Preparation method of sodium 3, 3 '-dithiodipropane sulfonate

Abstract

The invention relates to a preparation method of sodium 3-thiodipropane sulfonate, which comprises the following steps: (P1) dissolving allylmercaptan, an addition sulfonating agent and a compound catalyst in a solvent to form a mixed solution A, and reacting in a first-stage microchannel reactor to obtain a reactant solution containing sodium 3-mercaptopropanesulfonate; the molar ratio of the allyl mercaptan to the addition sulfonating agent is 1: (1.2-1.4); (P2) mixing the reactant solution with an oxidizing agent to form a mixed solution B, adjusting the pH value of the mixed solution B to be alkaline, and then carrying out oxidative polymerization reaction in a secondary microchannel reactor to obtain a sodium 3, 3 '-dithiodipropane sulfonate crude product; and (P3) purifying and drying the crude product to obtain the sodium 3, 3 '-dithiodipropane sulfonate. According to the preparation method taking the allylmercaptan and the addition sulfonating agent in the molar ratio as the initial raw materials, no side reaction exists, no harmful solvent exists in the reaction process, and finally the sodium 3, 3 '-dithiodipropane sulfonate with the yield of 96% or above and the purity of 98% or above is prepared.

Description

Technical Field

[0001] The invention belongs to the technical field of organic synthesis, and particularly relates to a method for preparing sodium polydipropane disulfide sulfonate. Background Art

[0002] Sodium polydisulfide propane sulfonate (SPS) is a widely used copper plating brightener in decorative electroplating and electronic electroplating. The common synthesis method currently uses 1,3-propane sultone (1,3-PS) as the initial raw material to prepare the intermediate sodium 3-mercaptopropane sulfonate (MPS), and then oxidizes MPS to generate SPS.

[0003] Patent CN101519369A discloses a method for synthesizing sodium polydisulfide propane sulfonate, which is to react sodium hydrosulfide with 1,3-propane sultone (1,3-PS) to generate sodium 3-thio(mercapto) propane sulfonate (MPS), and then oxidize sodium 3-thiopropane sulfonate (MPS) to generate SPS. However, currently, industrial-grade sodium hydrosulfide is generated by the reaction of industrial waste gas hydrogen sulfide and sodium hydroxide, which will generate sodium sulfide as a byproduct. The effective content of the final industrial-grade sodium hydrosulfide is about 70%, resulting in poor quality of the generated SPS. However, the use of high-purity sodium bisulfate will result in higher costs; at the same time, the synthesis temperature in this method is relatively high.

[0004] Patent CN106946753A discloses a synthesis process of sodium polydisulfide propane sulfonate, in which SPS is synthesized by a pentyl salt process, wherein 1,3-PS is reacted with sodium thiosulfate to obtain pentyl salt, and pentyl salt is subjected to alkaline hydrolysis and oxidation at 50-60°C to obtain SPS. The oxidation reaction temperature is relatively high, and the control requirements for process conditions are very strict, otherwise side reactions will occur preferentially in the alkaline hydrolysis step to generate a large amount of sodium sulfate, and the sodium sulfate crystals are in the form of a colloid, which cannot be removed by centrifugation, and it is easy to cause a sharp drop in the yield and purity of SPS to below 90% or even below 77%, which is not conducive to large-scale production.

[0005] Patent CN115611791B discloses a method for preparing sodium polydisulfide propane sulfonate, and the specific process route adopted is: (1) adding 1,3-propane sultone to a mixture of thiourea and a solvent, and filtering out UPS (3-isothiourea propane sulfonic acid solid) after the reaction; (2) mixing 3-isothiourea propane sulfonic acid and an aqueous ammonia solution, evaporating the solvent after an alkaline hydrolysis reaction, and then recrystallizing to obtain a solid 3-mercaptopropane sulfonic acid ammonium; (3) making an aqueous solution of 3-mercaptopropane sulfonic acid ammonium, and passing through a cation exchange resin to obtain a 3-mercaptopropane sulfonic acid aqueous solution; (4) adding hydrogen peroxide to the 3-mercaptopropane sulfonic acid aqueous solution to carry out an oxidation reaction, and then carrying out an alkali neutralization reaction, and rotating the reaction solution to dryness to obtain a crude SPS product. In this process, all three steps of the reaction need to be separated, and a large amount of ammonia water and resin are used, resulting in a large amount of wastewater. Summary of the invention

