| 摘要 |
PURPOSE:To obtain a compsn. high in photohardenability, improved in water developability, and suitable for a flexographic plate by using specified two kinds of prepolymers. CONSTITUTION:A photosensitive compsn. contains a photopolymn. initiator and (a) 30-100wt% prepolymer having 1,300-20,000 average mol.wt. and >=2 terminal groups each having a polymerizable ethylenical unsatd. double bond, and prepared by treating with a quaternizing agent (alkylating agent) a product formed by (A) an org. polyisocyanate, (B) when needed, a polyol, (C) a chain extending agent, such as N-diethanolamine having >=1 tertiary amine and >=2 active H, and (D) an ethylenically unsatd. compd. having active H, such as polyol acrylate represented by the formula (R<1> is H, methyl, or ethyl; R<2> is R<1> or halomethyl; and (n) is 2-10); and (b) 0-70wt% prepolymer prepared from (A) polyethylene glycol having >=2 active H at the terminal and <=5,000 average mol. wt. and (D). |
