Preparation method and application of high-purity carboxylic ester

Abstract

The invention relates to the technical field of fine chemical engineering, and discloses a carboxylic ester preparation method, which comprises: in the presence of an organic sulfonic acid catalyst, carrying out a reaction on an alcohol and an acid, separating the obtained reaction product to obtain carboxylic ester, and further purifying the carboxylic ester to obtain high-purity carboxylic ester, wherein the alcohol is selected from methanol, ethanol, butanol or propylene glycol monomethyl ether, and the acid is selected from acetic acid or lactic acid. The corresponding acid and the corresponding alcohol are catalyzed by the organic aliphatic sulfonic acid catalyst to generate esterification reaction, so that the corresponding ester is efficiently and highly selectively obtained. Compared with a traditional catalyst, the catalyst has the advantages that the service life is long, the selectivity is extremely high, lactic acid dimer and lactic acid lactone in a lactate synthesis process and propylene glycol dimethyl ether in a propylene glycol methyl ether acetate process are greatly reduced, and the production difficulty of subsequent semiconductor-grade ester is greatly reduced.

Description

Technical Field

[0001] The invention relates to the technical field of fine chemical industry, and in particular to a preparation method and application of high-purity carboxylic acid ester. Background Art

[0002] With the continuous development of the semiconductor industry and the continuous improvement of semiconductor processes, human requirements for wet electronic chemicals are also increasing. Ultra-clean and high-purity reagents have a variety of applications. Ultra-high purity, low metal ion content, low particle content, high-clean semiconductor-grade methyl lactate, ethyl lactate, butyl lactate, amyl lactate, and propylene glycol monomethyl ether acetate are widely used in photovoltaic, semiconductor, and PCB production processes.

[0003] At present, industrial synthetic esters are mainly produced by direct esterification, which uses the corresponding alcohol and acid as raw materials, traditional liquid acids such as concentrated sulfuric acid, phosphoric acid, p-toluenesulfonic acid, sulfonic acid resin, or supported solid superacid catalysts. However, this type of production method has poor reaction selectivity, low activity, low product purity, and catalyst deactivation due to problems such as excessive catalyst acidity, complex and non-single active centers, diffusion, and stability.

[0004] CN103435480A discloses a method for producing propylene glycol methyl ether acetate. In the presence of a supported catalyst, propylene glycol methyl ether and acetic acid are subjected to an esterification reaction to produce propylene glycol methyl ether acetate. The supported substance of the supported catalyst is any one of p-toluenesulfonic acid, phosphotungstic acid, phosphomolybdic acid, sulfuric acid or nitric acid. Although it is improved over homogeneous acid catalysis, it still has problems such as poor selectivity, excessive acidity resulting in severe catalyst coking and a large number of by-products.

[0005] CN202210841697.X discloses a method for producing ethyl lactate, which uses a composite catalyst with a mesoporous silica molecular sieve as a carrier and phosphomolybdic acid and ammonium phosphomolybdate as active components to carry out an esterification reaction to obtain an ethyl lactate product. However, as the catalyst load is lost, the catalyst activity decreases significantly, requiring frequent catalyst replacement during the production process.

[0006] CN113603585A discloses a method for producing methyl lactate, which uses an acidic ion exchange resin as a catalyst to catalyze the esterification reaction of lactic acid and methanol. Although the acidic ion exchange resin is more suitable for continuous production, it still cannot overcome the problem of limited service life and easy loss of catalytic active sites.

[0007] CN101914021B discloses a method for preparing butyl lactate, which mainly catalyzes the ester exchange reaction between propyl lactate and butanol to obtain butyl lactate. However, in the production process, the required catalysts are zinc catalysts and ion exchange resin catalysts, which still have problems such as poor catalyst selectivity and many byproducts.

[0008] With the continuous development of my country's semiconductor industry, the demand for semiconductor-grade methyl lactate, ethyl lactate, butyl lactate, and propylene glycol monomethyl ether acetate continues to grow. It is necessary to develop a highly selective and high-purity ester production technology to provide higher-quality and dedicated raw materials for subsequent semiconductor-grade purification, so as to improve the product quality and purity level of the final semiconductor-grade ester. Summary of the invention

[0009] The purpose of the present invention is to overcome the problems of poor catalyst selectivity, severe coking, and many by-products in the reaction system during the esterification production process of high-purity esters in the prior art, and to provide a preparation method and application of high-purity carboxylic acid esters.

[0010] In order to achieve the above object, the first aspect of the present invention provides a method for preparing high-purity carboxylic acid ester, which comprises the following steps:

[0011] In the presence of an organic sulfonic acid catalyst, alcohol and acid are reacted, and the obtained reaction product is separated to obtain a carboxylic acid ester, and the carboxylic acid ester is further purified to obtain a high-purity carboxylic acid ester;

[0012] Wherein, the alcohol is selected from methanol, ethanol, butanol or propylene glycol monomethyl ether, and the acid is selected from acetic acid or lactic acid.

