Abstract: A process for filmless production of a ready-to-print printing form and for using it in an offset printing press includes exposing a printing form sensitive in an emission range of light-emitting diodes to an image in an exposure unit by means of a computer-controlled LED bar, passing the exposed printing form through a developing stage wherein the printing form is developed, and then feeding-in the printing form via a high-speed feeding-in device for printing forms, and positioning the fed-in printing form on a plate cylinder; and apparatus for performing the process.

Abstract: A dry PS plate comprises a substrate provided thereon with in order a primer layer, a light-sensitive layer and a silicone rubber layer wherein the primer layer comprises at least one compound selected from the group consisting of those having urethane or/and urea bonds and is adhered to the substrate with a functional group containing silane coupling agent represented by the following general formula: ##STR1## wherein n is an integer ranging from 1 to 3; X represents an alkyl group, a vinyl group or an organic group having a functional group showing affinity to or capable of being bonded to the compound included in the primer layer; R represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms; and Y represents an organic group which generates a hydroxyl group through hydrolysis or a hydroxyl group.

Abstract: The invention relates to a method of forming of a patterned photopolymer coating on a printing roller in which a photopolymer coating, present on said roller, and covered by a light-sensitive intermediate layer is exposed in a first stage to form an image of opaque and translucent parts in said intermediate layer.Subsequently the photopolymer layer is exposed via the image formed in the intermediate layer, after which the photopolymer layer is developed.Between abovementioned exposures, in case of a relatively thick, flexible, photopolymer, a period is waited to ensure that depressed parts of the photopolymer layer have returned to their original state.The invention also relates to a printing roller thus obtained.

Abstract: Printing plates having a photosensitive layer coated on a support wherein said photosensitive layer contains a powdered solid adhered to the surface of said plate by means of powdering followed by the application of heat or solvent before exposure. Said powders are capable of being removed from said surface during the developing process.

Abstract: A printing plate having a photosensitive layer formed of a photosensitive polymer composition including the following components A, B, and C:A. 100 parts by weight of parially saponified polyvinyl acetate having a saponification degree of 60 to 99 mole %;B. 20 to 200 parts by weight of polyfunctional acrylate or methacrylate having a molecular weight of not more than 2000 and having at least two acryloyl or methacryloyl groups in the same molecule thereof and a number of a hydroxyl group or groups not more than the number of said acryloyl and methacryloyl groups in the same molecule thereof; andC. 1 to 60 parts by weight of a saturated compound having a molecular weight of not more than 1000 and a boiling point of not less than 150.degree. C. and having at least one hydroxyl group in the molecule thereof.

Abstract: A method for forming plate characters in a half-tone gravure platemaking process being characterized in that a laser beam moved so that the laser beam is intermittently irradiated onto a light sensitive material and a plate character is formed on the light-sensitive material by exposure. The character thus formed is made up with a character frame portion and a character fill portion surrounded by the character frame portion, the character frame portion being formed by a plurality of intermittently arranged groove-form cells each having a predetermined length and a width which can prevent flow of ink when ink is applied by wiping the plate surface with a doctor, and the character fill portion being formed by dot-form cells which have a shadow-portion dot percentage.

Abstract: A method for forming plate characters in a half-tone gravure platemaking process in which a laser beam intermittently irradiates a photosensitive material, thus forming plate characters therein as a result of exposure by the laser beam. The outline portion of each character is made up of continuous groove-form cells and inner portion of the character (the filled portion) is made up of independent dot-form cells corresponding to the dot percentage of a shadow portion or with island-form projections to the extent that ink flow (running) does not occur when the cells are filled with ink as a result of the plate surface being wiped by a doctor blade. The outline portion of each character is made up of groove-form cells having a narrow width without causing ink flow (running) when the cells are filled with ink as a result of the plate surface being wiped by a doctor blade.

Abstract: A method for manufacturing lithographic printing plates which comprises developing a presensitized plate for use in making lithographic printing plates imagewise opposed to light with an alkaline developer utilizing an automatic developing machine and then treating the developed presensitized plate with a finisher, wherein an initial pH of the finisher ranges from 2 to 8 and a pH of the finisher is controlled during running in proportion to concentration of the developer included in the finisher. The method makes it possible to prevent the formation of gel-like insoluble matters in the bath for treatment with the finisher due to the presence of the developer carried over from a developing bath and to stably process a large amount of lithographic printing plates over a long time period.

