Polypropylene composite material as well as preparation method and application thereof

Abstract

The invention discloses a polypropylene composite material which comprises the following components in parts by weight: 48-62 parts of co-polypropylene; 15-25 parts of an inorganic filler; 15 to 20 parts of POE (Polyolefin Elastomer); 3 to 6 parts of styrene-ethylene-butylene copolymer; and 2-3 parts of a scratch-resistant agent. The co-polypropylene with the rubber phase content of 7-18 wt%, the POE with the specific content and the styrene-ethylene-butylene copolymer with the number-average molecular weight of 100,000-23,000 are selected for synergistic effect, and the polypropylene composite material with low gloss, good blasting resistance and scratch resistance can be obtained and is suitable for preparing instrument boards.

Description

Technical Field

[0001] This invention relates to the field of polymer materials technology, and in particular to a polypropylene composite material, its preparation method, and its application. Background Technology

[0002] As a crucial decorative and functional component of a car's interior, the dashboard needs to meet technical standards such as low odor, high rigidity and toughness, and scratch resistance. Polypropylene (PP) is widely used in dashboards and other automotive components due to its advantages such as low density, low processing temperature, and low cost. However, existing polypropylene composite materials cannot simultaneously meet the requirements of low gloss and burst resistance. Traditional dashboards, catering to customers' pursuit of aesthetics, have a high surface gloss, which can easily cause glare under sunlight, interfering with the driver's vision and posing a high risk. Although painting can reduce surface gloss, it increases costs and enhances in-vehicle odor and VOCs, endangering the safety of drivers and passengers. Furthermore, as the automotive industry places increasingly higher demands on driving safety, major OEMs are gradually raising their requirements for the burst resistance of dashboards. For example, one car brand's dashboard burst resistance requirements are: regardless of low temperature (-30℃), normal temperature, or high temperature environments, in an emergency, when the airbag on the passenger side dashboard deploys, the dashboard must not scatter fragments towards the passenger, and the number of fragments ejected from the airbag assembly cover must not exceed 5 pieces, with a total weight not exceeding 1.5g. Therefore, it is particularly important to prepare dashboard materials with low gloss and blast resistance.

[0003] Numerous studies have addressed methods to reduce the gloss of polypropylene, such as increasing filler content, incorporating cross-linked polymers, and applying matte finish to molds. However, these methods may severely impair the mechanical properties of the material, introduce odors, and increase processing steps. Summary of the Invention

[0004] The purpose of this invention is to provide a low-gloss, blast-resistant, and scratch-resistant polypropylene composite material, as well as its preparation method and application.

[0005] This invention is achieved through the following technical solution:

[0006] A polypropylene composite material, by weight, comprises the following components:

[0007] 48-62 parts of copolymerized polypropylene;

[0008] 15-25 parts of inorganic filler;

[0009] POE 15-20 copies;

[0010] 3-6 parts of styrene-ethylene-butene copolymer;

[0011] 2-3 parts scratch-resistant agent;

[0012] The rubber phase content of the copolymerized polypropylene is 7-18 wt%.

[0013] The styrene-ethylene-butene copolymer has a number-average molecular weight of 100,000 to 230,000.

[0014] The D95 particle size range of the filler is 20-40 micrometers.

[0015] In the polypropylene composite material of the present invention, the copolymer polypropylene accounts for not less than 40 wt% of the total weight of the polypropylene composite material.

[0016] In the polypropylene composite material of the present invention, the content of copolymer polypropylene can be any value or a range between 48 parts, 50 parts, 52 parts, 54 parts, 56 parts, 58 parts, 60 parts, and 62 parts; the content of inorganic filler can be any value or a range between 15 parts, 16 parts, 17 parts, 18 parts, 19 parts, 20 parts, 21 parts, 22 parts, 23 parts, 24 parts, and 25 parts; and the content of POE can be 15 parts, 16 parts, 17 parts, 18 parts, 19 parts, 20 parts, 21 parts, 22 parts, 23 parts, 24 parts, and 25 parts. The content of styrene-ethylene-butene copolymer can be any value of 8 parts, 19 parts, or 20 parts, or a range between the two; the content of styrene-ethylene-butene copolymer can be any value of 3 parts, 3.5 parts, 4 parts, 4.5 parts, 5 parts, 5.5 parts, or 6 parts, or a range between the two; the content of scratch-resistant agent can be any value of 2 parts, 2.1 parts, 2.2 parts, 2.3 parts, 2.4 parts, 2.5 parts, 2.6 parts, 2.7 parts, 2.8 parts, 2.9 parts, or 3.0 parts, or a range between the two.

