Polypropylene composition as well as preparation method and application thereof

Abstract

The invention discloses a polypropylene composition as well as a preparation method and application thereof, and belongs to the technical field of high polymer materials. The polypropylene composition provided by the invention is prepared from the following components in parts by mass: 23 to 62 parts of PP resin, 18 to 32 parts of POE (Polyolefin Elastomer), 1 to 7 parts of chopped glass fiber and 13 to 27 parts of mica powder. The ratio [eta] PP / [eta] POE of the melt shear viscosity [eta] PP of the PP resin at the temperature of 200 DEG C and the shear rate of 100 S <-1 > to the melt shear viscosity [eta] POE of the POE elastomer at the temperature of 200 DEG C and the shear rate of 100 S <-1 > is 0.38-1.65; the length-diameter ratio of the chopped glass fiber is 280 to 350; and the D50 diameter of the mica powder is 15-35 [mu] m. The polypropylene composition provided by the invention has relatively low linear thermal expansion coefficient and relatively high spraying adhesive force.

Description

Technical Field

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

[0002] Polypropylene is a cost-effective general-purpose plastic. After modification, it has excellent mechanical properties such as high strength and high toughness, as well as chemical resistance and high heat resistance. It is widely used in home appliances and automotive products.

[0003] As the global call for environmental protection, energy saving and consumption reduction becomes stronger and stronger, automobile lightweighting has become a major trend in the automotive industry. Polypropylene has become a trend to replace metal parts or to be embedded with metal parts. At the same time, for automotive exteriors, the method of using water-based spraying to replace traditional oil-based spraying to reduce volatile organic compounds (VOC) in the automobile manufacturing process has also been adopted by many OEMs at home and abroad, which has put forward higher requirements on the spray adhesion performance of polypropylene materials.

[0004] Polypropylene is a semi-crystalline material. The glass transition temperature of the amorphous region is low. It exhibits high thermal expansion and contraction characteristics in a wide temperature range. Its linear thermal expansion coefficient (CLTE) is about 120*10 -6 / ℃, so when used in conjunction with metal parts, it is easy to cause size mismatch when the temperature changes, resulting in abnormal noise and inconsistent appearance during use. Therefore, reducing the CLTE of the material is an important direction for the development of polypropylene materials. At the same time, in this process, optimizing the spraying performance of the material can make the material suitable for more automotive application scenarios. Summary of the invention

[0005] The object of the present invention is to overcome the deficiencies of the above-mentioned prior art and provide a polypropylene composition having excellent spraying performance, high adhesion after spraying, and relatively low coefficient of linear thermal expansion (CLTE), as well as a preparation method and application thereof.

[0006] To achieve the above object, in a first aspect of the present invention, the present invention provides a polypropylene composition, wherein the polypropylene composition comprises the following components in parts by weight:

[0007] 23-62 parts of PP resin, 18-32 parts of POE elastomer, 1-7 parts of chopped glass fiber, 13-27 parts of mica powder;

[0008] The PP resin is heated at a temperature of 200°C and a shear rate of 100S -1 Melt shear viscosity η PP With POE elastomer at a temperature of 200°C and a shear rate of 100S -1 Melt shear viscosity η POEThe ratio η PP / η POE 0.38-1.65;

[0009] The aspect ratio of the chopped glass fibers is 280-350;

[0010] The D50 diameter of the mica powder is 15-35 μm.

[0011] The polypropylene composition provided by the present invention can effectively improve the spraying performance of the polypropylene composition by selecting components in appropriate mass parts and the components cooperate with each other, and the obtained polypropylene composition has a lower linear thermal expansion coefficient.

[0012] Specifically, compounding PP resin and POE elastomer in a specific melt shear viscosity ratio range can help form a continuous phase, thereby reducing the linear thermal expansion coefficient of the polypropylene composition; it is also beneficial for subsequent coatings to penetrate into the channel and improve the spray adhesion of the polypropylene composition. At the same time, by selecting short glass fibers in a suitable aspect ratio range and mica powder in a suitable D50 diameter range as fillers, the structure of the flaky filler and the fiber filler can be stacked to form a filler network structure inside the polypropylene composition, restricting the movement of the molecular chain, thereby reducing the linear thermal expansion coefficient of the polypropylene composition; in addition, since the present invention selects PP resin and POE elastomer with a specific melt shear viscosity ratio, the dispersibility of short glass fibers and mica powder in the entire system is also at an optimal level, which is beneficial to comprehensively improve the spray adhesion of the polypropylene composition.

