Patent US4246066A successfully refreshed from Google Patents.
US4246066A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for producing fibrous sheet
Assignee: Mitsubishi Paper Mills Ltd
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Filing: 1979-04-16
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Granted: 1981-01-20
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Expires: 1999-04-16
Abstract
Abstract A fibrous sheet having a high strength and water resistance and having no resin specks on the surface can be produced by producing a sheet from a fiber slury by the known paper making process, to said fiber slurry being added a flocculate of chlorinated polymer latices which has a particle size of 100 mu -500 mu and is prepared by heating said chlorinated polymer latices to a temperature of at least their minimum film-forming temperature and then adding a water soluble cationic polymer or a polyvalent metal salt with stirring. Examples of said chlorinated polymer latices are anionic polyvinyl chloride latex, polyvinylidene chloride latex or the combination thereof.
Inventors
- 👤 Masahiro Amano
- 👤 Takashi Koike
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 11:50
CPC Classifications
D; D21; D21H; D21H17/00; D21H17/20; D21H17/33; D21H17/34; D21H17/35
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
151 words
A method for producing a fibrous sheet which comprises the successive steps of: (1) heating chlorinated polymer latex having a minimum film-forming temperature of at least 50° C. and comprising an anionic polyvinyl chloride latex, or an anionic polyvinylidine chloride latex selected from the group consisting of homopolymer of vinyl chloride, homopolymer of vinylidene chloride, vinyl chloride-vinylidene chloride copolymer, vinyl chloride-vinyl acetate copolymer and vinylidene chloride-vinyl acetate copolymer, the latex being emulsified with an anionic surfactant; to a temperature of at least the minimum film-forming temperature of said latex, (2) adding a water soluble cationic polymer or a polyvalent metal salt to said latex with stirring producing a flocculate having a particle size of 100 microns to 500 microns, (3) adding the resultant flocculate to a separately prepared fiber slurry, (4) forming a sheet from said slurry by a wet paper making process, and thereafter (5) drying the thus formed sheet.
Claim 2
Independent Claim
151 words
A method for producing a fibrous sheet which comprises the successive steps of: (1) heating chlorinated polymer latex having a minimum film-forming temperature of at least 50° C. and comprising an anionic polyvinyl chloride latex, or an anionic polyvinylidine chloride latex selected from the group consisting of homopolymer of vinyl chloride, homopolymer of vinylidene chloride, vinyl chloride-vinylidene chloride copolymer, vinyl chloride-vinyl acetate copolymer and vinylidene chloride-vinyl acetate copolymer, the latex being emulsified with an anionic surfactant; to a temperature of at least the minimum film-forming temperature of said latex, (2) adding a water soluble cationic polymer or a polyvalent metal salt to said latex with stirring producing a flocculate having a particle size of 100 microns to 500 microns, (3) adding the resultant flocculate to a separately prepared fiber slurry, (4) forming a sheet from said slurry by a wet paper making process, and thereafter (5) drying the thus formed sheet.
Claim 3
Dependent Claim
19 words
A method according to claim 1 wherein the amount of flocculate is 10-30 parts per 100 parts of fibers.
Claim 4
Dependent Claim
38 words
A method according to claim 1 wherein there is added a water soluble cationic polymer which is a polyamide-polyamine-epichlorohydrin resin, a polyethyleneimine resin, a cationic modified melamine-formaldehyde resin, a cationic modified urea-formaldehyde resin or a cationic modified starch.
Claim 5
Dependent Claim
26 words
A method according to claim 1 wherein there is added a polyvalent metal salt which is an aluminum salt, a calcium salt, or a magnesium salt.
Claim 6
Dependent Claim
34 words
A method according to claim 1 wherein the amount of the water soluble cationic polymer or polyvalent metal salt is less than 1.5 times the minimum amount required for complete flocculation of the latex.
Claim 7
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 8
Dependent Claim
14 words
A method according to claim 1 wherein the chlorinated polymer is vinyl chloride homopolymer.
Claim 9
Dependent Claim
16 words
A method according to claim 1 wherein the minimum film-forming temperature is 50° to 70° C.
Claim 10
Dependent Claim
15 words
A method according to claim 1 wherein the chlorinated polymer is vinyl chloride-acrylate ester copolymer.
Claim 11
Dependent Claim
15 words
A method according to claim 1 wherein the chlorinated polymer is vinylidene chloride-acrylate ester copolymer.
Claim 12
Independent Claim
161 words
A method for producing a fibrous sheet which method comprises the successive steps of: (1) heating a chlorinated polymer latex having a minimum film-forming temperature of at least 50° C. and comprising an anionic polyvinyl chloride latex, or an anionic polyvinylidene chloride latex selected from the group consisting of homopolymer of vinyl chloride, homopolymer of vinylidene chloride, vinyl-chloride-vinylidene chloride copolymer, vinyl chloride-acrylate ester copolymer, vinylidene chloride-acrylate ester copolymer, vinyl chloride-vinyl acetate copolymer and vinylidene chloride-vinyl acetate copolymer, the latex being emulsified with an anionic surfactant to a temperature of at least the minimum film-forming temperature of said latex, (2) adding a water soluble cationic polymer or a polyvalent metal salt to said latex with stirring thereby producing a flocculate having a particle size of 100 microns to 500 microns, (3) adding the resultant flocculate to a separately prepared fiber slurry, (4) forming a sheet from said slurry by a wet paper making process, and thereafter (5) drying the thus formed sheet.
Claim 13
Independent Claim
161 words
A method for producing a fibrous sheet which method comprises the successive steps of: (1) heating a chlorinated polymer latex having a minimum film-forming temperature of at least 50° C. and comprising an anionic polyvinyl chloride latex, or an anionic polyvinylidene chloride latex selected from the group consisting of homopolymer of vinyl chloride, homopolymer of vinylidene chloride, vinyl-chloride-vinylidene chloride copolymer, vinyl chloride-acrylate ester copolymer, vinylidene chloride-acrylate ester copolymer, vinyl chloride-vinyl acetate copolymer and vinylidene chloride-vinyl acetate copolymer, the latex being emulsified with an anionic surfactant to a temperature of at least the minimum film-forming temperature of said latex, (2) adding a water soluble cationic polymer or a polyvalent metal salt to said latex with stirring thereby producing a flocculate having a particle size of 100 microns to 500 microns, (3) adding the resultant flocculate to a separately prepared fiber slurry, (4) forming a sheet from said slurry by a wet paper making process, and thereafter (5) drying the thus formed sheet.
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) | 1984-01-20 | 1984-07-21 | 1985-01-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-01-20 | 1988-07-21 | 1989-01-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-01-20 | 1992-07-21 | 1993-01-20 | $7700.00 | Window Closed / Lapsed |