A bisphenol A type high molecular weight polycarbonate polyether polyol and its production process
By adopting an integrated tube reaction device and gas-liquid conduction control process in the production of bisphenol A type high molecular weight polycarbonate polyether polyols, the problems of excessive CO2 consumption and yellowing of products are solved, and products with high ester content and stable color are achieved, which are suitable for large-scale industrial production.
Patent Information
- Application Number
- CN202411765165.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-04
- Publication Date
- 2025-03-14
- Estimated Expiration
- 2044-12-04
AI Technical Summary
In the one-step production process of bisphenol A type high molecular weight polycarbonate polyether polyol, excessive CO2 consumption leads to a decrease in the ester content, and the product is prone to yellowing, affecting the quality. At the same time, there is a problem of amplification effect, and it is difficult to ensure the stability of the quality of the product in industrial production.
A special integrated tube reaction device is adopted to ensure the gas-liquid mass transfer and solid-liquid gas mixing efficiency of reactants through gas-liquid conduction and temperature control processes, and sufficient heating and heat dissipation to avoid explosive accumulation. Meanwhile, the reaction conditions are controlled to ensure the ester content and color quality of the product.
It effectively improves the ester content and color stability of the product, avoids the problem of yellowing of the product, ensures the high quality of the product and the stability of industrial production, and reduces production costs.
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Figure CN119219905B_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of chemistry and chemical engineering, and in particular to a bisphenol A type high molecular weight polycarbonate polyether polyol and a production process thereof. Background Art
[0002] Polycarbonate polyether polyols are a class of polyols with carbonate groups in the molecule and hydroxyl groups at the ends of the molecular chain, which can be obtained by copolymerization of carbon dioxide and epoxy compounds. Carbon dioxide, as one of the raw materials, is cheap and easy to obtain, non-toxic and non-flammable, has a clear carbon dioxide chemical fixation effect, and requires low temperature and low energy consumption during the reaction. The copolymerization method of carbon dioxide and epoxy compounds has broad application prospects and high industrial value.
[0003] The process of synthesizing polycarbonate polyether polyols is mainly to synthesize carbon dioxide and epoxides through a bimetallic complex (abbreviated as DMC) catalyst. Taking propylene oxide as an example, CO 2 With propylene oxide, under the action of initiator and DMC catalyst, the main product polycarbonate polyether polyol and the by-product carbonate acrylate are synthesized. The synthesis route is as follows:
[0004]
[0005] Prior art CN115785435A discloses a one-step method for preparing polyether polyols. The one-step method is specifically as follows: at room temperature, epoxy compounds, initiators and catalysts are added to a reaction device at one time for polymerization reaction, and no reaction raw materials are added during the reaction process, thereby significantly improving the reaction efficiency.
[0006] However, the inventors found in the course of their research that when using bisphenol A as an initiator in the process of synthesizing bisphenol A type high molecular weight polycarbonate polyether polyol, on the one hand, the amount of bisphenol A and propylene oxide used is relatively small, that is, for the same amount of propylene oxide, the amount of bisphenol A used is less, and more chain links need to be connected to each bisphenol A molecule during the reaction. This makes it necessary to put propylene oxide and bisphenol A into the reactor at one time for the reaction when using the one-step method for production. 2 The gas will be consumed quickly, and the CO introduced into the reactor 2The amount of dissolved gas cannot keep up with the amount of consumption, and the ester content of the obtained product is low, which is difficult to meet the needs of the industry. On the other hand, when bisphenol A is used as an initiator for the one-step preparation of polyether polyols, the product turns yellow severely, affecting the product quality. The reason for the yellowing of the product may be that when the product is prepared by the one-step method, since all the raw materials are put into the polymerization process at one time, it is easy to cause a sharp increase in temperature in a short period of time (for example, the temperature rises by 5°C within 1 minute). When bisphenol A is exposed to high temperature for a long time, it is easy to undergo thermal decomposition and decompose into several small molecules. The decomposition products are easy to react with the intermediates and by-products of the polymerization reaction to form yellow substances, such as the small molecule substance dimethyl phthalate or the quinone structure with a chromophore, which causes the product to turn yellow and affects the downstream application of the product.
[0007] In addition, to realize the industrial production of bisphenol A type high molecular weight polycarbonate polyether polyol, it is also necessary to avoid the scaling up effect. The scaling up effect refers to the research results obtained by using small equipment to conduct chemical process (i.e. small-scale) experiments (such as laboratory scale). Under the same operating conditions, the results obtained from large-scale production equipment (such as industrial scale) are often very different. The impact of these differences is called the scaling up effect. Since the viscosity of the material increases during the synthesis of bisphenol A type high molecular weight polycarbonate polyether polyol, the heat generated by the reaction is difficult to release. The heat generated increases the temperature and accelerates the reaction rate, thereby generating more heat. The more materials, the higher the heat generated, and the scaling up effect is inevitable. How to avoid the scaling up effect and ensure product quality has become a difficult problem in the one-step production of bisphenol A type high molecular weight polycarbonate polyether polyol. Summary of the invention
[0008] The purpose of the present invention is to provide a bisphenol A type high molecular weight polycarbonate polyether polyol and its production process, which adopts a special integrated tube-in-tube reaction device, through gas-liquid conduction and temperature control process, to ensure the gas-liquid mass transfer of reactants and the solid-liquid-gas mixing efficiency, sufficient heating and heat dissipation, and can effectively avoid implosion, and synthesize bisphenol A type high molecular weight polycarbonate polyether polyol by a one-step method. The production process has no amplification effect, is suitable for industrial large-scale production of bisphenol A type high molecular weight polycarbonate polyether polyol, and can solve CO 2 The problem of rapid consumption causing the ester content to decrease and the product to turn yellow is solved, which effectively improves the overall conversion rate and safety, has high production efficiency, and effectively reduces production costs.
[0009] The present invention provides a production process of bisphenol A type high molecular weight polycarbonate polyether polyol, which is carried out in an integrated tube-in-tube reaction device, wherein the integrated tube-in-tube reaction device comprises a premixing unit and a reaction unit, wherein the premixing unit is used to introduce CO into the total amount of epoxy compound, bisphenol A and catalyst.2 Premixing is performed to obtain a premixed mixture; the reaction unit comprises at least one reaction pipe; the production process comprises:
[0010] The premixture is introduced into the reaction pipe at one time and CO at a first pressure value is introduced. 2 , then the reaction pipe is heated to 75-85° C. to carry out polymerization reaction;
[0011] In the polymerization process, the reaction materials are controlled to circulate in the reaction pipe along the first direction, and the CO 2 The gas circulates in the reaction pipe along a second direction, the first direction and the second direction are opposite; and when the temperature of the material in the reaction pipe rises sharply, CO with a second pressure value is introduced into the reaction pipe. 2 gas, until the material temperature in the reaction pipe drops to 75-85°C, wherein the judgment index of the rapid rise of the material temperature is that the temperature rises by not less than 5°C within 1 minute, and the second pressure value is greater than the first pressure value; so that the bisphenol A type high molecular weight polycarbonate polyether polyol separated after the reaction satisfies: carbonate chain segment ratio F CO2 Greater than 55%, and in the L*a*b* color system, the b* value does not exceed 0.1.
[0012] Specifically, the value of the L*a*b* color system can be obtained by a colorimeter. In the L*a*b* color system, the coordinate L* represents the color brightness, L*=0 indicates black, and L*=100 indicates white. The coordinate a* represents the position between red / magenta and green, a* is a negative value indicating green, and a* is a positive value indicating magenta. The coordinate b* represents the position between yellow and blue, b* is a negative value indicating blue, and b* is a positive value indicating yellow. The larger the b* value, the more serious the yellowing of the sample. Further, the product obtained by the embodiment of the present invention has an a* value of less than 0.1, and a b* value of less than 0.1, and the product is close to colorless.
