DE266356C - - Google Patents

Description

IMPERIAL

PATENT OFFICE.

PATENT LETTERING

- M 266356 CLASS 22 a. GROUP

in Basel.

Process for making nouns azo dyes. Patented in the German Empire on April 14, 1912.

R-N = NR ₁ -NH -CO-HN

combined with diazo compounds. The mixed urea derivatives of the above formula (where R and R ₁ denote two identical or different radicals of the benzene or naphthalene series, at least one of which contains the sulfo group) can be easily prepared by referring to a molecular mixture of 2: 5-aminonaphtol- 7-sulfonic acid and a sulfated aminoazo compound (such as, for example, aminoazobenzene sulfonic acid) in a solution containing soda-alkaline or sodium acetate allows phosgene to act. The urea derivatives obtainable in this way have substantive properties in and of themselves, in that they are absorbed from an alkaline solution onto cotton with a green-yellow to orange-yellow shade, which can be developed to brown by post-treatment with nitrodiazobenzene. However, these colorations are of no particular interest in coloring. In contrast, it has been shown that by combining these urea derivatives with diazotized amines or aminoazo compounds valuable dyes are obtained which, in addition to good acid fastness, are obtained

-SOoH

OH 40

partly characterized by particularly clear nuances and good lightfastness.

The possibility of using the existing constitution by means of mixed ureas Acquiring nouns azo dyes was not a given. Because, on the one hand, these urea derivatives differ of the known ureas, which contain two aminonaphthol sulfonic acids and are already used to build up azo dyes are, in that they contain only one aminonaphthol sulfonic acid residue and accordingly are only capable of forming monoazo dyes, whereas the ureas used in the known processes are capable of not only monoazo but also disazo dyes because of the presence of two aminonaphthol sulfonic acid residues to deliver. With regard to the monoazo dyes, however, it should be noted that they have only a low affinity for cotton. from Most of the known disazo dyes mentioned above are also used for cotton dyeing practically useless because they are too difficult to dissolve. The same lack of serious ones

Solubility is also shown by the dyes which differ from that of 2 · s-aminonaphthol-γ-sulfonic acid and p-aminoacetanilide derived urea. In contrast, own now the present dyes have a sufficient solubility for all purposes of dyeing, without this being associated with a reduction in the affinity for cotton.

The representation of the urea derivatives required as starting material ίο and their transfer in the dyes is illustrated by the following examples:

Example i.

130 parts of 2: 5-aminonaphthol-7-sulfonic acid (sodium salt) are dissolved together with 150 parts of aminoazobenzenesulfonic acid (sodium salt) in 3000 to 3500 parts of water with the addition of 80 parts of sodium acetate, and phosgene is then slowly introduced ^{at about 40 to 50 ° C.} Towards the end of the reaction, 210 parts of soda are added, so that at the end there is an alkaline reaction. It is then boiled and the mixed urea derivative is salted out in the form of the sodium salt. When dry, this forms a brownish powder which dissolves in water with a greenish-yellow color. The aqueous solution gives a purple precipitate on addition of ■ mineral acids. The urea derivative dissolves in concentrated sulfuric acid with a yellow-red color; when the sulfuric acid solution is diluted with water, a purple precipitate is formed.

Claims (1)

Patent claim: Process for the preparation of nouns azo dyes, consisting in that one from 1 mol. 2-Amino-5-naphthol-7-sulfonic acid and ι Mol. A sulfated The procedure is analogous when using homologues and analogs of the Aminoazobenzenesulfonic acid. Example 2. 60 parts of the urea obtainable according to Example 1 are dissolved in 1000 parts of water dissolved with the addition of 30 parts of soda. The solution is cooled to 10 ° C. and lets a diazobenzene solution prepared from 9.3 parts of aniline flow in with thorough stirring. The combination ends quickly. Then it is warmed up, salted out and the precipitated dye is filtered off. Same forms a brown-red powder that dissolves in water with an orange-red color. He colors unstained cotton in lightfast orange tones, Example 3. The procedure is as in Example 2, replacing the diazobenzene used there by a diazo solution prepared from 15 parts of p-aminoacetanilide. The one here forming dye dyes unstained cotton in vivid scarlet shades, which have good lightfastness. The dyes are produced in a completely analogous manner using any other diazo, diazoazo or tetrazo compounds or so-called intermediates from 1 mole of a tetrazo compound and 1 mole of a suitable azo component. Aminoazo compound mixed urea derivatives obtainable by treating with phosgene from the formula -N H-CO-NH-R ₁ -N ~ NR OH couples with diazo compounds.