Production process of methyl isobutyl ketone diimine for single-component polyurethane
By adopting reactive distillation and dual-effect distillation technologies in the single-component polyurethane production process, the major problems of heat management and equipment investment in traditional production methods are solved, and efficient and low-cost production results are achieved.
Patent Information
- Application Number
- CN202411860128.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-17
- Publication Date
- 2025-03-25
- Estimated Expiration
- 2044-12-17
AI Technical Summary
In the production process of single-component polyurethane, the traditional batch production method has problems such as insufficient heat exchange area, high heat consumption, frequent side reactions, large equipment investment and high energy consumption, making it difficult to achieve efficient production.
The reaction distillation method is used to couple the reaction process with the distillation process. Through the dual-effect distillation technology, the heat released by the reaction is used to distillate, which improves the reaction conversion rate and energy efficiency.
The reaction conversion rate has been achieved above 80%, energy consumption has been reduced by 30%, product purity is greater than 99.5%, and production cost is low. It is suitable for industrial continuous production.
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Figure CN119684152A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to a production process of methyl isobutyl ketone diimide for single-component polyurethane, belonging to the technical field of chemical industry. Background Art
[0002] Single-component polyurethane has become the current mainstream product due to its advantages such as easy construction, low construction cost and low labor load. It is widely used in sealants, coatings, flooring and other industries.
[0003] In order to increase the curing speed, one-component polyurethane must add organic tin and tertiary amine compounds as catalysts. The isocyanate group in the polyurethane is sensitive to moisture under the action of the catalyst, which causes the viscosity of the product to increase significantly during storage, resulting in gelation. The contradiction between the storage stability and curing speed of one-component moisture-curing polyurethane sealants has always been a difficult problem. The emergence of latent curing agents has successfully solved the above problem. Among them, methyl isobutyl ketone diimide is a very excellent latent curing agent, but its production process mainly adopts the traditional intermittent production method, and the reaction equipment is a reactor, which seriously limits its production capacity. The main shortcomings are as follows: 1. There is not enough heat exchange area, the reaction heat cannot be removed in time, and the heat consumption is high; the local concentration and temperature of the material are prone to be too high during the process, which is prone to side reactions and unstable product quality; 2. Intermittent production is difficult to achieve automatic control, and it takes time and manual work to adjust temperature and pressure, feed materials, and prepare for the next batch of materials.
[0004] 3. The reaction temperature required for methyl isobutyl ketone diimide is relatively high (usually around 160°C), and a large amount of heat energy is required during the production process. The heat energy cannot be recycled, resulting in serious waste.
[0005] 4. Methyl isobutyl ketone and water form an azeotrope, and it is difficult to separate them by ordinary distillation process.
[0006] Therefore, there is an urgent need for a production process of methyl isobutyl ketone diimide for one-component polyurethane that can solve the above-mentioned technical problems. Summary of the invention
[0007] The object of the present invention is to solve the deficiencies of the above-mentioned prior art and provide a production process of methyl isobutyl ketone diimide for single-component polyurethane. The process adopts a reaction distillation method, couples the reaction process and the distillation process into one device, and the reaction and separation are carried out simultaneously. The heat released by the reaction can be used in the distillation process, and products are continuously produced during the reaction, so that the reaction can be moved in the positive reaction direction, and the reaction conversion rate can reach more than 80%. The double-effect distillation method is adopted, and the heat of the produced material at the top of the reaction distillation tower is used for heating the tower kettle of the recovery tower, so that the heat is fully utilized and the energy consumption is reduced by 30%. The process flow is simple, the separation effect is good, the product purity is high, the product purity is greater than 99.5%wt, the production cost is low, and it can be suitable for industrial and continuous production.
