Preparation method and application of super-soft high-stripping polyurethane synthetic leather
By employing partial impregnation and multi-stage roller impregnation technology, the problem of balancing softness and peel strength in polyurethane synthetic leather has been solved, resulting in polyurethane synthetic leather with high softness and high peel strength, suitable for the preparation of materials for football boots.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-17
- Publication Date
- 2026-03-13
AI Technical Summary
Existing polyurethane synthetic leathers struggle to balance softness and peel strength, especially since the bonding between silicone-based materials and dry adhesive layers is poor, resulting in products failing to meet peel strength standards.
The base layer is precisely impregnated using a local impregnation process. A polyether polyurethane polymer slurry containing nano-silicon is used, combined with multi-stage roller impregnation technology to control the impregnation thickness of the base layer. A dry adhesive layer is then bonded to the unimpregnated portion to form an ultra-soft, high-peel polyurethane synthetic leather.
It achieves a balance between the softness and peel strength of polyurethane synthetic leather, ensuring that the product maintains a good feel while having high peel strength, and avoiding the problem of poor adhesion between silicone-based materials and dry adhesive layers.
Smart Images
Figure CN121653969A_ABST
Abstract
Description
Technical Field
[0001] This application belongs to the field of polyurethane synthetic leather technology, specifically relating to a method for preparing ultra-soft, high-peel polyurethane synthetic leather and its application. Background Technology
[0002] Polyurethane synthetic leather is gradually replacing natural leather due to its excellent physical properties. However, due to the constraints of its high performance, it is difficult to achieve the softness of natural leather. As a result, polyurethane synthetic leather generally feels stiff and is not very comfortable, such as shoe leather.
[0003] Soft polyurethane leather is one of the most widely used materials on the market. The related soft microfiber technology in the synthetic leather industry is relatively mature. Besides its high softness, elasticity, high abrasion resistance, and soft feel, it plays a crucial role in the pursuit of comfort, fashion, and the imitation of natural leather. Furthermore, with the development of material technology, its physical properties continue to improve.
[0004] Currently, the main process for preparing soft polyurethane synthetic leather is to impregnate the base layer with a silicone-containing polyurethane slurry. This is mainly because silicone materials can effectively improve the softness of synthetic leather. However, due to the poor adhesion between silicone-based materials and dry adhesive layers, the peel strength of the product cannot meet the standards. Summary of the Invention
[0005] In view of this, the primary objective of this application is to provide a method for preparing ultra-soft, high-peel polyurethane synthetic leather, which employs a local impregnation process to achieve precise local impregnation of the base layer, while the unimpregnated portion is bonded to a dry adhesive layer, thereby achieving a balance between the softness and peel strength of the finished leather.
[0006] To achieve the above objectives, this application adopts the following technical solution: One aspect of this application discloses an ultra-soft, high-peel-strength polyurethane synthetic leather, the polyurethane synthetic leather comprising a base layer, an adhesive layer, and a top layer sequentially disposed therefrom, the preparation method comprising the following steps: Provide a base layer and impregnated slurry; The base layer is partially immersed in the impregnation slurry, and multi-stage rollers are used for progressive impregnation to achieve precise local impregnation of the base layer; wherein, the impregnation slurry is a polyether polyurethane polymer containing nano-silicon; A top layer is provided, an adhesive layer is formed on the top layer, and the adhesive layer is bonded to the unimpregnated portion of the base layer to form an ultra-soft, high-peel polyurethane synthetic leather.
[0007] Another aspect of this application discloses the application of the preparation method described herein in the preparation of polyurethane synthetic leather for soccer shoes.
[0008] The beneficial effects of this application are: This application employs an aqueous liquid level control technology to achieve precise local impregnation of the substrate layer, controlling the impregnation thickness by altering the liquid level. The substrate layer is partially immersed in an impregnation solution containing nano-silicon-based materials. By precisely controlling the impregnation thickness, the silicon-based materials effectively enhance the product's softness, ensuring the impregnated portion maintains the finished product's softness and improves its feel. Simultaneously, the unimpregnated portion is bonded to the adhesive layer for dry lamination, ensuring high peel strength in the finished product. This not only guarantees softness but also avoids the problem of poor adhesion between the silicon-based materials and the dry adhesive layer affecting the product's peel strength.
