The purpose of the present invention is to provide a polymer having a low halogen atom content remaining in the polymer, a simple production method thereof, an active energy ray-curable composition that can be rapidly cured by an irradiation of a small amount of light, and a cured product thereof. These purpose can be achieved by an active energy ray-curable composition, including a polyisobutylene polymer (A) represented by the following general formula (1) (wherein R
1
represents a monovalent or polyvalent aromatic hydrocarbon group, or a monovalent or a polyvalent aliphatic hydrocarbon group; A represents a polyisobutylene polymer; R
2
represents a divalent saturated hydrocarbon group having 2-6 carbon atoms, which contains no hetero atoms; R
3
and R
4
each represent hydrogen, a monovalent hydrocarbon group having 1-20 carbon atoms, or an alkoxy group having 1-20 carbon atoms; R
5
represents hydrogen or a methyl group; and n denotes a natural number), and an active energy ray polymerization initiator (B).
本发明的目的是提供一种聚合物,其聚合物中保留有较低的卤素原子含量,以及其简单的生产方法,一种能够通过少量光辐照快速固化的活性能量射线固化组合物以及其固化产物。这些目的可以通过一种活性能量射线固化组合物来实现,包括以下通式(1)所表示的聚
异丁烯聚合物(A)(其中R1表示单价或多价
芳香烃基或单价或多价脂肪烃基;A表示聚
异丁烯聚合物;R2表示含有2-6个碳原子的二价饱和碳氢基团,不含杂原子;R3和R4分别表示氢、具有1-20个碳原子的单价碳氢基团或具有1-20个碳原子的烷氧基;R5表示氢或甲基基团;n表示自然数),以及活性能量射线聚合
引发剂(B)。