Weather-resistant modified particles for automobile exterior trimming parts and preparation method of weather-resistant modified particles

Abstract

The invention relates to the technical field of high polymer material modification technology, and discloses a weather-resistant modified particle for automobile exterior trimming parts, which comprises the following components in parts by weight: 60-80 parts of base material resin, 5-20 parts of weather-resistant elastomer, 3-8 parts of weather-resistant master batch, 5-10 parts of filler and 0.5-2 parts of assistant, wherein a preparation method of the weather-resistant master batch comprises the following steps: uniformly mixing carrier resin, a composite light stabilizer, an ultraviolet light absorber and an antioxidant in a high-speed mixer, and then blending, extruding, cooling and pelletizing through a double-screw extruder, thereby obtaining the weather-resistant master batch. The weather-resistant master batch prepared by dispersing in advance is adopted, so that the problem that auxiliaries in traditional simple mixing are easy to gather, migrate and lose is solved, effective protection components in the automobile exterior trimming part can continuously and stably play a role when the automobile exterior trimming part is subjected to strong ultraviolet rays, day and night temperature difference and damp and heat erosion for a long time, and the service life of the automobile exterior trimming part is prolonged. Therefore, the aging process of the material is obviously delayed.

Description

Technical Field

[0001] This invention relates to the field of polymer material modification technology, specifically to a weather-resistant modified particle for automotive exterior parts and its preparation method. Background Technology

[0002] Automotive exterior components, such as bumpers, door handles, and side skirts, are important parts of a car. They not only directly affect the vehicle's appearance and brand image, but are also exposed to complex outdoor environments for extended periods, requiring them to withstand various harsh factors such as ultraviolet radiation, high and low temperatures, rain and snow, humidity and heat, and pollutants.

[0003] Existing technologies commonly use plastics such as polypropylene and ABS as the base material, and modify them by adding additives such as ultraviolet absorbers, light stabilizers and antioxidants during the production process in order to improve the anti-aging ability of the material. These methods mainly use physical blending to mix various functional additives with the base resin, toughening agents and fillers in one step, and then melt extrusion granulation to prepare modified plastic granules that can be used for injection molding.

[0004] However, the above-mentioned existing technical solutions have obvious drawbacks: due to the large differences in the physical properties of each component, functional additives, especially small molecule additives in powder form, are difficult to achieve uniform dispersion in the matrix and are prone to local agglomeration. This not only reduces the utilization efficiency of the additives, but may also become stress defect points inside the material. During long-term use, these additives will gradually migrate to the material surface and precipitate, or be rapidly consumed under the action of environmental factors, resulting in a rapid decline in their protective effect. The material will still show obvious problems such as yellowing, surface powdering, and increased brittleness. Summary of the Invention

[0005] The purpose of this invention is to provide a weather-resistant modified particle for automotive exterior parts and its preparation method, so as to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A weather-resistant modified particle for automotive exterior parts, comprising the following components by weight:

[0008] 60-80 parts base resin, 5-20 parts weather-resistant elastomer, 3-8 parts weather-resistant masterbatch, 5-10 parts filler and 0.5-2 parts additives;

[0009] The weather-resistant masterbatch is prepared by mixing the carrier resin, composite light stabilizer, ultraviolet absorber and antioxidant in a high-speed mixer until uniform, and then melting, extruding, cooling and pelletizing it through a twin-screw extruder at a temperature 10-20°C lower than the conventional processing temperature of the carrier resin.

[0010] As a further embodiment of the present invention: the base resin is one or more of polypropylene, copolymer polypropylene, and high-impact polypropylene;

[0011] The weather-resistant elastomer is an ethylene-octene copolymer or an ethylene-butene copolymer.

[0012] As a further embodiment of the present invention: the filler is talc powder or barium sulfate that has been surface-treated with a silane coupling agent, and the median particle size of the filler is 1.5 to 3 μm.

[0013] As a further embodiment of the present invention: the carrier resin is linear low-density polyethylene or ethylene-vinyl acetate copolymer;

[0014] The composite light stabilizer is a hindered amine light stabilizer, and the hindered amine light stabilizer is a polymeric hindered amine light stabilizer with a molecular weight greater than 2000 g / mol;

[0015] The ultraviolet absorber is a benzotriazole or triazine ultraviolet absorber;

[0016] The antioxidant is a hindered phenolic antioxidant.

[0017] As a further aspect of the present invention, the additive is at least two of the following: lubricant, anti-hydrolysis agent, and pigment dispersant.

