Patent US3845486A successfully refreshed from Google Patents.
Patent US4294575A successfully refreshed from Google Patents.
US4294575A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Peroxide stabilization
Assignee: Solutia Inc
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Filing: 1980-07-18
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Granted: 1981-10-13
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Expires: 2000-07-18
Abstract
Abstract In aqueous peroxide-containing solutions used in bleaching of cellulose fiber, peroxide stability is very greatly increased by inclusion of alkali metal polyphosphate and alkali metal diethylene triamine penta(methylene phosphonate). Especially useful for addition of such stabilizers to the peroxide-containing solutions to increase such stability are essentially anhydrous compositions containing metal sequestering compounds comprising such polyphosphate and phosphonate in a weight ratio from about 10:1 to about 1:5.
Inventors
- 👤 Xavier Kowalski
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 22:28
CPC Classifications
C; C11; C11D; C11D3/00; C11D3/39; C11D3/3902; C11D3/3937; C11D3/394; D; D06; D06L; D06L4/00; D06L4/10; D06L4/12
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
59 words
In a process for bleaching cellulose fiber with an aqueous peroxide-containing solution having a pH from about 7 to about 12.5, the improvement which comprises including in said solution from about 0.2 to about 20 grams per liter of alkali metal polyphosphate and from about 0.1 to about 10 grams per liter of alkali metal diethylene triamine penta(methylene phosphonate).
Claim 2
Dependent Claim
59 words
In a process for bleaching cellulose fiber with an aqueous peroxide-containing solution having a pH from about 7 to about 12.5, the improvement which comprises including in said solution from about 0.2 to about 20 grams per liter of alkali metal polyphosphate and from about 0.1 to about 10 grams per liter of alkali metal diethylene triamine penta(methylene phosphonate).
Claim 3
Dependent Claim
11 words
Process improvement of claim 1 wherein said solution is essentially silicate-free.
Claim 4
Dependent Claim
17 words
Process improvement of claim 1, said solution comprising at least about 20 ppm alkaline earth metal ions.
Claim 5
Dependent Claim
50 words
Process improvement of claim 3 wherein said bleaching is carried out at a temperature between about 50° and about 150° C. and said solution contains from about 1 to about 10 grams per liter of said polyphosphate and from about 0.5 to about 5 grams per liter of said phosphonate.
Claim 6
Dependent Claim
12 words
Process improvement of claim 4 wherein said polyphosphate is predominantly sodium tripolyphosphate.
References Cited (Backward Citations)
US3751372A
Cited
US3860391A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-10-12 | 1985-04-13 | 1985-10-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-10-12 | 1989-04-13 | 1989-10-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-10-12 | 1993-04-13 | 1993-10-13 | $7700.00 | Window Closed / Lapsed |