Method for making lithographic printing plate using light wavelengths over 700 .mu.m
US4784933A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 12, 1986 |
| Grant date | Nov 15, 1988 |
| Priority date | — |
| Expiry date | Nov 12, 2006 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S430/145
- WIPO fieldOptics
- WIPO sectorInstruments
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%.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.