[0013] Specifically, the carbonate chain ratio F CO2 Used to characterize the ester content of the product, F CO2 The higher the F, the higher the ester content. CO2 With the help of 1 H-NMR was used to determine the product 1 The integral area of the H-NMR spectrum and its related proton peaks is used to calculate the carbonate chain ratio (molar ratio) F in the copolymerization reaction. CO2 , the specific calculation method is: F CO2 =(A 5.0 +A 4.2 -2×A 4.6 ) / [(A 5.0 +A4.2 -2×A 4.6 )+A 3.5 ]×100%; among which, A 5.0 represents the integrated area of the peak at 5.0 ppm, A 4.2 represents the integrated area of the peak at 4.2 ppm; A 4.6 represents the integrated area of the peak at 4.6 ppm, A 3.5 It represents the integrated area of the peak at 3.5ppm; 5.0ppm and 4.2ppm belong to the integrated area of the proton peaks on the methine and methylene on the polycarbonate chain segment; 4.9ppm, 4.6ppm, 4.5ppm and 4.1ppm belong to the proton peaks on the methine and methylene in the five-membered ring carbonate, and 3.5-3.8ppm belongs to the proton peak of the ether chain segment.
[0014] In an exemplary embodiment of the present invention, when the premixture is introduced into the reaction pipe, the premixture accounts for 50%-80% of the volume of the reaction pipe.
[0015] In an exemplary embodiment of the present invention, CO at a second pressure value is introduced into the reaction pipe. 2 Gas, control the CO 2 The temperature of the gas is 30~45℃.
[0016] In an exemplary embodiment of the present invention, the first pressure value is 2-6 MPa, and the second pressure value is 4-8 MPa.
[0017] In an exemplary embodiment of the present invention, a heat exchange medium circulates outside the reaction pipe to control the temperature of the material, and a CO with a second pressure value is introduced into the reaction pipe. 2 While the gas is being heated, the temperature of the heat exchange medium is reduced, and the reduced temperature of the heat exchange medium is roughly equal to the increased temperature of the material.
[0018] In an exemplary embodiment of the present invention, during the process of raising the temperature of the reaction pipe to 75-85° C., the temperature difference between the heat exchange medium and the temperature of the material in the reaction pipe is controlled to be no more than 3-5° C.
[0019] In an exemplary embodiment of the present invention, during the polymerization reaction, the lowered temperature of the heat exchange medium is controlled to be approximately equal to the increased temperature of the reaction pipe, so that the material temperature in the reaction pipe is maintained at 75-85°C.
[0020] In an exemplary embodiment of the present invention, the reaction pipeline includes an upper dispersion sheet, a gas-liquid mass transfer zone, a solid-liquid mixing zone and a lower dispersion sheet arranged in sequence from top to bottom, wherein the upper dispersion sheet is used to disperse and control the material to be dispersed into liquid beads in the gas-liquid mass transfer zone for mass transfer and heat transfer without contacting the pipeline wall; the solid-liquid mixing zone is used to realize real-time mixing and polymerization reaction of the material; the lower dispersion sheet is used to disperse CO 2 , so that the bottom material of the reaction pipe is 2 Full contact; after the material in the reaction pipeline is dispersed by the upper dispersion sheet, it flows from the gas-liquid mass transfer zone to the solid-liquid mixing zone, and then flows back to the gas-liquid mass transfer zone through the upper dispersion sheet.
[0021] In an exemplary embodiment of the present invention, the length of the gas-liquid mass transfer zone accounts for 20% to 50% of the length of the reaction pipe.
[0022] In an exemplary embodiment of the present invention, the solid-liquid mixing zone is provided with a static mixer or a dynamic mixer.
[0023] In an exemplary embodiment of the present invention, the upper dispersion sheet is disposed at a position of 10 to 50 mm near the top of the reaction pipe, and the lower dispersion sheet is disposed at a position of 10 to 50 mm near the bottom of the reaction pipe.
[0024] In an exemplary embodiment of the present invention, the circulating flow of the reaction material is controlled by a liquid circulation pump, the reaction pipeline has a feed end and a discharge end, and the first direction is the direction from the feed end to the discharge end.
[0025] In an exemplary embodiment of the present invention, CO is controlled by a gas circulation pump. 2 The gas circulates in a direction from the discharge end to the feed end.
[0026] In an exemplary embodiment of the present invention, one cycle is defined as the reaction mixture product flowing through the discharge end of the reaction pipe being circulated to the feed end of the reaction pipe via the liquid circulation pump, and reaching the discharge end after passing through the upper dispersion plate, gas-liquid mass transfer zone, solid-liquid mixing zone and lower dispersion plate of the reaction pipe.
[0027] In an exemplary embodiment of the present invention, the circulation flow rate of the liquid circulation pump is 1-20 minutes to complete one cycle. Further preferably, the circulation flow rate of the liquid circulation pump is 10-15 minutes to complete one cycle, and more preferably, the circulation flow rate of the liquid circulation pump is 10 minutes to complete one cycle.
[0028] In an exemplary embodiment of the present invention, the pressure increase ratio of the gas circulation pump is 20:1-60:1.
[0029] In an exemplary embodiment of the present invention, the reaction unit is provided with a plurality of the reaction pipes arranged in parallel, and each of the reaction pipes is provided with the gas circulation pump to realize gas circulation in the reaction pipe.
[0030] In an exemplary embodiment of the present invention, the feed ends of the plurality of reaction pipes are connected to a liquid distributor through a connecting pipe, and the discharge ends of the plurality of reaction pipes are connected to a liquid circulation pump through a connecting pipe. One end of the liquid distributor is provided with a feed port connected to the premixing unit, and the other end is connected to the liquid circulation pump. Each of the reaction pipes is provided with a CO supply port. 2 The mixed products flowing out of the multiple reaction pipes are gathered together in the liquid circulation pump, and after being pumped into the liquid distributor by the liquid circulation pump, they are dispersed into the multiple reaction pipes.
[0031] In an exemplary embodiment of the present invention, the number of the reaction pipes is 2 to 20.
[0032] In an exemplary embodiment of the present invention, during the reaction process, the gas-liquid volume ratio in the reaction pipe is controlled to be 1:1-4.
[0033] In an exemplary embodiment of the present invention, the mass ratio of the bisphenol A to the volume ratio of the epoxy compound is (40-50) g:1L.
[0034] In an exemplary embodiment of the present invention, during the premixing process of the premixing unit, the temperature of the premixing unit is controlled to be 0-40°C, and CO is introduced. 2 The pressure is 0.1~2MPa and the premixing time is 1~2h.
[0035] In an exemplary embodiment of the present invention, when the materials of the premixing unit are fed into the reaction unit, the temperature of the reaction pipe is controlled to be 35-45°C.
[0036] In an exemplary embodiment of the present invention, when the density of the reaction product reaches 1.1-1.3 g / cm 3 , and the change is less than 0.01g / cm within 5min 3 The polymerization reaction is terminated.
[0037] In an exemplary embodiment of the present invention, the metal elements of the catalyst are only two metal elements, zinc and cobalt, except for impurities; the catalyst is obtained by reacting water-soluble metal salts of zinc and cobalt in a water-soluble solvent, and the water-soluble metal salt of cobalt is a cyanide salt of cobalt; the catalyst is modified by a mixed acid during synthesis, and the mixed acid contains at least one organic acid and at least one water-soluble inorganic acid, wherein: the water-soluble inorganic acid is selected from dilute sulfuric acid and dilute hydrochloric acid, and the pH value is between 0 and 5; the organic acid is selected from any one or more of succinic acid, glutaric acid, phthalic acid, iminodiacetic acid, pyromellitic acid and butanetetracarboxylic acid, and the molar ratio of the water-soluble inorganic acid to the organic acid is 1:10 to 10:1.
[0038] According to a second aspect of the present invention, there is provided a bisphenol A type high molecular weight polycarbonate polyether polyol prepared according to any one of the production processes described above, wherein the structural formula of the bisphenol A type high molecular weight polycarbonate polyether polyol is represented by formula (1):
[0039] Formula (1);
[0040] In formula (1), R 1 , R 2 Selected from formula (2) or OH,
[0041] Formula (2);
[0042] Wherein, in formula (2), 1≤n≤38, 1≤m≤65, * represents the connection position;
[0043] The bisphenol A type high molecular weight polycarbonate polyether polyol has a number average molecular weight of ≥3000 g / mol, a molecular weight polydispersity index PDI ≤1.5, a hydroxyl value ≤35 mgKOH / g, and a carbonate segment ratio F CO2 ≥45%.
