Wear-resistant stress-whitening-resistant modified polypropylene composite material applied to automotive trim

Abstract

The invention provides a wear-resistant stress-whitening-resistant modified polypropylene composite material applied to automotive interiors, which is prepared from the following formula in percentage by weight: 40 to 90 percent of polypropylene, 5 to 15 percent of flexibilizer, 2 to 10 percent of compatilizer, 15 to 40 percent of polyethylene, 5 to 10 percent of glass fiber, 10 to 20 percent of inorganic filler, 1 to 5 percent of lubricant, 1 to 5 percent of scratch-resistant agent and 0.3 to 3 percent of antioxidant. 0.3-2% of a light stabilizer and 0-5% of other additives. The wear-resistant stress-whitening-resistant modified polypropylene composite material applied to the automotive trim, which is obtained by adopting the technical scheme, has wear resistance and stress whitening resistance, and meanwhile, has comprehensive mechanical properties, low emission, illumination resistance and scratch resistance.

Description

Technical Field

[0001] The invention relates to a polypropylene composite material, in particular to a polypropylene automobile interior material which has the properties of wear resistance and stress whitening resistance, and also has comprehensive mechanical properties, low emission, light resistance and scratch resistance, and belongs to the field of polymer composite materials. Background Art

[0002] PP (polypropylene) can be modified by toughening, filling, reinforcing, blending and other modification methods to obtain materials with different properties. Due to its low cost and excellent comprehensive performance, modified PP has been widely used in automotive interiors. However, because PP materials are not wear-resistant and prone to scratches, and stress whitening problems often occur during injection molding, assembly and use, they often cause complaints and complaints from consumers.

[0003] In recent years, the momentum of new energy vehicles has developed rapidly. With the electrification and intelligent development of new energy vehicles, people's requirements for cars are no longer limited to the driving experience, and they also have higher requirements for car interiors. Among them, the diversification and personalization of car interior colors have also put forward more and higher requirements on the color system of polypropylene materials for car interiors. The characteristics of polypropylene materials themselves determine that modified polypropylene materials are not wear-resistant, easy to scratch, and easy to produce stress whitening. These problems are more prominent in this stage of diversified development of car interior colors. This research project aims to develop polypropylene composite materials for car interiors that are wear-resistant, stress-whitening-resistant, and take into account comprehensive mechanical properties, low emission, and light resistance. Summary of the invention

[0004] The invention provides a modified polypropylene composite material which is wear-resistant and stress-whitening-resistant for automobile interior decoration, which has the characteristics of wear resistance and stress-whitening resistance, and is a polypropylene automobile interior decoration material which has comprehensive mechanical properties, low emission, light resistance and scratch resistance.

[0005] The present invention can be implemented through the following technical solutions.

[0006] A modified polypropylene composite material for automobile interior decoration, which is wear-resistant and stress-whitening-resistant, is composed of the following raw materials in percentage by weight: 40-90% polypropylene, 5-15% toughening agent, 2-10% compatibilizer, 15-40% polyethylene, 5-10% glass fiber, 10-20% inorganic filler, 1-5% lubricant, 1-5% scratch-resistant agent, 0.3-3% antioxidant, 0.3-2% light stabilizer, and 0-5% other additives.

[0007] The polypropylene is homopolypropylene or copolymer polypropylene, preferably copolymer polypropylene.

[0008] The toughening agent is any suitable polyolefin elastomer, including but not limited to one or a combination of two or more of polybutadiene rubber, ethylene-propylene-diene rubber (EPDM), ethylene-octene copolymer (POE), etc., preferably POE elastomer, with a melt flow rate (230°C, 2.16kg) of 0.5-50g / 10min.

[0009] The compatibilizer is polypropylene grafted with maleic anhydride.

[0010] The polyethylene is high-density polyethylene (HDPE) or low-density linear polyethylene (LLDPE), preferably high-density polyethylene (HDPE), and has a melt flow rate (190° C., 2.16 kg) of 5-30 g / 10 min.

