Polypropylene composite material for automobile thin-wall door panel and preparation method of polypropylene composite material

Abstract

The invention discloses a polypropylene composite material for an automobile thin-wall door panel and a preparation method thereof, and belongs to the technical field of high polymer materials. The composite material comprises the following raw materials in parts by mass: 35-45 parts of first copolymerized PP; 30 to 40 parts of second copolymerized PP (polypropylene); 6-10 parts of a toughening agent; 10-20 parts of an inorganic filler; 0.5 to 2 parts of deodorizing master batch; 2-3 parts of a scratch resistant agent; 0.2 part of a lubricant; 0.5 part of an antioxidant; and 0.3 part of a weather-resistant agent. Wherein the low-odor PP base material and the self-made odor removal master batch are selected and matched with the gas stripping agent and the baking process to jointly improve the low-odor property of the composite material. The PP base material has low gloss and is matched with inorganic powder filling to reduce the glossiness of the composite material, and the special rheological lubricant is added, so that the fluidity of the composite material can be further improved on the premise of keeping the mechanical properties of the material basically unchanged, the good appearance of a workpiece can be ensured, and the composite material is excellent in comprehensive performance and good in application prospect. The method is very suitable for producing large-scale interior parts, especially thin-wall door plates.

Description

Technical Field

[0001] The present invention belongs to the technical field of polymer materials, and particularly relates to a polypropylene composite material for automotive thin-wall door panels and a preparation method thereof. Background Art

[0002] With the rapid development of the automotive industry, consumers' requirements for the quality and performance of automobiles are constantly increasing. As an important part of the automotive interior, automotive thin-wall door panels not only need to have excellent mechanical properties to ensure safety and stability during use, but also require high fluidity to adapt to the thin-wall molding process, reduce production costs and improve production efficiency. At the same time, low odor and low gloss are also key factors in enhancing the overall quality and market competitiveness of automobiles.

[0003] Currently, conventional polypropylene materials have many problems when used for automotive thin-wall door panels. Firstly, insufficient fluidity makes it easy to appear defects such as poor filling and poor surface quality during the thin-wall molding process, affecting the appearance and performance of the product. Secondly, in terms of appearance, traditional polypropylene materials may have problems such as strong odor, high gloss, uneven color, and rough surface, making it difficult to meet consumers' requirements for the comfort and aesthetics of automotive interiors. In addition, in terms of mechanical properties, the strength, stiffness, and wear resistance of traditional polypropylene materials may not meet the requirements of automotive thin-wall door panels in complex use environments.

[0004] To solve these problems, researchers have carried out a large number of explorations and attempts. However, existing solutions often have some limitations. For example, some flow modifiers may have an adverse impact on other properties of the material, such as reducing mechanical strength and affecting thermal stability. At the same time, in terms of improving the appearance quality, simply relying on additives may not achieve the ideal effect, and comprehensive considerations need to be made from aspects such as material formulation design and preparation process. Therefore, developing a low-odor and low-gloss polypropylene composite material for automotive thin-wall door panels has important practical significance and application value. Summary of the Invention

[0005] Aiming at the deficiencies of the prior art, the purpose of the present invention is to provide a field-effect transistor sensor for calcium ion detection and a preparation method thereof, which solves the problems in the prior art.

[0006] The purpose of the present invention can be achieved by the following technical solutions:

[0007] A polypropylene composite material for automotive thin-wall door panels, comprising the following raw materials in parts by mass:

[0008]

[0009] Further, the first copolymerized PP is a medium impact copolymerized PP with a melt index range of 50 - 120 g / 10 min under the test conditions of 230 °C and 2.16 Kg; the second copolymerized PP is a high impact copolymerized PP with a melt index range of 10 - 30 g / 10 min under the test conditions of 230 °C and 2.16 Kg; the density of both is 0.88 - 0.91 g / cm 3 .

[0010] Further, the toughening agent is one or several of ethylene octene copolymer or ethylene butene copolymer.

[0011] Further, the inorganic filler is one or several of talc powder, calcium carbonate, wollastonite, mica powder, whiskers.

[0012] Further, the deodorant masterbatch includes a PP substrate, diatomaceous earth, and a carboxylate nucleating agent.

[0013] Further, the scratch resistant agent is selected from one or several of silicone masterbatch, oleic acid amide, erucic acid amide, ethylene bisstearamide, a blend of erucic acid amide and ethylene - ethyl acrylate copolymer.