Abstract: A printing plate precursor comprises a substrate coated with a radiation sensitive composition comprising a photoinitiator and a photopolymerizable urethane acrylate or methacrylate. The urethane acrylate or methacrylate is produced by partial acrylation or methacrylation of a tetrafunctional polyol and the remaining hydroxy groups of the polyol are reacted with a di or polyisocyanate.

Abstract: A photosensitive composition is described, comprising a diazonium compound and a polyurethane resin having a carboxyl group in its main chain. The composition can be developed with an aqueous alkali developer to provide a lithographic printing plate having a long press life.

Abstract: The invention relates to the use of a thermal transfer printer and of an ink ribbon containing a pigment or dye that absorbs light in the range from 350 to 450 nm for the direct production of a photomask from an electronically coded sources of information on a metal plate (PS plate) coated with a positively working photopolymer which is sensitive to light in the range from 350 to 450 nm, and, as surface layer, with a polymer which is soluble in alkaline solution and is permeable to light in the range from 350 to 450 nm, such that the image produced by the thermal transfer printer on the PS plate is used direct as photomask.

Abstract: Disclosed is a photopolymerizable composition comprising (i) a monomer having at least one ethylenic unsaturated group which is polymerizable by means of active light, (ii) an organoboron compound, and (iii) a pyrylium or thiopyrylium dye. The composition is useful, for example, as photosensitive layers for photosensitive printing plates which are sensitive and respond to an argon laser light source.

Abstract: A photosensitive and heat-sensitive polymer having conjugated polyenes and sulfonic acid groups and an absorbance ratio of a strong band in the region of 1200 cm.sup.-1 to 1300 cm.sup.-1 assignable to sulfonic acid groups adjacent to conjugated polyenes of at least 3 sequence lengths to a strong band near 1050 cm.sup.-1 assignable to sulfonic acid groups in the IR spectrum of at least 0.6. The photosensitive and heat-sensitive polymer is obtained by the sulfonation of a polymer of an ethylenically unsaturated monomer having a number average molecular weight of at least 10,000 or a polymer having conjugated polyenes and a number average molecular weight of at least 10,000 and selected from specified polymers and copolymers. The photosensitive and heat-sensitive polymer is useful for information recording materials capable of being recorded by a laser beam or a thermal head for preparing printing plates, especially offset printing plates.

Abstract: A developer for PS plates requiring no dampening water which comprise a substrate provided thereon with a primer layer, photopolymerizable light-sensitive layer and a silicone rubber layer in this order, comprises: (i) an organic solvent which can dissolve or swell non-exposed portions of the photopolymerizable light-sensitive layer and whose solubility in water at ordinary temperature is not more than 20% by weight; (ii) a surfactant; and (iii) water. The developer is excellent in developing properties and dot reproduction, shows high stability and does not cause scratches on the silicone rubber layer during development.

Abstract: Disclosed is a photosensitive flexographic resin plate having excellent wear resistance and giving relief image faithful to a negative film. The photosensitive flexographic printing plate is composed of a base plate and a photosensitive resin layer thereon wherein said photosensitive resin layer is formed from a resin composition comprising a resin having rubber elasticity, an unsaturated monomer, a photopolymerization initiator and resin particles having an average particle size of about 0.01 to 6 micron, and when said photosensitive resin layer is cured, the cured layer has a JIS A hardness of 30.degree. to 80.degree. and an impact resilience of at least 20%.

Abstract: A photosensitive recording element possessing a photosensitive recording layer which is applied to a dimensionally stable base, if desired on top of one or more intermediate layers, and has good photochemical properties and a long shelf life contains special sulfo-containing azo or azoxy dyes for controlling the photochemical properties in the photosensitive recording layer and/or in any intermediate layer present. Dyes which are suitable for use according to the invention can be obtained, for example, by autocondensation of 5-nitro-o-toluenesulfonic acid.

