Enclosed soft high-solid-content polyurethane resin prepared from modified bio-based polyol and preparation method of closed soft high-solid-content polyurethane resin

Abstract

The invention relates to the field of bio-based polyurethane materials, in particular to closed type soft high-solid-content polyurethane resin prepared from modified bio-based polyol and a preparation method of the closed type soft high-solid-content polyurethane resin. The closed type soft high-solid-content polyurethane resin is prepared from 40 to 60 parts of modified bio-based polyol, 10 to 30 parts of petroleum-based polyol, 15 to 25 parts of diisocyanate, 0.1 to 1 part of an end-capping reagent, 0.01 to 0.05 part of a catalyst, 0.1 to 1 part of a leveling agent and 10 to 30 parts of an organic solvent. The modified bio-based polyol is a composite polyol obtained by decompressing and dehydrating epoxidized soybean oil-based polyol and castor oil-based polyester polyol. The closed type soft high-solid-content polyurethane resin is long in operation time, the solid content is larger than or equal to 70%, the bio-based content is larger than or equal to 50%, the viscosity is (1-3) * 10 < 4 > mPa.s, and the closed type soft high-solid-content polyurethane resin has excellent storage stability and film-forming flexibility and is suitable for the fields of clothes, furniture soft packages, synthetic leather and the like.

Description

Technical Field

[0001] This invention relates to the field of bio-based polyurethane materials, and in particular to a modified bio-based polyol for use in a closed-type soft high-solids-content polyurethane resin and its preparation method. Background Technology

[0002] Traditional polyurethane resins rely on petroleum-based polyols, which suffer from problems such as non-renewability and high VOC emissions. To reduce dependence on petroleum-based polyols, researchers have begun using bio-based polyols to prepare polyurethane resins. Reported bio-based polyols include castor oil derivatives, soybean oil, palm oil, and vegetable oils. While the prepared bio-based polyurethane resins meet environmental protection requirements, they have limitations. When directly used in high-solids-content systems, these bio-based polyurethane resins exhibit high viscosity, low reactivity, and high film brittleness, restricting their application and development. Therefore, the inventors provide a modified bio-based polyol for use in closed-cell, flexible, high-solids-content polyurethane resins and its preparation method. Summary of the Invention

[0003] To address the technical shortcomings of existing high-solids-content bio-based polyurethane resins, such as high viscosity, low reactivity, and high film brittleness, this invention provides a modified bio-based polyol for use in closed-type soft high-solids-content polyurethane resins and its preparation method.

[0004] The present invention provides a modified bio-based polyol for use in blocked soft high-solids-content polyurethane resin, which is achieved through the following technical solution: A modified bio-based polyol for use in blocked soft high-solids polyurethane resin comprises 40-60 parts of modified bio-based polyol, 10-30 parts of petroleum-based polyol, 15-25 parts of diisocyanate, 0.1-1 parts of end-capping agent, 0.01-0.05 parts of catalyst, 0.1-1 parts of leveling agent, and 10-30 parts of organic solvent; wherein the modified bio-based polyol is obtained by compounding epoxidized soybean oil-based polyol and castor oil-based polyester polyol and then dehydrating under reduced pressure; wherein the mass of the modified bio-based polyol accounts for 70-80 wt% of the total mass of the modified bio-based polyol and the petroleum-based polyol.

[0005] The high primary hydroxyl content of the epoxidized soybean oil polyol in this invention can enhance its reactivity, while the excellent flexibility of the castor oil-based polyester polyol can improve film-forming flexibility. The combination of epoxidized soybean oil-based polyol and castor oil-based polyester polyol regulates the functionality (2.5-3) and plays a role in balancing crosslinking density and flexibility, thus endowing the closed-type soft high-solids polyurethane resin with excellent storage stability, film-forming flexibility, and reactivity.

[0006] Preferably, the modified bio-based polyol is prepared by a ring-opening reaction of epoxidized soybean oil and a fluorinated alcohol ring-opening agent under the catalysis of boron trifluoride ether. The molar ratio of the hydroxyl group in the fluorinated alcohol ring-opening agent to the epoxy group in the epoxidized soybean oil is (1.2-1.5):1. The fluorinated alcohol ring-opening agent is at least one of trifluoroethanol, pentafluoropropanol, and heptafluorobutanol. The hydroxyl value of the epoxidized soybean oil-based polyol is 150-200 mg KOH / g.

[0007] Preferably, the castor oil-based polyester polyol in the modified bio-based polyol is prepared by transesterification of castor oil and a low-crystallinity diol under the action of a titanate catalyst; the molar ratio of castor oil to the low-crystallinity diol is 1:(2-2.1); the low-crystallinity chain extender is at least one of 1,2-propanediol, 1,3-propanediol, 3-methyl-1,3-butanediol, and 3-methyl-1,5-pentanediol; and the hydroxyl value of the castor oil-based polyester polyol is 180-220 mg KOH / g.

[0008] Preferably, the modified bio-based polyol is obtained by compounding epoxidized soybean oil-based polyol and castor oil-based polyester polyol in a mass ratio of (6-8): (2-4) and then dehydrating under reduced pressure.

