Seawater erosion-resistant fabric and preparation method thereof

Abstract

This invention provides a seawater-resistant fabric and its preparation method, comprising the following steps: S1: pre-impregnating the fabric at low temperature to obtain a skeleton layer; S2: applying an adhesive layer to both sides of the skeleton layer obtained in step S1; S3: extruding and casting to coat a double-sided TPU film layer, thereby obtaining a seawater-resistant fabric. The beneficial effects of this invention are: This invention creatively uses low-temperature pre-impregnation of water-based acrylic resin, followed by high-temperature coating with polyester-type polyurethane, effectively improving the polyurethane's resistance to salt water; the use of polyester-type polyurethane achieves higher peel strength, and the addition of an anti-hydrolysis agent enhances the hydrolysis resistance of the polyester-type polyurethane; after immersion in 5% salt water, the wet interlayer peel strength can still reach over 90%, avoiding safety issues caused by decreased interlayer peel strength due to seawater erosion during the use of life rafts.

Description

Technical Field

[0001] This invention belongs to the technical field of coated composite fabrics, and in particular relates to a seawater-resistant fabric and its preparation method. Background Technology

[0002] Inflatable life rafts are one of the main life-saving equipment on modern ships. In the event of an emergency, inflatable life rafts, with their small size, light weight, and ease of use, can provide temporary life-saving conditions. High-quality inflatable life rafts can help personnel effectively avoid maritime risks and increase the survival rate in the event of an emergency. Currently, most domestically produced life raft fabrics are made of rubber, but rubber products have problems such as high weight per unit area and a noticeable odor. Thermoplastic polyurethane (TPU), due to its excellent comprehensive properties—high strength, high elasticity, and excellent wear and weather resistance—is widely used in the preparation of composite functional fabrics. Because TPU composite fabrics are lightweight while possessing excellent airtightness, tensile strength, and processability, they are gradually being used in life rafts. However, since life rafts need to be in contact with seawater for extended periods, prolonged seawater erosion may cause a decrease in the interlayer peel strength of the TPU composite fabric, leading to deflation of the raft and posing a safety hazard. Summary of the Invention

[0003] In view of this, the present invention aims to propose a seawater-resistant fabric and its preparation method to solve the problem that long-term seawater erosion may lead to a decrease in the interlayer peel strength of TPU composite fabric, causing air leakage in the raft and posing a safety hazard.

[0004] To achieve the above objectives, the technical solution of the present invention is implemented as follows:

[0005] A seawater-resistant fabric and its preparation method, comprising the following steps:

[0006] S1: The fabric is pre-impregnated at low temperature to obtain the skeleton layer;

[0007] S2: Apply adhesive layers to both sides of the skeleton layer obtained in step S1;

[0008] S3: Extrusion casting coating: Double-sided TPU coating to obtain a fabric resistant to seawater corrosion.

[0009] Further, in step S1, the fabric pre-impregnation involves mixing 10-20 parts by weight of waterborne acrylic resin and 80-100 parts by weight of water, drying at 115-125°C for 2.5-3.5 minutes, and performing a low-temperature pre-impregnation treatment on the fabric. Waterborne acrylic resin possesses excellent wash resistance and adhesion. Pre-impregnating the polyacrylic resin at a low temperature, followed by coating with polyurethane and curing at high temperature, effectively improves the polyurethane adhesive's resistance to seawater.

[0010] Furthermore, the fabric in step S1 is a nylon fabric with a denier of 180-200D. It is also a 90A polyether-type TPU. Compared to lower-hardness TPU, 90A TPU molecules are more tightly packed and less susceptible to water erosion.

[0011] Further, the adhesive layer in step S2 comprises, by weight, the following components:

[0012]

[0013] To achieve higher interlayer peel strength, polyester-based polyurethane adhesives are used. Polyester-based polyurethane has high strength, large cohesive energy, and tighter intermolecular bonds, resulting in good adhesion. However, polyester-based polyurethane is not resistant to hydrolysis. During hydrolysis, -COON is generated. The presence of -COON further promotes the hydrolysis of the material, causing the peel performance to decline rapidly in a short period of time. To avoid accelerating hydrolysis, carbodiimide-based hydrolysis-resistant agents are used. These agents can react with -COON, preventing further hydrolysis.

[0014] Furthermore, the solvent is toluene-2,4-diisocyanate or toluene.

[0015] Furthermore, in step S2, the adhesive is applied by coating. When applying the adhesive, the viscosity of the adhesive is 70,000-80,000 mPa·s, and the amount used is 25 g / m2. Then, the fabric is heated and dried in an oven at a temperature of 155-165℃ for 2.5-3.5 min to obtain a coated fabric.

[0016] Furthermore, in step S3, the extrusion casting coating involves double-sided film coating with a TPU layer thickness of 0.1 mm on each side. After being melted and plasticized at high temperature by the screw of the extrusion casting coating machine, the film is uniformly extruded through a flat die with precise thickness control, and then bonded to the coated fabric to obtain the finished product.

[0017] Furthermore, the TPU is a polyether-type TPU granule with a hardness of 90A.

