Abstract: A thermally imagable element suitable for use as a lithographic printing plate is disclosed. Imagable element contains an ink repellent, thermally sensitive surface layer on a substrate. The surface layer contains an ink repellent, thermally sensitive co-polymer which is both thermally sensitive and has the physical properties needed for handling and printing. The thermally sensitive co-polymer contains two types of segments: (a) soft silicone segments, which repel ink, and (b) hard segments, which provide physical integrity and impart thermal sensitivity to the co-polymer. The element can be imaged by imagewise expose either by infrared radiation or by heat. The process requires no wet development step and no wiping. Thermally labile crosslinked polymers are also disclosed.

Abstract: A lithographic imaging member has a support having thereon a melanophobic silicone copolymer layer and a contiguous surface melanophilic layer composed of an inorganic or organic polymeric matrix. Either or both layers includes a photothermal conversion material capable of converting irradiation, such as IR radiation, to heat in exposed regions. The imaging member can include in one or more layers a material capable of promoting adhesion across the interface of the contiguous layers. This imaging member can be digitally imaged, for example using a laser, and used for printing without wet processing.

Abstract: A lithographic printing plate made by coating a support web with a coextensive hydrophilic layer of a crosslinked polymeric matrix containing a member of the group consisting of colloids of beryllium, magnesium, aluminum, silicon, gadolinium, germanium, arsenic, indium, tin, antimony, tellurium, lead, bismuth and the transition metal oxides, along with a photothermal conversion material capable of accepting ink when exposed to high intensity radiation.

Abstract: This invention relates to a binder containing the units A, B, C, D and E, wherein A is present in an amount of 10 to 60 mole % and is of the formula ##STR1## B is present in an amount of 1 to 30 mole % and is of the formula ##STR2## C is present in an amount of 5 to 60 mole % and is of the formula ##STR3## D is present in an amount of 0 to 60 mole % and is of the formula ##STR4## and E is present in an amount of 1 to 40 mole % and is of the formula ##STR5## wherein X is an aliphatic, aromatic or araliphatic spacer group,R.sup.1 is hydrogen or an aliphatic, aromatic or araliphatic group,R.sup.2, R.sup.3 and R.sup.4 are hydrogen or alkyl groups with carbon numbers of from 1 to 18 andY is a saturated or unsaturated chain- or ring-shaped spacer group, and photosensitive compositions containing this binder.

Abstract: There is described a method of preparing water-less lithographic plate which comprises imagewise exposing a lithographic plate coated with a photosensitive composition, processing the exposed plate in an aqueous based developing liquid to remove those areas of the photosensitive composition which are removable by the developing liquid, drying the plate and coating the plate with an ink releasing coating composition which adheres to those areas of the plate from which the photosensitive composition has been removed, but which does not adhere to those areas of the plate from which the photosensitive composition which has not been removed, further treating the plate to cure or fix the ink-releasing composition thus providing ink-receptive areas of the plate which are those areas of the plate from which the photosensitive composition which has not been removed in the developing liquid and ink-releasing areas of the plate which are covered with the cured ink-releasing composition.

Abstract: There is described a lithographic plate which comprises a base coated with a photopolymerisable composition which comprises a polymeric binder, at least one free-radically polymerisable ethylenically unsaturated compound and as the photoinitiator combination a metallocene compound, N-phenyl glycine or a substituted N-phenyl glycine or an N-phenyl glycine derivative together with a third component which is a substance which helps in the reaction initiation but also increases the sensitivity of the photopolymerisable composition to a desired region of the spectrum.

Abstract: A photosensitive composition can be used to prepare negative-working photosensitive elements such as lithographic printing plates. The composition includes a first photocrosslinkable aromatic resin having photocrosslinkable groups and a number average molecular weight of at least about 1500. Also included is a polymerizable monomer, a photocrosslinkable polyester, a photoinitiator, and an aromatic thiazoline photosensitizer. The photosensitive resins are present at a total weight ratio to the monomer of at least 1.5:1.

Abstract: A direct write lithographic printing plate comprises a support, a melanaphilic layer, a melanophobic layer with a non-ionic crosslinker and a melanophobic layer with an ionic crosslinker.

Abstract: An alkaline developing composition for processing a lithographic printing plate includes an alkali metal silicate, at least 6 weight % of a thickener such as glycerine, and a nonionic fluorosurfactant or a phosphate ester hydrotrope. Lithographic printing plates that can be developed using this composition are either positive- or negative-working, and include both positive- and negative-working thermal plates.

Abstract: A lithographic imaging member, such as a printing plate, has a support having thereon an ink-accepting melanophilic layer and an ink-rejecting siloxane surface melanophobic layer. Within the printing plate is a photothermal conversion material capable of converting irradiation, such as IR radiation, to heat in exposed regions. Also within one of the layers is a compound that upon imaging releases a moiety that facilitates degradation of the surface melanophobic layer. The released moiety can be fluoride ion or a fluoride ion-containing compound. In some imaging members, a barrier layer may be interposed between the two other layers. Such imaging members can be digitally imaged and used for printing without post-imaging processing.

