A foaming material composition and its preparation process

Abstract

This application relates to the technical field of polymer materials, and specifically discloses a foaming material composition and its preparation process. The foaming material composition includes 60 - 80 parts by mass of a matrix 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 erucic acid amide, and 0.3 - 0.5 parts by mass of an antioxidant; the matrix material includes polypropylene and high impact polypropylene. The foaming material composition prepared in this application has good mechanical properties at both normal and low temperatures.

Description

Technical Field

[0001] This application relates to the technical field of polymer materials. More specifically, it relates to a foaming material composition and its preparation process. Background Art

[0002] Currently, there are many kinds of foaming materials on the market. The main varieties are polyurethane foaming materials, polystyrene foaming materials, and polyethylene foaming materials. However, they have disadvantages such as poor high-temperature resistance, difficult to degrade, and difficult to recycle. Polypropylene foaming materials have advantages such as good thermal stability, excellent degradability, and environmental friendliness, making them good substitutes for foaming materials such as polystyrene and becoming a new generation of green foaming materials.

[0003] Polypropylene foaming materials have the characteristic of low density. Compared with traditional automotive materials such as steel and plastic, they can significantly reduce the weight of automotive parts. According to statistics, using polypropylene foaming materials to replace traditional materials can achieve a weight reduction of 30% to 50% in some parts. Polypropylene foaming materials also have excellent elasticity and energy absorption characteristics. They can quickly deform at the moment of collision, absorb a large amount of collision energy, thereby reducing the impact force on the passengers in the car. The buffer structures made of polypropylene foaming materials for parts such as bumpers and anti-collision beams of cars can effectively reduce the damage to the vehicle and passengers during collisions. In some collision tests, cars using EPP buffer structures showed better safety performance. In addition, EPP foaming materials also have good heat resistance, environmental sustainability, and design flexibility. These properties enable polypropylene materials to be applied in many fields such as automotive interiors, exteriors, safety systems, and power systems, bringing new opportunities and challenges to the development of the automotive industry.

[0004] However, polypropylene foaming materials have poor low-temperature brittleness and poor impact resistance. Especially in the fields of automotive interior parts and bumpers, in alpine regions, the brittleness of the materials increases, and the impact resistance is greatly reduced. The parts are easily broken under impact, affecting the safety and service durability of the cars.

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

[0006] In this patent application document, only dry mixing of polypropylene, polyethylene, and polyolefin elastomer is adopted, followed by granulation through a twin-screw extruder and drying to obtain the product. In this way, it is very difficult to achieve 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 likely to develop cracks and expand, reducing the tensile strength; during impact, the interface is also more likely to be damaged, making the impact resistance of the material poor. Summary of the Invention

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

[0008] The present application provides a foamed material composition, including 60-80 parts by mass of matrix 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 compatibilizer, 1.5-3 parts by mass of foaming agent, 0.5-1.2 parts by mass of foaming aid, 0.5-1.5 parts by mass of erucic acid amide, and 0.3-0.5 parts by mass of antioxidant;

[0009] The matrix material includes polypropylene and high-impact polypropylene.

[0010] Preferably, the foaming agent is azodicarbonamide.

[0011] Preferably, the foaming aid includes zinc oxide and zinc stearate, and the mass ratio of zinc oxide to zinc stearate is 1:(8-14).

[0012] By adopting the above technical solutions: Metallocene polyethylene can, to a certain extent, regulate the crystallization behavior of the matrix materials (polypropylene, high impact polypropylene), promote the crystallinity of the matrix materials to be more uniform, and optimize the crystallization distribution. The modified polyamide can significantly reduce the activation energy of crystallization, making the crystallization process more likely to occur. More importantly, the modified polyamide can also guide the crystallization to be more evenly distributed in the foamed material composition, thus avoiding the situation of excessive or insufficient local crystallization, which helps to improve the overall mechanical properties and stability of the foamed material composition. In addition, the modified polyamide can also strengthen the connection between various parts. This tight connection structure can not only enhance the overall strength of the foamed material composition, but also prevent the bubbles from bursting due to the loose structure of the foamed material during the growth and stabilization process. Especially in a low-temperature environment, this connection can more effectively transfer stress and improve the impact resistance of the foamed material composition.

