Efficient environment-friendly production method of diallyl terephthalate and application of diallyl terephthalate to organic optoelectronic device
Through the reaction of dimethyl terephthalate and allyl alcohol in a n-heptane solvent, solid base catalyst and co-catalyst are used to simplify the separation and purification process, and the synthesis of diallyl terephthalate in the prior art was solved. The long reaction cycle, low yield and environmental pollution problems have achieved efficient and environmentally friendly production and are suitable for industrial applications.
Patent Information
- Application Number
- CN202411456464.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-18
- Publication Date
- 2025-01-10
AI Technical Summary
The existing diallyl terephthalate synthesis method has problems such as long reaction cycles, low yields, complex operations, many impurities and serious environmental pollution, making it difficult to achieve industrial production.
The reaction of dimethyl terephthalate and allyl alcohol in a n-heptane solvent was carried out, and the solid base catalyst and co-catalyst were used to carry out continuous and efficient environmentally friendly production through primary and secondary kettle reactors, simplifying the separation and purification process , recycle solvents to avoid the use of dangerous catalysts.
It has achieved efficient and environmentally friendly production of diallyl terephthalate, with a conversion rate of 98%, a selectivity of 90%, a simple and efficient process, safe and environmentally friendly, and has the value of industrial production.
Smart Images
Figure CN119285467A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the field of chemical synthesis, and specifically relates to a high-efficiency and environment-friendly production method of diallyl terephthalate and an application of the same in an organic optoelectronic device. Background Art
[0002] Diallyl terephthalate is an important monomer for synthesizing optical materials. The resin obtained by self-polymerization or copolymerization with other monomers is widely used in the manufacture of optical lenses, optical discs, optical fibers, optoelectronic devices, etc.
[0003] There are few documents on the synthesis of diallyl terephthalate. One of the public methods is to use benzene or toluene as a water-carrying agent and to use concentrated sulfuric acid to catalyze the reaction of terephthalic acid and allyl alcohol to prepare the target product. The second method is to react sodium terephthalate with allyl chloride in the presence of CuCl. However, in the direct esterification method, benzene or toluene azeotropes with water and allyl alcohol, and allyl alcohol accounts for a large proportion of the azeotropes, and allyl alcohol is miscible with water, so the loss of allyl alcohol in the water-carrying process is extremely large. The main disadvantage of the sodium salt method is that the solubility of sodium terephthalate in water is extremely low and the reaction rate is very slow, while the hydrolysis rate of allyl chloride in the alkaline system is very fast, so allyl chloride needs to be multiple times excessive, resulting in a waste of raw materials, and the wastewater containing allyl alcohol seriously pollutes the environment. Therefore, these two methods are not worth scaling up production. Therefore, finding a simple, efficient, low-pollution, low-cost, and green synthesis method that meets the needs of industrial production has become the focus of many researchers. Summary of the invention
[0004] In view of the problems and shortcomings of the prior art, the present invention provides a high-efficiency and environmentally friendly production method of diallyl terephthalate and an organic optoelectronic device application thereof.
[0005] In order to achieve the above-mentioned purpose of the present invention, the following technical solutions are particularly adopted: The first aspect of the present invention provides a highly efficient and environmentally friendly production method of diallyl terephthalate, comprising the following steps: (1) Dimethyl terephthalate and n-heptane solvent are mixed, heated, and then introduced into a primary autoclave reactor containing catalyst A to react with allyl alcohol that is introduced into the reactor in a closed manner. Diallyl terephthalate and methanol are produced as the main reaction, and methyl allyl terephthalate is also produced as a byproduct. (2) conveying the mixture obtained by the reaction in step (1) to a distillation tower to separate methanol and n-heptane to obtain a mixed liquid of the main product diallyl terephthalate and the by-product methyl allyl terephthalate; (3) subjecting the mixed solution separated in step (2) to sedimentation treatment, and pumping the obtained supernatant into a secondary autoclave reactor, into which catalyst B and allyl alcohol are added, to react to obtain a crude product of diallyl terephthalate; (4) conveying the crude diallyl terephthalate obtained in step (3) to a distillation tower to separate methanol and n-heptane, cooling, filtering, centrifuging and washing the bottom liquid to obtain a finished diallyl terephthalate; The catalyst A is composed of a solid base catalyst and a co-catalyst in a mass ratio of 2.5:1; The catalyst B is a solid base catalyst.
