| abstract |
[Problem] CTP excellent in workability, economy and storage stability Provided is a photopolymerizable composition used as a material for a lithographic printing plate for scanning exposure or an original plate for a lithographic printing plate having high sensitivity to the oscillation wavelength of an inexpensive short-wavelength semiconductor laser suitable for the system. SOLUTION: It is not sensitive to light of 500 nm or more, and 350 n corresponding to a short wavelength laser having an exposure light source wavelength from m to 450 nm, (i) an electron donating initiator and a sensitizing dye, (ii) an electron-accepting initiator and a sensitizing dye, and (iii) one of an electron-donating initiator, a sensitizing dye, and an electron-accepting initiator (ternary initiator). A photopolymerizable composition characterized by containing. |