A polypropylene composite material and its preparation method and application

Abstract

The present invention discloses a polypropylene composite material, its preparation method, and application. The composite material comprises the following components, measured in parts by weight: 60-80 parts of polypropylene resin A; 5-20 parts of polypropylene resin B; 10-25 parts of propylene-based elastomer; 0.5-3 parts of three-dimensional thermally conductive filler; and 0.1-1 parts of flaky thermally conductive filler. The melt index of polypropylene resin A at 230°C and 2.16 kg is ≤10g / 10min; the melt index of polypropylene resin B at 230°C and 2.16 kg is ≥20g / 10min. The average particle size of the flaky thermally conductive filler is higher than that of the three-dimensional thermally conductive filler, and the average particle size of the flaky thermally conductive filler is no higher than 200μm. By using low-melt-index polypropylene as the base resin, adding high-melt-index polypropylene, compounding large-particle-size flaky thermally conductive filler and small-particle-size three-dimensional thermally conductive filler, and using the propylene-based elastomer as a toughening agent, the composite material can have good thermal conductivity while maintaining transparency.

Description

Technical Field

[0001] The present invention belongs to the technical field of polymer materials, and more specifically, relates to a polypropylene composite material and a preparation method and application thereof. Background Art

[0002] In recent years, miniaturization and high integration have driven the development of microelectronic components. However, this generates increased heat during operation, significantly impacting performance and energy consumption. Thermally conductive polymer composites, due to their low density, ease of processing, and low manufacturing costs, have become a research hotspot for alleviating heat dissipation.

[0003] Polypropylene is a thermoplastic polymer obtained by polymerizing propylene monomers. It has advantages such as low density, wide availability, non-toxicity, and low odor. It is widely used in many fields, including home appliances, kitchen utensils, bathroom fixtures, automobiles, and packaging. In some application areas, such as transparent containers (pipettes, culture dishes, etc.) in the biomedical field, they are all made of glass and often require heating during use. However, the thermal conductivity of polypropylene is only 0.2 W·m -1 ·K -1 , there are drawbacks such as high energy consumption and long production time when used to make heating containers. During the application process, it was found that if thermal conductive materials were directly added, the haze would increase. In other words, polypropylene composite materials cannot achieve both good thermal conductivity and low haze. Summary of the Invention

[0004] The object of the present invention is to provide a polypropylene composite material to overcome the defects or shortcomings of the prior art polypropylene composite materials that cannot have both good thermal conductivity and low haze.

[0005] Another object of the present invention is to provide a method for preparing the polypropylene composite material.

[0006] Another object of the present invention is to provide applications of the polypropylene composite material.

[0007] To achieve the above object, the present invention is implemented through the following technical solutions:

[0008] A polypropylene composite material comprising the following components calculated in parts by weight:

[0009] 60-80 parts of polypropylene resin A;

[0010] 5-20 parts of polypropylene resin B;

[0011] 10-25 parts of toughening agent;

[0012] 0.5~3 parts of three-dimensional thermal conductive filler;

[0013] 0.1~1 part of flaky thermal conductive filler;

[0014] Among them, the melt flow rate of the polypropylene resin A at 230°C and 2.16kg is ≤10g / 10min; the melt flow rate of the polypropylene resin B at 230°C and 2.16kg is ≥20g / 10min; the average particle size of the sheet-like thermal conductive filler is higher than that of the three-dimensional thermal conductive filler, and the average particle size of the sheet-like thermal conductive filler is not higher than 200μm; the toughening agent is a propylene-based elastomer.

[0015] Through experimental research, the inventors discovered that by using a low-melt-flow-rate polypropylene as the base resin, adding a certain amount of high-melt-flow-rate polypropylene to it, and then compounding it with a flake-shaped thermally conductive filler and a three-dimensional thermally conductive filler, and adjusting the average particle size of the three-dimensional thermally conductive filler to be smaller than that of the flake filler, the three-dimensional thermally conductive filler can act as a "bridging" agent, improving the thermal conductivity of the polypropylene composite while using a smaller amount of thermally conductive filler, while not significantly reducing the transparency of the polypropylene composite. Furthermore, by adding a propylene-based elastomer as a toughening agent, the toughness of the composite system can be increased, further enhancing the transparency of the polypropylene composite.

