DE2521650A1 - PROCESS FOR THE SAFE MANUFACTURING OF DIAZONIUM SALT PREPARATIONS AND THEIR PREPARATIONS - Google Patents

Description

HIGHEST MTIERGESELLSCHAFT

File number: HOE 75 / F 12 5

Date: May 14, 1975 Dr.ST/St

Process for the safe production of diazonium salt preparations and their preliminary stages

The invention relates to a process for the safe production of moist diazonium salts and dry ones obtainable therefrom Diazonium salt preparations.

Solid diazonium salts are generally unstable, easily decomposing, often even explosive compounds (see, for example, Houben-Veyl, Methods of Organic Chemistry, Volume 10/3, pp. 1 -? Λ2 (1965) 1 The reason for their explosiveness becomes like that of others Explosives - assessed according to the specified test procedures of the Federal Institute for Materials Testing (BAM) (compare, for example, "Law on Explosive Substances (Explosives Act) of August 25, 1969 ¹ S Federal Law Gazette No. 85, page 1558 (1969)) The test procedures are carried out as follows:

a) Testing by heating: A deep-drawn, cylindrical Steel sleeve with a wall thickness of 0.5 mm, filled with 25 cm examination material and closed with a plate, The device is provided with a nozzle with a circular cross-section and is heated by means of four Teclu burners. certainly becomes the largest nozzle diameter at which there is still an explosion he follows.

b) Impact test: 40 mm lintersuehungsgut are enclosed in a steel ring with an inner diameter of 10 mm by means of two steel punches. Falls thereon a weight of I ₁ 5 or 10 kg. The smallest impact stress is determined; (in rkp), which still explodes.

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INSPECTED

c) Testing by friction: 10 mirr material to be examined rubbed between a porcelain plate and a loaded porcelain pencil. The smallest pin load is determined (in kp) at which an explosion still occurs.

The numerical values obtained in these investigations are a measure of the danger and make comparisons with others Fabrics possible.

The explosiveness of diazonium salts can be increased by adding inert substances, e.g. sodium sulfate or sodium chloride, be reduced. This has always been used in the manufacture of diazonium preparations for ice dye dyeing Use.

Such diazonium salt preparations are made as follows:

An aromatic amine is diaaotated - and the resulting Clarified diazonium salt solution. By adding a precipitant, e.g. zinc chloride solution, sodium tetrafluoborate solution, aryl sulfonate solution, Sodium chloride or sulfuric acid, the diazonium salt is precipitated in crystalline form and using a suction filter or a filter press separated from the aqueous phase. Spinning in a basket centrifuge can reduce the amount of adhering mother liquor can be further reduced. To avoid the particularly explosive dry, concentrated Form, the resulting moist product is diluted with an inert salt, e.g. sodium sulfate or sodium chloride, and only then thermally dried. The final adjustment to the intended purity is then carried out.

A very popular drying method because it is safe and gentle on the product consists in the addition of a hydrate-forming salt, whereby the water still adhering to the moist product is removed from the aggregate is bound as crystal water. Prerequisite for this is in addition to the compatibility of the desiccant with the

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Diazonium salt and its intended use a lower one Water vapor partial pressure and a certain temperature resistance (to at least i? 5 ° C) of the hydrate formed. Particularly suitable Magnesium sulphate, zinc sulphate and, above all, aluminum sulphate.

The more inert additives the diazonium salt preparations contain, the greater the reduction in explosivity. Man makes them so insensitive that they are no longer explosive and guarantee their safe and risk-free handling is. Experience has shown that this is the case when the products only explode through exposure to stress that are beyond the limit specified in the Explosives Act. When testing by heating, a Explosion can only occur with a nozzle diameter of <2 mm. An explosion may occur during the impact test only occur at an impact energy above 4 mkp and at the Frictional testing must withstand a pin load of at least 36 mkg without an explosion.

The moist diazonium salt isolated from the diazotization solution is to a certain extent due to the adhering moisture phlegmatized compared to dry goods “Nevertheless, in many cases the explosiveness is not in terms of safety tolerable fourth. A reduction of the same by increasing the water content is seldom possible, since on the one hand most of the time Set very coarse crystalline products narrow limits on further water absorption and on the other hand for further processing (Mixing, drying) as crumbly as possible, not caking Products are desired.

