Polyurethane material, polyurethane-fiber fabric cloth and preparation method thereof

Abstract

This invention discloses a polyurethane material, a polyurethane-fiber fabric, and a method for preparing the same. The polyurethane material comprises high-melting-point polyurethane and low-melting-point polyurethane. The high-melting-point polyurethane has a melting point of 175℃ to 185℃ and a molecular weight of 150,000 to 200,000. The low-melting-point polyurethane has a melting point of 140℃ to 155℃ and a molecular weight of 60,000 to 100,000. This polyurethane material exhibits good hot-melt adhesion and film-forming properties. The polyurethane-fiber fabric prepared using this material possesses good flexibility, excellent peel strength, and resistance to rubbing.

Description

Technical Field

[0001] This invention belongs to the field of polyurethane composite materials technology, specifically relating to a polyurethane material, a polyurethane-fiber fabric and its preparation method. Background Technology

[0002] Currently, polyurethane TPU fiber fabric is a common and widely used composite material on the market. After laminating the fiber fabric with TPU, the product possesses certain barrier properties and can be used in inflatable products such as massage chair airbags, airships, and hovercraft. During processing, stacking, storage, transportation, and recycling, these TPU fiber fabrics inevitably undergo repeated folding and crumpling due to the combination of the soft TPU film and the high-strength fiber fabric. To ensure the product is not damaged during transportation, requirements for crumpling resistance and peel strength are imposed. However, the fiber fabric has stable properties but poor surface properties, resulting in poor bonding between the fiber fabric and polyurethane TPU, making it difficult to tightly adhere the TPU layer to the mesh surface.

[0003] There are two main methods for preparing polyurethane (TPU) fiber fabrics. One method involves first creating a TPU film and then hot-pressing it onto the fiber fabric. This process first prepares a thin film from the raw materials, then applies adhesive to it and bonds it to the fabric, creating a multi-functional laminated composite fabric. Another method is online lamination, where adhesive is applied to the fiber fabric, and the TPU is directly cast onto it. To improve peel strength, sufficient adhesive is needed to ensure thorough penetration and adhesion to the fabric. However, adhesives can cause environmental pollution and increase the number of steps involved. Furthermore, the bonding between the fiber fabric and the polyurethane TPU is poor, leading to easy cracking and peeling, resulting in low peel strength. On the other hand, hot lamination, where the polyurethane film and fiber fabric are bonded together under the pressure of a pair of rollers, uses high temperatures and results in weak adhesion, making the fiber fabric and polyurethane layer prone to peeling.

[0004] Therefore, existing polyurethane TPU fiber fabrics need to be improved. Summary of the Invention

[0005] This invention aims to at least partially solve one of the technical problems in related technologies. Therefore, one object of this invention is to provide a polyurethane material, a polyurethane-fiber fabric, and a method for preparing the same. This polyurethane material possesses good hot-melt bonding properties and film-forming properties, and the polyurethane-fiber fabric prepared using this material exhibits good flexibility while also possessing excellent peel strength and abrasion resistance.

[0006] In one aspect of the invention, a polyurethane material is provided. According to an embodiment of the invention, the polyurethane material comprises: a high-melting-point polyurethane and a low-melting-point polyurethane, wherein the high-melting-point polyurethane has a melting point of 175°C to 185°C and a molecular weight of 150,000 to 200,000, and the low-melting-point polyurethane has a melting point of 140°C to 155°C and a molecular weight of 60,000 to 100,000.

