Hydroxyl composition for preparing bio-based polyurethane and bio-based polyurethane

Abstract

This application provides a hydroxyl composition for preparing a bio-based polyurethane, and the bio-based polyurethane. The hydroxyl composition comprises a combination of a vegetable oil polyol, a bio-based polyol, and a chain extender, the bio-based polyol comprising a bio-based polyether polyol and / or a bio-based polyester polyol, and the polymerizable monomers of the bio-based polyester polyol comprise a dimer acid and a dibasic acid other than a dimer acid. By combining the two polyols within a specific range, the resulting hydroxyl composition is more suitable as the A component of a two-component bio-based polyurethane. When combined with the B component, the synthesized bio-based polyurethane exhibits both excellent low-temperature folding resistance and high peel strength.

Description

【Technical Field】 【0001】 This application belongs to the technical field of polyurethane synthetic leather, for example, a hydroxyl composition and a bio-based polyurethane for preparing bio-based polyurethane. 【Background Art】 【0002】 In recent years, the polyurethane synthetic leather industry is facing model change and upgrade, and is converting from traditional environmentally unfriendly production manufacturing technology to more advanced environmentally friendly production manufacturing technology. Due to the large content ratio of organic solvents used in the traditional manufacturing technology of polyurethane synthetic leather, different restrictive requirements are put forward for the organic solvents used in polyurethane synthetic leather in terms of new national and industrial policies, downstream customer requirements, market demands, etc. 【0003】 The ecological environmental protection process technology of polyurethane synthetic leather mainly focuses on aqueous and solvent-free technologies at present, but its raw materials still mainly come from petroleum-based materials. The main reasons are that as a kind of polymer material, polyurethane synthetic leather has high requirements for both functions and performance. However, compared with petroleum-based materials, bio-based materials have relatively poor stability and poor structural controllability. When used in polyurethane synthetic leather, there are several problems to be solved: 1. The bonding property between general bio-based materials and polyurethane materials is poor, and improving the compatibility between the two is one of the difficult problems; 2. The physical properties such as wear resistance, scratch resistance, and hydrolysis resistance of most bio-based resin materials are poor, and it is necessary to improve the durability of synthetic leather materials based on bio-based polyurethane resins; 3. The toughness of bio-based base fabrics is poor and the strength is low, which greatly affects the mechanical properties of polyurethane synthetic leather and limits its use. 【0004】 CN111732711A discloses a method for preparing and using a bio-based modified polyurethane resin, first by preparing a bio-based modified half-ester, then by preparing a bio-based modified isocyanate component B and an aqueous bio-based modified high-solids polyol component A, and finally by thoroughly reacting the aqueous bio-based modified high-solids polyol component A and the bio-based modified isocyanate component B to produce the bio-based modified polyurethane resin. The invention further discloses the use of the bio-based modified polyurethane resin, mainly for bonding an aqueous polyurethane resin surface layer and a solvent-free polyurethane resin intermediate layer in aqueous solvent-free polyurethane synthetic leather, improving the bonding ability between the aqueous polyurethane resin surface layer and the solvent-free polyurethane resin intermediate layer, avoiding quality problems such as temporary adhesion and peeling at the interface between the two due to insufficient adhesive strength, and ensuring the physical performance of the aqueous solvent-free polyurethane synthetic leather product. The above invention effectively solves the problem of low adhesive strength present in bio-based modified polyurethane resins, but its low-temperature resistance is poor, resulting in poor low-temperature folding resistance of the manufactured synthetic leather, and thus it cannot achieve both high peel strength and excellent low-temperature resistance. 【0005】 Therefore, we develop a hydroxyl composition in order to obtain a bio-based polyurethane prepared with a hydroxyl composition that has high peel strength and excellent low-temperature folding resistance. [Overview of the Initiative] [Problems that the invention aims to solve] 【0006】 The following is a summary of the subject matter described in detail herein. This summary does not limit the scope of the claims. 