Patent US4264676A successfully refreshed from Google Patents.
US4264676A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for preparing superfine ion-exchange fibers
Assignee: Nitivy Co Ltd
•
Filing: 1979-08-16
•
Granted: 1981-04-28
•
Expires: 1999-08-16
Abstract
Abstract Superfine fibers of polyvinyl alcohol type having a single fiber diameter of 0.1-1.0μ and a fineness of 0.8-80×10 -4 d/f are baked in the presence of a dehydration catalyst so that the weight loss ratio of fibers falls under the range of about 5 to 40%. When ion-exchange radicals are introduced into the partially dehydrated fiber, superfine fibers with a high ion-exchange rate are obtained.
Inventors
- 👤 Mitsutaka Uzumaki
- 👤 Masahiko Takashio
- 👤 Akihisa Shirasaka
- 👤 Tadayoshi Utsumi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 13:12
CPC Classifications
B; B01; B01J; B01J47/00; B01J47/12; B01J47/127; Y; Y10; Y10T; Y10T428/00; Y10T428/29; Y10T428/2913; Y10T428/298
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
70 words
A process for preparing superfine fibers with ion-exchange capacity which comprises baking superfine fibers of a polyvinyl alcohol type having a single fiber diameter of 0.1-1.0μ and a fineness of 0.8-80×10 -4 d/f in the presence of a dehydration catalyst at temperatures of about 80°-350° C. so that a weight loss ratio of fibers falls within the range of about 5-40% and introducing an ion-exchange radical into the baked fibers.
Claim 2
Dependent Claim
70 words
A process for preparing superfine fibers with ion-exchange capacity which comprises baking superfine fibers of a polyvinyl alcohol type having a single fiber diameter of 0.1-1.0μ and a fineness of 0.8-80×10 -4 d/f in the presence of a dehydration catalyst at temperatures of about 80°-350° C. so that a weight loss ratio of fibers falls within the range of about 5-40% and introducing an ion-exchange radical into the baked fibers.
Claim 3
Dependent Claim
20 words
The process of claim 1 wherein the dehydration catalyst is ammonium polyphosphate, phosphoric acid, ammonium phosphate salts and hydrogen chloride.
Claim 4
Dependent Claim
34 words
The process of claim 1 wherein said baking is effected in air, in an atmosphere of an inert gas or in a vacuum under the condition of having the dehydration catalyst involved in fibers.
Claim 5
Dependent Claim
28 words
The process of claim 1 wherein said baking is effected in an atmosphere of a gaseous hydrogen chloride or gaseous mixture of hydrogen chloride with an inert gas.
Claim 6
Dependent Claim
38 words
The process of claim 1 wherein said weight loss ratio of fibers falls within the range of about 5-25% and sulfuric ester radicals are introduced by a sulfation reaction with hydroxyl groups of the remaining vinyl alcohol units.
Claim 7
Dependent Claim
25 words
The process of claim 1 wherein said weight loss ratio of fibers falls within the range of about 20-40% and sulfonic acid radicals are introduced.
Claim 8
Dependent Claim
29 words
Superfine fibers of a polyvinyl alcohol type having a single fiber diameter of 0.1-1.0μ and a fineness of 0.8-80×10 -4 d/f, prepared according to the process of claim 1.
References Cited (Backward Citations)
US3546063A
Cited
US3097991A
Cited
US3644225A
Cited
US3629161A
Cited
US3770666A
Cited
US3741945A
Cited
JPS5138526A
Cited
SU574488A1
Cited
JPS534787A
Cited
JPS5430930A
Cited
JPS5477720A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-04-27 | 1984-10-27 | 1985-04-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-04-27 | 1988-10-27 | 1989-04-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-04-27 | 1992-10-27 | 1993-04-28 | $7700.00 | Window Closed / Lapsed |