[0013] The second aspect of the present invention provides the use of the high-purity carboxylic acid ester obtained by the preparation method of the present invention in semiconductor-grade photoresist raw materials.

[0014] Through the above technical scheme, the present invention uses an organic sulfonic acid catalyst to catalyze the corresponding alcohol (methanol, ethanol, butanol, amyl alcohol, propylene glycol monomethyl ether) and the corresponding acid (acetic acid, lactic acid) to react, thereby efficiently and selectively obtaining high-purity corresponding esters (methyl lactate, ethyl lactate, butyl lactate, amyl lactate, propylene glycol monomethyl ether acetate). The catalyst has moderate acidity and high selectivity, and can effectively improve the problems of catalyst coking, poor selectivity, and many reaction by-products, thereby greatly reducing the by-products in the system-dimerization in the lactic acid reaction system and lactolactone, and propylene glycol dimethyl ether in the propylene glycol methyl ether system, thereby greatly reducing the difficulty of subsequent semiconductor-grade ester production.

[0015] The present invention applies an organic sulfonic acid catalyst to the esterification production process of methyl lactate, ethyl lactate, butyl lactate, pentyl lactate and propylene glycol monomethyl ether acetate. Compared with strongly acidic homogeneous catalysts such as sulfuric acid or heterogeneous ion exchange resin catalysts used in traditional production processes, the organic sulfonic acid catalyst has a longer service life and better selectivity, a simple preparation method and high product purity, and the organic sulfonic acid catalyst is used in the production process of semiconductor-grade methyl lactate, ethyl lactate, butyl lactate, pentyl lactate and propylene glycol monomethyl ether acetate. DETAILED DESCRIPTION

[0016] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0017] The first aspect of the present invention provides a method for preparing a high-purity carboxylic acid ester, which comprises the following steps:

[0018] In the presence of an organic sulfonic acid catalyst, alcohol and acid are reacted, and the obtained reaction product is separated to obtain a carboxylic acid ester, and the carboxylic acid ester is further purified to obtain a high-purity carboxylic acid ester;

[0019] Wherein, the alcohol is selected from methanol, ethanol, butanol or propylene glycol monomethyl ether, and the acid is selected from acetic acid or lactic acid.

[0020] In the present invention, the organic sulfonic acid catalyst is used to catalyze the esterification reaction between the corresponding acid and the corresponding alcohol, thereby obtaining the corresponding ester with high efficiency and selectivity. Compared with traditional catalysts, this type of catalyst has a good service life and extremely high selectivity, and greatly reduces the generation of byproducts such as lactic acid dimerization and lactolactone in the lactate synthesis process, and propylene glycol dimethyl ether in the propylene glycol methyl ether acetate process, thereby greatly reducing the difficulty of subsequent semiconductor-grade ester production.

[0021] In some specific embodiments of the present invention, the carboxylic acid esters obtained by carrying out esterification reaction with different acids and alcohols can be methyl lactate, ethyl lactate, butyl lactate, methyl acetate, ethyl acetate, butyl acetate or propylene glycol monomethyl ether acetate.

[0022] In some specific embodiments of the present invention, the organic sulfonic acid catalyst is selected from one or more of morpholineethanesulfonic acid, 1-pyrenesulfonic acid, piperazine-N,N'-di(2-ethanesulfonic acid), 3-morpholinepropanesulfonic acid, camphorsulfonic acid, and 2-(4-pyridyl)ethanesulfonic acid.

[0023] In some specific embodiments of the present invention, preferably, the organic sulfonic acid catalyst is selected from morpholineethanesulfonic acid and 1-pyrenesulfonic acid, and the molar ratio of morpholineethanesulfonic acid to 1-pyrenesulfonic acid is 0.01-0.6:0.4-1.

[0024] In some specific embodiments of the present invention, preferably, the organic sulfonic acid catalyst is selected from morpholineethanesulfonic acid and 2-(4-pyridyl)ethanesulfonic acid, and the molar ratio of morpholineethanesulfonic acid to 2-(4-pyridyl)ethanesulfonic acid is 0.01-0.3:0.7-1.

[0025] In some specific embodiments of the present invention, preferably, the organic sulfonic acid catalyst is selected from camphorsulfonic acid and piperazine-N,N'-di(2-ethanesulfonic acid), and the molar ratio of camphorsulfonic acid to piperazine-N,N'-di(2-ethanesulfonic acid) is 0.6-1:0.01-0.4.

[0026] In some specific embodiments of the present invention, preferably, the organic sulfonic acid catalyst is selected from 3-morpholinepropanesulfonic acid and piperazine-N,N'-di(2-ethanesulfonic acid), and the molar ratio of 3-morpholinepropanesulfonic acid to piperazine-N,N'-di(2-ethanesulfonic acid) is 0.7-1:0.01-0.3.