[0011] The glass fiber is chopped short or direct untwisted roving, and the diameter of the glass fiber is 12-23 μm.

[0012] The inorganic filler is one or a combination of two or more of talc, calcium carbonate and barium sulfate, and has an average particle size of 1-20 μm; preferably, barium sulfate has an average particle size of 1-20 μm.

[0013] The lubricant is molybdenum disulfide.

[0014] The anti-scratch agent is one or a combination of two or more of erucamide, oleamide, stearyl erucamide and silicone masterbatch.

[0015] The antioxidant includes a primary antioxidant and an auxiliary antioxidant, wherein the primary antioxidant is a hindered phenol or thioester antioxidant, including but not limited to 1330 (1,3,5-trimethyl-2,4,6.(3,5-di-tert-butyl-4-hydroxybenzyl)benzene), 1010 (chemical name is pentaerythritol tetrakis[β-(3,5-di-tert-butyl 4-hydroxyphenyl)propionate), DSTP (chemical name is stearyl thiodipropionate) or a combination of two or more thereof; the auxiliary antioxidant is a phosphite or ester antioxidant, including but not limited to 618 (chemical name is dioctadecyl pentaerythritol diphosphite) or 168 (chemical name is tris(2,4-di-tert-butylphenyl) phosphite) or a combination of two or more thereof.

[0016] The light stabilizer is one or a combination of two or more of a hindered amine light stabilizer and an ultraviolet absorber.

[0017] The other additives include one or a combination of two or more of colorants, nucleating agents, foaming agents, surfactants, plasticizers, coupling agents, flame retardants, light stabilizers, processing aids, antistatic aids, antimicrobial aids, and lubricants that are considered necessary by those skilled in the art.

[0018] The wear-resistant and stress-whitening-resistant modified polypropylene composite material for automobile interior obtained by the scheme of the present invention has the characteristics of wear resistance and stress-whitening resistance, and is a polypropylene automobile interior material having comprehensive mechanical properties, low emission, light resistance and scratch resistance. DETAILED DESCRIPTION

[0019] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. It should also be understood that after reading the content described in the present invention, those skilled in the art may make changes or modifications to the present invention, and these equivalent forms fall within the scope limited by the appended claims of the application equally.

[0020] Raw materials used in the embodiments of the present invention:

[0021] Polypropylene: copolymer polypropylene with a melt index of 50 g / 10 min (230° C., 2.16 kg), Lanzhou Petrochemical Company.

[0022] Toughening agent: POE with a melt index of 1 g / 10 min (190° C., 2.16 kg), Dow Chemical.

[0023] Compatibilizer: Polypropylene grafted with maleic anhydride, Ningbo Nengzhiguang Company.

[0024] Polyethylene: Melt index is 7g / 10min (190℃, 2.16Kg), high-density polyethylene, Dushanzi Petrochemical Company.

[0025] Glass fiber: Chopped fiberglass, Taishan Fiberglass Company.

[0026] Inorganic filler: barium sulfate, talc, commercially available.

[0027] Lubricant: Molybdenum disulfide, commercially available.

[0028] Scratch resistant agent: stearyl erucamide, silicone masterbatch, commercially available.

[0029] Antioxidants: 1010 (hindered phenol antioxidant), 168 (phosphate antioxidant), commercially available.

[0030] Light stabilizer: UV-3808 (hindered amine light stabilizer), Cyanotec Chemical, Light stabilizer 119 (high molecular weight hindered amine light stabilizer), BASF.

[0031] Other additives: carbon black, commercially available.

[0032] Product performance test method:

[0033] Tensile strength: According to ISO 527 method, sample specification: 1A specimen.

[0034] Flexural modulus: According to ISO 178 method, sample specifications: 80*10*4mm.

[0035] Izod notched impact strength: according to ISO 180 method, sample size: 80*10*4mm.

