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: The invention relates to a radiation-sensitive recording material for the production of offset printing plates having a dimensionally stable support, a radiation-sensitive layer located on the front of the support, and a layer which comprises an organic polymeric material having a glass transition temperature of 35° C. or above and in which pigment particles are embedded and which is resistant to processing chemicals and is located on the back of the support. The pigment particles are preferably silica gel particles having a mean diameter of from 0.1 to 50 &mgr;m or organic particles having a mean diameter of from 3 to 10 &mgr;m. The image layer on the front may be matted or pigmented. The back coating enables the recording material to be stacked without separating paper. The image layer located on the front is not scratched by the pigmented back coating during storage and transport and during removal from the stack.

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.

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: The invention relates to a process for the production of a photosensitive recording material for the production of offset printing plates which comprises a dimensionally stable, two-dimensional support of a metal or metal alloy and a silver halide-containing, photosensitive layer on the front of the support and a layer which essentially consists of an organic polymeric material and is resistant to processing chemicals on the back of the support. The layer on the back of the support is applied before the photosensitive coating on the front. The invention furthermore relates to a corresponding recording material in which the layer on the back comprises at least one organic polymer having a glass transition temperature Tg of 50° C. or above. Due to the back coating, the formation of local elements between the metallic support and the silver-containing layer is reliably prevented when the recording materials are stacked.

Abstract: The invention relates to a developer concentrate which comprises water, at least one agent which is alkaline in water and an amphoteric surfactant and additionally at least one anionic surfactant, at least one complexing agent, at least one aminoalcohol and at least one N-alkoxylated mono- or polyfunctional amine. A ready-to-use developer can be prepared from this concentrate by dilution with tap water advantageously in the ratio of from 1:0.5 to 1:10, preferably in the ratio of from 1:2 to 1:6. The developer or the replenisher is preferably used in the production of printing plates.

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) 1

Abstract: The invention relates to a recording material for the production of an offset printing plate, having a substrate on whose front a photosensitive image layer is present and on whose back a layer of an organic polymeric material having a glass transition temperature Tg of 45° C. or more is present. The photosensitive image layer, or any top layer present thereon, has a pigment layer formed thereon.

Abstract: According to the present invention there is provided a method for making a lithographic printing plate comprising the steps of a) exposing imagewise to IR-radiation a heat mode imaging element 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 which top layer is unpenetrable by an alkaline developer and contains a compound capable of converting light into heat, wherein said first layer and said top layer may be one and the same layer; and b) developing said imagewise exposed heat mode imaging element with said alkaline developer whereby the exposed areas of the first and the top layer, which may be the same, are dissolved and the unexposed areas of the first layer remain undissolved characterized in that said alkaline developer has a pH of at least 12 and a surface tension of at least 30 mN/m.

Abstract: 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 dye, is described. A daylight-insensitive recording material which can be provided with an image using IR radiation and has a substrate and a layer comprising the mixture is also disclosed. After imagewise exposure, in particular to IR laser beams, and development with an aqueous alkaline solution, an offset printing plate can be formed therefrom.

Abstract: A dummy plate is provided for offset printing which essentially consists of a plate-, sheet- or band-form, mechanically and/or electro-chemically roughened, anodically oxidized and optionally hydrophilized aluminium support and a non-photosensitive, water-soluble protective layer applied thereto, characterized in that the layer contains a water-soluble organic compound which contains at least one OH- or NH-acidic group having a pKa value of ≦8 as acid or salt, and has a layer thickness which is smaller than the average roughness ra of the support material, determined by optical means. Even after extended storage at elevated temperature, the dummy plate can easily be used without an additional development step and exhibits no tendency to stick.

Abstract: The present invention relates to a recording material having a substrate and a negative-working, radiation-sensitive layer which contains a diazonium salt, metal-free colored pigments dispersed in an organic polymeric binder, transparent spacer pigments having a pore volume of more than 1.0 ml/g and a polymeric binder. The predispersal of the colored pigments is achieved by milling with an organic polymeric binder containing hydroxyl groups, some or all of which have been reacted with a di- or polycarboxylic anhydride so that the binder has an acid number of from 20 to 200. Printing plates in which the printing parts have a clearly visible contrast relative to the substrate can be produced from the recording material.

Abstract: The invention relates to polymers containing N-substituted maleimide units, to a positive- or negative-working radiation-sensitive mixture comprising a) a polymeric binder which is insoluble in water, but soluble in aqueous-alkaline solutions, and b) at least one radiation-sensitive compound, where the binder comprises a polymer containing N-substituted maleimide units of the formula (I) The invention furthermore relates to a recording material having a support and a radiation-sensitive layer, where the layer includes the mixture. The recording material is particularly suitable for the production of chemical-resistant relief recordings. The planographic printing plates produced from the recording material allow long print runs and are resistant to processing chemicals.