【0007】 In response to the lack of related technologies, the object of this application is to provide a hydroxyl composition for preparing bio-based polyurethane and a bio-based polyurethane, wherein the bio-based polyurethane prepared with the hydroxyl composition has excellent low-temperature resistance, and furthermore, synthetic leather containing it possesses excellent low-temperature fold resistance and high peel strength. [Means for solving the problem] 【0008】 To achieve this objective, this application proposes the following technical solutions. 【0009】 In Embodiment 1, the embodiment of the present application is: In the heavy section, 10 to 30 parts by weight of vegetable oil polyol, Bio-based polyol 15-80 parts by weight, It contains 3 to 10 parts by weight of a chain extender, The bio-based polyol includes a bio-based polyether polyol and / or a bio-based polyester polyol. The polymerizable monomer of the bio-based polyester polyol includes a dimer acid and other dibasic acids other than dimer acids. This invention provides a hydroxyl composition for preparing bio-based polyurethanes. 【0010】 Here, the amount of the vegetable oil polyol may be 12 parts by weight, 14 parts by weight, 16 parts by weight, 18 parts by weight, 20 parts by weight, 22 parts by weight, 24 parts by weight, 26 parts by weight, or 28 parts by weight, etc. 【0011】 The bio-based polyol may be in amounts of 20 parts by weight, 30 parts by weight, 40 parts by weight, 50 parts by weight, 60 parts by weight, or 70 parts by weight, etc. 【0012】 The chain extender may be in amounts of 4 parts by weight, 5 parts by weight, 6 parts by weight, 7 parts by weight, 8 parts by weight, or 9 parts by weight, etc. 【0013】 The hydroxyl composition for preparing the bio-based polyurethane according to the embodiment of the present application comprises a combination of a vegetable oil polyol, a bio-based polyol, and a chain extender, wherein the bio-based polyol is restricted to include a bio-based polyether polyol and / or a bio-based polyester polyol, and further restricted to include a dimer acid and other dibasic acids other than dimer acid, the obtained hydroxyl composition is more suitable as component A of a two-component bio-based polyurethane, and when combined with component B, the obtained bio-based polyurethane has excellent low-temperature resistance, and furthermore, the synthetic leather containing the bio-based polyurethane can have excellent low-temperature fold resistance and high peel strength. 【0014】 In one embodiment, the vegetable oil polyol comprises one or at least two of the following: castor oil polyol, soybean oil polyol, or palm oil polyol. 【0015】 In one embodiment, the vegetable oil polyol further comprises a modified product thereof, the modified product being modified with one or at least two of the following: a low molecular weight diol, a low molecular weight polyether diol, or a low molecular weight epoxy substance. The purpose of modification is to increase the reaction activity or compatibility of the vegetable oil polyol. 【0016】 In one embodiment, the low molecular weight diol is ethylene glycol and / or propylene glycol. 【0017】 In one embodiment, the bio-based polyether polyol comprises bio-based polytrimethylene ether glycol. 【0018】 In one embodiment, the prepared monomer of the bio-based polyester polyol further comprises a bio-based diol. 【0019】 In one embodiment, the bio-based diol includes bio-based 1,3-propylene glycol and / or bio-based 1,4-butanediol, and more preferably, is bio-based 1,3-propylene glycol. 【0020】 In one embodiment, the other dibasic acids other than the dimer acid include bio-based succinic acid and / or bio-based sebacic acid. 【0021】 In one embodiment, the chain extender includes C2-C12 (such as C4, C6, C8, C10 or C12, etc.) low molecular weight diols. 【0022】 In one embodiment, the C2-C12 low molecular weight diols include any one or at least a combination of two of ethylene glycol, propylene glycol, butanediol or hexanediol. 【0023】 In one embodiment, the hydroxyl composition further includes a non-bio-based polyether polyol. 【0024】 In one embodiment, the content of the non-bio-based polyether polyol in the hydroxyl composition is 0 to 70 parts by weight, and is not equal to 0, for example, 10 parts by weight, 20 parts by weight, 30 parts by weight, 40 parts by weight, 50 parts by weight or 60 parts by weight, etc. 