Polypropylene composite material as well as preparation method and application thereof

Abstract

The invention belongs to the field of polypropylene materials, and particularly discloses a polypropylene composite material and a preparation method and application thereof. The polypropylene composite material comprises the following components in parts by weight: 100 parts of polypropylene, 12-26 parts of a liquid crystal polymer A, 0.05-0.5 part of a nucleating agent and 0.4-1.6 parts of a brightener, the thermal deformation temperature of the liquid crystal polymer A is less than or equal to 210 DEG C. In the polypropylene composite material, the liquid crystal polymer A, the nucleating agent and the brightener act together, so that the high temperature resistance of the polypropylene composite material is remarkably improved, and the polypropylene composite material can still keep higher glossiness and impact property when working at high temperature for a long time.

Description

Technical Field

[0001] The invention belongs to the field of polypropylene materials, and in particular relates to a polypropylene composite material and a preparation method and application thereof. Background Art

[0002] Polypropylene (PP) has the advantages of low density, low cost, corrosion resistance, and good insulation, and is widely used in household appliances and automobiles. With the growing demand for lightweight in people's lives, the application of polypropylene materials in automobiles and household appliances is showing an upward trend. There are many household appliance components made mainly of polypropylene materials, such as heaters, microwave ovens, kettles, etc. These household appliances need to be used in a high temperature environment (above 60°C). However, long-term operation at such high temperatures will aggravate the aging trend of polypropylene materials, resulting in a sharp decline in the mechanical properties of polypropylene materials, shortening the service life of such polypropylene material appliances. In addition, in order to improve certain properties of polypropylene materials, various functional additives are usually added to polypropylene materials. For example, in order to improve the surface gloss of polypropylene materials, brighteners are added to polypropylene substrates. However, in a high temperature use environment, additives are prone to migration and precipitation on the surface of the material, resulting in poor gloss and mechanical properties of the material.

[0003] Therefore, it is necessary to provide a high temperature resistant polypropylene material that can maintain good gloss and mechanical properties after being used at high temperatures. Summary of the invention

[0004] In view of the defect that the mechanical properties and glossiness of the polypropylene material involved in the above-mentioned prior art are significantly reduced after being used at high temperature, the present invention will provide a polypropylene composite material and a preparation method and application thereof.

[0005] To achieve the above purpose, the following technical solutions are specifically included:

[0006] In one aspect, the present invention provides a polypropylene composite material comprising the following components in parts by weight:

[0007] 100 parts of polypropylene, 12-26 parts of liquid crystal polymer A, 0.05-0.5 parts of nucleating agent, 0.4-1.6 parts of brightening agent; the thermal deformation temperature of the liquid crystal polymer A is ≤210°C.

[0008] The polypropylene material of the present invention contains a liquid crystal polymer A with a heat deformation temperature below 210°C. The processing temperature of the polypropylene material during the preparation process is generally below 210°C. During the processing process, the liquid crystal polymer A has a lower heat deformation temperature and gradually changes from a solid state to a molten state during the processing process, presenting thermotropic liquid crystal properties and forming a two-phase state with the polypropylene matrix crystal phase, so that a certain degree of disorder (amorphous phase) can exist in the liquid crystal polymer A phase and the polypropylene crystal phase. In this way, on the one hand, the liquid crystal resin A itself can improve the high temperature impact resistance of the polypropylene composite material. On the other hand, the thermotropic liquid crystal phenomenon can be used to adsorb the decomposition products and / or small molecules of the additives (such as brightener) in the polypropylene composite material at high temperature into the amorphous phase to prevent their migration in the matrix, thereby significantly improving the high temperature resistance of the polypropylene composite material and maintaining the high gloss and high impact performance of the polypropylene composite material when used at high temperature. In addition, the nucleating agent dispersed in the system can increase the crystallization rate in the system and improve the gloss and impact resistance of the material through fine crystal strengthening. The brightener dispersed in the system can further assist in increasing the gloss of the material.

