Eastman-kodak Company

Kodak Polychrome Graphics, Gmbh

Kodak Graphic Communications Gmbh

Michael Flugel

Harald Baumann

Udo Dwars

Christopher D Simpson

Saija Werner

Eduard Kottmair

Akira Igarashi

Bernd Strehmel

Hans-Horst Glatt

Detlef Pietsch

Oliver Piestert

Yuuki Torihata

Harold Baumann

Lithographic printing plates are provided by imagewise exposing negative-working lithographic printing plate precursors having a negative-working radiation-sensitive imageable layer, followed by contacting with a processing solution that has a pH of at least 7 and up to and including 11. This processing solution also includes component (1) that is a nitrogen-containing base having an atmospheric pressure melting point of at least 40&#xb0; C.; component (2) that is a non-ionic surfactant that independently has an atmospheric pressure melting point, glass transition temperature, or pour point of at least 40&#xb0; C.; component (3) that is a hydroxy-containing solution promoter; and component (4) that is a hydrophilic surface protective compound. The method is carried out in a manner such that the exposed and processed precursor is not further treated with any liquid (such as gumming or rinsing solution) between processing and mounting onto a printing press.

Method for making lithographic printing plates

Negative-working lithographic printing plate precursors have improved bakeability and good shelf life and can be imaged using either UV or infrared radiation. These precursors have a negative-working imageable layer that has a unique polymeric binder comprising a polymeric backbone and further comprising at least (a) and (b) pendant groups distributed in random order along the polymeric backbone. The (a) pendant groups are ethylenically unsaturated polymerizable groups, and the (b) pendant groups are defined by Structures (I), (II), and (III) described in the disclosure.

Negative-working lithographic printing plate precursor

Negative-working lithographic printing plate precursor a negative-working imageable layer and an outermost water-soluble overcoat layer that is disposed directly on the negative-working imageable layer. The outermost water-soluble overcoat layer comprises: (1) one or more film-forming water-soluble polymeric binders, (2) organic wax particles, and (3) non-wax matte particles. The outermost water-soluble overcoat layer has a dry thickness (t) that is defined by the following equation (I):wherein w is the dry coverage of the outermost water-soluble overcoat layer in g/m, and r is 1 g/cm. The organic wax particles have an average largest dimension D(wax) that is less than 0.9 of t (in &#x3bc;m), and the non-wax matte particles have an average largest dimension D(matte) that defined by the following equation (II):1.5 times(matte)&#x2266;40 times(in &#x3bc;m).

Lithographic printing plate precursors and use

Negative-working imageable elements such as lithographic printing plate precursors, include a free-radically polymerizable component, an initiator composition that is capable of generating free radicals sufficient to initiate polymerization of the free-radically polymerizable component upon exposure to imaging radiation in the presence of a radiation absorbing compound, a radiation absorbing compound, an aerobic free radical inhibitor, optionally a polymeric binder that is not a free radically polymerizable component, and an anaerobic free radical inhibitor. The molar ratio of the anaerobic free radical inhibitor to the aerobic free radical inhibitor is at least 1:1. This combination of inhibitors provides increased shelf life and good latent image stability particularly when the element includes a polymeric topcoat layer that functions as an oxygen barrier.