[0007] The polyurethane material according to the above embodiments of the present invention includes high-melting-point polyurethane and low-melting-point polyurethane. The high-melting-point polyurethane has a molecular weight of 150,000 to 200,000 and a melting point of 175°C to 185°C. Because of its large molecular weight, it improves the physical cross-linking network structure and molecular chain entanglement of the polyurethane material, thereby increasing the adhesive properties of the polyurethane. Adding low-melting-point polyurethane with a melting point of 140°C to 155°C and a molecular weight of 60,000 to 100,000 has two advantages: firstly, the low-melting-point polyurethane has a smaller molecular weight, resulting in lower viscosity, which improves the flowability of the polyurethane material, thus giving it better film-forming properties; secondly, the low-melting-point polyurethane... Polyurethane exhibits excellent wetting and penetration properties for fibers, improving the interfacial bonding between the fiber fabric and the polyurethane material. This lowers the thermal bonding temperature of the polyurethane material and the fiber fabric, allowing for thermal bonding of the polyurethane material with the fiber fabric over a wider and lower temperature range. This significantly enhances the hot-melt bonding performance of the polyurethane material, achieving good adhesion between the polyurethane material and the fiber fabric without the need for high-temperature hot pressing. Specifically, under the influence of pressure and temperature, the molten polyurethane material penetrates into the pores of the fiber fabric, resulting in a polyurethane-fiber fabric with high peel strength and excellent abrasion resistance and bonding properties. Therefore, this polyurethane material possesses good hot-melt bonding properties and film-forming properties. The polyurethane-fiber fabric prepared using this polyurethane material exhibits good flexibility while also possessing excellent peel strength and abrasion resistance.

[0008] In addition, the polyurethane material according to the above embodiments of the present invention may also have the following technical features:

[0009] In some embodiments of the present invention, at least one of a lubricant, a dispersant, and an antioxidant is also included.

[0010] In some embodiments of the present invention, the high-melting-point polyurethane is 60-80 parts by weight, the low-melting-point polyurethane is 20-40 parts by weight, the lubricant is 0.1-0.5 parts by weight, the dispersant is 0.5-1.5 parts by weight, and the antioxidant is 0.1-1 parts by weight. Thus, the polyurethane material has good hot-melt adhesion and film-forming properties.

[0011] In some embodiments of the present invention, the viscosity ratio of the low-melting-point polyurethane at 190°C and at an angular frequency of 0.1 rad / s and 100 rad / s is 1.5 to 3. Therefore, the polyurethane material exhibits good hot-melt bonding properties and film-forming properties.

[0012] In some embodiments of the present invention, the lubricant includes at least one of zinc stearate, sodium stearate, calcium stearate, and barium stearate.

[0013] In some embodiments of the present invention, the dispersant includes at least one of liquid paraffin and solid paraffin.

[0014] In some embodiments of the present invention, the antioxidant includes at least one of antioxidant 1010, antioxidant 168, and antioxidant 264.

[0015] In a second aspect, the present invention provides a polyurethane-fiber fabric. According to embodiments of the present invention, the polyurethane-fiber fabric comprises:

[0016] Fiber fabric;

[0017] A polyurethane material layer, wherein the polyurethane material layer is disposed on at least a portion of the surface of the fiber fabric and at least a portion of the polyurethane layer is embedded in the fiber fabric, the polyurethane material layer comprising the polyurethane material described above.

[0018] By allowing molten polyurethane material to penetrate into the pores of the fiber fabric, the adhesion between the fiber fabric and the polyurethane material layer is enhanced. As a result, the polyurethane-fiber fabric exhibits good flexibility while also possessing excellent peel strength and abrasion resistance.

[0019] In addition, the polyurethane-fiber fabric according to the above embodiments of the present invention may also have the following technical features:

[0020] In some embodiments of the present invention, the fiber fabric includes polyester fabric or aramid fabric.

[0021] In some embodiments of the present invention, the areal density of the fiber fabric is 140 g / m². 2 ~210g / m 2 .

[0022] In some embodiments of the present invention, the thickness of the polyurethane material layer is 30 μm to 100 μm.

[0023] A third aspect of the present invention provides a method for preparing polyurethane-fiber fabric. According to embodiments of the present invention, the method includes:

[0024] (1) The polyurethane material described above is melted and extruded from the die to obtain an extruded melt;

[0025] (2) The extruded melt is placed between the casting roller and the pressure roller, and the fiber fabric is introduced through the casting roller into the space between the extruded melt and the casting roller. Then the pressure roller applies pressure to the cooling roller to obtain the polyurethane-fiber fabric.

[0026] By subjecting molten polyurethane material and fiber fabric to specific temperature and pressure, the molten polyurethane material permeates into the pores of the fiber fabric, increasing the adhesion between the fiber fabric and the polyurethane material layer. This allows the polyurethane material layer and the fiber fabric to form a unified whole, increasing the peel strength between them. Therefore, this method can produce polyurethane-fiber fabrics with good flexibility, excellent peel strength, and resistance to rubbing. Furthermore, this method is simple and low-cost.

