WO2014026498A1

WO2014026498A1 - Preparation method for organic thiosulfate

Info

Publication number: WO2014026498A1
Application number: PCT/CN2013/077270
Authority: WO
Inventors: 董栋; 赵丽丽; 甄博鸣
Original assignee: 北京彤程创展科技有限公司
Priority date: 2012-08-14
Filing date: 2013-06-14
Publication date: 2014-02-20
Also published as: KR20150042281A; KR102037196B1; CN102816095B; CN102816095A

Abstract

Disclosed are an after-vulcanization stabilizer organic thiosulfate for rubber industry, and especially a preparation method for the organic thiosulfate. According to the preparation method, urea is subjected to a hydrolysis reaction under heating to generate NH3 to adjust the pH value of the reaction solution to an alkaline state, an organic halogenated alkane and a water-soluble inorganic thiosulfate can be subjected to a complete reaction, and generation of thiol compound as a byproduct is inhibited, such that reaction efficiency is effectively improved, the resulting product has high purity, and the preparation process has characteristics of simpleness, easy performing, and low energy consumption.

Description

Preparation method of organic thiosulfate

Technical field

The present invention relates to a post-vulcanization stabilizer for rubber industry, an organic thiosulfate, and more particularly to a process for preparing an organic thiosulfate. Background technique

Rubber is a chain polymer material. The addition of a vulcanizing agent can form a cross-linking reaction with it to form a three-dimensional network structure, which makes the rubber change from a plastic material to an elastic material, so that the rubber has high elasticity in a wide temperature range. Small plasticity and high strength performance. When the vulcanized rubber is over-vulcanized during the production process or exposed to anaerobic heat aging conditions during use, the vulcanized vulcanizate will undergo vulcanization and reversion. In addition, the heat of many rubber compounds during use is sufficient to cause cross-linking. Network degradation, in turn, accelerates the generation of heat, causing the product to be easily damaged, shortening the service life, and the reversion of the original product can result in uneven internal and surface properties of the rubber product, thus limiting the improvement of the vulcanization temperature during the rubber mixing process and the product. Performance of use.

In the tire industry, the traditional method used to improve the resistance of the rubber to reversion is to increase the amount of accelerator and reduce the amount of sulfur, effectively use the added sulfur, and reduce the formation of polysulfide bonds to obtain higher stability. There are also some additives with improved effects, such as fatty acid salts as a multi-functional processing aid, which can improve the processing performance and improve the vulcanization effect. It is also widely used in the rubber industry, the most representative of which is aromatic acids. The zinc soap compound can effectively improve the anti-reversion property of NR vulcanization. In addition, some companies have introduced compensating vulcanization systems to compensate for the loss of crosslinks and maintain the crosslink density of the compounds, such as Duralink HTS (disodium hexamethylene hexamethyl disulfate disodium salt), Perkalink 900 ( 1,3- liminimidomethyl) benzene, etc.

Monsanto developed the Duralink HTS in the 1980s to improve the stability of polysulfide crosslinks, but later found it to increase operational safety. Duralink HTS contains a sulfur atom and a carbon atom. During vulcanization, HTS inserts a hexamethylene disulfide group into the polysulfide crosslink, and a long soft, thermally stable sulfhydryl group is embedded in the crosslink bond structure. The formation of a composite cross-linking bond can improve the anaerobic aging resistance of the vulcanizate and improve the thermal stability of the cross-linking bond, thereby improving the flexibility of the rubber compound under dynamic operation and improving the anti-reversion property of the rubber compound.

There have been many studies and reports on the synthesis of Duralink HTS. In the U.S. Patent No. 4,587,296, the entire disclosure of which is incorporated herein by reference to U.S. Patent No. 4,587, 296, the disclosure of which is incorporated herein by reference. Thiosulfate, a large amount of organic solvent used in this process, is not conducive to industrial production and environmental protection requirements.

Lanxess, in the patent document US Pat. No. 7,217,834, mentions that as the reaction of 16-dichlorohexanide with thiosulfate ions proceeds, the reaction mixture becomes more acidic. The use of water as a solvent avoids the addition of alcohol and/or diol. On the other hand, the organic base or inorganic base is continuously added during the reaction by the metering pump, and the pH value of the solution is detected in real time through the pH electrode, so that the pH of the reaction solution is maintained at 7.2. ± 0.1, to avoid the acidity of the reaction solution, improve the conversion rate, although the preparation is used Smaller, and the values of C and H differ greatly from the calculated values. For example, the difference between the C element content and the calculated value is 1.16%, indicating that the purity of the product obtained by this production process is slightly insufficient, possibly due to other possible products in the product. Impurities, in addition, under the factory production conditions, the metering pump and pH meter in this process are used to detect the pH value of the reaction solution in real time, and the equipment has many demands and energy consumption.

Chinese Patent No. 200610040688.1 provides a separation and purification method, wherein a hydrated hexamethylene 1,6-dithiosulfate disodium salt is obtained by using a water/ethanol mixed solvent as a reaction solvent, and ethanol is added after the reaction is completed. Then, water is added to the temperature, and the product is crystallized. Although this process reduces environmental pollution during the production process, the synthesis process can be reproduced according to this process, and the product can be smelled with a foul odor, indicating that a by-product thiol compound is formed during the reaction, which is inconvenient for industrial production. In addition, after the end of the reaction, ethanol is added to continue the reflux, and the temperature is lowered to 60-70 ° C. Then, water is added, which causes a certain amount of disodium hexamethylene dihydrate, disodium hexa-disulfate dihydrate dissolved in the process. In water, after cooling, it still cannot be completely crystallized, and the yield of the product is lowered.

During the reaction between the halogenated anthracene and the thiosulfate, the reaction solution becomes an acidic solution. On the one hand, the acidic solution lowers the reaction rate, prolongs the reaction time, and consumes more energy; on the other hand, the acidic solution promotes by-products The formation of a thiol compound reduces the purity of the product; in addition, under acidic conditions, sodium thiosulfate undergoes a decomposition reaction, and the concentration of sodium thiosulfate decreases, slowing down the reaction rate, which is not conducive to the progress of the reaction.

