紫外線吸収フイルターに関すろ研究

抄録

For the ultraviolet absorbing filters which are abailable now-adays, such absorbent as tartrazine, ultrazine, R-acid, G-acid and aesculin are used, but they have the defects that they transmit-near ultraviolet light, absorb blue light, or are fluorescent or unstable to light.
We intended to make ultraviolet absorbing filters which are colorless, non-fluoresent, clear, stable to light and sharp cut. The light transmittance of flavene, flavanone, chalcone and coumarin groups were measured at the concentration of absorbents 3g/m² in alcohol or benzene.
There are interesting relations between absorption curves and chemical constitutions.
The absorption edges of flavones shift according to the number of OH and other radicals. They shift to longer wave length with the increase of OH groups and to shorter wave length with the decrease.
Flavone and coumarin group have sharp absorption curves but chalcone and flavanone group have rather flat curves.
Flavon group is the most excellent absorbent as the ultraviolet absorbing filters, because, besides being sharp cut of the ultraviolet light, it is non-fluorescent and light-fast. With these ultraviolet absorbing agents several kinds of filters were made.