[0027] In addition, the method for preparing polyurethane-fiber fabric according to the above embodiments of the present invention may also have the following technical features:

[0028] In some embodiments of the present invention, in step (1), the extrusion temperature of the die is 190°C to 195°C. This ensures the molten state of the polyurethane material.

[0029] In some embodiments of the present invention, in step (1), the temperature in the middle of the die head is 0°C to 10°C lower than the temperature on both sides. This allows for a more uniform flow rate of the polyurethane melt in the width direction of the die head.

[0030] In some embodiments of the present invention, in step (1), the distance between the die head and the gap between the casting roller and the pressure roller is 10mm to 15mm. This prevents the polyurethane melt temperature from dropping too quickly, causing premature crystallization of the melt before casting.

[0031] In some embodiments of the present invention, in step (2), the temperature of the casting roller and the pressure roller is 120°C to 130°C. Therefore, the molten polyurethane material can penetrate into the pores of the fiber fabric.

[0032] In some embodiments of the present invention, in step (2), the pressure between the casting roller and the pressure roller is 200 kPa-500 kPa. This allows the molten polyurethane material to penetrate into the pores of the fiber fabric.

[0033] In some embodiments of the present invention, in step (2), the temperature of the cooling roller is 0°C to 10°C. This results in a smooth polyurethane material layer.

[0034] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0035] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0036] Figure 1 This is a schematic diagram of the process of casting to prepare polyurethane-fiber fabric according to an embodiment of the present invention;

[0037] Figure 2 This is a SEM image of the cross-section of the polyurethane-fiber fabric of Embodiment 1 of the present invention. Detailed Implementation

[0038] The embodiments of the present invention are described in detail below, and are intended to explain the present invention, but should not be construed as limiting the present invention.

[0039] In one aspect of the invention, a polyurethane material is provided. According to an embodiment of the invention, the polyurethane material comprises: a high-melting-point polyurethane and a low-melting-point polyurethane, wherein the high-melting-point polyurethane has a melting point of 175°C to 185°C and a molecular weight of 150,000 to 200,000, and the low-melting-point polyurethane has a melting point of 140°C to 155°C and a molecular weight of 60,000 to 100,000.

[0040] The polyurethane material according to the above embodiments of the present invention includes high-melting-point polyurethane and low-melting-point polyurethane, wherein the high-melting-point polyurethane has a melting point of 175°C to 185°C and a molecular weight of 150,000 to 200,000, and the low-melting-point polyurethane has a melting point of 140°C to 155°C and a molecular weight of 60,000 to 100,000. The inventors discovered that high-melting-point polyurethane has a larger molecular weight, which improves the physical cross-linking network structure and molecular chain entanglement of the polyurethane material, thereby increasing its adhesive properties. Adding low-melting-point polyurethane with a melting point of 140℃~155℃ and a molecular weight of 60,000~100,000 has two advantages: firstly, the lower molecular weight of low-melting-point polyurethane results in lower viscosity, improving the fluidity of the polyurethane material and thus giving it better film-forming properties; secondly, low-melting-point polyurethane has good wetting and penetration properties for fibers, improving the interfacial bonding performance between the fiber fabric and the polyurethane material, thereby lowering the thermal bonding temperature between the polyurethane material and the fiber fabric. This allows the polyurethane material to be thermally bonded to the fiber fabric over a wider and lower temperature range, greatly improving the thermal melt bonding performance of the polyurethane material. Without high-temperature hot pressing, the polyurethane material and the fiber fabric can achieve good adhesion. Specifically, under the action of pressure and temperature, the molten polyurethane material can penetrate into the pores of the fiber fabric, giving the prepared polyurethane-fiber fabric high peel strength and exhibiting excellent rubbing resistance and adhesion performance. Therefore, this polyurethane material has good hot melt bonding properties and film-forming properties. The polyurethane-fiber fabric prepared using this polyurethane material has good flexibility, as well as excellent peel strength and rubbing resistance.