[0006] Preferably, in step (1), the molar ratio of dimethyl terephthalate, allyl alcohol and n-heptane is 1:(4-6):(0.6-0.8), and the amount of catalyst A accounts for 20wt% to 30wt% of the mass of dimethyl terephthalate.
[0007] Preferably, the reaction temperature in the first-stage reactor in step (1) is 100-160°C, the reaction time is 5-7h, and the material volume space velocity is 0.4 h -1 ~0.6 h -1 , the heating temperature is 60-80℃.
[0008] Preferably, the top temperature of the distillation tower in step (2) and step (4) is 50-60°C.
[0009] Preferably, the amount of allyl alcohol used in step (3) is 1 / 2 of the amount of allyl alcohol used in step (1), and the amount of catalyst B accounts for 2 wt% to 3 wt% of the mass of allyl alcohol.
[0010] Preferably, in step (3), the reaction temperature is 100-160° C. and the reaction time is 3-5 h.
[0011] Furthermore, the reaction in step (3) is that the by-product methyl terephthalate allyl ester reacts with allyl alcohol to be completely converted into diallyl terephthalate.
[0012] Furthermore, the n-heptane and methanol separated by distillation are respectively transported to the n-heptane intermediate tank and the methanol intermediate tank for reuse.
[0013] Preferably, the co-catalyst is tetrabutyl titanate, isopropyl titanate or isobutyl titanate, and the solid base catalyst is prepared by hydrothermal synthesis of a metal salt solution and an alkaline solution.
[0014] Preferably, the metal salt is one or more of Fe(NO3)3·9H2O, Mg(NO3)2·6H2O and Al(NO3)3·9H2O; and the alkaline solution is a mixed solution of NaOH and Na2CO3.
[0015] Preferably, in the metal salt solution, Fe 3+ Mg 2+ and Al 3+The molar ratio of is 4:30:6; in the alkaline solution, the molar ratio of NaOH and Na2CO3 is 16:1.
[0016] Preferably, the catalyst is loaded in a manner of being fixed on a stirring paddle in the reactor.
[0017] The second aspect of the present invention provides the use of diallyl terephthalate prepared by the method of the first aspect in an organic optoelectronic device.
[0018] The organic optoelectronic device is an organic light emitting diode or an organic solar cell.
[0019] Compared with the prior art, the present invention has the following beneficial effects: (1) The present invention uses dimethyl terephthalate and allyl alcohol as raw materials and n-heptane as solvent to synthesize diallyl terephthalate, and uses a co-catalyst and a solid base catalyst as catalysts, thereby simplifying the separation and purification process and shortening the reaction time. The present invention effectively solves the problems of long reaction cycle, low yield, complicated operation, and more impurities in the synthesis of diallyl terephthalate in the prior art. The conversion rate of dimethyl terephthalate in the present invention is about 98%, and the selectivity of diallyl terephthalate reaches more than 90%, which is an ideal process for realizing industrial production.
[0020] (2) The present invention uses a two-stage series reactor and a direct method to carry out continuous, efficient and environmentally friendly production of diallyl terephthalate. The excess n-heptane is separated and recycled. The methanol generated in the reaction process can be collected and used. At the same time, the reaction avoids the use of dangerous catalysts such as concentrated sulfuric acid. The solid base catalyst used is easy to separate and can be used again after separation. No post-treatment of the catalyst is required, thereby avoiding the generation of waste liquid. The production process is simple and efficient, safe and environmentally friendly, and has broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS
[0021] Figure 1 This is a simplified diagram of the production process of diallyl terephthalate. DETAILED DESCRIPTION
[0022] In order to make the objectives, technical solutions and advantages of the present application clearer, the implementation methods of the present application are further described in detail below.
