Fiber for artificial hairs, artificial hair, method for producing fiber for artificial hairs, and method for producing artificial hair

1 . An artificial hair comprising a fiber bundle comprising a plurality of single yarns of fiber, each yarn having a diameter of about 15 μm or more, and wherein at least one of the single yarns of fiber has a predetermined shape including a curved part,

the fiber comprising a synthetic fibroin fiber containing a modified fibroin, and

the artificial hair expanding when placed in a wet state and contracting when dried from a wet state,

wherein the modified fibroin comprises a protein containing a domain sequence represented by Formula 1: [(A) n motif-REP] m or Formula 2: [(A) n motif-REP] m -(A) n motif,

wherein the (A) n motif comprises an amino acid sequence including alanine residues, a proportion of a number of alanine residues with respect to a total number of amino acid residues in the (A) n motif is 40% or more, and wherein REP comprises an amino acid sequence containing from 2 to 200 amino acid residues.

2 . A method for producing the artificial hair according to claim 1 , the method comprising producing at least one single yarn of fiber having a predetermined shape by retaining a fibroin fiber containing a modified fibroin in a state conforming to the predetermined shape.

3 . The method according to claim 2 , wherein the fibroin fiber is retained in a state conforming to a shape including a curved part, by being wound around a core material.

4 . The method according to claim 2 , wherein the diameter of the fibroin fiber is more than 30 μm.

5 . The method according to claim 2 , wherein the fibroin fiber that is retained in the state conforming to a predetermined shape is heated.

6 . The method according to claim 5 , wherein the fibroin fiber that is retained in the state conforming to a predetermined shape is heated to a temperature below 100° C.

7 . The method according to claim 2 , further comprising drying the fibroin fiber, wherein the dried fibroin fiber is retained in the state conforming to a predetermined shape.

8 . A method for producing the artificial hair according to claim 1 ,

the method comprising obtaining at least one single yarn of fiber that is given a predetermined shape by heating a fibroin fiber that contains a modified fibroin and has been wetted with water, while retaining the fibroin fiber in a state conforming to the predetermined shape.

9 . The method according to claim 8 , further comprising wetting the fibroin fiber with water before retaining the fibroin fiber in the state conforming to the predetermined state.

10 . The method according to claim 8 , wherein the fibroin fiber that is retained in the state conforming to the predetermined shape is immersed in heated water.

11 . The method according to claim 8 , wherein the fibroin fiber that is retained in the state conforming to the predetermined shape is exposed to water vapor.

12 . The method according to claim 8 , wherein the fibroin fiber is retained in the state conforming to the predetermined shape including a curved part by being wound around a core material.

13 . The method according to claim 2 , wherein the fibroin fiber is a fiber that expands when placed in a wet state and contracts when dried from a wet state.

14 . The method according to claim 2 , wherein the modified fibroin includes a modified spider thread fibroin.

15 . The artificial hair as claimed in claim 1 , wherein each yarn has a diameter of from about 15 μm to about 100 μm.