Polyurethane synthetic leather with high bio-based content as well as preparation method and application of polyurethane synthetic leather

Abstract

The invention discloses polyurethane synthetic leather with high bio-based content as well as a preparation method and application of the polyurethane synthetic leather. The polyurethane synthetic leather sequentially comprises a polyurethane surface layer, a polyurethane foaming layer and a base material, wherein the polyurethane foaming layer is formed by coating the surface of the polyurethane surface layer with foaming layer resin, and the foaming layer resin comprises a solvent-free material A and a solvent-free material B; the solvent-free material A is a polyol prepolymer and is prepared from the following raw materials in parts by mass: 60 to 80 parts of chitosan polyol, 15 to 30 parts of polyether polymeric polyol, 2 to 8 parts of a small molecule chain extender and 10 to 30 parts of chitin; the solvent-free material B comprises isocyanate; the base material is formed by compounding jute fibers and polyamide fibers. According to the polyurethane synthetic leather disclosed by the invention, the bio-based content of the polyurethane synthetic leather is remarkably increased, and meanwhile, the finished leather has excellent physical properties and can be used for middle-grade and high-grade sports and leisure shoes.

Description

Technical Field

[0001] The invention belongs to the technical field of polyurethane synthetic leather, and particularly relates to polyurethane synthetic leather with high bio-based content, a preparation method and application thereof. Background Art

[0002] Polyurethane synthetic leather (PU synthetic leather) has become an ideal shoe material for sports and leisure shoes due to its high strength, wear resistance, cold resistance, breathability, aging resistance and soft texture. Among them, in mid-to-high-end sports and leisure shoes, the physical properties of polyurethane synthetic leather are required to be high, especially the peel strength and tensile strength of the finished leather.

[0003] At present, in order to obtain good physical properties, petroleum-based polyols or additives are mostly used for polyurethane synthetic leather for sports and leisure shoes. However, with the depletion of oil resources and the impact of non-biochemical pollution on human health, research and development of environmentally friendly materials based on natural polymer materials has become a key research direction in this field.

[0004] By introducing bio-based polyols into polyurethane synthetic leather, the bio-based content of the finished leather can be increased to a certain extent. However, currently most bio-based resins are plant polyols, and the raw materials for production mainly come from grains and other food crops. On the one hand, their biocompatibility is general, and on the other hand, they are difficult to meet the physical property requirements of leather for sports and leisure shoes.

[0005] Based on the above reasons, the present invention is dedicated to clarifying a polyurethane synthetic leather with a high bio-based content and meeting the physical property requirements of leather for sports and leisure shoes. Summary of the invention

[0006] In view of this, the primary purpose of the present invention is to provide a polyurethane synthetic leather with a high bio-based content. By selecting the substrate and the polyurethane foam layer resin, the bio-based content of the polyurethane synthetic leather is significantly improved, and at the same time, the finished leather has excellent physical properties to meet the needs of mid-to-high-end sports and leisure shoes.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions: The first aspect of the present invention provides a high bio-based content polyurethane synthetic leather, which comprises a polyurethane surface layer, a polyurethane foam layer and a substrate in sequence; The polyurethane foam layer is formed by coating the foam layer resin on the surface of the polyurethane surface layer, and the foam layer resin includes solvent-free A material and solvent-free B material; in terms of parts by mass, the solvent-free A material is a polyol prepolymer, and its raw materials include 60-80 parts of chitosan polyol, 15-30 parts of polyether polymer polyol, 2-8 parts of small molecule chain extender and 10-30 parts of chitin; the solvent-free B material includes isocyanate; The base material is a composite of hemp fiber and nylon fiber.

[0008] The second aspect of the present invention provides a method for preparing the polyurethane synthetic leather with a high bio-based content as described in the first aspect of the present invention, comprising the following steps: forming a polyurethane surface layer; The solvent-free material A and the solvent-free material B are mixed to obtain a foaming layer resin, which is coated on the surface of the polyurethane surface layer, baked to semi-dry, laminated to a substrate, and further dried and matured to obtain a polyurethane synthetic leather with a high bio-based content.

[0009] The third aspect of the present invention provides use of the polyurethane synthetic leather as described in the first aspect of the present invention in the preparation of sports and leisure shoes.

