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 disclosed by the invention is prepared from the following components in parts by weight: 39 to 96 parts of polypropylene, 4 to 41 parts of styrene-ethylene / butylene segmented copolymer, 4 to 36 parts of lamellar filler, 4 to 36 parts of fibrous filler, 0.09 to 0.6 part of saturated fatty acid ester, 0.9 to 3.2 parts of polysiloxane and 0.09 to 1.1 parts of auxiliaries. The lamellar filler, the fibrous filler, the saturated fatty acid ester and the polysiloxane in the polypropylene composite material can be matched with one another, so that the effects of high transparency, low glossiness and shrinking percentage are comprehensively realized, and the polypropylene composite material is more suitable for preparing automobile parts to replace PC (Polycarbonate) or PMMA (Polymethyl Methacrylate) products in the prior art; and the goals of cost reduction and light weight of automobile parts are achieved.

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 a lower density and cost than polycarbonate (PC) or polymethyl methacrylate (PMMA). If polypropylene can be used to replace PC or PMMA, the weight and cost of the product will be significantly reduced, and the purpose of lightweight and low cost will be achieved, so that PP has a wide application space in automobile door panels, pillars, auxiliary instrument panels and other parts. However, compared with PC or PMMA products, PP has worse transparency and low gloss. When polypropylene is injection molded into automobile parts or automobile accessories, the plastic feeling is too strong, which makes people feel that the product is not high-end. In addition, as an automobile part, it requires a certain rigidity and toughness, and it is necessary to overcome the high shrinkage caused by the properties of polypropylene itself to achieve the dimensional stability of the product. Generally, inorganic fillers are added to increase rigidity, and elastomers are added to increase toughness. However, both inorganic fillers and elastomer toughening agents will significantly reduce the light transmittance of the product, resulting in a further decrease in the transparency of polypropylene composite materials, and it is impossible to replace the highly transparent PC or PMMA products in the prior art. Therefore, it is still necessary to continue to develop a class of polypropylene materials that take into account the effects of dimensional stability, high transparency and low gloss, so as to further achieve the goal of lightweight and low cost of automobile parts products. Summary of the invention

[0003] In view of the problem that the polypropylene material involved in the above-mentioned prior art cannot have both dimensional stability, high transparency and low gloss, the present invention will provide a polypropylene composite material and a preparation method and application thereof.

[0004] To achieve the above purpose, the following technical solutions are specifically included:

[0005] A polypropylene composite material comprises the following components in parts by weight: 39-96 parts of polypropylene, 4-41 parts of styrene-ethylene / butylene block copolymer, 4-36 parts of lamellar filler, 4-36 parts of fibrous filler, 0.09-0.6 parts of saturated fatty acid ester and 0.9-3.2 parts of polysiloxane.

[0006] In the polypropylene composite material of the present invention, the sheet layer and the fibrous filler are used to form an interactive structure, which not only increases the rigidity and reduces the shrinkage rate of the material, but also the two types of fillers constituting the interactive structure have little negative impact on the light transmittance, thereby improving the transparency and reducing the glossiness to a certain extent; at the same time, the saturated fatty acid ester and the polysiloxane can cooperate with each other to improve the compatibility of the two types of fillers in the system with other components (especially with PP and SEBS), improve the dispersion effect of the fillers, and then improve the light transmittance of the polypropylene composite material and reduce the glossiness; in addition, after the polysiloxane is mixed with other components in the system, it cannot be completely miscible with the matrix resin, and will be dispersed in the system in the form of small particles, forming small granular aggregates on the surface of the material, which can further reduce the glossiness, and it can interact with the filler (such as the Si-O bond in the polysiloxane interacts with the -OH on the surface of the filler to generate hydrogen bonds, etc.), therefore, the sheet layer filler, the fibrous filler, the saturated fatty acid ester and the polysiloxane in the system can cooperate with each other to comprehensively achieve the purpose of high transparency, low glossiness and shrinkage rate.

[0007] Preferably, the polysiloxane is a linear polysiloxane, and specifically polyoctamethylcyclotetrasiloxane can be selected.

[0008] Preferably, the polypropylene composite material comprises the following components in parts by weight: 40-95 parts of polypropylene, 5-40 parts of styrene-ethylene / butylene block copolymer, 5-35 parts of lamellar filler, 5-35 parts of fibrous filler, 0.1-0.5 parts of saturated fatty acid ester, 1-3 parts of polysiloxane, and 0.1-1 parts of additives.

