Polypropylene composition, process for its preparation and use thereof

Abstract

This invention discloses a polypropylene composition, its preparation method, and its applications. The polypropylene composition comprises the following components in parts by weight: 30-50 parts block copolymer polypropylene, 10-25 parts thermoplastic elastomer A and thermoplastic elastomer B, and 30-50 parts polybutene; wherein the glass transition temperature of thermoplastic elastomer A is -63℃ to -53℃; and the glass transition temperature of thermoplastic elastomer B is -43℃ to -31℃. The polypropylene composition of this invention exhibits strong self-healing properties.

Description

Technical Field

[0001] This invention relates to the field of polymer materials technology, and more specifically, to a polypropylene composition, its preparation method, and its application. Background Technology

[0002] As automotive interiors evolve towards "high durability, intelligence, and environmental friendliness," traditional automotive polypropylene compositions exhibit low hardness in high-frequency contact areas such as door panels and center consoles. This makes them susceptible to scratches from metal objects (such as keys and zippers), leading to surface whitening and reduced gloss, severely impacting the interior's aesthetics. Luxury models and new energy vehicles demand even higher interior quality, requiring a smooth feel and exceptional durability. While polypropylene (PP) is a commonly used material for automotive interiors, its poor self-healing properties make it difficult for scratches on automotive interiors made from PP to self-repair after being struck by metal objects (such as keys and zippers).

[0003] Therefore, developing a polypropylene composition with strong self-healing properties is of great significance. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a polypropylene composition, its preparation method, and its application.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: In a first aspect, the present invention provides a polypropylene composition comprising the following components in parts by weight: 30-50 parts block copolymer polypropylene (PP-B), 10-25 parts thermoplastic elastomer A and thermoplastic elastomer B, 30-50 parts polybutene; The glass transition temperature of the thermoplastic elastomer A is -63℃ to -53℃; The glass transition temperature of the thermoplastic elastomer B is -43℃ to -31℃.

[0006] The polypropylene composition of the present invention has strong self-healing properties, specifically: This invention uses block copolymer polypropylene crystals as the "skeleton" to provide mechanical strength, polybutene crystals as the "muscles" to achieve temperature-responsive behavior, and thermoplastic elastomers A and B with low glass transition temperatures as amorphous regions to simulate "soft tissue" function and promote chain segment diffusion, constructing a synergistic "skeleton-muscle-soft tissue" system. The amorphous regions provided by thermoplastic elastomers A and B, with different specific glass transition temperatures, have different lubricity in different areas, which can promote the mutual diffusion of block copolymer polypropylene and polybutene in the amorphous regions, improve the compatibility between block copolymer polypropylene and polybutene, and enable the block copolymer polypropylene crystals and polybutene crystals to crystallize synergistically. Simultaneously, under thermal action, the block copolymer polypropylene crystals form a network that maintains the overall structural stability of the system, while the polybutene crystals melt and transform into an amorphous form, synergistically enhancing the chain segment mobility in the amorphous regions with different lubricity, achieving scratch self-healing, and improving the self-healing performance of the polypropylene composition.

[0007] Preferably, the glass transition temperature of the thermoplastic elastomer A is a range of one or any two of the following: -63°C, -62°C, -61°C, -60°C, -59°C, -58°C, -57°C, -56°C, -55°C, -54°C, and -53°C.

[0008] More preferably, the glass transition temperature of the thermoplastic elastomer A is -62℃ to -55℃.

[0009] Preferably, the glass transition temperature of the thermoplastic elastomer B is a range of one or any two of the following: -43°C, -42°C, -41°C, -40°C, -39°C, -38°C, -37°C, -36°C, -35°C, -34°C, -33°C, -32°C, and -31°C.

[0010] Preferably, the glass transition temperature of the thermoplastic elastomer B is -42℃ to -33℃.

[0011] In this invention, the glass transition temperatures of thermoplastic elastomers A and / or B are measured according to standard GB / T 19466-2016.

[0012] Preferably, the thermoplastic elastomer A and / or B includes at least one of POE (ethylene-α-olefin copolymer elastomer), OBC (olefin block copolymer), and POP (polyolefin plasmon).