[0009] In terms of precisely controlling the impregnation thickness, this application changes the traditional fully immersed impregnation equipment and roller extrusion method. The substrate layer is fixed at a certain height, and the impregnation thickness is controlled by adjusting the height of the impregnation liquid. The substrate layer moves in the impregnation tank at a certain speed. After the impregnation time is met, the substrate layer is removed from the impregnation liquid surface and is pressed step by step by multi-stage rollers to remove excess impregnation slurry, thereby ensuring the precise requirements of the substrate layer impregnation thickness. Attached Figure Description
[0010] Figure 1 This is a schematic diagram of the impregnation process equipment for ultra-soft, high-peel polyurethane synthetic leather in a preferred embodiment of this application.
[0011] Figure 2 This is a schematic diagram of the structure of an ultra-soft, high-peel polyurethane synthetic leather according to a preferred embodiment of this application. Detailed Implementation
[0012] The embodiments of this application will be clearly and completely described below. The technical solutions in the embodiments described below are exemplary and only possible technical implementations of this application, not all possible implementations. Those skilled in the art can combine the embodiments of this application to obtain other embodiments without creative effort, and these embodiments are also within the protection scope of this application.
[0013] The first aspect of this application discloses a method for preparing ultra-soft, high-peel polyurethane synthetic leather. The polyurethane synthetic leather includes a base layer, an adhesive layer, and a top layer arranged sequentially. It is understood that the base layer, adhesive layer, and top layer are the basic components of polyurethane synthetic leather. For polyurethane synthetic leather with different application directions, corresponding functional layers can also be set as needed to meet the performance requirements of the application field. Those skilled in the art can set them as needed without any particular limitation.
[0014] The preparation method in this application includes the following steps: Provide a base layer and impregnated slurry; The base layer is partially immersed in the impregnation slurry, and multi-stage rollers are used for progressive impregnation to achieve precise local impregnation of the base layer; wherein, the impregnation slurry is a polyether polyurethane polymer containing nano-silicon; A top layer is provided, an adhesive layer is formed on the top layer, and the adhesive layer is bonded to the unimpregnated portion of the base layer to form an ultra-soft, high-peel polyurethane synthetic leather.
[0015] This application optimizes and improves the impregnation process, thereby achieving both the softness of polyurethane synthetic leather and high peel strength, resulting in a polyurethane synthetic leather with high softness and high peel strength.
[0016] In this application, there are no particular restrictions on the material of the base layer; suitable substrates can be selected according to different product positioning. Taking polyurethane synthetic leather for soccer shoes as an example, a microfiber substrate can be selected for the base layer. Similarly, there are no specific requirements for the thickness of the base layer; generally, a substrate of appropriate thickness is selected according to the product positioning. In some specific examples, the thickness of the base layer is 1.0-1.4 mm.
[0017] In this application, considering both softness and peel strength, it is necessary to control the thickness of the base layer impregnated in the impregnating slurry to achieve a balance between high softness and high peel strength. Preferably, the thickness of the base layer impregnated in the impregnating slurry is 70%-95% of the base layer thickness. If the impregnation thickness is too small, insufficient impregnation will result in poor improvement in softness; if the impregnation thickness is too large, after subsequent roller impregnation, the impregnating slurry may be squeezed into the unimpregnated portion of the base layer, thus affecting the bonding force between the base layer and the adhesive layer.
[0018] In this application, there are no particular limitations on the impregnation slurry, but a polyurethane slurry containing nano-silica is preferred. It can use formulations well-known in the art or formulations developed in-house. In some specific examples, the impregnation slurry comprises 70-90 parts water, 10-30 parts polyether polyurethane resin, 3-5 parts nano-silica, and 0-10 parts pigment. The polyether polyurethane resin possesses high physical properties and durability, which can further improve the performance of the finished leather.
