Foaming material composition and preparation process thereof

Abstract

The invention relates to the technical field of high polymer materials, and particularly discloses a foaming material composition and a preparation process thereof. The foaming material composition is prepared from the following components in parts by mass: 60 to 80 parts of a base material, 10 to 20 parts of metallocene polyethylene, 15 to 25 parts of modified polyamide, 6 to 10 parts of modified organic silicon resin micro powder, 4 to 8 parts of a compatilizer, 1.5 to 3 parts of a foaming agent, 0.5 to 1.2 parts of a foaming aid, 0.5 to 1.5 parts of erucyl amide and 0.3 to 0.5 part of an antioxidant, the base material comprises polypropylene and high-impact polypropylene. The foaming material composition prepared in the invention has good mechanical properties at normal and low temperatures.

Description

Technical Field

[0001] The present application relates to the technical field of polymer materials, and more specifically, to a foaming material composition and a preparation process thereof. Background Art

[0002] At present, there are many kinds of foaming materials on the market, the main varieties are polyurethane foaming materials, polystyrene foaming materials, polyethylene foaming materials, but they have disadvantages such as poor high temperature resistance, not easy to degrade, and difficult to recycle. Polypropylene foaming material has the advantages of good thermal stability, excellent degradability and environmental protection, making it a good substitute for polystyrene and other foaming materials, and a new generation of green foaming material.

[0003] Polypropylene foam material has the characteristics of low density. Compared with traditional automotive materials such as steel and plastic, it can significantly reduce the weight of automotive parts. According to statistics, the use of polypropylene foam materials to replace traditional materials can achieve a 30% to 50% weight reduction on some parts. Polypropylene foam materials also have excellent elasticity and energy absorption characteristics. They can deform quickly at the moment of collision and absorb a large amount of collision energy, thereby reducing the impact on passengers in the car. The buffer structure made of polypropylene foam materials in the bumper, anti-collision beam and other parts of the car can effectively reduce the damage to the vehicle and passengers in the event of a collision. In some collision tests, cars using EPP buffer structures have shown better safety performance. In addition, EPP foam materials also have good heat resistance, environmental sustainability and design flexibility. These properties have enabled polypropylene materials to be used in many fields such as automotive interiors, exteriors, safety systems, power systems, etc., bringing new opportunities and challenges to the development of the automotive industry.

[0004] However, polypropylene foam materials have poor low-temperature brittleness and impact resistance, especially in the fields of automotive interiors and bumpers. In high-altitude and cold areas, the brittleness of the material increases, the impact resistance is greatly reduced, and the components are easily broken under impact, affecting the safety and durability of the vehicle.

[0005] The patent application document with publication number CN116178820A discloses a low-temperature resistant polypropylene material. The raw materials for its preparation include, by weight: 35-55 parts of polypropylene, 40-60 parts of polyethylene, and 1-10 parts of polyolefin elastomer; the isotactic index of the polypropylene is 96.6%, and the ash content is 90ppm; the polyethylene is high-density polyethylene; the tensile yield strength of the high-density polyethylene is 22-30MPa, the flexural modulus is 1000-1500MPa, and the elongation at break is 350%-550%; the melt index of the polyolefin elastomer at 190°C is 0.5-2g / 10min, the ethylene content is 10-20wt%, and the tear strength is 30-38kN / m; the weight ratio of the polypropylene, polyethylene and polyolefin elastomer is (7-12):(8-13):1.

[0006] The patent application only uses dry mixing of polypropylene, polyethylene and polyolefin elastomer, granulation through a twin-screw extruder and drying. It is difficult to achieve a good mixing of the three materials at the molecular or microstructural level. During the stretching process, stress concentration at the interface will make the material more prone to cracks and expansion, reducing the tensile strength; during impact, the interface is also more likely to be damaged, making the material's impact resistance worse. Summary of the invention

[0007] In order to make the foaming material have good mechanical properties at normal low temperatures, the present application provides a foaming material composition and a preparation process thereof.

[0008] The present application provides a foaming material composition, comprising 60-80 parts by mass of a base material, 10-20 parts by mass of metallocene polyethylene, 15-25 parts by mass of modified polyamide, 6-10 parts by mass of modified silicone resin micropowder, 4-8 parts by mass of a compatibilizer, 1.5-3 parts by mass of a foaming agent, 0.5-1.2 parts by mass of a foaming aid, 0.5-1.5 parts by mass of erucamide and 0.3-0.5 parts by mass of an antioxidant; The matrix material includes polypropylene and high impact polypropylene.

[0009] Preferably, the foaming agent is azodicarbonamide.

[0010] Preferably, the foaming aid comprises zinc oxide and zinc stearate, and the mass ratio of zinc oxide to zinc stearate is 1:(8~14).

[0011] By adopting the above technical solution: metallocene polyethylene can regulate the crystallization behavior of the base material (polypropylene, high-impact polypropylene) to a certain extent, promote the more uniform crystallinity of the base material, and optimize the crystallization distribution. The modified polyamide can significantly reduce the activation energy of crystallization, making the crystallization process easier to occur. More importantly, the modified polyamide can also guide the crystallization to be more evenly distributed in the foaming material composition, thereby avoiding excessive or insufficient local crystallization, which helps to improve the overall mechanical properties and stability of the foaming material composition. In addition, the modified polyamide can also strengthen the connection between the various parts. This tight connection structure can not only enhance the overall strength of the foaming material composition, but also prevent the bubbles from bursting due to the loose structure of the foaming material during the growth and stabilization process. Especially in low temperature environments, this connection can more effectively transmit stress and improve the impact resistance of the foaming material composition.

