Polypropylene material as well as preparation method and application thereof

Abstract

The invention provides a polypropylene material as well as a preparation method and application thereof. The polypropylene material comprises regenerated polypropylene, diatomite, alginate fibers, a polyolefin elastomer, a compatilizer, an antioxidant and a light stabilizer. By adding the diatomite and the alginate fiber, the mechanical property of the material is improved, it is ensured that the material meets the high-strength and high-toughness standard of the automobile industry, and the production cost is reduced. Besides, due to the adsorption performance of the diatomite and the alginate fiber, the charring smell of the regenerated polypropylene can be better covered, small molecules generated in the using and processing process of the regenerated polypropylene in the previous life cycle can be adsorbed, the emission performance of the polypropylene material is optimized, and the requirement of the market for the low-smell automotive trim is met.

Description

Technical Field

[0001] The present application relates to the field of polymer materials, and in particular to a polypropylene material and a preparation method and application thereof. Background Art

[0002] For automobile manufacturers, the use of green and environmentally friendly materials and green processes needs to be considered during the design and development stage. This is not only a need for corporate product upgrades and technological innovation, but also a reflection of corporate social responsibility. Polypropylene is the largest material in automotive plastics. The rational use of recycled polypropylene materials and their optimized application in the entire vehicle can effectively achieve the goal of reducing carbon emissions in automotive plastics. However, recycled polypropylene is prone to aging after being affected by heat, force and light for a long time, resulting in a significant decrease in its stiffness, toughness and aging properties. In addition, as consumers' requirements for interior air quality and environmental comfort in cars increase, the low odor and low emission of materials become increasingly important. Due to the destruction of molecular chains and various degradation factors, recycled materials are prone to release small molecules, resulting in a serious burnt smell.

[0003] Therefore, in order to meet the needs of automotive applications, it is necessary to carry out targeted modification of recycled polypropylene and develop a new type of polypropylene material. Summary of the invention

[0004] The present application aims to solve one of the technical problems in the related art at least to some extent.

[0005] In a first aspect of the present application, the present application proposes a polypropylene material. According to an embodiment of the present application, the polypropylene material comprises: recycled polypropylene, diatomaceous earth, seaweed fiber, polyolefin elastomer, a compatibilizer, an antioxidant and a light stabilizer.

[0006] The polypropylene material of the present application not only improves the mechanical properties of the material by adding diatomaceous earth and seaweed fiber, ensuring that it meets the high strength and high toughness standards of the automotive industry, but also reduces production costs. In addition, due to the adsorption properties of diatomaceous earth and seaweed fiber, it can better cover up the burnt smell of the recycled polypropylene itself, adsorb small molecules produced during the use and processing of the recycled polypropylene in the previous life cycle, optimize the emission performance of the polypropylene material, and meet the market demand for low-odor automotive interiors. Furthermore, the introduction of seaweed fiber not only reduces the weight of the material, replaces the traditional glass fiber reinforced polypropylene material, but also can form the appearance effect of flocking or fabric-like coated fabrics, which can be used in appearance or non-appearance parts. Therefore, the polypropylene material of the present application can achieve low-carbon environmental protection and green circulation, and is suitable for industrial use.

[0007] According to an embodiment of the present application, the polypropylene material may further include at least one of the following additional technical features:

[0008] According to an embodiment of the present application, the polypropylene material includes: 50-80 parts by weight of recycled polypropylene; 0.1-30 parts by weight of diatomaceous earth; 0.1-10 parts by weight of seaweed fiber; 5-20 parts by weight of polyolefin elastomer; 0.1-6 parts by weight of compatibilizer; 0.1-2 parts by weight of antioxidant; and 0.1-1 parts by weight of light stabilizer.

[0009] According to an embodiment of the present application, the recycled polypropylene is made from waste household appliances, automobiles, and daily necessities as raw materials.

[0010] According to an embodiment of the present application, the density of the recycled polypropylene is 0.90 g / cm 3 ~0.95g / cm 3 .

[0011] According to an embodiment of the present application, based on the total mass of the recycled polypropylene, the mass proportion of ash in the recycled polypropylene is no more than 2%.

[0012] According to an embodiment of the present application, the melt index of the recycled polypropylene is (12-22) g / 10min.

[0013] According to an embodiment of the present application, the tensile strength of the recycled polypropylene is 15 MPa-20 MPa.

[0014] According to an embodiment of the present application, the flexural modulus of the recycled polypropylene is 1200 MPa-1500 MPa.

[0015] According to an embodiment of the present application, the particle size of the diatomaceous earth is 45 μm-150 μm.

[0016] According to an embodiment of the present application, the diatomaceous earth is treated with a surface treatment agent, and the surface treatment agent includes at least one of a silane coupling agent, acetic acid, stearic acid, aluminate, and titanate.

[0017] According to an embodiment of the present application, the seaweed fiber includes at least one of calcium alginate fiber, sodium alginate fiber, alginate fiber and ammonium alginate fiber.

[0018] According to an embodiment of the present application, the polyolefin elastomer includes at least one of an ethylene-octene copolymer, an ethylene-propylene copolymer, an ethylene-hexene copolymer, and an ethylene-butene copolymer.

[0019] According to an embodiment of the present application, the compatibilizer includes polypropylene grafted with maleic anhydride / styrene.

[0020] According to an embodiment of the present application, the antioxidant includes a primary antioxidant and a secondary antioxidant, the primary antioxidant includes at least one of a hindered phenol antioxidant and a thioester antioxidant, and the secondary antioxidant includes at least one of a phosphite antioxidant and an ester antioxidant.

[0021] According to an embodiment of the present application, the light stabilizer includes a hindered amine light stabilizer, an ultraviolet absorber, or a light stabilizer compounded with a hindered amine and an ultraviolet absorber.

[0022] According to an embodiment of the present application, the seaweed fiber is selected from calcium alginate fiber, the length of the calcium alginate fiber is 2mm-25mm, and the fineness of the calcium alginate fiber is 2dtex-5dtex.

[0023] According to an embodiment of the present application, the polyolefin elastomer is selected from ethylene-octene copolymer, and the density of the ethylene-octene copolymer is 0.88 g / cm 3 -0.90g / cm 3 The melt index of the ethylene-octene copolymer is (0.5-14) g / 10min.

[0024] According to an embodiment of the present application, the grafting rate of maleic anhydride in the polypropylene grafted maleic anhydride / styrene is 0.5% to 3%, and the melt index of the polypropylene grafted maleic anhydride / styrene is (40 to 150) g / 10 min.

