DE1469719B - Isolation of metallizable black monoazo dyes - Google Patents

Description

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■; ■ The processing of the metallizable black product, if you have the desired color tone and monoazo dyes CI Mordant Black 9 and CI the desired color strength through corresponding Zu-Mordant Black 7 (Color Index, 2nd edition, 1956, sets in a certain ratio already in CI No. 16500 and 16505) runs from the time reaction vessel in which the dye is obtained, one point of completion up to the point of completion that is ready for sale. This also applies in particular to the multiple stages above. First, the mentioned mixtures of the two dyes, be it dyes in the aqueous medium immediately after that these are made Congo acidic by mixing two reaction solutions completion of the coupling, because they or suspensions of the individual dyes or due to their sensitivity to Luftoxyda- through mixed coupling in a single Decompose the reaction in the alkaline coupling medium. io vessel have been obtained. After a certain amount of salt has been added, the additives, such as adjusting materials and nuancier, are then deposited or precipitated, the dye slurry or substances and then the isolation in filter press solution in a pH range between 4 and 6 sent. Dye pastes are obtained which are also used to avoid corrosive influences on the drying moisture content. In this apparatus, to prevent the mother liquors or processing simultaneously accumulating through a Lei process, and then fed to the atomization dryer. In many cases, spray liquors still contain considerably more dryers, with pressure atomization delivering the lent amounts of colored organic by-products, dry dye in low-dust granulate products and inorganic salts. According to the new form, which in the handling and in many cases also in the laws to keep waste water clean, these 20 coloring behavior of the previous powder form must not be superior to the dyestuff company. In general, a better solution will leave the original state. The cleaning of the dyes is achieved,
In many cases, the process according to the invention also presents an unsolved technical problem, and the advantage that it can be very costly because it is largely to be managed. 25 automation - compared to conventional

The dyes obtained as pastes are now borrowed methods of isolating dyes -

fed to the drying, with aggregates, such as is much less labor-intensive. Furthermore

steam-heated rollers and vacuum cabinets, it makes an ideal solution of the increasingly urgent

can be turned. After drying, sewage problems must arise, as there are no drainage

the dyes are subjected to a grinding and mixing process, which is more diverted from the coupling reaction

need to be pulled in order to be finer, more packable.

To obtain powder form and around the 'manufacture' "The finding that such a process in the

of a standardized type, d. H. of a sales prp- technical manufacture by C, I. Mordant Black 9

to make it possible to produce this in ever more constant and C. I. Mordant Black 7 and their mixtures

Color strength and consistent color tone is obtained. Can be applied to 35 is extraordinarily over-

For this purpose, additions to control material are surprising, as had to be accepted and so far

Salt, dextrin, phosphates, etc., as well as other coloring also had always been assumed that the

substances (nuance dyes) in small quantities required secondary problems arising in the manufacture of the dyes.

so. They give the end product the desired products, which in the previous way of working

Shade and the required strength. 40 precipitated dye in the filtrate (mother liquor or

The dyes C.I. Mordant Black 9 and C.I. effluent broth) were separated, the quality or

Mordant Black 7 is not only used as an indi - the coloring properties of the final dye

viduen, but also in a mixture with one another would adversely affect them in an undesirable manner. It has

However, the addition of suitable thickening agents and shading dyes has now shown that this reduction in quality

in trade. Since, contrary to expectations, these mixtures do not occur.

excellent fastness properties, such as light fastness, from the German patent specification 285322 is

Potting fastness and wet fastness, which can be re-chrome-plated, dye-leuco compounds, which until then

ten wool dyeings, they have as well as by evaporation in an indifferent gas flow

the individual dyes had a significant entrance in or been dried in a vacuum, now-

found practice. To evaporate 50 more in such a way that you can get the

The process of separating the dyes from leuco compounds into the finest mist is atomized and

their aqueous coupling solutions, drying, these mists generate a stream of hot gas or air.

Mixing and milling are time consuming and necessary. The problem was with that one

the one not inconsiderable amount of work, so the invention is a more rational process for

which also with physiologically very undesirable evaporation of solutions or pasty preparations

annoyance (dirt and dust). of leuco compounds of dyes

It has now been found that one can find isolation. The problem became with the atomization named dyes the processes of deposition drying solved. In contrast, the color dens of the dyes from their production solutions, substances C. I. Mordant Black 9 and C. I. Mordant of drying on the above-described work- 60 Black 7 never before by evaporation of the Kuppwendigen Aggregates and possibly also the solution solutions have been isolated. Rather, one stopped Mixing and grinding advantageously thereby made it necessary to turn off the dyes from each can that one in the production oily coupling solutions by suitable measures Aqueous dye solutions produced by dyes (adjustment of a Congo acid medium and genes or slurries without prior separation (precipitation with salt) and with the filtering of the dyes directly of the spray liquors the secondary drying that occurs during coupling subject. products or unconverted output compounds

In this case, you immediately get a ready-to-sell end to run. These procedures have several

multiple disadvantages, and it was to be expected, for the reasons already set out, that spray drying the coupling broth tend to increase these disadvantages rather than reduce them and the quality of the dyes would be very detrimental.

example 1

C. I. Mordant Black 9 dye (Color Index No. 16500) is prepared in a known manner. the Congo-acid dyestuff suspension resulting from this is blunted to pH 4 to 6 by adding sodium acetate solution and then by removal a sample tested for color strength and hue. According to the result of this sample will be the required amount of adjusting material and shading dyes added. Leave for about 1 hour stir and then feed the dye slurry to the spray dryer. The drying takes place according to the usual regulations for these devices. A dye powder that is ready for sale is then obtained with a residual moisture content of 1 to 3%. If the spray drying is carried out Pressure at 15 to 20 atmospheres, the dye is obtained in low-dust granulate form, which is a better one Has solubility in water as the dye isolated by a conventional method.

Example 2

After the completion of the dye C. I. Mordant Black 7 (Color Index No. 16505) Congo-acid dyestuff suspension is treated as described in Example 1. In amendments However, this information can also be used for the dyestuff suspension truncated to pH 4 to 6 the spray dryer and the setting up with adjusting materials and shading dyes make the standardized sales type after drying in a mixing drum.

Example 3

To get a mixture of the colors C. I. Mordant Black 9 and C. I. Mordant Black 7, in which the dyes in the ratio about 32 to 47 to about 42%, calculated on pure dye, are included, mix the diazo components of both dyes in the appropriate ratio and then carries out the coupling analogously to the process for ίο the production of the individual dyes. The one with it The resulting suspension of the dye mixture is spray-dried according to Example 1 fed.

Claims (4)

Patent claims: 1. A process for isolating metallizable black monoazo dyes, characterized in that the in the preparation of C. I. Mordant Black 9 or C. I. ao Mordant Black 7 or mixtures of these two dyes resulting aqueous dye solutions or slurries without prior separation of the dyes immediately after spray drying subject. as 2. The method according to claim 1, characterized in that that one in the manufacture of C. I. Mordant Black 9 or C. I. Mordant Black 7 or mixtures of these two dyes accruing aqueous dye solutions or slurries before spray drying Adding adjusters and / or shading dyes. 3. The method according to claim 1 and 2, characterized in that one by mixing coupling obtained aqueous solution or slurry of the dyes C. I. Mordant Black 9 and C. I. Mordant Black 7 without prior separation of the dyes immediately after spray drying subject. 4. The method according to claim 1 to 3, characterized in that the spray drying carried out in a spray dryer with pressure atomization.