Low-elongation high-strength aramid netted PVC material and preparation method thereof

Abstract

The application relates to the technical field of PVC (polyvinyl chloride) sandwich materials, and particularly discloses a low-elongation high-strength aramid sandwich PVC material and a preparation method thereof. The low-elongation high-strength aramid sandwich PVC material comprises an aramid mesh cloth layer, the two sides of the aramid mesh cloth layer are both provided with a paste layer, and the surface of the paste layer away from the aramid mesh cloth layer is provided with a PVC adhesive film layer; the preparation raw materials of the paste layer are polyvinyl chloride resin, tackifying resin, a crosslinking agent, a filler and a plasticizer; the preparation method of the tackifying resin comprises the following steps: adding a photoinitiator into acetone, dispersing, adding trifunctional aliphatic polyurethane acrylate and monomers, stirring and mixing to obtain a mixed solution A; adding resorcinol and a catalyst into water, dispersing, adding a formaldehyde solution, dispersing, reacting to obtain a mixed solution B; and blending the mixed solution A and the mixed solution B to obtain the tackifying resin. The low-elongation high-strength aramid sandwich PVC material disclosed by the application has low elongation, high strength and large peeling strength.

Description

Technical Field

[0001] This application relates to the technical field of PVC mesh materials, and more specifically, to a low-elongation, high-strength aramid mesh PVC material and its preparation method. Background Technology

[0002] PVC mesh material is made of two layers of PVC film sandwiched with wire mesh. It has good flexibility, corrosion resistance, wear resistance and bending resistance. It also has the advantages of being waterproof, moisture-proof and UV-resistant. It is widely used in membrane structure buildings, tents, roller shutters, truck canopies and protective covers and other fields.

[0003] Membrane structures and tent materials have specific requirements regarding load-bearing elongation. For example, the elastic modulus must be used to design and cut the overlap length during the design and manufacturing process. After construction, the surface will also sag under load, such as from snow or water accumulation. As for roller shutter materials, especially large roller shutters with spans of tens or even hundreds of meters, the load-bearing bars underneath can cause the entire curtain to grow by more than a meter over time, directly affecting its usability and appearance.

[0004] Currently, there is a type of PVC mesh material where the mesh is made of polyester fiber fabric. However, the inherent properties of polyester fiber fabric result in high elongation and low strength, making it difficult to meet the requirements for membrane structures and tent materials in snow-covered and water-accumulated environments. To address these issues, some manufacturers use aramid fiber, which has low elongation and high strength, instead of polyester. However, the surface inertness of aramid fiber leads to insufficient peel strength between it and the PVC film, affecting its service life. Summary of the Invention

[0005] To improve the peel strength between aramid and PVC film, this application provides a low-elongation, high-strength aramid-PVC mesh material and its preparation method.

[0006] In a first aspect, this application provides a low-elongation, high-strength aramid-reinforced PVC material, employing the following technical solution: A low-elongation, high-strength aramid mesh PVC material includes an aramid mesh layer, with a paste layer disposed on both sides of the aramid mesh layer, and a PVC film layer disposed on the surface of the paste layer away from the aramid mesh layer. The raw materials for preparing the paste layer include the following components in parts by weight: The mixture comprises 90-100 parts of polyvinyl chloride resin, 3-5 parts of tackifying resin, 1-2 parts of crosslinking agent, 15-20 parts of filler, and 60-75 parts of plasticizer; the tackifying resin is prepared by: Add a photoinitiator to acetone, disperse, then add trifunctional aliphatic polyurethane acrylate and monomer, stir and mix to obtain mixture A; add resorcinol and catalyst to water, disperse, add formaldehyde solution, disperse, react to obtain mixture B; mix mixture A and mixture B together to obtain the final product.

[0007] By adopting the above technical solution—using an aramid mesh layer as the substrate—its strength is 2.5-3 times that of polyester fiber, and its elongation at break (3-5%) is far lower than that of polyester fiber (25-40%), giving the mesh material the characteristics of low elongation and high strength. The paste layer is improved to address the problem of insufficient peel strength between aramid and the PVC film layer due to the surface inertness of aramid. The addition of a tackifying resin, primarily composed of resorcinol and formaldehyde, allows the hydroxymethyl groups in the resin to condense with the amide groups in the aramid fiber molecules. The oxygen atoms of the phenolic hydroxyl groups form hydrogen bonds with the oxygen atoms of the amide groups, resulting in better adhesion of the paste layer to the surface of the aramid mesh layer and thus improving the peel strength between the layers of the mesh material. Further introduction of a trifunctional aliphatic polyurethane acrylate allows the tackifying resin to first form a highly flexible matrix during photocuring, upon which plasticizing and molding can then be performed, reducing the problem of increased brittleness in the paste layer caused by the introduction of the tackifying resin.