[0025] According to an embodiment of the present application, the primary antioxidant is selected from at least one of 3,5-di-tert-butyl-4-hydroxybenzyl diethyl phosphate, pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate (Irganox1010) and octadecyl thiodipropionate, and the secondary antioxidant is selected from at least one of pentaerythritol distearyl diphosphite (AP-618) and tris(2,4-di-tert-butylbenzyl) phosphite.

[0026] In the second aspect of the present application, the present application proposes a method for preparing the polypropylene material described in the first aspect. According to an embodiment of the present application, the method comprises: mixing recycled polypropylene, diatomaceous earth, seaweed fiber, polyolefin elastomer, compatibilizer, antioxidant and light stabilizer to obtain a mixture; and melt-extruding and granulating the mixture to obtain the polypropylene material. By adopting the method of the present application, a polypropylene material with high strength and high toughness can be prepared, the emission performance of the polypropylene material can be improved, and the market demand for low-odor automotive interiors can be met. In addition, the method is simple to prepare and easy to operate, which not only improves production efficiency and reduces costs, but also recycles waste plastics, and makes full use of renewable resources and biomass resources on the earth, effectively reducing the exploitation of petrochemical resources, and can achieve low-carbon environmental protection and green circulation, and is suitable for industrial expansion of production.

[0027] In the third aspect of the present application, the present application proposes the use of the polypropylene material described in the first aspect or the polypropylene material prepared by the method described in the second aspect in the manufacture of automotive interior parts. As mentioned above, the polypropylene material of the present application has high strength and high toughness, can meet the mechanical performance requirements of automotive materials, and also has a light weight and low emission performance. By using the polypropylene material of the present application to manufacture automotive interior parts, it can not only meet the market's requirements for low odor of automotive interiors, effectively reduce volatile organic compounds (VOCs) in the car, but also form an appearance effect with flocking or similar fabrics.

[0028] According to an embodiment of the present application, the interior trim part includes at least one of an instrument panel, a door panel, a storage box, and a glove box.

[0029] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0031] Figure 1 A schematic diagram of the preparation process of the polypropylene material of an embodiment of the present application is shown. DETAILED DESCRIPTION

[0032] The embodiments of the present application are described in detail below. The embodiments described below are exemplary and are only used to explain the present application, and cannot be understood as limiting the present application.

[0033] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0034] For simplicity, only some numerical ranges are specifically disclosed herein. However, any lower limit can be combined with any upper limit to form an unspecified range; and any lower limit can be combined with other lower limits to form an unspecified range, and any upper limit can be combined with any other upper limit to form an unspecified range. In addition, each separately disclosed point or single value can itself be combined as a lower limit or upper limit with any other point or single value or with other lower limits or upper limits to form an unspecified range.

[0035] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0036] It should be noted that the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. Further, in the description of this application, unless otherwise specified, the meaning of "plurality" is two or more.

[0037] In the present application, the terms "comprise" or "include" are open expressions, that is, including the contents specified in the present application but not excluding other contents.

[0038] Unless otherwise specified, all embodiments and optional embodiments of the present application can be combined with each other to form a new technical solution.

[0039] The application of recycled materials in automobiles is an important direction for low-carbon emission reduction in the automobile industry. Recycled polypropylene will age after being exposed to heat, force, and light for a long time during its use. The stiffness, toughness, and aging properties of the material will decrease significantly during multiple processing. Therefore, recycled polypropylene needs to be modified and improved in a targeted manner to meet the needs of automotive applications. As consumers' requirements for interior air quality and environmental comfort in cars increase, the low odor and low emission of materials become increasingly important. However, due to the destruction of molecular chains and various degradation factors, recycled materials are prone to release small molecules, resulting in an increase in small molecules and a serious burnt smell of the material. Based on the above application requirements and technical problems, a material with excellent comprehensive performance is developed, which has the characteristics of low emission and low odor, while achieving low-carbon emission reduction and protecting the environment to the greatest extent.

[0040] Based on this, the present application proposes a polypropylene material for automotive interior that is low in emission (low in odor, low in volatile organic compounds (VOCs)), low in carbon and environmentally friendly, and has a flocking effect. By adding diatomaceous earth and seaweed fiber to the recycled polypropylene system, on the one hand, the prepared polypropylene material has high strength and high toughness, which can meet the mechanical performance requirements of automotive materials and reduce material costs; on the other hand, due to the adsorption properties of diatomaceous earth and seaweed fiber, the burnt smell of the recycled polypropylene itself can be better concealed, thereby optimizing the emission performance of the polypropylene material. In addition, the seaweed fiber itself has certain antibacterial, flame retardant and deodorizing functions, and is suitable for use in the field of human perception of interior decoration. The addition of seaweed fiber can replace glass fiber to enhance the mechanical properties of polypropylene materials and effectively reduce the weight of the material. At the same time, it can also form a flocking or fabric-like appearance effect, which can be used in appearance or non-appearance parts.

[0041] Polypropylene material

[0042] In a first aspect of the present application, the present application proposes a polypropylene material. According to an embodiment of the present application, the polypropylene material comprises: recycled polypropylene, diatomaceous earth, seaweed fiber, polyolefin elastomer, compatibilizer, antioxidant and light stabilizer.

[0043] The polypropylene material of the present application not only improves the mechanical properties of the material by adding diatomaceous earth and seaweed fiber, ensuring that it meets the high strength and high toughness standards of the automotive industry, but also reduces production costs. In addition, due to the adsorption properties of diatomaceous earth and seaweed fiber, it can better cover up the burnt smell of the recycled polypropylene itself, adsorb the small molecules produced during the use and processing of the recycled polypropylene in the previous life cycle, optimize the emission performance of the polypropylene material, and meet the market demand for low-odor automotive interiors. Furthermore, the introduction of seaweed fiber not only reduces the weight of the material, replaces the traditional glass fiber reinforced polypropylene material, but also can form the appearance effect of flocking or fabric-like coated fabrics, which can be used in appearance or non-appearance parts. Therefore, the polypropylene material of the present application can achieve low-carbon environmental protection and green circulation, and is suitable for industrial applications.

[0044] In some embodiments of the present application, the polypropylene material includes: 50-80 parts by weight of recycled polypropylene; 0.1-30 parts by weight of diatomaceous earth; 0.1-10 parts by weight of seaweed fiber; 5-20 parts by weight of polyolefin elastomer; 0.1-6 parts by weight of compatibilizer; 0.1-2 parts by weight of antioxidant; 0.1-1 parts by weight of light stabilizer. By making the weight of each substance within the above range, the prepared polypropylene material can have good strength and toughness, meet the mechanical performance requirements of automotive materials, reduce material costs, and reduce the emission performance of polypropylene materials, effectively reducing the content of volatile organic compounds (VOCs).