[0017] Preferably, the rubber phase content of the copolymer polypropylene is 8-12 wt%, and the test method refers to the standard GB / T24282-2009 "Determination of xylene-soluble content in polypropylene plastics".

[0018] The rubber phase content of the copolymer polypropylene can be any value or a range between 7 wt%, 8 wt%, 9 wt%, 10 wt%, 11 wt%, 12 wt%, 13 wt%, 14 wt%, 15 wt%, 16 wt%, 17 wt%, and 18 wt%.

[0019] The inorganic filler is selected from at least one of talc, wollastonite, mica powder, and magnesium hydroxide whiskers;

[0020] The scratch-resistant agent is selected from at least one of silicone-based scratch-resistant agents and amide-based scratch-resistant agents.

[0021] Silicone-based scratch-resistant agents can be silicone (i.e., polysiloxane). Silicone can be added by silicone powder or silicone masterbatch, such as silicone / PP masterbatch with PP as the carrier (30-60wt% silicone + 40-70wt% PP), where the molecular weight of silicone is 1.4 million to 1.8 million.

[0022] Amide-based scratch-resistant agents are oleic amides or erucic amides with a molecular weight of 250-350.

[0023] Preferably, the D95 particle size range of the filler is 25-35 micrometers, and the test method is laser particle size analyzer testing.

[0024] The sum of the mass fractions of POE and styrene-ethylene-butene copolymer accounts for 16.6-28.6 wt% of the polypropylene composite material in this case.

[0025] The mass ratio of POE to styrene-ethylene-butene copolymer is (2.5-6.7):1, preferably (3-6):1, and even more preferably (3.2-4.8):1.

[0026] The POE is selected from at least one of ethylene-octene copolymer and ethylene-butene copolymer;

[0027] The overall crystallinity of the POE can be 11%-28%; preferably, the overall crystallinity of the POE is 13-23%. The test method for overall crystallinity refers to ISO 11357-3: Plastics - Differential scanning calorimetry (DSC) - Part 3: Determination of melting and crystallization temperatures and enthalpy.

[0028] The overall crystallinity of POE can be any value or a range between 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, and 28%.

[0029] Preferably, the styrene-ethylene-butene copolymer is a styrene-ethylene-butene-styrene block copolymer (SEBS).

[0030] Preferably, the number-average molecular weight of the styrene-ethylene-butene copolymer is 140,000-170,000. The molecular weight of the styrene-ethylene-butene copolymer is determined by gel permeation chromatography. The styrene-ethylene-butene copolymer sample is dissolved in a suitable solvent, and then the solution is passed through a chromatographic column packed with porous gel packing. Smaller molecules can enter the gel pores, resulting in a longer path and longer retention time; while larger molecules are excluded from the pores and are eluted first. The molecular weight of the styrene-ethylene-butene copolymer is calculated by detecting the concentration of the eluent.

[0031] The molecular weight of the styrene-ethylene-butene copolymer can be any value or a range between 100,000, 105,000, 110,000, 115,000, 120,000, 125,000, 130,000, 135,000, 140,000, 145,000, 150,000, 160,000, 170,000, 180,000, 190,000, 200,000, 210,000, 220,000, and 230,000.

[0032] The present invention does not limit the melt index of the copolymer polypropylene. The melt index range of the copolymer polypropylene can be 50-120g / 10min, preferably 60-100g / 10min, and the test conditions are 230℃ / 2.16kg.

