Abstract: A plate-making system, in which a light-sensitive lithographic printing plate carrying an interleaf paper superimposed thereon and/or an original plate for making a dummy plate carrying an interleaf paper superimposed thereon are processed in a plate-setter provided with an automatic interleaf paper-removing mechanism and an automatic developing machine, is characterized in that it comprises a means for detecting the presence of any interleaf paper on the lithographic printing plate and/or the original plate or a means for discriminating the interleaf paper, the light-sensitive lithographic printing plate and the original plate.

Abstract: A photopolymerizable composition contains: (A) addition polymerizable compound having an ethylenically unsaturated double bond; (B) one of an alkali-soluble binder and an alkali swelling binder, (C) a titanocene compound, and (D) a triazine compound represented by the following formula (I): wherein Q1 and Q2 each independently represents a halomethyl group; X represents an electron withdrawing substituent having a Hammett's ? value of from 0 to +0.8, exclusive of a COOH group; and n represents an integer of from 0 to 5.

Abstract: A method for producing a lithographic printing plate is disclosed, comprising performing the plate-making by scan exposing a lithographic printing original plate comprising a hydrophilic support having thereon a photosensitive layer containing i) at least one polyurethane resin binder, ii) at least one compound having an addition polymerizable ethylenically unsaturated bond, and iii) at least one photopolymerization initiation system. Also disclosed are a photosensitive composition for use in the photosensitive layer of the lithographic printing original plate.

Abstract: A plate-making system, in which a light-sensitive lithographic printing plate carrying an interleaf paper superimposed thereon and/or an original plate for making a dummy plate carrying an interleaf paper superimposed thereon are processed in a plate-setter provided with an automatic interleaf paper-removing mechanism and an automatic developing machine, is characterized in that it comprises a means for detecting the presence of any interleaf paper on the lithographic printing plate and/or the original plate or a means for discriminating the interleaf paper, the light-sensitive lithographic printing plate and the original plate.

Abstract: A method for preparing a lithographic printing plate involving the steps of subjecting, to imagewise exposure, a presensitized plate for use in making a lithographic printing plate comprising an aluminum substrate provided thereon with a light-sensitive layer formed from a photopolymerizable light-sensitive composition, which comprises a compound having an ethylenically unsaturated double bond, a photopolymerization initiator and a polyurethane resin binder and then developing the imagewise exposed plate with a developer containing an inorganic alkaline agent and a nonionic surfactant, carrying a polyoxyalkylene ether group, having a pH value ranging from 10.0 to 12.5 and an electrical conductivity ranging from 3 to 30 mS/cm.

Abstract: The present invention relates to a photopolymerizable presensitized plate used for preparing a lithographic printing plate comprising an aluminum substrate provided thereon with at least a photopolymerizable light-sensitive layer, the lithographic printing plate is characterized in that the edges of the opposed two sides or four sides are curved from the light-sensitive layer towards the back face, wherein a drop observed in the curved portion at the section has a height ranging from 30 to 200 &mgr;m and wherein the area of notched portion on the curved portion ranges from 200 to 100,000 &mgr;m2. The lithographic printing plate prepared from the presensitized plate permits the solution of the problem such that the surface area of paper corresponding to the edges of the printing plate is stained and the achievement of excellent setter-conveying characteristics.

Abstract: [Object]

Abstract: A lithographic printing plate precursor is disclosed, comprising an aluminum support having thereon a photopolymerizable photosensitive layer which contains (1) an alkali-soluble urethane binder having at least one ethylenically unsaturated polymerizable group on the side chain thereof, (2) an addition polymerizable compound having an ethylenically unsaturated double bond, and (3) a photopolymerization initiator.

