Лако-красочные материалы — производство

Xylene blue belongs to the group of so-called patent blues which are sulfonated triphenylmethane dyes that are stable to alkali. The dyes are all characterized by having a sulfo group in the position ortho to the central carbon atom as in the following general formula: s Na Sandmeyer first explained the relation between structure and […]

In a 300-cc. flask, a mixture of 36.3 grams (0.3 mole) of dimethyl — aniline, 24 grams (0.2 mole) of 30 per cent hydrochloric acid, and 10.6 grams (0.1 mole) of benzaldehyde is heated for 12 hours under reflux. The end of the condenser should be closed with a plug of cotton or glass wool […]

Auramine OO[60] In an apparatus such as that shown in Figure 36a and b, a mixture of 127 grams (0.5 mole) of 4,4′-tetramethyldiaminodiphenylmethane (page 137), 32 grams of sulfur, 70 grams of ammonium chloride, and 1000 grams of pure sodium chloride, is heated to 110°C. It is essential that all of the materials be very […]

100 grams of p-nitrotoluene is added to 280 grams of 25 per cent oleum, and the mixture is heated to 100°C. while being stirred with a glass or iron stirrer. The sulfonation should be complete within 20 min­utes; if necessary, additional fuming sulfuric acid is added. A test sample, mixed with water, should have no […]

Cl ^ —N— N— OH — HO N^N—/ OH HOOC COOH HOOC COOH in. p. 288° (dec.) m. p. 277° (dec.) A solution containing the equivalent of 17 grams of pure chloro — aminobenzoic acid, prepared, for example, as described on page 169, is acidified with 30 cc. 30 per cent hydrochloric acid and cooled […]

0. 1 mole (18.4 grams) of technical benzidine is tetrazotized as de­scribed on page 261. The clear tetrazo solution is poured rapidly into a solution of 15 grams of pure salicylic acid and 40 grams of soda ash in 300 cc. water at 5°C. The orange yellow intermediate compound separates, and the reaction is completed […]

Benzidine can be combined with all of the phenols and amines which are commonly used in preparing azo dyes. It happens that only one of the two diazo groups in tetrazobenzidine is highly reactive while the other is rather inactive. It is possible, therefore, to make not only the benzidine dyes employing two molecules of […]

A solution is made by dissolving 36.6 grams of pure toluylenediamine in 1 liter water at 40°C., and to this solution, after cooling, is added 16.5 grams of 100 per cent sodium nitrite. The volume is brought to 1600 cc. by adding ice, and a mixture of 60 grams of concentrated hydrochloric acid and 40 […]

A paste is made of the reprecipitated disazo dye with 75 cc. 2 N soda solution and 150 cc. water, the equivalent of 3.5 grams of pure sodium nitrite is added, and the mixture is heated to 80°C. to form a clear solution. The solution is cooled to about 60° and added, over a period […]

The filtered solution of the monoazo dye from (a) is treated with 22 cc. 20 per cent sodium nitrite solution (30 per cent excess is used; the excess sodium nitrite assists in bringing about complete diazotization), and the resulting diazo solution is added from a dropping funnel to a well stirred, cooled (10°C., but not […]