[0013] Preferably, the weight ratio of thermoplastic elastomer A to thermoplastic elastomer B is 1:(0.05-3.5).

[0014] Preferably, the weight ratio of the thermoplastic elastomer A and the thermoplastic elastomer B is one or any two of the following: 1:0.05, 1:0.06, 1:0.07, 1:0.08, 1:0.09, 1:0.1, 1:0.2, 1:0.3, 1:0.5, 1:0.7, 1:0.8, 1:1, 1:1.2, 1:1.3, 1:1.5, 1:1.7, 1:1.8, 1:2, 1:2.2, 1:2.3, 1:2.5, 1:2.7, 1:2.8, 1:3, 1:3.1, 1:3.2, 1:3.3, 1:3.4, and 1:3.5.

[0015] More preferably, the weight ratio of thermoplastic elastomer A to thermoplastic elastomer B is 1:(0.2-3).

[0016] More preferably, the weight ratio of the thermoplastic elastomer A to the thermoplastic elastomer B is 1:(1-2).

[0017] In this invention, the thermoplastic elastomers A and / or B can be obtained commercially or can be prepared in-house.

[0018] Preferably, the melting point of the polybutene is 70°C to 105°C.

[0019] Preferably, the melting point of the polybutene is within the range of one or any two of the following: 70°C, 73°C, 75°C, 76°C, 78°C, 80°C, 81°C, 82°C, 83°C, 84°C, 85°C, 86°C, 87°C, 88°C, 89°C, 90°C, 91°C, 92°C, 93°C, 95°C, 97°C, 98°C, 100°C, 102°C, 103°C, and 105°C.

[0020] More preferably, the polybutene includes polybutene C and polybutene D, wherein the melting point of polybutene C is 75°C to 90°C and the melting point of polybutene D is 91°C to 100°C.

[0021] More preferably, the melting point of the polybutene C is one or any two of the following: 75°C, 76°C, 78°C, 80°C, 81°C, 82°C, 83°C, 84°C, 85°C, 86°C, 87°C, 88°C, 89°C, and 90°C.

[0022] More preferably, the melting point of the polybutene C is 75°C to 85°C.

[0023] More preferably, the melting point of the polybutene D is a range of one or both of 91°C, 92°C, 93°C, 95°C, 97°C, 98°C, and 100°C.

[0024] More preferably, the melting point of the polybutene D is 92°C to 98°C.

[0025] More preferably, the weight ratio of polybutene C to polybutene D is 1:(0.1-3).

[0026] More preferably, the weight ratio of polybutene C to polybutene D is one or any two of the following: 1:0.1, 1:0.2, 1:0.3, 1:0.5, 1:0.7, 1:0.8, 1:1, 1:1.2, 1:1.3, 1:1.5, 1:1.7, 1:1.8, 1:2, 1:2.2, 1:2.3, 1:2.5, 1:2.7, 1:2.8, and 1:3.

[0027] More preferably, the weight ratio of polybutene C to polybutene D is 1:(0.5-2).

[0028] In this invention, the melting point of polybutene is tested by using differential scanning calorimetry (DSC) to test the melting endothermic peak of the material. The temperature corresponding to the peak value of the melting endothermic peak is the melting point, and the heating rate is 10℃ / min.

[0029] In this invention, the polybutene can be obtained by purchasing commercially available products or by making them in-house.

[0030] Preferably, the melt flow rate (melt mass flow rate, MFR) of the block copolymer polypropylene (PP-B) at 230°C and 2.16 kg is 10-65 g / 10 min, specifically 16-60 g / 10 min.

[0031] Preferably, the melt flow rate (melt mass flow rate, MFR) of the block copolymer polypropylene (PP-B) at 230°C and 2.16 kg is 10 g / 10 min, 11 g / 10 min, 12 g / 10 min, 13 g / 10 min, 14 g / 10 min, 15 g / 10 min, 16 g / 10 min, 17 g / 10 min, 18 g / 10 min, 20 g / 10 min, 25 g / 10 min, 27 g / 10 min, and 28 g / 10 min. The values ​​are within the range of one or both of the following: 10 min, 29 g / 10 min, 30 g / 10 min, 32 g / 10 min, 33 g / 10 min, 35 g / 10 min, 40 g / 10 min, 45 g / 10 min, 50 g / 10 min, 55 g / 10 min, 57 g / 10 min, 58 g / 10 min, 59 g / 10 min, 60 g / 10 min, 62 g / 10 min, 63 g / 10 min, and 65 g / 10 min.