[0013] Exemplarily, the PP resin can be any point value or any two point range value between 23-62 parts, such as 25-60 parts, or 23 parts, 25 parts, 28 parts, 30 parts, 32 parts, 35 parts, 38 parts, 40 parts, 42 parts, 45 parts, 48 ​​parts, 50 parts, 52 parts, 55 parts, 58 parts, 60 parts, 62 parts, etc.; the POE elastomer can be any point value or any two point range value between 18-32 parts, such as 20-30 parts, or 18 The chopped glass fiber can be any point value or any two-point range value between 1-7 parts, for example, it can be 2-6 parts, or it can be 1 part, 2 parts, 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, etc.; the mica powder can be any point value or any two-point range value between 13-27 parts, for example, it can be 15-25 parts, or it can be 13 parts, 15 parts, 17 parts, 19 parts, 21 parts, 23 parts, 25 parts, 27 parts, etc.

[0014] Preferably, in the polypropylene composition, the mass percentage of PP resin is ≥25%.

[0015] More preferably, in the polypropylene composition, the mass percentage of PP resin is 32-56%.

[0016] It should be noted that the PP resin is heated to 230°C and the shear rate is 100S -1 Melt shear viscosity η PP The test was performed according to ISO 11443-2005 standard, specifically using a Goettfert RG20 capillary rheometer, wherein the aspect ratio was 20 / 1 and the capillary was a 90-degree angle capillary.

[0017] It should be noted that POE elastomer is heated to 200°C and sheared at 100S -1 Melt shear viscosity η POE The test results are obtained by referring to ISO 11443-2005 standard, specifically, the test is carried out by using a Goettfert RG 20 capillary rheometer, wherein the aspect ratio is 20 / 1 and the capillary is a 90-degree angle capillary.

[0018] For example, the PP resin is heated at a temperature of 200°C and a shear rate of 100S -1 Melt shear viscosity η PP With POE elastomer at a temperature of 200°C and a shear rate of 100S -1 Melt shear viscosity η POE The ratio η PP / η POE It can be any point value or any two point range value between 0.38-1.65, for example, it can be 0.4-1.63, or it can be 0.38, 0.4, 0.42, 0.45, 0.48, 0.5, 0.52, 0.55, 0.58, 0.6, 0.62, 0.65, 0.68, 0.7, 0.72, 0.75, 0.78, 0.8, 0.82, 0.85, 0.88, 0.9, 0.92, 0.95, 0.98, 1, 1.05, 1.1, 1.15, 1.2, 1.25, 1.3, 1.35, 1.4, 1.45, 1.5, 1.55, 1.6, 1.63, 1.65, etc.

[0019] It should be noted that the aspect ratio of the chopped glass fibers is obtained by first measuring the length and diameter of the chopped glass fibers by scanning electron microscopy and then calculating the aspect ratio of the chopped glass fibers by length / diameter.

[0020] Exemplarily, the aspect ratio of the chopped glass fiber can be any point value or any two point range value between 280-350, for example, it can be 285-346, 315-325, or it can be 280, 285, 290, 295, 300, 305, 310, 315, 320, 325, 330, 335, 340, 345, 350, etc.

[0021] Preferably, the aspect ratio of the chopped glass fibers is 315-325.

[0022] The present invention has no particular limitation on the length and diameter of the chopped glass fibers, and the effects of the present invention can be achieved within the conventional length and diameter range of the chopped glass fibers. For example, the length of the chopped glass fibers may be 3.0-4.5 mm, and the diameter may be 10-14 μm.

[0023] It should be noted that the D50 diameter of the mica powder is tested using a laser particle size analyzer with reference to GB / T 19077-2016.

[0024] The D50 diameter of the mica powder of the present invention is the Dv50 diameter, that is, the particle diameter corresponding to when the cumulative particle size distribution percentage reaches 50% when the mica powders are arranged in order from small to large diameters.

[0025] Exemplarily, the D50 diameter of the mica powder can be any point value or any two point range values ​​between 15-35μm, such as 16-33μm, 22-27μm, or 15μm, 18μm, 20μm, 22μm, 24μm, 26μm, 28μm, 30μm, 32μm, 34μm, 35μm, etc.

