Polypropylene composite material, and preparation method and application thereof

Abstract

The application discloses a polypropylene composite material and a preparation method and application thereof, and belongs to the technical field of high polymer materials. The polypropylene composite material with high impact strength, high transparency and excellent low-temperature toughness is prepared by using the first polypropylene with a certain melt index, the second polypropylene, a polypropylene-based elastomer toughening agent and a processing aid. The properties of the obtained polypropylene composite material are close to the level of transparent ABS material, and the polypropylene composite material has the advantages of low cost and food-grade application, is suitable for fields such as household appliances, medical devices and commodity packaging, and has a good market application prospect.

Description

Technical Field

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

[0002] Polypropylene (PP) is a thermoplastic polymer prepared by polymerization of propylene monomers. It possesses characteristics such as low density, abundant raw materials, low cost, non-toxicity, and low odor, and exhibits excellent chemical resistance. Due to these advantages, PP has been widely used in various fields, including household appliances, kitchenware, bathroom products, automotive manufacturing, and packaging. In the small household appliance sector, some transparent water tanks typically require materials with good impact resistance to prevent cracking upon drop. Previously, only transparent ABS and PC materials were generally used. However, compared to PP, these materials have poorer weather resistance, higher cost, and are unsuitable for food-grade applications. Therefore, modifying PP to replace ABS and PC has become a research hotspot.

[0003] Traditionally used PP homopolymer materials have relatively low impact strength, and due to their high crystallinity, they are typically accompanied by low light transmittance and high haze, which limits the use of PP in certain applications. To improve the toughness of PP materials, researchers have developed copolymer PP materials, enhancing their impact performance by adding nucleating agents or introducing a second monomer during the polymerization process. However, even with these methods that improve transparency to levels approaching those of ABS materials, the resulting materials still do not perform as well as ABS in terms of impact resistance.

[0004] Existing technology discloses a high-toughness, high-stability polypropylene composite material modified with polypropylene, nucleating agent, glass fiber, toughening agent, and other additives. The toughening agent is an ethylene-octene copolymer or an ethylene-propylene copolymer. However, the raw materials are complex, and there is insufficient data support. There is no research on the transparency of the material, which limits its application scope.

[0005] Therefore, developing a polypropylene composite material that combines high impact strength, high transparency, and excellent low-temperature toughness is of great research significance and application value. Summary of the Invention

[0006] To address the challenge of achieving both high impact strength and high transparency in existing polypropylene composite materials, the primary objective of this invention is to provide a polypropylene composite material that combines high and low melt flow index polypropylene, a toughening agent polypropylene elastomer, and processing aids through comprehensive modification. The resulting polypropylene composite material exhibits high impact strength, high transparency, and excellent low-temperature toughness.

[0007] Another object of the present invention is to provide a method for preparing the above-mentioned polypropylene composite material.

[0008] Another object of the present invention is to provide the application of the above-mentioned polypropylene composite material in the manufacture of household appliances, medical devices and commodity packaging.

[0009] Another object of the present invention is to provide the application of the above-mentioned polypropylene composite material in the preparation of vacuum cleaner water tanks, floor scrubber water tanks, garment steamer water tanks and food packaging.

[0010] To achieve the above-mentioned objectives, the present invention adopts the following technical solution:

[0011] A polypropylene composite material comprising the following components in parts by weight: 40-60 parts of first polypropylene, 30-50 parts of second polypropylene, 10-25 parts of toughening agent, and 1-6 parts of processing aid.

[0012] Wherein, both the first polypropylene and the second polypropylene are ethylene-propylene random copolymers;

[0013] The melt index of the first polypropylene is 15-35 g / 10 min at 230℃ and 2.16 kg.

[0014] The melt index of the second polypropylene is 0.3–10 g / 10 min at 230°C and 2.16 kg.

[0015] The toughening agent is a polypropylene-based elastomer, which is mainly composed of isotactic repeating monomers of propylene and randomly distributed ethylene.

