DE263431C - Process for the preservation of diazotized nitroaniline solutions - Google Patents

Description

IMPERIAL

PATENT OFFICE.

PATENT LETTERING

CLASS Sm. GROUP

When using the diazotized nitroanilines in dyeing and printing you have with to fight the problem that the diazo solutions or the printing inks produced from them quickly become unusable.

The observation has now been made that the addition of aromatic Sulfonic acids or their salts, such as naphthalene sulfonic acids or anthraquinone sulfonic acids

ίο the diazo solutions in a simple way this Can help. You can add this before or after the diazotization Make Nitraniline.

It is noteworthy that even relatively small amounts of the sulfonic acids are sufficient for this purpose. If you use z. B. a naphthalene ^{trisulfonic acid, 1} / _i to ^x / _{3 of} the weight of the nitroaniline used is sufficient to achieve an excellent shelf life. However, it is known from the literature that stable salts of p-nitrodiazobenzene can be prepared in solid form with the aid of sulfonic acids of naphthalene. From this fact, however, one could not foresee that the aqueous solutions of the diazotized nitroanilines could be preserved even with amounts of these sulfonic acids that were far below theoretical.

the

Example.

For the production of Paranitranilinrot, fabric is made with a solution 250 g ß-naphtol,

250 ecm caustic soda, 36 ⁰ Be., 3000 ecm water,
500 g Turkish red oil, 50 percent, 100 g clay soda,
1000 ecm of water,

500 g tragacanth ⁶⁵ t

₁₀₀₀

40

On this preparation

45

10

padded, dried,
is printed:

17.7 g of paranitraniline base are in 51.6 ecm hydrochloric acid, 22 ° Be.,
51.6 ecm of boiling water dissolved. 128.9 ^{cc of} ice water are added and
64.5 g of ice and slowly stirred 9.9 g of sodium nitrite, in

64.5 ecm of water dissolved, too. Leave for 15 minutes stand, then add g · 3 · 6-naphthalene trisulfonic acid, stir Add 560.3 g of starch-tragacanth thickener and sodium acetate before use.

ι kg.

^! 3391

The naphthalene trisulfonic acid can as well

after stirring in the thickening or after adding the sodium acetate can be added. After printing, the goods are dried and washed.

Likewise, other aromatic sulfonic acids or their salts, such as ι · 6-, 1-5-, 2 · 7-, 2 · 6-naphthalene disulfonic acids, benzene mono- and disulfonic acids or toluenesulfonic acids or their Salts are used.

Claims (1)

Patent claim: Process for the preservation of diazotized nitroaniline solutions, consisting therein that the nitroanilines before or after the diazotization less than the corresponding amounts of aromatic Adds sulfonic acids or their salts.