Abstract: A positive-type photosensitive resin composition containing a resin which results from reactions between a specific polyepoxide compound, a carboxylic acid compound having a specific phenolic hydroxyl group, a carboxylic acid compound having no specific phenolic hydroxyl group, and 1,2-quinone diazide sulfonyl halide. The resin composition has high exposure sensitivity, is capable of inhibiting swell or dissolution of unexposed areas during the stage of development, and yet retains other favorable properties. The resin composition has also attained short developing time.

Abstract: The present invention provides an improved method for forming a patterned solder mask having preferred electric insulating property, heat resistance-and chemical resistance on a printed circuit board with high resolution.

Abstract: A positive type photosensitive resinous composition comprising a binder resin and a quinone diazide compound, the binder resin being a copolymer of(a) at least one phosphoric acid ester monomer represented by the formula: ##STR1## (b) at least one acid group containing .alpha.,.beta.-ethylenically unsaturated monomer, and(c) other copolymerizable .alpha.,.beta.-ethylenically unsaturated monomers than (a) and (b), which is specifically useful for the formation of resist coating in the preparation of printed circuit board.

Abstract: A water developable photosensitive resin composition comprising a water soluble polymer, photopolymerizable unsaturated monomer(s) and a photopolymerization initiator, which is characterized in that as the whole or a part of said photopolymerizable unsaturated monomer(s), there is employed a product made by mixing of 1 mole of urea, thiourea or an alkyl derivative thereof and 0.75 to 1.3 moles of an N-alkylol acryl amide or an N-alkylol methacrylamide. The composition is useful for an image formation through a photopolymerization reaction and developable by water treatment to give a soft and rubber like resilient cured product.

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 water developable, photopolymerizable composition and printing plates prepared from such composition are disclosed. The photopolymerizable composition includes at least one water soluble polymer, such as polyvinyl alcohol or partially saponified polyvinyl acetate, at least one photopolymerization initiator, and the condensation reaction product of N-methylol acrylamide, N-methylol methacrylamide, N-alkyloxymethyl acrylamide or N-alkyloxymethyl methacrylamide with a melamine derivative of the following formula: ##STR1## wherein, R.sub.1 is CH.sub.2 OR, R.sub.2 is H or CH.sub.2 OR, and R is C.sub.1 -C.sub.4 alkyl. A thermal polymerization inhibitor may also be included in the composition.Plates prepared from the composition demonstrate improved hardness and water resistance, compared to previously known photopolymerizable compositions, and also achieve excellent image quality.

Abstract: A photosensitive resin composition useful for preparation of flexographic printing plates, which comprises syndiotactic 1,2-polybutadiene, an ethylenically unsaturated monomer and a photo-polymerization initiator, the syndiotactic 1,2-polybutadiene having an average molecular weight of from about 10,000 to 300,000, a 1,2-unit content of at least about 80 percent and a crystallinity of about 10 to 30 percent, said ethylenically unsaturated monomer being an ester of acrylic or methacrylic acid with an alkanol having from 4 to 20 carbon atoms, and the photo-polymerization initiator being benzoin or an alkyl ether thereof. The photosensitive resin composition, when formed into sheets, exhibits satisfactory resistance to liquids used for washing out the uncured areas and at also to aqueous or alcoholic printing inks, thereby producing patterns in relief that give excellent overall sharpness. It also possesses desired hardness and elasticity for flexographic printing plates.

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 photopolymer intaglio printing plate comprising a support member and a photopolymer layer provided thereon, said layer having concave portions of a constant depth as ink cells and the lowermost part of each of the concave portions reaching to the surface of the support member so that the surface of the support member is exposed to air at least as a point at said lowermost part, prepared by subjecting a photosensitive plate comprising the support member and a layer of a photopolymerizable composition provided thereon to exposure through a halftone negative or positive film to such an extent that the photopolymerizable composition at the exposed parts is cured down to the bottom of the photopolymerizable composition layer but the photopolymerizable composition at the non-exposed part having a minimum area remains uncured at the lowermost part corresponding to the center of the said non-exposed part and washing out completely the photopolymerizable composition at the non-exposed parts.

Abstract: A process for formation of a relief image which comprises exposing a layer of a photosensitive composition in liquid provided on the surface of a support material to light through a negative to make cured the photosensitive composition at the exposed part and eliminating the non-cured photosensitive composition at the non-exposed part by suctioning for development, the photosensitive composition comprising as the essential components only (1) at least one addition polymerizable unsaturated monomer having at least one acryloyl or methacryloyl group per each molecule and a molecular weight of not more than about 1000 per each acryloyl or methacryloyl group and (2) at least one photopolymerization initiator.

Abstract: A process for preparing an image plate with continuous gradation having a continuous unevenness which comprises exposing a photosensitive resin plate comprising a supporting material and a layer of a photopolymerizable resin composition being in a solid or liquid state at room temperatures and comprising an addition polymerizable, ethylenically unsaturated compound, a binding agent of polymer and a photopolymerization initiator provided thereon through a film with continuous gradation and subjecting the exposed resin plate to development, characterized in that the exposure is made in such a condition that oxygen or a gas containing oxygen is present between the photopolymerizable resin layer and the film.