Method for synthesizing and purifying electronic-grade alpha-terpinene

Abstract

The invention discloses a synthesis and purification method of electronic-grade alpha-terpinene. During synthesis, beta-phellandrene, trimethylbromosilane, p-toluene sulfonic acid and hydrogen peroxide are used as reaction raw materials, and concentrated sulfuric acid is used as a catalyst; according to purification, a water filtering molecular sieve, a microporous quartz filter and a specially manufactured quartz cation exchange column are adopted for early-stage purification, desolventizing treatment is carried out through a quartz desolventizing tower, and finally rectification is carried out through a quartz rectifying tower by adopting a method that a filler is corrugated filler and the number of theoretical plates is 50-110. And finally, packaging in a quartz container in a vacuum cavity. The method has the characteristics of simple reaction, high yield, efficient impurity removal and pure physical purification.

Description

Technical Field

[0001] The present invention relates to a high-purity semiconductor dopant, and particularly to a method for synthesizing and purifying electronic-grade α-terpinene. Background Art

[0002] α-Terpinene has been used in the fragrance and flavor industry to enhance the aroma of products. However, with the recent rise of the electrochemistry industry, ordinary synthesis and distillation cannot achieve electronic-grade purity, and a rectification and purification process is necessary. α-Terpinene has begun to be widely used in the fields of photovoltaics and semiconductors and can be used as an interlayer dielectric in the CMOS manufacturing process, which is a porous low-k material.

[0003] In the prior art, there are two common synthesis methods as follows: 1. Obtained by catalytic isomerization using α-pinene as a raw material. The catalysts that can be used include concentrated sulfuric acid, heteropolyacid, solid superacid, etc. The product is usually a mixture of various dipentene products, with low selectivity for α-terpinene, and the yield is usually no more than 40%. The preparation efficiency needs to be further improved.

[0004] 2. Add β-phellandrene or turpentine containing β-phellandrene, a catalyst, and an auxiliary agent into a reaction device, stir and react fully at a certain temperature, and then remove the unreacted catalyst and auxiliary agent through post-treatment to obtain α-terpinene or turpentine containing α-terpinene. When H2O2 is used as the reaction auxiliary agent, the conversion rate of β-phellandrene is 88.4%, and the selectivity for α-terpinene is 94%; when H2O is used as the reaction auxiliary agent, the conversion rate of β-phellandrene is 78.6%, and the selectivity for α-terpinene is 85.5%.

[0005] Compared with method 1, the synthesis scheme and yield of method 2 are better, and the selectivity is higher. However, the problems faced are that the post-treatment is troublesome, and there are still other substances such as salts and water in the system after post-treatment, which are difficult to remove completely, and the purity cannot meet the requirements of the electronics industry. Moreover, there is no effective purification method in the prior art to address this pain point.

[0006] In the current prior art, there is no related technology to solve the above problems. Currently, a method for synthesizing and purifying electronic-grade α-terpinene with simple reaction, high yield, efficient impurity removal, and pure physical method for purification is needed. Summary of the Invention

[0007] The present invention aims to provide a method for synthesizing and purifying electronic-grade α-terpinene with simple reaction, high yield, efficient impurity removal, and pure physical method for purification.