[0006] In view of the above-mentioned defects of preparing sodium polydipropane disulfide sulfonate in the prior art, the present invention provides a production method of sodium polydipropane disulfide sulfonate to overcome the problems of complex production process, low yield and purity, and high cost of preparing sodium polydipropane disulfide sulfonate. To achieve the above-mentioned purpose, the present invention adopts the following technical scheme:

[0007] A method for preparing sodium polydipropane disulfide sulfonate comprises the following steps:

[0008] (P1) allyl mercaptan, an addition sulfonating agent, and a composite catalyst are dissolved in a solvent to form a mixed solution A, and the pH thereof is adjusted to 6 to 8 using an inorganic acid, and then the mixed solution A is put into a primary microchannel reactor for reaction to obtain a reactant solution containing sodium 3-mercaptopropane sulfonate; the molar ratio of allyl mercaptan to the addition sulfonating agent is 1:(1.2 to 1.4); the composite catalyst is a composite of hydrogen peroxide and tert-butyl hydroperoxide in a molar ratio of 1:(1 to 1.5);

[0009] (P2) mixing the reactant solution with an oxidant to form a mixed solution B, adjusting the mixed solution to alkalinity using a pH adjuster, and then feeding the mixed solution B into a secondary microchannel reactor for oxidative polymerization to obtain a crude product of sodium polydisulfide dipropane sulfonate;

[0010] The crude product of (P3) sodium poly(dipropane disulfide sulfonate) is purified and dried to obtain sodium poly(dipropane disulfide sulfonate).

[0011] Taking the case where the added sulfonating agent in step P1 is sodium sulfite and the oxidizing agent in step P2 is hydrogen peroxide as an example, the chemical reaction formula of the present invention is as follows:

[0012]

[0013] The present invention uses allyl mercaptan and an addition sulfonating agent in the above molar ratio as starting materials, reacts under the action of a composite catalyst of hydrogen peroxide and tert-butyl hydroperoxide to generate an intermediate sodium 3-mercaptopropane sulfonate, and then the intermediate is oxidatively polymerized to obtain sodium polydipropane disulfide sulfonate. Compared with the preparation of the intermediate using 1,3-propane sultone as the starting material, the preparation method of the present invention has no side reaction, and the reaction process has no harmful solvent, and finally obtains sodium polydipropane disulfide sulfonate with high yield and high purity.

[0014] Furthermore, in step (P1), the addition sulfonating agent is at least one of sodium sulfite, sodium bisulfite, potassium bisulfite, sodium pyrosulfite, and sodium disulfate.

[0015] Furthermore, in step (P1), the molar ratio of allyl mercaptan to the addition sulfonating agent is 1:(1.3-1.4). When the molar ratio of allyl mercaptan to sodium sulfite is low, the reaction of allyl mercaptan is incomplete; when the molar ratio of propanethiol to sodium sulfite is high, more sodium sulfite remains, and more sodium sulfite is likely to cause polymerization of allyl mercaptan, resulting in a decrease in the purity and yield of sodium polydisulfide propane sulfonate; therefore, the molar ratio of allyl mercaptan to sodium sulfite needs to be controlled within the above range.

[0016] Furthermore, in step (P1), the molar ratio of the composite catalyst to allyl mercaptan is (0.04-0.06):1.

[0017] The composite catalyst described in the present invention is a composite of hydrogen peroxide and tert-butyl hydroperoxide. When hydrogen peroxide is used as a single oxidant or the content of hydrogen peroxide is too high, more free radicals are provided, which easily causes allyl mercaptan to self-polymerize; when tert-butyl hydroperoxide is used as a single oxidant or the content of tert-butyl hydroperoxide is too high, the efficiency of the addition sulfonation reaction is low; therefore, hydrogen peroxide and tert-butyl hydroperoxide should be within the above composite ratio range.

[0018] Furthermore, in step (P1), the solvent is a mixture of alcohol and water, and the alcohol is at least one of ethanol, propanol, and isopropanol; preferably, the solvent is a mixture of alcohol and water in a mass ratio of 1:(1-3). Allyl mercaptan is an organic substance, and the addition sulfonating agent is an inorganic substance. The solubility of the two is different, and the alcohol-water solution is more conducive to forming a uniform phase.