[0018] A seawater-resistant fabric and its preparation method. The fabric includes a first TPU layer, a first adhesive layer, a skeleton layer, a second adhesive layer, and a second TPU layer, which are arranged sequentially.

[0019] Furthermore, the first TPU layer and the second TPU layer are polyether-type TPU granules with a hardness of 90A;

[0020] The first adhesive layer and the second adhesive layer comprise, by weight:

[0021]

[0022] Compared with existing technologies, the seawater-resistant fabric and its preparation method described in this invention have the following advantages:

[0023] This invention creatively uses low-temperature pre-impregnation of water-based acrylic resin, followed by high-temperature coating with polyester-type polyurethane, which effectively improves the polyurethane's resistance to salt water. The use of polyester-type polyurethane achieves higher peel strength, and the addition of anti-hydrolysis agents enhances the hydrolysis resistance of the polyester-type polyurethane. After immersion in 5% salt water, the wet-state interlayer peel strength can still reach over 90%, avoiding safety issues caused by reduced interlayer peel strength due to seawater erosion during the use of the life raft. Detailed Implementation

[0024] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0025] The present invention will now be described in detail with reference to the embodiments.

[0026] Example 1

[0027] A seawater-resistant functional textile fabric, comprising, from top to bottom: a TPU layer, an adhesive layer, a reinforcing material, another adhesive layer, and a TPU layer.

[0028] The preparation method includes the following steps:

[0029] Step 1: Fabric pre-impregnation. Use 200D nylon fabric with low twist yarn to increase the penetration of the adhesive layer into the fabric and improve the interlayer peel force. Mix 10 parts water-based acrylic resin and 100 parts water by weight, dry at 120℃ for 3 minutes, and perform low-temperature pre-impregnation treatment on the fabric.

[0030] Step Two: Adhesive Application: The adhesive layer is applied to both sides of the skeleton material. By weight, it contains 80 parts polyurethane adhesive, 4 parts polyisocyanate crosslinking agent, 30 parts solvent (TOL or toluene), and 8 parts carbodiimide hydrolysis-resistant agent. The adhesive is applied using a coating method. During application, the viscosity of the adhesive is 70,000-80,000 mPa·s, and the dosage is 25 g / m³. 2 Then, the coated fabric is heated and dried in an oven at 160℃ for 3 minutes to obtain the coated fabric.

[0031] Step 3: Extrusion Cast Coating: Double-sided film coating, with a TPU layer thickness of 0.1mm on each side. The polyether-type 90A hardness TPU granules are melted and plasticized at high temperature by the screw of the extrusion cast coating machine, and then uniformly extruded into a film through a flat die with precise thickness control. The film is then bonded to the coated fabric to obtain the finished product.

[0032] Comparative Example 1

[0033] Step 1: Using 200D nylon fabric, apply adhesive: The adhesive layer is a double-sided coating on the skeleton material, containing 80 parts by weight of polyurethane adhesive, 4 parts of polyisocyanate crosslinking agent, 30 parts of solvent (TOL or toluene), and 8 parts of carbodiimide hydrolysis-resistant agent. Apply the adhesive using a coating method. During application, the adhesive viscosity should be 70,000-80,000 mPa·s, and the dosage should be 25 g / m³. 2 Then, the coated fabric is heated and dried in an oven at 160℃ for 3 minutes to obtain the coated fabric.

[0034] Step 2: Extrusion Cast Coating: Double-sided film coating, with a TPU layer thickness of 0.1mm on each side. The polyether-type 90A hardness TPU granules are melted and plasticized at high temperature by the screw of the extrusion cast coating machine, and then uniformly extruded into a film through a flat die with precise thickness control. The film is then bonded to the coated fabric to obtain the finished product.

[0035] The difference from Example 1 is that step 1 was not performed, and the low-temperature pre-soaking treatment was not performed.

[0036] Comparative Example 2

[0037] Step 1: Fabric pre-impregnation. Use 300D nylon fabric and high-twist yarn. Mix 10 parts water-based acrylic resin and 100 parts water by weight, dry at 120℃ for 3 minutes, and perform low-temperature pre-impregnation treatment on the fabric.

[0038] Step Two: Adhesive Application: The adhesive layer is applied to both sides of the skeleton material. By weight, it contains 80 parts polyurethane adhesive, 4 parts polyisocyanate crosslinking agent, 30 parts solvent (TOL or toluene), and 8 parts carbodiimide hydrolysis-resistant agent. The adhesive is applied using a coating method. During application, the viscosity of the adhesive is 70,000-80,000 mPa·s, and the dosage is 25 g / m³. 2 Then, the coated fabric is heated and dried in an oven at 160℃ for 3 minutes to obtain the coated fabric.

[0039] Step 3: Extrusion Cast Coating: Double-sided film coating, with a TPU layer thickness of 0.1mm on each side. The polyether-type 90A hardness TPU granules are melted and plasticized at high temperature by the screw of the extrusion cast coating machine, and then the thickness is precisely controlled.

