A composite material of low-warpage PPO and PA66 and its preparation method

Abstract

The present invention relates to the technical field of polymer alloy materials, and particularly relates to a composite material of low-warpage PPO and PA66 and a preparation method thereof. The composite material of low-warpage PPO and PA66 uses polyphenylene ether resin and PA66 as the main materials, and adds polystyrene, compatibilizer, toughening agent, carbon nanotubes, chain extender and other auxiliaries to act synergistically. On the basis of ensuring the antistatic effect of the overall material, the electrophoretic painting effect of the overall composite material is effectively improved, the surface performance of the material is improved, and the low-temperature toughness and warpage deformation resistance of the material are enhanced; among them, the combined action of the special chain extender and polystyrene can maintain the overall physical properties while being more beneficial to the electrophoretic painting effect. In addition, the combination of PPO and PA66 can better maintain the balance during electrophoresis at 170 °C to avoid warpage deformation; the special toughening agent added can enable the material to still maintain good toughness at low temperatures.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer alloy materials, and particularly relates to a composite material of low-warpage PPO and PA66 and a preparation method thereof. Background Art

[0002] The small fuel filler door of an automobile refers to the fuel filler door or fuel tank cap. It is the inlet part of the fuel tank of the automobile, usually located at the rear of the vehicle body, and is closed, and is only connected to the fuel tank through a small door that can be opened. The function of the fuel filler door is to protect the fuel tank, prevent oil leakage and external sundries from entering the fuel tank.

[0003] The traditional small fuel filler door of an automobile uses stainless steel as the base material, and presents the gloss and color of the finished automobile appearance after electrophoresis and painting treatment. However, stainless steel has a large density and a heavy weight, and is gradually being replaced by raw materials such as PPO. However, after making the small fuel filler door of an automobile with raw materials such as PPO, the electroplating effect is poor, there are pockmarks on the surface of the small fuel filler door of the automobile, and the defect of the pockmarks will be further amplified under the condition of an electrophoresis baking temperature of 170 °C, the antistatic effect is insufficient, and more importantly, the low-temperature resistance is not good, and there are problems such as serious warping and deformation resulting in loose assembly. Summary of the Invention

[0004] In order to overcome the disadvantages and deficiencies existing in the prior art, the purpose of the present invention is to provide a composite material of low-warpage PPO and PA66.

[0005] Another purpose of the present invention is to provide a preparation method of a composite material of low-warpage PPO and PA66. The preparation method is simple in operation, convenient to control, high in production efficiency, low in production cost, and can be used for large-scale production.

[0006] The purpose of the present invention is achieved by the following technical solutions: A composite material of low-warpage PPO and PA66, comprising the following raw materials in parts by weight:

[0007]

[0008]

[0009] The composite material of low-warpage PPO and PA66 of the present invention uses polyphenylene ether resin and PA66 as the main materials, and adds polystyrene, compatibilizer, toughening agent, carbon nanotubes, chain extender and other additives to act synergistically. On the basis of ensuring the antistatic effect of the overall material, it effectively improves the electrophoretic painting effect of the overall composite material, improves the surface performance of the material, and improves the low-temperature toughness and warpage deformation resistance of the material; among them, the special chain extender and polystyrene are used together, which can maintain the overall physical properties while being more beneficial to the electrophoretic painting effect. Coupled with the cooperation of PPO and PA66, it can better maintain the balance during electrophoresis at 170 °C to avoid warpage and deformation; the special toughening agent added can make the material still maintain good toughness at low temperature.

[0010] Preferably, the melt index of the polyphenylene ether resin at 316 °C under a load of 5 kg is 300-500 g / 10 min; the relative viscosity of the PA66 is 2.5-3.0.

[0011] Adopting the above technical solution can ensure the overall low-warpage performance, and the combination of the two is beneficial to increasing the toughness of the material.

[0012] Preferably, the polystyrene is high-impact polystyrene HIPS, and the butadiene content is 20-28 wt%; the compatibilizer is PPO-g-MAH.

[0013] Adopting the above technical solution and acting together with the compatibilizer is beneficial to improving the processing dispersibility of the material, improving the overall dispersion effect of the material, avoiding pitting on the material surface due to dispersion problems, and the higher butadiene content of high-impact polystyrene HIPS is beneficial to providing more electrophoretic painting "anchor points", improving the electrophoretic effect, and avoiding the appearance of pitting caused by the aggregation of secondary crystallization of the material after electrophoretic baking.