It has now been found that moist diazonium salts which can be readily processed further and dry diazonium salt preparations which can be prepared therefrom can be obtained with good storage stability, appealing application properties and impeccable safety Safe behavior can be established if you can

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Diazonium salt from the diazo ti erungslosimg in the usual way separates, adds sodium sulfate decahydrate to the reaction mixture or generates the diazonium salt-sodium sulfate mixture therein isolated together and this thermally or by mixing with water-binding, stable hydrates forming Fabrics dries.

As water-binding substances that form stable hydrates Magnesium sulfate and aluminum sulfate are used. They are expediently used as partially dehydrated salts, e.g. magnesium sulf at-monohydrate or aluminum sulfate-hexa-hydrate, are used, as these absorb water much more quickly than completely dehydrated salts.

Examples of diazonium salts for the process according to the invention are: benzene diazonium salts, ITaphthalenediazonium salts, anthraquinonediazonium salts, azobenzene diazonium salts, diphenyl-bis-diazonium salts and diazonium salts of heterocycles, the aromatic radicals being replaced by halogen, alkyl, aryloxy, trifluoric, , Sulfonic acid amide, carboxylic acid amide alkyl sulfone, arylamino, dialkylamino and aryl sulfone groups can be substituted. The anion of the diazonium salt can be chloride, sulfate, tetrachlorozincate, tetrafluoborate or aryl sulfonate. The process according to the invention is particularly suitable for diazonium salts which are derived from amines used in ice dye dyeing, such as, for example, 2-nitro-benzene-diazonium-tetrafluoborate, 4-ChlO3> 2-nitro-benzene-diazonium-tetrachlorozincate, 5-nitro- 2-methoxy-benzene-diazonium-tetrachlorozincate, 6-nitro-4-methoxybenzene-diazonium-tetrachlorozincate, 5-trifluoromethyl-phenylethylsulfon-2-diazonium-tetrachlorozincate, 6'-nitro-2,4 ¹ -dimethyl- »5-methoxy -1,1 'azobenzene - ^ - diazonium tetrachlorozincate and ^3i5'-I) imethoxy-diphenyl-4,4 ^{l-bis-diazonium} tetrafluoroborate.

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Sodium sulfate decahydrate can be introduced into the batch as such; however, it is expediently generated in the batch after the deposition of the diazonium salt. ^{The working temperature in both cases is close to 0} ° C. because of the rapidly decreasing solubility of sodium sulfate as the temperature falls. The crystal size of approx avoid.

Sodium sulfate decahydrate can be produced in the batch by uniformly adding commercially available calcined sodium sulfate preferably with a metering device such as a Vibrating chute, a dosing screw or a conveyor belt device. However, the transition to the decahydrate is not complete, as the individual anhydrous sodium sulfate crystals are surrounded by a layer of solid decahydrate, which makes deeper hydration very difficult. Quantitatively Decahydrate is formed if saturated temperatures of approx. 55> ° C are added to the cooled batch because of the maximum solubility Run in sodium sulfate solution.

The sodium sulfate decahydrate is not used in the approach itself it can also be added to it - ideally as a crystal pulp, which can be obtained by cooling a concentrated Has prepared sodium sulfate solution with stirring.

The water of hydration of the sodium sulfate decahydrate is used to render the moist diazonium salt inert Amount of water introduced without the product losing its crumbly structure, which is important for further processing. This Water of hydration is very loosely bound (water vapor partial pressure approx. 80% of the vapor pressure of water, resistance of the hydrate only up to 3> 2 ° C). When mixing with the water-binding substances it is bound by these as a much more permanent hydrate.

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25.B. Magnesium sulfate tetrahydrate has a water vapor partial pressure of approx. 20% of the vapor pressure of water and a temperature resistance of up to 67 ° C. For aluminum sulfate decahydrate these values are approx. 1 % and 1O5 ° C, for aluminum sulfate hexadecahydrate approx. 6 % and 82 ° C.