[0044] Specifically, the polydispersity index PDI is measured by gel permeation chromatography (GPC). The smaller the PDI value, the narrower the molecular weight distribution and the more uniform the product quality. More preferably, the molecular weight polydispersity index PDI of the product obtained by this production process can be controlled between 1.1 and 1.2.
[0045] The beneficial effects of the bisphenol A type high molecular weight polycarbonate polyether polyol and its production process according to the embodiment of the present invention are:
[0046] (1) The product of the embodiment of the present invention is a bisphenol A type high molecular weight polycarbonate polyether polyol, whose molecular weight is greater than 3000, and can show unique advantages in special fields. For example, it can be used in high-performance elastomers or structural adhesives such as vibration absorbing materials, and show special properties.
[0047] (2) In the production process of bisphenol A type high molecular weight polycarbonate polyether polyol, more chain links need to be connected to bisphenol A, and CO is consumed in the material. 2 The rate becomes faster. In the reaction pipeline, the closer the material is to the bottom, the longer it takes to be heated by the tube wall, the deeper the reaction, and the CO 2 The greater the consumption, the carbon dioxide at the top will be pumped to the bottom through the liquid circulation and gas circulation process in opposite directions, forming a counter-flow with the downward moving materials, increasing the amount of carbon dioxide dissolved in the materials in the pipeline. Through the gas-liquid dual circulation, and when the temperature rises sharply, a higher pressure of CO2 is introduced. 2 Gas, through the coordinated control of the two, not only greatly improves the ester content of the product, but also can effectively avoid the yellowing problem of the product caused by reaction explosion and temperature runaway in the one-step reaction process.
[0048] (3) The molecular weight distribution of the product obtained by the present invention is narrow, and there is no amplification effect. The product molecular weight is highly controllable, the production between batches is stable, and the product quality is high. At the same time, the production process is safe, does not produce explosion, and has no amplification effect, which is suitable for industrial large-scale production. BRIEF DESCRIPTION OF THE DRAWINGS
[0049] The accompanying drawings herein are incorporated into the specification and constitute a part of the specification, illustrate embodiments consistent with the present disclosure, and together with the specification are used to explain the principles of the present disclosure. Obviously, the accompanying drawings described below are only some embodiments of the present disclosure, and for ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without creative work.
[0050] Figure 1 This is a schematic diagram of the structure of the reaction zone of the integrated tube-in-tube reaction device provided in an embodiment of the present invention, wherein the pink arrow indicates the material flow direction and the green arrow indicates the gas flow direction.
[0051] Figure 2 for Figure 1 Schematic diagram of the structure of a single reaction pipeline in the reaction zone.
[0052] Icons: 101-reaction pipeline; 102-liquid distributor; 103-liquid circulation pump; 104-feed port; 105-discharge port; 106-gas circulation pump; 201-gas replenishment port; 202-upper dispersion plate; 203-gas-liquid mass transfer area; 204-jacket; 205-temperature sensor; 206-static mixer; 207-lower dispersion plate. DETAILED DESCRIPTION
[0053] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the technical scheme in the embodiments of the present invention will be described clearly and completely below. If the specific conditions are not specified in the embodiments, they are carried out according to conventional conditions or conditions recommended by the manufacturer. If the manufacturer of the reagents or instruments used is not specified, they are all conventional products that can be purchased commercially.
[0054] The following is a detailed description of the bisphenol A type high molecular weight polycarbonate polyether polyol and its production process according to the embodiment of the present invention. The embodiment of the present invention provides a production process of bisphenol A type high molecular weight polycarbonate polyether polyol. Specifically, the bisphenol A type high molecular weight polycarbonate polyether polyol uses bisphenol A as an initiator, an epoxy compound and CO 2 Bisphenol A type high molecular weight polycarbonate polyether polyol synthesized under the action of DMC catalyst.
[0055] The structural formula of the bisphenol A type high molecular weight polycarbonate polyether polyol in the embodiment of the present invention is expressed as formula (1):
[0056] Formula (1);
[0057] In formula (1), R 1 , R 2 Selected from formula (2) or OH,
[0058] Formula (2);
[0059] Wherein, in formula (2), 1≤n≤38, 1≤m≤65, * represents the connection position;
[0060] The bisphenol A type high molecular weight polycarbonate polyether polyol has a number average molecular weight greater than 3000, a molecular weight polydispersity index PDI less than 1.5, and a carbonate chain segment ratio F CO2 Greater than 55%, and in the L*a*b* color system, the b* value does not exceed 0.1.
[0061] The present invention provides a production process for the bisphenol A type high molecular weight polycarbonate polyether polyol, which is carried out in an integrated tube reactor. By using a dedicated integrated tube reactor and controlling the gas-liquid circulation, temperature and CO 2 By finely regulating the pressure, bisphenol A type high molecular weight polycarbonate polyether polyol is synthesized in one step.
[0062] It should be noted that the one-step synthesis of bisphenol A type polycarbonate polyether polyol means that all epoxy compounds, bisphenol A and catalyst are put into the reaction device at one time, and then in the reaction process, CO 2No more raw materials are added. The epoxy compound is selected from one or more of ethylene oxide, propylene oxide, 2-butylene oxide, 1,4-butylene oxide, and epichlorohydrin. Preferably, in this embodiment, the epoxy compound is propylene oxide.
[0063] Furthermore, the DMC catalyst used in this embodiment is a mixed acid modified zinc-cobalt double metal cyanide catalyst, wherein the metal elements of the catalyst are only two metal elements, zinc and cobalt, except for impurities; the catalyst is obtained by reacting water-soluble metal salts of zinc and cobalt in a water-soluble solvent, wherein the water-soluble metal salt of cobalt is a cyanide salt of cobalt; the catalyst is modified by a mixed acid during synthesis, wherein the mixed acid comprises at least one organic acid and at least one water-soluble inorganic acid. Wherein, the water-soluble inorganic acid is selected from dilute sulfuric acid and dilute hydrochloric acid, and the pH value is between 0 and 5; the organic acid is selected from any one or more of succinic acid, glutaric acid, phthalic acid, iminodiacetic acid, pyromellitic acid and butanetetracarboxylic acid, and the molar ratio of the water-soluble inorganic acid to the organic acid is 1:10 to 10:1.
[0064] The integrated tube-lined reaction device includes a premixing zone, a reaction zone and a post-processing zone. The premixing zone includes a premixing unit, and the premixing unit has a premixing device. The raw materials are put into the premixing device for premixing. The premixed raw materials are passed into the reaction zone, and after the reaction is completed, the reaction products are passed into the post-processing zone.
[0065] Specifically, see Figure 1 and Figure 2 In a preferred embodiment, the reaction zone includes a feed port 104, a discharge port 105 and a reaction unit. The reaction unit includes a reaction pipe 101, a liquid distributor 102, a gas circulation pump 106, a liquid circulation pump 103 and a carbon dioxide gas replenishment port 201. There are multiple reaction pipes 101, and the multiple reaction pipes 101 are arranged in parallel. A jacket 204 is provided on the outside of each reaction pipe 101, and a heat exchange medium such as steam, water, and heat transfer oil is introduced into the jacket 204 to control the temperature of the reaction pipe 101. The space between the multiple reaction pipes 101 is filled with a heat exchange medium, and an insulation layer is provided on the outside of the heat exchange medium. Each reaction pipe 101 is provided with a CO supply 2The gas replenishment port 201 is used to replenish carbon dioxide into the reaction pipe 101. The feed ends of multiple reaction pipes 101 are connected to the liquid distributor 102 through connecting pipes, and the discharge ends are converged to the liquid circulation pump 103 through connecting pipes. One end of the liquid distributor 102 is provided with a feed port 104 connected to the premixing unit, and the other end is connected to the liquid circulation pump 103. Under the action of the liquid circulation pump 103, the material moves downward. Each reaction pipe 101 is connected to a gas circulation pump 106. Specifically, the air inlet of the gas circulation pump 106 is connected to the feed end of the reaction pipe 101, and the air outlet is connected to the discharge end of the reaction pipe 101, so that the CO at the top of the reaction pipe 101 is discharged. 2 Gas is input to the bottom, and CO is input to the bottom 2 The gas moves upward and the liquid material moves downward, so that the material can also absorb CO while moving in the pipeline. 2 .
