Diazotype material having enhanced water-wet properties and especially suitable when imaged for being drawn or written upon, and for use as an intermediate original, is made of a support such as a transparent polymeric film carrying on one of its sides a light sensitive diazo layer formed of a dispersion of a light sensitive diazonium compound and a large amount of amorphous hydrated silica particles having a bound water content of at least 50% by weight in a polymeric binder consisting essentia...

A diazotype material is disclosed containing a novel 2-substituent-3-thio-5-alkoxybenzene diazonium compound of formula I ##SPC1## wherein X is an anion, A is the group ##EQU1## or -- OR.sub.4 in which R.sub.1 is hydrogen, an alkyl radical with 1-8 carbon atoms, a substituted phenyl, cycloalkyl, or aralkyl radical or a heterocyclic radical, R.sub.2 is an alkyl radical with 1-8 carbon atoms, a --COOR.sub.5 group in which R.sub.5 signifies hydrogen, an alkyl radical with 1-8 carbon atoms, a cycloa...

A diazotype material for use in making copies of X-ray films which comprises a support carrying a light-sensitive layer containing at least one diazonium compound, a coupler and a non-light-sensitive ultra-violet absorber, the ultra-violet absorber being effective in screening out radiation in the range of 3,400 to 4,000 A, being transparent to all radiation at or above 4,300 A and being present in an amount such as to give a background absorbance of at least 0.9 at 4,000 A.

Two-component diazotype sheet materials are described which form dense azo dye images and produce only slight bleeding and background coloration. The sheet material is coated with a conventional light-sensitive diazo compound and a coupling component of the formula ##SPC1## Wherein R is lower alkyl or lower hydroxyalkyl, R' is hydrogen or lower alkyl, and X and X' are hydrogen, halogen, lower alkyl, lower alkoxyl, sulfo or nitro.

Modifying the surface of a diazotype material by incorporating an acrylic or methacrylic polymer into the diazotype sensitizing coating composition or coating the assembly with it so as to roughen the surface of the material thereby enabling nitrogen, which is liberated when the material is exposed to light, to escape from between the master and the diazotype material to prevent nitrogen accumulating between the two and hence avoiding slippage of one relative to the other.

This invention relates to an improvement in a diazotype material comprising, in the light-sensitive layer, a diazo component and a coupling component which yields a black dyestuff image, the improvement that the diazo component is a 2,5-dialkoxy-4-morpholino-benzene diazonium salt and the coupling component is a combination of (a) 6-methoxy-2-hydroxy-3-naphthoic acid-N(.omega.-aminoalkyl)-amide as a blue coupler, (b) a 2-alkyl- or 2-aryl-1,3-dihydroxybenzene or a cyanoacetoamide as a yellow coup...

Diazotizable amines of the general formula ##SPC1## Wherein R is substituted or unsubstituted alkyl, hydroxyalkyl, aryl, or aralkyl, and X is a radical of the formula ##SPC2## Wherein Z is a direct linkage, a divalent atom, or a divalent radical.

Erasable diazotype second originals on a translucent base have become very popular because they permit correcting, deletions and additions of new information to drawings without the need to redo an entire drawing. A new barrier film composition that acts simultaneously as matrix for the diazotype coating components and controls the ease of mechanical erasure is disclosed. The second originals exhibit almost film like reprographic continuity.

Diazo-type material readily developable by heat, having good keeping quality, and producible economically by aqueous coating techniques, comprises a light-sensitive layer containing, with a diazo compound, an acid-reacting stabilizer and a water-soluble hydrophilic organic binder, a substantially water insoluble acylacetamide as azo-coupling component and a substantially water insoluble developing agent, each dispersed as particles of .01-10 microns average size, the developing agent when heated...

Caprolactam, caprylolactam, and azacyclooctanone have been found to be equally effective as thiourea in stabilizing diazotype compositions and materials against pre-coupling, loss of shelf life, and dye image fading.