Polypropylene composite material, and preparation method and application thereof

Abstract

The application discloses a kind of polypropylene composite material and its preparation method and application, belong to high polymer material technical field.Polypropylene composite material is prepared by the following components by weight fraction: polypropylene resin 40~80 parts;Short glass fiber 10~30 parts;Modified hollow glass microsphere 10~30 parts;Processing aid 0.4~1.2 parts;Wherein, the modified hollow glass microsphere is made of low melting point polybutylene modified hollow glass microsphere.The synergy of the modified hollow glass microsphere and glass fiber prepared by low melting point polybutylene in advance is realized simultaneously, and low density and high flexural modulus are realized.The density of the polypropylene composite material of the application is not more than 0.988g / cm 3 , as low as 0.921g / cm 3 , and the flexural modulus can reach more than 3500MPa, up to 4500MPa.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of high polymer materials, more particularly to a polypropylene composite material and a preparation method and application thereof. BACKGROUND

[0002] Polypropylene materials have low density, chemical resistance and excellent cost performance, and are widely used in all parts of automotive interior and exterior.

[0003] With the development of lightweight demand for new energy materials, the application of polypropylene materials in automobiles has attracted more widespread attention, so polypropylene needs to be modified to meet different performance requirements. The common modification method is to add glass fibers, talc, calcium carbonate, wollastonite, whiskers and other materials to enhance its scratch resistance, rigidity and creep resistance. However, the above processing methods of polypropylene composite will cause the density to increase, which does not meet the development trend of automobile lightweight.

[0004] Hollow glass microspheres are used in many material fields, such as fillers for thermal insulation materials, cable insulation material fillers, etc. Hollow glass microsphere products have high dimensional stability, do not produce orientation and warping phenomena. However, the use of hollow glass microspheres in modified plastics causes damage to hollow glass microspheres due to the shearing of the twin-screw, especially in glass fiber reinforced polypropylene materials, the density reduction does not achieve the ideal effect.

[0005] The prior art discloses a polypropylene composite material, which comprises 44-75 parts of polypropylene with a degree of isotacticity greater than 90%, 10-20 parts of low isotactic polypropylene with a degree of isotacticity of 30-60%, 10-30 parts of hollow glass microspheres, 13 parts of thermoplastic hollow polymer microspheres and 3-4 parts of processing aids. After introducing a certain proportion of low isotactic polypropylene into the base material, the low isotactic polypropylene can quickly coat the surface of the hollow glass microspheres, avoiding damage to the hollow glass microspheres due to extrusion. Moreover, the density of the polypropylene composite material is lower and more lightweight. However, in its system, the damage to the hollow glass microspheres will increase after glass fiber reinforcement, although the modulus can be improved, the density will increase, so it is difficult to simultaneously achieve low density and high flexural modulus. SUMMARY

[0006] The technical problem to be solved by the present application is to overcome the defects and deficiencies of the prior art polypropylene that is difficult to simultaneously achieve low density and high flexural modulus, and to provide a polypropylene composite material that simultaneously achieves low density and high flexural modulus through the synergistic effect of specific modified hollow glass microspheres and chopped glass fibers.

[0007] Still another object of the present application is to provide a preparation method of the polypropylene composite material.

[0008] Another object of the present application is to provide an application of the polypropylene composite material in preparing an automotive interior or an automotive exterior.

[0009] Another object of the present application is to provide an automotive part.

[0010] The above objects of the present application are achieved by the following technical solutions.

[0011] A polypropylene composite material is prepared from the following components in parts by weight:

[0012]

[0013] The modified hollow glass microbeads are made of low-melting-point polybutylene modified hollow glass microbeads, the melting point of the low-melting-point polybutylene is less than or equal to 100℃, the low-melting-point polybutylene modified hollow glass microbeads have a core-shell structure, and the low-melting-point polybutylene is coated on the surface of the glass microbeads.

[0014] The low-melting-point polybutylene is used to prepare the modified hollow glass microbeads in advance to realize the synergistic effect of the low-melting-point polybutylene and the short-cut glass fibers, and to achieve low density and high flexural modulus at the same time.

