Patent US4752522A successfully refreshed from Google Patents.
US4752522A
Expired / Lapsed
US
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Electrostatic recording material
Assignee: Mitsubishi Chemical Corp
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Filing: 1986-04-03
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Granted: 1988-06-21
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Expires: 2006-04-03
Abstract
Abstract An electrostatic recording material comprising a substrate treated for low electric resistance and a dielectric layer formed on the substrate and composed of a composition comprising an insulating resin having a volume specific resistance of at least 1012 OMEGA cm and a powder of an acrylonitrile-type polymer having a copolymerized acrylonitrile content of at least 95% by weight and containing substantially no ionic groups, said powder having a volume average particle size of from 1.5 to 4 mu m and a content of particles having a size exceeding 8 mu m as measured by a particle size distribution measuring apparatus, being at most 0.02% by number.
Inventors
- 👤 Teruhiko Sugimori
- 👤 Fumio Suzuki
- 👤 Naoyuki Fukabori
- 👤 Hideaki Habara
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 16:56
CPC Classifications
G; G03; G03G; G03G5/00; G03G5/02; G03G5/0202; G03G5/0205; G03G5/0208; Y; Y10; Y10T; Y10T428/00; Y10T428/24; Y10T428/24802; Y10T428/24934; Y10T428/25; Y10T428/31504; Y10T428/31855; Y10T428/3188; Y10T428/31895; Y10T428/31899; Y10T428/31902; Y10T428/31906
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
115 words
An electrostatic recording material comprising a substrate treated for low electric resistance and a dielectric layer formed on the substrate and composed of a composition comprising an insulating resin having a volume specific resistance of at least 10 12 Ωcm and a powder of a homopolymer or a copolymer of acrylonitrile, containing substantially no ionic groups, which is a polymer of a monomer or a monomer mixture containing at least 95% by weight of acrylonitrile said powder having a volume average particle size of from 1.5 to 4 μm and a content of particles having a size exceeding 8 μm as measured by a particle size distribution measuring apparatus, being at most 0.02% by number.
Claim 2
Dependent Claim
115 words
An electrostatic recording material comprising a substrate treated for low electric resistance and a dielectric layer formed on the substrate and composed of a composition comprising an insulating resin having a volume specific resistance of at least 10 12 Ωcm and a powder of a homopolymer or a copolymer of acrylonitrile, containing substantially no ionic groups, which is a polymer of a monomer or a monomer mixture containing at least 95% by weight of acrylonitrile said powder having a volume average particle size of from 1.5 to 4 μm and a content of particles having a size exceeding 8 μm as measured by a particle size distribution measuring apparatus, being at most 0.02% by number.
Claim 3
Dependent Claim
33 words
The electrostatic recording material according to claim 1, wherein the homopolymer or the copolymer of acrylonitrile powder is formed by agglomeration of particles having a particle size of from 0.1 to 2 μm.
Claim 4
Dependent Claim
22 words
The electrostatic recording material according to claim 1, wherein the homopolymer or the copolymer of acrylonitrile powder is composed of porous particles.
Claim 5
Dependent Claim
22 words
The electrostatic recording material according to claim 2, wherein the homopolymer or the copolymer of acrylonitrile powder is composed of porous particles.
Claim 6
Dependent Claim
43 words
The electrostatic recording material according to claim 1, wherein the homopolymer or the copolymer of acrylonitrile powder has a content of particles having a size exceeding 6 μm as measured by a particle size distribution measuring apparatus, being at most 0.02% by number.
Claim 7
Dependent Claim
47 words
The electrostatic recording material according t claim 1, wherein the homopolymer or the copolymer of acrylonitrile powder has a content of particles having a particle size exceeding 10 μm as measured by a particle size distribution measuring apparatus, being at most 30 particles per 500,000 particles counted.
Claim 8
Dependent Claim
47 words
The electrostatic recording material according to claim 2, wherein the homopolymer or the copolymer of acrylonitrile powder has a content of particles having a particle size exceeding 10 μm as measured by a particle size distribution measuring apparatus, being at most 30 particles per 500,000 particles counted.
Claim 9
Dependent Claim
47 words
The electrostatic recording material according to claim 3, wherein the homopolymer or the copolymer of acrylonitrile powder has a content of particles having a particle size exceeding 10 μm as measured by a particle size distribution measuring apparatus, being at most 30 particles per 500,000 particles counted.
Claim 10
Dependent Claim
47 words
The electrostatic recording material according to claim 4, wherein the homopolymer or the copolymer of acrylonitrile powder has a content of particles having a particle size exceeding 10 μm as measured by a particle size distribution measuring apparatus, being at most 30 particles per 500,000 particles counted.
Claim 11
Dependent Claim
47 words
The electrostatic recording material according to claim 5, wherein the homopolymer or the copolymer of acrylonitrile powder has a content of particles having a particle size exceeding 10 μm as measured by a particle size distribution measuring apparatus, being at most 30 particles per 500,000 particles counted.
Claim 12
Dependent Claim
18 words
The electrostatic recording material according to claim 1, which has a recording density of at least 8 dots/mm.
Claim 13
Dependent Claim
45 words
The electrostatic recording material according to claim 1, wherein the homopolymer or the copolymer of acrylonitrile has a reduced viscosity of from 1 to 8 calculated by measuring the viscosity of a dimethylformamide solution having a polymer concentration of 0.5% by weight at 25° C.
Claim 14
Dependent Claim
26 words
The electrostatic recording material according to claim 12, wherein the homopolymer or the copolymer of acrylonitrile contains at most 5×10 -5 mol/g (polymer) of ionic groups.
Claim 15
Dependent Claim
26 words
The electrostatic recording material according to claim 13, wherein the homopolymer or the copolymer of acrylonitrile contains at most 2×10 -5 mol/g (polymer) of ionic groups.
References Cited (Backward Citations)
US3097964A
Cited
US4542059A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-06-21 | 1991-12-21 | 1992-06-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-06-21 | 1995-12-21 | 1996-06-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-06-21 | 1999-12-21 | 2000-06-21 | $7700.00 | Window Closed / Lapsed |