[0019] In this application, the multi-stage roller impregnation refers to the gradual reduction of the roller layer thickness until it reaches 0. "Multi-stage" refers to two or more stages, such as two, three, four, or five stages, which can be set according to needs. "Gradually decreasing" means that the thickness of the roller layer in the next stage is less than the thickness of the roller layer in the previous stage. The specific number of stages and the roller layer thickness can be designed according to needs (such as the substrate material, substrate thickness, impregnation thickness, etc.) without particular limitation. In some specific examples, taking a substrate layer with a thickness of 1.0-1.4 mm as an example, a four-stage roller impregnation is used, with roller layer thicknesses of 0.8-1.2 mm, 0.6-0.8 mm, 0.3-0.4 mm, and 0 mm respectively.
[0020] In some specific examples of this application, taking the leather for football boots as an example, in addition to having softness and high peel strength, its abrasion resistance also needs to be considered. Therefore, its polyurethane synthetic leather also includes an intermediate layer, which is formed between the adhesive layer and the top layer.
[0021] In some specific examples, the intermediate layer is formed by coating the surface of the top layer with an intermediate layer slurry. The specific composition can be selected as needed and is not particularly limited. As a preferred example, the intermediate layer slurry comprises, by weight, a material with a number average molecular weight of 3 × 10⁻⁶. 4 -5×10 5 The mixture comprises 100 parts of polyoxypropylene ether glycol resin, 3-8 parts of curing agent, 3-8 parts of catalyst, and 0-10 parts of pigment. The catalyst is a commonly used reagent in the art to accelerate polyurethane reactions, and will not be described in detail here. Any well-known catalyst or a self-developed catalyst can be used. By using high-molecular-weight polyoxypropylene ether glycol resin in the intermediate layer, the chain segment flexibility is extended; simultaneously, the curing agent, through a cross-linking reaction with the polyurethane resin, makes the polymer chains more stable, thereby improving its strength, abrasion resistance, chemical resistance, and other related properties. Furthermore, since polyoxypropylene ether glycol resin is a polyether-type polyurethane resin, it can provide the product with better durability, hydrolysis resistance, and yellowing resistance, meeting the high physical property requirements of the product. The obtained leather meets the requirements for leather used in football boots.
[0022] There are no particular limitations on the formation process of each layer. For example, the coating thickness of the intermediate layer slurry is 0.1-0.3 mm, and the drying temperature is 70-130℃. After the adhesive layer is bonded to the unimpregnated portion of the base layer, the curing and setting temperature is 130-170℃. These temperatures can be selected or adjusted as needed, as long as the drying and setting purposes are achieved.
[0023] Furthermore, it is understood that this application does not have specific requirements regarding the composition of the topcoat and adhesive layer. Topcoat and adhesive layer compositions well-known in the art or independently developed can be selected according to product requirements. In some examples, the topcoat uses a one-component polyurethane resin slurry, composed of resin and solvent, wherein the resin content is 15%-25%, the viscosity is 2000-4000 cps, and the coating thickness is 0.1-0.2 mm. The adhesive layer also uses a one-component polyurethane resin slurry, composed of resin and solvent, wherein the resin content is 25%-35%, the viscosity is 5000-8000 cps, and the coating thickness is 0.08-0.12 mm.
[0024] The present application will be further illustrated below with reference to specific embodiments. It should be noted that the specific embodiments below are for illustrative purposes only and do not limit the scope of the present application in any way.
[0025] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the specification of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application.
[0026] In addition, unless otherwise specified, methods without detailed conditions or steps are conventional methods, and the reagents and materials used are commercially available.
[0027] The following examples and comparative examples, using soccer shoe leather as an example, illustrate how the preparation method of this application achieves a balance between leather softness and high peel strength. The main raw material information involved is as follows: Nano-silicon (mesoporous silica particles), spherical powder particles with a particle size of 50±10nm, Xi'an Ruixi Biotechnology Co., Ltd.
[0028] Polyether polyurethane resins KTL772 and KTL776, Hefei Ketian Waterborne Technology Co., Ltd.
[0029] Polyoxypropylene ether glycol resin KTT7251, Hefei Ketian Waterborne Technology Co., Ltd.