[0008] The production process of methyl isobutyl ketone diimide for one-component polyurethane of the present invention is characterized in that it comprises the following steps: Step 1: adding 40-60% by weight of methyl isobutyl ketone, 20-40% by weight of m-xylylenediamine, 10-20% by weight of water, and 10-25% by weight of methyl isobutyl ketone diimide into the reactor Ⅰ2 of the reaction distillation tower 1. When the liquid level of the reactor Ⅰ2 reaches 80%, the feeding is stopped, and the reaction distillation tower 1 is preheated to start the total reflux of the reaction distillation tower 1. Preferably, the reaction distillation tower 1 comprises from bottom to top: a reactor Ⅰ2, a stripping section Ⅰ3, a reaction section Ⅰ4, and a distillation section Ⅰ5; the stripping section Ⅰ3 and the distillation section Ⅰ5 are filled with θ ring-shaped fillers, and the reaction section Ⅰ4 is filled with θ ring-shaped fillers or solid catalysts. The pressure of the reaction distillation tower 1 is 0.2-2 MPa; Step 2: methyl isobutyl ketone and meta-xylylenediamine are continuously fed from the bottom and top of reaction section Ⅰ4 respectively, and at the same time, the top of reaction distillation tower 1 and bottom Ⅰ2 begin to be produced, methyl isobutyl ketone diimine is produced from bottom Ⅰ2, and a mixture of methyl isobutyl ketone and water is produced from the top of reaction distillation tower 1; Preferably, the step 2 is specifically as follows: after the step 1 is fully refluxed for 30 minutes, methyl isobutyl ketone and meta-xylylenediamine are fed again at a mass ratio of (3-12): 1 (by increasing the feed ratio of methyl isobutyl ketone, the reaction conversion rate is improved), and at the same time, the top of the reaction distillation tower 1 and the bottom of the tower Ⅰ2 begin to be extracted, the liquid level of the bottom of the tower Ⅰ2 is kept at 50%, and the liquid level of the reflux tank Ⅰ6 is kept at 50%, the reflux ratio of the reaction distillation tower 1 is controlled to be 2-8, and the bottom of the tower Ⅰ2 is provided with a heater, and the heating power is 4000-6000W; Step 3: The mixture of methyl isobutyl ketone and water taken out from the top of the reaction distillation tower 1 exchanges heat with the liquid in the tower reactor II 12 through the heat exchanger 8, and a part of it flows back to the top of the reaction distillation tower 1, and the other part is added to the liquid-liquid phase separator 17 to perform preliminary separation of water and methyl isobutyl ketone, and then enters the recovery tower 11 for further separation and purification; Preferably, the other part is cooled to 10-30°C by condenser I7 and then enters liquid-liquid phase separator 17; Preferably, the liquid-liquid phase separator 17 comprises a water phase feed port, a water phase outlet and an oil phase outlet, wherein the water phase feed port is used to improve the separation degree of the water phase and the oil phase, the oil phase outlet is connected to the feed port of the recovery tower 11, and the water phase outlet is used for wastewater treatment; Step 4: The azeotrope of methyl isobutyl ketone and water is produced from the top of the recovery tower 11, which is returned to the liquid-liquid phase separator 17 to continue separating excess water, and the methyl isobutyl ketone produced from the bottom of the recovery tower 11 is returned to the methyl isobutyl ketone feed tank 10 for recycling; Preferably, after the bottom liquid level of the recovery tower 11 reaches 50%, heating is started, the recovery tower pressure is 0.03-0.1MPa, the top reflux ratio is 1-3, and the liquid level of the reflux tank II 16 is maintained at 50%; Preferably, the recovery tower 11 comprises from bottom to top: a tower reactor II 12, a stripping section II 13, and a rectifying section II 14. The gas phase outlet at the top of the recovery tower 11 is connected to a condenser II 15 and a reflux tank II 16 in sequence. One end of the discharge port of the reflux tank II 16 is connected to the liquid phase feed port at the top of the recovery tower 11, and the other end is connected to the feed port of the condenser I7. The high-purity methyl isobutyl ketone extracted from the tower reactor II 12 is connected to the methyl isobutyl ketone feed tank 10 for recycling. Preferably, the rectifying section II14 and the stripping section II13 of the recovery tower 11 are both filled with θ-ring-shaped fillers; Preferably, the tower kettle II 12 is heated by the heat exchanger 8 during normal operation, and is heated by a heater in the initial preparation stage in the form of an electric heating jacket. The heating power of the tower kettle of the recovery tower 11 is 1000-2000W.
[0009] Preferably, the reaction distillation tower 1 and the recovery tower 11 are externally wrapped with electric heating wires for heat preservation.
