Abstract: A heat-sensitive stencil having a thermoplastic resin film, and a porous resin layer formed thereon. The stencil has an air permeability in the range of 1.0 cm.sup.3 /cm.sup.2 .multidot.sec to 157 cm.sup.3 /cm.sup.2 .multidot.sec in a portion thereof when the thermoplastic resin film of the portion is perforated to form perforations providing an open ratio S.sub.O /S.sub.P of at least 0.2, wherein S.sub.O represents a total area of the perforations and S.sub.P represents the area of the portion. The heat-sensitive stencil is prepared by applying a coating liquid containing the resin of the porous resin layer to the thermoplastic resin film and drying the coating. The coating liquid contains a mixture of a good solvent and a poor solvent less vaporizable than the good solvent so that the porous resin layer is formed after drying.

Abstract: The object of the present invention is to provide a novel and useful thermal developing type diazo copying material wherein an initial image quality and an initial image reliability are maintained, while undesired coloring can be avoided and long-term preservation characteristics can be improved. The present invention comprises a support, a photosensitive layer formed on said support, said photosensitive layer including a diazo compound, and a coupler layer formed on said support, said coupler layer including a coupler component, said coupler layer having a copolymer including a monomer having a carboxylic acid and water-soluble guanidine salt.

Abstract: A thermal development diazo copying material is composed of a support, a diazo layer which contains a diazo compound, and a coupler layer which contains a coupling component, an alkali-soluble resin and a thermofusible material, which are overlaid on the support.

Abstract: A thermal development diazo copying material is composed of a support, and a photosensitive layer formed thereon, which includes a diazo compound, a coupler, an alkali-soluble resin, and a sensitizer, with only the coupler being contained in microcapsules made of the alkali-soluble resin.

Abstract: A diazo-type thermosensitive recording material is disclosed, which comprises a support material and a thermosensitive coloring layer formed on the support material, which thermosensitive coloring layer comprises a diazonium compound, a coupler and a thermo-fusible or thermo-softening material, the coupler being a combination of a hydrazone-type coupler of the formula of R.sup.1 --NH--N.dbd.CH--R.sup.2 (wherein R.sup.1 and R.sup.2 are defined in detail in the specification) and a two-valence metal compound capable of chelating with the coupled product produced by the coupling of the diazonium compound and the hydrazone-type coupler.

Abstract: A two-component type diazo copying material according to this invention, which comprises a support and a photosensitive layer formed thereon, said layer consisting essentially of a diazo compound expressed by the following general formula I and a coupler mixture consisting of a compound expressed by the following formula II, a compound expressed by the following general formula III and a compound expressed by the following general formula IV, can form a genuine black-color image and is especially optimum for preparing a secondary original used in electrophotographic copying machines. General formula I ##STR1## (wherein R represents alkyl radical having 1 to 5 carbon atoms; R.sub.1 and R.sub.2 represent substituted or non-substituted alkyl radical, aralkyl radical or cycloalkyl radical, or R.sub.1 and R.sub.2 may form a heterocyclic ring together with the nitrogen atom to which they bond; and X represents anion.) ##STR2## (wherein X is of no account or represents O, S, SO or SO.sub.2.) ##STR3## [wherein R.sub.

Abstract: This invention provides yellow-developing couplers for use in diazo copying materials, which couplers are superior in light fastness and are expressed by the general formula: ##STR1## wherein X and Y represent hydrogen atom, halogen, or alkyl radical or alkoxy radical having 1 to 6 carbon atoms.