PURPOSE: To improve aging stability by incorporating novolak resin having a specified mol.wt. and a specified o-quinonediazido compd.
CONSTITUTION: This photosensitive compsn. contains novolak resin consisting of m-cresol and p-cresol and having a mol.wt. of ≥4,500 and ≥30% o- quinonediazido compd. The top of a surface-treated substrate is coated with a photosensitive layer contg. this photo-sensitive compsn. and the layer is dried to obtain the objective photosensitive planographic printing plate. The o- quinonediazido compd. is, e.g., a polycondensed resin having o-quinonediazido groups, e.g., an ester compd. of o-naphthoquinonediazidosulfonic acid with a polycondensed resin consisting of phenol and aldehyde or ketone. The phenol may be o-cresol, m-cresol, p-cresol, 3,5-xylenol or carvacrol.
OTA TOMOHISA
MATSUBARA SHINICHI
MITSUBISHI CHEM CORP