Matric plate for electrophotographic platemaking, production thereof and printing plate

An electrophotographic plate-making quality matrix plate provided on an electroconductive substrate thereof with a photosensitive layer formed of an alkali-soluble binder resin containing an organic photoelectroconductive compound, which matric plate is characterized by the fact that said organic photoelectroconductive compound is a zinc phthalocyanine represented by the general formula I: (I) wherein R is a -SZ group (where Z is a phenyl group, a phenyl group substituted with an alkyl group of 1 to 5 carbon atoms, or a naphthyl group), and said binder resin is a copolymer obtained by polymerizing a monomer mixture comprising (a) at least one compound selected from the group consisting of hydroxyalkyl acrylates and hydroxyalkyl methacrylates, (b) at least one copolymerizable unsaturated carboxylic acid, (c) at least one styrene compound, and (d) at least one compound selected from among acrylic esters other than said hydroxyalkyl acryaltes of (a).