A gasoline-resistant polypropylene composite material and its preparation method and application

Abstract

The present invention provides a gasoline-resistant polypropylene composite material and a preparation method and application thereof. The gasoline-resistant polypropylene composite material comprises the following components by weight: 49 to 91 parts of polypropylene resin; 1 to 11 parts of polyethylene resin; 9 to 31 parts of fibrous fillers; 0.4 to 7 parts of compatibilizer; 0.4 to 6 parts of epoxy resin; the epoxy equivalent of the epoxy resin is 700 to 1000 g / eq. The polypropylene composite material provided by the present invention comprises a combination of polypropylene resin, polyethylene resin, fibrous fillers, compatibilizers and epoxy resins. Through the screening and coordinated compounding of specific components, especially the introduction of epoxy resin, polyethylene resin and fibrous fillers, the polypropylene composite material has both good gasoline resistance and excellent mechanical properties.

Description

Technical Field

[0001] The invention belongs to the technical field of polypropylene composite materials and relates to a gasoline-resistant polypropylene composite material and a preparation method and application thereof. Background Art

[0002] With the development of lightweight automobiles, polymer composite materials are increasingly used in automobile interior and exterior parts. Polypropylene materials are gradually gaining an advantage in use due to their wide sources, low cost, low density, and easy molding. According to statistics, the amount of polypropylene materials used in a single car currently exceeds 50kg.

[0003] However, polypropylene also has natural deficiencies, such as easy aging, poor cold resistance, poor adhesion, and poor chemical resistance. Therefore, it is often necessary to modify it before use. Polypropylene is used in automobiles, mainly for interior and exterior decoration, with some parts covered and some exposed. Therefore, the main engine manufacturers have increasingly higher requirements for the chemical resistance of polypropylene. In terms of modifying the chemical resistance of polypropylene, it is more difficult to improve its gasoline resistance.

[0004] CN109517265A discloses a solvent-resistant polypropylene composition and a preparation method thereof, which uses HDPE to replace all or part of POE, adds a scratch-resistant agent, and improves the crystallinity of the material. The three work together to improve the solvent resistance of the polypropylene composition, but the synergistic system is complex, which increases the difficulty of processing.

[0005] CN109776971A discloses a polypropylene composite material and a preparation method thereof, wherein inorganic surface modifiers and organic surface modifiers and other additives are added to make the composite material have good gasoline solvent resistance. However, the inorganic surface modifier is complicated to process, and the use of polytetrafluoroethylene powder for modification is likely to affect the coating.

[0006] Therefore, it is desirable in the art to develop a polypropylene composite material which has good gasoline resistance, a wide source of raw materials, and a simple preparation method. Summary of the invention

[0007] In view of the deficiencies in the prior art, the object of the present invention is to provide a gasoline-resistant polypropylene composite material and a preparation method and application thereof.

[0008] To achieve this object, the present invention adopts the following technical solutions:

[0009] In a first aspect, the present invention provides a gasoline-resistant polypropylene composite material, wherein the gasoline-resistant polypropylene composite material comprises the following components in parts by weight:

[0010]

[0011] The epoxy equivalent of the epoxy resin is 700 to 1000 g / eq.

[0012] The polypropylene composite material provided by the present invention comprises a combination of polypropylene resin, polyethylene resin, fibrous filler, compatibilizer and epoxy resin. Through the screening and coordinated compounding of specific components, especially the introduction of epoxy resin, polyethylene resin and fibrous filler, the polypropylene composite material has both good gasoline resistance and excellent mechanical properties.