[0016] It should be noted that the three-dimensional thermally conductive filler described in the present invention is 0.5~3 parts, for example, but not limited to, it can be 0.5 parts, 0.6 parts, 0.7 parts, 0.8 parts, 0.9 parts, 1 part, 1.1 parts, 1.2 parts, 1.3 parts, 1.4 parts, 1.5 parts, 1.6 parts, 1.7 parts, 1.8 parts, 1.9 parts, 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 parts, etc., as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the specific point values ​​included in the range are no longer exhaustively listed in the present invention.

[0017] The flake thermal conductive filler described in the present invention is 0.1 to 1 part, for example, but not limited to 0.1 part, 0.15 part, 0.2 part, 0.25 part, 0.3 part, 0.35 part, 0.4 part, 0.45 part, 0.5 part, 0.55 part, 0.6 part, 0.65 part, 0.7 part, 0.75 part, 0.8 part, 0.85 part, 0.9 part, 0.95 part or 1 part, etc., as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the specific point values ​​included in the range are no longer exhaustively listed in the present invention.

[0018] Furthermore, the mass ratio of the three-dimensional thermally conductive filler to the sheet-shaped thermally conductive filler is (1.5~24):1, for example but not limited to 1.5:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, 15:1, 20:1, 24:1, etc., as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention will no longer exhaustively list the specific point values ​​included in the said range.

[0019] Furthermore, the mass ratio of the three-dimensional thermally conductive filler to the sheet-shaped thermally conductive filler is (3-10): 1. Within this range, the three-dimensional thermally conductive filler and the sheet-shaped thermally conductive filler can better "bridge" and have lower haze.

[0020] It should be noted that the polypropylene resin A in the polypropylene composite material is preferably not less than 50 wt %.

[0021] Furthermore, the polypropylene composite material includes the following components calculated in parts by weight:

[0022] 65-75 parts of polypropylene resin A;

[0023] 8-15 parts of polypropylene resin B;

[0024] 12-20 parts of toughening agent;

[0025] 1.5-2.5 parts of three-dimensional thermal conductive filler;

[0026] 0.2~0.8 parts of flaky thermal conductive filler.

[0027] The average particle size of the flaky thermally conductive filler described in the present invention is not higher than 200μm, for example but not limited to not higher than 200μm, 190μm, 180μm, 170μm, 160μm, 150μm, 140μm, 130μm, 120μm, 110μm, 100μm, 90μm, 80μm, 70μm, 60μm, 50μm or 40μm, etc., as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the specific point values ​​included in the range are no longer exhaustively listed in the present invention.

[0028] Furthermore, the average particle size of the flaky thermal conductive filler is 50-200 μm.

[0029] Specifically, the diameter-to-thickness ratio of the sheet-shaped thermal conductive filler is 100:1 to 300:1.

[0030] It should be noted that the melt flow rate of the polypropylene resin A described in the present invention at 230° C. and 2.16 kg is ≤10 g / 10 min, for example, but not limited to ≤10 g / 10 min, 9.5 g / 10 min, 9 g / 10 min, 8.5 g / 10 min, 8 g / 10 min, 7.5 g / 10 min, 7 g / 10 min, 6.5 g / 10 min, 6 g / 10 min, 5.5 g / 10 min, 5 g / 10 min, 4.5 g / 10 min, 4 g / 10 min, 3.5 g / 10 min, 3 g / 10 min, 2.5 g / 10 min, 2 g / 10 min, 1.5 g / 10 min, 1 g / 10 min, 0.5 g / 10 min, 0.2 g / 10 min, etc., as well as specific values ​​between the above points. Due to space limitations and for the sake of brevity, the specific points included in the range are no longer exhaustively listed in the present invention.

[0031] Furthermore, the melt flow rate of the polypropylene resin A at 230° C. and 2.16 kg is 0.5-10 g / 10 min.

