TPV of pa substrate, modified pa vacuum bag film and preparation method and application thereof

Abstract

The application belongs to the technical field of composite material processing and relates to a PA base material TPV, a modified PA vacuum bag film and a preparation method and application thereof. The preparation raw material of the PA base material TPV comprises EPDM-g-MAH, PA66 resin, an antioxidant and a vulcanizing agent. The PA base material TPV obtained by selecting and matching the raw materials is added to the PA vacuum bag film material, the use performance of the obtained modified PA vacuum bag film at low temperature is greatly improved, the modified PA vacuum bag film has good flexibility and sealing performance in a low-temperature and low-humidity environment, and the modified PA vacuum bag film also has excellent high-temperature resistance, and can meet the strength and temperature resistance requirements of a vacuum bag film in the composite material forming of the aerospace field.

Description

Technical Field

[0001] This invention belongs to the field of composite material processing technology, and relates to a TPV of PA substrate, a modified PA vacuum bag film, its preparation method and application. Background Technology

[0002] With the continuous advancement of aerospace technology, more and more composite materials are being used in the aerospace field, leading to a rapid increase in demand for high-temperature resistant vacuum bag films. This also places extremely high demands on the quality of these films. Currently, conventional high-temperature resistant vacuum bag films mostly use nylon (PA) materials. However, pure nylon films exhibit brittleness and hardness at low temperatures, making them prone to creases and wrinkles due to movement and contact during use, potentially causing air leakage and resulting in poor operability.

[0003] In existing technologies, thermoplastic elastomers are often used to toughen and improve nylon films. However, thermoplastic elastomers generally have low melting points, with most below 200°C. Even those exceeding 200°C have high hardness, thus failing to achieve a toughening effect. As a result, existing nylon films are unlikely to meet the toughening and improvement requirements of vacuum bag films that require high temperatures of 230°C.

[0004] Dynamically vulcanized thermoplastic elastomers (TPVs) are elastomers prepared by blending rubber and plastic under high shear stress and through dynamic vulcanization, forming a "sea-island" structure in which cross-linked rubber microparticles are dispersed in a continuous plastic phase. This results in an elastomer that combines the elasticity of rubber with the processing properties of plastic. Currently, the most widely used TPV in China is based on PP. For example, CN112778676A discloses a TPV material that is secondary-coated with a PA substrate, its preparation method, and its application. The TPV material provided by this invention includes the following components: PP resin, POE elastomer, EPDM rubber, petroleum resin, paraffin oil, vulcanizing agent, vulcanization accelerator, antioxidant, light stabilizer, lubricant, maleic anhydride, acid scavenger, and filler. This invention achieves a certain degree of grafting and cross-linking between maleic anhydride and PP resin, POE elastomer, EPDM rubber, petroleum resin, vulcanizing agent, and maleic anhydride through the synergistic effect of these components. This effectively improves the polarity of the TPV material and enhances its compatibility and adhesion with the PP substrate. However, TPV based on PP substrates cannot be applied to nylon films due to its poor temperature resistance and cross-compatibility with PA resins, while TPV based on PA substrates has not yet seen market application.

[0005] Therefore, there is an urgent need to develop a TPV based on PA and add it to the material of PA vacuum bag film, so that the resulting modified PA vacuum bag film has excellent high temperature resistance and good low temperature flexibility. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the present invention aims to provide a PA-based TPV, a modified PA vacuum bag film, its preparation method, and its application. The modified PA vacuum bag film exhibits excellent flexibility and sealing properties in low-temperature and low-humidity environments, while also possessing superior high-temperature resistance, thus meeting the strength and temperature resistance requirements of vacuum bag films for composite material molding in the aerospace field.

[0007] To achieve this objective, the present invention employs the following technical solution: In a first aspect, the present invention provides a TPV for a PA substrate. The raw materials for preparing the TPV of the PA substrate are as follows, in parts by weight: EPDM-g-MAH 10~50 parts by weight; 40-90 parts by weight of PA66 resin; Anti-aging agent: 2-10 parts by weight; Vulcanizing agent 1-5 parts by weight.

[0008] The raw materials for preparing the PA-based TPV provided by this invention include EPDM-g-MAH (maleic anhydride-grafted EPDM rubber) and PA66 resin, which gives it excellent compatibility with PA66 resin. The addition of the above-mentioned specific raw materials to the vacuum bag film material to make the PA-based TPV greatly improves the performance of the obtained modified PA vacuum bag film at low temperatures, giving it good flexibility and sealing performance in low temperature and low humidity environments, while also having excellent high temperature resistance, which can meet the strength and temperature resistance requirements of vacuum bag films for composite material molding in the aerospace field.

