Eastman-kodak Company

Kodak Polychrome Graphics, Gmbh

Scott A Beckley

Ting Tao

Kevin Barry Ray

Jianbing Huang

Shashikant Saraiya

Heidi M Munnelly

John Kalamen

Thomas R Jordan

Jeffrey James Collins

Paul R West

Jayanti Patel

Kevin Wieland

Eric E Clark

Frederic E Mikell

James Laurence Mulligan

Nicki R Miller

Joanne Ray

Eduard Kottmair

Chris McCullough

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

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

A radiation-sensitive composition includes a radically polymerizable component and an iodonium borate initiator composition capable of generating radicals sufficient to initiate polymerization of the free radically polymerizable component upon exposure to imaging radiation. The iodonium borate composition includes a particular diaryliodonium borate compound having organic substituents to provide a sum of at least 6 carbon atoms on the iodonium cation phenyl rings. This composition can be applied to a suitable substrate to provide a negative-working imageable element with improved digital speed and good shelf life and that can be imaged to provide lithographic printing plates. The imaged elements can be developed either on-press or off-press using alkaline developers.

Sulfated polymers, imageable elements containing these polymers, and methods for preparing images useful as lithographic printing plates from these imageable elements are disclosed. The sulfate groups are attached either to aryl groups that are pendent to the polymer backbone, and/or to alkyl groups that are either pendant to the polymer backbone and/or part of the polymer backbone. The elements can be thermally imaged and developed in water or in fountain solution so that an alkaline developer is not required. They can be imaged and developed on press using fountain solution so that it is unnecessary to mount them in a separate exposure device.

Imageable element comprising sulfated polymers

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 polymeric material that is removable using an alkaline developer and comprises a backbone and attached groups represented by the following Structure Q: wherein L, L, and Lindependently represent linking groups, T, T, and Tindependently represent terminal groups, and a, b, and c are independently 0 or 1. The imageable elements have improved resistance to development and printing chemicals and solvents.

Multilayer imageable element with improved chemical resistance

A radiation-sensitive composition and negative-working imageable element includes a polymeric binder comprising pendant allyl ester groups to provide solvent resistance, excellent digital speed (sensitivity) and can be imaged and developed without a preheat step to provide lithographic printing plates. The polymeric binder can be prepared with a precursor polymer having pendant carboxy groups that are converted to allyl ester groups using an allyl-containing halide in the presence of a base in order to avoid gelation.

Negative-working imageable elements can be imaged and then developed using a lower pH organic-based single-phase developer that is less toxic and corrosive and that can be more readily disposed of after use. This developer has a pH less than 12 and comprises a) an amphoteric surfactant comprising a nitrogen-containing heterocycle, b) an amphoteric surfactant having two or more nitrogen atoms, or c) an amphoteric surfactant of a) and an amphoteric surfactant of b).

Method of imaging and developing negative-working elements

A radiation-sensitive composition includes a radically polymerizable component and a borate initiator composition capable of generating radicals sufficient to initiate polymerization of the radically polymerizable component upon exposure to imaging radiation. This composition also includes a radiation absorbing compound (such as an IR-sensitive dye), a polymeric binder comprising a polymer backbone to which is directly or indirectly linked a pendant group comprising a reactive vinyl group, and a primary additive that is a poly(alkylene glycol) or an ether or ester thereof that has a number average molecular weight of from about 200 and up to 4000 and comprises from about 2 to about 50 weight % based on the total composition solids content. This composition can be used to prepare a negative-working imageable element that can be imaged at relatively low energy and developed without a preheat step.

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 of preparing negative-working, single-layer imageable elements improves their storage stability in a humid environment. The method includes enclosing the coated imageable elements in a water-impermeable sheet material that substantially inhibits the transfer of moisture to and from the imageable element. Such imageable elements include a radiation-sensitive composition that includes a radically polymerizable component, an initiator composition to provide radicals upon exposure to imaging radiation, a radiation absorbing compound, and a polymeric binder having poly(alkylene glycol) side chains.

Method of preparing negative-working radiation-sensitive elements

A negative-working radiation-sensitive composition includes a polymeric binder comprising a polymer backbone and having attached thereto a carbazole derivative represented by the following Structure (I): wherein Y is a direct bond or a linking group, and Rto Rare independently hydrogen, or an alkyl, alkenyl, aryl, halo, cyano, alkoxy, acyl, acyloxy, or carboxylate groups, or any adjacent Rthrough Rgroups can together form a carbocyclic or heterocyclic group or a fused aromatic ring. The composition can be sensitive to radiation having a maximum wavelength of from about 150 to about 1500 nm, and can be used to prepare negative-working imageable elements that be imaged and developed as lithographic printing plates.

Radiation-sensitive compositions and imageable materials

A convenient and economical method for preparing infrared absorbing cyanine dyes useful in lithographic printing plate precursors is disclosed. The reaction is generally carried out by condensation of a heterocyclic base containing an activated methylene group and an unsaturated bisaldehyde or its equivalent in a solvent or solvent mixture at about 20&#x2013;150&#xb0; C. All the reactions necessary for production of the infrared absorbing cyanine dye may be carried out in one reaction vessel without isolating any intermediate products.

Process for the preparation of cyanine dyes with polysulfonate anions

Imageable elements with improved dot stability are disclosed. The imageable elements comprise a layer of an imageable composition over a support. The imageable composition comprises an infrared absorbing compound, an acid generator, an acid activatable crosslinking agent, a polymeric binder, and about 0.01 wt % to 1 wt % of an added onium compound. The elements may be thermally imaged and developed to produce images useful as lithographic printing plates.

Imageable elements with improved dot stability

Infrared absorbing compounds are disclosed. The compounds are co-polymers that comprise covalently attached ammonium, sulfonium, phosphonium, and/or iodonium cations, and infrared absorbing cyanine anions that have two to four sulfonate groups and/or sulfate groups, and/or infrared absorbing oxonol anions. The infrared absorbing compounds can be used in aqueous developable lithographic printing plate precursors.

Infrared absorbing compounds and their use in imageable elements

A method for forming images useful as lithographic printing plate precursors is disclosed. An imageable element in which the imageable layer comprises an acid generator, a crosslinking agent, and a binder is imaged with ultraviolet radiation and developed with a solvent based developer. The acid generator is an iodonium, sulfonium, or diazonium salt in which the anion is an organic sulfate or thiosulfate anion. The binder comprises a copolymer that contains a reactive pendent group capable of undergoing acid crosslinking, in which the reactive pendent group is hydroxyl, carboxylic acid, sulfonamide, alkoxymethyl, or a mixture thereof. The method is especially suited for use with direct digital ultraviolet imaging devices. The resulting image is useful as a lithographic printing plate.

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Windsor, CO, United States of America

Scott A Beckley