131-55-5 2,2',4,4'-Tetrahydroxybenzophenone 2,2'4,4'-Tetrahydroxybenzophenone 2,4,2',4'-Tetrahydroxybenzophenone Benzophenone, 2,2',4,4'-tetrahydroxy- Benzophenone-2 Methanone, bis(2,4-dihydroxyphenyl)- NSC38556 Uvinol D-50 Uvinul D-50