A lithographic printing plate precursor is disclosed including a support and a coating comprising a sensitizer and an onium salt wherein the onium salt and the sensitizer are capable of inducing a print-out image upon UV light exposure.

The present invention relates to an apparatus (10) for developing printing precursors (11) comprising a developing station (20) comprising a rotating drum (22) having a fixation mechanism (24) for the precursor (11) and at least one brush (26). The apparatus (10) further comprises a pre-cleaning station (30) and a first transport mechanism (12), the first transport mechanism (12) being configured for transporting the precursor (11) through the pre-cleaning station (30) and, after the precursor (11) has passed the pre-cleaning station (30), to the developing station (20). Further aspects relate to a method for developing a printing precursor using such an apparatus.

Lithographic printing plate precursors are prepared with a unique substrate using two separate anodizing processes to provide an inner aluminum oxide layer of average dry thickness (T.sub.i) of 650-3,000 nm and a multiplicity of inner micropores of average inner micropore diameter (D.sub.i) of 15 nm. An outer aluminum oxide layer comprises a multiplicity of outer micropores of average outer micropore diameter (D.sub.o) of 15-30 nm; dry thickness (T.sub.o) of 130-650 nm; and a micropore density (C.sub.o) of 500-3,000 micropores/m.sup.2. The ratio of D.sub.o to D.sub.i is greater than 1.1:1. A hydrophilic layer disposed on the outer aluminum oxide layer has a copolymer composed of (a) recurring units and (b) recurring units, wherein the (a) recurring units have an amide group, and the (b) recurring units have at least a phosphonic acid, a phosphoric acid, a salt of a phosphonic acid, or a salt of a phosphoric acid group.

The present invention relates to a water-based or solvent-based washing unit for washing a flexographic plate. The washing unit comprises a containment structure which defines a lower basin and at least two side basins which are supplied with the washing liquid and are arranged so that the water overflowing from the side basins is collected in the lower basin. A brush partially immersed in the liquid bath defined by the basin itself is installed at each basin.

Provided are a planographic printing plate precursor including: a support; and an image recording layer provided on the support, in which the image recording layer contains an infrared absorbing agent, a polymerization initiator, a polymerizable compound containing a hydrogen bonding group, and a hard polymer particle containing at least one group selected from the group consisting of a urethane group, a urea group, an imide group, an amide group, and a sulfonamide group on the surface of the hard polymer particle, and a number average primary particle diameter of the hard polymer particle is in a range of 0.01 to 1 m; and a plate-making method for a planographic printing plate obtained by using the planographic printing plate precursor.

Provided are a lithographic printing plate precursor having an image-recording layer on a hydrophilic support, in which the image-recording layer includes an organic polymer particle, and the organic polymer particle is a reaction product obtained by at least reacting an aromatic polyvalent isocyanate compound having a structure represented by Formula PO and water, a method for making a lithographic printing plate having excellent printing resistance in the case of using an ultraviolet-curable ink in printing, a new organic polymer particle, and a resin composition including the organic polymer particle.

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Lithographic printing plate precursors are prepared with a unique aluminum-containing substrate prepared using two separate anodizing processes to provide an inner aluminum oxide layer of average dry thickness (T.sub.i) of 300-3,000 nm and a multiplicity of inner micropores of average inner micropore diameter (D.sub.i) of ?100 nm. An outer aluminum oxide layer is also provided to have a multiplicity of outer micropores of average outer micropore diameter (D.sub.o) of 15-30 nm and a dry thickness (T.sub.o) of 30-650 nm. A hydrophilic layer disposed on the outer aluminum oxide layer at 0.0002-0.1 g/m.sup.2 has at least a hydrophilic copolymer composed of (a) recurring units having an amide group and (b) recurring units comprising an OM group directly connected to a phosphorus atom, wherein M represents a hydrogen, sodium, potassium, or aluminum atom.

There are provided a regeneration treatment apparatus, a washout processor, and a manufacturing method of a flexographic printing plate in which attachment of a resin aggregate generated as a non-exposed portion of an imagewise exposed flexographic printing plate precursor is removed through development using a washing solution can be suppressed and the resin aggregate can be easily cleaned off even in a case of being attached. The regeneration treatment apparatus removes, from a used washing solution containing the resin aggregate generated as the non-exposed portion of the imagewise exposed flexographic printing plate precursor having a photosensitive resin layer is removed through development using the washing solution of which a main component is water, the resin aggregate. The regeneration treatment apparatus has a centrifuge that has a rotating body for separating out the resin aggregate from the used washing solution and an induction path through which the resin aggregate from the centrifuge passes. A portion in contact with the resin aggregate has a critical surface tension of 31 mN/m or less and a dynamic friction coefficient of 0.2 or less.

The present invention provides a support for a lithographic printing plate, from which a lithographic printing plate precursor having excellent scratch resistance can be obtained by combining the support with an image recording layer, a lithographic printing plate precursor, and a method of producing a lithographic printing plate. The support for a lithographic printing plate according to the present invention, including an aluminum plate, and an anodized aluminum film disposed on the aluminum plate, in which a plurality of projections are present on a surface of the support for a lithographic printing plate on a side of the anodized film, an average value of equivalent circular diameters of the projections in a cut surface at a position that is 0.5 ?m greater than a position of the projections with an average height is in a range of 3.0 to 10.0 ?m, and a density of the projections with a height of 0.5 ?m or greater from the position of the projections with the average height is in a range of 3,000 to 9,000 pc/mm.sup.2.

Flexographic printing members are prepared by developing an exposed flexographic printing member precursor with an aqueous flexographic developer. The aqueous flexographic developer comprises: a) a fatty acid composition consisting of one or more saturated or unsaturated fatty acids or alkali metal salts thereof, each saturated or unsaturated fatty acid or alkali metal salt thereof independently having 12 to 20 carbon atoms, the fatty acid composition being present in an amount of 0.25-2.0 weight %, and at least 85 weight % of the fatty acid composition is composed of one or more C.sub.18 mono- or poly-unsaturated fatty acids or alkali metal salts thereof; b) an aminopolycarboxylic acid or alkali metal salt thereof in an amount of 0.05-0.30 weight %; c) a buffer compound in an amount of 05-0.60 weight %; and d) water. Such aqueous flexographic developers can also be provided in concentrated form and appropriately diluted before or during use.