[0012] The compatibilizer plays the role of "bridge" and "lubricant" in the entire foam material composition system. On the one hand, it helps to achieve uniform distribution of various components such as modified silicone resin powder, compatibilizer, foaming agent, foaming aid and erucamide in the matrix material; on the other hand, it can also effectively improve the interfacial bonding force between the components and strengthen the connection between the materials, so that the foam material composition can maintain good integrity and mechanical properties at room temperature and low temperature. At the same time, the evenly distributed modified silicone resin powder, foaming agent, foaming aid and erucamide cooperate and work synergistically with each other, so that the foam material composition has more excellent comprehensive performance. It not only has good mechanical properties and high stability, but also has the characteristics of light weight, heat insulation, sound absorption, etc., so it can be suitable for more different application scenarios.

[0013] Preferably, the preparation method of the modified polyamide comprises the following steps: Polyamide and thermoplastic polyester elastomer are added into a high-speed mixer in a mass ratio of (70-80): (20-30), mixed for 10-15 minutes, then maleic anhydride grafted polypropylene and modified silicone resin powder are added, mixed for 15-20 minutes, and then molecular sieves and antioxidants are added, mixed for 8-12 minutes to obtain a modified extrusion material; the modified extrusion material is transported to a twin-screw extruder for extrusion, granulation, and cooling to obtain a modified polyamide; the amount of the maleic anhydride grafted polypropylene is 3%-5% of the total mass of the polyamide and the thermoplastic polyester elastomer, and the amount of the modified silicone resin powder is 5%-10% of the total mass of the polyamide and the thermoplastic polyester elastomer.

[0014] Preferably, the molecular sieve is 3A molecular sieve, and the usage of the 3A molecular sieve is 2.5% to 3.5% of the total mass of the polyamide and the thermoplastic polyester elastomer.

[0015] Preferably, the antioxidant is used in an amount of 0.5% to 1% of the total mass of the polyamide and the thermoplastic polyester elastomer.

[0016] Preferably, the temperature of each section of the twin-screw extruder is set as follows: zone 1 190-200°C, zone 2 200-230°C, zone 3 220-230°C, zone 4 230-240°C, die head temperature 240-250°C, screw speed 100-200r / min.

[0017] Preferably, the particle size of the modified polyamide is 3-5 mm.

[0018] By adopting the above technical solution: under the action of maleic anhydride grafted polypropylene, the thermoplastic polyester elastomer and modified silicone resin powder can be evenly dispersed in the polyamide matrix, giving the modified polyamide good toughness and strength, so that when it is compounded with the matrix material and metallocene polyethylene, it can promote the crystallization of the matrix material to be more uniform, and the uniform crystal structure helps to provide a stable rigid support structure, so that the foaming material composition can maintain a certain flexibility while also having sufficient rigidity to meet specific application requirements. At low temperatures, the modified polyamide and the thermoplastic polyester elastomer and other components that cooperate with it can also limit the excessive increase of crystallinity to a certain extent by affecting the movement and interaction of the molecular chain, which helps to maintain a relatively reasonable ratio of crystalline and non-crystalline areas inside the material, thereby ensuring that the foaming material composition can still maintain a certain rigid support and flexibility at low temperatures.

[0019] Preferably, the method for preparing the modified silicone resin powder comprises the following steps: S1: Disperse the silane coupling agent in toluene, then add the silicone resin powder, mix evenly, heat to 60-100°C, keep warm for 2-4 hours, cool, separate the solid and liquid, wash, and obtain the pretreated silicone resin powder; S12: after the pretreated organic silicone resin powder is evenly mixed with the mixed solution of butyl acrylate and styrene, an initiator is added, the mixture is evenly mixed, the temperature is raised to 70-90° C., the reaction is performed for 4-6 hours, the temperature is lowered, the solid-liquid separation is performed, the washing is performed, and the drying is performed to obtain the modified organic silicone resin powder; The amount of the silane coupling agent is 2% to 4% of the mass of the silicone resin powder; The mass ratio of the silicone resin powder, butyl acrylate and styrene is 1:(0.4-0.6):(0.4-0.6).

[0020] Preferably, the particle size distribution of the silicone resin powder is 3-5 μm.

[0021] Preferably, the initiator is azobisisobutyronitrile, and the amount of azobisisobutyronitrile used is 0.5% to 1% of the total mass of butyl acrylate and styrene.

[0022] By adopting the above technical solution: butyl acrylate and styrene can be grafted and copolymerized on the surface of pre-treated silicone resin micropowder under the action of initiator, which can significantly improve the stability and elastic adaptability of silicone resin micropowder in low temperature environment, thereby reducing brittle fracture caused by temperature reduction. The surface properties of silicone resin micropowder after graft copolymerization are improved, which can better disperse external force, thereby reducing stress concentration, helping to prevent local damage to the material when subjected to external force, and improving the durability of the overall material.