[0009] Preferably, the modified bio-based polyol is prepared as follows: S1. The preparation method of epoxidized soybean oil-based polyol is as follows: epoxidized soybean oil and fluorinated alcohol ring-opening agent are mixed evenly at a molar ratio of (1.2~1.5):1. Boron trifluoride diethyl ether is added and mixed evenly. The mass of the boron trifluoride diethyl ether is equal to 0.2-0.5wt% of the mass of the epoxidized soybean oil. The mixture is heated to 68-75℃ and reacted for 3-5 hours. At the same time, a vacuum is drawn to remove the water and excess alcohol monomers generated in the reaction. After the reaction is completed, a sample is taken to detect the hydroxyl value of the product. When the hydroxyl value of the product is 150-200mg KOH / g, the reaction is stopped. Nitrogen gas is introduced to restore the temperature and pressure to room temperature, and the epoxidized soybean oil-based polyol can be obtained by discharging the product. Simultaneously, castor oil-based polyester polyol is prepared using the following method: Castor oil and low-crystallinity diol are mixed evenly at a molar ratio of 1:(2-2.1), and a titanate catalyst is added. The mass of the titanate catalyst is equal to 0.08-0.12 wt% of the total mass of the castor oil and low-crystallinity diol. After mixing evenly, the temperature is raised to 210-230℃ and reacted for 100-150 min. At the same time, a vacuum is drawn to remove the water and excess alcohol monomers produced in the reaction. After the reaction is completed, a sample is taken to detect the hydroxyl value of the product. When the hydroxyl value of the product is 180-220 mg KOH / g, the reaction is stopped, nitrogen is introduced to restore the temperature and pressure to room, and the castor oil-based polyester polyol is obtained by discharging. S2. Epoxidized soybean oil-based polyol and castor oil-based polyester polyol are mixed evenly at a mass ratio of (6-8): (2-4), and vacuum dehydrated at 100-120℃ for 1-2 hours to obtain modified bio-based polyol.

[0010] Preferably, the petroleum-based polyol is at least one of poly(1,2-propanediol) PPG, polyethylene glycol (PEG), and polytetrahydrofuran ether diol (PTMEG) with a number average molecular weight of 1000-2000.

[0011] Preferably, the diisocyanate is at least one selected from toluene diisocyanate, terephthalic diisocyanate, naphthalene diisocyanate, and diphenylmethane diisocyanate.

[0012] More preferably, the diisocyanate is toluene diisocyanate (TDI), which has good flexibility, a relatively mild reaction, and good compatibility with bio-based polyols.

[0013] Preferably, the catalyst is an organobismuth catalyst.

[0014] More preferably, the catalyst is bismuth isooctanoate.

[0015] Preferably, the organic solvent is at least one selected from ethyl acetate, acetone, butanone, and DMF.

[0016] Preferably, the capping agent is at least one selected from methyl ethyl ketone oxime, butanone oxime, isopropanol, phenol, 2,6-dimethylphenol, caprolactam, and 3,5-dimethylpyrazole. More preferably, the capping agent is methyl ethyl ketone oxime, and the decapsulation temperature is 120-140℃.

[0017] The closed-cell, soft, high-solids-content polyurethane resin of this invention has a long operating time, a solids content ≥70%, a bio-based content ≥50%, and a viscosity of (1~3)*10. 4 It has excellent storage stability and film-forming flexibility, and is suitable for clothing, furniture upholstery, synthetic leather and other fields.

[0018] The present invention provides a method for preparing a modified bio-based polyol for a blocked, flexible, high-solids-content polyurethane resin, which is achieved through the following technical solution: A method for preparing a modified bio-based polyol for use in a blocked, flexible, high-solids-content polyurethane resin includes the following steps: Step 1: Accurately metered modified bio-based polyols and petroleum-based polyols are added to the reaction vessel, mixed evenly, and then heated to 100-130℃ for vacuum dehydration treatment for 1-3 hours. Step 2: After cooling to 60-65℃, add accurately measured diisocyanate and mix thoroughly. Adjust the system temperature to 78-85℃ and react for 3-4 hours under nitrogen protection. Step 3: After the reaction is complete, add an accurately measured amount of organic solvent and stir for 10-15 minutes. Then add an accurately measured amount of end-capping agent, catalyst, and leveling agent. After mixing evenly, adjust the temperature to 78-85℃ and continue the reaction under nitrogen protection for 45-120 minutes. After the reaction is complete, cool down to below 40℃ and discharge the modified bio-based polyol for use in closed-type soft high-solids polyurethane resin.

[0019] In summary, the present invention has the following advantages: 1. In this invention, the modified bio-based polyol obtained by compounding epoxidized soybean oil-based polyol and castor oil-based polyester polyol and then dehydrating it under reduced pressure plays a role in balancing crosslinking density and flexibility. This endows the closed-type soft high-solids-content polyurethane resin with excellent storage stability, film-forming flexibility, and reactivity, solving the technical defects of existing high-solids-content bio-based polyurethane resins, such as high viscosity, low reactivity, and high film brittleness. This expands the application range and practical value of high-solids-content bio-based polyurethane resins.

