Antimicrobial polmerizable composition, the polymer and article obtained from the same

A polymerizable composition comprising an ethylenically unsaturated monomer, at least one di- or trifunctional monomer in an amount of 0.01 to 50% by weight selected from the group represented by the following formulas II and III and having antimicrobial activity, and a polymerization initiator ##STR19## wherein R.sub.1 represents a hydrogen atom or a methyl group, R.sub.2 represents an alkylene group having 2 to 18 carbon atoms, X represents an oxygen atom, a sulfur atom or an imide group and Y' and Y" represent any one selected from the following respective formulas:

• ##STR20## wherein R.sub.3 represents a hydrogen atom or an alkyl group having 1 to 18 carbon atoms, R.sub.4 represents a methyl group, an ethyl group or a hydroxyethyl group and Z represents a chlorine atom or bromine atom.