A method of producing metals dimethyldithiocarbamate

 

Describes how to obtain dimethyldithiocarbamate metals - rubber vulcanization accelerators of the formula I where n is 1, m represents 2 or 3, IU means Zn, Fe, Ni, Pb, SB or Bi, by reacting 2,6-di-tert-butylphenol, carbon disulfide and aminecontaining agent in the environment of methanol followed by treatment received at the first stage, an alcohol solution of the corresponding dimethyldithiocarbamate water-soluble salt of the above metal. As aminecontaining agent using lightweight fraction of amines of the following composition, wt. %: trimethylamine 0,01-1, dimethylamine 13-18, N,N-tetramethylethylenediamine (bitamin) 15-35, water 1-10, methanol - the rest is up to 100, and the interaction of dimethyldithiocarbamate dimethylammonio with a water-soluble salt of the metal is carried out at a molar ratio of 1.0:0.3 to 0.5. The described method allows to simplify the process, reduce the cost of the target product, dispose of waste production 4-methyl-2,6-di-tert-butylphenol and to eliminate wastewater. 3 table.

The invention relates to petrochemistry, specifically to the production dialkyldithiocarbamate accelerators of vulcanization of rubbers.

The known method recip is legido, amine, carbon disulfide, 40% caustic soda. Then the resulting product is mixed with an aqueous solution of zinc chloride. The output of dialkyldithiocarbamate zinc 83% of theoretical [A. O. Fitton, A. Rigby, R. I. Hurlock, I. of the Chem.Soc.,, 1969, 230-233].

The disadvantages of the method include its multi-stage, which complicates its use on an industrial scale, as well as a low yield of the final product and the formation of large quantities of wastewater.

A known method of producing dialkyldithiocarbamate zinc, according to which in the first stage receive ethylenedicarboxylic sodium, then it vymalivayut and filtered, and the third stage is diluted, neutralized and subjected to two-time cleaning, then it is subjected to reaction with zinc chloride [Birko C. M. Dithiocarbamate. M.: Nauka, 1984, S. 17].

A method of obtaining consisting of the following stages: 2,6-di-tert-butylphenol in alcoholic medium is mixed with aqueous solutions of formaldehyde, dimethylamine and then there was added carbon disulfide at 65^oC. the precipitation of 4-hydroxy-3,5-di-tert-butylbenzyl-N, N-dimethyldithiocarbamate mixed with methyl alcohol at 65^oC and added dropwise 40% solution of caustic soda. Water-alcohol is lorida zinc at a temperature of 30-40^oC. Output dimethyldithiocarbamate zinc is 83% of theoretical [Bloch, A. Organic accelerators of vulcanization of rubbers. M.-L.: Chemistry, 1964, S. 35-36].

The disadvantage of these methods is a multi-stage and the formation of large quantities of wastewater, which complicates their use on an industrial scale, and the relatively low yield of the final product.

The closest method of the prototype to the present invention is a method of obtaining a dialkyl or disubstituted dithiocarbamato metals the interaction of 2,6-dialkylphenol, amine, carbon disulfide, alkali environment of the solvent in the first stage followed by treatment of the resulting dialkyl or disubstituted of dithiocarbamate water-soluble alkali metal salt of the metal in the second stage, where the amine in the first stage using N,N-Tetra-substituted metrebian containing as a substituent a lower alkyl, cyclonite alkyl, aryl, substituted lower alkyl, or a heterocyclic amine radical of the type [RF patent 2059617, 6 C 07 C 332/16].

The first stage is formed ester of 3,5-dialkyl(diaryl or dialkyl)-4-hydroxybenzoato alcohol, precipitating, and sodium (K, Li) salt of N, N-dialkyl (cycloalkyl, aralkyl Il the Hai is mixed with a water-soluble salt of any metal, dialkyldithiocarbamate you want to get deposited precipitate is filtered off and subjected to further processing in a known manner.

The process is carried out according to scheme 1.

The disadvantage of this method is the use of the first stage as the alkali reagent and the use of water for absorption generated during the synthesis of amine, which increases the cost of the final product and contributes to the formation of large amounts of wastewater, thereby complicating the process of obtaining the target product.

The technical object of the present invention is to reduce the cost of the target product, disposal of waste Agidol-1 (2,6-di-tert-butyl-4-METHYLPHENOL), process simplification and exclusion of sewage.

The technical problem of the process of obtaining dimethyldithiocarbamate metals is achieved by using as aminecontaining agent waste production Agidol-1 (2,6-di-tert-butyl-4-METHYLPHENOL) from the stage of selection of Mannich bases. This waste is not currently finds qualified use.