[0018] This invention also discloses a method for preparing weather-resistant modified particles for automotive exterior parts, comprising the following steps:

[0019] S1. Initial mixing: The base resin, weather-resistant elastomer and filler are added to a high-speed mixer to obtain initial mixture A;

[0020] S2. Final mixing: Transfer the initial mixture A to a high-speed mixer, add the weather-resistant masterbatch and processing aid package to obtain mixture B;

[0021] S3. Granulation: The mixture B is fed into a twin-screw extruder and melt-blended, extruded, cooled, pelletized and dried at a screw speed of 300-500 rpm and a processing temperature of 180-220°C to obtain the weather-resistant modified granules for automotive exterior parts.

[0022] As a further embodiment of the present invention: in S1, the high-speed mixer mixes at 60-80°C for 5-10 minutes; in S2, the high-speed mixer mixes at 40-60°C for 3-5 minutes.

[0023] As a further embodiment of the present invention: in S3, the screw assembly of the twin-screw extruder includes at least 3 sets of kneading blocks, and the last kneading block is located downstream of the feed port of the weather-resistant masterbatch.

[0024] As a further embodiment of the present invention: in S3, the melt blending process is carried out in the exhaust section with a vacuum degree of -0.04 to -0.06 MPa for devolatilization; the extruded strip is cooled by a water tank with the water temperature controlled at 25 to 35°C; the drying conditions are hot air drying at 80 to 100°C for 2 to 4 hours.

[0025] Compared with the prior art, the beneficial effects of the present invention are:

[0026] This invention utilizes pre-dispersed weather-resistant masterbatch and a granulation process to construct a weather-resistant protection system. This solves the problem of additives easily agglomerating, migrating, and being lost in traditional simple mixing processes. As a result, the effective protective components inside automotive exterior parts can continuously and stably function when exposed to strong ultraviolet radiation, diurnal temperature differences, and humid heat over long periods of time. This significantly slows down the aging process of the materials and overcomes problems such as yellowing, loss of gloss, chalking, and performance degradation that easily occur in automotive exterior parts during long-term outdoor use.

[0027] This invention scientifically combines a micron-sized filler, which has been surface-treated with a silane coupling agent, with a specific type and amount of base resin, weather-resistant elastomer, and weather-resistant masterbatch. This results in a tighter bond between the components within the material, allowing it to achieve sufficient hardness and strength while maintaining good flexibility and impact resistance. Attached Figure Description

[0028] Figure 1 This is a graph showing experimental data from Experiment 1 of a weather-resistant modified particle for automotive exterior parts and its preparation method.

[0029] Figure 2 This is a graph showing experimental data from Experiment 2 of a weather-resistant modified particle for automotive exterior parts and its preparation method. Detailed Implementation

[0030] Example 1

[0031] A type of weather-resistant modified granule for automotive exterior parts, comprising the following components by weight: 60 parts base resin, 5 parts weather-resistant elastomer, 3 parts weather-resistant masterbatch, 10 parts filler and 2 parts additives;

[0032] The base resin is polypropylene;

[0033] The weather-resistant elastomer is an ethylene-octene copolymer;

[0034] The weather-resistant masterbatch is prepared as follows: The carrier resin, composite light stabilizer, UV absorber, and antioxidant are mixed evenly in a high-speed mixer, and then melt-blended, extruded, cooled, and pelletized using a twin-screw extruder at a temperature 10°C lower than the conventional processing temperature of the carrier resin. The carrier resin is linear low-density polyethylene; the composite light stabilizer is a hindered amine light stabilizer, specifically a polymeric hindered amine light stabilizer with a molecular weight greater than 2000 g / mol; the UV absorber is a benzotriazole derivative; and the antioxidant is a hindered phenolic antioxidant.

[0035] The filler is talc powder that has been surface-treated with a silane coupling agent, and the median particle size of the filler is 1.5 μm;

[0036] The additives are lubricants and anti-hydrolysis agents.

[0037] A method for preparing weather-resistant modified particles for automotive exterior parts includes the following steps:

[0038] S1. Initial mixing: Add the base resin, weather-resistant elastomer and filler to a high-speed mixer to obtain initial mixture A; mix in the high-speed mixer at 60-80°C for 5-10 minutes;

[0039] S2. Final mixing: Transfer the initial mixture A to a high-speed mixer, add the weather-resistant masterbatch and processing aid package to obtain mixture B; mix in the high-speed mixer at 40-60℃ for 3-5 minutes;

[0040] S3. Granulation: The mixture B is fed into a twin-screw extruder and melt-blended, extruded, cooled, pelletized, and dried at a screw speed of 300-500 rpm and a processing temperature of 180-220℃ to obtain weather-resistant modified granules for automotive exterior parts. The twin-screw extruder consists of at least three sets of kneading blocks, with the last kneading block located downstream of the feed port of the weather-resistant masterbatch. The melt-blending process is carried out in the exhaust section with a vacuum of -0.04 to -0.06 MPa. The extruded strip is cooled in a water bath at a temperature controlled at 25-35℃. The drying conditions are hot air drying at 80-100℃ for 2-4 hours.

