Patent US4572885A successfully refreshed from Google Patents.
US4572885A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Developer composition for developing an electrostatic image
Assignee: Konica Minolta Inc
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Filing: 1982-07-07
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Granted: 1986-02-25
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Expires: 2002-07-07
Abstract
Abstract There are disclosed an electrostatic image developer which comprises a carrier comprising iron powder particles coated with a resin and a toner comprising a low molecular weight polypropylene, and an electrostatic image developer which further comprises as binder a homopolymer of a styrene or a copolymer of a styrene with an another vinyl monomer containing 10 to 70% by weight of a high molecular component having a molecular weight of 100,000 to 10,000,000. The electrostatic image developer of the present invention can accomplish good developing without forming fogging even when provided in a great number of developments, thus exhibiting a great durability, and is also free from image contamination by the off-set phenomenon to give an excellent copied image.
Inventors
- 👤 Keiji Sato
- 👤 Takahira Kasuya
- 👤 Goichi Yamakawa
- 👤 Tsuneo Wada
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 08:56
CPC Classifications
G; G03; G03G; G03G9/00; G03G9/08; G03G9/10; G03G9/113; G03G9/1132; G03G9/1133; G03G9/087; G03G9/08702; G03G9/08704; G03G9/08706; G03G9/08708; G03G9/08711; G03G9/08724; G03G9/1135
Claims Analysis
Total Claims: 30
Claim 1
Independent Claim
68 words
A developer for developing an electrostatic image, which comprises a carrier comprising iron powder particles coated with a resin selected from the group consisting of a resin containing structural units of an α, β-unsaturated ethylenic monomer, an epoxy resin, a cellulose resin, a polyvinyl butyral resin, a styrene-butadiene resin and a fluorinated resin and a toner comprising a having a softening point of 60° to 180° C. polypropylene.
Claim 2
Dependent Claim
68 words
A developer for developing an electrostatic image, which comprises a carrier comprising iron powder particles coated with a resin selected from the group consisting of a resin containing structural units of an α, β-unsaturated ethylenic monomer, an epoxy resin, a cellulose resin, a polyvinyl butyral resin, a styrene-butadiene resin and a fluorinated resin and a toner comprising a having a softening point of 60° to 180° C. polypropylene.
Claim 3
Dependent Claim
58 words
The developer according to claim 1, wherein the toner further comprises a binder selected from a homopolymer of a styrene containing compound and a copolymer of said styrene containing compound with a vinyl monomer, said homopolymer and copolymer containing 10 to 70% by weight of a high molecular weight component having a molecular weight of 100,000 to 10,000,000.
Claim 4
Dependent Claim
36 words
The developer according to claim 1 or 2, wherein said polypropylene is selected from the group consisting of a homopolymer of propylene, a copolymer of propylene and ethylene, and a copolymer of propylene and vinyl acetate.
Claim 5
Dependent Claim
20 words
The developer according to claim 1 or 2, wherein said polypropylene has a softening point of 100° to 160° C.
Claim 6
Dependent Claim
20 words
The developer according to claim 1 or 2, wherein said polypropylene has an average molecular weight of 1,000 to 45,000.
Claim 7
Dependent Claim
13 words
The developer according to claim 2, wherein said styrene containing compound is styrene.
Claim 8
Dependent Claim
16 words
The developer according to claim 2, wherein said another vinyl monomer is an α,β-unsaturated ethylenic monomer.
Claim 9
Dependent Claim
18 words
The developer according to claim 7, wherein said α,β-unsaturated ethylenic monomer is an α-methylene aliphatic mono-carboxylic acid ester.
Claim 10
Dependent Claim
19 words
The developer according to claim 8, wherein said α-methylene aliphatic mono-carboxylic acid ester is an acrylate or a methacrylate.
Claim 11
Dependent Claim
14 words
The developer according to claim 2, wherein said another vinyl monomer is a butadiene.
Claim 12
Dependent Claim
29 words
The developer according to claim 2, wherein said polymer contains 10 to 50% by weight of a high molecular weight component having a molecular weight of 100,000 to 5,000,000.
Claim 13
Dependent Claim
32 words
The developer according to claim 1, wherein said resin containing structural units of an α,β-unsaturated ethylenic monomer is a copolymer of a styrene containing compound and an α-methylene aliphatic mono-carboxylic acid ester.
Claim 14
Dependent Claim
13 words
The developer according to claim 12, wherein said styrene is styrene containing compound.
Claim 15
Dependent Claim
19 words
The developer according to claim 12, wherein said α-methylene aliphatic mono-carboxylic acid ester is an acrylate or a methacrylate.
Claim 16
Dependent Claim
28 words
The developer according to claim 12, wherein said copolymer is a copolymer of a styrene containing compound and an acrylate or a styrene containing compound and a methacrylate.
