Mitsubishi Paper Mills Limited

Dainippon Screen Mfg. Co., Ltd.

Shin-etsu Chemical Ltd.

Eiji Kanada

Toshiro Kondo

Masahiko Saikawa

Shoji Yamada

Kazunaka Endo

Yasuo Tsubai

Yoshikazu Takaya

Kyonosuke Yamamoto

Akira Tanaka

Shigeyoshi Suzuki

Hiroshi Nishinoiri

Kazuyoshi Yamamoto

Kenichi Isobe

Hidetoshi Miura

Takao Senga

Kozo Haino

Eiji Miyasaka

Jun Urasaki

Motozo Yamano

Shoichi Horii

Mamoru Nakatani

Iwao Hirose

Hiroshi Ikeda

Yoshikazu Takano

Tamotsu Iwata

Kenji Kawai

Koji Yamashita

Kyonosuke Yammamoto

Toshiyuki Morito

Noboru Itoh

Eiji Mathubara

Satoshi Katano

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.

Method for processing photosensitive material and apparatus therefor

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.

Panchromatic silver halide photographic element

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.

Method for preventing penetration of damping solution between supporting

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.

Deleting fluid for printing plates and method for deletion

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.

Lithographic printing plate with benzotriazoles improved in printing

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%.

Method for making lithographic printing plate using light wavelengths

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.

Lithographic printing plate materials with light insensitive silver

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):

Light sensitive materials for lithographic printing plates

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.

Lithographic printing plate excellent in printing endurance

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.

Lithographic ink additives

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 sensitive material and then shielding the latter against light in such a manner that the sensitive material can be released of the shield at the time of the second step exposure, the contact screen being absent at least in the exposure region at the time of second step exposure and subsequently (c) exposing the sensitive material to the line image (second step exposure), or (B) in case of the first step exposure being made to the line image, (a') exposing the sensitive material to the line image in the first step, then (b'-1) moving the contact screen, which is in front of the sensitive material and kept outside the exposure region, to establish close contact with the sensitive material while the sensitive material being remained as such, or (b'-2) shielding the sensitive material against light in such a manner that the sensitive material can be released of the shield at the time of bringing the contact screen into close contact with the sensitive material and moving the contact screen from a position in front of the sensitive material to establish a close contact with the photosensitive, and subsequently (c') exposing the sensitive material to the continuous tone image (second step exposure).

Method of exposing photosensitive material

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.

Lithographic printing plate

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. The apparatus may be provided with a guide plate for guiding the photosensitive material while the same is being fed onto the transparent platen by the pair of rollers.

Process camera apparatus

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.

Method for direct plate making from multicolor original

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.

Growing community of inventors

Nagaokakyo, Japan

Eiji Kanada