Patent ID: 8486303

Claim:
A process for producing a granule mass, comprising stirring-granulating a mixture containing a sulfur-based antioxidant represented by the following formula (2) and a phenol-based antioxidant represented by the following formula (1) in a temperature range of 40 to 70° C., wherein the content of the sulfur-based antioxidant (2) relative to a total of 100 parts by weight of the phenol-based antioxidant (1) and the sulfur-based antioxidant (2) is 8 to 35 parts by weight, wherein a dust flying rate of the granule mass measured by a Heubach test is not more than 1% by weight, and wherein a fluidity index of the granule mass determined by measuring a bulk density, a response angle, a spatula angle and a uniformity degree using a powder tester is not less than 72% wherein R 1 represents an alkyl group of a carbon number of 1 to 8, X represents a n-hydric alcohol residue of a carbon number of 1 to 18 optionally containing a heteroatom and/or a cyclic group, n represents an integer of 1 to 4, R 2 represents an alkyl group of a carbon number of 12 to 18, Y represents a single bond or a —C 2 H 4 CO 2 —group, Z represents a m-hydric alcohol residue of a carbon number of 5 to 18, and m represents an integer of 1 to 4.