Surface modification method and surface-modified elastic body

A method for surface-modifying a rubber vulcanizate or a thermoplastic elastomer as a modification target, the method comprising:

• step 1 of forming polymerization initiation points A on a surface of the modification target;
• step 2 of radically polymerizing a monomer A starting from the polymerization initiation points A to grow polymer chains A;
• and
• step 3 of forming polymerization initiation points B on a surface of the polymer chains A, radically polymerizing a polymerizable silane compound starting from the polymerization initiation points B, and further reacting a perfluoroether group-containing silane compound to grow functional polymer chains, or step 3′ of adding a silane compound to a surface of the polymer chains A and further reacting a perfluoroether group-containing silane compound to grow functional polymer chains,
• wherein the monomer A is at least one selected from the group consisting of acrylic acid, acrylic acid esters, alkali metal salts of acrylic acid, amine salts of acrylic acid, acrylamide, dimethylacrylamide, diethylacrylamide, isopropylacrylamide, hydroxyethylacrylamide, acryloylmorpholine, methoxymethyl acrylate, hydroxyethyl acrylate, methacrylic acid, methacrylic acid esters, alkali metal salts of methacrylic acid, amine salts of methacrylic acid, methacrylamide, dimethylmethacrylamide, diethylmethacrylamide, isopropylmethacrylamide, hydroxyethylmethacrylamide, methacryloylmorpholine, methoxymethyl methacrylate, hydroxyethyl methacrylate, and acrylonitrile.