Process stabilizer, organic material composition, and method for stabilizing organic material

An organic material composition, comprising:

• a compound (I) represented by Formula (I):
• [in Formula (I),
• R1, R2, R4, and R5 each independently represent a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 5 to 8 carbon atoms, an alkylcycloalkyl group having 6 to 12 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, or a phenyl group,
• R3s each independently represent a hydrogen atom or an alkyl group having 1 to 8 carbon atoms,
• X represents a single bond, a sulfur atom, or a —CH(—R6)— group (wherein, R6 represents a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or a cycloalkyl group having 5 to 8 carbon atoms),
• A represents an alkylene group having 1 to 8 carbon atoms or a *—C(═O)—R7— group (wherein, R7 represents a single bond or an alkylene group having 1 to 8 carbon atoms, and * represents a bond on the oxygen side), and
• one of Y and Z represents a hydroxyl group, an alkoxy group having 1 to 8 carbon atoms, or an aralkyloxy group having 7 to 12 carbon atoms, while the other represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms];
• a compound (II) represented by Formula (II):
• [in Formula (II),
• R1 and R2 each independently represent a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 5 to 8 carbon atoms, an alkylcycloalkyl group having 6 to 12 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, or a phenyl group,
• R3s each independently represent a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, and
• X represents a single bond, a sulfur atom, or a —CH(—R6)— group (wherein, R6 represents a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or a cycloalkyl group having 5 to 8 carbon atoms)];
• an amine compound (A) having a hydroxyalkyl group;
• and
• an organic material
• wherein, with respect to 100 parts by mass of the compound (I), the content of the compound (II) is 0.005 to 4 parts by mass, and the content of the amine compound (A) is 0.01 to 15 parts by mass.