auxiliary agent; adjuvant
Technical term used in chemistry and dyeing for a substance added to assist a process.
Auxiliary agents play an important role in the dyeing process.
この助剤は反応を促進するために添加される。
This adjuvant is added to accelerate the reaction.
processing aid; processing material
Compound of 助 (じょ, 'help') and 剤 (ざい, 'agent, preparation'). The exact historical derivation is uncertain; the spelling is conventionally associated with the meaning of an auxiliary chemical agent.