The composition of the waste (light fraction amines, the LFA Dep.), wt.%: Trimethylamine - 0,01-1 Dimethylamine - 13-18 Beamin the rotary Agidol-1 formalin (at the stage of synthesis bisamine) by the reaction of CH₂O+2(CH₃)₂NH-->(CH₃)₂NCH₂N(CH₃)₂+ H₂O contains 5-9% methanol. In this regard, there is a constant accumulation of methanol in the system at the expense of recycling. On the site of the synthesis of Mannich bases according to reaction (see scheme 2) in the separation of the target product from light fractions outputs of excess methanol to burning. Composed of methanol also contains unreacted beamin generated during the formation of the Mannich bases of dimethylamine, and as a side connection trimethylamine. The composition of the waste in wt.% above.

The process is carried out as follows.

Charged to the reactor 2,6-di-tert-butylphenol and aminecontaining agent. At the same time introducing portions small doses of carbon disulfide. The reaction is carried out at a temperature of 80-100^oC for 1.5-2 hours. At this stage the formed 4-hydroxy-3,5-di-tert-butylbenzyl-N, N-dimethyldithiocarbamate, precipitating, and dimethyldithiocarbamate dimethylammonio. In the second stage, the filtrate from the first stage is mixed with a water-soluble salt of any metal, dimethyldithiocarbamate which you want to retrieve. The mixture is stirred at 30-40^oWith, and then the precipitation is Canisius agents. The output is 98% of theoretical. The filtrate after separation of dimethyldithiocarbamate metal accelerates the purpose of distillation of methanol.

The proposed method is described by equations of the reactions (see scheme 3).

An unexpected effect is that in the first stage simultaneously take place the following transformation:
- 2,6-di-tert-butylphenol is reacted with N, N-tetramethylethylenediamine (bisamino) and carbon disulphide with the formation of 4-hydroxy-3,5-di-tert-butylbenzyl-N,N-dimethyldithiocarbamate
- dimethylamine, which is part of the LFA Dep. and released in the course of the above reaction, interacts with carbon disulphide c education dimethyldithiocarbamate dimethylammonio, which positively affects the selectivity of the process.

The solvent is methanol, which is part of waste (LFA Dep.).

For implementing the method of the initial reagents must meet the following requirements:
CS₂corresponds to THE MHP 2407-50;
ZnCl₂- GOST 4529-48;
Fl₃- GOST 4147-48;
BiCl₃- WUT MHP 3314-52;
NiCl₂- GOST 4038-48;
SnCl₂- GOST 36-40;
bl₂- GOST 4210-48;
CoCl₂- GOST 4525-48;
2,6-di-tert-butylphenol - TU 38.103378-86.

The essence of the proposed method podtverjdaete the following composition, wt.%:
Trimethylamine - 0,05
Dimethylamine - 9
Beamin - 30
Water - 3
Methanol - 57,95
The reaction of lead in a glass ampoule at a temperature of 80-100^oC. At the same time in the ampoule is injected in small portions 6 g of carbon disulphide for 1.5-2 hours. Next, the ampoule is cooled. The precipitation, which is 4-hydroxy-3,5-di-tert-butylbenzyl-N, N-dimethyldithiocarbamate, recrystallized and dried. Exit leaves of 33.8,

Second stage:
An alcoholic solution from the first stage, containing 11 g of dimethyldithiocarbamate dimethylammonio, treated with stirring 10 ml of 68% methanolic solution of zinc chloride. The mixture is stirred at 30-40^oC and then precipitated precipitate is filtered, washed from chlorine ions and dried. Formed of 17.5 g dimethyldithiocarbamate zinc (timate) that meets all the requirements of vulcanizing agents. The output of cimate is 98.3% of theoretical.

Examples with other ratios and compositions of the raw materials shown in table 1 (first stage).

In tables 2, 3 examples get dimethyldithiocarbamate various metals (second stage) and information about their physico-chemical constants.

Thus, it is possible to get dimethyldithiocarbamate, used as a stabilizer for rubbers, thermoplastic elastomers and plastics, to dispose of the waste production Agidol-1 and extract the methanol.

Claims

The method of producing dimethyldithiocarbamate metals General formula

where n is 1;
m represents 2 or 3;
IU mean Zn, Fe, Ni, Pb, SB or Bi,
the interaction of 2,6-di-tert-butylphenol, aminecontaining agent and carbon disulfide in an environment of methanol, followed by treatment received at the first stage, an alcohol solution of the corresponding dimethyldithiocarbamate water-soluble salt of the above metal, characterized in that as aminecontaining agent in the first stage, use a light fraction of amines of the following composition, wt. %:
Trimethylamine - 0,01-1
Dimethylamine - 13-18
N, N-tetramethylethylenediamine (bitamin) - 15-35
Water - 1-10
Methanol - the Rest is up to 100
and interaction dimethyldithiocarbamate dimethylammonio with a water-soluble salt of the metal is carried out at a molar ratio of 1.0: 0.3 to 0.5.