Abstract: This invention is directed to a precursor for preparing a resist pattern by heat mode imaging, the precursor comprising a heat sensitive composition, the solubility of which in an aqueous alkaline developer is arranged to increase in heated areas, and a means for increasing the resistance of non-heated areas of the heat sensitive composition to dissolution in an aqueous alkaline developer (the “developer resistance means”), wherein said developer resistance means comprises one or more compounds selected from the group consisting of: (A) compounds which include a poly(alkylene oxide) unit; (B) siloxanes; and (C) esters, ethers and amides of polyhydric alcohols, wherein said heat-sensitive composition comprises an aqueous alkaline developer soluble polymeric substance (i.e. the “active polymer”) and a compound which reduces the aqueous alkaline developer solubility of the polymeric substance (i.e.

Abstract: A positive working lithographic plate precursor comprising a support having a hydrophilic surface and a coating thereon comprising a positive working, photosensitive composition and an aryl alkyl polysiloxane. A method of preparing a positive working lithographic plate precursor comprising coating on a support having a hydrophilic surface a coating comprising, in admixture, a positive working photosensitive composition and an aryl alkyl polysiloxane.

Abstract: A method for preparing a printing form and a method of printing are disclosed. A coating of a radiation sensitive ink on a lithographic support having a hydrophilic surface is imaged. The unexposed areas of the coating are removed to produce a printing form, which is used for printing. Preferably, the same radiation sensitive ink is used for printing as is used in the coating, and, preferably, the desired printing run length is predetermined and the thickness of the coating determined according to the desired run length.

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,

Abstract: A method for preparing a waterless lithographic plate is disclosed. A mixture that contains a water-repellant release material and a compound that becomes aqueous developable on heating is coated on a support, heated imagewise, and developed to produce the printing plate. Preferred water-repellant release materials are acrylic and methacrylic polymers with fluorinated side chains and silicone containing polymers, especially organo functional siloxanes. Preferred compounds that become aqueous developable on heating are phenolic resins as well as complexes of phenolic resins with quinolinium compounds, benzothiazolium compounds, pyridinium compounds, and imidazoline compounds.

Abstract: There is described a method of preparing a water-less lithographic plate by coating a positive working photosensitive composition onto an oleophilic base imagewise exposing the plate and developing it to remove the areas of the photosensitive composition which have been light exposed, coating overall the surface of the plate with a layer of a composition which is ink-releasing or when cured becomes ink releasing, then either as a separate step or as a combined step curing the ink-releasing composition or drying the ink-releasing composition and light exposing overall the plate, then redeveloping the plate to remove the photosensitive composition remaining after the first development and any ink-releasing composition overlying the photosensitive composition.

Abstract: There is described a water-less lithographic plate precursor which comprises on an aluminium plate a light-sensitive composition which comprises a polymer with hydroxy functional groups, an acid generator which when light exposed yields an acid together with a silyl ether of general formula (I), where Rf is a fluoroaliphatic group having 3 to 10 carbon atoms, Y is oxygen, SO.sub.2, carbonyl or a direct link, X is N R.sub.4 where R.sub.4 is hydrogen or lower alkyl having up to six carbon atoms or is a direct link, each of R.sub.1, R.sub.2 and R.sub.3 are lower alkyl groups having up to six carbon atoms and R.sub.5 is a lower alkyl group having up to six carbon atoms.

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.