Patent US5143583A successfully refreshed from Google Patents.
US5143583A
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Preparation and synthesis of magnetic fibers
Assignee: Individual
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Filing: 1991-04-02
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Granted: 1992-09-01
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Expires: 2011-04-02
Abstract
Abstract Magnetic paper-forming fibers have a particulate magnetic material incorporated within the fibers, as distinct from between the fibers; this can be achieved by loading the lumens of cellulosic fibers with magnetic particles or by generating magnetic particles in situ in a paper-forming fiber which contains ionic groups effective for ion exchange with ferrous ions; the fibers can be employed to produce single layer or multi-layererd magnetic papers for information storage, security paper applications, paper handling, reprographic applications such as magnetographic printing substrate as well as for speciality uses such as electromagnetic shielding, magnetic separation of antibodies based on selective adsorption.
Inventors
- 👤 Robert H. Marchessault
- 👤 Patrice Rioux
- 👤 Serge Ricard
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 12:31
CPC Classifications
D; D21; D21H; D21H21/00; D21H21/14; D21H21/40; D21H21/44; D21H21/48; D21H17/00; D21H17/63; D21H17/67; D21H17/675; D21H17/70; D21H23/00; D21H23/02; D21H23/04; D21H23/06; D21H23/14; D21H23/16
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
81 words
A method of producing magnetic papermaking fibers comprising: providing a biopolymer papermaking fiber mass of fibers having ionic groups bearing cations which undergo ion exchange with ferrous ions, contacting the fiber mass with an aqueous ferrous salt solution and allowing ion exchange to proceed between said cations and said ferrous ions, precipitating said ferrous ions as ferrous hydroxide within said fibers, oxidizing the ferrous hydroxide to form fine particles of magnetic iron oxide within said fibers, and drying the fiber mass.
Claim 2
Independent Claim
81 words
A method of producing magnetic papermaking fibers comprising: providing a biopolymer papermaking fiber mass of fibers having ionic groups bearing cations which undergo ion exchange with ferrous ions, contacting the fiber mass with an aqueous ferrous salt solution and allowing ion exchange to proceed between said cations and said ferrous ions, precipitating said ferrous ions as ferrous hydroxide within said fibers, oxidizing the ferrous hydroxide to form fine particles of magnetic iron oxide within said fibers, and drying the fiber mass.
Claim 3
Dependent Claim
13 words
A method according to claim 1 wherein said fibers are of sodium carboxymethylcellulose.
Claim 4
Dependent Claim
13 words
A method according to claim 1 wherein said fibers are sulfated cellulosic fibers.
Claim 5
Dependent Claim
13 words
A method according to claim 1 wherein said fibers are sulfonated lignocellulose fibers.
Claim 6
Dependent Claim
15 words
A method according to claim 1 wherein said fibers comprise continuous filament alginic acid fibers.
Claim 7
Dependent Claim
13 words
A method according to claim 1 wherein said fibers comprise sodium alginate fibers.
Claim 8
Dependent Claim
18 words
A method according to claim 1 wherein said fibers comprise a cross-linked gel of a sulfonic acid-containing polysaccharide.
Claim 9
Dependent Claim
14 words
A method according to claim 1 wherein said fibers are of an iron-complexing polysaccharide.
Claim 10
Dependent Claim
16 words
A method according to claim 1 wherein said fibers are of an oxidized particulate carbohydrate polymer.
Claim 11
Dependent Claim
26 words
A method according to claim 2 wherein said ferrous salt is ferrous chloride, and said oxidizing comprises bubbling oxygen through the ferrous hydroxide within the fibers.
Claim 12
Dependent Claim
87 words
A magnetic biopolymer papermaking fiber mass of fibers containing free particles of magnetic iron oxide within said fibers produced by contacting a fiber mass of biopolymer papermaking fibers having ionic groups bearing cations which undergo ion exchange with ferrous ions, with an aqueous ferrous salt solution, allowing ion exchange to proceed between said cations and said ferrous ions, precipitating said ferrous ions as ferrous hydroxide within said fibers, oxidizing the ferrous hydroxide to form fine particles of magnetic iron oxide within said fibers, and drying the fibers.
Claim 13
Dependent Claim
87 words
A magnetic biopolymer papermaking fiber mass of fibers containing free particles of magnetic iron oxide within said fibers produced by contacting a fiber mass of biopolymer papermaking fibers having ionic groups bearing cations which undergo ion exchange with ferrous ions, with an aqueous ferrous salt solution, allowing ion exchange to proceed between said cations and said ferrous ions, precipitating said ferrous ions as ferrous hydroxide within said fibers, oxidizing the ferrous hydroxide to form fine particles of magnetic iron oxide within said fibers, and drying the fibers.
Claim 14
Dependent Claim
14 words
A magnetic mass according to claim 11 wherein said fibers are of sodium carboxymethylcellulose.
Claim 15
Dependent Claim
14 words
A magnetic mass according to claim 11 wherein said fibers are sulfated cellulosic fibers.
Claim 16
Dependent Claim
14 words
A magnetic mass according to claim 11 wherein said fibers are sulfonated lignocellulose fibers.
Claim 17
Dependent Claim
16 words
A magnetic mass according to claim 11 wherein said fibers comprise continuous filament alginic acid fibers.
Claim 18
Dependent Claim
14 words
A magnetic mass according to claim 11 wherein said fibers comprise sodium alginate fibers.
Claim 19
Dependent Claim
17 words
A magnetic mass according to claim 11 wherein said fibers comprise a cross-linked gel of a polysaccharide.
Claim 20
Dependent Claim
15 words
A magnetic mass according to claim 11 wherein said fibers are of an iron-complexing polysaccharide.
Claim 21
Dependent Claim
17 words
A magnetic mass according to claim 11 wherein said fibers are of an oxidized particulate carbohydrate polymer.
Claim 22
Dependent Claim
92 words
A magnetic paper comprising a layer of biopolymer papermaking fibers containing fine particles of magnetic iron oxide within said fibers, said fibers being produced by contacting a fiber mass of biopolymer papermaking fibers having ionic groups bearing cations which undergo ion exchange with ferrous ions, with an aqueous ferrous salt solution, allowing ion exchange to proceed between said cations and said ferrous ions, precipitating said ferrous ions as ferrous hydroxide within said fibers, oxidizing the ferrous hydroxide to form fine particles of magnetic iron oxide within said fibers, and drying the fibers.
Claim 23
Dependent Claim
92 words
A magnetic paper comprising a layer of biopolymer papermaking fibers containing fine particles of magnetic iron oxide within said fibers, said fibers being produced by contacting a fiber mass of biopolymer papermaking fibers having ionic groups bearing cations which undergo ion exchange with ferrous ions, with an aqueous ferrous salt solution, allowing ion exchange to proceed between said cations and said ferrous ions, precipitating said ferrous ions as ferrous hydroxide within said fibers, oxidizing the ferrous hydroxide to form fine particles of magnetic iron oxide within said fibers, and drying the fibers.
Claim 24
Dependent Claim
23 words
A magnetic paper according to claim 20, further including at least a second layer of bleached, non-magnetic, cellulosic fibers laminated to said layer.
References Cited (Backward Citations)
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 7.5 Years (Year 8) | 1999-09-01 | 2000-03-02 | 2000-09-01 | $3760.00 | Window Closed / Lapsed |
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