[0023] Example 1 Preparation of solid base catalyst The preparation method of the solid base catalyst comprises the following steps: (1) Prepare metal salt solution: weigh 0.004 mol Fe(NO3)3·9H2O, 0.03 mol Mg(NO3)2·6H2O, and 0.006 mol Al(NO3)3·9H2O (molar ratio 2:15:3) and dissolve them in 80 mL ultrapure water to obtain a mixed metal salt solution; (2) Prepare alkaline solution: weigh 4.8 g NaOH and 0.8 g anhydrous Na2CO3 respectively and dissolve them in 100 mL ultrapure water to prepare an alkaline mixed solution; (3) Hydrothermal synthesis: Alkaline solution and salt solution are added dropwise under vigorous stirring at room temperature to mix. During the addition, the pH value of the mixed solution is controlled within the range of 9.5 to 10.5. After the addition is completed, rapid stirring is continued for 30 min. The mixture is heated to 70°C in a water bath and then aged with low-speed stirring for 20 h. After cooling to room temperature, the mixture is washed with ultrapure water and filtered until neutral. The filter cake is placed at 80°C and vacuum dried for 12 h. The dried filter cake is ground to obtain a MgAlFe hydrotalcite precursor. The obtained MgAlFe hydrotalcite precursor is placed in a muffle furnace and calcined at 200 to 600°C to obtain a solid base catalyst.
[0024] Example 2 A highly efficient and environmentally friendly production method for diallyl terephthalate, the process of which is shown in Figure 1 , including the following steps: (1) Dimethyl terephthalate and n-heptane solvent are mixed, heated to 80°C by a heater, and then introduced into a first-stage autoclave reactor containing catalyst A to react with allyl alcohol that is sealed in. The molar ratio of dimethyl terephthalate, allyl alcohol, and n-heptane is 1:4:0.7. The mass of catalyst A is 20wt% of the total mass of dimethyl terephthalate. The volume space velocity of dimethyl terephthalate is 0.4 h / min. -1 , the reaction temperature is 95℃, the reaction time is 5 h, the main reaction produces diallyl terephthalate and methanol, and the by-product methyl terephthalate allyl ester is also produced; (2) conveying the mixture obtained by the reaction in step (1) to a distillation tower, separating methanol and n-heptane at a temperature of 55° C., conveying the distilled methanol to a methanol collection tank for storage, and refluxing the distilled n-heptane to the n-heptane intermediate tank in step (1) for reuse, thereby obtaining a mixed liquid of the main product diallyl terephthalate and the by-product methyl terephthalate allyl ester; (3) The mixed solution separated in step (2) is transported to an intermediate reactor and allowed to stand for solid sedimentation. The obtained supernatant is pumped into a secondary reactor, into which catalyst B and allyl alcohol are added. The amount of allyl alcohol used is 1 / 2 of the amount of allyl alcohol used in step (1), and the amount of catalyst B accounts for 2wt% to 3wt% of allyl alcohol. The reaction temperature is 95° C. and the reaction time is 3 h, so that the by-product methyl terephthalate allyl ester described in step (1) is completely converted into dimethyl terephthalate to obtain a crude product of diallyl terephthalate; (4) The crude diallyl terephthalate obtained in step (3) is conveyed to a distillation tower for distillation at a temperature of 55° C. to separate methanol and n-heptane. The distilled methanol is conveyed to a methanol collection tank for storage, and the evaporated n-heptane is refluxed to the n-heptane intermediate tank of step (1) for reuse; the bottom liquid is cooled, filtered, centrifuged and washed to obtain a finished diallyl terephthalate product.
[0025] Catalyst A is a solid base catalyst and a co-catalyst in a mass ratio of 2.5:1; Catalyst B is a solid base catalyst; and the catalyst is filled in a manner of fixing the catalyst on a stirring paddle.
