. "It was confirmed that Sample B containing Compound I-1 of the present invention showed extremely less color fading as compared to other Samples A, C and D, and particularly with Samples C and D, these samples were hardly effective in preventing color fade notwithstanding that 2,5-di-tert-octylhydroquinone was incorporated in amounts equimolar to or 10 times moles that of Compound I-1 of the presen" . . .