Method for preparing bio-based polyol and use of bio-based polyol

Abstract

To provide a method for preparing a bio-based polyol and a use of the bio-based polyol.SOLUTION: A first ring-opening reaction of epoxy is performed by using tartaric acid ester as a first ring-opening reagent, then, a second ring-opening reaction is performed by using a second ring-opening reagent containing secondary alcohol, and finally, a third ring-opening reaction of remained epoxy is performed by using primary alcohol to obtain a bio-based polyol product having an epoxy value of approximately 0.EFFECT: Bio-based polyol prepared in the present invention is appropriately and uniformly distributed, has low viscosity, and can replace conventional petrochemical material-derived polyol, and polyurethane coating produced by using bio-based polyol prepared by the method of the present invention has significantly improved performance.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to the technical field of polyol production, and specifically to a method for producing and using bio-based polyols.

Background Art

[0002] Polyurethane is a polymer having a repeating structural unit of urethane segments, which is produced by the reaction of polyol and isocyanate. Polyurethane products are classified into two categories: foamed products and non-foamed products. Foamed products include soft, hard, and semi-hard polyurethane foams, and non-foamed products include paints, binders, synthetic leathers, elastomers, and elastic fibers. Among the two types of monomers used in the synthesis of polyurethane, one type of isocyanate product has few varieties, mainly including MDI, TDI, etc. The other monomer, alcohol, has many varieties, various qualities, and diverse downstream applications, so further research is needed.

[0003] The development of vegetable oil polyols is considered to be an effective method for developing bio-based materials. Vegetable oil polyols, as an important monomer of bio-based polyurethane materials, are derived from a chemically modified molecular structure using vegetable oil as a raw material. They are important renewable resources, react with isocyanate-based compounds to produce polyurethane, and are suitable as alternative raw materials for petroleum-based polyols.

[0004] Currently, in the field of bio-based polyurethane foamed products, many brands are on the market. However, in the field of paints, the development of bio-based polyols derived from vegetable oils is relatively lagging behind. Especially in anticorrosive paints, currently, polyurethane paints developed using bio-based polyols are difficult to achieve both performance in terms of hardness, toughness, and corrosion resistance.

[0005] Scientific researchers have conducted a lot of research in this field. The main methods for synthesizing vegetable oil polyols are as follows. 1) An alcoholysis reaction is carried out between vegetable oil and polyol using the basic core of triglyceride to produce a polyhydroxy compound. In this method, a highly functional polyol monomer can be obtained, but due to the non-uniform hydroxy group distribution and inability to control it, its applications are limited. 2) Ozone is used to oxidize the unsaturated double bonds in vegetable oil to produce a polyhydroxy compound with terminal hydroxy groups. In this method, highly reactive terminal hydroxy groups can be obtained, but due to low atom economy and low functionality, downstream applications are also greatly restricted. 3) Vegetable oil is oxidized to epoxidized vegetable oil, and a polyhydroxy compound is produced through ring-opening reactions, etc. This method has the advantages of high atom economy, flexibility, structure controllability, and molecular diversity, and is currently the main method used for developing bio-based polyols.

[0006] The long-chain groups within the structure of vegetable oils replace the repeating units of polyethers or polyesters of conventional petrochemical polyols. The basic core of triglycerides within their structure has a star-shaped spatial structure, which gives more functional characteristics and application possibilities to downstream polyurethanes. However, vegetable oil polyols often have performance defects. The main reason is that it is difficult to control the reaction process. In the functional group conversion process, multiple epoxy groups and ester groups are often involved in multiple side reactions. Therefore, it is difficult to construct the designed molecular structure using conventional chemical methods, and the quality of the polyol is greatly restricted. In many cases, it is necessary to mix with conventional petrochemical polyols to achieve specific application effects. Through the analysis of the reaction mechanism, it has been found that the main reasons are as follows. Oil esters often have low miscibility with reaction reagents, low reactivity, and require long-term and high-intensity reactions. However, due to the influence of multiple functional groups within the structure, it is difficult to achieve both reaction selectivity and conversion rate, the controllability of the process is poor, and as a result, the molecular uniformity is poor, the viscosity is high, and the difference between the macroscopic index and the microscopic index of a single molecule becomes large. Therefore, although the price of vegetable oils is often lower than that of petrochemical repeating unit monomers, it is difficult to obtain vegetable oil polyol products that are advantageous in both cost and quality. Quality control of products through the control of chemical processes is necessary. In this reaction system, the use of microreaction technology to strengthen and continuously and accurately control the chemical reaction process is an effective solution.

[0007] Generally, polyurethane products formed from polyester polyols have better mechanical strength than those formed from polyether polyols. This is presumably due to the potential action of hydrogen bonds formed between the ester groups of the polyol and ammonia of the isocyanate. Therefore, it is conceivable to cause a ring-opening reaction between an epoxidized vegetable oil and a ring-opening reagent having an ester group, and adjust the hydroxyl value according to the structure of the ring-opening reagent to impart specific functionality. Of course, an increase in the hydroxyl value is helpful for improving strength and hardness, but it may lead to an increase in the viscosity of the polyol and a decrease in toughness. Also, previous studies have shown that although the corrosion resistance performance improves when epoxy remains, the functionality may decrease. As described above, the adjustment of functionality within the structure, the ratio of residual epoxy, the number and spatial arrangement of ester groups, the hydroxyl value, and the spatial arrangement of hydroxy groups all have a great impact on the results. These parameters also affect each other, but there is a lack of a complete structure-activity correlation, which is the main reason why the development in this field is restricted.

