Process of making lithographic plate, and plate from photosensitive element
US4226931A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 10, 1978 |
| Grant date | Oct 7, 1980 |
| Priority date | — |
| Expiry date | May 10, 1998 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB41C2210/24
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
The adherence of the oleophilic polymer printing surface of a lithographic printing plate to the support of the lithographic printing plate is improved by an anchoring layer formed from a hydrophobic oleophilic ester colloid which is capable of being rendered hydrophilic by treatment with an aqueous alkali solution. After an image-wise exposure of the photosensitive layer of the presensitized photosensitive sheet used to prepare the lithographic printing plate and removal of the non-polymerized (non-image) portions of the photosensitive layer the plate is contacted with an aqueous alkali solution to render those portions of the anchoring layer, which have been exposed by removal of the non-polymerized portions of the photosensitive layer, hydrophilic. Accordingly, the portions of the anchoring layer underlying the oleophilic hardened polymeric printing surface remain hydrophobic oleophilic and therefore can increase the number of satisfactory printings which can be made from the lithographic printing plate.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.