Airless polyurethane base sheet, method for preparing the same, and use thereof

Abstract

The application provides a polyurethane base sheet without air holes and a preparation method and application thereof. The preparation raw material of the polyurethane base sheet comprises a two-component polyurethane stock solution, and the polyurethane base sheet is obtained by pouring and pressure forming the two-component polyurethane stock solution. The two-component polyurethane stock solution is matched with the pouring and pressure forming process, air remaining in the mold texture in the pouring process of the two-component polyurethane stock solution is effectively extruded out of the mold, the air remaining in the mold is completely expelled, and thus the polyurethane base sheet obtained after forming is free of air holes and bubbles, has the characteristics of good light transmission and an attractive appearance.

Description

[0001] This application claims priority to patent application number 202210185701.1 (the earlier application was filed on February 28, 2022, and is entitled "A non-porous polyurethane substrate and its preparation method and application"). Technical Field

[0002] This invention belongs to the field of polyurethane technology, specifically relating to a non-porous polyurethane substrate, its preparation method, and its application. Background Technology

[0003] Currently, footwear molding technology has developed rapidly. Traditional shoe soles mainly consist of pre-molded midsoles and outsoles. These are formed by repeatedly brushing a treatment agent onto the pre-molded midsole and outsole one or two times, then applying adhesive and bonding them together. With the rapid development of materials and manufacturing technologies, current common outsoles are mainly formed using polyurethane materials combined with molding.

[0004] Traditional PU outsoles are produced by pouring polyurethane (PU) liquid into a mold using a casting machine, and then molding the outsoles by locking the mold together. However, manual mold locking can result in insufficient pressure inside the mold, which prevents air bubbles trapped in the mold's texture during the pouring process and those trapped when the mold plate comes into contact with the liquid during mold closing from being effectively expelled. As a result, the finished products have many pores and trapped air bubbles, which greatly affects the appearance of the products and prevents traditional cast PU from being widely used in outsoles.

[0005] CN109810236A discloses a method for manufacturing polyurethane shoe soles, as well as polyurethane raw materials and preparation methods that can be used in this method. The method includes the following steps: cleaning a collapsible mold; preheating the mold to 50-80°C; closing the mold; evacuating the mold cavity to 0.1 MPa and maintaining the pressure within the mold cavity at the set vacuum level; pouring a mixture of defoamed CPU-type polyurethane prepolymer and a curing agent into the mold cavity; allowing it to cure while maintaining the mold temperature at 50-80°C; after curing, opening the mold, removing the formed polyurethane shoe sole, and allowing it to stand at room temperature for 6-8 hours until the physical properties meet requirements; and trimming to obtain the final polyurethane shoe sole product. Using this method to manufacture shoe soles offers simple process conditions, low production temperature, high production efficiency, and no volatile substances generated during the production process. The midsole and outsole are integrally molded, eliminating the need for glue between them, resulting in a strong bond, resistance to deformation after shaping, and a long service life for the shoe sole. The curing of polyurethane raw materials is catalyzed by organic amines, resulting in environmentally friendly and non-toxic polyurethane shoe sole products that meet the conventional physical property requirements of shoe soles.

[0006] CN110423330A discloses a one-piece molded shoe outsole and its preparation method, including the following steps: Preparing abrasion-resistant sole: Polyurethane abrasion-resistant sole material is mixed evenly, poured into a preheated mold, vacuum-degassed, and pressurized to obtain the abrasion-resistant sole of the shoe outsole; Injection molding: The mold is preheated, the cooled abrasion-resistant sole is placed at the bottom of the mold cavity, polyurethane midsole material is mixed evenly, vacuum-degassed, and partially poured into the mold, then dried TPU granules are added, and the remaining polyurethane midsole material is poured in. Pressurization is applied at the gel point to allow the polyurethane midsole material to melt and bond with the upper surface of the abrasion-resistant sole to form the midsole of the shoe outsole. This invention replaces existing technologies with an one-piece molding method of injection molding or hot pressing for the midsole and abrasion-resistant sole, shortening process time, reducing labor costs, and eliminating the need for glue, making it more environmentally friendly.

