Presstek, Inc.

Mark Andy, Inc.

Verico Technology LLC

Kevin Ray

Sonia Rondon

Travis Softic

Frederick R Kearney

Michael Karp

Anthony Paul Kitson

Donald Sundberg

Oren Etziony

Alan Doyle

John Tsavalas

Geula Zegnioyev

Maria Sypek

Thuan Nguyen

Flexographic printing members amenable to aqueous (or organic) development do not exhibit the deleterious effects on printing performance characteristic of some conventional alternatives. Embodiments of the invention utilize a photopolymerizable layer comprising, consisting of, or consisting essentially of a photopolymerization initiator and a water-dilutable (but not water-soluble) monomer.

Solvent-free flexographic imaging and printing with photoresponsive printing members

Embodiments of the present invention involve three-layer printing members having a central layer that is non-conductive yet abalatable at commercially realistic fluence levels. In various embodiments, the central layer is polymeric with a dispersion of nonconductive carbon black particles therein at a loading level sufficient to provide at least partial layer ablatability and water compatibility of the resulting ablation debris.

Lithographic imaging and printing without defects of electrostatic origin

Dry, ablation-type, nitrocellulose-containing lithographic printing members include dual adjacent imaging layers, both including an absorber and at least one containing a binder (which may include or consist essentially of a melamine resin). The absorber of the nitrocellulose-containing layer is a pigment and this layer contains no absorbing dye, while the absorber of the other imaging layer includes or consists essentially of a dye.

Ablation-type lithographic printing members having improved exposure sensitivity and related methods

Negative-working, IR-sensitive dry printing plates utilize an oleophobic topmost layer, a nitrocellulose-based imaging layer ablatable by laser discharge, and a grained metal substrate with no heat-insulating layer intervening between the imaging layer and the substrate.

Dry lithographic imaging and printing with printing members having aluminum substrates

The blanket cylinder of a printing press is used to remove oleophobic debris from an imaged dry printing member. Following imaging&#x2014;e.g., imagewise exposure of the printing member to radiation that ablates the layer below the oleophobic layer, or de-anchors it from the oleophobic layer without ablation&#x2014;the printing member is brought into rolling contact with the blanket cylinder, and the press is operated 'on impression.' This rolling contact may remove not only the oleophobic top layer but ablation debris of the underlying imaging layer as well.

Dry printing with simplified plate cleaning

A recording medium comprises an oleophilic substrate and, thereover, a topmost oleophobic layer comprising a cured polymeric silicone matrix that consists essentially of the addition-cure reaction product of a vinyl-functional polydialkylsiloxane and a silane cross-linking agent. The vinyl-functional polydialkylsiloxane has a molecular weight ranging from 30,000 to 75,000 or 110,000 to 130,000. If the molecular weight of the vinyl-functional polydialkylsiloxane is within the range of 30,000 to 75,000, the molar ratio of silane groups to vinyl groups is within the range of about 11:1 to about 25:1; and if the molecular weight of the vinyl-functional polydialkylsiloxane is within the range of 110,000 to 130,000, the molar ratio of silane groups to vinyl groups is from about 5:1 to about 27:1. The recording medium may be used as a lithographic printing plate.

Recording media and related methods

In ablation-type printing plates involving silicone acrylate top layers, curing at high oxygen levels not only substantially reduces or eliminates toning, but does not adversely affect plate durability or printing performance.

Ablation-type lithographic imaging with silicone acrylate layers

Ablation-type printing plates having improved exposure sensitivity are produced using a thin imaging layer&#x2014;i.e., the plate layer that absorbs and ablates in response to imaging radiation&#x2014;whose composition includes a large proportion of radiation absorber.

Ablation-type printing plates having increased shelf-life are produced using a melamine resin free of water prior to use. A representative production sequence includes providing a substrate having an oleophilic surface; coating, over the substrate, an oleophilic resin composition having (A) a resin phase consisting essentially of a melamine resin substantially free of water and a resole resin, the resole resin being present in an amount ranging from 0% to 28% by weight of dry film, (B) a near-IR absorber dispersed within the resin phase, and (C) a sulfonic acid catalyst dispersed within the resin phase and being present in an amount ranging from 0.7% to 1.6% by weight of dry film; curing the resin composition to produce a dry film; following resin curing, coating an oleophobic polymer composition over the cured resin composition; and curing the oleophobic polymer composition.

Ablation-type lithographic printing members having improved shelf life and related methods

Ablation-type printing plates having improved exposure sensitivity are produced using an imaging layer&#x2014;i.e., the plate layer that absorbs and ablates in response to imaging radiation&#x2014;whose composition includes a large proportion of crosslinker.

Sequentially subjecting an imaged ablation-type printing member having a silicone topmost layer to, first, a cleaning liquid that is not a solvent for silicone, followed by subjecting to a second cleaning liquid that is a silicone solvent, conditions the printing member for subsequent printing with high-solids inks.

Ablation-type lithographic imaging with enhanced debris removal

Embodiments of the present invention involve printing members that utilize a particle-fusion imaging mechanism but avoid susceptibility to handling damage. In particular, printing plates in accordance with the invention may utilize two phases, and these may originate, during manufacture, as two particle systems. Both systems are initially dispersed in a single coating applied as a layer, or in multiple coatings applied as adjacent layers, on a substrate. The second particle system exhibits a glass-transition or thermal coalescing temperature well above room temperature and also above the temperature at which the coating is dried. The coalescing temperature of the first particle system is below the drying temperature. As a result, when the coating is dried, the first particle system coalesces and forms a binder that entrains the second particle system, which has not coalesced. The binder formed by the first particle system is preferably insoluble in aqueous liquids, but is swellable or softened by such liquids, whereas the binder formed by the second particle system is preferably insoluble in and not swellable by aqueous liquids. Aqueous insolubility allows the dried (and ready-to-image) coating to resist handling damage, while swellability facilitates development.

Lithographic imaging and printing with printing members having fusible polymeric particles

Low-VOC cleaning compositions effective in removing stubborn UV inks from printing-press components include at least one non-ionic surfactant selected from the group consisting of a sorbitan ester, an ethoxylated sorbitan ester, an ethoxylated castor oil, polyethylene glycol ester and an alcohol ethoxylate; and at least one carrier comprising or consisting essentially of at least one of (i) an organic solvent miscible therewith or (ii) D-limonene. The cleaning composition has a VOC limit less than 100 g/L.

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Windham, NH, United States of America

Kevin Ray