Patent US4520088A successfully refreshed from Google Patents.
US4520088A
Expired / Lapsed
US
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Method for making printing plates
Assignee: MITSUBISHIKI PAPER MILLS Ltd
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Filing: 1983-01-11
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Granted: 1985-05-28
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Expires: 2003-01-11
Abstract
Abstract Disclosed is a method for electrophotographically making a printing plate excellent in resolving power and having a high printing endurance by using a liquid developer containing a copolymer comprising an acrylate ester or methacrylate ester having an alkyl group of 4 or more and a styrene or a styrene derivative, preferably said copolymer additionally containing an acrylate ester or a methacrylate ester having an alkyl group of 3 or less carbon atoms, more preferably said binary or ternary copolymer additionally containing a vinyl monomer having a basic group or an acidic group.
Inventors
- 👤 Takao Senga
- 👤 Jun Yamada
- 👤 Shigeyoshi Suzuki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 17:01
CPC Classifications
G; G03; G03G; G03G9/00; G03G9/08; G03G9/087; G03G9/08702; G03G9/08726
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
129 words
A method for making a printing plate which comprises charging an original printing plate comprising an electroconductive base and, provided thereon, at least a layer containing an organic photoconductive compound, exposing the charged plate, developing the exposed element with a liquid developer containing a copolymer comprising 5 to 60% by weight of an acrylate ester or methacrylate ester having an alkyl group of 4 or more carbon atoms, 30 to 90% by weight of a styrene or a styrene derivative and 5 to 40% by weight of an acrylate ester or a methacrylate ester having an alkyl group of 3 or less carbon atoms to form a toner image, fixing the toner image and removing the layer of the non-image areas by etching it with an alkaline etching solution.
Claim 2
Independent Claim
129 words
A method for making a printing plate which comprises charging an original printing plate comprising an electroconductive base and, provided thereon, at least a layer containing an organic photoconductive compound, exposing the charged plate, developing the exposed element with a liquid developer containing a copolymer comprising 5 to 60% by weight of an acrylate ester or methacrylate ester having an alkyl group of 4 or more carbon atoms, 30 to 90% by weight of a styrene or a styrene derivative and 5 to 40% by weight of an acrylate ester or a methacrylate ester having an alkyl group of 3 or less carbon atoms to form a toner image, fixing the toner image and removing the layer of the non-image areas by etching it with an alkaline etching solution.
Claim 3
Independent Claim
26 words
A method for making a printing plate according to claim l wherein the amount of the styrene or styrene derivative is 35 to 80% by weight.
Claim 4
Dependent Claim
29 words
A method for making a printing plate according to claim 1 herein the copolymer additionally contains 1 to 15% by weight of a vinyl monomer having a basic group.
Claim 5
Dependent Claim
29 words
A method for making a printing plate according to claim 1 wherein the copolymer additionally contains 1 to 15% by weight of a vinyl monomer having an acidic group.
Claim 6
Dependent Claim
36 words
A method for making a printing plate according to claim 1 wherein at least one of the acrylate ester or methacrylate ester of the first component has an alkyl group of 4 to 8 carbon atoms.
Claim 7
Dependent Claim
32 words
A method for making a printing plate according to claim 3 wherein the liquid developer additionally contains a resin soluble in a solvent and having an acid value of 50 or below.
Claim 8
Dependent Claim
28 words
A method for making a printing plate according to claim 4 wherein the liquid developer additionally contains a resin soluble in a solvent and having a basic group.
Claim 9
Independent Claim
107 words
A method for making a printing plate which comprises charging a photosensitive printing element comprising an electroconductive base sheet and, provided thereon, at least a layer containing an organic photoconductive compound, exposing the charged element, developing the exposed element with a liquid developer containing a copolymer comprising 5 to 60% by weight of an acrylate ester or methacrylate ester having an alkyl group of 4 or more carbon atoms and 90% by weight or less of a styrene or a styrene derivative to form a toner image, fixing the toner image and removing the layer of the non-image areas by etching it with an alkaline etching solution.
Claim 10
Independent Claim
107 words
A method for making a printing plate which comprises charging a photosensitive printing element comprising an electroconductive base sheet and, provided thereon, at least a layer containing an organic photoconductive compound, exposing the charged element, developing the exposed element with a liquid developer containing a copolymer comprising 5 to 60% by weight of an acrylate ester or methacrylate ester having an alkyl group of 4 or more carbon atoms and 90% by weight or less of a styrene or a styrene derivative to form a toner image, fixing the toner image and removing the layer of the non-image areas by etching it with an alkaline etching solution.
Claim 11
Dependent Claim
47 words
A method for making a printing plate according to claim 8 wherein the amount of the styrene or styrene derivative is 30 to 90% by weight and at least one of the acrylate ester or methacrylate ester has an alkyl group of 4 to 8 carbon atoms.
Claim 12
Dependent Claim
29 words
A method for making a printing plate according to claim 8 wherein the copolymer additionally contains 1 to 15% by weight of a vinyl monomer having a basic group.
Claim 13
Dependent Claim
29 words
A method for making a printing plate according to claim 8 wherein the copolymer additionally contains 1 to 15% by weight of a vinyl monomer having an acidic group.
Claim 14
Dependent Claim
32 words
A method for making a printing plate according to claim 10 wherein the liquid developer additionally contains a resin soluble in a solvent and having an acid value of 50 or below.
Claim 15
Dependent Claim
28 words
A method for making a printing plate according to claim 11 wherein the liquid developer additionally contains a resin soluble in a solvent and having a basic group.
Claim 16
Dependent Claim
19 words
A method for making a printing plate according to claim 1 wherein the base sheet is an aluminum sheet.
Claim 17
Dependent Claim
19 words
A method for making a printing plate according to claim 8 wherein the base sheet is an aluminum plate.
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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) | 1988-05-27 | 1988-11-26 | 1989-05-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-05-27 | 1992-11-26 | 1993-05-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-05-27 | 1996-11-26 | 1997-05-28 | $7700.00 | Window Closed / Lapsed |