Artificial hair fiber, use thereof and process for producing the same

Abstract

The present invention provides an artificial hair fiber having a good balance between a feel and a curly characteristic. The present invention also provides an artificial hair fiber having a better hackling efficiency and weaving efficiency, a fiber bundle for artificial hair, and a process for producing the same. Artificial hair fibers possess desired properties, the fibers having a flexural rigidity of from 0.001 to 0.01 gf·cm 2 or being subjected to crimping in which a crimp wave shape satisfies the following formulae: 0.2 mm≦R≦3 mm, 1 mm≦L≦15 mm, (wherein R is a length from the top to the bottom of a crimp wave shape), and (wherein L is a length between the tops (or between the bottoms) of a crimp wave shape).

1 . An artificial hair fiber, which is a fiber having a flexural rigidity of from 0.001 to 0.01 gf·cm 2  as measured by the KES method, wherein the fiber is formed of a synthetic resin. 
     
     
         2 . The artificial hair fiber according to  claim 1 , wherein a sectional shape of the fiber in the widthwise direction is an elliptical shape, a circular shape, a glasses shape, a cocoon shape, a 6-leaf flower shape, or a 8-leaf flower shape; or the mixed shape thereof. 
     
     
         3 . The artificial hair fiber according to  claim 1 , wherein the synthetic resin is a polyvinyl chloride resin. 
     
     
         4 . The artificial hair fiber according to  claim 3 , wherein the fiber is a polyvinyl chloride fiber produced by melt-spinning the polyvinyl chloride resin. 
     
     
         5 . The artificial hair fiber according to  claim 3 , wherein the polyvinyl chloride resin comprises 100 parts by mass of a vinyl chloride resin and 0.5 to 10 parts by mass of a chlorinated vinyl chloride resin. 
     
     
         6 . The artificial hair fiber according to  claim 1 , wherein the synthetic resin is at least one synthetic resin selected from the group consisting of nylon 6, nylon 6/6, nylon 4/6, nylon 1/2, nylon 6/10, and nylon 6/12. 
     
     
         7 . The artificial hair fiber according to  claim 1 , wherein the synthetic resin is a modacrylic resin. 
     
     
         8 . The artificial hair fiber, wherein the artificial hair fibers according to  claim 3  are blended. 
     
     
         9 . The artificial hair fiber according to  claim 1 , wherein a wave shape of the artificial hair fiber is within a range satisfying the following formulae:
   0.2 mm≦R≦3 mm, 1 mm≦L≦15 mm,
   (R: amplitude of a wave of the fiber in the widthwise direction), and   (L: a cycle length of a wave of the fiber in the lengthwise direction).   
     
     
         10 . The artificial hair fiber according to  claim 9 , wherein the wave shape of the artificial hair fiber is formed by gear-crimping. 
     
     
         11 . A fiber bundle for artificial hair, wherein obtained by bundling the artificial hair fibers according to  claim 1 . 
     
     
         12 . A curly hair decoration using the artificial hair fiber according to  claim 1 . 
     
     
         13 . A woven hair decoration using the artificial hair fiber according to  claim 1 . 
     
     
         14 . A braid using the artificial hair fiber according to  claim 1 . 
     
     
         15 . An extension hair using the artificial hair fiber according to  claim 1 . 
     
     
         16 . A process for producing an artificial hair fiber, the process comprising:
 a mixing step of mixing a vinyl chloride resin and an additive;   a melt-spinning step of melt-spinning a composition containing the mixed vinyl chloride resin at a spinneret temperature of 160 to 190° C.;   a stretching step of stretching melt-spun fibers under an atmosphere at a stretching temperature of 90 to 120° C., at a stretching ratio of 200 to 400%;   a thermal relaxing step of subjecting the stretched fibers to thermal relaxing treatment under an atmosphere of air at a temperature of 110 to 140° C. until the entire length of the fibers becomes 60 to 95% of the length following the stretching step; and   a crimping step of crimping the fibers after the thermal relaxing treatment step.   
     
     
         17 . The process for producing an artificial hair fiber according to  claim 16 , wherein the crimping is gear-crimping carried out at a depth of gear waves of 0.2 mm to 6 mm, a gear surface temperature of 30 to 100° C., and a processing rate of 0.5 to 10 m/min. 
     
     
         18 . The process for producing an artificial hair fiber according to  claim 16 , wherein an orifice shape of a spinneret as used in the melt-spinning step include a circular shape, a cocoon shape, a Y-shape, an H-shape, or an X-shape; and the spinneret has a single or mixed shape thereof.