Abstract: Photosensitive polyesters having dye moieties incorporated into the polyester backbone are disclosed. The photosensitive polyesters contain an unsaturated photosensitive moiety comprising photopolymerizable —CH═CH—CO— groups and dye moieties derived from dyes that are copolymerizable diols. Negative-working photosensitive elements, such as negative-working printing plates, can be prepared using these photosensitive polyesters.

Abstract: A process for treating alkaline solutions obtained from lithographic printing plate processing comprises admixing at least one alkaline solution and at least one acidic solution in the presence of at least one aqueous solution to obtain a discharge solution having a pH in the range of about 5.0 to 11.5. Another process for treating alkaline solutions obtained from lithographic printing plate processing comprises admixing at least one alkaline solution and at least one aqueous waste water solution to obtain an aqueous alkaline solution, and admixing the resultant aqueous alkaline solution with at least one acidic solution to obtain a discharge solution having a pH in the range of about 5.0 to 11.5, and to control systems for such processes, and methods of controlling such processes. The alkaline solution has a pH greater than 7.0, preferably greater than about 12.5, and the acidic solution has a pH less than 7.0, preferably less than about 2.5.

Abstract: The present invention relates to particular acetal copolymers and radiation-sensitive compositions comprising said copolymers and, inter alia, are excellently suitable for the production of lithographic printing plates. In particular, the invention relates to acetal copolymers containing furylvinylidene, thienylvinylidene or pyrrolylvinylidene.

Abstract: There is described a method of preparing a lithographic plate which comprises coating on a lithographic support having a hydrophilic surface, a layer of a heat sensitive coating, digitally imaging the coating, then processing the plate with water to remove the unexposed areas of the coating to reveal the hydrophilic surface of the plate and to leave an ink receptive image, wherein the heat sensitive coating comprises a diazo salt of formula (I): wherein R1 is an anion, R2 and R3 represent optional substitution, R4 is —N— or —S— and R5 is a group which, after exposure of the plate, renders the residue of the diazo salt oleophilic and fount solution insoluble.

Abstract: A lithographic printing surface is prepared using a thermal lithographic printing plate which requires no chemical development to remove areas of the imaged plate. The processless thermal lithographic printing plate has a sheet substrate; a hydrophilic layer on the sheet substrate; and a thermally sensitive imaging layer on the hydrophilic layer. The hydrophilic layer contains about 30 weight % of an aluminosilicate or clay, and preferably has an exterior surface which is micro-porous. The imaging layer preferably is micro-porous. The imaging layer is exposed imagewise using infrared laser radiation to produce an imaged layer. The imaged layer is treated with a conditioner liquid to produce a lithographic printing surface.

Abstract: The invention is aqueous alkaline composition comprising at least one alkali metal silicate, glycerol, at least one glycol and phosphoric acid and/or phosphates. The composition can be used as a developer and replenisher for developing either positive-working or negative-working alkaline developable lithographic printing plates (including thermal plates) independently of the interlayer present in the printing plate.

Abstract: Imagable articles comprising positive working polymeric resins coating onto substrates are given a heat treatment comprising their controlled slow cooling from an elevated temperature. The imagable articles include precursors for lithographic printing plates and for printed circuits. The controlled slow cooling improves the development characteristics of the coatings after an imaging step.

Abstract: A method for producing a predetermined resist pattern on e.g. a lithographic printing plate, circuit board or mask, comprises the patternwise exposure to suitable radiation of a composition which comprises a novolac resin and a diazonium salt. The composition is rendered preferentially soluble to a developer in the regions which were exposed.

Abstract: A printable media, including: (a) a substrate having a hydrophilic, porous layer on at least one surface; and (b) an ink receptive, thermoplastic image layer adhered to the hydrophilic, porous layer, where the ink receptive layer contains a copolymer having a low surface energy and a plurality of tertiary amine sites, the amine sites being at least partially neutralized with an acid. The invention also relates to a method for preparing a printable media, including: (a) applying a hydrophilic porous layer onto a substrate; (b) applying a fluid composition onto the hydrophilic porous layer by means of an ink jet printing apparatus, where the fluid composition contains a copolymer having a plurality of tertiary amine sites, the amine sites being at least partially neutralized with an acid, and (c) drying the composition.

Abstract: Heat-imagable negative working lithographic printing forms employ negative working heat sensitive compositions comprising a water soluble binder and particles of pigment in association with a thermoplastic resin. Heat causes fusion of the particles to the binder. Heated regions are thereby rendered insoluble to aqueous developers. Unheated areas are soluble in developer or fount solutions, so development may take place “on-press” during the initial phase of a print run.

Abstract: There is described a method of preparing a water-less lithographic printing form using a precursor which includes a support having a coating thereon comprising a diazo salt formed from an aromatic diazonium compound and an abhesive counter anionic moiety, the method comprising heat mode imaging the precursor and processing the imaged percursor on press by the application of printing ink to remove the abhesive products of the imaging so that areas of the precursor which have been imaged are ink-accepting.

