Preparation method of tert-butyl peroxyisobutyrate

Abstract

The present invention belongs to the technical field of acyclic compounds, and specifically relates to a method for preparing tert-butyl peroxyisobutyrate. A solvent, an aqueous solution of tert-butyl hydroperoxide, and deionized water are stirred and cooled to obtain a mixed solution A. Liquid caustic soda and a solid base catalyst are added to the mixed solution A under stirring, and the reaction is continued with stirring to obtain a mixed solution B. Isobutyryl chloride and a water-soluble partitioning agent are added to the mixed solution B under stirring, and the reaction is continued with stirring to obtain a mixed solution C. The mixed solution C is allowed to stand for separation, and after separation, a crude tert-butyl peroxyisobutyrate product is obtained. The crude tert-butyl peroxyisobutyrate product is then refined to obtain tert-butyl peroxyisobutyrate. The present invention improves raw material utilization, accelerates reaction speed, reduces reaction time, and achieves a high product yield.

Description

Technical Field

[0001] The invention belongs to the technical field of acyclic compounds, and particularly relates to a method for preparing tert-butyl peroxyisobutyrate. Background Art

[0002] Tert-butyl peroxyisobutyrate is referred to as TBPI, and its chemical formula is C8H 16 O3. Tert-butyl peroxyisobutyrate is an organic peroxide used as a polymerization initiator for ethylene and styrene. Tert-butyl peroxyisobutyrate has poor thermal stability and presents a risk of combustion or explosion during storage and transportation.

[0003] Chinese patent CN 115536565A discloses a method for preparing tert-butyl perbenzoate, comprising the following steps: (1) adding a dehydrating agent to a tert-butyl hydroperoxide solution for dehydration, separating the liquids, and obtaining an organic layer; (2) adding a sodium hydroxide solution dropwise to the organic layer to adjust the pH of the mixed solution to alkaline, then adding a phase transfer catalyst and mixing uniformly; (3) mixing benzoyl chloride and a sensitizer uniformly; (4) simultaneously adding the mixed solution of step (3) and a sodium hydroxide solution dropwise to the mixed solution of step (2), and then heat-insulating and reacting after the addition is complete; (5) separating the reaction solution obtained in step (4) to obtain an organic layer, and sequentially washing the organic layer with alkali, washing with water, and vacuum flash drying to obtain the finished tert-butyl perbenzoate. This patent requires the water in the tert-butyl hydroperoxide solution to be removed first, which results in complicated operation steps and is not conducive to reducing the overall reaction time. Summary of the Invention

[0004] The invention aims to provide a method for preparing tert-butyl peroxyisobutyrate, which improves the utilization rate of raw materials, accelerates the reaction speed, reduces the reaction time and has a high product yield.

[0005] The preparation method of tert-butyl peroxyisobutyrate of the present invention comprises the following steps:

[0006] (1) stirring and cooling the solvent, tert-butyl hydroperoxide aqueous solution, and deionized water to obtain a mixed solution A;

[0007] (2) Adding liquid alkali and solid base catalyst to the mixed solution A under stirring conditions, and continuing to stir and react to obtain a mixed solution B;

[0008] (3) Add isobutyryl chloride and a water-soluble partitioning agent to the mixed solution B under stirring, and continue stirring to react to obtain a mixed solution C;

[0009] (4) The mixed solution C is allowed to stand for separation to obtain crude tert-butyl peroxyisobutyrate, which is then refined to obtain tert-butyl peroxyisobutyrate.

[0010] In step (1), the solvent is one or more of dodecane, n-hexane or silicone oil, the concentration of the tert-butyl hydroperoxide aqueous solution is 70-99 wt.%, and the stirring and cooling temperature is 0-20°C.

[0011] In step (1), the mass ratio of the aqueous solution of tert-butyl hydroperoxide, the solvent and the deionized water is 0.3-0.5:0-2:0.28-0.5.

