siccative vs chemical agent

siccative and chemical agent both are nouns.

Word	Noun	Adjective	Verb	Adverb
siccative	Yes	No	No	No
chemical agent	Yes	No	No	No

As nouns, chemical agent is a hypernym of siccative; that is, chemical agent is a word with a broader meaning than siccative:

siccative: a substance that promotes drying (e.g., calcium oxide absorbs water and is used to remove moisture)
chemical agent: an agent that produces chemical reactions

siccative (noun)	chemical agent (noun)
a substance that promotes drying (e.g., calcium oxide absorbs water and is used to remove moisture)	an agent that produces chemical reactions