Two-component diazotype - photo pressure material for use in wet development

摘要

1,259,849. Diazotype materials. RICOH K. K. April 21, 1969 [May 6, 1968], No.20153/69. Heading G2C. A two component diazotype material comprises a diazonium compound of formula:- wherein R is alkyl with 1-4 carbon atoms and X is an anion, two couplers giving blue and yellow dye images respectively and pyrophosphoric acid; the coupler or couplers giving a blue image being of one of the formula:- wherein R 1 and R 2 are alkyl with 1-3 carbon atoms or together complete a heterocyclic ring n is 2 or 3 and R 3 is hydrogen, halogen or alkoxy with 1-4 carbon atoms and the couplers giving the yellow image being of the formula wherein R 4 is hydrogen or aminoethyl, R 5 is aryl, benzyl, benzoryl or acetoacetaminoethyl. The photo-sensitive layer may also contain caffeine and methylene blue. The support may be subbed with a polyvinyl acetate/starch/silica layer which may contain one of the couples. Comparisons using sulphuric, malonic, naleic, oxalic and succinic acid instead of pyrophosphoric acid are given.