Abstract: One object of the present invention is to provide polymers suitable for use as medical materials. The present invention provides a polymer useful as a medical material having the general formula -(A)I-(B)m—(C)n— ??(I) in which A is derived from a non-ionic monomer; B is derived from a monomer containing a primary, secondary, tertiary or quaternary amine group; C is derived from a monomer containing an acid group; and 1+m+n=100,0<1,m,n<100.

Abstract: It is intended to provide a polymer for coating a leukocyte removal filter material which is excellent in the capability of removing leukocytes. It is further intended to provide a filter whereby both of leukocytes and platelets can be highly efficiently removed from a blood product containing leukocytes and platelets. The above objects can be achieved by using a polymer for coating a leukocyte removal filter material which comprises a unit originating in a hydrophobic polymerizable monomer, a unit originating in a polymerizable monomer containing a basic nitrogen-containing part, and a unit originating in a polymerizable monomer containing a protonic neutral hydrophilic part.