A polypropylene composition, process for its preparation and use

Abstract

The application discloses a polypropylene composition, a preparation method and application thereof, and belongs to the technical field of high polymer materials; the polypropylene composition provided by the application comprises the following components in parts by mass: 38-62 parts of a homopolymer polypropylene resin, 18-32 parts of a POE resin, 13-27 parts of talcum powder, 1-7 parts of hollow glass microbeads and 1-7 parts of nano fillers; the melt flow rate of the POE resin is greater than or equal to 3 g / 10 min under the condition of a temperature of 190 DEG C and a load of 2.16 kg. The polypropylene composition provided by the application has a low linear thermal expansion coefficient and density.

Description

Technical Field

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

[0002] Polypropylene, as a cost-effective general-purpose plastic, has excellent mechanical properties such as high strength and high toughness, as well as chemical resistance and high heat resistance after modification, and is widely used in home appliances and automotive products.

[0003] With the increasing demand for lightweight vehicles, the amount of plastic used in automobiles can now reach 300-400 kg, with polypropylene accounting for nearly 40% of this. Automotive polypropylene, due to its partially crystalline nature, has a linear coefficient of thermal expansion (CLTE) of approximately 120 x 10⁻⁶. -6 Because of its high temperature and humidity, it has obvious thermal expansion and contraction characteristics, which can easily lead to dimensional problems when it is used with other parts, especially metal parts. At the same time, since traditional low CLTE materials require a high filling ratio, the resulting material density is relatively high. Further lightweight design can reduce the material density and prepare low CLTE, low-density polypropylene materials, which is of great significance for automotive lightweighting. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a polypropylene composition, preparation method and application having a relatively low coefficient of linear thermal expansion (CLTE) and low density.

[0005] To achieve the above objectives, in a first aspect, the present invention provides a polypropylene composition comprising the following components in parts by weight:

[0006] 38-62 parts homopolymer polypropylene resin, 18-32 parts POE resin, 13-27 parts talc, 1-7 parts hollow glass microspheres, and 1-7 parts nanofiller;

[0007] The POE resin has a melt flow rate of ≥3g / 10min at a temperature of 190℃ and a load of 2.16kg.

[0008] The polypropylene composition provided by this invention, by selecting appropriate mass parts of the components, can effectively reduce the density of the polypropylene composition and obtain a polypropylene composition with a low linear coefficient of thermal expansion.

[0009] Specifically, homopolymer polypropylene is used as the resin matrix, and talc and nanofillers are selected for blending. The two can be well dispersed in the resin matrix to form a stable and complete filler network, thereby effectively improving the overall dispersion uniformity of the material and adjusting the rheological properties of the polypropylene matrix. This is beneficial for adjusting the phase morphology of the elastomer POE and helping to reduce the linear thermal expansion coefficient of the product. At the same time, the addition of POE resin within a suitable melt flow rate range can effectively avoid the formation of island structures, and is also beneficial for the stability of hollow glass microspheres and the adjustment effect of hollow glass microspheres on the volume ratio of homopolymer polypropylene and POE resin, thereby effectively reducing the density and linear thermal expansion coefficient of the product.

[0010] For example, the homopolymer polypropylene resin can be any point value or any two-point range value between 38 and 62 parts, such as 40-60 parts, or 38 parts, 40 parts, 42 parts, 44 parts, 46 parts, 48 ​​parts, 50 parts, 52 parts, 54 parts, 56 parts, 58 parts, 60 parts, 62 parts, etc.; the POE resin can be any point value or any two-point range value between 18 and 32 parts, such as 20-30 parts, or 18 parts, 20 parts, 22 parts, 25 parts, 28 parts, 30 parts, 32 parts, etc.; the talc powder can be 13-27 parts. The parts can be any point value or any two-point range value between 1 and 7, for example, 15-25 parts, or 13, 15, 17, 19, 21, 23, 25, 27 parts, etc.; the hollow glass microspheres can be any point value or any two-point range value between 1 and 7, for example, 3-5 parts, or 1, 2, 3, 4, 5, 6, 7 parts, etc.; the nanofiller can be any point value or any two-point range value between 1 and 7, for example, 2-5 parts, or 1, 2, 3, 4, 5, 6, 7 parts, etc.