[0014] Preferably, the toughening agent is SEBS-g-MAH.

[0015] Adopting the above technical solution is beneficial to the low-temperature toughness of the overall material, showing better impact resistance, weather resistance, chemical corrosion resistance and processing performance. At the same time, due to its good adhesion performance, it can effectively solve problems such as delamination and cracking of composite material products, and further improve the electrophoretic effect.

[0016] Preferably, the average length of the carbon nanotubes is 5-8 mm.

[0017] Adopting the above technical solution is beneficial to meeting the antistatic requirements of the material under low dosage, avoiding excessive use of antistatic agents from affecting mechanical properties, and avoiding pitting on the surface of material products due to material dispersion problems.

[0018] Preferably, the chain extender is an alternating copolymer of ethylene and maleic anhydride with a ratio of 1:1, and the maleic anhydride content is greater than 78 wt%.

[0019] Adopting the above technical solution can provide a better chain extension effect, maintain the original mechanical properties, and provide more polar groups for subsequent electroplating, further improving the electrophoretic painting effect.

[0020] Preferably, the other additives are at least one of color powder, color masterbatch, and lubricant.

[0021] Another object of the present invention is achieved by the following technical solution: The preparation method of the above-mentioned low-warpage composite material of PPO and PA66 includes the following steps:

[0022] (S1) Weigh polyphenylene ether resin, PA66, polystyrene, compatibilizer, toughening agent, carbon nanotubes, chain extender, and other additives by weight parts and set aside.

[0023] (S2) Premix the polyphenylene ether resin, PA66, polystyrene, compatibilizer, toughening agent, carbon nanotubes, chain extender, and other additives in a high-speed mixer for 1 - 3 minutes to obtain a premix.

[0024] (S3) Extrude and pelletize the premix through a twin-screw extruder to obtain coarse pellets.

[0025] (S4) Bake the coarse pellets at a temperature of 80 - 110 °C for 5 - 7 hours, and then extrude and pelletize them through a twin-screw extruder to obtain the low-warpage composite material of PPO and PA66.

[0026] Adopting the above technical solution, the effect of secondary extrusion is significantly better than that of primary extrusion. The main reason is that the dispersion in primary extrusion is insufficient to achieve a good dispersion effect. Due to the extremely poor fluidity of PPO, it is also difficult for carbon nanotubes to be evenly dispersed in the material. Although the addition of polystyrene and compatibilizer is beneficial to improving the fluidity of the material, it still cannot achieve a very good effect. Therefore, secondary extrusion can not only improve the performance but also achieve better dispersion of carbon nanotubes to achieve the antistatic effect. In step (S4), baking at a temperature of 80 - 110 °C for 5 - 7 hours is beneficial to drying the moisture remaining after pelletization in step (S3) and reducing the decomposition of the material.

[0027] Preferably, the processing temperatures of each section of the twin-screw extruder starting from the feeding section are as follows: 190 - 210 °C, 270 - 290 °C, 270 - 290 °C, 270 - 290 °C, 270 - 290 °C, 270 - 290 °C, 250 - 270 °C, 260 - 280 °C, 270 - 290 °C, 270 - 290 °C. The head temperature is 280 °C, the screw speed is 350 - 420 r / min, the screw length-diameter ratio is 40 - 46:1. If the screw is too long, it is prone to thermal decomposition; if the screw is too short, it is not conducive to material dispersion.

[0028] The beneficial effects of the present invention are as follows: The composite material of low-warpage PPO and PA66 of the present invention uses polyphenylene ether resin and PA66 as the main materials, and adds polystyrene, compatibilizer, toughening agent, carbon nanotubes, chain extender and other auxiliaries to act synergistically. On the basis of ensuring the antistatic effect of the overall material, it effectively improves the electrophoretic painting effect of the overall composite material, improves the surface performance of the material, and enhances the low-temperature toughness and warpage resistance of the material; among them, the combined action of the special chain extender and polystyrene can maintain the overall physical properties while being more conducive to the electrophoretic painting effect. Coupled with the cooperation of PPO and PA66, it can better maintain the balance during electrophoresis at 170 °C to avoid warpage deformation; the special toughening agent added can enable the material to still maintain good toughness at low temperatures.

