Abstract: A process for manufacturing a planographic printing plate using a photosensitive planographic printing plate comprising a conductive support and provided thereon, a photoconductive layer containing an alkali soluble resin, a photoconductor and a photosolubilizable photosensitive compound comprises the steps of forming an electrophotographic latent image on the photoconductive layer, developing the latent image with liquid developer to form a toner image layer, uniformly exposing overall to actinic light the entire photoconductive layer, and removing the photoconductive layer where no toner image layer has been formed, the transmission density of the toner image layer to the actinic light being not less than 0.6, and the transmission density per unit thickness of the toner image layer to the actinic light being not less than 0.03 dm.sup.2 /g.

Abstract: A light-sensitive coating liquid, comprising, as an organic solvent, at least one substance represented by the formulae (I) to (III) shown below: ##STR1## wherein R.sub.1 represents an alkyl group having 1 to 4 carbon atoms, R.sub.2 to R.sub.7 each represent hydrogen atom or an alkyl group having 1 to 3 carbon atoms, with the proviso that at least one of R.sub.2 to R.sub.7 is an alkyl group. The light-sensitive coating liquid of this invention is improved in odor, low in toxicity and yet excellent in storability, and is also suitable for preparation of a light-sensitive lithographic printing plate improved in press life and dye remaining.

Abstract: The invention provides an apparatus for conveying a pile of photosensitive printing plates in which a support is covered thereon with photosensitive resin. The apparatus comprises a base plate and a pair of end plates for holding the pile of photosensitive printing plates therebetween. The pair of end plates is vertically mounted on the base plate so that the pile of photosensitive printing plates is vertically held between the pair of end plates on the base plate.

Abstract: There are disclosed a photosensitive composition which comprises:(1) an o-naphtoquinonediazide compound;(2) an alkali soluble resin; and(3) any one selected from the groups consisting of:(a) an ester compound of a polyoxyalkylene sorbitol fatty acid and/or an ether compound of the fatty acid,(b) an alkylene oxide adduct of castor oil, hardened castor oil, lanolin alcohol, beeswax, phytosterol or phytostanol, and(c) at least one activator selected from the group consisting of polyoxypropylene alkyl ethers, polyoxypropylene alkylphenyl ethers and polyoxypropylene alkyl esters;.and a photosensitive lithographic printing plate which comprises a support; and a photosensitive layer formed by applying the above photosensitive composition.

Abstract: Disclosed is a light-sensitive litho printing plate comprising:a support, a light-sensitive layer and a silicone rubber layer provided thereon,wherein said light-sensitive layer contains a substance,whereby said substance forms a color during developing or after developing.

Abstract: A photosensitive composition comprising (a) a 1,2-naphthoquinone-2-diazido-4-sulfonic acid ester compound, (b) alkali-soluble resin, (c) a halomethyloxadiazole compound which releases halogen free radicals by irradiation with actinic rays and (a) a dye which interacts withthe decomposition product of said halomethyloxydiazole compound and discolors or develops color. The composition exhibits excellent development latitude, light safety, visible-on-exposure characteristic and printing resistance.

Abstract: A positive photosensitive planographic printing plate is disclosed which has a photosensitive layer comprising in combination a specific o-naphthoquinonediazidosulfonic ester and a resin having a specific structural unit(s). Said photosensitive layer may also contain a novolak resin and/or an organic acid.

Abstract: Disclosed is a light-sensitive lithographic printing plate which comprises an aluminum or aluminum alloy support having been pretreated and a light-sensitive layer provided thereon, wherein the surface of the support adjacent to the light-sensitive layer is treated by use of an aqueous solution containing at least one selected from the group consisting of nitric acid, nitrate, nitrous acid and nitrite. According to this invention, lithographic printing plates which are free from stain due to residual light-sensitive layer, excellent in developability, good in water retention at image area and excellent in press life, can be obtained.

Abstract: A photosensitive composition principally comprised of a photosensitive diazo resin and a lipophilic high molecular compound, wherein said photosensitive composition further contains a metal complex dye soluble in an organic solvent. Also disclosed is a photosensitive lithographic printing plate employing such a photosensitive composition.

Abstract: Light sensitive compositions are disclosed which comprise 2-halomethyl-1,3,4,-oxadiazole compounds having a heterocyclic radical in the fifth position containing at least one element selected from the group consisting of oxygen, nitrogen, sulphur, and selenium directly or through a vinyl radical.

Abstract: A photosensitive composition of this invention comprises:(a) a photosensitive diazo resin represented by the following general formula (I): ##STR1## wherein R.sup.1, R.sup.2 and R.sup.3 each represents a hydrogen atom, an alkyl or alkoxy group, R represents a hydrogen atom, an alkyl or phenyl group, X represents PF.sub.6 or BF.sub.4 and n represents a number of 1 to 200, in which a resin with the number n in the above formula being 5 or more is contained by more than 20 mol %,(b) an oleophilic high molecular weight compound with hydroxyl group and(c) a high molecular weight organic acid without hydroxyl group, and in which the content of the ingredient (c) is from 1.5 to 30% by weight based on the solid matter in said composition.The photosensitive composition of this invention can provide a photosensitive layer having high sensitivity and being excellent in storage stability and developability as well as excellent in the film strength.

