Eastman-kodak Company

Kodak Graphic Communications Gmbh

Other

Bernd Strehmel

Harald Baumann

Udo Dwars

Christopher D Simpson

Ulrich Fiebag

Tanja Ebhardt

Detlef Pietsch

Celin M Savariar-Hauck

Gerhard Hauck

Axel Draber

Mathias Jarek

Philip John Watkiss

Michael Flugel

Dietmar Frank

Uwe Tondock

Ursula Muller

Oliver Piestert

Friederike Von Gyldenfeldt

Daniela Lummel

Michael Mursal

Ulrike Dallmann

Oliver Plestert

Harold Baumann

A method is described for producing an imaged lithographic printing plate, wherein the developer comprises a hydrophilic polymer which comprises (m1) primary, secondary and/or tertiary amino groups, and (m2) acid groups selected from &#x2014;COOH, &#x2014;SOH, &#x2014;POH and &#x2014;POH, and (m3) optionally alkylene oxide units &#x2014;(CHR&#x2014;CH&#x2014;O)&#x2014;, wherein Ris H or &#x2014;CHand p is an integer from 1 to 50.

Processing of lithographic printing plates with a developer solution containing a hydrophilic polymer

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 (iii) at least one coinitiator capable of forming free radicals together with the sensitizer, said coinitiator being other than metallocenes, characterized in that the at least one sensitizer comprises a compound of formula (I) wherein at least one of the groups Rto Ris a bulky group which has a van der Waals volume of at least 55 &#x212b;. 

UV-sensitive lithographic printing plate precursor with benzoxazole derivative and analogues thereof as sensitizer

A method is described for producing an imaged lithographic printing plate, wherein the developer comprises a hydrophilic polymer comprising (m1) structural units derived from at least one compound comprising both a polyalkylene oxide chain and a free radical polymerizable group, and (m2) structural units derived from at least one compound copolymerizable with the free radical polymerizable group of (i) and comprising at least one functional group with pK&#x3c;5.

Method for developing and sealing of lithographic printing plates

Method for producing an imaged lithographic printing plate comprising the step of developing an imagewise exposed negative working precursor with a developer comprising an alkylene oxide derivative of formula (A), wherein Ris a linear or branched Cto Calkyl group or H, (n+m) is an integer from 2 to 30, and RRRand Rare each independently selected from H, methyl and ethyl, with the proviso that at least one of Rand Ris not H, and with the further proviso that at least one of Rand Ris not H. 

Method for making lithographic plates

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

Negative-working imageable element can be used to provide lithographic printing plates. The imageable element has a suitable radiation-sensitive imageable layer and a water-soluble overcoat disposed on the imageable layer. This overcoat comprises at least one poly(vinyl alcohol) having a saponification degree of at least 90%, an alkoxylation product of an alkanol, and either a 2-sulfonato succinic acid dialkylester or an alkoxylation product of a 1,4-butanediol.

Negative-working imageable elements with overcoat

Radiation-sensitive element comprising a substrate and a radiation-sensitive coating comprising (a) 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; (b) at least one free-radical polymerizable oligomer A having an average molecular weight in the range of 3,500 to 9,000 determined by GPC, obtainable by reacting a triisocyanate with (i) at least one acrylic or methacrylic monomer with two free OH groups and at least one (meth)acrylic group and (ii) at least one compound comprising one OH group, at least one (meth)acrylic group and at least one poly(alkyleneoxide) chain in the molecule, wherein the (meth)acrylic monomer (i) is present in an amount of 2 to 20 mole-%, based on the total amount of (meth)acrylic compounds with OH functionality.

Photopolymer composition usable for lithographic plates

Method is described for producing an imaged lithographic printing plate from a precursor comprising a free-radical polymerizable coating and an oxygen-impermeable overcoat, characterized in that removing the overcoat, developing and gumming is carried out in one single step.

Method for processing of photopolymer printing plates with overcoat

Negative-working imageable elements are prepared with radiation-sensitive imageable layers that contain surface-modified silica particles such as fumed silica particles and sol-gel silica particles, that are present in an amount of from about 1 to about 40 weight %, have an average particle size of from about 1 to about 500 nm, have surface hydroxy groups, and have a carbon content of from about 0.5 to about 15 weight % that is derived from surface hydrophobic groups having 1 to 30 carbon atoms. The presence of the surface-modified silica particles provides improved abrasion resistance, reduced tackiness, and various other desired properties.

Negative-working imageable elements with improved abrasion resistance

Negative-working imageable element can be used to prepared lithographic printing plates. These elements include a water-soluble contrast dye having a &#x3bb;in the range of from about 450 to about 750 nm and having an absorption that is lower than 10% with respect to the absorption of the radiation absorbing compound in the element at the wavelength used for exposure. The contrast dye is present in sufficient H-aggregation such that less than 40% of the entire absorption spectrum from the contrast dye is contributed by it in non-H-aggregated form.

Negative-working imageable elements

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

Radiation-sensitive compositions and imageable elements include a polymeric or non-polymeric component in an imageable layer, which component includes 1H-tetrazole groups. The non-polymeric components can be radically polymerizable compounds. The polymeric components can have 1H-tetrazole groups that are pendant to the backbone. The use of such components in negative- or positive-working imageable elements provides high photospeed and improved developability for providing imaged and developed elements, such as lithographic printing plates that show improved chemical resistance and run length.

Imageable elements with components having 1H-tetrazole groups

Process for the posttreatment of an imaged lithographic printing plate comprising (a) providing a lithographic printing plate comprising image areas and non-image areas on a lithographic substrate; (b) bringing the lithographic printing plate of step (a) into contact with a solution comprising a hydrophilic polymer comprising structural units derived from the following compounds: (i) a compound comprising both polyalkylene oxide chains and at least one structural unit which is free-radical polymerizable, and (ii) a monomer capable of copolymerizing with the free-radical polymerizable structural unit of (i) and furthermore comprising at least one acidic functional group with pK&#x3c;5, wherein the acidic functional group can be present as a free acid group or in the form of a salt; (c) drying.

Method for making a lithographic plate

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

A process for the post-treatment of an imaged lithographic printing plate comprises (a) Contacting a lithographic printing plate having image areas and non-image areas on a lithographic substrate with a solution comprising at least one phosphono-substituted siloxane of the following general formula (I) that is defined herein and (b) drying. 

Growing community of inventors

Berlin, Germany

Bernd Strehmel