Abstract: Negative-working, radiation-sensitive printing plates include or consist of a hydrophilic first layer or substrate and, thereover, an oleophilic imaging layer that includes an iodonium borate free-radical initiators in accordance herewith have the structure where X and Y are alkoxy, p and q range independently from 0 to 5, and p+q?5; or p and q may range independently from 0 to 4, with p+q?4.

Abstract: Negative-working, IR-sensitive printing plates utilize a radiation-sensitive composition having a component polymerizable by a free-radical mechanism, at least part of which comprises or consists essentially of a non-particulate, aliphatic urethane acrylic oligomer that is infinitely water-dilutable but not water-soluble.

Abstract: Embodiments of the present invention involve printing members that avoid ablation imaging mechanisms and, as a result, crosslinked topmost layers. Topmost layers as described herein exhibit good thermal stability and durability during printing, but can be cleaned (and thereby removed from unimaged areas) with water or aqueous cleaning fluids following imaging. It is found, in some embodiments, that the viability of certain topmost layers can be critically dependent on the nature of the underlying substrate, e.g., in terms of texture and/or surface volume.

Abstract: The present invention includes an imageable element, which can be: (a) an imageable element comprising an imaging layer which comprises: an aromatic diazonium salt containing compound having an alkoxy substituent and an aromatic diazonium salt containing compound free of an alkoxy substituent; a polyvinyl acetal binder; and a sheet substrate; or (b) an imageable element comprising an imaging layer which comprises: an aromatic diazonium salt containing compound having an alkoxy substituent and an aromatic diazonium salt containing compound free of an alkoxy substituent; and a sheet substrate. The imaging layer includes a total aromatic diazonium salt containing compound content of at least 10 weight percent. The molar ratio of the aromatic diazonium salt containing compound having an alkoxy substituent to the aromatic diazonium salt containing compound that is free of an alkoxy substituent is from about 1.0:1 to 70:1. Upon imagewise exposure and development, an imaged element is obtained.

Abstract: The present invention includes an imageable element, which can be: (a) an imageable element comprising an imaging layer which comprises: an aromatic diazonium salt containing compound having an alkoxy substituent and an aromatic diazonium salt containing compound free of an alkoxy substituent; a polyvinyl acetal binder; and a sheet substrate; or (b) an imageable element comprising an imaging layer which comprises: an aromatic diazonium salt containing compound having an alkoxy substituent and an aromatic diazonium salt containing compound free of an alkoxy substituent; and a sheet substrate. The imaging layer includes a total aromatic diazonium salt containing compound content of at least 10 weight percent. The molar ratio of the aromatic diazonium salt containing compound having an alkoxy substituent to the aromatic diazonium salt containing compound that is free of an alkoxy substituent is from about 1.0:1 to 70:1. Upon imagewise exposure and development, an imaged element is obtained.

Abstract: The present invention includes an imageable element, which can be: (a) an imageable element comprising an imaging layer which comprises: an aromatic diazonium salt containing compound having an alkoxy substituent and an aromatic diazonium salt containing compound free of an alkoxy substituent; a polyvinyl acetal binder; and a sheet substrate; or (b) an imageable element comprising an imaging layer which comprises: an aromatic diazonium salt containing compound having an alkoxy substituent and an aromatic diazonium salt containing compound free of an alkoxy substituent; and a sheet substrate. The imaging layer includes a total aromatic diazonium salt containing compound content of at least 10 weight percent. The molar ratio of the aromatic diazonium salt containing compound having an alkoxy substituent to the aromatic diazonium salt containing compound that is free of an alkoxy substituent is from about 1.0:1 to 70:1.

Abstract: The present invention includes an imageable element, which can be: (a) an imageable element comprising an imaging layer which comprises: an aromatic diazonium salt containing compound having an alkoxy substituent and an aromatic diazonium salt containing compound free of an alkoxy substituent; a polyvinyl acetal binder; and a sheet substrate; or (b) an imageable element comprising an imaging layer which comprises: an aromatic diazonium salt containing compound having an alkoxy substituent and an aromatic diazonium salt containing compound free of an alkoxy substituent; and a sheet substrate. The imaging layer includes a total aromatic diazonium salt containing compound content of at least 10 weight percent. The molar ratio of the aromatic diazonium salt containing compound having an alkoxy substituent to the aromatic diazonium salt containing compound that is free of an alkoxy substituent is from about 1.0:1 to 70:1.

Abstract: A light sensitive composition which is capable of photopolymerization which includes a photopolymerizable compound a free radical generating component and a benzanthrone or substituted benzanthrone which substantially prevents photopolymerization when the light sensitive composition is exposed to actinic radiation below a threshold amount but permits photopolymerization when the light sensitive composition is exposed to actinic radiation above a threshold amount. This achieves a gate effect which eliminates or decreases unwanted partial exposure in the nonimage areas and hence improves reproduction quality.

Abstract: Photopolymeric printing plates are presented wherein and electrochemically etched and anodized, silicated aluminum substrate has a single photosensitive coating thereon composed of a photopolymerizable combination which includes a photopolymerizable pigment dispersion, a photosensitive lithographic diazonium resin, multifunctional acrylate oligomer, multifunctional acrylate monomer, photopolymerizable binder and photoinitiator to yield a non-tacky, mar resistant, easily developed durable plate. In a preferred embodiment, an additional aqueous, non-photosensitive overcoat is applied over the initial coating to retard oxygen inhibition.

Abstract: Photopolymeric printing plates are presented wherein an electrochemically etched and anodized, silicated aluminum substrate has a single photosensitive coating thereon composed of a photopolymerizable combination which includes a photopolymerizable pigment dispersion, a photosensitive lithographic diazonium resin, multifunctional acrylate oligomer, multifunctional acrylate monomer, photopolymerizable binder and photoinitiator to yield a non-tacky, mar resistant, easily developed durable plate. In a preferred embodiment, an additional aqueous, non-photosensitive overcoat is applied over the initial coating to retard oxygen inhibition.

Abstract: Photopolymeric printing plates wherein an electrochemically etched, anodized and silicated aluminum plate has a plurality of coatings applied thereon and wherein at least one of the coatings include a solvent soluble diazo therein.