【0025】 In Mode 2, the examples of the present application are including mixing a vegetable oil polyol, a bio-based polyol, a chain extender and an optional non-bio-based polyester polyol to obtain the hydroxyl compound, providing a method for preparing the hydroxyl compound according to Mode 1. 【0026】 In Mode 3, the examples of the present application are The raw materials for preparing the bio-based polyurethane include Component A and Component B, where Component A includes the hydroxyl compound according to Mode 1, The aforementioned component B includes a bio-based polyurethane prepolymer. We provide bio-based polyurethane. 【0027】 In a preferred technical solution for the embodiments of the present application, the bio-based polyurethane prepolymer is prepared from a polyisocyanate and a bio-based polyol. 【0028】 In one embodiment, the polyisocyanate comprises MDI and / or carbodiimide-uretonimine-modified MDI. 【0029】 In one embodiment, the NCO group content in the bio-based polyurethane prepolymer is 15-25% by mass, for example, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, or 24%. 【0030】 In one embodiment, the mass ratio of component A to component B is 100:(50~150), for example, 100:60, 100:70, 100:80, 100:90, 100:100, 100:110, 100:120, 100:130, or 100:140. 【0031】 In one embodiment, component A further comprises one or a combination of at least two of the following: silicone oil, a leveling aid, or water. 【0032】 In one embodiment, component A is obtained by mixing a hydroxyl composition, an optional silicone oil, an optional leveling aid, and an optional water. 【0033】 In one embodiment, the raw material for preparing the bio-based polyurethane further contains a catalyst component. 【0034】 In one embodiment, the catalyst component includes an organobismuth catalyst and / or an organotin catalyst. 【0035】 In one embodiment, with the weight of component A being 100%, the weight of the catalyst component is 0.025 to 1%, for example, 0.05%, 0.1%, 0.15%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, or 0.9%. 【0036】 In Embodiment 4, the embodiment of the present application is: A bio-based polyurethane as described in Embodiment 3, We provide synthetic leather. 【0037】 In Embodiment 5, the embodiment of the present application is: Step (1) involves mixing component A with an optional catalyst component, adding component B and mixing to obtain a coating solution. Step (2) includes applying the coating solution obtained in step (1) to the surface layer and allowing it to react, bonding the base fabric, and curing to obtain the synthetic leather. The present invention provides a method for preparing synthetic leather as described in Embodiment 4. 【0038】 In one embodiment, the reaction temperature described in step (2) is 80 to 130°C, for example, 85°C, 90°C, 95°C, 100°C, 105°C, 110°C, 115°C, 120°C, or 125°C. 【0039】 In one embodiment, the curing temperature described in step (2) is 100 to 160°C, for example, 105°C, 110°C, 115°C, 120°C, 125°C, 130°C, 135°C, 140°C, 145°C, 150°C, or 155°C. 【0040】 In step (2) of the preparation method according to the embodiment of this application, after applying the coating liquid to the surface layer, components A and B in the coating liquid are reacted at 80 to 130°C to cause foaming, and when the viscosity reaches its maximum, the base fabric can be bonded together, and then cured and molded at 100 to 160°C. [Effects of the Invention] 【0041】 With respect to related technologies, this application offers the following beneficial effects. 【0042】 (1) The hydroxyl composition for preparing the bio-based polyurethane according to the present application comprises a combination of a vegetable oil polyol, a bio-based polyol, and a chain extender, wherein the bio-based polyol is restricted to include a bio-based polyether polyol and / or a bio-based polyester polyol, and further restricted to include a dimer acid and other dibasic acids other than dimer acid, thereby the obtained hydroxyl composition is more suitable as component A of a two-component bio-based polyurethane, and when combined with component B, the obtained bio-based polyurethane has excellent low-temperature resistance, and furthermore, the synthetic leather prepared with the bio-based polyurethane has excellent low-temperature fold resistance and high peel strength, solving the problem that two-component bio-based polyurethanes in related technologies cannot have both high peel strength and excellent low-temperature fold resistance. 