US3762862A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Solvent bleaching process
Assignee: Dow Chemical Co
•
Filing: 1972-06-07
•
Granted: 1973-10-02
•
Expires: 1992-06-07
Abstract
Abstract Cotton and other cellulosic fibers are effectively and rapidly bleached by wetting with a suspension of hydrogen peroxide in a chlorinated hydrocarbon solvent and drying the wetted material by exposure to hot chlorinated hydrocarbon solvent vapor. The process is particularly effective with raw cotton and cotton linters.
Inventors
- 👤 W Cunningham
- 👤 D Knight
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 14:30
CPC Classifications
D; D06; D06L; D06L4/00; D06L4/10; D06L4/17
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
13 words
The process of claim 1 wherein the vapor temperature is about 65*-145* C.
Claim 2
Dependent Claim
11 words
The process of claim 1 wherein the fiber material is cotton.
Claim 3
Dependent Claim
11 words
The process of claim 3 wherein the peroxide is hydrogen peroxide.
Claim 4
Dependent Claim
19 words
The process of claim 4 wherein the vaporized solvent and the solvent of the peroxide composition are the same.
Claim 5
Dependent Claim
10 words
The process of claim 5 wherein the solvent is perchloroethylene.
Claim 6
Dependent Claim
11 words
The process of claim 6 wherein the temperature is 122*-140* C.
Claim 7
Dependent Claim
34 words
The process of claim 1 wherein the aqueous peroxide-solvent mixture contains about 0.01-1 percent based on the weight of mixture of a surface active agent capable of converting said mixture into a stable suspension.
Claim 8
Dependent Claim
15 words
The process of claim 1 wherein the aqueous solution has a pH of about 7-11.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-10-01 | 1977-04-02 | 1977-10-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-01 | 1981-04-02 | 1981-10-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-01 | 1985-04-02 | 1985-10-02 | $7700.00 | Window Closed / Lapsed |