阅读说明：本技术 一种季戊四醇四（3-巯基丙酸）酯的制备方法 (Preparation method of pentaerythritol tetra (3-mercaptopropionate) ) 是由 孙志利 梁万根 张超 崔卫华 费潇瑶 袁新洁 任永平 周芳晶 江德阳 于 2019-09-23 设计创作，主要内容包括：本发明提供了一种季戊四醇四(3-巯基丙酸)酯的制备方法,包括以下步骤：a)将季戊四醇、巯基丙酸、甲基磺酸和复合吸水剂混合,进行反应,直至巯基丙酸反应剩余1wt％以下视为反应终点,得到反应混合物；所述复合吸水剂由4A分子筛、吸水硅胶和吸水树脂组成；b)将步骤a)得到的反应混合物进行真空抽滤,分别得到使用后的复合吸水剂和反应粗品；c)将步骤b)得到的反应粗品依次进行洗涤、液液分离、脱水和过滤,得到季戊四醇四(3-巯基丙酸)酯。与现有技术相比,本发明采用特定组分的复合吸水剂,在特定步骤及各步骤条件下进行季戊四醇四(3-巯基丙酸)酯的合成,能够在不影响产品品质的基础上,提高除水效率,从而加快反应速度。(The invention provides a preparation method of pentaerythritol tetra (3-mercaptopropionate), which comprises the following steps: a) mixing pentaerythritol, mercaptopropionic acid, methanesulfonic acid and a composite water absorbent, and reacting until less than 1 wt% of the remaining mercaptopropionic acid is regarded as a reaction end point to obtain a reaction mixture; the composite water absorbent consists of a 4A molecular sieve, water-absorbing silica gel and water-absorbing resin; b) carrying out vacuum filtration on the reaction mixture obtained in the step a) to respectively obtain a used composite water absorbent and a reaction crude product; c) and c) washing, liquid-liquid separation, dehydration and filtration are sequentially carried out on the reaction crude product obtained in the step b), so as to obtain pentaerythritol tetra (3-mercaptopropionate). Compared with the prior art, the synthesis method adopts the composite water absorbent with specific components, and the synthesis of pentaerythritol tetra (3-mercaptopropionic acid) ester is carried out under specific steps and various step conditions, so that the water removal efficiency can be improved on the basis of not influencing the product quality, and the reaction speed is accelerated.)

1. A preparation method of pentaerythritol tetra (3-mercaptopropionate) ester comprises the following steps:

a) mixing pentaerythritol, mercaptopropionic acid, methanesulfonic acid and a composite water absorbent, and reacting until less than 1 wt% of the remaining mercaptopropionic acid is regarded as a reaction end point to obtain a reaction mixture; the composite water absorbent consists of a 4A molecular sieve, water-absorbing silica gel and water-absorbing resin;

b) carrying out vacuum filtration on the reaction mixture obtained in the step a) to respectively obtain a used composite water absorbent and a reaction crude product;

c) and c) washing, liquid-liquid separation, dehydration and filtration are sequentially carried out on the reaction crude product obtained in the step b), so as to obtain pentaerythritol tetra (3-mercaptopropionate).

2. The preparation method according to claim 1, wherein the mass ratio of the pentaerythritol, the mercaptopropionic acid, the methanesulfonic acid and the composite water absorbent in step a) is (65-70): (200-230): (2-3.5): (10-30).

3. The production method according to claim 1, wherein the mass ratio of the 4A molecular sieve, the water-absorbing silica gel and the water-absorbing resin in the composite water-absorbing agent in step a) is 4: (3-8): (2-8).

4. The process according to claim 1, wherein the reaction in step a) is carried out under stirring; the stirring speed is 50 r/min-150 r/min; the reaction temperature is 70-90 ℃.

5. The preparation method according to claim 1, wherein the vacuum filtration in step b) is specifically performed by:

and transferring the reaction mixture into a Buchner funnel connected with a filter flask, carrying out suction filtration by vacuumizing, wherein medium-speed filter paper is adopted as the filter paper, the negative pressure is below-0.05 MPa, and the filter paper is maintained for 5-25 min after the suction filtration is finished so as to ensure that the product on the surface of the composite water absorbent is completely removed, and respectively obtain the used composite water absorbent and a reaction crude product.