Abstract: The invention relates to a recording material having a substrate and a radiation-sensitive, water-insoluble layer which contains a component absorbing IR radiation and which, after the action of infrared radiation, becomes soluble or at least swellable in an aqueous alkaline developer. A top layer which is opaque to white light but transparent to radiation in the IR range and can be removed with water or an aqueous solution is present on the radiation-sensitive layer. The recording material is substantially insensitive to daylight. By imagewise exposure to IR radiation and subsequent development with an aqueous alkaline developer, it is possible to produce a printing plate for offset printing from the recording material. If the top layer is washed off beforehand, the recording can also be carried out using conventional UV radiation.

Abstract: A positive-working or negative-working radiation-sensitive mixture includes as an IR absorbing component a carbon black pigment having a primary particle size smaller than 80 nm. The carbon black pigment is predispersed in a polymer containing acidic units having a pK.sub.a of less than 13. The radiation-sensitive component may include an ester of (i) a 1,2-naphthoquinone-2-diazide-4-sulfonic acid or a 1,2-naphthoquinone-2-diazide-5-sulfonic acid and (ii) a compound having at least one phenolic hydroxyl group, such as 3 to 6 phenolic hydroxyl groups. After imagewise radiation exposure, the recording material including the radiation-sensitive mixture can be developed without difficulties in an aqueous alkaline solution without leaving residual coating on the areas that became soluble or that remained soluble upon exposure.

Abstract: The invention relates to a developer for irradiated, radiation-sensitive recording materials, in particular for the production of offset printing plates, which contains water, a compound which is alkaline in aqueous solution and a copolymer which acts as an emulsifier and has units of (I) a hydrophobic vinyl compound which has at least one optionally substituted mono- or bicyclic (C.sub.6 -C.sub.14)aryl radical and (II) a hydrophilic, ethylenically unsaturated carboxylic acid. Some of the carboxyl groups of the copolymer are esterified with reaction products of (A) (C.sub.1 -C.sub.30)alkanols, (C.sub.8 -C.sub.25)alkanoic acids, (C.sub.1 -C.sub.12)-alkylphenols or di(C.sub.1 -C.sub.20)alkylamines with (B) (C.sub.2 -C.sub.4)-alkylene oxides or tetrahydrofuran, the molar ratio (A):(B) being in the range from 1:2 to 1:50. If it is intended to develop recording materials having a negative-working layer, the developer additionally contains a water-miscible organic solvent and a surface-active compound.

Abstract: A positive-working, radiation-sensitive recording material capable of being used for the production of planographic printing plates, comprising: an aluminum support and a radiation-sensitive layer coated thereon, whereinthe aluminum support has been grained in nitric acid, then cleaned in sulfuric acid, anodized in sulfuric acid, and subsequently hydrophilized with a compound comprising at least one unit with a phosphonic acid or phosphonate group; andthe radiation-sensitive layer comprisesa) a radiation-sensitive 1,2-naphthoquinone-2-diazide-4- or -5-sulfonic acid ester of a polycondensate having phenolic hydroxy groups, said polycondensate being obtained by reacting a phenolic compound with an aldehyde or ketone,b) a novolak or a polycondensation product obtained by reacting a polyphenol with an aldehyde or ketone, as an alkali-soluble resin,c) a vinyl-type polymer comprising at least one unit having a lateral hydroxyphenyl group,d) a clathrate-forming compound,e) a low-molecular weight compound which compr

Abstract: The invention relates to a sheet-like radiation-sensitive recording material whose surface is a discontinuous dulling layer comprising monodisperse particles is present. The dulling layer can be produced by spraying on a dulling liquid. An apparatus comprising an oscillation generator, which can transmit oscillations to the liquid in the apparatus, and has an orifice plate which has at least one hole with a diameter of from 5 to 250 .mu.m and from which the liquid emerges in the form of at least one laminar free jet which disintegrates into monodisperse drops is suitable for this purpose. The oscillation generator is preferably a piezoelectric ceramic.

Abstract: A developer for irradiated, radiation-sensitive recording materials, in particular for the production of offset printing plates, which contains water, a compound which is alkaline in aqueous solution and a copolymer which acts as an emulsifier and has units of (I) a hydrophobic vinyl compound which has alkyl radicals having up to 30 carbon atoms and (II) a hydrophilic, ethylenically unsaturated carboxylic acid. Some of the carboxyl groups of the copolymer are esterified with reaction products of (A) (C.sub.1 -C.sub.30)alkanols, (C.sub.8 -C.sub.25)alkanoic acids, (C.sub.1 -C.sub.12)alkylphenols or di(C.sub.1 -C.sub.20)alkylamines with (B) (C.sub.2 -C.sub.4)alkylene oxides or tetrahydrofuran.

Abstract: A process for developing irradiated radiation-sensitive recording materials using an aqueous-alkaline developer which contains compounds of the formula (I) ##STR1## wherein A is H, Na, K, NH.sub.4 or NR.sub.4, whereR is a substituted or unsubstituted alkyl radical,W and X, independently of one another are H or --CH.sub.2 --COOA,Y is H or COOA andZ is H or OH,wherein the compound of the formula (I) contains at least 3 COOA units.