Abstract: The present invention provides an imageable element including a lithographic substrate and an imageable layer disposed on the substrate. The imageable layer includes a radically polymerizable component, an initiator system capable of generating radicals sufficient to initiate a polymerization reaction upon exposure to imaging radiation, and a polymeric binder having a hydrophobic backbone and including constitutional units having a pendant group including a hydrophilic poly(alkylene oxide) segment. The imageable element can be developed using an aqueous developer solution. Alternatively, the imageable element can be developed on-press by contact with ink and/or fountain solution.

Abstract: An initiator composition and infrared radiation-sensitive composition include an onium cation and a boron-containing anion as well as a metallocene. These compositions can be used to provide negative-working imageable elements that can be imaged and developed to provide lithographic printing plates that have desired imaging speed, excellent run length, and shelf life without the need for a post-exposure baking step and oxygen barrier overcoat.

Abstract: A negative-working imageable element has an imageable layer that includes an infrared radiation absorbing dye that upon exposure to thermal irradiation, changes from colorless to a visible color or from one visible color to another visible color, providing a ?E of at least 5 between the exposed and non-exposed regions of the imageable layer within 3 hours of its exposure to 300 mJ/cm2 at a laser power of 15 Watts. The imageable element can be imaged to provide images with improved contrast for print-out. The imageable layer includes a primary polymeric binder that has a backbone to which are attached pendant poly(alkylene oxide) side chains, cyano groups, or both, and is optionally present in the form of discrete particles.

Abstract: A negative-working imageable element has an imageable layer that includes an initiator composition including an iodonium cation and a boron-containing anion at a molar ratio of at least 1.2:1, an infrared radiation absorbing compound, a primary polymeric binder, and a spirolactone or spirolactam colorant precursor. The imaged element exhibits improved print-out.

Abstract: An initiator composition and infrared radiation-sensitive composition include an onium cation and a boron-containing anion as well as a metallocene. These compositions can be used to provide negative-working imageable elements that can be imaged and developed to provide lithographic printing plates that have desired imaging speed, excellent run length, and shelf life without the need for a post-exposure baking step and oxygen barrier overcoat.

Abstract: 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 dye having a tetraaryl pentadiene chromophore, a polymeric binder comprising a polymer backbone to which are directly or indirectly linked poly(alkylene glycol) side chains, and a nonionic phosphate acrylate having a molecular weight of at least 250. This composition can be used to prepare a negative-working imageable element that is sensitive to suitable imaging radiation and can be imaged at relatively low energy and developed either on-press or off-press.

Abstract: 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 dye having a tetraaryl pentadiene chromophore, a polymeric binder comprising a polymer backbone to which are directly or indirectly linked poly(alkylene glycol) side chains, and a nonionic phosphate acrylate having a molecular weight of at least 250. This composition can be used to prepare a negative-working imageable element that is sensitive to suitable imaging radiation and can be imaged at relatively low energy and developed either on-press or off-press.

Abstract: 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.

Abstract: A radiation-sensitive composition includes a radically polymerizable component and an 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, a polymeric binder having poly(alkylene glycol) side chains, and a nonionic phosphate acrylate that has a molecular weight of at least 250. This composition can be used to prepare a negative-working imageable element that is sensitive to suitable imaging radiation and can be imaged at relatively low energy, developed either on-press or off-press, and then used for printing without a post-exposure baking step.

Abstract: The present invention provides an imageable element including a lithographic substrate and an imageable layer disposed on the substrate. The imageable layer includes a radically polymerizable component, an initiator system capable of generating radicals sufficient to initiate a polymerization reaction upon exposure to imaging radiation, and a polymeric binder having a hydrophobic backbone and including both constitutional units having a pendant cyano group attached directly to the hydrophobic backbone, and constitutional units having a pendant group including a hydrophilic poly(alkylene oxide) segment. When the imageable element is imaged and developed, the resulting printing plate may exhibit improved on-press solvent resistance and longer press life.