[0008] To achieve the above object, the present invention adopts the following technical solution: A method for synthesizing and purifying electronic-grade α-terpinene, and this process method includes the following stages: S1: Raw material preparation ① Raw material preparation: prepare sufficient amount of β-phellandrene, trimethylsilyl bromide, p-toluenesulfonic acid, concentrated sulfuric acid, hydrogen peroxide, sodium type cation exchange resin raw material, 5% sodium hydroxide aqueous solution with solute mass fraction, zinc sulfate, disodium ethylenediaminetetraacetate, and 1.5% hydrochloric acid aqueous solution with solute mass fraction; ② Preparation of tools and equipment: prepare water filter molecular sieve, microporous quartz filter with a pore size of 0.01 μm, quartz desolventizing tower with a theoretical plate number of 50-100, quartz distillation tower, vacuum degree 1×10 -4 Pa~1×10 -3 Pa vacuum chamber, quartz packaging container; all equipment transmission pipelines are made of polytetrafluoroethylene tubes; S2: α-terpinene synthesis ① Using the β-phellandrene, trimethylsilyl bromide, p-toluenesulfonic acid, and hydrogen peroxide prepared in step ① of stage S1 as reaction raw materials, concentrated sulfuric acid as a catalyst, hydrogen peroxide as an oxidizing agent, and deionized water as a reaction medium environment, the reaction is carried out at a reaction temperature of 60° C. to 100° C. and a reaction time of 1 h to 16 h to obtain an α-terpinene mixture; ② After the reaction is completed, the α-terpinene mixture is crudely distilled to obtain crude α-terpinene; S3: Quartz cation exchange column preparation ① Soak the sodium type cation exchange resin raw material prepared in step ① of stage S1 for 3h~5h in the sodium hydroxide aqueous solution prepared in step ① of stage S1, then wash it with deionized water, then soak it in the hydrochloric acid aqueous solution prepared in step ① of stage S1 for 3h~5h, then wash it with deionized water, and finally dry it at a temperature of 75℃~85℃ to obtain a pretreated cation exchange resin; ② Mix the zinc sulfate prepared in step ① of stage S1 with an appropriate amount of deionized water and stir to fully dissolve, to prepare a zinc sulfate aqueous solution with a molar ratio of 2.8 mol / L to 3.5 mol / L; ③ The pretreated cation exchange resin obtained in step ① and the zinc sulfate aqueous solution obtained in step ② are mixed in a mass ratio of 1:(5-6), then the temperature is raised to 75°C-85°C, and the reaction is carried out for 13h-16h, and then the cation exchange resin is taken out, cleaned with deionized water, and dried at 75°C-85°C to obtain the desired cation exchange resin; ④ Assemble the cation exchange resin obtained in step ③ with a frame substrate made of quartz material to obtain the desired quartz cation exchange column; S4: α-terpinene purification ①Purification pretreatment: Use the filtered water molecular sieve prepared in step ② of stage S1 to filter and remove water from the crude α-terpinene obtained in step ② of stage S2. After removing the water, dehydrated α-terpinene is obtained. Immediately, the dehydrated α-terpinene is finely filtered through the microporous quartz filter prepared in step ② of stage S1 to obtain finely filtered α-terpinene. Then, the finely filtered α-terpinene is subjected to photocatalytic ion exchange using the quartz cation exchange column obtained in step ④ of stage S3 for 2.5 h to 3.5 h to obtain pretreated α-terpinene. ②Desolventization treatment: Add the pretreated α-terpinene obtained in step ① to the quartz desolventization tower prepared in step ② of stage S1 to separate the solvent and obtain desolventized α-terpinene. ③Rectification: Add the desolventized α-terpinene obtained in step ② to the quartz rectification tower prepared in step ② of stage S1. The packing is corrugated packing, and the number of theoretical plates is 50 - 100. Rectify to obtain rectified α-terpinene. S5: Encapsulation ①Encapsulate the rectified α-terpinene obtained in step ③ of stage S4 in the vacuum chamber prepared in step ② of stage S1 using the quartz encapsulation container prepared in step ② of stage S1. After encapsulation and sealing, the required electronic-grade α-terpinene is obtained.

[0009] Compared with the prior art, due to the adoption of the above technical solutions, the present invention has the following advantages: (1) In the method of the present invention, by optimizing the synthesis method, improving the rectification materials, equipment and rectification conditions for the optimized synthesis method, and setting up a special cation exchange column, the method of the present invention can significantly improve the purification efficiency and purity of α-terpinene and reach the electronic-grade purity.

[0010] (2) Through the production practice of the applicant, when preparing zinc oxide cation exchange resin, under the condition that the reaction time is 13 h to 16 h, the ZnO / cation exchange resin composite material prepared has the best salt removal effect for the special requirements of the present invention. Through the repeated practice of the applicant, it is concluded that when removing the salt impurities, especially metal ion impurities, in the specially prepared crude rectified α-terpinene of the present invention, the reaction time is about 3 h, and the salt, especially metal ion removal effect in the prepared product is the best.