[0009] The amount of EPDM-g-MAH (maleic anhydride-grafted ethylene propylene diene monomer rubber) can be 10 parts by weight, 15 parts by weight, 20 parts by weight, 25 parts by weight, 30 parts by weight, 35 parts by weight, 40 parts by weight, 45 parts by weight, or 50 parts by weight, etc.

[0010] The amount of PA66 resin used can be 40 parts by weight, 45 parts by weight, 50 parts by weight, 55 parts by weight, 60 parts by weight, 65 parts by weight, 70 parts by weight, 75 parts by weight, 80 parts by weight, 85 parts by weight, or 90 parts by weight, etc.

[0011] The amount of the antioxidant can be 2 parts by weight, 3 parts by weight, 4 parts by weight, 5 parts by weight, 6 parts by weight, 7 parts by weight, 8 parts by weight, 9 parts by weight, or 10 parts by weight, etc.

[0012] The amount of the vulcanizing agent can be 1 part by weight, 1.5 parts by weight, 2 parts by weight, 2.5 parts by weight, 3 parts by weight, 3.5 parts by weight, 4 parts by weight, 4.5 parts by weight, or 5 parts by weight, etc.

[0013] Preferably, the grafting rate of the EPDM-g-MAH is 0.5~0.8%, such as 0.5%, 0.55%, 0.6%, 0.65%, 0.7%, 0.75% or 0.8%.

[0014] Preferably, the antioxidant includes any one or a combination of at least two of antioxidants 1010, 1098, or 1076.

[0015] Preferably, the vulcanizing agent includes any one or a combination of at least two of vulcanizing agents SP1045, SP1055, or 2402.

[0016] In a second aspect, the present invention provides a method for preparing a TPV based on a PA substrate as described in the first aspect, the method comprising: melt extruding and granulating EPDM-g-MAH, PA66 resin, antioxidant and vulcanizing agent to obtain the TPV based on the PA substrate.

[0017] Preferably, the melt extrusion granulation is carried out in a twin-screw extruder.

[0018] Preferably, the temperature of the melt extrusion granulation is 230~270℃, for example, 230℃, 240℃, 250℃, 260℃ or 270℃.

[0019] Preferably, the EPDM-g-MAH and PA66 resins are added from the main feed port of the twin-screw extruder, and the antioxidant and vulcanizing agent are added from the side feed port of the twin-screw extruder.

[0020] Thirdly, the present invention provides a modified PA vacuum bag film, wherein the material of the modified PA vacuum bag film comprises the following components in parts by weight: 40-80 parts by weight of PA66 resin; 20 to 60 parts by weight of TPV of the PA substrate as described in the first aspect; Heat stabilizer 2-5 parts by weight.

[0021] The modified PA vacuum bag film provided by this invention comprises PA66 resin, TPV of PA substrate as described in the first aspect, and heat stabilizer. By adding TPV of PA substrate made from specific raw materials to the material, this invention greatly improves the performance of the obtained vacuum bag film at low temperatures, giving it excellent flexibility and sealing performance in low temperature and low humidity environments, while also exhibiting excellent high temperature resistance, thus meeting the strength and temperature resistance requirements of vacuum bag films for composite material molding in the aerospace field.

[0022] The amount of PA66 resin used can be 40 parts by weight, 45 parts by weight, 50 parts by weight, 55 parts by weight, 60 parts by weight, 65 parts by weight, 70 parts by weight, 75 parts by weight, or 80 parts by weight, etc.

[0023] The amount of TPV used in the PA substrate can be 20 parts by weight, 25 parts by weight, 30 parts by weight, 35 parts by weight, 40 parts by weight, 45 parts by weight, 50 parts by weight, 55 parts by weight, or 60 parts by weight, etc.

[0024] The amount of heat stabilizer can be 2 parts by weight, 2.5 parts by weight, 3 parts by weight, 3.5 parts by weight, 4 parts by weight, 4.5 parts by weight, or 5 parts by weight, etc.

[0025] Preferably, the heat stabilizer comprises a copper salt heat stabilizer.

[0026] Preferably, the material of the modified PA vacuum bag film further includes 0.5 to 1 part by weight (e.g., 0.5 parts by weight, 0.55 parts by weight, 0.6 parts by weight, 0.65 parts by weight, 0.7 parts by weight, 0.75 parts by weight, 0.8 parts by weight, 0.85 parts by weight, 0.9 parts by weight, 0.95 parts by weight, or 1 part by weight, etc.) of color masterbatch.

