Polypropylene composite material as well as preparation method and application thereof

Abstract

The invention discloses a polypropylene composite material as well as a preparation method and application thereof, and relates to the technical field of polypropylene materials. The polypropylene composite material comprises a polypropylene matrix and a toughening agent, the polypropylene matrix comprises homo-polypropylene and / or co-polypropylene; the toughening agent comprises a styrene-ethylene-butylene-styrene block copolymer and / or an ethylene-alpha-olefin copolymer; the melt mass flow rate of the homo-polypropylene measured under the conditions that the temperature is 230 DEG C and the load is 2.16 Kg is 20-50g / 10min; and the melt mass flow rate of the co-polypropylene measured under the conditions of 230 DEG C and 2.16 Kg load is 20-90 g / 10 min. The polypropylene composite material disclosed by the invention has the comprehensive properties of high modulus, high impact and low shrinkage.

Description

Technical Field

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

[0002] With the increasing global call for environmental protection and energy conservation and emission reduction, the automotive industry, as one of the main carbon emission sources, is facing increasing emission reduction pressure. Carbon dioxide emitted by automobiles accounts for about 10% of the global total emissions, and there is a direct relationship between the weight of automobiles and their fuel consumption and emissions. Research shows that for every 10% reduction in the total weight of an automobile, fuel consumption can be reduced by 6%-8%, and corresponding emissions can also be significantly reduced. Therefore, automotive lightweighting has become an important means to address fuel efficiency and environmental regulations. To this end, various automobile manufacturers have tried to reduce the density of parts such as bumpers, door panels, and pillars to achieve the goal of lightweighting. Taking OEMs such as Mercedes-Benz, BMW, Volkswagen, General Motors, and BYD as examples, the bumper materials have gradually transitioned from traditional PP+EPDM-T20 materials to PP+EPDM-T15, PP+EPDM-T12, or even PP+EPDM-T10 materials. However, these materials usually have a relatively low modulus (1000-1400 MPa) and cannot meet the requirements of both high modulus and high impact resistance. Summary of the Invention

[0003] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a polypropylene composite material, a preparation method thereof, and an application thereof. The polypropylene composite material of the present invention has comprehensive properties of high modulus, high impact resistance, and low shrinkage.

[0004] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0005] In the first aspect, the present invention provides a polypropylene composite material, comprising a polypropylene matrix and a toughening agent; the polypropylene matrix comprises homopolypropylene and / or copolymerized polypropylene; the toughening agent comprises styrene-ethylene-butene-styrene block copolymer and / or ethylene-α-olefin copolymer;

[0006] The melt mass flow rate of the homopolypropylene measured according to ISO1133-2011 under the conditions of 230°C and a load of 2.16 Kg is 20-50 g / 10 min;

[0007] The melt mass flow rate of the copolymerized polypropylene measured according to ISO1133-2011 under the conditions of 230°C and a load of 2.16 Kg is 20-90 g / 10 min.

[0008] Preferably, the weight content of propylene monomer units in the polypropylene composite material is 45-72%, the weight content of styrene monomer units is 0-10%, the weight content of butene monomer units is 0-10%, and the weight content of ethylene monomer units is 5-18%.

[0009] Preferably, the polypropylene composite material includes a styrene-ethylene-butene-styrene block copolymer, and the weight content of propylene monomer units in the polypropylene composite material is 50-70%, the weight content of styrene monomer units is 1-9%, the weight content of butene monomer units is 5-9%, and the weight content of ethylene monomer units is 6-18%.

[0010] More preferably, the weight content of propylene monomer units in the polypropylene composite material is any one or a range value between any two of 50%, 52%, 55%, 58%, 60%, 62%, 65%, 68%, 70%.

[0011] More preferably, the weight content of styrene monomer units in the polypropylene composite material is any one or a range value between any two of 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%.

[0012] More preferably, the weight content of butene monomer units in the polypropylene composite material is any one or a range value between any two of 5%, 6%, 7%, 8%, 9%.

[0013] More preferably, the weight content of ethylene monomer units in the polypropylene composite material is any one or a range value between any two of 6%, 8%, 10%, 12%, 14%, 15%, 16%, 18%.

[0014] Preferably, the melt mass flow rate of the homopolypropylene measured at 230°C and a load of 2.16 Kg according to ISO1133-2011 is any one or a range value between any two of 20 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.

[0015] Preferably, the melt mass flow rate of the random copolymer polypropylene measured at 230°C and a load of 2.16 Kg according to ISO1133-2011 is any one or a range value between any two of 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.

