Blended yarn, knitted/woven body of same, and method for manufacturing said knitted/woven body

1 . A blended yarn consisting of:

a fiber from a modified fibroin derived protein, wherein the fiber from a modified fibroin derived protein is a shrunk fiber, and comprises a domain sequence represented by Formula 1: [(A) n motif-REP] m wherein in Formula 1,

(i) the (A) n motif represents an amino acid sequence composed of 2 to 27 amino acid residues and the number of alanine residues with respect to a total number of amino acid residues in the (A) n motif is 83% or more;

(ii) REP represents an amino acid sequence composed of 10 to 200 amino acid residues; m represents an integer of 2 to 300;

(iii) a plurality of the (A) n motifs may have the same amino acid sequence or amino acid sequences different from each other;

(iv) a plurality of REPs having the same amino acid sequence or amino acid sequences different from each other; and

(v) the domain sequence has an amino acid sequence with a reduced content of glycine residues, which corresponds to an amino acid sequence in which at least one or a plurality of glycine residues in at least one GGX motif, wherein X represents an amino acid residue other than glycine, of REP are substituted with other amino acid residues selected from the group of amino acids consisting of valine (V), leucine (L), isoleucine (I), methionine (M), proline (P), phenylalanine (F), tryptophan (W), glutamine (Q), asparagine (N), lysine (K), or glutamic acid (E); and

a regenerated cellulose fiber.

2 . The blended yarn according to claim 1 , wherein a shrinkage rate of the fiber from a modified fibroin derived protein as defined by the following formula is more than 7%:

Shrinkage rate={1−(Length of fiber after being brought into contact with aqueous medium/Length of fiber before being brought into contact with aqueous medium)}×100(%).

3 . The blended yarn according to claim 1 , wherein an amount of the fiber from a modified fibroin derived protein is 5% to 40% by mass.

4 . The blended yarn according to claim 1 , wherein the fiber from a modified fibroin derived protein is a modified spider silk fibroin fiber.

5 . The blended yarn according to claim 1 , wherein the regenerated cellulose fiber is a lyocell fiber.

6 . A knitted or woven body of the blended yarn according to claim 1 .

7 . A method for manufacturing a knitted or woven body, comprising steps of:

blend-spinning a fiber from a modified fibroin derived protein and a regenerated cellulose fiber to obtain the blended yarn of claim 1 ; and

knitted or weaving the blended yarn to obtain an unprocessed knitted or woven body.

8 . The manufacturing method according to claim 7 , wherein a shrinkage rate of the fiber from a modified fibroin derived protein as defined by the following formula is more than 7%:

Shrinkage rate={1−(Length of fiber from a modified fibroin derived protein after being brought into contact with aqueous medium/Length of fiber before being brought into contact with aqueous medium)}×100(%).

9 . The manufacturing method according to claim 7 , further comprising bringing the unprocessed knitted or woven body into contact with an aqueous medium to shrink the fiber from a modified fibroin derived protein contained in the unprocessed knitted or woven body.

10 . The manufacturing method according to claim 7 , wherein in the step of obtaining the blended yarn, the fiber from a modified fibroin derived protein and the regenerated cellulose fiber are blend-spun so that an amount of the fiber from a modified fibroin derived protein in the blended yarn becomes 5% to 40% by mass.

11 . The manufacturing method according to claim 7 , wherein the modified fibroin derived protein is derived from a spider silk fibroin protein.

12 . The manufacturing method according to claim 7 , wherein the regenerated cellulose fiber is a lyocell fiber.

13 . The blended yarn according to claim 1 , wherein

the fiber from a modified fibroin derived protein comprises a domain sequence represented by Formula 1: [(A) n motif-REP] m , and

the domain sequence has an amino acid sequence with a reduced content of (A) n motifs, which corresponds to an amino acid sequence in which at least one or a plurality of (A) n motifs are deleted, as compared with a naturally occurring fibroin,

wherein in Formula 1, the (A) n motif represents an amino acid sequence composed of 2 to 27 amino acid residues and the number of alanine residues with respect to a total number of amino acid residues in the (A) n motif is 83% or more;

REP represents an amino acid sequence composed of 10 to 200 amino acid residues;

m represents an integer of 2 to 300;

a plurality of the (A) n motifs may have the same amino acid sequence or amino acid sequences different from each other; and

a plurality of REPs may have the same amino acid sequence or amino acid sequences different from each other.

14 . The blended yarn according to claim 1 , wherein

the fiber from a modified fibroin derived protein comprises a domain sequence represented by Formula 1: [(A) n motif-REP] m , and

the domain sequence has an amino acid sequence comprising a region having a locally high hydropathy index, which corresponds to an amino acid sequence in which one or a plurality of amino acid residues in REP are substituted with an amino acid residue having a high hydropathy index and/or one or a plurality of amino acid residues having a high hydropathy index is inserted into REP, as compared with a naturally occurring fibroin,

wherein in Formula 1, the (A) n motif represents an amino acid sequence composed of 2 to 27 amino acid residues and the number of alanine residues with respect to a total number of amino acid residues in the (A) n motif is 83% or more;

REP represents an amino acid sequence composed of 10 to 200 amino acid residues;

m represents an integer of 2 to 300;

a plurality of the (A) n motifs may have the same amino acid sequence or amino acid sequences different from each other; and

a plurality of REPs may have the same amino acid sequence or amino acid sequences different from each other.

15 . The blended yarn according to claim 1 , wherein

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

the domain sequence has an amino acid sequence with a reduced content of glutamine residues, which corresponds to an amino acid sequence in which one or a plurality of glutamine residues in REP are deleted or substituted with other amino acid residues, as compared with a naturally occurring fibroin,

wherein in Formula 1 and Formula 2, the (A) n motif represents an amino acid sequence composed of 2 to 27 amino acid residues and the number of alanine residues with respect to a total number of amino acid residues in the (A) n motif is 80% or more;

REP represents an amino acid sequence composed of 10 to 200 amino acid residues;

m represents an integer of 2 to 300;

a plurality of the (A) n motifs may have the same amino acid sequence or amino acid sequences different from each other; and

a plurality of REPs may have the same amino acid sequence or amino acid sequences different from each other.

16 . The blended yarn according to claim 1 , wherein

the modified fibroin derived protein has a limiting oxygen index (LOI) value of 26.0 or more.

17 . The blended yarn according to claim 1 , wherein

the modified fibroin derived protein has

a maximum hygroscopic heat generation, as determined according to the following formula A, of the derived protein is more than 0.025° C./g:

Maximum hygroscopic heat generation={(Highest temperature of a sample when the sample has been transferred to a high humidity environment after being placed in a low humidity environment until a temperature of the sample reaches equilibrium)−(Temperature of the sample when the sample is being transferred to the high humidity environment after being placed in the low humidity environment until the temperature of the sample reaches equilibrium)} (° C.)/Sample weight (g),  Formula A:

wherein in Formula A, the low humidity environment means an environment of a temperature of 20° C. and a relative humidity of 40%, and the high humidity environment means an environment of a temperature of 20° C. and a relative humidity of 90%.