[0010] The production process of methyl isobutyl ketone diimide for one-component polyurethane of the present invention has the following beneficial effects: (1) The distillation process can continuously extract products from the system, so that the reaction continuously shifts toward the positive reaction direction, while reducing the occurrence of side reactions, and the product quality is stable. The single-pass conversion rate in this process can reach more than 80%. The reaction process and the distillation process are carried out simultaneously. The reaction is an exothermic reaction, and the reaction heat can be used in the distillation process, which can reduce energy consumption by 10%.
[0011] (2) Intermittent production requires time and manual effort to adjust temperature and pressure, add materials, prepare the next batch of materials, etc., and the process flow is complex and the equipment investment is large. The present invention can complete the reaction and distillation processes in one device, reducing equipment investment by 20%, and can also realize automated production, reducing labor costs by 50%.
[0012] (3) Double-effect distillation is adopted. The top steam of reaction distillation tower 1 is used as the heat source of the reboiler of the bottom of recovery tower 11. The two parts of heat are coupled by adjusting the pressure and reflux ratio of reaction distillation tower 1 and recovery tower 11. The heat removed from the top of reaction distillation tower 1 is exactly equal to the heat required for heating recovery tower 11, thereby reducing the energy consumption of the distillation process by 20%.
[0013] (4) Taking advantage of the characteristics of methyl isobutyl ketone (MIBK) being azeotropic with water and being slightly soluble in water, the liquid-liquid phase separator 17 is combined with the distillation tower 1 to improve the separation effect and reduce energy consumption by 20%. In addition, methyl isobutyl ketone is recycled, reducing production costs by 30%, making it suitable for industrial production. BRIEF DESCRIPTION OF THE DRAWINGS
[0014] Figure 1 This is a diagram of the production device of methyl isobutyl ketone diimide for the single-component polyurethane of the present invention. DETAILED DESCRIPTION
[0015] The specific implementation of the present invention is further described below in conjunction with the accompanying drawings and technical solutions.
[0016] Example 1 The production process of methyl isobutyl ketone diimide for one-component polyurethane of this embodiment comprises the following steps: Add 40% methyl isobutyl ketone, 30% m-xylenediamine, 15% water and 15% methyl isobutyl ketone diimide by mass into the bottom Ⅰ2 of the reaction distillation tower 1 until the liquid level of the bottom Ⅰ2 reaches 80%, add a certain amount of zeolite to prevent boiling over, heat the bottom Ⅰ2, control the heating power of the bottom Ⅰ2 to 4500 W, turn on the tower body insulation switch, and control the pressure in the reaction distillation tower 1 to 1.8 MPa.
[0017] When the temperature of the bottom of the tower Ⅰ2 reaches 200℃, the feeding starts, and the feeding amount of methyl isobutyl ketone is controlled to 6kg / h, and the feeding amount of meta-xylylenediamine is controlled to 1.5kg / h. Both are fed at room temperature until the reaction distillation tower 1 starts to reflux. The feeding is stopped and the full reflux is carried out for about 30 minutes. Methyl isobutyl ketone and meta-xylylenediamine are started to be fed again, and the reflux ratio at the top of the tower is controlled to 3.
[0018] Open the switch of liquid-liquid phase separator 17 to start feeding. After the liquid-liquid phase separator 17 is stable, open the regulating valve of the recovery tower to start feeding. After the liquid level of the tower kettle II reaches 50%, start heating, and turn on the tower body insulation switch to control the top reflux ratio to 1.2 and the recovery tower pressure to 0.05MPa. The output is when the system reaches a stable state, the composition of the reaction distillation tower kettle, liquid-liquid phase separator water phase, and recovery tower kettle products is shown in Table 1-3 below.
