A polyurethane synthetic leather based on polyurethane waste and its preparation method

Abstract

This invention provides a polyurethane synthetic leather based on polyurethane waste and its preparation method, relating to the field of polyurethane waste recycling. The preparation method includes the following steps: first, pulverizing and classifying polyurethane waste to obtain recycled polyurethane particles; coating an aqueous polyurethane topcoat slurry onto the surface of release paper, then spraying the recycled polyurethane particles onto the topcoat slurry to obtain an aqueous polyurethane topcoat coating; then sequentially performing steps such as coating with a high-solids polyurethane topcoat slurry, coating with an aqueous polyurethane adhesive topcoat slurry, and bonding to a substrate to obtain the final product. The method provided by this invention can produce solvent-free, pollution-free, safe, reliable, mechanically sound, and high-quality polyurethane synthetic leather, while simultaneously processing polyurethane waste into reusable polyurethane raw materials, aligning with the concept of sustainable development in today's society.

Description

Technical Field

[0001] This invention relates to the field of polyurethane waste recycling technology, specifically to a polyurethane synthetic leather based on polyurethane waste and its preparation method. Background Technology

[0002] Polyurethane is a multifunctional and versatile synthetic polymer material. With its widespread application, industrial production generates a large amount of waste material, which has become a new source of pollution. Therefore, the recycling and reuse of waste polyurethane materials is becoming increasingly important, both in terms of reducing resource consumption and preventing environmental pollution. Enterprises across all sectors are also increasingly emphasizing their social responsibility and contributing to global green environmental protection.

[0003] When applying for this invention, the applicant discovered, through a search, a Chinese patent disclosed a "method for recycling and reusing polyurethane materials," application number "CN113150374A." This patent mainly uses waste polyurethane foam as raw materials and performs alcoholysis on polyurethane waste under specific process conditions to achieve polyurethane degradation. However, the method involves high temperatures of 160-180℃ and 170-210℃, which places excessive demands on the production equipment. Furthermore, this degradation method involves complex processes and high energy consumption, which does not conform to the global ecological concept of energy conservation and environmental protection. In addition, it has poor economic benefits, low recycling and reuse value, and cannot fully utilize the economic value of waste polyurethane materials. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the present invention aims to provide a polyurethane synthetic leather based on polyurethane waste and its preparation method. This invention recycles polyurethane waste through simple and easy-to-operate physical decomposition and directly inputs it into the production and synthesis of new products, forming a closed loop of production-recycling-new product re-production. This bypasses the high-energy-consuming process of chemical degradation and solves the problem of complex equipment in the recycling and reuse of polyurethane materials. It is in high demand in the market and has high economic value.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A method for preparing polyurethane synthetic leather based on polyurethane waste includes the following steps:

[0007] Crushing and Sorting: Polyurethane waste generated during the production of polyurethane composite materials is collected, crushed by a high-speed crusher, and then sorted by a color sorter to separate polyurethane recycled particles of the required particle size and color for later use. Using a color sorter facilitates control over the size and uniformity of recycled particles in the finished product and increases the diversity of the final product. Preferably, the particle size of the polyurethane recycled particles is between 20 and 200 mesh. If the particle size is too large, it cannot meet the process requirements of the spraying equipment; if the particle size is too small, it cannot meet the requirement for product recycling visualization.

[0008] Preparation of the water-based polyurethane topcoat: The water-based polyurethane topcoat slurry is applied to the surface of the release paper. After the topcoat slurry passes through the coating head, recycled polyurethane particles are evenly sprayed onto the topcoat slurry using a powder spray gun. The content of recycled polyurethane particles in the topcoat is 10-30 g / m². 3 Then, it is heated and dried at a temperature of 120-140℃ to obtain a water-based polyurethane surface coating.

[0009] Preparation of polyurethane high-solids layer: Apply polyurethane high-solids layer slurry onto water-based polyurethane topcoat, and dry and cure in an oven at 130-140℃ to obtain polyurethane high-solids layer.

[0010] Water-based polyurethane adhesive slurry is applied to a polyurethane high-solids layer and then baked in an oven at 120-140℃ until it reaches a molten state. It is then bonded to a pre-prepared substrate (non-woven fabric or cloth base, etc.), and after bonding, it is put into an oven at 120-140℃ and driven out at a speed of 4-6m / min. After drying and cooling to set, it is peeled off from the release paper to obtain the finished product.