【0043】 (2) All synthetic leathers further prepared with the bio-based polyurethane according to the present invention reached 20,000 cycles in a -20°C low-temperature folding resistance test, exhibiting a peel strength of 52N or higher, and having a maturation time of 3-4 min. Therefore, according to the present invention, the synthesized bio-based polyurethane can combine excellent low-temperature folding resistance and high peel strength. [Modes for carrying out the invention] 【0044】 The technical proposal of this application will be further described below with reference to specific embodiments. Those skilled in the art should understand that the above embodiments are merely for the purpose of understanding this application and should not be considered as specifically limiting it. 【0045】 Detailed information regarding the raw materials for the specific embodiment of this application is as follows. Castor oil polyol: Refined first-grade castor oil from Guangzhou Chenshi Chemical Co., Ltd. Palm oil polyol: Maskimi Ltd., Malaysia, product model number PKF 3000 It was obtained by polymerizing a bio-based polyester polyol (1 part) with a molecular weight of 2000, a dimer acid, and a bio-based succinic acid in a mass ratio of 1:1 with propylene glycol. It was obtained by polymerizing bio-based polyester polyol 2: dimer acid and bio-based sebacic acid, with a molecular weight of 2000 and a mass ratio of 1:1, with propylene glycol. Bio-based polyester polyol 3: Molecular weight 2000, obtained by polymerization reaction of bio-based succinic acid and propylene glycol. Bio-based polyester polyol 4: Molecular weight 2000, obtained by polymerization reaction of dimer acid and propylene glycol. It was obtained by polymerizing bio-based polyester polyol 5: bio-based succinic acid, bio-based sebacic acid, and propylene glycol in a molecular weight of 2000 and a mass ratio of 1:1. Bio-based polyether polyol: Bio-based polytrimethylene ether glycol, molecular weight 2000. Non-biobased polyether polyol: KPX Chemical, KE-825. Diisocyanate: MDI (Manka Chemical). Carbodiimide-uretonimine-modified MDI: Kaleidoscope MDI-100HL. Leveling silicone oil: BYK-9565. Foam-regulating silicone oil: Momentive, L-417. 【0046】 (Example 1) The bio-based polyurethane was prepared using raw materials containing components A and B in a mass ratio of 100:66, and further containing a catalyst component. The total amount of component A added was 100%, and the amount of catalyst component added was 0.25%. 【0047】 Here, component A is in parts by weight, Castor oil polyol 20 parts by weight, Bio-based polyester polyol 1 40 parts by weight, 35 parts by weight of non-biobased polyether polyol, 5 parts by weight of 1,3-propylene glycol, Leveling silicone oil, 1 part by weight, Foam-regulating silicone oil 1 part by weight and 0.5 parts by weight of water, It included. 【0048】 The method for preparing component A includes mixing castor oil polyol, bio-based polyester polyol 1, non-bio-based polyether polyol, 1,3-propylene glycol, leveling silicone oil, foam-regulating silicone oil, and water to obtain component A. 【0049】 The aforementioned component B is a bio-based polyurethane prepolymer, in which the NCO group content was 20% by mass. 【0050】 The method for preparing component B involves reacting 35 parts by weight of bio-based polyester polyol 1, 55 parts by weight of MDI, and 10 parts by weight of carbodiimide-uretonimine-modified MDI at 70°C and under nitrogen gas protection conditions for 3.5 hours to obtain component B. 【0051】 The catalyst component contained 0.05 parts by weight of bismuth neodecanoate and 0.2 parts by weight of zinc neodecanoate. 【0052】 (Example 2) The bio-based polyurethane was prepared using raw materials containing components A and B in a mass ratio of 100:100, and further containing a catalyst component. The total amount of component A added was 100%, and the amount of catalyst component added was 0.25%. 【0053】 Here, component A is in parts by weight, 10 parts by weight of palm oil polyol, 20 parts by weight of bio-based polyether polyol, 5 parts by weight of 1,3-propylene glycol, It included. 【0054】 The method for preparing component A includes mixing palm oil polyol, bio-based polyether polyol, and 1,3-propylene glycol to obtain component A. 【0055】 The aforementioned component B is a bio-based polyurethane prepolymer, in which the NCO group content was 20% by mass. 【0056】 The method for preparing component B included reacting 5 parts by weight of castor oil polyol, 30.5 parts by weight of bio-based polyether polyol, 54.5 parts by weight of MDI, and 10 parts by weight of carbodiimide-uretonimine-modified MDI at 70°C and under nitrogen gas protection conditions for 3.5 hours to obtain component B. 【0057】 The catalyst component contained 0.05 parts by weight of bismuth neodecanoate and 0.2 parts by weight of zinc neodecanoate. 【0058】 (Example 3) The bio-based polyurethane was prepared using raw materials containing components A and B in a mass ratio of 100:60, and further containing a catalyst component. The total amount of component A added was 100%, and the amount of catalyst component added was 0.25%. 