Kodak Polychrome Graphics, Gmbh

Eastman-kodak Company

Jianbing Huang

Shashikant Saraiya

Kevin Barry Ray

Heidi M Munnelly

Ting Tao

Ken-ichi Shimazu

S Peter Pappas

Jayanti Patel

Scott A Beckley

Celin M Savariar-Hauck

Eiji Hayakawa

Thomas R Jordan

Jeffrey James Collins

Hans-Joachim Timpe

Yasushi Miyamoto

Xing-Fu Zhong

Nishith Merchant

Paul R West

Ophira Melamed

Christopher D Simpson

Thi N Do

Frederic E Mikell

Kevin Wieland

Alan Stanley Monk

Joanne Ray

Nicki R Miller

Saija Werner

Stefanie Hansmann

Kouji Hayashi

Richard M Goodman

Barbara N&uuml;ssel

Livia T Memetea

Efrat Konstantini

Anthony Paul Kitson

Gerhard Hauck

Neil F Haley

Mathias Jarek

Akira Igarashi

Moshe Levanon

Eric E Clark

Koji Hayashi

Eynat Matzner

John Kalamen

Richard R Durand, Jr

James Laurence Mulligan

Eugene Lynn Sheriff

Patrick Friedman

Dietmar Frank

Michel Moulin

Ajay Shah

Paul Kitson

Tobias Wittig

Ursula Muller

Jianfei Yu

Leonid Askadsky

Socrates Peter Pappas

Jerome Philip Kesselman

Oliver Piestert

Andrea Pauls

Scott Wertz

Mohammad Zaki Ali

Andrew Krebs

Joseph Hunter

Saraiya Shashikant

Chris McCullough

Geoffrey Horne

Shahhikant Saraiya

Peter S Pappas

Xing Fu Zhong

Hirokazu Fujii

Grant Thomas Donald Shouldice

Celin Savariar-Hauck

IR-sensitive lithographic printing plate precursors provide a stable print-out image using a unique IR radiation-sensitive composition in an infrared radiation-sensitive image-recording layer. This IR radiation-sensitive composition includes: (1) a free radical initiator composition that comprises an electron-donating agent; (2) a free radically polymerizable composition; and (3) a color-changing compound that is represented by the Structure (I) having a conjugated carbon chain between the aromatic terminal groups. The compound also has a —SO—Rgroup wherein Rrepresents alkyl, aryl or heteroaryl groups. After IR imaging, these precursors exhibit desirable printout images both fresh and after dark storage. The precursors can be developed off-press or on-press.

Lithographic printing plate precursor and method of use

IR-sensitive lithographic printing plate precursors provide a stable print-out image using a unique IR-sensitive image-recording layer. The IR radiation-sensitive layer includes: (1) a free radical initiator composition with an electron-donating agent and one or more iodonium cations; (2) a free radically polymerizable composition; and (3) a color-changing compound of Structure (I) having an indene ring in the conjugated chain between the aromatic terminal groups. The IR radiation-sensitive composition and layer also contains one or more borate ions such that the molar ratio of one or more borate ions to the one or more iodonium ions is at least 0.5:1. After IR imaging, these precursors exhibit desirable printout images both fresh and after dark storage. The precursors can be developed on-press.

Lithographic printing plates are formed by imagewise exposing a single-layer or dual-layer positive-working lithographic printing plate precursor. The precursor has an outermost ink receptive layer containing a phenolic resin. The exposed precursor can be processed using a silicate-free developer composition having a pH of at least 12.5. This composition also includes an alkali metal hydroxide; a coating protecting agent that is a quaternary ammonium salt or phosphonium salt, or a mixture thereof, and a moderator for the coating protecting agent that is represented by the following general formula (I): wherein m is at an integer of at least 1 and up to and including 10 and M represents one or more counterions sufficient to balance the negatively-charged sulfonate groups.

Lithographic developer composition and method of use

A method is used to prepare lithographic printing plates by developing positive-working lithographic printing plate precursor that has a single imageable layer that comprises a polymer binder having recurring units represented by Structure (Ib) below: wherein the recurring units of Structure (Ib) are present in an amount of at least 25 and up to and including 60 mol %, all based on total recurring units in the polymer binder, and Ris a substituted or unsubstituted hydroxyaryl group in which the hydroxyl group is ortho to the ester linkage, to form exposed and non-exposed regions in the imageable layer. The resulting imaged lithographic printing plate is developed using a silicate-free developer composition having a pH of at least 12 and comprising at least 0.001 gram-atom/kg of a metal cation Mselected from the group consisting of barium, calcium, strontium, and zinc cations.

Methods of processing using silicate-free developer compositions

Lithographic printing plate precursors have been designed so that they can be stored, shipped, and used in stacks without interleaf paper between individual precursors. This is achieved by incorporating polymeric particles having an average diameter of from about 3 to about 20 &#x3bc;m into the outermost precursor layer such as an imagable layer or topcoat. The polymeric particles comprise a core of a crosslinked polymer and have grafted hydrophilic polymeric surface groups that are grafted onto the particle surfaces by polymerizing hydrophilic monomers in the presence of the crosslinked polymeric particles. The lithographic printing plates can be either negative- or positive-working elements.