[0011] Therefore, the present invention has the characteristics of simple reaction, high yield, efficient impurity removal, and purification by pure physical methods. Description of the Drawings

[0012] Figure 1 It is the reaction principle diagram of the synthesis of α-terpinene of the present invention. Detailed Embodiments Examples

[0013] A reaction principle is as Figure 1The synthesis and purification method of electronic-grade α-terpinene, and this process method includes the following stages: S1: Raw material preparation ① Raw material preparation: Prepare sufficient amounts of β-phellandrene, trimethylbromosilane, p-toluenesulfonic acid, concentrated sulfuric acid, hydrogen peroxide, sodium-type cation exchange resin raw material, sodium hydroxide aqueous solution with a solute mass fraction of 5%, zinc sulfate, disodium ethylenediaminetetraacetate, and hydrochloric acid aqueous solution with a solute mass fraction of 1.5%; ② Tooling and equipment preparation: Prepare a filter molecular sieve, a microporous quartz filter with a filtration pore diameter of 0.01 μm, a quartz desolventization tower with a theoretical plate number of 50 - 100, a quartz rectification tower, a vacuum chamber with a vacuum degree of 1×10 -4 Pa - 1×10 -3 Pa, and a quartz encapsulation container; all the transmission pipelines of the equipment are made of polytetrafluoroethylene tubes; S2: α-Terpinene synthesis ① Use β-phellandrene, trimethylbromosilane, p-toluenesulfonic acid, and hydrogen peroxide prepared in step ① of stage S1 as reaction raw materials, concentrated sulfuric acid as a catalyst, hydrogen peroxide as an oxidation assistant, and deionized water as the reaction medium environment to carry out the reaction. The reaction temperature is 60°C - 100°C, and the reaction time is 1h - 16h to obtain an α-terpinene mixture; ② After the reaction ends, the α-terpinene mixture is obtained as crude α-terpinene through rough distillation; S3: Preparation of quartz cation exchange column ① Immerse the sodium-type cation exchange resin raw material prepared in step ① of stage S1 in the sodium hydroxide aqueous solution prepared in step ① of stage S1 for 3h - 5h, then wash it clean with deionized water, then immerse it in the hydrochloric acid aqueous solution prepared in step ① of stage S1 for 3h - 5h, then wash it clean with deionized water again, and finally dry it at a temperature of 75°C - 85°C to obtain a pretreated cation exchange resin; ② Mix the zinc sulfate prepared in step ① of stage S1 with an appropriate amount of deionized water and stir to dissolve it fully to prepare a zinc sulfate aqueous solution with a molar ratio of 2.8mol / L - 3.5mol / L; ③ Mix the pretreated cation exchange resin obtained in step ① with the zinc sulfate aqueous solution obtained in step ② at a mass ratio of 1:(5 - 6), then heat it to 75°C - 85°C and react for 13h - 16h. Then take out the cation exchange resin, wash it clean with deionized water, and dry it at 75°C - 85°C to obtain the required cation exchange resin; ④ Assemble the cation exchange resin obtained in step ③ with a quartz frame matrix to obtain the required quartz cation exchange column; S4: α-Terpinene purification ① Pretreatment for purification: Use the filtered water molecular sieve prepared in step ② of stage S1 to perform water removal filtration on the crude α-terpinene obtained in step ② of stage S2. After removing water, dehydrated α-terpinene is obtained. Immediately, the dehydrated α-terpinene is finely filtered through the microporous quartz filter prepared in step ② of stage S1 to obtain finely filtered α-terpinene. Then, the finely filtered α-terpinene is subjected to photocatalytic ion exchange using the quartz cation exchange column obtained in step ④ of stage S3 for 2.5 h to 3.5 h to obtain pretreated α-terpinene. ② Solvent removal treatment: Add the pretreated α-terpinene obtained in step ① to the quartz solvent removal tower prepared in step ② of stage S1 to separate the solvent and obtain solvent-removed α-terpinene. ③ Rectification: Add the solvent-removed α-terpinene obtained in step ② to the quartz rectification tower prepared in step ② of stage S1, with the packing being corrugated packing and the number of theoretical plates being 50 to 100. Rectified α-terpinene is obtained through rectification. S5: Encapsulation ① Encapsulate the rectified α-terpinene obtained in step ③ of stage S4 in the vacuum chamber prepared in step ② of stage S1 using the quartz encapsulation container prepared in step ② of stage S1. After the encapsulation is completed and sealed, the required electronic-grade α-terpinene is obtained.

