This invention relates to an improved method for the preparation of highly or substantially pure Indigotindisulfonate sodium (1). It further relates to the novel crystalline form I of Indigotindisulfonate sodium (1) and the process for its preparation.

This invention relates to an improved method for the preparation of highly or substantially pure Indigotindisulfonate sodium (1). It further relates to the novel crystalline form I of Indigotindisulfonate sodium (1) and the process for its preparation.

This invention relates to an improved method for the preparation of highly or substantially pure Indigotindisulfonate sodium (1). It further relates to the novel crystalline form I of Indigotindisulfonate sodium (1) and the process for its preparation.

This invention relates to an improved method for the preparation of highly or substantially pure Indigotindisulfonate sodium (1). It further relates to the novel crystalline form I of Indigotindisulfonate sodium (1) and the process for its preparation.

The present invention refers to a process for purifying leucoindigo salt solutions, for removal of aromatic amines, particularly aniline and N-methylaniline, comprising: adding to a purification vessel a leucoindigo salt solution containing aromatic amines, said solution in the form of a stationary mass; bubbling with a controlled flow rate an inert gas in the purification vessel, by means of a device submerged at the surface of the stationary mass; injecting with a controlled flow rate a gas purification current into the vessel, by means of a device submerged at the stationary mass; and recovering the purified solution from the vessel. It also refers to the use of inert gas in a process for purifying leucoindigo salt solutions, acting as a gas anti-foaming agent, to reduce foam and chances of product stripping during processing.

The present invention refers to a process for purifying leucoindigo salt solutions, for removal of aromatic amines, particularly aniline and N-methylaniline, comprising: adding to a purification vessel a leucoindigo salt solution containing aromatic amines, said solution in the form of a stationary mass; bubbling with a controlled flow rate an inert gas in the purification vessel, by means of a device submerged at the surface of the stationary mass; injecting with a controlled flow rate a gas purification current into the vessel, by means of a device submerged at the stationary mass; and recovering the purified solution from the vessel. It also refers to the use of inert gas in a process for purifying leucoindigo salt solutions, acting as a gas anti-foaming agent, to reduce foam and chances of product stripping during processing.

The present invention relates to the use of indigo derivatives for dyeing synthetic textiles to a process for dyeing synthetic textiles and to dyed textiles and articles containing them. The invention also relates to novel indigo derivatives per se and to a process for the preparation thereof.

The present invention relates to the use of indigo derivatives for dyeing synthetic textiles to a process for dyeing synthetic textiles and to dyed textiles and articles containing them. The invention also relates to novel indigo derivatives per se and to a process for the preparation thereof.

The present disclosure provides methods for digital printing using modified indigo dye compounds.

The present disclosure provides methods for digital printing using modified indigo dye compounds.