[0045] Illustratively, based on the total weight of the polypropylene material, the weight portion of the recycled polypropylene can be 50, 55, 60, 65, 70, 75, 80, etc., or can be a range consisting of any of the above values.

[0046] Exemplarily, based on the total weight of the polypropylene material, the weight of the diatomaceous earth can be 0.1, 1, 5, 10, 15, 20, 25, 30, etc., or can be a range composed of any of the above values. Thus, by making the weight of the diatomaceous earth within the above range, the strength of the polypropylene material can be improved, and the probability of the polypropylene material becoming brittle, and the impact resistance and toughness decreasing can be reduced. At the same time, it can adsorb small molecules emitted by the recycled polypropylene, effectively reducing the odor intensity of the polypropylene material. According to an embodiment of the present application, 10-30 weight parts of diatomaceous earth are preferred.

[0047] Exemplarily, based on the total weight of the polypropylene material, the weight portion of the seaweed fiber can be 0.1, 1, 5, 6, 7, 8, 9, 10, etc., or can be a range composed of any of the above numerical values. Thus, by making the weight portion of the seaweed fiber within the above range, the toughness of the polypropylene material can be improved, and the probability of affecting other physical properties of the polypropylene material such as rigidity or heat resistance can be reduced. At the same time, it is possible to adsorb small molecules emitted by the regenerated polypropylene, effectively reducing the odor intensity of the polypropylene material. According to an embodiment of the present application, 5-10 weight portions of seaweed fiber are preferred.

[0048] For example, based on the total weight of the polypropylene material, the weight of the polyolefin elastomer can be 5, 8, 10, 12, 15, 18, 20, etc., or can be a range consisting of any of the above values. Thus, by making the weight of the polyolefin elastomer within the above range, not only the impact resistance and toughness of the polypropylene material can be improved, but also the wear resistance of the polypropylene material can be improved, and its service life in friction and wear environments can be extended.

[0049] For example, based on the total weight of the polypropylene material, the weight of the compatibilizer can be 0.1, 1, 2, 3, 4, 5, 6, etc., or can be a range of any of the above values. Thus, by making the weight of the compatibilizer within the above range, the affinity between different components can be increased, so that the filler or other polymer is more evenly dispersed in the polypropylene material.

[0050] For example, based on the total weight of the polypropylene material, the weight of the antioxidant can be 0.1, 0.5, 1, 1.5, 2, etc., or can be a range composed of any of the above values. Thus, by making the weight of the antioxidant within the above range, it helps to improve the aging resistance of the polypropylene material, so that it can still maintain good performance under long-term exposure to environmental factors such as sunlight, oxygen, moisture and heat, and extend the service life of the polypropylene material in actual use.

[0051] For example, based on the total weight of the polypropylene material, the weight of the light stabilizer can be 0.1, 0.2, 0.4, 0.6, 0.8, 1, etc., or can be a range composed of any of the above values. Thus, by making the weight of the light stabilizer within the above range, the damaging effect of ultraviolet rays on the polypropylene material can be reduced, which helps to delay the light aging process of the polypropylene material and maintain its long-term performance and appearance.

[0052] In some embodiments of the present application, the recycled polypropylene is made from waste household appliances, automobiles, and daily necessities, and the density of the recycled polypropylene is 0.90 g / cm 3 ~0.95g / cm 3, the mass proportion of ash in the recycled polypropylene is not higher than 2%. Thus, by making the density of the recycled polypropylene and the mass proportion of ash within the above range, the consistency and reliability of the recycled polypropylene material can be ensured, the quality and performance of the recycled polypropylene can be improved, and a polypropylene material with high strength and high toughness can be produced.

[0053] It should be noted that the recycled polypropylene of the present application can be purchased and produced using waste home appliances, automobiles, and daily necessities as raw materials, or it can be produced by itself using waste home appliances, automobiles, and daily necessities as raw materials.

[0054] Exemplarily, the density of the recycled polypropylene is 0.90 g / cm 3 、0.91g / cm 3 、0.92g / cm 3 , 0.93g / cm 3 、0.94g / cm 3 , 0.95g / cm 3 The above-mentioned arbitrary numerical ranges may also be used.

[0055] Illustratively, the mass proportion of ash in the recycled polypropylene is 0%, 0.1%, 0.5%, 1%, 1.2%, 1.5%, 1.8%, 2%, etc., or can be a range consisting of any of the above values.

[0056] In some embodiments of the present application, the melt index of the recycled polypropylene is (12-22) g / 10min. For example, it can be 12 g / 10min, 15 g / 10min, 18 g / 10min, 20 g / 10min, 22 g / 10min, etc., or it can be a range composed of any of the above values. Therefore, by making the melt index of the recycled polypropylene within the above range, the obtained polypropylene material can have better performance and meet the mechanical performance requirements of automotive materials.

[0057] In some embodiments of the present application, the tensile strength of the recycled polypropylene is 15MPa-20MPa. For example, it can be 15MPa, 16MPa, 17MPa, 18MPa, 19MPa, 20MPa, etc., or can be a range composed of any of the above values. Therefore, by making the tensile strength of the recycled polypropylene within the above range, the obtained polypropylene material can have better performance and meet the mechanical performance requirements of automotive materials.

[0058] In some embodiments of the present application, the flexural modulus of the recycled polypropylene is 1200MPa-1500MPa. For example, it can be 1200MPa, 1250MPa, 1300MPa, 1350MPa, 1400MPa, 1450MPa, 1500MPa, etc., or can be a range composed of any of the above values. Therefore, by making the flexural modulus of the recycled polypropylene within the above range, the obtained polypropylene material can have better performance and meet the mechanical performance requirements of automotive materials.

[0059] In some embodiments of the present application, the particle size of the diatomite is 45 μm-150 μm. For example, it can be 45 μm, 60 μm, 75 μm, 90 μm, 105 μm, 120 μm, 135 μm, 150 μm, etc., or can be a range composed of any of the above values. Therefore, by making the particle size of the diatomite within the above range, it is helpful to improve the interface interaction between the diatomite and the recycled polypropylene, thereby improving the strength of the polypropylene material.

[0060] In some embodiments of the present application, the diatomite is treated with a surface treatment agent, and the surface treatment agent includes at least one of a silane coupling agent, acetic acid, stearic acid, aluminate, and titanate. By using the surface treatment agent to activate the surface of the diatomite, the compatibility between the diatomite and the recycled polypropylene can be improved, and their interface bonding force can be enhanced, thereby improving the overall performance of the polypropylene material.

