Лако-красочные материалы — производство

A solution of 350 grams of lead nitrate in 1 liter hot water is treated carefully at 95°C. with about 120 grams of soda ash and the precipitated basic lead carbonate is washed thoroughly with water. The moist material is transferred to a 2-liter flask fitted with stirrer and reflux condenser (Fig. 6) and mixed […]

Although the Sandmeyer indigo synthesis is no longer used, it is such an interesting example of the combined efforts of science and in­dustry that it deserves a place in this book. The process involves the following steps: (a) Aniline is converted to thiocarbanilide (A. W. Hoffmann) by heating with carbon bisulfide: 2 (/’4’j NH2 + […]

1, Heumann Synthesis[66] [67] (a) Phenylglycine-o-carboxylic Acid" COONa л COOH /V I + C1CH,—COONa = + NaC1 NH—CH,—COONa A paste of 137 grams (1.0 mole) of anthranilic acid (page 174) in a small amount of water is exactly neutralized with approximately 120 grams of 40° Вё sodium hydroxide solution. A second solution is pre­pared by […]

Quinizarin Green or Alizarin Cyanine Green G In a 1.5- to 2-liter round-bottomed flask fitted with a downward con­denser, stirrer, and thermometer, a mixture of 500 grams of p-toluidine and 60 grams (0.25 mole) of quinizarin (page 237) is heated to 80°C., and to it is added, with stirring, a mixture of 18 grams of […]

(a) Mordant Dyes Alizarin CO CO CO Anthraquinone-2′ 1-Hydroxyanthra — Alizarir sulfonic acid quinone-2-sulfonic acid Alizarin (1,2-dihydroxyanthraquinone) is formed by alkali fusion of sodium anthraquinone-2-sulfonate (“silver salt”). The reaction is rather remarkable in that not only is the sulfo group replaced by hy­droxyl, but a second hydroxyl is also introduced. The presence of an oxidizing […]

The formation of methylene blue is interesting both scientifically and technically, and should be reviewed briefly before the actual pro­cedure is described. (a) Nitrosodimethylaniline is prepared from dimethylaniline by treament with nitrite in acid solution. The nitroso compound is then reduced to form p-aminodimethylaniline. NO NH2 (b) The p-aminodimethylaniline is oxidized in acid solution with […]

In a glass vessel equipped with reflux condenser and stirrer (Fig. 6), a solution of 20 grams of gallamide (page 170) of about 92 per cent purity (the purity is determined by distilling off the ammonia from a sodium hydroxide solution and titrating) in 500 cc. 90 per cent alcohol is heated to boiling, and […]

Gallamine Blue from Gallamide Nitrosodialkylanilines react with gallic acid or gallamide under the influence of heat to form well defined compounds designated as oxa — zines. The gallic acid is obtained exclusively from natural tannins. p-Nitrosodi — Gallamide Gallamine blue methylaniline (One molecule of nitrosodimethylaniline serves asan oxidizing agent.)(a) Nitroiodimethylaniline A mixture of 100 grams […]

The solution from (b) is mixed with 45 grams of sulfuric acid (66° Вё) and 100 grams of diethylaniline, and boiled under reflux for 2 days. The mixture is then made strongly alkaline by the addition of about 100 grams of 30 per cent sodium hydroxide solution, and the excess diethyl­aniline is driven off with […]

To the acid mixture from (a) is added, in small portions, 125 grams of 80 per cent Weldon mud.* The additions are made over a period of 2 to 3 hours at a temperature of about 25°C. When the addi­tions are completed, the mixture is stirred for 3 hours at 30°, and then is heated […]