Kodak Polychrome Graphics, Gmbh

Eastman-kodak Company

Polychrome Corporation

Jayanti Patel

Ken-ichi Shimazu

Jianbing Huang

Shashikant Saraiya

Ting Tao

Kevin Barry Ray

Celin M Savariar-Hauck

Frederic E Mikell

Nishith Merchant

Paul R West

Hans-Joachim Timpe

S Peter Pappas

Scott A Beckley

Eric E Clark

John Kalamen

Kevin W Williams

Anthony Paul Kitson

My T Nguyen

Mathias Jarek

Christopher David McCullough

Robert W Hallman

James Laurence Mulligan

Nicki R Miller

Ajay Shah

Paul Kitson

Omkar J Natu

Steven Michael Sartuche, Jr

William Richard Davin, Jr

Shahhikant Saraiya

Jill Tolfree

Frederic Eugene Mikell

An infrared radiation-sensitive positive-working imageable element has a substrate and single imageable layer that includes a first polymeric binder having urethane or urea moieties in its backbone. The first polymeric binder is also insoluble in water and soluble in a weakly alkaline solution. This imageable element can be imaged and processed using weakly alkaline processing solutions that are free of silicates and metasilicates, which processing solutions may also be used to 'gum' the imaged and developed printing surface.

Positive-working imageable elements and method of use

A negative-working lithographic printing plate precursor can be imaged with infrared radiation and processed in a single step using a single processing solution having a pH of from about 3 to 11. The precursor has a primary polymeric binder that comprises recurring units derived from one or more N-alkoxymethyl(meth)acrylamides, provided that such recurring units are present in the primary polymeric binder in an amount of at least 10% based on the total dry primary polymeric binder weight. In addition, the primary polymeric binder is present in an amount of from about 12 to about 70% based on total imageable layer dry weight. The imaged precursor can be processed off-press or on-press.

Method of preparing lithographic printing plates

Single- and multi-layer positive-working imageable elements include a first polymeric binder that is soluble in an alkaline developer upon exposure to imaging radiation and a radiation absorbing compound. The first polymeric binder comprises a backbone to which are attached pendant groups represented by the following Structure (I): wherein Rand Rare independently hydrogen or alkyl groups having 1 to 8 carbon atoms or aryl groups having 6 or 10 carbon atoms in the carbocyclic ring, L is a direct bond or a linking group having at least 1 carbon atom and optionally one or more nitrogen, oxygen, and sulfur atoms in the linking chain, and X is oxy, thio, or &#x2014;NR&#x2014; wherein R is hydrogen or an alkyl group having 1 to 8 carbon atoms or an aryl group having 6 or 10 carbon atoms in the carbocyclic ring.

Positive-working imageable elements with chemical resistance

Positive-working imageable elements comprise a radiation absorbing compound and inner and outer layers on a substrate having a hydrophilic surface. The inner layer comprises a specific polymeric binder represented by Structure (I):-(A)-(B)-(C)-(D)&#x2003;&#x2003;(I)

Multi-layer imageable element with improved properties

Positive-working imageable elements comprise a radiation absorbing compound and inner and outer layers on a substrate having a hydrophilic surface. The inner layer comprises a combination of two different polymeric binders one of which has an acid number of at least 30, which combination of polymers provides improved post-development bakeability (more quickly baked or cured at lower temperatures) and desired digital speed with no loss in chemical resistance.

Both single-layer and multilayer imageable elements have a substrate and at least one imageable layer. The elements can be used to prepare either negative- or positive-working imaged elements, for example as lithographic printing plates. The imageable elements also include a radiation absorbing compound and a solvent-resistant polymer comprising pendant phosphoric acid groups, pendant adamantyl groups, or both. When this polymer comprises pendant adamantyl groups, they are connected to the polymer backbone through a urea or urethane group. The imageable elements have improved chemical resistance and thermal bakeability from the presence of the unique solvent-resistant polymer.

Imageable members with improved chemical resistance

A method for preparing lithographic printing plates is disclosed. Imaged positive-working, thermally imageable, multi-layer imageable elements useful as lithographic printing plate precursors are developed using solvent based developers. Development may be carried out by immersing the imaged imageable element in the developer.

Method for preparing lithographic printing plates

Multilayer, thermally imageable elements useful as lithographic printing plate precursors are disclosed. The imageable elements comprise a substrate, an underlayer over the substrate, an underlayer over the substrate, and a top layer over the underlayer. The top layer contains a co-polymer that alkylene glycol side chains, polyalkylene glycol side chains, side chains that have silyl groups substituted with three alkoxy and/or phenoxy groups, and/or side chains that have alkyl ammonium side chains. The imageable elements have excellent resistance to press room chemicals.

Multilayer imageable element

A method for forming an image by imaging and developing a multi-layer imageable element is disclosed. When thermally imageable, multi-layer imageable elements that have been imaged using stochastic screening are developed, a much smaller variation in dot percentage throughout the developer loading cycle is observed when a smaller initial charge of developer and a higher replenishment rate than are used in a conventional developing process are used. The developer is a solvent based developer with a pH below about 10.5. The developed imageable elements are useful as lithographic printing plates.

Method for developing multilayer imageable elements

A positive working, multi-layer thermally imageable element is disclosed. The element comprises a substrate, an underlayer, and a top layer. The top layer comprises a crosslinked polymeric material. The element may be thermally imaged and developed to form a lithographic printing plate.

Multi-layer imageable element with a crosslinked top layer

Processes for imaging and developing imageable elements useful as lithographic printing plate precursors either thermally or with ultraviolet radiation that use the same developer are disclosed. The imageable elements comprise a top layer and an underlayer. The top layer contains a phenolic polymer and a material that has either the o-benzoquinonediazide functionality or the o-diazonaphthoquinone functionality. The developer is a 20:80 to 80:20 mixture of (1) an aqueous alkaline developer that has a pH greater than 11 and contains about 2 wt % to about 8 wt % of an alkali metal silicate, and (2) a solvent based developer that contains about 0.5 wt % to about 15 wt % of an organic solvent or mixture of organic solvents.

Preparation of lithographic printing plates

Positive-working thermally imageable elements, useful as printing plate precursors and having reduced ablation when thermally imaged, and methods for their preparation are disclosed. In one aspect, the elements contain a hydrophilic substrate, an underlayer, a barrier layer, and a top layer. The underlayer comprises a photothermal conversion material.

Minimization of ablation in thermally imageable elements

Multi-layer thermally imageable elements, useful as a lithographic printing plate precursors, are disclosed. The elements contain a top layer, an absorber layer that contains a photothermal conversion material and a hydrophilic substrate. An optional underlayer may also be present between the absorber layer and the hydrophilic substrate. The elements can be thermally imaged and processed with an aqueous alkaline developer.

Multi-layer thermally imageable element

A thermally imageable element, useful as a lithographic printing plate precursor is disclosed. The element comprises a hydrophilic substrate; an underlayer comprising a first polymeric material; and an ink-receptive top layer comprising a second polymeric material and a solubility-suppressing component. The solubility-suppressing component may be a separate dissolution inhibitor compound and/or the second polymeric material may also function as a solubility-suppressing component. On thermal exposure the exposed regions of the top layer becomes more readily soluble in an aqueous developer, allowing the developer to remove the top layer and reveal the surface of the hydrophilic substrate. The lithographic printing plate thus formed has excellent properties, including the absence of sludging of the developer.

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Fort Collins, CO, United States of America

Jayanti Patel