[0008] Testing revealed that the peel strength of the mesh material without tackifying resin was 16.67 (25N / 5cm), and the folding endurance was only 235 cycles, making it prone to delamination. After adding tackifying resin, the peel strength of the mesh material increased to over 30.21 (25N / 5cm), and the folding endurance increased to over 432 cycles, indicating that the tackifying resin effectively reduced the delamination problem. When a tackifying resin without mixture A is added, the mesh material's folding endurance is only 337 cycles; when a hexafunctional aliphatic polyurethane acrylate is added instead of a trifunctional aliphatic polyurethane acrylate tackifying resin, the mesh material's folding endurance is 398 cycles; when a tackifying resin without mixture B is added, the mesh material's peel strength is only 15.20 (25 N / 5 cm), indicating that tackifying resins without mixture A or mixture B, or those made with other functional acrylates, cannot achieve optimal results.

[0009] Optionally, the weight ratio of acetone, photoinitiator, trifunctional aliphatic polyurethane acrylate, and monomer is 0.75:1.7-2.2:13-17:13-17.

[0010] By adopting the above technical solution, when the weight ratio of acetone, photoinitiator, trifunctional aliphatic polyurethane acrylate, and monomer is within the above range, the performance of the prepared tackifying resin is better when added to the paste layer.

[0011] Optionally, the monomer is one or a mixture of ethoxylated trimethylolpropane triacrylate, ethoxylated bisphenol A diacrylate, ethoxylated 1,6-hexanediol diacrylate, and ethoxylated pentaerythritol tetraacrylate.

[0012] By adopting the above technical solutions, all of the above monomers can be used to prepare paste layers.

[0013] Optionally, the weight ratio of resorcinol to formaldehyde solution is 4:5.2-5.8.

[0014] By adopting the above technical solution, when the weight ratio of resorcinol to formaldehyde solution is within the above range, the performance of the prepared mesh material is better.

[0015] Optionally, the catalyst is an aqueous solution of sodium hydroxide.

[0016] Optionally, the weight ratio of the mixture A to the mixture B is 0.3-0.4:1.

[0017] By adopting the above technical solution: when mixture A and mixture B are within the above range, the ratio of the two is appropriate, and the prepared tackifying resin effectively enhances the bonding strength between the paste layer and the mesh layer, while the paste layer is not easily brittle.

[0018] Optionally, the crosslinking agent is dicumyl peroxide or bis-tert-butylperoxide.

[0019] By adopting the above technical solution, this application appropriately increases the amount of crosslinking agent to increase the peel strength between the paste layer and the mesh layer.

[0020] Secondly, this application provides a method for preparing a low-elongation, high-strength aramid-reinforced PVC material, employing the following technical solution: A method for preparing a low-elongation, high-strength aramid-reinforced PVC material includes the following steps: S1. Mix the plasticizer, tackifying resin, filler, and crosslinking agent, add polyvinyl chloride resin, mix, and obtain a paste; S2. The paste is applied to the upper and lower surfaces of the aramid mesh layer, and then cured by UV and dried to form a paste layer, thus obtaining a semi-finished product. S3. The surface of the semi-finished product with the paste layer is laminated with a PVC film layer, and then cooled and shaped to obtain the final product.

[0021] By adopting the above technical solution, the process is simple and involves fewer steps, which is conducive to the industrial-scale production of mesh materials. The produced mesh material is based on a low-elongation, high-strength aramid fabric. In the process, it is first photocured to form a highly flexible main body, and then dried and plasticized. This results in a mesh material that not only has high peel strength, but also has a thick paste layer that is not brittle.

[0022] In summary, this application has the following beneficial effects: 1. This application uses an aramid mesh layer as the substrate to provide a low elongation and high strength body. Furthermore, a self-made tackifying resin is added to the paste layer. The tackifying resin not only makes the paste layer adhere better to the surface of the aramid mesh layer, thereby improving the peel strength between the layers of the mesh material, but also makes it less brittle. This increases the peel strength of the mesh material to over 30.21 (25N / 5cm) and the number of folding cycles to over 432, resulting in high peel strength and long service life. 2. In this application, the amount of each component in the tackifying resin is controlled, and a trifunctional aliphatic polyurethane acrylate is specifically used to provide a flexible matrix, thereby improving the brittleness problem after the introduction of the tackifying resin. 3. The method of this application is simple and has fewer steps. First, it is photocured to form a highly flexible main body, and then dried and plasticized, so that the mesh material not only has high peel strength, but also has a thick paste layer that is not brittle. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the overall structure of a low-elongation, high-strength aramid-mesh PVC material according to Embodiment 1 of this application.