[0009] Preferably, in the polypropylene composite material, the mass percentage of the polypropylene is not less than 40%, more preferably not less than 50%, and even more preferably not less than 60%.

[0010] Preferably, the weight parts of polypropylene can be 39, 40, 50, 60, 70, 80, 90, 96 parts, etc., as well as specific points between the above points. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific points included in the range.

[0011] Preferably, the polypropylene includes homopolymer polypropylene, and the melt mass flow rate of the polypropylene measured at 230°C and 2.16Kg load conditions according to ISO1133-2011 is 10-50g / 10min, and the polypropylene melt mass flow rate can be 10, 15, 20, 25, 30, 35, 40, 45, 50g / 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.

[0012] At the above melt mass flow rate, the polypropylene composite material can maintain lower gloss and higher light transmittance, and can be better formed into products with excellent dimensional stability through injection molding.

[0013] Preferably, the mass percentage of styrene in the styrene-ethylene / butylene block copolymer is 13-20%, and the mass percentage of styrene in the styrene-ethylene / butylene block copolymer can be 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 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.

[0014] Preferably, the styrene-ethylene / butylene block copolymer is SEBS. As a toughening elastomer, the styrene-ethylene / butylene block copolymer can increase the toughness of the material and reduce the shrinkage of the material to a certain extent. However, the styrene-ethylene / butylene block copolymer has an adverse effect on the transparency of the material. The inventors of the present invention have found that the transparency of the polypropylene composite material is better within the mass percentage range of styrene in the above styrene-ethylene / butylene block copolymer.

[0015] Preferably, the total number of carbon atoms in the saturated fatty acid ester is 9-20.

[0016] Preferably, the saturated fatty acid ester includes at least one of ethyl caprate, ethyl hexadecanoate, and octadecyl acetate.

[0017] Preferably, the lamellar filler includes at least one of montmorillonite, talc and hydrotalcite.

[0018] Preferably, the average particle size of the lamellar filler is 2-5 μm, and the average particle size of the lamellar filler can be 2, 2.5, 3, 3.5, 4, 4.5, 5 μm, 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.

[0019] The average particle size of the lamellar filler is usually measured using conventional methods, and specifically, the average particle size can be measured using a laser diffraction method.

[0020] When the lamellar and fibrous fillers form an interactive structure, the combination effect of the two affects the reflection and transmission effects of the polypropylene composite material on light. The combination effect of the two is related to the type and diameter of the lamellar filler. By selecting the above-mentioned type of lamellar filler and the diameter of the lamellar filler within the above-mentioned range, the polypropylene composite material has higher transparency, lower glossiness and shrinkage.

[0021] Preferably, the fibrous filler includes at least one of whiskers, wollastonite, boehmite and glass fiber.

[0022] Preferably, the average particle size of the fibrous filler is 4-5 μm, and the aspect ratio is 12-18. The average particle size of the fibrous filler may be 4, 4.5, 5 μm, etc., and the aspect ratio of the fibrous filler may be 12, 13, 14, 15, 16, 17, 18, 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.

[0023] The average particle size and aspect ratio of the fibrous filler are usually measured using conventional methods. Specifically, the average particle size can be measured by laser diffraction, and the aspect ratio can be measured by scanning electron microscopy.

[0024] When the flakes and fibrous fillers form an interactive structure, the combination effect of the two affects the reflection and transmission effects of the polypropylene composite material on light. The combination effect of the two is related to the type, diameter and aspect ratio of the fibrous filler. By selecting the above-mentioned type of fibrous filler and the diameter and aspect ratio of the fibrous filler within the above-mentioned range, the polypropylene composite material has higher transparency, lower gloss and shrinkage.

[0025] Preferably, the polypropylene composite material further comprises 0.09-1.1 parts of an auxiliary agent.

[0026] More preferably, the auxiliary agent includes at least one of an antioxidant and a light stabilizer.

[0027] More preferably, the antioxidant includes at least one of hindered phenols and phosphites.

[0028] Further preferably, the light stabilizer includes at least one hindered amine light stabilizer.

[0029] The present invention also includes a method for preparing the polypropylene composite material, comprising the following steps:

[0030] (1) mixing a lamellar filler, a fibrous filler, and an additive to obtain a premix;

[0031] (2) The premix and the remaining raw materials are melted, extruded, and granulated to obtain the polypropylene composite material.

[0032] Preferably, in step (1), the mixing temperature is 80-100°C.

