Digital printing plate comprising a thermal mask
US5948596A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 27, 1997 |
| Grant date | Sep 7, 1999 |
| Priority date | — |
| Expiry date | May 27, 2017 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB41C2210/24
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
Presensitized lithographic plates are prepared which permit direct formation of printable images on plates by digital computerization without the intervening formation of a photographic image with a quality that allows the plates to be used for high volume printing applications. The lithographic printing plate has a structure which contains a substrate; a positive or negative working photosensitive layer; and a thermally sensitive masking layer which is opaque to the actinic radiation but which is soluble in an aqueous medium. The masking layer contains a heat softenable disperse phase which is insoluble in the aqueous medium; a polymeric continuous phase which is soluble or swellable in the aqueous medium; and a colorant which strongly absorbs radiant energy and converts the radiant energy to heat. In use the masking layer is digitally exposed to a computer controlled laser image so that exposed image areas of the masking are insolublized in the aqueous medium; soluble areas of the mask layer are then removed to form an opaque image mask on the photosensitive layer which is then exposed to actinic radiation passing through the mask to solubilize or insolubilize exposed areas of th…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.