US3658640A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pulping of wet strength broke containing polyvinylamide-glyoxal resin
Assignee: Wyeth Holdings LLC
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Filing: 1970-04-29
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Granted: 1972-04-25
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Expires: 1990-04-29
Abstract
Abstract Wet strength paper broke composed of fibers bonded together by a wet strength polyvinylamide-glyoxal resin in thermoset state is pulped by contacting the broke with an aqueous medium substantially free from oxidizing agent having a pH between 5 and 10 and a temperature above 100* F. and subjecting the broke to mechanical pulping.
Inventors
- 👤 Anthony Thomas Coscia
- 👤 Laurence Lyman Williams
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 15:48
CPC Classifications
D; D21; D21C; D21C5/00; D21C5/02; Y; Y02; Y02W; Y02W30/00; Y02W30/50; Y02W30/64
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
21 words
A method according to claim 1 wherein the aqueous medium has a temperature above 100* F. and a pH above 9.
Claim 2
Dependent Claim
22 words
A method according to claim 1 wherein the contacting of the broke with aqueous medium and the mechanical pulping are performed simultaneously.
Claim 3
Dependent Claim
58 words
A method for the manufacture of wet strength paper, which consists essentially in forming an aqueous suspension of cellulose fibers pulped by a process according to claim 1, forming said fibers into a wet web without addition of wet strength resin thereto, and drying said web on rollS having a surface temperature between 190* F. and 250* F.
Claim 4
Dependent Claim
32 words
A process according to claim 4 wherein said polyvinylamide-glyoxal polymer is cationic, and a water-soluble cationic cellulose-substantive strengthening agent is added to said suspension before said fibers are formed into a web.
Claim 5
Dependent Claim
40 words
Papermaking pulp composed of water-laid cellulose fibers having a water content of 20 percent - 30 percent by weight and having a uniformly absorbed content of a water-soluble thermosetting ionic polyacrylamide-glyoxal resin in non-thermoset state as latent wet strengthening agent.
Claim 6
Dependent Claim
19 words
Pulp according to claim 6 the aqueous phase whereof has a pH in the range of 4 to 6.
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) | 1975-04-25 | 1975-10-25 | 1976-04-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-04-25 | 1979-10-25 | 1980-04-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-04-25 | 1983-10-25 | 1984-04-25 | $7700.00 | Window Closed / Lapsed |