Abstract: According to the present invention there is provided a heat-sensitive material for making lithographic plates comprising in the order given on a support an IR-sensitive oleophilic layer and a cross-linked hydrophilic layer comprising an inorganic pigment and a hardener, characterized in that the ratio of said inorganic pigment over the hardener is comprised between 75/25 and 25/75 by weight.

Abstract: A lithographic printing plate having an average curvature in a rolling direction of 1.5×10−3 mm−1 or less, a curvature distribution in a crosswise direction of 1.5×10−3 mm−1 or less, and a curvature in a direction perpendicular to said rolling direction of 1.0×10−3 mm−1 or less and a method for producing the printing plate are disclosed. A method for producing a support for a lithographic printing plate is also disclosed, which comprises roughening a surface of an aluminum web having a center line average surface roughness of 0.15 to 0.35 &mgr;m and a maximum surface roughness of 1 to 3.5 &mgr;m by at least one of mechanical surface roughening, chemical etching and electrochemical surface roughening, and then applying anodization thereto.

Abstract: A lithographic printing plate precursor comprises: a support; and an image-forming layer including a fluoroaliphatic group-containing copolymer, wherein the fluoroaliphatic group-containing copolymer contains a repeating unit corresponding to monomer (i) below and a repeating unit corresponding to monomer (ii) below:

Abstract: On-press ink and/or fountain solution developable lithographic printing plates having on a roughened substrate a substantially conformal thermosensitive layer capable of hardening upon exposure to an infrared radiation; The surface of the thermosensitive layer has peaks and valleys substantially corresponding to the major peaks and valleys of the substrate microscopic surface, allowing low tackiness and good block resistance. The plate can be imagewise exposed with an infrared radiation and then on-press developed with ink and/or fountain solution by rotating the plate cylinder and engaging ink and/or fountain solution roller. The developed plate can ten directly print images to the receiving sheets. The imagewise exposure can be performed off press or with the plate being mounted on the plate cylinder of a lithographic press.

Abstract: A lithographic printing plate precursor is disclosed which comprises (i) a support having a hydrophilic surface or which is provided with a hydrophilic layer and (ii) a coating provided thereon, the coating comprising an oleophilic layer which, upon image-wise exposure to heat or infrared light and subsequent immersion in an aqueous alkaline developer, dissolves in the developer at a higher dissolution rate in exposed areas than in unexposed areas, wherein the oleophilic layer comprises a polymer that is soluble in the developer and an organic dye in a amount sufficient to provide a visible color to the coating, characterized in that said organic dye does not reduce the dissolution rate of the unexposed areas in the developer.

Abstract: A photosensitive composition comprising (a) an ethylenically unsaturated double bond-containing compound, (b) a sensitizing dye and (c) a photopolymerization initiator, wherein the sensitizing dye is a phthalocyanine compound showing the maximum absorption within a range of from 750 to 1,200 nm.

Abstract: A cost efficient method of making a lithographic printing plate precursor is disclosed, the method comprising the steps of coating a silver halide emulsion layer on a hydrophilic base which is provided with physical development nuclei; simultaneously with the preceding step, coating on the emulsion layer a solution that induces silver salt diffusion transfer reversal development of the silver halide; allowing diffusion of complexed silver ions to the physical development nuclei, thereby forming silver metal that is deposited on the hydrophilic base; a wash-off step wherein the emulsion layer is removed from the silver metal. The material thus obtained can be exposed image-wise in heat-mode, e.g. by means of an infrared laser, thereby ablating the silver metal and revealing the hydrophilic base at exposed areas. Immediately after exposure, it can be used as a lithographic printing plate without the need for a wet processing step.

Abstract: A positive acting, composition that can be heat-sensitive is presented, either coated on a lithographic base, or on a printing circuit board base, and comprises a water soluble heat-sensitive resin, a novel adhesion promoter and a radiation absorbing agent—a dye or a pigment. An excellent film forming polymer that comprises acetal units directly pendant from the polymer polyvinyl alcohol backbone may be the only binder resin, when other resins being optional. The solubility of the coated material in the areas exposed to near -IR laser radiation in mild alkaline developers becomes considerably higher, allowing to obtain high resolved patterns of the etch-resistant material on printing circuit boards or lithographic printing plates. The composition can be applied on the substrate from a liquid of laminated as a dry film. Sensitizers may be added to render the composition sensitive to radiation in a non-thermal sense.