[0033] The melt flow index of POE can range from 1 to 6 g / 10 min, the test conditions are 190℃ / 2.16 kg, and the test standard is ISO 1133-1.

[0034] The melt index range of styrene-ethylene-butene copolymer can be 15-40 g / 10 min, the test conditions are 230℃ / 5 kg, and the test standard is ISO 1133-1.

[0035] 0-1 parts of additives may be added as needed; the additives are selected from at least one of antioxidants, light stabilizers, and lubricants.

[0036] Antioxidants can be: 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene; 2,5-di-tert-butyl-4-hydroxybenzyl dimethylamine; diethyl-3,5-di-tert-butyl-4-hydroxybenzyl phosphate; stearyl-3,5-di-tert-butyl-4-hydroxybenzyl phosphate; 3,5-di-tert-butyl-4-hydroxyphenyl-3,5-distearate-thiotriazolylamine; 2,6-di-tert-butyl-4-hydroxymethylphenol; 2,4-di-(n-octylthio)-6-(4-hydroxy-3,5-di-tert-butylglycerol allyl ether)-1,3,5-triazine; N,N'-hexamethylene di( 3,5-Di-tert-butyl-4-hydroxy-hydrogenated cinnamamide; N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexamethylenediamine; octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate; pentaerythritol-tetra[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]; triethylene glycol-bis[3-(3,5-dimethyl-4-hydroxyphenyl)propionate]; triethylene glycol bis[β-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate]; 2,2'-thiodiethyl-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, etc.

[0037] The lubricant may be at least one of the following: stearate lubricant, fatty acid lubricant, and stearate ester lubricant; the stearate lubricant is selected from at least one of calcium stearate, magnesium stearate, and zinc stearate; the fatty acid lubricant is selected from at least one of fatty acids, fatty acid derivatives, and fatty acid esters; and the stearate ester lubricant is selected from pentaerythritol stearate.

[0038] The preparation method of the polypropylene composite material of the present invention includes the following steps: mixing the components evenly according to the formula, and extruding and granulating them through a twin-screw extruder to obtain the polypropylene composite material.

[0039] The present invention also relates to an instrument panel containing the polypropylene composite material of the present invention.

[0040] The present invention has the following beneficial effects:

[0041] This invention utilizes copolymerized polypropylene, a specific amount of ethylene-butene copolymer and styrene-ethylene-butene copolymer for synergistic effects, a specific amount of inorganic filler, and the addition of a scratch-resistant agent to obtain a low-gloss, high-explosion-resistance, and scratch-resistant polypropylene composite material suitable for manufacturing instrument panels. Detailed Implementation

[0042] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention. These all fall within the scope of protection of the present invention.

[0043] The raw materials for this invention are sourced as follows:

[0044] Copolymer PP-1: Rubber phase content is 8wt%, grade: PP 7945E1, manufacturer: ExxonMobil;

[0045] Copolymer PP-2: Rubber phase content is 9wt%, grade: PP 7935E1, manufacturer: ExxonMobil;

[0046] Copolymer PP-3: Rubber phase content is 11wt%, grade: PP EP648U, manufacturer: CNOOC Shell Petrochemicals Co., Ltd.;

[0047] Copolymer PP-4: Rubber phase content is 17.5wt%, grade: PP K7100, manufacturer: Yanshan Petrochemical;

[0048] Copolymer PP-5: Rubber phase content 19.4wt%, Grade: PP 7555KNE2, Manufacturer: ExxonMobil;

[0049] Homopolymer polypropylene: Grade: PPH-MN60 (BEIHAI), Manufacturer: Sinopec Beihai Refining & Chemical Co., Ltd.