[0041] According to embodiments of the present invention, the polyurethane material further includes at least one of a lubricant, a dispersant, and an antioxidant. It should be noted that the lubricant, dispersant, and antioxidant are conventional reagents in the art, and those skilled in the art can select them according to actual needs. For example, the lubricant includes at least one of zinc stearate, sodium stearate, calcium stearate, and barium stearate. The dispersant includes at least one of liquid paraffin and solid paraffin. The antioxidant includes at least one of antioxidant 1010, antioxidant 168, and antioxidant 264.

[0042] According to embodiments of the present invention, the high-melting-point polyurethane comprises 60-80 parts by weight, the low-melting-point polyurethane comprises 20-40 parts by weight, the lubricant comprises 0.1-0.5 parts by weight, the dispersant comprises 0.5-1.5 parts by weight, and the antioxidant comprises 0.1-1 parts by weight. The inventors have found that if the proportion of low-melting-point polyurethane is too high or the proportion of high-melting-point polyurethane is too low, the viscosity of the polyurethane material will be too low, resulting in a polyurethane material layer that is prone to cracking, has low strength, and is prone to shrinkage, leading to poor film-forming properties. Conversely, if the proportion of low-melting-point polyurethane is too low or the proportion of high-melting-point polyurethane is too high, the viscosity of the polyurethane material will be too high, resulting in poor processing performance and making it difficult for the polyurethane material to embed into the pores of the fiber fabric, thus reducing the adhesion between the polyurethane material and the fiber fabric. Therefore, the polyurethane material using the above-mentioned component mass proportions in this application has good film-forming properties, is easy to process, and adheres more tightly to the fiber fabric.

[0043] According to embodiments of the present invention, the viscosity ratio of the low-melting-point polyurethane at 0.1 rad / s and 100 rad / s at 190°C is 1.5 to 3. The inventors have found that if the viscosity ratio of the low-melting-point polyurethane at 0.1 rad / s and 100 rad / s at 190°C is less than 1.5, the conditions for preparing the polyurethane raw material are more stringent; if the viscosity ratio of the low-melting-point polyurethane at 0.1 rad / s and 100 rad / s at 190°C is greater than 3, it is highly sensitive to shear rate. Therefore, this application uses a low-melting-point polyurethane with a viscosity ratio of 1.5 to 3 at 0.1 rad / s and 100 rad / s at 190°C, which allows the polyurethane material to be thermally bonded to fiber fabrics over a wider and lower temperature range, greatly improving the thermal melt bonding performance of the polyurethane material.

[0044] In a second aspect, the present invention provides a polyurethane-fiber fabric. According to an embodiment of the present invention, the polyurethane-fiber fabric comprises: a fiber fabric and a polyurethane material layer, the polyurethane material layer being disposed on at least a portion of the surface of the fiber fabric and at least a portion of the polyurethane layer being embedded in the fiber fabric, the polyurethane material layer comprising the aforementioned polyurethane material.

[0045] The inventors discovered that by allowing molten polyurethane material to penetrate into the pores of the fiber fabric, the adhesion between the fiber fabric and the polyurethane material layer is increased. As a result, the polyurethane-fiber fabric exhibits good flexibility while also possessing excellent peel strength and abrasion resistance. It should be noted that the fiber fabric is a conventional material in the art, and those skilled in the art can select it according to actual needs. For example, the fiber fabric includes polyester fabric or aramid fabric.

[0046] According to an embodiment of the present invention, the areal density of the fiber fabric is 140 g / m². 2~210g / m 2 The inventors discovered that if the areal density of the fiber fabric is too high, the polyurethane material cannot easily penetrate into the fabric; if the areal density is too low, it cannot meet the requirements of the final product. Therefore, this application uses an areal density of 140 g / m². 2 ~210g / m 2 Polyurethane materials can be well incorporated into fiber fabrics.

[0047] According to embodiments of the present invention, the thickness of the polyurethane material layer is 30μm to 100μm. The inventors have found that if the polyurethane material layer is too thick, the finished product is too heavy and the cost is high; if the polyurethane material layer is too thin, the equipment requirements are too stringent. Therefore, this application uses a polyurethane material layer with a thickness of 30μm to 100μm to achieve the desired final performance. It should be noted that the thickness of the polyurethane material layer refers to the thickness of the polyurethane material layer on one side of the fiber fabric, specifically the thickness of the polyurethane material layer on one side of the fiber fabric above the fiber fabric.