[0015] The melting point of the low-melting-point polybutylene directly affects the density of the material, and a too high melting point will affect the coating effect of the polybutylene on the glass microbeads, which is not conducive to reducing the density.

[0016] Preferably, the weight ratio of the short-cut glass fibers to the modified hollow glass microbeads is (0.3-3):1.

[0017] Preferably, the weight ratio of the short-cut glass fibers to the modified hollow glass microbeads is (0.5-2.2):1.

[0018] Optionally, in the modified hollow glass microbeads, the weight ratio of the low-melting-point polybutylene to the hollow glass microbeads is (0.2-1.6):1.

[0019] Preferably, in the modified hollow glass microbeads, the weight ratio of the low-melting-point polybutylene to the hollow glass microbeads is (0.6-1):1.

[0020] Optionally, the melting point of the low-melting-point polybutylene is 88-96℃, and the test standard is ISO 11357-3-2011.

[0021] Preferably, the melting point of the low-melting-point polybutylene is 90-94℃, and the test standard is ISO 11357-3-2011.

[0022] Optionally, the low-melting-point polybutylene has a melt mass-flow rate of 40-800 g / 10 min, tested according to GB / T 3682.1-2018 at 190°C and 2.16 kg.

[0023] Preferably, the low-melting-point polybutylene has a melt mass-flow rate of 40-100 g / 10 min, tested according to GB / T 3682.1-2018 at 190°C and 2.16 kg.

[0024] Optionally, the hollow glass microspheres have an average particle size of 20-50 μm.

[0025] Preferably, the hollow glass microspheres have an average particle size of 20-30 μm.

[0026] Preferably, the hollow glass microspheres have an apparent density of 0.35-0.64 g / cm 3 .

[0027] Preferably, the hollow glass microspheres have an apparent density of 0.38-0.46 g / cm 3 .

[0028] Optionally, the chopped glass fibers have an average retention length of 400-600 μm. The average retention length is tested according to ISO 22314-2006.

[0029] Preferably, the chopped glass fibers have an average retention length of 530-550 μm. The average retention length is tested according to ISO 22314-2006.

[0030] Preferably, the chopped glass fibers have an average diameter of 12-15 μm.

[0031] Optionally, the polypropylene resin has a melt mass-flow rate of 10-150 g / 10 min, tested according to GB / T 3682.1-2018 at 230°C and 2.16 kg.

[0032] Preferably, the polypropylene resin has a melt mass-flow rate of 30-100 g / 10 min, tested according to GB / T 3682.1-2018 at 230°C and 2.16 kg.

[0033] Preferably, the polypropylene resin is a homopolymer polypropylene.

[0034] Preferably, the processing aid comprises an antioxidant and / or a lubricant.

[0035] The antioxidant is one or more of hindered phenolic antioxidant, phosphite antioxidant or phosphite antioxidant.

[0036] Optionally, the hindered phenolic antioxidant is one or more of totally hindered phenolic antioxidant 1010, 1076 or AO-330.

[0037] Optionally, the phosphite antioxidant is one or more of phosphite 168, 626 or PEP-36.

[0038] Optionally, the weight ratio of the hindered phenolic antioxidant and the phosphite antioxidant is (0.5-1.0):1.

[0039] Optionally, the weight ratio of the hindered phenolic antioxidant and the phosphite antioxidant is (0.8-1.0):1.

[0040] The antioxidant can improve the oxidation resistance of the polypropylene composite material.

[0041] The lubricant can improve the lubrication effect of the polypropylene composite material.

[0042] Preferably, the lubricant is ethylene bis-stearamide.

[0043] Preferably, the weight fraction of the antioxidant is 0.2-2 parts; and the weight fraction of the lubricant is 0.2-1.0 parts.

[0044] The application also protects a preparation method of the polypropylene composite material, comprising the following steps: mixing the components, melt extruding through a double-screw extruder, granulating, and drying to obtain the polypropylene composite material.

[0045] The preparation method of the polypropylene composite material of the application can be prepared by the following steps:

[0046] S1. mixing and extruding the low-melting-point polybutene resin and the hollow glass microbeads to obtain modified hollow glass microbeads;

[0047] S2. mixing the polypropylene resin, the antioxidant and the lubricant, adding them into the extruder from the main feeding port of the extruder, adding the chopped glass fiber and the modified hollow glass microbeads into the extruder from the side feeding port of the extruder, melt extruding, granulating, and drying to obtain the polypropylene composite material.