[0026] Preferably, the D50 diameter of the mica powder is 22-27 μm.

[0027] As a preferred embodiment of the polypropylene composition of the present invention, the polypropylene composition comprises the following components in parts by mass: 48-52 parts of PP resin, 23-27 parts of POE elastomer, 3-5 parts of chopped glass fibers, and 20-24 parts of mica powder.

[0028] The present invention has found that the mass parts of the components in the polypropylene composition will also affect the performance of the product. When the mass parts of the components in the polypropylene composition are further selected to be within the above range, the comprehensive effect of the obtained product is better.

[0029] As a preferred embodiment of the polypropylene composition of the present invention, the PP resin is heated at a temperature of 200°C and a shear rate of 100S -1 Melt shear viscosity η PP With POE elastomer at a temperature of 200°C and a shear rate of 100S-1 Melt shear viscosity η POE The ratio η PP / η POE It is 0.80-1.50.

[0030] The present invention has found that when the ratio of the melt shear viscosity of the PP resin and the POE elastomer is further selected to be 0.80-1.50, the compatibility between the two is better, so that not only the two can better form a continuous phase, but also the dispersion of short glass fibers and mica powder can be promoted, thereby better reducing the linear thermal expansion coefficient of the polypropylene composition and improving the spraying performance of the polypropylene composition.

[0031] As a preferred embodiment of the polypropylene composition of the present invention, the PP resin is heated at a temperature of 200°C and a shear rate of 100S -1 Melt shear viscosity η PP 50-700Pa*s.

[0032] For example, the PP resin is heated at a temperature of 200°C and a shear rate of 100S -1 Melt shear viscosity η PP It can be a point value between 50-700Pa*s or any two point range values, for example, it can be 60-688Pa*s, or it can be 50Pa*s, 60Pa*s, 100Pa*s, 150Pa*s, 200Pa*s, 250Pa*s, 300Pa*s, 350Pa*s, 400Pa*s, 450Pa*s, 500Pa*s, 550Pa*s, 600Pa*s, 650Pa*s, 700Pa*s, etc.

[0033] Preferably, the PP resin is heated at a temperature of 200°C and a shear rate of 100S -1 Melt shear viscosity η PP It is 120-400Pa*s.

[0034] More preferably, the PP resin is heated at a temperature of 200°C and a shear rate of 100 s -1 Melt shear viscosity η PP It is 280-360Pa*s.

[0035] As a preferred embodiment of the polypropylene composition of the present invention, the PP resin includes at least one of homopolypropylene and copolymer polypropylene.

[0036] As a preferred embodiment of the polypropylene composition of the present invention, the melt index of the PP resin at a temperature of 230° C. and a load of 2.16 kg is 10-150 g / 10 min. The melt index is obtained by testing with reference to ASTM D-1238:10.

[0037] As a preferred embodiment of the polypropylene composition of the present invention, the POE elastomer is subjected to a temperature of 200°C and a shear rate of 100S -1 Melt shear viscosity η POE It is 130-1350Pa*s.

[0038] For example, the POE elastomer is heated at a temperature of 200°C and a shear rate of 100S -1 Melt shear viscosity η POE It can be a point value between 130-1350Pa*s or any two point range values, for example, it can be 136-1320Pa*s, or it can be 130Pa*s, 150Pa*s, 200Pa*s, 250Pa*s, 300Pa*s, 350Pa*s, 400Pa*s, 450Pa*s, 500Pa*s, 550Pa*s, 600Pa*s, 650Pa*s, 700Pa*s, 750Pa*s, 800Pa*s, 850Pa*s, 900Pa*s, 950Pa*s, 1000Pa*s, 1100Pa*s, 1200Pa*s, 1300Pa*s, 1350Pa*s, etc.

[0039] Preferably, the POE elastomer is heated at a temperature of 200°C and a shear rate of 100S -1 Melt shear viscosity η POE It is 200-700Pa*s.

[0040] More preferably, the POE elastomer is heated at a temperature of 200°C and a shear rate of 100S -1 Melt shear viscosity η POE It is 245-350Pa*s.

[0041] The present invention has found that, on the basis of satisfying the ratio of the melt shear viscosity of the PP resin and the POE elastomer being within a specific range, when the melt shear viscosity of the PP resin and the POE elastomer are further selected to be within the above ranges respectively, the comprehensive performance of the obtained polypropylene composition is better.