[0011] in:

[0012] The water-based polyurethane topcoat slurry is a water-based slurry with high abrasion resistance and excellent physical properties, and its composition by mass parts is as follows:

[0013]

[0014] The waterborne polyurethane resin A used above features high wear resistance and high cold resistance. Utilizing the principle of incompatibility between recycled polyurethane particles and waterborne resin, a high-performance surface layer containing the desired recycled polyurethane particles can be prepared. Preferably, this layer is 1036R produced by Guangzhou Slocor Technology Co., Ltd.; the thickener is HY-1048 produced by Shanghai Huiyan New Materials Co., Ltd.; the leveling agent is BYK-301 produced by BYK Chemical Co., Ltd.; the curing agent is BYK-4509 produced by BYK Chemical Co., Ltd.; and the defoamer is BYK-012 produced by BYK Chemical Co., Ltd. The use of waterborne polyurethane, relying on its advantages of being pollution-free, safe, reliable, and having good mechanical properties, results in a final product that is not only more environmentally friendly but also of high quality. Furthermore, by using a color sorter to select recycled polyurethane particles of the desired color and size and uniformly spraying them onto the surface coating, the uniformity of the finished product's appearance and the diversity of colors are increased.

[0015] The polyurethane high-solids slurry is composed of the following parts by weight:

[0016] High-solids polyurethane resin B, 80-120 parts.

[0017] 5-10 parts of curing agent

[0018] The high-solids polyurethane resin B used above has a solids content of 92%-95%, and features high content, high elongation, and resistance to wear and hydrolysis. It is preferably HDPS-9025 produced by Shanghai Huide Technology Co., Ltd., and the curing agent is HDC4020 produced by Haihuide Technology Co., Ltd. Utilizing the characteristics of the high-solids resin ensures the smoothness of the surface coating, solving the problem of unevenness caused by recycled polyurethane particles filling the waterborne polyurethane surface layer, which affects the bonding strength with the waterborne polyurethane intermediate layer. Simultaneously, it improves the overall wear resistance and flexural strength of the finished product.

[0019] The water-based polyurethane resin slurry is composed of the following parts by weight:

[0020]

[0021] The aforementioned waterborne polyurethane resin C features high peel strength and high abrasion resistance. Preferably, it is SH-700 produced by Songjing Chemical Co., Ltd., the thickener is HY-1048 produced by Shanghai Huiyan New Materials Co., Ltd., the leveling agent is BYK-301 produced by BYK Chemical Co., Ltd., the curing agent is BYK-4509 produced by BYK Chemical Co., Ltd., and the defoamer is BYK-012 produced by BYK Chemical Co., Ltd. The use of waterborne polyurethane, relying on its advantages of being pollution-free, safe, reliable, and having good mechanical properties, results in a final product that is not only more environmentally friendly but also of high quality.

[0022] The present invention has the following beneficial effects:

[0023] 1. This invention crushes polyurethane waste into granules for reuse, which is more convenient for subsequent spraying. Furthermore, the crushed polyurethane recycled granules are classified using a color sorter, which helps to increase the diversity of the final product.

[0024] 2. This invention uses a high-solids polyurethane slurry, which utilizes the high solids content, large elongation, wear resistance and hydrolysis resistance of high-solids polyurethane resin to ensure the smoothness of the coating containing recycled polyurethane particles. This solves the problem that the unevenness of the recycled polyurethane particles filling the water-based polyurethane surface layer affects the bonding strength with the water-based polyurethane intermediate layer, while improving the overall wear resistance and bending resistance of the finished product.

[0025] 3. This invention uses water-based polyurethane, which, due to its advantages such as being pollution-free, safe and reliable, and having good mechanical properties, makes the final product not only more environmentally friendly but also of high quality.

