US4927498A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Retention and drainage aid for papermaking
Assignee: Interlates Ltd
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Filing: 1988-06-30
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Granted: 1990-05-22
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Expires: 2008-06-30
Abstract
Abstract An improvement in a papermaking process in which an aqueous paper furnish containing cellulosic pulp, and optionally also mineral fillers is formed and dried, the improvement being the addition of a drainage and retention aid comprising a water soluble alkali metal polyaluminosilicate microgels formed from the reaction of polysilicic acid and an alkali metal aluminate, the polyaluminosilicate having an alumina/silica mole ratio greater than about 1/100, together with a cationic polymer selected from the group consisting of cationic starch, cationic guar and cationic polyacrylamide.
Inventors
- 👤 John D. Rushmere
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 04:08
CPC Classifications
D; D21; D21H; D21H21/00; D21H21/06; D21H21/10; D21H3/00; D21H17/00; D21H17/63; D21H17/66; D21H17/20; D21H17/21; D21H17/24; D21H17/28; D21H17/31; D21H17/32; D21H17/33; D21H17/34; D21H17/37
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
130 words
In a papermaking process in which an aqueous paper furnish containing cellulosic pulp, and optionally also mineral fillers is formed and dried, the improvement comprising adding to said pulp from about 0.01 to about 1.0 wt. percent, based on the dry weight of the paper furnish, of a water soluble alkali metal polyaluminosilicate microgel formed from the reaction of polysilicic acid and an alkali metal aluminate and comprising aggregates of particles in which each particle has a surface area of at least about 1000 meters 2 /gram, the polyaluminosilicate microgel having an alumina/silicate mole ratio greater than about 1/100, and from about 0.01 to about 2.0 wt. percent, based on the dry weight of the paper furnish of a water soluble cationic polymer capable of flocculating fiber and filler fines.
Claim 2
Dependent Claim
130 words
In a papermaking process in which an aqueous paper furnish containing cellulosic pulp, and optionally also mineral fillers is formed and dried, the improvement comprising adding to said pulp from about 0.01 to about 1.0 wt. percent, based on the dry weight of the paper furnish, of a water soluble alkali metal polyaluminosilicate microgel formed from the reaction of polysilicic acid and an alkali metal aluminate and comprising aggregates of particles in which each particle has a surface area of at least about 1000 meters 2 /gram, the polyaluminosilicate microgel having an alumina/silicate mole ratio greater than about 1/100, and from about 0.01 to about 2.0 wt. percent, based on the dry weight of the paper furnish of a water soluble cationic polymer capable of flocculating fiber and filler fines.
Claim 3
Dependent Claim
19 words
The process of claim 1 in which the polyaluminosilicate has an alumina/silica mole ratio between about 1/15 and 1/4.
Claim 4
Dependent Claim
19 words
The process of claim 1 in which the polyaluminosilicate has an alumina/silica mole ratio between about 1/6 and 1/7.
Claim 5
Dependent Claim
14 words
The process of claim 1 in which the alkali metal aluminate is sodium aluminate.
Claim 6
Dependent Claim
20 words
The method of claim 4 in which the polyaluminosilicate has an alumina/silica mole ratio between about (1/15) 1/25 and 1/4.
Claim 7
Dependent Claim
19 words
The process of claim 4 in which the polyaluminosilicate has an alumina/silica mole ratio between about 1/6 and 1/7.
Claim 8
Dependent Claim
29 words
The process of claim 1 or claim 4 in which the water soluble cationic polymer is selected from the group consisting of cationic starch, cationic guar and cationic polyacrylamide.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-05-21 | 1993-11-20 | 1994-05-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-05-21 | 1997-11-20 | 1998-05-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-05-21 | 2001-11-20 | 2002-05-22 | $7700.00 | Window Closed / Lapsed |