[0040] The difference from Example 1 is that 300D nylon fabric is used, in which the yarn has a high twist.

[0041] Comparative Example 3

[0042] Step 1: Fabric pre-impregnation. Use 200D nylon fabric with low twist yarn to increase the penetration of the adhesive layer into the fabric and improve the interlayer peel force. Mix 10 parts water-based acrylic resin and 100 parts water by weight, dry at 180℃ for 3 minutes, and pre-impregnate the fabric.

[0043] Step Two: Adhesive Application: The adhesive layer is applied to both sides of the skeleton material. By weight, it contains 80 parts polyurethane adhesive, 4 parts polyisocyanate crosslinking agent, 30 parts solvent (TOL or toluene), and 8 parts carbodiimide hydrolysis-resistant agent. The adhesive is applied using a coating method. During application, the viscosity of the adhesive is 70,000-80,000 mPa·s, and the dosage is 25 g / m³. 2 Then, the coated fabric is heated and dried in an oven at 160℃ for 3 minutes to obtain the coated fabric.

[0044] Step 3: Extrusion Cast Coating: Double-sided film coating, with a TPU layer thickness of 0.1mm on each side. The polyether-type 90A hardness TPU granules are melted and plasticized at high temperature by the screw of the extrusion cast coating machine, and then uniformly extruded into a film through a flat die with precise thickness control. The film is then bonded to the coated fabric to obtain the finished product.

[0045] The difference from Example 1 is that the drying temperature after pre-impregnation with acrylic resin is different.

[0046] Table 1. Results obtained from conventional fabrics and Example 1:

[0047]

[0048] As shown in Table 1, Example 1 demonstrates that the functional textile fabric obtained by this application exhibits a significantly higher initial interlayer peel strength than the fabric without low-temperature pre-impregnation treatment. Furthermore, the interlayer peel strength after immersion in 5% salt water is similar to the initial interlayer peel strength. In Comparative Example 2, the use of high-twist yarn shows that the initial interlayer peel strength is much lower than that of this application, and the interlayer peel strength is greatly reduced after immersion in 5% salt water. The composite fabric obtained in Comparative Example 3, with a different temperature than that in Example 1, shows that the initial interlayer peel strength is much lower than that of Example 1. Therefore, this application improves the hydrolysis resistance of polyester-type polyurethane by adding an anti-hydrolysis agent. After immersion in 5% salt water, the wet interlayer peel strength can still reach over 90%, avoiding safety issues caused by the decrease in interlayer peel strength due to seawater erosion during the use of life rafts.

[0049] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing a seawater-resistant fabric, characterized in that: Includes the following steps: S1: The fabric is pre-impregnated at low temperature to obtain the skeleton layer; S2: Apply adhesive layers to both sides of the skeleton layer obtained in step S1; S3: Extrusion casting coating: Double-sided TPU coating to obtain a fabric resistant to seawater corrosion; In step S1, the fabric pre-impregnation process involves mixing 10-20 parts by weight of water-based acrylic resin and 80-100 parts by weight of water, drying at 115-125°C for 2.5-3.5 minutes, and performing a low-temperature pre-impregnation treatment on the fabric. The fabric used in step S1 is a nylon fabric with a denier of 180-200D. The adhesive layer in step S2 comprises, by weight, the following components: 60-80 parts of polyester-based polyurethane adhesive; 4-6 parts of polyisocyanate crosslinking agent; 5-10 parts of carbodiimide-based hydrolysis resistant agent; Solvent 20-30 parts; In step S2, the adhesive is applied using a coating method. The viscosity of the adhesive is 70,000-80,000 mPa•s, and the dosage is 25 g / m³. 2 Then, the fabric is heated and dried in an oven at a temperature of 155-165℃ for 2.5-3.5 minutes to obtain a coated fabric.

2. The method for preparing a seawater-resistant fabric according to claim 1, characterized in that: The solvent is toluene.

3. The method for preparing a seawater-resistant fabric according to claim 1, characterized in that: In step S3, extrusion casting coating involves double-sided film coating with a TPU layer thickness of 0.1 mm on each side. After being melted and plasticized at high temperature by the screw of the extrusion casting coating machine, the film is uniformly extruded through a flat die with precise thickness control, and then bonded to the coated fabric to obtain the finished product.

4. The method for preparing a seawater-resistant fabric according to claim 1, characterized in that: The TPU is a polyether-type TPU granule with a hardness of 90A.

5. The fabric prepared by the method for preparing a seawater-resistant fabric according to any one of claims 1-4, characterized in that: It includes a first TPU layer, a first adhesive layer, a skeleton layer, a second adhesive layer, and a second TPU layer, which are arranged sequentially.

6. The seawater-resistant fabric according to claim 5, characterized in that: The first TPU layer and the second TPU layer are polyether-type TPU granules with a hardness of 90A. The first adhesive layer and the second adhesive layer comprise, by weight: 60-80 parts of polyester-based polyurethane adhesive; 4-6 parts of polyisocyanate crosslinking agent; 5-10 parts of carbodiimide-based hydrolysis resistant agent; Solvent 20-30 parts.

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