[0024] Reference numerals: 1. PVC film layer; 2. Paste layer; 3. Aramid mesh layer. Detailed Implementation

[0025] The present application will be further described in detail below with reference to the embodiments. Unless otherwise specified below, the raw materials are commercially available: trifunctional aliphatic polyurethane acrylate, sourced from Changxing Chemical Industry Co., Ltd., model ETERCURE6130B-80; Hexafunctional aliphatic polyurethane acrylate, sourced from Dongguan Jing Shang New Material Development Co., Ltd., model UV-6042; Bisphenol A diacrylate ester oxyacetylene oxide, sourced from Jining Tangyi Chemical Co., Ltd., model BPA3EODA; Chlorinated paraffin, sourced from Wuhan Xindongyi Chemical Co., Ltd., item number 14; Titanium dioxide, sourced from Hebei Laiyi New Material Technology Co., Ltd., model BA-100; Polyvinyl chloride resin, sourced from Wuhan Jiyesheng Chemical Co., Ltd., TYPE:SG5; Calcium-zinc composite stabilizer, sourced from Shanghai Kaiyin Chemical Co., Ltd., model BPR618R; Zinc borate, sourced from Shandong Xinghai Chemical Co., Ltd., model XH-101; Antioxidant 1076, brand name: BASF (Germany); UV-P, an ultraviolet absorber, was sourced from Jinan Lianghong Chemical Technology Co., Ltd. The aramid mesh layer, sourced from Jiangsu Tiandizao New Material Technology Co., Ltd., has a basis weight of 200 g / m². 2 The yarn count is 32s, and the thickness is 2mm; the PVC film layer is sourced from Qingzhou Luxing Industry and Trade Co., Ltd., and the thickness is 1mm.

[0026] Preparation Example 1 A tackifying resin is prepared by the following steps: Add 1.7 kg of photoinitiator 184 to 0.75 kg of acetone, stir and mix at 300 rpm for 10 min, then add 13 kg of trifunctional aliphatic polyurethane acrylate and 13 kg of monomer (bisphenol A diacrylate ethoxylate), stir and mix at 300 rpm for 20 min to obtain mixture A. Add 0.4 kg of resorcinol and 0.13 kg of catalyst (10 wt% sodium hydroxide aqueous solution) to 7 kg of water, stir and mix at 500 rpm for 20 min, add 0.52 kg of formaldehyde solution, and react at 25 °C for 6 h to obtain mixture B; Mixture A and mixture B at a weight ratio of 0.25:1 to obtain the final product.

[0027] Preparation Example 2 A tackifying resin is prepared by the following steps: Add 2 kg of photoinitiator 184 to 0.75 kg of acetone, stir and mix at 300 rpm for 10 min, then add 15 kg of trifunctional aliphatic polyurethane acrylate and 15 kg of monomer (ethoxylated 1,6-hexanediol diacrylate), stir and mix at 300 rpm for 20 min to obtain mixture A. Add 0.4 kg of resorcinol and 0.15 kg of catalyst (10 wt% sodium hydroxide aqueous solution) to 7 kg of water, stir and mix at 500 rpm for 20 min, add 0.55 kg of formaldehyde solution, and react at 25 °C for 6.5 h to obtain mixture B; Mixture A and mixture B at a weight ratio of 0.25:1 to obtain the final product.

[0028] Preparation Example 3 A tackifying resin is prepared by the following steps: Add 2.2 kg of photoinitiator 184 to 0.75 kg of acetone, stir and mix at 300 rpm for 10 min, then add 17 kg of trifunctional aliphatic polyurethane acrylate and 17 kg of monomer (ethoxylated 1,6-hexanediol diacrylate and ethoxylated pentaerythritol tetraacrylate in a weight ratio of 1:1), stir and mix at 300 rpm for 20 min to obtain mixture A; Add 0.4 kg of resorcinol and 0.17 kg of catalyst (10 wt% sodium hydroxide aqueous solution) to 7 kg of water, stir and mix at 500 rpm for 20 min, add 0.58 kg of formaldehyde solution, and react at 25 °C for 7 h to obtain mixture B; Mixture A and mixture B at a weight ratio of 0.25:1 to obtain the final product.