[0032] More preferably, the melt flow rate (melt mass flow rate, MFR) of the block copolymer polypropylene (PP-B) at 230°C and 2.16 kg is 16-30 g / 10 min.

[0033] In this invention, the melt flow rate (melt mass flow rate, MFR) of the block copolymer polypropylene is obtained by testing according to the ISO 1133-1-2011 standard.

[0034] Preferably, the polypropylene composition further includes an antioxidant.

[0035] More preferably, the antioxidant is present in 0-5 parts by weight, specifically 0.2-2 parts.

[0036] More preferably, the antioxidant is expressed in parts by weight of one or any two of the following: 0 parts, 0.1 parts, 0.2 parts, 0.3 parts, 0.4 parts, 0.5 parts, 0.6 parts, 0.7 parts, 0.8 parts, 0.9 parts, 1 part, 1.3 parts, 1.5 parts, 1.8 parts, 2 parts, 2.3 parts, 2.5 parts, 2.8 parts, 3 parts, 3.3 parts, 3.5 parts, 3.8 parts, 4 parts, 4.3 parts, 4.5 parts, 4.8 parts, and 5 parts.

[0037] More preferably, the antioxidant includes at least one of hindered phenolic antioxidants and phosphite antioxidants.

[0038] More preferably, the hindered phenolic antioxidant includes at least one of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] (antioxidant 1010), octadecyl β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate (antioxidant 1076), and N,N'-(hexane-1,6-diyl)bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionamide] (antioxidant 1098).

[0039] More preferably, the phosphite antioxidant includes at least one of tris(2,4-di-tert-butyl)phosphite (antioxidant 168), bis(2,4-di-tert-butylphenol) pentaerythritol diphosphite (antioxidant 626), and triphenyl phosphite (antioxidant TPP).

[0040] Preferably, in the polypropylene composition, the block copolymer polypropylene (PP-B) is in the range of 30 parts, 32 parts, 33 parts, 35 parts, 37 parts, 38 parts, 40 parts, 42 parts, 43 parts, 45 parts, 47 parts, 48 ​​parts, or 50 parts by weight, or any two of these values; the total weight of plastic elastomer A and thermoplastic elastomer B is in the range of 10 parts, 12 parts, 13 parts, 14 parts, 15 parts, 16 parts, 17 parts, 18 parts, 19 parts, 20 parts, 21 parts, 22 parts, 23 parts, 24 parts, or 25 parts by weight, or any two of these values; and the polybutene is in the range of 30 parts, 32 parts, 33 parts, 35 parts, 37 parts, 38 parts, 40 parts, 42 parts, 43 parts, 45 parts, 47 parts, 48 ​​parts, or 50 parts by weight, or any two of these values.

[0041] Preferably, the polypropylene composition comprises the following components in parts by weight: 35-45 parts block copolymer polypropylene (PP-B), 15-20 parts thermoplastic elastomer A and thermoplastic elastomer B, and 35-45 parts polybutene.

[0042] Preferably, based on the weight of the polypropylene composition, the block copolymer polypropylene (PP-B) has a weight percentage of ≥28%, specifically 34%-47%.

[0043] Secondly, the present invention provides a method for preparing a polypropylene composition, comprising the following steps: The components are mixed and melt-extruded to obtain a polypropylene composition.

[0044] Preferably, a twin-screw extruder is used for the melt extrusion.

[0045] More preferably, the length-to-diameter ratio of the twin-screw extruder is (38-48):1.

[0046] More preferably, the temperature of the twin-screw extruder is 80-120℃ in zone 1, 180-200℃ in zone 2, 180-220℃ in zone 3, 180-220℃ in zone 4, 180-220℃ in zone 5, 180-220℃ in zone 6, 180-220℃ in zone 7, 180-220℃ in zone 8, and 180-220℃ in zone 9.

