An apparatus for developing diazo material according to a semi-dry process comprising an applicator roll with a liquid absorbing cover, a press roll having a grooved hard surface, a backing roll biased against the press roll, and a blade for reducing the amount of developer liquid on the applicator roll and the press roll. The press roll is displaceable toward the applicator roll. The plane of transport of the diazo material to be developed passes between the applicator roll and the press roll. ...

The invention is an improvement in an apparatus for developing sheets of diazotype copying material by the semi-dry process and includes at least two rotatable rolls being biased together with a gap between them for passage of the sheets of diazotype material, with an additional force being exerted on at least one of the rolls which force transfers a plane of deflection of one of the rolls to a position outside of a principal plane in which axes of the rolls are located in such a manner that a f...

Diazotype copies are produced from one-component diazotype material in a practically dry state without adversely affecting their feel or the speed of development. The diazotype material comprises a support and a light-sensitive surface layer having an average maximum thickness of not more than 8 micrometers and comprising 0.2-2 milligram molecules of one or more diazo compounds, which, in vitro, couple more actively than 4-diazo-2-chloro-N.N.-diethylaniline. After imagewise exposure the copy is ...

Light sensitive diazonium hexafluoroarsenate and hexafluoroantimonate salts which are employed in the preparation of diazo formulations for the sensitization of base materials.

Diazotype material includes a light-sensitive diazonium compound of the general formula ##SPC1## Wherein: R.sub.1 and R.sub.2 are substituted or unsubstituted alkyl, aralkyl, or cycloalkyl groups, or form, with the nitrogen atom, a heterocyclic radical, which may be substituted; R.sub.3 is hydrogen or the group OR.sub.6 ; R.sub.4 and R.sub.5 are hydrogen, halogen, alkyl, or OR.sub.6 groups; R.sub.6 is alkyl; or fluorinated alkyl, alkenyl, cycloalkyl, or cycloalkenyl; and X is the anion of the di...

Written, typed, penciled, printed and other markings on paper and foils can be erased easily by mechanical means by utilizing an improved interlayer between the surface of the base material and the markings. The interlayer includes a copolymer resin of acrylate-vinyl chloride. The provision of such an interlayer is particularly useful for diazotype intermediate prints.

There is disclosed herein a method of making a light-sensitive diazotype film adapted for the development of azo dye images thereon by using an alkaline liquid developer. The method of making the diazotype film produces a porous surface of the film substrate by coating a sub-layer composition comprising a film-forming cellulose ester, a volatile water miscible organic solvent, and an aqueous solution of an inorganic perchlorate onto the film substrate which is then overcoated with a light-sensit...

A light-sensitive, heat-developable diazotype element comprising a light-sensitive diazonium salt, a solid carbodiimide dehydrating agent, and a solid coupler precursor in the form of an aminocarboxylic acid capable of producing a diazo coupler upon dehydration; and the method of using it to produce a visible dye image wherein the element is exposed to actinic radiation and then heated to the melting point of the dehydrating agent or coupler precursor to activate the dehydrating agent, and gener...

A method for developing a diazo-type photographic light-sensitive material containing at least one light-sensitive diazonium compound (Component A) selected from the compounds represented by the general formula; ##SPC1## Wherein R.sub.1 and R.sub.2 each represents an alkyl group having 1-6 carbon atoms or a cycloalkyl group having 5-6 carbon atoms, and X represents an anion, which comprises developing the light-sensitive material in the presence of: at least one compound selected from the compou...

An improved diazotype photoprinting material of high printing speed and its method of preparation are disclosed. The improvement is achieved by distributing through the film coating a substantially uniform distribution of sites having a refractive index substantially different from that of the remainder of the coating. The sites consist of either voids or finely divided solids. Voids are created by contacting the film coating with an aqueous fluid at elevated temperature or an organic solvent fo...