Abstract: [Object]

Abstract: A presensitized plate comprising a support for a lithographic printing plate including an anodized layer formed on an aluminum plate and a recording layer recordable by infrared laser exposure on the support, wherein in a section of the anodized layer after the recording layer is provided, an atomicity ratio of carbon to aluminum (C/Al) represented by Auger Electron Spectroscopic analysis is 1.0 or less. In the case of being used as an on-machine development type, it exhibits a good on-machine development characteristic, a high sensitivity, a high press life, and high scum resistance during printing and while left (ink discharging). In the case of being used as a conventional thermal positive or negative working type, it exhibits an efficient use of heat for image formation, a high sensitivity, a high press life, and a slight possibility of scum occurrence at non-image areas.

Abstract: Aluminium sheet suitable for use as a lithographic plate support has a surface that is uniformly rough by virtue of: a rippled topography having an aspect ratio of at least 1.3 on a sale of 5-200 &mgr;m; and a superimposed pitted structure on a scale of 1-20 &mgr;m. A method of making the aluminium sheet involves pack rolling two aluminium ribbons to generate facing surfaces having the transverse rippled structure; followed by a small amount of a conventional roughening or graining treatment to develop the pitted structure.

Abstract: The present invention provides a photosensitive lithographic printing plate with a long press life, high sensitivity, and excellent storage stability, and a photosensitive composition for a lithographic printing plate for producing such a photosensitive lithographic printing plate. The photosensitive composition for the lithographic printing plate includes (A) a binder resin, (B) a diazo resin, (C) a monomer or oligomer, a molecule of which has at least two polymerizable ethylenically unsaturated double bonds, (D) a photopolymerization initiator, (E) an o-tert-butylphenol derivative, and (F) a 2-mercaptoimidazole derivative such as 2-mercaptobenzimidazole.

Abstract: A photosensitive lithographic printing plate having a photosensitive resin layer formed on an aluminum substrate subjected to electrolytic surface roughening in nitric acid or in an electrolyte composed mainly of nitric acid and further to anodic oxidation treatment, wherein the photosensitive resin layer is made of a photopolymerizable composition comprising (A) an addition-polymerizable ethylenically unsaturated bond-containing monomer, (B) a photopolymerization initiator, and (C) a polymer binder, wherein the addition-polymerizable ethylenically unsaturated bond-containing monomer (A) contains a phosphate compound having at least one (meth)acryloyl group.

Abstract: In accordance with the present invention there is provided an imaging element for lithographic offset printing. The imaging element comprises hydrophobic polymer particles in an aqueous medium, a substance for converting light into heat, and a metal complex. The imaging element may be used for printing long run lengths on lower quality paper and in the presence of set-off powder. The imaging element may be imaged and developed on-press and may be sprayed onto a hydrophilic surface to create a printing surface that may be processed wholly on-press. The hydrophilic surface may be a printing plate substrate, the printing cylinder of a printing press, or a seamless sleeve around the printing cylinder of a printing press. This cylinder may be conventional or seamless.

Abstract: A cost efficient method of making a lithographic printing plate precursor is disclosed, the method comprising the steps of

Abstract: Polymer materials are described that undergo a 2-level 3 dimensional crosslinking process. During this process, hydrophilic polymers are crosslinked at two levels, the first results in a low level of crosslinking which leads to a toughening of the layer preventing dissolution by the fountain solution but with the layer remaining hydrophilic. The second level of crosslinking is higher and is the result of exposure to a laser diode thermal imaging device. The crosslinking at this second level results in a loss of hydrophilicity and provides instead an oleophilic image capable of accepting and transferring oil based ink. The polymer materials are particularly useful in lithographic printing systems where they may used in articles such as a printing plate comprising a substrate having coated thereon a layer that becomes that becomes less hydrophilic upon exposure to thermal energy (e.g.

Abstract: The present invention provides a method of preparing a lithographic printing plate, said method comprising:

Abstract: The present invention provides a method of preparing a lithographic printing plate, said method comprising: providing a lithographic printing plate precursor comprising: i) a grained and anodized aluminum substrate where the anodic weight is between 6.0 and 20 g/m2, having coated thereon; ii) a metallic layer; and image-wise exposing the precursor on an external drum thermal imaging device. The method provides press ready plates showing high image quality, good press properties and high durability on press without the requirement for the use of costly intermediate film and developer chemistry, and the attendant inconvenience resulting from the use of these materials.