[0020] 2. The closed-type soft high-solids polyurethane resin in this invention has a long operating time, a solids content ≥70%, a bio-based content ≥50%, and a viscosity of (1~3)*10. 4 It has excellent storage stability and film-forming flexibility, and is suitable for clothing, furniture upholstery, synthetic leather and other fields.

[0021] 3. The preparation method of the closed-type soft high-solids polyurethane resin in this invention is relatively simple, has low operation difficulty, requires conventional production equipment, facilitates industrial-scale production, and optimizes product production costs. Detailed Implementation

[0022] To further understand the inventiveness and technical advancements of this invention, the preferred embodiments of this invention will be discussed in detail below with reference to examples and comparative examples.

[0023] Example: A modified bio-based polyol for use in blocked soft high-solids polyurethane resin comprises 40-60 parts modified bio-based polyol, 10-30 parts petroleum-based polyol, 15-25 parts diisocyanate, 0.1-1 parts end-capping agent, 0.01-0.05 parts catalyst, 0.1-1 parts leveling agent, and 10-30 parts organic solvent.

[0024] The R value of the closed-type soft high-solids polyurethane resin is 1.2-2.0, which means that the ratio of the total molar amount of hydroxyl groups in petroleum-based polyols and modified bio-based polyols to the molar amount of -NCO in diisocyanates is 1 / 1.2-2.

[0025] The diisocyanate is at least one selected from toluene diisocyanate, terephthalic diisocyanate, naphthalene diisocyanate, and diphenylmethane diisocyanate. Preferably, the diisocyanate is toluene diisocyanate (TDI), which has good flexibility, a mild reaction, and good compatibility with bio-based polyols.

[0026] The catalyst is an organobismuth catalyst, specifically bismuth isooctanoate. The organic solvent is at least one selected from ethyl acetate, acetone, butanone, and DMF, preferably ethyl acetate.

[0027] The capping agent is at least one of methyl ethyl ketone oxime, butanone oxime, isopropanol, phenol, 2,6-dimethylphenol, caprolactam, and 3,5-dimethylpyrazole, preferably butanone oxime.

[0028] The leveling agent chosen was a polyether-modified siloxane leveling agent, specifically BYK-333 from BYK Chemicals.

[0029] The petroleum-based polyol is at least one of poly(1,2-propanediol) PPG, polyethylene glycol (PEG), and polytetrahydrofuran ether glycol (PTMEG) with a number average molecular weight of 1000-2000. Preferably, the petroleum-based polyol is polytetrahydrofuran ether glycol (PTMEG) with a number average molecular weight of 1000.

[0030] Modified bio-based polyols are obtained by compounding epoxidized soybean oil-based polyols and castor oil-based polyester polyols in a mass ratio of (6-8):(2-4) and then dehydrating under reduced pressure. The modified bio-based polyol accounts for 70-80 wt% of the total mass of modified bio-based polyols and petroleum-based polyols, ensuring that the amount of modified bio-based polyols used in closed-cell soft high-solids polyurethane resins is above 50%, which is in line with the development trend of environmentally friendly and green polyurethane.

[0031] Epoxidized soybean oil-based polyols are prepared by a ring-opening reaction of epoxidized soybean oil and a fluorinated alcohol ring-opening agent under the catalysis of boron trifluoride diethyl ether. The molar ratio of the hydroxyl groups in the fluorinated alcohol ring-opening agent to the epoxy groups in the epoxidized soybean oil is (1.2–1.5):1. The fluorinated alcohol ring-opening agent is at least one selected from trifluoroethanol, pentafluoropropanol, and heptafluorobutanol, preferably trifluoroethanol.

[0032] The preparation method of epoxidized soybean oil-based polyol is as follows: Epoxidized soybean oil and fluorinated alcohol ring-opening agent are mixed evenly at a molar ratio of (1.2-1.5):1. Boron trifluoride diethyl ether is added and mixed evenly. The mass of boron trifluoride diethyl ether is equal to 0.2-0.5 wt% of the mass of epoxidized soybean oil. The mixture is heated to 68-75℃ and reacted for 3-5 hours. At the same time, vacuum is applied to remove water and excess alcohol monomers generated during the reaction. After the reaction is completed, a sample is taken to test the hydroxyl value of the product. When the hydroxyl value of the product is 150-200 mg KOH / g, the reaction is stopped. Nitrogen gas is introduced to restore the temperature and pressure to room temperature. The epoxidized soybean oil-based polyol with a hydroxyl value of 150-200 mg KOH / g is then obtained.

[0033] Castor oil-based polyester polyols are prepared by transesterification of castor oil and low-crystallinity diols in the presence of titanate catalysts. The molar ratio of castor oil to the low-crystallinity diol is 1:(2-2.1). The low-crystallinity chain extender is at least one selected from 1,2-propanediol, 1,3-propanediol, 3-methyl-1,3-butanediol, and 3-methyl-1,5-pentanediol. Preferably, the low-crystallinity chain extender is 1,3-propanediol or 3-methyl-1,3-butanediol.

