US4784933A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for making lithographic printing plate using light wavelengths over 700 μm
Assignee: Mitsubishi Paper Mills Ltd
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Filing: 1986-11-12
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Granted: 1988-11-15
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Expires: 2006-11-12
Abstract
Abstract Lithographic printing plates which have such a high sensitivity as permitting use of semiconductor laser beam of low output, a high resolving power and a high printing endurance and are free from occurrence of scumming are made by a method which comprises imagewise exposing a light sensitive material which comprises a support and at least a silver halide emulsion layer and a surface physical development nuclei layer provided on the support, said emulsion layer comprising silver halide grains which contain at least silver bromide and containing at least one sensitizing dye having a maximum spectral sensitivity in the region of longer than 700 mu m and then developing the exposed light sensitive material with a silver complex diffusion transfer developer containing at least a thiocyanate. Further improvement can be obtained by providing an antihalation means to keep the reflectance of a light of longer than 700 mu m at 13-40%.
Inventors
- 👤 Eiji Kanada
- 👤 Yasuo Tsubai
- 👤 Akira Tanaka
- 👤 Toshiro Kondo
- 👤 Yoshikazu Takaya
- 👤 Masahiko Saikawa
- 👤 Hiroshi Nishinoiri
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 23:36
CPC Classifications
G; G03; G03F; G03F7/00; G03F7/004; G03F7/06; G03F7/07; Y; Y10; Y10S; Y10S430/00; Y10S430/145
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
100 words
A method for making a lithographic printing plate which comprises imagewise exposing to light of wavelength greater than 700 mμ, a light sensitive material which comprises a support and at least a silver halide emulsion layer and a surface physical development nuclei layer provided on the support, said emulsion layer comprising silver halide grains which contain at least silver bromide and containing at least one sensitizing dye having a maximum spectral sensitivity in the region of longer than 700 mμ and then developing the exposed light sensitive material with a silver complex diffusion transfer developer containing at least a thiocyanate.
Claim 2
Independent Claim
100 words
A method for making a lithographic printing plate which comprises imagewise exposing to light of wavelength greater than 700 mμ, a light sensitive material which comprises a support and at least a silver halide emulsion layer and a surface physical development nuclei layer provided on the support, said emulsion layer comprising silver halide grains which contain at least silver bromide and containing at least one sensitizing dye having a maximum spectral sensitivity in the region of longer than 700 mμ and then developing the exposed light sensitive material with a silver complex diffusion transfer developer containing at least a thiocyanate.
Claim 3
Dependent Claim
36 words
A method for making a lithographic printing plate according to claim 1 wherein an antihalation means to keep the reflectance to a light of longer than 700 mμ at 13-40% is provided under the emulsion layer.
Claim 4
Dependent Claim
204 words
A method for making a lithographic printing plate according to claim 1 wherein the sensitizing dye is represented by the following general formula (I), (II), (III) or (IV): ##STR3## wherein Z 1 and Z 2 which may be identical or different represent a group of atoms necessary for forming a 5- or 6-membered nitrogen containing heterocyclic ring; R 1 and R 2 which may be identical or different represent alkyl group or alkenyl group; R 3 represents an alkyl group, an alkenyl group or an aryl group; R 4 -R 10 which may be identical or different represent hydrogen atom, halogen atom, alkyl group, aryl group or alkoxy group and R 6 and R 7 or R 8 and R 9 may link to each other to form a 5- or 6-membered ring; R 11 and R 12 which may be identical or different represent alkyl group or aryl group and R 11 and R 12 may link to each other to form a 5- or 6-membered ring; Y represents sulfur atom, oxygen atom or >N-R 13 (R 13 represents an alkyl group); X represents an acid anion; Q represents an ethylene group; and l, m, n, p and q represent 1 or 2.
Claim 5
Dependent Claim
35 words
A method for making a lithographic printing plate according to claim 1 wherein the amount of the sensitizing dye is in the range of 1×10 -5 -1×10 -2 mole for 1 mole of silver halide.
Claim 6
Dependent Claim
27 words
A method for making a lithographic printing plate according to claim 1 wherein the thiocyanate contained in the developer is potassium thiocyanate, sodium thiocyanate, or ammonium thiocyanate.
Claim 7
Dependent Claim
22 words
A method for making a lithographic printing plate according to claim 1 wherein the amount of the thiocyanate is about 0.05-0.3 mole/l.
Claim 8
Dependent Claim
23 words
A method for making a lithographic printing plate according to claim 1 wherein content of the silver bromide is about 3-about 60 mole%.
Claim 9
Dependent Claim
25 words
A method for making a lithographic printing plate according to claim 2 wherein the amount of the sensitizing dye is 3×10 -5 -3×10 -4 mole.
Claim 10
Dependent Claim
32 words
A method for making a lithographic printing plate according to claim 2 wherein the antihalation means is provided in at least one of the undercoat layer, the support and a backing layer.
Claim 11
Dependent Claim
33 words
A method for making a lithographic printing plate according to claim 2 wherein the antihalation means is provided by containing a substance capable of absorbing a laser beam of longer than 700 mμ.
Claim 12
Dependent Claim
27 words
A method for making a lithographic printing plate according to claim 9 wherein the antihalation means is provided in the undercoat layer contiguous to the emulsion layer.
Claim 13
Dependent Claim
27 words
A method for making a lithographic printing plate according to claim 1 wherein the exposure is carried out with a laser beam of longer than 700 mμ.
Claim 14
Dependent Claim
27 words
A method for making a lithographic printing plate according to claim 12 wherein the exposure is carried out with a laser beam of longer than 750 mμ.
Claim 15
Independent Claim
130 words
A method of printing which comprises the steps of: (1) imagewise exposing to light of wavelength greater than 700 μm, a light sensitive material which comprises a support and at least a silver halide emulsion layer and a surface physical development nuclei layer provided on the support, said emulsion layer comprising silver halide grains which contain at least silver bromide and containing at least one sensitizing dye having a maximum spectral sensitivity in the region of longer than 700 μm; (2) developing the exposed light sensitive material with a silver complex diffusion transfer developer containing at least a thiocyanate to obtain a lithographic printing plate; (3) mounting the lithographic printing plate on a printing machine; (4) applying an ink on the lithographic printing plate; and (5) carrying out printing operation.
Claim 16
Independent Claim
130 words
A method of printing which comprises the steps of: (1) imagewise exposing to light of wavelength greater than 700 μm, a light sensitive material which comprises a support and at least a silver halide emulsion layer and a surface physical development nuclei layer provided on the support, said emulsion layer comprising silver halide grains which contain at least silver bromide and containing at least one sensitizing dye having a maximum spectral sensitivity in the region of longer than 700 μm; (2) developing the exposed light sensitive material with a silver complex diffusion transfer developer containing at least a thiocyanate to obtain a lithographic printing plate; (3) mounting the lithographic printing plate on a printing machine; (4) applying an ink on the lithographic printing plate; and (5) carrying out printing operation.
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) | 1991-11-15 | 1992-05-16 | 1992-11-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-11-15 | 1996-05-16 | 1996-11-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-11-15 | 2000-05-16 | 2000-11-15 | $7700.00 | Window Closed / Lapsed |