[0029] The preparation method of the present invention is simple to operate, convenient to control, has high production efficiency and low production cost, and can be used for large-scale production. Description of the Drawings

[0030] Figure 1 is a schematic diagram of the sample prepared in Example 1 of the present invention after electrophoretic treatment;

[0031] Figure 2 is a schematic diagram of the sample prepared in Comparative Example 1 of the present invention after electrophoretic treatment;

[0032] Figure 3 is Figure 2 a schematic diagram after being magnified 100 times. Detailed Embodiments

[0033] For the convenience of understanding by those skilled in the art, the present invention will be further described below in conjunction with examples and drawings. The content mentioned in the embodiments is not a limitation to the present invention.

[0034] Example 1

[0035] A composite material of low-warpage PPO and PA66, comprising the following raw materials in parts by weight:

[0036]

[0037] The polyphenylene ether resin has a melt index of 400 g / 10 min at 316° C. and a load of 5 kg.

[0038] The relative viscosity of the PA66 is 2.8.

[0039] The polystyrene is high impact polystyrene HIPS, and the butadiene content is 24 wt %.

[0040] The compatibilizer is PPO-g-MAH; the toughening agent is SEBS-g-MAH.

[0041] The average length of the carbon nanotubes is 6 mm.

[0042] The chain extender is a 1:1 alternating copolymer of ethylene and maleic anhydride, and the content of maleic anhydride is 80 wt%.

[0043] The other auxiliary agent is toner.

[0044] The method for preparing the composite material of low warpage PPO and PA66 comprises the following steps:

[0045] (S1), taking polyphenylene ether resin, PA66, polystyrene, compatibilizer, toughening agent, carbon nanotubes, chain extender and other additives according to weight parts for later use;

[0046] (S2), premixing polyphenylene ether resin, PA66, polystyrene, compatibilizer, toughening agent, carbon nanotubes, chain extender and other additives in a high-speed mixer for 2 minutes to obtain a premix;

[0047] (S3), extruding the premix through a twin-screw extruder to obtain coarse granules;

[0048] (S4), baking the coarse granules at 100°C for 6 hours, and then extruding and granulating them through a twin-screw extruder to obtain a composite material of low warpage PPO and PA66.

[0049] The processing temperatures of the twin-screw extruder in each section starting from the feeding section are: 200°C, 280°C, 280°C, 280°C, 280°C, 280°C, 260°C, 270°C, 280°C, 280°C, the head temperature is 280°C, the screw speed is 400r / min, and the screw aspect ratio is 44:1.

[0050] Example 2

[0051] A low-warpage PPO and PA66 composite material comprises the following raw materials in parts by weight:

[0052]

[0053] The melt index of the polyphenylene ether resin at 316 °C under a load of 5 kg is 300 g / 10 min.

[0054] The relative viscosity of the PA66 is 2.5.

[0055] The polystyrene is high impact polystyrene (HIPS), and the butadiene content is 20 wt%.

[0056] The compatibilizer is PPO-g-MAH; the toughening agent is SEBS-g-MAH.

[0057] The average length of the carbon nanotubes is 5 mm.

[0058] The chain extender is an alternating copolymer of ethylene and maleic anhydride with a 1:1 ratio, and the maleic anhydride content is 80 wt%.

[0059] The other auxiliary agent is color powder.

[0060] The preparation method of the above-mentioned low warpage PPO and PA66 composite material includes the following steps:

[0061] (S1) Weigh and take polyphenylene ether resin, PA66, polystyrene, compatibilizer, toughening agent, carbon nanotubes, chain extender and other auxiliary agents by weight parts for standby;

[0062] (S2) Premix the polyphenylene ether resin, PA66, polystyrene, compatibilizer, toughening agent, carbon nanotubes, chain extender and other auxiliary agents in a high-speed mixer for 1 min to obtain a premix;

[0063] (S3) Extrude and pelletize the premix through a twin-screw extruder to obtain coarse pellets;

[0064] (S4) Bake the coarse pellets at 100 °C for 6 h, and then extrude and pelletize them through a twin-screw extruder to obtain the low warpage PPO and PA66 composite material.

[0065] The processing temperatures of each section of the twin-screw extruder starting from the feeding section are: 200 °C, 280 °C, 280 °C, 280 °C, 280 °C, 280 °C, 260 °C, 270 °C, 280 °C, 280 °C, the head temperature is 280 °C, the screw speed is 400 r / min, and the screw length-diameter ratio is 44:1.