Abstract: The invention relates to a positive-working, radiation-sensitive mixture which contains an organic polymeric binder which is insoluble in water but soluble or at least swellable in aqueous alkaline solution and at least one IR-absorbing cyanine dye having a betaine structure or having a betaine structure and containing an anion and having the formula (I) in which R1 to R8 independently of one another, are a hydrogen or halogen atom, a sulfonate, carboxylate, phosphonate, hydroxyl, (C1-C4)alkoxy, nitro, amino, (C1-C4)alkylamino, di(C1-C4)alkylamino group or a (C6-C10)aryl group which in turn may be substituted by one or more halogen atoms and/or one or more sulfonate, carboxylate, phosphonate, hydroxyl, (C1-C4)alkoxy, nitro, amino, (C1-C4)alkylamino and/or di(C1-C4)alkylamnino groups, R9 and R10 independently of one another, are a straight-chain or branched (C1-C6)alkyl, a (C7-C6)aralkyl or a (C6-C10)aryl group, each of which in turn may be substituted by one or more halogen atoms and/or on

Abstract: A lithographic printing plate precursor is disclosed, comprising a metal support having formed thereon an anodic oxide film, and an image-forming layer containing a light-to-heat converting agent, or a light-sensitive layer capable of image-forming with infrared laser exposure provided in this order from the support.

Abstract: According to the present invention there is provided an IR radiation-sensitive imaging element comprising on a hydrophilic surface of a lithographic base an image forming layer comprising (1) a water insoluble, alkali soluble or swellable resin having a phenolic hydroxy group, (2) a latent Bronsted acid, and (3) an amino crosslinking agent capable of reacting with the water insoluble, alkali soluble or swellable resin under the influence of an acid, characterized in that said image forming layer comprises a carbon black pigment as infrared absorber.

Abstract: The invention provides a lithographic printing for precursor having an imagable coating on an aluminum support, wherein the imagable coating comprises a polymeric substance comprising colorant groups, and wherein the aluminum support on which the coating is provided is anodized but not subsequently modified by means of a post-anodic treatment compound, and the coating does not comprise a colorant dye. The polymeric substance may also comprise pendent infra-red or developer dissolution inhibiting groups, and these groups may also be the colorant groups themselves.

Abstract: This patent describes on-press ink and/or fountain solution development of lithographic plates having on a substrate a thermosensitive layer capable of hardening or solubilization upon exposure to an infrared laser radiation. The plate can be imagewise exposed with an infrared laser and then on-press developed with ink and/or fountain solution by rotating the plate cylinder and engaging ink and/or fountain solution roller. The developed plate can then directly print images to the receiving sheets. The imagewise exposure can be performed off the press or with the plate being mounted on the plate cylinder of a lithographic press.

Abstract: A lithographic printing plate precursor is disclosed, comprising an aluminum support having thereon a photopolymerizable photosensitive layer which contains (1) an alkali-soluble urethane binder having at least one ethylenically unsaturated polymerizable group on the side chain thereof, (2) an addition polymerizable compound having an ethylenically unsaturated double bond, and (3) a photopolymerization initiator.

Abstract: The present invention provides a planographic printing plate capable of ensuring improvement of productivity and stability of a small dot net portion due to improvement of adhesion. There is provided a planographic printing plate, characterized in that a surface of an aluminum plate being a support element of the planographic printing plate has been subjected to preliminarily polishing mechanically by at least 0.1 &mgr;m; chemical etching treatment by at least 0.1 &mgr;m; electrochemically surface-roughening; and anodic oxidation, and for a surface structure of the aluminum plate: (a) an area (S) for a graphic formed by a reference straight line drawn from a top of a third highest mountain of a two-dimensional roughness curve downwardly by 1 &mgr;m and a roughness curve upper than the reference straight line is 30 &mgr;m2≦S≦150 &mgr;m2; (b) an average roughness Ra of average lines is 0.15 &mgr;m≦S≦Ra≦0.

