Two-component diazotype material with ultraviolet light-absorbing dye salt of a benzothiazole
AssigneeHoechst Aktiengesellschaft
InventorSiegfried Scheler
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AssigneeHoechst Aktiengesellschaft
InventorSiegfried Scheler
Estimating the term…
The present invention relates to a two-component diazotype material comprising a support and one or several light-sensitive layers, each of which contains at least one light-sensitive diazonium salt, a coupler component and an acid stabilizer, and at least one of the layers contains a compound which absorbs light in the ultraviolet spectral region. The light-absorbing compound is present in the form of a dye salt of at least one benzothiazole which is converted into its leuco base under the action of an alkaline medium. It thus partially or completely loses its absorptivity toward radiation in the long-wave ultraviolet and short-wave visible spectral regions. The light-absorbing compound comprises a benzothiazole, in particular according to the general formula: ##STR1## wherein R.sub.1 denotes hydrogen, alkyl or aralkyl, R.sub.2 denotes hydrogen or an optionally substituted alkyl, aralkyl, aryl, pyridylalkyl, carbalkyl, carboxyalkyl, carboxyaryl, carbamoyl, or sulfamoyl radical, or R.sub.1 and R.sub.2 denote members of a heterocyclic radical, and R.sub.3 denotes hydrogen or alkyl.
A two-component diazotype material, comprising a support and at least one light-sensitive layer provided on said support, said layer containing in admixture at least one light-sensitive diazonium salt, a coupler component, and an acid stabilizer, wherein at least one layer further contains in said admixture a light-absorbing compound which absorbs light in the ultraviolet spectral region, said light-absorbing compound (i) being present in an amount between about 2 and 30%, based on the weight of said diazonium salt and (ii) comprising a dye salt of at least one benzothiazole which is capable of converting into a corresponding leuco base by the action of an alkaline medium, whereby said dye salt at least partially loses absorptivity toward radiation in the long-wave ultraviolet and short-wave visible spectral region.
Dependencies are inferred from the claim text.