Abstract: A method for processing a photosensitive material characterized in that an exposed photosensitive material is subjected to dip coating with a processing solution, according to which there are no problems encountered in plate making by the conventional dip developing method and coating developing method, rapid processing can be attained, maintenance is easy, less waste processing solution is produced, and lithographic printing plates on which uniform print images can be formed from the top end portion thereof by silver complex diffusion transfer process, and an apparatus used for the processing.

Abstract: Disclosed is a panchromatic silver halide photographic emulsion for use in DTR process which exhibits a high sensitivity, especially to blue light, a high contrast and a high resolving power and a photographic element containing said silver halide emulsion layer. Said emulsion contains a blue-sensitizing dye represented by the general formula [I]: ##STR1## (wherein Z.sub.1, Z.sub.2, R.sub.1, R.sub.2, X.sub.1 and m are as defined before).Said emulsion may contain, as green- and red-sensitizing dyes, those represented by the general formula [II] and [III] to attain more effectively the objects: ##STR2## (wherein Z.sub.3, Z.sub.4, Z.sub.5, Z.sub.6, R.sub.3, R.sub.4, R.sub.5, R.sub.6, R.sub.7, R.sub.8, X.sub.2, X.sub.3 and m are as defined before).Said photographic element is an excellent ligtographic printing plate.

Abstract: A method for lithographic printing of paginal publications which comprises applying onto a flexible supporting base two or more lithographic printing plates arranged in the rotational direction of a master cylinder and to form such a structure with front and rear edge portions of the adjacent lithographic printing plates as to prevent penetration of damping solution between the supporting base and the lithographic printing plates, the portion of said structure receiving substantially no ink. This supporting base is mounted on a master cylinder of a printing machine and printing is carried out.

Abstract: This invention provides a method for deleting images formed on offset printing plates which comprises treating the surface of undesired portion of the images formed by exposure and development with a deletion fluid which contains a ferric complex salt of an organic acid and 0.3 mol/liter or more of at least one compound selected from the group consisting of a soluble bromide and a soluble iodide. Preferred ferric complex salt is a ferric complex salt of aminopolycarboxylic acid.

Abstract: A lithographic printing plate made by silver complex diffusion transfer process from a lithographic printing plate material which contains a compound represented by the general formula [I] in photographic constituting layer is markedly improved in its printing endurance: ##STR1## wherein M represents hydrogen, an alkali metal or ammonium ion and R.sup.1 -R.sup.4 each represents hydrogen atom, alkyl group, alkenyl group, aralkyl group, aryl group, halogen atom, alkoxy group, hydroxyl group, amino group, carboxyl group, sulfone group, alkoxycarbonyl group, acylamide group or sulfonamide group and two of R.sup.1 -R.sup.4 may jointly form a ring.

Abstract: Lithographic printing plates which have such a high sensitivity as permitting use of semiconductor laser beam of low output, a high resolving power and a high printing endurance and are free from occurrence of scumming are made by a method which comprises imagewise exposing a light sensitive material which comprises a support and at least a silver halide emulsion layer and a surface physical development nuclei layer provided on the support, said emulsion layer comprising silver halide grains which contain at least silver bromide and containing at least one sensitizing dye having a maximum spectral sensitivity in the region of longer than 700 .mu.m and then developing the exposed light sensitive material with a silver complex diffusion transfer developer containing at least a thiocyanate. Further improvement can be obtained by providing an antihalation means to keep the reflectance of a light of longer than 700 .mu.m at 13-40%.

Abstract: Printing characteristics of a lithographic printing plate material using the silver complex diffusion transfer process and comprising a support and a silver halide emulsion layer and a surface physical development nuclei layer are markedly improved when the emulsion layer comprises two emulsion layers, the lower layer of which has substantially no light-sensitivity.

Abstract: Disclosed is a light sensitive material for lithographic printing plate which comprises a support and at least a silver halide emulsion layer and a surface physical development nuclei layer provided on said support wherein said silver halide emulsion layer contains at least one of the sensitizing dyes represented by the following general formulas (I), (II), (III), (IV) and (V):General formula (I) ##STR1## General formula (II) ##STR2## General formula (III) ##STR3## General formula (IV) ##STR4##

Abstract: Disclosed is a lithographic printing plate material which comprises a support and at least an undercoat layer, a silver halide emulsion layer and a catalytic layer containing physical development nuclei provided in this order on said support and which utilizes silver complex diffusion transfer process, wherein content of calcium ion in at least one of lime treated gelatin-containing layers is 1000 ppm or less.

Abstract: Disclosed is an additive for lithographic printing ink improved in flow, drying and interfacial properties. This additive contains a compound having an alkylene oxide unit and of a HLB value of 3 to 13. Further improvement can be attained by the use of additive which contains a combination of at least one compound having an alkylene oxide unit and a hydrocarbon radical of 1 to 8 carbon atoms and at least one compound having an alkylene oxide unit and a hydrocarbon radical of 9 or more carbon atoms, the average HLB value of said combination being 3 to 13.