Abstract: A photopolymerizable composition that is cured with visible light or an infrared laser and is used as a recording layer in a negative planographic printing plate precursor. The photopolymerizable composition is cured by exposure and includes (A) a polymerizable compound that is solid at 25° C. and has at least one radical-polymerizable ethylenically unsaturated double bond in a molecule, (B) a radical polymerization initiator, (C) a binder polymer and, as required, (D) a compound generating heat by infrared exposure.

Abstract: The present invention relates to a presensitized plate useful for making a lithographic printing plate comprising an intermediate layer and a photopolymerizable photosensitive layer on an aluminum substrate in this order, wherein the roughness of a surface of said aluminum substrate (Ra) is in the range of 0.2 to 0.55 &mgr;m and the intermediate layer comprises a polymer compound comprising at least one monomer unit having a sulfonic acid group and a method for making a lithographic printing plate by imagewise exposing the presensitized plate described above and developing the imagewise exposed presensitized plate with a developer comprising an inorganic alkali salt and a nonionic surfactant comprising a polyoxyalkylene ether group. The presensitized plate or the method of the present invention provides a lithographic printing plate showing good contrast between an image area and non-image area, no background contamination during printing, good stability with time and good printing durability.

Abstract: A heat-sensitive lithographic printing plate precursor is disclosed, which comprises an aluminum support having provided thereon an ink-receptive layer and a hydrophilic layer containing a colloidal particle oxide or hydroxide of at least one element selected from the group consisting of beryllium, magnesium, aluminum, silicon, titanium, boron, germanium, tin, zirconium, iron, vanadium, antimony and transition metals, wherein at least one layer of the ink-receptive layer and the hydrophilic layer contains a compound capable of converting light into heat, the aluminum support has an anodic oxide film in an amount of 2 g/m2 or more, and the anodic oxide film has been subjected to sealing treatment at a sealing rate of 50% or more.

Abstract: Lithographic imaging techniques begin with a donor member having substrate substantially transparent to imaging radiation and a transferable material thereover; the substrate and the transferable material differ in affinity for ink and/or a liquid to which ink will not adhere. The donor member is exposed to imaging radiation in an imagewise pattern so as to cause displacement of the transfer material from the donor member in accordance with that pattern. Following the imagewise displacement, the donor member can be used as a lithographic printing member.

Abstract: The present invention includes an imageable element, which includes a sheet substrate, an imaging layer and a silicone layer, which comprises a crosslinked silicone polymer. The crosslinked silicone polymer is the curing product of a vinyl functional polysiloxane copolymer and a hydrosiloxane compound. The curing is catalyzed by a platinum carbonyl complex. Upon imagewise exposure and development, an imaged element is obtained, which is mounted on a dry printing press containing lithographic ink and used to produce printed stock.

Abstract: A negative photosensitive lithographic printing plate comprises: a support; and a photosensitive layer containing: i) a modified poly(vinyl alcohol) resin binder having a radical-polymerizable group and an acid group; and ii) at least one of a photo-polymerization initiator and a heat-polymerization initiator.

Abstract: A positive planographic printing plate precursor comprising a recording layer containing a water-insoluble and alkali-soluble resin, an infrared absorbent and an organic quaternary ammonium salt. A positive planographic printing plate precursor comprising at least two recording layers containing the resin and the infrared absorbent with a coating amount of an upper positive recording layer being in the range of 0.05 to 0.45 g/m2.

Abstract: A lithographic printing plate precursor comprises a grained and anodized aluminum substrate coated with a metallic layer, preferably a silver layer, on top of which is applied a layer comprising at least one oleophilising agent and at least one hydrophilic stain-reducing agent, the hydrophilic agent being chosen such that it adsorbs onto the metallic layer but is not so strongly adsorbed thereon as to displace the oleophilising agent. Preferably, the oleophilising agent comprises a mercaptotetrazole or mercaptooxadiazole derivative, the hydrophilic stain-reducing agent comprises a material which includes at least one sulfur, selenium or tellurium containing group, and the layer additionally comprises an additional hydrophilic material.