[0011] Preferably, the mass percentage of homopolymer polypropylene resin in the polypropylene composition is ≥34%.

[0012] More preferably, the mass percentage of homopolymer polypropylene resin in the polypropylene composition is 40-56%.

[0013] It should be noted that the melt flow rate of the POE resin at a temperature of 190°C and a load of 2.16 kg was obtained by testing with reference to ASTM D-1238:10.

[0014] In a preferred embodiment of the polypropylene composition of the present invention, the POE resin includes at least one of ethylene-butene copolymer and ethylene-octene copolymer.

[0015] As a preferred embodiment of the polypropylene composition of the present invention, the polypropylene composition comprises the following components in parts by weight: 45-50 parts homopolymer polypropylene resin, 23-27 parts POE resin, 18-22 parts talc, 3-4 parts hollow glass microspheres, and 4-5 parts nanofiller.

[0016] This invention has found that the mass fraction of components in a polypropylene composition also affects the performance of the product. When the mass fraction of components in the polypropylene composition is further selected within the above-mentioned range, the overall performance of the obtained product is better.

[0017] As a preferred embodiment of the polypropylene composition of the present invention, the homopolymer polypropylene has a melt flow rate of 20-75 g / 10 min at a temperature of 230°C and a load of 2.16 kg.

[0018] It should be noted that the melt flow rate of the homopolymer polypropylene was obtained by testing in accordance with ASTM D-1238-2004, under the conditions of a temperature of 230°C and a load of 2.16 kg.

[0019] For example, the melt flow rate of the homopolymer polypropylene at a temperature of 230°C and a load of 2.16 kg can be any point value or any two-point range value between 20-75 g / 10 min, such as 21-73 g / 10 min, or 20 g / 10 min, 21 g / 10 min, 25 g / 10 min, 30 g / 10 min, 35 g / 10 min, 40 g / 10 min, 45 g / 10 min, 50 g / 10 min, 55 g / 10 min, 60 g / 10 min, 65 g / 10 min, 70 g / 10 min, 73 g / 10 min, 75 g / 10 min, etc.

[0020] Preferably, the homopolymer polypropylene has a melt flow rate of 40-60 g / 10 min at a temperature of 230°C and a load of 2.16 kg.

[0021] This invention has found that the melt flow rate of homopolymer polypropylene can affect the compatibility between components to a certain extent. When the melt flow rate of homopolymer polypropylene is further selected to be 20-75 g / 10 min, especially 40-60 g / 10 min, the density and linear thermal expansion coefficient of the obtained product are lower.

[0022] As a preferred embodiment of the polypropylene composition of the present invention, the POE resin has a melt flow rate of 4-32 g / 10 min at a temperature of 190°C and a load of 2.16 kg.

[0023] For example, the melt flow rate of the POE resin at a temperature of 190°C and a load of 2.16 kg can be a point value between 4 and 32 g / 10 min or any two points within a range, such as 4-30 g / 10 min, or 4 g / 10 min, 8 g / 10 min, 10 g / 10 min, 12 g / 10 min, 14 g / 10 min, 16 g / 10 min, 18 g / 10 min, 20 g / 10 min, 22 g / 10 min, 24 g / 10 min, 26 g / 10 min, 28 g / 10 min, 30 g / 10 min, 32 g / 10 min, etc.

[0024] Preferably, the POE resin has a melt flow rate of 13-18 g / 10 min at a temperature of 190°C and a load of 2.16 kg.

[0025] The present invention has found that the melt flow rate of POE resin affects the formation of the continuous phase in the product. When the melt flow rate of POE resin is further selected to be 4-32 g / 10 min, especially 13-18 g / 10 min, the overall performance of the obtained product is better.

[0026] In a preferred embodiment of the polypropylene composition of the present invention, the talc powder has a D50 particle size of 0.6-8.5 μm.

[0027] It should be noted that the D50 particle size of the talc powder was obtained by testing with a laser particle size analyzer in accordance with GB / T 19077-2016.

