| Name | Sulphur Brown 4 |
| Synonyms | C.I. 53210 Diresul Brown R Sulphur Brown 4 Sofral Brown CGN Sulfanol Olive TR Pirocard Brown CGN Sofral Dark Brown CRN Thionol Black Brown R |
| CAS | 硫化棕4 |
| Physical and Chemical Properties | Chemical brown powder. Easy to absorb moisture. Insoluble in water, soluble in sodium sulfide solution. It produces black-brown precipitate in hydrochloric acid; it is blue-green in concentrated sodium hydroxide solution. |
| Use | Uses vulcanized deep brown GN is mainly used for dyeing cotton, hemp, viscose fiber and its fabrics, and also used for dyeing of Vinylon and cotton blended fabrics, with poor levelness. It is also used for dark brown dyeing. |
Using mixed cresol (or m-cresol, p-cresol) as raw materials, the mixed cresol (or m-cresol, p-cresol) and sodium polysulfide are baked at 270-755 ℃. Copper sulfate can be added or not added. The finished product is obtained by crushing.