[0008] Since vegetable oils do not have a single component and the structure-activity correlation is not clear, it is only possible to control the quality of polyol products through the reaction process and macroscopic index control. Therefore, controlling the uniformity of the product through process control as much as possible plays an important role in the development of new polyol products and downstream applications.

Summary of the Invention

Problems to be Solved by the Invention

[0009] In view of the drawbacks of the prior art, the present invention provides a method for producing and using bio-based polyols.

Means for Solving the Problems

[0010] To achieve the above object, the present invention is achieved by the following technical solutions. In one aspect, the present invention Mix the epoxidized vegetable oil and the catalyst to obtain a first mixed solution. Dissolve at least one of dimethyl tartrate, diethyl tartrate, and diisopropyl tartrate, which are the first ring-opening reagents, in an organic solvent to obtain a second mixed solution. Pump the first mixed solution and the second mixed solution into the first micro-reactor of the micro-channel modular reactor simultaneously to perform a first ring-opening reaction and obtain a first reaction effluent in Step 1. Dissolve 1,2-propylene glycol, which is the second ring-opening reagent, in an organic solvent to obtain a third mixed solution. Pump the third mixed solution and the first reaction effluent into the second micro-reactor of the micro-channel modular reactor simultaneously to perform a second ring-opening reaction and obtain a second reaction effluent in Step 2. Dissolve at least one of methanol and ethanol, which are the third ring-opening reagents, in an organic solvent to obtain a fourth mixed solution. Pump the fourth mixed solution and the second reaction effluent into the third micro-reactor of the micro-channel modular reactor simultaneously to perform a third ring-opening reaction and obtain a third reaction effluent in Step 3. Provide a method for producing a bio-based polyol, including Step 4: Concentrate the third reaction effluent to a predetermined volume, add a predetermined volume of ethyl acetate, wash it sequentially with a sodium bicarbonate solution and water, perform layer separation, dry the organic phase, perform suction filtration and concentration to obtain a bio-based polyol.

[0011] Preferably, the epoxidized vegetable oil is at least one of epoxidized olive oil, epoxidized peanut oil, epoxidized rapeseed oil, epoxidized cottonseed oil, epoxidized soybean oil, epoxidized coconut oil, epoxidized palm oil, epoxidized sesame oil, epoxidized corn oil, and epoxidized sunflower oil.

[0012] Preferably, the organic solvent is at least one of ethyl acetate, dichloromethane, dichloroethane, chloroform, n-hexane, tetrahydrofuran, 1,4-dioxane, carbon tetrachloride, toluene, and xylene, and the catalyst is at least one of fluoroboric acid, phosphoric acid, phosphotungstic acid, and lipase CALB.

[0013] Preferably, the mass-volume ratio (g / ml) of the first ring-opening reagent to the organic solvent is 1:0.5 to 2, the mass ratio of the epoxidized vegetable oil to the catalyst is 1:0.02 to 0.1, and the volume of the first microreactor in the epoxidized vegetable oil is 5 to 20 ml.

[0014] Preferably, in the first ring-opening reaction, the reaction temperature is 80 to 120 °C, and the reaction time is 3 to 15 min.

[0015] Preferably, the molar ratio of the epoxy in the epoxidized vegetable oil to the second ring-opening reagent is 1:0.1 to 0.2, and the mass-volume ratio (g / ml) of the second ring-opening reagent to the organic solvent is 1:1 to 4.

[0016] Preferably, in the second ring-opening reaction, the reaction temperature is 80 to 120 °C, and the reaction time is 3 to 15 min.

[0017] Preferably, the molar ratio of the epoxy in the epoxidized vegetable oil to the third ring-opening reagent is 1:0.4 to 0.6, and the mass-volume ratio (g / ml) of the third ring-opening reagent to the organic solvent is 1:4 to 8.

[0018] Preferably, in the third ring-opening reaction, the reaction temperature is 80 to 120 °C, and the reaction time is 3 to 15 min.

[0019] Preferably, the microchannel modular reactor includes a first supply pump, a second supply pump, a third supply pump, a fourth supply pump, a first micromixer, a second micromixer, a third micromixer, a micro reaction pipeline, a tubular temperature control module, a first microreactor, a second microreactor, a third microreactor, and a collection container. The first supply pump and the second supply pump are connected in parallel to the first micromixer. The first micromixer and the first microreactor are connected via a micro reaction pipeline. The first microreactor and the third supply pump are connected in parallel to the second micromixer. The second micromixer and the second microreactor are connected via a micro reaction pipeline. The second microreactor and the fourth supply pump are connected in parallel to the third micromixer. The third micromixer, the third microreactor, and the collection container are connected in series via a micro reaction pipeline.

[0020] The first micromixer, the second micromixer, and the third micromixer are preferably of the model slit plate mixer LH25. The first microreactor, the second microreactor, and the third microreactor are preferably of the model Vapotech. The volume of any of the first microreactor, the second microreactor, and the third microreactor is 5 to 20 ml. The reaction temperatures of the first microreactor, the second microreactor, and the third microreactor are all controlled by heating with an oil bath.

[0021] In another aspect, the present invention also provides the use of the bio-based polyol produced by the above production method in the production of polyurethane paint.