[0016] Preferably, the melt mass flow rate of the styrene-ethylene-butene-styrene block copolymer measured according to ISO1133-2011 under the conditions of 230 °C and 5.0 Kg load is 5-25 g / 10 min.

[0017] More preferably, the melt mass flow rate of the styrene-ethylene-butene-styrene block copolymer is any one or the range value of both of 5 g / 10 min, 10 g / 10 min, 15 g / 10 min, 20 g / 10 min, 25 g / 10 min.

[0018] Preferably, the melt mass flow rate of the ethylene-α-olefin copolymer measured according to ISO1133-2011 under the conditions of 190 °C and 2.16 Kg load is 0.7-15 g / 10 min.

[0019] More preferably, the melt mass flow rate of the ethylene-α-olefin copolymer is any one or the range value of both of 0.7 g / 10 min, 1 g / 10 min, 1.5 g / 10 min, 2 g / 10 min, 2.5 g / 10 min, 3 g / 10 min, 5 g / 10 min, 10 g / 10 min, 15 g / 10 min.

[0020] The weight content of styrene monomer in the present invention is measured by the ASTM D5775-2019 standard test method. The content of propylene monomer is obtained by conventional high-temperature GPC / SEC test.

[0021] Preferably, the homopolypropylene is polymerized from propylene monomer.

[0022] Preferably, the random copolymer polypropylene is composed of a propylene homopolymer and a block copolymer of ethylene and propylene, and the block copolymer of ethylene and propylene is synthesized from ethylene monomer and propylene monomer.

[0023] Preferably, the styrene-ethylene-butene-styrene block copolymer is synthesized from styrene monomer, ethylene monomer and butene monomer.

[0024] Preferably, the ethylene-α-olefin copolymer is synthesized from ethylene monomer, octene monomer or butene monomer.

[0025] Preferably, the weight content of octene monomer unit in the polypropylene composite material is 0.1-11%.

[0026] More preferably, the weight content of octene monomer unit in the polypropylene composite material is any one or the range value of both of 1%, 2%, 5%, 6%, 8%, 10%, 11%.

[0027] When the ethylene-α-olefin copolymer is synthesized from ethylene monomer and octene monomer, the weight content of octene is calculated by subtracting the weight content of ethylene in the ethylene-α-olefin copolymer from the weight content of the ethylene-octene copolymer.

[0028] Preferably, the polypropylene composite further comprises a filler, and the weight ratio of the filler in the polypropylene composite is 10-15%.

[0029] Preferably, the filler is a flaky filler, preferably at least one of graphene, montmorillonite, talc powder, and hydrotalcite.

[0030] Preferably, the average diameter of the filler is 2-5 μm, and the diameter-to-thickness ratio is 10-15.

[0031] Preferably, the average diameter of the filler is any one or both of the range values of 2 μm, 3 μm, and 4 μm.

[0032] Preferably, the diameter-to-thickness ratio of the filler is any one or both of the range values of 10, 11, 12, 13, 14, and 15.

[0033] Preferably, the polypropylene composite further comprises 1-2 parts of an additive.

[0034] Preferably, the additive comprises at least one of an antioxidant, a lubricant, and a light stabilizer.

[0035] More preferably, the antioxidant comprises a hindered phenol antioxidant or a phosphite antioxidant.

[0036] More preferably, the light stabilizer comprises a hindered amine light stabilizer.

[0037] More preferably, the lubricant comprises esters, amides, or silicones.

[0038] Preferably, the polypropylene composite comprises the following components in parts by weight:

[0039] Homopolypropylene or copolymerized polypropylene 58-75 parts; styrene-ethylene-butene-styrene block copolymer 15-25 parts; filler 10-13 parts; additive 1-2 parts.

[0040] Preferably, the polypropylene composite comprises the following components in parts by weight:

[0041] Homopolypropylene 58-75 parts; styrene-ethylene-butene-styrene block copolymer or ethylene-α-olefin copolymer 15-25 parts; filler 10-13 parts; additive 1-2 parts.

[0042] Preferably, the polypropylene composite comprises the following components in parts by weight:

[0043] 58 - 75 parts of copolymerized polypropylene; 15 - 25 parts of ethylene-α-olefin copolymer; 10 - 13 parts of filler; 1 - 2 parts of auxiliary agent.

[0044] In the polypropylene composite material of the present invention, the mass percentage of polypropylene is not less than 50%.

[0045] In the second aspect, the present invention also discloses a preparation method of a polypropylene composite material, comprising the following steps:

[0046] Mix each component and then add it to a twin-screw extruder, and obtain the polypropylene composite material after granulation and cooling.

