Phosphite antioxidant composition and synthetic resin composition using same

The invention discloses a phosphite antioxidant composition and a synthetic resin composition using the same, and the phosphite antioxidant composition is characterized by comprising a phosphite antioxidant compound which has a cardanol structure and is shown as a general formula (1), in the general formula (1), R represents a hydrogen atom, a hydroxyl group, an alkyl group with 1-30 carbon atoms or an alkoxy group with 1-30 carbon atoms, and the alkyl group and the alkoxy group are optionally interrupted by one or more oxygen atoms or carbonyl groups; n, m and k in the general formula (1) respectively represent the number of anacardol groups containing monoene, diene and triene, n, m and k are integers greater than or equal to 0 and less than or equal to 3, and the sum of n, m and k is 3. The invention provides a novel compound of normal-temperature liquid phosphite, which is superior to TNPP in heat resistance and antioxidant effect and is easy to synthesize, and a synthetic resin composition using the comp