DE926385C - Process for the preparation of a new copper-containing disazo dye - Google Patents

Description

Process for the preparation of a new copper-containing disazo dye The invention relates to the production of a copper complex compound of a disazo dye, which is very lightfast and relatively cheap to produce, and cotton dyes delivers in very valuable reddish blue tones.

It is already known that valuable blue to blue-green dyes Can be made by coppering disazo dyes by coupling of z moles of tetrazotized 4,4'-diamino-3, 3'-dimethoxydiphenyl with 2 moles of a naphthol, such as aminonaphthol disulfonic acids or naphthol disulfonic acids and the like.

These dyes are very lightfast and relatively cheap to produce. In addition, the tone and the lightfastness are also retained when using the dyes dyed fabric with a resin, such as a urea-formaldehyde, melamine-formaldehyde or dicyandiamide-formaldehyde resin and the like. The aftercare the fabric dyed with these dyes with the resins is made from various Reasons, for example to increase the crease resistance, to stiffen or to make the fabric water repellent and for similar purposes.

Among the most valuable blue dyes are those which colorings deliver in a reddish blue tone. However, with the older dyes, although they have many advantages, only colorations ranging from blue to bluish green Preserved tone: It has now been found that a coloration is very appealing reddish blue tone producing dye is obtained by adding x moles of the tetrazo compound of 4,4'-diamino-3, 3'-dimethoxydiphenyl with z moles of 2-oxynaphthalene-3, 6-disulfonic acid and 1 mol of 1- (3'-sulfophenyl) -3-methyl-5-pyrazolone coupled and the dye obtained is converted into the copper complex compound. This copper complex compound has the further advantage that it is cheaper to manufacture than. -the known dyes and is very suitable for post-treatment with resins made from formaldehyde and an organic compound containing an amino group, such as urea, melamine, Dicyandiamide, thiourea and the like.

The copper complex compound in question can be represented by the following structural formula: illustrated.

The dye to be coppered to obtain the complex compound is made by adding 4, 4'-diamino - 3, 3 '- dimethoxydiphenyl with sodium nitrite and Hydrochloric acid tetrazotized at a temperature below io °, an alkali such as sodium bicarbonate, added to the reaction mixture to neutralize the excess acid, then while maintaining the temperature below 10 ° the 2-oxynaphthalene-3, 6-disulfonic acid was added and the resulting solution in a solution, for example with sodium carbonate Poured alkaline solution of 1- (3'-sulfophenyl) -3-methyl-5-pyrazolone is cooled to a temperature below 10 °.

The dye can also be made by first using the pyrazolone and then coupled with the naphthol disulfonic acid. The first mentioned way of working however, it is preferable as the yields are better when coupling first is carried out with the naphthol disulfonic acid.

To the dye prepared as above in the copper complex compound To transfer, a paste of the metal-free disazo dye with water, ammonium hydroxide and slurried copper sulfate at a temperature of about 50 to 12o °. The dye is then precipitated by sight, filtered off and dried to a powder.

The copper-containing disazo dye obtainable according to the process is the example? the Austrian patent 164 015 known copper-containing Disazo dye with the composition i-amino-8-oxynaphthalene-3, 6-disulfonic acid 4,4'-Diamino-3, 3'-di: methoxydiphenyl i-J.'henyl-3-methyl-5-pyrazolone 4'-sulfonic acid superior in the lightfastness of its cotton dyes.

The invention is illustrated in more detail by the following example. .

Example Tetrazotization of 4,4'-diamino-3, 3'-dimethoxydiphenyl 130 ccm of water containing 0.1 g of the sodium salt of di-n-butylnaphthalenesulfonic acid are heated to 95 °, whereupon 10 ccm of concentrated hydrochloric acid (36 ° / oig) can be added. The temperature rises by 2 °.

The solution is stirred vigorously, with 12.2 9 (0.05 M01) q., 4'-diamino-3, 3'-dimethoxydiphenyl being added rapidly. The solution is stirred further until the 4,4'-diamino-3, 3'-dimethoxydiphenyl has completely dissolved. Stirring is continued, adding Zoo g of finely chopped ice, causing the temperature to drop to 0-5 °.

24 cc of concentrated hydrochloric acid are then added. Should the If the temperature rises above 5 °, more ice is added to keep the temperature below 5 ° to bring.

