The method of producing dibenzothiazoledisulphide

 

(57) Abstract:

The invention relates to a method of producing dibenzothiazoledisulphide oxidation alkaline solution of 2-mercaptobenzthiazole oxygen in the presence of a catalyst - derived phthalocyanine cobalt at the 50oWith, the process is carried out at 3-10-fold excess of 2-mercaptobenzthiazole solubility in a weak alkaline medium, where the concentration of the alkali metal hydroxide is 0.35 to 1.0 wt.%, in the presence of desulfosarcina cobalt as a catalyst in number (3-5)X10-4mol 1 mol 2-mercaptobenzthiazole. Effect: simplified method of obtaining.

The invention relates to a method of producing dibenzothiazoledisulphide (altaxe), which is used as a vulcanization accelerator in the rubber industry.

A method of obtaining altaxe oxidation of an aqueous solution of 2-mercaptobenzthiazole (captax) oxygen in the presence of a catalyst-disulfonate 29,31-metal-28,5-14,19-di-(DirectLOGIC [a, i]-7,12-21,26-dibenzo[h, s] tetraazaporphyrin (USSR author's certificate 595334, 07 F 15/02, 1978 ). The process is carried out at 50oWith 10% alkali solution with the high alkalinity of the process, promotes the decomposition of the target product and require further acidification to highlight.

The objective of the invention is the creation of such a method of producing dibenzothiazoledisulphide, which would increase the yield of the target product and simplify the process.

The task is solved in that the process is carried out at 3-10-fold excess of 2-mercaptobenzothiazole (2-MBT) solubility in alkaline medium (the concentration of sodium hydroxide of 0.35 to 1.0 wt.%) at a temperature of 50oIn the presence of a catalyst of desulfosarcina cobalt, which take in the amount of (35)X10-4mol 1 mol 2-mercaptobenzthiazole. The lower limit on the alkalinity of the reaction solution is determined by the solubility of captax, the upper limit is determined by the decomposition of altaxe. The lower limit on the concentration of the catalyst is determined by the inefficiency of the process, the violation of the upper limit leads to deterioration of the selectivity of the process for dibenzothiazoledisulphide. Application of less than 3-fold excess captax reduces the yield of the target product, and the use of more than 10-fold excess is not technological. Oxidizing agent is molecular oxygen or oxygen. To have not remained unreacted impurities captax (the spectrum in the UV region in chloroform). The yield of the target product is up to 85%.

Example 1.

Mix in the reactor of 0.91 g (0,00544 mol) 2-the office (which is 8-fold excess of solubility) and 6.7 ml of aqueous NaOH (0.5 weight%), make 1,h-6mole desulfosarcina cobalt. The reaction is carried out at 50oC in oxygen atmosphere with vigorous stirring for 4 hours Altex filtered off, washed successively with 1% aqueous solution of NaOH and water, dried at 60oC. Output altaxe (MP.=168o(C) counting on the reacted 2-mercaptobenzthiazole, and 97.8% for the conversion of 2-mercaptobenzthiazole 87.1 percent. The output altaxe, considering the number of downloaded captax, was 85.2%.

Example 2.

of 0.91 g (0,00544 mol) 2-the office (which is 10-fold excess of solubility) and 6.7 ml of aqueous NaOH (0.35 wt.%) bring in the reactor, add 2,h-6mol catalyst - desulfosarcina cobalt. After 3.5 h of intensive mixing of the reaction mixture in oxygen atmosphere at 50oWith the stop process, the formed Altex filtered off, washed successively with 1% aqueous solution of NaOH and water and dried at 60oC. Conversion of 2-mercaptobenzthiazole amounted to 76.3%. Received altaxe esto loaded captax, amounted to 75.1%.

Example 3.

Mix in the reactor of 0.91 g (0,00544 mol) of 2-MBT and 6.7 ml of 0.5% aqueous solution of NaOH, make 1,820h10-6mole desulfosarcina cobalt. In a period of 7.5 h at 50oServed with air at a rate of 2 l/h, then the process stops, the resulting Altex filtered off, washed successively with 1% aqueous solution of NaOH and water and dried at 60oC. Output altaxe, considering reacted on captax, 96,3% conversion captax 74,2%. The output altaxe, considering the number of loaded 2-mercaptobenzthiazole amounted to 71.5%.

Example 4.

Mix in the reactor of 0.91 g (0,00544 mol) 2-the office (which is 3-fold excess of solubility) and 6.7 ml of aqueous NaOH solution (1.0 wt%), make 1,h-6mole desulfosarcina cobalt. The reaction is carried out at 50oC in oxygen atmosphere with vigorous stirring for 5 hours Altex filtered off, washed successively with 1.5% aqueous NaOH solution and water, dried at 60oC. Output altaxe (MP.=168o(C) counting on the reacted 2-mercaptobenzthiazole, 90.1% of conversion of 2-mercaptobenzthiazole 68,9%. The output altaxe, considering the number of loaded 2-mercaptobenzthiazole was 62,0%.

The method of producing dibenzothiazoledisulphide oxidation alkaline solution of 2-mercaptobenzthiazole oxygen in the presence of a catalyst - derived phthalocyanine cobalt at the 50o, Characterized in that the process is carried out at 3-10-fold excess of 2-mercaptobenzthiazole solubility in a weak alkaline medium, where the concentration of the alkali metal hydroxide is 0.35 to 1.0 wt.%, in the presence of desulfosarcina cobalt as a catalyst in number (3-5)X10-4mol 1 mol 2-mercaptobenzthiazole.

 

Same patents:

The invention relates to methods for obtaining compounds based on 2-mercaptobenzthiazole used as an accelerator in the vulcanization of rubber, rubber and in the synthesis of vulcanization accelerators

FIELD: chemistry.

SUBSTANCE: invention relates to a method of producing 2,2'-dibenzthiazolyl-disulphide via electrochemical oxidation of an alkaline solution of 2-mercaptobenzthiazole at temperature of 70°C and current density of 1 A/cm2, wherein the process is carried out on alternating current with frequency of 55…575 Hz, preferably 100…120 Hz and more preferably 105…115 Hz. The highest current output is achieved using alternating current with frequency of 110 Hz.

EFFECT: high efficiency of the electrolysis cell, reduced electric power consumption, avoiding use of toxic and expensive reagents.

2 cl, 7 ex

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