[0034] The preparation method of castor oil-based polyester polyol is as follows: Castor oil and low-crystallinity diol are mixed evenly at a molar ratio of 1:(2~2.1). Then, a titanate catalyst is added, the mass of which is equal to 0.08-0.12wt% of the total mass of castor oil and low-crystallinity diol. After mixing evenly, the temperature is raised to 210-230℃ and reacted for 100-150 min. At the same time, a vacuum is drawn to remove the water and excess alcohol monomers produced in the reaction. After the reaction is completed, a sample is taken to detect the hydroxyl value of the product. When the hydroxyl value of the product is 180-220 mgKOH / g, the reaction is stopped. Nitrogen gas is introduced to restore the temperature and pressure to room temperature, and the castor oil-based polyester polyol with a hydroxyl value of 180-220 mgKOH / g is obtained by discharging.

[0035] The modified bio-based polyol is prepared as follows: epoxidized soybean oil-based polyol and castor oil-based polyester polyol are mixed evenly at a mass ratio of (6-8): (2-4), and vacuum dehydrated at 100-120℃ for 1-2 hours to obtain the modified bio-based polyol.

[0036] The method for preparing modified bio-based polyols for use in blocked, flexible, high-solids-content polyurethane resins is as follows: Step 1: Accurately metered modified bio-based polyols and petroleum-based polyols are added to the reaction vessel, mixed evenly, and then heated to 100-130℃ for vacuum dehydration treatment for 1-3 hours. Step 2: After cooling to 60-65℃, add accurately measured diisocyanate and mix thoroughly. Adjust the system temperature to 78-85℃ and react for 3-4 hours under nitrogen protection. Step 3: After the reaction is complete, add an accurately measured amount of organic solvent and stir for 10-15 minutes. Then add an accurately measured amount of end-capping agent, catalyst, and leveling agent. After mixing evenly, adjust the temperature to 78-85℃ and continue the reaction under nitrogen protection for 45-120 minutes. After the reaction is complete, cool down to below 40℃ and discharge the modified bio-based polyol for use in closed-type soft high-solids polyurethane resin.

[0037] Preparation Example 1: The preparation method of epoxidized soybean oil-based polyol is as follows: 500g of epoxidized soybean oil (CAS: 8013-07-8, molecular weight 975.38, BYD AR grade, epoxy value 4.8wt%) and 50.5g of trifluoroethanol (CAS: 75-89-8, molecular weight 100.04, Shandong Shouhua Chemical Co., Ltd.) were added to a reaction vessel equipped with a fractionation tower and a distillation receiver and mixed evenly. 1.5g of boron trifluoride ether (Aladdin, 98%, CAS: 109-63-7) was added and mixed evenly. The mixture was heated to 70℃ and reacted for 4.0h. At the same time, a vacuum was drawn to remove the water and excess alcohol monomers produced in the reaction. After the reaction was completed, a sample was taken and the hydroxyl value of the product was measured to be 176.5mgKOH / g. The reaction was then stopped, nitrogen was introduced to restore the temperature and pressure to room, and the epoxidized soybean oil-based polyol was discharged. The hydroxyl value of the epoxidized soybean oil-based polyol was measured and found to be 174.9mgKOH / g.

[0038] The difference between Preparation Example 2 and Preparation Example 1 is as follows: The preparation method of the epoxidized soybean oil-based polyol is as follows: 500g of epoxidized soybean oil and 76.6g of pentafluoropropanol (CAS: 422-05-9, molecular weight 150.05, Ron) are added to a reaction vessel equipped with a fractionation tower and a distillation receiver and mixed evenly. 1.5g of boron trifluoride diethyl ether is added and mixed evenly. The mixture is heated to 70℃ and reacted for 250min. At the same time, a vacuum is drawn to remove the water and excess alcohol monomers produced in the reaction. After the reaction is completed, a sample is taken and the hydroxyl value of the product is measured to be 173.9mgKOH / g. The reaction is then stopped, nitrogen is introduced to restore the temperature and pressure to room, and the epoxidized soybean oil-based polyol is discharged. A sample is taken and the hydroxyl value of the epoxidized soybean oil-based polyol is measured to be 172.5mgKOH / g.

[0039] The difference between Preparation Example 3 and Preparation Example 1 is as follows: The preparation method of the epoxidized soybean oil-based polyol is as follows: 500g of epoxidized soybean oil and 102.1g of heptafluorobutanol (Aladdin, CAS: 375-01-9, molecular weight 200.055) are added to a reaction vessel equipped with a fractionation tower and a distillation receiver and mixed evenly. 1.5g of boron trifluoride diethyl ether is added and mixed evenly. The mixture is heated to 70℃ and reacted for 265min. At the same time, a vacuum is drawn to remove the water and excess alcohol monomers produced in the reaction. After the reaction is completed, a sample is taken and the hydroxyl value of the product is measured to be 178.1mgKOH / g. The reaction is then stopped, nitrogen is introduced to restore the temperature and pressure to room, and the epoxidized soybean oil-based polyol is discharged. A sample is taken and the hydroxyl value of the epoxidized soybean oil-based polyol is measured to be 177.4mgKOH / g.

