Abstract: The present invention provides an improvement of the direct lithographic printing plate making process using ink-jet printing, which provides a printing plate having excellent resolution. Accordingly, the present invention provides an improvement of a process for producing a lithographic printing plate comprising selectively forming a light transmittable oxygen barrier film on a photopolymerizable layer of a photosensitive plate, exposing to light and then removing uncured portion on which the oxygen barrier film is not covered, wherein a protective layer which is capable of transmitting oxygen gas and the light to cure the photopolymerizable layer is formed on the photopolymerizable layer, a photosensitive plate therefor and an aqueous ink composition therefor.

Abstract: Disclosed is an alkali developable photosensitive resin composition useful for an offset printing plate, which has excellent developability and provides long life of a developer. The photosensitive resin composition comprising:(a) an alkali-soluble type binder resin,(b) a photosensitive substance, and(c) a dye;said binder resin (a) having an ampho-ionic group represented by the formula: ##STR1## [wherein R.sup.1 is H or a C.sub.1-10 alkyl group which optionally has a substituent or a functional group in a chain, R is a substituted or non-substituted C.sub.1-20 alkylene or phenylene group, and A is --COO or --SO.sub.3 ]and/or an ampho-ionic group represented by the formula: ##STR2## [wherein each R.sup.2 is the same or different and respectively indicates a C.sub.1-10 alkyl group which optionally has a substituent or a functional group in a chain, and R and A are as defined above] in a molecule and containing a resin having total acid value of 5 to 150.

Abstract: Disclosed is a photosensitive composition used for offset printing, which provides an offset printing plate with excellent durability and developability. The photosensitive composition comprises:(I) a film-forming binder resin,(II) a photosensitive substance, and(III) a microgel having a particle size of 0.01 to2.0 .mu. prepared by emulsion polymerization using a polymeric emulsifier having an Sp value of 9 to 16.

Abstract: A photopolymerizable composition comprising(A) an addition-polymerizable compound having an ethylenically unsaturated double bond,(B) a compound of the formula: ##STR1## [wherein R.sup.1 is a substituted or nonsubstituted phenyl group, R.sup.2 and R.sup.3 are the same or different and indicate a hydrogen atom or a C.sub.1-4 alkyl group, R.sup.4 in an alkylene group which may have at least one substituent selected from alkyl, hydroxyl and oxo (.dbd.O) on a main chain, or which may contain at least one member selected from an oxygen atom and a cycloalkylene group in a main chain, R.sup.5 is a hydrogen atom or a methyl group, and a and b are independently 0 or 1],(C) a light absorbing compound, and(D) a film-forming polymer having alkaline solubility or alkaline swelling characteristic is disclosed. There is also disclosed a photosensitive lithographic printing plate comprising the photopolymerizable composition.

Abstract: The present invention provides an improved process by which dissolved oxygen is effectively removed from a photosensitive resin layer of a photosensitive resin plate. The process comprises preliminarily exposing the photosensitive resin to light to quench oxygen dissolved in said photosensitive resin layer before conducting a main exposure. The photosensitive resin layer is prepared from a photosensitive resin composition which comprises:(a) a polymer binder,(b) a radically polymerizable monomer,(c) a sensitizing dye, and(d) a photopolymerization initiator which is excited by a light of a different wave length from a light exciting the sensitizing dye.The preliminary exposure is conducted with a light only exciting the sensitizing dye and the main exposure is conducted with a light exciting the photopolymerization initiator.

Abstract: Disclosed herein is a polyether acrylamide derivative of the following general formula (I): ##STR1## as well as an active energy ray curable resin composition comprising at least one polyether acrylamide derivative of the above general formula (I) and a cured product produced by curing such an active energy curable resin composition with active energy rays.

Abstract: Disclosed is a method for making printing plates which comprises:forming an image on a substrate having an ink absorbing layer for lithographic plates by ink-jet printing using a photopolymerizable ink composition, andexposing it to an active light in the wavelength region with which said ink composition is sensitized to cure the image.