[0028] For example, the D50 particle size of the talc powder can be any point value or any two-point range value between 0.6-8.5μm, such as 0.65-8μm, 0.65-5μm, or 0.6μm, 1μm, 1.5μm, 2μm, 2.5μm, 3μm, 3.5μm, 4μm, 4.5μm, 5μm, 5.5μm, 6μm, 6.5μm, 7μm, 7.5μm, 8μm, 8.5μm, etc.

[0029] Preferably, the D50 particle size of the talc powder is 0.65-5μm.

[0030] As a preferred embodiment of the polypropylene composition of the present invention, the hollow glass microspheres have a D50 particle size of 15-55 μm and a compressive strength of 1500-16500 psi.

[0031] It should be noted that the D50 particle size of the hollow glass microspheres was obtained by laser particle size analyzer according to GB / T 19077-2016, and the compressive strength was obtained by isostatic pressure test (hydraulic pressure method) according to JCT2284-2014 standard.

[0032] For example, the D50 particle size of the hollow glass microspheres can be any point value or any two-point range value between 15-55μm, such as 20-50μm, 20-40μm, or 15μm, 20μm, 25μm, 30μm, 35μm, 40μm, 45μm, 50μm, 55μm, etc. The compressive strength of the hollow glass microspheres can be any point value or any two points within the range of 1500-16500 psi, such as 2000-16000 psi, 8000-16000 psi, or 1500 psi, 2000 psi, 3000 psi, 4000 psi, 5000 psi, 6000 psi, 7000 psi, 8000 psi, 9000 psi, 10000 psi, 11000 psi, 12000 psi, 13000 psi, 14000 psi, 15000 psi, 16000 psi, 16500 psi, etc.

[0033] Preferably, the hollow glass microspheres have a D50 particle size of 20-40 μm and a compressive strength of 8000-16000 psi.

[0034] This invention has found that the D50 particle size of hollow glass microspheres affects their dispersibility in homopolymer polypropylene resin matrix, thereby affecting the density of the polypropylene composition. It also affects their interaction with nanofillers and talc, thus influencing overall compatibility and consequently the linear thermal expansion coefficient of the polypropylene composition. Furthermore, the D50 particle size and compressive strength of the hollow glass microspheres are related to their stability. When the D50 particle size and compressive strength of the hollow glass microspheres are further selected within the aforementioned ranges, the resulting product exhibits superior overall performance.

[0035] In a preferred embodiment of the polypropylene composition of the present invention, the bulk density of the hollow glass microspheres is 0.15-0.4 g / cm³. 3 The bulk density of the hollow glass microspheres was obtained by testing in accordance with GB / T 17431.2-2010.

[0036] In a preferred embodiment of the polypropylene composition of the present invention, the nanofiller has a dimension of 25-195 nm.

[0037] It should be noted that the dimension of 25-195nm in the nanofiller refers to the following: when the nanofiller includes sheet-like structure filler, the interlayer spacing of the sheet-like structure filler is 25-195nm; when the nanofiller includes spherical particle filler, the D50 particle size of the spherical particle filler is 25-195nm; when the nanofiller includes fibrous structure filler, the diameter of the fibrous structure filler is 25-195nm.

[0038] It should be noted that when the nanofiller is a spherical particle filler, one dimension is obtained by measuring with a laser particle size analyzer in accordance with GB / T19077-2016; when the nanofiller is a sheet-like structure filler, one dimension is obtained by measuring with a scanning electron microscope; and when the nanofiller is a fibrous structure filler, one dimension is obtained by measuring with a scanning electron microscope.

[0039] For example, the nanofiller has a dimension that can be any point value or any two-point range value between 25-195nm, such as 25nm, 35nm, 45nm, 55nm, 65nm, 75nm, 85nm, 95nm, 105nm, 115nm, 125nm, 135nm, 145nm, 155nm, 165nm, 175nm, 185nm, 195nm, etc.

[0040] Preferably, the nanofiller has a dimension of 30-50 nm.

[0041] This invention has found that when one dimension of the nanofiller is within the range given in this invention, it can better interact with talc to form a complete structural network; at the same time, it can also better interact with hollow glass microspheres, thereby reducing the product's density and linear thermal expansion coefficient.