[0019] Furthermore, in step (P1), the total concentration of the mixed solution A is 25-40 wt %.

[0020] Furthermore, in step (P1), the inorganic acid is at least one of hydrochloric acid and sulfuric acid. Organic acids will undergo esterification reaction with mercaptans to produce impurities and are not suitable for use.

[0021] Furthermore, in step (P1), the reaction conditions are: pressure 0.2-1 MPa, temperature 40-70° C., and time 40-80 s.

[0022] Furthermore, in step (P2), the molar ratio of the oxidant to allyl mercaptan is (0.5-1):1; the oxidant is at least one of hydrogen peroxide, persulfate, tert-butyl hydroperoxide, and benzoyl peroxide.

[0023] Furthermore, in step (P2), the pH adjuster is at least one of sodium hydroxide and potassium hydroxide; and the alkalinity is that the pH of the mixed solution B is 9 to 11.

[0024] Furthermore, in step (P2), the oxidative polymerization reaction conditions are: pressure 0.2-1 MPa, temperature 10-40° C., and time 10-30 s. This reaction process is an exothermic reaction, and the temperature of the system is controlled by a refrigerant.

[0025] Furthermore, in step (P3), the purification is performed by nanofiltration purification using a nanofiltration membrane with a cutoff of 200-500 Dowells; and the drying is spray drying.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] 1) The present invention uses allyl mercaptan and an addition sulfonating agent as starting materials, reacts in a microchannel reactor under the action of a composite catalyst of hydrogen peroxide and tert-butyl hydroperoxide, and purifies in a nanofiltration manner to obtain a product, polydipropane disulfide sodium sulfonate. The obtained polydipropane disulfide sodium sulfonate has a high yield and purity, the yield can reach more than 96%, and the purity can reach more than 98%.

[0028] 2) The preparation method of the present invention has a simple process, no side reaction, no harmful solvents are used in the reaction process, and the cost of raw materials is low, which is suitable for industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is the infrared spectrum of the sodium polydipropane disulfide sulfonate prepared in Example 1.

[0030] Figure 2 The NMR spectrum of sodium polydipropane disulfide sulfonate prepared in Example 1. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0032] The primary microchannel reactor and the secondary microchannel reactor used in the embodiment are both Corning G microchannel reactors, wherein the primary microchannel reactor has one microchannel plate and the secondary microchannel reactor has two plates.

[0033] Example 1

[0034] (P1) 74.1 g (1 mol) of allyl mercaptan, 151.2 g (1.2 mol) of sodium sulfite, 0.68 g (0.02 mol) of hydrogen peroxide, and 1.8 g (0.02 mol) of tert-butyl hydroperoxide were dissolved in 500 g of an ethanol-water mixture (including 150 g of ethanol and 350 g of water) to form a mixed solution A, and the pH value thereof was adjusted to 6 using a 37 wt % aqueous solution of hydrochloric acid, and then the mixed solution was put into a primary microchannel reactor, and the back pressure valve after the primary microchannel reactor was adjusted to control the pressure at 0.5 MPa, and the mixture was reacted at 50° C. for 40 s to obtain a reactant solution containing sodium 3-mercaptopropane sulfonate;

[0035] (P2) The above reactant solution was mixed with 17 g (0.5 mol) of hydrogen peroxide to form a mixed solution B, and the pH thereof was adjusted to 10 with a 30 wt % aqueous sodium hydroxide solution, and then the mixed solution was put into a secondary microchannel reactor, and the back pressure valve behind the secondary microchannel reactor was adjusted to control the pressure at 0.4 MPa, and the mixture was reacted at 10° C. for 20 s to obtain a crude product of sodium polydisulfide dipropane sulfonate;

[0036] (P3) The solution obtained from the crude product is purified by nanofiltration through a nanofiltration membrane with a retention rate of 200-500 Dowells, and the retentate is spray-dried (the feed rate is set at 10-25 g / s, the nozzle temperature is 130-150° C., and the atomizing disk speed is 16000-18000 rpm) to obtain sodium polydisulfide dipropane sulfonate.

[0037] The infrared spectrum of the prepared sodium polydisulfide dipropane sulfonate is as follows: Figure 1 shown.

[0038] The NMR spectrum of the prepared sodium polydisulfide propane sulfonate is as follows: Figure 2 shown.