6. The method according to claim 1, wherein the washing in step c) is performed by:

adding 0.5-1.5 times of water into the reaction crude product, heating to 50-70 ℃, stirring for 20-40 min, and washing.

7. The preparation method of claim 1, wherein the dehydration in step c) is carried out at 60-90 ℃, under a pressure of-0.095 MPa or less, and for 1.5-3 h.

8. The production method according to any one of claims 1 to 7, further comprising:

and (4) performing regeneration treatment on the used composite water absorbent.

9. The preparation method according to claim 8, wherein the regeneration treatment is carried out by:

transferring the used composite water absorbent into a glass tube with the diameter of 1-3 cm and the length of 4-6 cm and provided with a sand core at the bottom, introducing nitrogen at the temperature of 130-180 ℃ at the bottom, controlling the flow at 0.5-2L/min, keeping for 60-90 min, and dehydrating and regenerating to obtain the regenerated composite water absorbent.

Technical Field

The invention relates to the technical field of pentaerythritol tetra (3-mercaptopropionic acid) ester, and more specifically relates to a preparation method of pentaerythritol tetra (3-mercaptopropionic acid) ester.

Background

Pentaerythritol tetra (3-mercaptopropionic acid) ester is mainly used as an intermediate for organic synthesis, a modifier, a cross-linking agent, an acidic ion exchange catalyst, a low-temperature curing agent and the like in polymerization reactions of UV coatings, inks, adhesives and the like.

Pentaerythritol tetra (3-mercaptopropionic acid) ester is usually produced by esterification synthesis of raw materials pentaerythritol and mercaptopropionic acid in the presence of a catalyst, wherein the catalyst mainly comprises sulfuric acid and sulfonic acid; the water generated in the reaction needs to be removed from the reaction system to ensure that the esterification reaction is carried out in the esterification direction, and the removal of the water is carried out by adopting an azeotropic water-carrying agent. The process has the problem of low water removal efficiency and slow reaction speed, and mainly has the following two reasons: (1) pentaerythritol is tetrahydric alcohol, mercaptopropionic acid has higher molecular weight, and particularly, the generated product has higher steric hindrance, so that the reaction speed is slower; (2) generally, water has a certain solubility in a general water-carrying agent, and the water-carrying agent and the water have an entrainment phenomenon, so that the water is difficult to be quickly separated from the water-carrying agent, the system contains more water, particularly, in the later reaction period, even if trace water exists in the system, the reaction is difficult to be carried out, the reaction time is long, the energy consumption is increased, and meanwhile, side reactions are caused, so that the product quality is influenced.

Disclosure of Invention

In view of the above, the present invention provides a method for preparing pentaerythritol tetrakis (3-mercaptopropionate), which has high water removal efficiency and high reaction speed on the basis of not affecting the product quality.

The invention provides a preparation method of pentaerythritol tetra (3-mercaptopropionate), which comprises the following steps:

a) mixing pentaerythritol, mercaptopropionic acid, methanesulfonic acid and a composite water absorbent, and reacting until less than 1 wt% of the remaining mercaptopropionic acid is regarded as a reaction end point to obtain a reaction mixture; the composite water absorbent consists of a 4A molecular sieve, water-absorbing silica gel and water-absorbing resin;

b) carrying out vacuum filtration on the reaction mixture obtained in the step a) to respectively obtain a used composite water absorbent and a reaction crude product;

c) and c) washing, liquid-liquid separation, dehydration and filtration are sequentially carried out on the reaction crude product obtained in the step b), so as to obtain pentaerythritol tetra (3-mercaptopropionate).

Preferably, the mass ratio of the pentaerythritol, the mercaptopropionic acid, the methanesulfonic acid and the composite water absorbent in the step a) is (65-70): (200-230): (2-3.5): (10-30).

Preferably, the mass ratio of the 4A molecular sieve, the water-absorbing silica gel and the water-absorbing resin in the composite water absorbent in the step a) is 4: (3-8): (2-8).

Preferably, the course of the reaction in step a) is carried out with stirring; the stirring speed is 50 r/min-150 r/min; the reaction temperature is 70-90 ℃.

