阅读说明：本技术 一种乙二醇单叔丁醚的制备方法 (Preparation method of ethylene glycol mono-tert-butyl ether ) 是由 周玉文 于 2019-10-23 设计创作，主要内容包括：本发明涉及一种乙二醇单叔丁醚的制备方法,经过选用K-MgO/γ-氧化铝作为催化剂,采用叔丁醇和环氧乙烷作为反应原料,提供了一种适应于工业化生产的乙二醇单叔丁醚的制备方法,该制备方法收率大于95％,纯度大于99％,且工艺简单、适合工业化生产的要求。(The invention relates to a method for preparing ethylene glycol mono-tert-butyl ether, which is suitable for industrial production by selecting K-MgO/gamma-alumina as a catalyst and adopting tert-butyl alcohol and ethylene oxide as reaction raw materials, and has the advantages of yield of more than 95 percent, purity of more than 99 percent, simple process and suitability for the requirements of industrial production.)

1. A method for preparing ethylene glycol mono-tert-butyl ether adopts tert-butyl alcohol and ethylene oxide as reaction raw materials and solid alkali as a catalyst, and comprises the following specific steps:

adding tert-butyl alcohol and solid alkali into a reaction kettle, uniformly stirring, heating to 30-50 ℃, slowly dropwise adding an ethylene oxide tetrahydrofuran solution, after dropwise adding, keeping the temperature for reaction for a period of time, after the reaction is finished, filtering to remove the solid alkali, and carrying out reduced pressure distillation to obtain high-purity ethylene glycol mono-tert-butyl ether; the solid alkali is K-MgO/gamma-alumina, and the addition amount of the solid alkali is 0.1-2% of the mass of the tertiary butanol.

2. The method for producing ethylene glycol mono-tert-butyl ether according to claim 1, characterized in that: the molar ratio of tert-butyl alcohol to ethylene oxide is 3-8: 1.

3. The method for producing ethylene glycol mono-tert-butyl ether according to claim 1, characterized in that: the reaction time is kept for 2 to 12 hours.

4. The method for producing ethylene glycol mono-tert-butyl ether according to claim 1, characterized in that: the preparation method of the solid alkali comprises the following steps:

dissolving magnesium chloride in deionized water, stirring uniformly, adding gamma-alumina, soaking for 3-5 hours, filtering, taking a filter cake, drying for 3-5 hours at 80-100 ℃, then placing the filter cake into a muffle furnace for high-temperature roasting for a period of time, cooling to room temperature, completely adding the filter cake into a vacuum grinding reactor, simultaneously adding a certain amount of metal potassium, and carrying out grinding reaction for 2-10 hours to obtain the K-MgO/gamma-alumina solid alkali.

5. The process for producing ethylene glycol mono-tert-butyl ether according to claim 4, characterized in that: according to the metal atom number, the charging molar ratio of the magnesium chloride, the gamma-alumina and the metal potassium is 1:20-30: 0.1-0.2.

6. The process for producing ethylene glycol mono-tert-butyl ether according to claim 4, characterized in that: the molar concentration of magnesium chloride dissolved in deionized water is 1-5 mol/L.

7. The process for producing ethylene glycol mono-tert-butyl ether according to claim 4, characterized in that: the high-temperature roasting temperature is 500-700 ℃, and the time is 3-8 hours.

Technical Field

The invention belongs to the field of organic synthesis, and particularly relates to a preparation method of ethylene glycol mono-tert-butyl ether.

Background

Ethylene glycol mono-tertiary butyl ether (TMBE) can be mixed with most organic solvents and can dissolve amino/nitro/alkyd/acrylic acid resin. Is miscible with water at room temperature (25 ℃). The solvent is mainly used for latex water dispersion paint in the paint industry, and the HLB value of the solvent is close to 9.0, so that the function of the solvent in a dispersion system plays a role of a dispersant/an emulsifier/a rheological agent/a cosolvent. It can improve the drying speed, the flatness, the brightness and the adhesion fastness of the water dispersible paint. Due to the tertiary butyl structure, the material has higher photochemical stability and safety. The water dispersed paint prepared with the solvent has excellent storage stability, especially in winter.

