阅读说明：本技术 一种利用微通道反应器连续反应生产聚硫醇的方法 (Method for producing polythiol by using microchannel reactor through continuous reaction ) 是由 许倩倩 梁万根 张超 孙志利 崔卫华 费潇瑶 周芳晶 于 2019-12-03 设计创作，主要内容包括：本发明提供了一种利用微通道反应器连续生产聚硫醇的方法,包括：S1)将巯基醇类化合物与碱溶液在第一微通道反应器中搅拌混合,得到均相混合液；S2)将所述均相混合液通入第二微通道反应器中与表氯醇进行反应,得到硫代多元醇溶液；S3)将所述硫代多元醇溶液通入第三微通道反应器中与硫脲的酸性溶液进行反应,得到异硫脲盐溶液；S4)将所述异硫脲盐溶液通入第四微通道反应器中与碱解试剂进行反应,得到聚硫醇。与现有技术相比,本发明利用微通道反应器进行连续生产,传质传热效果好,能够精确控制反应温度,有效抑制了杂质的生成,缩短了反应时间,进一步降低了副反应的发生,提高了产品的品质,进一步提高了下游产品的纯度。(The invention provides a method for continuously producing polythiol by using a microchannel reactor, which comprises the following steps: s1) stirring and mixing the thiol alcohol compound and the alkali solution in a first microchannel reactor to obtain homogeneous mixed solution; s2) introducing the homogeneous mixed solution into a second microchannel reactor to react with epichlorohydrin to obtain a thiopolyol solution; s3) introducing the thiopolyol solution into a third microchannel reactor to react with an acid solution of thiourea to obtain an isothiourea salt solution; s4) introducing the isothiourea salt solution into a fourth microchannel reactor to react with an alkaline hydrolysis reagent to obtain polythiol. Compared with the prior art, the invention utilizes the microchannel reactor to carry out continuous production, has good mass and heat transfer effects, can accurately control the reaction temperature, effectively inhibits the generation of impurities, shortens the reaction time, further reduces the occurrence of side reactions, improves the quality of products and further improves the purity of downstream products.)

1. A method for continuously producing polythiol by using a microchannel reactor, comprising:

s1) stirring and mixing the thiol alcohol compound and the alkali solution in a first microchannel reactor to obtain homogeneous mixed solution;

s2) introducing the homogeneous mixed solution into a second microchannel reactor to react with epichlorohydrin to obtain a thiopolyol solution;

s3) introducing the thiopolyol solution into a third microchannel reactor to react with an acid solution of thiourea to obtain an isothiourea salt solution;

s4) introducing the isothiourea salt solution into a fourth microchannel reactor to react with an alkaline hydrolysis reagent to obtain polythiol.

2. The method according to claim 1, wherein the molar ratio of epichlorohydrin, thiol-based alcohol compound and alkali in the alkali solution in step S1) is 1: (1.92-1.99): (1.1-1.5).

3. The method as claimed in claim 1, wherein the temperature of the reaction in the step S2) is 30-60 ℃; the reaction pressure is 0.1-1.3 MPa; the reaction time is 10-60 s.

4. The method as claimed in claim 1, wherein the temperature of the reaction in the step S2) is 45-55 ℃; the reaction pressure is 0.3-0.8 MPa; the reaction time is 20-40 s.

5. The method as claimed in claim 1, wherein the temperature of the reaction in the step S3) is 80-120 ℃; the reaction pressure is 0.1-1.0 MPa; the reaction time is 20-80 s.

6. The method as claimed in claim 1, wherein the temperature of the reaction in the step S3) is 95-115 ℃; the reaction pressure is 0.4-0.7 MPa; the reaction time is 40-60 s.

7. The method as claimed in claim 1, wherein the temperature of the reaction in the step S4) is 45-65 ℃; the reaction pressure is 0.2-0.9 MPa; the reaction time is 10-80 s.

8. The method as claimed in claim 1, wherein the temperature of the reaction in the step S4) is 50-60 ℃; the reaction pressure is 0.3-0.6 MPa; the reaction time is 30-70 s.

9. The method according to claim 1, wherein the pH value of the acidic solution of thiourea in the step S3) is 0.8-1.5; the mole ratio of epichlorohydrin to thiourea is 1: (3-7).

10. The method according to claim 1, wherein the alkaline hydrolysis reagent in step S4) is selected from one or more of ammonia gas, ammonia water, organic amines, potassium hydroxide and sodium hydroxide; the mole ratio of the epichlorohydrin to the alkaline hydrolysis reagent is 1: (4-7); the mercaptoalcohol compound is one or more of mercaptoethanol, 3-mercaptopropanol and 6-mercapto-1-hexanol.