[0042] As a preferred embodiment of the polypropylene composition of the present invention, the POE elastomer includes at least one of ethylene butene copolymer and ethylene octene copolymer.

[0043] Preferably, the POE elastomer is ethylene-octene copolymer.

[0044] As a preferred embodiment of the polypropylene composition of the present invention, the melt index of the POE elastomer at a temperature of 190° C. and a load of 2.16 kg is 4-30 g / 10 min. The melt index is obtained by testing with reference to ASTM D-1238:10.

[0045] As a preferred embodiment of the polypropylene composition of the present invention, the polypropylene composition further comprises 0-1 part of an auxiliary agent.

[0046] As a preferred embodiment of the polypropylene composition of the present invention, the auxiliary agent includes at least one of an antioxidant and a light stabilizer.

[0047] Exemplarily, the antioxidant includes at least one of antioxidant 1010 and antioxidant 168. The light stabilizer includes at least one of UV-3808, UV-3853, and UV-944.

[0048] In the second aspect of the present invention, the present invention provides a method for preparing the polypropylene composition, the preparation method comprising the following steps: mixing and melt-extruding the components to obtain the polypropylene composition.

[0049] As a preferred embodiment of the preparation method of the present invention, the melting temperature is 190-210°C.

[0050] In a third aspect of the present invention, the present invention provides a spray-coated part, comprising the above-mentioned polypropylene composition. The spray-coated part is used as an interior and exterior decoration of an automobile.

[0051] Illustratively, the coating of the dashboard, door panel, tailgate, bumper of an automobile comprises the polypropylene composition.

[0052] Compared with the prior art, the present invention has the following beneficial effects:

[0053] The polypropylene composition provided by the present invention can effectively improve the spraying performance of the polypropylene composition by selecting components of appropriate mass parts, and the components cooperate with each other, and the obtained polypropylene composition has a lower linear thermal expansion coefficient. At the same time, the preparation method of the polypropylene composition provided by the present invention is simple to operate and is conducive to actual production. DETAILED DESCRIPTION

[0054] In order to better illustrate the purpose, technical solutions and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments.

[0055] Unless otherwise specified, the reagents, methods and equipment used in the present invention are all conventional reagents, methods and equipment in the art; and unless otherwise specified, the raw materials used in parallel experiments are from the same batch of raw materials.

[0056] PP-1: Homopolymer polypropylene, PPH-Y26, at a temperature of 200°C and a shear rate of 100S -1 The melt shear viscosity is 280Pa*s, Sinopec;

[0057] PP-2: Homopolymer polypropylene, PPH-M16, at a temperature of 200°C and a shear rate of 100S -1 The melt shear viscosity is 360Pa*s, Sinopec;

[0058] PP-3: Homopolymer polypropylene, HP500N-Z, at 200°C and shear rate of 100S -1 The melt shear viscosity is 400Pa*s, CNOOC Shell Petrochemical;

[0059] PP-4: Copolymer polypropylene, K7100, at 200°C and shear rate of 100S -1 The melt shear viscosity is 120Pa*s, Sinopec Yanshan Branch;

[0060] PP-5: Homopolymer polypropylene, PPH-MN150, at a temperature of 200°C and a shear rate of 100S -1 The melt shear viscosity is 60Pa*s, Sinopec Luoyang Branch;

[0061] PP-6: Homopolymer polypropylene, PP-T03, at a temperature of 200°C and a shear rate of 100S -1 The melt shear viscosity is 688Pa*s, Sinopec;

[0062] POE-1: Ethylene-octene copolymer, ENGAGE 11527, at 200°C and shear rate of 100S -1 The melt shear viscosity at 245 Pa*s, Dow Chemical;

[0063] POE-2: Ethylene-octene copolymer, ENGAGE 8137, at 200°C and shear rate of 100S -1 The melt shear viscosity is 350Pa*s, Dow Chemical;

[0064] POE-3: Ethylene-butene copolymer, ENGAGE 7447, at 200°C and shear rate of 100S -1 The melt shear viscosity at is 694Pa*s, Dow Chemical;

[0065] POE-4: Ethylene-butene copolymer, ENGAGE 7467, at 200°C and a shear rate of 100S -1 The melt shear viscosity at 1320Pa*s, Dow Chemical;

[0066] POE-5: Ethylene-octene copolymer, ENGAGE 8407, at 200°C and shear rate of 100S -1 The melt shear viscosity at 136Pa*s, Dow Chemical;

[0067] Chopped glass fiber 1: ECS14-4.5-508A, aspect ratio 320, Jushi Group Co., Ltd.

