DE102821C - - Google Patents

Description

IMPERIAL / ί

PATENT OFFICE

By the action of a little concentrated sulfuric acid on diphenylamine at high Merz and Weith (Ber. D. D. Former Ges. 6, 1512) have a mono and a temperature Obtained disulto acid of diphenylamine. Other products appear from the action of Sulfuric acid on diphenylamine has not yet been observed.

It has been shown that if you have a. larger amount more common or better weakly fuming sulfuric acid is allowed to act on diphenylamine at temperatures between 80 and 10 °, one in the main, a mixture of two different bodies, which are distinguished by their different solubility in benzene or toluene let them separate from each other.

50 kg of diphenylamine are dissolved in 50 kg of common sulfuric acid, and after this solution has cooled, 150 kg of oleum of 20 pCt are added. 50 ₃ added and heated to 80 to 100 ° for 10 to 20 hours. A sample is taken from time to time, diluted with water and oversaturated with sodium hydroxide solution. At first the precipitate is white and forms oil droplets when heated. After several hours, however, the oil droplets disappear more and more and the white precipitate takes on a yellowish color. When the reaction is complete, the sulfuric acid mixture is poured onto water and ice, filtered, and all the sulfuric acid is washed out with water. The substance obtained in this way forms a pale yellowish powder. It is insoluble in water, alkalis and dilute acids. Diluted hydrochloric acid or sulfuric acid turn the powder brown. In concentrated sulfuric acid the substance dissolves with a green color. When heated, the green color turns into an intense blue.

You can use alcohol, acetone or, even better, boiling benzene or toluene break the substance down into two components.

I. The substance A, which is soluble in boiling toluene, crystallizes therefrom on cooling in white leaflets with a melting point of 240 °. They are in boiling alcohol, acetone, Benzene and toluene fairly soluble. The cold benzene or toluene solution fluoresces strong blue. Concentrated sulfuric acid dissolves substance A colorlessly in the cold Upon intense heating, the colorless solution changes from deep blue to dirty red-violet. When it cools down, the blue one comes out Color again.

II. Part B, which is insoluble in boiling toluene, forms a yellowish to brownish powder and is also sparingly soluble or soluble in the other solvents mentioned under I. completely insoluble. Up to now it could not be kept in a state of complete purity. * "Its melting point is above 260 ^° . In cold, concentrated sulfuric acid it dissolves with a pale green color. With strong. Heating, this color changes through a more intense blue into a dirty gray-blue, which color remains even when cooled.

Both substances are obtained in almost equal amounts when exposed to the Sulfuric acid on diphenylamine takes place at approx. 90 ° and does not take much longer * than until the diphenylamine disappeared

Claims (1)

... w ^ -l ^ al. is. At a higher temperature and if the process takes longer, more of the sparingly soluble substance B obtained. In this case the finished product has a yellow to brownish yellow color. Both substances A and B are converted into vigorous reaction by strong nitric acid Polvnitroproducte transferred. It has now been found that these nitro products on heating with sodium sulphide, with or without the addition of sulfur, valuable brown coloring matter deliver, which stain cotton very realistically in an alkaline bath. Since the dyes of the two substances A and B differ only slightly from one another, a separation of the two is unnecessary for the technical production of the dye; four times the amount of nitric acid enters of 44 ⁰ B. with the caution, that the temperature does not exceed 25 °. After it has been completely added, the nitrate mixture is first left to itself and, after a few hours, heated to 50 to 60 °, until the rather lively reaction has ended. It is then diluted with water, filtered, washed very well, and dried. The nitration product forms a brown powder. It is insoluble in most solvents; in alcohol it dissolves with a brownish-red color on the addition of caustic soda. To produce the dye, 60 kg of sodium sulphide (Na ₂ S + 9 aq) are melted in an iron kettle with the addition of 3 kg of water. As soon as the liquid has reached 100 ° ^C. , 9 kg of the nitro product are slowly introduced with thorough stirring. After the reaction is over, is heated further until the mixture at 180 to 200 ⁰ dry has become powdery. The dark brown powder thus obtained is used directly for dyeing. It easily dissolves in warm water with a yellow-brown color. Acids produce in the Solution a dark brown precipitate, which easily dissolves in solutions of alkaline sulfur dissolves again with yellow-brown paint. The solution makes cotton extremely washable and lightfast in cold or warm conditions stained brown tones. Addition of sulfur to the dye melt only affects the properties of the dye little influence. Pa τ ε ν τ - A ν s ρ R υ c η: Process for the preparation of a brown dye directly staining cotton therein insisting that the nitro product obtained in the treatment of the by action from sulfuric acid to diphenylamine at 80 to ι io ° resulting, in water, alkalis and diluted acids of insoluble products with nitric acid - with the proviso that the temperature should not exceed 25 ° during the entry into the nitric acid runs and then heated to 60 ° - is formed, with sodium sulphide with or without additives of sulfur fuses at temperatures of 150 to 2oo °. .