Advantages of the Invention

[0022] Compared with the prior art, the present invention has the following beneficial effects. 1. In order to improve the mechanical properties of downstream products of polyester polyol, in the present invention, tartrate ester is used as the first ring-opening reagent to carry out the first ring-opening reaction of epoxy. Next, a second ring-opening reaction is carried out using a second ring-opening reagent containing a secondary alcohol, and finally, a third ring-opening reaction of the remaining epoxy is carried out using a primary alcohol to obtain a vegetable oil polyol product with an epoxy value of approximately zero. In order to avoid causing cross-linking side reactions due to non-selective ring-opening in the ring-opening reaction, in the present invention, the micro reaction technology is utilized, and a microchannel modular reaction device is used as the reaction device to further control the ring-opening group.

[0023] 2. In the present invention, the bio-based polyol produced using a new ring-opening reagent contains an ester group structure and has a predetermined improvement effect on the structural performance of the product. Also, since the selected ring-opening reagent contains a secondary alcohol, the toughness of the bio-based polyol can be improved.

[0024] 3. In the present invention, the bio-based polyol produced using a new ring-opening reagent has a new structure, this polyol is appropriately and uniformly distributed, has a low viscosity, and can replace the conventionally petroleum-chemical material-derived polyol. The polyurethane paint produced using the bio-based polyol manufactured by the method of the present invention has significantly improved performance.

Brief Description of the Drawings

[0025] To more clearly explain the technical solutions in the embodiments of the present invention or the prior art, the following briefly explains the drawings necessary for the description of the embodiments or the prior art. However, the drawings in the following description are only some embodiments of the present invention, and it is obvious that those skilled in the art can obtain other drawings based on these drawings without creative effort.

[0026]

Figure 1

Modes for Carrying Out the Invention

[0027] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described. However, it is obvious that the described embodiments are only part of the embodiments of the present invention and not all implementation forms. All other embodiments obtained by those skilled in the art without creative labor based on the embodiments of the present invention belong to the protection scope of the present invention.

[0028] The related measurement methods for the bio-based polyol and polyurethane paint manufactured by the present invention are as follows. (1) Measure the hydroxyl value according to GB / T 12008.3-2009. (2) Measure the viscosity according to GB / T 12008.7-2010. (3) Measure the drying time of the paint according to GB / T 1728-1979(1989). (4) Measure the pencil hardness of the paint according to GB / T 6739-2006. (5) Measure the impact resistance of the paint according to GB / T 1732-1993. (6) Measure the flexibility of the paint according to GB / T 1731-1993.

[0029] Referring to FIG. 1, the microchannel reactions of the following examples and comparative examples are all realized based on a microchannel modular reaction device, including a first supply pump, a second supply pump, a third supply pump, a fourth supply pump, a first micromixer, a second micromixer, a third micromixer, a micro reaction pipeline, a tubular temperature control module, a first micro reactor, a second micro reactor, a third micro reactor, and a collection container. The first supply pump and the second supply pump are connected in parallel to the first micromixer. The first micromixer and the first micro reactor are connected via a micro reaction pipeline. The first micro reactor and the third supply pump are connected in parallel to the second micromixer. The second micromixer and the second micro reactor are connected via a micro reaction pipeline. The second micro reactor and the fourth supply pump are connected in parallel to the third micromixer. The third micromixer, the third micro reactor, and the collection container are connected in series via a micro reaction pipeline.

[0030] The first micromixer, the second micromixer, and the third micromixer are of the model slit plate mixer LH25. The first micro reactor, the second micro reactor, and the third micro reactor are all of the model Vapotech. The reaction temperatures of the first micro reactor, the second micro reactor, and the third micro reactor are all controlled by heating with an oil bath. The first supply pump, the second supply pump, the third supply pump, and the fourth supply pump are all high-precision and low-pulsation supply pumps. The first supply pump is responsible for pumping the first mixed solution, the second supply pump is responsible for pumping the second mixed solution, the third supply pump is responsible for pumping the third mixed solution, and the fourth supply pump is responsible for pumping the fourth mixed solution.

[0031] Example 1: Production of Bio-based Polyol Step 1: Mix 100 g of epoxidized soybean oil (epoxy value 6.5%) and 0.2 g of fluoroboric acid (20 mg, 50%) to obtain a first mixed solution. Mix 28.55 g of diisopropyl tartrate and 29 ml of 1,4-dioxane to obtain a second mixed solution. Adjust the temperature of the first microreactor to 100°C, and simultaneously pump the first mixed solution and the second mixed solution into a 10-ml first microreactor at rates of 1 ml / min and 0.56 ml / min, respectively, to perform a first ring-opening reaction and obtain a first reaction effluent. Step 2: Mix 4.64 g of 1,2-propylene glycol and 14 ml of 1,4-dioxane to obtain a third mixed solution. Adjust the temperature of the second microreactor to 100°C, and pump the third mixed solution and the first reaction effluent into a 15-ml second microreactor at a rate of 0.18 ml / min individually and simultaneously to perform a second ring-opening reaction and obtain a second reaction effluent. Step 3: Mix 7.16 g of methanol and 29 ml of 1,4-dioxane to obtain a fourth mixed solution. Adjust the temperature of the third microreactor to 100°C, and simultaneously pump the fourth mixed solution at a rate of 0.35 ml / min and the second reaction effluent individually into a 20-ml third microreactor to perform a third ring-opening reaction and obtain a third reaction effluent. Step 4: After the reaction is completed, concentrate the third reaction effluent to 200 ml, add 200 ml of ethyl acetate, wash with 50 ml of 5% sodium bicarbonate solution, then wash twice with 50 ml of water each time, separate the layers, dry the organic phase, perform suction filtration and concentration to obtain a bio-based polyol with a hydroxyl value of 226 mg KOH / g and a viscosity of 796 mPa·s.