The water of crystallization must be used in practical diazo preparations be bound so tightly that the products do not release any water when standing in the air, which increases the purity and explosiveness and that they do not dissolve due to the fall of the hydrate, even at tropical temperatures. ITodium sulfate decahydrate is therefore unsuitable as an adjusting agent for diazonium preparations that can be used under practical conditions, whereas it is because of its high water content to reduce explosivity

very suitable substance for the moist diazonium salts is. In addition, it is very economical because of its low solubility at the usual working temperatures.

The crumbly structure: * the moist that can be obtained according to the process Diazonium salts allow intimate mixing with the substances to be added without excessive mechanical stress on the product «, It is also responsible for the creation of free-flowing products with a uniform aspect ^ free of crusts and lumps, which can be sold directly without further grinding.

The following examples serve to explain the invention. The temperature data relate to ⁰ C.

Example Λ :

270 parts of 4-nitro-2-amino-1-methoxy-benzene are converted into 860 parts Water and 590 parts of 52% hydrochloric acid entered. By External cooling is cooled to 0 ° and at 0-5 ° by feed

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diazotized by 283 parts of 40% sodium nitrite solution under the surface. When the diazotization has ended, 2.4 parts of kieselguhr and 10 parts of clarifying charcoal are added. After half an hour, it is filtered through a suction filter or press covered with kieselguhr. The residue is washed with a little water and the filtrate and washing water are combined. To the clear diazo solution, 121 parts of zinc chloride run as an approximately 65% strength aqueous solution at 5 °. In this case, the ^{5-nitro-2-methoxy-benzene-y} l-diazonium-tetrachlorozincate in coarse crystal deposits en -ab.

After 30 minutes, to complete the precipitation, about 300 parts of evaporated salt (= 15 % of the volume) are salted. At 500 parts of sodium sulfate calc with a metering device. entered within 30 minutes. After half an hour of sampling at this temperature, suction is carried out through a suction filter. The filtered product is packed into an acid-proof lined basket centrifuge and dewatered for 5 minutes at a radial acceleration of 450 g. The result is 900 parts of moist product with a content of 39 »5 % 5-nitro-2-methoxy-benzene-1-diazonium tetrachlorozincate, 44.5 % sodium sulfate (calculated as free of water of crystallization) and 16.5% water (mostly as Water of crystallization bound). The sodium sulphate has only partially passed into the decahydrate, as the individual particles are surrounded by a coat of decahydrate, which greatly inhibits further hydration.

To prepare a diazonium salt preparation that can be used in practice, 560 parts of partially dehydrated aluminum sulphate with a residual water content of the formula Al ₂ (SO ^) ₇ are placed in an acid-proof lined mixer with a cooling jacket and slowly shoveling the material to be mixed. 6 H ^ O, submitted. The moist diazonium salt-sodium sulfate mixture is added in portions, cooling with water at approx. 15 °.

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After a check of the diazoniuni content it becomes so much partially dehydrated aluminum sulfate added that the resulting Diazonium preparation 25.3% 5-nitro-2-methoxy-benzene-1-diazonium tetrachlorozincate contains. The preparation has a good shelf life and is well suited for use in Manufacture of ice colors.

The moist diazonium salt-sodium sulfate mixture obtained explodes when tested by heating with a nozzle diameter of 1 mm.

If, on the other hand, one examines moist 5- ^ i "fcJCo-2-methoxy-benzene-1 ~ diazoniuin-tetrachlorozincate, as is obtained when separating without adding sodium sulphate (composition 89% diasonium tetrachlorozincate, 9 % v / water, 2 % inorganic salts), An explosion is already detected at a nozzle diameter of 5 mm. Both preparations cannot be caused to explode by impact (10 mkg) or frictional stress (36 kp).