[0050] Talc powder was purchased from Imery Company, and the following raw materials with a D95 particle size were obtained through screening:

[0051] Talc-1:D95 has a particle size of 23.1 micrometers;

[0052] Talc-2: D95 has a particle size of 25.3 micrometers;

[0053] Talc-3:D95 has a particle size of 35.0 micrometers;

[0054] Talc-4:D95 has a particle size of 38.6 micrometers;

[0055] Talc-5: D95 has a particle size of 12.2 micrometers;

[0056] Talc-6:D95 has a particle size of 57.7 micrometers;

[0057] Mica powder: D95 particle size is 38 micrometers, Lingshou County Huajing Mica Co., Ltd.;

[0058] Calcium carbonate: Purchased from Guangdong Dongyuan High-Tech Materials Co., Ltd., and obtained through screening with a D95 particle size of 22.3 micrometers;

[0059] POE-1: Ethylene-butene copolymer, crystallinity 12%, grade: POE ENGAGE 7467, manufacturer: Dow;

[0060] POE-2: Ethylene-butene copolymer, crystallinity 13%, grade: POE ENGAGE 7447, manufacturer: Dow;

[0061] POE-3: Ethylene-butene copolymer, crystallinity 23%, grade: POE ENGAGE 7256, manufacturer: Dow;

[0062] POE-4: Ethylene-butene copolymer, crystallinity 25%, grade: HM7280, manufacturer: Dow;

[0063] POE-5: Ethylene-octene copolymer, crystallinity 16%, grade: POE ENGAGE 8180, manufacturer: Dow;

[0064] POE-6: Ethylene-octene copolymer, crystallinity 13%, grade: POE ENGAGE 8137, manufacturer: Dow;

[0065] Styrene-ethylene-butene copolymer-1: Molecular weight 66,000, grade: SEBS S6552, manufacturer: Zhejiang Zhongli Synthetic Materials Technology Co., Ltd.

[0066] Styrene-ethylene-butene copolymer-2: Molecular weight 110,000, grade: SEBS G1657V, manufacturer: KETEN Polymer Trading (Shanghai) Co., Ltd.

[0067] Styrene-ethylene-butene copolymer-3: molecular weight 150,000, grade: SEBS S6554, manufacturer: Zhejiang Zhongli Synthetic Materials Technology Co., Ltd.

[0068] Styrene-ethylene-butene copolymer-4: molecular weight 220,000, grade: SEBS 7551, manufacturer: Lee Chang Yung Chemical Industry Co., Ltd.

[0069] Silicone scratch-resistant agent: silicone masterbatch, silicone content approximately 50wt%, brand: BZPP301, manufacturer: Chongqing Baozhuan New Material Technology Co., Ltd.

[0070] Amide-based scratch-resistant agent: Oleamide, brand name: WK1618, manufacturer: Jiangxi Weike Oil & Chemical Co., Ltd.

[0071] Antioxidant: 1010, Manufacturer: Linyi Sanfeng Chemical Co., Ltd.

[0072] Preparation method of polypropylene composite material in the examples and comparative examples: According to the formula, the components are mixed evenly and granulated by extrusion through a twin-screw extruder to obtain polypropylene composite material; wherein, the barrel temperature range is 190-220℃ and the rotation speed range is 350 rpm.

[0073] Test methods:

[0074] (1) Bursting resistance: Static burst test at room temperature: The airbag module was operated at 23℃ for 4 hours and detonated within 120 seconds at room temperature. The test results were divided into: 1. No edge facing the occupant (optimal); 2. There were ejected objects, the number of ejected particles ≤ 5, and the total weight was less than 1.5g; 3. If neither of the above two conditions is met, it is considered unqualified. For ease of description, the above results are defined as: qualified 1, qualified 2, and unqualified NG.

[0075] (2) Surface gloss: Measured using a gloss meter at a 60° angle. This invention requires a gloss level below 2.0, the lower the better.

[0076] (3) Scratch resistance: The test was performed using an electric cross-cut tester with a scraper head diameter of 1 mm and a load of 13 N. Twenty parallel lines were drawn at a constant speed in one direction. The sample was then rotated 90° and the above operation was repeated to form a grid. The L value before and after the scratch was measured using a colorimeter, and the difference ΔL was calculated. The lower the absolute value of ΔL, the better the scratch resistance.