[0032] Manufacture of bio-based polyurethane paint: The bio-based polyol and isocyanate obtained in this example were mixed so that the molar ratio of the NCO functional group to the OH functional group was 1.25:1. Then, a catalyst was added in an amount of 3‰ based on the mass of the polyol, and the mixture was reacted for 2 h to obtain a prepolymer mixture solution. A predetermined amount of hydrophilic chain extender was added to the prepolymer mixture solution, and the mixture was reacted for 3 h to obtain a polymer mixture solution. An appropriate amount of neutralizing agent was added to neutralize the polymer mixture solution, and a diluent was added and sheared at a high speed for emulsification to form a polyurethane emulsion. The polyurethane emulsion was sprayed onto a steel plate substrate, with the thickness of the dry film formed by one spray being 60 μm. After leaving it in the laboratory environment for 168 h, it was tested.

[0033] Example 2: Manufacture of bio-based polyol Step 1: 100 g of epoxidized soybean oil (epoxy value 6%) and 0.2 g of fluoroboric acid (20 mg, 50%) were mixed to obtain a first mixture solution, and 27.06 g of diethyl tartrate and 27 ml of 1,4-dioxane were mixed to obtain a second mixture solution. The temperature of the first microreactor was adjusted to 100 °C, and the first mixture solution and the second mixture solution were simultaneously pumped into a 10-ml first microreactor at rates of 1 ml / min and 0.53 ml / min, respectively, to perform a first ring-opening reaction and obtain a first reaction effluent. Step 2: 4.28 g of 1,2-propylene glycol and 13 ml of 1,4-dioxane were mixed to obtain a third mixture solution. The temperature of the second microreactor was adjusted to 100 °C, and the third mixture solution was pumped into a 15-ml second microreactor at a rate of 0.17 ml / min, separately from the first reaction effluent, to perform a second ring-opening reaction and obtain a second reaction effluent. Step 3: 6.01 g of methanol and 24 ml of 1,4-dioxane were mixed to obtain a fourth mixture solution. The temperature of the third microreactor was adjusted to 100 °C, and the fourth mixture solution was pumped into a 20-ml third microreactor at a rate of 0.29 ml / min, separately from the second reaction effluent, to perform a third ring-opening reaction and obtain a third reaction effluent. Step 4: After the reaction was completed, the third reaction effluent was concentrated to 200 ml, 200 ml of ethyl acetate was added, and it was washed with 50 ml of 5% sodium bicarbonate solution. Then, it was washed twice with 50 ml of water each time, the layers were separated, the organic phase was dried, suction filtered and concentrated to obtain a bio-based polyol with a hydroxyl value of 217 mg KOH / g and a viscosity of 759 mPa·s.

[0034] Production of bio-based polyurethane paint: The bio-based polyol obtained in this example and isocyanate were mixed so that the molar ratio of NCO functional group to OH functional group was 1.25:1.05. Then, a catalyst was added in an amount of 3‰ based on the mass of the polyol, and the mixture was reacted for 2 h to obtain a prepolymer mixture. A predetermined amount of hydrophilic chain extender was added to the prepolymer mixture and reacted for 3 h to obtain a polymer mixture. An appropriate amount of neutralizing agent was added to neutralize the polymer mixture, and a diluent was added and sheared at a high speed for emulsification to form a polyurethane emulsion. The polyurethane emulsion was sprayed onto a steel plate substrate, the thickness of the dry film by one spraying was set to 80 μm, and after leaving it standing in a laboratory environment for 168 h, it was tested.

[0035] Example 3: Production of bio-based polyol Step 1: 100 g of epoxidized soybean oil (epoxy value 6.5%) and 0.2 g of fluoroboric acid (20 mg, 50%) were mixed to obtain a first mixture, and 24.61 g of dimethyl tartrate and 25 ml of 1,4-dioxane were mixed to obtain a second mixture. The temperature of the first microreactor was adjusted to 100°C, and the first mixture and the second mixture were simultaneously pumped into a 10-ml first microreactor at rates of 1 ml / min and 0.48 ml / min, respectively, to perform a first ring-opening reaction to obtain a first reaction effluent. Step 2: 4.95 g of 1,2-propylene glycol and 15 ml of 1,4-dioxane were mixed to obtain a third mixture. The temperature of the second microreactor was adjusted to 100°C, and the third mixture was pumped into a 15-ml second microreactor at a rate of 0.19 ml / min simultaneously and separately from the first reaction effluent to perform a second ring-opening reaction to obtain a second reaction effluent. Step 3: Mix 6.51 g of methanol and 26 ml of 1,4-dioxane to obtain a fourth mixed solution. Adjust the temperature of the third microreactor to 100 °C, and simultaneously pump the fourth mixed solution and the second reaction effluent into a 20-ml third microreactor at a rate of 0.31 ml / min, respectively, to perform the third ring-opening reaction and obtain a third reaction effluent. Step 4: After the reaction, concentrate the third reaction effluent to 200 ml, add 200 ml of ethyl acetate, wash with 50 ml of 5% sodium bicarbonate solution, then wash twice with 50 ml of water each time, separate the layers, dry the organic phase, perform suction filtration and concentration to obtain a bio-based polyol with a hydroxyl value of 241 mg KOH / g and a viscosity of 864 mPa·s.

