Polymer system with switchable physical properties and its use in direct exposure printing plates
US7129021B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 25, 2003 |
| Grant date | Oct 31, 2006 |
| Priority date | — |
| Expiry date | Aug 25, 2023 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S430/146
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
Polymer materials are described that undergo a two-level three-dimensional crosslinking process. During this process, hydrophilic polymers are crosslinked at two levels, the first results in a low level of crosslinking which leads to a toughening of the layer preventing dissolution by the fountain solution but with the layer remaining hydrophilic. The second level of crosslinking is higher and is the result of exposure to a laser diode thermal imaging device. The crosslinking at this second level results in a loss of hydrophilicity and provides instead an oleophilic image capable of accepting and transferring oil-based ink. The polymer materials are particularly useful in lithographic printing systems where they may used in articles such as a printing plate comprising a substrate having coated thereon a layer that becomes less hydrophilic upon exposure to thermal energy (e.g., heat applied by a laser, other collimated light, or thermal printhead) that effects crosslinking (initial crosslinking or increased crosslinking) in the layer, the layer comprising a mixture of a crosslinked polymer and a thermally active crosslinking metal compound. The invention also provides an overcoat la…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.