ANTIOXIDANT COMPOSITION EXCELLENT IN DISCOLORATION RESISTANCE AND METHOD FOR PREVENTING DISCOLORATION OF ANTIOXIDANT

摘要

PROBLEM TO BE SOLVED: To obtain an antioxidant compsn. excellent in discoloration resistance by incorporating a specified phosphorus compd. into a phenolic antioxidant to improve the discoloration resistance of the phenolic antioxidant. ;SOLUTION: An antioxidant compsn. is obtained by incorporating a dihydrooxaphosphaphenanthrene-base phosphorus compd. of formula (I) (R¹ and R² being H, a halogen or lower alkyl) into a phenolic antioxidant. As the dihydrooxaphosphaphenanthrene-base phosphorus compd., 9,10-dihydro-9- oxa-10-phosphaphenanthrene 10-oxide is preferred. The phosphorus compd. is contained in an amount of usually about 0.001 to 5 pts.wt. for 100 pts.wt. of the phenolic antioxidant. As the phenolic antioxidant, those having a phenol skeleton having a substituent, particularly a bulky substituent such as t-butyl or t-pentyl, at the o-position are preferred.;COPYRIGHT: (C)1997,JPO