[0010] In the present invention, the high bio-content polyurethane synthetic leather mainly comprises a polyurethane surface layer, a polyurethane foaming layer and a substrate.

[0011] Wherein, the polyurethane surface layer is formed by a surface layer slurry, and there is no particular limitation on the surface layer slurry in the present invention. Specifically, a suitable surface layer slurry can be selected according to actual needs to form a polyurethane surface layer with corresponding performance. Those skilled in the art can make corresponding selections or designs based on actual performance requirements, so there is no particular limitation. In some specific embodiments of the present invention, the polyurethane synthetic leather in the present invention is mainly used in sports and leisure shoes, and therefore, its surface layer adopts a polyurethane surface layer commonly used in sports and leisure shoes in the art, which will not be specifically described here.

[0012] In the present invention, the foaming layer resin includes solvent-free A material and solvent-free B material, wherein the solvent-free A material is a polyol prepolymer and the solvent-free B material is an isocyanate component. The polyurethane resin synthetic leather can be formed in one step by online reaction of the solvent-free A material and the B material.

[0013] In some implementation cases, the solvent-free A material includes 60 to 80 parts of chitosan polyol, 15 to 30 parts of polyether polymer polyol, 2 to 8 parts of small molecule chain extender and 10 to 30 parts of chitin in terms of mass. By selecting low molecular weight chitosan polyol and polyether polymer polyol for compounding in the solvent-free A material, the physical property requirements of the leather for sports and leisure shoes can be met while significantly increasing the bio-based content of the polyurethane synthetic leather. The solvent-free A material in the present invention can be obtained by the polyol prepolymer preparation process well known in the art without special restrictions, so it will not be specifically described here.

[0014] In the present invention, the chitosan polyol refers to a polyol synthesized and extracted from low molecular weight chitosan, and has a number average molecular weight of 1000-5000.

[0015] In the present invention, the polyether polymerized polyol refers to a polyol compound having an ether bond (-ROR-) in the main chain of its molecular structure and having more than two hydroxyl groups (-OH) in the terminal or side group. The present invention can adopt the more common types in the art, and specific examples include at least one of polytetrahydrofuran ether glycol and polyoxytetramethylene glycol. In some specific implementation cases, the number average molecular weight of the polyether polymerized polyol is 1000-5000.

[0016] In the present invention, the small molecule chain extender refers to a compound that can react with the isocyanate group in the polyurethane prepolymer to generate a carbamate or urea group, thereby achieving a molecular chain extension effect. In this field, it mainly refers to a diol chain extender, and specific examples that can be mentioned include one or more of 1,4-butanediol, 1,6-hexanediol, ethylene glycol, propylene glycol, diethylene glycol, and neopentyl glycol, but are not limited thereto. In some specific implementation cases, the small molecule chain extender used is preferably ethylene glycol.

[0017] In the present invention, the chitosan refers to a crushed shell biomaterial, a bio-based shell insoluble in solvent. The source of the shell biomaterial is not limited to at least one of shrimp shells, crab shells, green algae, and squid. In the present invention, by adding a certain amount of chitosan, on the one hand, the bio-based content of the polyurethane synthetic leather is provided, and on the other hand, the film-forming performance and strength are improved. Among them, if the content of chitosan is too low, it has almost no effect on the film-forming performance and strength; if the content is too high, it will significantly reduce the physical strength of the film. Therefore, in the present invention, chitosan is preferably 10 to 30 parts.

[0018] In addition, it is understandable that some catalysts or additives may be added to the raw materials of the solvent-free A material according to performance requirements to improve the progress and efficiency of the reaction or to impart corresponding functions.

[0019] In some specific implementation cases, the raw materials of the solvent-free material A contain a catalyst, and the catalyst is an organic amine catalyst or an organic tin catalyst well known in the art.

[0020] In some other specific implementation cases, the raw materials of the solvent-free material A further contain additives, and specific examples of the additives include but are not limited to at least one of an organic silicon leveling agent, moisture, and an anti-yellowing additive.

