Abstract
Textile dyeing with vat dyes has the highest color fastness although one and the same dye of all vat dyes cannot always satisfy every color fastness requirement. So we examined cotton, nylon 6, and polyester fabrics dyed with vat dyes. Cotton, nylon 6 and polyester fabrics were dyed with vat dyes such as C. I. Vat Blue 1, Blue 19, Black 9, Green 1, Orange 2, and Violet 1 containing sodium hydrosulfite and NaOH. Oxidation were carried out by a sodium peroxoborate after dyeing. The dyed materials were soaped at the boil after oxidation. Especially hydrolysis and overreduction for dyed polyester with vats dyes containing -NHCO- and -NH- groups such as C. I. Vat Blue 6, Black 25, Black 27, Red 10, and Green 3 occurred. It seems that these phenomena are due to a high dyeing temperature. Wash and rubbing fastness of nylon are higher than that of cotton and polyester. Light fastness of cotton is higher than that of polyester and nylon.