Patent ID: 7279509

Claim:
An antimicrobial composition for a medical tool made of a vinyl chloride resin, which comprises (a) a cyclic organic phosphoric ester compound represented by formula (I): wherein R 1 , R 2 , and R 3 each represent a hydrogen atom or a straight-chain or branched alkyl group having 1 to 18 carbon atoms; R 4 represents a hydrogen atom or a methyl group; n represents 1 or 2; and M represents a hydrogen atom or an alkali metal when n is 1, or an alkaline earth metal or a zinc atom when n is 2; (b) a pyrithione compound represented by formula (II): wherein M 2 represents an alkali metal, an alkaline earth metal, a zinc atom, a copper atom or an aluminum atom; and n 2 represents the same number as the valence of M 2 ; and wherein component (a) is present in an amount of 0.005 to 10 parts by weight per 100 parts by weight of the vinyl chloride resin; and component (b) is present in an amount of 0.001 to 0.1 part by weight per 100 parts by weight of the vinyl chloride resin.