US5066558A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Developer for developing electrostatic images
Assignee: Canon Inc
•
Filing: 1989-09-29
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Granted: 1991-11-19
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Expires: 2009-09-29
Abstract
Abstract A developer for developing electrostatic images, comprising: 100 wt. parts of a toner comprising toner particles, and 0.01-3 wt. parts of silica powder which has a particle size of 0.006-0.2 micron and is not fixed to the surfaces of the toner particles; the toner particles comprising 100 wt. parts of colored resinous particles (A) and 0.05-5 wt. parts of silica powder comprising silica particles which have a particle size of 0.002-0.2 micron and have been embedded in the surfaces of the colored resinous particles by mechanical impact means.
Inventors
- 👤 Norio Hikake
- 👤 Naoto Kitamori
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 22:09
CPC Classifications
G; G03; G03G; G03G9/00; G03G9/08; G03G9/097; G03G9/09708; G03G9/09725
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
170 words
A developer for developing electrostatic images, comprising: 100 wt. parts of a toner comprising toner particles and 0.01-3 wt. parts of silica powder (C) which has a particle size of 0.005-0.2 micron and is not fixed to the surfaces of the toner particles; said toner particles and said silica powder (C) having been dispersed and mixed with each other by means of a mixer having a stirring vane rotating at a peripheral speed at the tip of the stirring vane of 5-50 m/sec; said toner particles comprising 100 wt. parts of colored resinous particles (A) and 0.05-5 wt. parts of silica powder (B) comprising silica particles which have a particle size of 0.002-0.2 micron and have been embedded in the surfaces of the colored resinous particles (A) by a mechanical impact means; and the amount of the silica powder (B) embedded in the surface of the colored resinous particles (A) is larger than the amount of the silica powder (C) not being fixed to the surfaces of the toner particles.
Claim 2
Dependent Claim
170 words
A developer for developing electrostatic images, comprising: 100 wt. parts of a toner comprising toner particles and 0.01-3 wt. parts of silica powder (C) which has a particle size of 0.005-0.2 micron and is not fixed to the surfaces of the toner particles; said toner particles and said silica powder (C) having been dispersed and mixed with each other by means of a mixer having a stirring vane rotating at a peripheral speed at the tip of the stirring vane of 5-50 m/sec; said toner particles comprising 100 wt. parts of colored resinous particles (A) and 0.05-5 wt. parts of silica powder (B) comprising silica particles which have a particle size of 0.002-0.2 micron and have been embedded in the surfaces of the colored resinous particles (A) by a mechanical impact means; and the amount of the silica powder (B) embedded in the surface of the colored resinous particles (A) is larger than the amount of the silica powder (C) not being fixed to the surfaces of the toner particles.
Claim 3
Dependent Claim
20 words
A developer according to claim 1, wherein the colored resinous particles (A) have a volume-average particle size of 2-20 microns.
Claim 4
Dependent Claim
19 words
A developer according to claim 1, wherein the colored resinous particles (A) comprise a binder resin and a colorant.
Claim 5
Dependent Claim
115 words
A developer according to claim 1, wherein the silica powder (B) and the colored resinous particles (A) have been dispersed and mixed with each other by means of a mixer having a stirring vane rotating at a peripheral speed at the tip of the stirring vane of 5-50 m/sec and then subjected to the impact means having an impacting member rotating at a peripheral speed at the tip of 30-100 m/sec to embed the silica powder (B) particles in the surfaces of the colored resinous particles (A) in a sufficiently dispersed state so that the silica powder (B) particles are not substantially observed through a field emission-type scanning electron microscope at a magnification of 10,000.
Claim 6
Dependent Claim
62 words
A developer according to claim 1, wherein the amount of the silica powder embedded in the surfaces of the colored resinous particles (A) is 0.1-5 wt. parts per 100 wt. parts of the colored resinous particles (A), and the amount of the silica powder not being fixed to the toner particles is 0.05-3 wt. parts per 100 wt. parts of the toner.
Claim 7
Dependent Claim
62 words
A developer according to claim 1, wherein the amount of the silica powder embedded in the surfaces of the colored resinous particles (A) is 0.3-3 wt. parts per 100 wt. parts of the colored resinous particles (A), and the amount of the silica powder not being fixed to the toner particles is 0.1-1 wt. parts per 100 wt. parts of the toner.
