Mitsubishi Paper Mills Limited

Motozo Yamano

Akio Yoshida

Hideaki Baba

Toshiro Kondo

Satoshi Shimonodan

Akira Furukawa

Takashi Miyazaki

Yasuo Tsubai

Eiji Kanada

Hiroyuki Kurokawa

Hidetoshi Miura

Kozo Haino

Jun Urasaki

Hiroshi Nishinoiri

Shigeru Iguchi

Kunihiro Nakagawa

Kazuhisa Nakao

Kazunaka Endo

Makiko Oko

Tetsunobu Murakata

Etsuji Tanaka

There is disclosed a process for making a lithographic printing plate, which comprises subjecting a lithographic printing material having at least a silver halide emulsion layer and a physical development nuclei layer on a support and having a sensitivity at a wavelength of 400 nm to 440 nm of 20 &mgr;J/cm or less, and having substantially no sensitivity at a wavelength of 450 nm or longer to scanning exposure by a scanning type exposure device on which a violet laser diode is mounted, and then subjecting to developing treatment.

Process for making lithographic printing plate

There is disclosed an aluminum lithographic printing plate material which comprises an aluminum substrate, a silver halide emulsion layer and a physical development nuclei layer between the aluminum substrate and the silver halide emulsion layer, said silver halide emulsion layer contains photographic gelatin and gelatin having a weight average molecular weight of about 50,000 or less is contained in said silver halide emulsion layer and/or under said layer.

Lithographic printing plate material

Disclosed is a method for making a lithographic printing plate from a photographic element according to the silver complex diffusion transfer process employing a coating development process with a small amount of developer, wherein the coating amount of the developer is 60 ml or less per 1 m.sup.2 of the photographic element and the developer contains a mercaptooxadiazole having an alkyl group of 4 or more carbon atoms or aryl group and an alkanolamine and/or a meso-ionic compound. The resulting lithographic printing plate has a high printing endurance and free from stains on the background in spite of carrying out the development by a coating method with a small amount of the developer for a short period of time.

Method for making lithographic printing plate

Disclosed is a lithographic printing plate having a silver halide emulsion layer and a layer containing physical development nuclei on a support, the improvement wherein a water-soluble polymer having a structural unit represented by the formula (I): ##STR1## wherein R.sup.1 represents H or alkyl; Q represents divalent linking group; R.sup.2 represents divalent linking group or direct bond; and A represents a functional group represented by the formula: --S--C(.dbd.N--R.sup.4)--NH--R.sup.3, --Z--X(.dbd.Y)--(R.sup.5).sub.m or --W--(SH).sub.n where respective substituents are defined in the specification is contained in the layer containing physical development nuclei.

Lithographic printing plate

Disclosed is a lithographic printing plate excellent in scratch resistance, stain resistance, print image quality and ink-removability. The lithographic printing plate comprises a support and, coated thereon in succession, at least one undercoat layer, a silver halide emulsion layer and a physical development nuclei layer, characterized in that the lithographic printing plate has an arithmetical mean deviation of the profile Ra of 0.6 or less and the layers on the silver halide emulsion layer-provided side of the support contain 2.0 g/m.sup.2 or more of a matting agent.

Disclosed is a lithographic printing plate material comprising a support and, provided thereon, at least a silver halide emulsion layer and a physical development nuclei layer wherein the physical development nuclei layer and/or a layer contiguous thereto contains at least one of water-soluble polymers represented by the following formula (I) or at least one of water-soluble polymers represented by the following formula (II): ##STR1## wherein R.sub.1 represents H or an alkyl group, R.sub.2 represents H or an alkali metal atom, n is 1-100 mol %, m is 0-50 mol % and l is 0-5 mol %, ##STR2## wherein R.sub.3 and R.sub.4 each represent a hydrogen atom or a lower alkyl group and A represents a residue of an ethylenically unsaturated monomer, l is 99.9-40 mol %, m is 0.1-10 mol % and n is 0-50 mol %. The polymer of the formula (I) may be used in combination with a water-soluble polysaccharide.

Disclosed is a light-sensitive element for lithographic printing plates excellent in stain resistance and water-carrying capacity which comprises a support and, coated thereon in succession, at least one undercoat layer, a silver halide emulsion layer and a physical development nuclei layer wherein at least one of the layers on the silver halide emulsion layer-provided side of the support contains 0.1-2.0 g/m.sup.2 of a matting agent of 5.mu. in average particle size and the light-sensitive element has an arithmetical mean deviation of profile Ra of 1.2 or less.

Lithography printing plate

The present invention provides a lithographic printing plate material utilizing silver complex diffusion transfer process which can provide a lithographic printing plate markedly improved in water retentivity and prevented from deterioration of printability after storage. The lithographic printing plate material comprises a support and at least a silver halide emulsion layer and a physical development nuclei layer, wherein at least one of the physical development nuclei layer and a layer contiguous to the nuclei layer contains at least one water-soluble synthetic polymer selected from those which are represented by the following formulas: ##STR1## wherein R.sub.1 represents H or an alkyl group and n represents 100-3500 and ##STR2## wherein R.sub.2 represents H or an alkyl group, R.sub.3 represents H or an alkali metal, the ratio of n:m is 10:0-1:9, and polymerization degree is 100-3500.

Lithographic printing plate with polyacrylamide polymer in physical

Printing endurance of a lithographic printing plate made by using silver complex diffusion transfer process is markedly improved and besides staining which occurs during printing can be effectively inhibited by containing in at least one of a layer which contains nuclei for physical development comprising a heavy metal of a sulfide thereof and a layer contiguous to said layer at least one water-soluble synthetic polymer having the following structural units: ##STR1## wherein A:B=100:0-50:50 (molar ratio)

Lithographic printing plate material improved in water retention

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.

Growing community of inventors

Tokyo, Japan

Motozo Yamano