Abstract: A radiation-sensitive mixture, in particular photosensitive mixture, is disclosed that contains a compound which forms a strong acid on exposure to actinic radiation and a polymeric reaction product of (i) a polymeric organic compound containing free OH groups, (ii) an organic compound containing at least two isocyanate groups or at least two epoxy groups, and (iii) a compound containing repeating acid-cleavable acetal or ketal groups and at least one free OH group. The mixture yields printing plates or photoresists with a longer storage life.

Abstract: This invention relates to a radiation polymerizable composition for use in a photographic element such as a lithographic printing plate comprising in admixture(a) a polymeric binder;(b) a photoinitiator;(c) a diazonium salt; and(d) a photopolymerizable mixture of(i) a polyfunctional acrylic monomer having from 3 to 6 unsaturated groups; and(ii) a monofunctional acrylic monomer having 1 unsaturated group.

Abstract: A polyvinyl acetal is described which contains 4 to 40 mol-% vinyl alcohol units, 1 to 20 mol-% vinyl acetate units, 0 to 85 mol-% vinyl acetal units derived from an aldehyde free of OH groups and 1 to 85 mol-% vinyl acetal units derived from an aldehyde containing OH groups. The polymer is suitable as binder for photosensitive mixtures, in particular for the preparation of printing plates and photoresists. The layers obtained therewith can be developed with neutral or weakly alkaline, purely aqueous solutions and produce printing plates with a high print run performance and good ink receptivity.

Abstract: A photographic element formed from a substrate and light sensitive coating on the substrate wherein the coating comprises a mixture of a diazo compound and an aromatic carboxylic coupling agent having phenolic hydroxy groups, in an acidic medium.

Abstract: Compositions comprising a free radical sensitive compound and a thermally stable substituted diazene which upon exposure to electromagnetic radiation is convertible to a thermally unstable substituted diazene may be formed and processed utilizing thermally intense techniques and thereafter the free radically initiated changes initiated by exposing the substituted diazene to light and heat.

Abstract: A sensitized lithographic printing plate is produced from an aluminum base which has been mechanically, chemically and/or electrochemically pretreated and anodically oxidized in a conventional manner and a photosensitive copying layer which is applied to this base, by a process in which a thin layer which imparts hydrophilic properties and consists of a hydrolysis product or condensate of one or more silanes is applied between the base and the copying layer.These lithographic printing plates are particularly useful for offset printing.

Abstract: A relief flexographic printing plate is prepared by image-wise exposure of the "printing face" of a layer of photocurable polymer through a negative 7 and image-wise back exposure of the layer 4 through a support sheet 3 and a positive 6 of the image to be printed, thereby selectively curing the floor regions 9 of the printing plate in register with the uncured areas 8 left in the printing face of said layer.Preferably a further non-selective back exposure operation is carried out for additionally curing the floor regions.

Abstract: Orifices, cavities or spaces which are formed when printing plates are mounted on a plate cylinder are closed and/or sealed by means of a pasty, photocurable sealing or closing compound consisting of one or more photopolymerizable, ethylenically unsaturated low molecular weight compounds (a), one or more polymeric binder (b) which are compatible with the said compounds of component (a), one or more photopolymerization initiators (c) and one or more finely divided oxidic fillers (d) which, when mixed with components (a) to (c), give mixtures which are transparent to long-wavelength UV light. After it has been applied, this sealing or closing compound is cured by exposure and can then be mechanically processed. The process is particularly suitable for closing and/or sealing orifices, cavities or spaces in gravure printing plates mounted on plate cylinders.

Abstract: Mixtures which can be cross-linked by photopolymerization and are based on soluble elastomeric block copolymers, photopolymerizable monomers which are compatible with these, photoinitiators and plasticizers contain, as the plasticizer, a chloroalkane of 8 to 40 carbon atoms which has a chlorine content of from 30 to 73% by weight.

Abstract: A photopolymerizable composition comprising an addition polymerizable unsaturated compound having at least two ethylenically unsaturated double bonds in the molecule, a photopolymerization initiator, and a binder, wherein the binder is a tetrapolymer having a weight average molecular weight of from 10,000 to 50,000 represented by formula (I): ##STR1## wherein R represents a hydrogen atom or a methyl group; and w, x, y and z each represents mol percent (mol %), w ranging from about 45 to 65; x ranging from about 5 to 18; y ranging from about 2 to 10; and z ranging from about 20 to 40 and where C.sub.4 H.sub.9 (n) represents an n-butyl group. The photopolymerizable composition can be developed with a weakly alkaline aqueous solution, has sufficient flexibility to be laminated on a base as a dry film, high adhesiveness to a base and reduced surface tackiness.