[0040] Preparation Example 4: The preparation method of castor oil-based polyester polyol is as follows: 1008.1g of castor oil (Shandong Shunyong Castor Oil Co., Ltd., CAS: 8001-79-4) was used. 165.2 g of 1,3-propanediol (CAS: 57-55-6, Taizhou Jiayin Chemical Co., Ltd., molecular weight 76.1) with a molecular weight of 933.4 and 165.2 g of 1,3-propanediol were mixed evenly at a molar ratio of 1:2.01. Then, 1.2 g of tetraisopropyl titanate catalyst (CAS: 546-68-9, Ron, purity 99.9%) was added and mixed evenly. The mixture was heated to 20°C and reacted for 120 min. At the same time, a vacuum was drawn to remove the water and excess alcohol monomers produced in the reaction. After the reaction was completed, a sample was taken and the hydroxyl value of the product was measured to be 195.9 mg KOH / g. The reaction was then stopped, and nitrogen was introduced to restore the temperature and pressure to room temperature. The castor oil-based polyester polyol was then discharged. The hydroxyl value of the castor oil-based polyester polyol was measured to be 195.1 mg KOH / g.

[0041] The difference between Preparation Example 5 and Preparation Example 4 is as follows: The preparation method of castor oil-based polyester polyol is as follows: 1008.1g of castor oil and 165.2g of 1,2-propanediol (CAS: 504-63-2, Taizhou Jiayin Chemical Co., Ltd., molecular weight 76.1) are mixed evenly at a molar ratio of 1:2.01. Then, 1.2g of tetraisopropyl titanate catalyst is added and mixed evenly. The mixture is heated to 20℃ and reacted for 120min. At the same time, a vacuum is drawn to remove the water and excess alcohol monomers produced in the reaction. After the reaction is completed, a sample is taken and the hydroxyl value of the product is measured to be 196.2mgKOH / g. The reaction is then stopped, nitrogen is introduced to restore the temperature and pressure to room, and the castor oil-based polyester polyol is discharged. The hydroxyl value of the castor oil-based polyester polyol is measured to be 195.4mgKOH / g.

[0042] The difference between Preparation Example 6 and Preparation Example 4 is as follows: The preparation method of castor oil-based polyester polyol is as follows: 1008.1g of castor oil and 256.6g of 3-methyl-1,5-pentanediol (CAS: 4457-71-0, molecular weight 118.174, Kuraray, Japan) are mixed evenly at a molar ratio of 1:2.01. Then, 1.3g of tetraisopropyl titanate catalyst is added and mixed evenly. The mixture is heated to 20°C and reacted for 130min. At the same time, a vacuum is drawn to remove the water and excess alcohol monomers produced in the reaction. After the reaction is completed, a sample is taken and the hydroxyl value of the product is measured to be 193.1mgKOH / g. The reaction is then stopped, nitrogen is introduced to restore the temperature and pressure to room, and the castor oil-based polyester polyol is obtained by discharging the product. The hydroxyl value of the castor oil-based polyester polyol is measured to be 192.4mgKOH / g.

[0043] Preparation Example 7: The modified bio-based polyol was prepared as follows: The epoxidized soybean oil-based polyol from Preparation Example 1 and the castor oil-based polyester polyol from Preparation Example 4 were mixed evenly at a mass ratio of 7:3, and then vacuum dehydrated at 100°C for 2 hours to obtain the modified bio-based polyol.

[0044] The difference between Preparation Example 8 and Preparation Example 7 is that the modified bio-based polyol is prepared as follows: the epoxidized soybean oil-based polyol in Preparation Example 1 and the castor oil-based polyester polyol in Preparation Example 5 are mixed evenly at a mass ratio of 7:3, and then vacuum dehydrated at 100°C for 2 hours to obtain the modified bio-based polyol.

[0045] The difference between Preparation Example 9 and Preparation Example 7 is that the modified bio-based polyol is prepared as follows: the epoxidized soybean oil-based polyol in Preparation Example 1 and the castor oil-based polyester polyol in Preparation Example 6 are mixed evenly at a mass ratio of 7:3, and then vacuum dehydrated at 100°C for 2 hours to obtain the modified bio-based polyol.

[0046] The difference between Preparation Example 10 and Preparation Example 7 is that the epoxidized soybean oil-based polyol in Preparation Example 2 and the castor oil-based polyester polyol in Preparation Example 4 are mixed evenly at a mass ratio of 7:3, and then vacuum dehydrated at 100°C for 2 hours to obtain the modified bio-based polyol.

[0047] The difference between Preparation Example 11 and Preparation Example 7 is that the epoxidized soybean oil-based polyol in Preparation Example 3 and the castor oil-based polyester polyol in Preparation Example 4 are mixed evenly at a mass ratio of 7:3, and then vacuum dehydrated at 100°C for 2 hours to obtain the modified bio-based polyol.

[0048] The difference between Preparation Example 12 and Preparation Example 7 is that the epoxidized soybean oil-based polyol in Preparation Example 2 and the castor oil-based polyester polyol in Preparation Example 5 are mixed evenly at a mass ratio of 7:3, and then vacuum dehydrated at 100°C for 2 hours to obtain the modified bio-based polyol.

[0049] The difference between Preparation Example 13 and Preparation Example 7 is that the epoxidized soybean oil-based polyol in Preparation Example 1 and the castor oil-based polyester polyol in Preparation Example 4 are mixed evenly at a mass ratio of 1:1, and then vacuum dehydrated at 100°C for 2 hours to obtain the modified bio-based polyol.