The printing ink prepared by using the ethylene glycol mono-tertiary butyl ether as a solvent or used as a diluent in the printing ink can greatly improve the rheological property of the printing ink, and improve the quality, the glossiness and the adhesion fastness of high-speed printing. Due to its low toxicity and low irritation, butyl cellosolve has been replaced in the United states, Japan, and Europe for many years, and has been used in large quantities in automotive and architectural coatings, especially in water-dispersed coatings. Ethylene glycol mono-tertiary-butyl ether is generally obtained by the addition reaction of isobutylene and ethylene glycol.

Due to the limited selectivity of the catalyst in the production process, ethylene glycol di-tert-butyl ether is often associated with the generated ethylene glycol di-tert-butyl ether, and the ethylene glycol di-tert-butyl ether have azeotropic property, so that the separation and purification are difficult. There is a document of using azeotropic distillation of diethylene glycol di-t-butyl ether with water at 98-90 ℃, but the azeotropic distillation process requires a large amount of water and is very energy intensive. The literature discloses extractive distillation processes for removing impurities from dipropylene glycol tert-butyl ether using a glycol extractant such as dipropylene glycol.

Chinese patent application No. CN201110159782AX discloses a method for separating glycol alkyl ether compounds by an extraction process using hydrophilic and lipophilic extraction agents. However, the above methods all require the addition of the 3 rd component, and the process flow is very complicated.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides the preparation method of the ethylene glycol mono-tert-butyl ether, which has simple process flow and is beneficial to industrial production.

A method for preparing ethylene glycol mono-tert-butyl ether adopts tert-butyl alcohol and ethylene oxide as reaction raw materials and solid alkali as a catalyst, and comprises the following specific steps:

adding tert-butyl alcohol and solid alkali into a reaction kettle, uniformly stirring, heating to 30-50 ℃, slowly dropwise adding an ethylene oxide tetrahydrofuran solution, after dropwise adding, keeping the temperature for reaction for a period of time, after the reaction is finished, filtering to remove the solid alkali, and carrying out reduced pressure distillation to obtain high-purity ethylene glycol mono-tert-butyl ether; the solid alkali is K-MgO/gamma-alumina, and the addition amount of the solid alkali is 0.1-2% of the mass of the tertiary butanol.

The molar ratio of the tertiary butanol to the ethylene oxide is 3-8:1, and the reaction time is 2-12 hours under the condition of heat preservation.

The preparation method of the solid alkali comprises the following steps:

dissolving magnesium chloride in deionized water, stirring uniformly, adding gamma-alumina, soaking for 3-5 hours, filtering, taking a filter cake, drying for 3-5 hours at 80-100 ℃, then placing the filter cake into a muffle furnace for high-temperature roasting for a period of time, cooling to room temperature, completely adding the filter cake into a vacuum grinding reactor, simultaneously adding a certain amount of metal potassium, and carrying out grinding reaction for 2-10 hours to obtain the K-MgO/gamma-alumina solid alkali.

Preferably, the charging molar ratio of the magnesium chloride, the gamma-alumina and the metal potassium is 1:20-30:0.1-0.2 according to the number of metal atoms.

Preferably, the magnesium chloride is dissolved in the deionized water at a molar concentration of 1-5 mol/L.

Preferably, the high-temperature roasting temperature is 500-700 ℃ and the time is 3-8 hours.