Abstract: Disclosed is a photosensitive resin composition which, can be hot melt molding and and is water-developable. The composition does not need the preliminary exposure process and when cured has suitable hardness and printing properties. The photosensitive resin composition comprises;(A) a water soluble or water dispersible polyvinyl alcohol prepared by saponifying a copolymer obtained by copolymerizing 90 to 99.9 mol % of a vinyl ester and 0.1 to 10 mol % of an ionic group-containing monomer; said polyvinyl alcohol having a saponification degree of the vinyl ester unit of 60 to 75 mol % and a hot melt flow starting temperature of 95.degree. to 170.degree. C.,(B) a polymerizable compound prepared by reacting in the presence of an acid catalyst, (i) N-methylol (meth)acrylamide or N-alkoxymethyl (meth)acrylamide and (ii) a compound selected from the group consisting of monoalcohols, polyhydric alcohols, amides, haloalkylamides, aromatic compounds, ureas and mixtures thereof, and(C) a photopolymerization initiator.

Abstract: A photosensitive resin composition which comprises as an essential component a resin emulsion comprising resin particles, which do not make coalescence to form a continuous film when the resin emulsion is applied on a substrate and dried, obtained by subjecting a polymerizable composition comprising at least one polymerizable vinyl monomer and at least one of a photo-reactive compound and a photo-initiator dissolved therein to emulsion polymerization.

Abstract: A method for producing a lithographic printing plate which comprises, as a support, an iron foil prepared by electroforming and electroplated with a hydrophilic metal on both surfaces, and an oleophilic image on the surface of the iron foil in contact with the electrolyte during the electroforming.

Abstract: A photosensitive plate suitable for preparation of a waterless lithographic printing plate, which comprises a support material and a photosensitive layer provided thereon, said photosensitive layer being made of a photosensitive composition comprising an emulsion polymerization product of an acrylic or methacrylic monomer having a perfluoroalkyl group in the side chain and a water-soluble photosensitive substance resin whose water-solubility is variable by irradiation of ultraviolet rays.

Abstract: A lithographic printing plate which comprises:(a) a support comprising an iron foil prepared by electroforming,wherein one surface of said foil is in contact with an electrolyte and the opposite surface is in contact with a negative electrode,said foil being electroplated with a hydrophilic metal on both surfaces, and(b) an oleophilic image area formed from a photo-sensitive resin on said surface of the hydrophilic metal coated iron foil, which was in contact with said electrolyte and a non-image area where said resin is not present on said surface of said hydrophilic metal coated iron foil which was in contact with said electrolyte,said non-image area exhibiting good hydrophilic and water retentive properties in lithographic printing.

Abstract: A process for preparing photosensitive resin cylinders which-comprises winding a photosensitive resin sheet on and around the surface of a cylinder without any material overlapping of or spaces between the edge portions of the wound resin sheet, and applying to the cylinder under rotation a roll rotating in contact with the surface of the resin sheet while heating so as to join the edge portions of the resin sheet to one another by melting and to make uniform the thickness of the resin sheet.

Abstract: A toner composition for electrostatic photography which comprises (A) toner powder comprising a base resin and a coloring agent and having an average particle size of not more than 30 microns and (B) silica powder coated on its surface with the base resin of the toner powder.

Abstract: Printing plate production apparatus wherein a latent image is formed at the surface of photoconductive insulating sheet, either by an optical system for effecting sheet exposure or by a laser emission scanning system which constitutes the terminal of a facsimile transmission system, this latent image is developed by toner particles, for example, which are applied on, but not fixed on the photoconductive sheet, the developed image is temporarily transferred onto a printing plate with which the photoconductive sheet is brought into pressure contact, and the printing plate carrying the developed image is exposed to light which may effect chemical changes in the printing plate to harden portion thereof unprotected by toner particles after which the printing plate receives treatment to remove toner particles and unhardened portions thereof.