US4298428A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Use of additives in pulp bleaching processes to preserve pulp strength
Assignee: ChampionX LLC
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Filing: 1980-08-07
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Granted: 1981-11-03
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Expires: 2000-08-07
Abstract
Abstract Improved pulp strength and brightness of chemically produced pulp can be obtained by treating the pulp with the addition of 0.05-0.5% based on the weight of the dry fiber of certain amine materials in the hypochlorite bleaching stage.
Inventors
- 👤 Michael D. Breslin
- 👤 David R. Cosper
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 15:33
CPC Classifications
D; D21; D21C; D21C9/00; D21C9/10; D21C9/1026; D21C9/1036
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
84 words
In a method for the alkaline bleaching of aqueous slurries of chemically produced cellulosic materials utilizing a hypochlorite bleaching agent selected from the group consisting of sodium hypochlorite and calcium hypochlorite, the improvement comprising maintaining in the alkaline aqueous slurry of the chemically produced cellulosic material during treatment with said bleaching agent from 0.01-0.5% by weight of an amine compound selected from the group consisting of: ethylamine, methoxypropylamine, monoethanolamine, n-butylamine, 3-aminopropanol, isopropylamine, ethylenediamine, aniline, 2 amino-2 methylpropanol, 2-aminopropanediol triethylenetetramine, 1,3-diaminopropane, diaminohydroxypropane, ethylenediamine, hexamethylenediamine, morpholine.
Claim 2
Dependent Claim
84 words
In a method for the alkaline bleaching of aqueous slurries of chemically produced cellulosic materials utilizing a hypochlorite bleaching agent selected from the group consisting of sodium hypochlorite and calcium hypochlorite, the improvement comprising maintaining in the alkaline aqueous slurry of the chemically produced cellulosic material during treatment with said bleaching agent from 0.01-0.5% by weight of an amine compound selected from the group consisting of: ethylamine, methoxypropylamine, monoethanolamine, n-butylamine, 3-aminopropanol, isopropylamine, ethylenediamine, aniline, 2 amino-2 methylpropanol, 2-aminopropanediol triethylenetetramine, 1,3-diaminopropane, diaminohydroxypropane, ethylenediamine, hexamethylenediamine, morpholine.
Claim 3
Dependent Claim
12 words
The method of claim 1 wherein the bleaching agent is sodium hypochlorite.
Claim 4
Dependent Claim
12 words
The method of claim 1 wherein the bleaching agent is calcium hypochlorite.
Claim 5
Dependent Claim
23 words
The method of claim 1 wherein said amine is selected from the group consisting of: ethylamine, methoxypropylamine, monoethanolamine, n-butylamine, triethylenetetramine, 1,3-diaminopropane, diaminohydroxypropane, ethylenediamine.
Claim 6
Dependent Claim
21 words
The method of claim 4 wherein the amine bleaching agent is selected from the group consisting of ethylamine, monoethanolamine, and methoxypropylamine.
Claim 7
Dependent Claim
25 words
The method of claim 5 wherein the amine additive is utilized at a level of from 0.02-0.01% based upon the dry weight of the pulp.
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) | 1984-11-02 | 1985-05-04 | 1985-11-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-11-02 | 1989-05-04 | 1989-11-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-11-02 | 1993-05-04 | 1993-11-03 | $7700.00 | Window Closed / Lapsed |