[0066] Further preferably, each reaction pipeline 101 has the same material circulation path as the connecting pipeline and the liquid circulation pump 103. The number of reaction pipelines 101 is 2 to 20, for example, 4, 8, etc. The multiple reaction pipelines 101 are independent of each other and are provided with independently controllable valves. By independently controlling each reaction pipeline 101, when the local temperature of a certain reaction pipeline 101 is too high or other undesirable conditions occur, it can be controlled separately in time to avoid affecting the entire reaction process.
[0067] Further preferably, the center distance between two adjacent reaction pipes 101 is less than or equal to 2 times the inner diameter of the reaction pipe 101. Further preferably, the inner diameter of the reaction pipe 101 is 100-1500 mm. Further preferably, the ratio of the length L of the reaction pipe 101 to the inner diameter d is 10≤L:d≤40. When the inner diameter of the reaction pipe 101 is too small, the efficiency of gas-liquid mass transfer is insufficient, and the ideal bisphenol A type high molecular weight product cannot be obtained, and it is easy to cause implosion due to the lack of carbon dioxide participation. When the inner diameter is too large, it is easy to cause the solid-liquid mixing unit to fail to mix the material heat uniformly in time, and the temperature difference between the central area and the outer area of the raw material in the pipe is too large, resulting in a wide molecular weight distribution of the product, and the polydispersity index PDI is greater than 1.5. By adjusting the aspect ratio of the reaction pipe 101 between 10 and 40, the gas-liquid mass transfer efficiency can be improved and the solid-liquid mixing requirements can be met, and the heat release requirements can be met at the same time, thereby ensuring the uniformity and stability of the product quality.
[0068] For further details, please refer to Figure 2As shown, the reaction pipe 101 is provided with an upper dispersion sheet 202, a gas-liquid mass transfer area 203, a solid-liquid mixing area and a lower dispersion sheet 207 from top to bottom. The upper dispersion sheet 202 is used to disperse and control the material to disperse into liquid droplets in the gas-liquid mass transfer area 203 for mass transfer and heat transfer without contacting the pipe wall. The solid-liquid mixing area is used to achieve real-time mixing and polymerization of the material. The lower dispersion sheet 207 is used to disperse CO 2 , so that the bottom material of the reaction pipe is 2 After being dispersed by the upper dispersion sheet 202, the material in the reaction pipe 101 flows from the gas-liquid mass transfer area 203 to the solid-liquid mixing area, and then flows back to the gas-liquid mass transfer area 203 through the upper dispersion sheet 202. The upper dispersion sheet 202, the gas-liquid mass transfer area 203, the lower dispersion sheet 207, the gas circulation pump 106 and the liquid circulation pump 103 together constitute a gas-liquid mixing heat conduction unit, so that the material and CO 2 Mass transfer and heat transfer are carried out to make CO 2 Mixtures with lower content redissolve CO 2 , and heat exchange is performed in the gas-liquid mixing heat conduction unit at the same time. The solid-liquid mixing area and the liquid circulation pump 103 together constitute a solid-liquid mixing unit to evenly disperse the catalyst and disperse the reaction heat in the reaction pipeline, reduce the temperature difference between the center temperature and the tube wall in the reaction pipeline, and avoid the generation of explosion points. A static mixer or a dynamic mixer is provided in the solid-liquid mixing area. Preferably, in this embodiment, a static mixer is provided in the solid-liquid mixing area. The static mixer can be, for example, a DSR static mixer, a Kenics mixer, etc., but is not limited thereto.
[0069] Further preferably, during the reaction process, the gas-liquid volume ratio in the reaction pipe 101 is controlled to be 1:1-4. For example, the gas-liquid volume ratio of the reaction pipe is 1:1, 1:2, 1:4, etc. It is understandable that, for example, if the volume of the reaction pipe is 8L and 4L of material is introduced, the gas-liquid volume ratio is 1:1. By controlling the gas-liquid ratio in the reaction pipe, the ratio of gas to liquid is ensured to be appropriate. If the gas-liquid ratio is too low, it will not only cause the CO 2 The regional mass transfer and heat transfer efficiency deteriorates, causing the ester content to decrease and the color to turn yellow. It is also easy to cause the heat of generation of the material during the reaction to increase, making temperature control more difficult and prone to explosion.
[0070] Further preferably, the upper dispersion sheet 202 is arranged at a position of 10 to 50 mm near the top of the reaction pipe 101, and the lower dispersion sheet 207 is arranged at a position of 10 to 50 mm near the bottom of the reaction pipe 101. A plurality of dispersion holes are provided on the upper dispersion sheet 202 and the lower dispersion sheet 207. More preferably, the plurality of dispersion holes are arranged in an array, for example, in a rectangular array or an annular array. More preferably, the spacing between two adjacent dispersion holes is 2 to 5 mm, and the dispersion holes are circular, elliptical or polygonal. For example, in one preferred embodiment, the dispersion hole is elliptical, with a major axis of 2 mm and a minor axis of 1 mm. More preferably, the hole spacing between two adjacent dispersion holes is 3 mm. By setting the upper dispersion sheet 202, the reaction materials can be evenly dispersed, and flow down in a water droplet shape at the end, increasing the mass transfer and heat transfer area. The static mixer 206, the liquid circulation pump 103 and the gas circulation pump 106 built in the coordinated reaction pipe 101, the entire circulation dispersion system can replace the traditional stirring process to continuously mix the reaction materials during the circulation process. At the same time, the upper dispersion sheet 202 and the lower dispersion sheet 207 can effectively enable the reaction materials to perform better gas-liquid mass transfer in the gas region and release excess heat.
[0071] Further preferably, a temperature sensor is provided inside the reaction pipe 101, and a density detector is provided at the outlet, and the jacket temperature is adjusted according to the material density and the temperature inside the reactor to control the reaction rate. Specifically, in one embodiment, the reaction pipe 101 is provided with at least three temperature sensors 205 in the area where the material reacts, for example, temperature sensors are provided in the upper part, the middle part and the lower part, so as to more comprehensively monitor the temperature inside the reaction pipe 101.
[0072] The production process of bisphenol A type high molecular weight polycarbonate polyether polyol provided in the embodiment of the present invention comprises the following steps:
[0073] (1) At a temperature of 0-40°C, add all the epoxy compounds, bisphenol A and catalyst to the premixing unit at once, and introduce CO 2 Mix to obtain a premix. Specifically, in the premix unit, carbon dioxide is provided by a carbon dioxide storage tank or carbon dioxide recovered and purified by a carbon dioxide purification device, and is passed into the premix unit. The propylene oxide raw material is purified by the propylene oxide purification device and enters the premix unit in the carbon dioxide atmosphere through a metering pump. A fixed amount of bisphenol A and a catalyst are added to the premix unit using a weighing bucket. After the raw materials are mixed in the premix unit, a premix is obtained. Preferably, CO is passed into 2 The pressure is 0.1-2 MPa and the premixing time is 1-2 hours. More preferably, the premixing time is 1 hour.
[0074] (2) The premix is fed into the reaction pipe 101 of the reaction zone through the feed port 104 at one time. When the raw materials enter the reaction pipe 101, the reaction unit is controlled to meet the following conditions: the temperature of the reaction pipe 101 is 35-45°C, CO 2 The pressure is 0.1-2 MPa. More preferably, during the feeding process, the temperature is low to prevent the initiator from decomposing into small molecules.
[0075] (3) When the raw materials are completely fed in, the feeding is completed. Carbon dioxide is supplemented through the carbon dioxide gas inlet 201 to make the pressure in the reaction pipe 101 a first pressure value. Preferably, the first pressure value is 2-6 MPa, and more preferably, the first pressure value is 3 MPa. When the pressure is too low, carbon dioxide is introduced from the carbon dioxide gas inlet 201 to supplement the pressure. Specifically, CO2 is supplemented in the reaction pipe 101. 2 Automatic control via a pressure regulating valve.
