Patent ID: 7399508

Claim:
A recording medium comprising a recording layer on a substrate, wherein the recording layer comprises at least one polymer that has a thioether bond, has a sulfur equivalent of no less than 1.2 meq/g, and has an inorganic/organic ratio (I/O value) represented in an organic-inorganic conceptional diagram of no less than 0.5, wherein the polymer has a partial structure represented by the following formula (1), (2), (3) or (4): Formula (1) wherein in the formula (1), P represents a polymer residue or oligomer residue having a repeating unit, and Y represents a single bond or a divalent linking group; wherein in the formula (2), R 1 represents a hydrogen atom or a methyl group, R 2 represents an alkyl group or an aryl group, and J represents a single bond or a divalent linking group; wherein in the formula (3), R 11 and R 12 each independently represent a hydrogen atom or a methyl group, R 13 represent an alkyl group or an aryl group, R 14 , R 15 and R 16 each independently represent a hydrogen atom or an alkyl group, Y 1 and Z each independently represent a divalent linking group, m 1 and n 1 represent percentages by mole of repeating units in the polymer and satisfy relationships of 10≦m 1 ≦95 and 5≦n 1 ≦90, and X − represents a counter-anion; and wherein in the formula (4), R 20 represents a hydrogen atom or a methyl group, R 21 represents an alkyl group or an aryl group, W represents a divalent linking group, A represents a unit having an ethylenically unsaturated group, and m 2 and n 2 represent percentages by mole of repeating units in the polymer and satisfy relationships of 50≦m 2 ≦95 and 5≦n 2 50 .