[0012] The liquid caustic soda in step (2) is a sodium hydroxide aqueous solution or a potassium hydroxide aqueous solution, the concentration of the liquid caustic soda is 20-50 wt.%, and the mass ratio of the liquid caustic soda to the tert-butyl hydroperoxide aqueous solution in step (1) is 22-58:24-35.

[0013] In step (2), the solid base catalyst is magnesium aluminum tert-butoxide hydrotalcite, and the mass of the solid base catalyst is 0.9-10% of the mass of the liquid caustic soda.

[0014] The addition time in step (2) is 10-30 minutes, and the addition temperature is 0-20°C; the temperature for continuing the stirring reaction is 5-15°C, and the stirring reaction time is 10-30 minutes.

[0015] The mass ratio of isobutyryl chloride in step (3) to the liquid caustic soda in step (2) is 1: 0.82-2.06.

[0016] In step (3), the water-soluble partitioning agent is one or both of tetramethylammonium chloride and methyltributylammonium chloride, and the mass ratio of isobutyryl chloride to the water-soluble partitioning agent is 1:0.01-0.03.

[0017] The addition time in step (3) is 10-30 min, and the addition temperature is 0-20°C; the temperature for continuing the stirring reaction is 5-20°C, and the stirring reaction time is 10-120 min.

[0018] In step (4), the temperature for standing and stratifying is 0-15° C., and the time for standing and stratifying is 20-30 min. The crude product of tert-butyl peroxyisobutyrate is washed with alkali solution, sodium bicarbonate aqueous solution and deionized water respectively, wherein the alkali solution is one or both of sodium hydroxide solution and potassium hydroxide solution, the concentration of the alkali solution is 5wt.% to saturation concentration, the concentration of the sodium bicarbonate aqueous solution is 1-10wt.%, and the number of washings is 2-3 times. The pH value of the tert-butyl peroxyisobutyrate after washing is 7-8.

[0019] The beneficial effects of the present invention are as follows:

[0020] The magnesium aluminum tert-butoxide hydrotalcite used in the present invention has a layered double hydroxide structure and a special ion layer arrangement. The layered structure greatly increases the specific surface area of ​​the magnesium aluminum tert-butoxide hydrotalcite. The high price of the active site in the magnesium aluminum tert-butoxide hydrotalcite and the high specific surface area of ​​the magnesium aluminum tert-butoxide hydrotalcite make the active site (Mg 2+ and Al 3 + ) is more likely to adsorb chloride ions (Cl - ) forms unstable intermediate transition states MgCl2 and AlCl3, promoting the decomposition of isobutyryl chloride and accelerating the reaction rate; when the metal peroxide intermediate (tert-butyl peroxide salt) generated by the reaction of liquid caustic soda and tert-butyl hydroperoxide is attracted to the vicinity of the active site, it reacts with isobutyryl to generate tert-butyl peroxyisobutyrate, and at the same time, sodium ions or potassium ions react with the unstable intermediate transition states MgCl2 and AlCl3 to generate NaCl or KCl and desorb from the active site, and the active site is reactivated, forming a synergistic catalysis between the liquid caustic soda and the solid base catalyst.

[0021] After tert-butoxy groups are introduced into the interlayers of the hydrotalcite, the magnesium aluminum tert-butoxide hydrotalcite exhibits stronger alkalinity than ordinary hydrotalcite, thereby having more excellent base catalytic performance. At the same time, the use of the magnesium aluminum tert-butoxide hydrotalcite does not introduce new impurities.

[0022] Tert-butyl hydroperoxide is also an organic peroxide that decomposes to produce impurities such as tert-butyl alcohol. The tert-butyloxy group in the magnesium aluminum tert-butylate hydrotalcite used in the present invention is introduced between the hydrotalcite layers to inhibit the decomposition of tert-butyl hydroperoxide, thereby improving raw material utilization and achieving good economic efficiency.