[0050] Example 1: Modified bio-based polyol for use in blocked soft high-solids polyurethane resin was prepared by reacting the following raw materials in parts by weight: 50 parts of the modified bio-based polyol used in Preparation Example 7, 10 parts of polytetrahydrofuran ether diol (PTMEG) with a number average molecular weight of 1000 from Hyosung Chemical (Jiaxing) Co., Ltd., 20 parts of toluene diisocyanate (TDI) (provided by Wanhua Chemical Group Co., Ltd.), 0.1 parts of butanone oxime (Zhejiang Shengan Chemical Co., Ltd.), 0.03 parts of bismuth isooctanoate (Hubei Qiansheng Biotechnology Co., Ltd.), 0.3 parts of leveling agent BYK333, and 20 parts of ethyl acetate (Qianxin Chemical Group).

[0051] A method for preparing a modified bio-based polyol for use in a blocked, flexible, high-solids-content polyurethane resin includes the following steps: Step 1: Add 50 parts of the modified bio-based polyol from Preparation Example 1 and 10 parts of polytetrahydrofuran ether diol (PTMEG) with a number average molecular weight of 1000 to the reaction vessel, mix them evenly, and then heat them to 120°C for vacuum dehydration treatment for 2 hours. Step 2: After cooling to 60°C, add 20 parts of toluene diisocyanate (TDI) and mix thoroughly. Adjust the system temperature to 80°C and react for 3 hours under nitrogen protection. Step 3: After the reaction is complete, add 20 parts of accurately measured ethyl acetate and stir for 10 minutes. Then add 0.1 parts of accurately measured butanone oxime, 0.03 parts of bismuth isooctanoate, and 0.3 parts of leveling agent. After mixing evenly, adjust the temperature to 80°C and continue the reaction for 60 minutes under nitrogen protection. After the reaction is complete, cool down to below 40°C and discharge the modified bio-based polyol for use in closed-type soft high-solids polyurethane resin.

[0052] The difference between Example 2 and Example 1 is that 50 parts of the modified bio-based polyol in Preparation Example 7 were replaced with 50 parts of the modified bio-based polyol in Preparation Example 8 in the closed-type soft high-solids polyurethane resin formulation, while the other components remained unchanged.

[0053] The difference between Example 3 and Example 1 is that 50 parts of the modified bio-based polyol used in the closed-type soft high-solids polyurethane resin formulation in Preparation Example 7 were replaced with 50 parts of the modified bio-based polyol in Preparation Example 9, while the other components remained unchanged.

[0054] The difference between Example 4 and Example 1 is that 50 parts of the modified bio-based polyol used in the closed-type soft high-solids polyurethane resin formulation in Preparation Example 7 were replaced with 50 parts of the modified bio-based polyol in Preparation Example 10, while the other components remained unchanged.

[0055] The difference between Example 5 and Example 1 is that 50 parts of the modified bio-based polyol used in the closed-type soft high-solids polyurethane resin formulation in Preparation Example 7 were replaced with 50 parts of the modified bio-based polyol in Preparation Example 11, while the other components remained unchanged.

[0056] The difference between Example 6 and Example 1 is that 50 parts of the modified bio-based polyol used in the closed-type soft high-solids polyurethane resin formulation in Preparation Example 7 were replaced with 50 parts of the modified bio-based polyol in Preparation Example 12, while the other components remained unchanged.

[0057] The difference between Example 7 and Example 1 is that 10 parts of polytetrahydrofuran ether diol (PTMEG) with a number average molecular weight of 1000 in the modified bio-based polyol used in the closed-type soft high-solids polyurethane resin formulation were replaced with 10 parts of poly(1,2-propanediol) PPG-1000 (BASF) with a number average molecular weight of 1000, while the other components remained unchanged.

[0058] The difference between Example 8 and Example 1 is that 10 parts of polytetrahydrofuran ether glycol (PTMEG) with a number average molecular weight of 1000 in the modified bio-based polyol used in the closed-type soft high-solids polyurethane resin formulation were replaced with 10 parts of polyethylene glycol (PEG-1000) with a number average molecular weight of 1000 (Liaoning Aoke Pharmaceutical Co., Ltd.), while the other components remained unchanged.

[0059] The difference between Example 9 and Example 1 is that in the modified bio-based polyol used in the closed-type soft high-solids polyurethane resin formulation, 20 parts of toluene diisocyanate (TDI) were replaced with 28.74 parts of diphenylmethane diisocyanate (MDI) (Yantai Wanhua), while the other components remained unchanged.

[0060] The difference between Example 10 and Example 1 is that in the modified bio-based polyol used in the closed-type soft high-solids polyurethane resin formulation, 20 parts of toluene diisocyanate (TDI) were replaced with 18.38 parts of terephthalic diisocyanate (PPDI) (Yantai Wanhua), while the other components remained unchanged.

[0061] The difference between Comparative Example 1 and Example 1 is that the closed-type soft-mass polyurethane resin was prepared by reacting the following raw materials in parts by weight: 50 parts of the epoxidized soybean oil-based polyol in Preparation Example 1, 10 parts of polytetrahydrofuran ether diol (PTMEG) with a number average molecular weight of 1000, 20 parts of toluene diisocyanate (TDI), 0.1 parts of butanone oxime, 0.03 parts of bismuth isooctanoate, 0.3 parts of leveling agent, and 30 parts of ethyl acetate.