[0013] In the present invention, the epoxy resin has a suitable epoxy equivalent, which is easy to migrate to the surface of the polypropylene composite material. The epoxy resin contains more polar ether bonds in its molecular chain, has oleophobicity, and is easy to form an oleophobic layer on the surface of the polypropylene composite material; in addition, the epoxy resin has good oil resistance due to the effect of its own benzene ring, does not change its own performance after oil absorption, and is easy to form a barrier layer on the surface of the polypropylene composite material, so the gasoline resistance of the polypropylene composite material can be improved. If the epoxy equivalent of the epoxy resin is too small, the epoxy resin cannot adhere to the substrate after precipitation and is easily wiped away, thereby failing to achieve the gasoline resistance effect; if the epoxy equivalent of the epoxy resin is too large, the epoxy resin solidifies in the substrate and cannot migrate to the surface of the substrate, and the effect of improving the gasoline resistance of the substrate cannot be achieved.

[0014] In the present invention, the addition of fibrous fillers, due to their anisotropic effect, is conducive to forming a grid structure on the surface of the workpiece, preventing gasoline molecules from penetrating and diffusing further, thereby achieving good gasoline resistance.

[0015] In the present invention, the gasoline resistant polypropylene composite material can be composed of 49 parts, 50 parts, 55 parts, 60 parts, 65 parts, 70 parts, 75 parts, 80 parts, 85 parts, 90 parts, 91 parts, etc. of polypropylene resin in parts by weight.

[0016] In the present invention, the gasoline-resistant polypropylene composite material can be composed of 1 part, 2 parts, 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts, 11 parts, etc. of polyethylene resin in parts by weight.

[0017] In the present invention, the amount of fibrous filler in the gasoline-resistant polypropylene composite material can be 9 parts, 10 parts, 12 parts, 14 parts, 16 parts, 18 parts, 20 parts, 22 parts, 24 parts, 26 parts, 28 parts, 30 parts, 31 parts, etc. by weight.

[0018] In the present invention, the amount of the compatibilizer in the gasoline resistant polypropylene composite material can be 0.4 parts, 0.5 parts, 1 parts, 1.5 parts, 2 parts, 2.5 parts, 3 parts, 3.5 parts, 4 parts, 4.5 parts, 5 parts, 5.5 parts, 6 parts, 6.5 parts, 7 parts, etc., calculated by weight.

[0019] In the present invention, the amount of epoxy resin in the gasoline resistant polypropylene composite material can be 0.4 parts, 0.5 parts, 1 parts, 1.5 parts, 2 parts, 2.5 parts, 3 parts, 3.5 parts, 4 parts, 4.5 parts, 5 parts, 5.5 parts, 6 parts, etc., calculated by weight.

[0020] In the gasoline-resistant polypropylene composite material, the content of polypropylene resin is not less than 45wt%.

[0021] Preferably, the polypropylene resin is homopolypropylene.

[0022] Preferably, the melt flow rate of the polypropylene resin at 230°C and 2.16kg is 5 to 60g / 10min, for example, 5g / 10min, 10g / 10min, 15g / 10min, 20g / 10min, 25g / 10min, 30g / 10min, 35g / 10min, 40g / 10min, 45g / 10min, 50g / 10min, 55g / 10min, 60g / 10min, etc. The melt flow rate of the polypropylene resin is tested at 230°C and 2.16kg according to ISO 1133-1:2022 standard method.

[0023] Preferably, the polyethylene resin is linear low-density polyethylene. The present invention uses linear low-density polyethylene as a toughening agent, avoids the use of a rubber phase that easily absorbs oil, and increases the gasoline resistance of the polypropylene composite matrix.

[0024] Preferably, the melt flow rate of the polyethylene resin at 190°C and 2.16kg is 0.5 to 10g / 10min, for example, 0.5g / 10min, 1g / 10min, 2g / 10min, 3g / 10min, 4g / 10min, 5g / 10min, 6g / 10min, 7g / 10min, 8g / 10min, 9g / 10min, 10g / 10min, etc. The melt flow rate of the polyethylene resin is tested according to ISO1133-1:2022 standard method at 190°C and 2.16kg.

[0025] Preferably, the compatibilizer comprises maleic anhydride grafted polypropylene.