[0026] The formulas for calculating the mass of each substance, the conversion rate of dimethyl terephthalate and the selectivity of diallyl terephthalate are as follows: Where: C n ——Conversion rate of dimethyl terephthalate (%) ɑ n ——Conversion amount of dimethyl terephthalate (g) b n ——Liquid intake of dimethyl terephthalate (g) Where: S n ——Selectivity of diallyl terephthalate based on dimethyl terephthalate (%) c n ——The mass of diallyl terephthalate produced ɑ n ——Conversion amount of dimethyl terephthalate (g) The reaction results are shown in Table 1.
[0027] Example 3 A highly efficient and environmentally friendly method for producing diallyl terephthalate, wherein the steps are substantially the same as those of Example 2, except that in step (1), the amount of catalyst A used accounts for 30% of the total mass of dimethyl terephthalate. The reaction results are shown in Table 1.
[0028] Example 4 A highly efficient and environmentally friendly production method for diallyl terephthalate, wherein the steps are substantially the same as those of Example 3, except that: in step (1), the material volume space velocity is 0.5 h -1 The reaction results are shown in Table 1.
[0029] Example 5 A highly efficient and environmentally friendly method for producing diallyl terephthalate, wherein the steps are substantially the same as those of Example 3, except that the reaction time of step (1) is 5 h, and the reaction time of step (3) is 5 h. The reaction results are shown in Table 1.
[0030] Example 6 A highly efficient and environmentally friendly method for producing diallyl terephthalate, wherein the steps are substantially the same as those of Example 3, except that the reaction time of step (1) is 7 h, and the reaction time of step (3) is 5 h. The reaction results are shown in Table 1.
[0031] Table 1 Reaction results of Examples 2 to 6 It can be seen from Table 1 that the present invention has a volume space velocity of 0.4-0.6 h -1 Within the range, the selectivity of diallyl terephthalate reaches more than 95%, and the conversion rate of dimethyl terephthalate reaches more than 98%. When the total reaction time of step (1) and step (3) is 8-10 h, the conversion rate of dimethyl terephthalate reaches more than 98%. When the total reaction time is as long as 12 h, the conversion rate is slightly reduced because extending the reaction time may cause other reactions to occur.
[0032] Comparative Example 1 A highly efficient and environmentally friendly method for producing diallyl terephthalate, wherein the steps are substantially the same as those of Example 2, except that in step (1), catalyst A is a solid base catalyst. The reaction results are shown in Table 2.
[0033] Comparative Example 2 A highly efficient and environmentally friendly method for producing diallyl terephthalate, wherein the steps are substantially the same as those of Example 2, except that: in step (1), catalyst A is tetrabutyl titanate, and the reaction results are shown in Table 2.
[0034] Comparative Example 3 A highly efficient and environmentally friendly method for producing diallyl terephthalate, wherein the steps are substantially the same as those of Example 3, except that: in step (1), catalyst A is isopropyl titanate. The reaction results are shown in Table 2.
[0035] Comparative Example 4 A highly efficient and environmentally friendly method for producing diallyl terephthalate, wherein the steps are substantially the same as those of Example 3, except that: in step (1), catalyst A is isobutyl titanate. The reaction results are shown in Table 2.
[0036] Table 2 Reaction results of comparative examples 1 to 4 From the comparison in Table 2, it can be seen that when alkyl titanate and solid base catalyst are used in synergistic catalysis, the conversion rate of dimethyl terephthalate and the selectivity of diallyl terephthalate are better than those when only alkyl titanate or solid base is used as a catalyst. This is because the solid base provides active sites, promotes the ester exchange, and synergistically catalyzes the conversion of diallyl terephthalate with alkyl titanate.
[0037] Comparative Example 5 A highly efficient and environmentally friendly method for producing diallyl terephthalate, wherein the steps are substantially the same as those of Example 3, except that: in step (1), catalyst A is a Ti-OMMT catalyst, and the amount of the catalyst is 25% of the total mass of dimethyl terephthalate. The reaction results are shown in Table 3.
[0038] The preparation method of the Ti-OMMT catalyst comprises the following steps: (1) Weigh 15 g of OMMT, add 45 mL of anhydrous ethanol to dissolve, place in a 500 mL three-necked flask, stir at 125 r / min, and reflux at 80°C for 2 h. The purpose is to remove the water between the montmorillonite layers as quickly as possible by azeotropic azeotropy, and to allow the montmorillonite to fully swell in the ethanol medium. Then cool the system to 60°C.