Abstract: The invention describes a process for the post-treatment of developed relief printing forms for use in flexographic printing. The relief printing forms are reexposed in a customary manner and thereafter treated according to the invention, using a solution which comprises an organic solvent and, dissolved therein, an aryl- or hetaryl-bis(trihalogenomethyl)-s-triazine; they are then dried and briefly reexposed to UV light. The process of the invention eliminates the tackiness of the surfaces of light-hardened flexographic printing forms comprising a photopolymer and it also considerably enhances the resistance of these printing forms to air containing ozone.

Abstract: This invention relates to a process for making a printing relief from a flexographic photosensitive element comprising:(a) imagewise exposing to actinic radiation a layer of a photosensitive composition, said photosensitive composition comprising a binder having thermoplastic and elastomeric domains, a first addition polymerizable, ethylenically unsaturated monomer having some compatibility with both domains of the binder, and an addition polymerization initiator or initiating system;(b) removing the unexposed portions; and(c) applying post development treatment; wherein the improvement comprises increasing the flexibility of the flexographic printing relief by adding at least one additional ethylenically unsaturated monomer so that the ratio of first monomer to the additional monomer is in the range 1:4 to 4:1 based on total weight of monomer, said additional monomer is added to the photosensitive composition prior to imagewise exposing the layer provided that said additional monomer is substantially incompa

Abstract: A silver halide photographic plate and a pattern transfer method comprising forming an original picture pattern on a first photographic plate having a silver halide emulsion layer on a glass support and contact transferring the original picture pattern onto a second photographic plate having a silver halide emulsion layer on a glass support or a substrate having a photoresist layer,characterized in that the first and second photographic plates comprise a silver halide emulsion contained in the emulsion layer which is a silver iodobromide emulsion containing 8 mol % or less of silver iodide and with its mean grain size being 0.1 .mu.m or less; or contain a silver halide emulsion in the emulsion layer which contains 50 mol % or more of silver chloride; andthat at least one of the first and second photographic plates has an emulsion layer with surface roughness of 0.3 .mu.m to 3 .mu.m, anda silver halide photographic plate to be used for the method.

Abstract: Method of preparing a contoured plate by selectively hardening a photopolymer plate in a zone which is adjacent the lower surface of the plate and increases continuously in thickness from one portion of the plate to another by a first exposure of the upper surface of the plate to a quantity of light energy which increases continuously per unit area of the surface from said one portion of the plate to the other. Discrete portions of the upper surface of the plate are masked in the portions on which it is desired to form a recessed design, and the non-masked portions of the plate are hardened by a second exposure of its upper surface to light energy, so that the masked portions remain unhardened from their upper surface to the upper region of said hardened zone. The unhardened portions are removed to provide a recessed design in the upper surface of the plate. The design varies continuously in depth independently of the width of the design.

Abstract: Photopolymeric printing plates wherein an electrochemically etched, anodized and silicated aluminum plate has a plurality of coatings applied thereon and wherein at least one of the coatings include a solvent soluble diazo therein.

Abstract: For the seamless and firm joining of the end and/or lateral areas of thermoplastically processible photosensitive layers, the end and/or lateral areas of one or more solvent-free and unsupported thermoplastically processible photosensitive layers are overlapped avoiding bubbles and with displacement of the air between the end and/or lateral areas, the total layer material is then heated under pressure and with joining of the overlapping end and/or lateral areas, and the resulting continuously joined photosensitive layer is then aftertreated and smoothed with shaping to exact size.

Abstract: A presensitized lithographic plate comprises a hydrophilic layer and a light-sensitive layer containing silver halide, a reducing agent, a polymerizable compound and a hydrophilic binder provided in order of a hydrophilic support wherein the silver halide, the reducing agent and the polymerizable compound are contained in lipophilic microcapsules which are dispersed in the light-sensitive layer. Another presensitized lithographic plate comprising a hydrophilic layer and a light-sensitive layer containing a photo polymerizable composition or a photo polymerizable compound provided in order on a hydrophilic support wherein the photo polymerizable composition or the photo polymerizable compound are contained in lipophilic microcapsules which are dispersed in the light-sensitive layer is also disclosed.