Negative-working imaging elements and methods of use

Radiation-sensitive composition comprising (a) at least one photopolymerizable compound with at least one ethylenically unsaturated group accessible to a free-radical polymerization, wherein the at least one photopolymerizable compound has a molecular weight of 3,000 or less and can be obtained by reacting a diisocyanate with (I) an ethylenically unsaturated compound with a hydroxy group, and at the same time (ii) a saturated organic compound with an NH group and an OH group, wherein the reactants are used in amounts according to the following condition: Number of moles of isocyanate groups &#x2266;number of moles of OH plus NH groups; (b) at least one sensitizer which absorbs radiation from the wavelength range of 250 to 450 nm of the electromagnetic spectrum and is selected from: dihydropyridines of formula (I) and oxazole derivatives of formula (II): (II) (c) at least one coinitiator capable of forming free radicals together with the sensitizer (b) and selected from 2,2',4,4&#x2032;,5&#x2032;5-hexaarylbiimidazoles, compounds with at least one photolytically cleavable trihalogenmethyl group, diaryliodonium salts, triarylsulfonium salts and N-heterocyclic compounds with at least one nitrogen atom in the ring, having an oxy substituent at least one ring nitrogen atom, and mixtures of the above compounds; and (d) optionally one or more components selected from alkali-soluble binders, colorants, exposure indicators, plasticizers, chain transfer agents, leuco dyes, surfactants, inorganic fillers and thermopolymerization inhibitors; with the proviso that the radiation-sensitive composition does not comprise a metallocene. 

Radiation-sensitive compositions and imageable elements based thereon

Radiation-sensitive element comprising: (a) one or more types of monomers each comprising at least one ethylenically unsaturated group accessible to a free-radical polymerization, (b) at least one sensitizer, (c) at least one coinitiator capable of forming free radicals together with the sensitizer (b) and selected from the following classes of compounds: metallocenes; 1,3,5-triazine derivatives with one to three CXgroups, wherein X represents chlorine or bromine; peroxides; hexaarylbiimidazoles; oxime ethers; oxime esters; N-aryl glycines and derivatives thereof; thiol compounds; N-aryl, S-aryl and O-aryl polycarboxylic acids with at least 2 carboxyl groups of which at least one is bonded to the N, S or O atom of the aryl unit; alkyltriarylborates; benzoin ethers; benzoin esters; trihalogenomethylarylsulfones; amines; N,N-dialkylaminobenzoic acid esters; aromatic sulfonyl halides; trihalogenomethylsulfones; imides; diazosulfonates; 9,10-dihydroanthracene derivatives; a-hydroxy and a-amino acetophenones; and (d) optionally one or more components selected from alkali-soluble binders, colorants, exposure indicators, plasticizers, chain transfer agents, leuco dyes, surfactants, inorganic fillers and thermopolymerization inhibitors characterized in that the at least one sensitizer is an oxazole derivative of the formula (I), wherein each R, Rand Ris independently selected from a halogen atom, an optionally substituted alkyl group, an optionally substituted aryl group, which may also be fused, an optionally substituted aralkyl group, a group &#x2014;NRRand a group &#x2014;, wherein Rand Rare independently selected from a hydrogen atom, an alkyl, aryl or ralkyl group, Ris an alkyl, aryl or aralkyl group or a hydrogen atom and k, m and n are independently 0 or an integer from 1 to 5. 

Radiation-sensitive compositions comprising oxazole derivatives and imageable elements based thereon

Radiation-sensitive element comprising (a) a substrate with at least one hydrophilic surface and (b) a radiation-sensitive coating on at least one hydrophilic surface of the substrate, wherein the coating comprises: (i) at least one free-radical polymerizable monomer and/or oligomer and/or polymer with at least one ethylenically unsaturated group each, (ii) at least one absorber selected from photoinitiators and sensitizers, which is capable of absorbing radiation of a wavelength in the range of 250 to 1,200 nm and (iii) at least one stabilizer comprising in its molecule at least one group capable of inhibiting free-radical polymerization, and at least one other group capable of sorption at the hydrophilic surface of the substrate.

Radiation-sensitive elements and their storage stability

Radiation-sensitive elements are described whose radiation-sensitive coating comprises both a photopolymerizable oligomer with a biuret structural unit and a photopolymerizable phosphazene oligomer.

Photopolymer composition suitable for lithographic printing plates

A visible radiation sensitive composition is disclosed. The composition comprises at least one ethylenically unsaturated monomer capable of free radical initiated addition polymerization; optionally, at least one binder; and a photoinitiator system comprising a coinitiator and a cyanopyridone sensitizer. The coinitiator preferably comprises a metallocene and an onium compound.

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Osterode, Germany

Michael Flugel