[0032] Furthermore, the polypropylene resin A is copolymerized PP.

[0033] The melt flow rate of the polypropylene resin B described in the present invention at 230° C. and 2.16 kg is ≥20 g / 10 min, for example, but not limited to, ≥20 g / 10 min, 21 g / 10 min, 22 g / 10 min, 23 g / 10 min, 24 g / 10 min, 25 g / 10 min, 26 g / 10 min, 27 g / 10 min, 28 g / 10 min, 29 g / 10 min, 30 g / 10 min, 31 g / 10 min, 32 g / 10 min, 33 g / 10 min, 34 g / 10 min, 35 g / 10 min, 36 g / 10 min, 37 g / 10 min, 38 g / 10 min, 39 g / 10 min or 40 g / 10 min, as well as specific values ​​between the above points. Due to space limitations and for the sake of brevity, the specific values ​​included in the range are no longer exhaustively listed in the present invention.

[0034] Furthermore, the polypropylene resin B has a melt flow rate of 22-35 g / 10 min at 230° C. and 2.16 kg.

[0035] Furthermore, the polypropylene resin B is copolymerized PP.

[0036] The test standard for the melt flow rate in the present invention is ISO 1133-1:2011.

[0037] Specifically, the flaky thermal conductive filler includes one or more of copper powder, copper-zinc powder, aluminum powder or iron powder.

[0038] Furthermore, the three-dimensional thermally conductive filler is a non-sheet-shaped thermally conductive filler.

[0039] Specifically, the non-sheet-shaped thermally conductive filler may be spherical and / or polyhedral.

[0040] Specifically, the polyhedral solid shape may be one or more of a columnar shape, a hexahedral solid shape or an octahedral solid shape.

[0041] Furthermore, the average particle size of the three-dimensional thermal conductive filler is 10-100 μm.

[0042] In some preferred embodiments, the difference in average particle size between the sheet-shaped thermally conductive filler and the three-dimensional thermally conductive filler is 40-150 μm.

[0043] Specifically, the three-dimensional thermal conductive filler includes one or more of copper powder, copper-zinc powder, aluminum powder or iron powder.

[0044] Specifically, the average particle size is measured using a laser scattering method.

[0045] Specifically, the testing method of the aspect ratio is to measure it using a two-dimensional microscope combined with image analysis software.

[0046] Furthermore, the propylene content in the toughening agent is 82 wt% to 96 wt%.

[0047] Specifically, the propylene content is determined by infrared spectroscopy.

[0048] Specifically, the toughening agent is composed of isotactic propylene and randomly distributed ethylene.

[0049] Furthermore, the polypropylene composite material also includes 0.1 to 5 parts of an auxiliary agent.

[0050] Furthermore, the auxiliary agent includes a lubricant and / or an antioxidant.

[0051] In the present invention, commonly used lubricants may be selected, such as but not limited to one or more of ester lubricants, amide lubricants or stearate lubricants.

[0052] Specifically, the ester lubricant is oleic acid-based aliphatic polyester and / or erucic acid-based aliphatic polyester; the amide lubricant is erucamide and / or oleamide; the stearate lubricant is one or more of calcium stearate, magnesium stearate or zinc stearate.

[0053] In the present invention, commonly used antioxidants may be selected, such as but not limited to at least one of hindered amine antioxidants, hindered phenol antioxidants, phosphite antioxidants or thioester antioxidants.

[0054] Specifically, the hindered amine antioxidant may be one or more of UV-3808, LA-402XP or LA-402AF; the hindered phenol antioxidant may be N, N'-hexamethylene bis(3,5-di-tert-butyl-4-hydroxyphenylpropionamide (Irganox 1098), pentaerythritol tetrakis[β-3,5-di-tert-butyl-4-hydroxyphenyl) propionate (Irganox 1010), triethylene glycol bis-3-(3-tert-butyl-4-hydroxy-5-methylphenyl) propionate (Irganox 259), β-(4-hydroxy-3,5-di-tert-butylphenyl) propionate n-octadecyl (Irganox 1076) or spiroglycol bis[β-(3-tert-butyl-4-hydroxy-5-methylphenyl) propionate] (ADK The phosphite antioxidant may be one or more of 2,4-di-tert-butylphenol (Irganox 168), bis(2,6-di-tert-butyl-4-methylphenyl) pentaerythritol phosphite (PEP-36) or 627A; the thioester antioxidant may be one or more of distearyl thiodipropionate, dilauryl thiodipropionate or pentaerythritol dodecylthioate.