[0026] 4. The polyurethane synthetic leather product prepared by this invention can be applied to clothing, shoes, balls and other products, realizing the recycling of polyurethane waste, which is in line with the concept of sustainable development, and the recycling is visualized in appearance. Attached Figure Description

[0027] Figure 1 This is a flowchart of a method for preparing polyurethane synthetic leather based on polyurethane waste materials proposed in this invention;

[0028] Figure 2 Appearance image of the synthetic leather prepared in Example 2 of this invention ( Figure 2 (Right) Appearance of ordinary polyurethane synthetic leather prepared in Comparative Example 2. Figure 2 Left). Detailed Implementation

[0029] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] Example 1:

[0031] The polyurethane synthetic leather prepared in this embodiment includes a waterborne polyurethane surface layer, a polyurethane high-solids layer, and a waterborne polyurethane adhesive layer, wherein:

[0032] The waterborne polyurethane topcoat is made from a waterborne polyurethane topcoat slurry prepared by the following components in parts by weight:

[0033]

[0034] The polyurethane high-strength layer is made from a polyurethane high-strength layer slurry prepared by the following components in parts by weight:

[0035] High-solids polyurethane resin B 100 parts

[0036] 6 parts curing agent;

[0037] The waterborne polyurethane adhesive layer is made from a waterborne polyurethane adhesive layer slurry prepared by the following components in parts by weight:

[0038]

[0039] The high-property waterborne polyurethane surface layer resin A is 1036R produced by Guangzhou Slocor Technology Co., Ltd., the high-solids polyurethane layer B is HDPS-9025 produced by Shanghai Huide Technology Co., Ltd., the waterborne polyurethane adhesive layer C is SH-700 produced by Songjing Chemical, the curing agent in the polyurethane high-solids slurry is HDC4020 produced by Haihuide Technology Co., Ltd., the curing agent in the surface layer and adhesive layer is BYK-4509 produced by BYK Chemical Co., Ltd., the thickener is HY-1048 produced by Shanghai Huiyan New Materials Co., Ltd., the leveling agent is BYK-301 produced by BYK Chemical Co., Ltd., and the defoamer is BYK-012 produced by BYK Chemical Co., Ltd.

[0040] The method for preparing polyurethane synthetic leather based on polyurethane waste in this embodiment is referred to... Figure 1 This includes the following steps:

[0041] (a) Collect the polyurethane waste generated during the production of polyurethane composite materials, crush it through a high-speed pulverizer, and then sort it into a color sorter to separate the polyurethane recycled particles of the required particle size and color for later use.

[0042] (b) Apply water-based polyurethane topcoat slurry to the surface of the release paper. The coating gap between the blades is 15 mils. After the topcoat slurry passes through the coating head, spray 80-mesh recycled polyurethane granules evenly onto the topcoat slurry using a powder spray gun (particle content is 25 g / m²). 3 The water-based polyurethane surface layer is obtained by heating and drying at 120℃.

[0043] (c) Apply polyurethane high-solids slurry onto water-based polyurethane surface layer, with a blade coating gap of 20 mils, and heat and dry at 140℃ to obtain polyurethane high-solids layer.

[0044] (d) Apply water-based polyurethane adhesive layer slurry to polyurethane high-solids layer, with a blade coating gap of 20 mils, heat at 140℃ to molten state, then bond with pre-prepared non-woven fabric, and after bonding, put into an oven at 130℃, drive out at a speed of 6m / min, dry and cool to set, and then peel off from the release paper to obtain the finished product.

[0045] Example 2:

[0046] The polyurethane synthetic leather prepared in this embodiment includes a waterborne polyurethane surface layer, a polyurethane high-solids layer, and a waterborne polyurethane adhesive layer, wherein:

[0047] The waterborne polyurethane topcoat is made from a waterborne polyurethane topcoat slurry prepared by the following components in parts by weight:

[0048]

[0049]

[0050] The polyurethane high-strength layer is made from a polyurethane high-strength layer slurry prepared by the following components in parts by weight:

[0051] High-solids polyurethane resin B 80 parts

[0052] 5 parts curing agent;

[0053] The waterborne polyurethane adhesive layer is made from a waterborne polyurethane adhesive layer slurry prepared by the following components in parts by weight:

[0054]

[0055] The high-performance waterborne polyurethane topcoat resin A is 1036R produced by Guangzhou Slocor Technology Co., Ltd., the high-solids polyurethane B is HDPS-9025 produced by Shanghai Huide Technology Co., Ltd., and the waterborne polyurethane adhesive layer C is SH-700 produced by Songjing Chemical. The curing agent in the high-solids polyurethane slurry is HDC4020 produced by Haihuide Technology Co., Ltd., the curing agent for the topcoat and adhesive layers is BYK-4509 produced by BYK Chemical Co., Ltd., the thickener is HY-1048 produced by Shanghai Huiyan New Materials Co., Ltd., the leveling agent is BYK-301 produced by BYK Chemical Co., Ltd., and the defoamer is BYK-012 produced by BYK Chemical Co., Ltd.

