US4702986A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrophotographic method uses toner of polyalkylene and non-magnetic inorganic fine powder
Assignee: Canon Inc
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Filing: 1985-08-27
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Granted: 1987-10-27
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Expires: 2005-08-27
Abstract
Abstract A dry developer for developing electrostatic images comprises (a) toner particles comprising 100 parts by weight of a binder resin and 1-20 parts by weight of polyalkylene having a ratio of weight average molecular weight to number average molecular weight of 2.0-10.0 and Z average molecular weight determined by gel permeation chromatography of 10,000-200,000, and containing 5-60% by weight of a component soluble in n-hexane at boiling point, kinetic friction coefficient of the toner particles being 0.20-0.50, and (b) non-magnetic inorganic fine powders having BET specific surface area according to a nitrogen adsorbing method of 0.5-500 m 2 /g. An image forming method comprises using the dry developer to develop electrostatic latent images on a photosensitive member having a surface hardness of 8 g or more, transferring the developed images to a receiving member, and removing the toner particles remaining on the photosensitive member by a cleaning means accompanying abrasion.
Inventors
- 👤 Eiichi Imai
- 👤 Kiichiro Sakashita
- 👤 Seiichi Takagi
- 👤 Tsutomo Kukimoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 14:38
CPC Classifications
G; G03; G03G; G03G9/00; G03G9/08; G03G9/097; G03G9/09708; G03G9/09725; G03G9/087; G03G9/08702; G03G9/08704; G03G9/09716
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
150 words
An image forming method which comprises: forming electrostatic latent images on a photosensitive member having a surface hardness of 8 g or more; developing the electrostatic latent images with a dry developer comprising (a) toner particles comprising 100 parts by weight of a binder resin and 1-20 parts by weight of polyalkylene having a ratio of weignt average molecular weight to number average molecular weight of 5-8 and Z average molecular weight determined by gel permeation chromatography of 10,000-200,000, and containing 5-60% by weight of a component soluble in n-hexane at boiling point, the toner particles having a kinetic friction coefficient of 0.20-0.50, and (b) non-magnetic inorganic fine powder having BET specific surface area according to a nitrogen adsorbing method of 0.5-500 m 2 /g; transferring the developed visible images to a receiving member; and removing the toner particles remaining on the photosensitive member by a cleaning means accompanying abrasion.
Claim 2
Dependent Claim
150 words
An image forming method which comprises: forming electrostatic latent images on a photosensitive member having a surface hardness of 8 g or more; developing the electrostatic latent images with a dry developer comprising (a) toner particles comprising 100 parts by weight of a binder resin and 1-20 parts by weight of polyalkylene having a ratio of weignt average molecular weight to number average molecular weight of 5-8 and Z average molecular weight determined by gel permeation chromatography of 10,000-200,000, and containing 5-60% by weight of a component soluble in n-hexane at boiling point, the toner particles having a kinetic friction coefficient of 0.20-0.50, and (b) non-magnetic inorganic fine powder having BET specific surface area according to a nitrogen adsorbing method of 0.5-500 m 2 /g; transferring the developed visible images to a receiving member; and removing the toner particles remaining on the photosensitive member by a cleaning means accompanying abrasion.
Claim 3
Dependent Claim
20 words
An image forming method according to claim 1 in which the surface hardness of the photosensitive member is 10-100 g.
Claim 4
Dependent Claim
20 words
An image forming method according to claim 1 in which the polyalkylene has a weight average molecular weight of 3,000-80,000.
Claim 5
Dependent Claim
54 words
An image forming method according to claim 3 in which the chromatograph by gel permeation chromatography of the polyalkylene has at least two peaks and the molecular weight corresponding to the main peak is 2,000-80,000, at least one of the other peaks being present at the lower molecular weight region than the main peak.
Claim 6
Dependent Claim
29 words
An image forming method according to claim 1 in which the non-magnetic inorganic fine powder is composed of metal salts of titanic acid, cerium oxide, silica or silicon carbide.
Claim 7
Dependent Claim
33 words
An image forming method according to claim 5 in which the non-magnetic inorganic fine powder is silica having BET specific surface area according to a nitrogen adsorbing method of 50-400 m 2 /g.
Claim 8
Dependent Claim
41 words
An image forming method according to claim 6 in which the silica is treated with a silicone oil having a substituted or unsubstituted amino group at a side chain or a silane coupling agent having a substituted or unsubstituted amino group.
Claim 9
Dependent Claim
23 words
An image forming method according to claim 7 in which the silica has a hydrophobicity determined by a methanol titration test of 30-80.
Claim 10
Dependent Claim
20 words
An image forming method according to claim 1 in which the toner particles contain 10-70% by weight of magnetic powders.
Claim 11
Dependent Claim
35 words
An image forming method according to claim 9 in which the magnetic particles have a BET specific surface area according to a nitrogen adsorbing method of 2-20 m 2 /g and Mohs hardness of 5-7.
Claim 12
Dependent Claim
19 words
An image forming method according to claim 2 in which the photosensitive member is an organic photoconductive photosensitive member.
Claim 13
Dependent Claim
26 words
An image forming method according to claim 1 in which the photosensitive member is an organic photoconductive photosensitive member, and the developer comprises magnetic toner particles.
Claim 14
Dependent Claim
26 words
An image forming method according to claim 12 in which the electrostatic latent images are developed by bringing the developer into contact with the photosensitive member.
Claim 15
Dependent Claim
21 words
An image forming method according to claim 1 in which the cleaning means is a cleaning blade composed of urethane rubber.
Claim 16
Dependent Claim
29 words
An image forming method according to claim 1, in which the silica is added to the developer in an amount of 0.1-3% by weight based on the toner particles.
Claim 17
Dependent Claim
41 words
An image forming method according to claim 1, in which the polyalkylene is polypropylene or a thermally modified product thereof and the non-magnetic inorganic fine powder is silica particles having a hydrophobicity of 30-80 as determined by a methanol titration test.
Claim 18
Dependent Claim
42 words
An image forming method according to claim 1, in which the toner is a positive chargeable toner containing polypropylene and the non-magnetic inorganic fine powder is a positively chargeable silica having a hydrophobicity of 30-80 as determined by a methanol titration test.
Claim 19
Dependent Claim
46 words
An image forming method according to claim 17, in which the positive chargeable silica is prepared by treating a silica with either a silicone oil having a substituted or unsubstituted side chain amino group or a silane coupling agent having a substituted or unsubstituted amino group.
Claim 20
Dependent Claim
14 words
An image forming method according to claim 1, in which the polyalkylene comprises polypropylene.
Claim 21
Dependent Claim
29 words
An image forming method according to claim 19, in which the polypropylene is contained in the toner particles in an amount of from 1 to 10 parts by weight.
Claim 22
Dependent Claim
16 words
An image forming method according to claim 1, in which the polyalkylene comprises an ethylene-propylene copolymer.
Claim 23
Dependent Claim
30 words
An image forming method according to claim 21, in which the ethylene-propylene copolymer is contained in the toner particles in an amount of from 1 to 10 parts by weight.
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) | 1990-10-26 | 1991-04-27 | 1991-10-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-10-26 | 1995-04-27 | 1995-10-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-10-26 | 1999-04-27 | 1999-10-27 | $7700.00 | Window Closed / Lapsed |