[0041] Example 2

[0042] A weather-resistant modified granule for automotive exterior parts comprises, by weight, the following components: 70 parts base resin, 12.5 parts weather-resistant elastomer, 5.5 parts weather-resistant masterbatch, 7.5 parts filler, and 1.25 parts additives;

[0043] The base resin is polypropylene and copolymer polypropylene;

[0044] The weather-resistant elastomer is an ethylene-butene copolymer;

[0045] The weather-resistant masterbatch is prepared as follows: The carrier resin, composite light stabilizer, UV absorber, and antioxidant are mixed evenly in a high-speed mixer, and then melt-blended, extruded, cooled, and pelletized using a twin-screw extruder at a temperature 15°C lower than the conventional processing temperature of the carrier resin. The carrier resin is an ethylene-vinyl acetate copolymer; the composite light stabilizer is a hindered amine light stabilizer, specifically a polymeric hindered amine light stabilizer with a molecular weight greater than 2000 g / mol; the UV absorber is a triazine UV absorber; and the antioxidant is a hindered phenolic antioxidant.

[0046] The filler is barium sulfate that has been surface-treated with a silane coupling agent, and the median particle size of the filler is 2.25 μm;

[0047] The additives are lubricants and pigment dispersants;

[0048] The rest of the content is the same as in Example 1.

[0049] Example 3

[0050] A weather-resistant modified granule for automotive exterior parts comprises, by weight, the following components: 80 parts base resin, 20 parts weather-resistant elastomer, 8 parts weather-resistant masterbatch, 5 parts filler, and 0.5 parts additives;

[0051] The base resin is polypropylene, copolymer polypropylene, and high-impact polypropylene;

[0052] The weather-resistant elastomer is an ethylene-butene copolymer;

[0053] The weather-resistant masterbatch is prepared as follows: The carrier resin, composite light stabilizer, UV absorber, and antioxidant are mixed evenly in a high-speed mixer, and then melt-blended, extruded, cooled, and pelletized using a twin-screw extruder at a temperature 20°C lower than the conventional processing temperature of the carrier resin. The carrier resin is linear low-density polyethylene; the composite light stabilizer is a hindered amine light stabilizer, specifically a polymeric hindered amine light stabilizer with a molecular weight greater than 2000 g / mol; the UV absorber is a triazine UV absorber; and the antioxidant is a hindered phenolic antioxidant.

[0054] The filler is talc powder that has been surface-treated with a silane coupling agent, and the median particle size of the filler is 3 μm;

[0055] The additives are anti-hydrolysis agents and pigment dispersants;

[0056] The rest of the content is the same as in Example 1.

[0057] To better illustrate the technical effects of the present invention, the following experiments were conducted for verification:

[0058] like Figure 1 As shown:

[0059] Experiment 1: Verify that using weather-resistant masterbatch, compared to the traditional method of directly blending powder additives with matrix resin, can achieve better and more durable weather resistance.

[0060] Comparative Example 1: The traditional direct blending method was used; the formulation of Example 2 was adjusted: instead of preparing weather-resistant masterbatch, equal amounts of linear low-density polyethylene, hindered amine light stabilizer, triazine ultraviolet absorber, and hindered phenolic antioxidant were mixed in powder form with PP, POE, fillers, etc. in a high-speed mixer in one step, and then granulated by twin-screw extruder using the same process.

[0061] Experimental example group: Samples from Example 2 of the present invention.

[0062] Test sample preparation: The two types of granules were injection molded into standard test strips under the same conditions.

[0063] Dispersion evaluation: The sample was broken into brittle pieces, and the cross-section was treated with gold sputtering. The micro-dispersion state of the filler and auxiliary phases was observed using a scanning electron microscope.

[0064] Weather resistance test:

[0065] Test method: Accelerated aging test was conducted using a xenon lamp aging test chamber according to GB / T16422.2-2014 standard; conditions: black panel temperature 65±3℃, chamber temperature 38±3℃, relative humidity 50±5%, irradiance 0.51W / m². 2 @340nm, using a light / dark cycle (102 minutes of light exposure followed by 18 minutes of spraying).

[0066] Test indicators and cycles: Samples were taken and tested after aging for 0 hours, 500 hours, 1000 hours and 1500 hours respectively.

[0067] Color change: Use a colorimeter to measure and assess the degree of yellowing.

[0068] Surface gloss retention (60°): Measured using a gloss meter.

[0069] Mechanical property retention rate: The notched impact strength of the simply supported beam of the specimen after aging is tested, and the retention rate relative to the initial value at 0 hours is calculated.

[0070] Experimental table: such as Figure 1 As shown.