The invention utilizes urea to undergo hydrolysis reaction under heating conditions to generate NH ₃ to adjust the acidity and alkalinity of the reaction solution, so that the reaction solution can be well maintained in alkaline conditions, inhibit the formation of thiol compounds, and effectively improve the reaction. The efficiency makes the product have higher purity, and the preparation process is simple and easy, and the energy consumption is low. Summary of the invention

In the invention, urea is used to adjust the pH value of the reaction solution, the pH value of the reaction solution can be well controlled, the acid-base change of the solution during the reaction process can be effectively avoided, the operation process can be simplified, and the mercaptan can be suppressed. The formation of compounds improves the purity of the product, and the process is simple and economical.

An object of the present invention is to provide a method for preparing an organic thiosulfate, which is capable of controlling the formation of a thiol compound and improving the reaction efficiency by controlling the pH of the reaction solution with urea. Specifically, the following steps are included:

Step (1), using a reaction vessel equipped with a mechanical stirring device, a thermometer and a reflux condenser, respectively, weigh the water-soluble inorganic thiosulfate and urea into a reaction vessel, and add water to mechanically stir and dissolve to prepare inorganic thio An aqueous solution having a molar concentration of 0.5 to 2.8 mol/L;

Step (2), adding halogenated anthracene hydrocarbon under stirring condition, heating the reaction liquid at a temperature to control the reaction temperature to be 80-120 ° C, the pH value of the solution is controlled at 7-9, and the reaction is stirred under reflux conditions for 4-9 hours _;

Step (3), after the reaction is finished, the solution is poured out and ethanol is added, and the solution is allowed to stand at 0 to 20 ° C for 1 to 5 hours, and a large amount of solid is precipitated, and the solid is filtered, and dried at 45 to 55 ° C to obtain an organic Thiosulfate.

Wherein, the water-soluble inorganic thiosulfate in the step (1) may be one of sodium thiosulfate, potassium thiosulfate, and ammonium thiosulfate; The halogenated hydrocarbon in the step (2) may be a chlorinated hydrocarbon such as 1,4-dichlorobutyl hydrazine, 1,6-dichlorohexidine, 1,8-dichlorooctyl hydrazine, 1,10-dichloro One of hydrazine and 1,12-dichlorododecafluorene, which may also be a brominated hydrazine, such as 1,4-dibromobutane, 1,6-dibromohexanide, 1,8-dibromo One of Xinzhi, 1,10-dibromofluorene and 1,12-dibromoindene, the molar ratio of water-soluble inorganic thiosulfate to halogenated anthracene is 1.8:1~2.1:1. The molar ratio of water-soluble inorganic thiosulfate to urea is 4:1~1:1 _;

The volume ratio of the ethanol added in the step (3) to the water added in the step (1) is 1:1 to 6:1.

In the present invention, sodium thiosulfate, potassium thiosulfate, or ammonium thiosulfate can be reacted with a halogenated anthracene to prepare a corresponding organic thiosulfate. The halogenated anthracene hydrocarbon used may be a chlorohydrazine or a brominated anthracene hydrocarbon, and the corresponding organic thiosulfate can be obtained under the same reaction conditions. The present invention adds ethanol to precipitate the target product at the end of the reaction, and the ethanol can be recycled and reused to reduce environmental pollution in the production process.

Another object of the present invention is to provide a method for preparing an organic thiosulfate, which comprises reacting an inorganic thiosulfate with a halogenated anthracene at 80 to 120 ° C, and during the reaction. Urea is used to maintain the pH of the reaction system between 7 and 9.

Urea is used to adjust the pH value of the reaction solution, which can well control the pH value of the reaction solution, effectively avoiding the acid-base change of the solution during the reaction, which can simplify the operation process and not smell bad during the preparation process. The generation of odor, thus indicating that the preparation method of the present invention can effectively inhibit the formation of thiol compounds, improve the purity of the product, and the process is simple, easy, and economical. In order to better control the progress of the reaction, the reaction temperature of the inorganic thiosulfate and the halogenated anthracene is preferably 80 to 102 ° C, more preferably 80 to 100 ° C, still more preferably 90 to 100 ° C.

In a preferred embodiment of the present invention, the above preparation method further comprises: Step (1), mixing inorganic thiosulfate and urea in water to form an aqueous solution, and the inorganic thiosulfate is a water-soluble inorganic thiosulfate And the molar concentration is 0.5~2.8mol/L _{; in} step (2), adding a halogenated anthracene hydrocarbon to the aqueous solution under stirring to form a reaction liquid, and the reaction liquid is heated to 80-120 ° C, and stirring is continued under reflux conditions. Organic thiosulfate.

In the above embodiment, a sufficient amount of urea can be added at a time before the start of the reaction to maintain a stable pH of 7 to 9 in the reaction solution, which does not need to be continuously added during the reaction, thereby simplifying the production process; using water as a solvent to reduce The use of organic solvents, the preparation method is more environmentally friendly; the slow hydrolysis of urea during the reaction to stabilize the pH of the reaction solution, after the reaction is completed, the urea can be made neutral by decomposing the residual urea in the solution, avoiding the alkaline solution Post processing.

The purification of the organic thiosulfate synthesized by the above preparation method can be purified by a separation and purification method commonly used in the prior art, for example, the separation and purification method disclosed in Application No. 200610040688.1. Preferably, after the step (2) of the preparation method provided by the present invention, the method further comprises: mixing the reaction liquid of the completion step (2) with ethanol to form a mixed solution, and placing the mixed solution at 2 to 20 ° C for 1 to 5 hours. After filtration, the resulting filter cake was dried to give an organic thiosulfate. The above method for purifying organic thiosulfate is simpler and easier to operate and control than the existing purification method.