[0048] A third aspect of the present invention provides a method for preparing polyurethane-fiber fabric. According to embodiments of the present invention, the method includes:

[0049] S100: Polyurethane material is melted and extruded from the die.

[0050] In this step, the components of the polyurethane material are mixed evenly and melted, then extruded through a die to obtain an extruded melt. Furthermore, the extrusion temperature is controlled at 190℃~195℃ to ensure the molten state of the polyurethane material. It should be noted that if liquid paraffin is used, it needs to be dried before being mixed and melted with other raw materials; alternatively, liquid paraffin can be added during the melting process of other raw materials.

[0051] According to an embodiment of the present invention, the temperature in the center of the die head is 0°C to 10°C lower than the temperature on both sides. The inventors have discovered that for melt extruded through a die head, the edges dissipate heat quickly, resulting in differences in viscosity and flowability compared to the center. Therefore, the temperature in the center of the die head should be lower than the temperatures on both sides. Thus, the 0°C to 10°C lower temperature in the center of the die head compared to the temperatures on both sides in this application allows for a more uniform flow rate of the melt along the width of the die head.

[0052] According to an embodiment of the present invention, the distance between the die head and the gap between the casting roller and the pressure roller is 10mm to 15mm. The inventors have found that if the distance between the die head and the gap between the casting roller and the pressure roller is too large, the temperature of the melt extruded from the die head will drop significantly before casting, causing the melt to crystallize prematurely and making it difficult to penetrate into the fiber fabric. If the distance between the die head and the gap between the casting roller and the pressure roller is too small, it will easily cause melt disturbance, making film formation difficult. Therefore, the distance between the die head and the gap between the casting roller and the pressure roller in this application is 10mm to 15mm, which can prevent the temperature of the polyurethane material melt from dropping too quickly, causing premature crystallization of the melt before casting, and also results in excellent film-forming properties.

[0053] S200: Outputs extruded melt and fiber fabric casting.

[0054] In this step, refer to Figure 1 The extruded melt is placed between the casting roller 200 and the pressure roller 300 by the die 100. Simultaneously, the fiber fabric 400 is introduced through the casting roller 200 between the extruded melt 500 and the casting roller 200. The pressure between the casting roller 200 and the pressure roller 300 forces the melt 500 into the fiber fabric 400. The melt then travels around the casting roller 200 and exits through the gap between the casting roller 200 and the cooling roller 600, and is conveyed to the forward winding mechanism for winding, resulting in a polyurethane-fiber fabric. By subjecting the molten polyurethane material and the fiber fabric to specific temperatures and pressures, the molten polyurethane material penetrates into the pores of the fiber fabric, increasing the adhesion between the fiber fabric and the polyurethane material layer. This allows the polyurethane material layer and the fiber fabric to form a unified whole, increasing the peel strength between them.

[0055] According to embodiments of the present invention, the temperature of the casting roller and the pressure roller is 120°C to 130°C. The inventors have discovered that by using a casting roller and pressure roller at a temperature of 120°C to 130°C, the polyurethane material can penetrate into the fiber fabric, and the peel strength between the two is high. Compared to existing polyurethane materials that require roller temperatures above 150°C to achieve bonding, the required roller temperature for bonding the polyurethane material to the fiber fabric in this application is significantly lower than that required for bonding existing polyurethane materials to fiber fabrics. Therefore, the preparation process of this application can effectively reduce energy consumption and save costs. Furthermore, the polyurethane-fiber fabric prepared after bonding at the lower temperature exhibits excellent peel strength.

[0056] According to an embodiment of the present invention, the pressure between the casting roller and the pressure roller is 200 kPa to 500 kPa. The inventors have discovered that within this pressure range, if the pressure between the casting roller and the pressure roller is too low, the bonding force between the fiber fabric and the polyurethane material is insufficient. Therefore, in this application, the pressure between the casting roller and the pressure roller is 200 kPa to 500 kPa, allowing the molten polyurethane material to penetrate into the pores of the fiber fabric.

[0057] According to an embodiment of the present invention, the temperature of the cooling roller is 0°C to 10°C. The inventors have found that if the temperature of the cooling roller is too high, it is prone to sticking; if the temperature of the cooling roller is too low, energy is wasted. Therefore, this application uses a cooling roller with a temperature of 0°C to 10°C, which can produce a polyurethane material layer with a smooth surface.