[0021] Furthermore, in the present invention, the solvent-free B material includes isocyanate, which is a type of compound containing one or more isocyanate groups (-NCO) in the structure used in the preparation of polyurethane synthetic leather. It can be a common type in the art, and specific examples include at least one of 4,4′-diphenylmethane diisocyanate, hexamethylene diisocyanate, dicyclohexylmethane diisocyanate, toluene diisocyanate, isophorone diisocyanate, and polymethylene polyphenyl polyisocyanate, but is not limited thereto.

[0022] It is to be understood that the ratio of the raw materials in the present invention can be determined based on the experience of those skilled in the art or experiments using known methods, and therefore there is no particular limitation.

[0023] In some specific implementation cases, chitosan polyol and polyether polymer polyol together constitute a mixed polyol, and the molar ratio of the mixed polyol to the small molecule chain extender is 1:0~1; the molar ratio of the mixed polyol to isocyanate is 1.0~1.5:1 in terms of hydroxycyanate ratio.

[0024] In some specific implementation cases, the mass ratio of the solvent-free A material to the solvent-free B material is 100:(50-120), for example, it can be any ratio of 100:50, 100:60, 100:70, 100:80, 100:100, 100:120, which can be determined by those skilled in the art without any special limitation.

[0025] In the present invention, the substrate is a composite of hemp fiber and nylon fiber.

[0026] The hemp fiber is a common type in the art, and specific examples include ramie, jute, hemp, industrial hemp, flax, or a combination of two or more thereof.

[0027] In some specific implementation cases of the present invention, the substrate is prepared by co-spinning 1 part by mass of hemp fiber and 0-1 part by mass of nylon fiber. By adjusting the hemp fiber content to 50%-100%, not only the bio-based content of the polyurethane synthetic leather is increased, but also the basic physical properties of the substrate are improved to meet the physical properties of synthetic leather for sports and leisure shoes.

[0028] In the present invention, the parameters of the substrate are not particularly limited and can be adjusted or optimized according to performance requirements. In some specific implementation cases of the present invention, the thickness of the substrate is 0.8 mm to 1.2 mm, and the gram weight is 180 g / cm 2 ~280g / cm 2 .

[0029] Furthermore, the method for preparing the polyurethane synthetic leather with high bio-based content in the present invention comprises the following steps: forming a polyurethane surface layer; The solvent-free material A and the solvent-free material B are mixed to obtain a foaming layer resin, which is coated on the surface of the polyurethane surface layer, baked to semi-dry, laminated to a substrate, and further dried and matured to obtain a polyurethane synthetic leather with a high bio-based content.

[0030] The polyurethane surface layer is formed by coating a conventional surface layer slurry in the art on a release paper.

[0031] Beneficial effects of the present invention: The polyurethane synthetic leather product with high bio-based content prepared by the present invention adopts a base material of hemp fiber and nylon fiber blended in a certain proportion, wherein the hemp fiber content reaches 50% to 100%, which not only improves the bio-based content of the polyurethane synthetic leather, but also improves the basic physical properties of the base material, and meets the physical properties of the synthetic leather for sports and leisure shoes. In the polyurethane foaming layer, chitosan polyol and polyether polymer polyol are compounded, and chitosan components are added at the same time, which improves the uniformity and film-forming property of the foaming layer resin while improving the bio-based content of the polyurethane synthetic leather. By combining the foaming layer of the present invention with a specific base material, the peel strength and tensile strength of the polyurethane synthetic leather are significantly improved.

[0032] In addition, the foaming layer in the polyurethane synthetic leather of the present invention adopts solvent-free A and B materials as two components, and a high bio-based content polyurethane synthetic leather can be formed through a solvent-free online reaction one-step molding process. The raw materials are derived from nature, the production process is solvent-free, and it is a low-carbon and environmentally friendly process. DETAILED DESCRIPTION

[0033] Embodiments of the present invention are described in detail below. The embodiments described below are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0034] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. In addition, unless otherwise specified, methods that do not specifically record conditions or steps are conventional methods, and the reagents and materials used can be obtained from commercial sources.