[0039] Example 2

[0040] The rest is the same as Example 1, except that, in step (P1), the amounts of raw materials used are: 74.1 g (1 mol) of allyl mercaptan, 163.8 g (1.3 mol) of sodium sulfite, 0.68 g (0.02 mol) of hydrogen peroxide, and 1.8 g (0.02 mol) of tert-butyl hydroperoxide.

[0041] Example 3

[0042] The rest is the same as Example 1, except that, in step (P1), the amounts of raw materials used are: 74.1 g (1 mol) of allyl mercaptan, 176.4 g (1.4 mol) of sodium sulfite, 0.68 g (0.02 mol) of hydrogen peroxide, and 1.8 g (0.02 mol) of tert-butyl hydroperoxide.

[0043] Example 4

[0044] The rest is the same as Example 2, except that in step (P1), the pH of the mixed solution A is 8.

[0045] Example 5

[0046] The rest is the same as Example 2, except that in step (P1), the amount of tert-butyl hydroperoxide is 2.7 g (0.03 mol), that is, the composite catalyst is a composite of hydrogen peroxide and tert-butyl hydroperoxide in a molar ratio of 1:1.5.

[0047] Example 6

[0048] The rest is the same as Example 2, except that: in step (P1), sodium bisulfite is used instead of sodium sulfite; in step (P2), 1 mol of benzoyl peroxide is used instead of 0.5 mol of hydrogen peroxide.

[0049] Comparative Example 1

[0050] The rest is the same as Example 1, except that, in step (P1), the amounts of raw materials used are: 74.1 g (1 mol) of allyl mercaptan, 126 g (1 mol) of sodium sulfite, 0.68 g (0.02 mol) of hydrogen peroxide, and 1.8 g (0.02 mol) of tert-butyl hydroperoxide.

[0051] Comparative Example 2

[0052] The rest is the same as Example 1, except that, in step (P1), the amounts of raw materials used are: 74.1 g (1 mol) of allyl mercaptan, 201.6 g (1.6 mol) of sodium sulfite, 0.68 g (0.02 mol) of hydrogen peroxide, and 1.8 g (0.02 mol) of tert-butyl hydroperoxide.

[0053] Comparative Example 3

[0054] The rest is the same as Example 1, except that, in step (P1), the amount of hydrogen peroxide is 0.34 g (0.01 mol), and the amount of tert-butyl hydroperoxide is 2.7 g (0.03 mol), that is, the composite catalyst is a composite of hydrogen peroxide and tert-butyl hydroperoxide in a molar ratio of 1:3.

[0055] Comparative Example 4

[0056] The rest is the same as Example 1, except that, in step (P1), the amount of hydrogen peroxide is 0.85 g (0.025 mol), and the amount of tert-butyl hydroperoxide is 1.35 g (0.015 mol), that is, the composite catalyst is hydrogen peroxide and tert-butyl hydroperoxide in a molar ratio of 1:0.6.

[0057] Results and Analysis

[0058] (1) Material structure analysis

[0059] from Figure 1 It can be seen from the infrared spectrum that 500-600cm -1 There are two absorption peaks in the vicinity, at 531 cm -1 and 603cm -1 The maximum absorption peak appears at 1000-1200cm -1 The region is consistent with the characteristic peaks of CS.

[0060] from Figure 2 From the NMR spectrum, it can be seen that the chemical shifts δ = 2.99ppm, 2.82ppm, and 2.11ppm are consistent with the chemical shifts of hydrogens connected to the methylene group and to the sulfonic acid group and to the disulfide bond and to the methylene group.

[0061] The combined infrared spectrum and nuclear magnetic spectrum prove that the structure of Sodium acid.

[0062] (2) The purity of the sodium polydisulfide dipropane sulfonate prepared in the above examples and preparation examples was detected by HPLC external standard method, and its yield was calculated. The results are shown in Table 1.

[0063] Table 1 Test results

[0064]

[0065]

[0066] As can be seen from Table 1, the polysodium disulfide dipropane sulfonate obtained by the preparation method of the present invention has a high yield and purity, the yield can reach more than 96%, and the purity can reach more than 98%.

[0067] In Comparative Example 1, the molar ratio of allyl mercaptan: sodium sulfite is 1:1, and the purity and yield of sodium polydipropylene disulfide sulfonate are lower than those of the examples. The main reason is that allyl mercaptan is not completely reacted and there is a large amount of residue, resulting in a low final yield and purity.

