Abstract:
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.
Abstract:
Multilayer thermally imageable elements useful as lithographic printing plate precursors are disclosed. The imageable elements comprise a substrate, an underlayer over the substrate, and a top layer over the underlayer. The top layer contains a polymer containing anhydride groups. This polymer is present in the top layer in an amount of at least 60% based on the dry weight of the layer. The imageable elements have excellent resistance to press room chemicals.
Abstract:
Thermally imageable elements comprising a masking layer and a substrate are disclosed. The masking layer contains a sulfobetaine and/or a carboxybetaine containing co-polymer or a mixture of a sulfobetaine and/or a carboxybetaine containing co-polymers and absorbs both infrared and ultraviolet radiation. When the masking layer is on the substrate, the imageable element may be imaged and developed to form a photomask. When the imageable element additionally comprises a photosensitive layer, the masking layer may be imaged and developed to form an integral photomask. The imageable elements that comprise a photosensitive layer are useful as flexographic printing plate precursors.
Abstract:
Thermally imageable elements comprising a masking layer and a substrate are disclosed. The masking layer contains a sulfobetaine and/or a carboxybetaine containing co-polymer or a mixture of a sulfobetaine and/or a carboxybetaine containing co-polymers and absorbs both infrared and ultraviolet radiation. When the masking layer is on the substrate, the imageable element may be imaged and developed to form a photomask. When the imageable element additionally comprises a photosensitive layer, the masking layer may be imaged and developed to form an integral photomask. The imageable elements that comprise a photosensitive layer are useful as flexographic printing plate precursors.
Abstract:
Multilayer, positive working, thermally imageable, bakeable imageable elements have a substrate, an underlayer, and a top layer. The underlayer comprises a polymeric material that comprises, in polymerized form from about 5 mol % to about 30 mol % of recurring units derived from an ethylenically unsaturated polymerizable monomer having a carboxy group; from about 20 mol % to about 75 mol % of recurring units derived from N-phenylmaleimide, N-cyclohexylmaleimide, N-benzylmaleimide, or a mixture thereof; and from about 3 mol % to about 50 mol % of recurring units derived from a compound represented by the formula: CH2═C(R2)—C(O)—NH—CH2—OR1, in which R1 is C1 to C12 alkyl, phenyl, C1 to C12 substituted phenyl, C1 to C12 aralkyl, or Si(CH3)3; and R2 is hydrogen or methyl. Other materials, such as a resin or resins having activated methylol and/or activated alkylated methylol groups, such as a resole resin, may be present in the underlayer. The elements can be used to produce bakeable lithographic printing plates that are resistant to press chemistries.
Abstract:
The present invention provides a positive-working, thermally imageable element generally comprising a multi-layered imageable coating. The invention provides an imageable element comprising a substrate, an ink-receptive top layer, and an underlayer, the underlayer including a specific copolymer described herein. The copolymer can be a polymer comprising constitutional units derived from: a) a monomer having a cyclic urea group; b) a monomer comprising an N-substituted maleimide; c) a (meth)acrylamide or (meth)acrylate monomer; and d) a (meth)acrylic acid or vinyl benzoic acid monomer. In another embodiment, the copolymer can be a polymer comprising constitutional units derived from: a) a monomer having a cyclic urea group; b) a (meth)acrylic acid or vinyl benzoic acid monomer; c) and a (meth)acrylonitrile monomer. The imageable element may be used to prepare a lithographic printing plate that is resistant to press chemistry and can optionally be baked to increase press runlength.
Abstract:
A method for forming an image useful as a lithographic printing plate is disclosed. The imageable precursor comprises a water solubilized phenolic resin made up of an insoluble phenolic resin and a surfactant. The precursor can be imaged with an imaging solution, either off press or on press, using ink jet imaging techniques. The resulting imaged precursor can be developed using an aqueous liquid, such as water or a fountain solution, either off press or on press.
Abstract:
Multilayer, positive working, thermally imageable elements are disclosed. The elements produce bakeable lithographic printing plates that are resistant to press chemistries. The elements have a substrate, an underlayer, and a top layer. The underlayer comprises a resin or resins having activated methylol and/or activated alkylated methylol groups, such as a resole resin, and a polymeric material that comprises, in polymerized form, (a) methacrylic acid; (b) N-phenylmaleimide, N-cyclohexylmaleimide, N-benzylmaleimide, or a mixture thereof; and (c) one or more monomers of the structure: in which: R1 is H or methyl; X is —(CH2)n—, where n is an integer from 2 to 12; —(CH2—CH2—O)p—CH2—CH2—, where p is an integer from 1 to 3; or —Si(R′)(R″)— where R′ and R″ are each independently methyl or ethyl; and m is 1, 2, or 3.
Abstract:
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.
Abstract:
The blanket cylinder of a printing press is used to remove oleophobic debris from an imaged dry printing member. Following imaging—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—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.