[0023] The addition of a water-soluble partitioning agent further accelerates the ion exchange between the organic phase and the inorganic phase, greatly speeding up the reaction rate and reducing the reaction time. Isobutyryl chloride is insoluble in water, tert-butyl hydroperoxide exists in the form of an aqueous solution, and water-soluble partitioning agents such as tetramethylammonium chloride (TMAC) tetramethylammonium cation [(CH3)4N + ] has amphiphilicity: the cationic head can react with the conjugate base of tert-butyl hydroperoxide (tert-butyloxy anion (CH3)3COO in the aqueous phase - ) forms an ion pair through electrostatic interaction, and the four methyl side chains make it soluble in the organic phase. Therefore, TMAC converts the nucleophile (CH3)3COO in the aqueous phase into - It is transferred to the organic phase and undergoes acylation reaction with isobutyryl chloride to produce TBPI. The phase transfer effect allows the two phases of reactants that were originally isolated to fully contact each other, thereby increasing the reaction rate. In the aqueous phase, the dissociation of tert-butyl hydroperoxide is limited by its weak acidity (pKa≈12), while the cation of TMAC [(CH3)4N + ] can react with (CH3)3COO- The formation of a tight ion pair reduces its solvation effect and enhances nucleophilicity. This activation effect makes the acylation reaction easier to proceed, especially at low temperatures (0-10°C). In addition, the reaction of isobutyryl chloride with tert-butyl hydroperoxide releases HCl, which needs to be neutralized with a base (such as NaOH). After HCl is generated in the organic phase, the cation [(CH3)4N + ] and Cl - Combined to form an ion pair, accelerating the transfer of HCl from the organic phase to the aqueous phase to avoid its inhibition of the reaction. TMAC can also reduce the excess OH in the aqueous phase. - , preventing excessive decomposition of tert-butyl hydroperoxide under alkaline conditions, thereby improving the product yield. The product yield of the present invention reaches more than 90%. DETAILED DESCRIPTION

[0024] The present invention is further described below with reference to the following examples.

[0025] Example 1

[0026] (1) 40.02 g of dodecane, 30.55 g of an 80 wt.% aqueous solution of tert-butyl hydroperoxide, and 30.01 g of deionized water were stirred and cooled to 0°C to obtain a mixed solution A;

[0027] (2) Under stirring conditions, 22.85 g of a 50 wt.% sodium hydroxide aqueous solution and 2.28 g of tert-butyl magnesium aluminum hydrotalcite were added to the mixed solution A at 0°C for 10 min. After the addition was completed, stirring was continued at 5°C for 30 min to obtain a mixed solution B;

[0028] (3) Under stirring conditions, 27.79 g of isobutyryl chloride and 0.28 g of tetramethylammonium chloride were added to the mixed solution B for 10 min at a temperature of 20°C. After the addition was completed, stirring was continued at 20°C for 30 min to obtain a mixed solution C;

[0029] (4) The mixed solution was allowed to stand at 0°C for 30 min, separated and the mother liquor was separated to obtain crude tert-butyl peroxyisobutyrate. The crude tert-butyl peroxyisobutyrate was washed three times with a 5 wt.% sodium hydroxide solution, a 1 wt.% sodium bicarbonate aqueous solution and deionized water, respectively, to obtain 77.47 g of solvent-based tert-butyl peroxyisobutyrate product. The content of pure tert-butyl peroxyisobutyrate in the solvent-based tert-butyl peroxyisobutyrate product was found to be 49.5 wt.%, with a pH of 7.1 and a chlorine content of 77 ppm. The solvent in the solvent-based tert-butyl peroxyisobutyrate product was removed to obtain 37.45 g of tert-butyl peroxyisobutyrate product. The product yield was calculated to be 90%.