Abstract: According to the present invention there is provided a method for the preparation of a lithographic printing plate comprising the steps of exposing with IR light an imaging element comprising on a lithographic base with a hydrophilic surface a first layer including a polymer, soluble in an aqueous alkaline solution and a top layer on the same side of the lithographic base as the first layer which top layer is IR-sensitive and unpenetratable for or insoluble in an alkaline developer wherein said first layer and said top layer may be one and the same layer, said imaging element comprising a siloxane surfactant; developing said exposed imaging element with an alkaline solution; gumming said developed imaging element with a baking gum solution; subjecting said gummed imaging element to a thermal treatment at a temperature above 50° C.

Abstract: According to the present invention there is provided a heat mode imaging element for making a lithographic printing plate having on a lithographic base with a hydrophilic surface a first layer including a polymer soluble in an aqueous alkaline solution, and a top layer on the same side of the lithographic base as the first layer that is IR-sensitive and unpenetrable for an aqueous alkaline developer wherein said first layer and said top layer may be one and the same layer; characterized in that the surface of said element upon exposure and treatment with an aqueous alkaline developer is such that a) the contact angle between the unexposed areas of the imaging element and the aqueous alkaline developer changes for at most 6° during the first minute of contact with said developer; b) the contact angle between the exposed areas of the imaging element and the aqueous alkaline developer changes more than 15° during the first minute of contact with said developer; c) the difference in contact angle betwe

Abstract: A litho strip for use as an offset printing plate is described which has a composition of 0.05-0.25% Si, 0.30-0.40% Fe, 0.10-0.30% Mg, max. 0.05% Mn, and max. 0.04% Cu. The strip is produced from a continuous cast ingot of the above composition which is hot rolled to a thickness of up to 2-7 mm. The residual resistance ratio of the hot rolled strip is RR=10-20. The cold rolling is carried out with or without intermediate annealing, wherein the degree of rolling reduction after intermediate annealing is >60%. The further processing up to the EC roughening takes place with the microstructure adjusted in the rolling process at <100° C. The litho strip is characterized by a high thermal stability, a good roughening behavior in the EC processes, and a high reverse bending fatigue strength perpendicular to the rolling direction.

Abstract: The invention relates to a recording material having a dimensionally stable, two-dimensional support, preferably an aluminium support, and a negative-working, radiation-sensitive layer which comprises a diazonium salt, a polymeric binder and a sulphobetaine. In addition, the layer may also comprise a polymerizable monomer or oligomer and a photopolymerization initiator. The front of the recording material may be matted or pigmented, and the back may be coated with an organic polymeric material. The sulphobetaine improves the solubility of the diazonium salts in aqueous-alkaline developers without reducing the resistance of the offset printing plates produced from the recording material.

Abstract: An imageable lithographic printing plate has a substrate with an aluminum base and a quantity of alumina particles embedded and retained in the aluminum base. The quantity of embedded and retained particles is relatively high thereby increasing the hydrophilicity of the base. The regions of the aluminum base between the embedded particles may optionally be anodized. The substrate has a coating which is imageable by absorbing the selective imaging radiation.

Abstract: The printing plate comprises a rolled and embossed aluminium support whose surface has a coarse structure of pits, on which a fine structure of indents produced by electrochemical roughening is superimposed. The indents have a diameter of from 0.1 to 6 &mgr;m, and the average roughness Ra of the surface of the embossed aluminium support is in the range from 0.63 to 0.82 &mgr;m.

Abstract: A process for preparing a printing plate. In this process a photopolymer printing plate is exposed to a source of actinic radiation, and this exposure causes the photopolymer to change at least one of its physical properties. Thereafter, a portion of the photopolymer is removed. The developed printing plate is then irradiated with deep ultraviolet radiation with a wavelength of from about 170 to about 290 nanometers.

Abstract: A planographic printing original plate which comprises an intermediate layer which contains a polymer including, as a monomer unit, at least a monomer having an acid group and a monomer having an onium group; and a photosensitive layer comprised of a positive-type photosensitive composition for an infrared laser which contains: (A) at least an alkali-soluble polymeric compound; (B) a compound which has a function to deteriorate the solubility of the alkali-soluble polymeric compound in an alkaline aqueous solution due to compatibility with the alkali-soluble polymeric compound, the function being deteriorated by compound (B) being heated; and (C) a compound which generates heat by absorbing light, the intermediate layer and the photosensitive layer being formed sequentially on a support which has been subjected to a hydrophilizing treatment.

