阅读说明：本技术 一种季戊四醇酯的制备方法 (Preparation method of pentaerythritol ester ) 是由 许倩倩 梁万根 张超 崔卫华 费潇瑶 孙志利 卞文 于 2020-07-23 设计创作，主要内容包括：本发明提供了季戊四醇酯的制备方法,包括以下步骤：季戊四醇和3-巯基丁酸在催化剂的作用下,发生酯化反应,生成季戊四醇四(3-巯基丁酸)酯；所述催化剂按照以下方法制备：A)将模板剂和钛源化合物或硅源化合物在溶剂中混合均匀,得到第一混合溶液；B)将第一混合溶液和杂多酸,带有磺酸基团的有机化合物混合均匀,得到第二混合溶液；C)将第二混合溶液除去溶剂,得到凝胶；D)对凝胶进行老化处理,焙烧去除模板剂,得到催化剂。本发明采用负载型复合酸催化剂合成季戊四醇四(3-巯基丁酸)酯,替代了无机酸和有机酸催化剂,所述催化剂具有更高的酸性和催化活性,能够提高酯化效率,缩短反应时间,可多次重复使用,更加绿色环保经济。(The invention provides a preparation method of pentaerythritol ester, which comprises the following steps: pentaerythritol and 3-mercaptobutyric acid are subjected to esterification reaction under the action of a catalyst to generate pentaerythritol tetra (3-mercaptobutyric acid) ester; the catalyst is prepared according to the following method: A) uniformly mixing a template agent and a titanium source compound or a silicon source compound in a solvent to obtain a first mixed solution; B) uniformly mixing the first mixed solution with heteropoly acid and organic compounds with sulfonic acid groups to obtain a second mixed solution; C) removing the solvent from the second mixed solution to obtain gel; D) and (4) carrying out aging treatment on the gel, and roasting to remove the template agent to obtain the catalyst. The invention adopts the supported composite acid catalyst to synthesize pentaerythritol tetra (3-mercaptobutanoic acid) ester, replaces inorganic acid and organic acid catalysts, has higher acidity and catalytic activity, can improve esterification efficiency, shortens reaction time, can be repeatedly used, and is more environment-friendly and economical.)

1. A preparation method of pentaerythritol ester comprises the following steps:

pentaerythritol and 3-mercaptobutyric acid are subjected to esterification reaction under the action of a catalyst to generate pentaerythritol tetra (3-mercaptobutyric acid) ester;

the catalyst is prepared according to the following method:

A) uniformly mixing a template agent and a titanium source compound or a silicon source compound in a solvent to obtain a first mixed solution;

B) uniformly mixing the first mixed solution with heteropoly acid and organic compounds with sulfonic acid groups to obtain a second mixed solution;

C) removing the solvent from the second mixed solution to obtain gel;

D) and (3) aging the gel, and then baking to remove the template agent to obtain the catalyst.

2. The method of claim 1, wherein the templating agent is p 123;

the titanium source compound is isopropyl titanate or n-butyl titanate;

the silicon source compound is tetraethoxysilane;

the heteropoly acid is H₃PW₁₂O₄₀、H₄PW₁₁O₄₀、H₄SiW₁₂O₄₀And H₃PMo₁₂O₄₀One or more of;

the organic compound with the sulfonic acid group is one or more of methanesulfonic acid, sulfamic acid and p-toluenesulfonic acid.

3. The production method according to claim 1, wherein the mass ratio of the template to the titanium source compound or the silicon source compound, the heteropoly acid, and the organic compound having a sulfonic acid group is (0.5-2): 5-12): (1-5):(1-3).

4. The method according to claim 1, wherein the solvent of step a) is an alcohol solvent or a nitrile solvent.

5. The process according to claim 1, wherein the removal of the solvent in step C) is in particular:

the solvent was evaporated at 40 ℃.

6. The preparation method according to claim 1, wherein in the step D), the aging temperature is 100 ℃, and the aging time is 10-14 h.

7. The preparation method according to claim 1, wherein in the step D), the roasting temperature is 350-400 ℃, and the roasting time is 1-3 h.

8. The method as claimed in claim 1, wherein the catalyst has a particle size of 3-5nm and a specific surface area of 180-250m²/g。

9. The preparation method according to claim 1, wherein the temperature of the esterification reaction is 70 to 140 ℃ and the time of the esterification reaction is 2 to 7 hours.

