Лако-красочные материалы — производство

These two important sulfonic acids can be prepared in various ways. Three methods are used for preparing у acid, while J acid, so far as is known, is prepared only from naphthylamine, although by varying procedures. The starting material in all cases is /З-naphthol; the reac­tions involved are shown in the following scheme. We shall […]

(the preparation starting with 1 mole would require too large a volume) of Д-naphthol is dissolved at 50°C. in a mixture of 65 grams of 35 per cent sodium hydroxide solution and 750 cc. water. To this solution, which should have a distinct, but weak, reaction to thiazole paper, are added 36 grams of 100 […]

The filter cake of sodium 2-naphthol-l-sulfonate, obtained under (a) , is placed in an enameled autoclave of about 1-liter capacity with 250 cc. 20 per cent ammonia and an ammonium bisulfite solution prepared by saturating 60 cc. 20 per cent ammonia with S02 with cooling. The mixture is heated in the autoclave for 8 hours […]

In a 1-liter, five-necked flask, fitted with a stirrer, preferably of the paddle type, operating through a mercury seal in the center neck, a dropping funnel, a thermometer, a gas inlet tube, and a gas outlet tube, 72 grams (0.5 mole) of dry Д-naphthol is treated with 280 grams of hot (100°C.) completely dry nitrobenzene. […]

If G acid is desired as the chief product, the reaction is effected with a larger quantity of sulfuric acid and higher acid strength, at a moderate temperature, in no case over 60°C. To 200 grams of 100 per cent sulfuric acid, well stirred and cooled in running water, is added 72 grams (0.5 mole) […]

To 250 grams of concentrated sulfuric acid (66° Вё) is added, with stirring, 144 grams (1.0 mole) of finely powdered, pure /ї-naphthol. The temperature rises to about 30°C. The mixture is heated for 8 hours in a boiling water bath, and then poured while still warm into 1 liter water. The diluted solution is held […]

Sulfonation of /З-naphthol under various conditions of temperature and sulfuric acid concentration gives rise to a whole series of mono — and polysulfonic acids. Only a few of the typical reactions will be described in detail here in order to give the beginner a picture of this field of intermediates. The first product formed by […]

p Salt and NaCl (grams in 100 grams of solution) 25 °С. 30°c. 40°C. 50°C. 65′ ■c. p Salt NaCl p Salt Nad P Salt NaCl p Salt Nad p Salt NaCl 5.58 0 6.24 0 7.98 0. 9.75 0 14.6 0 3.46 2.38 1.21 4.84 1.46 5.62 4.15 2.9 8.47 2.93 0.31 9.19 0.16 […]

The rfaphthalenesulfonic acids find very little direct use in the preparation of dyes, but they are of great technical importance as steps in the preparation of important intermediates such as /З-naphthol and ft- naphthylamine, dihydroxynaphthalenes and aminonaphthols, and numerous naphthylamine-, naphthol-, and aminonaphthol-sulfonic acids. As was pointed out in the section on orientation rules, the […]

In the preparation of naphthalene derivatives, good yields are ob­tained only if the naphthalene used as the starting material is of the highest purity. If a good grade of naphthalene is not at hand, it is recommended that the material be purified, first by distillation, and then by treating it with 5 per cent of […]