Abstract: Mixtures crosslinkable by photopolymerization and based on binders, photopolymerizable monomers compatible therewith and photoinitiators, contain as binders copolymers prepared from (a.sub.1) from 30 to 70% by weight of ethylene, (a.sub.2) from 5 to 40% by weight of (meth)acrylic acid and (a.sub.3) from 5 to 50% by weight of one or more vinyl ester, vinyl ether, (meth)acrylic acid ester and/or (meth)acrylamide.

Abstract: Photoresist compositions which operate positively and contain at least one ocmpound of the formula I ##STR1## in which X is --C.sub.n H.sub.2n --, --O--, --S-- or --C(O)--, n being a number from 1 to 6. These compositions are particularly suitable for use as positively-operating copying lacquers.

Abstract: For coating printing cylinders or sleeves with a seamless, smooth photosensitive layer, two or more strata of a thin, prefabricated, essentially solvent-free, unsupported, thermoplastically processible, solid, photosensitive layer are applied to the printing cylinder or the sleeve, without bubbles and with displacement of the air between the individual strata, and the total photosensitive layer material is then heated under pressure and with joining or fusion of the individual strata to form a single, continuous photosensitive layer, and the surface of the resulting photosensitive layer is aftertreated to shape it exactly to size and is smoothed, with formation of an exactly cylindrical shape.

Abstract: A printing cylinder or a sleeve is coated with a continuous photosensitive recording layer by applying a first jointless stratum of a photosensitive recording layer to the printing cylinder or the sleeve, and uniformly preexposing this first stratum to actinic light and thereafter applying one or more further jointless strata of the photosensitive recording layer to this preexposed first stratum.

Abstract: A liquid photosensitive composition is introduced into a hollow cylindrical element and the latter is spun at a high speed to centrifugally deposit the liquid photosensitive composition uniformly on the inner surface of the hollow cylindrical element and cause the resin composition to cure in situ. The above process provides a seamless cylindrical photosensitive resin structure. After the centrifugal formation of a photosensitive resin layer on the inner surface of the hollow cylindrical element, the photosensitive resin may be back-exposed from within the hollow cylindrical element and relief-exposed from outside of the hollow cylindrical element though an image carrier.By the above method, resin plates and particularly those suited for flexographic printing can be manufactured, and using these resin plates, seamless image printing can be performed.

Abstract: An electrophotographic printing plate comprises a substrate having formed thereon a photoconductive layer comprising (a) a disazo based compound, (b) a perynone based compound, (c) a hole transport material, and (d) an alkali-soluble resin.

Abstract: Disclosed is a radiation-sensitive recording material comprising a support, a radiation-sensitive recording layer and a rough covering layer which is applied by spraying and drying a solution which has substantially the same composition as the recording layer. Due to its rough surface, the material provides for accelerated vacuum contact in the copying process. Also disclosed is a process for producing the radiation-sensitive recording material described above.

Abstract: A printing plate having a photosensitive layer formed of a photosensitive polymer composition including the following components A, B, and C:A. 100 parts by weight of partially saponified polyvinyl acetate having a saponification degree of 60 to 99 mole %;B. 20 to 200 parts by weight of polyfunctional acrylate or methacrylate having a molecular weight of not more than 2000 and having at least two acryloyl or methacryloyl groups in the same molecule thereof and a number of a hydroxyl group or groups not more than the number of said acryloyl and methacryloyl groups in the same molecule thereof; andC. 1 to 60 parts by weight of a saturated compound having a molecular weight of not more than 1000 and a boiling point of not less than 150.degree. C. and having at least one hydroxyl group in the molecule thereof.

Abstract: A method of producing plate machining masks in which a mask forming film having a support and a masking forming layer mostly transparent is put on a press-ready copy. Lines are cut through the mask forming layer in conformity to patterns observed therethrough on the press-ready copy. Encircled or encircling portions of the masks forming layer defined by the cut lines are peeled off. Either the mask forming layer has some color or reflectance properties and thus the remaining portions are used as a photographic mask over the press-ready copy or a paint is applied through the missing mask forming layer to the support and the remaining mask forming layer is removed to leave a paint-defined mask.

