摘要:
A method is used to prepare lithographic printing plates by developing positive-working lithographic printing plate precursor that has a single imageable layer that comprises a polymer binder having recurring units represented by Structure (Ib) below: wherein the recurring units of Structure (Ib) are present in an amount of at least 25 and up to and including 60 mol %, all based on total recurring units in the polymer binder, and R2 is a substituted or unsubstituted hydroxyaryl group in which the hydroxyl group is ortho to the ester linkage, to form exposed and non-exposed regions in the imageable layer. The resulting imaged lithographic printing plate is developed using a silicate-free developer composition having a pH of at least 12 and comprising at least 0.001 gram-atom/kg of a metal cation M2+ selected from the group consisting of barium, calcium, strontium, and zinc cations.
摘要:
A negative-working lithographic printing plate precursor is used for making lithographic printing plates from infrared radiation imaging. The precursor comprises free radical chemistry and a specific infrared radiation absorber that is a cyanine dye and defined by Formula (1a) described in the disclosure. This particular infrared radiation absorber provides both IR sensitivity and print out after imaging.
摘要:
A method for producing a printable lithographic plate from a negative working, radiation imageable plate having an oleophilic resin coating that reacts to radiation by cross linking and is non-ionically adhered to a hydrophilic substrate. Steps include imagewise radiation exposing the coating to produce an imaged plate having partially reacted image areas including unreacted coating material, and completely unreacted nonimage areas; developing the plate by removing only the unreacted, nonimage areas from the substrate while retaining unreacted material in the image areas; and blanket exposing the developed plate with a source of energy which further reacts the retained unreacted material in the image areas. A plate with a coating containing resin particles can be imaged to produce initial cross-linking, then mechanically developed. Hardening of the imaged areas is completed with a relatively intense post-heating at 160 deg. C., which further cross links the monomer and fuses the resin particles.
摘要:
A lithographic printing plate precursor comprises an imageable layer comprising a free radically polymerizable component, an initiator composition capable of generating free radicals upon exposure to imaging infrared radiation, an infrared radiation absorbing dye that is defined by Structure (I) shown in the disclosure, which dyes comprise one or more ethylenically unsaturated polymerizable groups in an organic group that is attached to the methine chain. These infrared radiation absorbing dyes exhibit a reduced tendency to crystallize in the imageable layers in the presence of tetraaryl borate counter anions and therefore provide improved shelf life.
摘要:
Negative-working imageable elements such as lithographic printing plate precursors, include a free-radically polymerizable component, an initiator composition that is capable of generating free radicals sufficient to initiate polymerization of the free-radically polymerizable component upon exposure to imaging radiation in the presence of a radiation absorbing compound, a radiation absorbing compound, an aerobic free radical inhibitor, optionally a polymeric binder that is not a free radically polymerizable component, and an anaerobic free radical inhibitor. The molar ratio of the anaerobic free radical inhibitor to the aerobic free radical inhibitor is at least 1:1. This combination of inhibitors provides increased shelf life and good latent image stability particularly when the element includes a polymeric topcoat layer that functions as an oxygen barrier.
摘要:
A lithographic printing plate precursor includes, in the following order: a support; an image-recording layer which is capable of forming an image by removing an unexposed area of the image-recording layer with at least one of printing ink and dampening water on a printing machine after exposure and contains an infrared absorbing dye, a polymerization initiator, a polymerizable compound and a binder polymer having an alkylene oxide group; and a protective layer containing a hydrophilic polymer which contains at least a repeating unit represented by the formula (1) as defined herein, a repeating unit represented by the formula (2) as defined herein, and a repeating unit represented by the formula (4) as defined herein, and in which a content of the repeating unit represented by the formula (4) is from 0.3 to 5.0% by mole based on total repeating units of the hydrophilic polymer.
摘要:
A lithographic printing plate precursor comprising a support, tin image-recording layer which contains (A) an infrared absorbing agent, (B) a radical polymerization initiator and (C) a radical polymerizable compound and in which an unexposed area can be removed by supplying printing ink and dampening water after exposure, and an overcoat layer in this order, wherein the overcoat layer contains at least two kinds of inorganic stratiform compounds having different crystal structures.
摘要:
A negative-working lithographic printing plate precursor can be imaged with infrared radiation and processed in a single step using a single processing solution having a pH of from about 3 to 11. The precursor has a primary polymeric binder that comprises recurring units derived from one or more N-alkoxymethyl(meth)acrylamides, provided that such recurring units are present in the primary polymeric binder in an amount of at least 10% based on the total dry primary polymeric binder weight. In addition, the primary polymeric binder is present in an amount of from about 12 to about 70% based on total imageable layer dry weight. The imaged precursor can be processed off-press or on-press.
摘要:
A lithographic printing plate precursor is provided which comprises an aluminum support having a hydrophilic surface and a coating provided thereon, said coating comprising a photopolymerisable composition having a polymerisable compound, a pigment dispersed with a dispersant, a polymerization initiator and a binder, characterized in that the dispersant is a compound free of —COOH, —PO3H2 or —OPO3H2 groups, and the polymerization initiator is a trihalomethyl-aryl sulphone wherein the aryl group is substituted by at least one electron-donating group and wherein the sum of the Hammett constants (sigma) of the substituting groups on said aryl group has a negative value. The printing plate precursor exhibits an excellent daylight stability and shelf-life.
摘要:
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.