Preparation method and application of novel vinyl lactam catalyst
Through the preparation method of the new vinyl lactam catalyst, the combination of aluminum phosphate molecular sieve and active component solution is used to solve the problem of moisture affecting the reaction in the acetylene method, and an efficient catalytic and environmentally friendly production process is achieved.
Patent Information
- Application Number
- CN202411805837.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-10
- Publication Date
- 2025-03-28
AI Technical Summary
When the acetylene method is used to produce vinyl lactam, the water generated during the catalyst preparation process will affect the reaction process, resulting in a reduced catalytic effect. In addition, traditional solid alkali catalysts are prone to corrode the equipment and the environment, and it is difficult to separate the catalyst from the product and cannot be reused.
Using the preparation method of a new vinyl lactam catalyst, a solid alkali metal alcohol solution and ammonia water are gradually added to form a colloidal state, and dried and calcined to obtain a solid alkali catalyst.
The catalyst has good performance, solves the problem of moisture affecting the reaction, avoids equipment corrosion and environmental pollution, and realizes effective separation and recycling of catalysts and products, improving catalytic effect and production efficiency.
Smart Images
Figure CN119702066A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of catalysis, in particular to a preparation method and application of a novel vinyl lactam catalyst. Background Art
[0002] Vinyl lactams are widely used. Due to the presence of vinyl groups, they can polymerize themselves or participate in the synthesis of polymers. At the same time, due to their unique structural units, they can participate in the polymerization reaction of different polymer monomers to modify various types of polymers. For example, N-vinyl pyrrolidone (NVP) used to synthesize water-soluble comonomers and copolymers obtained by polymerizing N-vinyl lactams are used as solubilizers for bioactive substances that are difficult to dissolve in water in the cosmetic or pharmaceutical industries. They also have the advantages of being compatible with biological systems, non-toxic, and stable over a large pH range. 4-Vinyl-5-methyloxazolidinone (VMOX) has attracted widespread attention in the printing industry due to the excellent adhesion of its copolymers with acrylates on all common substrates. Therefore, this type of substance has a wide range of applications and good market prospects, such as the production of paper coatings, adhesives, printing inks, detergents, engine oil additives, textile auxiliaries, radiation solid surface coatings, cosmetics, drugs, oil recovery aids, and photographic chemicals.
[0003] The synthesis methods of vinyl lactams are mainly acetylene method and non-acetylene method.
[0004] Currently, the most widely used method for producing vinyl lactam is still the acetylene method because its reaction process is conducive to industrialization.
[0005] The acetylene method has the most extensive raw material sources and the catalyst is easy to obtain. It has high requirements for production equipment, which needs to be corrosion-resistant, pressure-resistant, and high-temperature-resistant. The reaction mechanism is as follows:
[0006]
[0007] However, the acetylene method will produce a large amount of water during the preparation of the catalyst. Although most of the water can be removed in time through methods such as reduced pressure distillation, the small amount of residual water will still have a great impact on the entire reaction process. Summary of the invention
[0008] The purpose of the present invention is to provide a preparation method and application of a novel vinyl lactam catalyst to solve the problems raised in the above background technology.
[0009] To achieve the above object, the present invention provides the following technical solutions:
[0010] A method for preparing a novel vinyl lactam catalyst comprises the following steps:
[0011] (1) dispersing the carrier in a certain molar fraction of the active component solution, heating and stirring for 12-24 hours;
[0012] The carrier is a molecular sieve carrier selected from aluminum phosphate molecular sieve (AIPO4-5);
[0013] The active component in the active component solution is one of K, Na, and Mg, and specifically can be NaOH solution, KOH solution, or Mg(OH)2 solution;
[0014] (2) cooling the mixed solution in step (1) to room temperature, adding a certain amount of acid to adjust the solution pH to 7, and then gradually adding an alkali metal alcohol solution under stirring, wherein the volume of the alkali metal alcohol solution added is 1-5% of the volume of the active component solution added;
[0015] (3) Slowly add aqueous ammonia (25-28%) to the solution obtained in step (2) until it is in a colloidal state, place the obtained paste solid in an oven at 80-120° C. for drying, and finally place it in a muffle furnace at 500-600° C. for calcining for 2-6 hours to obtain a novel vinyl lactam catalyst.
