A photoradical generator which produces no low-molecular decomposition material but a radical during a photoradical generating process, does not generate a radical during a heating process, exists in a chemically stable state in a resulting product of a radical reaction such as a cured coating layer or the like, has high heat resistance, stability and preserving ability, and is excellent in compatibility or solubility is provided. The photoradical generator is comprised of a compound (a) having a seven-membered ring imide structure-containing group represented by the following formula (1), wherein, R
1
to R
8
respectively represent a hydrogen atom or a substituent and may be a cyclic structure in which they are bonded to each other.
一种光致自由基发生器,其在光致自由基生成过程中不产生低分子分解物质,而是产生自由基,在加热过程中不生成自由基,在自由基反应的产物中(如固化涂层层等)处于
化学稳定状态,具有高耐热性,稳定性和保持能力,并且在兼容性或溶解性方面表现出色。该光致自由基发生器由以下式(1)所表示的含有七元环
酰亚胺结构基团的化合物(a)组成,其中,R1至R8分别表示氢原子或取代基,可以是它们彼此相连的环状结构。