| 摘要 |
539,703. Resinous azo dyes. KODAK, Ltd. (Eastman Kodak Co.). Jan. 18, 1940, No. 1094. [Class 2 (iii)] [Also in Group XX] A light sensitive photographic material contains a colouring-matter obtained by reaction of formaldehyde or a formaldehydeyielding substance with an azo dye containing an aryl nucleus comprising a benzene ring carrying a hydroxyl or amino group and having at least one position, other than a m-position in relation to the hydroxyl or amino .group, unsubstituted. Specified azo dyes so reacted are Brilliant paper yellow conc., Fast fuchsine G, Diamond flavine GA and Hessian bordeaux and the reaction products are dyes of resinous character and have little or no tendency to diffuse in colloid media. An alkaline solution of the azo dye may be heated for several hours under reflux with an excess of aqueous formaldehyde or a solution of the dye in diethyleneglycol-mono-butyl ether may be heated under reflux with hexamethylenetetramine or paraformaldehyde. Specifications 133,034, [Class 98 (ii)], 477,524, 521,836 and 521,837, [all in Group XX], are referred to. Specification 468,560, [Group XX], also is referred to in the Provisional Specification.
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