Compared with the prior art, the present invention is beneficial in that:

(1) A sufficient amount of urea can be added at a time before the start of the reaction to maintain a stable pH of 7-9, which does not need to be continuously added during the reaction, thereby simplifying the production process;

(2) Slow hydrolysis of urea during the reaction to stabilize the pH of the reaction solution and pass through the decomposition solution after the reaction is completed. The residual urea can make the solution neutral, avoiding the post-treatment of the alkaline solution;

(3) Utilizing the pH value of the urea stabilized reaction solution, on the one hand, it can effectively solve the acidification of the solution, inhibit the formation of by-product thiol compounds, improve the reaction efficiency, shorten the reaction time, improve the purity of the product, and reduce the energy consumption;

(4) The organic solvent is not added during the reaction, the use of the organic solvent is reduced, and no odorous by-products are formed during the reaction, and the preparation process is more environmentally friendly.

The invention adopts the simple process, low energy consumption, good repeatability, and meets the development direction of safety, greenness and environmental protection, and thus has great development prospects. detailed description

The principle of the present invention is: Under the heating condition, urea is hydrolyzed in water to form? "3⁄4 and C0 ₂ , and NH ₃ is more soluble in aqueous solution than CO ₂ gas, causing CO ₂ gas to escape the reaction solution, and NH _{3 is} dissolved in the aqueous solution to adjust the pH of the solution to be alkaline. In addition, by controlling the reaction temperature, the urea can be continuously hydrolyzed in the aqueous solution, the pH of the aqueous solution can be stabilized within the reaction requirement range, and no fluctuation occurs, and the heating is continued after the reaction is completed to completely decompose the residual urea in the solution. And make it generated? 43⁄4 and 03⁄4 escape the solution, thereby avoiding post-treatment of the alkaline solution.

In the reaction of halogenated anthracene with inorganic thiosulfate, a odorous thiol by-product is formed. In addition, the residual inorganic halide and the thiosulfate pentahydrate in the product also affect the purity of the product. The content of C, H, S and other elements in the product was found to be different from the calculated value. In the present invention, urea is added to adjust the acidity and alkalinity of the reaction solution, and the formation of the thiol compound can be inhibited. After the reaction is completed, ethanol is added to precipitate the organic thiosulfate product, and the content of the C, H, and S elements in the product is obtained. The calculated values are closer.

The process of the invention comprises the following steps:

Step (2), adding a halogenated hydrazine hydrocarbon while stirring, heating the reaction liquid at a temperature, controlling the reaction temperature to be 80-120 ° C, controlling the pH value of the solution to 7-9, and stirring the reaction for 4-9 hours under reflux conditions _;

Step (3), after the reaction is completed, the solution is poured out and ethanol is added, and the solution is allowed to stand at 0 to 20 ° C for 1 to 5 hours, and then the solid is filtered, and dried at 45 to 55 ° C to obtain an organic thiosulfuric acid. salt.

When the reaction is stirred under reflux conditions, the residual organic halogenated hydrocarbon and inorganic thiosulfate in the reaction solution are respectively tested by gas chromatography (GC) and liquid chromatography (HPLC) using an internal standard method, and the reaction can be determined. Time, you can calculate the conversion rate at the same time. By adding ethanol to the solution after stopping the stirring reaction, the target product organic thiosulfate can be precipitated from the aqueous solution, and the inorganic halogenated product and the residual inorganic thiosulfate formed by the reaction remain in the aqueous solution, thereby improving the product. purity.

The invention is further illustrated below in conjunction with specific embodiments. It should be noted that the following are only the examples of the present invention. The embodiments of the present invention are intended to be illustrative only and not to limit the scope of the present invention, and all other variations derived or directly derived from the present disclosure should be It is considered to be the scope of protection of the present invention.

Example 1

A 200 mL four-necked flask equipped with a mechanical stirring device, a thermometer and a reflux condenser was used as a reaction vessel, and 12.4 g of sodium thiosulfate pentahydrate and 0.75 g of urea were weighed into a four-necked flask, and 100 mL of water was added thereto to mechanically dissolve and dissolve. 3.9 g of 1,6-dichlorohexidine was added while stirring, and the solution was heated at a temperature to raise the pH of the solution to 102 ° C. The pH of the solution was 7, and after stirring for 6 hours under reflux, the solution was poured out. And adding 100 mL of ethanol, the solution was allowed to stand at 0 ° C for 1 h, a large amount of solid precipitated, and the solid product was filtered, and dried at 55 ° C to obtain hexamethylene hexamethyl 1,6-dithiosulfate disodium salt.

Example 2

A 200 mL four-necked flask equipped with a mechanical stirring device, a thermometer and a reflux condenser was used as a reaction vessel, and 24.8 g of sodium thiosulfate pentahydrate and 5.0 g of urea were weighed into a four-necked flask, and mechanically stirred and dissolved by adding 100 mL of water. Add 7.8 gl, 6-dichlorohexan with stirring, heat the above solution, raise the temperature of the reaction solution to 102 ° C, the pH of the solution is 9, and stir the reaction under reflux for 5 h, then pour out the solution and add 200 mL of ethanol, the solution was allowed to stand at 4 ° C for 3 h, and a large amount of solid was precipitated. The solid product was filtered off, and dried at 45 ° C to obtain hexamethylene hexamethyl 1,6-dithiosulfate dihydrate.

Example 3

A 200 mL four-necked flask equipped with a mechanical stirring device, a thermometer and a reflux condenser was used as a reaction vessel, and 49.6 g of sodium thiosulfate pentahydrate and 6.0 g of urea were weighed into a four-necked flask, and mechanically stirred and dissolved by adding 100 mL of water. Add 15.5g of 1,6-dichlorohexidine to the mixture while stirring, and heat the solution to raise the temperature of the reaction solution to 102 ° C. The pH of the solution is 9. After stirring for 6 hours under reflux conditions, the solution is poured out and added. 150 mL of ethanol, the solution was allowed to stand at 10 ° C for 5 h to precipitate a solid, and the solid product was filtered off, and dried at 55 ° C to obtain hexamethylene hexamethyl 1,6-dithiosulfate disodium salt.

