Dot-etchable photopolymerizable elements
AssigneeE. I. Du Pont de Nemours and Company
InventorsMartin D. Bratt, Abraham B. Cohen
Life of this patent
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Abstract
High contrast, dot-etchable solvent-processable lithographic film elements are described comprising a sheet support, a photopolymerizable layer having a thickness of, at most, 0.0004 inch (0.010 mm) and an optical density of at least 3.0 in the actinic region. Images made from these elements may be reduced in area by a process of chemically undercutting the image areas and then spraying or rubbing them. The elements are useful as contact speed lithographic films and for other graphic arts applications.
Claims25
A high contrast, dot-etchable solvent-processable lithographic film element comprising a support bearing a very thin actinic radiation photopolymerizable layer no more than 0.010 mm thick and having an optical density of at least 3.0 to the actinic radiation, the photopolymerizable layer comprised of an ethylenically unsaturated compound capable of forming a high polymer by free radical initiated, chain propagating, addition polymerization, an organic polymeric binder, a free radical generating addition polymerization initiator system activatable by actinic radiation in the spectral region of 300 nm or above, and optionally containing an actinic radiation absorber, the photopolymerizable layer being the outermost layer of the element or being contiguous to a removable cover sheet or an overcoat layer which is at least partially soluble in or permeable to a developer solvent for the photopolymerizable layer.
Dependencies are inferred from the claim text.