[0066] Example 3

[0067] A low warpage PPO and PA66 composite material, comprising the following raw materials by weight parts:

[0068]

[0069] The melt index of the polyphenylene ether resin at 316 °C under a load of 5 kg is 500 g / 10 min.

[0070] The relative viscosity of the PA66 is 3.0.

[0071] The polystyrene is high-impact polystyrene (HIPS), and the butadiene content is 28 wt%.

[0072] The compatibilizer is PPO-g-MAH; the toughening agent is SEBS-g-MAH.

[0073] The average length of the carbon nanotubes is 6 mm.

[0074] The chain extender is an alternating copolymer of ethylene and maleic anhydride with a 1:1 ratio, and the maleic anhydride content is 80 wt%.

[0075] The other auxiliary agent is color powder.

[0076] The preparation method of the above low-warpage PPO and PA66 composite material includes the following steps:

[0077] (S1) Weigh the polyphenylene ether resin, PA66, polystyrene, compatibilizer, toughening agent, carbon nanotubes, chain extender and other auxiliary agents by weight parts for standby;

[0078] (S2) Premix the polyphenylene ether resin, PA66, polystyrene, compatibilizer, toughening agent, carbon nanotubes, chain extender and other auxiliary agents in a high-speed mixer for 3 min to obtain a premix;

[0079] (S3) Extrude and pelletize the premix through a twin-screw extruder to obtain coarse pellets;

[0080] (S4) Bake the coarse pellets at 100 °C for 6 h, and then extrude and pelletize them through a twin-screw extruder to obtain the low-warpage PPO and PA66 composite material.

[0081] The processing temperatures of each section of the twin-screw extruder starting from the feeding section are: 200 °C, 280 °C, 280 °C, 280 °C, 280 °C, 280 °C, 260 °C, 270 °C, 280 °C, 280 °C, the head temperature is 280 °C, the screw speed is 400 r / min, and the screw length-diameter ratio is 44:1.

[0082] Comparative Example 1

[0083] The difference between this comparative example and Example 1 is:

[0084] A low-warpage PPO and PA66 composite material, comprising the following raw materials by weight parts:

[0085]

[0086] The melt index of the polyphenylene ether resin at 316 °C under a load of 5 kg is 400 g / 10 min.

[0087] The relative viscosity of the PA66 is 2.8.

[0088] The polystyrene is high impact polystyrene (HIPS), and the butadiene content is 24 wt%.

[0089] The compatibilizer is PPO-g-MAH; the toughening agent is SEBS-g-MAH.

[0090] The average length of the carbon nanotubes is 6 mm.

[0091] The chain extender is an alternating copolymer of ethylene and maleic anhydride with a 1:1 ratio, and the maleic anhydride content is 80 wt%.

[0092] The other additives are color powder.

[0093] The preparation method of the above-mentioned low warpage PPO and PA66 composite material comprises the following steps:

[0094] (S1) Weigh and take the polyphenylene ether resin, PA66, polystyrene, compatibilizer, toughening agent, carbon nanotubes, chain extender and other additives by weight parts for standby;

[0095] (S2) Premix the polyphenylene ether resin, PA66, polystyrene, compatibilizer, toughening agent, carbon nanotubes, chain extender and other additives in a high-speed mixer for 2 min to obtain a premix;

[0096] (S3) Extrude and pelletize the premix through a twin-screw extruder to obtain the low warpage PPO and PA66 composite material.

[0097] The processing temperatures of each section of the twin-screw extruder starting from the feeding section are respectively: 200 °C, 280 °C, 280 °C, 280 °C, 280 °C, 280 °C, 260 °C, 270 °C, 280 °C, 280 °C. The temperature of the die head is 280 °C, the screw speed is 400 r / min, and the screw length-diameter ratio is 44:1.

[0098] Comparative Example 2

[0099] The difference between this comparative example and Example 1 is that:

[0100] The carbon nanotubes are replaced with conductive carbon black with an average particle size of 40 nm.

[0101] Comparative Example 3

[0102] The difference between this comparative example and Example 1 is that:

[0103] The chain extender is N,N-bis(2-hydroxypropyl)aniline.