[0014] Further, the lubricant is a rheological lubricant.

[0015] Further, the antioxidant is selected from one or several of antioxidant 1010, antioxidant 168, antioxidant 1076; the weathering agent is selected from one or several of benzotriazoles, benzophenones, salicylate esters, triazines, substituted acrylonitriles, hindered amines, organonickel chelates.

[0016] The preparation method of the above - mentioned polypropylene composite material for automotive thin - wall door panels is characterized by comprising the following steps:

[0017] S1, putting the first copolymerized PP, the second copolymerized PP, the toughening agent, the inorganic filler, the deodorant masterbatch, the scratch resistant agent, the antioxidant, the weathering agent, and the lubricant into a high - speed mixer, and mixing to obtain a premix;

[0018] S2, pouring the obtained premix into the hopper of an extruder, entering the screw barrel of the extruder through the feeding port, and extruding and pelletizing after mixing, plasticizing, and melting in the extruder;

[0019] S3, cooling, screening, and uniformly mixing the pelletized material, and then drying and cooling to obtain the product.

[0020] The application of the above - mentioned polypropylene composite material for automotive thin - wall door panels in the preparation of automotive thin - wall door panels.

[0021] The beneficial effects of the present invention:

[0022] 1. The present invention uses a low-odor PP substrate and a self-made deodorizing masterbatch, and cooperates with a gas stripping agent and a baking process to improve the low-odor property of the composite material. The PP substrate also has low gloss, and the inorganic powder filling reduces the gloss of the composite material. The addition of a special rheological lubricant can further improve the fluidity of the composite material while keeping the mechanical properties of the material basically unchanged, thereby ensuring the good appearance of the product. The composite material has excellent comprehensive performance and is very suitable for the production of large interior parts, especially thin-walled door panels.

[0023] 2. The polypropylene composite material prepared by the present invention is not only simple in process and easy to produce, but also has low overall cost, and is very suitable for large-scale industrial application.

[0024] 3. The homemade deodorizing masterbatch of the present invention is composed of a PP substrate, diatomaceous earth, and a carboxylate nucleating agent, wherein the nucleating agent can introduce a large number of crystal nuclei into the matrix, greatly improving the crystallinity of the polymer. The crystallinity changes the regularity of the internal structure of the polymer, the molecules are arranged tightly and orderly, the release of volatile organic compounds is hindered, and the volatility is reduced. Compared with adsorbents such as zeolite and metal oxides, the diatomaceous earth with a multi-level pore structure has a porous pore size and a high specific surface area, which enables it to more widely absorb volatile organic compounds of different types and sizes. The two can synergistically reduce the emission of organic volatiles, thereby effectively improving the odor of the modified material. DETAILED DESCRIPTION

[0025] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solution of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] A polypropylene composite material for automobile thin-wall door panels, comprising the following raw materials in parts by weight:

[0027]

[0028] A polypropylene composite material for automobile thin-wall door panels further comprises, by weight: 0.4-0.6 parts of antioxidant, 0.2-0.4 parts of weathering agent, and 0.1-0.3 parts of lubricant.

[0029] The first copolymer PP is a medium-impact copolymer PP with a melt index range of 50-120 g / 10 min under the test conditions of 230°C and 2.16 kg; the second copolymer PP is a high-impact copolymer PP with a melt index range of 10-30 g / 10 min under the test conditions of 230°C and 2.16 kg; the density of both is 0.88-0.91 g / cm 3 .

[0030] The toughening agent is one or more of ethylene octene copolymer or ethylene butene copolymer, with a melt index range of 2 - 30 g / 10 min and a density of 0.8 g / cm 3 - 0.9 g / cm 3 .

[0031] The inorganic filler is one or more of talc powder, calcium carbonate, wollastonite, mica powder, and whiskers, with a mesh number of 1250 - 5000 meshes.

[0032] The scratch - resistant agent is selected from one or more of silicone masterbatch, oleic acid amide, erucic acid amide, ethylene bisstearamide, and a compound blend of erucic acid amide and ethylene - ethyl acrylate copolymer.

[0033] The deodorant masterbatch includes 50% by mass of PP substrate, 40% by mass of diatomite, and 10% by mass of carboxylate nucleating agent;

[0034] The lubricant is a special rheology lubricant modified based on behenic acid ester, which can effectively improve the fluidity and lubricity of the polypropylene system;

[0035] The antioxidant is selected from one or more of antioxidant 1010, antioxidant 168, and antioxidant 1076.