[0013] The compatibilizer plays the roles of "bridge" and "lubricant" in the entire foamed material composition system. On the one hand, it helps the components such as modified silicone resin micropowder, compatibilizer, foaming agent, foaming aid, and erucic acid amide to achieve uniform distribution in the matrix material; on the other hand, it can effectively improve the interfacial bonding force between the components, strengthen the connection between the materials, and enable the foamed material composition to maintain good integrity and mechanical properties at both normal temperature and low temperature. At the same time, the uniformly distributed modified silicone resin micropowder, foaming agent, foaming aid, and erucic acid amide cooperate with each other and work synergistically, making the foamed material composition possess more excellent comprehensive properties. It not only has good mechanical properties and high stability, but also has characteristics such as light weight, heat insulation, and sound absorption, so that it can be applied to more different application scenarios.

[0014] Preferably, the preparation method of the modified polyamide includes the following steps:

[0015] Add polyamide and thermoplastic polyester elastomer into a high-speed mixer according to a mass ratio of (70~80):(20~30), mix for 10~15 min, then add maleic anhydride grafted polypropylene and modified silicone resin micropowder, mix for 15~20 min, and then add molecular sieve and antioxidant, mix for 8~12 min to obtain a modified extruded material; convey the modified extruded material to a twin-screw extruder for extrusion, granulation, and cooling to obtain the modified polyamide; the dosage of the maleic anhydride grafted polypropylene is 3%~5% of the total mass of the polyamide and the thermoplastic polyester elastomer, and the dosage of the modified silicone resin micropowder is 5%~10% of the total mass of the polyamide and the thermoplastic polyester elastomer.

[0016] Preferably, the molecular sieve is 3A molecular sieve, and the dosage of the 3A molecular sieve is 2.5%~3.5% of the total mass of the polyamide and the thermoplastic polyester elastomer.

[0017] Preferably, the dosage of the antioxidant is 0.5% - 1% of the total mass of the polyamide and the thermoplastic polyester elastomer.

[0018] Preferably, the temperature of each section of the twin - screw extruder is set as follows: the first zone is 190 - 200 °C, the second zone is 200 - 230 °C, the third zone is 220 - 230 °C, the fourth zone is 230 - 240 °C, the head temperature is 240 - 250 °C, and the screw speed is 100 - 200 r / min.

[0019] Preferably, the particle size of the modified polyamide is 3 - 5 mm.

[0020] By adopting the above - mentioned technical solution: under the action of maleic anhydride - grafted polypropylene, the thermoplastic polyester elastomer and the modified silicone resin micropowder can be evenly dispersed inside the polyamide matrix, endowing the modified polyamide with better toughness and strength. When compounded with the matrix material and metallocene polyethylene, it can promote the more uniform crystallization of the matrix material. The uniform crystal structure helps to provide a stable rigid support structure, enabling the foam material composition to have sufficient rigidity to meet specific application requirements while maintaining a certain flexibility. At low temperatures, components such as the modified polyamide and the thermoplastic polyester elastomer that cooperate with it can also limit the excessive increase in crystallinity to a certain extent by affecting the movement and interaction of molecular chains, helping to maintain a relatively reasonable ratio of crystalline and non - crystalline regions inside the material, thus ensuring that the foam material composition can still maintain a certain rigid support and flexibility at low temperatures.

[0021] Preferably, the preparation method of the modified silicone resin micropowder includes the following steps:

[0022] S1: Disperse the silane coupling agent in toluene, then add the silicone resin micropowder, mix evenly, heat up to 60 - 100 °C, keep warm for 2 - 4 h, cool down, perform solid - liquid separation, wash, and obtain the pretreated silicone resin micropowder;

[0023] S12: After mixing the pretreated silicone resin micropowder with the mixture of butyl acrylate and styrene evenly, add the initiator, mix evenly, heat up to 70 - 90 °C, react for 4 - 6 h, cool down, perform solid - liquid separation, wash, and dry to obtain the modified silicone resin micropowder;

[0024] The dosage of the silane coupling agent is 2% - 4% of the mass of the silicone resin micropowder;

[0025] The mass ratio of the silicone resin micropowder, butyl acrylate, and styrene is 1:(0.4 - 0.6):(0.4 - 0.6).

[0026] Preferably, the particle size distribution of the silicone resin micropowder is 3 - 5 μm.

[0027] Preferably, the initiator is azobisisobutyronitrile, and the amount of azobisisobutyronitrile is 0.5% - 1% of the total mass of butyl acrylate and styrene.