[0039] (2) Prepare the dropping solution: Weigh 4.8 g NaOH and 0.8 g anhydrous Na2CO3 respectively and dissolve them in 100 mL ultrapure water to prepare an alkaline mixed solution.
[0040] (3) Weigh 2.7 g of tetrabutyl titanate (Ti molar amount is 0.00795 mol) into a beaker, wash the beaker with a small amount of ethanol, and add it dropwise into the three-necked flask using a funnel. Simultaneously with the addition of the liquid, slowly drip it into the flask for about two hours. At the same time, increase the stirring rate to 180 r / min and control the pH to about 9-10.
[0041] (4) After the addition is completed, mechanically stir at 60°C for 20 h and age at 60°C for 15 h.
[0042] (5) Filter, wash the filter cake with deionized water, and dry in an oven at 80°C overnight.
[0043] (6) Calcination: programmed temperature rise: room temperature-30 min-180°C-30 min-180°C-180 min-500°C-180 min-500°C-natural cooling to obtain a Ti-OMMT catalyst.
[0044] Comparative Example 6 A highly efficient and environmentally friendly method for producing diallyl terephthalate, wherein the steps are substantially the same as those of Example 3, except that: in step (1), catalyst A is a Ti-Zr-OMMT catalyst, and the reaction results are shown in Table 3.
[0045] The preparation method of the Ti-Zr-OMMT catalyst is basically the same as that of the preparation of the Ti-OMMT catalyst in Comparative Example 5, except that in step (3), in addition to 2.7 g of tetrabutyl titanate (Ti molar amount is 0.00795 mol), 0.41 g of zirconium n-propoxide solution (Zr molar amount is 0.00087 mol) is added to the beaker.
[0046] Comparative Example 7 A highly efficient and environmentally friendly method for producing diallyl terephthalate, wherein the steps are substantially the same as those of Example 3, except that: in step (1), catalyst A is a urea solid base catalyst. The reaction results are shown in Table 3.
[0047] The preparation method of urea solid base catalyst comprises the following steps: (1) Prepare a metal salt solution; weigh Fe(NO3)3·9H2O, Mg(NO3)2·6H2O, Al(NO3)3·9H2O, and CO(NH2)2 in a molar ratio of 4:3:6:2 and dissolve them in 80 mL of ultrapure water to obtain a mixed metal salt solution; (2) Prepare alkaline solution: weigh 4.8 g NaOH and 0.8 g anhydrous Na2CO3 respectively and dissolve them in 100 mL ultrapure water to prepare an alkaline mixed solution; (3) Hydrothermal synthesis: Alkaline solution and salt solution were added dropwise under vigorous stirring at room temperature to mix. During the addition process, the pH value of the mixed solution was controlled within the range of 9.5-10.5. After the addition was completed, rapid stirring was continued for 30 min. The mixture was heated to 70°C in a water bath and then aged with low-speed stirring for 20 h. After cooling to room temperature, the mixture was washed with ultrapure water and filtered until neutral. The filter cake was placed at 80°C and vacuum dried for 12 h. The dried filter cake was ground to obtain a MgAlFe hydrotalcite precursor. The obtained MgAlFe hydrotalcite precursor was placed in a muffle furnace and calcined at 600°C for 6 h to obtain a urea solid base catalyst.
[0048] Comparative Example 8 A highly efficient and environmentally friendly method for producing diallyl terephthalate, wherein the steps are substantially the same as those of Example 3, except that the catalyst in step (1) is a urea-KF solid base catalyst. The reaction results are shown in Table 3.
[0049] The preparation method of urea-KF solid base catalyst is as follows: A KF solution with a mass fraction of 20% was prepared, and the prepared KF solution was used to spray and saturate the urea solid base catalyst prepared in Comparative Example 7. The specific amount was determined according to the actual operation. The impregnated catalyst was dried and calcined at 600° C. for 6 h to obtain a urea-KF solid base catalyst.