The finished diazonium preparations with 23.3% diazonium salt content obtained from both moist products do not explode when exposed to impact (10 mkg), rubbing (36 kp) or hitting (1 mm 0) «

Example 2:

270 parts of 4-NitrO "2-amino-1-methoxy-benzene are, as in Example 1 indicated, diazotized * After the deposition of the Diazonium salt runs at + 5 ° within 15 minutes an approx. warm solution of 300 parts of anhydrous sodium sulfate in 630 Allocate water. External cooling increases the temperature 5 held. After stirring for half an hour, it is filtered off with suction and the product is dehydrated as in Example 1. It result 800 parts of moist goods with a content of 55% 5-nitro-2-ynethoxy-benzene-1-diazonium tetrachiorozincate, 21% sodium sulfate (calculated as free of water of crystallization) and 24% water (mostly bound as water of crystallization).

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To prepare a diazonium salt preparation which can be used in practice, the moist product thus obtained is, as indicated in Example 1, introduced into 700 parts of partially dehydrated aluminum sulfate. A further addition of this salt sets a content of 25.3 % diazonium salt. This preparation can also be stored well and is well suited for use in the production of ice colors.

The wet mixture of diazonium salt and sodium sulfate just explodes when testing by heating, namely with a nozzle passage of 1 mm. The finished diazonium preparation is like the one in Example 1 not to explode under the conditions specified there.

example 3 '

100 parts 4-, 4 -'-diamino-3,3'-dimethoxy-diphenyl are in 600 Parts of water stirred well. 230 parts of 32% hydrochloric acid are used added, whereby the chlorohydrate formation takes place. After some stirring, the mixture is cooled to 5 ° by external cooling and at this temperature by adding 1 ^ 0 parts of 40% sodium nitrite solution diazotized in about 30 minutes. After about 30 minutes - Nitrite should always be present in a slight excess - 1 part clarifying coal, 6 parts kieselguhr and 175 parts Sodium chloride entered. After another 30 minutes, again 1 part of clarifying charcoal was added and then filtered. 61.5 run to the light yellow filtrate at 5 ° in approx. 30 minutes Parts of zinc chloride as an approx. 70% solution. After stirring briefly 100 parts of sodium chloride are added. Then a 40 ° warm solution of runs within 20 - 30 minutes 100 parts of anhydrous sodium sulphate in 220 parts of V / water, with external cooling preventing a rise in temperature.

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After stirring for half an hour, suction is carried out on a suction filter. The crystals are freed from most of the adhering mother liquor by centrifugation in a basket centrifuge at a radial acceleration of 450 g. Its composition is now 68 % 3,3 'dimethoxydiphenyl-4,4 ^l -bis-diazonium-tetrachlorozincate, 16 % sodium sulfate (mol 142) and 16% water (mainly bound as water of crystallization); it does not explode when subjected to an impact load of 10 mkp, nor a frictional load with 36 kp pin load, nor during the heating test with a nozzle diameter of 1 mm. In contrast, a 3? 3-dimethoxy-diphenyl-4,4'-bis-diazonium tetrachlorozincate, as it is obtained with an identical representation except for the addition of sodium sulfate (composition 93 % tetrachlorozincate, 7% water) and when subjected to an impact load of 3 Bikp as well as in the heating test with a nozzle diameter of 1 mm.

For conversion into a dry diazonium preparation, the 272 parts of diazonium salt sodium sulfate decahydrate obtained are mixed with 13 parts of aluminum sulfate hexahydrate and 97 parts of magnesium sulfate monohydrate in a mixer according to Example 1. This product is again to explode with an impact load of 10 mkp, a frictional load with J> 6 kp pin load, still during a heating test with a nozzle diameter of 1 mm.

Example 4:

172.5 parts of 4-chloro-2-nitro-1-aminobensol v / earth with 450 parts Mix water well. After adding 360 parts of 32% Hydrochloric acid is cooled to 5 ° and diazotized at this temperature with 175 parts of 40% sodium nitrite solution (duration approx. 2 hours). To be in compliance with the temperature of 5

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thrown in about 170 parts of ice. After the end of the diazotization 0.7 parts of sewage charcoal are added.