[0056] The method for preparing polyurethane synthetic leather based on polyurethane waste in this embodiment includes the following steps:

[0057] (a) Collect the polyurethane waste generated during the production of polyurethane composite materials, crush it through a high-speed pulverizer, and then sort it into a color sorter to separate the polyurethane recycled particles of the required particle size and color for later use.

[0058] (b) Apply water-based polyurethane topcoat slurry to the surface of the release paper. The coating gap between the blades is 15 mils. After the topcoat slurry passes through the coating head, 60-mesh recycled polyurethane granules (particle content 30 g / m²) are evenly sprayed onto the topcoat slurry using a powder spray gun. 3 The water-based polyurethane surface layer is obtained by heating and drying at 130℃.

[0059] (c) Apply polyurethane high-solids slurry onto water-based polyurethane surface layer, with a blade coating gap of 20 mils, and heat and dry at 140℃ to obtain polyurethane high-solids layer.

[0060] (d) Apply water-based polyurethane adhesive slurry to the polyurethane high-solids layer with a blade coating gap of 20 mils. Heat at 140℃ until it is molten. Then, attach the pre-prepared fabric base. After attachment, put it into an oven at 130℃ and drive it out at a speed of 5m / min. After drying and cooling, peel it off from the release paper to obtain the finished product.

[0061] Example 3:

[0062] The polyurethane synthetic leather prepared in this embodiment includes a waterborne polyurethane surface layer, a polyurethane high-solids layer, and a waterborne polyurethane adhesive layer, wherein:

[0063] The waterborne polyurethane topcoat is made from a waterborne polyurethane topcoat slurry prepared by the following components in parts by weight:

[0064]

[0065] The polyurethane high-strength layer is made from a polyurethane high-strength layer slurry prepared by the following components in parts by weight:

[0066] High-solids polyurethane resin B 120 parts

[0067] 10 parts curing agent;

[0068] The waterborne polyurethane adhesive layer is made from a waterborne polyurethane adhesive layer slurry prepared by the following components in parts by weight:

[0069]

[0070]

[0071] The high-performance waterborne polyurethane topcoat resin A is 1036R produced by Guangzhou Slocor Technology Co., Ltd., the high-solids polyurethane B is HDPS-9025 produced by Shanghai Huide Technology Co., Ltd., and the waterborne polyurethane adhesive layer C is SH-700 produced by Songjing Chemical. The curing agent in the high-solids polyurethane slurry is HDC4020 produced by Haihuide Technology Co., Ltd., the curing agent for the topcoat and adhesive layers is BYK-4509 produced by BYK Chemical Co., Ltd., the thickener is HY-1048 produced by Shanghai Huiyan New Materials Co., Ltd., the leveling agent is BYK-301 produced by BYK Chemical Co., Ltd., and the defoamer is BYK-012 produced by BYK Chemical Co., Ltd.

[0072] The method for preparing polyurethane synthetic leather based on polyurethane waste in this embodiment includes the following steps:

[0073] (a) Collect the polyurethane waste generated during the production of polyurethane composite materials, crush it through a high-speed pulverizer, and then sort it into a color sorter to separate the polyurethane recycled particles of the required particle size and color for later use.

[0074] (b) Apply water-based polyurethane topcoat slurry to the surface of the release paper. The coating gap between the blades is 15 mils. After the topcoat slurry passes through the coating head, spray 80-mesh recycled polyurethane granules (particle content 20 g / m²) evenly onto the topcoat slurry using a powder spray gun. 3 The water-based polyurethane surface layer is obtained by heating and drying at 120℃.

[0075] (c) Apply polyurethane high-solids slurry onto water-based polyurethane surface layer, with a blade coating gap of 20 mils, and heat and dry at 135℃ to obtain polyurethane high-solids layer.

[0076] (d) Apply water-based polyurethane adhesive slurry to the polyurethane high-solids layer with a blade coating gap of 20 mils. Heat at 140℃ until it is molten. Then, attach the pre-prepared fabric base. After attachment, put it into an oven at 130℃ and drive it out at a speed of 5m / min. After drying and cooling, peel it off from the release paper to obtain the finished product.