[0077] Table 1: Weight contents and test results of each component in the polypropylene composite materials of Examples 1-7

[0078] Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Copolymer PP grade -1 -1 -1 -2 -3 -4 -1 Copolymer PP content 48 54 62 54 54 54 54 Talc-1 25 20 15 20 20 20 Talc-2 20 POE-1 15 20 18 20 20 20 20 Styrene-ethylene-butene copolymer-2 4 6 3 6 6 6 6 silicone 2 2.5 2.5 2.5 2.5 2.5 Amide-based scratch-resistant agents 3 antioxidants 0.3 Explosion resistance Pass 2 Pass 2 Pass 2 Pass 1 Pass 1 Pass 1 Pass 2 Surface gloss 1.9 1.8 2.0 1.7 1.8 1.9 1.6 Scratch resistance ΔL 0.99 0.93 0.78 0.90 0.88 0.92 0.87

[0079] Note: Silicone is derived from silicone-based scratch-resistant agents. The silicone content in Table 1 is the actual silicone content after adding silicone-based scratch-resistant agents.

[0080] As can be seen from Examples 2 / 4 / 5 / 6, when the rubber phase content of the copolymer PP is within the preferred range, the burst resistance and scratch resistance are better, and the surface gloss is ≤2.0.

[0081] Table 2: Weight parts of each component and test results of polypropylene composite materials in Examples 8-14

[0082] Example 8 Example 9 Example 10 Example 11 Example 12 Example 13 Example 14 Copolymer PP grade -1 -1 -1 -1 -1 -1 -1 Copolymer PP content 54 54 54 54 54 54 54 Talc-1 20 20 20 20 20 Talc-3 20 Talc-4 20 POE designation -1 -1 -2 -3 -4 -5 -6 POE content 20 20 20 20 20 20 20 Styrene-ethylene-butene copolymer-2 6 6 6 6 6 6 6 silicone 2.5 2.5 2.5 2.5 2.5 2.5 2.5 Explosion resistance Pass 2 Pass 2 Pass 1 Pass 1 Pass 2 Pass 1 Pass 1 Surface gloss 1.5 1.7 1.8 1.9 1.9 1.8 1.9 Scratch resistance ΔL 0.89 0.95 0.92 0.90 0.91 0.92 0.90

[0083] As can be seen from Examples 2 / 7 / 8 / 9 / 17, inorganic fillers with a preferred D95 ​​particle size of 25-35 micrometers exhibit lower surface gloss and better scratch resistance.

[0084] As can be seen from Examples 2 / 10 / 11 / 12, POE with a crystallinity of 13-17% exhibits better burst resistance, while surface gloss and scratch resistance are at the same level.

[0085] Table 3: Weight parts of each component and test results of polypropylene composite materials in Examples 15-17

[0086] Example 15 Example 16 Example 17 Copolymer PP-1 54 54 54 Talc-1 20 20 mica powder 20 POE-1 20 20 20 Styrene-ethylene-butene copolymer-2 6 Styrene-ethylene-butene copolymer-3 6 Styrene-ethylene-butene copolymer-4 6 silicone 2.5 2.5 2.5 Explosion resistance Pass 1 Pass 1 Pass 2 Surface gloss 1.8 1.9 2.0 Scratch resistance ΔL 0.88 0.90 1.02

[0087] As can be seen from Examples 2 / 15 / 16, styrene-ethylene-butene copolymers with a preferred molecular weight of 140,000-170,000 exhibit better burst resistance and scratch resistance, but lower surface gloss.

[0088] Table 4: Weight parts of each component and test results of polypropylene composites in Comparative Examples 1-6

[0089] Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 Copolymer PP-1 54 54 54 54 54 Homopolymer polypropylene 54 Talc-1 20 20 20 20 20 20 POE-1 20 0 10 24 26 20 Styrene-ethylene-butene copolymer-2 6 26 16 2 0 6 silicone 2.5 2.5 2.5 2.5 2.5 0 Explosion resistance NG NG NG NG NG Pass 1 Surface gloss 2.3 2.1 1.9 1.9 2.0 1.8 Scratch resistance ΔL 0.79 0.92 0.89 0.90 1.01 2.52

[0090] As shown in Comparative Example 1, homopolymer polypropylene exhibits poor burst resistance but high surface gloss.

