US5721083A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Dry color toner for electrophotography and production process thereof
Assignee: Ricoh Co Ltd
•
Filing: 1995-09-18
•
Granted: 1998-02-24
•
Expires: 2015-09-18
Abstract
Abstract A color toner that is able of forming a projected image having excellent color reproducibility when a toner image is produced on an optically transparent film by electrophotography, and a color toner that is excellent in chargeability and contaminates the developing roller to a minimum extent is provided. A process for producing the toner is also provided, wherein a color toner containing at least a binder resin, a pigment and a charge controller is produced in a first step of preliminarily kneading a blend of the color toner having a haze degree of 1 through 10% and the pigment with an organic solvent at a temperature lower than the melting temperature of the binder resin followed by a second step of thermal melting and kneading with addition of the binder resin and charge controller.
Inventors
- 👤 Minoru Masuda
- 👤 Akio Matsui
- 👤 Masami Tomita
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 03:40
CPC Classifications
G; G03; G03G; G03G9/00; G03G9/08; G03G9/09; G03G9/0906; G03G9/0802; G03G9/081; G03G9/0821; G03G9/091; G03G9/097; G03G9/09783
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
47 words
A dry color toner for electrophotography comprising a binder resin, a pigment dispersed in said binder resin and a charge controller, wherein said color toner has a haze factor of 1% through 10%, and said pigment has an average dispersed diameter of not more than 0.2 μm.
Claim 2
Dependent Claim
47 words
A dry color toner for electrophotography comprising a binder resin, a pigment dispersed in said binder resin and a charge controller, wherein said color toner has a haze factor of 1% through 10%, and said pigment has an average dispersed diameter of not more than 0.2 μm.
Claim 3
Dependent Claim
17 words
The dry color toner for electrophotography of claim 1, wherein said pigment comprises C.I. Pigment Yellow 180.
Claim 4
Dependent Claim
22 words
The dry color toner for electrophotography of claim 1, wherein said charge controller comprises a metal salt of a salicylic acid compound.
Claim 5
Dependent Claim
29 words
The dry color toner for electrophotography of claim 1, wherein said dry color toner comprises hydrophobic silica fine powder having a degree of hydrophobicity of not less than 50%.
Claim 6
Dependent Claim
68 words
A process for producing the dry color toner for electrophotography of claim 1, comprising the steps of: first kneading a blend of said binder resin and said pigment with an organic solvent at a temperature lower than the melting temperature of said binder resin; adding said kneaded binder resin and pigment and said charge controller to form a mixture and subjecting said mixture to thermal melting and kneading.
Claim 7
Dependent Claim
28 words
The process of claim 5, wherein 5 through 20 parts by weight of said organic solvent are added to 100 parts by weight of binder resin plus pigment.
Claim 8
Dependent Claim
26 words
The dry color toner for electrophotography of claim 3, wherein said metal salt of a salicylic acid is present in an amount of 0.5-8% by weight.
Claim 9
Dependent Claim
24 words
The dry color toner for electrophotography of claim 4, wherein said hydrophobic silica fine powder is present in an amount of 0.1-2% by weight.
Claim 10
Dependent Claim
24 words
The dry color toner for electrophotography of claim 8, wherein said hydrophobic silica fine powder is present in an amount of 0.5-1% by weight.
Claim 11
Dependent Claim
68 words
The dry color toner for electrophotography of claim 1, prepared by a process comprising the steps of: first kneading a blend of said binder resin and said pigment with an organic solvent at a temperature lower than the melting temperature of said binder resin; adding said kneaded binder resin and pigment and said charge controller to form a mixture; and subjecting said mixture to thermal melting and kneading.
Claim 12
Dependent Claim
30 words
The dry color toner for electrophotography of claim 10, wherein 5-20 parts by weight of said organic solvent are added to 100 parts by weight of binder resin plus pigment.
Claim 13
Dependent Claim
26 words
The dry color toner for electrophotography of claim 10, wherein said organic solvent is selected from the group consisting of acetone, toluene and methyl ethyl ketone.
Claim 14
Dependent Claim
28 words
The dry color toner for electrophotography of claim 11, wherein said charge controller comprises a metal salt of a salicylic acid in an amount of 0.5-8% by weight.
Claim 15
Dependent Claim
28 words
The dry color toner for electrophotography of claim 11, further comprising 0.1-2% by weight hydrophobic silica fine powder having a degree of hydrophobicity of not less than 50%.
Claim 16
Dependent Claim
22 words
The process of claim 6, wherein said organic solvent is selected from the group consisting of acetone, toluene and methyl ethyl ketone.
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) | 2001-02-23 | 2001-08-25 | 2002-02-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-02-23 | 2005-08-25 | 2006-02-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-02-23 | 2009-08-25 | 2010-02-24 | $7700.00 | Window Closed / Lapsed |