Abstract: The present invention relates to a polymerizable coating composition suitable for the manufacture of printing plates, which may be developable on-press. The coating composition comprises (i) a polymerizable compound and (ii) a polymeric binder comprising polyethylene oxide segments, wherein the polymeric binder is selected from the group consisting of at least one graft copolymer comprising a main chain polymer and polyethylene oxide side chains, a block copolymer having at least one polyethylene oxide block and at least one non-polyethylene oxide block, and a combination thereof. The invention is also directed to an imageable element comprising a substrate and the polymerizable coating composition.

Abstract: The present invention provides methods of imagewise exposing a thermally sensitive composition formed from a nanopaste comprising inorganic nanoparticles, a carrier, and preferably certain polymeric binders. The composition has been applied to a substrate and treated to improve adhesion. Exposure affects the solubility of exposed portions of the applied and treated layer relative to unexposed portions of the applied layer. The imaged layer is then developed on-press with a fountain solution, lithographic ink, or both, to remove the exposed portions or unexposed portions of the layer to form an image in a printing plate.

Abstract: 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.

Abstract: The present invention provides an imageable element including a lithographic substrate and an imageable layer disposed on the substrate. The imageable layer includes a radically polymerizable component, an initiator system capable of generating radicals sufficient to initiate a polymerization reaction upon exposure to imaging radiation, and a polymeric binder having a hydrophobic backbone and including both constitutional units having a pendant cyano group attached directly to the hydrophobic backbone, and constitutional units having a pendant group including a hydrophilic poly(alkylene oxide) segment. The invention also provides a method for preparing a suitable polymeric binder. The method comprises contacting a combination of co-monomers in a solvent mixture consisting essentially of a (C1–C6) alkanol and water.

Abstract: A radiation-sensitive composition includes a radically polymerizable component that comprises carboxy groups, an initiator composition to generate radicals, and a polymeric binder comprising poly(alkylene oxide) segments and optionally pendant cyano groups. This composition can be used to prepare imageable elements such as negative-working, on-press developable printing plate precursors.

Abstract: 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.

Abstract: The present invention provides an initiator system including an infrared-absorbing compound that exhibits an electronic transition band in the near-infrared region, an initiator, and a metallocene compound. Upon exposure to infrared radiation, the initiator system is capable of producing radicals sufficient to initiate a photopolymerization reaction. Suitable infrared-absorbing compounds include indocyanine dyes, for example. Trihalomethyl triazine compounds and onium compounds are suitable initiators. Suitable metallocene compounds include ferrocenes and titanocenes. The present invention also provides an infrared-sensitive composition including an ethylenically unsaturated polymerizable component, an infrared-absorbing compound that exhibits an electronic transition band in the near-infrared region, an initiator, and a metallocene compound. The infrared-sensitive composition provides improved photospeed and sensitivity in some embodiments.

Abstract: The present invention relates to a polymerizable coating composition suitable for the manufacture of printing plates developable on-press. The coating composition comprises (i) a polymerizable compound and (ii) a polymeric binder comprising polyethylene oxide segments, wherein the polymeric binder is selected from the group consisting of at least one graft copolymer comprising a main chain polymer and polyethylene oxide side chains, a block copolymer having at least one polyethylene oxide block and at least one non-polyethylene oxide block, and a combination thereof. The invention is also directed to an imageable element comprising a substrate and the polymerizable coating composition.

Abstract: Negative working thermally imageable elements useful as lithographic printing plate precursors and methods for their use are disclosed. The elements have a substrate, a layer of imageable composition over the substrate, and, optionally, an overcoat layer over the layer of imageable composition. The imageable composition has an allyl-functional polymeric binder. Optimum resolution and on-press performance can be attained without a post-exposure bake. The elements do not require a post-exposure bake and can be used in on-press development applications.

Abstract: The present invention provides an imageable element including a lithographic substrate and an imageable layer disposed on the substrate. The imageable layer includes a radically polymerizable component, an initiator system capable of generating radicals sufficient to initiate a polymerization reaction upon exposure to imaging radiation, and a polymeric binder having a hydrophobic backbone and including both constitutional units having a pendant cyano group attached directly to the hydrophobic backbone, and constitutional units having a pendant group including a hydrophilic poly(alkylene oxide) segment. The invention also provides a method for preparing a suitable polymeric binder. The method comprises contacting a combination of co-monomers in a solvent mixture consisting essentially of a (C1-C6) alkanol and water.