[0033] Preferably, in step (2), the melting temperature is 180-240°C.

[0034] The present invention also provides an application of the polypropylene composite material in the preparation of automobile parts, specifically, an application of the polypropylene composite material in the preparation of automobile door panels, automobile pillars, automobile auxiliary instrument panels, and bumpers.

[0035] Compared with the prior art, the present invention has the following beneficial effects: the present invention can cooperate with each other through the lamellar filler, fibrous filler, saturated fatty acid ester and polysiloxane in the polypropylene composite material to comprehensively achieve the effects of high transparency, low gloss and shrinkage, so that the polypropylene composite material is more suitable for the preparation of automotive parts, thereby replacing the PC or PAMM products in the prior art, and achieving the goal of reducing the cost and lightweighting of automotive parts. DETAILED DESCRIPTION

[0036] In order to better illustrate the purpose, technical scheme and advantages of the present invention, the present invention will be further described below through specific examples. The test methods used in the examples and / or comparative examples are conventional methods unless otherwise specified; the materials, reagents, etc. used can be obtained from commercial channels unless otherwise specified.

[0037] Homopolymer polypropylene (PP-1): PP H9018, manufacturer: PetroChina, melt mass flow rate: 60g / 10min;

[0038] Homopolymer polypropylene (PP-2): PP PPH-T26, manufacturer: Sinopec, melt mass flow rate: 26g / 10min;

[0039] Homopolymer polypropylene (PP-3): PP HP500N, manufacturer: CNOOC Shell, melt mass flow rate: 10g / 10min;

[0040] Styrene-ethylene / butylene block copolymer (SEBS1): SEBS1657, manufacturer: Kraton, USA, styrene mass percentage is 13%;

[0041] Styrene-ethylene / butylene block copolymer (SEBS2): SEBSDX410, manufacturer: Kraton, USA, styrene mass percentage is 18%;

[0042] Styrene-ethylene / butylene block copolymer (SEBS 3): SEBS G1642 H, manufacturer: Kraton, USA, styrene mass percentage is 20%;

[0043] Flaky filler 1: talcum powder, the average particle size of the flaky layer is 3 μm, obtained by crushing and screening talcum powder with an average particle size of 6 mm, manufacturer: Lingshou County Runshan Mineral Powder Factory;

[0044] Flaky filler 2: talcum powder, the average particle size of the flaky layer is 2 μm, obtained by crushing and sieving talcum powder with an average particle size of 6 mm, manufacturer: Lingshou County Runshan Mineral Powder Factory;

[0045] Flaky filler 3: talcum powder, the average particle size of the flaky layer is 5 μm, obtained by crushing and sieving talcum powder with an average particle size of 6 mm, manufacturer: Lingshou County Runshan Mineral Powder Factory;

[0046] Flake filler 4: montmorillonite, Clay 5538, after screening, the average particle size of the flakes is 3 μm, manufacturer: Lingshou County Runshan Mineral Powder Factory;

[0047] Fibrous filler 1: potassium titanate whisker TISMO, sieved, average particle size 4 μm, aspect ratio 12, manufacturer: Otsuka Chemical Co., Ltd.

[0048] Fibrous filler 2: basic magnesium sulfate whisker WS-1S2, sieved, average particle size 5 μm, aspect ratio 13, manufacturer: Yingkou Weiske Chemical Co., Ltd.;

[0049] Fibrous filler 3: zinc oxide whisker JC-01, sieved, average particle size 4 μm, aspect ratio 14, manufacturer: Chengdu Tianyou Jingchuang Technology Co., Ltd.;

[0050] Fibrous filler 4: Wollastonite NYAD G, sieved, average particle size 4 μm, aspect ratio 14, manufacturer: Shanghai Huazhongrong Industry and Trade Co., Ltd.;

[0051] Fibrous filler 5: boehmite AF60, sieved, average particle size 4 μm, aspect ratio 15, manufacturer: Shanghai Huazhongrong Industry and Trade Co., Ltd.;

[0052] Fibrous filler 6: glass fiber ECS4F, sieved, average particle size 4 μm, aspect ratio 18, manufacturer: China Jushi Group Co., Ltd.;

[0053] Saturated fatty acid ester 1: ethyl decanoate, Jinan Zhiyuancheng Chemical Co., Ltd.;

[0054] Saturated fatty acid ester 2: hexadecanoic acid ethyl ester, Henan Xiangduo Industrial Co., Ltd.;

[0055] Saturated fatty acid ester 3: octadecyl acetate, Beijing Bailingwei Technology Co., Ltd.;

[0056] Polyoctamethylcyclotetrasiloxane: commercially available;

[0057] Auxiliary agent 1: hindered phenol antioxidant, pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, commercially available, the same one was used in the parallel examples and comparative examples;

[0058] Auxiliary agent 2: phosphite antioxidant, tris(2,4-di-tert-butylphenyl) phosphite, commercially available, the same one is used in the parallel examples and comparative examples.