[0027] Preferably, the thickness of the modified PA vacuum bag film is 50~80 μm, such as 50 μm, 55 μm, 60 μm, 65 μm, 70 μm, 75 μm or 80 μm.

[0028] Fourthly, the present invention provides a method for preparing a modified PA vacuum bag film as described in the third aspect, the method comprising: melting and plasticizing a PA substrate TPV, PA66 resin, heat stabilizer and optionally color masterbatch as described in the first aspect, and extruding, blowing and cooling to obtain the modified PA vacuum bag film.

[0029] Preferably, the melting and plasticizing temperature is 220~270℃, such as 230℃, 240℃, 250℃, 260℃ or 270℃.

[0030] Fifthly, the present invention provides an application of the modified PA vacuum bag film as described in the third aspect in composite material molding.

[0031] Compared with the prior art, the present invention has the following beneficial effects: (1) By selecting EPDM-g-MAH, PA66 resin, antioxidant and vulcanizing agent as raw materials for TPV of PA substrate, the TPV of PA substrate obtained has good compatibility with PA66 resin. Then, by adding the TPV of PA substrate made of the above specific raw materials to PA vacuum bag film material, the performance of the obtained modified PA vacuum bag film at low temperature is greatly improved, so that it has good flexibility and sealing in low temperature and low humidity environment, and also has excellent high temperature resistance, which can meet the strength and temperature resistance requirements of vacuum bag film for composite material molding in the aerospace field.

[0032] (2) Specifically, the modified PA vacuum bag film provided by the present invention has a tensile modulus of 530~800 MPa after being treated at -10℃ for 48 h, indicating that it has excellent low-temperature flexibility; the initial tensile strength is as high as 72~83 MPa, indicating that it has excellent mechanical properties; at the same time, the tensile strength after aging at 230℃ for 6 h is still as high as 61~66 MPa, and the elongation at break is 200~230%, indicating that it also has excellent high-temperature resistance. Detailed Implementation

[0033] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0034] The following is some information about the raw materials used in the examples and comparative examples: (1) PA66 resin: purchased from Ascend, grade 66R; (2) Heat stabilizer: Specifically, copper salt heat stabilizer, purchased from Brügmann, brand name H318; (3) Color masterbatch: purchased from Shenzhen Chenmei, brand name CMS-305; (4) EPDM-g-MAH: grafting rate of 0.7%, purchased from Ningbo Nengzhiguang, brand name N429A; (5) PP substrate TPV: purchased from Shandong Daon, brand name 21-73A.

[0035] Example 1 A TPV based on PA substrate, wherein the raw materials comprise the following components by weight: 80 parts by weight of PA66 resin; EPDM-g-MAH25 parts by weight; Anti-aging agent 10108 parts by weight; Vulcanizing agent SP1045 2.5 parts by weight; The preparation method of the PA-based TPV provided in Example 1 includes the following steps: EPDM-g-MAH and PA66 resin are mixed evenly and then added to the main feed hopper of a twin-screw extruder. Antioxidant 1010 and SP1045 are mixed evenly and then added to the side feed hopper of the twin-screw extruder. The feeding ratio of the main feed and the side feed is set, and melt extrusion granulation is performed. The temperature of the screw zone 1 is 230°C, the temperature of the screw zone 2 is 250°C, the temperature of the screw zone 3 is 270°C, the temperature of the screw zone 4 is 270°C, the temperature of the screw zone 5 is 270°C, and the temperature of the die head is 270°C. The main machine speed is 500 rpm. After vacuum drying at 80°C for 24 h, the product is sealed and stored to obtain the PA-based TPV.

[0036] Example 2 A TPV based on PA substrate, wherein the raw materials comprise the following components by weight: 45 parts by weight of PA66 resin; EPDM-g-MAH15 parts by weight; Anti-aging agent 10103 parts by weight; Vulcanizing agent SP1045 1.5 parts by weight; The preparation method of the PA substrate TPV provided in Example 2 is the same as that in Example 1.

[0037] Example 3 A TPV based on PA substrate, wherein the raw materials comprise the following components by weight: 85 parts by weight of PA66 resin; EPDM-g-MAH49 parts by weight; Anti-aging agent: 10109 parts by weight; Vulcanizing agent SP1045 4.5 parts by weight; The preparation method of the PA substrate TPV provided in Example 3 is the same as that in Example 1.