[0036] Production of bio-based polyurethane paint: Mix the bio-based polyol obtained in this example and isocyanate so that the molar ratio of NCO functional group to OH functional group is 1.25:1, then add a catalyst in an amount of 3‰ based on the mass of the polyol, react for 2 h to obtain a prepolymer mixed solution. Add a predetermined amount of hydrophilic chain extender to the prepolymer mixed solution, react for 3 h to obtain a polymer mixed solution, add an appropriate amount of neutralizing agent to neutralize the polymer mixed solution to neutrality, add a diluent and shear at high speed for emulsification to form a polyurethane emulsion. Spray the polyurethane emulsion on a steel plate substrate, set the thickness of the dry film by one spray to 60 μm, leave it standing in a laboratory environment for 168 h, and then test.

[0037] Example 4: Production of bio-based polyol Step 1: Mix 100 g of epoxidized soybean oil (epoxy value 6%) and 0.2 g of fluoroboric acid (20 mg, 50%) to obtain a first mixed solution, and mix 28.99 g of diisopropyl tartrate and 29 ml of 1,4-dioxane to obtain a second mixed solution. Adjust the temperature of the first microreactor to 100 °C, and simultaneously pump the first mixed solution and the second mixed solution into a 10-ml first microreactor at rates of 1 ml / min and 0.57 ml / min, respectively, to perform the first ring-opening reaction and obtain a first reaction effluent. Step 2: Mix 4.85 g of 1,2-propylene glycol and 15 ml of 1,4-dioxane to obtain a third mixed solution. Adjust the temperature of the second micro-reactor to 100 °C, and simultaneously pump the third mixed solution and the first reaction effluent into a 15-ml second micro-reactor at a rate of 0.19 ml / min respectively, to conduct the second ring-opening reaction and obtain a second reaction effluent. Step 3: Mix 8.64 g of ethanol and 35 ml of 1,4-dioxane to obtain a fourth mixed solution. Adjust the temperature of the third micro-reactor to 100 °C, and simultaneously pump the fourth mixed solution and the second reaction effluent into a 20-ml third micro-reactor at a rate of 0.42 ml / min respectively, to conduct the third ring-opening reaction and obtain a third reaction effluent. Step 4: After the reaction is completed, concentrate the third reaction effluent to 200 ml, add 200 ml of ethyl acetate, wash with 50 ml of 5% sodium bicarbonate solution, then wash twice with 50 ml of water each time, separate the layers, dry the organic phase, perform suction filtration and concentration to obtain a bio-based polyol with a hydroxyl value of 203 mg KOH / g and a viscosity of 768 mPa·s.

[0038] Manufacture of bio-based polyurethane paint: Mix the bio-based polyol obtained in this example and isocyanate so that the molar ratio of the NCO functional group to the OH functional group is 1.25:1, then add a catalyst in an amount of 3‰ based on the mass of the polyol, and react for 2 h to obtain a prepolymer mixed solution. Add a predetermined amount of hydrophilic chain extender to the prepolymer mixed solution and react for 3 h to obtain a polymer mixed solution. Add an appropriate amount of neutralizing agent to neutralize the polymer mixed solution, add a diluent and shear at high speed for emulsification to form a polyurethane emulsion. Spray the polyurethane emulsion onto a steel plate substrate, with the thickness of the dry film being 60 μm for each spray, and leave it in the laboratory environment for 168 h and then test.

[0039] Example 5: Manufacture of bio-based polyol Step 1: 100 g of epoxidized soybean oil (epoxy value 6.5%) and 0.2 g of fluoroboric acid (20 mg, 50%) were mixed to obtain a first mixed solution. 33.51 g of diisopropyl tartrate and 34 ml of 1,4-dioxane were mixed to obtain a second mixed solution. The temperature of the first microreactor was adjusted to 100°C, and the first mixed solution and the second mixed solution were simultaneously pumped into a 10-ml first microreactor at rates of 1 ml / min and 0.66 ml / min, respectively, to perform a first ring-opening reaction and obtain a first reaction effluent. Step 2: 4.64 g of 1,2-propylene glycol and 14 ml of 1,4-dioxane were mixed to obtain a third mixed solution. The temperature of the second microreactor was adjusted to 100°C, and the third mixed solution was pumped into a 15-ml second microreactor at a rate of 0.18 ml / min, separately from the first reaction effluent, to perform a second ring-opening reaction and obtain a second reaction effluent. Step 3: 8.42 g of ethanol and 34 ml of 1,4-dioxane were mixed to obtain a fourth mixed solution. The temperature of the third microreactor was adjusted to 100°C, and the fourth mixed solution was pumped into a 20-ml third microreactor at a rate of 0.41 ml / min, separately from the second reaction effluent, to perform a third ring-opening reaction and obtain a third reaction effluent. Step 4: After the reaction was completed, the third reaction effluent was concentrated to 200 ml, 200 ml of ethyl acetate was added, and it was washed with 50 ml of a 5% sodium bicarbonate solution, and then washed twice with 50 ml of water each time. After layer separation, the organic phase was dried, suction filtered, and concentrated to obtain a bio-based polyol with a hydroxyl value of 228 mg KOH / g and a viscosity of 807 mPa·s.

[0040] Manufacture of bio-based polyurethane paint: The bio-based polyol and isocyanate obtained in this example were mixed so that the molar ratio of the NCO functional group to the OH functional group was 1.25:1. Then, a catalyst was added in an amount of 3‰ based on the mass of the polyol, and the mixture was reacted for 2 h to obtain a prepolymer mixture. A predetermined amount of hydrophilic chain extender was added to the prepolymer mixture, and the mixture was reacted for 3 h to obtain a polymer mixture. An appropriate amount of neutralizing agent was added to neutralize the polymer mixture, and a diluent was added and sheared at a high speed to form an emulsion, thereby forming a polyurethane emulsion. The polyurethane emulsion was sprayed onto a steel plate substrate with a dry film thickness of 60 μm per spray, left in a laboratory environment for 168 h, and then tested.