[0019] Table 1 Reaction distillation tower kettle product composition ; Table 2 Composition of aqueous phase products in liquid-liquid phase separator ; Table 3 Composition of recovery tower kettle products ;
[0020] Example 2 The production process of methyl isobutyl ketone diimide for one-component polyurethane of this embodiment comprises the following steps: Add 50% methyl isobutyl ketone, 30% m-xylenediamine, 10% water, and 10% methyl isobutyl ketone diimine by mass fraction to the reactor I of the reaction distillation tower, and reach 80% of the liquid level of the reactor I. Add a certain amount of zeolite to prevent boiling, heat the reactor I, control the heating power of the reactor I to 4800W, turn on the tower body insulation switch, control the pressure in the tower to 1.2 MPa, and start feeding when the reactor temperature reaches 200℃. Control the feed rate of methyl isobutyl ketone to 8kg / h, and the feed rate of m-xylenediamine to 1.5kg / h, both at room temperature. Stop feeding until the reaction distillation tower begins to reflux, and reflux for about 30 minutes. Methyl isobutyl ketone and m-xylenediamine begin to be fed again, and the reflux ratio at the top of the tower is controlled to be 4. Open the liquid-liquid phase separator switch to start feeding. After the liquid-liquid phase separator is stable, open the recovery tower regulating valve to start feeding. After the tower kettle II liquid level reaches 60%, start heating, and turn on the tower body insulation switch to control the tower top reflux ratio to 1.2 and the recovery tower pressure to 0.06MPa. The output is when the system reaches a stable state. The composition of the reaction distillation tower kettle, liquid-liquid phase separator water phase, and recovery tower kettle products is shown in Table 1-3 below.
[0021] Table 1 Reaction distillation tower kettle product composition ; Table 2 Liquid-liquid phase separator aqueous product composition ; Table 3 Recovery tower kettle product composition ;
[0022] Example 3 The production process of methyl isobutyl ketone diimide for one-component polyurethane of this embodiment comprises the following steps: Add 60% methyl isobutyl ketone, 20% m-xylenediamine, 10% water, and 10% methyl isobutyl ketone diimide by mass fraction to the reactor I of the reaction distillation tower, and reach 80% of the liquid level of the reactor I. Add a certain amount of zeolite to prevent boiling, heat the reactor I, control the heating power of the reactor I to 4500W, turn on the tower body insulation switch, control the pressure in the tower to 0.6 MPa, and start feeding when the reactor temperature reaches 200℃. Control the feed rate of methyl isobutyl ketone to 10kg / h and the feed rate of m-xylenediamine to 1kg / h, both at room temperature. Stop feeding until the reaction distillation tower begins to reflux, and reflux for about 30 minutes. Methyl isobutyl ketone and m-xylenediamine begin to be fed again, and the reflux ratio of the top of the reaction distillation tower is controlled to 6. Open the liquid-liquid phase separator switch to start feeding. After the liquid-liquid phase separator is stable, open the recovery tower regulating valve to start feeding. After the tower kettle II liquid level reaches 70%, start heating, and turn on the tower body insulation switch to control the top reflux ratio of the recovery tower to 2, and the recovery tower is at normal pressure. The output volume is when the system reaches a stable state, the composition of the reaction distillation tower kettle, liquid-liquid phase separator water phase, and recovery tower kettle products is shown in Table 1-3 below.
[0023] Table 1 Reaction distillation tower kettle product composition ; Table 2 Liquid-liquid phase separator aqueous product composition ; Table 3 Composition of recovery tower kettle products ; The present invention couples the reaction process and the distillation process into one device by means of reactive distillation, and the reaction and separation are carried out simultaneously. The heat released by the reaction can be used in the distillation process, and products are continuously extracted during the reaction, so that the reaction can be moved in the positive reaction direction, and the reaction conversion rate can reach more than 80%. The double-effect distillation method is adopted, and the heat of the extracted material at the top of the reactive distillation tower is used for heating the tower kettle of the recovery tower, so that the heat is fully utilized and the energy consumption is reduced by 30%. The process flow is simple, the separation effect is good, the product purity is high, the product purity is greater than 99.5%wt, the production cost is low, and the process can be suitable for industrial and continuous production.
[0024] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.
