Antibacterial fiber and method for producing antibacterial fiber

Abstract

Antibacterial fibers exhibiting sufficient antibacterial properties even with a small amount of antibacterial glass, and an efficient method for producing such antibacterial fibers. Disclosed is an antibacterial fiber containing a thermoplastic resin and an antibacterial glass as mixing components, the antibacterial fiber having an average diameter adjusted to a value within the range of 1 to 50 μm, the antibacterial fiber including a core portion and a sheath portion, in which 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).

1 . An antibacterial fiber comprising a thermoplastic resin and an antibacterial glass as mixing components,
 the antibacterial fiber having an average diameter adjusted to a value within the range of 1 to 50 μm, and   the antibacterial fiber including a core portion and a sheath portion,   wherein 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).
     Q 1< Q 2  (1).
 
   
     
     
         2 . The antibacterial fiber according to  claim 1 , wherein Q1 is 0 or below 1% by weight (provided that 0% by weight is excluded). 
     
     
         3 . The antibacterial fiber according to  claim 1 , wherein Q2 has a value within the range of 1% to 10% by weight. 
     
     
         4 . The antibacterial fiber according to  claim 1 , further comprising aggregated silica particles as a mixing component. 
     
     
         5 . The antibacterial fiber according to  claim 1 , wherein a volume average particle size of the antibacterial glass is adjusted to a value within the range of 0.1 to 5 μm. 
     
     
         6 . The antibacterial fiber according to  claim 1 , wherein the thermoplastic resin is any one or more of a polyester resin, a polyamide resin, and a polyolefin resin. 
     
     
         7 . The antibacterial fiber according to  claim 1 , wherein the antibacterial fiber is in the form of any one of a woven fabric, a nonwoven fabric, and a felt. 
     
     
         8 . 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):
     Q 1< Q 2  (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.