Artificial hair fiber and hairpiece product

Abstract

An artificial hair fiber is provided that is easy to curl or set. An artificial hair fiber is usually formed and processed within a temperature range from 90 to 150° C. The artificial hair fiber has a storage elastic modulus E′ in the formation temperature range. A ratio (E′ 90 /E′ 150 ) of a storage elastic modulus E′ at a temperature of 90° C. to a storage elastic modulus E′ at a temperature of 150° C. is 3 to 20. By this means, the artificial hair fiber can be well curled or transformed, maintaining a desired dynamic characteristic without being melted. The artificial hair fiber can be formed and processed into such a curled hair, so that it is possible to provide a hairpiece product that meets the fashion needs of users.

1 . An artificial hair fiber having a storage elastic modulus E′, wherein a ratio (E′ 90 /E′ 150 ) of a storage elastic modulus E′ at a temperature of 90° C. to a storage elastic modulus E′ at a temperature of 150° C. is 3 to 20. 
     
     
         2 . The artificial hair fiber according to  claim 1 , wherein:
 a curve of the storage elastic modulus E′ includes a glass state range in which the storage elastic modulus E′ is constant and a transition range in which a change rate in the storage elastic modulus E′ becomes maximum, the transition range being on a higher temperature side than the glass state range; and   a temperature coordinate of an intersection at which a tangent line of a curve of the storage elastic modulus E′ passing through the glass state range intersects a tangent line of a curve of the storage elastic modulus E′ passing through the transition range is located between 180 to 240° C.   
     
     
         3 . The artificial hair fiber according to  claim 1 , wherein said artificial hair fiber is made of a resin composition primarily consisting of one or both of thermoplastic polyester resin and thermoplastic polyimide resin. 
     
     
         4 . The artificial hair fiber according to  claim 3 , wherein:
 said artificial hair fiber is manufactured by melting and discharging the resin composition from a nozzle hole to produce an un-stretched yarn, and applying a stretching process to the un-stretched yarn,   a ratio (D 1 /D 2 ) of a stretch D 1  while the un-stretched yarn is produced after the resin composition is melted and discharged to a stretch D 2  during the stretching process is 1.5 to 14.0.   
     
     
         5 . A hairpiece product produced with the artificial hair fiber according to  claim 1 . 
     
     
         6 . The artificial hair fiber according to  claim 2 , wherein said artificial hair fiber is made of a resin composition primarily consisting of one or both of thermoplastic polyester resin and thermoplastic polyamide resin. 
     
     
         7 . The artificial hair fiber according to  claim 6 , wherein:
 said artificial hair fiber is manufactured by melting and discharging the resin composition from a nozzle hole to produce an un-stretched yarn, and applying a stretching process to the un-stretched yarn,   a ratio (D 1 /D 2 ) of a stretch D 1  while the un-stretched yarn is produced after the resin composition is melted and discharged to a stretch D 2  during the stretching process is 1.5 to 14.0.   
     
     
         8 . A hairpiece product produced with the artificial hair fiber according to  claim 2 . 
     
     
         9 . A hairpiece product produced with the artificial hair fiber according to  claim 3 . 
     
     
         10 . A hairpiece product produced with the artificial hair fiber according to  claim 6 . 
     
     
         11 . A hairpiece product produced with the artificial hair fiber according to  claim 4 . 
     
     
         12 . A hairpiece product produced with the artificial hair fiber according to  claim 7 .