[0038] Example 4 A TPV based on PA substrate, wherein the raw materials comprise the following components by weight: 56 parts by weight of PA66 resin; EPDM-g-MAH30 parts by weight; Anti-aging agent 10108 parts by weight; Vulcanizing agent SP1045 3.5 parts by weight; The preparation method of the PA substrate TPV provided in Example 4 is the same as that in Example 1.

[0039] Comparative Example 1 A PA-based TPV differs from Example 1 only in that the amount of PA66 resin used is 95 parts by weight and the amount of EPDM-g-MAH used is 10 parts by weight. All other substances, amounts, and preparation methods are the same as in Example 1.

[0040] Comparative Example 2 A modified PA vacuum bag film differs from Example 1 only in that the amount of PA66 resin used is 35 parts by weight and the amount of EPDM-g-MAH used is 70 parts by weight. All other substances, amounts, and preparation methods are the same as in Example 1.

[0041] Application Example 1 A modified PA vacuum bag film, the material comprising the following components by weight: 65 parts by weight of PA66 resin; 50 parts by weight of TPV for PA substrate (Example 1); Heat stabilizer 4 parts by weight; 0.8 parts by weight of color masterbatch; The method for preparing the modified PA vacuum bag film provided in Application Example 1 includes the following steps: PA66 resin, PA substrate TPV, heat stabilizer and color masterbatch are mixed evenly and added to a hopper. The mixture is then melted and plasticized by a screw. The temperatures of the screw are as follows: Zone 1: 220°C; Zone 2: 235°C; Zone 3: 250°C; Zone 4: 265°C; Zone 5: 270°C; Zone 6: 270°C; Zone 7: 270°C; Zone 8: 270°C; Screen changer: 270°C; Sub-material rod: 270°C; Die: 270°C; Screw speed: 30 rpm; Traction speed: 20 m / m; The mixture is then extruded from a circular die, blown, cooled and shaped to obtain a modified PA vacuum bag film with a thickness of 60 μm.

[0042] Application Example 2 A modified PA vacuum bag film, the material comprising the following components by weight: 45 parts by weight of PA66 resin; 25 parts by weight of TPV for PA substrate (Example 2); 2.5 parts by weight of heat stabilizer; 0.6 parts by weight of color masterbatch; The method for preparing the modified PA vacuum bag film provided in Application Example 2 is the same as that in Application Example 1.

[0043] Application Example 3 A modified PA vacuum bag film comprises the following components in parts by weight: 79 parts by weight of PA66 resin; 59 parts by weight of TPV of PA substrate (Example 3); 4.5 parts by weight of heat stabilizer; 0.9 parts by weight of color masterbatch; The method for preparing the modified PA vacuum bag film provided in Application Example 3 is the same as that in Application Example 1.

[0044] Application Example 4 A modified PA vacuum bag film comprises the following components in parts by weight: 78 parts by weight of PA66 resin; 56 parts by weight of TPV of PA substrate (Example 4); 3.5 parts by weight of heat stabilizer; The method for preparing the modified PA vacuum bag film provided in Application Example 4 is the same as that in Application Example 1.

[0045] Comparative Application Example 1 A modified PA vacuum bag film, which differs from Application Example 1 only in that the TPV of the PA substrate provided in Comparative Example 1 is used instead of the TPV of the PA substrate provided in Example 1, while the other substances, amounts and preparation methods are the same as in Application Example 1.

[0046] Comparative Application Example 2 A modified PA vacuum bag film, which differs from Application Example 1 only in that the TPV of the PA substrate provided in Comparative Example 2 is used instead of the TPV of the PA substrate provided in Example 1, while the other substances, amounts and preparation methods are the same as in Application Example 1.

[0047] Comparative Application Example 3 A modified PA vacuum bag film differs from Application Example 1 only in that no PA-based TPV is added; all other substances, amounts, and preparation methods are the same as in Application Example 1.

[0048] Comparative Application Example 4 A modified PA vacuum bag film differs from Application Example 1 only in that a PP-based TPV is used instead of a PA-based TPV; all other materials, amounts, and preparation methods are the same as in Application Example 1.

[0049] Comparative Application Example 5 A modified PA vacuum bag film differs from Application Example 1 only in that the amount of PA66 resin used is 20 parts by weight and the amount of TPV of PA substrate is 95 parts by weight. All other substances, amounts and preparation methods are the same as in Application Example 1.

[0050] Comparative Application Example 6 A modified PA vacuum bag film differs from Application Example 1 only in that the amount of PA66 resin used is 100 parts by weight and the amount of TPV of PA substrate is 15 parts by weight. All other substances, amounts and preparation methods are the same as in Application Example 1.

