US4019993A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Manufacturing process for liquid developer
Assignee: Fujifilm Holdings Corp
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Filing: 1971-10-20
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Granted: 1977-04-26
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Expires: 1991-10-20
Abstract
Abstract A manufacturing process for liquid developer intended for developing the electrostatic latent image characterized by polymerizing one or more kinds of addition-polymerizable monomers with a mixture containing pigment and polymerization initiator to thereby obtain a graft polymer of the monomers and the pigments and treating the resultant polymerized product with a polar solvent of 12 or higher in dielectric constant, and then dispersing the component of the resultant product insoluble in the solvent in the carrier liquid of the liquid developer with high electric resistance whereby (a) the electric resistance of the developer, (b) the uniformity of the charge of the toner in the developer, and (c) the length of charge stability are enhanced because of the treating step.
Inventors
- 👤 Yasuo Tamai
- 👤 Sadao Osawa
- 👤 Satoru Honjo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 00:48
CPC Classifications
G; G03; G03G; G03G9/00; G03G9/08; G03G9/12; G03G9/125
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
152 words
A process for making a liquid developer intended for developing an electrostatic latent image, said process comprising the steps of (1) polymerizing one or more kinds of addition-polymerizable monomers with a mixture containing pigment and polymerization initiator to thereby obtain a graft polymer of said monomers and said pigments and treating the resultant polymerized product with a polar solvent of 12 or higher in dielectric constant, and then (2) dispersing the component of said resultant product insoluble in the said polar solvent in the carrier liquid of said liquid developer, said carrier liquid having high electric resistance and being selected from the group consisting of aliphatic hydrocarbon solvents, alicyclic hydrocarbon solvents, silicone, oil, and fluoro chloro hydrocarbon solvents whereby (a) the electric resistance of said developer, (b) the uniformity of the charge of the toner in the developer, and (c) the length of charge stability are enhanced because of said treating step.
Claim 2
Dependent Claim
152 words
A process for making a liquid developer intended for developing an electrostatic latent image, said process comprising the steps of (1) polymerizing one or more kinds of addition-polymerizable monomers with a mixture containing pigment and polymerization initiator to thereby obtain a graft polymer of said monomers and said pigments and treating the resultant polymerized product with a polar solvent of 12 or higher in dielectric constant, and then (2) dispersing the component of said resultant product insoluble in the said polar solvent in the carrier liquid of said liquid developer, said carrier liquid having high electric resistance and being selected from the group consisting of aliphatic hydrocarbon solvents, alicyclic hydrocarbon solvents, silicone, oil, and fluoro chloro hydrocarbon solvents whereby (a) the electric resistance of said developer, (b) the uniformity of the charge of the toner in the developer, and (c) the length of charge stability are enhanced because of said treating step.
Claim 3
Dependent Claim
15 words
A process as claimed in claim 1 wherein said solvent is water, alcohols or ketones.
Claim 4
Dependent Claim
16 words
A process as claimed in claim 2 wherein said alcohols are methanol, ethanol, propanol or butanol.
Claim 5
Dependent Claim
21 words
A process as claimed in claim 2 wherein said ketones are acetone, methyl ethyl ketone, diethyl ketone or methyl isobutyl ketone.
Claim 6
Dependent Claim
18 words
A process as claimed in claim 1 wherein said pigment is aniline black, phthalocyanine, blue, and phthalocyanine black.
Claim 7
Dependent Claim
13 words
A process as claimed in claim 1 wherein said pigment is carbon black.
Claim 8
Dependent Claim
16 words
A process as claimed in claim 1 wherein said monomer is acrylic ester or methacrylic ester.
Claim 9
Dependent Claim
20 words
A process as claimed in claim 1 wherein said carrier liquid has an electric resistance exceeding 10 10 ohm cm.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-04-25 | 1980-10-25 | 1981-04-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-04-25 | 1984-10-25 | 1985-04-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-04-25 | 1988-10-25 | 1989-04-26 | $7700.00 | Window Closed / Lapsed |