[0061] In some embodiments of the present application, the seaweed fiber includes at least one of calcium alginate fiber, sodium alginate fiber, alginate fiber and ammonium alginate fiber. Thus, by selecting the seaweed fiber from the above types, the toughness of the polypropylene material can be improved to meet the mechanical performance requirements of automotive materials. In addition, it can absorb small molecules produced by recycled polypropylene and optimize the emission performance of the polypropylene material. In addition, it can form the appearance effect of flocking or fabric-like coated fabrics, and can be used in appearance or non-appearance parts.

[0062] In some embodiments of the present application, the seaweed fiber is selected from calcium alginate fiber, the length of the calcium alginate fiber is 2mm-25mm, and the fineness of the calcium alginate fiber is 2dtex-5dtex. Thus, by making the length of the calcium alginate fiber within the above range, the calcium alginate fiber can better bridge and transfer stress in the recycled polypropylene, thereby improving the tensile strength and modulus of the polypropylene material. By making the fineness of the calcium alginate fiber within the above range, the contact area between the calcium alginate fiber and the recycled polypropylene can be increased, which helps to improve the interface bonding and reinforcement effect, thereby improving the impact resistance of the polypropylene material.

[0063] Illustratively, the length of the calcium alginate fiber can be 2 mm, 5 mm, 10 mm, 15 mm, 20 mm, 25 mm, etc., or can be a range consisting of any of the above values.

[0064] Illustratively, the fineness of the calcium alginate fiber can be 2dtex, 3dtex, 4dtex, 5dtex, etc., or can be a range consisting of any of the above values.

[0065] In some embodiments of the present application, the polyolefin elastomer includes but is not limited to at least one of ethylene-octene copolymer, ethylene-propylene copolymer, ethylene-hexene copolymer and ethylene-butene copolymer. Thus, by selecting the polyolefin elastomer from the above types, the impact resistance and toughness of the polypropylene material can be improved.

[0066] In some embodiments of the present application, the polyolefin elastomer is selected from ethylene-octene copolymer, and the density of the ethylene-octene copolymer is 0.88 g / cm 3 -0.90g / cm 3 The melt index of the ethylene-octene copolymer is (0.5-14) g / 10 min. Therefore, by making the density and melt index of the ethylene-octene copolymer within the above range, it helps to improve the toughness of the polypropylene material.

[0067] Exemplarily, the density of the ethylene-octene copolymer may be 0.88 g / cm 3 , 0.89g / cm 3 , 0.90g / cm 3 The above-mentioned arbitrary numerical ranges may also be used.

[0068] Illustratively, the melt index of the ethylene-octene copolymer can be 0.5 g / 10 min, 1 g / 10 min, 3 g / 10 min, 5 g / 10 min, 8 g / 10 min, 10 g / 10 min, 14 g / 10 min, etc., or can be a range consisting of any of the above values.

[0069] In some embodiments of the present application, the compatibilizer includes but is not limited to polypropylene grafted maleic anhydride / styrene (PP-g-MAH / st). Thus, the affinity between different components can be improved, so that fillers or other polymers are more evenly dispersed in the polypropylene material, and the tensile strength, flexural strength, impact strength and other mechanical properties of the polypropylene material can be improved.

[0070] In some embodiments of the present application, the grafting rate of maleic anhydride in the polypropylene grafted maleic anhydride / styrene is 0.5% to 3%, and the melt index of the polypropylene grafted maleic anhydride / styrene is (40 to 150) g / 10min. Thus, by making the grafting rate of maleic anhydride in the polypropylene grafted maleic anhydride / styrene within the above range, the compatibility and interfacial bonding between the recycled polypropylene and other materials can be improved, and the tensile strength, bending strength and impact strength of the polypropylene material can be improved. By making the melt index of the polypropylene grafted maleic anhydride / styrene within the above range, it is helpful to improve the toughness of the polypropylene material.

[0071] For example, the grafting rate of maleic anhydride can be 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, etc., or can be a range consisting of any of the above values.

[0072] Illustratively, the melt index of the polypropylene grafted maleic anhydride / styrene can be 40 g / 10 min, 60 g / 10 min, 80 g / 10 min, 100 g / 10 min, 120 g / 10 min, 150 g / 10 min, etc., or can be a range consisting of any of the above values.

[0073] In some embodiments of the present application, the antioxidant includes a primary antioxidant and a secondary antioxidant, wherein the primary antioxidant includes but is not limited to at least one of a hindered phenolic antioxidant and a thioester antioxidant, and the secondary antioxidant includes but is not limited to at least one of a phosphite antioxidant and an ester antioxidant. Among them, the primary antioxidant plays an important role in eliminating the generation of free radicals in the system, and the secondary antioxidant inhibits the degradation of the material during processing. By selecting the primary antioxidant and the secondary antioxidant from the above types, it is helpful to improve the aging resistance of the polypropylene material, so that it can still maintain good performance under long-term exposure to environmental factors such as sunlight, oxygen, moisture and heat, and extend the service life of the polypropylene material in actual use.

[0074] In some embodiments of the present application, the primary antioxidant is selected from at least one of 3,5-di-tert-butyl-4-hydroxybenzyl diethyl phosphate (3114), pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate (Irganox1010) and octadecyl thiodipropionate (DSTP), and the secondary antioxidant is selected from at least one of pentaerythritol distearyl diphosphite (AP-618) and tris(2,4-di-tert-butylbenzyl) phosphite (168). Thus, by selecting the primary antioxidant and the secondary antioxidant from the above types, the aging resistance of the polypropylene material can be improved, so that it can still maintain good performance under long-term exposure to environmental factors such as sunlight, oxygen, moisture and heat.

[0075] In some embodiments of the present application, the light stabilizer is selected from hindered amine light stabilizers, ultraviolet absorbers, or light stabilizers compounded with hindered amines and ultraviolet absorbers. Thus, by selecting the light stabilizer from the above types, it is possible to absorb or disperse ultraviolet rays, thereby reducing their destructive effects on polypropylene materials. At the same time, it helps to delay the light aging process of polypropylene materials and maintain their long-term performance and appearance.

[0076] For example, the hindered amine light stabilizer includes but is not limited to at least one of LS-944, LS-622, LS-119, etc.; the ultraviolet absorber includes but is not limited to at least one of UV-531, UV-329, UV-1164, etc.; the light stabilizer compounded with the hindered amine and the ultraviolet absorber includes but is not limited to LX TM 313, 3050LIQ, At least one of 3051-2DISP, etc.