[0030] Example 2

[0031] (1) 40.02 g of n-hexane, 24.68 g of a 99 wt.% aqueous solution of tert-butyl hydroperoxide, and 40.02 g of deionized water were stirred and cooled to 15°C to obtain a mixed solution A;

[0032] (2) Under stirring conditions, 57.13 g of a 20 wt.% aqueous solution of potassium hydroxide and 0.57 g of tert-butyl magnesium aluminum hydrotalcite were added to the mixed solution A at a temperature of 15° C. for 30 min. After the addition was completed, stirring was continued at 15° C. for 10 min to obtain a mixed solution B;

[0033] (3) Under stirring conditions, 27.79 g of isobutyryl chloride and 0.56 g of tetramethylammonium chloride were added to the mixed solution B for 30 min at a temperature of 0°C. After the addition was completed, the stirring reaction was continued at 5°C for 120 min to obtain a mixed solution C;

[0034] (4) The mixed solution C was allowed to stand at 5°C for 25 minutes, separated and the mother liquor was separated to obtain crude tert-butyl peroxyisobutyrate. The crude tert-butyl peroxyisobutyrate was washed three times with a saturated potassium hydroxide solution, a 10 wt.% sodium bicarbonate aqueous solution and deionized water, respectively, to obtain 77.88 g of solvent-based tert-butyl peroxyisobutyrate product. The content of pure tert-butyl peroxyisobutyrate in the solvent-based tert-butyl peroxyisobutyrate product was 50.02 wt.%, the pH value was 7.3, and the chlorine content was 88 ppm. The solvent in the solvent-based tert-butyl peroxyisobutyrate product was removed to obtain 37.86 g of tert-butyl peroxyisobutyrate product. The product yield was calculated to be 91%.

[0035] Example 3

[0036] (1) 150.34 g of silicone oil, 34.91 g of a 70 wt.% aqueous solution of tert-butyl hydroperoxide, and 23.34 g of deionized water were stirred and cooled to 20°C to obtain a mixed solution A;

[0037] (2) Under stirring conditions, 32.65 g of a 35 wt.% sodium hydroxide aqueous solution and 1.63 g of tert-butyl magnesium aluminum hydrotalcite were added to the mixed solution A at a temperature of 20° C. for 20 min. After the addition was completed, stirring was continued at 10° C. for 20 min to obtain a mixed solution B;

[0038] (3) Under stirring conditions, 27.79 g of isobutyryl chloride and 0.60 g of methyltributylammonium chloride were added to the mixed solution B for 20 min at a temperature of 15°C. After the addition was completed, stirring was continued at 15°C for 60 min to obtain a mixed solution C;

[0039] (4) The mixed solution C was allowed to stand at 15°C for 20 minutes, separated and the mother liquor was separated to obtain crude tert-butyl peroxyisobutyrate. The crude tert-butyl peroxyisobutyrate was washed three times with a 5 wt.% sodium hydroxide solution, a 3 wt.% sodium bicarbonate aqueous solution and deionized water, respectively, to obtain 187.98 g of solvent-based tert-butyl peroxyisobutyrate product. The content of pure tert-butyl peroxyisobutyrate in the solvent-based tert-butyl peroxyisobutyrate product was found to be 20.06 wt.%, with a pH of 7.2 and a chlorine content of 84 ppm. The solvent in the solvent-based tert-butyl peroxyisobutyrate product was removed to obtain 37.64 g of tert-butyl peroxyisobutyrate product. The product yield was calculated to be 90.5%.

