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US4178205A
Expired / Lapsed
US
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High strength non-woven fibrous material
Assignee: Dow Chemical Co
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Filing: 1977-08-17
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Granted: 1979-12-11
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Expires: 1997-08-17
Abstract
Abstract A high strength, non-woven fibrous material is prepared by (a) mixing an aqueous slurry of a negatively charged, water-insoluble natural or synthetic fiber or blend of fibers with an amount up to the fiber charge reversal point of a structured particle latex having pH independent cationic charges bound at or near the particle surface to form an aqueous suspension, (b) draining water from the aqueous suspension to form a wet web (c) wet pressing the web and (d) drying the web by heating.
Inventors
- 👤 Ritchie A. Wessling
- 👤 William A. Foster
- 👤 Dale M. Pickelman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 09:47
CPC Classifications
D; D21; D21H; D21H17/00; D21H17/20; D21H17/33; D21H17/34; D21H17/41; D21H17/44
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
156 words
A method for preparing non-woven fibrous web comprising: (a) mixing an aqueous slurry of a negatively charged, water-insoluble, natural or synthetic fiber or a blend of such fibers with a structured particle latex having particles consisting of a non-ionic organic polymer core encapsulated by a thin polymer layer having bound charges of pH independent cationic groups, said charges being present in an amount of from about 0.15 milliequivalent to about 0.6 milliequivalent per gram of polymer in the latex; the non-ionic polymer core having a glass transition temperature of from about -80° C. to about 100° C.; the amount of said latex being not greater than the amount required to cause charge reversal on the fiber; (b) draining water from the aqueous suspension to form a wet web; (c) wet pressing the web; and (d) heating the wet web; whereby there is formed a non-woven fibrous web having polymer uniformly distributed and bonded to the fiber.
Claim 2
Independent Claim
156 words
A method for preparing non-woven fibrous web comprising: (a) mixing an aqueous slurry of a negatively charged, water-insoluble, natural or synthetic fiber or a blend of such fibers with a structured particle latex having particles consisting of a non-ionic organic polymer core encapsulated by a thin polymer layer having bound charges of pH independent cationic groups, said charges being present in an amount of from about 0.15 milliequivalent to about 0.6 milliequivalent per gram of polymer in the latex; the non-ionic polymer core having a glass transition temperature of from about -80° C. to about 100° C.; the amount of said latex being not greater than the amount required to cause charge reversal on the fiber; (b) draining water from the aqueous suspension to form a wet web; (c) wet pressing the web; and (d) heating the wet web; whereby there is formed a non-woven fibrous web having polymer uniformly distributed and bonded to the fiber.
Claim 3
Dependent Claim
18 words
The process of claim 1 in which the fiber is a paper-making pulp and the product is paper.
Claim 4
Dependent Claim
13 words
The process of claim 1 in which the pH independent group is sulfonium.
Claim 5
Dependent Claim
15 words
The process of claim 1 in which the pH independent cationic group is quaternary ammonium.
Claim 6
Dependent Claim
15 words
The process of claim 1 in which the particle diameter is less than 1500 Angstroms.
Claim 7
Dependent Claim
19 words
The process of claim 5 in which the particle diameter is from about 600 Angstroms to about 1000 Angstroms.
Claim 8
Dependent Claim
32 words
The process of claim 1 in which the amount of latex is from about 0.5 percent to about 5 percent of the weight of the fiber, calculated on a dry weight basis.
Claim 9
Dependent Claim
20 words
The process of claim 1 in which the glass transition temperature is from about -25° C. to about 40° C.
Claim 10
Dependent Claim
28 words
The process of claim 1 in which the amount of bound charge is from about 0.18 milliequivalent to about 0.4 milliequivalent per gram of polymer in the latex.
Claim 11
Dependent Claim
11 words
The non-woven fibrous material obtained by the process of claim 1.
Claim 12
Dependent Claim
11 words
The non-woven fibrous material obtained by the process of claim 2.
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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) | 1982-12-10 | 1983-06-11 | 1983-12-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-12-10 | 1987-06-11 | 1987-12-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-12-10 | 1991-06-11 | 1991-12-11 | $7700.00 | Window Closed / Lapsed |