[0007] CN110840016A discloses a production process for shaping leather shoes using a mold, relating to the field of shoemaking technology. The process includes the following steps: Step 1: Mold making; Step 2: Mold sorting; Step 3: Mold placement; Step 4: Preparing for pressing; Step 5: Pressing; Step 6: Demolding. This invention uses molds to assist in the lasting of leather shoes and uses a pressing device to extrude the product, effectively reducing labor and production costs. Different sizes of leather shoes can be produced by casting various types of molds. By setting movable push rods on the sole plate, and through the cooperation of the movable push rods, push blocks, and buffer springs, a certain buffer space can be provided for the mold, thus preventing damage to the mold during pressing. By setting silicone pillars in the buffer groove, when the sole plate bears excessive pressure, the sole plate will contact the silicone pillars, increasing the load-bearing capacity of the sole plate under the combined action of the silicone pillars and buffer springs, thus maintaining stable support.

[0008] However, the polyurethane substrates prepared by the above-mentioned prior art still contain air bubbles. The molding method used cannot effectively remove the air remaining in the mold pattern during the casting process, thus failing to fundamentally solve the problem of air bubbles and air bubbles in polyurethane products. Summary of the Invention

[0009] To address the shortcomings of existing technologies, the present invention aims to provide a non-porous polyurethane substrate, its preparation method, and its application. The raw materials for preparing the polyurethane substrate include a two-component polyurethane stock solution, and the polyurethane substrate is obtained by casting and pressurizing the two-component polyurethane stock solution. The polyurethane substrate prepared by casting and pressing the two-component polyurethane stock solution has the advantages of being non-porous and bubble-free.

[0010] To achieve this objective, the present invention adopts the following technical solution:

[0011] In a first aspect, the present invention provides a non-porous polyurethane substrate, wherein the raw materials for preparing the polyurethane substrate include a two-component polyurethane stock solution.

[0012] The polyurethane substrate is obtained by casting and pressurizing the two-component polyurethane raw liquid.

[0013] The non-porous polyurethane substrate provided by this invention uses a two-component polyurethane stock solution as the raw material. Combined with a casting and pressure molding process, when the two components of the obtained two-component polyurethane stock solution are cast into the mold, the reactive components come into contact with each other and begin to react, causing the viscosity of the material in the mold to increase. Then, by pressure molding, a non-porous and bubble-free polyurethane substrate can be obtained.

[0014] Preferably, the two-component polyurethane raw material includes component A and component B.

[0015] Component A includes a polymeric polyol and a curing agent;

[0016] Component B includes a polyurethane prepolymer.

[0017] Preferably, the mass ratio of component A to component B is (0.3 to 2):1, for example, 0.3:1, 0.6:1, 0.9:1, 1.4:1, 1.7:1, or 2:1, etc.

[0018] In a second aspect, the present invention provides a method for preparing a polyurethane substrate as described in the first aspect, the method comprising: pouring a two-component polyurethane stock solution into a mold, pressing and molding, demolding, and obtaining the polyurethane substrate.

[0019] The present invention provides a method for preparing a polyurethane substrate, which includes first pouring a two-component polyurethane raw liquid into a mold, and then performing pressure molding and demolding steps in sequence; wherein, the pressure molding step can effectively squeeze the air remaining in the mold texture during the pouring process to the outside of the mold, so that the air remaining in the mold is completely expelled, thereby making the polyurethane substrate free of pores and bubbles after molding.

[0020] Preferably, the pouring temperature is 40-60°C, such as 42°C, 44°C, 46°C, 48°C, 50°C, 52°C, 54°C, 56°C, or 58°C.

[0021] Preferably, the step of allowing the material to stand before the pressure molding process is further included.