Example 4

A 200 mL four-necked flask equipped with a mechanical stirring device, a thermometer and a reflux condenser was used as a reaction vessel, and 69.5 g of sodium thiosulfate pentahydrate and 15.0 g of urea were weighed into a four-necked flask, and 100 mL of water was added thereto to mechanically dissolve and dissolve. Add 21.7 gl, 6-dichlorohexan with stirring, heat the above solution, set the temperature of the reaction solution to 120 ° C, the pH of the solution is 9, and stir the reaction for 9 h under reflux conditions, pour out the solution and add 600 mL of ethanol. After the solution was allowed to stand at 20 ° C for 5 h, the solid was filtered off, and after drying at 45 ° C, hexamethylene hexamethyl 1,6-dithiosulfate disodium salt was obtained.

Example 5:

A 200 mL four-necked flask equipped with a mechanical stirring device, a thermometer and a reflux condenser was used as a reaction vessel, and 34.2 g of potassium thiosulfate and 6.0 g of urea were weighed into a four-necked flask, and 100 mL of water was added thereto to mechanically stir and dissolve, and then stirred. Add 15.5g of 1,6-dichlorohexanide, heat the above solution, raise the temperature of the reaction solution to 102 ° C, the pH of the solution is 9, after stirring for 6 hours under reflux conditions, pour out the solution and add 100 mL of ethanol. After the solution was allowed to stand at 10 ° C for 3 h, the solid product was filtered off, and dried at 55 ° C to obtain hexamethylene hexamethyl 1,6-dithiosulfate dipotassium salt. Example 6

A 200 mL four-necked flask equipped with a mechanical stirring device, a thermometer and a reflux condenser was used as a reaction vessel, and 31.1 g of ammonium thiosulfate and 6.0 g of urea were weighed into a four-necked flask, and 100 mL of water was added thereto to be mechanically stirred and dissolved, followed by stirring. Add 15.5 gl, 6-dichlorohexanide, heat the above solution, keep the temperature of the reaction solution at 90 ° C, the pH of the solution is 8, and stir the reaction under reflux for 9 h, then pour out the solution and add 400 mL of ethanol. After the solution was allowed to stand at 10 ° C for 3 h, the solid product was filtered off, and dried at 55 ° C to obtain hexamethylene hexamethyl 1,6-dithiosulfate diammonium salt.

Example 7

A 200 mL four-necked flask equipped with a mechanical stirring device, a thermometer and a reflux condenser was used as a reaction vessel, and 39.6 g of sodium thiosulfate pentahydrate and 6.0 g of urea were weighed into a four-necked flask, and dissolved by mechanical stirring after adding 120 mL of water. While stirring, 19.6 g of 1,6-dibromohexanide was added, and the solution was heated at a temperature to maintain the temperature of the reaction solution at 80 ° C. The pH of the solution was 9, and after stirring for 5 hours under reflux, the solution was poured out and added. After 400 mL of ethanol was placed at 10 ° C for 3 hours, the solid product was filtered off, and dried at 55 ° C to obtain hexamethylene hexamethyl 1,6-dithiosulfate disodium salt.

Example 8

A 200 mL four-necked flask equipped with a mechanical stirring device, a thermometer and a reflux condenser was used as a reaction vessel, and 19.8 g of sodium thiosulfate pentahydrate and 2.0 g of urea were weighed into a four-necked flask, and dissolved by mechanical stirring after adding 120 mL of water. 9.8g of 1,6-dibromohexanide was added while stirring, and the solution was heated at a temperature to maintain the temperature of the reaction solution at 90 ° C. The pH of the solution was 9, and after stirring for 4 hours under reflux, the solution was poured out. After adding 200 mL of ethanol, the solution was allowed to stand at 4 ° C for 5 h, and the solid product was filtered off, and dried at 55 ° C to obtain hexamethylene hexamethyl 1,6-dithiosulfate disodium salt.

Example 9

A 200 mL four-necked flask equipped with a mechanical stirring device, a thermometer and a reflux condenser was used as a reaction vessel, and 33.0 g of sodium thiosulfate pentahydrate and 9.0 g of urea were weighed into a four-necked flask, and 100 mL of water was added thereto to mechanically dissolve and dissolve. Add 8.5 gl, 4-dichlorobutane with stirring, heat the above solution, and keep the temperature of the reaction solution at 100 ° C. The pH of the solution is 9. After stirring for 4 hours under reflux conditions, the solution is poured out and added. After 400 mL of ethanol, the solution was allowed to stand at 4 ° C for 5 h, and the solid product was filtered off. After drying at 55 ° C, tetramethylene 1,4-dithiosulfate dihydrate salt was obtained.

Example 10

A 200 mL four-necked flask equipped with a mechanical stirring device, a thermometer and a reflux condenser was used as a reaction vessel, and 33.0 g of sodium thiosulfate pentahydrate and 7.0 g of urea were weighed into a four-necked flask, and 100 mL of water was added thereto to mechanically dissolve and dissolve. Add 12.5g of 1,8-dichlorooctane to the mixture while stirring, heat the solution at a temperature to maintain the temperature of the reaction solution at 100 ° C, the pH of the solution is 9, and the reaction is stirred for 9 hours under reflux conditions, and the solution is poured out. After adding 400 mL of ethanol, the solution was allowed to stand at 4 ° C for 5 h, and the solid product was filtered off, and dried at 55 ° C to obtain octamethyl 1,8-dithiosulfate dihydrate salt.

According to the specific embodiment of Example 1, the chemical formula of the obtained disodium hexamethylene 1,6-dithiosulfate dihydrate is obtained by using sodium thiosulfate and 1,6-dichlorohexanide as raw materials: Na0 ₃ S ₂ (CH ₂ ) ₆ S ₂ 0 ₃ Na · 2H ₂ 0.