[0077] Comparative Example 1:

[0078] The polyurethane synthetic leather prepared in this embodiment includes a waterborne polyurethane top layer, a polyurethane intermediate layer, and a waterborne polyurethane adhesive layer, wherein:

[0079] The waterborne polyurethane topcoat is made from a waterborne polyurethane topcoat slurry prepared by the following components in parts by weight:

[0080]

[0081] The polyurethane interlayer is made from a polyurethane interlayer slurry prepared by the following components in parts by weight:

[0082] 80 parts of waterborne polyurethane resin D

[0083] 5 parts curing agent;

[0084] The waterborne polyurethane adhesive layer is made from a waterborne polyurethane adhesive layer slurry prepared by the following components in parts by weight:

[0085]

[0086] This embodiment includes a waterborne polyurethane top layer, a polyurethane intermediate layer, and a waterborne polyurethane adhesive layer. The high-property waterborne polyurethane top layer resin A is 1036R produced by Guangzhou Slocor Technology Co., Ltd., the waterborne polyurethane resin D is 1033R (solid content 28%-35%) produced by Guangzhou Slocor Technology Co., Ltd., and the waterborne polyurethane resin layer C is SH-700 produced by Songjing Chemical Co., Ltd. The thickener is HY-1048 produced by Shanghai Huiyan New Materials Co., Ltd., the leveling agent is BYK-301 produced by BYK Chemical Co., Ltd., the curing agent is BYK-4509 produced by BYK Chemical Co., Ltd., and the defoamer is BYK-012 produced by BYK Chemical Co., Ltd.

[0087] The comparative method for preparing polyurethane synthetic leather includes the following steps:

[0088] (a) Collect the polyurethane waste generated during the production of polyurethane composite materials, crush it through a high-speed pulverizer, and then sort it into a color sorter to separate the polyurethane recycled particles of the required particle size and color for later use.

[0089] (b) Apply water-based polyurethane topcoat slurry to the surface of the release paper. The coating gap between the blades is 15 mils. After the topcoat slurry passes through the coating head, spray 80-mesh recycled polyurethane granules (particle content 30 g / m²) evenly onto the topcoat slurry using a powder spray gun. 3 The water-based polyurethane surface layer is obtained by heating and drying at 120℃.

[0090] (c) Apply the waterborne polyurethane intermediate layer slurry onto the obtained waterborne polyurethane surface layer, with a blade coating gap of 18 mils, and heat and dry at 110℃ to obtain the polyurethane intermediate layer.

[0091] (e) Apply water-based polyurethane adhesive layer slurry to water-based polyurethane intermediate layer with a blade coating gap of 20 mils, heat at 140℃ to molten state, then bond with pre-prepared fabric base, and after bonding, put into an oven at 130℃, drive out at a speed of 6m / min, dry and cool to set, and then peel off from the release paper to obtain the finished product.

[0092] Comparative Example 2:

[0093] The difference between Comparative Example 2 and Comparative Example 1 is that step (a) is omitted in the preparation method of polyurethane synthetic leather, and in step (b), polyurethane recycled particles are not sprayed into the surface slurry. Instead, the water-based polyurethane surface slurry is directly applied to the surface of the release paper to obtain the water-based polyurethane surface layer, and then other subsequent steps are carried out.

[0094] Comparative Example 3:

[0095] The difference between Comparative Example 3 and Example 1 is as follows:

[0096] The high-solids polyurethane resin E was used to replace the high-property-value waterborne polyurethane resin A, and all other processes were the same as in Example 1. The high-solids polyurethane resin E was HDPS-9050 (solid content 85%-90%) produced by Shanghai Huide Technology Co., Ltd.

[0097] Comparative Example 4:

[0098] The difference between Comparative Example 4 and Example 1 is as follows:

[0099] The high-solids polyurethane resin F was used to replace the high-property-value waterborne polyurethane resin A, and all other processes were the same as in Example 1. The high-solids polyurethane resin F was HDPS-1080 (solid content 95%-100%) produced by Shanghai Huide Technology Co., Ltd.

