Лако-красочные материалы — производство

SO3H SO3H SOaH SO3H Freund acid Monoazo dye (valueless) SO3H One-tenth mole of Freund acid (mol. wt. 325; acid sodium salt, C10H8O(jS2NNa) is dissolved in 300 cc. warm water containing 5.6 grams of soda ash. (Freund acid is usually only 75 to 80 per cent pure since it must be precipitated with large amounts of […]

The reaction of diazotized sulfanilic acid with diphenylamine is an sible to carry out the* reaction in neutral or alkaline solution because interesting example of coupling in mineral acid solution. It is not pos — diazosulfanilic acid is immediately decomposed by soda and, surprising­ly, does not react at all in neutral solution. Furthermore, diphenylamine Coupling […]

10 grams of the dye prepared above is boiled under reflux with 250 cc. water and 25 cc. 2 N sodium hydroxide until solution is com­plete. The solution is cooled and filtered through a fluted filter. The fil­trate is added slowly to a vigorously stirred solution, held at 25-30°C., containing 8 grams of crystalline calcium […]

14.3 grams (0.1 mole) of a-naphthylamine is dissolved by boiling in a mixture of 280 cc. water and 10 cc. concentrated hydrochloric acid, and the solution is cooled under the tap with shaking so that the naph — thylamine hydrochloride crystallizes out in as finely divided a state as possible. An additional 75 cc. concentrated […]

This is the simplest member of the pyrazolone dyes which are pre­pared in two ways: (a) from dihydroxytartaric acid and phenylhy — drazine (tartrazines), and (b) from phenylmethylpyrazolones by cou­pling with diazo compounds. The second method is simpler and has largely displaced the older, first method. The pyrazolone is prepared from a given phenylhydrazine (e. […]

Single Coupling Reactions with Hydroxy Compounds Acid Orange A or Orange II OH

(o-Tolidine, o-Dianitidine) A solution is made by heating to 70°C. a mixture of 18.4 grams (0.1 mole) of technically pure benzidine, 23 cc. 30 per cent hydrochloric acid, and 150 cc. water. (If a perfectly clear solution is desired, hydro­chloric acid which is free from sulfuric acid must be used.) The solu­tion is cooled to […]

(Metanilic Acid, Naphthionic Acid, ISitroanilinetulfonic Acid,Cldoroanilinemlfonic Acid, Diaminostilbenedimlfonic Acid,Primulineeulfonic Acid, etc.) A solution of sulfanilic acid, equivalent to 17.3 grams (0.1 mole) of 100 per cent material, in 100 cc. water containing 5.5 grams of soda (if the sulfonate is used instead of the free sulfonic acid, the soda is omit­ted, of course) is treated […]

a-Naphthylamine (14.3 grams, 0.1 mole) is dissolved in 22 grams of 30 per cent hydrochloric acid and 100 cc. hot water, and the solution is cooled to 0°C. by the addition of 200 grams of ice. 60 grams of salt is then added, and when the temperature has dropped to about —5°, 20 grams of […]

Since p-nitroaniline does not form water stable salts, the base must be obtained in a highly divided state before the diazotization reaction. A clear solution of 13.8 grams (0.1 mole) of technical p-nitroaniline in 30 cc. concentrated hydrochloric acid and 30 cc. water at 80-90°C. is added with good stirring to a mixture of 50 […]