[0055] The present invention also provides a method for preparing the polypropylene composite material, comprising the following steps:

[0056] S1. The components other than the polypropylene resin B, the flaky thermally conductive filler and the three-dimensional thermally conductive filler are mixed to obtain a premix;

[0057] S2. The premix of step S1 is fed into the extruder through the main feeding port, and the polypropylene resin B, the sheet-shaped thermal conductive filler and the three-dimensional thermal conductive filler are fed from the side feeding port, and the polypropylene composite material is obtained by melt extrusion and granulation.

[0058] Furthermore, in step S2, the extruder is a twin-screw extruder; the screw aspect ratio is 48:1.

[0059] Furthermore, in step S2, the rotation speed of the extruder is 250 to 350 rpm.

[0060] Furthermore, in step S2., the melting temperature is 160-210°C.

[0061] The present invention also protects the use of the polypropylene composite material in the manufacture of household items, electronic components, household appliances, gardening equipment, medical equipment, motor vehicle components, and vehicle body parts. In particular, the polypropylene composite material can be used to manufacture articles having excellent transparency and thermal conductivity. In particular, it can be used to manufacture transparent containers for use in the biopharmaceutical field.

[0062] Compared with the prior art, the present invention has the following beneficial effects:

[0063] The present invention provides a polypropylene composite material. The polypropylene resin with a low melt flow rate is used as a base resin, a certain amount of polypropylene resin with a high melt flow rate is added, and a flaky thermally conductive filler and a three-dimensional thermally conductive filler are compounded. The average particle size of the three-dimensional thermally conductive filler is adjusted to be smaller than the average particle size of the flaky filler. This allows the three-dimensional thermally conductive filler to play a "bridging role", thereby improving the thermal conductivity of the polypropylene composite material with a smaller amount of thermally conductive filler added, while not significantly reducing the transparency of the polypropylene composite material. DETAILED DESCRIPTION

[0064] The present invention is further described in detail below with reference to specific examples. The examples are intended only to illustrate the present invention and are not intended to limit the scope of the present invention. The experimental methods used in the following examples are conventional methods unless otherwise specified; the materials and reagents used are commercially available reagents and materials unless otherwise specified.

[0065] 1. Experimental materials:

[0066] Polypropylene resin A:

[0067] Polypropylene resin A1: PP SM198, melt flow rate of 1.6 g / 10 min at 230° C. and 2.16 kg, purchased from LOTTE CHEMICAL TITAN(M) SDN. BHD.;

[0068] Polypropylene resin A2: PP Moplen RP215MX B, melt flow rate 6 g / 10 min at 230 °C and 2.16 kg, purchased from LyondellBasell;

[0069] Polypropylene resin B:

[0070] Polypropylene resin B1: PP RP346R, melt flow rate 25 g / 10 min at 230 °C and 2.16 kg, purchased from CNOOC and Shell Petrochemical Co., Ltd.

[0071] Polypropylene resin B2: PP Moplen RP348S, melt flow rate 35 g / 10 min at 230 °C and 2.16 kg, purchased from LyondellBasell;

[0072] Polypropylene resin C: PP Moplen RP344NK, melt flow rate 13 g / 10 min at 230 °C and 2.16 kg, purchased from LyondellBasell;

[0073] Flaky thermal conductive fillers:

[0074] Flaky thermal conductive filler 1: aluminum powder, LX-10020, with an aspect ratio of 150 and an average particle size of 100 μm, purchased from Hefei Xuyang Aluminum Pigment Co., Ltd.

[0075] Flaky thermal conductive filler 2: copper-zinc powder, copper-zinc powder 160, aspect ratio 150, average particle size 160 μm, purchased from Hefei Xuyang Aluminum Pigment Co., Ltd.