[0026] Preferably, in the maleic anhydride grafted polypropylene, the grafting rate of maleic anhydride is 0.6-0.9wt.%, for example, 0.6wt.%, 0.65wt.%, 0.7wt.%, 0.75wt.%, 0.8wt.%, 0.85wt.%, 0.9wt.%, etc. The grafting rate of maleic anhydride is obtained by acid-base neutralization method.

[0027] Preferably, the epoxy resin comprises bisphenol A type epoxy resin.

[0028] Preferably, the fibrous filler includes any one of glass fiber, carbon fiber or whisker, or a combination of at least two of them.

[0029] Preferably, the average length of the fibrous filler is 10-6000 μm, for example, 10 μm, 20 μm, 30 μm, 40 μm, 50 μm, 100 μm, 200 μm, 500 μm, 800 μm, 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, etc.

[0030] Preferably, the average length of the glass fiber is 3-5 mm, for example, 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm, etc.

[0031] Preferably, the average length of the carbon fibers is 5-7 mm, for example, 5 mm, 5.5 mm, 6 mm, 6.5 mm, 7 mm, etc.

[0032] Preferably, the average length of the whiskers is 10-40 μm, for example, 10 μm, 20 μm, 30 μm, 40 μm, etc.

[0033] Preferably, the gasoline-resistant polypropylene composite material also includes a colorant.

[0034] Preferably, the weight proportion of the colorant is 0.5 to 2 parts, for example, 0.5 parts, 1 part, 1.5 parts, 2 parts, etc.

[0035] Preferably, the colorant includes carbon black. The colorant may be added in the form of a masterbatch, for example, the colorant may be polyethylene-based carbon black, which is a carbon black masterbatch dispersed in polyethylene as a carrier resin.

[0036] Preferably, the gasoline-resistant polypropylene composite material also includes an antioxidant.

[0037] Preferably, the weight portion of the antioxidant is 0.2 to 1 part, for example, 0.2 part, 0.3 part, 0.5 part, 0.8 part, 1 part, etc.

[0038] Preferably, the antioxidant comprises a hindered phenol antioxidant and / or a phosphite antioxidant.

[0039] Preferably, the gasoline-resistant polypropylene composite material also includes a light stabilizer.

[0040] Preferably, the weight portion of the light stabilizer is 0.1 to 0.5 parts, for example, 0.1 parts, 0.2 parts, 0.3 parts, 0.4 parts, 0.5 parts, etc.

[0041] Preferably, the light stabilizer comprises a hindered amine light stabilizer.

[0042] As a preferred technical solution of the present invention, the gasoline-resistant polypropylene composite material comprises the following components in parts by weight:

[0043]

[0044]

[0045] In a second aspect, the present invention provides a method for preparing the gasoline-resistant polypropylene composite material as described in the first aspect, the preparation method comprising the following steps:

[0046] (1) mixing a formulated amount of polypropylene resin, polyethylene resin, compatibilizer, epoxy resin, and an optional colorant, an optional antioxidant, and an optional light stabilizer to obtain a premix;

[0047] (2) placing the premix obtained in step (1) at the main feed port of a twin-screw extruder, placing the fibrous filler at the side feed port of the twin-screw extruder, and performing melt blending and extrusion granulation to obtain the gasoline-resistant polypropylene composite material.

[0048] Preferably, the mixing in step (1) is carried out in a high-speed mixer.

[0049] Preferably, the mixing speed in step (1) is 500-1500 rpm, for example, 500 rpm, 600 rpm, 700 rpm, 800 rpm, 900 rpm, 1000 rpm, 1100 rpm, 1200 rpm, 1300 rpm, 1400 rpm, 1500 rpm, etc., and the mixing time is 1-3 min, for example, 1 min, 2 min, 3 min, etc.