[0022] As a preferred technical solution of the present invention, setting a settling step before pressure molding helps to further reduce pores and bubbles in polyurethane products. When the reactive components of the two-component polyurethane raw liquid come into contact and react, the viscosity of the material in the mold will begin to rise. Therefore, setting the material to stand for a period of time before pressure molding, and observing that the material no longer flows obviously but still has plasticity, helps to further reduce pores and bubbles in the polyurethane product after molding.

[0023] Preferably, the settling time is 3 to 20 seconds, for example 4 seconds, 5 seconds, 8 seconds, 11 seconds, 14 seconds, 17 seconds, or 20 seconds, as well as specific values ​​between the above values. Due to space limitations and for the sake of brevity, this invention will not exhaustively list all the specific values ​​included in the range.

[0024] Preferably, the pressure molding includes a process of increasing pressure and holding pressure.

[0025] As a preferred technical solution of the present invention, the pressure molding step in the preparation method provided by the present invention is carried out under pressure increase and pressure holding conditions. The "pressure increase and pressure holding" means that the pressure in the pressure molding process is increased from low to high over a period of time and then held at the highest level for a period of time. This can effectively remove air from the mold and effectively reduce pores and bubbles in the polyurethane product. If the pressure is directly increased to the highest pressure or if the pressure is not held for a period of time, it is not possible to effectively remove air from the mold.

[0026] Preferably, the pressurization specifically includes: increasing the system pressure at a pressurization rate of 0.5 to 5 MPa / s (e.g., 0.5 MPa / s, 1 MPa / s, 1.5 MPa / s, 2 MPa / s, 2.5 MPa / s, 3 MPa / s, 3.5 MPa / s, 4 MPa / s, 4.5 MPa / s, or 5 MPa / s, etc.) to a pressure not lower than 5 MPa (e.g., 5 MPa, 8 MPa, 11 MPa, 14 MPa, 17 MPa, 20 MPa, 22 MPa, or 25 MPa, etc.) to complete the pressurization.

[0027] It should be noted that in the polyurethane substrate preparation method provided in this invention, the two-component polyurethane raw liquid is first poured into the mold, and then pressure molding is performed. The pressure acting on the mold during the pressure molding process is related to the mold texture and the surface area of ​​the mold. The more complex the mold texture, the more bubbles will be formed during pouring, and the greater the pressure required for pressure molding. Similarly, the larger the surface area of ​​the mold, the more bubbles will be formed during pouring, and the greater the pressure required for pressure molding.

[0028] Preferably, the pressure boosting time is 5.5s, 6s, 6.5s, 7s, 7.5s, 8s, 8.5s, 9s, or 9.5s, as well as specific values ​​between the above values. Due to space limitations and for the sake of brevity, this invention will not exhaustively list all the specific values ​​included in the range.

[0029] Preferably, the pressure holding time is 1 to 5 minutes, for example 1.5 minutes, 2 minutes, 2.5 minutes, 3 minutes, 3.5 minutes, 4 minutes, 4.5 minutes or 5 minutes, and specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0030] Preferably, the temperature for pressure molding is 50 to 90°C, for example, 50°C, 55°C, 60°C, 65°C, 70°C, 75°C, 80°C, 85°C, or 90°C, as well as specific values ​​between the above values. Due to space limitations and for the sake of brevity, this invention will not exhaustively list all the specific values ​​included in the range.

[0031] Preferably, the pressure molding is carried out in a high-pressure flat plate mold closing machine or a flat plate vulcanizing machine.

[0032] As a preferred technical solution of the present invention, the preparation method includes: pouring the two-component polyurethane raw liquid into a mold at 40-60°C, letting it stand for 3-20 seconds, and then placing it in a high-pressure flat mold clamping machine or flat vulcanizing apparatus at 50-90°C, increasing the pressure of the system to not less than 5MPa at a pressurization rate of 0.5-5MPa / s, holding the pressure for 2-5 minutes, and demolding to obtain the polyurethane substrate.