Lithographic printing plate precursors and stacks

A negative-working lithographic printing plate precursor have an outermost imageable layer that includes an oxygen scavenger and shelf-life stabilizer that is represented by either Structure (I) or Structure (II) below:HOOC&#x2014;Ar&#x2014;N(R)(R)&#x2003;&#x2003;(I)HOOC&#x2014;R&#x2014;N(R)(R)&#x2003;&#x2003;(II)wherein Ar is a phenylene or naphthylene group, Rand Rare independently alkyl, alkenyl, alkynyl, phenyl, phenoxy, &#x2014;ROH, &#x2014;CH&#x2014;C(&#x2550;O)&#x2014;R, or &#x2014;CH&#x2014;C(&#x2550;O)O&#x2014;Rgroups, Ris hydrogen or an alkyl or phenyl group, Ris an alkyl or phenyl group, Ris an alkylene group, Rand Rare independently hydrogen or an alkyl, &#x2014;ROH, &#x2014;RC(&#x2550;O)&#x2014;R, or &#x2014;RC(&#x2550;O)ORgroup, Ris hydrogen or an alkyl group, and Ris an alkyl group, provided that the oxygen scavenger has no more than one carboxyl group.

Negative-working lithographic printing plate precursors

An imageable element can be imaged using non-ablative processes. This element has a non-silicone, non-crosslinked layer contiguous to and under an ink-repelling crosslinked silicone rubber layer. These elements can be used for providing lithographic printing plates useful for waterless printing (no fountain solution). Processing after imaging is relatively simple with either water or an aqueous solution consisting essentially of a surfactant or mechanical means to remove the crosslinked silicone rubber layer and a minor portion of the non-silicone, non-crosslinked layer in the imaged regions.

Imageable elements and methods useful for providing waterless printing plates

Lithographic printing plates can be prepared with enhanced contrast between the image and background by coloring the imaged or exposed regions using a coloring fluid containing a water-insoluble colorant (dye or pigment) and an organic solvent that swells the imaged regions sufficiently for the colorant to be embedded or diffused therein.

Preparing lithographic printing plates with enhanced contrast

A negative-working imageable element has an imageable layer and a topcoat layer that contains a composition that will change color upon exposure to imaging infrared radiation. The imageable element can be imaged and developed on-press to provide images with improved contrast for print-out.

On-press developable imageable elements

A non-ablative negative-working imageable element has first and second polymeric layers under a crosslinked silicone rubber layer. These elements can be used in a simple method to provide lithographic printing plates useful for waterless printing (no fountain solution). Processing after imaging is relatively simple using either water or an aqueous solution containing very little organic solvent to remove the imaged regions. The crosslinked silicone rubber layer is ink-repelling and only the first layer that is closest to the substrate contains an infrared radiation absorbing compound to provide thermal sensitivity.

Imageable elements useful for waterless printing

A radiation-sensitive composition and negative-working imagable element includes a polymeric binder that has a hydrophobic backbone and pendant salt groups that comprise a cation covalently attached to the hydrophobic backbone and a boron-containing anion forming a salt with the cation. The use of these particular polymers provides fast digital speed (high imaging sensitivity) and good printability (good shelf-life) even when the preheat step normally used between exposure and development, is omitted.

Negative-working radiation-sensitive compositions and imageable materials

A radiation-sensitive composition includes a free-radically polymerizable component, an initiator composition capable of generating free radicals sufficient to initiate polymerization upon exposure to imaging radiation, an infrared radiation absorbing compound, and a polymeric binder. The initiator composition includes a unique polyonium borate comprising a polyvalent onium cation with multiple onium moieties and sufficient organic borate counterions to provide a net neutral charge. The radiation-sensitive composition can be used to prepare a negative-working imageable element that is sensitive to suitable imaging infrared radiation, can be imaged at relatively low energy, and can be developed either on-press or off-press.

Polyonium borates and radiation-sensitive composition and imageable elements containing same

The present invention relates to negative-working imageable elements that can be used for the manufacture of printing plates. These imageable elements can be developed on on-press by the action of a lithographic printing ink used in combination with either water or a fountain solution. The imageable elements comprise an imageable layer that is not removable in water or fountain solution alone. The imageable layer includes a free radically polymerizable compound, a free radical initiator composition, an infrared radiation absorbing compound, and a polymeric binder comprising poly(alkylene oxide) pendant groups, and preferably additionally pendant cyano groups.

On-press developable negative-working imageable elements

An apparatus and method for providing substantially intimate rolling contact between a portion of a donor sheet and a portion of an acceptor element in a laser-induced thermal transfer printer comprises a rotatably mounted cylindrical drum, an acceptor element affixed to and supported by the cylindrical drum, a rotatably mounted dispensing roller for dispensing a donor sheet, and a rotatably mounted receiving roller for receiving the donor sheet, so that the donor sheet is extended between the dispensing roller and the receiving roller. A plurality of rotatably mounted contact rollers configured to bring a portion of the donor sheet extended between the dispensing roller and the receiving roller into contact with a portion of the acceptor element is also included.

Method and apparatus for laser induced thermal transfer printing

The present invention provides a radiation sensitive composition suitable for us in on-press developable printing plates. The radiation sensitive composition comprises an initiator system including an onium salt and a radiation absorber. The initiator system is combined with a polymerizable material, and a polymeric binder including polyethylene oxide segments.

On-press developable IR sensitive printing plates containing an onium salt initiator system

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Trumbull, CT, United States of America

Jianbing Huang