[0068] Chopped glass fiber 2: ECS14-04-508A, aspect ratio 285, Jushi Group Co., Ltd.

[0069] Chopped glass fiber 3: ECS13-4.5-508A, aspect ratio 346, Jushi Group Co., Ltd.

[0070] Chopped glass fiber 4: ECS10-4-508A, aspect ratio 400, Jushi Group Co., Ltd.

[0071] Chopped glass fiber 5: ECS13-3-508A, aspect ratio 230, Jushi Group Co., Ltd.

[0072] Mica powder 1: 1060HC, D50 diameter 24.29μm, Lingshou County Huajing Mica Co., Ltd.

[0073] Mica powder 2: 300HC, D50 diameter 16.56μm, Lingshou County Huajing Mica Co., Ltd.

[0074] Mica powder 3: C-325, D50 diameter 32.35 μm, Lingshou County Huajing Mica Co., Ltd.

[0075] Mica powder 4: SW500, D50 diameter 12.15 μm, Suzhou Zhongwei Non-metallic Materials Co., Ltd.;

[0076] Mica powder 5: 120HC, D50 diameter 52.86μm, Lingshou County Huajing Mica Co., Ltd.

[0077] Antioxidant: a mixture of antioxidant 1010 and antioxidant 168 in a mass ratio of 1:1, wherein antioxidant 1010 and antioxidant 168 are commercially available products;

[0078] Light stabilizer: UV-3808, commercially available.

[0079] Examples 1-14 and Comparative Examples 1-8

[0080] The embodiments of the present invention and the comparative examples provide a polypropylene composition, and the component contents (parts by weight) of the polypropylene composition are shown in Table 1-2;

[0081] Table 1

[0082]

[0083]

[0084] Table 2

[0085]

[0086] The preparation method of the polypropylene composition provided in Example 1 is:

[0087] The dried raw materials are weighed, mixed and fed into a twin-screw extruder, and subjected to extrusion, stranding, cooling, pelletizing and drying to obtain a polypropylene composition;

[0088] Among them, the parameters of the twin-screw extruder are: the length-to-diameter ratio of the twin-screw extruder is 40:1, the screw speed is 400 rpm, and the extrusion temperatures in each zone are 190°C, 190°C, 200°C, 200°C, 200°C, 210°C, and 200°C respectively.

[0089] The preparation methods of the polypropylene compositions provided in Examples 2-14 and Comparative Examples 1-8 are consistent with that in Example 1, except that no relevant components are added.

[0090] Effect example

[0091] The effect example of the present invention verifies the performance of the polypropylene composition prepared in the embodiment and the comparative example; the prepared polypropylene composition is injection molded, the injection molding temperature is 200°C, the original size of the injection molding sample is 100mm*100mm*3mm, which can be used for spray adhesion grade test, and at the same time, a small square of 10mm*10mm*3mm is cut for CLTE test:

[0092] 1. CLTE test: refer to standard GB / T 36800.2-2018, test temperature range -30-100℃;

[0093] 2. Spray adhesion test: According to the relevant provisions of standard NES M0141 [2016-1], the material is sprayed with three layers of paint, baked at 80℃ for 30 minutes, and subjected to tensile test to calculate and record the paint peeling force of the material;

[0094] The test results are shown in Table 3;

[0095] Table 3

[0096]

[0097]

[0098] It can be seen from Table 3 that when the technical solution of the present invention is adopted, the obtained polypropylene composition has a lower linear thermal expansion coefficient and a higher adhesion; specifically, the linear thermal expansion coefficient of the obtained product is between 58*10 -6 / ℃ or below, the adhesion is above 952N / cm;

[0099] It can be seen from Example 1, Examples 4-10 and Comparative Examples 1-2 that the ratio of the melt shear viscosity of the PP resin and the POE elastomer used in the polypropylene composition will affect the comprehensive performance of the product. When the ratio of the melt shear viscosity of the PP resin and the POE elastomer in Comparative Examples 1-2 is not within the range given in the present invention, the linear expansion coefficient of the obtained product is greatly increased, the spray adhesion is greatly reduced, and the effect of the present invention cannot be achieved;