[0028] By adopting the above technical solutions: Butyl acrylate and styrene can graft copolymerize on the surface of the pretreated silicone resin micropowder under the action of the initiator, which can significantly improve the stability and elastic adaptability of the silicone resin micropowder in a low-temperature environment, thereby reducing embrittlement and cracking caused by temperature reduction. The surface properties of the graft copolymerized silicone resin micropowder are improved, and it can better disperse external forces, thereby reducing stress concentration, which helps to prevent local damage of the material when subjected to external forces and improves the durability of the overall material.

[0029] When this modified silicone resin micropowder 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, which helps to form a more compact structure during the material mixing process and improves the mechanical properties and durability of the overall material. In addition, using silicone resin micropowder can not only achieve the lightweight of the foaming material composition, but also improve the uniformity and stability of the foaming material, reduce the coalescence and rupture of bubbles, and thus obtain a finer foaming structure.

[0030] Preferably, the compatibilizer is at least one of ethylene-ethyl acrylate copolymer and styrene-maleic anhydride copolymer.

[0031] Preferably, the mass ratio of the ethylene-ethyl acrylate copolymer to the styrene-maleic anhydride copolymer is (3 - 5):(5 - 7).

[0032] Preferably, the amount of the high-impact polypropylene is 35% - 40% of the total mass of the matrix material.

[0033] By adopting the above technical solutions: The high-impact polypropylene can fully exert the advantages of its rubber phase and can better balance the strength and toughness of the material at low temperatures. The combination of the strength of the polypropylene resin and the toughness of the high-impact polypropylene enables the material to have sufficient load-bearing capacity and good impact resistance at low temperatures.

[0034] Preferably, the foaming material composition further includes 6 - 8 parts by mass of methyl methacrylate-butadiene-styrene copolymer.

[0035] By adopting the above technical solution: After the addition of methyl methacrylate-butadiene-styrene copolymer, its shell structure can have good compatibility with other main components (such as polypropylene, high impact polypropylene, etc.), enabling it to be evenly distributed inside the foam material composition. When the foam material composition is subjected to external forces, methyl methacrylate-butadiene-styrene can form a continuous stress transfer network inside the material, and the impact force will be quickly conducted and dispersed through this network, avoiding the occurrence of cracks and expansion in local areas due to excessive stress, and ultimately leading to the rupture of the material. This mechanism of uniform stress dispersion significantly improves the impact resistance and overall toughness of the foam material composition at normal and low temperatures, enabling the material to better maintain its structural integrity and not be easily damaged whether it is subjected to collisions and squeezes during daily use at normal temperature or external force impacts in a low-temperature environment.

[0036] In addition, the methyl methacrylate-butadiene-styrene copolymer can also adsorb on the surface of the bubbles, reducing the surface tension of the bubble surface, which helps to form smaller and more uniform bubble structures.

[0037] Preferably, the foam material composition further comprises 8 to 10 parts by mass of dioctyl phthalate.

[0038] By adopting the above technical solution: Dioctyl phthalate can penetrate between the polymer molecular chains, increasing the distance between the molecular chains and improving the mobility of the 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 subjected to impacts, thereby improving the impact strength.

[0039] This application also provides a preparation process for the above foam material composition, including the following steps:

[0040] Add the matrix material, metallocene polyethylene, modified polyamide, compatibilizer, erucamide, antioxidant, and foaming aid to a high-speed mixer according to the compounding ratio and mix for 10 to 15 minutes. Then add the foaming agent and continue to mix for 10 to 15 minutes. Then transfer to a two-roll mill and open mill at 140 to 160 °C for 5 to 8 minutes. Then raise the temperature to 170 to 180 °C and open mill for 3 to 5 minutes. Then convey it to a single-screw extruder for extrusion, pelletize, and cool to obtain the foam material composition.

[0041] Preferably, the temperature of each section of the single-screw extruder is set as follows: the feeding section is 150 to 160 °C, the pressure is 0 to 0.5 MPa, the compression section is 170 to 180 °C, the pressure is 2 to 3 MPa, the metering section is 190 to 210 °C, the pressure is 4 to 5 MPa, the die temperature is 210 to 230 °C, the pressure is 6 to 8 MPa, and the screw speed is 40 to 60 r / min.

[0042] Preferably, the particle size distribution is 2 - 5 mm.

[0043] Preferably, the cooling is air cooling. The granulated particles are passed through an air cooling pipeline with an air velocity of 3 - 5 m / s, and the cooling time is 5 - 8 min.