[0016] As a further embodiment of the present invention: in step (1), the mass of the aluminum phosphate molecular sieve dispersed in each milliliter of the active component solution is 0.05-0.2 g;
[0017] More preferably, it is 0.1-0.15 g / mL.
[0018] As a further solution of the present invention: in the step (1), the heating temperature of the aluminum phosphate molecular sieve and the active component solution is 50-80° C.;
[0019] More preferably, it is 60-70°C.
[0020] As a further embodiment of the present invention: the concentration of the alkali metal alcohol solution in step (2) is 0.1-2 mol / L;
[0021] More preferably, it is 0.5-1 mol / L.
[0022] As a further embodiment of the present invention: the acid in step (2) is any one of acetic acid, hydrochloric acid and phosphoric acid.
[0023] As a further solution of the present invention: the alkali metal alcohol solution in step (2) is any one of magnesium acetate and potassium acetate dissolved in methanol, ethanol, isopropanol and n-butanol.
[0024] The present invention provides a novel vinyl lactam catalyst prepared according to the preparation method. The novel vinyl lactam catalyst consists of a carrier and active components on the carrier. The novel vinyl lactam catalyst is a solid base catalyst.
[0025] The invention discloses an application of a novel vinyl lactam catalyst, wherein the novel vinyl lactam catalyst is applied in the production of vinyl lactam generated by the reaction of lactam substance with acetylene.
[0026] The invention discloses an application of a novel vinyl lactam catalyst, which specifically comprises the following steps: taking a certain amount of caprolactam dehydrated by vacuum distillation and 10 wt% of the novel vinyl lactam catalyst, pouring them into a stainless steel high-pressure reactor, and sealing the high-pressure reactor; introducing nitrogen to exhaust the air in the reactor, and then introducing acetylene gas to exhaust the nitrogen in the reactor, the water content of the caprolactam dehydrated is 100-200 ppm, the reaction pressure is 0.1-0.2 MPa, the reaction temperature is set to 150-180 DEG C, and the reaction time is 5-10 hours; after the reaction is completed, the reactor is cooled to room temperature, the remaining acetylene gas therein is replaced with nitrogen, and finally the reaction liquid is separated from the novel vinyl lactam catalyst, and the novel vinyl lactam catalyst is recovered, and the target product is obtained by separation.
[0027] As a further solution of the present invention: the water content of the dehydrated caprolactam is preferably 100 ppn, the reaction pressure is preferably 0.15 MPa, the reaction temperature is preferably 170° C., and the reaction time is preferably 5 hours.
[0028] Compared with the prior art, the present invention has the following beneficial effects:
[0029] 1) The catalyst preparation process is relatively simple, the raw material price is low, and it has good application prospects.
[0030] 2) The catalyst has good performance and solves the problem that traditional solid base catalysts will produce water during use, thereby causing hydrolysis and polymerization of the material and reducing the catalytic effect. At the same time, it avoids the problem of homogeneous catalysts corroding equipment and polluting the environment, and also solves the problem of difficulty in separating the catalyst from the product and non-reusability. BRIEF DESCRIPTION OF THE DRAWINGS
[0031] Figure 1 This is a graph showing the relationship between the number of cycles of the new vinyl lactam catalyst and the product conversion rate.
[0032] Figure 2 This is the XRD diagram of MgO / Na2O / AIPO4-5.
[0033] Figure 3 This is the physical adsorption diagram of MgO / Na2O / AIPO4-5. DETAILED DESCRIPTION
[0034] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0035] Example 1
[0036] Preparation of a novel vinyl lactam catalyst: first weigh 10.0g of aluminum phosphate molecular sieve AIPO-5, add 50-200mL of sodium hydroxide solution, heat to 50-80°C and stir for 12-24 hours, cool the mixed solution after alkali etching and stripping to room temperature, add a certain amount of acid to make the solution pH = 7, then gradually add 5mL of alkali metal alcohol solution under stirring, and then slowly drop ammonia water (25-28%) until it is in a colloidal state, place the obtained paste solid in an oven at 80-120°C for drying, and finally place it in a muffle furnace at 500-600°C for calcination for 2-6 hours to obtain a novel vinyl lactam catalyst (hereinafter referred to as catalyst);
[0037] To facilitate subsequent experiments, 18 groups of catalysts were prepared according to the above preparation method and different preparation conditions, as shown in Table 1.