Abstract: A photosensitive composition comprising: a titanocene compound; and at least one dye selected from: carbonyl compounds represented by formula (I): wherein Y represents a nonmetallic atom group for forming a nitrogen-containing heterocyclic ring together with the adjacent N and carbon atom, and X represents a monovalent nonmetallic atom group; and merocyanine compounds represented by formula (II): wherein A represents S atom or NR1, R1 represents an alkyl group or an aryl group, Y represents a nonmetallic atom group for forming a basic nucleus of the dye together with the adjacent A and carbon atom, X1 and X2 each independently represents a monovalent nonmetallic atom group, and X1 and X2 may be combined with each other to form the acidic nucleus of a dye. Also disclosed is a method for manufacturing a lithographic printing plate using the photosensitive composition.

Abstract: A compact liquid discharge regulator is provided at low cost by arranging a channel spirally formed in the surface of a passage forming member. The surface of the passage forming member is brought into close contact with the inner surface of a housing part, and the channel functions as a liquid passage. In this construction, the sectional form and length of the channel can be formed at high precision in accordance with the design. Therefore, a desired pipe loss is obtainable only by designing in advance the sectional form and length of the channel so as to correspond to the pipe loss. Particularly, with injection molding, mass production of a passage forming member of identical pipe loss can be effected merely by preparing a mold corresponding to the pipe loss, thus leading to a considerable reduction in the manufacturing cost of the discharge regulator.

Abstract: A compact liquid discharge regulator is provided at low cost by arranging a channel spirally formed in the surf ace of a passage forming member. The surface of the passage forming member is brought into close contact with the inner surface of a housing part, and the channel functions as a liquid passage. In this construction, the sectional form and length of the channel can be formed at high precision in accordance with the design. Therefore, a desired pipe loss is obtainable only by designing in advance the sectional form and length of the channel so as to correspond to the pipe loss. Particularly, with injection molding, mass production of a passage forming member of identical pipe loss can be effected merely by preparing a mold corresponding to the pipe loss, thus leading to a considerable reduction in the manufacturing cost of the discharge regulator.

Abstract: A photopolymerizable composition which comprises a compound having one or more addition-polymerizable ethylenically unsaturated bonds and a specific oxime ether compound. The photopolymerizable composition has high sensitivity to actinic rays in a wide region, ranging from ultraviolet to visible light, and gives a photosensitive material which has improved film strength in exposed areas.

Abstract: A photosensitive lithographic printing plate comprising a substrate having provided on the surface thereof a photosensitive layer through a layer which is formed by coating and drying a composition prepared by hydrolyzing and polycondensing a compound represented by formula (I) in a solvent having dissolved therein a phenol having a molecular weight of 1,000 or less or an organic phosphoric acid compound:A.sub.m M(R).sub.n (I)wherein M represents silicon, aluminum, titanium or zirconium, A represents a hydrogen atom, an alkyl group, an aryl group, an alkenyl group, a propargyl group, an alkoxy group, an epoxyalkyl group, a silyl group, a siloxy group or a functional group capable of addition reaction by a radical, m and n each represents 0 or a positive integer, provided that m+n=3 or 4, and R represents one of the groups (a) to (e) defined in the specification.

Abstract: A presensitized plate for use in making a lithographic printing plate requiring no fountain solution excellent in scratch resistance and press life is disclosed, which comprises support and, formed thereon in order from support, a photosensitive layer and a silicone rubber layer, wherein the silicone rubber layer is a crosslinked and cured product obtained by addition reaction of (a) polysiloxane having alkenyl groups with (b) hydrogen polysiloxane having .tbd.Si--H groups so that the number of .tbd.Si--H groups in (b) is from 11 to 30 based on the number of alkenyl groups in (a), wherein polysiloxane (a) has at least two alkenyl groups directly bonded to silicon atoms per molecule, average repeating number x of --[Si(R.sup.1)(R.sup.2)--O].sub.x -- group of 100 .ltoreq.x.ltoreq.600 (wherein R.sup.1 and R.sup.2 each represents a alkyl group, aryl group, aralkyl group, alkenyl group, polydimethylsiloxane group or halogenated hydrocarbon group, provided that 70% or more of R.sup.1 and R.sup.

