| 摘要 |
PROBLEM TO BE SOLVED: To obtain the subject ultraviolet absorber excellent in transparency, absorptivity of ultraviolet rays of UV-A and UV-B, and having extremely low photocatalytic activities by using a ceric phosphate-based compound in a specific composition as an active ingredient. SOLUTION: This ultraviolet absorber is the one of formula I [M is a cationic element or a cationic group; A is an anionic element or an anionic group; 0.2<=(x)<=2, 1<=(y)<=2, 0<=(z)<=1.5, 0<(n)<=5], and has 0.01-1μm average particle diameter. The ultraviolet absorber of formula I is obtained by mixing the basic aqueous solution containing a phosphate ion and an aqueous solution containing ceric ion regulated so as to have pH 1-11 to provide a slurry, and subjecting the obtained slurry with the generated amorphous precipitate to a wet-heat treatment and aging at 120-200 deg.C. The ultraviolet absorber of formula II [1.5<=(v)<=2.5, 1.8<=(w)<=2.2, 0<(m)<=5] having the strongest diffraction line at d=14-15Åin an X-ray diffraction, 0.3-30μm average particle diameter, and 0.02-0.5μm thickness is also provided.
|
