摘要:
Thermally imageable elements and methods for their preparation and use are disclosed. The elements contain, in order, a substrate; an underlayer; and an ink-repellent layer. The underlayer contains a crosslinked allyl functional polyurethane. A photothermal conversion material is present in either in the underlayer or in an absorber layer between the underlayer and the ink-repellent layer. Thermal imaging and development removes the ink-repellent layer and reveals the underlayer in the exposed regions to form an imaged element useful as a waterless lithographic printing plate.
摘要:
This invention relates to an imageable element that can be imaged and developed to produce a printing plate. The imageable element comprises a substrate and a radiation-sensitive imageable composition applied to the substrate. The imageable composition comprises (a) a first layer having (i) a photosensitive composition which undergoes a decrease in solubility in developer upon absorption of actinic radiation and (ii) an inhibitor, and (b) a second layer comprising an ink-repellent polymeric material. In one embodiment, the inhibitor is activated by heat or radiation of longer wavelength than actinic radiation. Upon activation, the inhibitor retards the solubility decrease of the photosensitive composition upon absorption of actinic radiation. In another embodiment, the inhibitor initially retards the solubility decrease of the photosensitive composition upon absorption of actinic radiation. However, the inhibitor is deactivated by heat or radiation of longer wavelength than actinic radiation, and upon deactivation the inhibitor no longer retards the solubility decrease of the photosensitive composition.
摘要:
QHB-Modified free radical polymerizable compounds and free radical polymerizable compositions that comprise these compounds are disclosed. A QBH-modified free radical polymerizable compound has at least one moiety that comprises at least one free radical polymerizable group; a supporting backbone, and at least one and preferably at least two moieties capable of forming four or more, typically four, hydrogen bonds with similar or complementary units on other molecules or portions of molecules. Free radical polymerizable compositions that contain these compounds may be used in any of the well-known applications for free radical polymerizable compositions. They are especially useful for the formation of imageable elements useful as lithographic printing plate precursors.
摘要:
The present invention provides an imageable element, which includes: a substrate; a crosslinked layer disposed on the substrate; and an imageable ink-receptive layer disposed on the crosslinked layer, the imageable ink-receptive layer including an ablation free imageable composition. The present invention provides methods of producing the above imaged element.
摘要:
The present invention relates to a polymerizable coating composition suitable for the manufacture of printing plates, which may be developable on-press. The coating composition comprises (i) a polymerizable compound and (ii) a polymeric binder comprising polyethylene oxide segments, wherein the polymeric binder is selected from the group consisting of at least one graft copolymer comprising a main chain polymer and polyethylene oxide side chains, a block copolymer having at least one polyethylene oxide block and at least one non-polyethylene oxide block, and a combination thereof. The invention is also directed to an imageable element comprising a substrate and the polymerizable coating composition.
摘要:
An imageable element comprises: (A) a substrate; and (B) an imageable composition applied to the substrate comprising: (1) a first layer, comprising: (a) a photosensitive composition capable of absorbing actinic radiation; and (b) a photothermal converter; and (2) an ablatable second layer contiguous to the first layer, wherein the second layer is opaque to the actinic radiation. This imageable element advantageously is useful in both positive and negative working printing plate applications, increases the efficiency of use of mask-generating radiation such as IR radiation and eliminates the need for chemicals and additional time to create a mask.
摘要:
A waterless or driographic printing plate which can be thermally imaged by an infrared laser is composed of a substrate; a thermal imaging layer containing a photothermal conversion material, such as an infrared absorbing material, and a thermoplastic polyurethane with pendent allyl groups; and a crosslinked silicone polymer top layer. It was discovered that when the imaging layer contains an allyl functional polyurethane mixed with an infrared absorbing dye or pigment, the polymeric layer will have enhanced solubility in certain solvents when exposed to infrared radiation. In addition, the polymeric layer continues to exhibit excellent adhesion to the silicone in unexposed areas so that the infrared absorbing layer can endure development with a suitable organic solvent, or a solvent mixture. Mild brushing or rubbing with the developing solvent readily removes laser-struck portions of the infrared imaging layer while unexposed areas remain firmly intact.
摘要:
The present invention also includes an imageable element, comprising a substrate and a thermally imageable composition comprising a thermally sensitive polymer which exhibits an increased solubility in an aqueous developer solution upon heating. The thermally sensitive polymer includes at least one covalently bonded unit and at least one thermally reversible non-covalently bonded unit, which includes a two or more centered H-bond within each of the non-covalently bonded unit. The present invention also includes a method of producing the imaged element. The present invention still further includes a thermally imageable composition comprising comprising a thermally sensitive polymer according to the present invention and a process for preparing the thermally sensitive polymer, which is a supramolecular polymer. The process includes contacting a hydrocarbyl-substituted isocytosine and a diisocyanate to produce a mono-adduct and contacting the mono-adduct and a polyfunctional material to produce the supramolecular polymer.
摘要:
A radiation sensitive composition containing an adduct of a diazonium resin having pendant diazonium groups, with a sulfonated acrylic copolymer having pendant sulfonate groups. The sulfonated acrylic copolymer contains an acrylic moiety and a sulfonated styryl or acrylic moiety. The copolymer may optionally contain styryl moieties. The composition is useful as a radiation sensitive layer in imaging elements for graphic arts applications and is particularly useful in preparing durable, long-wear, printing plates.
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.