10. The production method according to claim 1, characterized in that the mass ratio of the catalyst to the total mass of pentaerythritol and 3-mercaptobutanoic acid is 0.5% to 3%.

Technical Field

The invention relates to the technical field of chemical synthesis, in particular to a preparation method of pentaerythritol ester.

Background

The light curing technology is known as a 'green' technology, and a mercapto-alkene light curing system is widely applied to the fields of paint, adhesive, photoresist, photosensitive materials, 3D printing and the like. The addition of sulfydryl can effectively solve the problem of surface oxygen inhibition of the traditional acrylate system. However, all the currently used hydrosulfur monomers are primary mercaptan, and the problems of poor storage stability, large odor and the like exist.

Pentaerythritol tetra (3-mercaptobutanoic acid) ester is an important chemical and organic synthesis intermediate, has low odor, and can form a high-stability mercapto-alkene formula. The UV curing adhesive is mainly applied to UV curing adhesives, UV printing ink, epoxy curing agents and the like.

At present, pentaerythritol tetra (3-mercaptobutanoic acid) ester is generally prepared by esterification of pentaerythritol and mercaptobutanoic acid under the action of a catalyst. The reaction equation is as follows:

the catalyst commonly used in the above reaction is an inorganic acid or an organic acid. The inorganic acid has the advantages of low price and high activity, but reaction equipment is easy to corrode in the synthesis process, byproducts are more, and a large amount of waste acid is generated to pollute the environment. Although the organic acid catalyst such as p-toluenesulfonic acid does not corrode equipment and has small pollution to the environment, the organic acid catalyst belongs to homogeneous reaction, the catalyst is difficult to recycle, and the post-treatment difficulty of the product is large.

In addition, the yield of the reaction is low, and the requirement of industrial application is difficult to achieve.

Disclosure of Invention

In view of the above, the technical problem to be solved by the present invention is to provide a method for preparing pentaerythritol ester, which has high yield and purity.

The invention provides a preparation method of pentaerythritol ester, which comprises the following steps:

pentaerythritol and 3-mercaptobutyric acid are subjected to esterification reaction under the action of a catalyst to generate pentaerythritol tetra (3-mercaptobutyric acid) ester;

the catalyst is prepared according to the following method:

A) uniformly mixing a template agent and a titanium source compound or a silicon source compound in a solvent to obtain a first mixed solution;

B) uniformly mixing the first mixed solution with heteropoly acid and organic compounds with sulfonic acid groups to obtain a second mixed solution;

C) removing the solvent from the second mixed solution to obtain gel;

D) and (3) aging the gel, and then baking to remove the template agent to obtain the catalyst.

The supported composite acid catalyst prepared by the method is used for synthesizing pentaerythritol tetra (3-mercaptobutanoic acid) ester and has higher catalytic activity.

In the invention, the template agent adopted by the synthetic catalyst is P123.

The titanium source compound is preferably isopropyl titanate or n-butyl titanate.

The silicon source compound is preferably ethyl orthosilicate.

The solvent of step a) is preferably an alcohol solvent or a nitrile solvent, and more preferably methanol, ethanol or acetonitrile.

And (3) mixing the template agent and the titanium source compound or the silicon source compound in a solvent, and preferably stirring for 1-3 hours.

And then uniformly mixing the first mixed solution with heteropoly acid and organic compound with sulfonic acid groups.

The heteropoly acid is preferably H₃PW₁₂O₄₀、H₄PW₁₁O₄₀、H₄SiW₁₂O₄₀And H₃PMo₁₂O₄₀One or more of (a).

The organic compound having a sulfonic acid group is preferably one or more of methanesulfonic acid, sulfamic acid and p-toluenesulfonic acid.

The mass ratio of the template agent to the titanium source compound or the silicon source compound, the heteropoly acid and the organic compound with the sulfonic acid group is (0.5-2) to (5-12): (1-5): 1-3, more preferably (0.5-1): 5-10): (1-3):(1-2).

And after uniform mixing, preferably stirring for 0.5-1.5 h.

The solvent was then removed to give a gel.

In the present invention, the solvent is preferably removed by volatilization under the condition that the temperature of the system is raised to 40 ℃.

