Лако-красочные материалы — производство

Dehydrothiotoluidinesulfonic acid—N ^ ^N "Dehydrothiotoluidinesulfonic acid—NH An amount of dehydrothiotoluidinesulfonic acid, equivalent to 14 grams of sodium nitrite, is dissolved in 25 grams of 30 per cent sodium hydroxide. Half of this solution is acidified with 25 cc. concentrated hydrochloric acid and diazotized at 10°C. in the course of 2 hours with 7 grams of […]

Dehydrothiotoluidinesulfonic acid—N II Dehydrothiotoluidinesulfonic acid—N A solution of 67.4 grams (0.2 mole) of the pure (100 per cent) am­monium salt of dehydrothiotoluidinesulfonic acid (equivalent to 14 101 Cf. Brunner, Dissertation, Zurich, 1943. grams of sodium nitrite) in 300 cc. water containing 8.2 grams of pure sodium hydroxide is boiled to expel ammonia. Traces of ammonia […]

In the early days of primuline manufacture, dehydrothiotoluidine was a by-product and was remelted with sulfur to make primuline base. Today, the situation is reversed, and the previously worthless dehydro­thiotoluidine has become the main product, while primuline is the by­product. The dehydrothiotoluidine can be obtained pure by vacuum distillation.101 Unfortunately, it is not possible to […]

Method 1. The cooled, solidified melt is pulverized and mixed in­timately with 1 per cent of its weight of soda ash which serves to prevent clumping in the sulfonation. 100 grams of the melt is added to 300 grams of 100 per cent sulfuric acid at any desired temperature. When solution is complete (about 1 […]

Primuline Chloramine Yellow FF (Naphthamine Yellow NN) and Thiazole Yellow NH, 0" CH, p-Toluidine In general, the reaction of sulfur with an aromatic amine gives a substitution product in which the aromatic nuclei of two molecules are connected through a sulfur atom. Such reactions, however, always give mixtures of products, and it is usually impossible […]

The product from (b) is dissolved in 1 liter water and treated with 50 grams of concentrated sulfuric acid, previously somewhat diluted. 40 grams of flowers of sulfur is added and the mixture is stirred for 3 hours at 95°C., adding water from time to time. The resulting dye is allowed to settle, and is […]

A mixture of 50 grams of well dried О acid and 100 grams of technical sodium hydroxide is ground in a ball mill for 24 hours. The mixture is then placed in a vacuum baking apparatus (Fig. 30, page 181) which is evacuated and heated, as uniformly as possible by means of an oilbath, to […]

To prepare indigo from the sulfuric acid solution of isatinanilide, it is not necessary to isolate the pure anilide or its hydrochloride. A solu­tion of sodium hydrosulfide is prepared by introducing hydrogen sul­fide into a solution of 45 grams of sodium hydroxide in 150 cc. water. This solution is mixed with the sulfuric acid solution […]

The ring closure to an isatin derivative takes place only under cer­tain, accurately controlled conditions. It is important that the reaction be carried out in hot sulfuric acid. In the course of 15 minutes, 200 grams of pure, dry, finely divided “thioamide” is added to 800 grams of 94 per cent sulfuric acid (66° Be) […]

The addition of hydrogen sulfide to the hydrocyanocarbodiphenyli­mide takes place very easily if the latter is finely powdered. The material is therefore ground in a roller mill or sifted. 200 grams of the finely divided material is emulsified by vigorous stirring at 35°C. in 500 grams of yellow ammonium sulfide solution. (The reaction can be […]