[0040] Example 4

[0041] (1) 30.55 g of 80 wt.% aqueous tert-butyl hydroperoxide solution and 30.01 g of deionized water were stirred and cooled to 0°C to obtain a mixed solution A;

[0042] (2) Under stirring conditions, 22.85 g of a 50 wt.% aqueous sodium hydroxide solution and 1.14 g of tert-butyl magnesium aluminum hydrotalcite were added to the mixed solution A at 0°C for 10 min. After the addition was completed, stirring was continued at 5°C for 30 min to obtain a mixed solution B;

[0043] (3) Under stirring conditions, 27.79 g of isobutyryl chloride and 0.30 g of methyltributylammonium chloride were added to the mixed solution B for 10 min at a temperature of 15°C. After the addition was completed, stirring was continued at 20°C for 10 min to obtain a mixed solution C;

[0044] (4) The mixed solution C was allowed to stand at 10°C for 25 min, separated and the mother liquor was removed to obtain crude tert-butyl peroxyisobutyrate. The crude tert-butyl peroxyisobutyrate was washed three times with a 5 wt.% sodium hydroxide solution, a 1 wt.% sodium bicarbonate aqueous solution and deionized water, respectively, to obtain 37.59 g of tert-butyl peroxyisobutyrate product. The content of tert-butyl peroxyisobutyrate was 98.86 wt.%, the pH value was 7.2, the chlorine content was 76 ppm, and the product yield was calculated to be 90.4%.

[0045] Comparative Example 1

[0046] (1) 40.02 g of dodecane, 30.55 g of an 80 wt.% aqueous solution of tert-butyl hydroperoxide, and 30.01 g of deionized water were stirred and cooled to 0°C to obtain a mixed solution A;

[0047] (2) Under stirring conditions, 22.85 g of a 50 wt.% sodium hydroxide aqueous solution was added to the mixed solution A at 0°C for 10 min. After the addition was completed, stirring was continued at 5°C for 30 min to obtain a mixed solution B;

[0048] (3) Under stirring conditions, 27.79 g of isobutyryl chloride and 0.28 g of tetramethylammonium chloride were added to the mixed solution B for 10 min at a temperature of 20°C. After the addition was completed, stirring was continued at 20°C for 60 min to obtain a mixed solution C;

[0049] (4) The mixed solution C was allowed to stand at 0°C for 30 min, separated and the mother liquor was separated to obtain crude tert-butyl peroxyisobutyrate. The crude tert-butyl peroxyisobutyrate was washed three times with a 5 wt.% sodium hydroxide solution, a 1 wt.% sodium bicarbonate aqueous solution and deionized water, respectively, to obtain 74.45 g of solvent-based tert-butyl peroxyisobutyrate product. The content of pure tert-butyl peroxyisobutyrate in the solvent-based tert-butyl peroxyisobutyrate product was found to be 47.17 wt.%, with a pH value of 7.1 and a chlorine content of 98 ppm. The solvent in the solvent-based tert-butyl peroxyisobutyrate product was removed to obtain 34.43 g of tert-butyl peroxyisobutyrate product. The product yield was calculated to be 82.8%.

[0050] Comparative Example 2

[0051] (1) 40.02 g of dodecane, 30.55 g of an 80 wt.% aqueous solution of tert-butyl hydroperoxide, and 30.01 g of deionized water were stirred and cooled to 0°C to obtain a mixed solution A;

[0052] (2) Under stirring conditions, 22.85 g of a 50 wt.% sodium hydroxide aqueous solution and 2.28 g of tert-butyl magnesium aluminum hydrotalcite were added to the mixed solution A at 0°C for 10 min. After the addition was completed, stirring was continued at 5°C for 30 min to obtain a mixed solution B;

[0053] (3) Under stirring conditions, 27.79 g of isobutyryl chloride was added to the mixed solution B for 10 minutes at a temperature of 20°C. After the addition was completed, the stirring reaction was continued at 20°C for 50 minutes to obtain a mixed solution C;

[0054] (4) The mixed solution C was allowed to stand at 0°C for 30 min, separated and the mother liquor was separated to obtain crude tert-butyl peroxyisobutyrate. The crude tert-butyl peroxyisobutyrate was washed three times with a 5 wt.% sodium hydroxide solution, a 1 wt.% sodium bicarbonate aqueous solution and deionized water, respectively, to obtain 73.45 g of solvent-based tert-butyl peroxyisobutyrate product. The content of pure tert-butyl peroxyisobutyrate in the solvent-based tert-butyl peroxyisobutyrate product was found to be 47.13 wt.%, with a pH value of 7.3 and a chlorine content of 104 ppm. The solvent in the solvent-based tert-butyl peroxyisobutyrate product was removed to obtain 33.43 g of tert-butyl peroxyisobutyrate product. The product yield was calculated to be 80.4%.

