US4599139A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Dewatering of wet paper webs using Mannich acrylamide polymers
Assignee: Wyeth Holdings LLC
•
Filing: 1984-03-26
•
Granted: 1986-07-08
•
Expires: 2004-03-26
Abstract
Abstract Dewatering of wet paper webs in general and particularly under high vacuum is improved by the addition of a Mannich acrylamide polymer having a molecular weight of not greater than about 300,000 to an aqueous slurry of papermaking fibers having a pH less than about 5.5.
Inventors
- 👤 Robert E. Scalfarotto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 07:15
CPC Classifications
D; D21; D21C; D21C9/00; D21C9/18; D21H; D21H17/00; D21H17/20; D21H17/33; D21H17/34; D21H17/41; D21H17/44; D21H17/45; D21H17/455; D21H17/37
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
122 words
In a method for the production of paper wherein an aqueous slurry of paper-producing fibers containing from about 0.01 to about 0.3 percent solids, by weight, based on the fiber content of the furnish, of a water-soluble, essentially linear, polymer having the formula: ##STR2## wherein R is an alkyl group of 1-2 carbon atoms, inclusive, R 1 is hydrogen or methyl, n is an integer of 1-6, inclusive, the ratio of x:y range from about 1:3 to about 3:1, respectively, and z is the degree of polymerization, is wet laid to form paper, the improvement wherein z is such that the molecular weight of the polymer is not greater than 300,000 and the pH of the slurry is less than about 5.5.
Claim 2
Dependent Claim
122 words
In a method for the production of paper wherein an aqueous slurry of paper-producing fibers containing from about 0.01 to about 0.3 percent solids, by weight, based on the fiber content of the furnish, of a water-soluble, essentially linear, polymer having the formula: ##STR2## wherein R is an alkyl group of 1-2 carbon atoms, inclusive, R 1 is hydrogen or methyl, n is an integer of 1-6, inclusive, the ratio of x:y range from about 1:3 to about 3:1, respectively, and z is the degree of polymerization, is wet laid to form paper, the improvement wherein z is such that the molecular weight of the polymer is not greater than 300,000 and the pH of the slurry is less than about 5.5.
Claim 3
Dependent Claim
12 words
A method according to claim 1 wherein both R radicals are methyl.
Claim 4
Dependent Claim
10 words
A method according to claim 1 wherein n is 1.
Claim 5
Dependent Claim
16 words
A method according to claim 1 wherein n is 1 and both R radicals are methyl.
Claim 6
Dependent Claim
19 words
A method according to claim 1 wherein n is 1, both R radicals are methyl and R' is hydrogen.
Claim 7
Dependent Claim
26 words
A method according to claim 1 wherein n is 1, both R radicals are methyl, R' is hydrogen and the ratio of x:y is about 3:1.
Claim 8
Dependent Claim
13 words
A method according to claim 1 wherein the pH is from about 4-5.
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) | 1989-07-07 | 1990-01-06 | 1990-07-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-07-07 | 1994-01-06 | 1994-07-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-07-07 | 1998-01-06 | 1998-07-08 | $7700.00 | Window Closed / Lapsed |