[0042] In a preferred embodiment of the polypropylene composition of the present invention, the nanofiller includes at least one of nano-organic clay, nano-titanium dioxide, and nano-silica.

[0043] In a preferred embodiment of the polypropylene composition of the present invention, the polypropylene composition further includes 0-1 parts of processing aids, wherein the processing aids include at least one of antioxidants and light stabilizers.

[0044] For example, the antioxidant includes at least one of antioxidant 1010, antioxidant 168, antioxidant 1098, antioxidant 3114, and antioxidant 330; the light stabilizer includes at least one of UV-3808, UV-944, and UV-3853.

[0045] In a second aspect, the present invention provides a method for preparing the polypropylene composition, the method comprising the following steps:

[0046] (1) Homopolymer polypropylene resin, talc powder and nanofiller are mixed and then melt-extruded to obtain a one-step polypropylene composition;

[0047] (2) The polypropylene composition, hollow glass microspheres and POE resin are mixed and melt-extruded to obtain the polypropylene composition.

[0048] In a preferred embodiment of the preparation method of the present invention, in step (1), the temperature of melt extrusion is 200-210℃ and the screw speed is 350-450r / min.

[0049] In a preferred embodiment of the preparation method of the present invention, in step (2), the temperature of melt extrusion is 200-210℃ and the screw speed is 350-450r / min.

[0050] In a third aspect, the present invention provides the use of the polypropylene composition in the preparation of automotive devices.

[0051] For example, the automotive device includes any one of a dashboard, door panel, tailgate, and bumper.

[0052] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0053] The polypropylene composition provided by this invention, through the selection of appropriate mass proportions of components, exhibits synergistic effects among the components, effectively reducing the density of the polypropylene composition and resulting in a polypropylene composition with a low coefficient of linear thermal expansion. Furthermore, the preparation method of the polypropylene composition provided by this invention is simple to operate and beneficial for practical production. Detailed Implementation

[0054] To better illustrate the purpose, technical solution, and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments.

[0055] Unless otherwise specified, the reagents, methods and equipment used in this invention are all conventional reagents, methods and equipment in the field; and unless otherwise specified, the raw materials used in parallel experiments are from the same batch.

[0056] PP-1: Homopolymer polypropylene, PP M60T, with a melt flow rate of 59 g / 10 min at a temperature of 230℃ and a load of 2.16 kg, Zhenhai Refining & Chemical Co., Ltd.

[0057] PP-2: Homopolymer polypropylene, HJ4045, melt flow rate of 43g / 10min at 230℃ and 2.16kg load, Daehan Oil Chemical.

[0058] PP-3: Homopolymer polypropylene, MH20, melt flow rate of 21 g / 10 min at temperature 230℃ and load 2.16 kg, Lanzhou Petrochemical;

[0059] PP-4: Homopolymer polypropylene, MN70, melt flow rate of 73 g / 10 min at temperature 230℃ and load 2.16 kg, Lanzhou Petrochemical;

[0060] PP-5: Copolymer polypropylene, PP7935E1, with a melt flow rate of 55 g / 10 min at a temperature of 230°C and a load of 2.16 kg, ExxonMobil;

[0061] POE-1: Ethylene-octene copolymer, INFUSE 9807, melt flow rate of 15 g / 10 min at 190 °C and 2.16 kg load, Dow Chemical;

[0062] POE-2: Ethylene-octene copolymer, DF8200, melt flow rate of 18 g / 10 min at 190 °C and 2.16 kg load, Mitsui Chemicals;

[0063] POE-3: Ethylene-octene copolymer, ENGAGE 8137, melt flow rate of 13 g / 10 min at 190 °C and 2.16 kg load, Dow Chemical;

[0064] POE-4: Ethylene-octene copolymer, ENGAGE 8407, melt flow rate of 30 g / 10 min at 190 °C and 2.16 kg load, Dow Chemical;

[0065] POE-5: Ethylene-butene copolymer, ENGAGE 7447, melt flow rate of 4 g / 10 min at 190°C and 2.16 kg load, Dow Chemical;

