US4121966A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for producing fibrous sheet
Assignee: Mitsubishi Paper Mills Ltd
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Filing: 1977-02-04
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Granted: 1978-10-24
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Expires: 1997-02-04
Abstract
Abstract A fibrous sheet bonded with a latex flocculate is produced by adding zinc white powders to a carboxyl modified anionic latex, adjusting the pH to at least 7, adding thereto a water soluble cationic polymer to obtain a latex flocculate, adding thus obtained flocculate to a fiber slurry and subjecting the fiber slurry to a known wet paper making process.
Inventors
- 👤 Masahiro Amano
- 👤 Takashi Koike
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 11:15
CPC Classifications
D; D21; D21H; D21H17/00; D21H17/20; D21H17/33; D21H17/34; D21H17/41; D21H17/42; D21H17/43; D21H17/35; D21H17/36; D21H17/37
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
83 words
A method for producing a fibrous sheet which consists of adding zinc white to a carboxyl modified anionic latex to disperse the zinc white in the latex, adjusting pH of the dispersion to at least 7, adding a water soluble cationic polymer to the dispersion at said pH while stirring to produce a latex flocculate having a particle size of 100μ-500μ, adding said latex flocculate to a fiber slurry, producing a sheet therefrom by wet paper making process and drying the resultant sheet.
Claim 2
Independent Claim
83 words
A method for producing a fibrous sheet which consists of adding zinc white to a carboxyl modified anionic latex to disperse the zinc white in the latex, adjusting pH of the dispersion to at least 7, adding a water soluble cationic polymer to the dispersion at said pH while stirring to produce a latex flocculate having a particle size of 100μ-500μ, adding said latex flocculate to a fiber slurry, producing a sheet therefrom by wet paper making process and drying the resultant sheet.
Claim 3
Dependent Claim
25 words
A method according to claim 1, wherein the amount of zinc white is 1-10% by weight of solid matter of the carboxyl modified anionic latex.
Claim 4
Dependent Claim
51 words
A method according to claim 1, wherein the carboxyl modified anionic latex is the latex of a carboxyl modified styrene.butadiene copolymer, a acrylonitrile.butadiene copolymer, a methylmethacrylate.butadiene copolymer, a polyacrylate, a polyvinyl chloride, a polyvinyl acetate, a vinylacetate.ethylene copolymer, a vinyl acetate.acrylate copolymer, a vinyl chloride.acrylate ester copolymer or a mixture thereof.
Claim 5
Dependent Claim
29 words
A method according to claim 1, wherein the water soluble cationic polymer is polyamide.polyamine.epichlorohydrin resin, polyethyleneimine resin, cationic modified melamine.formaldehyde resin, cationic modified urea.formaldehyde resin or cationic modified starch.
Claim 6
Dependent Claim
18 words
A method according to claim 1, wherein the latex has a solid matter concentration of 0.5-10% by weight.
Claim 7
Dependent Claim
29 words
A method according to claim 1, wherein amount of the water soluble cationic polymer is less than 1.5 times the minimum amount required for complete flocculation of the latex.
Claim 8
Dependent Claim
25 words
A method according to claim 1, wherein the fibers are natural fibers, regenerated fibers, synthetic fibers, inorganic fibers, metallic fibers, collagen fibers or mixtures thereof.
Claim 9
Dependent Claim
16 words
A method according to claim 1 wherein the particle size of the latex flocculate is 100-300.
References Cited (Backward Citations)
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US2301998A
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US2971879A
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US3223580A
Cited
US3344017A
Cited
US3776812A
Cited
GB1338759A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-10-23 | 1982-04-24 | 1982-10-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-10-23 | 1986-04-24 | 1986-10-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-10-23 | 1990-04-24 | 1990-10-24 | $7700.00 | Window Closed / Lapsed |