| abstract |
To provide a use of quercetin as a dye. To provide a method for staining with quercetin. [MEANS FOR SOLVING PROBLEMS] By using quercetin sulfonic acid or a salt thereof and a metal (aluminum, iron, copper, etc.) in combination, a protein product such as silk is dyed. Further, by using quercetin sulfonic acid or a metal salt thereof together with a protein such as soybean protein and a metal or a metal compound, even a cellulose product such as cotton, which is considered difficult to dye, is dyed. [Selection figure] None |