[0071] Experimental conclusion: The data from Experiment 1 fully demonstrate that the uniformity of the dispersion of additives in the matrix is ​​fundamentally improved after adopting weather-resistant masterbatch technology, effectively preventing local agglomeration. This allows the additive system to function more efficiently and for longer, thus exhibiting color stability, surface gloss retention, and mechanical property retention far superior to the traditional direct blending method during long-term aging.

[0072] like Figure 2 As shown:

[0073] Experiment 2: The technical effect of micron-sized fillers treated with silane coupling agents and specific compound systems on improving interfacial bonding and achieving a balance between rigidity and toughness.

[0074] Comparative Example 2: The formulation and processing technology are exactly the same as those in Example 3, except that the filler was not surface-treated with silane coupling agent and untreated talc powder was added directly.

[0075] Experimental methods: Tensile strength was tested according to ISO 527-2 standard, and notched impact strength of simply supported beams was tested according to ISO 179-1 standard.

[0076] Experimental table: such as Figure 2 As shown.

[0077] Experimental conclusions: The data from Example 3 show that the material maintains high rigidity while exhibiting excellent toughness. In contrast, in Comparative Example 2, due to the lack of surface treatment of talc powder, the interfacial compatibility between the powder and the polypropylene matrix and elastomer is poor, resulting in weak adhesion. When subjected to impact, it is prone to interfacial debonding, leading to a significant decrease in both tensile strength and impact strength.

[0078] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

[0079] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

Claims

1. A type of weather-resistant modified particle for automotive exterior parts, characterized in that, By weight, it includes the following components: 60-80 parts base resin, 5-20 parts weather-resistant elastomer, 3-8 parts weather-resistant masterbatch, 5-10 parts filler and 0.5-2 parts additives; The weather-resistant masterbatch is prepared by mixing the carrier resin, composite light stabilizer, ultraviolet absorber and antioxidant in a high-speed mixer until uniform, and then melting, extruding, cooling and pelletizing it through a twin-screw extruder at a temperature 10-20°C lower than the conventional processing temperature of the carrier resin.

2. The weather-resistant modified particles for automotive exterior parts according to claim 1, characterized in that, The base resin is one or more of polypropylene, copolymer polypropylene, and high-impact polypropylene; The weather-resistant elastomer is an ethylene-octene copolymer or an ethylene-butene copolymer.

3. The weather-resistant modified particles for automotive exterior parts according to claim 1, characterized in that, The filler is talc or barium sulfate that has been surface-treated with a silane coupling agent, and the median particle size of the filler is 1.5 to 3 μm.

4. The weather-resistant modified particles for automotive exterior parts according to claim 1, characterized in that, The carrier resin is linear low-density polyethylene or ethylene-vinyl acetate copolymer; The composite light stabilizer is a hindered amine light stabilizer, and the hindered amine light stabilizer is a polymeric hindered amine light stabilizer with a molecular weight greater than 2000 g / mol; The ultraviolet absorber is a benzotriazole or triazine ultraviolet absorber; The antioxidant is a hindered phenolic antioxidant.

5. The weather-resistant modified particles for automotive exterior parts according to claim 1, characterized in that, The additive is at least two of the following: lubricant, anti-hydrolysis agent, and pigment dispersant.

6. A method for preparing weather-resistant modified particles for automotive exterior parts according to any one of claims 1 to 5, characterized in that, Includes the following steps: S1. Initial mixing: The base resin, weather-resistant elastomer and filler are added to a high-speed mixer to obtain initial mixture A; S2. Final mixing: Transfer the initial mixture A to a high-speed mixer, add the weather-resistant masterbatch and processing aid package to obtain mixture B; S3. Granulation: The mixture B is fed into a twin-screw extruder and melt-blended, extruded, cooled, pelletized and dried at a screw speed of 300-500 rpm and a processing temperature of 180-220°C to obtain the weather-resistant modified granules for automotive exterior parts.

7. The method for preparing weather-resistant modified particles for automotive exterior parts according to claim 6, characterized in that, In step S1, the high-speed mixer mixes at 60–80°C for 5–10 minutes; in step S2, the high-speed mixer mixes at 40–60°C for 3–5 minutes.

8. The method for preparing weather-resistant modified particles for automotive exterior parts according to claim 6, characterized in that, In S3, the screw assembly of the twin-screw extruder includes at least 3 sets of kneading blocks, and the last kneading block is located downstream of the feed port of the weather-resistant masterbatch.

9. The method for preparing weather-resistant modified particles for automotive exterior parts according to claim 6, characterized in that, In S3, the melt blending process is carried out in the exhaust section with a vacuum degree of -0.04 to -0.06 MPa for devolatilization; the extruded strip is cooled by a water tank with the water temperature controlled at 25 to 35°C; the drying conditions are hot air drying at 80 to 100°C for 2 to 4 hours.

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