To provide an excellent ultraviolet absorber capable of improving ultraviolet resistance of a polymer material using the absorber, hardly causing precipitation and bleeding out, capable of maintaining the long-wave length ultraviolet-absorbing power for a long period, and having high solubility and low volatility.
The ultraviolet absorber comprises a compound represented by general formula (1): L-(UV)n [wherein, UV is a monovalent residue obtained by taking one hydrogen atom away from a compound represented by general formula (2) {wherein, A21 and A22 are each independently a hetero atom; Y21 and Y22 are each independently a hydrogen atom or a monovalent substituent; with the proviso that at least one of Y21 and Y22 is a substituent having 0.2 p value of Hammett's substituent constant; Y21 and Y22 may form a ring by bonding to each other; (B) is an atomic group required for forming a 5- or 6-membered ring together with A21, A22 and carbon atoms; and the bond with L is carried out in A21, A22 or (B)}; n is 2-6; and L is an n-valent linking group].
MIKOSHIBA NAO
Wataru Sasaki
Naosuke Miyamae
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