[0030] LT68 surface resin, Hefei Anli Polyurethane New Materials Co., Ltd.
[0031] Adhesive layer resin SA36, Hefei Anli Polyurethane New Materials Co., Ltd.
[0032] Curing agent, isocyanate MDI-100, Wanhua Chemical Group Co., Ltd.
[0033] Example 1 A nano-silicon impregnation slurry (90 parts water, 10 parts KTL772, 3 parts nano-silicon, and 3 parts pigment) was prepared according to the following weight ratios. The microfiber substrate (1.0 mm thick) was then impregnated using this process. Figure 1 The liquid level is adjusted to achieve a substrate impregnation thickness of 0.8 mm. The substrate is then impregnated through multiple rollers at different stages (with lamination thicknesses of 0.6 mm, 0.4 mm, 0.2 mm, and 0 mm, respectively), dried in an oven, and then rolled up for later use.
[0034] The surface layer slurry is coated onto the release paper to a thickness of 0.15 mm, and then dried to form the surface layer.
[0035] An intermediate layer slurry (100 parts of polyoxypropylene ether glycol resin KTT7251, 5 parts of curing agent, 5 parts of bismuth isooctanoate catalyst, and 10 parts of pigment) was prepared according to the following weight ratios. The intermediate layer slurry was then coated onto the top layer to a thickness of 0.3 mm and dried to obtain the intermediate layer. An adhesive slurry was then coated onto the intermediate layer (to a thickness of 0.1 mm). The adhesive layer was then bonded to the unimpregnated portion of the substrate, cured, and wound up to obtain an ultra-soft, high-peel polyurethane synthetic leather for soccer shoes. Its structure can be found in [reference needed]. Figure 2 .
[0036] Example 2 A nano-silicon impregnation slurry (90 parts water, 10 parts KTL772, 3 parts nano-silicon, and 3 parts pigment) was prepared according to the specified ratio. The microfiber substrate (1.2 mm thick) was impregnated using the impregnation process, and the liquid level was adjusted to make the substrate impregnation thickness 1.15 mm. Then, it was rolled by rollers (with lamination thicknesses of 0.8 mm, 0.6 mm, 0.4 mm, and 0 mm, respectively), dried in an oven, and rolled up for later use.
[0037] The intermediate layer slurry (100 parts of polyoxypropylene ether glycol resin KTT7251, 5 parts of curing agent, 5 parts of bismuth isooctanoate catalyst, and 1 part of pigment) was prepared according to the specified ratio. The intermediate layer slurry was coated on the surface layer with a coating thickness of 0.3 mm and dried to obtain the intermediate layer. The adhesive slurry was then coated on the intermediate layer, and the adhesive layer was bonded to the unimpregnated part of the substrate. After curing and shaping, the material was rolled up to obtain the ultra-soft, high-peel polyurethane synthetic leather for soccer shoes.
[0038] The preparation of the surface layer and adhesive layer is the same as in Example 1.
[0039] Example 3 A nano-silicon impregnation slurry (80 parts water, 20 parts KTL776, 4 parts nano-silicon, and 5 parts pigment) was prepared according to the specified ratio. The microfiber substrate (1.4 mm thick) was impregnated using the impregnation process, and the liquid level was adjusted to make the substrate impregnation thickness 1.2 mm. Then, it was impregnated through multiple stages of rollers (with lamination thicknesses of 0.7 mm, 0.5 mm, 0.3 mm, and 0 mm, respectively), dried in an oven, and rolled up for later use.
[0040] The intermediate layer slurry (100 parts of polyoxypropylene ether glycol resin KTT7251, 5 parts of curing agent, 5 parts of bismuth isooctanoate catalyst, and 10 parts of pigment) was prepared according to the specified ratio. The intermediate layer slurry was coated on the surface layer with a coating thickness of 0.3 mm and dried to obtain the intermediate layer. The adhesive slurry was then coated on the intermediate layer, and the adhesive layer was bonded to the unimpregnated portion of the substrate. After curing and shaping, the material was rolled up to obtain the ultra-soft, high-peel polyurethane synthetic leather for soccer shoes.