[0038] Table 1 shows the preparation conditions of 18 groups of catalysts
[0039]
[0040]
[0041] Example 2
[0042] Application of new vinyl lactam catalysts: New vinyl lactam catalysts are used in the production of vinyl lactam by the reaction of lactam substances with acetylene.
[0043] Take 1000g of caprolactam and 100g of the solid catalyst of 10wt% and add them into a stainless steel autoclave with stirring and no problem of pressure maintenance, cover the sealing cover of the equipment, seal the equipment, replace it with nitrogen three times first, the purpose is to replace the air in the autoclave, and then replace it with acetylene three times, the purpose is to replace the nitrogen in the autoclave, and then start heating. When the material is heated to 170°C, start to pass acetylene gas, control the reaction temperature at about 170°C, the reaction pressure at 0.15MPa (close the air inlet valve after reaching the reaction pressure to start the reaction, and continue to pass acetylene gas after the pressure drops), the reaction is 5h, after the reaction is completed, cool to below 80°C, replace it with nitrogen twice, and then open the sealing cover to discharge. After discharging, the catalyst and the reaction solution are centrifuged, and the conversion rate of the product is obtained by gas chromatography, as shown in Table 2.
[0044] Table 2 Catalytic performance evaluation results of the catalysts prepared in each example
[0045]
[0046]
[0047] Reaction conditions: reaction temperature 170°C, reaction time 5 hours, acetylene gas pressure 0.15 MPa, catalyst concentration 10 wt%.
[0048] As shown in Table 2, the activity of the catalyst is closely related to the mass volume ratio of the sodium hydroxide solution and the heating temperature during the preparation process. If the mass volume ratio of the sodium hydroxide solution and the heating temperature are too high or too low during the preparation of the catalyst, the catalytic activity of the catalyst will be affected. The preferred mass volume ratio of the sodium hydroxide solution is 0.1-0.15 g / mL, and the preferred heating temperature is 60-70°C. Under these conditions, the activity of the catalyst obtained is relatively high.
[0049] Example 3
[0050] Take 1000g of caprolactam and 100g of 10wt% of the solid catalyst and add them to a stainless steel autoclave with stirring and pressure maintenance. Cover the equipment with a sealing lid, seal the equipment, replace it with nitrogen three times first to completely replace the air in the autoclave, and then replace it with acetylene three times to completely replace the nitrogen in the autoclave, and then start heating. When the material is heated to 170°C, start to introduce acetylene gas, control the reaction temperature at around 170°C and the reaction pressure at 0.15MPa (close the air inlet valve after reaching the reaction pressure to start the reaction, and continue to introduce acetylene gas when the pressure drops), react for 5h, and after the reaction is completed, cool to below 80°C, replace it with nitrogen twice, and then open the sealing lid to discharge the material. After discharging, centrifuge the catalyst and the reaction liquid, recover the solid catalyst, re-add caprolactam to verify the recycling effect. The experimental results show that within six cycles (see Figure 1 ), the conversion rate of the target product is stable and the recycling performance is good.
[0051] Example 4
[0052] Take 1000g of caprolactam and 100g of the solid catalyst of 10wt% and add them into a stainless steel autoclave with stirring and no problem of pressure maintenance, cover the sealing lid of the equipment, seal the equipment, replace with nitrogen three times first, the purpose is to replace the air in the autoclave cleanly, then replace with acetylene three times, the purpose is to replace the nitrogen in the autoclave cleanly, then start heating, when the material is heated to 170°C, start to pass acetylene gas, control the reaction temperature at about 170°C, the reaction pressure at 0.15MPa (after reaching the reaction pressure, close the air inlet valve to start the reaction, and continue to pass acetylene gas after the pressure drops), the reaction is 5h, after the reaction is completed, cool to below 80°C, replace with nitrogen twice, and then open the sealing cover to discharge. The control group has the same reaction conditions, and the catalyst is KOH, NaOH, etc., as shown in Table 3.