[0016] Using the polypropylene-based elastomer with the special structure described in this invention as a toughening agent can improve the impact strength of transparent polypropylene, especially its excellent low-temperature toughness, without significantly affecting its transparency. The polypropylene-based elastomer is mainly composed of isotactic repeating propylene monomers and randomly distributed ethylene. Compared to traditional ethylene-octene copolymer (POE) toughening agents, the polypropylene-based elastomer's macromolecular backbone consists of polypropylene monomer units, exhibiting better compatibility with the polypropylene substrate and a more significant toughening effect on the system. Simultaneously, the polypropylene-based elastomer possesses better low-temperature resistance, resulting in higher low-temperature toughness in the composite material. The polypropylene-based elastomer also has less impact on the material's transparency.

[0017] By selecting a polypropylene-based elastomer mainly composed of repeating monomers of isotactic propylene and randomly distributed ethylene, and by introducing a second type of low melt index atactic polypropylene material, the transparency of the material can be further adjusted and improved, resulting in a high-impact-strength and high-transparency polypropylene composite material.

[0018] When the melt flow rate of the first polypropylene is within this range, the polypropylene composite material system exhibits good fluidity, which is beneficial for the uniform mixing of each raw material component, resulting in a polypropylene composite material with both high impact resistance and excellent transparency. The melt flow rate of the polypropylene was measured according to the standard method of ISO 1133-1-2011.

[0019] When the melt flow rate of the second polypropylene is within this range, the polypropylene composite system exhibits good toughness, which is beneficial for the uniform mixing of each raw material component, resulting in a polypropylene composite material with both excellent transparency and high impact resistance. The melt flow rate of the polypropylene was measured according to the standard method of ISO 1133-1-2011.

[0020] Preferably, the polypropylene composite material comprises the following components in parts by weight: 45-60 parts of first polypropylene, 30-45 parts of second polypropylene, 15-25 parts of toughening agent, and 1-6 parts of processing aid.

[0021] Preferably, the toughening agent has a melt index of 0.2–25 g / 10 min at 190°C and 2.16 kg.

[0022] More preferably, the toughening agent is selected from at least one of Vistamaxx 6102, Vistamaxx 3020FL, Vistamaxx 6502 or Vistamaxx 3000.

[0023] Preferably, the processing aids include lubricants and antioxidants.

[0024] Preferably, the lubricant is an ester-based lubricant.

[0025] More preferably, the lubricant is selected from at least one of calcium stearate, magnesium stearate, or zinc stearate.

[0026] Preferably, the antioxidant is at least one of hindered amines, hindered phenols, phosphites, or thioesters.

[0027] More preferably, the hindered amine antioxidant is selected from at least one of UV-3808, LA-402XP, or LA-402AF.

[0028] More preferably, the hindered phenolic antioxidant is selected from at least one of antioxidant 1098, antioxidant 1010, antioxidant 259, antioxidant 1076 or spiroethylene glycol bis[β-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate] (ADK AO-80).

[0029] More preferably, the phosphite antioxidant is selected from at least one of antioxidant 168, antioxidant PEP-36, or 627A.

[0030] More preferably, the thioester antioxidant is selected from at least one of distearate thiodipropionate, dilaurate thiodipropionate, or pentaerythritol-based dodecathiopropyl ester.

[0031] This invention also provides a method for preparing a polypropylene composite material, comprising the following steps:

[0032] The first polypropylene, the second polypropylene, the toughening agent, and the processing aid are mixed evenly, melt-extruded, granulated and dried to obtain the polypropylene composite material.

[0033] Preferably, the temperature of the melt extrusion is 160–210°C.

[0034] Preferably, the melt extrusion equipment is a twin-screw extruder with a screw length-to-diameter ratio of 40:1 to 48:1 and a screw speed of 300 to 600 rpm.

[0035] The application of the above-mentioned polypropylene composite material in the manufacture of household appliances, medical devices and commodity packaging is also within the scope of protection of this invention.

[0036] Preferably, the polypropylene composite material is used in the preparation of vacuum cleaner water tanks, floor scrubber water tanks, garment steamer water tanks, and food packaging.

[0037] Compared with the prior art, the present invention has the following beneficial effects:

[0038] 1. A polypropylene composite material with high impact strength, high transparency and excellent low-temperature toughness is prepared by using a first polypropylene, a second polypropylene, a polypropylene-based elastomer toughening agent and processing aids with a certain melt index range.