[0050] Table 3 Reaction results of comparative examples 5 to 8 From the comparison in Table 3, it can be seen that when alkyl titanate and solid base catalyst are used for synergistic catalysis, the conversion rate of dimethyl terephthalate is better than that when other types of catalysts are used. This is because the titanium element in tetrabutyl titanate plays a catalytic role. The titanium element in the titanate ester molecule forms a complex with the ester group to increase the activity of the reaction, thereby promoting the conversion of dimethyl terephthalate.
[0051] Since diallyl terephthalate has a stable molecular structure and high electronic conduction and optical properties, it can be applied to organic optoelectronic devices; in particular, it can be applied to organic light-emitting diodes or organic solar cells.
[0052] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present application and are not intended to limit it. Although the present application has been described in detail with reference to the preferred embodiments, a person of ordinary skill in the art should understand that the technical solution of the present application can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution of the present application, which should be included in the scope of the claims of the present application.
Claims
1. A highly efficient and environmentally friendly production method for diallyl terephthalate, characterized in that: The following steps are involved: (1) Dimethyl terephthalate and n-heptane solvent are mixed, heated, and then introduced into a primary autoclave reactor containing catalyst A to react with allyl alcohol that is introduced into the reactor in a closed manner. Diallyl terephthalate and methanol are produced as the main reaction, and methyl allyl terephthalate is also produced as a byproduct. (2) conveying the mixture obtained by the reaction in step (1) to a distillation tower to separate methanol and n-heptane to obtain a mixed liquid of the main product diallyl terephthalate and the by-product methyl allyl terephthalate; (3) subjecting the mixed solution separated in step (2) to sedimentation treatment, and pumping the obtained supernatant into a secondary autoclave reactor, into which catalyst B and allyl alcohol are added, to react to obtain a crude product of diallyl terephthalate; (4) conveying the crude diallyl terephthalate obtained in step (3) to a distillation tower to separate methanol and n-heptane, cooling, filtering, centrifuging and washing the bottom liquid to obtain a finished diallyl terephthalate; The catalyst A is composed of a solid base catalyst and a co-catalyst in a mass ratio of 2.5:1; The catalyst B is a solid base catalyst.
2. The production method according to claim 1, characterized in that In step (1), the molar ratio of dimethyl terephthalate, allyl alcohol and n-heptane is 1:(4-6):(0.6-0.8), and the amount of catalyst A used is 20wt% to 30wt% of the mass of dimethyl terephthalate.
3. The production method according to claim 2, characterized in that: In step (1), the reaction temperature in the first-stage reactor is 100-160°C, the reaction time is 5-7 h, and the material volume space velocity is 0.4 h -1 ~0.6 h -1 , the heating temperature is 60-80℃.
4. The production method according to claim 1, characterized in that The top temperature of the distillation tower in step (2) and step (4) is 50-60°C.
5. The production method according to claim 3, characterized in that: The amount of allyl alcohol used in step (3) is 1 / 2 of the amount of allyl alcohol used in step (1), and the amount of catalyst B used is 2 wt% to 3 wt% of the mass of allyl alcohol.
6. The production method according to claim 5, characterized in that In step (3), the reaction temperature is 100-160° C. and the reaction time is 3-5 h.
7. The production method according to claim 1, characterized in that: The co-catalyst is tetrabutyl titanate, isopropyl titanate or isobutyl titanate, and the solid base catalyst is prepared by hydrothermal synthesis of a metal salt solution and an alkaline solution.
8. The production method according to claim 7, characterized in that: The metal salt is one or more of Fe(NO3)3·9H2O, Mg(NO3)2·6H2O and Al(NO3)3·9H2O; the alkaline solution is a mixed solution of NaOH and Na2CO3.
9. The production method according to claim 8, characterized in that: In the metal salt solution, Fe 3+ Mg 2+ and Al 3+ The molar ratio of is 2:15:3; in the alkaline solution, the molar ratio of NaOH and Na2CO3 is 16:
1.
10. Use of diallyl terephthalate prepared according to the method of claims 1-9 in organic optoelectronic devices.