Claim 17
Dependent Claim
18 words
The developer according to claim 1, wherein said resin has an average molecular weight of 50,000 to 300,000.
Claim 18
Dependent Claim
44 words
The developer according to claim 1, wherein said α,β-unsaturated ethylenic monomer is at least one selected from the group consisting of a styrene containing compound, a vinyl halide, a vinyl ester, an α-methylene aliphatic mono-carboxylic acid ester, a vinyl ether and a vinyl ketone.
Claim 19
Dependent Claim
19 words
The developer according to claim 17, wherein said α-methylene aliphatic mono-carboxylic acid ester is an acrylate or a methacrylate.
Claim 20
Dependent Claim
28 words
The developer according to claim 1, wherein said fluorinated resin is selected from the group consisting of a homopolymer of tetrafluoroethylene, and a copolymer of tetrafluoroethylene and hexafluoropropylene.
Claim 21
Dependent Claim
65 words
The developer according to claim 1, wherein the toner further comprises a binder having at least one member selected from the group consisting of a homopolymer of a styrene containing compound, a homopolymer of an α-methylene aliphatic mono-carboxylic acid ester, a copolymer of a styrene containing compound and an α-methylene aliphatic mono-carboxylic acid ester, a polyester resin, a polyvinyl butyral resin and a styrene-butadiene resin.
Claim 22
Dependent Claim
13 words
The developer according to claim 20, wherein said styrene containing compound is styrene.
Claim 23
Dependent Claim
19 words
The developer according to claim 20, wherein said α-methylene aliphatic mono-carboxylic acid ester is an acrylate or a methacrylate.
Claim 24
Dependent Claim
42 words
The developer according to claim 20, wherein said copolymer of a styrene containing compound and α-methylene aliphatic mono-carboxylic acid ester is a copolymer of a styrene containing compound and an acrylate or a copolymer of a styrene containing compound and a methacrylate.
Claim 25
Dependent Claim
19 words
The developer according to claim 23, wherein said copolymer is a copolymer of styrene, methyl methacrylate and butyl methacrylate
Claim 26
Dependent Claim
17 words
The developer according to claim 20, wherein said styrene-butadiene resin is a copolymer of styrene and butadiene.
Claim 27
Dependent Claim
142 words
In a method for forming a toner image comprising uniformly charging a photoconductive element, exposing imagewise said electrically charged photoconductive element to light to form imagewise an electrostatic latent image, developing said electrostatic latent image with a developer comprising toner and carrier, transferring said toner image formed on said photoconductive element onto a transfer sheet and fixing said transferred toner image on said transfer sheet by bringing said transfer sheet into pressure contact with a heated roller, the improvement which comprises said developer comprising a carrier comprising iron powder particles coated with a resin selected from the group consisting of resin containing structural units of an α, β-unsaturated ethylenic monomer, an epoxy resin, a cellulose resin, a polyvinyl butyral resin, a styrene-butadiene resin and a fluorinated resin and a toner comprising a polypropylene having an average molecular weight of 1,000 to 45,000.
Claim 28
Dependent Claim
142 words
In a method for forming a toner image comprising uniformly charging a photoconductive element, exposing imagewise said electrically charged photoconductive element to light to form imagewise an electrostatic latent image, developing said electrostatic latent image with a developer comprising toner and carrier, transferring said toner image formed on said photoconductive element onto a transfer sheet and fixing said transferred toner image on said transfer sheet by bringing said transfer sheet into pressure contact with a heated roller, the improvement which comprises said developer comprising a carrier comprising iron powder particles coated with a resin selected from the group consisting of resin containing structural units of an α, β-unsaturated ethylenic monomer, an epoxy resin, a cellulose resin, a polyvinyl butyral resin, a styrene-butadiene resin and a fluorinated resin and a toner comprising a polypropylene having an average molecular weight of 1,000 to 45,000.
Claim 29
Dependent Claim
63 words
The method for forming a toner image according to claim 26, wherein the toner further comprises a binder selected from a homopolymer of a styrene containing compound and a copolymer of said styrene containing compound with a vinyl monomer, said homopolymer and copolymer containing 10 to 70% by weight of a high molecular weight component having a molecular weight of 100,000 to 10,000,000.
Claim 30
Dependent Claim
41 words
The method for forming a toner image according to claim 26 or 27, wherein said polypropylene is selected from the group consisting of a homopolymer of propylene, a copolymer of propylene and ethylene, and a copolymer of propylene and vinyl acetate.
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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) | 1989-02-24 | 1989-08-26 | 1990-02-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-02-24 | 1993-08-26 | 1994-02-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-02-24 | 1997-08-26 | 1998-02-25 | $7700.00 | Window Closed / Lapsed |