[0058] Therefore, this method can be used to prepare polyurethane-fiber fabrics with good flexibility, excellent peel strength and rubbing resistance. Moreover, the method is simple and low in cost.

[0059] The present invention will now be described with reference to specific embodiments. It should be noted that these embodiments are merely descriptive and do not limit the present invention in any way.

[0060] Example 1

[0061] Polyurethane material: High-melting-point polyurethane, melting point 180℃, molecular weight 160,000, weight percentage 74.4%; Low-melting-point polyurethane, melting point 150℃, molecular weight 80,000, weight percentage 24%, the viscosity ratio of low-melting-point polyurethane at 190℃ and angular frequencies of 0.1 rad / s and 100 rad / s is 2; 0.3 wt% antioxidant 1010; 0.3 wt% lubricant (calcium stearate). The dried mixture is melted and plasticized at high temperature in an extruder. During the melting process, 1% by weight of liquid paraffin is added. The die temperature is 195℃-190℃-195℃ (edge-middle-edge), at which point the viscosity is moderately adjusted, and the melt flows continuously from the die to the rollers with good fluidity. The mixture is extruded through the die between two temperature-controlled, oppositely moving casting rollers and a pressure roller. The distance from the die exit to the casting rollers is 10 mm. The casting roller and pressure roller are at a temperature of 125℃ and a pressure of 400 kPa. The fiber fabric is drawn into the space between the molten plasticized TPU and the casting roller by the traction of the casting roller. It then wraps around the casting roller and exits from the gap between the casting roller and the cooling roller (temperature 5℃). The fabric is then conveyed to the forward winding mechanism for winding, resulting in a polyurethane-fiber fabric. The obtained TPU film has a smooth and transparent surface and is less prone to sticking to the rollers. Figure 2 As shown, the polyurethane material is completely incorporated into the interior of the fiber fabric, wherein the areal density of the fiber fabric is 180 g / m². 2 The thickness of the polyurethane material layer is 80μm.

[0062] Example 2

[0063] Polyurethane material: High-melting-point polyurethane, melting point 180℃, molecular weight 160,000, weight percentage 72%; Low-melting-point polyurethane, melting point 150℃, molecular weight 80,000, weight percentage 27%, the viscosity ratio of low-melting-point polyurethane at 190℃ and angular frequencies of 0.1 rad / s and 100 rad / s is 2.5; 0.2 wt% antioxidant 1010; 0.3 wt% lubricant (calcium stearate). The dried mixture is melted and plasticized at high temperature in an extruder. During the melting process, 0.5% by weight of liquid paraffin is added. The die temperature is 195℃-190℃-195℃ (edge-middle-edge), at which point the viscosity is moderately adjusted, and the melt flows continuously from the die to the rollers with good fluidity. The mixture is extruded through the die between two temperature-controlled, oppositely moving casting rollers and a pressure roller. The distance from the die exit to the casting rollers is 10 mm. The casting roller and pressure roller are at a temperature of 130℃ and a pressure of 500KPa. The fiber fabric is drawn into the space between the molten plasticized TPU and the casting roller by the traction of the casting roller. It then wraps around the casting roller and exits through the gap between the casting roller and the cooling roller (temperature 5℃). The fabric is then conveyed to the forward winding mechanism for winding, resulting in a polyurethane-fiber fabric. The obtained TPU film has a smooth and transparent surface and is not prone to sticking to the rollers. The polyurethane material is completely penetrated into the interior of the fiber fabric, which has an areal density of 180g / m³. 2 The thickness of the polyurethane material layer is 62μm.

