Polymer, and oxygen absorbent and resin composition using same

A polymer comprising a structural unit derived from a compound (A) represented by formula (I):

• wherein:
• X and Y each independently represent a chalcogen atom;
• R1, R2, R7, and R8 each independently represent any one selected from the group consisting of an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, an aryl group, and an aralkyl group;
• R3, R4, R5, and R6 each independently represent any one selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, an aryl group, and an aralkyl group;
• J represents a linking group comprising an aliphatic hydrocarbon having 3 to 15 carbon atoms which has at least one substituent selected from the group consisting of a hydroxy group, a (meth)acryloyloxy group, a 4-vinylphenoxy group, and an alkenyloxy group having 2 to 6 carbon atoms;
• at least one selected from the at least one substituent is any one selected from the group consisting of a (meth)acryloyloxy group, a 4-vinylphenoxy group, and an alkenyloxy group having 2 to 6 carbon atoms;
• a carbon atom in the linking group may be replaced by an oxygen atom;
• and
• n represents an integer of 1 to 5;
• provided that Ys, R5's, R6's, R7's, and R8's, if present, may represent different atoms or groups, respectively.