[0047] Preferably, the temperature of the twin-screw extruder is 80 - 210 °C, and the screw speed is 200 - 500 r / min.

[0048] Preferably, the length-diameter ratio of the twin-screw extruder is 40:1.

[0049] In the third aspect, the present invention also discloses an application of the polypropylene composite material in automotive parts, which can be specifically used for bumpers, door panels, columns, lower instrument panels, and glove boxes.

[0050] In the fourth aspect, the present invention also discloses an automotive part, comprising the above polypropylene composite material.

[0051] Compared with the prior art, the beneficial effects of the present invention are:

[0052] The polypropylene composite material of the present invention has the advantages of high rigidity, high toughness, and low shrinkage rate, and can achieve the balance of high rigidity and high toughness while maintaining a low shrinkage rate. Specific Embodiments

[0053] 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, but the protection scope and implementation manner of the present invention are not limited thereto.

[0054] The materials, reagents, etc. used in the following embodiments are, unless otherwise specified, reagents and materials that can be obtained from commercial channels.

[0055] Examples 1 - 14

[0056] Examples of the polypropylene composite material and its preparation method of the present invention, and the composition components of the polypropylene composite material are shown in Table 1.

[0057] The preparation method of the polypropylene composite material comprises the following steps:

[0058] Mix each component and then add it to a twin-screw extruder, and obtain the polypropylene composite material after granulation and cooling.

[0059] Among them, the temperature of the twin-screw extruder is 80 - 210 °C, and the screw rotation speed is 200 - 500 r / min.

[0060] Comparative Examples 1 - 10

[0061] The differences between each comparative example and the example are only the types and ratios of the components, as shown in Table 2.

[0062] In the components of each example and comparative example:

[0063] The homopolypropylene (PPH-1): PP H9018, manufacturer: PetroChina, melt mass flow rate is 50 g / 10 min;

[0064] The homopolypropylene (PPH-2): PP PPH-T26, manufacturer: Sinopec, melt mass flow rate is 26 g / 10 min;

[0065] The homopolypropylene (PPH-3): PP HP500N, manufacturer: CNOOC and Shell, melt mass flow rate is 10 g / 10 min;

[0066] The homopolypropylene (PPH-4): PP M60T, manufacturer: Sinopec, melt mass flow rate is 60 g / 10 min.

[0067] The copolymerized polypropylene (PPB-1): PP BX3800, manufacturer: SK Korea, the content of propylene homopolymer is 85%, the content of ethylene-propylene block copolymer is 15%, the ethylene content in the ethylene-propylene block copolymer is 46%, and the melt mass flow rate is 30 g / 10 min;

[0068] The copolymerized polypropylene (PPB-2): PP BX3900, manufacturer: SK Korea, the content of propylene homopolymer is 83%, the content of ethylene-propylene block copolymer is 17%, the ethylene content in the ethylene-propylene block copolymer is 28%, and the melt mass flow rate is 60 g / 10 min;

[0069] The copolymerized polypropylene (PPB-3): PP KF-BM901C, manufacturer: Ningbo Jinfa, the content of propylene homopolymer is 72%, the content of ethylene-propylene block copolymer is 28%, the ethylene content in the ethylene-propylene block copolymer is 45%, and the melt mass flow rate is 90 g / 10 min;

[0070] The copolymer polypropylene (PPB-4): PP EP300M, manufacturer: CNOOC and Shell Chemicals, the content of propylene homopolymer is 81%, the content of ethylene-propylene block copolymer is 19%, the ethylene content in the ethylene-propylene block copolymer is 56%, and the melt mass flow rate is 10 g / 10 min;

[0071] The copolymer polypropylene (PPB-5): PP BX3920, manufacturer: SK of South Korea, the content of propylene homopolymer is 91%, the content of ethylene-propylene block copolymer is 9%, the ethylene content in the ethylene-propylene block copolymer is 47%, and the melt mass flow rate is 100 g / 10 min.