[0064] Example 3

[0065] Polyurethane material: High-melting-point polyurethane, melting point 180℃, molecular weight 160,000, weight percentage 72%; Low-melting-point polyurethane, melting point 150℃, molecular weight 80,000, weight percentage 27%, the viscosity ratio of low-melting-point polyurethane at 190℃ and angular frequencies of 0.1 rad / s and 100 rad / s is 2; 0.2 wt% antioxidant 1010; 0.3 wt% lubricant (calcium stearate). The dried mixture is melted and plasticized at high temperature in an extruder. During the melting process, 0.5% by weight of liquid paraffin is added. The die temperature is 195℃-192℃-195℃ (edge-middle-edge), at which point the viscosity is moderately adjusted, and the melt flows continuously from the die to the rollers with good fluidity. The mixture is extruded through the die between two temperature-controlled, oppositely moving casting rollers and a pressure roller. The distance from the die exit to the casting rollers is 15 mm. The casting roller and pressure roller are at a temperature of 130℃ and a pressure of 500KPa. The fiber fabric is drawn into the space between the molten plasticized TPU and the casting roller by the traction of the casting roller. It then wraps around the casting roller and exits through the gap between the casting roller and the cooling roller (temperature 5℃). The fabric is then conveyed to the forward winding mechanism for winding, resulting in a polyurethane-fiber fabric. The obtained TPU film has a smooth and transparent surface and is not prone to sticking to the rollers. The polyurethane material is completely penetrated into the interior of the fiber fabric, which has an areal density of 180g / m³. 2 The thickness of the polyurethane material layer is 70μm.

[0066] Comparative Example 1

[0067] Polyurethane material: High-melting-point polyurethane, melting point 180℃, molecular weight 160,000, weight percentage 95%; Low-melting-point polyurethane, melting point 150℃, molecular weight 80,000, weight percentage 5%. The viscosity ratio of the low-melting-point polyurethane at 190℃ and angular frequencies of 0.1 rad / s and 100 rad / s is 8. The dried mixture is melt-extruded at high temperature using an extruder with a die temperature of 195℃-190℃-195℃ (edge-middle-edge). The extrusion passes through the die between two temperature-controlled, oppositely moving casting rollers and a pressure roller. The distance between the die exit and the casting roller is 10 mm. The casting roller and pressure roller are at a temperature of 125℃ and a pressure of 400KPa. The fiber fabric is drawn into the space between the molten plasticized TPU and the casting roller by the traction of the casting roller. It then wraps around the casting roller and exits from the gap between the casting roller and the cooling roller. The cooling roller is at a temperature of 5℃. The fabric is then conveyed to the forward winding mechanism for winding, resulting in polyurethane-fiber fabric. Due to its high melt viscosity, the TPU easily sticks to the rollers, making it difficult to form on the two rollers. The fiber fabric has poor permeability, and the TPU does not penetrate into the fiber interior.

[0068] Comparative Example 2

[0069] Polyurethane material: High-melting-point polyurethane, melting point 180℃, molecular weight 160,000, weight percentage 50%; Low-melting-point polyurethane, melting point 150℃, molecular weight 80,000, weight percentage 45%. The viscosity ratio of the low-melting-point polyurethane at 190℃ and angular frequencies of 0.1 rad / s and 100 rad / s is 3. Add 0.2 wt% antioxidant 1010 and 0.3 wt% lubricant (calcium stearate). The dried mixture is then melted and plasticized at high temperature using an extruder. During the melting process, 4.5% liquid paraffin is added. The die temperature is 195℃-190℃-195℃ (edge-middle-edge). The mixture is extruded through the die between two temperature-controlled, oppositely moving casting rollers and a pressure roller. The distance from the die exit to the casting roller is 10 mm. The temperature of the casting roller and the pressure roller is 125℃ and the pressure is 400KPa. The fiber fabric is drawn into the space between the molten plasticized TPU and the casting roller by the traction of the casting roller. Then it is wrapped around the casting roller and output from the gap between the casting roller and the cooling roller. The temperature of the cooling roller is 5℃. It is then conveyed to the forward winding mechanism for winding to obtain polyurethane-fiber fabric. The TPU has poor film-forming properties.

[0070] The properties of the TPU-fiber fabrics prepared in Example-3 and Comparative Examples 1-2 were measured, and the specific results are shown in Table 1.