[0053] Table 3 Evaluation results of different catalyst performances in various examples
[0054]
[0055] The experimental results show that compared with the original solid base catalyst, the yield of the target product is increased by 10%, and no polymer will appear during the reaction, indicating that this catalyst solves the problem of existing catalysts producing water, avoiding the hydrolysis and polymerization of raw materials and reducing catalytic activity.
[0056] The above description of the embodiments is to facilitate the understanding and use of the invention by those skilled in the art. It is obvious that those familiar with the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative work. Therefore, the present invention is not limited to the above embodiments. Improvements, modifications, substitutions and combinations made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the present invention should be equivalent replacement methods and should be within the protection scope of the present invention.
Claims
1. A method for preparing a novel vinyl lactam catalyst, characterized in that: The steps are as follows: (1) Dispersing the carrier in the active component solution and heating and stirring for 12-24 hours; The carrier is a molecular sieve carrier selected from aluminum phosphate molecular sieve; (2) cooling the mixed solution in step (1) to room temperature, adding acid to adjust the solution pH to 7, and then gradually adding an alkali metal alcohol solution under stirring, wherein the volume of the alkali metal alcohol solution added is 1-5% of the volume of the active component solution added; (3) Slowly adding aqueous ammonia to the solution obtained in step (2) until it is in a colloidal state, placing the obtained paste solid in an oven at 80-120° C. for drying, and finally placing it in a muffle furnace at 500-600° C. for calcining for 2-6 hours to obtain a novel vinyl lactam catalyst.
2. The method for preparing the novel vinyl lactam catalyst according to claim 1, characterized in that: The active component solution is any one of NaOH solution, KOH solution or Mg(OH)2 solution, and the active components in the active component solution are K ions, Na ions and Mg ions.
3. The method for preparing the novel vinyl lactam catalyst according to claim 1 or 2, characterized in that: In the step (1), the mass of the aluminum phosphate molecular sieve dispersed in each milliliter of the active component solution is 0.05-0.2 g.
4. The method for preparing the novel vinyl lactam catalyst according to claim 3, characterized in that: In the step (1), the heating temperature of the aluminum phosphate molecular sieve and the active component solution is 50-80°C.
5. The method for preparing the novel vinyl lactam catalyst according to claim 4, characterized in that: The concentration of the alkali metal alcohol solution in step (2) is 0.1-2 mol / L.
6. The method for preparing the novel vinyl lactam catalyst according to claim 5, characterized in that: The acid in step (2) is any one of acetic acid, hydrochloric acid and phosphoric acid.
7. The method for preparing the novel vinyl lactam catalyst according to claim 6, characterized in that: The alkali metal alcohol solution in step (2) is any one of magnesium acetate and potassium acetate dissolved in methanol, ethanol, isopropanol and n-butanol.
8. A novel vinyl lactam catalyst obtained by the method for preparing the novel vinyl lactam catalyst as claimed in claim 7.
9. Application of a novel vinyl lactam catalyst, characterized in that: A novel vinyl lactam catalyst is used in the production of vinyl lactam by reacting a lactam substance with acetylene.
10. Use of the novel vinyl lactam catalyst according to claim 9, characterized in that: Specifically, the method comprises the following steps: pouring caprolactam dehydrated by vacuum distillation and 10 wt% of the novel vinyl lactam catalyst into a stainless steel autoclave, and sealing the autoclave; introducing nitrogen to exhaust the air in the autoclave, and then introducing acetylene gas to exhaust the nitrogen in the autoclave, the dehydrated water content of caprolactam is 100-200 ppm, the reaction pressure is 0.1-0.2 MPa, the reaction temperature is set to 150-180° C., and the reaction time is 5-10 hours; after the reaction is completed, cooling the autoclave to room temperature, replacing the remaining acetylene gas therein with nitrogen, and finally separating the reaction liquid from the novel vinyl lactam catalyst, and recovering the novel vinyl lactam catalyst, and obtaining the target product by separation.