Abstract: There is disclosed a method for exposing in two steps a photosensitive material to an original of a continuous tone image mingled with a line image through a lens of a process camera of the daylight type, which comprises feeding said photosensitive material to an exposure unit disposed in nearly vertical position in said camera and provided with a suction mechanism, and setting the sensitive material in place; (A) in case of the first step exposure being made to an original of a continuous tone image, (a) moving a contact screen from a position in front of the photosensitive material to establish a close contact with the photosensitive material and exposing the sensitive material imagewise to the continuous tone image, subsequently (b-1) moving the contact screen by the internal shift to the position in front of the sensitive material so that it is out of the exposure region while the sensitive material being remained as such, or (b-2) moving the contact screen internally to a position in front of the sensiti

Abstract: Disclosed is a method for plate-making which comprises imagewise exposing by scanning type flash exposure a lithographic printing plate comprising a support and at least a silver halide emulsion layer containing at least 70 mol % of silver chloride and prepared with addition of a water soluble iridium compound during emulsification or physical ripening of silver halide and a water soluble gold compound at any time before coating of the emulsion and thereafter subjecting the exposed emulsion to diffusion transfer development.

Abstract: A process camera apparatus for forming a halftone image and a line image on a photosensitive material such as a positive or negative film. The apparatus comprises a base; a transparent platen provided on the base; a light-shielding cover covering the upper side of the transparent platen such as to form a light-shielded region on the transparent platen; a screen device including a contact screen and a screen frame for supporting the contact screen, the screen device being withdrawably disposed on the portion of the transparent platen within the light-shielded region; a pair of rollers disposed adjacent one end of the base and adapted for conveying the photosensitive material into the light-shielded region; and a light-shielded condition maintaining device adapted to maintain the light-shielded condition in the light-shielded region when the screen device is being taken out from the light-shielded region.

Abstract: Disclosed is a method for the direct making of printing plates for multicolor lithography capable of faithfully reproducing repeatedly continuous gradation multicolor original, which comprises using color separation filters for at least blue, green, and, red and repeating a sequence of the steps of shielding an exposure section against light by a light shielding means; feeding to said exposure section a magazine containing a sensitive material convertible into lithographic printing plate, which material bears a panchromatically sensitized photographic layer; bringing said sensitive material into close contact with a contact screen; exposing said sensitive material through a lens and a color separation filter to the reflected light from a continuous gradation multicolor original; and sending the exposed sensitive material to a processing bath section.

Abstract: Use of an ink composition containing an organopolysiloxane having at least one hydrophilic group can bring about such a lithographic printing using a dampening solution as the non-image area is hardly stained, the image area is given a sufficient density, emulsification hardly occurs and tolerance for change of printing conditions is high.

Abstract: Disclosed is a photosensitive element for the production of lithographic printing plates improved in printing endurance comprising a support, a physical development nuclei layer, and at least one gelatin-containing layer including a silver halide emulsion layer disposed under said nuclei layer, which is adapted to the silver complex diffusion transfer process to utilize the transferred silver image on said nuclei layer as ink-receptive areas, all of the gelatin-containing layers having a pH value below the isoelectric point of the gelatin used in each layer. Further improvement can be attained by using a photographic gelatin and a low molecular weight gelatin in at least one of said gelatin-containing layers.

Abstract: Disclosed is a process for making a lithographic printing plate by utilizing the silver complex diffusion transfer process and using a neon-helium laser or an LED which comprises imagewise exposing to the radiation a photosensitive element including an emulsion layer which is spectrally sensitized with an anion- or betaine-type meso-substituted trimethine cyanine dye having at least one .beta.-naphthothiazole nucleus and developing the element by the silver complex diffusion transfer process.

Abstract: A lithographic printing plate with a markedly improved printing endurance is obtained by the silver complex diffusion transfer process when the diffusion transfer development treatment is carried out in the presence of at least one thione compound having a non-enolizable thione group, an adjacent nitrogen atom with an attached substituent R and represented by >N-R, and a group of atoms selected from carbon, nitrogen, oxygen and sulfur atoms which may carry the substituent R, said group of atoms being necessary for forming a 5- or 6-membered ring having no aromatic condensed ring, said substituent R having 1 to 3 carbon atoms or no carbon atom.

Abstract: Disclosed are a deletion fluid for offset printing plates which contains an S-triazine compound represented by the following general formula: ##STR1## (wherein R.sub.1 and R.sub.2 represent --SH or --OH and when either one of R.sub.1 or R.sub.2 is --SH, the other may be NHR wherein R is H or --R'---COOH wherein R' is an alkylene group or arylene group) and a method for deletion of undesired portion of images formed on an offset printing plate with said deletion fluid.

Abstract: Surface treatment of lithographic printing plate which utilizes as ink receptive areas a photographically formed image silver per se or image silver halide per se is carried out in the presence of an organic compound having at least one mercapto or thione group and at least one hydrophilic group in the same molecule and an inorganic water-insoluble fine powder having a particle size of 0.1.mu. or less after imagewise exposure of a silver halide emulsion layer and processing thereof to develop an image, whereby ink receptivity, anti-staining property and printing endurance of the plate can be improved.