US4842974A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Toner for use in compositions for developing latent electrostatic images, method of making the same, and liquid composition using the improved toner
Assignee: HP Indigo BV
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Filing: 1987-06-11
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Granted: 1989-06-27
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Expires: 2007-06-11
Abstract
Abstract A liquid composition for developing latent electrostatic images comprising toner particles associated with a pigment dispersed in a nonpolar liquid. The salient feature of the invention is that the toner particles are formed with a plurality of fibers of tendrils from a thermoplastic polymer and carry a charge of a polarity opposite to the polarity of the latent electrostatic image. The polymer is insoluble or insolvatable in the dispersant liquid at room temperature. The toner particles are formed by plasticizing the polymer and pigment at elevated temperature and then either permitting a sponge to form and wet-grinding pieces of the sponge or diluting the plasticized polymer-pigment while cooling and constantly stirring to prevent the forming of a sponge while cooling. When cool, the diluted composition will have a concentration of toner particles formed with a plurality of fibers.
Inventors
- 👤 Benzion Landa
- 👤 Peretz Ben-Auraham
- 👤 Joseph Hall
- 👤 George A. Gibson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 17:05
CPC Classifications
G; G03; G03G; G03G9/00; G03G9/08; G03G9/12; Y; Y10; Y10T; Y10T428/00; Y10T428/24; Y10T428/24058; Y10T428/24074; Y10T428/24091; Y10T428/24099; Y10T428/24107; Y10T428/24132; Y10T428/29; Y10T428/2913; Y10T428/2982; Y10T428/2991; Y10T428/2998
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
72 words
A method of producing toner particles adapted for electrophoretic movement through a nonpolar liquid comprising the steps of plasticizing a thermoplastic polymer and a pigment with a nonpolar liquid to form a sponge, shredding said sponge into pieces, adding more nonpolar liquid, wet-grinding the pieces into particles, and continuing the grinding step to pull the particles apart to form fibers extending therefrom, said particles having a diameter of less than 5 microns.
Claim 2
Independent Claim
72 words
A method of producing toner particles adapted for electrophoretic movement through a nonpolar liquid comprising the steps of plasticizing a thermoplastic polymer and a pigment with a nonpolar liquid to form a sponge, shredding said sponge into pieces, adding more nonpolar liquid, wet-grinding the pieces into particles, and continuing the grinding step to pull the particles apart to form fibers extending therefrom, said particles having a diameter of less than 5 microns.
Claim 3
Independent Claim
85 words
A method of producing toner particles adapted for electro-phoretic movement through a nonpolar liquid comprising the steps of plasticizing an ethylene copolymer resin and a pigment with a nonpolar liquid at an elevated temperature to form a sponge, cooling said sponge, shredding the sponge into pieces, adding more nonpolar liquid, wet-grinding the pieces into particles, continuing the grinding step to pull the particles apart to form fibers extending therefrom, and adding a charge director to impart a charge of predetermined polarity to the toner particles.
Claim 4
Independent Claim
85 words
A method of producing toner particles adapted for electro-phoretic movement through a nonpolar liquid comprising the steps of plasticizing an ethylene copolymer resin and a pigment with a nonpolar liquid at an elevated temperature to form a sponge, cooling said sponge, shredding the sponge into pieces, adding more nonpolar liquid, wet-grinding the pieces into particles, continuing the grinding step to pull the particles apart to form fibers extending therefrom, and adding a charge director to impart a charge of predetermined polarity to the toner particles.
Claim 5
Independent Claim
114 words
A method of producing toner particles adapted for electro-phoretic movement through a nonpolar liquid comprising the steps of plasticizing a thermoplastic polymer at an elevated temperature with a nonpolar liquid, stirring a pigment into the plasticized polymer to disperse the pigment, continuing the stirring step to prevent the formation of a sponge while reducing the viscosity of the mixture by adding additional nonpolar liquid to the mixture to form a dispersion, cooling the dispersion while continuing the stirring to permit the precipitation of the pigmented polymer out of the dispersion to form pigmented toner particles having a plurality of fibers, and withdrawing the dispersion having a concentration of toner particles from the mixing step.
Claim 6
Independent Claim
114 words
A method of producing toner particles adapted for electro-phoretic movement through a nonpolar liquid comprising the steps of plasticizing a thermoplastic polymer at an elevated temperature with a nonpolar liquid, stirring a pigment into the plasticized polymer to disperse the pigment, continuing the stirring step to prevent the formation of a sponge while reducing the viscosity of the mixture by adding additional nonpolar liquid to the mixture to form a dispersion, cooling the dispersion while continuing the stirring to permit the precipitation of the pigmented polymer out of the dispersion to form pigmented toner particles having a plurality of fibers, and withdrawing the dispersion having a concentration of toner particles from the mixing step.
Claim 7
Dependent Claim
16 words
A method as in claim 3 in which the thermoplastic polymer comprises an ethylene copolymer resin.
Claim 8
Dependent Claim
16 words
A method as in claim 3 in which the pigment comprises a finely divided ferromagnetic material.
Claim 9
Dependent Claim
12 words
A method as in claim 3 in which the pigment comprises silioa.
Claim 10
Dependent Claim
13 words
A method as in claim 3 in which the pigment comprises carbon black.
Claim 11
Dependent Claim
14 words
A method as in claim 3 in which the pigment comprises a colored material.
Claim 12
Dependent Claim
28 words
A method as in claim 3 in which a charge director is added to the dispersion to impart an electrostatic charge of predetermined polarity to the toner particles.
Claim 13
Dependent Claim
13 words
A method as in claim 3 in which the cooling step is accelerated.
Claim 14
Dependent Claim
19 words
A method as in claim 3 in which a plurality of thermo-plastic polymers are employed in the plasticizing step.
Claim 15
Dependent Claim
18 words
A method as in claim 3 including the additional step of diluting the dispersion with more nonpolar liquid.
Claim 16
Dependent Claim
37 words
A method as in claim 3 in which the dilating step is conducted to reduce the concentration of toner particles to between 3 percent by weight and 0.2 percent by weight in respect of the nonpolar liquid.
References Cited (Backward Citations)
US3234017A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-06-26 | 1992-12-26 | 1993-06-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-06-26 | 1996-12-26 | 1997-06-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-06-26 | 2000-12-26 | 2001-06-27 | $7700.00 | Window Closed / Lapsed |