[0059] Auxiliary agent 3: hindered amine light stabilizer, 2,2,6,6-tetramethyl-4-piperidinyl stearate, commercially available, the same one was used in the parallel examples and comparative examples.

[0060] Examples 1-17 and Comparative Examples 1-6

[0061] A method for preparing a polypropylene composite material comprises the following steps:

[0062] (1) According to the ratio of raw materials in Table 1-2, the lamellar filler, fibrous filler and additives are first mixed at 90° C. to obtain a premix;

[0063] (2) The premix and other raw material components are added into a twin-screw extruder, melted and extruded at 220° C., and a polypropylene composite material is obtained after granulation and cooling.

[0064] Table 1

[0065]

[0066] Table 2

[0067]

[0068]

[0069] The obtained polypropylene composite material was subjected to performance tests of transparency, glossiness and shrinkage, and the test method was as follows:

[0070] (1) Transparency: Test the light transmittance of a 2.5 mm square plate according to method B in GB / T 2410-2008, and take the average value of three tests;

[0071] (2) Glossiness: The test was conducted using a gloss meter in accordance with ASTM D532-2009. The test angle was 60°. Three test results were selected as the glossiness value. The test plate grain was Volkswagen K4T grain.

[0072] (3) Shrinkage rate: The test was conducted in accordance with ISO294-4-2001 standard. The mold size was 199.85 mm*50 mm*2 mm. The average value of 5 tests was taken as the shrinkage rate.

[0073] The test results are shown in Table 3;

[0074] Qualification standards: glossiness is 1.2-1.8, shrinkage is below 0.8%, and transmittance is above 30%.

[0075] Table 3

[0076]

[0077]

[0078] It can be seen from Example 1 and Comparative Examples 1-2 that in Example 1, a lamellar filler and a fibrous filler are compounded, and in Comparative Examples 1 and 2, either a lamellar filler or a fibrous filler is used alone in an equal amount. Both the lamellar filler and the fibrous filler have excellent stiffness enhancement properties and can significantly reduce the shrinkage of the polypropylene composite material. However, when either the lamellar filler or the fibrous filler is used alone, the filler has a significant negative impact on the transmittance. When both the lamellar filler and the fibrous filler are present, not only can the polypropylene composite material maintain a low shrinkage, but also an interactive structure is formed by using the lamellar filler and the fibrous filler, and the filler has a small negative impact on the transmittance, while achieving the purpose of improving transparency and reducing gloss. At the same time, it can be seen from Example 1 and Comparative Examples 3-5 that Example 1 includes saturated fatty acid esters and polyoctamethylcyclotetrasiloxane, and Comparative Examples 3-5 lack any one or two of saturated fatty acid esters and polyoctamethylcyclotetrasiloxane. The system lacks saturated fatty acid esters and polyoctamethylcyclotetrasiloxane. Even if there are both lamellar and fibrous fillers, the compatibility of these two types of fillers with PP and SEBS is poor, resulting in poor dispersion of the filler in the system, and the light transmittance of the material cannot be significantly improved, and a higher light transmittance cannot be achieved. Saturated fatty acid esters and polyoctamethylcyclotetrasiloxane can synergistically improve the compatibility of the two types of fillers with other components in the system, improve the dispersion effect of the filler, and thereby improve the light transmittance of the polypropylene composite material and reduce the gloss; at the same time, polyoctamethylcyclotetrasiloxane is easy to form small granular aggregates on the surface of the material, which can further reduce the gloss, and it can interact with the surface of the filler. Therefore, the lamellar filler, fibrous filler, saturated fatty acid ester and polyoctamethylcyclotetrasiloxane in the system can cooperate with each other to comprehensively achieve high transparency, low gloss and shrinkage.