[0027] In some specific embodiments of the present invention, preferably, the molar ratio of the alcohol to the acid is 1:1-1.5.

[0028] In some specific embodiments of the present invention, preferably, relative to the total molar amount of the alcohol and the acid of 0.4-0.5 mol, the amount of the organic sulfonic acid catalyst is 0.5-1.5 g.

[0029] In some specific embodiments of the present invention, the reaction temperature is 100-150° C., and the reaction time is 2-6 h, preferably 3-5 h.

[0030] In the present invention, the above reaction conditions can make the esterification reaction faster and more complete, thereby obtaining the corresponding ester with high efficiency and selectivity.

[0031] In some specific embodiments of the present invention, the separation is selected from gas-liquid separation, and the separation conditions include: pressure ≤ 0.1 MPa, temperature 40-95°C.

[0032] In some specific embodiments of the present invention, alcohol and acid are reacted, and the obtained reaction product is separated to obtain carboxylic acid ester, and the gas chromatography purity of the carboxylic acid ester is>99%. The present invention uses an organic sulfonic acid catalyst to catalyze the esterification reaction between the corresponding acid and the corresponding alcohol, thereby obtaining the corresponding ester with high efficiency and high selectivity. The above-mentioned specific organic sulfonic acid catalyst composition can make the esterification reaction more efficient and have fewer by-products, which has the technical effect of improving the selectivity of the product. This type of catalyst has a good service life, extremely high selectivity, and greatly reduces the generation of by-products, thereby greatly reducing the difficulty of subsequent production of semiconductor-grade esters.

[0033] In some specific embodiments of the present invention, the purification is selected from sub-boiling distillation or multi-stage purification.

[0034] In some specific embodiments of the present invention, the conditions for the sub-boiling distillation are: temperature of 40-120° C. and pressure of 0.01-0.1 MPa.

[0035] In some specific embodiments of the present invention, the multi-stage purification is selected from one or more of membrane separation, ion exchange and adsorption.

[0036] In some specific embodiments of the present invention, the carboxylic acid ester is further purified to obtain a high-purity carboxylic acid ester, wherein the gas chromatographic purity of the high-purity carboxylic acid ester is >99.99%, the acetic acid content is ≤50ppm, the single metal element content is <50ppb, and the concentration of particles with an average particle size >0.5μm is less than 15pcs / mL. The present invention uses an organic sulfonic acid catalyst to catalyze the esterification reaction between the corresponding acid and the corresponding alcohol, thereby obtaining the corresponding ester with high efficiency and selectivity. This type of catalyst has a good service life, extremely high selectivity, and greatly reduces the generation of by-products, thereby greatly reducing the difficulty of subsequent semiconductor-grade ester production. Further purification obtains a higher purity of the high-purity carboxylic acid ester, which improves the product quality and purity level of the final semiconductor-grade carboxylic acid ester.

[0037] The second aspect of the present invention provides the use of high-purity carboxylic acid esters obtained by the preparation method of the present invention in semiconductor-grade photoresist raw materials. The high-purity carboxylic acid ester can be high-purity methyl lactate, ethyl lactate, butyl lactate, methyl acetate, ethyl acetate, butyl acetate or propylene glycol monomethyl ether acetate. The purity of the above-mentioned various high-purity carboxylic acid esters can meet the following requirements: the gas chromatographic purity of the high-purity carboxylic acid ester is greater than 99.99%, the acetic acid content is less than 50ppm, the single metal element content is less than 50ppb, and the concentration of particles with an average particle size greater than 0.5μm is less than 15pcs / mL.

[0038] The present invention will be described in detail below through examples.

[0039] Product purity was measured by gas chromatography.

[0040] Method for measuring the acidity of the product: acid-base neutralization titration is used for analysis.

[0041] The content of single metal elements in the product was measured by ICP-MS.

[0042] The particle measurement method of the product is to use a particle counter for analysis.

[0043] In the following examples and comparative examples, if no specific conditions are specified, the experiments were carried out under conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used, if no manufacturer is specified, are all conventional products that can be obtained through commercial channels.

[0044] Examples 1-9

[0045] The corresponding alcohol, acid and catalyst are added to a reaction kettle, reacted at a certain temperature, and the obtained reaction product is separated to obtain carboxylic acid ester, and the reaction results are detected by gas chromatography. The feeding amounts of alcohol, acid and catalyst are shown in Table 1, and the catalytic esterification results are shown in Table 2.