[0014] The above description of the disclosed embodiments is only to enable those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to these embodiments shown herein, but rather will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for synthesizing and purifying electronic grade α-terpinene, characterized in that: The process The following phases are included: S1: Raw material preparation ① Raw material preparation: prepare sufficient amount of β-phellandrene, trimethylsilyl bromide, p-toluenesulfonic acid, concentrated sulfuric acid, hydrogen peroxide, sodium type cation exchange resin raw material, 5% sodium hydroxide aqueous solution with solute mass fraction, zinc sulfate, disodium ethylenediaminetetraacetate, and 1.5% hydrochloric acid aqueous solution with solute mass fraction; ② Preparation of tools and equipment: prepare water filter molecular sieve, microporous quartz filter with a pore size of 0.01 μm, quartz desolventizing tower with a theoretical plate number of 50-100, quartz distillation tower, vacuum degree 1×10 -4 Pa~1×10 -3 Pa vacuum chamber, quartz packaging container; all equipment transmission pipelines are made of polytetrafluoroethylene tubes; S2: α-terpinene synthesis ① Using β-phellandrene, trimethylsilyl bromide, p-toluenesulfonic acid, and hydrogen peroxide prepared in step ① of stage S1 as reaction raw materials, concentrated sulfuric acid as a catalyst, hydrogen peroxide as an oxidizing agent, and deionized water as a reaction medium environment for reaction, the reaction temperature is 60° C. to 100° C., and the reaction time is 1 h to 16 h to obtain an α-terpinene mixture; ② After the reaction is completed, the α-terpinene mixture is crudely distilled to obtain crude α-terpinene; S3: Quartz cation exchange column preparation ① Soak the sodium type cation exchange resin raw material prepared in step ① of stage S1 for 3h~5h in the sodium hydroxide aqueous solution prepared in step ① of stage S1, then wash it with deionized water, then soak it in the hydrochloric acid aqueous solution prepared in step ① of stage S1 for 3h~5h, then wash it with deionized water, and finally dry it at a temperature of 75℃~85℃ to obtain a pretreated cation exchange resin; ② Mix the zinc sulfate prepared in step ① of stage S1 with an appropriate amount of deionized water and stir to fully dissolve, to prepare a zinc sulfate aqueous solution with a molar ratio of 2.8 mol / L to 3.5 mol / L; ③ The pretreated cation exchange resin obtained in step ① and the zinc sulfate aqueous solution obtained in step ② are mixed in a mass ratio of 1:(5-6), then the temperature is raised to 75°C-85°C, and the reaction is carried out for 13h-16h, and then the cation exchange resin is taken out, cleaned with deionized water, and dried at 75°C-85°C to obtain the desired cation exchange resin; ④ Assemble the cation exchange resin obtained in step ③ with a frame substrate made of quartz material to obtain the desired quartz cation exchange column; S4: α-terpinene purification ① Purification pretreatment: the crude α-terpinene obtained in step ② of step S2 is filtered by the water-filtering molecular sieve prepared in step ② of step S1 to remove water and obtain dehydrated α-terpinene; the dehydrated α-terpinene is finely filtered through the microporous quartz filter prepared in step ② of step S1 to obtain finely filtered α-terpinene; the finely filtered α-terpinene is then subjected to photocatalytic ion exchange using the quartz cation exchange column obtained in step ④ of step S3 for an exchange time of 2.5 h to 3.5 h to obtain pretreated α-terpinene; ② Desolventization treatment: adding the pre-treated α-terpinene obtained in step ① into the quartz desolventization tower prepared in step ② of stage S1 to separate the solvent and obtain desolventized α-terpinene; ③ Distillation: adding the desolventized α-terpinene obtained in step ② to the quartz distillation tower prepared in step ② of stage S1, using corrugated packing with a theoretical plate number of 50 to 110; distilling to obtain distilled α-terpinene; S5: Encapsulation ① The distilled α-terpinene obtained in step ③ of stage S4 is packaged in the vacuum chamber prepared in step ② of stage S1 using the quartz packaging container prepared in step ② of stage S1. After the packaging is completed and sealed, the desired electronic grade α-terpinene is obtained.

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