[0044] Preferably, in the preparation process, after erucamide, a step of adding a methyl methacrylate - butadiene - styrene copolymer is further included.

[0045] Preferably, in the preparation process, after the methyl methacrylate - butadiene - styrene copolymer, a step of adding dioctyl phthalate is further included.

[0046] In summary, the present application has the following beneficial effects:

[0047] 1. On the one hand, by means of the regulation of the crystallization behavior of metallocene polyethylene and the positive effects of the modified polyamide in aspects such as crystallization regulation, enhanced connection, and stress transfer, it is more conducive to achieving a good balance between the strength and toughness of the material under both normal temperature and low temperature conditions, thereby improving the overall mechanical properties, stability, and impact resistance of the foamed material composition. On the other hand, under the action of the compatibilizer, the uniformly distributed modified silicone resin micropowder, blowing agent, blowing aid, and erucamide cooperate and synergistically act with each other, enabling the foamed material composition to possess more excellent comprehensive properties, not only having good mechanical properties and high stability, but also being lightweight, heat - insulating, sound - absorbing, etc., so as to be applicable to more different application scenarios.

[0048] 2. The present application uses a polypropylene and high - impact polypropylene blended matrix material, which can better balance the strength and toughness of the material at low temperature. The combination of the strength of polypropylene and the toughness of high - impact polypropylene enables the material to have sufficient load - bearing capacity and good impact resistance at low temperature.

[0049] 3. The present application further adds a methyl methacrylate - butadiene - styrene copolymer, which can form a continuous stress transfer network inside the material. The impact force will be quickly conducted and dispersed through this network. This mechanism of uniform stress dispersion significantly improves the impact resistance and overall toughness of the foamed material composition in normal and low - temperature environments. Specific Embodiments

[0050] The following further elaborates on the present application in detail with reference to the embodiments.

[0051] The raw materials of the embodiments and comparative examples of the present application are all ordinary commercially available products unless otherwise specified.

[0052] Thermoplastic polyester elastomer (TPEE) was purchased from Dongguan Hongyi Plastic Technology Co., Ltd.

[0053] The polyamide was purchased from Dongguan Hongyi Plastic Technology Co., Ltd.;

[0054] The metallocene polyethylene was purchased from Xinhongshou Plasticizing (Suzhou) Co., Ltd.;

[0055] The polypropylene was purchased from Xinhongshou Plasticizing (Suzhou) Co., Ltd.;

[0056] The high impact polypropylene was purchased from Xinhongshou Plasticizing (Suzhou) Co., Ltd.;

[0057] The silicone resin micropowder with a particle size of 3 - 5 μm was purchased from Hubei Longsheng Sihai New Materials Co., Ltd.

[0058] Preparation Examples 1 - 3 Modified Silicone Resin Micropowder

[0059] Preparation Example 1

[0060] 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 while stirring at a speed of 200 r / min. Keep stirring for 15 min until KH550 is completely dissolved. Then add 100 g of silicone resin micropowder, continue to stir and mix for 30 min, then heat up to 60 °C, keep the temperature for 4 h, cool down, filter, and wash twice with absolute ethanol to obtain pretreated silicone resin micropowder;

[0061] S2: Slowly add 40 g of butyl acrylate and 60 g of styrene into 300 ml of toluene, stir and mix for 30 min at a speed of 200 r / min to obtain a mixed solution;

[0062] S3: Add the pretreated silicone resin micropowder 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 min at a speed of 200 r / min. Then slowly add 1 g of azobisisobutyronitrile, continue to stir and mix for 15 min, then heat up to 70 °C, react for 6 h, cool down, filter, wash twice with toluene, and then transfer it to an oven and dry at 80 °C for 4 h to obtain modified silicone resin micropowder.

[0063] Preparation Example 2

[0064] 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 while stirring at a speed of 200 r / min. Keep stirring for 25 min until KH550 is completely dissolved. Then add 100 g of silicone resin micropowder, continue to stir and mix for 30 min, then heat up to 100 °C, keep the temperature for 2 h, cool down, filter, and wash twice with absolute ethanol to obtain pretreated silicone resin micropowder;

[0065] S2: Slowly add 60 g of butyl acrylate and 40 g of styrene into 300 ml of toluene, stir and mix for 30 min at a rotation speed of 200 r / min to obtain a mixed solution.

