Patent ID: 7534820

Claim:
A photocurable composition containing an organic polymer (A) having a structure represented by formula (1), (2), or (3), and a cationic photoinitiator (B): wherein R 1 and R 2 are the same or different and each represent an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an aralkyl group having 7 to 20 carbon atoms, or a triorganosiloxy group represented by (R′) 3 SiO— wherein three R's are each a monovalent hydrocarbon group having 1 to 20 carbon atoms and may be the same or different, and when two or more R 1 s or R 2 s are present, they may be the same or different; X represents a monovalent organic group containing an epoxy group and/or an oxetane group; m represents an integer of 0 to 20; and n represents an integer of 1, 2, or 3 wherein X and R 2 are the same as the above, R 3 and R 4 each represent a methyl group or the same as X or R 2 , or either R 3 or R 4 is a bond part to the organic polymer; l′ is 1 on average and represents the number of a bond part to an end of the organic polymer, and when either R 3 or R 4 is a bond part to the organic polymer, l′ is 0; 1≦m′+n′≦50, 1≦m′, and 0≦n′; and the position of each of the units is not specified, and when a plurality of each unit is present, the units may be alternately or randomly positioned wherein X and R 2 are the same as the above; l″ is 1 on average and represents the number of a bond part to an end of the organic polymer; 1≦m″+n″≦20, 1≦m″, and 0≦n″; and the position of each of the units is not specified, and when a plurality of each unit is present, the units may be alternately or randomly positioned and, wherein the main chain skeleton of the organic polymer (A) is selected from a polyisobutylene and an oxyalkylene polymer.