[0046] Table 1

[0047]

[0048]

[0049] Table 2

[0050]

[0051] Note: *Conversion rate of lactic acid or propylene glycol monomethyl ether

[0052] The carboxylic acid ester separated after the reaction was further subjected to sub-boiling distillation. The sub-boiling distillation operating pressure was 0.1 MPa and the sub-boiling distillation temperature was 100° C. to obtain high-purity carboxylic acid ester. The product indicators are shown in Table 3.

[0053] Table 3

[0054]

[0055]

[0056] Comparative Example

[0057] Methyl lactate, ethyl lactate, butyl lactate and propylene glycol monomethyl ether were prepared in the same manner as in Examples 1-9, except that the catalysts were different. The reaction results were detected by gas chromatography, and the amounts of the corresponding alcohol, acid and catalyst were shown in Table 4. The results of the catalytic esterification are shown in Table 5.

[0058] Table 4

[0059]

[0060] Table 5

[0061]

[0062] Note: *Conversion rate of lactic acid or propylene glycol monomethyl ether

[0063] The carboxylic acid ester separated after the reaction is further subjected to sub-boiling distillation. The sub-boiling distillation operating pressure is 0.1 MPa and the sub-boiling distillation temperature is 100° C. to obtain high-purity carboxylic acid ester. The product indicators are shown in Table 6.

[0064] Table 6

[0065]

[0066] It can be seen from the results in Tables 1-6 that the selectivity of the target product obtained in the esterification reaction using the organic sulfonic acid catalyst of the present invention is significantly higher than that of other catalysts, the reaction by-products are significantly reduced, and the purity of the target product obtained after separation is higher, thereby greatly reducing the difficulty of subsequent semiconductor-grade ester production.

[0067] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. A method for preparing high-purity carboxylic acid esters, It is characterized in that The following steps are involved: In the presence of an organic sulfonic acid catalyst, alcohol and acid are reacted, and the obtained reaction product is separated to obtain a carboxylic acid ester, and the carboxylic acid ester is further purified to obtain a high-purity carboxylic acid ester; Wherein, the alcohol is selected from methanol, ethanol, butanol or propylene glycol monomethyl ether, and the acid is selected from acetic acid or lactic acid.

2. The preparation method according to claim 1, in, The organic sulfonic acid catalyst is selected from one or more of morpholineethanesulfonic acid, 1-pyrenesulfonic acid, piperazine-N,N'-di(2-ethanesulfonic acid), 3-morpholinepropanesulfonic acid, camphorsulfonic acid and 2-(4-pyridyl)ethanesulfonic acid.

3. The preparation method according to claim 1 or 2, in, The organic sulfonic acid catalyst is selected from morpholineethanesulfonic acid and 1-pyrenesulfonic acid, and the molar ratio of morpholineethanesulfonic acid to 1-pyrenesulfonic acid is 0.01-0.6:0.4-1; Or, the organic sulfonic acid catalyst is selected from morpholineethanesulfonic acid and 2-(4-pyridyl)ethanesulfonic acid, and the molar ratio of morpholineethanesulfonic acid to 2-(4-pyridyl)ethanesulfonic acid is 0.01-0.3:0.7-1; Or, the organic sulfonic acid catalyst is selected from camphorsulfonic acid and piperazine-N,N'-di(2-ethanesulfonic acid), and the molar ratio of camphorsulfonic acid to piperazine-N,N'-di(2-ethanesulfonic acid) is 0.6-1:0.01-0.4; Alternatively, the organic sulfonic acid catalyst is selected from 3-morpholinepropanesulfonic acid and piperazine-N,N'-di(2-ethanesulfonic acid), and the molar ratio of 3-morpholinepropanesulfonic acid to piperazine-N,N'-di(2-ethanesulfonic acid) is 0.7-1:0.01-0.

3.

4. The preparation method according to any one of claims 1 to 3, in, The molar ratio of the alcohol to the acid is 1:1-1.5; Preferably, the amount of the organic sulfonic acid catalyst is 0.5-1.5 g relative to the total molar amount of the alcohol and the acid of 0.4-0.5 mol.

5. The preparation method according to any one of claims 1 to 4, in, The reaction temperature is 80-150° C., and the reaction time is 2-6 h, preferably 3-5 h.

6. The preparation method according to any one of claims 1 to 5, in, The separation is selected from gas-liquid separation, and the separation conditions include: pressure ≤ 0.1 MPa, temperature 40-95°C.

7. The preparation method according to any one of claims 1 to 6, in, The purification is selected from sub-boiling distillation or multi-stage purification.

8. The preparation method according to claim 7, in, The conditions of the sub-boiling distillation are: temperature of 40-120° C. and pressure of 0.01-0.1 MPa.

9. The preparation method according to claim 7, in, The multi-stage purification is selected from one or more of membrane separation, ion exchange and adsorption.

10. Use of the high-purity carboxylic acid ester obtained by the preparation method according to any one of claims 1 to 9 in semiconductor-grade photoresist.

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