[0047] Thirdly, the present invention provides an application of a polypropylene composition in automotive interiors.

[0048] Fourthly, the present invention provides an automotive interior comprising the above-mentioned polypropylene composition, wherein the automotive interior includes at least one of automotive door panels and a center console.

[0049] Compared with the prior art, the beneficial effects of the present invention are as follows: The polypropylene composition of the present invention has strong self-healing properties, specifically: This invention uses block copolymer polypropylene crystals as the "skeleton" to provide mechanical strength, polybutene crystals as the "muscles" to achieve temperature-responsive behavior, and thermoplastic elastomers A and B with low glass transition temperatures as amorphous regions to simulate "soft tissue" function and promote chain segment diffusion, constructing a synergistic "skeleton-muscle-soft tissue" system. The amorphous regions provided by thermoplastic elastomers A and B, with different specific glass transition temperatures, have different lubricity in different areas, which can promote the mutual diffusion of block copolymer polypropylene and polybutene in the amorphous regions, improve the compatibility between block copolymer polypropylene and polybutene, and enable the block copolymer polypropylene crystals and polybutene crystals to crystallize synergistically. Simultaneously, under thermal action, the block copolymer polypropylene crystals form a network that maintains the overall structural stability of the system, while the polybutene crystals melt and transform into an amorphous form, synergistically enhancing the chain segment mobility in the amorphous regions with different lubricity, achieving scratch self-healing, and improving the self-healing performance of the polypropylene composition. Detailed Implementation

[0050] To better illustrate the purpose, technical solution, and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments.

[0051] The experimental methods in the following examples and comparative examples, where specific conditions are not specified, are generally performed under conventional conditions in the art or as recommended by the manufacturer; the raw materials and reagents used, unless otherwise specified, are all commercially available from the conventional market.

