The antioxidant 626, the antioxidant 9228, and the antioxidant bis (2, 6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite (PEP-36) are representative high-performance phosphite antioxidants containing spiro rings. Compared with the general phosphite antioxidants, the antioxidant has higher antioxidant activity due to the unique spiro structure. It can be widely applied to middle and high-end formulas of general plastics and engineering plastics with harsh processing conditions. Bis (2, 6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite is a highly effective phosphite antioxidant variety developed by Asahi Denka Kogyo Co, 20th century, late 80s to early 90s, molecular formula: C35H54O6P2, the molecular weight of 632.75, the melting point of 235-240 ℃, the flash point of 380.5 ℃ and the trade name of PEP-36.
