Method for making positive working printing plates
US6455229B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 3, 2000 |
| Grant date | Sep 24, 2002 |
| Priority date | — |
| Expiry date | Jan 3, 2020 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S430/165
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
According to the present invention there is provided a method for the preparation of a lithographic printing plate comprising the steps ofexposing with IR light an imaging element comprising on a lithographic base with a hydrophilic surface a first layer including a polymer, soluble in an aqueous alkaline solution and a top layer on the same side of the lithographic base as the first layer which top layer is IR-sensitive and unpenetratable for or insoluble in an alkaline developer wherein said first layer and said top layer may be one and the same layer, said imaging element comprising a siloxane surfactant;developing said exposed imaging element with an alkaline solution;gumming said developed imaging element with a baking gum solution;subjecting said gummed imaging element to a thermal treatment at a temperature above 50° C.;characterized in that said baking gum solution contains at least one surfactant making the contact angle between the baking gum solution and the surface of the plate less than 68° and/or at least one viscosity-regulating polymer making the viscosity of the baking gum solution between 1.7 cP and 5.0 cP.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.