Abstract: Mixtures crosslinkable by photopolymerization and based on binders, photopolymerizable monomers compatible therewith and photoinitiators, contain as binders copolymers prepared from (a.sub.1) from 30 to 70% by weight of ethylene, (a.sub.2) from 5 to 40% by weight of (meth)acrylic acid and (a.sub.3) from 5 to 50% by weight of one or more vinyl ester, vinyl ether, (meth)acrylic acid ester and/or (meth)acrylamide.

Abstract: A presensitized plate for use in making a lithographic printing plate requiring no dampening water which comprises a substrate having provided thereon a primer layer, a photodimerizable photosensitive layer containing at least one organotin compound and at least one silane coupling agent in a total amount of 0.1 to 20% by weight of the photosensitive resin and a silicone rubber layer, in order, the photosensitive layer of the presensitized plate is formed by previously incorporating the above two compounds into a photosensitive resin composition and then applying the composition to the surface of the primer layer or by contacting a solution containing the compounds with the previously formed photosensitive layer and penetrating the solution into the photosensitive layer. The dry presensitized plate is extremely strong in adhesiveness between the primer layer and the photosensitive layer and exhibits a relatively broad developing latitude and a good image reproducibility.

Abstract: This invention is a method for preventing sticking of a resin plate surface by coating the solution of binder and photopolymerizable monomer on the surface of a photosensitive resin composed of binder, photopolymerizable monomer, and photopolymerization initiator, developing relief images by a photomechanical process, and then by drying the coating solution.

Abstract: The invention relates to a method of preparing a varnish blanket. Instead of a proof being used for pre-location of required varnish-free zones on a blanket for blanked-out in-line varnishing in rotary presses, the zones required not to be varnished are transferred by means of a reference copy, and after physico-chemical pretreatment adapted to the surface properties of the blanket, to a blanket stuck to a support plate. In addition to polyvinyl alcohol copying layers or coatings sensitized by bichromate, wipe-on copying layers sensitized by diazo salts are suitable, a positive or negative original being copied by direct contact in known manner onto a blanket thus pretreated. The zones required not to be varnished can therefore be preformed by cutting out the top layer of the blanket.

Abstract: In a process for reducing halations during the imagewise irradiation of a reproduction layer exposed through a planar image original, at least one lubricant either is contained in the layer or is interposed between the layer and the image original. Suitable lubricants include organic polysiloxanes, hydrocarbon polymers, polyaryl esters, and alkanoic acids or alkenoic acids having at least 9 carbon atoms. Excluded are lubricants comprising copolymers of dimethyl dichlorosilane, ethylene oxide and propylene oxide, provided they are located in the reproduction layer.

Abstract: In the process of making relief printing plates a liquid photopolymerizably layer having substantially identical negatives on each of its two sides and being in registration and also having a transparent substrate is exposed to an external light source so that both sides are exposed to the same image and after removal of the negatives the unexposed areas of the plate are removed.

Abstract: A light-sensitive mixture containing a light-sensitive compound or a light-sensitive combination of compounds, the solubility of which is increased upon exposure, and a binder made from a polymer which has units of alkenylsulfonylaminocarbonyloxystyrenes or cycloalkenylsulfonylaminocarbonyloxystyrenes and which is insoluble in water and soluble in aqueous alkali. Moreover, a recording material is described which is particularly used in the production of printing plates coated with a light-sensitive layer of the indicated mixture. The printing form obtained after exposure and development of the material can be baked at temperatures ranging from 180.degree. C. to 250.degree. C. without forming difficult to remove deposits on the non-image areas of the plate. As a result, a printing form is produced, which has a particularly high resistance and yields a large print run.

Abstract: A laser-imageable assembly comprising a transparent substrate and an associated energy absorbent transfer layer comprising particles which absorb laser energy dispersed in a resin, the assembly comprising at least one further layer selected from(a) an intermediate priming layer,(b) a protective coating layer, and(c) a lubricant coating layer.The transfer layer is preferably rendered heterogeneous - for example, by appropriately drying the coated substrate.A preferred substrate is a polyester film.