Technical Field

The invention belongs to the technical field of organic synthesis, and particularly relates to a method for continuously producing polythiol by using a microchannel reactor.

Background

Compared with inorganic glass, the optical resin has obvious superiority in the aspect of applying glasses, is light and not easy to damage, can be dyed, and is a key direction for the development in recent years. At present, the common optical resin materials in the market are mainly polythiourethane resins, and the refractive index of the resins is obviously higher than that of other resins in the market, so that the preparation of the optical resin by using mercaptan as a raw material becomes one of the important points of research and development. Because various indexes of the resin, such as yellow index, water content, content and the like, directly determine the excellent performance of downstream materials, the synthesis of high-quality polythiol is very important.

The main methods for synthesizing thiols are as follows: (1) the olefin and hydrogen sulfide reaction method is a main method for preparing alkyl mercaptan, but the synthesis environment needs high temperature and high pressure, and simultaneously a supported catalyst needs to be added, so that the requirements on equipment and the catalyst are high; (2) halogenated hydrocarbon and sodium hydrosulfide are reacted, the method is easy to generate by-products such as thioether and the like, and the product quality is influenced; (3) the thioacid method, i.e. the method in which a halogenated hydrocarbon is first reacted with thioacid to form thiol ester and then hydrolyzed to thiol under acid-base conditions, is not high in yield; (4) the thiourea method is the most common method at present, the reaction condition is mild and stable, but the temperature in the experimental process is difficult to control and the reaction time is long, so that certain impurities are easily generated, and the subsequent performance evaluation of the product is influenced. Therefore, it is important to improve the quality of the product by controlling the reaction time and reaction impurities.

The micro chemical technology is a new green synthesis technology for preparing chemical intermediates such as pesticides, medicines and the like which is emerging in recent years. It is mainly used to strengthen the reaction process by changing the effects of fluid mass and heat transfer. Although the volume is small, the device has great advantages in the aspects of safety control, temperature control, time control and the like.

Thus, the present invention contemplates the preparation of polythiols by microfabrication techniques.

Disclosure of Invention

In view of the above, the present invention provides a method for continuously producing polythiol by using a microchannel reactor, which has short time, less side reactions, and high purity of polythiol.

The invention provides a method for continuously producing polythiol by using a microchannel reactor, which comprises the following steps:

s1) stirring and mixing the thiol alcohol compound and the alkali solution in a first microchannel reactor to obtain homogeneous mixed solution;

s2) introducing the homogeneous mixed solution into a second microchannel reactor to react with epichlorohydrin to obtain a thiopolyol solution;

s3) introducing the thiopolyol solution into a third microchannel reactor to react with an acid solution of thiourea to obtain an isothiourea salt solution;

s4) introducing the isothiourea salt solution into a fourth microchannel reactor to react with an alkaline hydrolysis reagent to obtain polythiol.

Preferably, in the step S1), the molar ratio of the epichlorohydrin to the mercapto alcohol compound to the alkali in the alkali solution is 1: (1.92-1.99): (1.1-1.5).

Preferably, the temperature of the reaction in the step S2) is 30-60 ℃; the reaction pressure is 0.1-1.3 MPa; the reaction time is 10-60 s.

Preferably, the temperature of the reaction in the step S2) is 45-55 ℃; the reaction pressure is 0.3-0.8 MPa; the reaction time is 20-40 s.

Preferably, the reaction temperature in the step S3) is 80-120 ℃; the reaction pressure is 0.1-1.0 MPa; the reaction time is 20-80 s.

Preferably, the temperature of the reaction in the step S3) is 95-115 ℃; the reaction pressure is 0.4-0.7 MPa; the reaction time is 40-60 s.

Preferably, the temperature of the reaction in the step S4) is 45-65 ℃; the reaction pressure is 0.2-0.9 MPa; the reaction time is 10-80 s.

Preferably, the temperature of the reaction in the step S4) is 50-60 ℃; the reaction pressure is 0.3-0.6 MPa; the reaction time is 30-70 s.

Preferably, the pH value of the acidic solution of thiourea in the step S3) is 0.8-1.5; the mole ratio of epichlorohydrin to thiourea is 1: (3-7).

Preferably, the alkaline hydrolysis reagent in step S4) is selected from one or more of ammonia gas, ammonia water, organic amines, potassium hydroxide and sodium hydroxide; the mole ratio of the epichlorohydrin to the alkaline hydrolysis reagent is 1: (4-7); the mercaptoalcohol compound is one or more of mercaptoethanol, 3-mercaptopropanol and 6-mercapto-1-hexanol.