Preferably, the vacuum filtration process in the step b) specifically comprises:

and transferring the reaction mixture into a Buchner funnel connected with a filter flask, carrying out suction filtration by vacuumizing, wherein medium-speed filter paper is adopted as the filter paper, the negative pressure is below-0.05 MPa, and the filter paper is maintained for 5-25 min after the suction filtration is finished so as to ensure that the product on the surface of the composite water absorbent is completely removed, and respectively obtain the used composite water absorbent and a reaction crude product.

Preferably, the washing process in step c) is specifically:

adding 0.5-1.5 times of water into the reaction crude product, heating to 50-70 ℃, stirring for 20-40 min, and washing.

Preferably, the dehydration temperature in the step c) is 60-90 ℃, the pressure is less than or equal to-0.095 MPa, and the time is 1.5-3 h.

Preferably, the method further comprises the following steps:

and (4) performing regeneration treatment on the used composite water absorbent.

Preferably, the regeneration treatment process specifically comprises:

transferring the used composite water absorbent into a glass tube with the diameter of 1-3 cm and the length of 4-6 cm and provided with a sand core at the bottom, introducing nitrogen at the temperature of 130-180 ℃ at the bottom, controlling the flow at 0.5-2L/min, keeping for 60-90 min, and dehydrating and regenerating to obtain the regenerated composite water absorbent.

The invention provides a preparation method of pentaerythritol tetra (3-mercaptopropionate), which comprises the following steps: a) mixing pentaerythritol, mercaptopropionic acid, methanesulfonic acid and a composite water absorbent, and reacting until less than 1 wt% of the remaining mercaptopropionic acid is regarded as a reaction end point to obtain a reaction mixture; the composite water absorbent consists of a 4A molecular sieve, water-absorbing silica gel and water-absorbing resin; b) carrying out vacuum filtration on the reaction mixture obtained in the step a) to respectively obtain a used composite water absorbent and a reaction crude product; c) and c) washing, liquid-liquid separation, dehydration and filtration are sequentially carried out on the reaction crude product obtained in the step b), so as to obtain pentaerythritol tetra (3-mercaptopropionate). Compared with the prior art, the synthesis method adopts the composite water absorbent with specific components, and the synthesis of pentaerythritol tetra (3-mercaptopropionic acid) ester is carried out under specific steps and various step conditions, so that the water removal efficiency can be improved on the basis of not influencing the product quality, and the reaction speed is accelerated. Experimental results show that the purity of pentaerythritol tetra (3-mercaptopropionic acid) ester obtained by the preparation method provided by the invention is over 99%, and the reaction time is not more than 5 h.

In addition, the composite water absorbent with specific components used in the preparation method provided by the invention is easy to regenerate, and the regenerated composite water absorbent also has a good water absorption effect and high water removal efficiency.

Detailed Description

The technical solutions of the present invention will be described clearly and completely with reference to the following embodiments of the present invention, and it should be understood that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The invention provides a preparation method of pentaerythritol tetra (3-mercaptopropionate), which comprises the following steps:

a) mixing pentaerythritol, mercaptopropionic acid, methanesulfonic acid and a composite water absorbent, and reacting until less than 1 wt% of the remaining mercaptopropionic acid is regarded as a reaction end point to obtain a reaction mixture; the composite water absorbent consists of a 4A molecular sieve, water-absorbing silica gel and water-absorbing resin;

b) carrying out vacuum filtration on the reaction mixture obtained in the step a) to respectively obtain a used composite water absorbent and a reaction crude product;

c) and c) washing, liquid-liquid separation, dehydration and filtration are sequentially carried out on the reaction crude product obtained in the step b), so as to obtain pentaerythritol tetra (3-mercaptopropionate).

The method comprises the steps of mixing pentaerythritol, mercaptopropionic acid, methanesulfonic acid and a composite water absorbent, reacting until the residual 1 wt% of the mercaptopropionic acid is regarded as a reaction end point, and obtaining a reaction mixture. In the present invention, pentaerythritol and mercaptopropionic acid are main raw materials for preparing pentaerythritol tetrakis (3-mercaptopropionic acid) ester, and methanesulfonic acid is a catalyst, and the sources of pentaerythritol, mercaptopropionic acid and methanesulfonic acid are not particularly limited; wherein the methanesulfonic acid is preferably added in the form of an aqueous solution; the concentration of the aqueous solution of methanesulfonic acid is preferably 60 wt% to 80 wt%, more preferably 70 wt%.