[0077] Method for preparing polypropylene material

[0078] In the second aspect of the present application, the present application proposes a method for preparing the polypropylene material described in the first aspect. According to the embodiments of the present application, referring to Figure 1 , the method comprising:

[0079] S100: Hybrid Processing

[0080] In this step, recycled polypropylene, diatomaceous earth, seaweed fiber, polyolefin elastomer, compatibilizer, antioxidant and light stabilizer are mixed to obtain a mixture.

[0081] In some embodiments of the present application, based on the total weight of the polypropylene material, the weight ratio of the recycled polypropylene, diatomaceous earth, seaweed fiber, polyolefin elastomer, compatibilizer, antioxidant and light stabilizer is (50-80): (0.1-30): (0.1-10): (5-20): (0.1-6): (0.1-2): (0.1-1). By making the weight ratio of each substance within the above range, the prepared polypropylene material can have good strength and toughness, meet the mechanical performance requirements of automotive materials, reduce material costs, and reduce the emission performance of the polypropylene material, effectively reducing the content of volatile organic compounds (VOCs).

[0082] In some embodiments of the present application, the mixing process is performed in a high-speed mixer.

[0083] In some embodiments of the present application, the rotation speed of the mixing process is 610 rpm-800 rpm, and the time is 3 min-5 min.

[0084] Illustratively, the rotation speed of the mixing process can be 610 rpm, 650 rpm, 700 rpm, 750 rpm, 800 rpm, etc., or can be a range consisting of any of the above numerical values.

[0085] Exemplarily, the mixing treatment time can be 3 min, 4 min, 3 min, etc., or can be a range consisting of any of the above values.

[0086] S200: Melt extrusion processing

[0087] In this step, the above mixture is melt-extruded to form a product with a special shape.

[0088] In some embodiments of the present application, the melt extrusion process is performed in a twin-screw extruder.

[0089] In some embodiments of the present application, the screw speed of the twin-screw extruder is 120-320 rpm, and the temperature of each section of the screw is 190-200°C in zone 1, 200-210°C in zone 2, 210-230°C in zone 3, and 205-220°C in zone 4.

[0090] Illustratively, the screw speed can be 120 rpm, 150 rpm, 200 rpm, 250 rpm, 300 rpm, 320 rpm, etc., or can be a range consisting of any of the above values.

[0091] Illustratively, the temperature of the first zone may be 190° C., 192° C., 195° C., 198° C., 200° C., etc., or may be a range consisting of any of the above values.

[0092] Illustratively, the temperature of the second zone may be 200° C., 202° C., 205° C., 208° C., 210° C., etc., or may be a range consisting of any of the above values.

[0093] Illustratively, the temperatures of the three zones may be 210° C., 215° C., 220° C., 225° C., 230° C., etc., or may be a range consisting of any of the above values.

[0094] Illustratively, the temperature of the four zones may be 205° C., 210° C., 215° C., 220° C., etc., or may be a range consisting of any of the above values.

[0095] By adopting the method of the present application, a polypropylene material with high strength and high toughness can be prepared, the emission performance of the polypropylene material can be improved, and the market demand for low-odor automotive interiors can be met. In addition, the method is simple to prepare and easy to operate, which not only improves production efficiency and reduces costs, but also recycles waste plastics, fully utilizes renewable resources and biomass resources on the earth, effectively reduces the exploitation of petrochemical resources, can achieve low-carbon environmental protection and green circulation, and is suitable for industrial expansion of production.

[0096] application

[0097] In the third aspect of the present application, the present application proposes the use of the polypropylene material described in the first aspect or the polypropylene material prepared by the method described in the second aspect in the manufacture of automotive interior parts. As mentioned above, the polypropylene material of the present application has high strength and high toughness, can meet the mechanical performance requirements of automotive materials, and also has a light weight and low emission performance. By using the polypropylene material of the present application to manufacture automotive interior parts, it can not only meet the market's requirements for low odor of automotive interiors, effectively reduce volatile organic compounds (VOCs) in the car, but also form an appearance effect with flocking or similar fabrics.

[0098] According to an embodiment of the present application, the interior trim parts include but are not limited to at least one of an instrument panel, a door panel, a storage box, and a glove box.

[0099] The scheme of the present application will be explained below in conjunction with the embodiments. It will be appreciated by those skilled in the art that the following embodiments are only used to illustrate the present application and should not be considered as limiting the scope of the present application. If no specific technology or conditions are indicated in the embodiments, the technology or conditions described in the literature in this area or the product specification are carried out. The reagents used or the instruments that do not indicate the manufacturer are all conventional products that can be obtained commercially.

[0100] In the recycled material formula of the embodiment and comparative example, the physical properties of recycled polypropylene are shown in Table 1 below, which can be purchased or prepared by oneself; the inorganic filler is modified diatomite; the seaweed fiber is commercially available calcium alginate fiber; the polyolefin elastomer is Engage 8180 produced by Dow Company of the United States; the compatibilizer is commercially available polypropylene grafted maleic anhydride / styrene (PP-g-MAH / st); the main antioxidant is DSTP produced by ICE Company of the United Kingdom, the chemical name is octadecyl thiodipropionate, and 3114 produced by Ciba Company, the chemical name is 3,5-di-tert-butyl-4-hydroxybenzyl diethyl phosphate. The auxiliary antioxidant is 168 produced by Ciba Company, the chemical name is tris (2,4-di-tert-butyl benzyl) phosphite; the light stabilizer is a UV absorber or a light stabilizer compounded with a hindered amine and a UV absorber.

[0101] Table 1 Physical properties of recycled polypropylene

[0102]

[0103] The specific preparation process of modified diatomite is as follows: 1000-3000 mesh diatomite is selected and dried at 150°C for 2 hours, mixed with a certain proportion of ethanol, and fully dispersed by ultrasound, 0.5-1% of silane coupling agent (KH550 / KH560 / KH570) and 0.1% of acetic acid are added as catalysts, and the reaction is stirred for 5-10 hours to obtain a solid. The solid material is fully washed with ethanol and dried to obtain modified diatomite.

[0104] Example 1

[0105] 63.6 parts by weight of recycled polypropylene, 15 parts by weight of modified diatomaceous earth, 5 parts by weight of seaweed fiber (calcium alginate fiber), 15 parts by weight of polyolefin elastomer (Engage 8180), 1 part by weight of compatibilizer (polypropylene grafted with maleic anhydride / styrene), 0.3 parts by weight of antioxidant (primary antioxidant: DSTP and 3114, secondary antioxidant: 168) and 0.1 parts by weight of light stabilizer are added into a high-speed mixer and stirred at a speed of 700±50 rpm for 4±1 minutes. The mixed raw materials are put into a twin-screw extruder for extrusion granulation, the screw speed is 200±50 rpm, the temperature of each section of the screw is: 195±5℃ in zone 1, 205±5℃ in zone 2, 220±10℃ in zone 3, 210±10℃ in zone 4, the residence time of the whole extrusion process is 1.5±0.5 minutes, and the pressure is 15±3MPa. After the long strips are extruded, they are cut into small particles to obtain polypropylene material.