[0009] Preferably, the polypropylene composite material comprises the following components in parts by weight: 100 parts of polypropylene, 15-20 parts of liquid crystal polymer A, 0.1-0.4 parts of nucleating agent, and 0.5-1.5 parts of brightener.

[0010] Preferably, the polypropylene composite material further comprises 5-10 parts by weight of liquid crystal polymer B, and the thermal deformation temperature of the liquid crystal polymer B is greater than 210°C.

[0011] In addition to the liquid crystal polymer A having a heat deformation temperature below 210°C, the polypropylene material of the present invention further contains a liquid crystal polymer B having a deformation temperature higher than 210°C. During processing, when the liquid crystal polymer A having a lower heat deformation temperature is in a molten state, the liquid crystal polymer B having a higher heat deformation temperature is still in a solid state and is uniformly dispersed in the system, ensuring that a certain degree of disorder (amorphous phase) exists in the liquid crystal polymer A phase and the polypropylene crystal phase, and the degree of disorder is more suitable than the disordered state when the liquid crystal polymer A exists alone; thus, on the basis of the liquid crystal resin A, the liquid crystal resin B can further improve the high temperature impact resistance and glossiness of the polypropylene composite material.

[0012] Common polypropylene resins in the art can be used in the present invention, and the polypropylene resin includes at least one of homopolymer polypropylene, random copolymer polypropylene, and block copolymer polypropylene.

[0013] Preferably, the melt mass flow rate (MFR) of the polypropylene tested at 230°C and 2.16Kg load according to ISO1133-2011 is 2.5-30g / 10min, specifically 2.5g / 10min, 5g / 10min, 10g / 10min, 15g / 10min, 20g / 10min, 25g / 10min, 30g / 10min, 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 no longer exhaustively lists the specific point values ​​included in the range. The polypropylene of the present invention may specifically include but is not limited to a homopolymer polypropylene having a melt mass flow rate of 2.5-30 g / 10 min as tested under ISO1133-2011 at 230° C. and 2.16 kg load, and preferably, the homopolymer polypropylene has a melt mass flow rate of 20-35 g / 10 min; it may also include but is not limited to a random copolymer polypropylene having a melt mass flow rate of 2.5-30 g / 10 min as tested under ISO1133-2011 at 230° C. and 2.16 kg load, and preferably, the random copolymer polypropylene has a melt mass flow rate of 2.5-5 g / 10 min; it may also include but is not limited to a block copolymer polypropylene having a melt mass flow rate of 2.5-30 g / 10 min as tested under ISO1133-2011 at 230° C. and 2.16 kg load, and preferably, the block copolymer polypropylene has a melt mass flow rate of 5-15 g / 10 min.

[0014] The mass percentage of the polypropylene resin in the polypropylene composite material of the present invention is not less than 45%, more preferably not less than 60%, and even more preferably not less than 75%.

[0015] The heat distortion temperature (DTUL) of the liquid crystal polymer A and the liquid crystal polymer B in the present invention is measured according to ASTM D648-2018 standard at a load of 1.82 MPa and a heating rate of 2° C. / min.

[0016] Preferably, the liquid crystal polymer B includes aromatic copolyesters and semi-aromatic copolyesters. More preferably, the monomers of the liquid crystal polymer B are independently selected from at least two of p-hydroxybenzoic acid, 6-hydroxy-2-naphthoic acid, biphenylene glycol, hydroquinone, terephthalic acid, isophthalic acid, and naphthalene dicarboxylic acid.

[0017] Preferably, the liquid crystal polymer A includes aromatic copolyesters and semi-aromatic copolyesters. Further preferably, the monomers of the liquid crystal polymer A are independently selected from at least two of ethylene glycol, p-hydroxybenzoic acid, 6-hydroxy-2-naphthoic acid, biphenylene glycol, hydroquinone, terephthalic acid, isophthalic acid, and naphthalene dicarboxylic acid.