[0100] It can be seen from Example 1, Examples 11-12 and Comparative Examples 3-4 that the aspect ratio of the chopped glass fibers in the polypropylene composition will also affect the comprehensive performance of the product. When the aspect ratio of the chopped glass fibers in Comparative Example 3 is too large, the chopped glass fibers in the obtained product are easily broken, which is not conducive to the construction of the filler network, and the broken chopped glass fibers make the appearance of the material poor, resulting in a significant increase in the linear expansion coefficient of the material and a significant decrease in the spray adhesion, and the effect of the present invention cannot be achieved; when the aspect ratio of the chopped glass fibers in Comparative Example 4 is too small, the network constructed by the glass fibers in the obtained product is imperfect, and the effect of the present invention cannot be achieved;

[0101] It can be seen from Example 1, Examples 13-14 and Comparative Examples 5-6 that the D50 diameter of the mica powder in the polypropylene composition will also affect the performance of the product. When the D50 diameter of the mica powder in Comparative Example 5 is too small, the filler network constructed by the obtained product is imperfect, and the effect of the present invention cannot be achieved; when the D50 diameter of the mica powder in Comparative Example 6 is too large, the mica powder in the obtained product is easy to break and difficult to be completely dispersed, and the constructed filler network is imperfect, and the effect of the present invention cannot be achieved;

[0102] It can be seen from Example 1 and Comparative Examples 7-8 that when either the chopped glass fiber or the mica powder is missing, the effect of the present invention cannot be achieved; specifically, when mica powder is not added in Comparative Example 7, the adhesion of the obtained product is significantly reduced; when chopped glass fiber is not added in Comparative Example 8, the linear thermal expansion coefficient of the obtained product is significantly increased, and the adhesion also shows a certain downward trend.

[0103] Finally, it should be noted that the above embodiments are intended to illustrate the technical solution of the present invention rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention may be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. A polypropylene composition, characterized in that The polypropylene composition comprises the following components in parts by weight: 23-62 parts of PP resin, 18-32 parts of POE elastomer, 1-7 parts of chopped glass fiber, 13-27 parts of mica powder; The PP resin is heated at a temperature of 200°C and a shear rate of 100S -1 Melt shear viscosity η PP With POE elastomer at a temperature of 200°C and a shear rate of 100S -1 Melt shear viscosity η POE The ratio η PP / η POE 0.38-1.65; The aspect ratio of the chopped glass fibers is 280-350; The D50 diameter of the mica powder is 15-35 μm.

2. The polypropylene composition according to claim 1, characterized in that The polypropylene composition comprises the following components in parts by weight: 48-52 parts of PP resin, 23-27 parts of POE elastomer, 3-5 parts of chopped glass fibers, and 20-24 parts of mica powder.

3. The polypropylene composition according to claim 1, characterized in that The PP resin is heated at a temperature of 200°C and a shear rate of 100S -1 Melt shear viscosity η PP With POE elastomer at a temperature of 200°C and a shear rate of 100S -1 Melt shear viscosity η POE The ratio η PP / η POE It is 0.80-1.

50.

4. The polypropylene composition according to claim 1, characterized in that The PP resin is heated at a temperature of 200°C and a shear rate of 100S -1 Melt shear viscosity η PP 50-700Pa*s.

5. The polypropylene composition according to claim 1, characterized in that The POE elastomer is heated at a temperature of 200°C and a shear rate of 100S -1 Melt shear viscosity η POE It is 130-1350Pa*s.

6. The polypropylene composition according to claim 1, characterized in that The POE elastomer includes at least one of ethylene butene copolymer and ethylene octene copolymer.

7. The polypropylene composition according to claim 1, characterized in that The polypropylene composition further comprises 0-1 part of an auxiliary agent.

8. The polypropylene composition according to claim 7, characterized in that The auxiliary agent includes at least one of an antioxidant and a light stabilizer.

9. The method for preparing the polypropylene composition according to any one of claims 1 to 8, characterized in that: The preparation method comprises the following steps: mixing the components and melt-extruding them to obtain a polypropylene composition.

10. A spray-coated part, comprising the polypropylene composition according to any one of claims 1 to 8.

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