[0106] Among them, the length of calcium alginate fiber is 15±5mm, the fineness is 3±1dtex; the density of Engage 8180 is 0.89g / cm 3 , the melt index is 0.5g / 10min, the grafting rate of maleic anhydride in polypropylene grafted maleic anhydride / styrene is 1±0.5%, and the melt index is 50±10g / 10min.

[0107] Example 2

[0108] The polypropylene material was prepared according to the method described in Example 1, except that the proportions of the various substances were different: 68.6 parts by weight of recycled polypropylene, 10 parts by weight of modified diatomaceous earth, 5 parts by weight of seaweed fiber (calcium alginate fiber), 15 parts by weight of polyolefin elastomer (Engage 8180), 1 part by weight of compatibilizer (polypropylene grafted with maleic anhydride / styrene), 0.3 parts by weight of antioxidant (primary antioxidant: DSTP and 3114, secondary antioxidant: 168) and 0.1 parts by weight of light stabilizer were added to a high-speed mixer.

[0109] Example 3

[0110] The polypropylene material was prepared according to the method described in Example 1, except that the proportions of the various substances were different: 58.6 parts by weight of recycled polypropylene, 20 parts by weight of modified diatomaceous earth, 5 parts by weight of seaweed fiber (calcium alginate fiber), 15 parts by weight of polyolefin elastomer (Engage 8180), 1 part by weight of compatibilizer (polypropylene grafted with maleic anhydride / styrene), 0.3 parts by weight of antioxidant (primary antioxidant: DSTP and 3114, secondary antioxidant: 168) and 0.1 parts by weight of light stabilizer were added to a high-speed mixer.

[0111] Example 4

[0112] The polypropylene material was prepared according to the method described in Example 1, except that the proportions of the various substances were different: 48.6 parts by weight of recycled polypropylene, 30 parts by weight of modified diatomaceous earth, 5 parts by weight of seaweed fiber (calcium alginate fiber), 15 parts by weight of polyolefin elastomer (Engage 8180), 1 part by weight of compatibilizer (polypropylene grafted with maleic anhydride / styrene), 0.3 parts by weight of antioxidant (primary antioxidant: DSTP and 3114, secondary antioxidant: 168) and 0.1 parts by weight of light stabilizer were added to the high-speed mixer.

[0113] Example 5

[0114] The polypropylene material was prepared according to the method described in Example 1, except that the proportions of the various substances were different: 38.6 parts by weight of recycled polypropylene, 40 parts by weight of modified diatomaceous earth, 5 parts by weight of seaweed fiber (calcium alginate fiber), 15 parts by weight of polyolefin elastomer (Engage 8180), 1 part by weight of compatibilizer (polypropylene grafted with maleic anhydride / styrene), 0.3 parts by weight of antioxidant (primary antioxidant: DSTP and 3114, secondary antioxidant: 168) and 0.1 parts by weight of light stabilizer were added to the high-speed mixer.

[0115] Example 6

[0116] The polypropylene material was prepared according to the method described in Example 1, except that the proportions of the various substances were different: 58.6 parts by weight of recycled polypropylene, 15 parts by weight of modified diatomaceous earth, 10 parts by weight of seaweed fiber (calcium alginate fiber), 15 parts by weight of polyolefin elastomer (Engage 8180), 1 part by weight of compatibilizer (polypropylene grafted with maleic anhydride / styrene), 0.3 parts by weight of antioxidant (primary antioxidant: DSTP and 3114, secondary antioxidant: 168) and 0.1 parts by weight of light stabilizer were added into a high-speed mixer.

[0117] Example 7

[0118] The polypropylene material was prepared according to the method described in Example 1, except that the proportions of the various substances were different: 53.6 parts by weight of recycled polypropylene, 15 parts by weight of modified diatomaceous earth, 15 parts by weight of seaweed fiber (calcium alginate fiber), 15 parts by weight of polyolefin elastomer (Engage 8180), 1 part by weight of compatibilizer (polypropylene grafted with maleic anhydride / styrene), 0.3 parts by weight of antioxidant (primary antioxidant: DSTP and 3114, secondary antioxidant: 168) and 0.1 parts by weight of light stabilizer were added into a high-speed mixer.

[0119] Example 8

[0120] The polypropylene material was prepared according to the method described in Example 1, except that the proportions of the various substances were different: 67.6 parts by weight of recycled polypropylene, 15 parts by weight of modified diatomaceous earth, 1 part by weight of seaweed fiber (calcium alginate fiber), 15 parts by weight of polyolefin elastomer (Engage 8180), 1 part by weight of compatibilizer (polypropylene grafted with maleic anhydride / styrene), 0.3 parts by weight of antioxidant (primary antioxidant: DSTP and 3114, secondary antioxidant: 168) and 0.1 parts by weight of light stabilizer were added to the high-speed mixer.

[0121] Example 9

[0122] The polypropylene material was prepared according to the method described in Example 1, except that the proportions of the various substances were different: 68.6 parts by weight of recycled polypropylene, 15 parts by weight of modified diatomaceous earth, 5 parts by weight of seaweed fiber (calcium alginate fiber), 10 parts by weight of polyolefin elastomer (Engage 8180), 1 part by weight of compatibilizer (polypropylene grafted with maleic anhydride / styrene), 0.3 parts by weight of antioxidant (primary antioxidant: DSTP and 3114, secondary antioxidant: 168) and 0.1 parts by weight of light stabilizer were added to a high-speed mixer.

[0123] Example 10

[0124] The polypropylene material was prepared according to the method described in Example 1, except that the proportions of the various substances were different: 58.6 parts by weight of recycled polypropylene, 15 parts by weight of modified diatomaceous earth, 5 parts by weight of seaweed fiber (calcium alginate fiber), 20 parts by weight of polyolefin elastomer (Engage 8180), 1 part by weight of compatibilizer (polypropylene grafted with maleic anhydride / styrene), 0.3 parts by weight of antioxidant (primary antioxidant: DSTP and 3114, secondary antioxidant: 168) and 0.1 parts by weight of light stabilizer were added to a high-speed mixer.

