US3619358A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for improving water drainage from a paper web on a wire-screen of a paper machine by using a modified polyacrylamide prepared from a water-soluble polyacrylamide by the hoffman reaction
Assignee: Seiko Kagaku Kogyo Co Ltd
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Filing: 1969-06-05
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Granted: 1971-11-09
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Expires: 1989-06-05
Abstract
Abstract The sheeting or paper web forming operation in a paper making process, can be facilitated by addition to a pulp stock, of a modified polyacrylamide prepared from a water-soluble polyacrylamide by the Hoffmann reaction.
Inventors
- 👤 Ten Yoshii
- 👤 Shigehiko Yoshioka
- 👤 Hazimu Hashimoto
- 👤 Iwao Sugiyama
- 👤 Tsuruo Okada
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 11:13
CPC Classifications
D; D21; D21H; D21H17/00; D21H17/20; D21H17/33; D21H17/34; D21H17/41; D21H17/44; D21H17/45; D21H17/455; D21H17/37
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
40 words
A method according to claim 1, wherein the aqueous solution of the modified polyacrylamide is added to the cellulosic pulp slurry, in an amount equivalent to 0.03-0.06 percent based on the dry weight of the pulp, of the modified polyacrylamide.
References Cited (Backward Citations)
US2729560A
Cited
US2890978A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-11-08 | 1975-05-10 | 1975-11-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-11-08 | 1979-05-10 | 1979-11-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-11-08 | 1983-05-10 | 1983-11-09 | $7700.00 | Window Closed / Lapsed |