[0035] The raw material information used in the following examples and comparative examples is as follows: Chitosan polyol, 149807, Chengdu Borite Chemical Technology Co., Ltd.; Polytetramethylene glycol, PTMEG2000, BASF AG; Amine catalyst, 92C-CC, purchased from BASF (China) Co., Ltd.; Organic tin catalyst, AUCAT-S029, Guangzhou Yourun Additives; Silicone leveling agent, LT-7110, Hefei Anli Polyurethane Material Technology Co., Ltd.; Solvent-free color paste, MUE WHITE GW043, Dagong Chemical Industry Co., Ltd.; Polycarbonate diol, T-5650J, Asahi Kasei Corporation, Japan; Isocyanate, AL-3055B, Hefei Anli Polyurethane Material Technology Co., Ltd.

[0036] The thickness of the substrate is 1.0 mm and the weight is 200 g / cm 2 .

[0037] The above reagents are only for illustrating the sources and components of the reagents used in the experiments of the present invention so as to fully disclose the information, and do not mean that the present invention cannot be realized by using other similar reagents or reagents provided by other suppliers.

[0038] Example 1 This embodiment provides a method for preparing polyurethane synthetic leather with high bio-based content, and the specific steps are as follows: S1. coating a surface layer slurry on the release paper to form a polyurethane surface layer; S2. Mix solvent-free material A and solvent-free material B (mass ratio 100:80) to form a foaming layer resin, apply the foaming layer resin on the surface of the polyurethane surface layer, put it into an oven for drying until it is semi-dry, then bond the foaming layer resin to the substrate, continue to dry and mature, and peel off the release paper to obtain a polyurethane synthetic leather with a high bio-based content.

[0039] The raw materials of solvent-free material A include 80 parts of chitosan polyol, 15 parts of polytetramethylene glycol, 8 parts of chain extender ethylene glycol, 0.02 parts of catalyst (92C-CC and AUCAT-S029 according to the mass ratio of 1:2), 0.5 parts of organosilicon leveling agent LT-7110 and 10 parts of chitin; The specific preparation method is to add chitosan polyol and silicone leveling agent LT-7110 into a reactor, stir evenly, add half of isocyanate AL-3055B, and react at 50°C for 30 minutes; then add polytetramethylene glycol and half of chain extender ethylene glycol to the reaction solution, and react at 60°C for 30 minutes to obtain a prepolymer; Add the remaining half of the chain extender ethylene glycol and the remaining half of the isocyanate AL-3055B to the prepolymer, react at 50-60°C, and as the viscosity of the system continues to increase. During the production and use process, the catalyst and chitin are added several times to obtain the polyurethane synthetic leather solvent-free A material.

[0040] The solvent-free B material is isocyanate AL-3055B.

[0041] The substrate is prepared by co-spinning hemp fiber and nylon fiber in a mass ratio of 1:1.

[0042] Example 2 This embodiment provides a method for preparing polyurethane synthetic leather with high bio-based content, and the specific steps are as follows: S1. coating a surface layer slurry on the release paper to form a polyurethane surface layer; S2. Mix solvent-free material A and solvent-free material B (mass ratio 100:80) to form a foaming layer resin, apply the foaming layer resin on the surface of the polyurethane surface layer, put it into an oven for drying until it is semi-dry, then bond the foaming layer resin to the substrate, continue to dry and mature, and peel off the release paper to obtain a polyurethane synthetic leather with a high bio-based content.

[0043] The raw materials of solvent-free material A include 75 parts of chitosan polyol, 20 parts of polytetramethylene glycol, 8 parts of chain extender ethylene glycol, 0.02 parts of catalyst (92C-CC and AUCAT-S029 according to the mass ratio of 1:2), 0.5 parts of organosilicon leveling agent LT-7110 and 20 parts of chitin; The specific preparation method is to add chitosan polyol and silicone leveling agent LT-7110 into a reactor, stir evenly, add half of isocyanate AL-3055B, and react at 50°C for 30 minutes; then add polytetramethylene glycol and half of chain extender ethylene glycol to the reaction solution, and react at 60°C for 30 minutes to obtain a prepolymer; Add the remaining half of the chain extender ethylene glycol and the remaining half of the isocyanate AL-3055B to the prepolymer, react at 50-60°C, and as the viscosity of the system continues to increase. During the production and use process, the catalyst and chitin are added several times to obtain the polyurethane synthetic leather solvent-free A material.

[0044] The solvent-free B material is isocyanate AL-3055B.

[0045] The substrate is prepared by co-spinning hemp fiber and nylon fiber in a mass ratio of 1:1.