[0048] In S2, the chopped glass fiber is added into the extruder from the fourth to the sixth screw of the extruder.

[0049] The modified hollow glass microbeads are added into the extruder from the seventh to the ninth screw of the extruder.

[0050] Preferably, the extruder is a double-screw extruder.

[0051] In the present application, by controlling the feeding time of the chopped glass fiber and the modified hollow glass microsphere, the average retention length of the glass fiber in the polypropylene composite material is controlled, and the breakage of the hollow glass microsphere in the polypropylene system is reduced, so that low density and high flexural modulus can be realized at the same time.

[0052] The polypropylene composite material prepared by the present application has low density and high flexural modulus, and can be widely used in the preparation of plastic products. The present application particularly protects the use of the polypropylene composite material in the preparation of automobile parts, especially automobile interiors and / or automobile exteriors.

[0053] Alternatively, the automobile exterior can be a bumper support, a tailgate inner panel, etc.

[0054] An automobile part prepared by injection molding of the polypropylene composite material according to any one of the above.

[0055] Preferably, the automobile part is an automobile interior.

[0056] The automobile interior is a door panel, an instrument panel skeleton, etc.

[0057] Compared with the prior art, the present application has the following advantages:

[0058] The polypropylene composite material of the present application comprises polypropylene resin; chopped glass fiber; modified hollow glass microsphere; and processing aid. The present application realizes low density and high flexural modulus at the same time by preparing the synergistic effect of the modified hollow glass microsphere and the chopped glass fiber in advance with low melting point polybutene. DETAILED DESCRIPTION

[0059] The present application will be further described below in conjunction with specific embodiments, but the embodiments do not limit the present application in any form. Unless otherwise specified, the raw materials used in the embodiments of the present application are commercially available raw materials.

[0060] The raw materials used in the embodiments and comparative examples of the present application are shown in Table 1 below.

[0061] Table 1

[0062]

[0063] The above self-made chopped glass fiber 3 and self-made chopped glass fiber 4 are purchased Taishan continuous fiber EDR300-T738, and then cut into 9.0mm and 2.0mm length of chopped fiber using scissors.

[0064] The preparation method of the modified hollow glass microsphere is as follows:

[0065] The low-melting-point polybutene resin and the hollow glass microbeads are mixed, extruded and granulated in a single-screw extruder to obtain modified hollow glass microbeads; the machine table setting temperature is 160°C, and the screw rotation speed is 250 revolutions per minute.

[0066] The composition of the modified hollow glass microbeads is shown in Table 2 below.

[0067] Table 2

[0068] Modified hollow glass microbeads 1 Hollow glass microbeads 1 Low-melting polybutylene 1 The weight ratio of low-melting polybutylene to hollow glass microbeads is 1 Modified hollow glass microbeads 2 Hollow glass microbeads 2 Low-melting polybutylene 1 The weight ratio of low-melting polybutylene to hollow glass microbeads is 1 Modified hollow glass microbeads 3 Hollow glass microbeads 3 Low-melting polybutylene 1 The weight ratio of low-melting polybutylene to hollow glass microbeads is 1 Modified hollow glass microbeads 4 Hollow glass microbeads 1 Low-melting polybutylene 2 The weight ratio of low-melting polybutylene to hollow glass microbeads is 1 Modified hollow glass microbeads 5 Hollow glass microbeads 1 High-melting polybutylene 3 The weight ratio of high-melting polybutylene to hollow glass microbeads is 1 Modified hollow glass microbeads 6 Hollow glass microbeads 1 Low-melting polybutylene 1 The weight ratio of low-melting polybutylene to hollow glass microbeads is 0.2 Modified hollow glass microbeads 7 Hollow glass microbeads 1 Low-melting polybutylene 1 The weight ratio of low-melting polybutylene to hollow glass microbeads is 0.6 Modified hollow glass microbeads 8 Hollow glass microbeads 1 Low-melting polybutylene 1 The weight ratio of low-melting polybutylene to hollow glass microbeads is 1.6 Modified hollow glass microbeads 9 Hollow glass microbeads 1 Low-melting polypropylene The weight ratio of low-melting polypropylene to hollow glass microbeads is 1

[0069] Examples 1-21

[0070] A polypropylene composite material is prepared from the following components in parts by weight: polypropylene resin; chopped glass fiber; modified hollow glass microbeads; lubricant; antioxidant.