[0041] The preparation of the surface layer and adhesive layer is the same as in Example 1.
[0042] Example 4 A nano-silicon impregnation slurry (70 parts water, 30 parts KTL776, 5 parts nano-silicon, and 5 parts pigment) was prepared according to the specified ratio. The microfiber substrate (1.2 mm thick) was impregnated using the impregnation process, and the liquid level was adjusted to make the substrate impregnation thickness 1.0 mm. Then, it was impregnated through multiple stages of rollers (with lamination thicknesses of 0.8 mm, 0.6 mm, 0.4 mm, and 0 mm, respectively), dried in an oven, and rolled up for later use.
[0043] The intermediate layer slurry (100 parts of polyoxypropylene ether glycol resin KTT7251, 8 parts of curing agent, 5 parts of bismuth isooctanoate catalyst, and 10 parts of pigment) was prepared according to the specified ratio. The intermediate layer slurry was coated on the surface layer with a coating thickness of 0.3 mm and dried to obtain the intermediate layer. The adhesive slurry was then coated on the intermediate layer, and the adhesive layer was bonded to the unimpregnated part of the substrate. After curing and shaping, the material was rolled up to obtain the ultra-soft, high-peel polyurethane synthetic leather for soccer shoes.
[0044] The preparation of the surface layer and adhesive layer is the same as in Example 1.
[0045] Example 5 In this embodiment, the preparation of polyurethane synthetic leather for soccer shoes follows the same method as in Example 1, except that a curing agent is not introduced into the intermediate layer. All other process steps and parameters are the same as in Example 1. The specific preparation method for this embodiment is as follows: A nano-silicon impregnation slurry (90 parts water, 10 parts KTL772, 3 parts nano-silicon, and 3 parts pigment) was prepared according to the specified ratio. The microfiber substrate (1.0 mm thick) was impregnated using the impregnation process, and the liquid level was adjusted to achieve an impregnation thickness of 0.9 mm. The substrate was then subjected to multi-stage roller impregnation (with lamination thicknesses of 0.6 mm, 0.4 mm, 0.2 mm, and 0 mm, respectively), dried in an oven, and then rolled up for later use.
[0046] The intermediate layer slurry (100 parts of polyoxypropylene ether glycol resin KTT7251, 5 parts of bismuth isooctanoate catalyst, and 10 parts of pigment) was prepared according to the specified ratio. The intermediate layer slurry was coated on the surface layer with a coating thickness of 0.3 mm and dried to obtain the intermediate layer. The adhesive slurry was then coated on the intermediate layer and bonded to the unimpregnated portion of the substrate. The mixture was then cured and shaped, and finally rolled up to obtain polyurethane synthetic leather for soccer shoes.
[0047] The preparation of the surface layer and adhesive layer is the same as in Example 1.
[0048] Example 6 In this embodiment, the preparation of polyurethane synthetic leather for soccer shoes follows the same method as in Example 1, except that an intermediate layer is not formed. All other process steps and parameters are the same as in Example 1. The specific preparation method in this embodiment is as follows: A nano-silicon impregnation slurry (90 parts water, 10 parts KTL772, 3 parts nano-silicon, and 3 parts pigment) was prepared according to the specified ratio. The microfiber (1.0 mm thick) was impregnated with the slurry, and the liquid level was adjusted to make the substrate impregnation thickness 0.8 mm. Then, it was rolled by rollers (with lamination thicknesses of 0.6 mm, 0.4 mm, 0.2 mm, and 0 mm, respectively), dried in an oven, and rolled up for later use.
[0049] The surface layer was prepared in accordance with the method described in Example 1.
[0050] The adhesive paste is applied to the surface layer, the adhesive layer is bonded to the unimpregnated portion of the substrate, then cured and shaped, and rolled up to obtain polyurethane synthetic leather for soccer shoes.