[0076] (4) Turn on the liquid circulation pump 103 and the gas circulation pump 106, and adjust the temperature of the heat exchange medium in the jacket 204 to raise the temperature of the reaction pipe 101 to a preset reaction temperature, wherein the preset reaction temperature is 80±5°C, for example, 80°C, and during the heating process of the reaction pipe 101, a slow heating control can be performed, that is, the temperature difference between the temperature of the heat exchange medium in the jacket 204 and the temperature of the material in the reaction pipe 101 is controlled to be no more than 3-5°C. Preferably, the temperature difference between the temperature of the heat exchange medium in the jacket 204 and the temperature of the material in the reaction pipe 101 is controlled to be 2°C, and the temperature of the reaction pipe 101 is slowly raised until the temperature of the reaction pipe 101 reaches 80±5°C. More preferably, during the heating process, the temperature value measured by the temperature sensor installed in the middle of the reaction pipe 101 is used as the actual temperature of the reaction pipe 101. Through the above slow heating process, it is possible to avoid the material temperature rising too fast, causing bisphenol A to be decomposed into small molecules, which affects the polymerization reaction effect and product quality.
[0077] (5) After the temperature is raised to the preset reaction temperature of 80±5°C, the liquid circulation pump 103 and the gas circulation pump 106 are kept turned on to carry out the polymerization reaction. During the polymerization reaction, the temperature in the reaction pipe 101 is monitored in real time. When the temperature of the reaction pipe 101 rises, the temperature of the medium in the jacket 204 is correspondingly reduced. The reduced temperature of the medium in the jacket 204 is roughly equal to the increased temperature of the reaction pipe 101, so that the material temperature is maintained at 80±5°C. Specifically, in the above process, when the temperature of any temperature sensor in the reaction pipe 101 rises, the temperature of the medium in the jacket 204 is correspondingly reduced, so that the temperatures of the upper, middle and lower regions of the reaction pipe 101 are kept relatively constant.
[0078] At the same time, during the above-mentioned polymerization reaction, when the reaction is more intense or the reaction rate in a local area is too fast, the temperature will rise sharply. When the temperature of any temperature sensor in the reaction pipeline 101 is detected to rise sharply, the purified CO provided by the carbon dioxide purification unit is 2 The gas is fed into the reaction pipe through the carbon dioxide gas inlet 201, and the temperature of the heat exchange medium in the jacket is reduced until the temperature of the reaction pipe 101 is reduced to a preset temperature of 80±5°C. 2 When the gas is added, the gas temperature is 35-45°C, and the pressure in the reaction zone is a second pressure value, which is 4-8 MPa and greater than the first pressure value. 2 The temperature of the gas is 40°C and the second pressure value is 4 MPa. Further, in this process, the lowered temperature of the heat exchange medium is roughly equal to the increased temperature of the reaction pipe 101. For example, if the temperature of the reaction pipe increases by 8°C, the temperature of the heat exchange medium is reduced by 8°C.
[0079] Among them, the judgment index for the rapid rise of material temperature is that the temperature rise is not less than 5℃ within 1 minute. When the temperature rises sharply, CO with a temperature of 40℃ is added. 2 Purify the gas and reduce the temperature of the heat exchange medium, and increase the gas-liquid mass transfer degree while rapidly cooling. The gas-liquid mixed heat transfer unit makes the CO 2 Mixtures with lower content redissolve CO 2 , so that there is always enough CO 2 Participate in the reaction and exchange heat in the gas-liquid mixed heat transfer unit. At the same time, the CO at the bottom of the reaction pipe 2 The raw material with lower content dissolves new CO 2 Participate in the reaction and return to the gas area at the top of the reaction pipe to fully dissolve CO 2 , ensuring that there will be no CO in all reaction unit areas during the synthesis process. 2 Furthermore, the mixing of the reactants and the release of reaction heat by the solid-liquid mixing unit and the gas-liquid mixing heat transfer unit further reduce the molecular weight distribution and consume CO 2 After that, CO 2 The air supply port continuously replenishes CO 2 To maintain the reaction pressure, the addition of low-temperature carbon dioxide allows the heat of reaction to be effectively released here.
[0080] Further preferably, in the above reaction process, the density is taken as the reaction end point, and when the density reaches 1.1-1.3 g / cm 3 The change is less than 0.01g / cm2 within 5 minutes. 3The polymerization reaction is terminated when the reaction is terminated.
[0081] Further preferably, in the above-mentioned reaction process, the reaction mixture product at the discharge end of the reaction pipeline 101 converges on the liquid circulation pump 103 via one end connecting pipeline, and converges on the liquid distributor 102 at the top of the reaction pipeline 101 through the liquid circulation pump 103 and the connecting pipeline at the other end, and then reaches the discharge end after passing through the upper dispersion sheet 202, the gas-liquid mass transfer area 203, the solid-liquid mixing area and the lower dispersion sheet 207 of the reaction pipeline 101, completing a cycle. The circulation flow rate of the liquid circulation pump 103 is 10~15min to complete a cycle. More preferably, the circulation flow rate of the liquid circulation pump is 10min to complete a cycle. By regulating the circulation flow rate of the liquid circulation pump 103, it is ensured that the reaction process fully carries out processes such as heat conduction, gas-liquid mass transfer and solid-liquid mixing, and the reaction process is ensured to be stable, and the quality and production efficiency of the product are improved.
[0082] (6) After the reaction is completed, the reaction product is a mixture containing polycarbonate polyether polyol, cyclic carbonate and unreacted raw material propylene oxide, which flows out from the discharge port 105. The single discharge of the discharge port 105 is not more than 80% of the volume of the reaction pipe 101. The reaction product is then passed into the separation unit of the post-treatment area, and the separation unit separates the propylene oxide and dissolved CO in the mixture. 2 The crude product is separated to obtain a crude product, and the viscosity of the crude product is adjusted at the same time. The crude product is passed into a refining unit, a refining agent is added for adsorption treatment, and a crude product with a catalyst metal content of less than 10 ppm is obtained after filtration. The refined crude product is passed into a rectification unit to separate the main product polycarbonate polyether polyol and the by-product cyclic carbonate, that is, the polycarbonate polyether polyol product is obtained, and enters a filling unit for filling.
[0083] It should be noted that the above-mentioned premixing unit, separation unit, refining unit, distillation unit, filling unit, etc. can all refer to the existing structure and will not be described in detail here.
[0084] The features and performance of the present invention are further described in detail below in conjunction with the embodiments.
[0085] Example 1
[0086] This embodiment provides a bisphenol A type high molecular weight polycarbonate polyether polyol, using the above-mentioned integrated tube reactor, the reaction process is as follows:
[0087] 8 L of propylene oxide, 4 g of DMC catalyst, and 373 g of bisphenol A were added to the premixing device respectively, and 0.4 Mpa of carbon dioxide was introduced and mixed and stirred at a temperature of 40 ° C. After stirring for 1 hour, the mixture was pressed into an 8L×2 integrated tube reactor, that is, the gas-liquid ratio was 1:1, the diameter of a single reaction pipe was 100 mm, and the length of the reaction pipe was 1000 mm. After all were pressed in, carbon dioxide was introduced into the reaction pipe to 3 Mpa and the pressure was maintained. The liquid circulation pump and the gas circulation pump were turned on, the reaction materials moved from top to bottom, and the gas moved from bottom to top. The liquid flow rate was controlled to complete a cycle for 10 minutes, and the pressure ratio of the gas circulation pump was 40:1. Then the temperature difference between the medium temperature in the jacket and the material temperature was controlled to be 3 ° C, and the temperature in the reaction pipe was slowly increased until the temperature of the material in the reaction pipe was increased to 80 ° C.
[0088] During the polymerization reaction, the temperature was monitored and the following steps were performed:
[0089] (1) When the temperature of the temperature sensor in the middle of the reaction pipe (i.e., the material temperature) is monitored to be higher than 80°C, the temperature of the heat exchange medium in the jacket is reduced. The reduced temperature of the heat exchange medium is equal to the difference of the temperature sensor greater than 80°C, so that the material temperature is kept balanced at 80°C.
[0090] (2) When the temperature of any temperature sensor in the reaction pipeline is greater than 85°C, CO 2 The purification system is fed with CO through the gas inlet. 2 , the gas temperature is 40°C, and the pressure is supplemented to 4MPa. At the same time, the medium temperature in the jacket is reduced (the reduced temperature is roughly equal to the increased temperature of the material) until the material temperature is reduced to 80°C.
