Hydrophilization agent and hydrophilization method

Provided is a hydrophilization agent capable of forming a hydrophilic coating that has a sufficiently high hydrophilicity and water resistance. This hydrophilization agent contains: a polymer (C1) having, in the structure thereof, a hydrophilic unit (B1) and a basic unit (A1) forming the basic backbone; and a polymer (C2) having, in the structure thereof, a hydrophilic unit (B2) and a basic unit (A2) forming the basic backbone having a structure different from that of the basic unit (A1). In addition, the basic unit (A1) and the basic unit (A2) are each preferably one selected from polyurethane, polyester, and polyvinyl alcohol. 本发明提供可形成具有充分高的亲水性和耐水性的亲水被膜的亲水化处理剂。上述亲水化处理剂含有聚合物(C1)和聚合物(C2)，上述聚合物(C1)在结构中具有构成基本骨架的基本单元(A1)和亲水性单元(B1)，上述聚合物(C2)在结构中具有构成基本骨架的基本单元(A2)和亲水性单元(B2)，上述基本单元(A2)与上述基本单元(A1)的结构不同。此外，上述基本单元(A1)和上述基本单元(A2)各自优选为选自由聚氨酯、聚酯和聚乙烯醇中的种。