[0068] In Comparative Example 2, the molar ratio of allyl mercaptan: sodium sulfite is 1:1.6, and the purity and yield of polydipropylene disulfide sodium sulfonate are both low. The main reason is that there is a lot of residual sodium sulfite, which will cause allyl mercaptan to undergo polymerization reaction, resulting in a decrease in product purity and yield.

[0069] In Comparative Example 3, the proportion of hydrogen peroxide is low and the proportion of tert-butyl hydroperoxide is high, and the yield of sodium polydipropylene disulfide sulfonate is significantly lower than that of the embodiment. The possible reason is that the efficiency of the addition sulfonation reaction is low and allyl mercaptan is not completely reacted.

[0070] In Comparative Example 4, the proportion of hydrogen peroxide is too high, and the purity and yield of sodium polydipropylene disulfide sulfonate are significantly lower than those in Example 1. The possible reason is that the proportion of hydrogen peroxide is too high, which provides more free radicals, and more free radicals are easy to make allyl mercaptan self-polymerized.

[0071] The specific implementation of the present invention described above does not constitute a limitation on the protection scope of the present invention. Any other corresponding changes and modifications made based on the technical concept of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A method for preparing sodium polydipropane disulfide sulfonate, characterized in that: The following steps are involved: (P1) allyl mercaptan, an addition sulfonating agent, and a composite catalyst are dissolved in a solvent to form a mixed solution A, and the pH thereof is adjusted to 6 to 8 using an inorganic acid, and then the mixed solution A is put into a primary microchannel reactor for reaction to obtain a reactant solution containing sodium 3-mercaptopropane sulfonate; the molar ratio of allyl mercaptan to the addition sulfonating agent is 1:(1.2 to 1.4); the composite catalyst is a composite of hydrogen peroxide and tert-butyl hydroperoxide in a molar ratio of 1:(1 to 1.5); (P2) mixing the reactant solution with an oxidant to form a mixed solution B, adjusting the mixed solution to alkalinity using a pH adjuster, and then feeding the mixed solution B into a secondary microchannel reactor for oxidative polymerization to obtain a crude product of sodium polydisulfide dipropane sulfonate; The crude product of (P3) sodium poly(dipropane disulfide sulfonate) is purified and dried to obtain sodium poly(dipropane disulfide sulfonate).

2. The preparation method according to claim 1, characterized in that: In step (P1), the addition sulfonating agent is at least one of sodium sulfite, sodium bisulfite, potassium bisulfite, sodium pyrosulfite, and sodium disulfate.

3. The preparation method according to claim 1, characterized in that: In step (P1), the molar ratio of allyl mercaptan to the added sulfonating agent is 1:(1.3-1.4).

4. The preparation method according to claim 1, characterized in that: In step (P1), the molar ratio of the composite catalyst to allyl mercaptan is (0.04-0.06):

1.

5. The preparation method according to claim 1, characterized in that: In step (P1), the solvent is a mixture of alcohol and water, and the alcohol is at least one of ethanol, propanol, and isopropanol; preferably, the solvent is a mixture of alcohol and water in a mass ratio of 1:(1-3); and / or The inorganic acid is at least one of hydrochloric acid and sulfuric acid.

6. The preparation method according to claim 1, characterized in that: In step (P1), the reaction conditions are: pressure 0.2-1 MPa, temperature 40-70° C., and time 40-80 s.

7. The preparation method according to claim 1, characterized in that: In step (P2), the molar ratio of the oxidant to allyl mercaptan is (0.5-1):1; the oxidant is at least one of hydrogen peroxide, persulfate, tert-butyl hydroperoxide, and benzoyl peroxide.

8. The preparation method according to claim 1, characterized in that: In step (P2), the pH adjuster is at least one of sodium hydroxide and potassium hydroxide; and the alkalinity is that the pH of the mixed solution B is 9 to 11.

9. The preparation method according to claim 1, characterized in that: In step (P2), the oxidative polymerization reaction conditions are: pressure 0.2-1 MPa, temperature 10-40° C., and time 10-30 s.

10. The preparation method according to claim 1, characterized in that: In step (P3), the purification is performed by nanofiltration using a nanofiltration membrane with a cutoff of 200-500 Dowells; and the drying is spray drying.

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