[0023] When this modified silicone resin powder is mixed with other components (such as polyamide, thermoplastic polyester elastomer, metallocene polyethylene, matrix material, etc.), the compatibility is significantly improved, thereby enhancing the bonding force with other components, helping to form a tighter structure during the material mixing process, and improving the mechanical properties and durability of the overall material. In addition, the use of silicone resin powder can not only achieve lightweight foaming material compositions, but also improve the uniformity and stability of foaming materials, reduce the merging and rupture of bubbles, and thus obtain a more delicate foaming structure.

[0024] Preferably, the compatibilizer is at least one of ethylene-ethyl acrylate copolymer and styrene-maleic anhydride copolymer.

[0025] Preferably, the mass ratio of the ethylene-ethyl acrylate copolymer to the styrene-maleic anhydride copolymer is (3-5):(5-7).

[0026] Preferably, the amount of the high impact polypropylene is 35% to 40% of the total mass of the base material.

[0027] By adopting the above technical solution: high-impact polypropylene can give full play to the advantages of its rubber phase and better balance the strength and toughness of the material at low temperatures. The combination of the strength of polypropylene resin and the toughness of high-impact polypropylene enables the material to have sufficient load-bearing capacity at low temperatures while maintaining good impact resistance.

[0028] Preferably, the foaming material composition further comprises 6 to 8 parts by mass of methacrylate-butadiene-styrene copolymer.

[0029] By adopting the above technical solution: after the addition of methacrylate-butadiene-styrene copolymer, its shell structure can have good compatibility with other main components (such as polypropylene, high-impact polypropylene, etc.), so that it can be evenly distributed inside the foam material composition. When the foam material composition is subjected to external force, methacrylate-butadiene-styrene can form a continuous stress transfer network inside the material, and the impact force will be quickly transmitted and dispersed through this network, avoiding the occurrence of cracks and expansion in local areas due to excessive stress, and eventually leading to material rupture. This mechanism of uniform stress dispersion significantly improves the impact resistance and overall toughness of the foam material composition under normal and low temperature environments, so that the material can better maintain structural integrity and is not easily damaged, whether it is subjected to collision and extrusion in daily use at room temperature or external force impact in low temperature environments.

[0030] In addition, methacrylate-butadiene-styrene copolymer can also adsorb on the surface of bubbles, reducing the surface tension of the bubble surface and helping to form a smaller and more uniform bubble structure.

[0031] Preferably, the foaming material composition further comprises 8 to 10 parts by mass of dioctyl phthalate.

[0032] By adopting the above technical solution: dioctyl phthalate can penetrate between polymer molecular chains, increase the distance between molecular chains, and improve the mobility of polymer molecular chains. When subjected to external forces, the molecular chains are more likely to deform and displace. These more mobile molecular chains can better absorb and disperse energy when impacted, thereby improving impact strength.

[0033] The present application also provides a preparation process of the above-mentioned foaming material composition, comprising the following steps: According to the compounding ratio, the base material, metallocene polyethylene, modified polyamide, compatibilizer, erucic acid amide, antioxidant and foaming aid are added to a high-speed mixer and mixed for 10 to 15 minutes. Then, the foaming agent is added and the mixture is mixed for 10 to 15 minutes. The mixture is then transferred to an open mill and mixed at 140 to 160° C. for 5 to 8 minutes. The mixture is then heated to 170 to 180° C. and mixed for 3 to 5 minutes. The mixture is then transported to a single screw extruder for extrusion, granulation, and cooling to obtain a foaming material composition.

[0034] Preferably, the temperature settings of each section of the single-screw extruder are: 150~160℃, pressure of 0~0.5MPa in the feeding section, 170~180℃, pressure of 2~3MPa in the compression section, 190~210℃, pressure of 4~5MPa in the metering section, 210~230℃, pressure of 6~8MPa, and screw speed of 40~60r / min.

[0035] Preferably, the particle size distribution is 2 to 5 mm.

[0036] Preferably, the cooling is air cooling, and the granulated particles are passed through an air cooling pipe with a wind speed of 3-5 m / s and a cooling time of 5-8 min.

[0037] Preferably, the preparation process further comprises the step of adding methacrylate-butadiene-styrene copolymer after erucamide.

[0038] Preferably, the preparation process further comprises the step of adding dioctyl phthalate after the methacrylate-butadiene-styrene copolymer.

[0039] In summary, this application has the following beneficial effects: 1. On the one hand, the present application makes use of the positive effects of metallocene polyethylene on crystallization behavior and modified polyamide in crystallization regulation, enhanced connection and stress transfer, etc., which are more conducive to achieving a good balance between material strength and toughness, whether at room temperature or low temperature, thereby improving the overall mechanical properties, stability and impact resistance of the foaming material composition. On the other hand, under the action of the compatibilizer, the evenly distributed modified silicone resin powder, foaming agent, foaming aid and erucic acid amide cooperate and synergize with each other, so that the foaming material composition has more excellent comprehensive performance, not only good mechanical properties and high stability, but also light weight, heat insulation, sound absorption and other characteristics, so that it can be applied to more different application scenarios.