In the invention, the composite water absorbent consists of a 4A molecular sieve, water-absorbing silica gel and water-absorbing resin; the mass ratio of the 4A molecular sieve to the water-absorbing silica gel to the water-absorbing resin in the composite water absorbent is preferably 4: (3-8): (2-8); in a preferred embodiment of the present invention, the mass ratio of the 4A molecular sieve, the water-absorbing silica gel and the water-absorbing resin in the composite water-absorbing agent is 4: 3: 2; in another preferred embodiment of the present invention, the mass ratio of the 4A molecular sieve, the water-absorbing silica gel and the water-absorbing resin in the composite water-absorbing agent is 4: 8: 8.

the sources of the 4A molecular sieve, the water-absorbing silica gel and the water-absorbing resin are not particularly limited in the present invention, and commercially available products or self-products known to those skilled in the art can be used. In a preferred embodiment of the present invention, the preparation method of the 4A molecular sieve specifically comprises:

roasting quantitative kaolin for 4-7 h at 400-800 ℃, then uniformly mixing with sodium hydroxide and water according to a certain proportion, and extruding into strips with the diameter of 3-5 mm; and drying the strips, roasting for 2-3 h at 500-700 ℃, cooling, adsorbing the strips to saturation with water vapor, immersing the strips into a 30 wt% sodium hydroxide solution at 80-110 ℃ for reaction for 2-5 h, washing with pure water to neutrality, and drying to obtain the 4A molecular sieve.

The composite water absorbent provided by the invention adopts the components with specific contents, has a good water absorption effect aiming at the reaction, and can quickly absorb the water generated by the reaction, so that the reaction can be quickly completed.

In the invention, the mass ratio of the pentaerythritol, the mercaptopropionic acid, the methanesulfonic acid and the composite water absorbent is preferably (65-70): (200-230): (2-3.5): (10-30), more preferably 68.8: 214.1: 2.83: (10-20).

The mixing apparatus of the present invention is not particularly limited, and a 500mL four-neck flask equipped with a mechanical stirrer and a thermometer, which are well known to those skilled in the art, may be used.

In the present invention, the course of the reaction is preferably carried out with stirring; the rotation speed of the stirring is preferably 50r/min to 150r/min, and more preferably 100 r/min. In the present invention, the temperature of the reaction is preferably 70 to 90 ℃, more preferably 80 ℃; preferably by an oil bath.

In the invention, the reaction is regarded as the end point of the reaction until the remaining 1 wt% (liquid phase normalized content) of the mercaptopropionic acid reaction is below; the progress of the reaction is followed in particular by liquid chromatography.

After the reaction mixture is obtained, the obtained reaction mixture is subjected to vacuum filtration to respectively obtain the used composite water absorbent and a reaction crude product. In the present invention, the vacuum filtration process preferably includes:

transferring the reaction mixture into a Buchner funnel connected with a filter flask, carrying out suction filtration by vacuumizing, wherein medium-speed filter paper is adopted as the filter paper, the negative pressure is below-0.05 MPa, and the filter paper is maintained for 5-25 min after the suction filtration is finished so as to ensure that the product on the surface of the composite water absorbent is completely removed, and respectively obtaining the used composite water absorbent and a reaction crude product;

more preferably:

transferring the reaction mixture into a Buchner funnel connected with a filter flask, carrying out suction filtration by vacuumizing, wherein medium-speed filter paper is adopted as the filter paper, the negative pressure is below-0.09 MPa, and the filter paper is maintained for 10-20 min after the suction filtration is finished so as to ensure that the product on the surface of the composite water absorbent is completely removed, and respectively obtaining the used composite water absorbent and a reaction crude product.