Claims
1. A process for producing methyl isobutyl ketone diimide for one-component polyurethane, characterized in that The following steps are involved: Step 1: adding 40-60% by weight of methyl isobutyl ketone, 20-40% by weight of m-xylylenediamine, 10-20% by weight of water, and 10-25% by weight of methyl isobutyl ketone diimide into the reactor I of the reaction distillation tower. When the liquid level of the reactor I reaches 80%, the feeding is stopped, the reaction distillation tower is preheated, and the reaction distillation tower starts to fully reflux. Step 2: methyl isobutyl ketone and meta-xylylenediamine are continuously fed from the bottom and top of the reaction section I respectively, and at the same time, the top of the reaction distillation tower and the bottom of the tower I start to be produced, methyl isobutyl ketone diimine is produced from the bottom of the tower I, and a mixture of methyl isobutyl ketone and water is produced from the top of the reaction distillation tower; Step 3: The mixture of methyl isobutyl ketone and water taken out from the top of the reaction distillation tower exchanges heat with the liquid in the bottom of the tower II through a heat exchanger, and a part of it flows back to the top of the reaction distillation tower, and the other part is added to the liquid-liquid phase separator to perform preliminary separation of water and methyl isobutyl ketone, and then enters the recovery tower for further separation and purification; Step 4: The azeotropic product of methyl isobutyl ketone and water is produced from the top of the recovery tower, which is returned to the liquid-liquid phase separator to continue to separate excess water, and the methyl isobutyl ketone produced from the bottom of the recovery tower is returned to the methyl isobutyl ketone feed tank for recycling.
2. The process for producing methyl isobutyl ketone diimide for one-component polyurethane according to claim 1, characterized in that The reaction distillation tower comprises from bottom to top: a reactor I, a stripping section I, a reaction section I, and a distillation section I; the stripping section I and the distillation section I are filled with θ ring-shaped fillers, and the reaction section I is filled with θ ring-shaped fillers or solid catalysts. The pressure of the reaction distillation tower is 0.2-2 MPa.
3. The process for producing methyl isobutyl ketone diimide for one-component polyurethane according to claim 2, characterized in that The step 2 specifically comprises: after the step 1 is fully refluxed for 30 minutes, methyl isobutyl ketone and meta-xylylenediamine are fed again at a mass ratio of (3-12):1, and at the same time, the top of the reaction distillation tower and the bottom of the tower I start to be extracted, the liquid level of the bottom of the tower I is kept at 50%, and the liquid level of the reflux tank I is kept at 50%, the reflux ratio of the reaction distillation tower is controlled to be 2-8, and the bottom of the tower I is provided with a heater with a heating power of 4000-6000W.
4. The process for producing methyl isobutyl ketone diimide for one-component polyurethane according to claim 1, characterized in that The other part described in step 3 is cooled to 10-30° C. in condenser I and then enters the liquid-liquid phase separator.
5. The process for producing methyl isobutyl ketone diimide for one-component polyurethane according to claim 4, characterized in that The liquid-liquid phase separator comprises a water phase feed port, a water phase outlet and an oil phase outlet. The purpose of the water phase feed port is to improve the separation degree of the water phase and the oil phase. The oil phase outlet is connected to the recovery tower feed port. The water phase outlet is for wastewater treatment.
6. The process for producing methyl isobutyl ketone diimide for one-component polyurethane according to claim 1, characterized in that After the recovery tower kettle liquid level reaches 50%, heating begins, the recovery tower pressure is 0.03-0.1MPa, the tower top reflux ratio is 1-3, and the reflux tank II liquid level is maintained at 50%.
7. The process for producing methyl isobutyl ketone diimide for one-component polyurethane according to claim 1, characterized in that The recovery tower comprises from bottom to top: a tower kettle II, a stripping section II, and a rectifying section II. The gas phase outlet at the top of the recovery tower is connected to a condenser II and a reflux tank II in sequence. One end of the discharge port of the reflux tank II is connected to a liquid phase feed port at the top of the recovery tower, and the other end is connected to a feed port of the condenser I. The high-purity methyl isobutyl ketone extracted from the tower kettle II is connected to a methyl isobutyl ketone feed tank for recycling.
8. The process for producing methyl isobutyl ketone diimide for one-component polyurethane according to claim 1, characterized in that The rectification section II and the stripping section II of the recovery tower are both filled with θ ring-shaped fillers.
9. The process for producing methyl isobutyl ketone diimide for one-component polyurethane according to claim 1, characterized in that The tower kettle II is heated by a heat exchanger during normal operation, and is heated by a heater in the initial preparation stage in the form of an electric heating jacket. The heating power of the recovery tower kettle is 1000-2000W.
10. The process for producing methyl isobutyl ketone diimide for one-component polyurethane according to claim 1, characterized in that The reaction distillation tower and the recovery tower are externally wound with electric heating wires for heat insulation.
Citation Information
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