Leather-like sheet and fiber structure

2:

• The leather-like sheet of claim 1, wherein the blue cationic dye having the azo bond comprises C.I. Basic Blue 54.

3:

• The leather-like sheet of claim 1, wherein the fibers have a fineness of 0.05 to 1 dtex.

4:

• The leather-like sheet of claim 1, wherein the fibers are polyester fibers.

5:

• The leather-like sheet of claim 1, which has a color difference (ΔE) before and after a moist heat treatment, determined when subjected to the moist heat treatment at 80° C. and a humidity of 90% for 48 hours, of ΔE≤2.

6:

• The leather-like sheet of claim 1, which has a surface having an L* of ≤35 in a color coordinate space (L*a*b* color space).

7:

• The leather-like sheet of claim 1, which is a suede-like artificial leather having a napped surface.

9:

• A fiber structure, comprising:
• fibers comprising a dye comprising a blue cationic dye having an azo bond;
• and a polyhydric phenol derivative having anionic properties.

10:

• The fiber structure of claim 9, wherein the blue cationic dye having the azo bond comprises C.I. Basic Blue 54.

11:

• The fiber structure of claim 9, wherein the fibers are polyester fibers having a fineness of 0.05 to 1 dtex.

12:

• The fiber structure of claim 9, which has a surface having a color difference (ΔE), determined when subjected to a moist heat treatment at 80° C. and a humidity of 90% for 48 hours, of ΔE≤2.

13:

• A fiber structure, comprising:
• polyester fibers comprising a dye comprising a blue cationic dye having an azo bond,
• wherein the fiber structure has a color difference (ΔE) before and after a moist heat treatment, determined when subjected to the moist heat treatment at 80° C. and a humidity of 90% for 48 hours, of ΔE≤2.