[0036] The weathering agent is selected from one or more of benzotriazoles, benzophenones, salicylate esters, triazines, substituted acrylonitriles, hindered amines, and organonickel chelates.

[0037] The preparation method of the above - mentioned polypropylene composite material for automotive thin - wall door panels includes the following steps:

[0038] S1. Put the first copolymerized PP, the second copolymerized PP, the toughening agent, the inorganic filler, the adsorbent, the nucleating agent, the scratch - resistant agent, the antioxidant, the weathering agent, and the lubricant into a high - speed mixer in sequence according to the ratio, and mix for 2 - 3 min to obtain a premix;

[0039] S2. Pour the obtained premix into the hopper of the extruder, enter the screw barrel of the extruder through the feeding port, and extrude and pelletize after mixing, plasticizing, and melting in the extruder. The structural feature of the extruder is that pure water is injected through the air - lifting agent port in zones 2 - 5, and double - vacuum systems are used to evacuate in zones 5 - 8 and 8 - 11;

[0040] The vacuum degree of the double vacuum system is ≥ 0.08 MPa, the proportion of the stripping agent is 1-6% of the total weight of the resin granulation material. Pure water enters the screw barrel through the water injection port, evaporates into water vapor in a high-temperature environment, contacts the surface of the plastic melt, and under the extraction effect of vacuum negative pressure, most of the odor small molecules are carried away, achieving the effect of reducing odor and VOC. The length-diameter ratio of the extruder screw is (40-48):1. The temperature of the extruder is: 80-120 °C in zone 1, 180-200 °C in zones 2-5, and 190-210 °C in other zones.

[0041] S3. After cooling, screening, and homogenizing the granulation material, it is dried in an environment of 110-130 °C for 6-8 h and then naturally cooled to obtain a low-odor and good-appearance polypropylene composite material for automotive thin-walled door panels.

[0042] The technical solutions of the present invention will be described below through the following examples and comparative examples. Among them, the raw material information used in the examples and comparative examples is shown in Table 1 below:

[0043] Table 1 Raw Material Information Table

[0044]

[0045]

[0046] The component ratios (parts by mass) of each group in Examples 1-9 are shown in Table 2, and the component ratios (parts by mass) of each group in Examples 10-12 and Comparative Examples 1-8 are shown in Table 3.

[0047] Table 2 Component Ratios and Performance Test Results of Each Group in Examples 1-9 (parts by mass)

[0048]

[0049] Table 3 Component Ratios and Performance Test Results of Each Group in Examples 10-12 and Comparative Examples 1-8 (parts by mass)

[0050]

[0051] The methods for preparing the polypropylene composite materials in Examples 1-12 and Comparative Examples 1-8 include the following steps:

[0052] S1. According to the raw material ratios in Table 2 and Table 3, all raw materials are added to a high-speed mixer and mixed for 2 min to obtain a premix.

[0053] S2. Pour the obtained premix into the hopper of the extruder, and enter the screw barrel of the extruder through the feeding port. After mixing, plasticizing, and melting in the extruder, granulation is carried out. The structural feature of the extruder is that pure water is injected through the air stripping agent port in zones 2-5, and a double-vacuum system is used to evacuate in zones 5-8 and 8-11. After cooling, screening, and uniform mixing of the granulated material, it is dried in an environment of 120 °C for 6 hours and then naturally cooled to obtain the polypropylene composite material.

[0054] Experimental tests

[0055] Perform performance tests on the products of Examples 1-12 and Comparative Examples 1-8;

[0056] The test items and test methods are as follows:

[0057] 1) Scratch resistance test: Make a leather grain board, use a cross cutter to draw orthogonal 20*20 stripes on the leather grain board with a load of 10 N, and evaluate the scratch resistance by measuring the ΔL value (change in black and white color) on the surface of the sample before and after scratching with a color difference meter. The smaller the value of ΔL, the better the scratch resistance.

[0058] 2) Odor level test: Conduct the odor level test according to the Volkswagen PV3900 standard. The odor level is divided into six levels, as shown in Table 4:

[0059] Table 4 Odor level classification

[0060]

[0061] Among them, the evaluation results of the odor assessors may not be integers, and the final rating result is the arithmetic mean of the scores given by five raters;

[0062] 3) Glossiness test: Make a leather grain board, the test standard is ISO 2813, use a glossiness meter to test, the test angle is 60°, and the test surface of the sample is the leather grain surface.