[0066] S3: Add the pretreated silicone resin micro-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 min at a rotation speed of 200 r / min, then slowly add 0.5 g of azobisisobutyronitrile, continue to stir and mix for 15 min, then raise the temperature to 90 °C, react for 4 h, cool down, filter, wash twice with toluene, then transfer to an oven and dry at 80 °C for 4 h to obtain the modified silicone resin micro-powder.

[0067] Preparation Example 3

[0068] S1: Add 200 ml of toluene into a three-necked flask equipped with a stirring device, a thermometer and a reflux condenser, slowly dropwise add 3 g of KH550 while stirring at a rotation speed of 200 r / min, continuously stir for 15 min until KH550 is completely dissolved, then add 100 g of silicone resin micro-powder, continue to stir and mix for 30 min, then raise the temperature to 80 °C, keep warm for 3 h, cool down, filter, wash twice with absolute ethanol to obtain the pretreated silicone resin micro-powder.

[0069] S2: Slowly add 50 g of butyl acrylate and 50 g of styrene into 300 ml of toluene, stir and mix for 30 min at a rotation speed of 200 r / min to obtain a mixed solution.

[0070] S3: Add the pretreated silicone resin micro-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 min at a rotation speed of 200 r / min, then slowly add 0.8 g of azobisisobutyronitrile, continue to stir and mix for 15 min, then raise the temperature to 80 °C, react for 5 h, cool down, filter, wash twice with toluene, then transfer to an oven and dry at 80 °C for 4 h to obtain the modified silicone resin micro-powder.

[0071] Modified polyamides of Preparation Examples 4 - 6

[0072] Preparation Example 4

[0073] Add 280 g of polyamide and 120 g of thermoplastic polyester elastomer to a high-speed mixer, mix at 600 r / min for 10 min, then add 20 g of maleic anhydride grafted polypropylene and 40 g of modified silicone resin micropowder, mix at 800 r / min for 20 min, then add 10 g of 3A molecular sieve and 2 g of antioxidant 1010, mix at 800 r / min for 8 min to obtain a modified extrusion material; convey the modified extrusion material to a twin-screw extruder for extrusion and granulation, and cool the granulated particles through an air-cooling pipeline with a wind speed of 2 m / s and a cooling time of 8 min to obtain modified polyamide; among them, the particle size distribution of the modified polyamide is 3 - 5 mm; the modified silicone resin micropowder is from Preparation Example 1.

[0074] The temperature of each section of the twin-screw extruder is set as follows: the first zone is 190 - 200 °C, the second zone is 200 - 230 °C, the third zone is 220 - 230 °C, the fourth zone is 230 - 240 °C, the head temperature is 240 - 250 °C, and the screw speed is 100 r / min.

[0075] Preparation Example 5

[0076] Add 320 g of polyamide and 80 g of thermoplastic polyester elastomer to a high-speed mixer, mix at 600 r / min for 15 min, then add 12 g of maleic anhydride grafted polypropylene and 20 g of modified silicone resin micropowder, mix at 800 r / min for 15 min, then add 14 g of 3A molecular sieve and 4 g of antioxidant 1010, mix at 800 r / min for 12 min to obtain a modified extrusion material; convey the modified extrusion material to a twin-screw extruder for extrusion and granulation, and cool the granulated particles through an air-cooling pipeline with a wind speed of 3 m / s and a cooling time of 5 min to obtain modified polyamide; among them, the particle size distribution of the modified polyamide is 3 - 5 mm; the modified silicone resin micropowder is from Preparation Example 2.

[0077] The temperature of each section of the twin-screw extruder is set as follows: the first zone is 190 - 200 °C, the second zone is 200 - 230 °C, the third zone is 220 - 230 °C, the fourth zone is 230 - 240 °C, the head temperature is 240 - 250 °C, and the screw speed is 200 r / min.

[0078] Preparation Example 6

[0079] Add 300 g of polyamide and 100 g of thermoplastic polyester elastomer to a high-speed mixer, mix at 600 r / min for 13 min, then add 18 g of maleic anhydride grafted polypropylene and 30 g of modified silicone resin micropowder, mix at 800 r / min for 18 min, and then add 12 g of 3A molecular sieve and 3 g of antioxidant 1010, mix at 800 r / min for 10 min to obtain a modified extrusion material; convey the modified extrusion material to a twin-screw extruder for extrusion and granulation, and pass the granulated particles through an air-cooling pipeline with a wind speed of 3 m / s and a cooling time of 8 min to obtain modified polyamide; wherein, the particle size distribution of the modified polyamide is 3 - 5 mm; the modified silicone resin micropowder comes from Preparation Example 3.