The sample obtained in Example 1 was tested for infrared spectrum by potassium bromide tableting method, which was consistent with the structural formula: 3564, 3457, 1619cm" ¹ : Infrared absorption peak of OH in crystal water

2927, 2858, 1465cm" ¹ : methylene symmetry and antisymmetric stretching vibration peak

1216, 1043cm" ¹ : Symmetric and antisymmetric stretching vibration peaks of S=0

728cm" ^1st : Characteristic absorption peak of methylene surface swing vibration

The obtained sample was subjected to elemental analysis, and the percentages of the three elements of C, H and S were tested, and the percentage of NaCl in the sample was tested. The results are shown in Table 1 below:

Table 1

Example 11

A 200 mL four-necked flask equipped with a mechanical stirring device, a thermometer and a reflux condenser was used as a reaction vessel, and 12.4 g of sodium thiosulfate pentahydrate and 0.75 g of urea were weighed into a four-necked flask, and 100 mL of water was added thereto to mechanically dissolve and dissolve. 3.9 g of 1,6-dichlorohexanide was added while stirring, and the solution was heated at a high temperature to raise the pH of the solution to 102 ° C, and the pH of the solution was 7, and the reaction was stirred for 6 hours under reflux, from the reaction solution. The sample was subjected to gas chromatography (GC) and liquid chromatography (HPLC) to separately measure the contents of 1,6-dichlorohexidine and sodium thiosulfate pentahydrate in the solution, and calculate the conversion rate. Using 1,6-dichlorohexidine as internal standard, the residual standard 1,6-dichlorohexanide <0.01% was tested by internal standard method, and the internal standard method was used to test the solution with sodium thiosulfate pentahydrate as internal standard. The residual sodium thiosulfate pentahydrate was 0.12%, and the corresponding conversion of 1,6-dichlorohexanide was >99.7%, and stirring was stopped.

The solution was poured out and 100 mL of ethanol was added. The solution was allowed to stand at 0 ° C for 1 h, and a large amount of solid was precipitated. The solid product was filtered off and dried at 55 ° C to obtain a hexamethylene dihydrate containing 1,6-dithiosulfate. A solid sample of the sodium salt. The content of sodium thiosulfate pentahydrate in the solid product was determined by HPLC to be 0, and the content of sodium chloride in the solid sample was measured by a potentiometric titrator to be 0.5%.

Example 12

A 200 mL four-necked flask equipped with a mechanical stirring device, a thermometer and a reflux condenser was used as a reaction vessel, and 24.8 g of sodium thiosulfate pentahydrate and 5.0 g of urea were weighed into a four-necked flask, and mechanically stirred and dissolved by adding 100 mL of water. 7.8 g, 6-dichlorohexidine was added while stirring, the solution was heated at a high temperature, the temperature of the reaction liquid was raised to 102 ° C, the pH of the solution was 9, and the reaction was stirred under reflux for 5 h, as in Example 11. The test method, taking a small amount of solution, the residual 1,6-dichlorohexidine content in the solution is determined by GC <0.01%, and the residual content of sodium thiosulfate pentahydrate in the solution is 0.15% by HPLC, corresponding to 1 The conversion of 6-dichlorohexanide was >99.8%, and the stirring was stopped.

The solution was poured out and 200 mL of ethanol was added, and the solution was allowed to stand at 4 ° C for 3 hours to precipitate a large amount of solid, and the solid product was filtered, and dried at 45 ° C to obtain a hexamethylene dihydrate containing 1,6-dithiosulfate. A solid sample of the sodium salt. Solidified by HPLC test The content of sodium thiosulfate pentahydrate in the body product was 0, and the content of sodium chloride in the solid sample was 0.4% by a potentiometric titrator.

Example 13

A 200 mL four-necked flask equipped with a mechanical stirring device, a thermometer and a reflux condenser was used as a reaction vessel, and 49.6 g of sodium thiosulfate pentahydrate and 6.0 g of urea were weighed into a four-necked flask, and mechanically stirred and dissolved by adding 100 mL of water. 15.5 g of 1,6-dichlorohexidine was added while stirring, the solution was heated at a high temperature, the temperature of the reaction liquid was raised to 102 ° C, the pH of the solution was 9, and the reaction was stirred for 6 hours under reflux, as in Example 11. The test method is to take a small amount of solution and determine the residual content of 1,6-dichlorohexidine in the solution by <0.01%. The residual content of sodium thiosulfate pentahydrate in the solution is 0.3% by HPLC. The conversion of 1,6-dichlorohexanide was >99.9%, and stirring was stopped.

The solution was poured out and 150 mL of ethanol was added, and the solution was allowed to stand at 10 ° C for 5 hours to precipitate a solid, and the solid product was filtered, and dried at 55 ° C to obtain a hexamethylene dihydrate 1,6-dithiosulfate disodium salt. Solid sample. The content of sodium thiosulfate pentahydrate in the solid product was determined by HPLC to be 0, and the content of sodium chloride in the solid sample was measured by a potentiometric titrator to be 0.5%.

Example 14

A 200 mL four-necked flask equipped with a mechanical stirring device, a thermometer and a reflux condenser was used as a reaction vessel, and 69.5 g of sodium thiosulfate pentahydrate and 15.0 g of urea were weighed into a four-necked flask, and 100 mL of water was added thereto to mechanically dissolve and dissolve. 21.7 gl, 6-dichlorohexidine was added while stirring, the solution was heated at a high temperature, the temperature of the reaction solution was set to 120 ° C, the pH of the solution was 9, and the reaction was stirred for 9 hours under reflux conditions, followed by the test in Example 11. Method, taking a small amount of solution by GC to determine the residual content of 1,6-dichlorohexidine in the solution <0.01%, HPLC determined that the residual content of sodium thiosulfate pentahydrate in the solution is 0.2%, corresponding to 1, The conversion of 6-dichlorohexanide was >99.9%, and the stirring was stopped.

The solution was poured out and 600 mL of ethanol was added. After the solution was allowed to stand at 20 ° C for 5 h, the solid was filtered off, and after drying at 45 ° C, the disodium hexamethylene dihydrate 1,6-dithiosulfate dihydrate was obtained. Solid sample. The content of sodium thiosulfate pentahydrate in the solid product was determined by HPLC to be 0, and the content of sodium chloride in the solid sample was measured by a potentiometric titrator to be 0.3%.