[0071] The specific content of each component is shown in Table 3 below.

[0072] Table 3 Composition of polypropylene composite material of each example (in parts by weight)

[0073] Component 1 2 3 4 5 Polypropylene resin 1 59.3 40 80 54.3 59.3 Chopped glass fiber 1 20 30 10 15 27 Modified hollow glass microbeads 1 20 30 10 30 13 Antioxidant 0.4 2 0.2 0.4 0.4 Lubricant 0.3 1 0.2 0.3 0.3

[0074] Table 3 (continued)

[0075]

[0076]

[0077] Table 3 (continued)

[0078] Component 14 15 16 17 18 19 20 21 22 Polypropylene resin 1 59.3 59.3 59.3 59.3 59.3 59.3 59.3 59.3 59.3 Chopped glass fiber 1 20 20 20 20 20 20 10 30 20 Modified hollow glass microbeads 1 30 10 20 Modified hollow glass microbeads 2 20 Modified hollow glass microbeads 3 20 Modified hollow glass microbeads 4 20 Modified hollow glass microbeads 6 20 Modified hollow glass microbeads 7 20 Modified hollow glass microbeads 8 20 Antioxidant 0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.4 Lubricant 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3

[0079] The preparation method of the polypropylene composite material described above comprises the following steps:

[0080] The polypropylene resin, antioxidant and lubricant are added to a high-speed mixer and mixed for 3 minutes, then added to a twin-screw extruder from the main feeding port for melt mixing and dispersion, the chopped glass fiber is added to the twin-screw extruder from the side feeding port, the modified hollow glass microbeads are added to the twin-screw extruder from the side feeding port, and the polypropylene composite material is obtained after melt extrusion, granulation and drying;

[0081] The length-diameter ratio of the twin-screw extruder is 40:1, the twin-screw extruder has a total of 10 screw barrels, the screw rotation speed is 350 revolutions per minute, and the processing temperatures from the feeding port to the die head are 100°C, 180°C, 180°C, 180°C, 180°C, 180°C, 180°C, 180°C, 180°C and 180°C, respectively.

[0082] The chopped glass fiber is added to the twin-screw extruder from the fifth screw barrel.

[0083] The modified hollow glass microbeads are added into the double screw extruder at the eighth screw cylinder.

[0084] Example 22

[0085] A polypropylene composite material, the formula is the same as that of Example 1, and the difference from Example 1 is the preparation method:

[0086] The polypropylene resin, the antioxidant and the lubricant are added into the high-speed mixer and mixed for 3 minutes, and then added into the double screw extruder from the main feeding port of the double screw extruder for melt mixing and dispersion, the chopped glass fiber is added into the double screw extruder from the side feeding port of the double screw extruder, the modified hollow glass microbeads are added into the double screw extruder from the side feeding port of the double screw extruder, and the polypropylene composite material is obtained after melt extrusion, granulation and drying.

[0087] The length-diameter ratio of the double screw extruder is 40:1, the double screw extruder has 10 screw cylinders, the screw rotation speed is 350 revolutions per minute, and the processing temperatures from the feeding port to the die head are 100℃, 180℃, 180℃, 180℃, 180℃, 180℃, 180℃, 180℃, 180℃ and 180℃, respectively.

[0088] The chopped glass fiber is added into the double screw extruder at the eighth screw cylinder.

[0089] The modified hollow glass microbeads are added into the double screw extruder at the fifth screw cylinder.

[0090] Comparative Example 1

[0091] A polypropylene composite material, which is different from Example 1 in that no glass fiber and modified hollow glass microbeads 1 are added.

[0092] The preparation method of the polypropylene composite material is the same as that of Example 1, and details are not repeated here.

[0093] Comparative Example 2

[0094] A polypropylene composite material, prepared from the following components by weight fraction: polypropylene resin 1; chopped glass fiber 1; low-melting-point polybutene 1; hollow glass microbeads 1; lubricant; antioxidant. The amount of each component is the same as that of Example 1.