[0125] Embodiment 11

[0126] The polypropylene material was prepared according to the method described in Example 1, except that the proportions of the various substances were different: 73.6 parts by weight of recycled polypropylene, 15 parts by weight of modified diatomaceous earth, 5 parts by weight of seaweed fiber (calcium alginate fiber), 5 parts by weight of polyolefin elastomer (Engage 8180), 1 part by weight of compatibilizer (polypropylene grafted with maleic anhydride / styrene), 0.3 parts by weight of antioxidant (primary antioxidant: DSTP and 3114, secondary antioxidant: 168) and 0.1 parts by weight of light stabilizer were added to a high-speed mixer.

[0127] Example 12

[0128] The polypropylene material was prepared according to the method described in Example 1, except that the proportions of the various substances were different: 60.6 parts by weight of recycled polypropylene, 15 parts by weight of modified diatomaceous earth, 5 parts by weight of seaweed fiber (calcium alginate fiber), 15 parts by weight of polyolefin elastomer (Engage 8180), 4 parts by weight of compatibilizer (polypropylene grafted with maleic anhydride / styrene), 0.3 parts by weight of antioxidant (primary antioxidant: DSTP and 3114, secondary antioxidant: 168) and 0.1 parts by weight of light stabilizer were added to a high-speed mixer.

[0129] Embodiment 13

[0130] The polypropylene material was prepared according to the method described in Example 1, except that the proportions of the various substances were different: 58.6 parts by weight of recycled polypropylene, 15 parts by weight of modified diatomaceous earth, 5 parts by weight of seaweed fiber (calcium alginate fiber), 15 parts by weight of polyolefin elastomer (Engage 8180), 6 parts by weight of compatibilizer (polypropylene grafted with maleic anhydride / styrene), 0.3 parts by weight of antioxidant (primary antioxidant: DSTP and 3114, secondary antioxidant: 168) and 0.1 parts by weight of light stabilizer were added to a high-speed mixer.

[0131] Embodiment 14

[0132] The polypropylene material was prepared according to the method described in Example 1, except that the proportions of the various substances were different: 61.8 parts by weight of recycled polypropylene, 15 parts by weight of modified diatomaceous earth, 5 parts by weight of seaweed fiber (calcium alginate fiber), 15 parts by weight of polyolefin elastomer (Engage 8180), 1 part by weight of compatibilizer (polypropylene grafted with maleic anhydride / styrene), 2 parts by weight of antioxidant (primary antioxidant: DSTP and 3114, secondary antioxidant: 168) and 0.1 parts by weight of light stabilizer were added to a high-speed mixer.

[0133] Embodiment 15

[0134] The polypropylene material is prepared according to the method described in Example 1, except that the proportions of the various substances are different: 62.7 parts by weight of recycled polypropylene, 15 parts by weight of modified diatomaceous earth, 5 parts by weight of seaweed fiber (calcium alginate fiber), 15 parts by weight of polyolefin elastomer (Engage 8180), 1 part by weight of compatibilizer (polypropylene grafted with maleic anhydride / styrene), 0.3 parts by weight of antioxidant (primary antioxidant: DSTP and 3114, secondary antioxidant: 168) and 1 part by weight of light stabilizer are added to a high-speed mixer.

[0135] Example 16

[0136] The polypropylene material was prepared according to the method described in Example 1, except that the seaweed fiber was selected from sodium alginate fiber.

[0137] Embodiment 17

[0138] The polypropylene material was prepared according to the method described in Example 1, except that the seaweed fiber was selected from alginate fiber.

[0139] Comparative Example 1

[0140] A polypropylene material was prepared according to the method described in Example 1, except that modified diatomaceous earth was not added, and the remaining substances were added in the following amounts: 78.6 parts by weight of recycled polypropylene, 5 parts by weight of seaweed fiber (calcium alginate fiber), 15 parts by weight of polyolefin elastomer (Engage 8180), 1 part by weight of compatibilizer (polypropylene grafted with maleic anhydride / styrene), 0.3 parts by weight of antioxidant (primary antioxidant: DSTP and 3114, secondary antioxidant: 168) and 0.1 parts by weight of light stabilizer were added to a high-speed mixer.

[0141] Comparative Example 2

[0142] A polypropylene material was prepared according to the method described in Example 1, except that no seaweed fiber was added, and the remaining substances were added in the following amounts: 68.6 parts by weight of recycled polypropylene, 15 parts by weight of modified diatomaceous earth, 15 parts by weight of polyolefin elastomer (Engage 8180), 1 part by weight of compatibilizer (polypropylene grafted with maleic anhydride / styrene), 0.3 parts by weight of antioxidant (primary antioxidant: DSTP and 3114, secondary antioxidant: 168) and 0.1 parts by weight of light stabilizer were added to a high-speed mixer.

[0143] Comparative Example 3

[0144] The polypropylene material was prepared according to the method described in Example 1, except that modified diatomaceous earth and seaweed fiber were not added, and the remaining substances were added in the following amounts: 83.6 parts by weight of recycled polypropylene, 15 parts by weight of polyolefin elastomer (Engage 8180), 1 part by weight of compatibilizer (polypropylene grafted with maleic anhydride / styrene), 0.3 parts by weight of antioxidant (primary antioxidant: DSTP and 3114, secondary antioxidant: 168) and 0.1 parts by weight of light stabilizer were added to the high-speed mixer.

[0145] Comparative Example 4

[0146] A polypropylene material was prepared according to the method described in Example 1, except that no compatibilizer was added, and the remaining substances were added in the following amounts: 64.6 parts by weight of recycled polypropylene, 15 parts by weight of modified diatomaceous earth, 5 parts by weight of seaweed fiber (calcium alginate fiber), 15 parts by weight of polyolefin elastomer (Engage 8180), 0.3 parts by weight of antioxidant (primary antioxidant: DSTP and 3114, secondary antioxidant: 168) and 0.1 parts by weight of light stabilizer were added to a high-speed mixer.

[0147] Table 2

[0148]

[0149]

[0150] Performance evaluation and implementation standards:

[0151] The polypropylene materials prepared according to Examples 1-17 and Comparative Examples 1-4 were placed in a 100°C blast drying oven for 2-3 hours, and then the dried pellets were injection molded on an injection molding machine to prepare samples. The tensile properties were tested according to ISO 527, the sample size was 170×10×4mm dumbbell-shaped specimens, and the tensile speed was 50mm / min; the bending properties were tested according to ISO 178, the sample size was 80×10×4mm, the bending speed was 2mm / min, and the span was 64mm; the cantilever beam notched impact strength was tested according to ISO 180, the sample size was 80×10×4mm, and the notch was of standard medium A type; for the odor test, the sample was placed in a 1L wide-mouth glass container for odor evaluation, the sample was aged at 80°C for 2h, taken out and cooled to 60°C for evaluation, and the sample size was 200m 2 (can be spliced), VOC is carried out according to HJ / T400, the sample size is 400cm 2 Sample (jointable) using 10L bag.