Abstract: The invention provides a light-sensitive lithographic printing plate containing a light-sensitive composition which has a different degree of solubility in an exposed area of said printing plate than in an unexposed area of said printing plate when said printing plate is developed in a developing solution. This printing plate is produced by a process which comprises coating on a support a solution prepared by dissolving a light-sensitive composition containing a light-sensitive material and at least one fluorinated surfactant having Formula (I) in a quantity of between 0.005% by weight and 0.05% by weight based on the weight of said composition, in at least one solvent having (A) a solubility parameter of at least 8(cal/cm.sup.3)1/2, and (B) a boiling point within the range of from 100.degree. to 200.degree. C. Said Formula (I) is Rf-A-Y, wherein Rf is a partially or completely fluorinated hydrophobic alkyl moiety, A is a single bind or bivalent moiety and Y is a hydrophilic moiety.

Abstract: There is disclosed a photosensitive composition comprising an o-quinonediazide compound and, as a binder resin, a resin containing in the molecule the unit represented by the following formula ##STR1## wherein R.sub.1, R.sub.2, R.sub.3 and R.sub.4 have the same meanings as defined in the specification.The photosensitive composition according to the present invention has excellent resistance to chemicals and long press-life, and is excellent in alkali-solubility and difficult to form scumming.

Abstract: A developer composition of an alkaline aqueous solution containing a reducing inorganic salt, typically an alkali metal salt of sulfurous acid such as sodium sulfite, is found to be applicable for development of a lithographic printing plate material containing a photosensitive o-quinonediazide compound and an organic polymer, with reduced deterioration in developing capacity caused by the air and enhanced stability with lapse of time. In particular, a developer composition composed of an alkaline aqueous solution of pH 11 or higher containing a water-soluble sulfurous acid salt is effective for developing both of a lithographic printing plate material having a nega-type photosensitive layer containing a photosensitive diazo compound and an organic polymer, and a lithographic printing plate material having a posi-type photosensitive layer containing an o-quinonediazide compound and an organic polymer.

Abstract: A photosensitive composition containing an o-naphthoquinonediazido compound of Formula I ##STR1## wherein X is an oxy or amino group, Y is a cyano or nitro group, and n is an integer of 2 to 5, and an organic dye capable of changing its color when the photosensitive composition is exposed.

Abstract: A photosensitive composition for making lithographic printing plate and for use as a photoresist material which comprises a photosensitive o-quinone diazide compound, an alkali-soluble resin, and 0.5 to 20% by weight 6-membered cyclic acid anhydride.

Abstract: Two rectifiers and two inverters are operated under the state under which they are connected in parallel by common transmission lines. These rectifiers and inverters are controlled an independent control apparatus respectively which can selectively apply either the constant current control or the constant voltage control.The control apparatus of each converter has bestowed thereon the reference value of a current to flow through the particular converter and the reference value of a terminal voltage of the particular converter. A signal for lowering the current reference value is added to the control apparatus of one or all of the converters which are to be operated as the inverters. On the other hand, a signal for essentially rendering the terminal voltage of the converter smaller than the voltage reference value is added to the control apparatus of the converter which is to be operated as the converter for determining the voltage of a direct current system.

Abstract: Control units are provided associative with forward and inverse converters in a multiterminal DC power transmission system, respectively. The control units set different constant voltages in the converters. Further, the minimum value of the constant voltage set values in the forward converters is set at a value larger than the maximum value of the constant voltage set values in the inverse converters.

Abstract: A process for the preparation of an esterified resin for ultraviolet light curable coating compositions which comprises reacting an ethylenically unsaturated five-membered cyclic compound, such as cyclopentadiene, with a compound having both at least a double bond and hydroxyl group in the molecule, such as allyl alcohol, to obtain a hydroxyl group-containing resin which is then esterified with a carboxyl group-containing benzophenone derivative and, if desired, further esterified with an unsaturated carboxylic acid thereby to obtain the esterified resin. This invention also relates to the esterified resin so obtained and ultraviolet light curable coating compositions containing the same.

Abstract: A process for preparing a curable coating resin comprising the steps of hydrogenating selectively the double bonds of a resin produced from a five-membered cyclic compound such as dicyclopentadiene and an unsaturated hydroxyl group-containing compound such as allyl alcohol and then esterifying the thus hydrogenated hydroxyl group-containing resin with acrylic and/or methacrylic acid thereby to obtain a curable coating resin; and a curable coating resin obtained by said process.