[0076] Flaky thermal conductive filler 3: aluminum powder, LX-28020, with an aspect ratio of 150 and an average particle size of 280 μm, purchased from Hefei Xuyang Aluminum Pigment Co., Ltd.

[0077] Three-dimensional thermal conductive filler:

[0078] Three-dimensional thermal conductive filler 1: aluminum powder, PE3606DSS, average particle size 35 μm, polyhedral three-dimensional shape, purchased from Shanghai Jincheng New Materials Co., Ltd.

[0079] Three-dimensional thermal conductive filler 2: aluminum powder, PE5506DSS, average particle size 55 μm, polyhedral three-dimensional shape, purchased from Shanghai Jincheng New Materials Co., Ltd.

[0080] Three-dimensional thermal conductive filler 3: aluminum powder, PE19001DSS, average particle size of 190 μm, polyhedral three-dimensional shape, purchased from Shanghai Jincheng New Materials Co., Ltd.

[0081] Toughening agent:

[0082] Toughener 1: Vistamaxx 6102, purchased from ExxonMobil Chemical Business (Shanghai) Co., Ltd.

[0083] Toughener 2: Vistamaxx 6202, purchased from ExxonMobil Chemical Business (Shanghai) Co., Ltd.;

[0084] Toughener 3: ENGAGE 7467, purchased from Dow Chemical (Shanghai) Co., Ltd.

[0085] Additives:

[0086] The lubricant is an ester lubricant; the antioxidant is a mixture of antioxidant 1010 and antioxidant 168 in a mass ratio of 1:1. The lubricant and antioxidant are both commercially available. The same lubricant and antioxidant are used in parallel experiments in the examples and comparative examples.

[0087] 2. The polypropylene composite materials described in each embodiment and comparative example were prepared according to the formulations in Tables 1 and 2 by the following preparation method, comprising the following steps:

[0088] S1. Except for the polypropylene resin B, the flaky thermally conductive filler and the three-dimensional thermally conductive filler, the other components are mixed uniformly in proportion to obtain a premix;

[0089] S2. The premix of step S1 is fed into a twin-screw extruder through the main feed port, and the polypropylene resin B, the flaky thermally conductive filler, and the three-dimensional thermally conductive filler are fed from the side feed port. The polypropylene composite material is obtained by melt extrusion and granulation; the screw aspect ratio of the twin-screw extruder is 48:1, and the screw speed is 300 rpm; the temperature of the melt extrusion is 160~210℃.

[0090] 3. Performance testing:

[0091] (1) Haze test: The polypropylene composite materials prepared in each embodiment and comparative example were injection molded to obtain test specimens with a size of 100 mm × 100 mm × 1 mm. The test was conducted in accordance with GB / T 2410-2008. The lower the haze, the higher the transparency.

[0092] (2) Thermal conductivity test: The polypropylene composite materials prepared in each embodiment and comparative example were subjected to laser flash method. The sample size was a circular sheet with a diameter of 6 cm and a thickness of 3 mm. The test was carried out in accordance with ASTM-E1461-01 standard.

[0093] (3) Izod notched impact strength test: The polypropylene composite materials prepared in each embodiment and comparative example were injection molded to obtain test specimens with a specimen size of 80 mm × 10 mm × 4 mm. The test was performed in accordance with ISO 180-2018 standard, and the specimens were type A.

[0094] Examples 1 to 10 and Comparative Examples 1 to 10

[0095] Table 1 Formulations (unit: parts by weight) and properties of polypropylene composite materials in Examples 1 to 10

[0096]

[0097] Table 2 Formulations (unit: parts by weight) and properties of polypropylene composite materials in Comparative Examples 1 to 10

[0098]

[0099] As can be seen from Table 1, the polypropylene composite material prepared by the present invention has good thermal conductivity and transparency. Specifically, the thermal conductivity coefficient is not less than 1.1 W·m -1 ·K -1 , the haze is not higher than 50%, and the cantilever beam notched impact strength is not less than 6KJ / m 2 .