[0040] 2. The present application adopts a composite matrix material of polypropylene and high-impact polypropylene, which can better balance the strength and toughness of the material at low temperatures. The combination of the strength of polypropylene and the toughness of high-impact polypropylene enables the material to have sufficient load-bearing capacity at low temperatures while maintaining good impact resistance.

[0041] 3. The further addition of methacrylate-butadiene-styrene copolymer in the present application can form a continuous stress transfer network inside the material, through which the impact force is rapidly transmitted and dispersed. This mechanism of uniform stress dispersion significantly improves the impact resistance and overall toughness of the foaming material composition in a normal low temperature environment. DETAILED DESCRIPTION

[0042] The present application is further described in detail below with reference to embodiments.

[0043] Unless otherwise specified, the raw materials used in the examples and comparative examples of the present application are all commercially available.

[0044] Thermoplastic polyester elastomer (TPEE) was purchased from Dongguan Hongyi Plastic Technology Co., Ltd.; Polyamide was purchased from Dongguan Hongyi Plastic Technology Co., Ltd.; Metallocene polyethylene was purchased from Xinhongshou Plastics (Suzhou) Co., Ltd.; Polypropylene was purchased from Xinhongshou Plastics (Suzhou) Co., Ltd.; High-impact polypropylene was purchased from Xinhongshou Plastics (Suzhou) Co., Ltd.; Silicone resin powder, with a particle size of 3-5 μm, was purchased from Hubei Longsheng Sihai New Materials Co., Ltd.

[0045] Preparation Examples 1-3 Modified Silicone Resin Micropowder Preparation Example 1 S1: Add 200 ml of toluene into a three-necked flask equipped with a stirring device, a thermometer and a reflux condenser, slowly drop 2 g of KH550, stir while dropping, the speed is 200 r / min, and continue stirring for 15 min until KH550 is completely dissolved, then add 100 g of silicone resin powder, continue stirring and mixing for 30 min, heat to 60 ° C, keep warm for 4 h, cool, filter, and wash twice with anhydrous ethanol to obtain pretreated silicone resin powder; S2: Slowly add 40 g of butyl acrylate and 60 g of styrene into 300 ml of toluene, and stir for 30 min at a speed of 200 r / min to obtain a mixed solution; S3: Add the pretreated silicone resin powder into a three-necked flask equipped with a stirring device, a thermometer and a reflux condenser, then add the mixed solution, stir and mix for 30 minutes at a speed of 200r / min, then slowly add 1g of azobisisobutyronitrile, continue stirring and mixing for 15 minutes, heat to 70°C, react for 6 hours, cool, filter, wash twice with toluene, then transfer to an oven, dry at 80°C for 4 hours to obtain modified silicone resin powder.

[0046] Preparation Example 2 S1: Add 200 ml of toluene into a three-necked flask equipped with a stirring device, a thermometer and a reflux condenser, slowly drop 4 g of KH550, stir while dropping, the speed is 200 r / min, and continue stirring for 25 min until KH550 is completely dissolved, then add 100 g of silicone resin powder, continue stirring and mixing for 30 min, heat to 100 ° C, keep warm for 2 h, cool, filter, and wash twice with anhydrous ethanol to obtain pretreated silicone resin powder; S2: Slowly add 60 g of butyl acrylate and 40 g of styrene into 300 ml of toluene, and stir for 30 min at a speed of 200 r / min to obtain a mixed solution; S3: Add the pretreated silicone resin powder into a three-necked flask equipped with a stirring device, a thermometer and a reflux condenser, then add the mixed solution, stir and mix for 30 minutes at a speed of 200r / min, then slowly add 0.5g of azobisisobutyronitrile, continue stirring and mixing for 15 minutes, heat to 90°C, react for 4 hours, cool, filter, wash twice with toluene, then transfer to an oven, dry at 80°C for 4 hours to obtain modified silicone resin powder.

[0047] Preparation Example 3 S1: Add 200 ml of toluene into a three-necked flask equipped with a stirring device, a thermometer and a reflux condenser, slowly drop 3 g of KH550, stir while dropping, the speed is 200 r / min, and continue stirring for 15 min until KH550 is completely dissolved, then add 100 g of silicone resin powder, continue stirring and mixing for 30 min, heat to 80 ° C, keep warm for 3 h, cool, filter, and wash twice with anhydrous ethanol to obtain pretreated silicone resin powder; S2: Slowly add 50 g of butyl acrylate and 50 g of styrene into 300 ml of toluene, and stir for 30 min at a speed of 200 r / min to obtain a mixed solution; S3: Add the pretreated silicone resin powder into a three-necked flask equipped with a stirring device, a thermometer and a reflux condenser, then add the mixed solution, stir and mix for 30 minutes at a speed of 200r / min, then slowly add 0.8g of azobisisobutyronitrile, continue stirring and mixing for 15 minutes, heat to 80°C, react for 5 hours, cool, filter, wash twice with toluene, then transfer to an oven, dry at 80°C for 4 hours to obtain modified silicone resin powder.