[0052] The reagents used in the various embodiments and comparative examples of this invention are as follows: Block copolymer polypropylene 1 (PP-B1) has a melt flow rate (melt mass flow rate, MFR) of 30 g / 10 min at 230℃ and 2.16 kg. PP EP548R, CNOOC Shell. Block copolymer polypropylene 2 (PP-B2) has a melt flow rate (melt mass flow rate, MFR) of 16 g / 10 min at 230℃ and 2.16 kg. PP LH-K9017H, Lihe Zhixin New Materials. Block copolymer polypropylene 3 (PP-B3) has a melt flow rate (melt mass flow rate, MFR) of 60 g / 10 min at 230℃ and 2.16 kg. PP EP648U, CNOOC Shell. Random copolymer polypropylene (PP-R) with a melt flow rate (melt mass flow rate, MFR) of 25 g / 10 min at 230 °C and 2.16 kg, PP RP346R, LyondellBasell; Thermoplastic elastomer A1 (A1), POE, glass transition temperature -58℃, ENGAGE 7467, DOW; Thermoplastic elastomer A2 (A2), POE, glass transition temperature -62℃, ENGAGE 11527, DOW; Thermoplastic elastomer A3 (A3), POE, glass transition temperature -55℃, ENGAGE 8137, DOW; Thermoplastic elastomer A4 (A4), POE, glass transition temperature -65℃, ENGAGE XLT 8677, DOW; Thermoplastic elastomer A5 (A5), POE, glass transition temperature -47℃, ENGAGE 8401, DOW; Thermoplastic elastomer B1 (B1), POE, glass transition temperature -36℃, ENGAGE 8402, DOW; Thermoplastic elastomer B2 (B2), POE, glass transition temperature -42℃, ENGAGE 7256, DOW; Thermoplastic elastomer B3 (B3), POE, glass transition temperature -33℃, ENGAGE 8440, DOW; Polybutene C1 (C1), melting point 81℃, was prepared in-house. The preparation method was as follows: At -20℃, n-butene was added to a mixed solution of dichloromethane and n-hexane (volume ratio 40:60) and mixed. Then, AlCl3, water, DCC (p-dicumyl chloride), and triphenylamine (TPA) were added, and the reaction was carried out for 4 hours. The reaction was then quenched by adding a methanol-hydrochloric acid mixed solution (volume ratio of methanol to 37% concentrated hydrochloric acid 10:1) at -10℃. The quenched reaction solution was then poured into an ice-cold methanol solution containing 5% sodium bicarbonate for precipitation. The crude product was filtered and washed three times each with deionized water and anhydrous ethanol, and dried under vacuum at 105°C to constant weight to obtain polybutene C1 (C1); wherein the volume ratio of the dichloromethane and n-hexane mixed solution to the mass ratio of n-butene was 100mL:20g, the mass ratio of AlCl3, water, DCC and triphenylamine was 1.5:0.0075:1.5:0.15, the mass ratio of AlCl3 to the mass ratio of n-butene was 1.5:100, and the volume ratio of the dichloromethane and n-hexane mixed solution to the methanol-hydrochloric acid mixed solution was 5:1; Polybutene C2 (C2), melting point 76℃, was prepared in-house. The preparation method was as follows: At -15℃, n-butene was added to a mixed solution of dichloromethane and n-hexane (volume ratio 40:60) and mixed. Then, AlCl3, water, DCC (p-dicumyl chloride), and triphenylamine (TPA) were added, and the reaction was carried out for 4 hours. The reaction was then quenched by adding a methanol-hydrochloric acid mixed solution (volume ratio of methanol to 37% concentrated hydrochloric acid 10:1) at -10℃. The quenched reaction solution was then poured into an ice-cold methanol solution containing 5% sodium bicarbonate for precipitation. The crude product was filtered and washed three times each with deionized water and anhydrous ethanol, and dried under vacuum at 105℃ to constant weight to obtain polybutene C1 (C1); wherein the volume ratio of the dichloromethane and n-hexane mixed solution to the mass ratio of n-butene was 100mL:20g, the mass ratio of AlCl3, water, DCC and triphenylamine was 1.5:0.0075:1.9:0.20, the mass ratio of AlCl3 to the mass ratio of n-butene was 1.5:100, and the volume ratio of the dichloromethane and n-hexane mixed solution to the methanol-hydrochloric acid mixed solution was 5:1; Polybutene C3 (C3), melting point 84℃, was prepared in-house. The preparation method was as follows: At -25℃, n-butene was added to a mixed solution of dichloromethane and n-hexane (volume ratio 40:60), followed by the addition of AlCl3, water, DCC (p-dicumyl chloride), and 2,6-dimethylpyridine (DMP) for 4 hours. The reaction was then quenched by adding a methanol-hydrochloric acid mixed solution (volume ratio of methanol to 37% concentrated hydrochloric acid 10:1) at -10℃. The quenched reaction solution was then poured into an ice-cold methanol solution containing 5% sodium bicarbonate. The precipitate was filtered to obtain a crude product, which was washed three times each with deionized water and anhydrous