[0100] It can be seen from Comparative Examples 1 and 10 that if the amounts of the two polypropylene resins are outside the scope of the present invention, the obtained polypropylene composite material has high haze and poor transparency.

[0101] It can be seen from Comparative Examples 2 and 3 that if only one thermally conductive filler is used, the "bridging" effect of the thermal conductive channel cannot be formed, and the thermal conductivity of the obtained polypropylene composite material is low, with a thermal conductivity coefficient of 0.9 W·m -1 ·K -1 Below; and using only flake thermal conductive fillers will significantly increase the haze.

[0102] It can be seen from Comparative Example 4 that by using only one thermally conductive filler and increasing its dosage, the thermal conductivity of the obtained polypropylene composite material can achieve the same effect as that of the embodiment, but its transparency is significantly reduced.

[0103] It can be seen from Comparative Example 5 that when the average particle size of the flake filler is too high, the overall haze of the composite material increases and the transparency decreases. At the same time, the larger particle size of the flake filler also reduces the impact strength of the material.

[0104] It can be seen from Comparative Example 6 that if the average particle size of the three-dimensional filler is too high, the transparency of the composite material decreases. At the same time, the three-dimensional filler with a larger particle size also reduces the impact strength of the material.

[0105] It can be seen from Comparative Examples 7 and 8 that if the polypropylene resin of the present invention is not used for compounding, the overall haze of the composite material increases, the transparency decreases, and the thermal conductivity decreases.

[0106] It can be seen from Comparative Example 9 that if the propylene-based elastomer is not used as a toughening agent, the overall haze of the prepared composite material increases and the transparency decreases significantly.

[0107] Obviously, the above embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Those skilled in the art will appreciate that other variations or modifications can be made based on the above description. It is not necessary and impossible to enumerate all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the claims of the present invention.

Claims

1. A polypropylene composite material, characterized in that The composition includes the following components calculated in parts by weight: 60-80 parts of polypropylene resin A; 5-20 parts of polypropylene resin B; 10-25 parts of toughening agent; 0.5~3 parts of three-dimensional thermal conductive filler; 0.1~1 part of flaky thermal conductive filler; Among them, the melt flow rate of the polypropylene resin A at 230°C and 2.16kg is 0.2~10g / 10min; the melt flow rate of the polypropylene resin B at 230°C and 2.16kg is 20~40g / 10min; the average particle size of the flake thermal conductive filler is higher than that of the three-dimensional thermal conductive filler, the average particle size of the flake thermal conductive filler is 50~200μm, and the aspect ratio is 100~300; the average particle size of the three-dimensional thermal conductive filler is 10~100μm; the toughening agent is a propylene-based elastomer; the toughening agent is composed of isotactic propylene and randomly distributed ethylene, and the propylene content is 82wt%~96wt%.

2. The polypropylene composite material according to claim 1, characterized in that The difference between the average particle size of the sheet-shaped thermal conductive filler and the average particle size of the three-dimensional thermal conductive filler is 40-150 μm.

3. The polypropylene composite material according to claim 1, characterized in that The melt flow rate of the polypropylene resin A at 230° C. and 2.16 kg is 0.5-10 g / 10 min.

4. The polypropylene composite material according to claim 1, characterized in that: The melt flow rate of the polypropylene resin B at 230° C. and 2.16 kg is 22-35 g / 10 min.

5. The polypropylene composite material according to claim 1, characterized in that: Also includes 0.1 to 5 parts of auxiliary agents.

6. A method for preparing the composite material according to any one of claims 1 to 5, characterized in that: The steps include: S1. The components other than the polypropylene resin B, the flaky thermally conductive filler and the three-dimensional thermally conductive filler are mixed to obtain a premix; S2. The premix of step S1 is fed into the extruder through the main feeding port, and the polypropylene resin B, the sheet-shaped thermal conductive filler and the three-dimensional thermal conductive filler are fed from the side feeding port, and the polypropylene composite material is obtained by melt extrusion and granulation.

7. Use of the polypropylene composite material according to any one of claims 1 to 5 in the preparation of a thermally conductive translucent material.

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