The invention provides a method for continuously producing polythiol by using a microchannel reactor, which comprises the following steps: s1) stirring and mixing the thiol alcohol compound and the alkali solution in a first microchannel reactor to obtain homogeneous mixed solution; s2) introducing the homogeneous mixed solution into a second microchannel reactor to react with epichlorohydrin to obtain a thiopolyol solution; s3) introducing the thiopolyol solution into a third microchannel reactor to react with an acid solution of thiourea to obtain an isothiourea salt solution; s4) introducing the isothiourea salt solution into a fourth microchannel reactor to react with an alkaline hydrolysis reagent to obtain polythiol. Compared with the prior art, the invention utilizes the microchannel reactor to carry out continuous production, has good mass and heat transfer effects, can accurately control the reaction temperature, effectively inhibits the generation of impurities, shortens the reaction time, further reduces the occurrence of side reactions, improves the product quality, further improves the purity of downstream products, simultaneously improves the safety in the reaction process, and has great social and economic benefits.

Drawings

FIG. 1 is a chart of the infrared spectrum of a crude polythiol obtained in example 1 of the invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious 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 method for continuously producing polythiol by using a microchannel reactor, which comprises the following steps: s1) stirring and mixing the thiol alcohol compound and the alkali solution in a first microchannel reactor to obtain homogeneous mixed solution; (ii) a S2) introducing the homogeneous mixed solution into a second microchannel reactor to react with epichlorohydrin to obtain a thiopolyol solution; s3) introducing the thiopolyol solution into a third microchannel reactor to react with an acid solution of thiourea to obtain an isothiourea salt solution; s4) introducing the isothiourea salt solution into a fourth microchannel reactor to react with an alkaline hydrolysis reagent to obtain polythiol.

In the present invention, the sources of all raw materials are not particularly limited, and they may be commercially available.

Stirring and mixing a thiol alcohol compound and an alkali solution in a first microchannel reactor to obtain a homogeneous mixed solution; the mercapto alcohol compound is preferably one or more of mercaptoethanol, 3-mercaptopropanol and 6-mercapto-1-hexanol. (ii) a The alkali solution is preferably one or more of sodium hydroxide solution, potassium hydroxide solution, sodium carbonate and potassium carbonate solution; the concentration of alkali in the alkali solution is preferably 10-20 wt%; the stirring and mixing time is preferably 10-30 s. The mercapto alcohol compound and the alkali solution are subjected to exothermic reaction to form salt, and then are subjected to reaction with epichlorohydrin, so that side reaction is avoided.

Introducing the homogeneous mixed solution into a second microchannel reactor to react with epichlorohydrin to obtain a thiopolyol solution; the mole ratio of the epichlorohydrin, the mercapto alcohol compound and the alkali in the alkali solution is preferably 1: (1.92-1.99): (1.1 to 1.5), more preferably 1: (1.94-1.97): (1.2-1.4), and more preferably 1: (1.95-1.97): (1.2-1.4); the reaction temperature is preferably 30-60 ℃, more preferably 40-55 ℃, and further preferably 45-55 ℃; in some embodiments provided herein, the temperature of the reaction is preferably 45 ℃; in some embodiments provided herein, the temperature of the reaction is preferably 55 ℃; in other embodiments provided herein, the temperature of the reaction is preferably 50 ℃; the pressure of the reaction is preferably 0.1-1.3 MPa, more preferably 0.3-0.8 MPa, and still more preferably 0.4-0.6 MPa; in some embodiments provided herein, the pressure of the reaction is preferably 0.4 MPa; in some embodiments provided herein, the pressure of the reaction is preferably 0.6 MPa; in some embodiments provided herein, the pressure of the reaction is preferably 0.5 MPa; the reaction time is preferably 10-60 s, more preferably 20-40 s, and further preferably 25-40 s; in some embodiments provided herein, the reaction time is preferably 25 s; in some embodiments provided herein, the reaction time is preferably 30 s; in other embodiments provided herein, the reaction time is preferably 40 s. The method ensures that the finally obtained product is the thio-polyol solution by adjusting the proportion of the raw materials and the concentration of reactants, avoids generating solids, ensures that the product can continuously react through a microchannel reactor, and can separate out solids if the concentration of the alkali solution is too high, so that the product cannot be reacted by using a microchannel.