[0018] Preferably, the thermal deformation temperature of the liquid crystal polymer A is 120-200°C, specifically 120°C, 130°C, 140°C, 150°C, 170°C, 180°C, 190°C, 200°C, 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 no longer exhaustively lists the specific point values ​​included in the said range.

[0019] The use of the liquid crystal polymer A within the above heat deformation temperature range can further improve the high temperature resistance of the polypropylene composite material, and can better maintain the glossiness and impact resistance when used in a high temperature environment.

[0020] Preferably, the thermal deformation temperature of the liquid crystal polymer B is 250-315°C, specifically 250°C, 270°C, 290°C, 310°C, 315°C, 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 no longer exhaustively lists the specific point values ​​included in the range.

[0021] Preferably, the mass ratio of the liquid crystal polymer A and the liquid crystal polymer B is (1.5-4):1, specifically 1.5:1, 2:1, 2.5:1, 3:1, 3.5:1, 4:1, 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 no longer exhaustively lists the specific point values ​​included in the range.

[0022] The liquid crystal polymer B in the above heat deformation temperature range can be better matched with the liquid crystal polymer A, can further improve the high temperature resistance of the polypropylene composite material, and can better maintain the glossiness and impact resistance when used in a high temperature environment.

[0023] Preferably, the brightener comprises at least one of barium sulfate and a copolymer containing acrylonitrile.

[0024] Further preferably, the acrylonitrile-containing copolymer includes at least one of a styrene-acrylonitrile copolymer and a methyl methacrylate-acrylonitrile copolymer.

[0025] Further preferably, the mesh size of the barium sulfate is 2000-4000 mesh, specifically 2000, 2500, 3000, 3500, 4000, 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 no longer exhaustively lists the specific point values ​​included in the range.

[0026] Further preferably, the copolymer of acrylonitrile has a melt mass flow rate of 10-60 g / 10 min as tested at 220 ° C and 10 kg load according to ISO 1133-2011, specifically 10 g / 10 min, 15 g / 10 min, 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, 55 g / 10 min, 60 g / 10 min, 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 no longer exhaustively lists the specific point values ​​included in the range.

[0027] The brightener mentioned above can be better matched with the liquid crystal polymer A, the liquid crystal polymer B and the nucleating agent, further improving the high temperature resistance of the polypropylene composite material, and can better maintain the glossiness and impact resistance when used in a high temperature environment.

[0028] Preferably, the brightener comprises barium sulfate and a copolymer containing acrylonitrile, and the mass ratio of barium sulfate to the copolymer containing acrylonitrile is 1:(1.5-9), specifically 1:1.5, 1:3, 1:4.5, 1:6, 1:7.5, 1:9, 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 no longer exhaustively lists the specific point values ​​included in the range.

[0029] The inventors of the present invention have found that when barium sulfate and a copolymer containing acrylonitrile are used simultaneously, the glossiness of the polypropylene composite material is improved to a greater extent. Also, because barium sulfate and the copolymer containing acrylonitrile are in the form of an inorganic and organic composite, the high temperature resistance of the polypropylene composite material is further improved, which is more conducive to maintaining its high glossiness and impact strength when used at high temperatures.

[0030] Preferably, the nucleating agent includes at least one of an α-nucleating agent and a β-nucleating agent.

[0031] More preferably, the nucleating agent comprises an α-nucleating agent and a β-nucleating agent, and even more preferably, the mass ratio of the α-nucleating agent to the β-nucleating agent is (1-3):1.

[0032] Preferably, the α nucleating agent includes at least one of substituted aryl phosphate nucleating agents and carboxylic acid metal salts; more preferably, the α nucleating agent includes at least one of substituted phenyl aluminum phosphate and substituted aryl heterocyclic aluminum phosphate. More preferably, the substituted phenyl aluminum phosphate includes di[2,2'-methylenebis(4,6-di-tert-butylphenyl)phosphate]hydroxyaluminum salt; the carboxylic acid metal salt includes at least one of sodium benzoate, aluminum benzoate, and aluminum p-tert-butylbenzoate.