Example 15

A 200 mL four-necked flask equipped with a mechanical stirring device, a thermometer and a reflux condenser was used as a reaction vessel, and 34.2 g of potassium thiosulfate and 6.0 g of urea were weighed into a four-necked flask, and 100 mL of water was added thereto to mechanically stir and dissolve, and then stirred. 15.5 g of 1,6-dichlorohexidine was added, the solution was heated at a high temperature, the temperature of the reaction solution was raised to 100 ° C, the pH of the solution was 9, and the reaction was stirred for 6 hours under reflux conditions, followed by the test in Example 11. Method, a small amount of solution was taken by GC to determine the residual content of 1,6-dichlorohexidine in the solution was 0.3%, and the residual potassium thiosulfate content in the solution was determined by HPLC to be <0.01%, corresponding to 1,6- The conversion of dichlorohexanide was >99.9%, and the stirring was stopped.

The solution was poured out and 100 mL of ethanol was added. After the solution was allowed to stand at 10 ° C for 3 h, the solid product was filtered off, and dried at 55 ° C to obtain dipotassium hexamethylene dihydrate, 1,6-dithiosulfate. A solid sample of salt. The content of potassium thiosulfate in the solid product was determined by HPLC to be 0, and the potassium chloride content in the solid sample was measured by a potentiometric titrator to be 0.5%.

Example 16 A 200 mL four-necked flask equipped with a mechanical stirring device, a thermometer and a reflux condenser was used as a reaction vessel, and 31.1 g of ammonium thiosulfate and 6.0 g of urea were weighed into a four-necked flask, and 100 mL of water was added thereto to be mechanically stirred and dissolved, followed by stirring. Add 15.5 gl, 6-dichlorohexanide, heat the above solution to maintain the temperature of the reaction solution at 90 ° C, the pH of the solution is 8, and stir the reaction under reflux conditions for 9 h, according to the test method in Example 11. The residual 1,6-dichlorohexidine content in the solution was determined by GC to be <0.01%, and the corresponding conversion ratio of 1,6-dichlorohexanide was >99.9%, and the stirring was stopped.

The solution was poured out and 400 mL of ethanol was added. After the solution was allowed to stand at 10 ° C for 3 h, the solid product was filtered off, and dried at 55 ° C to obtain diammonium hexamethyl 1,6-dithiosulfate dihydrate. A solid sample of salt. The content of ammonium thiosulfate in the solid product was determined by HPLC to be 0, and the content of ammonium chloride in the solid sample was measured by a potentiometric titrator to be 0.5%.

Example 17

A 200 mL four-necked flask equipped with a mechanical stirring device, a thermometer and a reflux condenser was used as a reaction vessel, and 39.6 g of sodium thiosulfate pentahydrate and 6.0 g of urea were weighed into a four-necked flask, and dissolved by mechanical stirring after adding 120 mL of water. 19.6 g of 1,6-dibromohexanide was added while stirring, the solution was heated at a high temperature, the temperature of the reaction solution was maintained at 80 ° C, the pH of the solution was 9, and the reaction was stirred for 5 hours under reflux, as in Example 11. The test method is to take a small amount of solution and determine the residual content of 1,6-dibromohexanide in the solution by <0.01%. The residual content of sodium thiosulfate pentahydrate in the solution is 0.2% by HPLC. The conversion of 1,6-dibromohexanide was >99.9%, and stirring was stopped.

The solution was poured out and 400 mL of ethanol was added. After the solution was allowed to stand at 10 ° C for 3 h, the solid product was filtered off, and dried at 55 ° C to obtain disodium hexamethylene dihydrate 1,6-dithiosulfate dihydrate. A solid sample of salt. The content of sodium thiosulfate pentahydrate in the solid product obtained by HPLC test was 0, and the content of sodium bromide in the solid sample was measured by a potentiometric titrator to be 0.2%.

Example 18

A 200 mL four-necked flask equipped with a mechanical stirring device, a thermometer and a reflux condenser was used as a reaction vessel, and 19.8 g of sodium thiosulfate pentahydrate and 2.0 g of urea were weighed into a four-necked flask, and dissolved by mechanical stirring after adding 120 mL of water. 9.8 g of 1,6-dibromohexanide was added while stirring, and the solution was heated at a high temperature to maintain the temperature of the reaction solution at 90 ° C. The pH of the solution was 9, and the reaction was stirred for 4 hours under reflux, as in Example 11. In the test method, the residual 1,6-dibromohexanthene content in the GC test solution is <0.01%, and the residual sodium thiosulfate pentahydrate in the solution is determined by HPLC to be 0.3%, corresponding to 1,6 - The conversion of dibromohexanide was >99.9%, and stirring was stopped.

The solution was poured out and 200 mL of ethanol was added. After the solution was allowed to stand at 4 ° C for 5 h, the solid product was filtered off, and after drying at 55 ° C, it was obtained to contain hexamethylene hexamethyl 1,6-dithiosulfate dihydrate. A solid sample of salt. The content of sodium thiosulfate pentahydrate in the solid product was determined by HPLC to be 0, and the content of sodium bromide in the solid sample was 0.4% by a potentiometric titrator.

Example 19

A 200 mL four-necked flask equipped with a mechanical stirring device, a thermometer and a reflux condenser was used as a reaction vessel, and 26.2 g of sodium thiosulfate pentahydrate and 4.0 g of urea were weighed into a four-necked flask, and after adding 100 mL of water, mechanically stirred and dissolved, 7.8 g, 6-dichlorohexanide was added while stirring, the solution was heated at a high temperature, the temperature of the reaction liquid was raised to 100 ° C, the pH of the solution was 9, and the reaction was stirred under reflux for 5 h, as in Example 11. The test method, taking a small amount of solution, the residual 1,6-dichlorohexidine content in the solution is determined by GC <0.01%, and the residual sodium thiosulfate pentahydrate in the solution is determined by HPLC to be 0.95%. The corresponding conversion of 1,6-dichlorohexanide was >99.9%, and stirring was stopped.

The solution was poured out and 400 mL of ethanol was added. The solution was allowed to stand at 4 ° C for 3 hours, and a large amount of solid was precipitated. The solid product was filtered off and dried at 45 ° C to obtain a hexamethylene dihydrate containing 1,6-dithiosulfate. A solid sample of the sodium salt. The content of sodium thiosulfate pentahydrate in the solid product was 0.01% by HPLC test, and the content of sodium chloride in the solid sample was 0.6% by a potentiometric titrator.

