Eastman-kodak Company

Kodak Graphic Communications Gmbh

Axel Draber

Harald Baumann

Udo Dwars

Bernd Strehmel

Detlef Pietsch

Christopher D Simpson

Saija Werner

Tanja Ebhardt

Michael Mursal

A negative-working lithographic printing plate precursor comprises a negative-working radiation-sensitive imageable layer and an outermost layer comprising a vinyl alcohol copolymer comprising at least one unit of each of the (a), (b), and (c) recurring units, in any order, defined in the disclosure. The (c) recurring units are present in the vinyl alcohol copolymer in an amount of at least 0.5 mol %, based on the total recurring units. These precursors can be used to prepare lithographic printing plates either on-press or off-press after imaging using near-UV, visible, or infrared radiation.

Negative-working lithographic printing plate precursors and use

Radiation-sensitive element comprising (a) a substrate and (b) a radiation-sensitive coating comprising (i) at least one component selected from photoinitiators and sensitizer/coinitiator systems which absorbs radiation of a wavelength in the range of 250 to 1,200 nm; (ii) at least one oligomer A of formula (I) wherein X, Xand Xare independently selected from straight-chain or cyclic C-Calkylene and C-Carylene, a heterocyclic group, a heteroaromatic group and combinations of two or more of the above, R, Rand Rare independently selected from (II) and (III) with the proviso that (1) n=0 in at least one of the groups R, Rand R, and (2) n&#x3e;2 in at least one of the groups R, Rand R, and (3) at least one group Ris different from H in formula (III). 

Photopolymer composition suitable for lithographic printing plates

Lithographic printing plate precursor comprising (a) a lithographic substrate with a hydrophilic surface and (b) a radiation-sensitive coating on the hydrophilic surface comprising (i) one or more types of monomers and/or oligomers and/or polymers, each comprising at least one ethylenically unsaturated group accessible to a free radical polymerization, (ii) at least one sensitizer, and at least one coinitiator capable of forming free radicals together with the sensitizer (ii); characterized in that the at least one sensitizer is an oligomeric or polymeric compound comprising the following structural unit (Formula (I)), wherein &#x3c0;is an aromatic or heteroaromatic unit or a combination of the two so that a conjugated n-system is present between the two groups Z in structure (I), each Z independently represents a heteroatom, each Rand Ris independently selected from a halogen atom, an alkyl, aryl, alkylaryl or aralkyl group, a group &#x2014;NRRand a group &#x2014;OR, each R, Rand Ris independently selected from an alkyl, aryl, alkylaryl and aralkyl group, a and b independently represent 0 or an integer from 1 to 4, n has a value of &#x3e;1 and AS is an aliphatic spacer. 

Lithographic printing plate precursors with oligomeric or polymeric sensitizers

Growing community of inventors

Osterode, Germany

Axel Draber