The reaction of tertiary butyl alcohol and epoxy ethanol in the presence of an alkaline catalyst is a nucleophilic reaction process, and alcoholic hydroxyl in the molecular structure of the tertiary butyl alcohol has lower nucleophilic activity even far lower than that of a ring-opening product of the tertiary butyl alcohol and the epoxy ethanol, namely ethylene glycol mono-tertiary butyl ether due to the existence of a larger space bit group, so that a satisfactory reaction result is generally difficult to obtain by a common alkaline catalyst, but the K-MgO/gamma-alumina solid alkaline catalyst adopted by the application has stronger alkalinity, and Mg ions contained in the catalyst can also activate ethylene oxide, so that the reaction activity of the catalyst and the tertiary butyl alcohol is greatly improved; the strength of the solid alkali is up to more than 42, when the catalyst is used for catalyzing the reaction of the tert-butyl alcohol and the ethylene oxide on the surface, the tert-butyl alcohol can be completely participated in the reaction in the form of tert-butoxy negative ions, and the nucleophilicity of the tert-butyl alcohol is greatly improved; the conversion rate of raw materials and the selectivity of products are greatly improved by the double activation of the tert-butyl alcohol and the ethylene oxide.

According to the invention, the tertiary butanol is always kept in large excess in the reaction process by dropwise adding the ethylene oxide into the tertiary butanol, so that the generation of byproducts is reduced to the maximum extent.

The main by-products of the method are the polyethylene glycol tertiary butyl ether which can not generate ethylene glycol di-tertiary butyl ether, the polyethylene glycol tertiary butyl ether and the ethylene glycol mono-tertiary butyl ether can not generate azeotrope, and the separation can be realized through simple distillation.

The invention has the advantages and effects that:

the invention provides a preparation method of ethylene glycol mono-tert-butyl ether, which is suitable for industrial production, by selecting K-MgO/gamma-alumina as a catalyst and adopting tert-butyl alcohol and ethylene oxide as reaction raw materials, wherein the yield of the preparation method is more than 95%, the purity is more than 99%, and the preparation method is simple in process and suitable for the requirements of industrial production.

Detailed Description

The technical solutions in the embodiments of the present invention are clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention.

[ example 1 ]

Preparation of S1, K-MgO/gamma-alumina solid alkali

Dissolving 1mol of magnesium chloride in 1L of deionized water, stirring uniformly, adding 30mol of gamma-alumina, soaking for 5 hours, filtering, taking a filter cake, drying for 5 hours at 100 ℃, then placing the filter cake into a muffle furnace, roasting for 5 hours at 700 ℃, cooling to room temperature, completely adding the filter cake into a vacuum grinding reactor, simultaneously adding 0.1mol of metal potassium, and grinding and reacting for 10 hours to obtain the K-MgO/gamma-alumina solid base.

S2 preparation of ethylene glycol mono-tertiary-butyl ether

Adding 3moL of tert-butyl alcohol and 2.5g of K-MgO/gamma-alumina solid base prepared in the step S1 into a reaction kettle, uniformly stirring, heating to 50 ℃, slowly dropwise adding 2L of ethylene oxide tetrahydrofuran solution with the concentration of 0.5moL/L, after dropwise adding, keeping the temperature for reaction for 12 hours, after the reaction is finished, filtering to remove the solid base, and carrying out reduced pressure distillation to obtain high-purity ethylene glycol mono-tert-butyl ether with the yield of 95.2 percent (calculated by ethylene oxide).

[ example 2 ]

Preparation of S1, K-MgO/gamma-alumina solid alkali

Dissolving 1mol of magnesium chloride in 0.2L of deionized water, stirring uniformly, adding 20mol of gamma-alumina, soaking for 5 hours, filtering, taking a filter cake, drying for 4 hours at 100 ℃, then placing the filter cake into a muffle furnace, roasting for 5 hours at 5000 ℃, cooling to room temperature, completely adding the filter cake into a vacuum grinding reactor, simultaneously adding 0.2mol of metal potassium, and grinding and reacting for 5 hours to obtain the K-MgO/gamma-alumina solid alkali.

S2 preparation of ethylene glycol mono-tertiary-butyl ether

Adding 5moL of tert-butyl alcohol (370g) and 5g of K-MgO/gamma-alumina solid base prepared in the step S1 into a reaction kettle, uniformly stirring, heating to 40 ℃, slowly dropwise adding 2L of ethylene oxide tetrahydrofuran solution with the concentration of 0.5moL/L, after dropwise adding, keeping the temperature for reaction for 6 hours, after the reaction is finished, filtering to remove the solid base, and carrying out reduced pressure distillation to obtain 113.6g of high-purity ethylene glycol mono-tert-butyl ether with the yield of 96.3% (calculated by ethylene oxide).