[0046] Example 3 This embodiment provides a method for preparing polyurethane synthetic leather with high bio-based content, and the specific steps are as follows: S1. coating a surface layer slurry on the release paper to form a polyurethane surface layer; S2. Mix solvent-free material A and solvent-free material B (mass ratio 100:80) to form a foaming layer resin, apply the foaming layer resin on the surface of the polyurethane surface layer, put it into an oven for drying until it is semi-dry, then bond the foaming layer resin to the substrate, continue to dry and mature, and peel off the release paper to obtain a polyurethane synthetic leather with a high bio-based content.

[0047] The raw materials of solvent-free material A include 60 parts of chitosan polyol, 30 parts of polytetramethylene glycol, 8 parts of chain extender ethylene glycol, 0.02 parts of catalyst (92C-CC and AUCAT-S029 according to the mass ratio of 1:2), 0.5 parts of organosilicon leveling agent LT-7110 and 30 parts of chitin; The specific preparation method is to add chitosan polyol and silicone leveling agent LT-7110 into a reactor, stir evenly, add half of isocyanate AL-3055B, and react at 50°C for 30 minutes; then add polytetramethylene glycol and half of chain extender ethylene glycol to the reaction solution, and react at 60°C for 30 minutes to obtain a prepolymer; Add the remaining half of the chain extender ethylene glycol and the remaining half of the isocyanate AL-3055B to the prepolymer, react at 50-60°C, and as the viscosity of the system continues to increase. During the production and use process, the catalyst and chitin are added several times to obtain the polyurethane synthetic leather solvent-free A material.

[0048] The solvent-free B material is isocyanate AL-3055B.

[0049] The substrate is prepared by co-spinning hemp fiber and nylon fiber in a mass ratio of 1:1.

[0050] Example 4 This embodiment provides a method for preparing polyurethane synthetic leather with a high bio-based content, which adopts the same implementation as that of Example 1, except that the substrate is prepared by co-spinning hemp fiber and nylon fiber in a mass ratio of 1:0.

[0051] Comparative Example 1 This comparative example provides a method for preparing polyurethane synthetic leather, which adopts the same implementation as Example 1, except that the polytetramethylene glycol in the raw material of solvent-free material A is replaced by an equal mass portion of chitosan polyol, and other raw material compositions and process conditions are the same as those in Example 1.

[0052] Comparative Example 2 This comparative example provides a method for preparing polyurethane synthetic leather, which adopts the same implementation as Example 1, except that the chitosan polyol in the raw material of solvent-free material A is replaced by an equal mass portion of polytetramethylene glycol, and other raw material compositions and process conditions are the same as those in Example 1.

[0053] Comparative Example 3 This comparative example provides a method for preparing polyurethane synthetic leather, which adopts the same implementation as Example 1, with the only difference being that the chitosan polyol in the raw material of solvent-free material A is replaced with an equal mass portion of lignin polyol, and the other raw material compositions and process conditions are the same as those in Example 1.

[0054] Comparative Example 4 This comparative example provides a method for preparing polyurethane synthetic leather, which adopts the same implementation as Example 1, except that chitosan is not added to the solvent-free material A, and other raw material compositions and process conditions are the same as those in Example 1.

[0055] Comparative Example 5 This comparative example provides a method for preparing polyurethane synthetic leather, which adopts the same implementation as Example 1, with the only difference that the substrate is prepared by co-spinning hemp fiber and nylon fiber in a mass ratio of 0:1, and other raw material compositions and process conditions are the same as those in Example 1.

[0056] Table 1 lists the composition and amount of the main components and substrate of the foaming layer in the polyurethane synthetic leather in the examples and comparative examples.

[0057] Table 1 Main components of the foaming layer and substrate in the examples and comparative examples

[0058] In Table 1, a indicates that 80 parts of lignin polyol were added in Comparative Example 3.

[0059] Performance Testing The polyurethane synthetic leathers in the examples and comparative examples were subjected to the following performance tests: Among them, the test methods of peel strength and tensile strength refer to GB / T 8949-2008 polyurethane dry process artificial leather; Biobased content test ASTM D6866-22 Method B.

[0060] The test results are shown in Table 2.