Abstract: A method of preparing a planographic printing member is disclosed. In one embodiment, the method comprises forming a hydrophilic layer by thermally spraying a hydrophilic particulate material onto an ablatable layer. Typical hydrophilic materials are SiO2, Al2O3, Cr2O3, TiO2 and ZrO2. Spraying a plasma containing the hydrophilic material in an inert gas atmosphere is preferred method for forming the hydrophilic layer.

Abstract: The invention relates to coating solutions, processes for the preparation of a printing plate using these coating solutions as well as printing plates prepared in this manner; in particular, the invention relates to printing plates the photosensitive layer of which contains homogeneously distributed polymer particles.

Abstract: An imaging device comprising an electro-optic modulator for modulating incident laser beams; an array of adjacent electrodes comprising a group of imaging electrodes addressed in accordance with image information; means to illuminate an area slightly larger than the width of said imaging electrodes; and one or more additional electrodes located on each side of said group of imaging electrodes to permanently direct extraneous marginal beams to light-stop means so that only the light emerging from the imaging electrodes is allowed to reach a light sensitive medium.

Abstract: A lithographic printing plate precursor element is made by coating a support web, with a thermal insulating layer, and then overcoating with a coextensive ink repellent layer. The coextensive ink repellant layer comprises a crosslinked polymeric matrix containing a colloid of an oxide or a hydroxide of a metal selected from the group consisting of beryllium, magnesium, aluminum, silicon, gadolinium, germanium, arsenic, indium, tin, antimony, tellurium, lead, bismuth, a transition metal and combinations thereof. A photothermal conversion material is present in the ink repellent layer, in a stratum located between the thermal insulating layer and the ink repellent layer, or in both the ink repellent layer and the stratum. The ink repellant layer contains less than 5% hydrocarbon groups by weight.

Abstract: A laser sensor holder apparatus for enabling a power sensor to be held in the path of a laser beam to measure the beams power comprises a base unit including a mounting frame, and translation stages to enable the movement of a sensor mounting plate to a desired position in the path of a laser beam. The apparatus is useful in measuring the power of a laser beam. Applications of the apparatus include its use in direct imaging systems whereby the previous method of manually holding a power sensor in the path of a class 4 laser and all of its inherent disadvantages may be avoided.

Abstract: An imaging member, such as a negative-working printing plate, can be prepared using a hydrophilic imaging layer comprised of a heat-sensitive hydrophilic polymer having a positively charged moiety, and optionally a photothermal conversion material. The heat-sensitive polymer has recurring units containing an N-alkylated aromatic heterocyclic group or an organoonium group that reacts to provide increased oleophilicity in areas exposed to energy that provides or generates heat. For example, heat can be supplied by laser irradiation in the IR region of the electromagnetic spectrum. Thus, the heat-sensitive polymer is considered “switchable” in response to heat, and provides an imaging means without wet processing.

Abstract: An imaging member, such as a negative-working printing plate, can be prepared using a hydrophilic heat-sensitive imaging layer comprised of a hydrophilic heat-sensitive, crosslinked vinyl polymer containing recurring organoonium groups. The imaging member can also include a photothermal conversion material such as carbon black or an infrared radiation absorbing dye. The heat-sensitive polymer has recurring units containing an organoammonium, organophosphonium or organosulfonium group that reacts to provide increased oleophilicity (ink receptivity) in response to heat. Heat is preferably generated by laser irradiation in the IR region of the electromagnetic spectrum. The heat-sensitive polymer is considered “switchable” in response to heat. The imaging member can be used in printing methods without the usual wet processing steps.

Abstract: A presensitized printing plate intermediate having an image mask on a UV radiation transparent removable coating layer; and a printing plate produced directly by reactants which polymerize alone or in combination with other reactants precoated on the plate substrate to form a printable hard resin image. A method of digitally forming an image on said printing plate intermediate.

Abstract: There is described a method of preparing a positive working water-less lithographic plate which comprises a support having an oleophilic surface, there being coated on the support a mixture which comprises as one component an ink-repellant and water-repellant polymer or a mixture of such polymers or polymer precursors, and as the other essential component of the mixture an infra-red or heat sensitive composition selected from (a) an organic solvent soluble diazo compound and an infra-red absorbing compound, (b) a photopolymer and an infra-red absorbing dye, or (c) a mixture of a free-radically polymerisable ethylenically unsaturated compound or compounds together with either a photoinitiator which is infra-red sensitive or an initiator which is heat sensitive together with an infra-red absorbing compound, the ratio of ink-repellant polymer to infra-red or heat sensitive composition (a), (b) or (c) in the mixture being from 20-80 ink repellant polymer to 80-20 infra-red or heat sensitive composition by weight,