[0152] The comprehensive performance of the material is evaluated by the notched impact strength, tensile strength, flexural modulus, odor, VOC and flocking effect obtained by testing. The test results of each performance are shown in Table 3.

[0153] Table 3

[0154]

[0155]

[0156] Among them, "*" indicates the imitation flocking effect, and the more "*" there are, the better the imitation flocking effect is.

[0157] From the comparison between Examples 1-5 and Comparative Examples 1 and 3, it can be seen that after adding diatomaceous earth and seaweed fiber, the rigidity and toughness of the material are greatly improved compared with the comparative example without adding diatomaceous earth and seaweed fiber, and the odor intensity of the material is significantly weakened.

[0158] Compared with Examples 1-5, with the addition of diatomaceous earth, the strength and modulus of the material increased, and the odor and emission properties of the material became better and better, but excessive diatomaceous earth would lead to a decrease in the toughness and strength of the material.

[0159] From the comparison between Examples 1, 6-8 and Comparative Examples 2 and 3, it can be seen that the addition of seaweed fiber can effectively improve the rigidity and toughness of the material, and the seaweed fiber can also play an adsorption role and reduce the precipitation of small molecules. When seaweed fiber is added, the surface of the material can have a flocking effect, but too much or too little seaweed fiber will lead to a decrease in the flocking effect. This is because the structure of seaweed fiber is straight and smooth, and a high proportion of seaweed fiber is not easy to disperse, resulting in poor surface effect of the material; a low proportion of seaweed fiber will not easily form a flocking effect, and will also cause poor surface material effect.

[0160] It can be seen from Examples 1 and 9-11 that the addition of elastomer can improve the toughness of the material, and a higher content will lead to an increase in material costs.

[0161] From the comparison between Examples 12-13 and Comparative Example 4, it can be seen that the addition of an appropriate amount of compatibilizer can improve the toughness of the recycled material, but the more the amount added, the higher the cost.

[0162] It can be seen from Examples 16-17 that different types of seaweed fibers have little effect on the performance, indicating that different seaweed fibers can be used to prepare the polypropylene material of the present application.

[0163] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in the field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A polypropylene material, characterized in that: include: Recycled polypropylene, diatomaceous earth, seaweed fiber, polyolefin elastomer, compatibilizer, antioxidant and light stabilizer.

2. The polypropylene material according to claim 1, characterized in that: include: 50-80 parts by weight of recycled polypropylene; 0.1-30 parts by weight of diatomaceous earth; 0.1-10 parts by weight of seaweed fiber; 5-20 parts by weight of a polyolefin elastomer; 0.1-6 parts by weight of a compatibilizer; 0.1-2 parts by weight of an antioxidant; 0.1-1 parts by weight of light stabilizer.

3. The polypropylene material according to claim 2, characterized in that: The recycled polypropylene is made from waste household appliances, automobiles, and daily necessities; And / or, the density of the recycled polypropylene is 0.90 g / cm 3 ~0.95g / cm 3 ; And / or, based on the total mass of the recycled polypropylene, the mass proportion of ash in the recycled polypropylene is no more than 2%.

4. The polypropylene material according to claim 3, characterized in that: The melt index of the recycled polypropylene is (12-22) g / 10min; And / or, the tensile strength of the recycled polypropylene is 15MPa-20MPa; And / or, the flexural modulus of the recycled polypropylene is 1200 MPa-1500 MPa.

5. The polypropylene material according to claim 2, characterized in that: The particle size of the diatomaceous earth is 45 μm-150 μm; And / or, the diatomaceous earth is treated with a surface treatment agent, and the surface treatment agent includes at least one of a silane coupling agent, acetic acid, stearic acid, aluminate, and titanate.

6. The polypropylene material according to claim 2, characterized in that: The seaweed fiber includes at least one of calcium alginate fiber, sodium alginate fiber, alginate fiber and ammonium alginate fiber; and / or, the polyolefin elastomer comprises at least one of ethylene-octene copolymer, ethylene-propylene copolymer, ethylene-hexene copolymer and ethylene-butene copolymer; And / or, the compatibilizer comprises polypropylene grafted with maleic anhydride / styrene; And / or, the antioxidant comprises a primary antioxidant and a secondary antioxidant, the primary antioxidant comprises at least one of a hindered phenol antioxidant and a thioester antioxidant, and the secondary antioxidant comprises at least one of a phosphite antioxidant and an ester antioxidant; And / or, the light stabilizer includes hindered amines, ultraviolet absorbers, or a light stabilizer compounded with hindered amines and ultraviolet absorbers.

7. The polypropylene material according to claim 6, characterized in that: The seaweed fiber is selected from calcium alginate fiber, the length of the calcium alginate fiber is 2mm-25mm, and the fineness of the calcium alginate fiber is 2dtex-5dtex; And / or, the polyolefin elastomer is selected from ethylene-octene copolymer, and the density of the ethylene-octene copolymer is 0.88 g / cm 3 -0.90g / cm 3 , the melt index of the ethylene-octene copolymer is (0.5-14) g / 10min; And / or, the grafting rate of maleic anhydride in the polypropylene grafted maleic anhydride / styrene is 0.5% to 3%, and the melt index of the polypropylene grafted maleic anhydride / styrene is (40 to 150) g / 10min; And / or, the primary antioxidant is selected from at least one of 3,5-di-tert-butyl-4-hydroxybenzyl diethyl phosphate, pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate and octadecyl thiodipropionate, and the secondary antioxidant is selected from at least one of pentaerythritol distearyl diphosphite and tris(2,4-di-tert-butylbenzyl) phosphite.

8. A method for preparing the polypropylene material according to any one of claims 1 to 7, characterized in that: include: The recycled polypropylene, diatomaceous earth, seaweed fiber, polyolefin elastomer, compatibilizer, antioxidant and light stabilizer are mixed to obtain a mixture; The mixture is subjected to melt extrusion and pelletization to obtain the polypropylene material.

9. Use of the polypropylene material according to any one of claims 1 to 7 or the polypropylene material prepared by the method according to claim 8 in manufacturing automotive interior parts.

10. The use according to claim 9, characterized in that: The interior trim part includes at least one of an instrument panel, a door panel, a storage box and a glove box.

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