[0062] The difference between Comparative Example 2 and Example 1 is that the closed-type soft-mass polyurethane resin was prepared by reacting the following raw materials in parts by weight: 50 parts of castor oil-based polyester polyol from Preparation Example 4, 10 parts of polytetrahydrofuran ether diol (PTMEG) with a number average molecular weight of 1000, 20 parts of toluene diisocyanate (TDI), 0.1 parts of butanone oxime, 0.03 parts of bismuth isooctanoate, 0.3 parts of leveling agent, and 40 parts of ethyl acetate.

[0063] The difference between Comparative Example 3 and Example 1 is that 50 parts of the modified bio-based polyol in Preparation Example 7 in the closed-type soft mass polyurethane resin formulation were replaced with 50 parts of the modified bio-based polyol in Preparation Example 13, while the other components remained unchanged.

[0064] The difference between Comparative Example 4 and Example 1 is that the blocked soft-mass polyurethane resin formulation does not contain polytetrahydrofuran ether diol (PTMEG) with a number average molecular weight of 1000. The blocked soft-mass polyurethane resin is made from the following raw materials in parts by weight: 60 parts of the modified bio-based polyol from Preparation Example 7, 20 parts of toluene diisocyanate (TDI), 0.1 parts of butanone oxime, 0.03 parts of bismuth isooctanoate, 0.3 parts of leveling agent, and 20 parts of ethyl acetate.

[0065] Table 1: Test parameters of the blocked soft mass polyurethane resins in Examples 1-10 and Comparative Examples 1-4

[0066] Notes: 1. The solid content of the blocked soft polyurethane resins in Examples 1-10 and Comparative Examples 1-4 was determined according to GB / T 1725-2007 "Determination of Non-volatile Content in Paints, Varnishes and Plastics". 2. The viscosity of the blocked soft polyurethane resins in Examples 1-10 and Comparative Examples 1-4 at 25°C was determined according to GB / T 22235-2008 "Determination of Viscosity of Liquids". 3. The 100% modulus of the blocked soft polyurethane resins in Examples 1-10 and Comparative Examples 1-4 was determined according to GB / T 1040.3-2006 "Determination of Tensile Properties of Plastics - Part 3: Test Conditions for Films and Sheets". 4. The elongation at break of the blocked soft polyurethane resins in Examples 1-10 and Comparative Examples 1-4 was determined according to ASTM D412 Method A. 5. The bio-based content of the blocked soft polyurethane resins in Examples 1-10 and Comparative Examples 1-4 was determined according to ASTM D6866. 6. Bending resistance: Synthetic leather samples prepared using the closed-type soft mass polyurethane resin in Examples 1-10 and Comparative Examples 1-4 were placed in an environment of 80°C and 75% humidity for 4 weeks, and then placed in an environment of -20°C for 30,000 bends. The samples were then observed to see if cracking occurred at the bending points.

[0067] In summary, the closed-cell, soft, high-solids-content polyurethane resin of this invention has a long operating time, a solids content ≥70%, a bio-based content ≥50%, and a viscosity of (1~3)*10. 4 It has excellent storage stability and film-forming flexibility, and is suitable for clothing, furniture upholstery, synthetic leather and other fields.

[0068] It should be noted that this specific embodiment is merely an explanation of the technical solution of the present invention and is not intended to limit the present invention. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but as long as they are within the scope of the claims of the present invention, they are protected by patent law.

Claims

1. A modified bio-based polyol for use in blocked, flexible, high-solids-content polyurethane resin, characterized in that: It comprises 40-60 parts modified bio-based polyol, 10-30 parts petroleum-based polyol, 15-25 parts diisocyanate, 0.1-1 parts end-capping agent, 0.01-0.05 parts catalyst, 0.1-1 parts leveling agent, and 10-30 parts organic solvent; the modified bio-based polyol is obtained by dehydration under reduced pressure after compounding epoxidized soybean oil-based polyol and castor oil-based polyester polyol; the mass of the modified bio-based polyol accounts for 70-80 wt% of the total mass of the modified bio-based polyol and the petroleum-based polyol.

2. The modified bio-based polyol according to claim 1 for use in blocked soft high-solids-content polyurethane resin, characterized in that: The modified bio-based polyol is prepared by a ring-opening reaction of epoxidized soybean oil and a fluorinated alcohol ring-opening agent under the catalysis of boron trifluoride ether. The molar ratio of the hydroxyl group in the fluorinated alcohol ring-opening agent to the epoxy group in the epoxidized soybean oil is (1.2-1.5):

1. The fluorinated alcohol ring-opening agent is at least one of trifluoroethanol, pentafluoropropanol, and heptafluorobutanol. The hydroxyl value of the epoxidized soybean oil-based polyol is 150-200 mg KOH / g.