Abstract: Coated paper stocks for electrostatic imaging comprising a substrate coated on at least one surface with a resin layer comprised of olefinic material and a pin-hole free, continuous coating layer over said resin layer. The continuous layer has a glass transition temperature above 100.degree. C. and is comprised of one or more natural or synthetic film forming polymers. As a single layer this continuous coating layer functions as both a heat protective and imaging layer. In an alternate embodiment two separate coating layers are provided with separate heat protective and imaging functionalities.

Abstract: Presensitized lithographic plates are prepared which permit direct formation of printable images on plates by digital computerization without the intervening formation of a photographic image with a quality that allows the plates to be used for high volume printing applications. The lithographic printing plate has a structure which contains a substrate; a positive or negative working photosensitive layer; and a thermally sensitive masking layer which is opaque to the actinic radiation but which is soluble in an aqueous medium. The masking layer contains a heat softenable disperse phase which is insoluble in the aqueous medium; a polymeric continuous phase which is soluble or swellable in the aqueous medium; and a colorant which strongly absorbs radiant energy and converts the radiant energy to heat.

Abstract: Improved photopolymerization initiator systems are comprised of a spectral sensitizer that sensitizes in the ultraviolet or visible regions of the spectrum and an N-aryl, O-aryl or S-aryl polycarboxylic acid co-initiator. The improved initiator systems are incorporated in photo-polymerizable compositions containing one or more addition-polymerizable ethylenically-unsaturated compounds to form compositions suitable for the preparation of radiation-sensitive layers in lithographic printing plates adapted to be imagewise-exposed with ultraviolet- or visible-light-emitting lasers such as argon-ion lasers and frequency doubled Nd:YAG lasers. Such plates are able to effectively meet the dual requirements of very high photospeed and very good shelf-life required in computer-to-plate systems.

Abstract: Nucleating agents that promote high contrast in photographic films are disclosed. The nucleating agents are aryl sulfonamido hydrazides having pyridinium, phosphonium or cycloalkenylpyridinium functional groups. The nucleating agents increase the speed and contrast of graphic arts films and improve dot quality in halftone applications. Boosters are not required to obtain good dot quality and photographic speed.

Abstract: A photosensitive composition can be used to prepare negative-working photosensitive elements such as lithographic printing plates. The composition includes a first photocrosslinkable aromatic resin having photocrosslinkable groups and a number average molecular weight of at least about 1500. Also included is a mixture of a polyalkyleneglycol diacrylate and polyacrylate polymerizable monomers, a photocrosslinkable polyester, a photoinitiator, and a photosensitizer. The photosensitive resins are present at a total weight ratio to the polymerizable monomers of at least 1.5:1.

Abstract: Polymeric binders for photosensitive compositions exhibiting improved ink acceptance, good developability and wetting, high photosensitivity, good image resolution, and larger printing runs for plates employing such photosensitive compositions.

Abstract: An imaging member, such as a negative-working printing plate, can be prepared using a heat sensitive imaging layer comprised of a heat-sensitive vinyl polymer and optionally a photothermal conversion material. The heat-sensitive polymer has recurring units containing a cyclic anhydride that decarboxylates upon application of thermal energy (such as from IR irradiation), rendering the polymer more hydrophobic in IR exposed areas. Upon contact with a neutral or acidic pH solution, the polymer is then rendered more hydrophilic in unexposed areas.

Abstract: Radiation-sensitive compositions, printing plates containing such compositions, imageable by infrared and ultraviolet/visible radiation and imaging method using same. The compositions comprise a thermal-activated acid generator; a crosslinking resin; a binder resin comprising a polymer containing reactive pendant groups selected from hydroxy, carboxylic acid, sulfonamide, and alkoxymethylamides; an infrared absorber; and optionally a UV/visible radiation-activated acid generator for UV/visible sensitization.

Abstract: A waterless or driographic printing plate which can be thermally imaged by an infrared laser is composed of a substrate; a thermal imaging layer containing a photothermal conversion material, such as an infrared absorbing material, and a thermoplastic polyurethane with pendent allyl groups; and a crosslinked silicone polymer top layer. It was discovered that when the imaging layer contains an allyl functional polyurethane mixed with an infrared absorbing dye or pigment, the polymeric layer will have enhanced solubility in certain solvents when exposed to infrared radiation. In addition, the polymeric layer continues to exhibit excellent adhesion to the silicone in unexposed areas so that the infrared absorbing layer can endure development with a suitable organic solvent, or a solvent mixture. Mild brushing or rubbing with the developing solvent readily removes laser-struck portions of the infrared imaging layer while unexposed areas remain firmly intact.

Abstract: The invention comprises a process for forming a high contrast photographic image including the steps of imagaewise exposing a silver halide photographic element containing a hydrazine compound which functions as a nucleating agent, wherein the element is free of incorporated amine boosters. The exposed element is developed with a chemically stable aqueous alkaline developing solution that is free of dihydroxybenzene developing agents and has a pH between 9.5 and 11. The developing solution comprises an ascorbic acid developing agent; an auxiliary developing agent; and a combination of an alkali metal carbonate and an alkali metal borate comprising between 0.125 and 0.5 molar concentration of the carbonate and between 0.04 and 0.35 molar concentration of the borate.