【0059】 Here, component A is in parts by weight, 30 parts by weight of castor oil polyol, Bio-based polyester polyol 1 80 parts by weight, 70 parts by weight of non-biobased polyether polyol, 10 parts by weight of 1,3-propylene glycol and Leveling silicone oil, 1 part by weight, Foam-regulating silicone oil 1 part by weight and 0.5 parts by weight of water, It included. 【0060】 The method for preparing component A includes mixing castor oil polyol, bio-based polyester polyol 1, non-bio-based polyether polyol, 1,3-propylene glycol, leveling silicone oil, foam-regulating silicone oil, and water to obtain component A. 【0061】 The aforementioned component B is a bio-based polyurethane prepolymer, in which the NCO group content was 20% by mass. 【0062】 The method for preparing component B involves reacting 35 parts by weight of bio-based polyester polyol 1, 55 parts by weight of MDI, and 10 parts by weight of carbodiimide-uretonimine-modified MDI at 70°C and under nitrogen gas protection conditions for 3.5 hours to obtain component B. 【0063】 The catalyst component contained 0.05 parts by weight of bismuth neodecanoate and 0.2 parts by weight of zinc neodecanoate. 【0064】 (Example 4) This is a bio-based polyurethane, and the only difference from Example 1 is that a bio-based polyether polyol was used instead of bio-based polyester polyol 1 in components A and B; all other components, amounts used, and preparation methods were the same as in Example 1. 【0065】 (Example 5) This is a bio-based polyurethane, and the only difference from Example 1 is that a non-bio-based polyether polyol was not added; all other components, amounts used, and preparation methods were the same as in Example 1. 【0066】 (Example 6) This is a bio-based polyurethane, and the only difference from Example 1 is that bio-based polyester polyol 2 was used instead of bio-based polyester polyol 1 in components A and B; all other components, amounts used, and preparation methods were the same as in Example 1. 【0067】 (Comparative Example 1) This is a bio-based polyurethane, and the only difference from Example 1 is that the amount of bio-based polyester polyol 1 added to component A was 10 parts by weight; all other components, amounts used, and preparation methods were the same as in Example 1. 【0068】 (Comparative Example 2) This is a bio-based polyurethane, and the only difference from Example 1 is that the amount of bio-based polyester polyol 1 added to component A was 90 parts by weight; all other components, amounts used, and preparation methods were the same as in Example 1. 【0069】 (Comparative Example 3) This is a bio-based polyurethane, and the only difference from Example 1 is that KPX Chemical GP-1000 (trifunctional, 1000 molecular weight) was used instead of castor oil polyol; all other components, amounts used, and preparation methods were the same as in Example 1. 【0070】 (Comparative Example 4) This is a bio-based polyurethane, and the only difference from Example 1 is that bio-based polyester polyol 3 was used instead of bio-based polyester polyol 1 in components A and B; all other components, amounts used, and preparation methods were the same as in Example 1. 【0071】 (Comparative Example 5) This is a bio-based polyurethane, and the only difference from Example 1 is that bio-based polyester polyol 4 was used instead of bio-based polyester polyol 1 in components A and B. All other components, amounts used, and preparation methods were the same as in Example 1. 【0072】 (Comparative Example 6) This is a bio-based polyurethane, and the only difference from Example 1 is that bio-based polyester polyol 5 was used instead of bio-based polyester polyol 1 in components A and B; all other components, amounts used, and preparation methods were the same as in Example 1. 【0073】 (Comparative Example 7) This is a bio-based polyurethane, and the only difference from Example 1 is that castor oil polyol was not added to component A; all other components, amounts used, and preparation methods were the same as in Example 1. 【0074】 (Comparative Example 8) This is a bio-based polyurethane, and the only difference from Example 1 is that bio-based polyester polyol 1 was not added to component A; the other components, amounts used, and preparation method were all the same as in Example 1. 【0075】 (Application Example 1) It is synthetic leather, and its preparation method includes the following steps. 【0076】 (1) The bio-based polyurethane in Example 1 was stirred for 1 minute, then component B was added and mixed at room temperature for 15 seconds to obtain the coating solution. 