Claim 8
Dependent Claim
26 words
A developer according to claim 1, wherein the colored resinous particles (A) comprise a crosslinked styrene-type copolymer or a crosslinked polyester resin as a binder resin.
Claim 9
Dependent Claim
108 words
A developer according to claim 1, wherein the colored resinous particles (A) contain a negative charge controller; 0.05-5 wt. parts of negatively chargeable hydrophobic colloidal silica is embedded in 100 wt. parts of the colored resinous particles (A); 0.01-3 wt. parts of negatively chargeable hydrophobic colloidal silica not being fixed to the surfaces of the toner particles has been mixed with 100 wt. parts of the toner, and the amount of the negatively chargeable hydrophobic colloidal silica embedded in the surfaces of the colored resinous particles (A) is larger than that of the negatively chargeable hydrophobic colloidal silica not being fixed to surface of the the toner particles.
Claim 10
Dependent Claim
108 words
A developer according to claim 1, wherein the colored resinous particles (A) contain a positive charge controller; 0.05-5 wt. parts of positively chargeable hydrophobic colloidal silica is embedded in 100 wt. parts of the colored resinous particles (A); 0.01-3 wt. parts of positively chargeable hydrophobic colloidal silica not being fixed to the surfaces of the toner particles has been mixed with 100 wt. parts of the toner, and the amount of the positively chargeable hydrophobic colloidal silica embedded in the surfaces of the colored resinous particles (A) is larger than that of the positively chargeable hydrophobic colloidal silica not being fixed to the surfaces of the toner particles.
Claim 11
Dependent Claim
52 words
A developer according to claim 1, wherein the toner is a negatively chargeable magnetic toner which comprises: colored resinous particles (A) comprising a crosslinked styrene-type copolymer, a negative charge controller, a releasing agent and a magnetic material; and negatively chargeable hydrophobic colloidal silica embedded in the surfaces of colored resinous particles (A).
Claim 12
Dependent Claim
64 words
A developer according to claim 1, wherein the toner is a positively chargeable magnetic toner which comprises: colored resinous particles (A) comprising a crosslinked styrene-type copolymer, a positive charge controller, a releasing agent and a magnetic material; and positively chargeable hydrophobic colloidal silica which has been treated with an amino-modified silicone oil and is embedded in the surfaces of the colored resinous particles (A).
Claim 13
Dependent Claim
22 words
A developer according to claim 10, wherein the toner has been mixed with positively chargeable hydrophobic colloidal silica and fluorine-containing polymer powder.
Claim 14
Dependent Claim
74 words
A developer according to claim 1, wherein the silica powder (B) particles have been embedded in the surfaces of the colored resinous particles (A) by the mechanical impact means having an impacting member rotating at a peripheral speed at the tip of 30 to 130 m/sec in a sufficiently dispersed state so that the silica powder (B) particles are not substantially observed through a field emission-type scanning electron microscope at a magnification of 10,000.
Claim 15
Dependent Claim
72 words
A developer according to claim 1, wherein the silica powder (B) particles have been embedded in the surfaces of the colored resinous particles (A) by the mechanical impact means having an impacting member rotating at a peripheral speed at the tip of 30 to 100 m/sec in a sufficiently dispersed state so that the silica powder (B) particles are not substantially observed through a scanning electron microscope at a magnification of 10,000.
Claim 16
Dependent Claim
115 words
A developer according to claim 1, wherein the silica powder (B) and the colored resinous particles (A) have been dispersed and mixed with each other by means of a mixer having a stirring vane rotating at a peripheral speed at the tip of the stirring vane of 5-50 m/sec and then subjected to the impact means having an impacting member rotating at a peripheral speed at the tip of 30-130 m/sec to embed the silica powder (B) particles in the surfaces of the colored resinous particles (A) in a sufficiently dispersed state so that the silica powder (B) particles are not substantially observed through a field emission-type scanning electron microscope at a magnification of 10,000.
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1994-11-18 | 1995-05-20 | 1995-11-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-11-18 | 1999-05-20 | 1999-11-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-11-18 | 2003-05-20 | 2003-11-19 | $7700.00 | Window Closed / Lapsed |