[0095] The preparation method of the polypropylene composite material is basically the same as that of Example 1, and the difference is that:

[0096] The low-melting-point polybutene 1 and the hollow glass microbeads 1 are added into the double screw extruder from the side feeding port of the double screw extruder.

[0097] The low-melting-point polybutene 1 and the hollow glass microbeads 1 are added into the double screw extruder at the eighth screw cylinder.

[0098] Comparative Examples 3-7

[0099] A polypropylene composite material was prepared from the following components in parts by weight: polypropylene resin; chopped glass fiber; modified hollow glass microsphere; lubricant; antioxidant.

[0100] The specific content of each component is shown in Table 4 below.

[0101] Table 4 Composition of polypropylene composite material of each comparative example (in parts by weight)

[0102] Component 3 4 5 6 7 Polypropylene resin 1 59.3 59.3 59.3 59.3 59.3 Chopped glass fiber 1 20 0 40 20 Modified hollow glass microbeads 1 80 40 0 Modified hollow glass microbeads 9 20 Modified hollow glass microbeads 5 20 Antioxidant 0.4 0.4 0.4 0.4 0.4 Lubricant 0.3 0.3 0.3 0.4 0.3

[0103] The preparation method of the polypropylene composite material was the same as that of Example 1.

[0104] Results detection

[0105] The polypropylene composite materials of each example and comparative example were tested according to the following methods:

[0106] (1) Density: Standard: ISO-1183-2006; 23℃ / 50% humidity.

[0107] (2) Flexural modulus: Standard: ISO-178-2006; 23℃ / 50% humidity.

[0108] (3) Average retention length of glass fiber: Standard: ISO 22314-2006, unit: μm.

[0109] The specific test results of the polypropylene composite materials of each example are shown in Table 5 below:

[0110] Table 5

[0111]

[0112] Table 5 (continued)

[0113]

[0114]

[0115] The specific test results of the polypropylene composite materials of each comparative example are shown in Table 6 below:

[0116] Table 6

[0117] Comparative example 1# 2# 3# 4# 5# 6# 7# Density / g / cm 3 ]] 0.900 0.997 0.968 0.856 1.21 1.034 1.022 Flexural modulus / MPa 1900 4300 3450 3000 6000 4450 4450 Glass fiber retention length / 525 532 / 544 521 523

[0118] It can be seen from the above data that the polypropylene composite material of the application realizes low density and high flexural modulus through the synergistic effect of the low-melting-point polybutene in advance preparing the modified hollow glass microbeads and the short-cut glass fibers. 3 , and the flexural modulus can be as high as 4500 MPa. 3 , and the flexural modulus can be as high as 4500 MPa.

[0119] It can be seen from Comparative Example 1 that the flexural modulus of the material is too low without adding the short-cut carbon fibers and the modified hollow glass microbeads 1, which cannot meet the requirements.

[0120] It can be seen from Comparative Example 2 that the low-melting-point polybutene 1 and the hollow glass microbeads 1 are not pre-reacted to prepare the modified hollow glass microbeads, the density of the material is too high, and the density reduction effect is not good.

[0121] It can be seen from Comparative Example 3 that the amount of the modified hollow glass microbeads is too much, the density of the material is not obviously reduced, and the modulus is lower than 3500 MPa.

[0122] It can be seen from Comparative Example 4 that only the modified hollow glass microbeads are added without adding the short-cut glass fibers, which can realize low density, but the modulus of the material is lower than 3500 MPa.

[0123] It can be seen from Comparative Example 5 that only the short-cut glass fibers are added without adding the modified hollow glass microbeads, which cannot realize low density.

[0124] It can be seen from Comparative Example 6 that the modified hollow glass microbeads are made of low-melting-point polypropylene modified hollow glass microbeads, and under the same processing process, the low-melting-point polypropylene modified master batch cannot realize low density.

[0125] It can be seen from Example 1, Example 4 and Example 5, Example 20 and Example 21 that the smaller the weight ratio of the short-cut glass fibers and the modified hollow glass microbeads, the lower the density of the material.