[0072] The styrene-ethylene-butene-styrene block copolymer (SEBS-1): SEBS G1657, manufacturer: Kraton of the United States, the melt mass flow rate is 22 g / 10 min, and the weight content of styrene measured by the ASTM D5775-2019 standard test method is 13%;

[0073] The styrene-ethylene-butene-styrene block copolymer (SEBS-2): SEBS 6552, manufacturer: Zhejiang Zhongli, the melt mass flow rate is 12 g / 10 min, and the weight content of styrene measured by the ASTM D5775-2019 standard test method is 13%;

[0074] The styrene-ethylene-butene-styrene block copolymer (SEBS-3): A1536 H, manufacturer: Kraton of the United States, the melt mass flow rate is 7 g / 10 min, and the weight content of styrene measured by the ASTM D5775-2019 standard test method is 42%;

[0075] The styrene-ethylene-butene-styrene block copolymer (SEBS-4): FG1924 G, manufacturer: Kraton of the United States, the melt mass flow rate is 40 g / 10 min, and the weight content of styrene measured by the ASTM D5775-2019 standard test method is 13%;

[0076] The styrene-ethylene-butene-styrene block copolymer (SEBS-5): SEBS 7551, manufacturer: Formosa Plastics Corporation, the melt mass flow rate is 2.0 g / 10 min, and the weight content of styrene measured by the ASTM D5775-2019 standard test method is 33%.

[0077] The ethylene-octene copolymer 1 (POE-1): POE ENGAGE 8150, manufacturer: Dow Chemical, the melt mass flow rate is 5.0 g / 10 min, and the ethylene weight content is 54%;

[0078] The ethylene-octene copolymer 2 (POE-2): POE ENGAGE 8137, manufacturer: Dow Chemical, melt mass flow rate is 13.0 g / 10 min, ethylene weight content is 57%;

[0079] The ethylene-octene copolymer 3 (POE-3): POE ENGAGE 8842, manufacturer: Dow Chemical, melt mass flow rate is 1.0 g / 10 min, ethylene weight content is 48%;

[0080] The ethylene-octene copolymer 4 (POE-4): POE 58705, manufacturer: Dow Chemical, melt mass flow rate is 0.3 g / 10 min, ethylene weight content is 38%;

[0081] The ethylene-octene copolymer 5 (POE-5): POE 8411, manufacturer: Dow Chemical, melt mass flow rate is 18 g / 10 min, ethylene weight content is 55%.

[0082] The filler includes talc powder, with an average lamellar diameter of 2 μm and an aspect ratio of 10, obtained by crushing and screening talc powder with an average diameter of 6 mm, manufacturer: Lingshou County Runshan Mineral Powder Factory.

[0083] The additives include an antioxidant and a light stabilizer with a mass ratio of 1:1. Among them, the antioxidant is pentaerythritol tetra[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], commercially available; the light stabilizer is 2,2,6,6-tetramethyl-4-piperidyl stearate, commercially available.

[0084] Unless otherwise specified, the component raw materials used in the examples and comparative examples of the present invention are all commercially available raw materials, and the component raw materials used in each parallel experiment are of the same kind.

[0085] Table 1

[0086]

[0087] Table 2

[0088]

[0089]

[0090] In order to verify the performance of the polypropylene composite material of the present invention, the polypropylene composite materials prepared in each example and comparative example were injection-molded into splines for testing the following properties.

[0091] Performance test method:

[0092] 1. Flexural modulus: Tested in accordance with the standard of "ISO 178-2019 Plastics - Determination of flexural properties", with a test speed of 2 mm / min;

[0093] 2. Notched impact strength: Tested in accordance with the standard of "ISO 179 / 1eA-2010 Plastics - Determination of pendulum impact properties".

[0094] 3. Shrinkage rate: Tested in accordance with the standard of "ISO 294-3:2020".

[0095] The performance parameters obtained from the above tests are shown in Table 3 and Table 4.

[0096] Table 3

[0097]

[0098]

[0099] Table 4

[0100]

[0101] According to Table 1, it can be seen that the flexural modulus of the polypropylene composite material described in the present invention can reach more than 1850 MPa, the notched impact strength can reach more than 35 MPa, and the shrinkage rate is not greater than 0.7%, indicating that the polypropylene composite material described in the present invention has comprehensive properties of high modulus, high impact and low shrinkage.

[0102] It can be seen from Examples 1-14 that the contents of propylene monomer, styrene monomer, butene monomer, ethylene monomer in the present invention, as well as the melt mass flow rates of homopolypropylene and copolymer polypropylene, styrene-ethylene-butene-styrene block copolymer, and ethylene-α-olefin copolymer can play a synergistic role under specific conditions, so that the prepared polypropylene composite material can meet the requirements of high modulus, high impact and low shrinkage rate under the condition of low powder filling. The propylene chain segment in polypropylene has good compatibility with the butene chain segment in the styrene-ethylene-butene-styrene block copolymer and the butene or octene chain segment in the ethylene-α-olefin copolymer, but the compatibility between the propylene chain segment and the ethylene chain segment in polypropylene is general. Therefore, an appropriate propylene content can form better compatibility with the ethylene-α-olefin copolymer or the styrene-ethylene-butene-styrene block copolymer, improving the toughness while maintaining the properties of the polypropylene substrate; the flexural modulus and impact of the composite material as a whole are also related to its own molecular weight. The most direct feedback of molecular weight is fluidity. The smaller the fluidity, the larger the molecular weight, and the higher the fluidity, the smaller the molecular weight. When the molecular weight is too high, the toughening component is not easily dispersed, there are many interfacial defects, and the rigidity and impact loss are large; when the molecular weight is too low, the toughness of the polypropylene substrate or the toughening agent is poor, and the rigidity and toughness of the composite material are naturally low.

