Abstract: Negative-working imageable elements can be imaged and processed on-press to provide lithographic printing plates, especially with sulfuric acid-anodized aluminum substrates. These elements have an imageable layer that contains two different polymeric binders, a first polymeric binder that is present a discrete particles, and a second polymeric binder that comprises pendant ethylenically unsaturated groups.

Abstract: The present invention provides an aqueous regenerator for addition to an aqueous developer that contains an organic solvent, a dispersing agent and a weak base, and has a pH of between about 8 and less than about 13. The aqueous regenerator includes an organic solvent, dispersing agent, and an effective amount of a strong base such that the regenerator has a greater pH than the developer into which the regenerator is to be added.

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: 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: 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: 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: Assemblages that comprise a donor element and a receptor are disclosed. The donor element comprises a binder and particles of a cyanoacrylate polymer. The assemblages can be thermally imaged to form lithographic printing plates.