[0079] The compatibility of saturated fatty acid esters and polyoctamethylcyclotetrasiloxane with polypropylene resin is poor. When the content of saturated fatty acid esters or polyoctamethylcyclotetrasiloxane is low, the dispersion or action ability of fillers is insufficient, and the light transmittance cannot be significantly improved or the gloss cannot be reduced. It can be seen from Example 1 and Comparative Examples 6-7 that when the amount of saturated fatty acid esters or polysiloxane added is too much, the compatibility of saturated fatty acid esters or polyoctamethylcyclotetrasiloxanes themselves with the polypropylene matrix leads to uneven dispersion of components in the system, which has an adverse effect on the gloss, shrinkage and light transmittance of the polypropylene composite material.

[0080] It can be seen from Examples 1-3 that, as the melt mass flow rate of PP decreases, the glossiness of the polypropylene composite material gradually decreases, the light transmittance gradually increases, and the shrinkage rate remains basically unchanged.

[0081] It can be seen from Examples 1, 4-5 that the styrene-ethylene / butylene block copolymer has excellent toughening properties, which can make the polypropylene composite material have a good shrinkage rate. At the same time, with the increase of the styrene content in SEBS, the shrinkage rate and light transmittance of the polypropylene composite material will gradually decrease, but the effect on the gloss of the polypropylene composite material is not significant.

[0082] It can be seen from Examples 1, 6-7, 8, 9-10, and 11-13 that in the polypropylene composite material, when the sheet layer and the fibrous filler form an interactive structure, the coordination effect of the two affects the reflection and transmission effect of the polypropylene composite material on light. Among them, in Examples 6 (2μm), 1 (3μm) and 7 (5μm), the average particle size of talcum powder gradually increases, the gloss gradually decreases, the shrinkage gradually increases, and the light transmittance first increases and then decreases; it can be seen from Examples 1 and 9-10 that increasing the diameter or aspect ratio of the fibrous filler has little effect on the gloss of the polypropylene composite material, but it will increase the shrinkage and reduce the light transmittance.

[0083] It can be seen from Examples 1 and 14-15 that as the number of carbon atoms in the saturated fatty acid ester alkane increases, the gloss and transmittance of the polypropylene composite material decrease, and the shrinkage first increases and then remains unchanged. Selecting the number of carbon atoms in the saturated fatty acid ester alkane to be 9-20 can maintain a lower gloss and a higher transmittance of the polypropylene composite material.

[0084] It can be seen from Examples 1 and 16-17 that the amount of each raw material component has an effect on the transparency, glossiness and shrinkage of the polypropylene composite material. Within the range of each raw material component required by the present invention, the transparency, glossiness and shrinkage of the polypropylene composite material of the present invention meet the requirements, meet actual needs, and are more conducive to application in automotive parts.

[0085] 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 composition comprises the following components in parts by weight: Polypropylene 39-96 parts, styrene-ethylene / butylene block copolymer 4-41 parts, lamellar filler 4-36 parts, fibrous filler 4-36 parts, saturated fatty acid ester 0.09-0.6 parts, polysiloxane 0.9-3.2 parts.

2. The polypropylene composite material according to claim 1, characterized in that The saturated fatty acid ester includes at least one of ethyl caprate, ethyl hexadecanoate, and octadecyl acetate.

3. The polypropylene composite material according to claim 1, characterized in that: The lamellar filler includes at least one of montmorillonite, talc and hydrotalcite.

4. The polypropylene composite material according to claim 1, characterized in that: The average particle size of the lamellar filler is 2-5 μm.

5. The polypropylene composite material according to claim 1, characterized in that: The fibrous filler includes at least one of whiskers, wollastonite, boehmite and glass fiber.

6. The polypropylene composite material according to claim 1, characterized in that: The average particle size of the fibrous filler is 4-5 μm, and the aspect ratio is 12-18.

7. The polypropylene composite material according to claim 1, characterized in that: The melt mass flow rate of the polypropylene measured at 230° C. and 2.16 kg load according to ISO1133-2011 is 10-50 g / 10 min.

8. The polypropylene composite material according to claim 1, characterized in that: Include at least one of the following: The mass percentage of styrene in the styrene-ethylene / butylene block copolymer is 13-20%; The polypropylene composite material further comprises 0.09-1.1 parts of auxiliary agent.

9. A method for preparing the polypropylene composite material according to any one of claims 1 to 8, characterized in that: The steps include: (1) mixing a lamellar filler, a fibrous filler, and an additive to obtain a premix; (2) The premix and the remaining raw materials are melted, extruded and granulated 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 automobile parts.

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