[0091] As can be seen from Comparative Examples 2-5, when the total content of POE and styrene-ethylene-butene copolymer remains unchanged, the blast resistance is poor when the content of POE and / or styrene-ethylene-butene copolymer is outside the scope of the present invention.

[0092] As shown in Comparative Example 6, the scratch resistance is poor when no scratch-resistant agent is contained.

[0093] Table 5: Weight parts of each component and test results of polypropylene composites in Comparative Examples 7-11

[0094] Comparative Example 7 Comparative Example 8 Comparative Example 9 Comparative Example 10 Comparative Example 11 Copolymer PP-1 54 54 54 54 Copolymer PP-5 54 Talc-1 20 20 Talc-5 20 Talc-6 20 Calcium carbonate 20 POE-1 20 20 20 20 20 Styrene-ethylene-butene copolymer-2 6 6 6 6 Styrene-ethylene-butene copolymer-1 6 silicone 2.5 2.5 2.5 2.5 2.5 Explosion resistance NG NG NG NG NG Surface gloss 1.9 2.1 2.0 1.8 1.9 Scratch resistance ΔL 0.94 0.97 0.99 1.02 0.94

[0095] As shown in Comparative Example 7, when the rubber phase content of the copolymer PP is too high, the burst resistance of the polypropylene composite material is poor.

[0096] As can be seen from Comparative Example 8, calcium carbonate has poor anti-explosion performance.

[0097] As can be seen from Comparative Examples 9-10, the burst resistance of polypropylene composites is poor when the D95 particle size of talc is too low or too high.

[0098] As shown in Comparative Example 11, when the number-average molecular weight of the styrene-ethylene-butene copolymer is too low, the burst resistance of the polypropylene composite material is poor.

Claims

1. A polypropylene composite material, characterized in that, By weight, it includes the following components: 48-62 parts of copolymerized polypropylene; 15-25 parts of inorganic filler; POE 15-20 copies; 3-6 parts of styrene-ethylene-butene copolymer; 2-3 parts scratch-resistant agent; The rubber phase content of the copolymerized polypropylene is 7-18 wt%. The styrene-ethylene-butene copolymer has a number-average molecular weight of 100,000 to 230,000. The D95 particle size range of the filler is 20-40 micrometers.

2. The polypropylene composite material according to claim 1, characterized in that, The rubber phase content of the copolymer polypropylene is 8-12 wt%.

3. The polypropylene composite material according to claim 1, characterized in that, The inorganic filler is selected from at least one of talc, wollastonite, mica powder, and magnesium hydroxide whiskers; the scratch-resistant agent is selected from at least one of silicone-based scratch-resistant agents and amide-based scratch-resistant agents.

4. The polypropylene composite material according to claim 1, characterized in that, The D95 particle size range of the filler is 25-35 micrometers, and the test method is laser particle size analyzer.

5. The polypropylene composite material according to claim 1, characterized in that, The POE is selected from at least one of ethylene-octene copolymer and ethylene-butene copolymer; the overall crystallinity of the POE is 11%-28%; preferably, the overall crystallinity of the POE is 13-23%.

6. The polypropylene composite material according to claim 1, characterized in that, The styrene-ethylene-butene copolymer has a number-average molecular weight of 140,000-170,000.

7. The polypropylene composite material according to claim 1, characterized in that, The melt index of the copolymer polypropylene is in the range of 50-120 g / 10 min, and the test conditions are 230℃ / 2.16 kg.

8. The polypropylene composite material according to claim 1, characterized in that, The product comprises 0-1 parts by weight of additives; the additives are selected from at least one of antioxidants, light stabilizers, and lubricants.

9. A method for preparing the polypropylene composite material according to any one of claims 1-8, characterized in that, The process includes the following steps: mixing the components evenly according to the formula, and granulating them by extrusion through a twin-screw extruder to obtain a polypropylene composite material.

10. An instrument panel, characterized in that, The composite material comprising any one of claims 1-8.