[0041] Example 6: Manufacture of bio-based polyol Step 1: 100 g of epoxidized soybean oil (epoxy value 6%) and 0.2 g of fluoroboric acid (20 mg, 50%) were mixed to obtain a first mixture, and 26.72 g of dimethyl tartrate and 27 ml of 1,4-dioxane were mixed to obtain a second mixture. The temperature of the first microreactor was adjusted to 100°C, and the first mixture and the second mixture were simultaneously pumped into a 10-ml first microreactor at rates of 1 ml / min and 0.52 ml / min, respectively, to perform a first ring-opening reaction and obtain a first reaction effluent. Step 2: 5.71 g of 1,2-propylene glycol and 17 ml of 1,4-dioxane were mixed to obtain a third mixture. The temperature of the second microreactor was adjusted to 100°C, and the third mixture was pumped into a 15-ml second microreactor at a rate of 0.22 ml / min, separately from the first reaction effluent, to perform a second ring-opening reaction and obtain a second reaction effluent. Step 3: 6.91 g of ethanol and 28 ml of 1,4-dioxane were mixed to obtain a fourth mixture. The temperature of the third microreactor was adjusted to 100°C, and the fourth mixture was pumped into a 20-ml third microreactor at a rate of 0.34 ml / min, separately from the second reaction effluent, to perform a third ring-opening reaction and obtain a third reaction effluent. Step 4: After the reaction was completed, the effluent of the third reaction was concentrated to 200 ml, 200 ml of ethyl acetate was added, and it was washed with 50 ml of 5% sodium bicarbonate solution. Next, it was washed twice with 50 ml of water each time, the layers were separated, the organic phase was dried, suction filtered and concentrated to obtain a bio-based polyol with a hydroxyl value of 229 mg KOH / g and a viscosity of 772 mPa·s.

[0042] Manufacture of bio-based polyurethane paint: The bio-based polyol obtained in this example and isocyanate were mixed so that the molar ratio of NCO functional group to OH functional group was 1.25:1. Then, a catalyst was added in an amount of 3‰ based on the mass of the polyol, and the mixture was reacted for 2 h to obtain a prepolymer mixture. A predetermined amount of hydrophilic chain extender was added to the prepolymer mixture and reacted for 3 h to obtain a polymer mixture. An appropriate amount of neutralizer was added to neutralize the polymer mixture, and a diluent was added and sheared at a high speed for emulsification to form a polyurethane emulsion. The polyurethane emulsion was sprayed onto a steel plate substrate with a dry film thickness of 60 μm per spray, and after being left in a laboratory environment for 168 h, it was tested.

[0043] Comparative Example 1: Manufacture of bio-based polyol Step 1: 100 g of epoxidized soybean oil (epoxy value 6.5%) and 0.2 g of fluoroboric acid (20 mg, 50%) were mixed to obtain a first mixture. 28.55 g of diisopropyl tartrate and 29 ml of 1,4-dioxane were mixed to obtain a second mixture. The first mixture and the second mixture were added to a reactor and subjected to a ring-opening reaction at 100 °C for 2 h. Step 2: 10.82 g of 1,2-propylene glycol and 32 ml of 1,4-dioxane were mixed to obtain a third mixture. The third mixture was added to the reactor and the ring-opening reaction was continued at 100 °C for 2 h. Step 3: 4.56 g of methanol and 18 ml of 1,4-dioxane were mixed to obtain a fourth mixture. The fourth mixture was added to the reactor and the ring-opening reaction was continued at 100 °C for 2 h. Step 4: After the reaction was completed, the reaction solution was concentrated to 200 ml, 200 ml of ethyl acetate was added, and it was washed with 50 ml of 5% sodium bicarbonate solution. Then, it was washed twice with 50 ml of water each time, the layers were separated, the organic phase was dried, suction filtered and concentrated to obtain a bio-based polyol with a hydroxyl value of 147 mg KOH / g and a viscosity of 1049 mPa·s.

[0044] Manufacture of bio-based polyurethane paint: The bio-based polyol and isocyanate obtained in this comparative example were mixed so that the molar ratio of the NCO functional group to the OH functional group was 1.25:1, and a catalyst was added in an amount of 3‰ based on the mass of the polyol, and reacted for 2 h to obtain a prepolymer mixture. A predetermined amount of a hydrophilic chain extender was added to the prepolymer mixture and reacted for 3 h to obtain a polymer mixture. An appropriate amount of a neutralizing agent was added to neutralize the polymer mixture to neutrality, and a diluent was added and sheared and emulsified at a high speed to form a polyurethane emulsion. The polyurethane emulsion was sprayed onto a steel plate substrate, the thickness of the dry film by one spraying was 60 μm, and it was left in a laboratory environment for 168 h and then tested.