[0126] It can be seen from Example 1, Example 6 to Example 10 that when the melt mass flow rate of the polypropylene resin is 30-60 g / 10 min, the density of the material is lower, and when the melt index is slightly higher or lower, the density will be increased.

[0127] It can be seen from Example 1, Example 11 to Example 13 that the average retention length of the short-cut fibers is 530-550 μm, which is more conducive to reducing the density.

[0128] It can be seen from Example 1, Example 14 to Example 15 that the smaller the average particle size of the hollow glass microbeads, the more conducive to reducing the density.

[0129] As can be seen from Examples 1, 16 and Comparative Example 7, the optimal melting point of low-melting-point polybutene is 90-94°C. When the melting point is higher than 100°C, the density becomes too high.

[0130] As can be seen from Examples 1 and 17 to 19, when the weight ratio of low-melting-point polybutene to hollow glass microspheres is (0.6 to 1): 1, the material has a lower density and a higher modulus.

[0131] As can be seen from Examples 1 and 22, the feeding method in Example 1, compared to the conventional addition process of chopped glass fibers and modified hollow glass microspheres in Example 24, is more conducive to achieving low density and high modulus.

[0132] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A polypropylene composite material, characterized in that, By weight, it includes the following components: 40-80 parts of polypropylene resin; 10-30 parts of chopped glass fiber; 10-30 parts of modified hollow glass microspheres; Processing aids: 0.4-1.2 parts; The modified hollow glass microspheres are made of low-melting-point polybutene-modified hollow glass microspheres. The low-melting-point polybutene has a melting point of 88℃~94℃ and the testing standard is ISO 11357-3-2011. The low-melting-point polybutene-modified hollow glass microspheres have a core-shell structure, and the low-melting-point polybutene is coated on the surface of the glass microspheres.

2. The polypropylene composite material as described in claim 1, characterized in that, The weight ratio of the chopped glass fibers to the modified hollow glass microspheres is (0.5~3):

1.

3. The polypropylene composite material as described in claim 1, characterized in that, In the modified hollow glass microspheres, the weight ratio of the low-melting-point polybutene to the hollow glass microspheres is (0.2~1.6):

1.

4. The polypropylene composite material as described in claim 1, characterized in that, The low-melting-point polybutene has a melting point of 90℃~94℃ and a melt mass flow rate of 40~800g / 10min. The test standard is GB / T 3682.1-2018, and the test conditions are 190℃ and 2.16kg.

5. The polypropylene composite material as described in claim 1, characterized in that, The hollow glass microspheres have an average particle size of 20~50μm.

6. The polypropylene composite material as described in claim 1, characterized in that, The average retained length of the chopped glass fibers is 400-600 μm, and the average diameter of the chopped glass fibers is 12-15 μm.

7. The polypropylene composite material as described in claim 1, characterized in that, The melt flow rate of the polypropylene resin is 10-150 g / 10 min, the test standard is GB / T 3682.1-2018, and the test conditions are 230℃ and 2.16 kg.

8. The polypropylene composite material as described in claim 1, characterized in that, The processing aids include antioxidants and / or lubricants; the antioxidants are hindered phenolic antioxidants and / or phosphite antioxidants; the lubricants are ethylene bis-stearamides; the antioxidants are present in an amount of 0.2 to 2 parts by weight; the lubricants are present in an amount of 0.2 to 1.0 parts by weight.

9. A method for preparing the polypropylene composite material according to any one of claims 1 to 8, characterized in that, Includes the following steps: S1. Low-melting-point polybutene resin and hollow glass microspheres are mixed and extruded to obtain modified hollow glass microspheres; S2. Mix polypropylene resin, antioxidant and lubricant, and feed into the extruder through the main feed port of the extruder. Add chopped glass fiber and modified hollow glass microspheres into the extruder through the side feed port of the extruder respectively. After melt extrusion, granulation and drying, the polypropylene composite material is obtained. In S2, chopped glass fibers are added to the extruder in the fourth to sixth screw sections; The modified hollow glass microspheres are added to the extruder in the seventh to ninth screw sections.

10. The use of the polypropylene composite material according to any one of claims 1 to 8 in the preparation of automotive interior or exterior materials.

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