Presensitized imaging element suitable for use as a lithographic printing plate with single hydrophilic layer which includes a light-sensitive diazonium salt and tetraalkyl orthosilicate cross-linking agent

US4970133A · kind A · utility

Assignee

• Agfa-Gevaert NV · BE

Inventors

• Joan Vermeersch · Deinze, BE
• Paul Coppens · Turnhout, BE

Key dates

• Filing date: Oct 13, 1988
• Grant date: Nov 13, 1990
• Expiry date: Oct 13, 2008

Classification

• Technology area (CPC G): Physics
• CPC primary: G03F7/016
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

Presensitized imaging element comprising a support and a light-sensitive hyrophilic layer thereon, said light-sensitive hydrophilic layer containing in homogeneously distributed state throughout the entire layer a hydrophilic (co)polymer or (co)polymer mixture, a tetraalkyl orthosilicate crosslinking agent in an amount of at least 0.2 parts by weight per part by weight of hydrophilic (co)polymer or (co)polymer mixture and a low-molecular weight diazonium salt and preferably also (a) substance(s) that increase(s) the mechanical strength and the porosity of the layer, by means of which a lithographic printing plate can be produced by imagewise exposing said imaging element to an ultraviolet radiation source, subsequently bringing it in the presence of an aqueous liquid in contact with a receptor element comprising a receiving layer containing a polyionic mordant for the diazonium salt and separating it from the receiving layer to leave the residual non-exposed diazonium salt on the receiving layer.