[0048] Preparation Examples 4-6 Modified Polyamide Preparation Example 4 280g of polyamide and 120g of thermoplastic polyester elastomer were added into a high-speed mixer, mixed at 600r / min for 10min, then 20g of maleic anhydride grafted polypropylene and 40g of modified silicone resin powder were added, mixed at 800r / min for 20min, then 10g of 3A molecular sieve and 2g of antioxidant 1010 were added, mixed at 800r / min for 8min to obtain a modified extrudate; the modified extrudate was transported to a twin-screw extruder for extrusion and granulation, and the granulated particles were passed through an air cooling pipe at a wind speed of 2m / s and a cooling time of 8min to obtain a modified polyamide; wherein the particle size distribution of the modified polyamide is 3-5mm; the modified silicone resin powder comes from Preparation Example 1.

[0049] The temperature settings of each section of the twin-screw extruder are: zone 1 190~200℃, zone 2 200~230℃, zone 3 220~230℃, zone 4 230~240℃, die head temperature 240~250℃, screw speed 100r / min.

[0050] Preparation Example 5 320g of polyamide and 80g of thermoplastic polyester elastomer were added into a high-speed mixer, mixed at 600r / min for 15min, then 12g of maleic anhydride grafted polypropylene and 20g of modified silicone resin powder were added, mixed at 800r / min for 15min, then 14g of 3A molecular sieve and 4g of antioxidant 1010 were added, mixed at 800r / min for 12min to obtain a modified extrudate; the modified extrudate was transported to a twin-screw extruder for extrusion and granulation, and the granulated particles were passed through an air cooling pipe at a wind speed of 3m / s and a cooling time of 5min to obtain a modified polyamide; wherein the particle size distribution of the modified polyamide is 3-5mm; the modified silicone resin powder comes from Preparation Example 2.

[0051] The temperature settings of each section of the twin-screw extruder are: zone 1 190~200℃, zone 2 200~230℃, zone 3 220~230℃, zone 4 230~240℃, head temperature 240~250℃, screw speed 200r / min.

[0052] Preparation Example 6 300g of polyamide and 100g of thermoplastic polyester elastomer were added into a high-speed mixer, mixed at 600r / min for 13min, then 18g of maleic anhydride grafted polypropylene and 30g of modified silicone resin powder were added, mixed at 800r / min for 18min, then 12g of 3A molecular sieve and 3g of antioxidant 1010 were added, mixed at 800r / min for 10min to obtain a modified extrudate; the modified extrudate was transported to a twin-screw extruder for extrusion and granulation, and the granulated particles were passed through an air cooling pipe at a wind speed of 3m / s and a cooling time of 8min to obtain a modified polyamide; wherein the particle size distribution of the modified polyamide is 3-5mm; the modified silicone resin powder comes from Preparation Example 3.

[0053] The temperature settings of each section of the twin-screw extruder are: zone 1 190~200℃, zone 2 200~230℃, zone 3 220~230℃, zone 4 230~240℃, head temperature 240~250℃, screw speed 150r / min.

[0054] Example 1 This embodiment provides a foaming material composition, including 180g of high-impact polypropylene, 420g of polypropylene, 100g of metallocene polyethylene, 150g of modified polyamide, 60g of modified silicone resin powder, 40g of compatibilizer, 15g of foaming agent, 5g of foaming aid, 5g of erucamide and 3g of antioxidant; Among them, the compatibilizer is ethylene-ethyl acrylate copolymer, the foaming agent is azodicarbonamide, the foaming aid includes 0.55g of zinc oxide and 4.45g of zinc stearate, and the antioxidant is antioxidant 1010.

[0055] This embodiment also provides a preparation process of the above-mentioned foaming material composition, comprising the following steps: According to the above proportions, polypropylene, high-impact polypropylene, metallocene polyethylene, modified polyamide, modified silicone resin powder, compatibilizer, erucic acid amide, antioxidant and foaming aid are added into a high-speed mixer, mixed at 600 r / min for 10 min, and then the foaming agent is added and mixed at 800 r / min for 10 min. The mixture is then transferred to an open mill and mixed at 140° C. for 8 min, then heated to 170° C. and mixed for 5 min. The mixture is then transported to a single-screw extruder for extrusion and granulation. The granulated particles are passed through an air cooling pipe at a wind speed of 3 m / s and a cooling time of 8 min to obtain a foaming material composition.

[0056] Wherein, the particle size distribution of the foaming material composition is 2-5 mm; the modified silicone resin powder comes from Preparation Example 1, and the modified polyamide comes from Preparation 4; The temperature settings of each section of the single-screw extruder are: feeding section 150~160℃, compression section 170~180℃, pressure 2MPa, metering section 190~210℃, pressure 4MPa, die temperature 210~230℃, pressure 6MPa, screw speed 40r / min.

[0057] Example 2 This embodiment provides a foaming material composition, including 280g of high-impact polypropylene, 520g of polypropylene, 200g of metallocene polyethylene, 250g of modified polyamide, 100g of modified silicone resin powder, 80g of compatibilizer, 30g of foaming agent, 12g of foaming aid, 15g of erucamide and 5g of antioxidant; Among them, the compatibilizer is ethylene-ethyl acrylate copolymer, the foaming agent is azodicarbonamide, the foaming aid includes 0.8g of zinc oxide and 11.2g of zinc stearate, and the antioxidant is antioxidant 1010.