[0100] The properties of the polyurethane synthetic leather prepared in the above embodiments and comparative examples were tested, and the test results are shown in Table 1:

[0101] Table 1

[0102]

[0103] As shown in Table 1, the test results demonstrate that the polyurethane synthetic leather containing a high-solids polyurethane resin layer prepared in Examples 1-3, compared with the polyurethane synthetic leather without a high-solids polyurethane resin layer in Comparative Example 1, ensures the smoothness of the surface coating by utilizing the high-solids resin's characteristics of high solids content, high elongation, wear resistance, and hydrolysis resistance. This solves the problem of unevenness in the waterborne polyurethane surface layer affecting the bonding strength with the waterborne polyurethane intermediate layer, thus ensuring its high wear resistance and flexural strength.

[0104] The polyurethane synthetic leather containing a high-solids polyurethane resin layer prepared in Example 1 and the high-solids resins with different solid content ratios in Comparative Examples 3 and 4 affect the bonding strength of the high-solids layer, thereby affecting the overall peel strength, flexural strength and other physical properties of the product. The preferred high-solids polyurethane resin B can make the finished properties of the product reach the optimal level.

[0105] Polyurethane synthetic leather was prepared through Example 2. Figure 2(Right) Appearance of ordinary polyurethane synthetic leather prepared in Comparative Example 2 ( Figure 2 Compared to the left side, the new polyurethane synthetic leather prepared by this invention has a significantly improved recyclability and visibility, which aligns with the concept of sustainable development.

[0106] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for preparing polyurethane synthetic leather based on polyurethane waste, characterized in that, It includes the following steps: Polyurethane waste is crushed to obtain recycled polyurethane particles; A water-based polyurethane topcoat slurry is coated onto the surface of release paper, and then polyurethane recycled particles are sprayed onto the water-based polyurethane topcoat slurry. After heating and drying, a water-based polyurethane topcoat coating is obtained. A high-solids polyurethane slurry is applied to a water-based polyurethane topcoat, and then dried and cured to obtain a high-solids polyurethane layer. The high-solids polyurethane slurry is composed of the following components in parts by weight: 120 parts high-solids polyurethane resin and 10 parts curing agent; the solids content of the high-solids polyurethane resin is 92-95%. Water-based polyurethane adhesive slurry is coated onto a polyurethane high-solids layer, then heated to a molten state and bonded to the substrate. After drying, cooling and setting, the release paper is peeled off to obtain the final product.

2. The method for preparing polyurethane synthetic leather based on polyurethane waste according to claim 1, characterized in that, The recycled polyurethane particles are sorted by a color sorter to obtain recycled polyurethane particles of the required particle size and color; the particle size of the recycled polyurethane particles is 20~200 mesh.

3. The method for preparing polyurethane synthetic leather based on polyurethane waste according to claim 1, characterized in that, The water-based polyurethane topcoat slurry is made from the following components in parts by weight: High-performance waterborne polyurethane resin A, 80-120 parts. Thickener 0.6-2 parts, 1-2 parts of hardener 1-2 parts leveling agent 2-4 parts of defoamer.

4. The method for preparing polyurethane synthetic leather based on polyurethane waste according to claim 3, characterized in that, The waterborne polyurethane surface layer slurry is heated and dried at a temperature of 120~140℃.

5. The method for preparing polyurethane synthetic leather based on polyurethane waste according to claim 1, characterized in that, The polyurethane high-solids slurry is dried and cured at a temperature of 120~140℃.

6. The method for preparing polyurethane synthetic leather based on polyurethane waste according to claim 1, characterized in that, The water-based polyurethane adhesive layer slurry is made from the following components in parts by weight: Waterborne polyurethane resin C100-120 parts, Leveling agent 1-1.5 parts, Defoamer 0.4-0.8 parts, Thickener 0.6-2 parts, 1-2 parts of curing agent.

7. The method for preparing polyurethane synthetic leather based on polyurethane waste according to claim 6, characterized in that, The water-based polyurethane adhesive layer slurry is heated to a molten state at a temperature of 120~140℃.

8. A method for preparing polyurethane synthetic leather based on polyurethane waste according to any one of claims 1 to 7, characterized in that, The substrate is nonwoven fabric or cloth-based.

9. A polyurethane synthetic leather based on polyurethane waste, characterized in that, It is prepared by the preparation method as described in any one of claims 1 to 8.

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