[0080] The temperatures of each section of the twin-screw extruder are set as follows: Zone 1: 190 - 200 °C, Zone 2: 200 - 230 °C, Zone 3: 220 - 230 °C, Zone 4: 230 - 240 °C, head temperature: 240 - 250 °C, screw speed: 150 r / min.

[0081] Example 1

[0082] This example provides a foaming material composition, including 180 g of high impact polypropylene, 420 g of polypropylene, 100 g of metallocene polyethylene, 150 g of modified polyamide, 60 g of modified silicone resin micropowder, 40 g of compatibilizer, 15 g of foaming agent, 5 g of foaming aid, 5 g of erucic acid amide and 3 g of antioxidant;

[0083] Among them, the compatibilizer is ethylene-ethyl acrylate copolymer, the foaming agent is azodicarbonamide, the foaming aid includes 0.55 g of zinc oxide and 4.45 g of zinc stearate, and the antioxidant is antioxidant 1010.

[0084] This example also provides a preparation process for the above foaming material composition, including the following steps:

[0085] Add polypropylene, high impact polypropylene, metallocene polyethylene, modified polyamide, modified silicone resin micropowder, compatibilizer, erucic acid amide, antioxidant and foaming aid into a high-speed mixer according to the above ratio, mix at 600 r / min for 10 min, then add the foaming agent, mix at 800 r / min for 10 min, then transfer to an open mill, knead at 140 °C for 8 min, then raise the temperature to 170 °C, knead for 5 min, convey to a single-screw extruder for extrusion and granulation, and pass the granulated particles through an air-cooling pipeline with a wind speed of 3 m / s and a cooling time of 8 min to obtain the foaming material composition.

[0086] Among them, the particle size distribution of the foaming material composition is 2 - 5 mm; the modified silicone resin micropowder comes from Preparation Example 1, and the modified polyamide comes from Preparation 4;

[0087] The temperature settings for each section of the single-screw extruder are as follows: the feeding section is 150 - 160 °C, the compression section is 170 - 180 °C with a pressure of 2 MPa, the metering section is 190 - 210 °C with a pressure of 4 MPa, the die temperature is 210 - 230 °C with a pressure of 6 MPa, and the screw speed is 40 r / min.

[0088] Example 2

[0089] This example provides a foaming material composition, including 280 g of high impact polypropylene, 520 g of polypropylene, 200 g of metallocene polyethylene, 250 g of modified polyamide, 100 g of modified silicone resin micropowder, 80 g of compatibilizer, 30 g of foaming agent, 12 g of foaming aid, 15 g of erucic acid amide, and 5 g of antioxidant.

[0090] Among them, the compatibilizer is ethylene-ethyl acrylate copolymer, the foaming agent is azodicarbonamide, the foaming aid includes 0.8 g of zinc oxide and 11.2 g of zinc stearate, and the antioxidant is antioxidant 1010.

[0091] This example also provides a preparation process for the above foaming material composition, including the following steps:

[0092] Add polypropylene, high impact polypropylene, metallocene polyethylene, modified polyamide, modified silicone resin micropowder, compatibilizer, erucic acid amide, antioxidant, and foaming aid into a high-speed mixer according to the above proportions, mix at 600 r / min for 15 min, then add the foaming agent, mix at 800 r / min for 15 min, then transfer to an open mill, open mill at 160 °C for 5 min, then raise the temperature to 180 °C, open mill for 3 min, convey to a single-screw extruder for extrusion and pelletizing, and cool the pellets through an air-cooling pipeline with a wind speed of 5 m / s for 5 min to obtain the foaming material composition.

[0093] Among them, the particle size distribution of the foaming material composition is 2 - 5 mm; the modified silicone resin micropowder is from Preparation Example 2, and the modified polyamide is from Preparation 5.

[0094] The temperature settings for each section of the single-screw extruder are as follows: the feeding section is 150 - 160 °C with a pressure of 0.5 MPa, the compression section is 170 - 180 °C with a pressure of 3 MPa, the metering section is 190 - 210 °C with a pressure of 5 MPa, the die temperature is 210 - 230 °C with a pressure of 8 MPa, and the screw speed is 60 r / min.

