Micro-reaction method for continuous synthesis of thiuram disulfide

A technology of tetraalkyl disulfide and thiuram, applied in organic chemistry and other directions, can solve the problems of backward cleanliness and safety mixed acid oxidation process, difficult to suppress side reactions, low utilization rate of raw materials, etc. High product yield, process safety and environmental protection effects

Inactive Publication Date: 2018-10-02
WILLING NEW MATERIALS TECH CO LTD +1
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

Chinese patent CN1069669935A discloses utilizing a microreactor to complete the oxidation reaction process of sodium dimethyldithiocarbamate, which uses chlorine and air as an oxidant to prepare tetramethylthiuram disulfide in a Y-shaped microchannel reactor. However, since the process is a gas-liquid two-phase process, there is a chlorine-containing tail gas emission problem, and the process is cleaner and safer than H 2 o 2 Mixed acid oxidation process lags behind
Chinese patents CN101717357A and CN106831515A respectively disclose the secondary amine CS 2 Condensation + hydrogen peroxide oxidation to prepare tetraalkylthiuram disulfide and tetrabenzylthiuram disulfide micro-reaction process, these two processes use alcohol as solvent, there is difficulty in solvent recovery, and in the case of no NaOH However, it is difficult to suppress the side reaction between dimethyl dithioaminocarboxylic acid and the secondary amine of the raw material, and the utilization rate of the raw material is low

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  • Micro-reaction method for continuous synthesis of thiuram disulfide
  • Micro-reaction method for continuous synthesis of thiuram disulfide
  • Micro-reaction method for continuous synthesis of thiuram disulfide

Examples

Experimental program
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Effect test

Embodiment 1

[0022] Prepare a NaOH aqueous solution with a mass fraction of 15%, 10% H 2 o 2 Sulfuric acid solution, the use of mass fraction is 41% dimethylamine aqueous solution as raw material, control dimethylamine, CS 2 , NaOH, H 2 SO 4 、H 2 o 2 The molar ratio between is 1.0:1.0:1.1:0.55:0.55, at room temperature (26 ℃) enters micro-mesh dispersing mixer (aperture 200 μm, hole number 5) successively through metering pump, micro-mesh condensation reactor ( The pore size is 200 μm, the number of holes is 10) and the micro-sieve oxidation reactor (the size of the hole is 500 μm, the number of holes is 10), and the discharge temperature of the intermediate heat exchanger is controlled by circulating water to 10 ° C. The product is collected in a 500mL stirred tank, filtered, washed and dried Finally, tetramethylthiuram disulfide with a purity of 98.1% was obtained, and the solid yield was 100%.

Embodiment 2

[0024] Prepare a NaOH aqueous solution with a mass fraction of 15%, 5% H 2 o 2 Sulfuric acid solution, the use of mass fraction is 41% dimethylamine aqueous solution as raw material, control dimethylamine, CS 2 , NaOH, H 2 SO 4 、H 2 o 2 The molar ratio between them is 1.0:1.0:1.0:0.5:0.5, and at room temperature (26°C) enters the micro-sieve dispersion mixer (aperture 800 μm, hole number 1) successively through the metering pump, and the micro-sieve condensation reactor ( Aperture 800μm, hole number 1) and micro-sieve oxidation reactor (pore size 800μm, hole number 2), through circulating water to control the discharge temperature of the intermediate heat exchanger to 10°C, collect the product in a 500mL stirred tank, filter, wash and dry Finally, tetramethylthiuram disulfide with a purity of 97.4% was obtained, and the solid yield was 99%.

Embodiment 3

[0026] Prepare a NaOH aqueous solution with a mass fraction of 15%, 5% H 2 o 2 Sulfuric acid solution, the use of mass fraction is 41% dimethylamine aqueous solution as raw material, control dimethylamine, CS 2 , NaOH, H 2 SO 4 、H 2 o2 The molar ratio between them is 1.0:1.0:1.05:0.52:0.55. At room temperature (28°C), they enter the T-shaped microchannel mixer (hydraulic diameter 300 μm, channel number 4) sequentially through the metering pump, and the T-shaped microchannel condenses Reactor (hydraulic diameter 300 μm, number of channels 4) and T-shaped microchannel oxidation reactor (hydraulic diameter 1000 μm, number of channels 1), through circulating water to control the discharge temperature of the intermediate heat exchanger to 10 ℃, in a 500mL stirred tank The product was collected internally, filtered, washed and dried to obtain tetramethylthiuram disulfide with a purity of 98.7%, and a solid yield of 99%.

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Abstract

The invention discloses a method for producing thiuram disulfide as thiofide by a continuous micro-reaction system. According to the method, three processes including secondary amine-NaOH solution mixing, CS2-secondary amine condensation reaction and sodium dithiocarbamate oxidation reaction are sequentially completed by a micro-mixer and a micro-reactor which are connected in series; reaction materials are efficiently mixed by the micro-reaction device, and side reactions such as overoxidation and the like are avoided; by means of a series-integrated operation mode, production efficiency is improved, and product stability is improved. The method can be applied to production of multiple thiuram vulcanizing agents such as tetramethyl thiuram disulfide, tetraethylthiuram disulfide, tetrabutylthiuram disulfide and the like, the yield can reach 98% or higher, and product purity is high.

Description

technical field [0001] The invention relates to the technical field of chemistry and chemical engineering, in particular to a preparation method of a rubber vulcanization accelerator tetraalkylthiuram disulfide. Background technique [0002] Tetraalkylthiuram disulfide compounds are an important class of rubber vulcanization accelerators, which can decompose and generate free radicals during the rubber vulcanization process, thereby promoting the rapid progress of the rubber vulcanization process. Tetraalkylthiuram disulfide compounds are mainly completed through two-step reactions of condensation and oxidation: first, the raw material secondary amine is reacted with CS in NaOH solution 2 The following condensation reaction takes place to generate an aqueous solution of sodium dialkyldithiocarbamate, [0003] [0004] The solution is further passed through H 2 o 2 / H 2 SO 4 Oxidation of the mixed solution forms a precipitate of tetraalkylthiuram disulfide which is in...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C333/32
CPCC07C333/16C07C333/32
Inventor 王凯骆广生章娟郭同新
Owner WILLING NEW MATERIALS TECH CO LTD
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