Abstract: Denim cotton warp yarns are rope-dyed with a benzoquinone dye of formula (I): ##STR1## wherein R.sub.1, R.sub.2, R.sub.3, R.sub.1 ', R.sub.2 ' and R.sub.3 ' commonly or independently represent a hydrogen atom, a halogen atom, alkyl, cycloalkyl, alkenyl, aryl, aralkyl, alkoxyl or alkoxyalkyl alone or in combination with a red .DELTA..sup.2,3' -biindolin-3,2'-dione dye and/or a blue indigoid dye or sequentially with the latter dye.

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.

Abstract: Dyed denim cotton yarns capable of meeting the market demand for color jeans can be provided by immersing denim cotton yarns in a dye bath containing a dye or dye composition comprising a specific indirubin derivative(s), a specific quinophthalone derivative(s) and/or an indigo dye, squeezing and air-oxidizing the dyed yarns, and repeating a series of these steps.

Abstract: Disclsoed herein is dye suitable for use in dyeing denim cotton yarns. The dye comprises at least one quinophthalone derivative represented by the following general formula (I) or (II): ##STR1## wherein X means H, Br or Cl and Y denotes H, COOR or --COOC.sub.2 H.sub.4 OR (R: alkyl), or a combination of said at least one quinophthalone derivative and an idigo dye. A dyeing process making use of the above dye and denim cotton yarns thus dyed are also disclosed.

Abstract: An optoelectronic semiconductor device for use in an optical transmission system comprises a stem for mounting an optoelectronic semiconductor element thereon and a cap within which an optical fiber, optically communicating with the optoelectronic semiconductor element, is arranged. An end of the optical fiber within the cap is exposed on the cap surface. A screw is formed on the outer suface of the cap and a nut, which engages the screw, is provided for optically connecting optical transmission fiber with the optical fiber within the cap.