[0066] POE-6: Ethylene-octene copolymer, ENGAGE 8150, melt flow rate of 0.5 g / 10 min at 190 °C and 2.16 kg load, Dow Chemical;

[0067] Talc 1: HTPultra 5 L, D50 particle size is 0.65μm, IMI ratio;

[0068] Talc powder 2: AH-3000N9, D50 particle size is 5μm, Liaoning Aihaiyimi Mining Co., Ltd.;

[0069] Talc powder 3: AH-1250N6, D50 particle size is 8μm, Liaoning Aihaiyimi Mining Co., Ltd.;

[0070] Nanofiller 1: Nano-organic clay, clay 20, fibrous structure, fiber diameter 30nm, TOLSA, Spain;

[0071] Nanofiller 2: Nano silica, HN-SP50, spherical particles, D50 particle size is 50nm, Hengna New Materials Co., Ltd.;

[0072] Nanofiller 3: Nano titanium dioxide, CR-340, spherical particles, D50 particle size of 190nm, Panzhihua Iron & Steel Vanadium Titanium Co., Ltd.

[0073] Hollow glass microspheres 1: IM16K, D50 particle size 20μm, compressive strength 16000psi, 3M Corporation;

[0074] Hollow glass microspheres 2: HL50, D50 particle size is 40μm, compressive strength is 8000psi, Zhengzhou Shenglait Company;

[0075] Hollow glass microspheres 3: HL60, D50 particle size 40μm, compressive strength 10000psi, Zhengzhou Shenglait Company;

[0076] Hollow glass microspheres 4: HL32, D50 particle size 50μm, compressive strength 2000psi, Zhengzhou Shenglait Company;

[0077] Hollow glass microspheres 5: HL40, D50 particle size 40μm, compressive strength 4000psi, Zhengzhou Shenglait Company;

[0078] Solid glass microspheres: 050-40-A0, D50 particle size is 40μm, PG Company, USA;

[0079] Antioxidant: Antioxidant 1010 and Antioxidant 168 are a mixture formed in a 1:1 mass ratio. Antioxidant 1010 and Antioxidant 168 are commercially available products.

[0080] Light stabilizer: UV-3808, commercially available.

[0081] Examples 1-18 and Comparative Examples 1-6

[0082] The present invention provides a polypropylene composition in the embodiments and comparative examples, wherein the component content (parts by weight) of the polypropylene composition is shown in Tables 1-2;

[0083] Table 1

[0084]

[0085] Table 2

[0086]

[0087]

[0088] The method for preparing the polypropylene composition provided in Example 1 is as follows:

[0089] (1) Homopolymer polypropylene resin, talc powder and nanofiller are mixed and melt extruded to obtain a one-step polypropylene composition; wherein, the temperatures of each zone of the melt extrusion are 190℃, 200℃, 200℃, 210℃ and 210℃, the screw speed is 400r / min and the screw length-to-diameter ratio is 40:1.

[0090] (2) The polypropylene composition, hollow glass microspheres and POE resin are mixed and melt extruded to obtain the polypropylene composition; wherein the temperatures of each zone of the melt extrusion are 190℃, 190℃, 200℃, 200℃, 200℃, 210℃ and 200℃, the screw speed is 400r / min and the screw length-to-diameter ratio is 40:1.

[0091] The preparation methods of the polypropylene compositions provided in Examples 2-18 and Comparative Examples 1-6 are consistent with those in Example 1, except that the relevant components are not added. In Comparative Example 6, hollow glass microspheres are not added, but solid glass microspheres are added.

[0092] Example of effect

[0093] The performance of the polypropylene compositions prepared in the embodiments and comparative examples of this invention is verified by the following examples: The prepared polypropylene compositions were injection molded at a temperature of 200°C. The original dimensions of the injection molded sample were 100mm*100mm*3mm, and small cubes of 10mm*10mm*3mm were cut out for CLTE and density testing.

[0094] 1. CLTE test: Refer to standard GB / T 36800.2-2018, test temperature range -30-100℃;

[0095] 2. Density test: The test was conducted in accordance with standard ISO 1183-1:2012;

[0096] The test results are shown in Table 3.