[0033] Thirdly, the present invention provides an application of a polyurethane sheet as described in the first aspect in shoe soles.

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] (1) The raw materials selected for the preparation of the non-porous polyurethane substrate provided by the present invention include a two-component polyurethane stock solution. Combined with the casting and pressure molding process, when the two components of the obtained two-component polyurethane stock solution are cast into the mold together, the reactive components will start to react when they come into contact with each other, which will increase the viscosity of the material in the mold. Then, a non-porous and bubble-free polyurethane substrate can be obtained by pressure molding.

[0036] (2) The present invention also provides a method for preparing a non-porous polyurethane substrate, the method comprising the steps of pouring polyurethane raw liquid into a mold, pressing and molding, demolding, and obtaining the polyurethane substrate; the preparation method can effectively squeeze out the air remaining in the mold texture during the pouring process, so that the surface and interior of the prepared polyurethane substrate are free of pores and bubbles, effectively solving the problem of polyurethane products with many pores and bubbles prepared by the traditional locking and mold closing method, and further improving the appearance of polyurethane products. Attached Figure Description

[0037] Figure 1 A complete image of the polyurethane film obtained in Example 1;

[0038] Figure 2 A partial image of the polyurethane film obtained in Example 1;

[0039] Figure 3 A complete image of the polyurethane film obtained in Example 2;

[0040] Figure 4 A partial image of the polyurethane film obtained in Example 3;

[0041] Figure 5 This is a partial image of the polyurethane film obtained in Example 4;

[0042] Figure 6 A partial image of the polyurethane film obtained in Example 5;

[0043] Figure 7 A partial image of the polyurethane film obtained in Example 6;

[0044] Figure 8 A partial image of the polyurethane film obtained in Example 7;

[0045] Figure 9 A partial image of the polyurethane film obtained in Example 8;

[0046] Figure 10 A partial image of the polyurethane film obtained in Example 9;

[0047] Figure 11 A complete image of the polyurethane film obtained in Comparative Example 1;

[0048] Figure 12 This is a partial image of the polyurethane film obtained in Comparative Example 2;

[0049] Figure 13 This is a partial image of the polyurethane film obtained in Comparative Example 3;

[0050] Figure 14 This is a partial image of the polyurethane film obtained in Comparative Example 4. Detailed Implementation

[0051] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention.

[0052] Example 1

[0053] A non-porous polyurethane substrate, the raw materials for which are prepared include component A and component B in a mass ratio of 2:1;

[0054] Component A is selected from JF-P-9996 of Zhejiang Huafeng New Material Co., Ltd., which includes a combination of polymer polyol and curing agent;

[0055] Component B is selected from JF-I-9818 of Zhejiang Huafeng New Materials Co., Ltd., which includes polyurethane prepolymer;

[0056] The method for preparing the polyurethane substrate provided in this embodiment includes: casting component A and component B together into a mold, letting it stand for 8 seconds, closing the mold and placing it together with the mold into a flat vulcanizing agent at 60°C, increasing the pressure of the flat vulcanizing agent to 20MPa at a pressurization rate of 2MPa / s, maintaining the pressure for 2.5 minutes, releasing the pressure and opening the mold, demolding, and obtaining the polyurethane substrate.

[0057] A complete image of the polyurethane film prepared in this embodiment is shown below. Figure 1 and Figure 2 As shown, from Figure 1 and Figure 2 As can be seen, the polyurethane substrate prepared by the preparation method provided in Example 1 is free of pores and bubbles, has clear textures, and has a smooth and flat surface.

