Abstract: A polymer based on the reaction of an excess of diisocyanate with saturated polyolefine diols to form an oligomer and further reaction of the oligomer with hydroxyacrylates or hydroxymethacrylates is discussed. The polymer is then blended with ethylenically unsaturated monomers and a photoinitiator to produce a photosensitive composition which is useful in fabricating printing plates.

Abstract: A method for curing a photosensitive resin composition includes use of an especially thin gauge protective cover film, preferably incorporating a coating to permit ease of removal after imaging. The method also uses a photosensitive resin composition incorporating a photospeed modified capping layer to selectively retard image growth during exposure. To eliminate undesirable defects in the cured photopolymer, a glass plate which had previously contacted and flattened the composition, is separated from the composition by at least 0.025 inches after partially curing the composition but prior to completely curing the composition. The partial cure of the composition is achieved by directing light to the composition from a source of actinic radiation positioned about 6 to 30 inches from the resin composition, where the actinic radiation has a wavelength of maximum intensity of about 365 to about 375 nm.

Abstract: A printing plate laminate is formed of a carrier sheet, sticky back, a substrate and photopolymer layer. The substrate has a thickness of only about 0.2 mil to about 3 mil. The printing plate laminate can be formed from a process wherein photopolymerizable resin is coated onto a bilayer substrate, where one layer of the substrate is in contact with the photopolymer layer and has a thickness of about 0.2 mil to about 3 mil, and a second layer of the substrate has a thickness of about 4 mil to about 7 mil. A pressure sensitive adhesive lies between the first and second layers of the substrate, so that the second layer may be easily peeled away from the first layer after selectively curing and then developing the photopolymer layer.

Abstract: A compressible printing plate is prepared by casting liquid photopolymerizable resin directly onto a compressible material having open cells on its surface. The photopolymerizable resin is incompletely cured by exposure to actinic radiation, preferably in the absence of a coverfilm covering the photopolymerizable resin. A further layer of photopolymerizable resin is then cast onto the incompletely cured resin, and the whole exposed to actinic radiation through an image-bearing transparency. A release composition may be placed between the image-bearing transparency and the photopolymerizable resin to provide for decreased adhesion therebetween. After development, an image-bearing laminate suitable as a printing plate for flexographic printing is obtained. The printing plate achieves excellent short and long term adhesion between the compressible layer and the photopolymer plate, without the necessity of a tie layer or adhesive therebetween.

Abstract: A photosensitive resin composition includes a urethane oligomer prepared from a hydroxy-functionalized acrylate and/or methacrylate, at least one diol, and 2,4-toluene diisocyanate and 2,6-toluene diisocyanate in a 65:35 weight ratio. The resin composition additionally contains a monomer having at least one acrylate or methacrylate group, and a photoreactive initiator. The photosensitive resin composition may be cured to provide a soft photopolymer printing plate, particularly well suited for printing on corrugated bard.

Abstract: An aqueous-developable dry-film photopolymerizable composition is disclosed wherein the photopolymerizable composition contains a hydroxyl-modified vinyl chloride/vinyl acetate polymer.