Лако-красочные материалы — производство

Aniline (Toluidine, Xylidine, m-Nitroaniline) A mixture of 9.3 grams (0.1 mole) of aniline in 30 cc. hot water is stirred with a glass rod while 25 cc. concentrated hydrochloric acid is added in a thin stream. The solution is allowed to cool to about 40°C., and enough ice is added to lower the temperature to […]

(a) Aminoazo Dyes. Dyes of this group which contain several amino groups, such as combinations with m-phenylenediamine, have, in general, pronounced basic characteristics (chrysoidine, Bismarck brown). They form water-stable salts with mineral acids and are gen­erally used in this form. Such salts can be isolated by acidifying the coupling reaction mixture with the acid concerned […]

The optimum conditions for coupling depend largely on the nature of the coupling component, but also on the nature of the diazo com­pound. Phenols and Enolizable Keto Compounds. These compounds are coupled in alkaline (soda) solution as a rule. If the coupler is a sul­fonic or carboxylic acid, or is soluble in water (e. g., […]

The following types of compounds undergo coupling reactions with diazo compounds: (a) Phenols, (fe) Enolizable keto compounds of an aliphatic character, having a “reactive methylene group” which may be part of an open chain or a ring system, either homocyclic or hetero­cyclic. This group of compounds may be represented by the formula: X—СН4—CO—V ±=Ї X—CH […]

1. Aniline. A solution of 9.3 grams (0.1 mole) of aniline (purified by redistillation if necessary) in 125 cc. 2 N hydrochloric acid is cooled in a beaker surrounded by ice and stirred with a turbine or electric motor. (The quantities given in all examples assume 100 per cent material; the quantities must be increased, […]

The diazotization reaction proceeds according to the equation: R—NHj + NaNO, + 2 HC1 = R—N==N + NaCl + 2 H,0 Cl Hydrochloric acid is usually employed in diazotizations in aqueous solutions because it gives, in general, the most soluble salts with aromatic amines. If sulfuric acid is used, only 0.5 mole is used in […]

(a) Fundamental Considerations The following points are of great importance: (1) The starting materials should be pure; (2) The quantities of materials should be measured accurately; (3) Vigorous and continuous stirring, or shaking, should be used, both in the diazotization and in the coupling; and (4) Diazo compounds should be protected from heat and light. […]

The azo dyes constitute the largest and most varied group of syn­thetic organic dyes in use today. They will therefore be treated in con­siderable detail. The discussion will deal first with the general factors involved in the preparation of azo dyes, and a series of diazotization procedures will be given which have proven satisfactory, particularly […]

Isomeric dinitroanthraquinones QUINIZAMN FROM p-CHLOROPHENOL(a) 1 £-Dinitroanthraquinone To a solution of 100 grams of pure anthraquinone (m. p. 278-279°C) in 2000 grams of 100 per cent sulfuric acid is added, at 25° and with good stirring over a period of 30 minutes, 460 grams of mixed acid (230 grams of nitric acid (sp. g. 1,52) […]

The preparation of 1-aminoanthraquinone is quite similar to that of the 2 isomer, except that the sulfonation is carried out in the presence of mercury salts which direct the sulfo group to the a position to the extent of 98 per cent. NH, / + Hg salt k J ) + Na nitroben x Co’ […]