Ultraviolet absorber, light stabilizer, and ultraviolet absorbing composition, light stabilizing composition and skin external preparation containing the same

摘要

Providing an ultraviolet absorbent or photostabilizer with excellent absorption over a wide ultraviolet wavelength range and great stability and a high safety profile, as well as an ultraviolet-absorbing composition, a photostabilized composition and an external preparation for skin, where the pyridazine derivative of the following general formula and/or a salt thereof is included as the effective component of the ultraviolet absorbent or photostabilizer, or is included in the ultraviolet-absorbing composition, the photostabilized composition and the external preparation for skin: CHEM Wherein R1, R2, R3 and R4 are not simultaneously hydrogen atom; and R2 and R3 are not simultaneously morpholino group.