Example 20

A 200 mL four-necked flask equipped with a mechanical stirring device, a thermometer and a reflux condenser was used as a reaction vessel, and 12.4 g of sodium thiosulfate pentahydrate and 2.4 g of urea were weighed into a four-necked flask, and dissolved by mechanical stirring after adding 125 mL of water. Add 5.2 gl, 6-dichlorohexan with stirring, heat the above solution, raise the temperature of the reaction solution to 120 ° C, the pH of the solution is 7, and stir the reaction under reflux for 3 h, as in Example 11. The test method was carried out by taking a small amount of solution, and the residual 1,6-dichlorohexanide content was 1.5% by GC, and the residual sodium thiosulfate pentahydrate content in the HPLC test solution was <0.01%.

The solution was poured out and 100 mL of ethanol was added. After the solution was allowed to stand at 4 ° C for 0.5 h, a large amount of solid was precipitated, and the solid product was filtered off. After drying at 45 ° C, the hexamethylene dichloride 1,6-dithiol was obtained. A solid sample of disodium sulfate. The content of sodium thiosulfate pentahydrate in the solid product was found to be 0% by HPLC, and the content of sodium chloride in the solid sample was 1.2% by a potentiometric titrator.

Example 21

A 200 mL four-necked flask equipped with a mechanical stirring device, a thermometer and a reflux condenser was used as a reaction vessel, and 74.4 g of sodium thiosulfate pentahydrate and 3.6 g of urea were weighed into a four-necked flask, and mechanically stirred and dissolved by adding 100 mL of water. 18.6 g of 1,6-dichlorohexanide was added while stirring, and the solution was heated at a high temperature to raise the temperature of the reaction solution to 100 ° C. The pH of the solution was 7.5, and the reaction was stirred under reflux for 10 hours, as in Example 11. The test method, a small amount of solution was used to test the residual 1,6-dichlorohexidine content <0.01% by GC, and the residual sodium thiosulfate pentahydrate content in the HPLC test was 7.6%.

The solution was poured out and 700 mL of ethanol was added. The solution was allowed to stand at 4 ° C for 6 h, and a large amount of solid was precipitated. The solid product was filtered off and dried at 45 ° C to obtain hexamethylene hexamethyl 1,6-dithiosulfate. A solid sample of disodium salt. The content of sodium thiosulfate pentahydrate in the solid sample was 1.8% by HPLC test, and the content of sodium chloride in the solid sample was 0.5% by potentiometric titrator.

Comparative example 1

The organic thiosulfate of Comparative Example 1 was synthesized by the synthetic process disclosed in Chinese Patent Application No. 200610040688.1, as follows:

A 200 mL four-necked flask equipped with a mechanical stirring device, a thermometer and a reflux condenser was used as a reaction vessel, and 24.8 g of sodium thiosulfate pentahydrate and 5.2 g of 1,6-dichlorohexanide were weighed into a four-necked flask, and 100 mL was added. 50% ethanol, reacted at 90 ° C for 60 min under reflux and stirring. According to the test method in Example 11, the content of 1,6-dichlorohexanide and sodium thiosulfate pentahydrate in the solution was determined by GC and HPLC respectively, and the content of 1,6-dichlorohexanide in the solution was 2.9%, the sodium thiosulfate pentahydrate content was 9.8%. Add 100% ethanol lOOmL to the solution, reflux at 80 ° C for 15 min, then filter while hot, add 50 mL of water to the filtrate, and then cool and dry to obtain white solid hexamethylene hexamethylene 1,6-dithiosulfate dihydrate. Disodium salt. During the drying of the sample, a foul odor escaped, indicating that a mercaptan by-product was formed during the reaction. The percentage of sodium thiosulfate pentahydrate in the white solid obtained by HPLC test was 18%, and the sodium chloride content was 3.2% by a potentiometric titrator.

Comparative example 2

The organic thiosulfate of Comparative Example 2 was synthesized by the synthesis process disclosed in U.S. Patent No. 7,217,834. The specific synthesis process is as follows:

A nitrogen-purged 200 mL four-necked flask equipped with a mechanical stirring device, a thermometer and a reflux condenser was used as a reaction vessel, and 45.5 g of sodium thiosulfate pentahydrate was weighed, and 100 mL of water was added thereto to mechanically dissolve and dissolve, and then stirred for 12.9. g 1,6- Dichlorohexan, heating the above solution at a temperature to raise the temperature of the reaction solution to 102 ° C, using a metering pump to add a mass percentage of 2.5% NaOH solution to maintain the pH of the reaction solution at 7.2 ± 0.1, during the reaction, a small amount of water was sprayed from the top of the reflux condenser by washing the bottle, and the 1,6-dichlorohexidine of the bottle wall was rinsed back into the flask, and the reaction was stirred under reflux conditions for 9 hours, followed by the test in Example 11. Method, a small amount of solution was taken by GC to test the residual content of 1,6-dichlorohexidine <0.01%, and the content of residual sodium thiosulfate pentahydrate in the HPLC test was 7.6%, corresponding to 1,6-dichloro The conversion rate of 垸 is >99.9%.

After the reaction solution was allowed to stand overnight, the solid precipitate was filtered off and washed twice with 25 mL of ethanol, and dried in a vacuum oven at 50 ° C to obtain a disodium hexamethyl 1,6-dithiosulfate dihydrate salt. Solid sample. The content of sodium thiosulfate pentahydrate in the solid sample was 0.15% by HPLC test, and the content of sodium chloride in the solid sample was 0.5% by a potentiometric titrator.

The test results of the inorganic salt impurity contents in the solid products of the above Examples 11 to 21 and Comparative Examples 1 and 2 are shown in Table 2.

