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.
Abstract:
A method for making a lithographic printing plate including the steps of providing a lithographic printing plate precursor including a heat sensitive image-recording layer, the image-recording layer including hydrophobic thermoplastic particles; image-wise exposing the precursor to infrared radiation having an energy density of 190 mJ/cm2 or less; mounting the exposed precursor on a printing press; developing the mounted precursor by supplying ink and/or fountain; and baking the plate by keeping the plate at a temperature above the glass transition temperature of the thermoplastic particles during a period between 5 seconds and 2 minutes.
Abstract translation:一种制备平版印刷版的方法,包括以下步骤:提供包括热敏图像记录层的平版印刷版原版,所述图像记录层包括疏水性热塑性颗粒; 将前体成像地曝光到能量密度为190mJ / cm 2以下的红外辐射; 将暴露的前体安装在印刷机上; 通过供应墨水和/或喷泉来显影所安装的前体; 并且在5秒至2分钟之间的时间内将板保持在高于热塑性颗粒的玻璃化转变温度的温度下烘烤该板。
Abstract:
An initiator composition and infrared radiation-sensitive composition include an onium cation and a boron-containing anion as well as a metallocene. These compositions can be used to provide negative-working imageable elements that can be imaged and developed to provide lithographic printing plates that have desired imaging speed, excellent run length, and shelf life without the need for a post-exposure baking step and oxygen barrier overcoat.
Abstract:
A planographic printing plate precursor comprising a hydrophilic support having a surface roughness (Ra) in a range of from 0.45 to 0.60, and, on the support, a recording layer containing a phenolic resin, an infrared absorber and a polymer having at least one selected from the group consisting of a structural unit represented by the following formula (I) and a structural unit represented by the following formula (II). In the Formulae (I) and (II), R1 represents a hydrogen atom or an alkyl group; z represents —O— or —NR2— wherein R2 represents a hydrogen atom, an alkyl group, an alkenyl group or an alkynyl group; Ar1 and Ar2 each independently represent an aromatic group, and at least one of Ar1 and Ar2 represents a heteroaromatic group; and a and b each independently represent 0 or 1.
Abstract:
An imaged and developed element, such as a lithographic printing plate, is provided by infrared radiation imaging of a negative-working imageable element having an outermost imageable layer that includes an acid generating compound that generates acid upon exposure to imaging infrared radiation, an infrared radiation absorbing compound, an acid activatable crosslinking agent that has acid activatable reactive groups, and a polymeric binder that is capable of undergoing an acid-catalyzed condensation reaction with the crosslinking agent. The imaged element is heated at from about 120 to about 150° C. for up to two minutes, and then developed with a single processing solution to remove only the non-exposed regions and to provide a protective layer prior to lithographic printing.