[0058] Example 2

[0059] A non-porous polyurethane substrate, the raw materials for which are prepared include component A and component B in a mass ratio of 2:1;

[0060] Component A is selected from JF-P-8465 of Zhejiang Huafeng New Materials Co., Ltd., which includes a combination of polymer polyol and curing agent;

[0061] Component B is selected from JF-I-4419 of Zhejiang Huafeng New Materials Co., Ltd., which includes polyurethane prepolymer;

[0062] The method for preparing the polyurethane substrate provided in this embodiment includes: casting component A and component B together into a mold, letting it stand for 5 seconds, closing the mold and placing it together with the mold into a flat vulcanizing agent at 50°C, increasing the pressure of the flat vulcanizing agent to 15MPa at a pressurization rate of 3MPa / s, maintaining the pressure for 2 minutes, releasing the pressure and opening the mold, demolding, and obtaining the polyurethane substrate.

[0063] A complete image of the polyurethane film prepared in this embodiment is shown below. Figure 3 As shown, from Figure 3 As can be seen, the polyurethane substrate prepared by the preparation method provided in Example 2 is also free of pores and bubbles, and has clear texture and a smooth surface.

[0064] Example 3

[0065] A non-porous polyurethane substrate, the raw materials for which are prepared include component A and component B in a mass ratio of 1:1;

[0066] Component A is selected from JI-621m of Zhejiang Huafeng New Materials Co., Ltd., which includes a combination of polymer polyol and curing agent;

[0067] Component B is selected from JF-P-521m of Zhejiang Huafeng New Materials Co., Ltd., which includes polyurethane prepolymer;

[0068] The method for preparing the polyurethane substrate provided in this embodiment includes: casting component A and component B together into a mold, letting it stand for 10 seconds, closing the mold and placing it together with the mold into a flat vulcanizing apparatus at 70°C, increasing the pressure of the flat vulcanizing apparatus to 25 MPa at a pressure increase rate of 2.5 MPa / s, maintaining the pressure for curing for 3 minutes, releasing the pressure, opening the mold, and demolding to obtain the polyurethane substrate.

[0069] A partial image of the polyurethane film prepared in this embodiment is shown below. Figure 4 As shown, from Figure 4 It can be seen that the polyurethane substrate prepared by the preparation method provided in Example 3 also has no pores, no bubbles, clear texture, and a smooth surface.

[0070] Example 4

[0071] A non-porous polyurethane substrate differs from Example 1 only in that the standing step is not included in the preparation process; all other components, conditions, and parameters are the same as in Example 1.

[0072] A partial image of the polyurethane film prepared in this embodiment is shown below. Figure 5 As shown, from Figure 5As can be seen, because the preparation method provided in this embodiment does not have a standing step during the pressurization and molding process, the viscosity of the polymer is slightly low, which is insufficient to generate enough pressure. Therefore, some air bubbles are not expelled in the obtained polyurethane film product.

[0073] Example 5

[0074] A non-porous polyurethane substrate differs from Example 1 only in the preparation method. Components A and B are jointly poured into a mold, left to stand for 8 seconds, and then the mold is placed in a high-pressure flat mold-forming machine at 60°C. It is directly pressurized and formed under 20MPa, and after holding the pressure for 2.5 minutes, the pressure is released and the mold is opened to obtain the polyurethane substrate.

[0075] A partial image of the polyurethane film prepared in this embodiment is shown below. Figure 6 As shown, from Figure 6 It can be seen that the polyurethane substrate prepared by the preparation method provided in Example 5, due to the lack of a step of gradual pressure increase and the use of instantaneous high pressure mold closing, the mold is sealed instantly, which also leads to some air bubbles inside not being able to be effectively discharged.

[0076] Example 6

[0077] A non-porous polyurethane substrate differs from Example 1 only in that the pressure of the flat vulcanizer is increased to 20 MPa at a pressurization rate of 0.4 MPa / s, while the other components, conditions and parameters are the same as in Example 1.

[0078] A partial image of the polyurethane film prepared in this embodiment is shown below. Figure 7 As shown, from Figure 7 It can be seen that the polyurethane substrate prepared by the preparation method provided in Example 6 has a poor plasticity due to the slow pressurization rate, which leads to expansion and sticking, and then exceeds the high pressure plasticity range of the sample, resulting in deformation and shrinkage.