[0058] This embodiment also provides a preparation process of the above-mentioned foaming material composition, comprising the following steps: According to the above proportions, polypropylene, high-impact polypropylene, metallocene polyethylene, modified polyamide, modified silicone resin powder, compatibilizer, erucic acid amide, antioxidant and foaming aid are added into a high-speed mixer, mixed at 600 r / min for 15 min, and then the foaming agent is added and mixed at 800 r / min for 15 min. The mixture is then transferred to an open mill and mixed at 160° C. for 5 min, then heated to 180° C. and mixed for 3 min. The mixture is then transported to a single-screw extruder for extrusion and granulation. The granulated particles are passed through an air cooling pipe at a wind speed of 5 m / s and a cooling time of 5 min to obtain a foaming material composition.

[0059] Wherein, the particle size distribution of the foaming material composition is 2-5 mm; the modified silicone resin powder comes from Preparation Example 2, and the modified polyamide comes from Preparation 5; The temperature settings of each section of the single-screw extruder are: feeding section 150~160℃, pressure 0.5MPa, compression section 170~180℃, pressure 3MPa, metering section 190~210℃, pressure 5MPa, die temperature 210~230℃, pressure 8MPa, screw speed 60r / min.

[0060] Example 3 This embodiment provides a foaming material composition, including 280g of high-impact polypropylene, 420g of polypropylene, 150g of metallocene polyethylene, 200g of modified polyamide, 80g of modified silicone resin powder, 70g of compatibilizer, 25g of foaming agent, 8g of foaming aid, 10g of erucamide and 4g of antioxidant; Among them, the compatibilizer is ethylene-ethyl acrylate copolymer, the foaming agent is azodicarbonamide, the foaming aid includes 0.8g of zinc oxide and 7.2g of zinc stearate, and the antioxidant is antioxidant 1010.

[0061] This embodiment also provides a preparation process of the above-mentioned foaming material composition, comprising the following steps: According to the above proportions, polypropylene, high-impact polypropylene, metallocene polyethylene, modified polyamide, modified silicone resin powder, compatibilizer, erucic acid amide, antioxidant and foaming aid are added into a high-speed mixer, mixed at 600 r / min for 13 min, and then the foaming agent is added and mixed at 800 r / min for 13 min. The mixture is then transferred to an open mill and mixed at 150° C. for 7 min, then heated to 170° C. and mixed for 5 min. The mixture is then transported to a single-screw extruder for extrusion and granulation. The granulated particles are passed through an air cooling pipe at a wind speed of 3 m / s and a cooling time of 8 min to obtain a foaming material composition.

[0062] Wherein, the particle size distribution of the foaming material composition is 2-5 mm; the modified silicone resin powder comes from Preparation Example 3, and the modified polyamide comes from Preparation 6; The temperature settings of each section of the single-screw extruder are: feeding section 150~160℃, pressure 0.5MPa, compression section 170~180℃, pressure 3MPa, metering section 190~210℃, pressure 5MPa, die temperature 210~230℃, pressure 8MPa, screw speed 50r / min.

[0063] Example 4 The difference between this embodiment and embodiment 3 is that: A foaming material composition, comprising 280 g of high-impact polypropylene, 420 g of polypropylene, 200 g of metallocene polyethylene, 250 g of modified polyamide, 100 g of modified silicone resin powder, 80 g of a compatibilizer, 25 g of a foaming agent, 8 g of a foaming aid, 15 g of erucamide and 5 g of an antioxidant; Among them, the compatibilizer includes 35g of ethylene-ethyl acrylate copolymer and 35g of styrene-maleic anhydride copolymer, the foaming agent is azodicarbonamide, the foaming aid includes 0.8g of zinc oxide and 7.2g of zinc stearate, and the antioxidant is antioxidant 1010.

[0064] The rest is the same as in Example 3.

[0065] Example 5 The difference between this embodiment and embodiment 4 is that: A foaming material composition, comprising 280 g of high-impact polypropylene, 420 g of polypropylene, 200 g of metallocene polyethylene, 250 g of modified polyamide, 100 g of modified silicone resin powder, 80 g of a compatibilizer, 25 g of a foaming agent, 8 g of a foaming aid, 15 g of erucamide, 5 g of an antioxidant, and 60 g of a methacrylate-butadiene-styrene copolymer; The compatibilizers included ethylene-ethyl acrylate copolymer 21 g and styrene-maleic anhydride copolymer 49 g.

[0066] A preparation process of the above-mentioned foaming material composition comprises the following steps: According to the above proportions, polypropylene, high-impact polypropylene, metallocene polyethylene, modified polyamide, modified silicone resin powder, compatibilizer, erucic acid amide, methacrylate-butadiene-styrene copolymer, antioxidant and foaming aid are added into a high-speed mixer, mixed at 600 r / min for 13 min, and then a foaming agent is added, mixed at 800 r / min for 13 min, and then transferred to an open mill, and refined at 150° C. for 7 min, then heated to 170° C. and refined for 5 min, and then transported to a single-screw extruder for extrusion and granulation. The granulated particles are passed through an air cooling pipe at a wind speed of 3 m / s and a cooling time of 8 min to obtain a foaming material composition.

[0067] The rest is the same as Example 4.