[0033] Preferably, the β-nucleating agent includes at least one of an amide β-nucleating agent, a rare earth β-nucleating agent, and an aliphatic dicarboxylate β-nucleating agent. Further preferably, the amide β-nucleating agent includes at least one of 2,6-phthalic acid cyclohexylamide, 2,6-naphthalene dicarboxylic acid cyclohexylamide, and aromatic dicarboxamide; the rare earth β-nucleating agent is selected from at least one of rare earth lanthanide mononuclear metal compounds, rare earth multi-complexes, and binuclear complexes formed by rare earth and Group IIA metals; the aliphatic dicarboxylate β-nucleating agent includes at least one of calcium tetrahydrophthalate, calcium suberate, calcium pimelate, polycarboxylic acid calcium salt, and polycarboxylic acid zinc salt.

[0034] The nucleating agent can cooperate with the liquid crystal polymer A to regulate the crystallization rate in the polypropylene composite material system during processing, achieve fine crystal strengthening, further improve the high temperature resistance of the polypropylene composite material, and enable the polypropylene composite material to maintain higher gloss and impact resistance.

[0035] Preferably, the polypropylene further comprises at least any one of the following components in parts by weight: 0.05-0.3 parts by weight of a lubricant, 0.01-1 parts by weight of a flame retardant, 0.01-1 parts by weight of an antioxidant, and 0.01-1 parts by weight of an antistatic agent.

[0036] More preferably, the lubricant includes at least one of an amide lubricant and a stearic acid lubricant.

[0037] More preferably, the antioxidant is at least one of a hindered phenol antioxidant and a phosphite antioxidant.

[0038] Further preferably, the flame retardant includes at least one of a bromine-based flame retardant, a phosphorus-nitrogen-based flame retardant, and a nitrogen-based flame retardant.

[0039] More preferably, the antistatic agent includes at least one of a polyamide antistatic agent and a quaternary ammonium salt antistatic agent.

[0040] In the present invention, other (functional) additives may be added as required, for example, including but not limited to lubricants, flame retardants, antioxidants, antistatic agents, etc. Conventional lubricants, flame retardants, antioxidants, and antistatic agents in the art may be used in the present invention to increase the functionality of the polypropylene composite material and improve the comprehensive performance of the polypropylene composite material. For example, the addition of lubricants may improve the compatibility of the polypropylene phase and the liquid crystal polymer phase, and further improve the gloss and impact properties of the polypropylene composite material.

[0041] On the other hand, the present invention provides a method for preparing the polypropylene composite material, comprising the following steps: uniformly mixing the raw materials, and sequentially subjecting the raw materials to melt extrusion and granulation to obtain the polypropylene composite material.

[0042] Preferably, the temperature of the melt extrusion is 170-210°C.

[0043] In addition, the present invention also provides an application of the polypropylene composite material in the preparation of household appliances, especially the polypropylene composite material of the present invention can maintain high gloss and impact resistance when used for a long time at a temperature as high as 60-80°C, has excellent high temperature resistance and long service life, and is particularly suitable for preparing household appliances such as heaters, microwave ovens, kettles, etc.

[0044] Compared with the prior art, the present invention has the following beneficial effects: in the polypropylene composite material, the liquid crystal polymer A, the nucleating agent and the brightener work together to significantly improve the high temperature resistance of the polypropylene composite material, so that the polypropylene composite material can still maintain a high gloss and impact resistance when working at high temperature for a long time. DETAILED DESCRIPTION

[0045] To better illustrate the purpose, technical scheme and advantages of the present invention, the present invention will be further described below through specific examples. Unless otherwise specified, the components and raw materials used in the embodiments and comparative examples of the present invention are all commercially available raw materials, and the components and raw materials used in each parallel experiment are all of the same kind.

