Patent US4820603A successfully refreshed from Google Patents.
US4820603A
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Magnetic toner
Assignee: Canon Inc
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Filing: 1987-05-27
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Granted: 1989-04-11
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Expires: 2007-05-27
Abstract
Abstract A magnetic toner comprises a binder resin and a magnetic iron oxide. The magnetic iron oxide has a silicon content of 0.1-1.5 wt. % based on the iron contained therein and is in the form fine particles containing the silicon preferentially in the inner part thereof. Because of these features, the magnetic iron oxide particles have a sharp particle size distribution, have uniform surface properties including those under various environmental conditions and freeness from agglomeration, have a good black hue, and are uniformly dispersed in the binder resin to provide a magnetic toner having uniform properties particularly suited for electrophotography.
Inventors
- 👤 Kiichiro Sakashita
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 06:53
CPC Classifications
G; G03; G03G; G03G9/00; G03G9/08; G03G9/083; G03G9/0837; G03G9/0831; G03G9/0834; G03G9/0836; Y; Y10; Y10S; Y10S430/00; Y10S430/001; Y10S430/104
Claims Analysis
Total Claims: 30
Claim 1
Independent Claim
109 words
A magnetic toner comprising a binder resin and a magnetic portion, said magnetic portion comprising iron oxide and 0.1-1.5 wt. % silicon (based on total iron content), provided that an amount (A) of at most 0.7 wt. % silicon (based on iron content) when said magnetic portion is dissolved in an amount of not more than about 10 wt. % based on said total iron content and an amount (B) of 0.2-5 wt. % silicon (based on iron content) when the magnetic portion is dissolved in an amount of about 90-100 wt. % based on said total iron content, are present in a ratio of B/A of above 1.
Claim 2
Dependent Claim
109 words
A magnetic toner comprising a binder resin and a magnetic portion, said magnetic portion comprising iron oxide and 0.1-1.5 wt. % silicon (based on total iron content), provided that an amount (A) of at most 0.7 wt. % silicon (based on iron content) when said magnetic portion is dissolved in an amount of not more than about 10 wt. % based on said total iron content and an amount (B) of 0.2-5 wt. % silicon (based on iron content) when the magnetic portion is dissolved in an amount of about 90-100 wt. % based on said total iron content, are present in a ratio of B/A of above 1.
Claim 3
Dependent Claim
19 words
A magnetic toner according to claim 1, wherein the magnetic portion has an average particle size of 0.1-2.0 microns.
Claim 4
Dependent Claim
19 words
A magnetic toner according to claim 2, wherein the magnetic portion has an average particle size of 0.1-0.6 micron.
Claim 5
Dependent Claim
33 words
A magnetic toner according to claim 1, wherein the magnetic portion has an average particle size of 0.1-0.6 micron and a BET specific surface area by nitrogen adsorption of 0.5-20 m 2 /g.
Claim 6
Dependent Claim
25 words
A magnetic toner according to claim 4, wherein the magnetic portion has a BET specific surface area by nitrogen adsorption of 4-20 m 2 /g.
Claim 7
Dependent Claim
28 words
A magnetic toner according to claim 1, wherein the magnetic portion is contained in a proportion of 20-200 wt. parts per 100 wt. parts of the binder resin.
Claim 8
Dependent Claim
28 words
A magnetic toner according to claim 6, wherein the magnetic portion is contained in a proportion of 30-150 wt. parts per 100 wt. parts of the binder resin.
Claim 9
Dependent Claim
16 words
A magnetic toner according to claim 6, wherein the binder resin comprises a crosslinked styrene copolymer.
Claim 10
Dependent Claim
15 words
A magnetic toner according to claim 6, wherein the binder resin comprises a polyester resin.
Claim 11
Dependent Claim
72 words
A magnetic toner according to claim 1, wherein the binder resin comprises a homopolymer or copolymer of a monomer having amine group represented by the formula: ##STR5## wherein R 1 represents H or CH 3 ; R 2 and R 3 each represent a substituted or unsubstituted alkyl group (C 1 -C 6 ); and R 4 represents --CH 2 --, --C 2 H 4 , or --C 3 H 6 .
Claim 12
Dependent Claim
34 words
A magnetic toner according to claim 10, wherein the binder resin comprises a copolymer of the monomer having amine group and a polymerizable monomer selected from the group consisting of styrene, acrylates, and methacrylates.
Claim 13
Dependent Claim
14 words
A magnetic toner according to claim 1, which further comprises a positive charge controller.
Claim 14
Dependent Claim
14 words
A magnetic toner according to claim 1, which is blended with silica fine powder.
Claim 15
Dependent Claim
17 words
A magnetic toner according to claim 13, wherein the silica fine powder comprises a positively chargeable silica.
Claim 16
Dependent Claim
19 words
A magnetic toner according to claim 13, wherein the silica fine powder has been produced through a wet process.
Claim 17
Dependent Claim
33 words
A magnetic toner according to claim 14, wherein the silica fine powder has been surface-treated with a silicone oil having an organo group cotaining at least one nitrogen atom in its side chain.
Claim 18
Dependent Claim
17 words
A magnetic toner according to claim 14, wherein the silica fine powder has a hydrophobicity of 30-80.
Claim 19
Dependent Claim
29 words
A magnetic toner according to claim 13, wherein the silica fine powder is blended in a proportion of 0.01-3 wt. parts with 100 wt. parts of the magnetic toner.
Claim 20
Dependent Claim
26 words
A magnetic toner according to claim 1, wherein the magnetic portion has a content of silicon element of 0.2-1.0 wt. % based on the iron element.
Claim 21
Dependent Claim
26 words
A magnetic toner according to claim 19, wherein the magnetic portion has a content of silicon element of 0.25-0.7 wt. % based on the iron content.
Claim 22
Dependent Claim
24 words
A magnetic toner according to claim 1, wherein the magnetic portion has a content A of silicon element as defined of 0.1-0.5 wt. %.
Claim 23
Dependent Claim
24 words
A magnetic toner according to claim 1, wherein the magnetic portion has a content B of silicon element as defined of 0.5-3 wt. %.
Claim 24
Dependent Claim
19 words
A magnetic toner according to claim 1, wherein the magnetic portion has an apparent bulk density of 0.10-0.25 g/cc.
Claim 25
Dependent Claim
32 words
A magnetic toner according to claim 1, wherein the magnetic portion has a dispersibility in toluene of 4 mm or less in terms of a sedimentation length after standing for 1 hour.
Claim 26
Dependent Claim
17 words
A magnetic toner according to claim 1, which is a dry, positively chargeable, insulating, onecomponent, magnetic toner.
Claim 27
Dependent Claim
14 words
A magnetic toner according to claim 1, which further comprises nigrosine or modified nigrosine.
Claim 28
Dependent Claim
30 words
A magnetic toner according to claim 26, wherein the nigrosine or modified nigrosine is contained in a proportion of 0.1-10 wt. parts per 100 wt. parts of the binder resin.
Claim 29
Dependent Claim
13 words
A magnetic toner according to claim 1, wherein said magnetic portion is octahedral.
Claim 30
Dependent Claim
19 words
A magnetic toner according to claim 25, wherein said magnetic portion has an apparent bulk density of 0.10-0.25 g/cc.
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) | 1992-04-10 | 1992-10-10 | 1993-04-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-04-10 | 1996-10-10 | 1997-04-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-04-10 | 2000-10-10 | 2001-04-11 | $7700.00 | Window Closed / Lapsed |