[0091] After 3 hours of reaction, the density increased uniformly to 1.12 g / cm 3 And stable (change within 5 minutes is less than 0.01g / cm 3 ), at which point the reaction is complete, the temperature is lowered and the product is taken out. After the catalyst is removed by the catalyst filter, the main and by-products are separated using a scraper evaporator.
[0092] The DMC catalyst is a zinc-cobalt double metal cyanide complex catalyst obtained by reacting water-soluble metal salts of zinc and cobalt in a water-soluble solvent. The specific preparation method is as follows: potassium hexacyanocobaltate and zinc bromide in a molar ratio of 1:4 are weighed, dissolved in an aqueous solvent containing water and tert-butyl alcohol, and stirred continuously, and the total mass of the metal salt (i.e., cobalt salt and zinc salt) and the mass ratio of the aqueous solvent are 1:5. Inorganic acid and organic acid are added, the inorganic acid is dilute hydrochloric acid, the pH value is 2, the organic acid is glutaric acid, the molar ratio of the inorganic acid to the organic acid is 5:1, and the total molar number of the metal salt to the molar number of the acid is 4:1. Stir for several hours at a temperature of 10-100°C, and precipitate is continuously generated. The above precipitate is filtered and dried to obtain a filter cake. The filter cake is re-slurried and washed with an aqueous solvent at a temperature of 10-100°C, specifically, the washing temperature is 100°C, washing for 3 minutes, stirring for several hours, and then filtered and dried to obtain a filter cake, and the above slurrying, washing, and drying steps are repeated for multiple times at a temperature of 10-100°C until the pH value of the system liquid is 6-7, specifically, the temperature is 60°C, and each time for 6 minutes. The filter cake is further dried under vacuum conditions at 80-100°C to obtain the final catalyst, and the catalyst is processed into powder particles by mechanical grinding under anhydrous drying conditions before use.
[0093] The purified product is sampled and analyzed. Specifically, the polymerization reaction product (polycarbonate-polyether polyol and cyclic propylene carbonate and unreacted propylene oxide) is sampled and collected in a container, and the polymerization reaction product sample is characterized by nuclear magnetic resonance hydrogen spectrum to calculate the ratio of polymer to cyclic small molecules in the crude product. After the polymer is purified, nuclear magnetic resonance hydrogen spectrum test is performed again to calculate the ratio of polycarbonate chain segments to polyether chain segments on the polymer main chain. There are only two structures, polycarbonate chain segments and polyether chain segments, on the polymer main chain, and the sum of the two percentages is 100%.
[0094] With the help of 1 The amount of carbon dioxide introduced in the obtained polycarbonate polyether polyol (carbonate segment content) and the ratio of propylene carbonate (cyclic carbonate) to polycarbonate polyether polyol were determined by H-NMR (Bruker, DPX400, 400 MHz; pulse program zg30, waiting time d1:10 s, 64 scans). In each case, the sample was dissolved in deuterated chloroform. 1 The relevant resonant proton peaks in H-NMR (based on TMS=0ppm) are as follows:
[0095] Among them, 5.0ppm and 4.2ppm belong to the proton peaks of the methine and methylene on the polycarbonate chain, 4.9ppm, 4.5ppm and 4.1ppm belong to the proton peaks of the methine and methylene in the five-membered ring carbonate, and 3.5-3.8ppm belong to the proton peak of the ether chain. The capital letter A plus a numerical subscript represents the integrated area of the peak at a certain ppm on the nuclear magnetic resonance hydrogen spectrum, for example, A5.0 represents the integrated area of the peak at 5.0 ppm. 1 The integral area of the H-NMR spectrum and its related proton peaks is used to calculate the carbonate chain ratio (molar ratio) F in the copolymerization reaction. CO2 and cyclic carbonate content mass fraction W PC、 The amount of carbon dioxide embedded M CO2 , the specific calculation method is as follows:
[0096] F CO2 =(A 5.0 +A 4.2 -2×A 4.6 ) / [(A 5.0 +A 4.2 -2×A 4.6 )+A 3.5 ]×100%;
[0097] W PC =102×A 1.5 / [102×(A 5.0 +A 4.2 -2×A 4.6 +A1.5)+58×A 3.5 ]×100%;
[0098] M CO2 =44×F CO2 / [102×F CO2 +58×(1-F CO2 )]×100%.
[0099] The coefficient 44 is the molar mass of carbon dioxide, the coefficient 58 is the molar mass of PO (propylene oxide), and the coefficient 102 is the sum of the molar masses of carbon dioxide (molar mass 44 g / mol) and PO (molar mass 58 g / mol).
[0100] The formula for calculating the product conversion rate n is n=m×(1-M CO2 ) / (Mm×M CO2 ), wherein m is the mass of the product after removing propylene oxide, and M is the total sample mass containing propylene oxide.
[0101] The polymer number average molecular weight (Mn) and polymer molecular weight polydispersity index (PDI) were determined by gel permeation chromatography (GPC).
[0102] The hydroxyl value (OHV) is obtained by GB / T 12008.3-2009 Plastic polyether polyols Part 3: Determination of hydroxyl value.
[0103] The final product was tested for colorimetry. 5g of the test object was placed in a cuvette and the cuvette was placed in a dark environment to reduce the influence of the light source on the test and cause errors. The NR10QC colorimeter was used for the test, and the test data included three basic indicators: L*, a*, and b*.
[0104] The L* value represents the color brightness, L*=0 indicates black, and L*=100 indicates white.
[0105] The a* value represents the position between red / magenta and green, with negative a* values indicating green and positive a* values indicating magenta.
[0106] The b* value represents the position between yellow and blue, with a negative b* value indicating blue and a positive b* value indicating yellow.
[0107] The smaller the absolute values of a* and b*, the better; the smaller they are, the closer they are to colorless.
[0108] The test results are shown in Table 1 below:
[0109] Table 1
[0110]
[0111] As can be seen from Table 1, the production process provided by the embodiment of the present invention can fully react the raw materials at 80°C, and the molecular weight distribution of the prepared polycarbonate polyether polyol is narrower, distributed around 1.1. The carbonate chain ratio is higher, above 55%, that is, the carbon dioxide fixation rate is high, and there is no CO2 reduction caused by the increase in bisphenol A content. 2 The fixation rate decreases. In addition, the above process can achieve a given conversion rate in a shorter time, and the energy consumption is relatively less. In addition, the obtained product has excellent quality, the b* value is less than 0.1 and close to 0, and no yellowing occurs.
[0112] Example 2
[0113] This embodiment provides a bisphenol A type high molecular weight polycarbonate polyether polyol, referring to the production process in Example 1, which differs from that in Example 1 in that:
[0114] The raw materials added were: 32L propylene oxide, 16g DMC catalyst, 1492g bisphenol A, and an 8L×8 integrated tube reactor was used.
[0115] Example 3
[0116] This embodiment provides a bisphenol A type high molecular weight polycarbonate polyether polyol, referring to the production process in Example 1, which differs from that in Example 1 in that:
[0117] The amount of raw materials added is: 300L propylene oxide, 150g DMC catalyst, 14kg bisphenol A, and a 240L×2 integrated tube reactor is used. The reaction pipe has a diameter of 220mm and a length of 8600mm. When the liquid in the reaction pipe is greater than 10%, the liquid circulation pump and the gas circulation pump are turned on.
[0118] Example 4
[0119] This embodiment provides a bisphenol A type high molecular weight polycarbonate polyether polyol, referring to the production process in Example 1, which differs from that in Example 1 in that:
[0120] The gas-liquid ratio is 1:4.
[0121] Example 5
[0122] This embodiment provides a bisphenol A type high molecular weight polycarbonate polyether polyol, referring to the production process in Example 1, which differs from that in Example 1 in that:
[0123] The length-to-diameter ratio of the reaction pipe is 40:1.
[0124] Example 6
[0125] This embodiment provides a bisphenol A type high molecular weight polycarbonate polyether polyol, referring to the production process in Example 1, which differs from that in Example 1 in that:
[0126] The reaction temperature was 75°C.