【0077】 (2) The coating solution obtained in step (1) was uniformly applied to the Huafon aqueous polyurethane surface layer JF-PDY-851HY, reacted at 100°C to cause foaming, and when the viscosity reached its maximum, the base fabric was bonded to it and cured at 150°C to obtain the synthetic leather. 【0078】 (Application Examples 2-6) This is a synthetic leather, and the only difference from Example 1 is that instead of components A, B, and catalyst in the bio-based polyurethane of Example 1, components A, B, and catalyst in the bio-based polyurethane of Examples 2 to 6 were used, respectively. All other conditions and steps were the same as in Example 1. 【0079】 (Comparative application examples 1-8) This is a synthetic leather, and the only difference from Example 1 is that instead of components A, B, and catalyst in the bio-based polyurethane of Example 1, the components A, B, and catalyst in the bio-based polyurethane of Comparative Examples 1 to 8 were used, respectively. All other conditions and steps were the same as in Example 1. 【0080】 Performance testing: (1) Peel strength: Tested according to the GB / T 1040.3-2006 standard. (2) Low-temperature bending resistance: Tests were conducted according to the QB / T 2714-2005 standard, with the low-temperature setting at -20°C. (3) Curing time: The shortest curing time required at 150°C was calculated when preparing the synthetic leather sample. 【0081】 The synthetic leather obtained in Application Examples 1-6 and Comparative Application Examples 1-8 was tested according to the above test method, and the test results are shown in Table 1. 【0082】 [Table 1] 【0083】 From the data in Table 1, the following was found: 【0084】 As can be seen from the data in Application Examples 1 to 6, synthetic leather further prepared with bio-based polyurethane prepared within the blending ratio range of the present invention all reached 20,000 cycles in the -20°C low-temperature folding resistance test, exhibited a peel strength of 52N or higher, and had a maturation time of 3 to 4 minutes. This indicates that the bio-based polyurethane synthesized according to the present invention can combine excellent low-temperature folding resistance with high peel strength. 【0085】 By comparing the data from Application Example 1 with comparative application examples 1, 5, and 8, it was found that the peel strength of the final prepared synthetic leather decreased in all cases: when the bio-based polyester polyol content was too low (comparative application example 1), when a simple dimer acid polyester polyol was used (comparative application example 5), and when no bio-based polyester polyol was added (comparative application example 8). 【0086】 By comparing the data from Application Example 1 and Comparative Application Example 2, it was found that when the bio-based polyester polyol content was too high, the low-temperature folding resistance of the final prepared synthetic leather actually decreased. 【0087】 By comparing the data from Application Example 1 with comparative Application Examples 4 and 6, it was found that polyester polyols without dimer acid also resulted in a deterioration of the low-temperature folding resistance of the final prepared synthetic leather. 【0088】 As can be seen from the data in Application Example 1 and Comparative Application Example 3, the low-temperature folding resistance and peel strength of synthetic leather prepared using a general polyether polyol with similar functional properties and molecular weight instead of castor oil polyol were both significantly reduced. 【0089】 Furthermore, data from Application Example 1 and Comparative Application Example 7 revealed that when the vegetable oil polyol was not added, the degree of cross-linking of the system was insufficient, and proper curing could not be achieved. 【0090】 Finally, data from Application Examples 1 and 5 showed that the absence of non-biobased polyether polyols also affected the low-temperature folding resistance of the final synthetic leather. 【0091】 While this application describes hydroxyl compositions for preparing bio-based polyurethanes and bio-based polyurethanes using the above-described examples, the applicant declares that this application is not limited to the above-described examples, that is, it does not mean that this application must be carried out in accordance with the above-described examples. Those skilled in the art should understand that any improvements to this application, equivalent substitutions and additions of auxiliary components to each of the raw materials of the product of this application, and selection of specific forms are all included within the scope of protection and disclosure of this application.

