Near-infrared absorbing fiber comprising tungsten oxide, and fiber article using same
An inexpensive fiber that has heat retaining properties, satisfactory weather resistance and heat absorption efficiency, and includes a heat absorbing material having excellent transparency; and a fiber article that uses the fiber. A particle dispersion of Cs 0.33 WO 3 is obtained by mixing Cs 0.33 WO 3 microparticles, toluene, and a microparticle dispersing agent to create a liquid dispersion, and then removing the toluene. The particle dispersion is added to and uniformly mixed with pellets of polyethylene terephthalate resin, after which the mixture is extruded, the strands thus obtained are formed into pellets, and a master batch including Cs 0.33 WO 3 microparticles is obtained. This master batch is mixed with a master batch to which inorganic microparticles have not been added, and the mixture thus obtained is melt spun and stretched to manufacture a polyester multifilament yarn. The polyester multifilament yarn is cut, polyester staple fibers are created, and a spun yarn is manufactured. A heat retentive knit article is obtained using the spun yarn.
1. A fiber comprising tungsten oxide microparticles and/or composite tungsten oxide microparticles in a surface and/or interior of the fiber, wherein:
the fiber is a near infrared absorbing fiber in which the content of the microparticles is 0.001 wt % to 80 wt % with respect to a solid portion of the fiber;
said tungsten oxide microparticles and/or composite tungsten oxide microparticles have a grain size of 1 nm to 800 nm;
said tungsten oxide microparticles are represented by the general formula WO x with 2.45≦X≦2.999; and
said composite tungsten oxide microparticles have a hexagonal crystal structure and are represented by the general formula M y WO z where M is at least one element selected from the group consisting of Cs, Rb, K, Tl, In, Ba, Li, Ca, Sr, Fe, and Sn; 0.001≦Y≦1.0; and 2.2≦Z≦3.0.
2. The near infrared absorbing fiber of claim 1 , further comprising microparticles of a far infrared radiating substance in the surface and/or interior of the near infrared absorbing fiber, wherein:
the microparticles of the far infrared radiating substance are contained in the near infrared absorbing fiber in an amount of 0.001 wt % to 80 wt % with respect to a solid portion of the fiber.
3. The near infrared absorbing fiber of claim 1 , wherein said fiber is a member selected from the group consisting of a synthetic fiber, a semisynthetic fiber, a natural fiber, a reclaimed fiber, and an inorganic fiber; or a textile blend, doubled yarn, or mixed yarn formed by combining filaments of the same.
4. The near infrared absorbing fiber of claim 3 , wherein said synthetic fiber is selected from the group consisting of polyurethane fiber, polyamide fiber, acrylic fiber, polyester fiber, polyolefin fiber, polyvinyl alcohol fiber, polyvinylidene chloride fiber, polyvinyl chloride fiber, and polyether ester fiber.
5. The near infrared absorbing fiber of claim 3 , wherein said semisynthetic fiber is selected from the group consisting of cellulose fiber, protein fiber, chlorinated rubber, and hydrochlorinated rubber.
6. The near infrared absorbing fiber of claim 3 , wherein said natural fiber is selected from the group consisting of vegetable fiber, animal fiber, and mineral fiber.
7. The near infrared absorbing fiber of claim 3 , wherein said reclaimed fiber is selected from the group consisting of cellulose fiber, protein fiber, algin fiber, rubber fiber, chitin fiber, and mannan fiber.
8. The near infrared absorbing fiber of claim 3 , wherein said inorganic fiber is selected from the group consisting of metal fiber, carbon fiber, and silicate fiber.
9. The near infrared absorbing fiber of claim 1 , wherein a surface of said tungsten oxide microparticles and/or composite tungsten oxide microparticles is covered by a compound that contains at least one element selected from the group consisting of silicon, zirconium, titanium, and aluminum.
10. The near infrared absorbing fiber of claim 9 , wherein said compound is an oxide.
11. A fiber article comprising the near infrared absorbing fiber of claim 1 .