Introducing the thiopolyol solution into a third microchannel reactor to react with an acidic solution of thiourea to obtain an isothiourea salt solution; the acid solution of the thiourea is preferably a strong acid solution, more preferably the pH value of the acid solution is 0.8-1.5, and further preferably the pH value of the acid solution is 1; the acidity of the thiourea acidic solution is preferably provided by one or two of hydrochloric acid, sulfuric acid, phosphoric acid, hydrobromic acid and hydroiodic acid; the molar ratio of epichlorohydrin to thiourea is preferably 1: (3-7), more preferably 1: (3-5), and more preferably 1: (3-4); in some embodiments provided herein, the epichlorohydrin to thiourea molar ratio is preferably 1: 3.5; in some embodiments provided herein, the epichlorohydrin to thiourea molar ratio is preferably 1: 4; in other embodiments provided herein, the epichlorohydrin to thiourea molar ratio is preferably 1: 3; the reaction temperature is preferably 80-120 ℃, more preferably 95-115 ℃, and further preferably 100-110 ℃; in some embodiments provided herein, the temperature of the reaction is preferably 100 ℃; in some embodiments provided herein, the temperature of the reaction is preferably 105 ℃; in other embodiments provided herein, the temperature of the reaction is preferably 110 ℃; the pressure of the reaction is preferably 0.1-1.0 MPa, more preferably 0.4-0.7 MPa, and still more preferably 0.4-0.6 MPa; in some embodiments provided herein, the pressure of the reaction is preferably 0.5 MPa; in some embodiments provided herein, the pressure of the reaction is preferably 0.6 MPa; in other embodiments provided herein, the pressure of the reaction is preferably 0.4 MPa; the reaction time is preferably 20-80 s, more preferably 20-60 s, and further preferably 40-50 s; in some embodiments provided herein, the reaction time is preferably 50 s; in some embodiments provided herein, the reaction time is preferably 40 s; in other embodiments provided herein, the reaction time is preferably 45 s.

Introducing the isothiourea salt solution into a fourth microchannel reactor to react with an alkaline hydrolysis reagent to obtain polythiol; the alkaline hydrolysis reagent is preferably one or more of ammonia gas, ammonia water, potassium hydroxide and sodium hydroxide; the molar ratio of epichlorohydrin to alkaline hydrolysis reagent is preferably 1: (4-7), more preferably 1: (4-6), and more preferably 1: (4.5-6); in some embodiments provided herein, the epichlorohydrin to alkaline hydrolysis agent molar ratio is preferably 1: 4.5; in some embodiments provided herein, the epichlorohydrin to alkaline hydrolysis agent molar ratio is preferably 1: 6; in other embodiments provided herein, the epichlorohydrin to alkaline hydrolysis agent molar ratio is preferably 1: 5.5; the reaction temperature is preferably 45-65 ℃, and more preferably 50-60 ℃; in some embodiments provided herein, the temperature of the reaction is preferably 50 ℃; in some embodiments provided herein, the temperature of the reaction is preferably 55 ℃; in other embodiments provided herein, the temperature of the reaction is preferably 60 ℃; the pressure of the reaction is preferably 0.2-0.9 MPa, more preferably 0.3-0.7 MPa, and still more preferably 0.3-0.6 MPa; in some embodiments provided herein, the pressure of the reaction is preferably 0.6 MPa; in some embodiments provided herein, the pressure of the reaction is preferably 0.3 MPa; in other embodiments provided herein, the pressure of the reaction is preferably 0.5 MPa; the reaction time is preferably 10-80 s, more preferably 20-70 s, and further preferably 30-70 s; in some embodiments provided herein, the reaction time is preferably 70 s; in some embodiments provided herein, the reaction time is preferably 40 s; in other embodiments provided herein, the reaction time is preferably 35 s.

The polythiol can be further purified according to the requirement, so as to further improve the purity of the polythiol.

In the present invention, the method is performed by using a first microchannel reactor, a second microchannel reactor, a third microchannel reactor and a fourth microchannel reactor which are sequentially communicated with each other, and the specific type of the microchannel reactor is not particularly limited, and the microchannel reactor known to those skilled in the art may be used, wherein the first, second, third and fourth are merely used as serial numbers for distinguishing and have no other meaning.

The invention uses the microchannel reactor for continuous production, has good mass and heat transfer effects, can accurately control the reaction temperature, effectively inhibits the generation of impurities, shortens the reaction time, further reduces the occurrence of side reactions, improves the product quality, further improves the purity of downstream products, simultaneously improves the safety in the reaction process, and has great social and economic benefits.

To further illustrate the present invention, a method for continuously producing polythiols by using a microchannel reactor, which is provided by the present invention, is described in detail below with reference to examples.

The reagents used in the following examples are all commercially available.