[0127] Example 7
[0128] This embodiment provides a bisphenol A type high molecular weight polycarbonate polyether polyol, referring to the production process in Example 1, which differs from that in Example 1 in that:
[0129] The reaction temperature was 85°C.
[0130] Example 8
[0131] This embodiment provides a bisphenol A type high molecular weight polycarbonate polyether polyol, referring to the production process in Example 1, which differs from that in Example 1 in that:
[0132] The circulation speed of the reaction liquid is 15 minutes to complete one cycle.
[0133] The products obtained in Examples 2 to 8 were tested according to the method in Example 1. The test results are shown in Table 2 below.
[0134] Table 2
[0135] parameter Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 Propylene oxide (L) 32 300 12.8 32 8 8 8 DMC (g) 16 150 6.4 16 4 4 4 Bisphenol A 1492g 14kg 596.8g 1492g 373g 373g 373g Gas-Liquid Ratio 1:1 1:1 1:4 1:1 1:1 1:1 1:1 Time for liquid to complete one cycle (min) 10 10 10 10 10 10 15 Reaction temperature (℃) 80 80 80 80 75 85 80 Product conversion rate n (%) 97 97 98 98 97 98 97 <![CDATA[Proportion F of carbonate chain links CO2 (%)]]> 59 60 60 60 59 60 59 Polymer number average molecular weight Mn (g / mol) 4187 4164 4095 4173 4145 4152 4168 Hydroxyl value (mgKOH / g) 26.8 26.9 27.4 26.8 27.1 27 26.9 Polymer molecular weight polydispersity index PDI 1.16 1.15 1.13 1.15 1.16 1.15 1.13 Raw material reaction end time (h) 3 3 3 3 3 3 3 Catalyst residue (ppm) Co=4.3, Zn=8.7 Co=4.5, Zn=9.1 Co=3.1, Zn=8.5 Co=3.7, Zn=7.9 Co=3.6, Zn=8.1 Co=3.9, Zn=7.8 Co=4.1, Zn=7.6 Chroma L*=69.72a*=0.02b*=0.04 L*=69.07a*=0.02b*=0.03 L*=69.33a*=0.02b*=0.03 L*=69.64a*=0.03b*=0.03 L*=69.28a*=0.03b*=0.04 L*=69.59a*=0.02b*=0.04 L*=69.14a*=0.03b*=0.04
[0136] Relative to Example 1, Example 2 and Example 3 were scaled up in production at different ratios. As can be seen from Table 2, there were no significant fluctuations in the molecular weight, molecular weight distribution, conversion rate and other indicators of the polymers obtained in Example 2 and Example 3. Relative to Example 1, Examples 4-8 made certain adjustments in the gas-liquid ratio, reaction temperature and liquid circulation speed. Within a certain range, changing one condition alone did not cause significant fluctuations in the molecular weight, molecular weight distribution, conversion rate and other indicators of the compound. The integrated tube-in-tube reaction device provided in the embodiment of the present invention will not affect the molecular weight, molecular weight distribution, ester-ether ratio and other indicators of the polymer after being scaled up, and there is no obvious amplification effect. When the production process is scaled up, the same parallel reaction pipelines can share a set of heating equipment, which can reduce energy consumption while carrying out the method production.
[0137] Comparative Example 1
[0138] This comparative example provides a bisphenol A type high molecular weight polycarbonate polyether polyol. The process method is different from that of Example 1 in that during the polymerization reaction, no low temperature CO is added when the temperature rises sharply. 2 , the other reaction conditions were the same as those in Example 1.
[0139] Comparative Example 2
[0140] This comparative example provides a bisphenol A type high molecular weight polycarbonate polyether polyol, using the same integrated tube reactor as in Example 1, only the liquid circulation pump is turned on during the reaction, and the gas circulation pump is not turned on, and the other reaction conditions are consistent with those in Example 1.
[0141] Comparative Example 3
[0142] This comparative example provides a bisphenol A type high molecular weight polycarbonate polyether polyol. The process method is different from that of Example 1 in that the flow rate of the liquid circulation pump in the reaction unit is 22 minutes to complete one cycle, and the other reaction conditions are consistent with those of Example 1.
[0143] Comparative Example 4
[0144] This comparative example provides a bisphenol A type high molecular weight polycarbonate polyether polyol, and the reaction device is different from that of Example 1 in that a liquid circulation pump is not provided in the reaction unit. During the reaction process, only gas circulation is performed, and liquid circulation is not performed. The other reaction conditions are consistent with those of Example 1.
[0145] Comparative Example 5
[0146] This comparative example provides a bisphenol A type high molecular weight polycarbonate polyether polyol. The process method is different from that of Example 1 in that the aspect ratio of the reaction device is 50:1, and the other reaction conditions are consistent with those of Example 1.
[0147] Comparative Example 6
[0148] This comparative example provides a bisphenol A type high molecular weight polycarbonate polyether polyol. The process method is different from that of Example 1 in that the gas-liquid ratio in the reaction pipeline is 1:5, and the other reaction conditions are consistent with those of Example 1.
[0149] Comparative Example 7
[0150] The present comparative example provides a bisphenol A type high molecular weight polycarbonate polyether polyol, which is reacted in a fixed bed reactor. The reaction process is as follows: 8 L of propylene oxide, 4 g of DMC catalyst, and 373 g of bisphenol A are added to a premixing device respectively, and 0.4 Mpa of carbon dioxide is introduced and mixed and stirred at a temperature of 40°C. After stirring for 1 hour, the mixture is pressed into a fixed bed reactor and reacted at 80°C until the density is uniformly increased to 1.12 g / cm 3 The reaction is complete and the temperature is lowered to remove the product. After the catalyst is removed by the catalyst filter, the main and by-products are separated by a scraper evaporator.
[0151] The products obtained in Comparative Examples 1 to 7 were tested according to the method in Example 1. The test results are shown in Table 3 below.
[0152] Table 3
[0153]
[0154] Comparative Example 1 is compared with Example 1, in which the temperature of the reaction unit is controlled by only using a heating jacket, without using a low temperature CO 2 In addition, this method is prone to uneven heating, and the temperature at a local point rises too quickly. After the reaction starts, the temperature inside the reaction system begins to rise. When the reaction is too fast at a high temperature, there is no excess CO 2 Supplementation, leading to CO 2 The dissolution rate cannot keep up with the consumption rate, resulting in too high PDI and relatively low ester content.
[0155] Comparative Example 2 does not use gas circulation compared to Example 1, but only uses pipeline reactor and liquid circulation. Although the liquid circulation has a good gas-liquid mass transfer and heat transfer space, the material consumes CO in the process of running in the pipeline. 2 The rate of flow has become faster, and CO has been consumed 2 The material cannot return to the top in time to reabsorb CO 2 , resulting in a significant reduction in the product ester consumption content and a broadening of the molecular weight distribution.
[0156] Compared with Example 1, the liquid circulation speed in Comparative Example 3 is lower. The lower circulation speed will cause the temperature generated by the reacted materials to accumulate, which is easy to cause explosion and high-temperature oxidation of bisphenol A, resulting in the product color turning yellow. At the same time, since it cannot return to the carbon dioxide area for mass transfer in time, the carbon dioxide content is insufficient, resulting in a decrease in ester content.
[0157] Compared with Example 1, Comparative Example 4 does not perform liquid circulation, but only uses a pipeline reactor and gas circulation. Using only gas circulation will result in the solid and liquid materials being unable to be mixed evenly in the pipeline, and the temperature being unable to be efficiently conducted in the pipeline, resulting in reaction explosion, extremely wide molecular weight distribution, and extremely low ester content.
[0158] Compared with Example 1, Comparative Example 5 increases the aspect ratio of the reaction pipe. At a higher aspect ratio, the same product passes through different areas of carbon dioxide, resulting in poor mass and heat transfer efficiency, reduced ester content, and a yellower product color.
[0159] Comparative Example 6 reduces the gas-liquid ratio compared to Example 1. The reduction in the gas-liquid ratio not only results in 2 The regional mass transfer and heat transfer efficiency deteriorates, causing the ester content to decrease and the color to turn yellow. At the same time, the heat of generation of the material during the reaction increases, the difficulty of temperature control increases, and it is very easy to explode.
