US4857433A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrophotographic toner for high speed electrophotography
Assignee: Mitsui Toatsu Chemicals Inc
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Filing: 1987-10-08
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Granted: 1989-08-15
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Expires: 2007-10-08
Abstract
Abstract An electrophotographic toner, which can exhibit good fixation in high-speed copying and is not affected by an environment such as high humidity, is provided by containing, as a principal component thereof, a resin blend composed of (a) 40-90 wt. % of a vinyl copolymer (I) formed of 70-97 wt. % of an aromatic vinyl monomer, 3-30 wt. % of an alkyl fumarate which is an C1-8 monoalkyl or dialkyl ester and 0-5 wt. % of an acid monomer and having a number average molecular weight of 2,000-15,000 and (b) 10-60 wt. % of a vinyl polymer (II) having a number average molecular weight of 20,000-500,000.
Inventors
- 👤 Masaaki Shin
- 👤 Akio Fujiwara
- 👤 Hiroshi Taniwaki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 21:43
CPC Classifications
G; G03; G03G; G03G9/00; G03G9/08; G03G9/087; G03G9/08702; G03G9/08706; G03G9/08708; G03G9/08711; G03G9/08726; G03G9/08733
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
113 words
In a process of developing latent electrostatic images in a high speed electrophotographic copying machine, the improvement comprising: contacting the latent electrostatic images with a toner material comprising a coloringly effective amount of a colorant in combination with a resin blend composed of: (A) 40-90 wt. % of a vinyl copolymer (I) forced of 70-97 wt. % of an aromatic vinyl monomer, 3-30 wt. % of an alkyl fumerate which is a C 1-8 monoalkyl or dialkyl ester and 0-5 wt. % of an acid monomer and having a number average molecular weight of 2,000-15,000; and (B) 10-60 wt. % of a vinyl polymer (II) having a number average molecular eight of 20,000-500,000.
Claim 2
Dependent Claim
113 words
In a process of developing latent electrostatic images in a high speed electrophotographic copying machine, the improvement comprising: contacting the latent electrostatic images with a toner material comprising a coloringly effective amount of a colorant in combination with a resin blend composed of: (A) 40-90 wt. % of a vinyl copolymer (I) forced of 70-97 wt. % of an aromatic vinyl monomer, 3-30 wt. % of an alkyl fumerate which is a C 1-8 monoalkyl or dialkyl ester and 0-5 wt. % of an acid monomer and having a number average molecular weight of 2,000-15,000; and (B) 10-60 wt. % of a vinyl polymer (II) having a number average molecular eight of 20,000-500,000.
Claim 3
Dependent Claim
23 words
The process of claim 1, wherein the toner is in the form of particles which have a particle size ranging from I0-20 μm.
Claim 4
Dependent Claim
23 words
The process of claim 2, wherein the aromatic vinyl monomer is selected from the group consisting of styrene, α-methylstyrene, p-methylstyrene, vinyltoluene and chlorostyrene.
Claim 5
Dependent Claim
17 words
The process of claim 2, wherein the alkyl fumerate is a C 4-8 monoalkyl or dialkyl ester.
Claim 6
Dependent Claim
27 words
The process of claim 2, wherein the acid monomer is selected from the group consisting of methacrylic acid, acrylic acid, itaconic acid, fumaric acid and cinnamic acid.
Claim 7
Dependent Claim
54 words
The process of claim 2, wherein the vinyl monomer forming the vinyl polymer (II) is selected from the group consisting of aromatic vinyl monomers, acrylic esters, methacrylic esters, vinyl monomers containing nitrile groups, unsaturated carboxylic acids, mono- and di-alkyl esters of unsaturated dibasic acids, vinyl monomers containing amide groups and other nitrogen-containing vinyl monomers.
Claim 8
Dependent Claim
22 words
The process of claim 2, wherein the total amount of the monoalkyl fumarate and acid monomer is 5 wt. % or less.
Claim 9
Dependent Claim
53 words
The process of claim 2, wherein the blending of the vinyl copolymer (I) and vinyl polymer (II) is effected by adding and mixing the vinyl polymer (II) with a polymerization mixture, which has been obtained upon completion of polymeriza-tion of the vinyl copolymer (I) and contains a solvent, and then removing the solvent.
Claim 10
Dependent Claim
52 words
The process of claim 2, wherein the blending of the vinyl copolymer (I) and vinyl polymer (II) is effected by adding dropwise the monomers for the vinyl copolymer (I) together with a catalyst to a solution of the vinyl polymer (II) in a solvent, polymerizing the monomers and then removing the solvent.
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) | 1992-08-14 | 1993-02-13 | 1993-08-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-08-14 | 1997-02-13 | 1997-08-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-08-14 | 2001-02-13 | 2001-08-15 | $7700.00 | Window Closed / Lapsed |