Antibacterial fiber and method for producing antibacterial fiber

A method for producing an antibacterial fiber including a core portion and a sheath portion and containing a thermoplastic resin and an antibacterial glass as mixing components, the method comprising the following steps (1) to (3);

• (1) a step of preparing antibacterial glass;
• (2) a step of dispersing the antibacterial glass thus obtained in a thermoplastic resin such that
• when a content of the antibacterial glass in the core portion is designated as Q1 (weight %) with respect to the total amount of the antibacterial fiber, and a content of the antibacterial glass in the sheath portion is designated as Q2 (weight %) with respect to the total amount of the antibacterial fiber,
• Q1 and Q2 satisfy the following relational expression (1):
• Q1<Q2 (1)
• and thereby preparing a spinning dope for the core portion and a spinning dope for the sheath portion;
• and
• (3) performing composite spinning using a core-sheath composite spinneret by arranging the spinning dope for the core portion as the core portion and the spinning dope for the sheath portion as the sheath portion, and thereby obtaining an antibacterial fiber having an average diameter of 1 to 50 μm.