Patent ID: 6977132

Claim:
A planographic printing plate precursor comprising: a support comprising a substrate and a hydrophilic layer disposed on a surface of the substrate, the hydrophilic layer including hydrophilic polymer and a crosslinked structure formed by hydrolysis or condensation polymerization of an alkoxide compound including an element selected from the group consisting of Si, Ti, Zr and Al; and a positive working recording layer disposed on the support and including a material for absorbing light and generating heat, and a polymer compound, which is insoluble in water and soluble in alkali; wherein a solubility of the positive working recording layer in an alkaline aqueous solution is increased by exposure to light, and the hydrophilic polymer is represented by a following general formula (1): wherein the general formula (1) represents a polymer compound including a silane coupling group represented by a structural unit (iii) at an end of polymer units represented by structural units (i) and (ii), wherein each of R 1 , R 2 , R 3 , R 4 , R 5 and R 6 independently represents a hydrogen atom or a hydrocarbon group of 1 to 8 carbon atoms; m represents 0, 1 or 2; x and y each represents a composition ratio in which x+y=100 and x:y is in a range from 100:0 to 1:99; each of L 1 , L 2 and L 3 independently represents a single bond or an organic connecting group; each of Y 1 and Y 2 independently represents —N(R 7 )(R 8 ), —OH, —NHCOR 7 , —COR 7 , —CO 2 M or —SO 3 M in which R 7 and R 8 independently represent a hydrogen atom or an alkyl group of 1 to 8 carbon atoms and M represents a hydrogen atom, an alkali metal, an alkali earth metal or an onium.