Patent US4243736A successfully refreshed from Google Patents.
US4243736A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Liquid developer and copolymer polarity control agent for use therewith
Assignee: Hoechst AG
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Filing: 1978-09-08
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Granted: 1981-01-06
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Expires: 1998-09-08
Abstract
Abstract This invention relates to an improvement in a liquid developer for the development of electrostatic charge images, comprising an electrically insulating carrier liquid in which pigments or dyestuffs, resinous binders, a polarity control agent, and conventional additives are dispersed or dissolved, the improvement that the polarity control agent is a copolymer which is soluble in the carrier liquid and is composed of 1 to 50 percent by weight of N-vinyl-2-pyrrolidone and 50 to 99 percent by weight of a methacrylic acid ester.
Inventors
- 👤 Heinz Herrmann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 09:50
CPC Classifications
G; G03; G03G; G03G9/00; G03G9/08; G03G9/12; G03G9/13; G03G9/131
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
95 words
In a liquid developer for the development of electrostatic charge images, comprising an electrically insulating carrier liquid in which pigments or dyestuffs, resinous binders, a polarity control agent, and conventional additives are dispersed or dissolved, the improvement that the polarity control agent is a negative charging copolymer which is soluble in the carrier liquid and is composed of 1 to 50 percent by weight of N-vinyl-2-pyrrolidone and 50 to 99 percent by weight of a methacrylic acid ester with an alcohol component which contains at least 6 carbon atoms in a straight or branched chain.
Claim 2
Dependent Claim
95 words
In a liquid developer for the development of electrostatic charge images, comprising an electrically insulating carrier liquid in which pigments or dyestuffs, resinous binders, a polarity control agent, and conventional additives are dispersed or dissolved, the improvement that the polarity control agent is a negative charging copolymer which is soluble in the carrier liquid and is composed of 1 to 50 percent by weight of N-vinyl-2-pyrrolidone and 50 to 99 percent by weight of a methacrylic acid ester with an alcohol component which contains at least 6 carbon atoms in a straight or branched chain.
Claim 3
Dependent Claim
42 words
A liquid developer according to claim 1 in which the charge control agent is a copolymer which is composed of at least 15 to 40 percent by weight of N-vinyl-2-pyrrolidone and 60 to 85 percent by weight of a methacrylic acid ester.
Claim 4
Dependent Claim
14 words
A liquid developer according to claim 1 in which the copolymer contains 2-ethylhexyl methacrylate.
Claim 5
Dependent Claim
14 words
A liquid developer according to claim 1 in which the copolymer contains dodecyl methacrylate.
Claim 6
Dependent Claim
14 words
A liquid developer according to claim 1 in which the copolymer contains octadecyl methacrylate.
Claim 7
Dependent Claim
22 words
A liquid developer according to claim 1 in which the charge control agent is a copolymer which additionally contains an acrylo monomer.
Claim 8
Dependent Claim
27 words
A liquid developer according to claim 6 in which the charge control agent is a copolymer which additionally contains an acrylo monomer with a polar side chain.
Claim 9
Dependent Claim
28 words
A liquid developer according to claim 7 in which the copolymer contains up to about 5 percent by weight of an acrylo monomer with a polar side chain.
Claim 10
Dependent Claim
32 words
A liquid developer according to claim 7 in which the acrylo monomer with the polar side chain is selected from the group consisting of methacrylic acid, acrylic acid amide, and hydroxyalkyl methacrylate.
Claim 11
Dependent Claim
35 words
A liquid developer according to claim 6 in which the charge control agent is a copolymer which additionally contains a methacrylic acid ester with an alcohol component which contains not more than six carbon atoms.
Claim 12
Dependent Claim
25 words
A liquid developer according to claim 10, in which the copolymer contains up to about 30 percent by weight of a short-chain methacrylic acid ester.
Claim 13
Dependent Claim
26 words
A liquid developer according to claim 1 which comprises 0.1 to 5.0 percent by weight--based on the weight of the pigment or dyestuff--of a halogen-containing wax.
Claim 14
Dependent Claim
17 words
A liquid developer according to claim 12 in which the halogen-containing wax is a highly chlorinated paraffin.
Claim 15
Dependent Claim
15 words
A liquid developer according to claim 12 in which the halogen-containing wax is fluorinated paraffin.
References Cited (Backward Citations)
US2497705A
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US3044873A
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US3542681A
Cited
JPS5080136A
Cited
US3993483A
Cited
JPS5140465A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-01-06 | 1984-07-07 | 1985-01-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-01-06 | 1988-07-07 | 1989-01-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-01-06 | 1992-07-07 | 1993-01-06 | $7700.00 | Window Closed / Lapsed |