[0045] Comparative Example 2: Manufacture of bio-based polyol Step 1: 100 g of epoxidized soybean oil (epoxy value 6%) and 0.2 g of fluoroboric acid (20 mg, 50%) were mixed to obtain a first mixture, 14.27 g of 1,2-propylene glycol and 14 ml of 1,4-dioxane were mixed to obtain a second mixture. The temperature of the first microreactor was adjusted to 100°C, and the first mixture and the second mixture were simultaneously pumped into a 10 ml first microreactor at rates of 1 ml / min and 0.28 ml / min, respectively, to perform a first ring-opening reaction to obtain a first reaction effluent. Step 2: 6.01 g of methanol and 18 ml of 1,4-dioxane were mixed to obtain a third mixture. The temperature of the second microreactor was adjusted to 100°C, and the third mixture was pumped into a 15 ml second microreactor at a rate of 0.23 ml / min separately from the first reaction effluent to perform a second ring-opening reaction to obtain a second reaction effluent. Step 3: After the reaction was completed, the second reaction effluent was concentrated to 200 ml, 200 ml of ethyl acetate was added, and it was washed with 50 ml of 5% sodium bicarbonate solution. Next, it was washed twice with 50 ml of water each time, the layers were separated, the organic phase was dried, suction filtered, concentrated, and a bio-based polyol with a hydroxyl value of 252 mg KOH / g and a viscosity of 652 mPa·s was obtained.

[0046] Production of bio-based polyurethane paint: The bio-based polyol and isocyanate obtained in this comparative example were mixed so that the molar ratio of the NCO functional group to the OH functional group was 1.25:1. A catalyst was added in an amount of 3‰ based on the mass of the polyol, and the mixture was reacted for 2 h to obtain a prepolymer mixture. A predetermined amount of a hydrophilic chain extender was added to the prepolymer mixture and reacted for 3 h to obtain a polymer mixture. An appropriate amount of a neutralizing agent was added to neutralize the polymer mixture, and a diluent was added and sheared at high speed for emulsification to form a polyurethane emulsion. The polyurethane emulsion was sprayed onto a steel plate substrate, the thickness of the dry film by one spray was set to 60 μm, and after leaving it in a laboratory environment for 168 h, it was tested.

[0047] Comparative Example 3: Production of bio-based polyol Step 1: 100 g of epoxidized soybean oil (epoxy value 6.5%) and 0.2 g of fluoroboric acid (20 mg, 50%) were mixed to obtain a first mixture. 47.58 g of diisopropyl tartrate and 48 ml of 1,4-dioxane were mixed to obtain a second mixture. The temperature of the first microreactor was adjusted to 100°C, and the first mixture and the second mixture were simultaneously pumped into a 10 ml first microreactor at rates of 1 ml / min and 0.93 ml / min, respectively, to perform a first ring-opening reaction and obtain a first reaction effluent. Step 2: 6.51 g of methanol and 20 ml of 1,4-dioxane were mixed to obtain a third mixture. The temperature of the second microreactor was adjusted to 100°C, and the third mixture was pumped into a 15 ml second microreactor at a rate of 0.26 ml / min separately from the first reaction effluent to perform a second ring-opening reaction and obtain a second reaction effluent. Step 3: After the reaction was completed, the second reaction effluent was concentrated to 200 ml, 200 ml of ethyl acetate was added, and it was washed with 50 ml of 5% sodium bicarbonate solution. Next, it was washed twice with 50 ml of water each time, the layers were separated, the organic phase was dried, suction filtered and concentrated to obtain a bio-based polyol with a hydroxyl value of 213 mg KOH / g and a viscosity of 825 mPa·s.

[0048] Manufacture of bio-based polyurethane paint: The bio-based polyol and isocyanate obtained in this comparative example were mixed so that the molar ratio of the NCO functional group to the OH functional group was 1.25:1, and a catalyst was added in an amount of 3‰ based on the mass of the polyol, and reacted for 2 h to obtain a prepolymer mixture. A predetermined amount of a hydrophilic chain extender was added to the prepolymer mixture and reacted for 3 h to obtain a polymer mixture. An appropriate amount of a neutralizing agent was added to neutralize the polymer mixture, and a diluent was added and sheared at high speed for emulsification to form a polyurethane emulsion. The polyurethane emulsion was sprayed onto a steel plate substrate, the thickness of the dry film by one spray was 60 μm, and it was left in a laboratory environment for 168 h and then tested.

[0049] Comparative Example 4: Manufacture of bio-based polyol Step 1: 100 g of epoxidized soybean oil (epoxy value 6%) and 0.2 g of fluoroboric acid (20 mg, 50%) were mixed to obtain a first mixture, 43.92 g of diisopropyl tartrate and 44 ml of 1,4-dioxane were mixed to obtain a second mixture. The temperature of the first microreactor was adjusted to 100 °C, and the first mixture and the second mixture were simultaneously pumped into a 10 ml first microreactor at rates of 1 ml / min and 0.86 ml / min respectively to carry out the first ring-opening reaction and obtain a first reaction effluent. Step 2: 14.27 g of 1,2-propylene glycol and 43 ml of 1,4-dioxane were mixed to obtain a third mixture. The temperature of the second microreactor was adjusted to 100 °C, and the third mixture was pumped into a 15 ml second microreactor at a rate of 0.55 ml / min separately from the first reaction effluent to carry out the second ring-opening reaction and obtain a second reaction effluent. Step 3: After the reaction was completed, the second reaction effluent was concentrated to 200 ml, 200 ml of ethyl acetate was added, and it was washed with 50 ml of 5% sodium bicarbonate solution. Next, it was washed twice with 50 ml of water each time, the layers were separated, the organic phase was dried, suction filtered and concentrated to obtain a bio-based polyol having a hydroxyl value of 249 mg KOH / g and a viscosity of 727 mPa·s.