[0063] 4) The mechanical test methods of the composite materials all refer to the ISO standard: Tensile strength is tested according to ISO 527, flexural modulus is tested according to ISO 178, and Izod notched impact strength is tested according to ISO 180.

[0064] The performance test results of the products of Examples 1-9 are shown in Table 2, and the performance test results of the products of Examples 10-12 and Comparative Examples 1-8 are shown in Table 3;

[0065] Based on the test data in Table 2 and Table 3, the analysis is as follows:

[0066] It can be seen from Examples 1-3 and Comparative Examples 1-2 that by adding the self-made deodorant masterbatch, cooperating with the low-odor substrate and appropriate process conditions, a composite material with good odor can be obtained. If the proportion of the added deodorant masterbatch is too large, the improvement of the odor is not obvious enough, and the impact strength is greatly affected, which is also not conducive to the control of the material cost. It can be seen from Example 1 and Comparative Examples 5-6 that by adding a rheological lubricant, the fluidity of the composite material is significantly improved, and the influence on the mechanical properties is small. The composite material has excellent comprehensive properties and is suitable for producing large interior parts such as thin-walled door panels.

[0067] In the description of this specification, the descriptions referring to the terms "one embodiment", "example", "specific example", etc. mean that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0068] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art of this industry should understand that the present invention is not limited by the above embodiments. The above embodiments and the descriptions in the specification only illustrate the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed.

Claims

1. A polypropylene composite material for automobile thin-walled door panels, characterized in that: Including the following raw materials by weight:

2. The polypropylene composite material for automobile thin-walled door panels according to claim 1, characterized in that: The first copolymer PP is a medium-impact copolymer PP with a melt index range of 50-120 g / 10 min under the test conditions of 230°C and 2.16 kg; the second copolymer PP is a high-impact copolymer PP with a melt index range of 10-30 g / 10 min under the test conditions of 230°C and 2.16 kg; the density of both is 0.88-0.91 g / cm 3 .

3. The polypropylene composite material for automobile thin-walled door panels according to claim 1, characterized in that: The toughening agent is one or more of ethylene octene copolymer or ethylene butene copolymer.

4. The polypropylene composite material for automobile thin-walled door panels according to claim 1, characterized in that: The inorganic filler is one or more of talc powder, calcium carbonate, wollastonite, mica powder and whisker.

5. The polypropylene composite material for automobile thin-walled door panels according to claim 1, characterized in that: The deodorizing masterbatch comprises a PP substrate, diatomaceous earth and a carboxylate nucleating agent.

6. The polypropylene composite material for automobile thin-walled door panels according to claim 1, characterized in that: The scratch resistant agent is selected from one or more of silicone masterbatch, oleamide, erucamide, ethylenebisstearamide, erucamide and ethylene-ethyl acrylate copolymer.

7. The polypropylene composite material for automobile thin-walled door panels according to claim 1, characterized in that: The lubricant is a rheological lubricant.

8. The polypropylene composite material for automobile thin-walled door panels according to claim 1, characterized in that: The antioxidant is selected from one or more of antioxidant 1010, antioxidant 168, and antioxidant 1076; the weathering agent is selected from one or more of benzotriazoles, benzophenones, salicylates, triazines, substituted acrylonitriles, hindered amines, and organic nickel chelates.

9. The method for preparing a polypropylene composite material for automobile thin-walled door panels according to any one of claims 1 to 8, characterized in that: The following steps are involved: S1, putting the first copolymer PP, the second copolymer PP, a toughening agent, an inorganic filler, a deodorizing masterbatch, a scratch resistance agent, an antioxidant, a weather resistance agent, and a lubricant into a high-speed mixer, and mixing to obtain a premix; S2, pouring the obtained premix into the extruder hopper, entering the extruder barrel through the feed port, and extruding and granulating after mixing, plasticizing and melting in the extruder; S3, cooling, screening, and uniformly mixing the granulated materials, and then drying and cooling them to obtain the granulated materials.

10. Use of the polypropylene composite material for automobile thin-walled door panels according to any one of claims 1 to 8 in the preparation of automobile thin-walled door panels.

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