RADICAL POLYMERIZATION INITIATOR, COMPOSITION CONTAINING SAME, CURED PRODUCT OF COMPOSITION, PRODUCTION METHOD FOR CURED PRODUCT, AND COMPOUND

摘要

Provided are: a radical polymerization initiator which has excellent sensitivity and solubility in water; a composition containing the same; a cured product of the composition; a method of producing the cured product; and a compound. The radical polymerization initiator contains a compound represented by Formula (A) below (wherein Z¹ represents a direct bond or the like; Z² represents >CR¹⁰²₂ or the like; R¹ to R⁸ each represent a hydrogen atom or the like, or a group containing a salt-forming group, which is represented by Formula (B1) below (wherein L₁ represents a direct bond or the like, B represents an acidic group salt or the like, b represents 1 to 10, and the asterisk (*) represents a binding site); at least one of R¹ to R⁸ is the group containing a salt-forming group; R¹⁰¹ and the like each represent a hydrogen atom or the like; one or more hydrogen atoms in the alkyl group and the like used as R¹ to R⁸ and the like are optionally substituted with an ethylenically unsaturated group or the like; one or more methylene groups in R¹ to R⁸ and the like are optionally substituted with a double bond or the like; adjacent groups such as R¹ and R² are optionally bound together to form a ring and optionally form a fused ring with a benzene ring in Formula (A); and R′ represents a hydrogen atom or the like).;