[0046] (1) Polypropylene:

[0047] PP-1: BX3500, block copolymer polypropylene, tested according to ISO1133-2011, MFR = 10g / 10min at 230℃ and 2.16kg load, purchased from Aiskai, Korea;

[0048] PP-2: SZ30S, homopolypropylene, MFR=30 g / 10 min at 230°C and 2.16 kg load as tested according to ISO1133-2011, purchased from Sino-Korean Petrochemical (Wuhan);

[0049] PP-3: SM198, random copolymer polypropylene, tested according to ISO1133-2011, MFR = 2.5 g / 10 min at 230 ° C and 2.16 kg load, purchased from Malaysia Datang;

[0050] (2) Liquid crystal polymer:

[0051] Liquid crystal polymer A: Rodrum LC-5000, DTUL of 170°C measured at a load of 1.82 MPa and a heating rate of 2°C / min, a semi-aromatic copolyester composed of polyethylene terephthalate (PET) and polyhydroxybenzoic acid (PHB), purchased from Unitika;

[0052] Liquid crystal polymer B-1: LCP E6810LH, according to ASTM D648-2018 standard, the DTUL measured at a load of 1.82 MPa and a heating rate of 2°C / min is 266°C, the monomers are terephthalic acid, biphenol, and p-hydroxybenzoic acid, purchased from Sumitomo Chemical of Japan;

[0053] Liquid crystal polymer B-2: Xydar MG450, according to ASTM D648-2018 standard, the DTUL measured at a load of 1.82 MPa and a heating rate of 2°C / min is 305°C, a copolymerized aromatic ester prepared from p-hydroxybenzoic acid, biphenol and terephthalic acid monomers, purchased from Shin Petrochemical of Japan;

[0054] (3) Nucleating agent:

[0055] Nucleating agent-1: α-type nucleating agent, TMP-6, a complex based on bis[2,2'-methylenebis(4,6-di-tert-butylphenyl)phosphate]hydroxyaluminum salt, Shanxi Chemical Research Institute;

[0056] Nucleating agent-2: β-type nucleating agent, TMB-5, 2,6-phthalic acid cyclohexylamide, Shanxi Chemical Research Institute;

[0057] (4) Brightener:

[0058] Brightener-1: melt mass flow rate of 40 g / 10 min at 220°C and 10 kg load according to ISO 1133-2011, PN-107, styrene-acrylonitrile copolymer, purchased from Chi Mei Industrial;

[0059] Brightener-2: 3000 mesh precipitated barium sulfate, brand AB-3000N1, purchased from Guangzhou Huangpu Tiantai Chemical Light Co., Ltd.;

[0060] (5) Lubricant: Ethylene bisstearamide, EBS HI-LUBE, purchased from Sinwon, Korea;

[0061] (6) Antistatic agent: PEBAX MH2030, purchased from Akema, France.

[0062] Examples 1-13 and Comparative Examples 1-4

[0063] A polypropylene composite material, the preparation method of which comprises the following steps:

[0064] The raw materials are added into a high-speed mixer according to the proportions in Table 1-2 and mixed evenly. The mixture is then fed into a twin-screw extruder for melt extrusion at 170-210° C. and granulation to obtain the polypropylene material.

[0065] Table 1

[0066]

[0067] Table 2

[0068]

[0069]

[0070] In order to verify the performance of the polypropylene composite material of the present invention, the polypropylene composite materials prepared in the examples and comparative examples were tested for glossiness and impact performance. The specific test methods are as follows:

[0071] (1) High temperature resistant gloss: The materials prepared in the above examples and comparative examples were injection molded into samples of the same specifications by conventional injection molding, and the gloss of the samples at 60° was tested by a gloss tester (5 parallel samples were tested 5 times and the average value was taken), and the gloss performance before and after drying in an 80°C oven for 30 hours was compared, and the gloss retention rate after high temperature treatment was calculated;

[0072] (2) Impact performance: The materials prepared in the above embodiments and comparative examples were injection molded into standard samples by conventional injection molding. The simply supported beam impact performance of the samples was measured according to GB / T1043.1-2008. The parallel specimens were heat treated at 80°C for 30 h, and then the impact strength of the specimens was tested. The retention rate of the impact strength after high temperature treatment at 80°C was calculated.