Table 2

Content of inorganic thiosulfate in solid product (%) Content of halide in solid sample (%) Example 11 0 0.5

Example 12 0 0.4

Example 13 0 0.5

Example 14 0 0.3

Example 15 0 0.5

Example 16 0 0.5

Example 17 0 0.2

Example 18 0 0.4

Example 19 0.01 0.6 Example 20 0 1.2

Example 21 1.8 0.5

Comparative example 1 18 3.2

Comparative example 2 0.15 0.5

As can be seen from the data in Table 2, the test results of the inorganic salt impurity content in the solid products obtained in Examples 11 to 21 were all superior to Comparative Example 1, and thus the organic thiosulfuric acid obtained by the production method of the present invention was explained. The salt has a higher purity and less by-products. Moreover, by comparison of the experimental procedures of Examples 11 to 21 and Comparative Example 2, it can be found that Comparative Example 2 requires a nitrogen purge during the experiment to result in low safety of the experiment; and it is necessary to measure the pH of the system in real time and utilize the metering pump in time. The NaOH solution is added to maintain a stable pH of the system, the experimental process is complicated, the equipment is more demanded than the preparation method of the present invention, and the power consumption is large; at the same time, the entire process takes a long time, and the embodiments 11 to 21 of the present application Not only the above drawbacks are overcome, but also the high purity of the organic thiosulfate is ensured.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the present invention, and various modifications and changes can be made to the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and scope of the present invention are intended to be included within the scope of the present invention.

Claims

Claim P70033TCCZ

A method for preparing an organic thiosulfate, which comprises the steps of:

Step (1), using a reaction vessel equipped with a mechanical stirring device, a thermometer and a reflux condenser, weighing the water-soluble inorganic thiosulfate and urea into a reaction vessel, adding water to mechanically stir and dissolve, and formulating the inorganic thiosulfuric acid An aqueous solution having a salt molar concentration of 0.5 to 2.8 mol/L;

Step (2), adding halogenated anthracene hydrocarbon under stirring condition, heating the reaction liquid to heat, controlling the reaction temperature to be 80-120 ° C, controlling the pH value of the solution to 7-9, and stirring the reaction for 4-9 hours under reflux conditions _;

Step (3), after the reaction is finished, the solution is poured out and ethanol is added, and the solution is allowed to stand at 0 to 20 ° C for 1 to 5 hours, and then the solid is filtered, and dried at 45 to 55 ° C to obtain an organic thiosulfuric acid. salt.

The method for preparing an organic thiosulfate according to claim 1, wherein the water-soluble inorganic thiosulfate in the step (1) is sodium thiosulfate, potassium thiosulfate, or thio One of ammonium sulfate; the halogenated anthracene hydrocarbon in the step (2) is a chlorinated hydrocarbon or a brominated anthracene hydrocarbon.

The method for producing an organic thiosulfate according to claim 2, wherein the chlorinated hydrocarbon is 1,4-dichloropyrene, 1,6-dichlorohexan, 1,8 - one of diclofenac, 1,10-dichloroindole and 1,12-dichlorododecadene, the brominated terpene hydrocarbon is 1,4-dibromobutane, 1,6-dibromo One of ruthenium, 1,8-dibromooctyl, 1,10-dibromoindole and 1,12-dibromoindene.

The method for producing an organic thiosulfate according to claim 1 or 2, wherein the water-soluble inorganic thiosulfate and the halogenated anthracene have a molar ratio of 1.8:1 to 2.1:1.

The method for producing an organic thiosulfate according to claim 1, wherein the water-soluble inorganic thiosulfate and urea have a molar ratio of 4:1 to 1:1.

The method for preparing an organic thiosulfate according to claim 1, wherein the volume ratio of the ethanol added in the step (3) to the water added in the step (1) is 1:1 to 6 : 1.

A method for producing an organic thiosulfate, characterized in that the preparation method comprises the reaction of an inorganic thiosulfate and a halogenated anthracene hydrocarbon at 80 to 120 ° C, and in the course of the reaction Urea is used to maintain the pH of the reaction system between 7 and 9.

The method according to claim 7, wherein the reaction temperature of the inorganic thiosulfate and the halogenated anthracene hydrocarbon is preferably 80 to 102 ° C, more preferably 80 to 100 ° C, further preferably 90~100°C.

The preparation method according to claim 8, wherein the preparation method further comprises:

Step (1), mixing the inorganic thiosulfate and the urea in water to form an aqueous solution, the inorganic thiosulfate is a water-soluble inorganic thiosulfate and having a molar concentration of 0.5 to 2.8 mol/L _;

Step (2), adding the halogenated anthracene hydrocarbon to the aqueous solution under stirring to form a reaction liquid, heating the reaction liquid to 80 to 120 ° C, and stirring under reflux to form the organic sulfur Sulfate.

The preparation method according to claim 9, wherein the preparation method further comprises: after the step (2), mixing the reaction liquid that completes the step (2) with ethanol to form a mixed solution, The mixed solution is allowed to stand at 2 to 20 ° C for 1 to 5 hours, and then filtered, and the obtained filter cake is dried to obtain the organic thiosulfate.

The preparation method according to any one of claims 7 to 10, wherein a molar ratio of the inorganic thiosulfate to the urea is 4: 1-1:1.

The production method according to any one of claims 7 to 10, wherein a molar ratio of the inorganic thiosulfate to the halogenated anthracene is 1.8:1 to 2.1:1.

The preparation method according to claim 10, wherein a volume ratio of the ethanol to the water added in the step (1) is 1:1 to 6:1.

The method according to claim 7, wherein the inorganic thiosulfate is selected from the group consisting of sodium thiosulfate, potassium thiosulfate, and ammonium thiosulfate; It is selected from a chlorinated hydrocarbon or a brominated hydrocarbon.

The method according to claim 14, wherein the chlorinated hydrocarbon is selected from the group consisting of 1,4-dichlorobutyl hydrazine, 1,6-dichlorohexanide, 1,8-dichlorooctyl hydrazine. And one of 1,10-dichloroindene and 1,12-dichlorododecadene; the brominated anthracene hydrocarbon is selected from the group consisting of 1,4-dibromobutane, 1,6-dibromohexanide, One of 1,8-dibromooctyl, 1,10-dibromofluorene and 1,12-dibromoindene.