[0036] Xenon lamp accelerated aging: According to SAE J2412 standard, energy value: 1250KJ / m 2 , measure the color difference △E value.

[0037] Total carbon VOC test: According to VDA277: the test value ≤50μgC / g is qualified.

[0038] Odor: According to PV3900, 80℃ / 2Hr, 50g particles: the test value is ≤3.5 level.

[0039] Stress whitening test: Tested according to PV3966 standard, Volkswagen K31 leather grain board, 3.4 mm thick specimen.

[0040] Scratch resistance test: Tested according to PV3952 standard, 10N, 1mm, sample specifications: Volkswagen K31 leather grain plate, 3.4mm thickness of the sample, measure △L.

[0041] Scratch resistance test: Tested according to PV3974 standard, sample specifications: 3N Volkswagen K31 leather grain plate, 3.4 mm thickness of the sample, measure △G.

[0042] Abrasion resistance: Tested according to ISO 105X12 standard, apply 9N force, rub back and forth 100 times, measure the fading color fastness grade of the material surface, sample size: 355*100*3.2mm.

[0043] Comparative Examples 1-2 and Examples 1-3:

[0044] Copolymerized polypropylene, POE, polypropylene grafted with maleic anhydride, HDPE, chopped glass fiber, barium sulfate, molybdenum disulfide, stearyl erucic acid amide, antioxidant 1010 / 168, UV-3808, carbon black, etc. are mixed uniformly according to the composition ratio in Table 1 and passed through the main barrel of a twin-screw extruder (screw diameter 35 mm, aspect ratio L / D=40). The main barrel is divided into 10 sections to control the temperature (from the feed port to the die outlet) at 200°C, 220°C, 210°C, 205°C, 200°C, 200°C, 200°C, 205°C, and 210°C. The twin-screw speed is 300 rpm. After multi-stage vacuum extraction of harmful gases, the extruded material strips are cooled in a water tank and pelletized to obtain the product. After the product pelletizing is completed, batch mixing is required. The above products were injected into standard specimens, Volkswagen K31 leather grain plates, and combustion plates (355*100*3.2mm) using a plastic injection molding machine at an injection temperature of 210°C. The injection-molded specimens and light plates were immediately placed in a glass desiccator at room temperature for at least 24 hours before performance and light tests. The test results are shown in Table 1.

[0045] Table 1 Composition and properties of polypropylene composition

[0046]

[0047]

[0048] From Comparative Examples 1 to 2 and Examples 1 to 3 in Table 1, it can be seen that even if the conventional talcum powder filled polypropylene material has a very good scratch performance, the wear resistance still cannot meet the requirements, and the stress whitening test will also have the problem of visual whitening. However, by using short-cut glass fiber compounded with barium sulfate and adding lubricant molybdenum disulfide, the wear resistance of the material is significantly improved. On this basis, increasing the proportion of HDPE addition, the wear resistance and stress whitening resistance of the material are significantly improved. At the same time, multi-stage vacuum has a significant contribution to odor and total carbon. After using two-stage vacuum, the odor and total carbon are significantly improved. The above embodiments can achieve excellent mechanical properties, and have good wear resistance and stress whitening resistance in the complex working conditions of new energy vehicles.

[0049] The invention provides a modified polypropylene composite material which is wear-resistant and stress-whitening-resistant for automobile interior decoration, which has the characteristics of wear resistance and stress-whitening resistance, and takes into account the comprehensive mechanical properties, low emission performance, light resistance and scratch resistance of the material.

Claims

1. A wear-resistant and stress-whitening-resistant modified polypropylene composite material for automobile interior, characterized in that: The invention is composed of the following raw materials in percentage by weight: 40-90% polypropylene, 5-15% toughening agent, 2-10% compatibilizer, 15-40% polyethylene, 5-10% glass fiber, 10-20% inorganic filler, 1-5% lubricant, 1-5% anti-scratch agent, 0.3-3% antioxidant, 0.3-2% light stabilizer and 0-5% other additives.