[0051] Comparative Example 1 The preparation of the polyurethane synthetic leather for soccer shoes in this comparative example follows the method described in Example 1, except that impregnation treatment is not performed. Other process steps and parameters are the same as in Example 1. The specific preparation of this comparative example is as follows: The microfiber substrate (1.0mm) is not impregnated. An intermediate layer slurry (100 parts of polyoxypropylene ether glycol resin KTT7251, 5 parts of curing agent, 5 parts of bismuth isooctanoate catalyst, and 10 parts of pigment) is prepared according to the following ratio. The intermediate layer slurry is coated on the surface layer with a coating thickness of 0.3mm and dried to obtain the intermediate layer. An adhesive slurry is coated on the intermediate layer and the adhesive layer is bonded to the microfiber substrate. Then, it is cured and shaped, and wound up to obtain polyurethane synthetic leather for football shoes.
[0052] The surface layer and adhesive layer were prepared according to Example 1.
[0053] Comparative Example 2 The preparation of the polyurethane synthetic leather for soccer shoes in this comparative example was carried out according to the method described in Example 1, with the only difference being that the entire substrate was impregnated in this comparative example. All other process steps and parameters were the same as in Example 1. The specific preparation of this comparative example is as follows: A nano-silicon impregnation slurry (90 parts water, 10 parts KTL772, 3 parts nano-silicon, and 3 parts pigment) was prepared according to the following weight ratio. The microfiber substrate (1.0 mm thick) was impregnated with the slurry by adjusting the liquid level to ensure that the substrate was completely immersed in the slurry, i.e., the impregnation thickness was 1.0 mm. Then, it was impregnated by multiple rollers in stages (with lamination thicknesses of 0.6 mm, 0.4 mm, 0.2 mm, and 0 mm, respectively), dried in an oven, and rolled up for later use.
[0054] The intermediate layer slurry (100 parts of polyoxypropylene ether glycol resin KTT7251, 5 parts of curing agent, 5 parts of bismuth isooctanoate catalyst, and 10 parts of pigment) was prepared according to the following weight ratio. The intermediate layer slurry was coated on the surface layer with a coating thickness of 0.3 mm and dried to obtain the intermediate layer. The adhesive slurry was then coated on the intermediate layer, and the adhesive layer was bonded to the substrate. Subsequently, the adhesive was cured and shaped, and then rolled up to obtain polyurethane synthetic leather for soccer shoes.
[0055] The surface layer and adhesive layer were prepared according to Example 1.
[0056] Comparative Example 3 The preparation of the polyurethane synthetic leather for soccer shoes in this comparative example was carried out according to the method described in Example 1, with the only difference being that the multi-stage roller pressing method was not used in this comparative example. All other process steps and parameters were the same as in Example 1. The specific preparation in this comparative example is as follows: The nano-silicon impregnation slurry (90 parts water, 10 parts KTL772, 3 parts nano-silicon, and 3 parts pigment) was prepared according to the formula. The microfiber substrate (1.0 mm thick) was impregnated, and the liquid level was adjusted to make the substrate impregnation thickness 0.8 mm. Then, it was rolled by rollers (the lamination thickness was 0 mm), dried in an oven, and rolled up for use.
[0057] The intermediate layer slurry (100 parts of polyoxypropylene ether glycol resin KTT7251, 5 parts of curing agent, 5 parts of bismuth isooctanoate catalyst, and 10 parts of pigment) was prepared according to the specified ratio. The intermediate layer slurry was coated on the surface layer with a coating thickness of 0.3 mm and dried to obtain the intermediate layer. The adhesive slurry was then coated on the intermediate layer, and the adhesive layer was bonded to the unimpregnated part of the substrate. After curing and shaping, the mixture was rolled up to obtain polyurethane synthetic leather for soccer shoes.
[0058] The surface layer and adhesive layer were prepared according to Example 1.
[0059] Performance testing The softness and peel strength of the polyurethane synthetic leather for soccer shoes prepared in Examples 1-6 and Comparative Examples 1-3 were tested according to the following criteria: Softness testing method, QB_T 5155-2017 Test method for softness of artificial leather and synthetic leather; Peeling test method, GB / T 8949-2008 Polyurethane dry process artificial leather.
[0060] The test results are shown in Table 1.