[ example 3 ]

Preparation of S1, K-MgO/gamma-alumina solid alkali

Dissolving 1mol of magnesium chloride in 0.5L of deionized water, adding 30mol of gamma-alumina after stirring uniformly, soaking for 4 hours, filtering, taking a filter cake, drying for 4 hours at 90 ℃, then placing the filter cake into a muffle furnace, roasting for 5 hours at 600 ℃, cooling to room temperature, completely adding the filter cake into a vacuum grinding reactor, simultaneously adding 0.2mol of metal potassium, and grinding and reacting for 3 hours to obtain the K-MgO/gamma-alumina solid base.

S2 preparation of ethylene glycol mono-tertiary-butyl ether

Adding 8moL of tert-butyl alcohol (592g) and 8g of K-MgO/gamma-alumina solid base prepared in the step S1 into a reaction kettle, uniformly stirring, heating to 50 ℃, slowly dropwise adding 2L of ethylene oxide tetrahydrofuran solution with the concentration of 0.5moL/L, after dropwise adding, keeping the temperature for reaction for 5 hours, after the reaction is finished, filtering to remove the solid base, and carrying out reduced pressure distillation to obtain high-purity ethylene glycol mono-tert-butyl ether with the yield of 114.8g and 97.3 percent (calculated by ethylene oxide).

Comparative example 1

S1 preparation of MgO/gamma-alumina solid base

Dissolving 1mol of magnesium chloride in 1L of deionized water, stirring uniformly, adding 30mol of gamma-alumina, soaking for 5 hours, filtering, taking a filter cake, drying for 5 hours at 100 ℃, then placing the filter cake into a muffle furnace, roasting for 5 hours at 700 ℃, cooling to room temperature, and completely adding the filter cake into a vacuum grinding reactor to carry out grinding reaction for 10 hours to obtain the MgO/gamma-alumina solid base.

S2 preparation of ethylene glycol mono-tertiary-butyl ether

Adding 3moL of tert-butyl alcohol and 2.5g of MgO/gamma-alumina solid base prepared in the step S1 into a reaction kettle, uniformly stirring, heating to 50 ℃, slowly dropwise adding 2L of ethylene oxide tetrahydrofuran solution with the concentration of 0.5moL/L, after dropwise adding, keeping the temperature for reaction for 12 hours, after the reaction is finished, filtering to remove the solid base, and carrying out reduced pressure distillation to obtain 52.3g of high-purity ethylene glycol mono-tert-butyl ether with the yield of 44.3% (calculated by ethylene oxide).

Comparative example 2

Preparation of S1, K/gamma-alumina solid alkali

Adding 30mol of gamma-alumina into a vacuum grinding reactor, simultaneously adding 0.1mol of metal potassium, and grinding and reacting for-10 hours to obtain the K/gamma-alumina solid base.

S2 preparation of ethylene glycol mono-tertiary-butyl ether

Adding 3moL of tert-butyl alcohol and 2.5g of K-MgO/gamma-alumina solid base prepared in the step S1 into a reaction kettle, uniformly stirring, heating to 50 ℃, slowly dropwise adding 2L of ethylene oxide tetrahydrofuran solution with the concentration of 0.5moL/L, after dropwise adding, keeping the temperature for reaction for 12 hours, after the reaction is finished, filtering to remove the solid base, and carrying out reduced pressure distillation to obtain high-purity ethylene glycol mono-tert-butyl ether 76.3g with the yield of 64.7 percent (calculated by ethylene oxide).

The foregoing description has disclosed fully preferred embodiments of the present invention. It should be noted that those skilled in the art can make modifications to the embodiments of the present invention without departing from the scope of the appended claims. Accordingly, the scope of the appended claims is not to be limited to the specific embodiments described above.