Claims

[Claim 1] It is a bio-based polyurethane, The raw materials for preparing the bio-based polyurethane consist of component A, component B, and a catalyst component, with a mass ratio of component A to component B being 100:(50-150), and with component A's weight being 100%, the catalyst component's weight being 0.025-1%. The aforementioned component B consists of a bio-based polyurethane prepolymer, and the aforementioned component A consists of a hydroxyl composition and one or at least two of the following: silicone oil, a leveling aid, or water. The hydroxyl composition is, in parts by weight, 10 to 30 parts by weight of vegetable oil polyol, Bio-based polyol 15 to 80 parts by weight, Chain extender: 3 to 10 parts by weight, It consists of 0 to 70 parts by weight of a non-biobased polyether polyol that is not equal to 0, The bio-based polyol is a bio-based polyester polyol, the polymerizable monomer of the bio-based polyester polyol consists of a dimer acid, another dibasic acid other than the dimer acid, and a bio-based diol, the mass ratio of the dimer acid to the other dibasic acid is 1:1, and the other dibasic acid is bio-based succinic acid or bio-based sebacic acid, and the bio-based diol is bio-based 1,3-propylene glycol. or, The aforementioned component A consists of a hydroxyl composition, and the hydroxyl composition is in parts by weight, 10 to 30 parts by weight of vegetable oil polyol, Bio-based polyol 15 to 80 parts by weight, Consists of 3 to 10 parts by weight of a chain extender. The bio-based polyol is a bio-based polyether polyol, and the bio-based polyether polyol is a bio-based polytrimethylene ether glycol. The NCO group content in the bio-based polyurethane prepolymer is 15-25% by mass. The bio-based polyurethane prepolymer is prepared from polyisocyanate and bio-based polyol. The polyisocyanate consists of MDI and / or carbodiimide-uretonimine-modified MDI. The bio-based polyol used in component B is the same as the bio-based polyol used in component A, or it is a mixture of castor oil polyol and the bio-based polyol used in component A. The chain elongator is a C2-C12 low molecular weight diol. The aforementioned vegetable oil polyol is one or at least two of the following: castor oil polyol, soybean oil polyol, or palm oil polyol. A bio-based polyurethane characterized by the following features. [Claim 2] The C2-C12 low molecular weight diol includes one or at least two of the following: ethylene glycol, propylene glycol, butanediol, or hexanediol. The bio-based polyurethane according to feature 1. [Claim 3] The hydroxyl composition is prepared by a method comprising mixing a vegetable oil polyol, a bio-based polyol, a chain extender, and an optional non-bio-based polyether polyol to obtain the hydroxyl composition. The bio-based polyurethane according to feature 1. [Claim 4] The aforementioned component A is obtained by mixing a hydroxyl composition, an optional silicone oil, an optional leveling aid, and an optional water. The bio-based polyurethane according to feature 1. [Claim 5] The catalyst component includes an organobismuth catalyst and / or an organotin catalyst. The bio-based polyurethane according to feature 1. [Claim 6] A bio-based polyurethane comprising any one of claims 1 to 5, Synthetic leather characterized by the following features. [Claim 7] A method for preparing synthetic leather according to claim 6, Step (1) involves mixing component A with an optional catalyst component, adding and mixing component B to obtain a coating solution, Step (2) includes applying the coating liquid obtained in step (1) to the surface layer, bonding the base fabric, and curing to obtain the synthetic leather. A method for preparing synthetic leather, characterized by the following:

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