[0061] Table 1 Results of leather softness and peel strength tests
[0062] After testing, the softness and peel strength of the leather in the embodiments both met the relevant standards, indicating that by precisely controlling the impregnation thickness through the preparation method in this application, both peel strength and softness can be effectively balanced.
[0063] Comparative Example 2, employing a full impregnation process, exhibits high softness and a good hand feel. However, the poor adhesion between the nano-silicon substrate and the adhesive layer directly impacts the peel strength of the finished leather. Comparative Example 3, lacking a step-by-step roller impregnation process, results in tighter roller pressing, directly penetrating the unimpregnated layers of the substrate with the squeezed slurry. While this also provides a good hand feel, it too directly affects the peel strength of the finished leather.
[0064] Furthermore, this application tested the abrasion resistance of the finished leather, referring to the abrasion resistance test method in QB / T 2726-2005 "Determination of Abrasion Resistance of Leather through Physical and Mechanical Tests". The results are shown in Table 2.
[0065] Table 2 Test results of abrasion resistance of finished leather
[0066] It can be seen that in Examples 5 and 6, the lack of curing agent and intermediate layer makes it difficult to meet the physical property requirements of leather for football shoes. This shows that, under the premise of taking into account both softness and high peel strength, the performance requirements of the product in the specific application field can be met by optimizing and improving other functional layers without affecting its softness and high peel strength.
[0067] It should be noted that this application is not limited to the above-described embodiments. The above embodiments are merely examples, and any embodiments with the same structure and effect as the technical concept within the scope of this application are included in the technical scope of this application. Furthermore, various modifications that can be conceived by those skilled in the art to the embodiments, and other ways of constructing by combining some of the constituent elements of the embodiments, without departing from the spirit of this application, are also included in the scope of this application.
Claims
1. A method for preparing ultra-soft, high-peel polyurethane synthetic leather, wherein the polyurethane synthetic leather comprises a base layer, an adhesive layer, and a surface layer arranged sequentially, characterized in that, The preparation method includes the following steps: Provide a base layer and impregnated slurry; The base layer is partially immersed in the impregnation slurry, and multi-stage rollers are used for progressive impregnation to achieve precise local impregnation of the base layer; wherein, the impregnation slurry is a polyether polyurethane polymer containing nano-silicon; A top layer is provided, an adhesive layer is formed on the top layer, and the adhesive layer is bonded to the unimpregnated portion of the base layer to form an ultra-soft, high-peel polyurethane synthetic leather.
2. The preparation method according to claim 1, characterized in that, The thickness of the impregnation slurry is 70%-95% of the thickness of the base layer.
3. The preparation method according to claim 1, characterized in that, The substrate is a microfiber substrate.
4. The preparation method according to claim 1, characterized in that, The impregnating slurry comprises, by weight, 70-90 parts water, 10-30 parts polyether polyurethane resin, 3-5 parts nano-silicon and 0-10 parts pigment.
5. The preparation method according to claim 1, characterized in that, The multi-stage roller progressive immersion refers to the process of gradually reducing the thickness of the roller layer until it reaches 0.
6. The preparation method according to any one of claims 1-5, characterized in that, The polyurethane synthetic leather also includes an intermediate layer formed between the adhesive layer and the top layer.
7. The preparation method according to claim 6, characterized in that, The intermediate layer is formed by coating the surface of the top layer with an intermediate layer slurry, wherein, by weight, the intermediate layer slurry comprises materials with a number average molecular weight of 3 × 10⁻⁶. 4 -5×10 5 The mixture consists of 100 parts of polyoxypropylene ether glycol resin, 3-8 parts of curing agent, 3-8 parts of catalyst, and 0-10 parts of pigment.
8. The preparation method according to claim 1, characterized in that, The coating thickness of the intermediate layer slurry is 0.1-0.3 mm, and the drying temperature is 70-130℃.
9. The preparation method according to claim 1, characterized in that, After the adhesive layer is bonded to the unimpregnated portion of the substrate, the curing and setting temperature is 130-170℃.
10. The application of the preparation method according to any one of claims 1-9 in the preparation of polyurethane synthetic leather for football boots.