygen compound is added prior to the comminution step.
Claim 4
Dependent Claim
15 words
The process of claim 2 wherein the peroxygen compound is added during the comminution step.
Claim 5
Dependent Claim
12 words
The process of claim 1 wherein the peroxygen compound is hydrogen peroxide.
Claim 6
Dependent Claim
17 words
The process of claim 6 wherein the hydrogen peroxide is in the form of an aqueous solution.
Claim 7
Dependent Claim
19 words
The process of claim 7 wherein the aqueous solution contains hydrogen peroxide, sodium silicate, sodium hydroxide and magnesium sulphate.
Claim 8
Dependent Claim
23 words
The process of claim 1 wherein the gaseous mixture comprises ozone - oxygen in concentrations of 4 percent on a weight/weight basis O3/O2.
Claim 9
Dependent Claim
18 words
The process of claim 1 wherein the gaseous mixture has been prepared by passing oxygen through an ozonizer.
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) | 1975-05-16 | 1975-11-15 | 1976-05-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-05-16 | 1979-11-15 | 1980-05-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-05-16 | 1983-11-15 | 1984-05-16 | $7700.00 | Window Closed / Lapsed |