[0097] Table 3

[0098]

[0099]

[0100] As can be seen from Table 3, when the preparation method provided by this invention is used, the obtained product has a low density and a low coefficient of linear thermal expansion; specifically, the coefficient of linear thermal expansion of the obtained product is 58*10.-6 Below ℃, the density is 1.037 g / cm³. 3 the following;

[0101] As can be seen from Examples 1-3 and Comparative Examples 1-3, the mass fraction of the components and whether or not a certain component is added have a certain impact on the performance of the product. When hollow glass microspheres are not added in Comparative Example 1, the linear thermal expansion coefficient of the obtained product increases significantly, and the density also increases significantly. When nanofillers are not added in Comparative Example 2, the linear thermal expansion coefficient of the obtained product shows a certain increasing trend. When talc is not added in Comparative Example 3, the linear thermal expansion coefficient of the obtained product increases significantly.

[0102] As can be seen from Examples 1, Examples 4-6 and Comparative Example 4, the type of polypropylene and the melt flow rate of homopolymer polypropylene also affect the density and linear thermal expansion coefficient of the product. When the polypropylene added in Comparative Example 4 is not homopolymer polypropylene, the linear thermal expansion coefficient of the product shows a certain increasing trend.

[0103] As can be seen from Examples 1, 7-10 and Comparative Example 5, the melt flow rate of POE resin affects the overall performance of the product. When the melt flow rate of POE resin in Comparative Example 5 is too low, the linear thermal expansion coefficient and density of the obtained product show an obvious increasing trend.

[0104] As can be seen from Examples 1, 13-16 and Comparative Example 6, the particle size and compressive strength of hollow glass microspheres also affect the overall performance of the product; when solid glass microspheres are used instead of hollow glass microspheres in Comparative Example 6, the linear thermal expansion coefficient and density of the obtained product are significantly increased.

[0105] Finally, it should be noted that the above embodiments are used to illustrate the technical solutions of the present invention and not to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A polypropylene composition, characterized in that, The polypropylene composition comprises the following components in parts by weight: 38-62 parts homopolymer polypropylene resin, 18-32 parts POE resin, 13-27 parts talc, 1-7 parts hollow glass microspheres, and 1-7 parts nanofiller; The melt flow rate of the POE resin at a temperature of 190℃ and a load of 2.16kg is 3-32g / 10min; The nanofiller includes at least one of nano-organic clay, nano-titanium dioxide, and nano-silica.

2. The polypropylene composition according to claim 1, characterized in that, The polypropylene composition comprises the following components in parts by weight: 45-50 parts homopolymer polypropylene resin, 23-27 parts POE resin, 18-22 parts talc, 3-4 parts hollow glass microspheres, and 4-5 parts nanofillers.

3. The polypropylene composition according to claim 1, characterized in that, The homopolymer polypropylene has a melt flow rate of 20-75 g / 10 min at a temperature of 230°C and a load of 2.16 kg.

4. The polypropylene composition according to claim 1, characterized in that, The POE resin has a melt flow rate of 4-32 g / 10 min at a temperature of 190°C and a load of 2.16 kg.

5. The polypropylene composition according to claim 1, characterized in that, The D50 particle size of the talc is 0.6-8.5 μm.

6. The polypropylene composition according to claim 1, characterized in that, The hollow glass microspheres have a D50 particle size of 15-55 μm and a compressive strength of 1500-16500 psi.

7. The polypropylene composition according to claim 1, characterized in that, The nanofiller has a dimension of 25-195 nm.

8. The polypropylene composition according to claim 1, characterized in that, The polypropylene composition further includes 0-1 parts of processing aids, which include at least one of antioxidants and light stabilizers.

9. The method for preparing the polypropylene composition according to claim 8, characterized in that, The preparation method includes the following steps: (1) Homopolymer polypropylene resin, talc powder and nanofiller are mixed and melt-extruded to obtain a one-step polypropylene composition; (2) The polypropylene composition, hollow glass microspheres and POE resin are mixed and melt-extruded to obtain the polypropylene composition.

10. The use of the polypropylene composition according to any one of claims 1-8 in the preparation of automotive devices.

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