81.5 parts of zinc chloride run as a 65% solution to the filtered diazo solution at 5 °. The precipitation of the diazonium salt is completed by adding 155 parts of sodium chloride. Then an approx. 5 warm suspension of sodium sulfate decahydrate crystals is added, which was prepared by cooling a warm solution of 150 parts of sodium sulfate in 450 parts of water with stirring. After about 20 minutes, the batch is separated from the mother liquor on a suction filter. The crystals are dehydrated in a basket centrifuge with a radial acceleration of 45Ο g. It has a composition of 75 ° / ° 4-chloro-2-nitro-benzene-i-diazonium tetrachlorozincate, 8 % sodium sulfate, 1 % sodium chloride and 22% water (partly bound as water of crystallization). During the heating test with a nozzle diameter of 1 mm, an explosion must be made using a 4-chloro-2-nitrobenzene-1-diazonium tetrachlorozincate prepared analogously without adding sodium sulfate (composition 90% tetrachlorozincate, 1 % sodium chloride, 9 ° / ° water) on the other hand already with a nozzle diameter of 3 * 5 ™ &. An impact load with 10 mkp and a frictional load with 36 kp pin load cannot cause both of them to explode.

For conversion into a dry diazonium preparation, the 390 parts obtained are mixed, as indicated in Example 1, into 520 parts of aluminum sulfate hexahydrate and adjusted to a content of 26.9 % diazonium tetrachlorozincate by adding further aluminum sulfate hexahydrate.

Example l ^:

At 45 ° 37-5 are added to 148 parts of 6 ^l -nitro-4-amino-5-methoxy-2,4 ^l- dimethyl-1 _i 1 ^{l of} azobenzene, which are well mixed in 5700 parts of water and 310 parts of hydrochloric acid Parts of sodium nitrate in 40% solution were added over the course of 5 minutes, after 30 minutes

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becomes after the addition of 2 parts of clarified coal and 20 parts Clarified diatomaceous earth.

33 ^ 5 parts of zinc chloride as a 20% solution run slowly to the clear filtrate at 40 °. It is salted with 700 parts of sodium chloride. After cooling to 5 °, 600 parts of anhydrous sodium sulfate are introduced in a steady stream over the course of 30 minutes. After a further 30 minutes, it is suctioned off on a suction filter and the crystals are then extracted in a basket centrifuge with a radial acceleration of 450 g * It consists of 30 % 6 ^s -Nitro-5 ™ metho3cy-2,4'-dimethyl ~ 1,1'azobenzene -4-diazonium ~ tetrachlorosilicate5 2% sodium chloride, 42 % sodium sulphate and 26% water (mostly bound as water of crystallization) and can neither be measured by an impact load of 10 mkp, a friction load with 36 kp pin load nor a heating test with a nozzle diameter of 1 mm Explosion. A mazonium tetrachlorozincate (composition 84% diazonium tetrachlorozincate, 2% sodium chloride and 14 % water), produced in the same way except for the addition of sodium sulfate, explodes in the heating test with a nozzle diameter of 2 mm.

The 590 parts of moist product obtained are converted into a dry, marketable diazonium salt with 60 parts of a partially dehydrated aluminum sulphate, the water content of which has the formula AIp (SO ^) ,,. 12 H "0 corresponds, mixed. After this Dry in a rack drying cabinet at an air temperature of 50, 30 parts of aluminum sulfate hexahydrate are mixed in; then a content of 24.2% is set with dehydrated sodium sulfate.

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Claims (3)

HOE 75 / F 125 - 15 - Patent claims: rl)! "Process for the safe production of moist diasonium ^ - ^ salts and dry diazonium salt preparations obtainable therefrom ,, characterized in that the diazonium salt is deposited from the diazotization solution, the resulting Crystal suspension adds sodium sulfate decahydrate or produced therein, the diazonium salt-sodium sulfate decahydrate mixture isolated together and this thermally or by mixing with water-binding, stable hydrates forming Fabrics dries. 2) Method according to claim 1, characterized in that there is aluminum sulfate as the water-binding, stable hydrates forming substances or magnesium sulfate is used. 3) Process according to claim 1 and 2, characterized in that there is used as the vrasserbindende, stable hydrates forming substances aluminum sulfate of the formula AIp (SO ^) -,. 6 HpO and magnesium sulfate of the formula MgSO. . HpO used. The diazonium salt preparations prepared according to claims 1 to 3. 609849/0957 ORIGINAL INSPECTED