US5272040A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Toner for developing electrostatic latent images
Assignee: Minolta Co Ltd
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Filing: 1992-03-27
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Granted: 1993-12-21
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Expires: 2012-03-27
Abstract
Abstract The present invention relates to a toner for developing electrostatic latent images which has silica and titania or alumina on the toner surface at specified ratio or in specified states, so that environmental stability in chargeability and stable copy images with fine texture can be obtained.
Inventors
- 👤 Shinobu Nakasawa
- 👤 Hiroshi Fukao
- 👤 Keiji Asakawa
- 👤 Toshikazu Muramatsu
- 👤 Ichiro Demizu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 02:18
CPC Classifications
G; G03; G03G; G03G9/00; G03G9/08; G03G9/0825; G03G9/097; G03G9/09708; G03G9/09725
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
58 words
A full-color toner for developing electrostatic latent images comprising; resin particles comprising a thermoplastic resin and a colorant selected from the group consisting of yellow colorants, magenta colorants, cyan colorants and black colorants, silica existing on the surface of resin particles in half-buried states and titania or alumina existing on the surface of resin particles in non-buried states.
Claim 2
Dependent Claim
58 words
A full-color toner for developing electrostatic latent images comprising; resin particles comprising a thermoplastic resin and a colorant selected from the group consisting of yellow colorants, magenta colorants, cyan colorants and black colorants, silica existing on the surface of resin particles in half-buried states and titania or alumina existing on the surface of resin particles in non-buried states.
Claim 3
Dependent Claim
20 words
A full-color toner of claim 1, in which the titania or the alumina is prepared by a liquid phase reaction.
Claim 4
Dependent Claim
14 words
A full-color toner of claim 2, in which the titania or alumina is hydrophobic.
Claim 5
Dependent Claim
12 words
A full-color toner of claim 1, in which the silica is hydrophobic.
Claim 6
Dependent Claim
52 words
A full-color toner of claim 1, in which the thermoplastic resin is a polyester resin having a number average molecular weight of 2500-12000, a ratio of weight average molecular weight to number average molecular weight (Mw/Mn) of 2-6, a glass transition point of 50°-70° C. and a softening point of 80°-120° C.
Claim 7
Dependent Claim
25 words
A full-color toner of claim 4, in which the hydrophobic silica is added at a content of 0.1-1.0% by weight on the basis of toner.
Claim 8
Dependent Claim
29 words
A full-color toner of claim 3, in which the hydrophobic titania or the hydrophobic alumina is added at a content of 0.2-3.0% by weight on the basis of toner.
Claim 9
Dependent Claim
63 words
A full-color toner for developing electrostatic latent images comprising; resin particles comprising a thermoplastic resin and a colorant selected from the group consisting of yellow colorants, magenta colorants, cyan colorants and black colorants, silica existing on the surface of resin particles in the states of primary particles and titania or alumina existing on the surface of resin particles in aggregated-states of primary particles.
Claim 10
Dependent Claim
63 words
A full-color toner for developing electrostatic latent images comprising; resin particles comprising a thermoplastic resin and a colorant selected from the group consisting of yellow colorants, magenta colorants, cyan colorants and black colorants, silica existing on the surface of resin particles in the states of primary particles and titania or alumina existing on the surface of resin particles in aggregated-states of primary particles.
Claim 11
Dependent Claim
18 words
A full-color toner of claim 8, in which the silica has a primary particle size of 5-20 mμm.
Claim 12
Dependent Claim
21 words
A full-color toner of claim 8, in which the titania or the alumina has a primary particle size of 10-60 mμm.
Claim 13
Dependent Claim
112 words
A toner for developing electrostatic latent images comprising; a starting toner put into a developing machine in advance which is prepared by mixing resin particles containing a thermoplastic resin and a colorant, hydrophobic silica and hydrophobic titania or hydrophobic alumina, and a replenishing toner for making up for consumed toner which is prepared by mixing resin particles containing a thermoplastic resin and a colorant, hydrophobic silica and hydrophobic titania or hydrophobic alumina; the addition amount T A (% by weight) of hydrophobic titania or hydrophobic alumina in the starting toner and the addition amount T B (% by weight) thereof in the replenishing toner satisfying the relationship: T B >T A .
Claim 14
Dependent Claim
112 words
A toner for developing electrostatic latent images comprising; a starting toner put into a developing machine in advance which is prepared by mixing resin particles containing a thermoplastic resin and a colorant, hydrophobic silica and hydrophobic titania or hydrophobic alumina, and a replenishing toner for making up for consumed toner which is prepared by mixing resin particles containing a thermoplastic resin and a colorant, hydrophobic silica and hydrophobic titania or hydrophobic alumina; the addition amount T A (% by weight) of hydrophobic titania or hydrophobic alumina in the starting toner and the addition amount T B (% by weight) thereof in the replenishing toner satisfying the relationship: T B >T A .
Claim 15
Dependent Claim
22 words
A toner of claim 11, in which T A and T B satisfy the following relation below; 0.1≦T A -T B ≦1.0
Claim 16
Dependent Claim
29 words
A toner of claim 11, in which the hydrophobic silica is added into the starting toner at a content of 0.1-1.0% by weight on the basis of untreated toner.
Claim 17
Dependent Claim
33 words
A toner of claim 11, in which the hydrophobic titania or the hydrophobic alumina is added into the starting toner at a content of 0.2-3.0% by weight on the basis of untreated toner.
Claim 18
Dependent Claim
29 words
A toner of claim 11, in which the hydrophobic silica is added into the replenishing toner at a content of 0.1-1.0% by weight on the basis of untreated toner.
Claim 19
Dependent Claim
44 words
A toner of claim 11, in which that a weight ratio of hydrophobic silica to hydrophobic titania or a weight ratio of hydrophobic silica to hydrophobic alumina is adjusted to the range between 1:7 and 1:1, in the starting toner and the replenishing toner.
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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) | 1996-12-20 | 1997-06-21 | 1997-12-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-12-20 | 2001-06-21 | 2001-12-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-12-20 | 2005-06-21 | 2005-12-21 | $7700.00 | Window Closed / Lapsed |