US4351857A
Expired / Lapsed
US
⏱️ 0.0 years remaining
New surface in cellulosic fibers by use of radiofrequency plasma of ammonia
Assignee: United States Department of Agriculture
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Filing: 1981-08-19
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Granted: 1982-09-28
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Expires: 2001-08-19
Abstract
Abstract A process for producing a polymeric-type film in the surface of cellulosic fibers is disclosed. Cellulosic fibers are irradiated in the colored area of a radiofrequency plasma of ammonia for a period of about 10 minutes to 2 hours in a reactor designed to admit ammonia between electrodes at a rate such that all of the ammonia molecules have been activated to plasma. A polymer coating is formed in the surface of the cellulosic fibers that is alkali resistant, water-repellent and improves the wrinkle recovery of the fabrics.
Inventors
- 👤 Truman L. Ward
- 👤 Ruth R. Benerito
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 22:33
CPC Classifications
D; D06; D06M; D06M10/00; D06M10/02; D06M10/025; D06M10/04; D06M10/06; D06M2101/00; D06M2101/02; D06M2101/04; D06M2101/06; D06M2200/00; D06M2200/10; D06M2200/12; Y; Y10; Y10S; Y10S8/00; Y10S8/12
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
62 words
A process for producing a polymeric-type film in the surface of cellulosic fibers which process comprises: irradiating cellulosic fibers in the colored area of a radiofrequency plasma of ammonia in a reactor designed so that the ammonia is admitted into the reactor area between electrodes and at such a rate so that all of the ammonia molecules have been activated to plasma.
Claim 2
Dependent Claim
62 words
A process for producing a polymeric-type film in the surface of cellulosic fibers which process comprises: irradiating cellulosic fibers in the colored area of a radiofrequency plasma of ammonia in a reactor designed so that the ammonia is admitted into the reactor area between electrodes and at such a rate so that all of the ammonia molecules have been activated to plasma.
Claim 3
Dependent Claim
20 words
The process of claim 1 wherein the fibers are irradiated for a period of about 10 minutes to 2 hours.
Claim 4
Dependent Claim
29 words
The process of claim 1 wherein the radiofrequency field is from about 1 to 30 megahertz and the power level will depend on the pressure in the reaction vessel.
Claim 5
Dependent Claim
143 words
The process of claim 1 including reducing the pressure in the reactor vessel to the range of about 100 to 500 millitorr, the radiofrequency generator operates at 13.56 megahertz and adjusted to a power level of between 20 and 80 watts of output power, and the ammonia gas is bled into the reactor through an inlet between the electrodes at a rate of about one to five standard cubic centimeters per minute, the impedance matching network between the electrodes and the rf generator is adjusted for maximum plasma glow, the sample is irradiated for about 10 minutes to 2 hours with the longer time period required at the lower end of the power range, and at the end of the allotted time period, the ammonia is turned off, the rf generator is stopped, the reactor pressure restored to atmospheric and the sample removed.
Claim 6
Dependent Claim
16 words
The process of claim 1 wherein the cellulosic fiber is desized, scoured and peroxide bleached cotton-printcloth.
Claim 7
Dependent Claim
12 words
The process of claim 1 wherein the cellulosic fiber is rayon fabric.
Claim 8
Dependent Claim
16 words
The process of claim 1 wherein the cellulosic fiber is filter paper made from wood 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) | 1985-09-27 | 1986-03-29 | 1986-09-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-09-27 | 1990-03-29 | 1990-09-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-09-27 | 1994-03-29 | 1994-09-28 | $7700.00 | Window Closed / Lapsed |