ethanol, and dried under vacuum at 105°C to constant weight to obtain polybutene C1 (C1). The volume ratio of the dichloromethane and n-hexane mixed solution to the mass of n-butene was 100 mL: 20 g, the mass ratio of AlCl3, water, DCC, and DMP was 1.5:0.0075:1.3:0.15, the mass ratio of AlCl3 to n-butene was 1.5:100, and the volume ratio of the dichloromethane and n-hexane mixed solution to the methanol-hydrochloric acid mixed solution was 5:1. Polybutene C4 (C4), melting point 88℃, was prepared in-house. The preparation method was as follows: At -30℃, n-butene was added to a mixed solution of dichloromethane and n-hexane (volume ratio 40:60) and mixed. Then, AlCl3, water, DCC (p-dicumyl chloride), and 2,6-dimethylpyridine (DMP) were added, and the reaction was carried out for 4 hours. The reaction was then quenched by adding a methanol-hydrochloric acid mixed solution (volume ratio of methanol to 37% concentrated hydrochloric acid 10:1) at -10℃. The quenched reaction solution was then poured into an ice-cold methanol solution containing 5% sodium bicarbonate for precipitation. The crude product was obtained by filtration. The mixture was washed three times each with deionized water and anhydrous ethanol, and then dried under vacuum at 105°C to constant weight to obtain polybutene C1 (C1). The volume ratio of the dichloromethane and n-hexane mixed solution to the mass of n-butene was 100 mL: 20 g; the molar ratio of isobutene to n-butene was 99:1; the mass ratio of AlCl3, water, DCC, and DMP was 1.5:0.0075:1.0:0.10; the mass ratio of AlCl3 to n-butene was 1.5:100; and the volume ratio of the dichloromethane and n-hexane mixed solution to the methanol-hydrochloric acid mixed solution was 5:1. Polybutene D1 (D1), melting point 95℃, is prepared in-house. The preparation method is as follows: Isobutylene is added to a mixed solution of dichloromethane and n-hexane (volume ratio 40:60) at -40℃ and mixed. AlCl3, water, DCC (p-dicumyl chloride), and triphenylamine (TPA) are then added, and the reaction is carried out for 4 hours. The reaction is then quenched by adding a methanol-hydrochloric acid mixed solution (volume ratio of methanol to 37% concentrated hydrochloric acid 10:1) at -10℃. The quenched reaction solution is then poured into an ice-cold methanol solution containing 5% sodium bicarbonate for precipitation. The crude product was filtered and washed three times each with deionized water and anhydrous ethanol, and then dried under vacuum at 105°C to constant weight to obtain polybutene C1 (C1). The ratio of the volume of the dichloromethane and n-hexane mixed solution to the mass of isobutene was 100 mL: 20 g; the mass ratio of AlCl3, water, DCC, and triphenylamine was 1.5:0.005:0.8:0.15; the mass ratio of AlCl3 to isobutene was 1.5:100; and the volume ratio of the dichloromethane and n-hexane mixed solution to the methanol-hydrochloric acid mixed solution was 5:1. Polybutene D2 (D2), melting point 92℃, PBR F0203, Sinopec Zhenhai Refining & Chemical Co., Ltd. Polybutene D3 (D3), melting point 98℃, was prepared in-house. The preparation method was as follows: Isobutylene was added to a mixed solution of dichloromethane and n-hexane (volume ratio 40:60) at -40℃ and mixed. AlCl3, water, DCC (p-dicumyl chloride), and triphenylamine (TPA) were then added, and the reaction was carried out for 4 hours. The reaction was then quenched by adding a methanol-hydrochloric acid mixed solution (volume ratio of methanol to 37% concentrated hydrochloric acid 10:1) at -10℃. The quenched reaction solution was then poured into an ice-cold methanol solution containing 5% sodium bicarbonate for precipitation. The crude product was filtered and washed three times each with deionized water and anhydrous ethanol, and then dried under vacuum at 105°C to constant weight to obtain polybutene C1 (C1). The ratio of the volume of the dichloromethane and n-hexane mixed solution to the mass of isobutene was 100 mL: 25 g; the mass ratio of AlCl3, water, DCC, and triphenylamine was 1.0:0.003:0.7:0.15; the mass ratio of AlCl3 to isobutene was 1.5:100; and the volume ratio of the dichloromethane and n-hexane mixed solution to the methanol-hydrochloric acid mixed solution was 5:1. Hindered phenolic antioxidant, pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] (antioxidant 1010), commercially available; Phosphite antioxidant, tris(2,4-di-tert-butyl)phosphite (antioxidant 168), commercially available; In this invention, the melt flow rate (melt mass flow rate, MFR) of the block copolymer polypropylene is obtained by testing according to the ISO 1133-1-2011 standard.