Abstract: A PS plate requiring no dampening water comprises a substrate provided thereon with, in order, a light-sensitive resin layer and a silicone rubber layer, wherein the light-sensitive resin layer is formed from a light-sensitive composition which comprises the following components:(i) at least one monomer represented by the following general formula (I): ##STR1## (wherein R.sup.1 represents, for instance, H or a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms; a to f each independently represents an integer; R.sup.2 and R.sup.3 each independently represents H or a methyl group); (ii) a photopolymerization initiator; and (iii) a polymeric compound having film-forming ability. The hardening properties of the silicone rubber layer is greatly improved and thus there can be obtained a PS plate exhibiting high sensitivity and hence lithographic printing plates having good printing durability.

Abstract: A photopolymerizable composition comprising: (a) a compound obtained by reacting one mole of a polyamine represented by the following general formula (I) with at least 2 moles of a compound having a group capable of reacting with the polyamine and a polymerizable ethylenically unsaturated group: ##STR1## wherein n is an integer of not less than 1 and (b) a photopolymerization initiator.A dry PS plate comprises a substrate provided thereon with, in order, a light-sensitive resin layer and a silicone rubber layer wherein the light-sensitive resin layer comprises the photopolymerizable composition and a polymeric compound having film-forming ability.The photopolymerizable composition and the dry PS plate have very high sensitivity.

Abstract: A dry PS plate having a substrate provided thereon with a photopolymerizable light-sensitive layer and a silicone rubber layer in that order. The silicone rubber layer comprises a product obtained by crosslinking through addition reaction the following components:(a) an alkenylpolysiloxane having at least two alkenyl groups directly bonded to the silicon atoms in each molecule thereof; and(b) a hydrogen polysiloxane of the following general formula I: ##STR1## wherein R.sup.1 and R.sup.2 independently represent a hydrogen atom or methyl group, R.sup.3 and R.sup.4 independently represent a methyl, vinyl or phenyl group, m+n is 5 to 30 and m:n is 3:1 to 1:3. The dry PS plate provides a lithographic printing plate exhibiting excellent tone reproducibility and printing durability as well as not being subject to background contamination.

Abstract: The present invention relates to a presensitized plate for use in making a lithographic plate requiring no dampening water and comprising, on a support, a light-sensitive resin layer and a silicone rubber layer, in this order, wherein the silicone rubber layer is crosslinked by addition reaction of an .fwdarw.SiH group with a --CH.dbd.CH-- group and wherein the light-sensitive resin layer comprises: (1) a monomer or oligomer having at least one photopolymerizable or photo-crosslinkable and olefinically unsaturated double bond, (2) an organic solvent-soluble polyurethane resin having a glass transition temperature of 20.degree. C. or below and being capable of forming a film, and (3) a photopolymerization initiator. According to the present invention, the PS plate has excellent image-forming properties and printing properties.

Abstract: A light-sensitive composition which comprises, (a) an ethylenically unsaturated addition polymerizable compound, (b) an alkaline water-soluble or swellable, and film-forming polymer, (c) a photopolymerization initiator, (d) a negative working diazo resin, and (e) at least one compound selected from the group consisting of a higher fatty acid and a higher fatty acid amide which are solid at ordinary temperatures.The light-sensitive composition is hardly influenced by oxygen and is suitable for a presensitized plate from which a printing plate is to be prepared.

Abstract: A presensitized plate for use in making a lithographic printing plate requiring no dampening water comprises a substrate provided thereon with in order: (1) a photopolymerizable light-sensitive layer which comprises a monomer or an oligomer having at least one photopolymerizable olefinically unsaturated double bond, an organic solvent-soluble polyurethane resin or polyamide resin which is solid at room temperature and has film-forming ability and a photopolymerization initiator; (2) a crosslinked silicone rubber layer; and (3) a transparent cover coat layer, wherein the photopolymerization initiator comprises dialkylaminoarylcarbonyl compounds and at least one member selected from the group consisting of xanthones, thioxanthones, acrydones, benzophenones which do not carry a dialkylamino group, benzanthrones and anthraquinones and the transparent cover coat layer is formed from a biaxially oriented polypropylene film having a thickness ranging from 6 to 22 .mu.