[0068] Example 6 The difference between this embodiment and embodiment 5 is that: The amount of methacrylate-butadiene-styrene copolymer used was 80 g.

[0069] The rest is the same as Example 5.

[0070] Example 7 The difference between this embodiment and embodiment 6 is that: A foaming material composition, comprising 280 g of high-impact polypropylene, 420 g of polypropylene, 200 g of metallocene polyethylene, 250 g of modified polyamide, 100 g of modified silicone resin powder, 80 g of a compatibilizer, 25 g of a foaming agent, 8 g of a foaming aid, 15 g of erucamide, 5 g of an antioxidant, 60 g of a methacrylate-butadiene-styrene copolymer and 80 g of dioctyl phthalate; A preparation process of the above-mentioned foaming material composition comprises the following steps: According to the above proportions, polypropylene, high-impact polypropylene, metallocene polyethylene, modified polyamide, modified silicone resin powder, compatibilizer, erucic acid amide, methacrylate-butadiene-styrene copolymer, dioctyl phthalate, antioxidant and foaming aid are added into a high-speed mixer, mixed at 600 r / min for 13 min, and then the foaming agent is added and mixed at 800 r / min for 13 min. The mixture is then transferred to an open mill and mixed at 150° C. for 7 min, then heated to 170° C. and mixed for 5 min. The mixture is then transported to a single-screw extruder for extrusion and granulation. The granulated particles are passed through an air cooling pipe at a wind speed of 3 m / s and a cooling time of 8 min to obtain a foaming material composition.

[0071] The rest is the same as Example 6.

[0072] Example 8 The difference between this embodiment and embodiment 7 is that: The amount of dioctyl phthalate used is 100g.

[0073] The rest is the same as Example 7.

[0074] Comparative Example 1 The difference between this comparative example and Example 1 is: Polyamide is not modified.

[0075] The rest is the same as in Example 1.

[0076] Comparative Example 2 The difference between this comparative example and Example 1 is: The silicone resin powder is not modified.

[0077] The rest is the same as in Example 1.

[0078] Performance Testing Testing standards: Tensile strength: ISO527 Impact strength: ISO180 Flexural strength and flexural modulus: ISO178 The foaming material compositions prepared in Examples 1 to 8 and Comparative Examples 1 to 2 were respectively added to the barrel of an injection molding machine, and after being heated to a molten state, the melt was respectively injected into the mold cavity by a screw. After the melt was cooled and solidified in the mold, the mold was opened to take out the sample, wherein the tensile sample was a dumbbell shape with a length of 150 mm ± 1 mm, a narrow parallel part width of 6 mm ± 0.4 mm, and a thickness of 2 mm ± 0.2 mm; the impact sample was injection molded into a standard sample shape with a V notch of 1 / 8″; the bending sample was a long strip sample with a length of 100 mm ± 1 mm, a width of 15 mm ± 0.4 mm, and a thickness of 6 mm ± 0.4 mm; the cellular sample was a cube with a side length of 20 mm ± 0.4 mm, and 6 corresponding samples were prepared for each Example and Comparative Example.

[0079] The corresponding samples prepared using the foaming material compositions in Examples 1 to 8 and Comparative Examples 1 to 2 were divided into two groups. The first group was placed in a test box at 23±2°C for 4 hours, and then taken out one by one for detection, and the average value was calculated, as shown in Table 1; the second group was placed in a test box at -20±2°C for 4 hours, and then taken out one by one for detection, and the average value was calculated, as shown in Table 2.

[0080] Table 1 Performance test data of the foaming material composition in Examples 1 to 8 and Comparative Examples 1 to 2 at room temperature

[0081] Table 2 Performance test data of the foaming material composition at low temperature in Examples 1 to 8 and Comparative Examples 1 to 2

[0082] Combining the performance test data analysis in Table 1 and Table 2, we can see that: It can be seen from Examples 1-8 and Comparative Examples 1-2 that at room temperature, by optimizing the ratio of each component and modifying the polyamide and silicone resin powder, the foaming material compositions obtained all exhibit good mechanical properties.

[0083] At room temperature, an appropriate amount of high-impact polypropylene can disperse stress and enhance toughness through its rubber phase. As the content of other components such as metallocene polyethylene, modified polyamide, modified silicone resin powder and compatibilizer gradually increases, the tensile strength, impact strength and bending performance are improved. This is because the flexibility of the flexible molecular chain of metallocene polyethylene promotes the uniform diffusion of stress inside the material, and cooperates with the rubber phase of high-impact polypropylene to optimize the overall stress distribution pattern and significantly improve the tensile strength. The addition of modified polyamide introduces high-strength chemical bonding and molecular chain entanglement structure. Its active groups are tightly cross-linked with the polypropylene matrix and other components to build a stable and efficient stress transfer path, greatly enhancing the material's ability to bear tensile and impact loads, while limiting excessive slippage of the molecular chain during bending and enhancing bending performance. As a rigid filler, the modified silicone resin powder is evenly dispersed in the matrix. At the same time, due to the modification treatment, it has a certain flexibility, which can not only improve the tensile strength and bending performance, but also buffer stress impact, prevent microcracks, and stabilize mechanical properties.