[0104] Performance test:

[0105] I. Take the composite materials of Example 1 and Comparative Example 1. After the samples prepared under the same conditions are electrophoretically treated, as Figure 1 and Figure 2 shown, after magnifying by 100 times with an electron microscope, as Figure 2 shown, by comparing the two, it can be seen that the surface of the sample of Example 1 is smooth, while the surface of the sample of Comparative Example 1 is rough and has pockmarks. Figure 3 shown, by comparing the two, it can be seen that the surface of the sample of Example 1 is smooth, while the surface of the sample of Comparative Example 1 is rough and has pockmarks.

[0106] II. Take the composite materials of Examples 1-3 and Comparative Examples 1-3, and test their impact strength, tensile strength, flexural strength, surface resistivity, electrophoretic painting appearance and molding shrinkage rate. The test results are shown in Table 1 below:

[0107]

[0108] As can be seen from Table 1 above, for the composite material of low-warpage PPO and PA66 of the present invention, with polyphenylene ether resin and PA66 as the main materials, adding polystyrene, compatibilizer, toughening agent, carbon nanotubes, chain extender and other additives to act synergistically, on the basis of ensuring the antistatic effect of the overall material, it effectively improves the electrophoretic painting effect of the overall composite material, improves the surface performance of the material, and improves the low-temperature toughness and warpage resistance of the material; among them, the combined action of the special chain extender and polystyrene can maintain the overall physical properties while being more beneficial to the electrophoretic painting effect. Coupled with the cooperation of PPO and PA66, it can preferably maintain the electrophoretic state at 170 °C to avoid warpage deformation and can maintain good balance; the special toughening agent added can enable the material to still maintain good toughness at low temperature. Among them, the longitudinal and transverse shrinkage rates of Comparative Example 1 and Comparative Example 3 differ greatly, and the warpage resistance is weaker.

[0109] The above embodiments are the preferred implementation schemes of the present invention. In addition, the present invention can also be implemented in other ways. Any obvious replacement without departing from the concept of the present invention is within the protection scope of the present invention.

Claims

1. A composite material of low - warpage PPO and PA66, characterized in that, It comprises raw materials in the following parts by weight: Polyphenylene ether resin: 10 - 40 parts PA66: 10 - 40 parts Polystyrene: 5 - 8 parts Compatibilizer: 5 - 10 parts Toughening agent: 4 - 10 parts Carbon nanotubes: 0.5 - 4 parts Chain extender: 0.1 - 0.5 part Other additives: 0.5 - 1.0 part; The average length of the carbon nanotubes is 5 - 8 mm; The chain extender is an alternating copolymer of ethylene and maleic anhydride with a 1:1 ratio, and the maleic anhydride content is greater than 78 wt%; The melt index of the polyphenylene ether resin at 316°C under a 5 kg load is 300 - 500 g / 10 min; The relative viscosity of the PA66 is 2.5 - 3.0; The polystyrene is high impact polystyrene (HIPS), and the butadiene content is 20 - 28 wt%; The compatibilizer is PPO-g-MAH; the toughening agent is SEBS-g-MAH.

2. The composite material of low-warpage PPO and PA66 according to claim 1, wherein: The other additives are at least one of color powder, color masterbatch and lubricant.

3. A method for preparing a composite material of low-warpage PPO and PA66 as described in any one of claims 1-2, characterized in that, It comprises the following steps: (S1) Weigh the polyphenylene ether resin, PA66, polystyrene, compatibilizer, toughening agent, carbon nanotubes, chain extender and other additives according to the parts by weight for standby; (S2) Premix the polyphenylene ether resin, PA66, polystyrene, compatibilizer, toughening agent, carbon nanotubes, chain extender and other additives in a high-speed mixer for 1 - 3 min to obtain a premix; (S3) Extrude and pelletize the premix through a twin-screw extruder to obtain coarse pellets; (S4) Bake the coarse pellets at a temperature of 80 - 110°C for 5 - 7 h, and then extrude and pelletize them through a twin-screw extruder to obtain a composite material of low warpage PPO and PA66.

4. The preparation method of a low-warpage composite material of PPO and PA66 according to claim 3, characterized in that: The processing temperatures of each section of the twin-screw extruder starting from the feeding section are respectively: 190 - 210°C, 270 - 290°C, 270 - 290°C, 270 - 290°C, 270 - 290°C, 270 - 290°C, 250 - 270°C, 260 - 280°C, 270 - 290°C, 270 - 290°C. The head temperature is 280°C, the screw speed is 350 - 420 r / min, and the screw length-diameter ratio is 40 - 46:1.

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