[0095] Example 3

[0096] This embodiment provides a foaming material composition, including 280 g of high impact polypropylene, 420 g of polypropylene, 150 g of metallocene polyethylene, 200 g of modified polyamide, 80 g of modified silicone resin micropowder, 70 g of compatibilizer, 25 g of foaming agent, 8 g of foaming aid, 10 g of erucamide and 4 g of antioxidant;

[0097] Among them, the compatibilizer is ethylene-ethyl acrylate copolymer, the foaming agent is azodicarbonamide, the foaming aid includes 0.8 g of zinc oxide and 7.2 g of zinc stearate, and the antioxidant is antioxidant 1010.

[0098] This embodiment also provides a preparation process of the above foaming material composition, including the following steps:

[0099] Add polypropylene, high impact polypropylene, metallocene polyethylene, modified polyamide, modified silicone resin micropowder, compatibilizer, erucamide, antioxidant and foaming aid into a high-speed mixer according to the above ratio, mix at 600 r / min for 13 min, then add the foaming agent, mix at 800 r / min for 13 min, then transfer to an open mill, open mill at 150 °C for 7 min, then raise the temperature to 170 °C, open mill for 5 min, convey to a single-screw extruder for extrusion and pelletizing, and cool the pellets through an air-cooling pipeline with a wind speed of 3 m / s and a cooling time of 8 min to obtain the foaming material composition.

[0100] Among them, the particle size distribution of the foaming material composition is 2 - 5 mm; the modified silicone resin micropowder comes from Preparation Example 3, and the modified polyamide comes from Preparation 6;

[0101] The temperature of each section of the single-screw extruder is set as follows: the feeding section is 150 - 160 °C, the pressure is 0.5 MPa, the compression section is 170 - 180 °C, the pressure is 3 MPa, the metering section is 190 - 210 °C, the pressure is 5 MPa, the die temperature is 210 - 230 °C, the pressure is 8 MPa, and the screw speed is 50 r / min.

[0102] Example 4

[0103] The difference between this embodiment and Example 3 is:

[0104] A foaming material composition, including 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 micropowder, 80 g of compatibilizer, 25 g of foaming agent, 8 g of foaming aid, 15 g of erucamide and 5 g of antioxidant;

[0105] Among them, the compatibilizer includes 35 g of ethylene-ethyl acrylate copolymer and 35 g of styrene-maleic anhydride copolymer, the foaming agent is azodicarbonamide, the foaming aid includes 0.8 g of zinc oxide and 7.2 g of zinc stearate, and the antioxidant is antioxidant 1010.

[0106] Others are the same as in Example 3.

[0107] Example 5

[0108] The difference between this example and Example 4 is that:

[0109] A foaming material composition includes 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 micropowder, 80 g of compatibilizer, 25 g of foaming agent, 8 g of foaming aid, 15 g of erucamide, 5 g of antioxidant, and 60 g of methyl methacrylate-butadiene-styrene copolymer;

[0110] The compatibilizer includes 21 g of ethylene-ethyl acrylate copolymer and 49 g of styrene-maleic anhydride copolymer.

[0111] A preparation process of the above foaming material composition includes the following steps:

[0112] Add polypropylene, high impact polypropylene, metallocene polyethylene, modified polyamide, modified silicone resin micropowder, compatibilizer, erucamide, methyl methacrylate-butadiene-styrene copolymer, antioxidant, and foaming aid into a high-speed mixer according to the above proportions, mix at 600 r / min for 13 min, then add the foaming agent, mix at 800 r / min for 13 min, transfer to a two-roll mill, open mill at 150 °C for 7 min, then raise the temperature to 170 °C, open mill for 5 min, convey to a single-screw extruder for extrusion and granulation, and cool the granulated particles through an air-cooling pipeline with a wind speed of 3 m / s and a cooling time of 8 min to obtain the foaming material composition.

[0113] Others are the same as in Example 4.

[0114] Example 6

[0115] The difference between this example and Example 5 is that:

[0116] The dosage of methyl methacrylate-butadiene-styrene copolymer is 80 g.

[0117] Others are the same as in Example 5.