[0029] Preparation Examples 4-6 A thickening resin differs from that in Preparation Example 2 in that the amount of mixture A is different, as detailed below: Preparation Example 4: The weight ratio of mixture A to mixture B is 0.3:1.

[0030] Preparation Example 5: The weight ratio of mixture A to mixture B is 0.35:1.

[0031] Preparation Example 6: The weight ratio of mixture A to mixture B is 0.4:1.

[0032] Comparative Preparation Example 1 A tackifying resin is prepared by the following steps: Add 0.4 kg of resorcinol and 0.15 kg of catalyst (10 wt% sodium hydroxide aqueous solution) to 7 kg of water, stir and mix at 500 rpm for 20 min, add 0.55 kg of formaldehyde solution, and react at 25 °C for 6 h to obtain the product.

[0033] Comparative Preparation Example 2 A tackifying resin is prepared by the following steps: Add 2 kg of photoinitiator 184 to 0.75 kg of acetone, stir and mix at 300 rpm for 10 min, then add 15 kg of trifunctional aliphatic polyurethane acrylate and 15 kg of monomer (ethoxylated 1,6-hexanediol diacrylate), stir and mix at 300 rpm for 20 min to obtain the final product.

[0034] Comparative preparation example 3 A tackifying resin, which differs from Preparation Example 2 in that an equal amount of hexafunctional aliphatic polyurethane acrylate is used instead of trifunctional aliphatic polyurethane acrylate.

[0035] Examples 1-3, Comparative Examples 1-2 A low-elongation, high-strength aramid mesh PVC material includes an aramid mesh layer 3, both sides of the aramid mesh layer 3 are coated with a paste layer 2, and a PVC film layer 1 is attached to the surface of the paste layer 2 away from the aramid mesh layer 3. The specific preparation method of the wire mesh PVC material is as follows: S1. The plasticizer (chlorinated paraffin), tackifying resin (prepared from Preparation Example 1), filler (titanium dioxide) and crosslinking agent are stirred and mixed at 100 rpm for 10 min. Polyvinyl chloride resin, calcium zinc composite stabilizer, flame retardant (zinc borate), antioxidant 1076 and ultraviolet absorber UV-P are added and stirred and mixed at 120°C for 15 min to obtain a paste. S2. Apply the paste to the upper and lower surfaces of the aramid mesh layer 3 using a coating machine, with a coating amount of 7 g / cm². 3 Sequentially cured with UV (using a high-pressure mercury lamp with a linear power of 120W / cm, a wavelength of 350nm, and a radiation dose of 1000mJ / cm). 2 Dry at 200℃ for 1.5 minutes (20 min) to plasticize and form paste layer 2, thus obtaining the semi-finished product; S3. Using a laminating machine, the surface of the semi-finished product with paste layer 2 is laminated with PVC film at high temperature (lamination temperature 110℃, lamination speed 10m / min, lamination pressure 400N), and then cooled and shaped by a cooling roller to obtain the final product.

[0036] The components and their corresponding weights in the raw materials for preparing the paste are shown in Table 1.

[0037] Table 1. Components and their weights (kg) in Examples 1-3 and Comparative Examples 1-2 Examples 4-8, Comparative Examples 4-6 A low-elongation, high-strength aramid mesh PVC material differs from Example 2 in that the use of tackifying resin is as shown in Table 2, but the amount of tackifying resin in the paste remains unchanged.

[0038] Table 2. Usage of tackifying resins in Examples 4-8 and Comparative Examples 4-6 Preparation example of tackifying resin 2 3 4 5 6 Comparative Example 4 5 6 \ \ Comparative preparation examples of tackifying resins 1 2 3 \ \ Performance testing The performance of the mesh materials prepared in the examples and comparative examples was tested as follows, and the test results are recorded in Table 3.

[0039] Detection methods 1. Peel strength test: Tested according to DIN53357-82.

[0040] 2. Folding Resistance Test: Cut each PVC mesh material to a size of 4.5cm*7cm. Then, use a blade to make a cross-shaped scratch on the surface of the PVC mesh material, with the scratch just breaking through the PVC film on the upper surface, to obtain a sample. Then, according to standard GB / T 4689.9-1984, place the sample in the sample holder for folding resistance test. The upper clamp of the sample holder is located within the cross-shaped scratch on the sample, and the lower clamp is fixed to the aramid mesh layer of the sample for the test. Record the number of folds.