[0050] Preferably, the process parameters of the twin-screw extruder are set as follows: the temperature of zone 1 is 60°C to 120°C (for example, 60°C, 70°C, 80°C, 90°C, 100°C, 110°C, 120°C, etc.), the temperatures of zones 2 to 4 are each independently 190°C to 220°C (for example, 190°C, 200°C, 210°C, 220°C, etc.), and the temperatures of zones 5 to 10 are each independently 180°C to 200°C (for example, 180°C, 190°C, 200°C, etc.); the rotation speed is 300 to 500rpm, for example, 300rpm, 350rpm, 400rpm, 450rpm, 500rpm, etc.

[0051] In a third aspect, the present invention provides an automobile interior and exterior trim component, wherein the automobile interior and exterior trim component is prepared using the gasoline-resistant polypropylene composite material described in the first aspect.

[0052] Preferably, the automobile interior and exterior trim components include automobile door substrates, instrument panel frames, auxiliary instrument panel frames, seat rails or brackets.

[0053] Compared with the prior art, the present invention has at least the following beneficial effects:

[0054] The polypropylene composite material provided by the present invention comprises a combination of polypropylene resin, polyethylene resin, fibrous filler, compatibilizer and epoxy resin. Through the screening and coordinated compounding of specific components, especially the introduction of epoxy resin, polyethylene resin and fibrous filler, the polypropylene composite material has both good gasoline resistance and excellent mechanical properties. DETAILED DESCRIPTION

[0055] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0056] The specific raw material information used in the examples and comparative examples of the present invention is as follows:

[0057] Polypropylene resin: homopolymer polypropylene, PP HP500N, with a melt flow rate of 12 g / 10 min when tested at 230 °C and 2.16 kg according to ISO 1133-1:2022 standard method, CNOOC Shell.

[0058] Polyethylene resin: linear low-density polyethylene, LLDPE EXCEED 3518PA, with a melt flow rate of 3.5 g / 10 min when tested at 190 °C and 2.16 kg according to ISO 1133-1:2022 standard method, ExxonMobil.

[0059] Fibrous filler 1: Glass fiber, glass fiber ECS13-04-508A, Jushi Chemical.

[0060] Fibrous filler 2: basic magnesium sulfate whisker, WS-1S2, Wisker.

[0061] Talc: TYT-777A, 3000 mesh, Tianyuan Chemical.

[0062] Compatibilizer: maleic anhydride grafted polypropylene, YBL-MPP300 NC001, the grafting rate of maleic anhydride is 0.7wt.%, Chengdu Jinfa.

[0063] Epoxy resin 1: bisphenol A type epoxy resin, epoxy equivalent weight is 730-840g / eq, KD-213, Guodu.

[0064] Epoxy resin 2: bisphenol A type epoxy resin, epoxy equivalent weight is 900-1000g / eq, CYD-014, Baling Petrochemical.

[0065] Epoxy resin 3: bisphenol A type epoxy resin, epoxy equivalent weight is 450-500g / eq, CYD-011, Baling Petrochemical.

[0066] Epoxy resin 4: bisphenol A type epoxy resin, epoxy equivalent weight is 1750-2100g / eq, CYD-017, Baling Petrochemical.

[0067] Colorant: polyethylene-based carbon black masterbatch, PE2718, Cabot, wherein the content of carbon black is 50 wt %, and the weight percentages of the colorants in Tables 1 and 2 below have been converted to the weight percentages of pure colorants.

[0068] Antioxidant 1: Hindered phenol antioxidant, Antioxidant 1010, Sanfeng Chemical.

[0069] Antioxidant 2: Phosphite antioxidant, Antioxidant 168, Sanfeng Chemical.

[0070] Light stabilizer: hindered amine light stabilizer, UV-3808PP5, cyanotera.

[0071] Examples 1-8

[0072] In Examples 1-8, a gasoline-resistant polypropylene composite material is provided respectively. The specific components and usage (in parts by weight) of the gasoline-resistant polypropylene composite material are shown in Table 1 or Table 2.

