US 2019/0235380 Al  21  Aug. 1, 2019  -continued  (ca-1-45)  [0220]  Specific suitable examples of the cation repre› sented by Formula ( ca-2) include a diphenyliodonium cation  and a bis( 4-tert-butylphenyl)iodonium cation.  [0221]  Specific suitable examples of the cation repre› sented by Formula (ca-4) include cations represented by  Formulae (ca-4-1) and (ca-4-2) shown below.  (ca-4-1)  (ca-1-46)  (ca-4-2)  (ca-5-1)  [0222]  As the cation represented by Formula (ca-5), cat› ions represented by Formulae (ca-5-1) to (ca-5-3) are pref› erable.  s  Q  ~syY  V  ~o 