A novel class of bridged indicator dyes is disclosed which possess absorption in the infrared region of the electromagnetic spectrum. These bridged indicator dyes are useful as light-absorbing, pH-sensitive optical filter agents in diffusion transfer photographic processes adapted to be performed in the presence of ambient light and to diffusion transfer products useful in such processes. These indicator dyes will also find utility in titrations and other analytical techniques and products where pH-sensitive indicator dyes are employed and absorption of infrared is useful.
揭示了一种新的桥接指示剂
染料类别,其在电磁光谱的红外区域具有吸收性。这些桥接指示剂
染料可用作光吸收、pH敏感的光学滤光剂,在扩散转移摄影过程中适用于在环境光的存在下进行,并且应用于在这种过程中有用的扩散转移产品。这些指示剂
染料也将在滴定和其他分析技术和产品中发挥作用,其中使用pH敏感指示剂
染料,并且红外吸收是有用的。