[0051] Comparative Application Example 7 A modified PA vacuum bag film differs from Example 1 only in that no heat stabilizer is added, while the other substances, amounts, and preparation methods are the same as in Example 1.

[0052] Performance testing: (1) Low temperature flexibility: The vacuum bag film was conditioned in a constant temperature and humidity chamber at -10℃ for 48 h, and then the tensile modulus of the film was tested according to GB / T 1040.3.

[0053] (2) High temperature resistance: The vacuum bag film was placed in a 230℃ oven for 6 hours. After taking it out, the tensile strength and elongation at break of the film were tested according to GB / T1040.3.

[0054] (3) Tensile strength: Tested in accordance with standard GB / T 1040.3.

[0055] The modified PA vacuum bag films provided in test cases 1-4 and comparative application examples 1-7 were tested according to the above test methods. The test results are shown in Table 1. Table 1 According to the data in Table 1: The modified PA vacuum bag films provided in Application Examples 1-4 have a tensile modulus of 530-800 MPa after low-temperature treatment, indicating excellent low-temperature flexibility. They also have a tensile strength of 72-83 MPa, indicating excellent mechanical properties. Furthermore, their tensile strength after high-temperature aging is still as high as 61-66 MPa, and their elongation at break is 200-230%, indicating excellent high-temperature resistance.

[0056] Compared to Application Example 1, the vacuum bag films provided in Comparative Application Examples 1, 3, and 6 have higher tensile modulus after low-temperature treatment, indicating poor low-temperature flexibility. The vacuum bag films provided in Comparative Application Examples 2 and 7 have lower tensile strength and elongation at break after high-temperature aging treatment, indicating poor high-temperature resistance. In Comparative Application Example 4, the use of PP-based TPV instead of PA-based TPV resulted in the incompatibility between PA-based TPV and PA66 resin, preventing film formation. In Comparative Application Example 5, the excessive addition of PA-based TPV also resulted in poor film formation.

[0057] The above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A TPV based on a PA substrate, characterized in that, The raw materials for preparing the TPV of the PA substrate are as follows, in parts by weight: EPDM-g-MAH 10~50 parts by weight; 40-90 parts by weight of PA66 resin; Anti-aging agent 2-10 parts by weight; Vulcanizing agent 1-5 parts by weight.

2. The TPV of the PA substrate according to claim 1, characterized in that, The grafting rate of the EPDM-g-MAH is 0.5~0.8%.

3. The TPV of the PA substrate according to claim 1 or 2, characterized in that, The antioxidant includes any one or a combination of at least two of antioxidants 1010, 1098, or 1076; Preferably, the vulcanizing agent includes any one or a combination of at least two of vulcanizing agents SP1045, SP1055, or 2402.

4. A method for preparing a TPV of a PA substrate as described in any one of claims 1 to 3, characterized in that, The preparation method includes: melt extruding and granulating EPDM-g-MAH, PA66 resin, antioxidant and vulcanizing agent to obtain the TPV of the PA substrate.

5. The preparation method according to claim 4, characterized in that, The melt extrusion granulation is carried out in a twin-screw extruder; Preferably, the temperature of the melt extrusion granulation is 230~270℃; Preferably, the EPDM-g-MAH and PA66 resins are added from the main feed port of the twin-screw extruder, and the antioxidant and vulcanizing agent are added from the side feed port of the twin-screw extruder.

6. A modified PA vacuum bag film, characterized in that, The modified PA vacuum bag film comprises the following components by weight: 40-80 parts by weight of PA66 resin; 20-60 parts by weight of TPV of the PA substrate as described in any one of claims 1 to 3; Heat stabilizer 2-5 parts by weight.

7. The modified PA vacuum bag film according to any one of claims 1 to 6, characterized in that, The heat stabilizer includes copper salt heat stabilizers; Preferably, the material of the modified PA vacuum bag film further includes 0.5 to 1 part by weight of color masterbatch; Preferably, the thickness of the modified PA vacuum bag film is 50~80 μm.

8. A method for preparing a modified PA vacuum bag film as described in claim 6 or 7, characterized in that, The preparation method includes: melting and plasticizing the PA substrate as described in any one of claims 1 to 3, the TPV, PA66 resin, heat stabilizer and optionally color masterbatch, and then extruding, blowing and cooling to obtain the modified PA vacuum bag film.

9. The preparation method according to claim 8, characterized in that, The melting and plasticizing temperature is 220~270℃.

10. The application of a modified PA vacuum bag film as described in claim 6 or 7 in composite material molding.

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