[0053] In this invention, the glass transition temperatures of thermoplastic elastomers A and / or B are measured according to standard GB / T 19466-2016.

[0054] In this invention, the melting point of polybutene is tested by using differential scanning calorimetry (DSC) to test the melting endothermic peak of the material. The temperature corresponding to the peak value of the melting endothermic peak is the melting point, and the heating rate is 10℃ / min.

[0055] Examples 1-23 and Comparative Examples 1-7 Examples 1-23 and Comparative Examples 1-7 provide different polypropylene compositions, which differ from each other only in the type and amount of each component. By weight, Examples 1-23 and Comparative Examples 1-7 include the components shown in Tables 1-4. The preparation methods of the polypropylene compositions of Examples 1-23 and Comparative Examples 1-7 include the following steps: The components are mixed at high speed in a high-speed mixer for 3 minutes to obtain a premix. Then, the mixture is melt-extruded and granulated using a twin-screw extruder (length to diameter ratio 40:1) to obtain a polypropylene composition. The twin-screw extruder has the following temperatures: Zone 1: 90℃; Zone 2: 180℃; Zone 3: 200℃; Zone 4: 200℃; Zone 5: 200℃; Zone 6: 200℃; Zone 7: 200℃; Zone 8: 200℃; Zone 9: 200℃; and the main extruder speed is 450 r / min. Table 1. Weight parts of each component in the polypropylene compositions of Examples 1-8 Table 2. Weight parts of each component in the polypropylene compositions of Examples 9-16 Table 3. Weight parts of each component in the polypropylene compositions of Examples 17-23 Table 4. Parts by weight of each component in the polypropylene compositions of Comparative Examples 1-7 Performance testing The self-healing properties of the polypropylene compositions in each embodiment and comparative example were tested, as follows: (1) Under the conditions of injection temperature of 220℃ and mold temperature of 50℃, the polypropylene composition was injection molded into a sample with a length of 80cm, a width of 10cm and a thickness of 4cm. (2) Make a 20mm long and 2mm deep scratch on the sample, and then bake it in a 100℃ oven for 60 minutes to allow the polypropylene composition to self-heal under heat. Take it out and measure the depth of the scratch at this time, which is recorded as H (unit: mm). Calculate the degree of self-healing of the polypropylene composition (%) according to the following formula: Self-repair rate (%) = (2-H) / 2 × 100%; The higher the self-healing value, the stronger the self-healing performance of the polypropylene composition. The experimental results are shown in the table below: Table 5 Performance test results of the polypropylene compositions of each example and comparative example. As shown in Table 5, the polypropylene composition of the present invention also has good self-healing properties, wherein the degree of self-healing is ≥60.0%.

[0056] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A polypropylene composition, characterized in that, The components include the following parts by weight: 30-50 parts block copolymer polypropylene, 10-25 parts thermoplastic elastomer A and thermoplastic elastomer B, 30-50 parts polybutene; The glass transition temperature of the thermoplastic elastomer A is -63℃ to -53℃; The glass transition temperature of the thermoplastic elastomer B is -43℃ to -31℃.

2. The polypropylene composition according to claim 1, characterized in that, Includes at least one of the following (1)-(2): (1) The weight ratio of thermoplastic elastomer A to thermoplastic elastomer B is 1:(0.05-3.5); (2) The thermoplastic elastomers A and / or B include at least one of POE, OBC, and POP.

3. The polypropylene composition according to claim 1, characterized in that, The weight ratio of thermoplastic elastomer A to thermoplastic elastomer B is 1:(1-2).

4. The polypropylene composition according to claim 1, characterized in that, The melting point of the polybutene is 70℃~105℃.

5. The polypropylene composition according to claim 4, characterized in that, Includes at least one of the following (1)-(2): (1) The polybutene includes polybutene C and polybutene D, wherein the melting point of polybutene C is 75℃~90℃ and the melting point of polybutene D is 91℃~100℃; (2) The weight ratio of polybutene C to polybutene D is 1:(0.1-3).

6. The polypropylene composition according to claim 5, characterized in that, The weight ratio of polybutene C to polybutene D is 1:(0.5-2).

7. The polypropylene composition according to claim 1, characterized in that, Includes at least one of the following (1)-(2): (1) The melt flow rate of the block copolymer polypropylene at 230℃ and 2.16kg is 10-65g / 10min; (2) The polypropylene composition further includes an antioxidant.

8. A method for preparing a polypropylene composition according to any one of claims 1-7, characterized in that, Includes the following steps: The components are mixed and melt-extruded to obtain a polypropylene composition.

9. The use of a polypropylene composition as described in any one of claims 1-7 in automotive interiors.

10. An automotive interior, characterized in that, The automotive interior comprises a polypropylene composition as described in any one of claims 1-7, and includes at least one of automotive door panels and a center console.

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