Abstract: A developer is disclosed for lithographic printing elements. The developer is single phase and contains an aliphatic cyclic carbonate, water, and optional ingredients.

Abstract: Emulsion developers for diazo-sensitized printing plates are disclosed which are characterized by an oil phase containing a partially water-soluble aliphatic cyclic carbonate having the formula: ##STR1## where n is an integar from 0-2, and Z is selected from hydrogen, C.sub.1 -C.sub.3 alkyl, hydroxyl alkyl or chloroalkyl, chlorine, hydroxy or phenyl. The preferred carbonate is propylene carbonate.

Abstract: Photopolymeric polyurethanes are provided which have a polymeric backbone including recurring urethane or urea groups or both and which have unsaturated hydrocarbon groups attached to this backbone. These photopolymers are combined with a solvent and have a selected and controlled molecular weight and viscosity. The photopolymeric polyurethane solutions are especially useful in providing plates that have a layer including a photopolymer, particularly plates for printing or photoresists that have a photopolymeric layer over a layer of light sensitive diazonium composition.

Abstract: A developer is provided for lithographic plates or the like having a layer including a diazonium material, which developer enhances the effectiveness of the photolysis to which the plate had been subjected, with the result that the exposure time needed for the plate is substantially reduced. The developer, which thus enhances the apparent photospeed of the plate, includes an insolubilizing reactant that reacts with diazonium groups of diazonium materials on the plate that were not removed by photolysis during exposure in order to decrease the solubility of the diazonium material.

Abstract: Plates such as those used in lithographic printing and photoresists such as those used in preparing printed circuit boards and the like are provided with a photopolymerizable photosensitive diazo resin that is unusually stable. The diazo resin is laid down from a stabilized diazonium composition that is an emulsion including the selected diazo resin, a purine derivative, especially a theophylline derivative, preferably in combination with a salt of a low molecular weight alkyl sulfonic acid or other supplementary stabilizer component.

Abstract: A liquid developer for developing electrostatic images comprises a dispersion in aliphatic hydrocarbon solvent of particles of imaging material, binder and polymeric carbamate having a linear carbon backbone and carbamate side chains in which the carbamate groups contain at least one alkyl group having at least 5 carbon atoms carried by the nitrogen atom thereof, the binder and the polymeric carbamate are soluble in the hydrocarbon solvent when hot and insoluble in said hydrocarbon solvent at room temperature so as to be present in coprecipitated form in the developer.

Abstract: Finely comminuted particles of a normally solid thermoplastic organic polymer, which is particularly useful as a toner base for electrostatic reproduction utilizing pressure fusing on the toner, is prepared by dissolving a polymer in a normally solid first solvent, cooling the resulting solution to form a friable solid, and removing the first solvent from the solid, preferably by extraction with a normally liquid, relatively volatile, second solvent in which the polymer is substantially insoluble. When using the process to make magnetic mono-component toners, powered magnetic material and/or carbon black or other pigment are added to the solution of polymer and first solvent.