Claims

1. A method for preparing tert-butyl peroxyisobutyrate, characterized in that The steps include: (1) stirring and cooling the solvent, tert-butyl hydroperoxide aqueous solution, and deionized water to obtain a mixed solution A; (2) Adding liquid alkali and solid base catalyst to the mixed solution A under stirring conditions, and continuing to stir and react to obtain a mixed solution B; (3) Add isobutyryl chloride and a water-soluble partitioning agent to the mixed solution B under stirring, and continue stirring to react to obtain a mixed solution C; (4) The mixed solution C is allowed to stand for separation to obtain crude tert-butyl peroxyisobutyrate, which is then refined to obtain tert-butyl peroxyisobutyrate; In step (1), the solvent is one or more of dodecane, n-hexane or silicone oil; The liquid alkali in step (2) is a sodium hydroxide aqueous solution or a potassium hydroxide aqueous solution; The solid base catalyst in step (2) is magnesium aluminum tert-butoxide hydrotalcite; In step (3), the water-soluble partitioning agent is one or both of tetramethylammonium chloride and methyltributylammonium chloride.

2. The preparation method of tert-butyl peroxyisobutyrate according to claim 1, wherein In step (1), the concentration of the aqueous solution of tert-butyl hydroperoxide is 70-99 wt.%, and the stirring and cooling temperature is 0-20°C.

3. The preparation method of tert-butyl peroxyisobutyrate according to claim 1, wherein In step (1), the mass ratio of the aqueous solution of tert-butyl hydroperoxide, the solvent and the deionized water is 0.3-0.5:0-2:0.28-0.

5.

4. The preparation method of tert-butyl peroxyisobutyrate according to claim 1, wherein The concentration of the liquid caustic soda in step (2) is 20-50 wt.%, and the mass ratio of the liquid caustic soda to the aqueous tert-butyl hydroperoxide solution in step (1) is 22-58:24-35.

5. The preparation method of tert-butyl peroxyisobutyrate according to claim 1, wherein The mass of the solid base catalyst in step (2) is 0.9-10% of the mass of the liquid caustic soda.

6. The preparation method of tert-butyl peroxyisobutyrate according to claim 1, wherein The addition time in step (2) is 10-30 minutes, and the addition temperature is 0-20°C; the temperature for continuing the stirring reaction is 5-15°C, and the stirring reaction time is 10-30 minutes.

7. The preparation method of tert-butyl peroxyisobutyrate according to claim 1, wherein The mass ratio of isobutyryl chloride in step (3) to the liquid caustic soda in step (2) is 1: 0.82-2.

06.

8. The preparation method of tert-butyl peroxyisobutyrate according to claim 1, wherein In step (3), the mass ratio of isobutyryl chloride to the water-soluble partitioning agent is 1:0.01-0.

03.

9. The preparation method of tert-butyl peroxyisobutyrate according to claim 1, wherein The addition time in step (3) is 10-30 min, and the addition temperature is 0-20°C; the temperature for continuing the stirring reaction is 5-20°C, and the stirring reaction time is 10-120 min.

10. The method for preparing tert-butyl peroxyisobutyrate according to claim 1, wherein In step (4), the temperature for standing and stratifying is 0-15° C., and the time for standing and stratifying is 20-30 min. The crude product of tert-butyl peroxyisobutyrate is washed with alkali solution, sodium bicarbonate aqueous solution and deionized water respectively.