Abstract:
A lithographic printing plate precursor, comprising a support having thereon an image-recording layer containing (A) an infrared absorbing agent, (B) a radical polymerization initiator, (C) a radical polymerizable compound, (D) a polymer compound containing a polyoxyalkylene structure and (E) an ultraviolet absorbing agent and being capable of forming an image by supplying at least one of printing ink and dampening water on a printing machine after imagewise exposure to remove an unexposed area of the image-recording layer.
Abstract:
A method for making a lithographic aluminum printing plate support comprising the steps of (i) graining said support by applying a charge density x; (ii) desmutting the grained support; (iii) graining the desmutted support by applying a charge density y; (iv) anodizing the support; characterized in that during each graining step a current density varying between 80 and 250 A/dm2 is applied and that the ratio x/x+y varies between 0.3 and 0.7.
Abstract:
The radiation-sensitive composition and the negative working imageable element include a cationic IR absorber with tetraarylborate counteranion and an onium initiator with tetraarylborate counteranion. The use of these components provides high imaging sensitivity, good shelflife and high print run length.
Abstract:
The present invention discloses printing plates comprising a substrate and a radiation-absorptive layer, wherein the radiation-absorptive layer comprises at least one modified pigment product. The modified pigment product comprises a pigment having attached at least one organic group and at least one amphiphilic counterion. Methods of imaging printing plates are also disclosed.
Abstract:
A method for making a lithographic printing plate precursor is disclosed comprising the steps of a. providing a lithographic printing plate precursor including a support having a hydrophilic surface or which is provided with a hydrophilic layer, a photopolymerizable coating comprising a photopolymerizable composition, and an overcoat layer comprising a water soluble low molecular weight acid, wherein said overcoat layer has a surface pH-value ranging between 1 to 6; b. image-wise exposing the precursor; c. optionally heating the exposed precursor; d. processing the obtained precursor by applying a gum solution and optionally brushing the precursor, and/or by mounting the precursor on a plate cylinder of a lithographic printing press and rotating the plate cylinder while feeding dampening liquid and/or ink to the coating. The printing plate obtained after imaging and processing in an off-press configuration with a gum solution or in an on-press configuration with fountain solution and ink shows an improved roll-up performance in the start-up of a printing process on a printing press.
Abstract:
The present invention provides a highly sensitive photosensitive lithographic printing plate material capable of being used in a CTP system, which allows on-press development and/or development with water and has superior printability. More specifically, the present invention provides a water-developable photosensitive lithographic printing plate material comprising a support; on the support, a hydrophilic layer containing a water-soluble polymer, a crosslinking agent which forms a cross-linking network with the water-soluble polymers, and colloidal silica, wherein the weight ratio of the water-soluble polymer to the colloidal silica is within the range of 1:1 to 1:3; and, on the hydrophilic layer, a photocurable photosensitive layer containing a polymer having a sulfonic acid group and a vinylphenyl group in a side chain wherein the vinylphenyl group is attached to a main chain through a linking group containing a hetero ring, a photopolymerization initiator, and a compound which sensitizes the photopolymerization initiator.
Abstract:
A method of making a lithographic printing plate includes the steps of: a) providing a lithographic printing plate precursor including (i) a support having a hydrophilic surface or which is provided with a hydrophilic layer, (ii) a coating on the support, including a photopolymerizable layer and, optionally, an intermediate layer between the photopolymerizable layer and the support, wherein the photopolymerizable layer includes a polymerizable compound, a polymerization initiator and a binder, b) image-wise exposing the coating in a plate setter, c) optionally, heating the precursor in a pre-heating unit, d) treating the precursor in a gumming station, including a first and at least a second gumming unit, wherein the precursor is consecutively developed in the first and the second gumming unit with a gum solution, thereby removing non-exposed areas of the photopolymerizable layer from the support and gumming the plate in a single step.
Abstract:
A plate making method of a lithographic printing plate precursor includes: exposing imagewise a lithographic printing plate precursor including a support and an image-forming layer and containing (A) a compound generating an acid with light or heat, (B) an aromatic hydrocarbon compound or heterocyclic compound substituted with a functional group containing a nitrogen atom and (C) an aromatic aldehyde protected with an acid-decomposable group; and removing an unexposed area of the image-forming layer of the lithographic printing plate precursor by supplying at least one of dampening water and ink on a cylinder of a printing machine.
Abstract:
A lithographic printing plate precursor includes: a support; and an image-recording layer containing (A) an infrared absorbing agent, (B) a radical polymerization initiator, (C) a polymerizable compound and (D) an epoxy compound having a molecular weight of 1,000 or less.
Abstract:
Positive-working imageable elements can be imaged and processed using a processing solution that comprises at least 0.03 N of an organic amine or a mixture thereof, whose conjugated acids have a pKa greater than 9 and a boiling point greater than 150° C. The imageable element is a single-layer, infrared radiation-sensitive positive-working imageable element comprising a substrate and an infrared radiation absorbing compound. It also has an imageable layer that comprises a developability-enhancing compound and a poly(vinyl acetal) in which at least 25 mol % of its recurring units comprise pendant phenol, naphthol, or anthracenol groups that are substituted with one or more electron-withdrawing groups.