7.1 g of sodium nitrite are then added dropwise as a 30 % solution (23.6 ccm) to the solution over a period of about 30 minutes. The solution is stirred for a further 1/2 hour and is kept at a temperature below 5 °. The excess nitrous acid is destroyed by a small amount of sulfamic acid. The mixture is now ready for the first clutch.

First coupling: the excess acid is added by careful addition neutralized by 21g sodium bicarbonate. The slow addition of the bicarbonate is required to prevent excessive foaming. At this point you should the solution is acidic against brilliant yellow paper, but alkaline against delta paper. The latter is a paper with a dye (from dianotized 2, 4-Dinitroanilin and i-oxynaphthalene-3, 6-disulfonic acid) is impregnated and in the pg range of 6 until 7 changes from yellow to blue.

The solution is stirred and kept at a temperature below 5 °, a solution of 21 g of 2-oxynaphthalene-3, 6-disulphonic acid sodium (0.0504M01) and 100 cc of water is added dropwise over the course of 1 hour. To the clutch more alkali has to be added to complete, and it usually becomes 5 g Sodium bicarbonate is sufficient.

The progress of the coupling can easily be followed. To do this, a drop of the reaction mixture is placed on filter paper. The insoluble semi-coupled product remains in the center, while the soluble components are carried away by the water as it expands. Unreacted tetrazo compound of 4,4'-diamino-3,3'-dimethoxydiphenyl can be detected with an alkaline H-acid solution, while the salt of 2-oxynaphthalene-3,6-disulfonic acid can be detected with any diazo solution . If the edge is colored, this indicates that strong coupling is taking place in the solution. At the end of the reaction, usually 30 minutes after the last amount of the salt of 2-oxynaphthalene-3, 6-disulfonic acid has been added, the edge should be practically colorless and there should be little or no evidence of tetrazotized 4,4'-diamino- Give 3, 3'-dimethoxydiphenyl. A very small excess of the salt of 2-oxynaphthalene-3,6-disulfonic acid is permissible.

Second coupling: The semi-coupled product is dissolved in a solution of 25.4 g of i-phenyl-3-methyl-5-pyrazolone-3'-sulfonic acid (0.055 mol) in 100 cc of water and poured 100 cc of 20% soda solution, which cooled from the outside to 0 to 5 ° has been. The mixture is packed in ice and stirred overnight. The dye is filtered off without further treatment. Filtration is smooth and quick and gives 116 g of color paste.

Copper complex formation: The paste is slurried again with 60o ccm of water and then placed in a three-necked flask with a capacity of 2,000 cc a motor-driven stirrer, a water-cooled reflux condenser and a thermometer. 100 cc are then concentrated in the mixture Ammonium hydroxide (28.8%) stirred in.

A solution of 33 g of water-containing copper sulphate (0, z35 Mol) in 80 cc of water was added, bringing the total volume to 100 cc will. The temperature is then increased to 85 ° and with constant stirring for 37 hours leave at this temperature.

220 g of table salt are then added and the product is at 7o ° filtered off. The paste obtained, weighing 296 g, is dried at 85 °, whereby 96.2 g of a powder are obtained.

Dyeing: 100 parts of cotton are moistened and put in a dye bath brought the 2,000 parts of water and 2 parts of the substantive prepared as above Contains copper complex compound. The temperature is increased to 95 ° and 45 minutes maintained, with 2o parts of table salt added to the exhaustion of the To support dye. The dyed fabric is then rinsed and dried.

It becomes an even, reddish-tinged blue tone of excellent quality Preserved lightfastness. The dye is excellent over cellulose fibers substantive, and the dye bath is almost completely exhausted.

Claims (1)

PATENT CLAIM: Process for the production of a new copper-containing disazo dye of the formula: characterized in that 4, 4'-diamino-3, 3'-dimethoxydiphenyl tetrazotized and 1 mole of the tetrazo compound obtained with 1 mole of 2-oxynaphthalene-3, 6-disulfonic acid and 1 mole of I- (3'-sulfophenyl) - 3-methyl-5-pyrazolone coupled and the dye obtained is converted into the copper complex compound in a conventional manner. Cited publications: Austrian patent specification No. 164 0i5.