2. The wear-resistant and stress-whitening-resistant modified polypropylene composite material for automobile interior decoration according to claim 1, characterized in that: The polypropylene is homopolymer polypropylene or copolymer polypropylene.

3. The wear-resistant and stress-whitening-resistant modified polypropylene composite material for automobile interior decoration according to claim 1, characterized in that: The toughening agent is any suitable polyolefin elastomer, including but not limited to one or a combination of two or more of polybutadiene rubber, ethylene-propylene-diene rubber (EPDM), ethylene-octene copolymer (POE), etc.

4. The wear-resistant and stress-whitening-resistant modified polypropylene composite material for automobile interior decoration according to claim 3, characterized in that: The toughening agent is a POE elastomer with a melt flow rate of 0.5-50 g / 10 min.

5. The wear-resistant and stress-whitening-resistant modified polypropylene composite material for automobile interior decoration according to claim 1, characterized in that: The compatibilizer is polypropylene grafted with maleic anhydride.

6. The wear-resistant and stress-whitening-resistant modified polypropylene composite material for automobile interior decoration according to claim 1, characterized in that: The polyethylene is high-density polyethylene or low-density linear polyethylene, and the melt flow rate is 5-30 g / 10 min.

7. The wear-resistant and stress-whitening-resistant modified polypropylene composite material for automobile interior decoration according to claim 1, characterized in that: The glass fiber is chopped short or direct untwisted roving, and the diameter of the glass fiber is 12-23 μm.

8. The wear-resistant and stress-whitening-resistant modified polypropylene composite material for automobile interior decoration according to claim 1, characterized in that: The inorganic filler is one of talcum powder, calcium carbonate and barium sulfate or a combination of two or more thereof, and has an average particle size of 1-20 μm.

9. The wear-resistant and stress-whitening-resistant modified polypropylene composite material for automobile interior decoration according to claim 8, characterized in that: The inorganic filler is selected from barium sulfate with an average particle size of 1-20 μm.

10. The wear-resistant and stress-whitening-resistant modified polypropylene composite material for automobile interior decoration according to claim 1, characterized in that: The lubricant is molybdenum disulfide.

11. The wear-resistant and stress-whitening-resistant modified polypropylene composite material for automobile interior decoration according to claim 1, characterized in that: The scratch-resistant agent is one of erucamide, oleamide, stearyl erucamide and silicone masterbatch, or a combination of two or more thereof.

12. The wear-resistant and stress-whitening-resistant modified polypropylene composite material for automobile interior decoration according to claim 1, characterized in that: The antioxidant includes a primary antioxidant and an auxiliary antioxidant, wherein the primary antioxidant is a hindered phenol or thioester antioxidant, including but not limited to 1330 (1,3,5-trimethyl-2,4,6-(3,5-di-tert-butyl-4-hydroxybenzyl)benzene), 1010 (chemical name is pentaerythritol tetrakis[β-(3,5-di-tert-butyl 4-hydroxyphenyl)propionate), DSTP (chemical name is stearyl thiodipropionate) or a combination of the above; the auxiliary antioxidant is a phosphite or ester antioxidant, including but not limited to 618 (chemical name is dioctadecyl pentaerythritol diphosphite) or 168 (chemical name is tris(2,4-di-tert-butylphenyl) phosphite) or a combination of the above.

13. The wear-resistant and stress-whitening-resistant modified polypropylene composite material for automobile interior decoration according to claim 1, characterized in that: The light stabilizer is one of a hindered amine light stabilizer and an ultraviolet absorber, or a combination of two or more thereof.

14. The wear-resistant and stress-whitening-resistant modified polypropylene composite material for automobile interior decoration according to claim 1, characterized in that: The other additives include one or more combinations of colorants, nucleating agents, foaming agents, surfactants, plasticizers, coupling agents, flame retardants, light stabilizers, processing aids, antistatic aids, antimicrobial aids, and lubricants that are considered necessary by those skilled in the art.

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