[0061] Table 2 Test results of polyurethane synthetic leather performance

[0062] It can be seen from the above data that the present invention adopts chitosan polyol and polyether polymer polyol for compounding through the design of polyurethane foam layer components, and adds an appropriate amount of chitin, and uses hemp fiber as a base material. Under the condition of meeting the high physical property requirements of shoe materials, the bio-based content of polyurethane synthetic leather is effectively improved, which promotes the application and development of environmentally friendly materials in the field of synthetic leather with high physical property requirements such as shoe materials.

[0063] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0064] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A polyurethane synthetic leather with a high bio-based content, characterized in that: It comprises a polyurethane surface layer, a polyurethane foam layer and a substrate in sequence; The polyurethane foam layer is formed by coating the foam layer resin on the surface of the polyurethane surface layer, and the foam layer resin includes solvent-free A material and solvent-free B material; in terms of parts by mass, the solvent-free A material is a polyol prepolymer, and its raw materials include 60-80 parts of chitosan polyol, 15-30 parts of polyether polymer polyol, 2-8 parts of small molecule chain extender and 10-30 parts of chitin; the solvent-free B material includes isocyanate; The substrate is a composite of hemp fiber and nylon fiber; Preferably, the hemp fiber is one or a combination of two or more of ramie, jute, hemp, industrial hemp, and flax; Preferably, the substrate is prepared by co-spinning 1 part by mass of hemp fiber and 0-1 part by mass of nylon fiber; Preferably, the thickness of the substrate is 0.8 mm to 1.2 mm, and the weight is 180 g / cm 2 ~280g / cm 2 .

2. The high bio-based content polyurethane synthetic leather according to claim 1, characterized in that: The mass ratio of the solvent-free A material to the solvent-free B material is 100:(50-120).

3. The high bio-based content polyurethane synthetic leather according to claim 1, characterized in that: The number average molecular weights of the chitosan polyol and the polyether polymer polyol are respectively 1000-5000.

4. The high bio-based content polyurethane synthetic leather according to claim 1, characterized in that: The polyether polymer polyol is at least one of polytetramethylene glycol and polyoxytetramethylene glycol.

5. The high bio-based content polyurethane synthetic leather according to claim 1, characterized in that: The small molecule chain extender is a diol chain extender, and the diol chain extender is one or a combination of two or more of 1,4-butanediol, 1,6-hexanediol, ethylene glycol, propylene glycol, diethylene glycol, and neopentyl glycol; And / or, the isocyanate is at least one of 4,4′-diphenylmethane diisocyanate, hexamethylene diisocyanate, dicyclohexylmethane diisocyanate, toluene diisocyanate, isophorone diisocyanate, and polymethylene polyphenyl polyisocyanate.

6. The high bio-based content polyurethane synthetic leather according to claim 1, characterized in that: The chitosan is a crushed product of shell biological materials, and the shell biological material is at least one of shrimp shells, crab shells, green algae, and squid.

7. The high bio-based content polyurethane synthetic leather according to claim 1, characterized in that: The raw materials of the solvent-free A material also include catalysts and additives; Preferably, the catalyst is at least one of an organic amine catalyst and an organic tin catalyst; Preferably, the auxiliary agent is at least one of an organic silicon leveling agent, moisture, and an anti-yellowing auxiliary agent.

8. The high bio-based content polyurethane synthetic leather according to claim 1, characterized in that: The molar ratio of the sum of the chitosan polyol and the polyether polymer polyol to the small molecule chain extender is 1:0-1; And / or, the molar ratio of the sum of the chitosan polyol and the polyether polymer polyol to the isocyanate is 1.0-1.5:1 in terms of hydroxycyanide ratio.

9. A method for preparing a polyurethane synthetic leather with a high bio-based content according to any one of claims 1 to 8, characterized in that: The following steps are involved: forming a polyurethane surface layer; The solvent-free material A and the solvent-free material B are mixed to obtain a foaming layer resin, which is coated on the surface of the polyurethane surface layer, baked to semi-dry, laminated to a substrate, and further dried and matured to obtain a polyurethane synthetic leather with a high bio-based content.

10. Use of the high bio-based content polyurethane synthetic leather according to any one of claims 1 to 8 in the preparation of sports and leisure shoes.

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