[0041] Table 3 Performance test results Example 1 30.21 432 Example 2 31.45 458 Example 3 30.73 440 Example 4 31.70 467 Example 5 31.33 451 Example 6 30.89 495 Example 7 30.11 517 Example 8 29.64 530 Comparative Example 1 16.67 235 Comparative Example 2 22.39 318 Comparative Example 3 31.50 460 Comparative Example 4 32.11 337 Comparative Example 5 15.20 296 Comparative Example 6 30.14 398 Referring to Table 3, in Examples 1-3, the use of the tackifying resin prepared in Preparation Example 1 resulted in a peel strength of over 30.21 (25 N / 5 cm) and a folding endurance of over 432 cycles for the prepared mesh materials. In contrast, Comparative Example 1, compared to Example 2, did not include the tackifying resin, leading to a significant decrease in the peel strength and folding endurance of the mesh material. Comparative Example 2, by reducing the amount of tackifying resin compared to Example 2, also showed a substantial decrease in peel strength and folding endurance. Combining Examples 2 and Comparative Examples 1-2, it can be seen that the tackifying resin improved the bonding strength between the layers of the mesh material and extended its service life.

[0042] The difference between Comparative Examples 4-6 and Example 2 is as follows: In the preparation of the tackifying resin, Comparative Example 4, without the addition of mixture A, resulted in a significant decrease in the number of folding cycles, possibly due to increased brittleness; Comparative Example 5, without the addition of mixture B, resulted in a significant decrease in peel strength, failing to achieve a superior tackifying effect; Comparative Example 6, using an equal amount of hexafunctional aliphatic polyurethane acrylate instead of trifunctional aliphatic polyurethane acrylate, also showed a decrease in the number of folding cycles, possibly due to brittleness issues as well.

[0043] The difference between Examples 4-5 and Example 2 is that the amounts of each component used in the preparation of the tackifying resin are different. Within the range of Examples 2 and 4-5, the performance of the mesh materials prepared is better.

[0044] The difference between Examples 6-8 and Example 4 is that, during the preparation of the tackifying resin, the amount of mixture A is increased. The peel strength of the resulting mesh material decreases slightly but still meets the overall requirements. Furthermore, the number of folding cycles increases significantly, resulting in superior performance of the resulting mesh material.

[0045] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A low-elongation, high-strength aramid mesh PVC material, comprising an aramid mesh layer (3), wherein a paste layer (2) is disposed on both sides of the aramid mesh layer (3), and a PVC film layer (1) is disposed on the surface of the paste layer (2) away from the aramid mesh layer (3); characterized in that: The raw materials for preparing the paste layer (2) include the following components in parts by weight: 90-100 parts of polyvinyl chloride resin, 3-5 parts of tackifying resin, 1-2 parts of crosslinking agent, 15-20 parts of filler, and 60-75 parts of plasticizer; The method for preparing the tackifying resin is as follows: Add a photoinitiator to acetone, disperse, then add trifunctional aliphatic polyurethane acrylate and monomer, stir and mix to obtain mixture A; add resorcinol and catalyst to water, disperse, add formaldehyde solution, disperse, react to obtain mixture B; mix mixture A and mixture B together to obtain the final product. The weight ratio of acetone, photoinitiator, trifunctional aliphatic polyurethane acrylate, and monomer is 0.75:1.7-2.2:13-17:13-17. The monomer is one or more of the following: ethoxytrimethylolpropane triacrylate, ethoxybisphenol A diacrylate, ethoxy1,6-hexanediol diacrylate, and ethoxypentaerythritol tetraacrylate; The weight ratio of the mixture A to the mixture B is 0.3-0.4:

1.

2. The low-elongation, high-strength aramid-reinforced PVC material according to claim 1, characterized in that: The weight ratio of resorcinol to formaldehyde solution is 4:5.2-5.

8.

3. The low-elongation, high-strength aramid-reinforced PVC material according to claim 1, characterized in that: The catalyst is an aqueous solution of sodium hydroxide.

4. The low-elongation, high-strength aramid-reinforced PVC material according to claim 1, characterized in that: The crosslinking agent is dicumyl peroxide or bis-tert-butylperoxide.

5. A method for preparing a low-elongation, high-strength aramid-reinforced PVC material according to any one of claims 1-4, characterized in that, Includes the following steps: S1. Mix the plasticizer, tackifying resin, filler, and crosslinking agent, add polyvinyl chloride resin, mix, and obtain a paste; S2. The paste is applied to the upper and lower surfaces of the aramid mesh layer (3), and then cured by UV and dried to form a paste layer (2) to obtain a semi-finished product. S3. Attach the PVC film layer (1) to the surface of the semi-finished product with the paste layer (2), cool and set, and you will get the product.

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