Rope dyeing process using halogen indigo derivative and dyed article thus obtained
AssigneeMitsui Toatsu Chemicals, Inc.
InventorsHitoshi Koshida, Tetsuo Sakagawa, Takayuki Nakayama, Hiroshi Suwa
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Abstract
Disclosed is a dyeing process for rope dyeing denim cotton yarns a fashion blue color which comprises the steps of forming the yarns into a rope; repeatedly immersing the rope in a dye bath containing a reduced water soluble form of a halogenated indigo derivative which is air oxidizable, squeezing the rope to remove dye bath liquid therefrom exposing the damp rope air to air oxidize the reduced form of the indigo derivative in the yarn; and then further oxidizing the incompletely oxidized reduced form of the indigo derivative in the yarn forming the rope in an oxidizing bath containing a chemical oxidant, e.g., sodium perborate.
Claims12
A process for rope-dyeing cotton yarn which comprising repeatedly immersing a rope of the yarns in an aqueous dye bath containing dissolved therein an air oxidizable reduced soluble form of an indigo derivative of the formula ##STR2## wherein X is a bromine or chlorine atom, and n is an integer from 1 to 6, squeezing dye bath liquid therefrom and air oxidizing the reduced form of indigo derivative in squeezed damp rope;
- and thereafter further oxidizing the reduced form of the indigo derivative in the squeezed and air oxidized rope in an oxidizing bath containing a chemical oxidant.
The process of claim wherein the steps are conducted continuously with a continuous length of rope.
Dependencies are inferred from the claim text.