[0073] Table 3

[0074]

[0075] From the above results we can see that:

[0076] As the content of liquid crystal polymer A in Examples 10, 1, 11, and 9 gradually increases (on the contrary, the content of liquid crystal polymer B gradually decreases), the initial glossiness of the polypropylene composite material before high temperature treatment is basically the same, and the glossiness after high temperature treatment first increases and then decreases. Comparing Examples 1, 9-11 with Comparative Example 1 without liquid crystal polymer A and only containing liquid crystal polymer B and Comparative Example 2 without any liquid crystal polymer, the initial glossiness of Comparative Examples 1-2 before high temperature treatment is basically the same as that of Examples 1, 9-11, but after high temperature treatment, the glossiness of Examples 1, 9-11 is significantly higher than that of Comparative Examples 1-2, so it can be confirmed that in the system of the present invention, when liquid crystal polymer A exists alone, the glossiness retention rate of the polypropylene composite material after high temperature treatment can be significantly improved, and when liquid crystal polymer A and liquid crystal polymer B exist at the same time, the glossiness retention rate of the polypropylene composite material after high temperature treatment is higher, and the use of liquid crystal polymer B alone cannot effectively improve the glossiness retention rate of the polypropylene composite material after high temperature treatment. As the content of liquid crystal polymer A in Examples 10, 1, 11, and 9 gradually increases (on the contrary, the content of liquid crystal polymer B gradually decreases), the initial impact strength first increases and then decreases, and after high temperature treatment, the impact strength retention first increases and then decreases. Comparing Examples 1, 9-11 with Comparative Example 1 without liquid crystal polymer A and only containing liquid crystal polymer B and Comparative Example 2 without any liquid crystal polymer, the impact strength and impact strength retention rate after high temperature treatment of the polypropylene composite materials of Examples 1, 9-11 are significantly higher than those of Comparative Examples 1-2. It can be seen that the addition of liquid crystal polymer A or liquid crystal polymer B can significantly improve the initial impact strength and the impact strength retention rate after high temperature treatment to a certain extent, but the single liquid crystal polymer A improves more than the single liquid crystal polymer B. When there is a single liquid crystal polymer A, the impact strength and impact strength after high temperature treatment of the polypropylene composite material meet the actual requirements. When there is a single liquid crystal polymer B alone, the impact strength of the polypropylene composite material after high temperature treatment cannot meet the actual requirements; and the inventors further found that compared with a single liquid crystal polymer A, when liquid crystal polymer A and liquid crystal polymer B are present at the same time, the impact strength and impact strength retention rate after high temperature treatment of the polypropylene composite material can be higher. Therefore, in the system of the present invention, a solution in which a single liquid crystal polymer A is present is selected, and a solution in which the liquid crystal polymer A and the liquid crystal polymer B are compounded is further preferred, so that the purpose of significantly improving the gloss retention rate and impact strength of the polypropylene composite material after high temperature treatment and the impact strength retention rate after high temperature treatment can be achieved, thereby comprehensively improving the high temperature resistance of the polypropylene composite material.

[0077] It can be seen from Examples 1-3 that by using block copolymer polypropylene, homopolymer polypropylene or random copolymer polypropylene as the matrix resin, a polypropylene composite material with good initial gloss, gloss retention after high temperature treatment, impact strength and impact strength retention after high temperature treatment can be obtained, which meets actual requirements.

