Hydrophilic member, hydrophilic graft polymer, and support of planographic printing plate

A support for a planographic printing plate comprising;

• a base material including a surface;
• and
• a hydrophilic surface disposed on the base material surface and including a hydrophilic graft chain and a cross-linked structure formed by hydrolysis and condensation polymerization of an alkoxide of a metal selected from Si, Ti, Zr, and Al;
• wherein,
• the hydrophilic surface includes a hydrophilic graft polymer, which is a copolymer of a macromer including a hydrophilic functional group and a structural unit having a silane coupling group.

A planographic printing plate precursor comprising:

• a support including a base material comprising a surface;
• and
• an image forming layer disposed on the support,
• wherein the support includes a hydrophilic surface disposed on the base material surface and comprising a hydrophilic graft chain and a cross-linked structure formed by hydrolysis of an alkoxide of a metal selected from Si, Ti, Zr, and Al and condensation polymerization the hydrophilic surface includes a hydrophilic graft polymer, which is a copolymer of a macromer comprising a hydrophilic functional group and a structural unit comprising a silane coupling group.