Kodak Polychrome Graphics, Gmbh

Omkar J Natu

S Peter Pappas

My T Nguyen

Robert W Hallman

Ajay Shah

Celin M Savariar-Hauck

Hans-Joachim Timpe

Shashikant Saraiya

Ken-ichi Shimazu

Gerhard Hauck

Jayanti Patel

Nishith Merchant

Jerome Philip Kesselman

Ken-Ichi Shimazu

A lithographic printing surface is prepared using a thermal lithographic printing plate which requires no chemical development to remove areas of the imaged plate. The processless thermal lithographic printing plate has a sheet substrate; a hydrophilic layer on the sheet substrate; and a thermally sensitive imaging layer on the hydrophilic layer. The hydrophilic layer contains about 30 weight % of an aluminosilicate or clay, and preferably has an exterior surface which is micro-porous. The imaging layer preferably is micro-porous. The imaging layer is exposed imagewise using infrared laser radiation to produce an imaged layer. The imaged layer is treated with a conditioner liquid to produce a lithographic printing surface. By this method, the printing plate can be digitally imaged by infrared laser radiation so that the exposed areas become ink receptive and the non-exposed areas repel ink after simple treatment with a conditioner such as an aqueous surfactant solution such as a fountain solution containing an amphoteric surfactant.

Processless, laser imageable lithographic printing plate

A method for directly imaging a lithographic printing surface using infrared radiation without the requirement of pre- or post-UV-light exposure, or heat treatment employs a printing plate which contains a support with a hydrophilic surface overcoated with an imaging layer. The imaging layer contains at least one polymer having bonded pendent groups which are hydroxy, carboxylic acid, tert-butyl-oxycarbonyl, sulfonamide, amide, nitrile, urea, or combinations thereof; as well as an infrared absorbing compound. The imaging layer may contain a second polymer which has bonded pendent groups which are 1,2-napthoquinone diazide, hydroxy, carboxylic acid, sulfonamide, hydroxymethyl amide, alkoxymethyl amide, nitrile, maleimide, urea, or combinations thereof. The imaging layer may also contain a visible absorption dye, a solubility inhibiting agent, or both. In practice, the imaging layer is imagewise exposed to infrared radiation to produce exposed image areas in the imaged layer which have transient solubility in aqueous alkaline developing solution, so that solubility is gradually lost over a period of time until the imaged areas become as insoluble as non-imaged areas. Within a short time period of the imaging exposure, the imaged layer is developed with an aqueous alkaline developing solution to form the lithographic printing surface. In this method, the infrared radiation preferably is laser radiation which is digitally controlled.

Thermal lithographic printing plates

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Warren, NJ, United States of America

Omkar J Natu