[0050] Manufacture of bio-based polyurethane paint: The bio-based polyol and isocyanate obtained in this comparative example were mixed so that the molar ratio of the NCO functional group to the OH functional group was 1.25:1, and a catalyst was added in an amount of 3‰ based on the mass of the polyol, and reacted for 2 h to obtain a prepolymer mixture. A predetermined amount of a hydrophilic chain extender was added to the prepolymer mixture and reacted for 3 h to obtain a polymer mixture. An appropriate amount of a neutralizing agent was added to neutralize the polymer mixture to neutrality, a diluent was added and sheared at high speed for emulsification to form a polyurethane emulsion. The polyurethane emulsion was sprayed onto a steel plate substrate, the thickness of the dry film by one spray was 60 μm, and after leaving it in a laboratory environment for 168 h, it was tested.

[0051] The performance indexes of the bio-based polyols manufactured in Examples 1 to 6 and Comparative Examples 1 to 4 are shown in Table 1, and the performance indexes of the bio-based polyurethane paints manufactured are shown in Table 2.

[0052] Performance indexes of bio-based polyols manufactured in Examples 1 to 6 and Comparative Examples 1 to 4 JPEG2025113983000002.jpg80170

[0053] Performance indexes of bio-based polyurethane paints manufactured in Examples 1 to 6 and Comparative Examples 1 to 4 JPEG2025113983000003.jpg78170

[0054] It is clearly shown from the data in Table 1 and Table 2 that the bio-based polyol manufactured in a normal reactor has a low hydroxyl value, significant attenuation is observed, there are many cross-linking side reactions, as a result, the molecular weight becomes large, the viscosity is high, and the reaction in the reactor is uncontrollable.

[0055] The basic principle, main features, and advantages of the present invention have been shown and described above. Those skilled in the art should understand that the present invention is not limited to the above embodiments, and the above embodiments and what is described in the specification are only for explaining the principle of the present invention. Without departing from the spirit and scope of the present invention, various modifications and improvements are possible, and all of these modifications and improvements should be understood to be included within the scope of the claimed present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for producing a bio-based polyol, comprising: mixing an epoxidized vegetable oil and a catalyst to obtain a first mixed solution, dissolving at least one of dimethyl tartrate, diethyl tartrate, and diisopropyl tartrate, which are first ring-opening reagents, in an organic solvent to obtain a second mixed solution, and simultaneously pumping the first mixed solution and the second mixed solution into a first micro-reactor of a microchannel modular reactor to perform a first ring-opening reaction to obtain a first reaction effluent in Step 1; dissolving 1,2-propylene glycol, which is a second ring-opening reagent, in an organic solvent to obtain a third mixed solution, and simultaneously pumping the third mixed solution and the first reaction effluent into a second micro-reactor of the microchannel modular reactor to perform a second ring-opening reaction to obtain a second reaction effluent in Step 2; dissolving at least one of methanol and ethanol, which are third ring-opening reagents, in an organic solvent to obtain a fourth mixed solution, and simultaneously pumping the fourth mixed solution and the second reaction effluent into a third micro-reactor of the microchannel modular reactor to perform a third ring-opening reaction to obtain a third reaction effluent in Step 3; concentrating the third reaction effluent to a predetermined volume, adding a predetermined volume of ethyl acetate, washing sequentially with a sodium bicarbonate solution and water, performing liquid-liquid separation, drying the organic phase, performing suction filtration and concentration to obtain a bio-based polyol in Step 4. The method for producing a bio-based polyol is characterized by comprising the above steps.

2. The method according to claim 1, wherein the epoxidized vegetable oil is at least one of epoxidized olive oil, epoxidized peanut oil, epoxidized rapeseed oil, epoxidized cottonseed oil, epoxidized soybean oil, epoxidized coconut oil, epoxidized palm oil, epoxidized sesame oil, epoxidized corn oil, and epoxidized sunflower oil.

3. The method according to claim 1, wherein the organic solvent is at least one of ethyl acetate, dichloromethane, dichloroethane, chloroform, n-hexane, tetrahydrofuran, 1,4-dioxane, carbon tetrachloride, toluene, and xylene, and the catalyst is at least one of fluoroboric acid, phosphoric acid, phosphotungstic acid, and lipase CALB.

4. The mass-volume ratio (g / ml) of the first ring-opening reagent to the organic solvent is 1:0.5 to 2, the mass ratio of the epoxidized vegetable oil to the catalyst is 1:0.02 to 0.1, and the molar ratio of the epoxy in the epoxidized vegetable oil to the first ring-opening reagent is 1:0.3 to 0.

4. The manufacturing method according to claim 1 is characterized by this.

5. In the first ring-opening reaction, the reaction temperature is 80 to 120 °C, and the reaction time is 3 to 15 min. The manufacturing method according to claim 1 is characterized by this.

6. The molar ratio of the epoxy in the epoxidized vegetable oil to the second ring-opening reagent is 1:0.1 to 0.2, and the mass-volume ratio (g / ml) of the second ring-opening reagent to the organic solvent is 1:1 to 4. The manufacturing method according to claim 1 is characterized by this.

7. In the second ring-opening reaction, the reaction temperature is 80 to 120 °C, and the reaction time is 3 to 15 min. The manufacturing method according to claim 1 is characterized by this.

8. The molar ratio of the epoxy in the epoxidized vegetable oil to the third ring-opening reagent is 1:0.4 to 0.6, and the mass-volume ratio (g / ml) of the third ring-opening reagent to the organic solvent is 1:4 to 8. The manufacturing method according to claim 1 is characterized by this.

9. In the third ring-opening reaction, the reaction temperature is 80 to 120 °C, and the reaction time is 3 to 15 min. The manufacturing method according to claim 1 is characterized by this.

10. Use of the bio-based polyol produced by the manufacturing method according to any one of claims 1 to 9 in the production of polyurethane paints.

Images