[0078] As the content of styrene-acrylonitrile copolymer in Examples 5, 7, 1, 6, and 4 gradually increases (on the contrary, the content of precipitated barium sulfate gradually decreases), the initial glossiness of the polypropylene composite materials in Examples 1 and 4-7 is basically the same, and the glossiness retention rate after high temperature treatment, the initial impact strength, and the impact strength retention rate after high temperature treatment all tend to increase first and then decrease. Comparing Examples 1 and 4-7 with the case of Comparative Example 4 without brightener, it can be seen that the brightener in the system of the present invention can significantly improve the initial glossiness, glossiness retention rate, and impact strength retention rate after high temperature treatment, and when the scheme of styrene-acrylonitrile copolymer and precipitated barium sulfate is adopted, on the basis of further improving the initial glossiness, glossiness retention rate after high temperature treatment, and impact strength retention rate after high temperature treatment of the polypropylene composite material, the initial impact strength can also be significantly improved, achieving the effect of improving the comprehensive performance of the polypropylene composite material. Compared with Example 1 and Comparative Example 3, the lack of nucleating agent in Comparative Example 3 will significantly reduce the glossiness retention rate, initial impact strength, and impact strength retention rate after high temperature treatment of the polypropylene composite material. And it can be observed from the comparative examples 1 and 4 that in the system of the present invention, the liquid crystal resin A, the nucleating agent and the brightener can synergistically improve the glossiness and impact strength retention rate after high temperature treatment. In summary, the components in the polypropylene composite material of the present invention work together to make it have good high temperature resistance, wherein the glossiness and impact strength retention rates of the polypropylene composite material after high temperature treatment are both above 80%.

[0079] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. A polypropylene composite material, characterized in that: The invention comprises the following components in parts by weight: 100 parts of polypropylene, 12-26 parts of liquid crystal polymer A, 0.05-0.5 parts of nucleating agent and 0.4-1.6 parts of brightening agent; the thermal deformation temperature of the liquid crystal polymer A is ≤210°C.

2. The polypropylene composite material according to claim 1, characterized in that: The polypropylene composite material further comprises 5-10 parts by weight of liquid crystal polymer B, and the thermal deformation temperature of the liquid crystal polymer B is greater than 210°C.

3. The polypropylene composite material according to claim 2, characterized in that: The thermal deformation temperature of the liquid crystal polymer B is 250-315°C.

4. The polypropylene composite material according to claim 1, characterized in that: The polypropylene resin includes at least one of homopolymer polypropylene, random copolymer polypropylene and block copolymer polypropylene; preferably, the polypropylene has a melt mass flow rate of 2.5-30 g / 10 min when tested at 230° C. and 2.16 kg load according to ISO1133-2011.

5. The polypropylene composite material according to claim 1, characterized in that: The brightener comprises at least one of barium sulfate and a copolymer containing acrylonitrile; preferably, the brightener comprises barium sulfate and a copolymer containing acrylonitrile, and more preferably, the mass ratio of the barium sulfate to the copolymer containing acrylonitrile is 1:(1.5-9).

6. The polypropylene composite material according to claim 1, characterized in that: The nucleating agent includes at least one of an α-nucleating agent and a β-nucleating agent.

7. The polypropylene composite material according to claim 6, characterized in that: The nucleating agent includes an α-nucleating agent and a β-nucleating agent; preferably, the mass ratio of the α-nucleating agent to the β-nucleating agent is (1-3):

1.

8. The polypropylene composite material according to claim 1, characterized in that: The polypropylene further comprises at least any one of the following components in parts by weight: 0.05-0.3 parts of lubricant, 0.01-1 parts of flame retardant, 0.01-1 parts of antioxidant, and 0.01-1 parts of antistatic agent.

9. A method for preparing the polypropylene composite material according to any one of claims 1 to 8, characterized in that: The method comprises the following steps: uniformly mixing various raw materials, sequentially subjecting the raw materials to melt extrusion and granulation to obtain the polypropylene composite material.

10. Use of the polypropylene composite material according to any one of claims 1 to 8 in the preparation of household appliances.

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