[0084] At low temperatures, components containing rubber phases such as high-impact polypropylene and methacrylate-butadiene-styrene copolymers can slow down the decline in tensile, impact and bending properties by virtue of the flexibility and buffering effect maintained by the rubber phase at low temperatures. This allows the foam material composition to maintain good mechanical properties in low temperature environments.

[0085] Methacrylate-butadiene-styrene copolymer has both a rubber phase and a hard phase, and has good compatibility with polypropylene. It can be evenly dispersed in the polypropylene matrix, ensuring that the rigidity of the material will not decrease excessively while toughening. In addition, when it is combined with reinforcing components such as polyamide, methacrylate-butadiene-styrene copolymer can enhance the toughness of the material while further optimizing the comprehensive mechanical properties of the material with the help of the high strength characteristics of polyamide.

[0086] Too high a content of dioctyl phthalate may weaken the interaction between polypropylene molecular chains, resulting in a weakened bonding force between molecular chains, which cannot effectively transmit stress during stretching, thus reducing tensile strength and bending properties. However, dioctyl phthalate penetrates between polymer molecular chains, increases the distance between molecular chains, and makes polymer molecular chains easier to move, which helps the material better absorb and disperse energy when impacted, thereby improving impact strength.

Claims

1. A foaming material composition, characterized in that: The invention comprises 60-80 parts by weight of base material, 10-20 parts by weight of metallocene polyethylene, 15-25 parts by weight of modified polyamide, 6-10 parts by weight of modified silicone resin powder, 4-8 parts by weight of compatibilizer, 1.5-3 parts by weight of foaming agent, 0.5-1.2 parts by weight of foaming aid, 0.5-1.5 parts by weight of erucamide and 0.3-0.5 parts by weight of antioxidant; The matrix material includes polypropylene and high impact polypropylene.

2. The foaming material composition according to claim 1, characterized in that: The preparation method of the modified polyamide comprises the following steps: (1) Adding polyamide and thermoplastic polyester elastomer in a mass ratio of (70-80): (20-30) into a high-speed mixer and mixing for 10-15 minutes, then adding maleic anhydride grafted polypropylene and modified silicone resin powder and mixing for 15-20 minutes, then adding molecular sieve and antioxidant and mixing for 8-12 minutes to obtain a modified extrudate; (2) conveying the modified extrudate to a twin-screw extruder for extrusion, granulation, and cooling to obtain a modified polyamide; The amount of maleic anhydride grafted polypropylene is 3% to 5% of the total mass of the polyamide and the thermoplastic polyester elastomer, and the amount of the modified silicone resin powder is 5% to 10% of the total mass of the polyamide and the thermoplastic polyester elastomer.

3. The foaming material composition according to claim 2, characterized in that: The method for preparing the modified silicone resin powder comprises the following steps: S1: Disperse the silane coupling agent in toluene, then add the silicone resin powder, mix evenly, heat to 60-100°C, keep warm for 2-4 hours, cool, separate the solid and liquid, wash, and obtain the pretreated silicone resin powder; S12: after the pretreated organic silicone resin powder is evenly mixed with the mixed solution of butyl acrylate and styrene, an initiator is added, the mixture is evenly mixed, the temperature is raised to 70-90° C., the reaction is performed for 4-6 hours, the temperature is lowered, the solid-liquid separation is performed, the washing is performed, and the drying is performed to obtain the modified organic silicone resin powder; The amount of the silane coupling agent is 2% to 4% of the mass of the silicone resin powder; The mass ratio of the silicone resin powder, butyl acrylate and styrene is 1:(0.4-0.6):(0.4-0.6).

4. The foaming material composition according to claim 3, characterized in that: The compatibilizer is at least one of ethylene-ethyl acrylate copolymer and styrene-maleic anhydride copolymer.

5. The foaming material composition according to claim 4, characterized in that: The amount of the high impact polypropylene is 35% to 40% of the total mass of the base material.

6. The foaming material composition according to claim 5, characterized in that: The foaming material composition further comprises 6 to 8 parts by weight of methacrylate-butadiene-styrene copolymer.

7. The foaming material composition according to claim 6, characterized in that: The foaming material composition further comprises 8 to 10 parts by weight of dioctyl phthalate.

8. A process for preparing the foaming material composition according to any one of claims 1 to 7, characterized in that: The steps include: According to the compounding ratio, the base material, metallocene polyethylene, modified polyamide, compatibilizer, erucic acid amide, antioxidant and foaming aid are added to a high-speed mixer and mixed for 10 to 15 minutes. Then, the foaming agent is added and the mixture is mixed for 10 to 15 minutes. The mixture is then transferred to an open mill and mixed at 140 to 160° C. for 5 to 8 minutes. The mixture is then heated to 170 to 180° C. and mixed for 3 to 5 minutes. The mixture is then transported to a single screw extruder for extrusion, granulation, and cooling to obtain a foaming material composition.

9. The process for preparing the foaming material composition according to claim 8, characterized in that: The preparation process further comprises the step of adding methacrylate-butadiene-styrene copolymer after erucamide.

10. The process for preparing the foaming material composition according to claim 9, characterized in that: The preparation process further comprises the step of adding dioctyl phthalate after the methacrylate-butadiene-styrene copolymer.

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