[0073] The preparation method comprises the following steps:

[0074] (1) putting the formulated amount of polypropylene resin, polyethylene resin, compatibilizer, epoxy resin, colorant, antioxidant, and light stabilizer into a high-speed mixer and mixing at a speed of 1000 rpm for 2 minutes to obtain a premix;

[0075] (2) placing the premix obtained in step (1) at the main feed port of a twin-screw extruder, placing the fibrous filler at the side feed port of the twin-screw extruder, and performing melt blending and extrusion granulation to obtain the gasoline-resistant polypropylene composite material.

[0076] Comparative Examples 1-7

[0077] In Comparative Examples 1-7, a polypropylene composite material is provided respectively. The specific components and amounts (parts by weight) of the polypropylene composite material are shown in Table 2.

[0078] The preparation method is the same as that of Example 1-8.

[0079] Table 1

[0080]

[0081] Table 2

[0082]

[0083] In Table 1 and Table 2, -- indicates that the corresponding component was not added.

[0084] The polypropylene composite materials prepared in the examples of the present invention and the comparative examples were subjected to performance tests, and the test methods were as follows:

[0085] (1) Tensile strength: tested in accordance with ISO 527-1:2019 standard.

[0086] (2) Flexural modulus: tested in accordance with ISO 178:2019 standard.

[0087] (3) Izod notched impact strength: tested in accordance with ISO 180:2019(E) standard.

[0088] (4) Gasoline resistance test: The selected reagent is solvent gasoline (No. 120 gasoline). The surface of the polypropylene composite material is wiped 10 times with a cloth soaked in the reagent. The material is placed vertically in an environment of 23°C for 1 hour, and then placed in an environment of 90°C for 1 hour before the sample status is tested.

[0089] Evaluation level: Focus on the color staining level on the cloth (i.e., after wiping the polypropylene composite material with a cloth, observe whether the cloth is stained with color and the degree of staining) and the whitening level (i.e., observe the whitening on the polypropylene composite material substrate), and divide it into 1 to 5 levels according to the severity.

[0090] The above staining and blushing levels are: Level 1 - no change in the surface; Level 2 - slight (need to turn the angle or effort to see); Level 3 - slight (no need to turn the angle); Level 4 - obvious; Level 5 - severe.

[0091] The performance test results are shown in Table 3.

[0092] Table 3

[0093]

[0094] It can be seen from Table 3 that the polypropylene composite materials provided in the embodiments of the present invention have both good gasoline resistance (staining grade: 1-2, whitening grade: 2-3) and good toughness (Izod notched impact strength: 11-18 KJ / m 2 ).

[0095] Compared with Examples 1-3, the toughness and gasoline resistance of the polypropylene composite material provided in Comparative Example 1 are both reduced, and the gasoline resistance of the polypropylene composite material provided in Comparative Example 2 is reduced, which indicates that excessive use of epoxy resin or no addition of epoxy resin will deteriorate the gasoline resistance of the polypropylene composite material.

[0096] Compared with Example 2, the gasoline resistance of the polypropylene composite material provided in Comparative Example 3 decreases, which indicates that the use of epoxy resin to improve the gasoline resistance of the polypropylene composite material in the present invention has a better effect than the use of antistatic agents in the prior art to improve the gasoline resistance of the polypropylene composite material.

[0097] Compared with Example 2, the gasoline resistance of the polypropylene composite material provided by Comparative Example 4 decreases, and its toughness is significantly reduced, which shows that the present invention uses linear low-density polyethylene as a toughening agent, which not only avoids the use of a rubber phase that is easily oil-absorbent, but also increases the gasoline resistance of the polypropylene composite matrix.

[0098] Compared with Example 2, the gasoline resistance of the polypropylene composite materials provided in Comparative Examples 5-6 is reduced, which indicates that too small or too large equivalent weight of epoxy resin will deteriorate the gasoline resistance of the polypropylene composite material.

[0099] Compared with Example 2, the gasoline resistance of the polypropylene composite material provided in Comparative Example 7 is reduced, and its toughness, tensile strength and flexural modulus are significantly reduced.

