Preparation of rubber vulcanization accelerator tetrabenzylthiuram disulfide

Abstract

The invention relates to a method for preparing a thiofide of tetraethylthiuram disulfide. The method uses raw materials with the mol ratio as follows: the mol ratio of dibenzyl amine, carbon bisulfide, sodium hydroxide, hydrogen peroxide and sulphuric acid is 1:1-1.30:1.0-1.2:0.5-0.6:0.28-0.35mol. The method comprises the technical process as follows: under normal pressure, the dibenzyl amine and the sodium hydroxide are sequentially added into a reaction kettle which contains purified water under the state of being stirred; subsequently, the temperature is reduced to 20 DEG C to 30 DEG C, liquid carbon bisulfide is dropwise added for 2 to 3 hours; after dropwise adding, reactant continues to be stirred for 0.5 hour; then, at the temperature of 58 DEG C to 63 DEG C, the hydrogen peroxide is dropwise added into the reactant for oxidation reaction which lasts 3 to 4 hours; when the oxidation reaction is going to finish, the sulphuric acid is added to adjust the pH value of reaction solution to be within the range of 6.5-7.5, and the reaction is finished; then the reaction is taken for 1 hour again by heat preservation for solid-liquid separation, and the solid is dried, crushed, filtered and packed to obtain a product. The method can improve the quality, the yield and the performance of the product effectively, reduce the potential safety hazard during the production process greatly, save energy, reduce consumption, reduce the waste water and exhaust emission during the production process and meet the national relative policy of environmental protection.

Description

1. Technical field: [0001] The invention relates to a preparation method of a rubber vulcanization accelerator, in particular to a preparation method of a rubber vulcanization accelerator tetrabenzylthiuram disulfide. 2. Background technology: [0002] In recent years, with the rapid development of the rubber processing industry, domestic automobile industry and communication industry, the rapid growth of the rubber processing industry has been driven, which has provided unprecedented good opportunities for the development of the rubber additives industry. Since my country's accession to the WTO, although the production of rubber accelerator products in China has been greatly improved, compared with foreign developed countries, there is still a big gap in product intrinsic quality and "green" environmental protection technology. China's auxiliaries industry will expand the market share of green and non-toxic auxiliaries, and greatly reduce the sulfenamide accelerators contai...

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Problems solved by technology

[0003] For the production technology of rubber vulcanization accelerator tetrabenzylthiuram disulfide (TBzTD), solvent methods such as methanol, ethanol, and isopropanol are commonly used in China. In addition to emitting a large amount of toxic gases of organic solvents during production, these processes; What's more serious is that there are major production safety hazards in the production process, because in the existing production process, the reaction process in the reactor is carried out under pressure, and each reaction in the reaction All substances exist in the gaseous state, and they are all flammable and explosive substances, which may explode if you are not careful, causing loss of personnel and property; at the same time, the process energy consumption of the prior art is high, and the reaction produces A large amount of waste water and waste gas bring great difficulties to environmental protection, making it difficult to achieve "clean and green" production, which does not meet the national environmental protection policy and energy-saving production requirements

Moreover, the product has a low melting point and a yellow appearance, which makes it difficult to meet the high-end requirements of the domestic and foreign sales markets.

[0004] Although the Chinese patent application CN1827596A also discloses a method for preparing tetrabenzylthiuram disulfide, there are still some problems in the method, firstly the yield of the product after the reaction (i.e. the yield in the application) is relatively low, resulting in Production efficiency is not high, although this application claims that its yield is more than 96%, as can be seen from its disclosed embodiment, its actual yield is only 95% and 91%,; In addition, the purity of gained product is not Well, it cannot meet the higher requirements of customers, and the product prepared by the method of this application has a low melting point and a yellow appearance, and cannot meet the needs of high-end customers

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