[0103] It can be seen from Comparative Examples 1-2 that when the melt flow rate of the homopolypropylene is lower than or higher than the defined value of the present invention, the rigidity and toughness of the polypropylene composite material are lower, and the shrinkage rate is larger.

[0104] It can be seen from Comparative Examples 3-4 that when the melt flow rate of the copolymerized polypropylene is lower than or higher than the defined value of the present invention, the rigidity and toughness of the polypropylene composite material are lower, and the shrinkage rate is larger. An excessively large melt index of polypropylene indicates that the molecules of polypropylene are too small, and its own modulus and toughness are lower. Even after toughening, the toughness of the composite material is still poor. Moreover, if the molecular weight is low, the molecular chains are more likely to fold during the cooling process, and the shrinkage rate will be large.

[0105] It can be seen from Comparative Examples 5-6 that when the butene monomer content in the polypropylene composite material exceeds 10%, the rigidity of the propylene composite material is lower, and the shrinkage rate is larger. A low butene content indicates a high ethylene content, poor compatibility with propylene, many interfacial defects, and poor rigidity and toughness.

[0106] It can be seen from Comparative Examples 7-8 that when the melt mass flow rate of the styrene-ethylene-butene-styrene block copolymer is lower than or higher than the defined value of the present invention, the rigidity and toughness of the polypropylene composite material are lower, and the shrinkage rate is larger.

[0107] It can be seen from Comparative Examples 9-10 that when the melt flow rate of the ethylene-α-olefin copolymer is lower than or higher than the defined value of the present invention, the rigidity and toughness of the polypropylene composite material are lower, and the shrinkage rate is larger.

[0108] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit the protection scope of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A polypropylene composite material, characterized in that: It comprises a polypropylene matrix and a toughening agent; the polypropylene matrix comprises homopolymer polypropylene and / or copolymer polypropylene; the toughening agent comprises styrene-ethylene-butylene-styrene block copolymer and / or ethylene-α-olefin copolymer; The melt mass flow rate of the homopolymer polypropylene measured at 230° C. and 2.16 kg load is 20-50 g / 10 min; The melt mass flow rate of the copolymerized polypropylene measured at 230° C. and 2.16 kg load is 20-90 g / 10 min.

2. The polypropylene composite material according to claim 1, characterized in that The weight content of the propylene monomer unit in the polypropylene composite material is 45-72%, the weight content of the styrene monomer unit is 0-10%, the weight content of the butene monomer unit is 0-10%, and the weight content of the ethylene monomer unit is 5-18%.

3. The polypropylene composite material according to claim 1, characterized in that: The polypropylene composite material comprises octene monomer units, and the weight content of the octene monomer units is 0.1-11%.

4. The polypropylene composite material according to claim 1, characterized in that: The melt mass flow rate of the styrene-ethylene-butylene-styrene block copolymer measured at 230° C. and 5.0 kg load is 5-25 g / 10 min.

5. The polypropylene composite material according to claim 1, characterized in that: The melt mass flow rate of the ethylene-α-olefin copolymer measured at 190° C. and 2.16 kg load is 0.7-15 g / 10 min.

6. The polypropylene composite material according to claim 1, characterized in that: The polypropylene composite material further comprises a filler.

7. The polypropylene composite material according to claim 6, characterized in that: The filler includes at least one of graphene, montmorillonite, talc and hydrotalcite, and / or the average diameter of the filler is 2-5 μm, and the diameter-to-thickness ratio is 10-15.

8. The method for preparing the polypropylene composite material according to any one of claims 1 to 7, characterized in that: The components are mixed and added into a twin-screw extruder, and a polypropylene composite material is obtained after granulation and cooling.

9. Use of the polypropylene composite material according to any one of claims 1 to 7 in automobile parts.

10. An automobile component, characterized in that: The invention comprises the polypropylene composite material according to any one of claims 1 to 7.

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