3. The modified bio-based polyol according to claim 2 for use in blocked soft high-solids-content polyurethane resin, characterized in that: The modified bio-based polyol, specifically the castor oil-based polyester polyol, is prepared by transesterification of castor oil and a low-crystallinity diol under the action of a titanate catalyst. The molar ratio of castor oil to the low-crystallinity diol is 1:(2-2.1). The low-crystallinity chain extender is at least one of 1,2-propanediol, 1,3-propanediol, 3-methyl-1,3-butanediol, and 3-methyl-1,5-pentanediol. The hydroxyl value of the castor oil-based polyester polyol is 180-220 mg KOH / g.

4. The modified bio-based polyol according to claim 3 for use in blocked soft high-solids-content polyurethane resin, characterized in that: The modified bio-based polyol is obtained by compounding epoxidized soybean oil-based polyol and castor oil-based polyester polyol in a mass ratio of (6-8): (2-4) and then dehydrating under reduced pressure.

5. The modified bio-based polyol according to claim 3 for use in blocked soft high-solids-content polyurethane resin, characterized in that: The modified bio-based polyol is prepared as follows: S1. The preparation method of epoxidized soybean oil-based polyol is as follows: epoxidized soybean oil and fluorinated alcohol ring-opening agent are mixed evenly at a molar ratio of (1.2~1.5):

1. Boron trifluoride diethyl ether is added and mixed evenly. The mass of the boron trifluoride diethyl ether is equal to 0.2-0.5wt% of the mass of the epoxidized soybean oil. The mixture is heated to 68-75℃ and reacted for 3-5 hours. At the same time, a vacuum is drawn to remove the water and excess alcohol monomers generated in the reaction. After the reaction is completed, a sample is taken to detect the hydroxyl value of the product. When the hydroxyl value of the product is 150-200mg KOH / g, the reaction is stopped. Nitrogen gas is introduced to restore the temperature and pressure to room temperature, and the epoxidized soybean oil-based polyol can be obtained by discharging the product. Simultaneously, castor oil-based polyester polyol is prepared using the following method: Castor oil and low-crystallinity diol are mixed evenly at a molar ratio of 1:(2-2.1), and a titanate catalyst is added. The mass of the titanate catalyst is equal to 0.08-0.12 wt% of the total mass of the castor oil and low-crystallinity diol. After mixing evenly, the temperature is raised to 210-230℃ and reacted for 100-150 min. At the same time, a vacuum is drawn to remove the water and excess alcohol monomers produced in the reaction. After the reaction is completed, a sample is taken to detect the hydroxyl value of the product. When the hydroxyl value of the product is 180-220 mg KOH / g, the reaction is stopped, nitrogen is introduced to restore the temperature and pressure to room, and the castor oil-based polyester polyol is obtained by discharging. S2. Epoxidized soybean oil-based polyol and castor oil-based polyester polyol are mixed evenly at a mass ratio of (6-8): (2-4), and vacuum dehydrated at 100-120℃ for 1-2 hours to obtain modified bio-based polyol.

6. The modified bio-based polyol according to claim 1 for use in blocked soft high-solids-content polyurethane resin, characterized in that: The petroleum-based polyol is at least one of poly(1,2-propanediol) PPG, polyethylene glycol (PEG), and polytetrahydrofuran ether diol (PTMEG) with a number average molecular weight of 1000-2000.

7. The modified bio-based polyol according to claim 1 for use in blocked soft high-solids-content polyurethane resin, characterized in that: The diisocyanate is at least one of toluene diisocyanate, terephthalic diisocyanate, naphthalene diisocyanate, and diphenylmethane diisocyanate; the catalyst is an organobismuth catalyst; and the organic solvent is at least one of ethyl acetate, acetone, butanone, and DMF.

8. The modified bio-based polyol according to claim 1 for use in blocked soft high-solids-content polyurethane resin, characterized in that: The capping agent is at least one selected from methyl ethyl ketone oxime, butanone oxime, isopropanol, phenol, 2,6-dimethylphenol, caprolactam, and 3,5-dimethylpyrazole.

9. The modified bio-based polyol according to claim 1 for use in blocked soft high-solids-content polyurethane resin, characterized in that: The petroleum-based polyol is polytetrahydrofuran ether diol (PTMEG) with a number average molecular weight of 1000; the diisocyanate is toluene diisocyanate; and the capping agent is butanone oxime.

10. A method for preparing a modified bio-based polyol according to any one of claims 1-9 for use in a blocked, soft, high-solids-content polyurethane resin, characterized in that: Includes the following steps: Step 1: Accurately metered modified bio-based polyols and petroleum-based polyols are added to the reaction vessel, mixed evenly, and then heated to 100-130℃ for vacuum dehydration treatment for 1-3 hours. Step 2: After cooling to 60-65℃, add accurately measured diisocyanate and mix thoroughly. Adjust the system temperature to 78-85℃ and react for 3-4 hours under nitrogen protection. Step 3: After the reaction is complete, add an accurately measured amount of organic solvent and stir for 10-15 minutes. Then add an accurately measured amount of end-capping agent, catalyst, and leveling agent. After mixing evenly, adjust the temperature to 78-85℃ and continue the reaction under nitrogen protection for 45-120 minutes. After the reaction is complete, cool down to below 40℃ and discharge the modified bio-based polyol for use in closed-type soft high-solids polyurethane resin.

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