Abstract: An imaging member, such as a negative-working printing plate or on-press cylinder, can be prepared with a hydrophilic imaging layer comprised of a heat-sensitive hydrophilic polymer having ionic moieties and an infrared radiation sensitive oxonol dye that has a &lgr;max of greater than 700 nm. The heat-sensitive polymer and IR dye can be formulated in water or water-miscible solvents to provide highly thermal sensitive imaging compositions. In the imaging member, the polymer reacts to provide increased hydrophobicity in areas exposed to energy that provides or generates heat. For example, heat can be supplied by laser irradiation in the IR region of the electromagnetic spectrum. The heat-sensitive polymer is considered “switchable” in response to heat, and provides a lithographic image without wet processing.

Abstract: Disclosed is a presensitized plate, having intermediate and photosensitive layers sequentially provided on a support for a lithographic printing plate, which is provided by subjecting an aluminum plate to graining, alkali etching and anodizing treatments. The amount of alkali etching is set in a range of 0.5 to 4 g/m2 for the alkali etching treatment, and an average thickness of thinnest 10% of the photosensitive layer on convex portions of a surface of the support is set in a range of 0.2 to 2 &mgr;m. This presensitized plate has wide development latitude, makes it difficult for scratch-like non-image portions to be generated, and facilitates handling in usual operation.

Abstract: The present invention relates to a printing plate precursor with an overcoat, where the printing plate precursor is preferably developable on a printing press after imagewise exposure. The printing plate precursor comprises the following components: (a) at least one polymeric organic binder, soluble in water or in organic solvents having a water content of at least 50 wt.

Abstract: The invention provides improved resist compositions and lithographic methods using the resist compositions of the invention. The resist compositions of the invention are acid-catalyzed resists which are characterized by the presence of an SiO-containing polymer. The invention also encompasses methods of forming patterned material layers (especially conductive, semiconductive, or magnetic material structures) using the combination of the SiO-containing resist and a halogen compound-containing pattern transfer etchant where the halogen is Cl, Br or I.

Abstract: A polyvinyl acetal copolymer compound comprises the units A, B, C and D, wherein A is present in an amount of 0.5 to 30 wt.

Abstract: A positive-working imaging member is composed of a heat-sensitive surface imageable layer having a heat-sensitive polymer containing heat-activatable sulfoimino, sulfoalkyl, or sulfoamide groups, and a photothermal conversion material. Upon application of thermal energy, such as from IR irradiation, the sulfonate groups decompose rendering exposed areas more hydrophilic. The exposed imaging member can be contacted with a lithographic printing ink and used for printing without post-imaging wet processing. This imaging member is particularly useful for direct write imaging using IR lasers or thermal printing heads.

Abstract: A lithographic printing plate precursor comprises a grained and anodised aluminium substrate which has been treated with a solution of water-soluble salt of a Group IVa metal fluoride and over which is provided a metallic layer, preferably a silver layer. Imagewise exposure of the precursor by means of a high intensity laser beam allows for the direct provision of press ready plates showing high image quality and clean background, good press properties and high durability on press, without the requirement for the use of intermediate film and developer chemistry. The plate precursors show enhanced sensitivity on exposure, whereupon removal of the metallic layer occurs in the exposed areas.

Abstract: A negative working image recording material which comprises the following four components (A) to (D): (A) at least one of compounds represented by following general formulas (I) to (V), or at least one of polymers obtained by radical polymerization using at least one of monomers represented by following general formulas (VI) to (X): (B) at least one cross-linking agent; (C) at least one infrared absorbing agent; (D) at least one novolak resin.

Abstract: The invention relates to a recording material having a substrate and a negative-working, radiation-sensitive layer which contains a diazonium salt, at least one film-forming, polymeric binder and organic colored pigments, on the surface of which an organic polymeric dispersant has been adsorbed and which are additionally dispersed in an organic polymeric binder which does not permanently combine with the pigments chemically or physically. The dispersant generally has groups, in particular primary, secondary or tertiary amino groups or derivatives thereof, which act as anchor groups on the colored pigment particles. The pigments themselves are preferably phthalocyanine pigments. As a result of the predispersing, aggregation of the pigment particles is effectively prevented so that uniform coloration of the radiation-sensitive layer is achieved. During development of the imagewise exposed recording materials, the colored pigment particles form virtually no insoluble precipitates.