The volatilization time is preferably 10-14 h, and more preferably 12 h.

The gel is then subjected to an aging treatment.

The temperature of the aging treatment is preferably 100 ℃, and the time of the aging treatment is preferably 10-14 h, and more preferably 12 h.

Then roasting to remove the template agent, thus obtaining the catalyst.

The roasting temperature is preferably 350-400 ℃, and the roasting time is preferably 1-3 h, and more preferably 2 h.

The catalyst prepared by the invention is heteropoly acid-sulfonic acid compound/mesoporous TiO₂(SiO₂) The supported composite acid catalyst has a high specific surface area. Preferably, the particle size of the catalyst is 3-5nm, the specific surface area is 180-250m²/g。

The catalyst can be repeatedly recycled, is easy to recycle and separate, and has higher catalytic activity in the practical application process.

Pentaerythritol and 3-mercaptobutyric acid are subjected to esterification reaction under the action of the catalyst to generate pentaerythritol tetra (3-mercaptobutyric acid) ester.

In some embodiments of the present invention, the preparation method specifically comprises:

pentaerythritol and 3-mercaptobutyric acid are added into a four-neck flask provided with a mechanical stirrer, a thermometer, a reflux condenser and a water separator, and the prepared supported composite acid catalyst is used for esterification.

The temperature of the esterification reaction is preferably 70-140 ℃, the further preferable temperature is 80-120 ℃, and the time of the esterification reaction is preferably 2-7 h, the further preferable time is 4-6 h.

The mass ratio of the 3-mercaptobutyric acid to pentaerythritol is preferably 4.0-8.0, and more preferably 4.5-6.0.

In the present invention, the mass ratio of the catalyst to the total mass of pentaerythritol and 3-mercaptobutyric acid is preferably 0.5% to 3%, and more preferably 1% to 2%.

In the present invention, preferably, the esterification reaction is carried out simultaneously with the refluxing water separation.

Preferably, in the reaction process, the reaction system further comprises: water-carrying agent and antioxidant.

The water-carrying agent is preferably one or a mixture of cyclohexane, toluene, methylcyclohexane, dichloromethane and the like.

The antioxidant is preferably 1010 and/or 1076.

Preferably, after the reaction is finished, placing the mixture after the reaction in a separating funnel, and standing for layering; extracting the lower crude product by using a solvent, and concentrating an extract phase to remove the solvent to obtain pentaerythritol tetra (3-mercaptobutanoic acid) ester.

Preferably, after layering, the water-carrying agent is recovered for reuse.

The concentration is preferably concentration by distillation under reduced pressure.

The temperature of the reduced pressure distillation is preferably 50-80 ℃, and the time of the reduced pressure distillation is preferably 1-4 h.

The solvent used for extraction is preferably an ether solvent or an alcohol solvent, and more preferably absolute methanol, absolute ethanol or absolute ethyl ether.

The invention also protects the catalyst.

Compared with the prior art, the invention provides a preparation method of pentaerythritol ester, which comprises the following steps: pentaerythritol and 3-mercaptobutyric acid are subjected to esterification reaction under the action of a catalyst to generate pentaerythritol tetra (3-mercaptobutyric acid) ester; the catalyst is prepared according to the following method: A) uniformly mixing a template agent and a titanium source compound or a silicon source compound in a solvent to obtain a first mixed solution; B) uniformly mixing the first mixed solution with heteropoly acid and organic compounds with sulfonic acid groups to obtain a second mixed solution; C) removing the solvent from the second mixed solution to obtain gel; D) and (3) aging the gel, and then baking to remove the template agent to obtain the catalyst. The invention adopts the supported composite acid catalyst to synthesize pentaerythritol tetra (3-mercaptobutanoic acid) ester, replaces the traditional inorganic acid and organic acid catalysts, has higher acidity and catalytic activity, can improve esterification efficiency, shortens reaction time, can be repeatedly used, is more environment-friendly and economic, and is suitable for large-scale industrial production.

Drawings

FIG. 1 is a nuclear magnetic hydrogen spectrum of pentaerythritol ester prepared according to the present invention.

Detailed Description

To further illustrate the present invention, the following examples are given to describe the preparation of pentaerythritol esters according to the present invention in detail.