After obtaining the used composite water absorbing agent, the present invention preferably further includes:

and (4) performing regeneration treatment on the used composite water absorbent. In the present invention, the regeneration treatment process is preferably specifically:

transferring the used composite water absorbent into a glass tube with the diameter of 1-3 cm and the length of 4-6 cm and provided with a sand core at the bottom, introducing nitrogen at the temperature of 130-180 ℃ at the bottom, controlling the flow at 0.5-2L/min, keeping for 60-90 min, and dehydrating and regenerating to obtain a regenerated composite water absorbent;

more preferably:

transferring the used composite water absorbent into a glass tube with the diameter of 2cm and the length of 5cm and a sand core at the bottom, introducing nitrogen at the temperature of 150-160 ℃ at the bottom, controlling the flow at 1-1.5L/min, keeping for 70-80 min, and dehydrating and regenerating to obtain the regenerated composite water absorbent.

The composite water absorbent with specific components used in the preparation method provided by the invention is easy to regenerate, and the regenerated composite water absorbent also has a good water absorption effect and high water removal efficiency.

Meanwhile, after the reaction crude product is obtained, the obtained reaction crude product is sequentially washed, subjected to liquid-liquid separation, dehydrated and filtered to obtain pentaerythritol tetra (3-mercaptopropionate). In the present invention, the washing process is preferably specifically:

adding 0.5-1.5 times of water into the reaction crude product, heating to 50-70 ℃, stirring for 20-40 min, and washing;

more preferably:

adding 1 time of water into the crude reaction product, heating to 60 ℃, stirring for 30min, and washing.

The catalyst methanesulfonic acid can be removed through the washing process, and the methanesulfonic acid is removed through subsequent liquid-liquid separation. The liquid-liquid separation device of the present invention is not particularly limited, and a separatory funnel well known to those skilled in the art may be used.

In the present invention, the temperature of the dehydration is preferably 60 ℃ to 90 ℃, more preferably 80 ℃; the pressure of the dehydration is preferably less than or equal to-0.095 MPa, more preferably less than or equal to-0.098 MPa; the time for dehydration is preferably 1.5 to 3 hours, more preferably 2 hours.

The present invention is not particularly limited to the filtration, and the object is to further obtain a pentaerythritol tetrakis (3-mercaptopropionate) refined product. The preparation method provided by the invention has simple post-treatment, can improve the atom utilization rate of the raw materials due to the early reaction, and completely reacts over 99.5 percent of mercaptopropionic acid, so that the post-treatment process can be simplified, and the catalyst is removed by adopting one-time water washing.

The invention adopts the composite water absorbent with specific components, and the synthesis of pentaerythritol tetra (3-mercaptopropionic acid) ester is carried out under specific steps and conditions of each step, so that the water removal efficiency can be improved on the basis of not influencing the product quality, and the reaction speed is accelerated.

The invention provides a preparation method of pentaerythritol tetra (3-mercaptopropionate), which comprises the following steps: a) mixing pentaerythritol, mercaptopropionic acid, methanesulfonic acid and a composite water absorbent, and reacting until less than 1 wt% of the remaining mercaptopropionic acid is regarded as a reaction end point to obtain a reaction mixture; the composite water absorbent consists of a 4A molecular sieve, water-absorbing silica gel and water-absorbing resin; b) carrying out vacuum filtration on the reaction mixture obtained in the step a) to respectively obtain a used composite water absorbent and a reaction crude product; c) and c) washing, liquid-liquid separation, dehydration and filtration are sequentially carried out on the reaction crude product obtained in the step b), so as to obtain pentaerythritol tetra (3-mercaptopropionate). Compared with the prior art, the synthesis method adopts the composite water absorbent with specific components, and the synthesis of pentaerythritol tetra (3-mercaptopropionic acid) ester is carried out under specific steps and various step conditions, so that the water removal efficiency can be improved on the basis of not influencing the product quality, and the reaction speed is accelerated. Experimental results show that the purity of pentaerythritol tetra (3-mercaptopropionic acid) ester obtained by the preparation method provided by the invention is over 99%, and the reaction time is not more than 5 h.

In addition, the composite water absorbent with specific components used in the preparation method provided by the invention is easy to regenerate, and the regenerated composite water absorbent also has a good water absorption effect and high water removal efficiency.

To further illustrate the present invention, the following examples are provided for illustration.