[0100] The applicant declares that the present invention illustrates the gasoline-resistant polypropylene composite material and its preparation method and application through the above-mentioned embodiments, but the present invention is not limited to the above-mentioned embodiments, that is, it does not mean that the present invention must rely on the above-mentioned embodiments to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of various raw materials of the product of the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A gasoline-resistant polypropylene composite material, characterized in that: The gasoline-resistant polypropylene composite material comprises the following components in parts by weight: The epoxy equivalent of the epoxy resin is 700 to 1000 g / eq; The polypropylene resin is homopolymer polypropylene; The polyethylene resin is linear low-density polyethylene; The fibrous filler comprises any one of glass fiber, carbon fiber or whisker or a combination of at least two thereof; The epoxy resin includes bisphenol A type epoxy resin.

2. The gasoline-resistant polypropylene composite material according to claim 1, characterized in that: The melt flow rate of the polypropylene resin at 230° C. and 2.16 kg is 5 to 60 g / 10 min.

3. The gasoline-resistant polypropylene composite material according to claim 1, characterized in that: The polyethylene resin has a melt flow rate of 0.5 to 10 g / 10 min at 190° C. and 2.16 kg.

4. The gasoline-resistant polypropylene composite material according to claim 1, characterized in that: The compatibilizer includes maleic anhydride grafted polypropylene.

5. The gasoline-resistant polypropylene composite material according to claim 4, characterized in that: In the maleic anhydride grafted polypropylene, the grafting rate of maleic anhydride is 0.6-0.9 wt.%.

6. The gasoline-resistant polypropylene composite material according to claim 1, characterized in that: The gasoline-resistant polypropylene composite material also includes a colorant.

7. The gasoline-resistant polypropylene composite material according to claim 6, characterized in that: The weight proportion of the colorant is 0.5 to 2 parts.

8. The gasoline-resistant polypropylene composite material according to claim 6, characterized in that: The colorant includes carbon black.

9. The gasoline-resistant polypropylene composite material according to claim 1, characterized in that: The gasoline-resistant polypropylene composite material also includes an antioxidant.

10. The gasoline-resistant polypropylene composite material according to claim 9, characterized in that: The weight portion of the antioxidant is 0.2 to 1 part.

11. The gasoline-resistant polypropylene composite material according to claim 9, characterized in that: The antioxidant includes a hindered phenol antioxidant and / or a phosphite antioxidant.

12. The gasoline-resistant polypropylene composite material according to claim 1, characterized in that: The gasoline-resistant polypropylene composite material also includes a light stabilizer.

13. The gasoline-resistant polypropylene composite material according to claim 12, characterized in that: The weight portion of the light stabilizer is 0.1 to 0.5 parts.

14. The gasoline-resistant polypropylene composite material according to claim 12, characterized in that: The light stabilizer includes a hindered amine light stabilizer.

15. The gasoline-resistant polypropylene composite material according to claim 1, characterized in that: The gasoline-resistant polypropylene composite material comprises the following components in parts by weight:

16. A method for preparing a gasoline-resistant polypropylene composite material according to any one of claims 1 to 15, characterized in that: The preparation method comprises the following steps: (1) mixing a formulated amount of polypropylene resin, polyethylene resin, compatibilizer, epoxy resin, and an optional colorant, an optional antioxidant, and an optional light stabilizer to obtain a premix; (2) placing the premix obtained in step (1) at the main feed port of a twin-screw extruder, placing the fibrous filler at the side feed port of the twin-screw extruder, and performing melt blending and extrusion granulation to obtain the gasoline-resistant polypropylene composite material.

17. An automotive interior and exterior decoration component, characterized in that: The automobile interior and exterior trim parts are prepared using the gasoline-resistant polypropylene composite material according to any one of claims 1 to 15.

18. The automotive interior and exterior decoration component according to claim 17, characterized in that: The automobile interior and exterior decoration parts include an automobile door substrate, an instrument panel frame, a sub-instrument panel frame, and a seat rail or bracket.

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