[0071] Table 1

[0072]

[0073] As can be seen from Table 1, the comparison of thickness range data between Examples 1-3 and Comparative Examples 1-2 shows that a high proportion of high-melting-point polyurethane results in high melt viscosity, poor appearance after sticking to the roller, large thickness fluctuations, and a large thickness range. When the content of low-melting-point TPU raw material is too high, the melt viscosity is too low, the melt is prone to cracking, the melt strength is low, it is easy to shrink, the film-forming properties are poor, and the thickness range is large. Therefore, the proportion of high-melting-point polyurethane should be within a suitable range. The peel strength of Examples 1-3 is much higher than that of Comparative Examples 1-2. Examples 1-3 have excellent rub resistance, and the polyurethane layer does not stick to the roller, has good film-forming properties, and a smooth surface. This shows that the selection of polyurethane materials with appropriate mass ratios of high-melting-point polyurethane and low-melting-point polyurethane has a significant impact on the performance of the prepared TPU-fiber fabric. At the same time, by comparing the data of Examples 2 and 3, the peel strength of Example 2 is much higher than that of Example 3. This is mainly because the distance between the die outlet and the casting roller in Example 2 is 10 mm, indicating that the size of the distance between the die outlet and the casting roller also has a certain impact on the performance of the product.

[0074] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0075] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A polyurethane material, characterized in that, include: The invention comprises high-melting-point polyurethane and low-melting-point polyurethane, wherein the high-melting-point polyurethane has a melting point of 175℃ to 185℃ and a molecular weight of 150,000 to 200,000, and the low-melting-point polyurethane has a melting point of 140℃ to 155℃ and a molecular weight of 60,000 to 100,000; the polyurethane material further comprises at least one of a lubricant, a dispersant, and an antioxidant; the high-melting-point polyurethane comprises 60 to 80 parts by weight, the low-melting-point polyurethane comprises 20 to 40 parts by weight, the lubricant comprises 0.1 to 0.5 parts by weight, the dispersant comprises 0.5 to 1.5 parts by weight, and the antioxidant comprises 0.1 to 1 part by weight; the viscosity ratio of the low-melting-point polyurethane at 190℃ and angular frequencies of 0.1 rad / s and 100 rad / s is 1.5 to 3.

2. The polyurethane material according to claim 1, characterized in that, The lubricant includes at least one of zinc stearate, sodium stearate, calcium stearate, and barium stearate.

3. The polyurethane material of claim 1, wherein, The dispersant includes at least one of liquid paraffin and solid paraffin.

4. The polyurethane material of claim 1, wherein, The antioxidant includes at least one of antioxidant 1010, antioxidant 168, and antioxidant 264.

5. A polyurethane-fiber fabric cloth, characterized by, include: A fiber fabric; a polyurethane material layer, the polyurethane material layer being disposed on at least a portion of the surface of the fiber fabric and at least a portion of the polyurethane layer being embedded in the fiber fabric, the polyurethane material layer comprising the polyurethane material of any one of claims 1-4.

6. The polyurethane-fiber fabric cloth according to claim 5, characterized by, The fiber fabric includes polyester fabric or aramid fabric.

7. The polyurethane-fiber fabric cloth according to claim 5, characterized by, The areal density of the fiber fabric is 140 g / m². 2 ~210g / m 2 .

8. The polyurethane-fiber fabric cloth according to claim 5, characterized by, The thickness of the polyurethane material layer is 30μm to 100μm.

9. A method for preparing polyurethane-fiber fabric, characterized in that, include: (1) The polyurethane material described in any one of claims 1-4 is melted and extruded from a die to obtain an extruded melt; (2) The extruded melt is placed between the casting roller and the pressure roller, and the fiber fabric is introduced through the casting roller into the space between the extruded melt and the casting roller. Then the pressure roller applies pressure to the cooling roller to obtain the polyurethane-fiber fabric.

10. The method according to claim 9, characterized in that, In step (1), the extrusion temperature of the die head is 190℃~195℃.

11. The method of claim 9, wherein, The temperature in the middle of the mold head is 0℃ to 10℃ lower than the temperature on both sides.

12. The method of claim 9, wherein, The distance between the die head and the gap between the casting roller and the pressure roller is 10mm to 15mm.

13. The method of claim 9, wherein, In step (2), the temperature of the casting roller and the pressure roller is 120℃~130℃.

14. The method of claim 9, wherein, The pressure between the casting roller and the pressure roller is 200 kPa to 500 kPa.

15. The method of claim 9, wherein, The temperature of the cooling roller is 0℃~10℃.

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