[0079] Example 7

[0080] A non-porous polyurethane substrate differs from Example 1 only in that the pressure of the flat vulcanizing apparatus is increased to 20 MPa in the preparation method with a pressure increase rate of 10 MPa / s. All other components, conditions and parameters are the same as in Example 1.

[0081] A partial image of the polyurethane film prepared in this embodiment is shown below. Figure 8 As shown, from Figure 8 It can be seen that due to the excessively rapid pressurization rate, air bubbles could not be expelled in time, resulting in the presence of encapsulated bubbles in the final sample. Example 8

[0082] A non-porous polyurethane substrate differs from Example 1 only in that the temperature of the flat vulcanizing apparatus is 40°C, while the other components, conditions, and parameters are the same as in Example 1.

[0083] A partial image of the polyurethane film prepared in this embodiment is shown below. Figure 9 As shown, from Figure 9 It can be seen that due to the low reaction temperature, the reaction was too slow, resulting in slow expansion and sticking. When the mold was closed, it was not possible to generate enough pressure to expel the air bubbles. At the same time, the curing was too slow, resulting in the presence of air bubbles that had not been expelled in the sample mold cavity. Furthermore, the sample was too soft during demolding, making it easy to stretch and deform.

[0084] Example 9

[0085] A non-porous polyurethane substrate, which differs from Example 1 only in that the temperature of the flat vulcanizing apparatus is 100°C, while the other components, conditions and parameters are the same as in Example 1.

[0086] A partial image of the polyurethane film prepared in this embodiment is shown below. Figure 10 As shown, from Figure 10 It can be seen that the high reaction temperature and fast reaction speed led to excessive expansion and sticking, resulting in poor plasticity and deformation and shrinkage of the sample.

[0087] Comparative Example 1

[0088] A non-porous polyurethane substrate, which differs from Example 1 only in its preparation method;

[0089] The preparation method of the polyurethane substrate provided in this comparative example specifically includes: casting component A and component B together into a mold, manually locking the mold, and molding at 60°C to obtain the polyurethane substrate.

[0090] A complete image of the polyurethane substrate prepared in this comparative example is shown below. Figure 11 As shown, from Figure 11 It can be seen that the polyurethane substrate prepared by the preparation method provided in Comparative Example 1 has a lot of pores and bubbles, which greatly affects the appearance of the product.

[0091] Comparative Example 2

[0092] A non-porous polyurethane substrate, which differs from Example 2 only in its preparation method;

[0093] The preparation method of the polyurethane substrate provided in this comparative example specifically includes: casting component A and component B together into a mold, manually locking the mold, and molding at 50°C to obtain the polyurethane substrate.

[0094] A complete image of the polyurethane substrate prepared in this comparative example is shown below. Figure 12 As shown, from Figure 12 It can be seen that the polyurethane substrate prepared by the preparation method provided in Comparative Example 2 has a lot of pores and bubbles, which greatly affects the appearance of the product.

[0095] Comparative Example 3

[0096] A non-porous polyurethane substrate, which differs from Example 3 only in its preparation method;

[0097] The preparation method of the polyurethane substrate provided in this comparative example specifically includes: casting component A and component B together into a mold, manually locking the mold, and molding at 70°C to obtain the polyurethane substrate.

[0098] A complete image of the polyurethane substrate prepared in this comparative example is shown below. Figure 13 As shown, from Figure 1 It can be seen that the polyurethane substrate prepared by the preparation method provided in Comparative Example 3 has a lot of pores and bubbles, which greatly affects the appearance of the product.

[0099] Comparative Example 4

[0100] A non-porous polyurethane substrate, which differs from Example 1 only in its preparation method;

[0101] The preparation method of the polyurethane substrate provided in this comparative example specifically includes: casting component A and component B together into a mold, letting it stand for 8 seconds, manually locking the mold, and molding at 60°C to obtain the polyurethane substrate.