[0160] Compared with Example 1, Comparative Example 7 does not use a pipeline reactor, but uses a fixed bed reactor. The special structure of the pipeline reactor allows sufficient heating reaction time inside and is in a state of continuous mixing. The use of a fixed bed reactor reduces the temperature difference between the center and the tube wall, but it also causes the material to be in a state where it cannot be mixed evenly. The fast-reacting part cannot be dispersed in time, so that the local reaction rate is accelerated due to the high temperature at some points, which spreads to the entire reactor, resulting in low ester content, wide molecular weight distribution, and partial oxidation of bisphenol A to produce mixed colors.
[0161] Based on the above embodiments and comparative examples, it can be seen that the production process of bisphenol A type high molecular weight polycarbonate polyether polyol of the present invention is carried out in an integrated tube-in-tube reaction device with a special structure, the material and the gas flow in the reaction pipeline in reverse direction, and when the temperature rises sharply, a low-temperature CO with a larger pressure value is introduced. 2 Gas, so that the PDI of the obtained product is small, the carbon dioxide conversion rate is high, and the product is close to white, which effectively solves the problems of low ester content and yellowing of the product caused by the one-step production process in the prior art, and the product molecular weight distribution is narrow, and there is no amplification effect, the product molecular weight is highly controllable, the production is stable between batches, and the product quality is high. At the same time, the production process is safe and controllable, it is not easy to produce explosion, there is no amplification effect, and it is suitable for industrial large-scale production.
[0162] The embodiments described above are part of the embodiments of the present invention, rather than all of the embodiments. The detailed description of the embodiments of the present invention is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. 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.
Claims
1. A production process for bisphenol A type high molecular weight polycarbonate polyether polyol, characterized in that: The process is carried out in an integrated tube-in-tube reaction device, which includes a premixing unit and a reaction unit. The premixing unit is used to introduce CO2 into the total amount of epoxy compound, bisphenol A and catalyst for premixing to obtain a premixed mixture. The reaction unit includes at least one reaction pipeline. The production process includes: Introducing the premixture into the reaction pipe at one time, and introducing CO2 with a first pressure value, and then raising the temperature of the reaction pipe to 75-85° C. to carry out a polymerization reaction; Wherein, during the polymerization reaction process, the reaction materials are controlled to circulate in the reaction pipe along a first direction, and the CO2 gas is controlled to circulate in the reaction pipe along a second direction, and the first direction and the second direction are opposite; the circulation of the reaction materials is controlled by a liquid circulation pump, and the circulation flow rate of the liquid circulation pump is 1 to 20 minutes to complete one cycle; the circulation of the CO2 gas is controlled by a gas circulation pump, and the pressure ratio of the gas circulation pump is 20:1 to 60:1; When the temperature of the material in the reaction pipe rises sharply, CO2 gas of a second pressure value is introduced into the reaction pipe until the temperature of the material in the reaction pipe drops to 75-85°C, wherein the judgment index of the sharp rise in the material temperature is that the temperature rises by not less than 5°C within 1 minute, and the second pressure value is greater than the first pressure value; so that the bisphenol A type high molecular weight polycarbonate polyether polyol separated after the reaction is completed satisfies: the carbonate segment ratio F CO2 Greater than 55%, and in the L*a*b* color system, the b* value does not exceed 0.1; When the CO2 gas of the second pressure value is introduced into the reaction pipe, the temperature of the CO2 gas is controlled to be 30-45° C., wherein the first pressure value is 2-6 MPa, and the second pressure value is 4-8 MPa; A heat exchange medium circulates outside the reaction pipe to control the temperature of the material. While CO2 gas with a second pressure value is introduced into the reaction pipe, the temperature of the heat exchange medium is reduced, and the reduced temperature of the heat exchange medium is equal to the increased temperature of the material.
2. The production process of bisphenol A type high molecular weight polycarbonate polyether polyol according to claim 1, characterized in that: When the premixture is introduced into the reaction pipe, the proportion of the premixture to the volume of the reaction pipe is 50%-80%.
3. The production process of bisphenol A type high molecular weight polycarbonate polyether polyol according to claim 1, characterized in that: The reaction pipeline includes an upper dispersion plate, a gas-liquid mass transfer zone, a solid-liquid mixing zone and a lower dispersion plate which are arranged in sequence from top to bottom. The upper dispersion plate is used to disperse and control the material in the gas-liquid mass transfer zone to be dispersed into liquid droplets for mass transfer and heat transfer without contacting the pipeline wall; the solid-liquid mixing zone is used to realize real-time mixing and polymerization reaction of the material; the lower dispersion plate is used to disperse CO2 so that the material at the bottom of the reaction pipeline is in full contact with CO2; after the material in the reaction pipeline is dispersed by the upper dispersion plate, it flows from the gas-liquid mass transfer zone to the solid-liquid mixing zone, and then flows back to the gas-liquid mass transfer zone through the upper dispersion plate.
4. The production process of bisphenol A type high molecular weight polycarbonate polyether polyol according to claim 3, characterized in that: The upper dispersion sheet is arranged at a position of 10 to 50 mm near the top of the reaction pipe, and the lower dispersion sheet is arranged at a position of 10 to 50 mm near the bottom of the reaction pipe.
5. The production process of bisphenol A type high molecular weight polycarbonate polyether polyol according to claim 1, characterized in that: The first direction is the direction from the feed end to the discharge end.
6. The production process of bisphenol A type high molecular weight polycarbonate polyether polyol according to claim 1, characterized in that: The reaction unit is provided with a plurality of reaction pipes arranged in parallel, each of the reaction pipes is provided with the gas circulation pump; the feed ends of the plurality of reaction pipes are converged to the liquid distributor through a connecting pipe, and the discharge ends of the plurality of reaction pipes are converged to the liquid circulation pump through a connecting pipe, one end of the liquid distributor is provided with a feed port connected to the premixing unit, and the other end is connected to the liquid circulation pump; the mixed products flowing out of the plurality of reaction pipes are converged together in the liquid circulation pump, and after being pumped into the liquid distributor by the liquid circulation pump, they are dispersed into the plurality of reaction pipes.
7. The production process of bisphenol A type high molecular weight polycarbonate polyether polyol according to claim 1, characterized in that: The catalyst is a DMC catalyst; the mass ratio of the bisphenol A to the epoxy compound is (40-50) g:1 L; during the mixing process of the premixing unit, the temperature of the premixing unit is controlled to be 0-40° C., the pressure of the CO2 introduced is 0.1-2 MPa, and the premixing time is 1-2 h; when the material of the premixing unit is fed into the reaction unit, the temperature of the reaction pipe is controlled to be 35-45° C.; when the density of the reaction product reaches 1.1-1.3 g / cm 3 , and the change is less than 0.01g / cm within 5min 3 The polymerization reaction is terminated; The metal elements of the catalyst are only zinc and cobalt except for impurities; the catalyst is obtained by reacting water-soluble metal salts of zinc and cobalt in a water-soluble solvent, and the water-soluble metal salt of cobalt is a cyanide salt of cobalt; the catalyst is modified by a mixed acid during synthesis, and the mixed acid contains at least one organic acid and at least one water-soluble inorganic acid, wherein: the water-soluble inorganic acid is selected from dilute sulfuric acid and dilute hydrochloric acid, and the pH value is between 0 and 5; the organic acid is selected from any one or more of succinic acid, glutaric acid, phthalic acid, iminodiacetic acid, pyromellitic acid and butanetetracarboxylic acid, and the molar ratio of the water-soluble inorganic acid to the organic acid is 1:10 to 10:
1.
8. A bisphenol A type high molecular weight polycarbonate polyether polyol prepared according to the production process according to any one of claims 1 to 7, characterized in that: The structural formula of the bisphenol A type high molecular weight polycarbonate polyether polyol is represented by formula (1): Formula (1); Wherein, in formula (1), R1 and R2 are selected from formula (2) or OH, Formula (2); Wherein, in formula (2), 1≤n≤38, 1≤m≤65, * represents the connection position; The bisphenol A type high molecular weight polycarbonate polyether polyol has a number average molecular weight of ≥3000 g / mol, a molecular weight polydispersity index PDI ≤1.5, a hydroxyl value ≤35 mgKOH / g, and a carbonate segment ratio F CO2 ≥45%.
Citation Information
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