[0118] Example 7

[0119] The difference between this example and Example 6 is that:

[0120] A foaming material composition includes 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 micropowder, 80 g of compatibilizer, 25 g of foaming agent, 8 g of foaming aid, 15 g of erucic acid amide, 5 g of antioxidant, 60 g of methyl methacrylate-butadiene-styrene copolymer and 80 g of dioctyl phthalate;

[0121] A preparation process of the above foaming material composition includes the following steps:

[0122] Add polypropylene, high impact polypropylene, metallocene polyethylene, modified polyamide, modified silicone resin micropowder, compatibilizer, erucic acid amide, methyl methacrylate-butadiene-styrene copolymer, dioctyl phthalate, antioxidant and foaming aid into a high-speed mixer according to the above proportions, mix at 600 r / min for 13 min, then add the foaming agent, mix at 800 r / min for 13 min, transfer to an open mill, open mill at 150 °C for 7 min, then raise the temperature to 170 °C, open mill for 5 min, convey to a single-screw extruder for extrusion and granulation, and cool the granulated particles through an air-cooling pipeline with a wind speed of 3 m / s for 8 min to obtain the foaming material composition.

[0123] Others are the same as in Example 6.

[0124] Example 8

[0125] The difference between this example and Example 7 is that:

[0126] The dosage of dioctyl phthalate is 100 g.

[0127] Others are the same as in Example 7.

[0128] Comparative Example 1

[0129] The difference between this comparative example and Example 1 is that:

[0130] The polyamide is not modified.

[0131] Others are the same as in Example 1.

[0132] Comparative Example 2

[0133] The difference between this comparative example and Example 1 is that:

[0134] The silicone resin micropowder is not modified.

[0135] Others are the same as in Example 1.

[0136] Performance detection

[0137] Detection standard:

[0138] Tensile strength: ISO527

[0139] Impact strength: ISO180

[0140] Flexural strength and flexural modulus: ISO178

[0141] The foam material compositions prepared in Examples 1 - 8 and Comparative Examples 1 - 2 were respectively added into the barrel of an injection molding machine. After heating to the molten state, the melt was injected into the mold cavity through a screw. After the melt cooled and solidified in the mold, the mold was opened to take out the specimens. Among them, the tensile specimens were dumbbell-shaped, with a length of 150 mm ± 1 mm, a width of the narrow parallel part of 6 mm ± 0.4 mm, and a thickness of 2 mm ± 0.2 mm; the impact specimens were injection-molded into the standard specimen shape with a V-notch of 1 / 8″; the flexural specimens were strip-shaped specimens, 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 cell specimens were cubes with a side length of 20 mm ± 0.4 mm, and 6 specimens were prepared for each example and comparative example for the corresponding specimens.

[0142] The corresponding specimens prepared from the foam material compositions in Examples 1 - 8 and Comparative Examples 1 - 2 were divided into two groups. The first group was left standing in a test chamber at 23 ± 2 °C for 4 h, then taken out one by one for testing, and the average value was obtained, as shown in Table 1; the second group was left standing in a test chamber at -20 ± 2 °C for 4 h, then taken out one by one for testing, and the average value was obtained, as shown in Table 2.

[0143] Table 1 Performance test data of the foam material compositions in Examples 1 - 8 and Comparative Examples 1 - 2 at room temperature

[0144]

[0145] Table 2 Performance test data of the foam material compositions in Examples 1 - 8 and Comparative Examples 1 - 2 at low temperature

[0146]

[0147] Combined with the analysis of the performance test data in Table 1 and Table 2, it can be seen that:

[0148] From Examples 1 - 8 and Comparative Examples 1 - 2, it can be seen that: at normal and low temperatures, by optimizing the ratio of each component and modifying the polyamide and silicone resin micropowders, the prepared foam material compositions all exhibit good mechanical properties.

[0149] 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.

[0150] 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.

[0151] 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.

[0152] 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; 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; 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).

2. The foaming material composition according to claim 1, characterized in that: The compatibilizer is at least one of ethylene-ethyl acrylate copolymer and styrene-maleic anhydride copolymer.

3. The foaming material composition according to claim 1, characterized in that: The amount of the high impact polypropylene is 35% to 40% of the total mass of the base material.

4. The foaming material composition according to claim 1, characterized in that: The foaming material composition further comprises 6 to 8 parts by weight of methacrylate-butadiene-styrene copolymer.

5. The foaming material composition according to claim 1, characterized in that: The foaming material composition further comprises 8 to 10 parts by weight of dioctyl phthalate.

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

7. The process for preparing the foaming material composition according to claim 6, characterized in that: The preparation process further comprises the step of adding methacrylate-butadiene-styrene copolymer after erucamide.

8. The process for preparing the foaming material composition according to claim 7, characterized in that: The preparation process further comprises the step of adding dioctyl phthalate after the methacrylate-butadiene-styrene copolymer.

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