[0102] A partial image of the polyurethane film prepared in this comparative example is shown below. Figure 14 As shown, from Figure 14 It can be seen that the polyurethane substrate prepared by the preparation method provided in Comparative Example 4 has many pores and bubbles, and there are also problems such as material shortage, excessive thickness of substrate and flash. This is because the molding pressure of manual clamping is too small, which makes it impossible to spread the high viscosity polymer evenly, which greatly affects the appearance of the product.

[0103] Performance testing:

[0104] (1) Appearance: Visually inspect for the presence of pores and bubbles;

[0105] (2) Light transmittance: Visual inspection.

[0106] (3) Base film and flash thickness: Observe the thickness of the gap when the mold is closed (the wider the gap, the thicker the flash of the product, which will affect the appearance of the final product and the overall thickness of the base film).

[0107] The polyurethane films obtained in Examples 1-9 and Comparative Examples 1-4 were tested according to the above test methods. The test results are shown in Table 1.

[0108] Table 1

[0109]

[0110]

[0111] As can be seen from the data in Table 1, the polyurethane substrate provided by the present invention has no pores or bubbles, excellent light transmission performance, and the substrate and flash are thick and without deformation.

[0112] Comparing the data of Example 1 and Comparative Examples 1-4, it can be found that the polyurethane film prepared by conventional manual molding process has a large number of pores and small bubbles, the transparency is only semi-transparent, and the film and flash are relatively thick.

[0113] Comparing the data from Examples 1 and 4-9, it can be seen that the polyurethane sheet obtained without the settling step (Example 4) has the problem of micropores; the polyurethane sheet obtained by directly pressing at 20 MPa without the pressurization step (Example 5) and by pressing at too fast a rate (Example 7) has the problem of bubble wrap; at the same time, the polyurethane sheet obtained by pressing at too slow a rate (Example 6) has the problems of flash and excessively thick sheet; furthermore, pressing at too low a temperature (Example 8) and too high a temperature (Example 9) will also affect the appearance of the final product.

[0114] The applicant declares that this invention illustrates a non-porous polyurethane substrate, its preparation method, and its application through the above embodiments. However, this invention is not limited to the above process steps, meaning that this invention does not necessarily rely on the above process steps to be implemented. Those skilled in the art should understand that any improvements to this invention, equivalent substitutions of the raw materials used in this invention, additions of auxiliary components, and selection of specific methods all fall within the protection and disclosure scope of this invention.

Claims

1. A non-porous polyurethane substrate, characterized in that, The raw materials for preparing the polyurethane substrate include a two-component polyurethane stock solution; The polyurethane film is prepared according to the following method: The two-component polyurethane raw material is poured into the mold at 40~60℃, left to stand for 3~20 s, and then placed in a flat vulcanizing machine or high-pressure flat mold closing machine at 50~90℃. The pressure of the system is increased to not less than 5MPa at a pressurization rate of 0.5~5 MPa / s, and the pressure is held for 1~5 min. The mold is then removed to obtain the polyurethane substrate.

2. The polyurethane substrate according to claim 1, characterized in that, The two-component polyurethane raw material includes component A and component B; component A includes polymeric polyol and curing agent; component B includes polyurethane prepolymer.

3. The polyurethane film according to claim 2, characterized in that, The mass ratio of component A to component B is (0.3~2):

1.

4. A method for preparing a polyurethane film as described in any one of claims 1-3, characterized in that, The preparation method includes: pouring the two-component polyurethane raw liquid into a mold at 40~60℃, letting it stand for 3~20 s, then placing it in a flat vulcanizing machine or a high-pressure flat mold clamping machine at 50~90℃, increasing the pressure of the system to not less than 5MPa at a pressurization rate of 0.5~5 MPa / s, holding the pressure for 1~5 min, demolding, and obtaining the polyurethane substrate.

5. The application of a polyurethane sheet as described in any one of claims 1-3 in a shoe sole.

Images