[0039] 2. The impact strength of the polypropylene material of this invention is 33.8 kJ / m. 2 The low-temperature impact strength reaches 9.8–14.1 kJ / m. 2 It possesses high impact strength and excellent low-temperature toughness;

[0040] 3. The polypropylene composite material of the present invention achieves a haze of less than 8.62%, which is close to the haze of transparent ABS, and can meet the requirements of food grade, and can be used as a substitute for ABS material. Detailed Implementation

[0041] The present invention is further illustrated below with reference to specific embodiments. These embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Experimental methods in the following embodiments that do not specify specific conditions are generally performed under conventional conditions in the art or as recommended by the manufacturer; the raw materials and reagents used, unless otherwise specified, are all commercially available from the conventional market. Any non-substantial changes and substitutions made by those skilled in the art based on the present invention are within the scope of protection claimed by the present invention.

[0042] The reagents used in the various embodiments and comparative examples of this invention are described below:

[0043] First polypropylene 1#: PP RP346R, purchased from CNOOC Shell Petrochemicals Co., Ltd., with a melt flow rate of 25g / 10min at 230℃ and 2.16kg load;

[0044] First polypropylene #2: Moplen RP344NK, Basell Asia Pacific Ltd., melt flow rate of 13 g / 10 min at 230℃ and 2.16 kg load;

[0045] First polypropylene 3#: Moplen RP348S, Basell Asia Pacific Ltd., melt flow rate of 35g / 10min at 230℃ and 2.16kg load;

[0046] First polypropylene 4#: Moplen RP348T HP, Basell Asia Pacific Ltd., melt flow rate of 48g / 10min at 230℃ and 2.16kg load;

[0047] Second polypropylene 1#: PP SM198, purchased from LOTTE CHEMICAL TITAN(M)SDN.BHD., with a melt flow rate of 1.6 g / 10 min at 230℃ and 2.16 kg load;

[0048] Second polypropylene #2: Moplen RP215MX B, Basell Asia Pacific Ltd., melt flow rate of 6 g / 10 min at 230℃ and 2.16 kg load;

[0049] Second polypropylene 3#: PP 4220, Sinopec Chemical Sales Co., Ltd., melt flow rate at 230℃ and 2.16kg load is 0.3g / 10min;

[0050] Second polypropylene #4: Moplen RP325M, Basell Asia Pacific Ltd., melt flow rate of 8.5 g / 10 min at 230℃ and 2.16 kg load;

[0051] Second polypropylene 5#: Moplen RP340N, Basell Asia Pacific Ltd., melt flow rate of 11g / 10min at 230℃ and 2.16kg load;

[0052] Toughening agent 1#: Vistamaxx 6102, purchased from ExxonMobil Chemicals (Shanghai) Co., Ltd., with a melt flow rate of 1.4 g / 10 min at 190℃ and 2.16 kg load;

[0053] Toughening agent #2: Vistamaxx 6502, purchased from ExxonMobil Chemicals (Shanghai) Co., Ltd., with a melt flow rate of 21 g / 10 min at 190℃ and 2.16 kg load;

[0054] Toughening agent 3#: polyolefin elastomer, ENGAGE 8440, purchased from Dow Chemical (Shanghai) Co., Ltd., with a melt flow rate of 1.6 g / 10 min at 190℃ and 2.16 kg load;

[0055] Lubricant: Ester-based lubricant BS-2818, Zhongshan Huamingtai Chemical Co., Ltd.;

[0056] Antioxidant: Antioxidant 1010 and Antioxidant 168 are compounded in a mass ratio of 1:1. Commercially available.

[0057] The polypropylene composite materials of the various embodiments and comparative examples of the present invention were prepared by the following process:

[0058] The first polypropylene, the second polypropylene, the toughening agent, the lubricant, and the antioxidant are mixed evenly in a certain proportion. The mixed raw materials are added to a twin-screw extruder and then granulated and dried after melt extrusion to obtain the polypropylene composite material.

[0059] The melt extrusion conditions for the twin-screw extruder are as follows: the screw length-to-diameter ratio is 48:1, the screw speed is 300 rpm, and the melt extrusion temperature is 160–210℃. Specifically, starting from the feed inlet, the temperature settings for each zone of the twin-screw extruder are as follows: 80℃, 160℃, 165℃, 170℃, 180℃, 190℃, 200℃, 210℃, and 200℃.

[0060] The performance testing methods and standards for the polypropylene composite materials of the various embodiments and comparative examples of the present invention are as follows:

[0061] The particle material prepared according to the above method is baked at 80°C for 4 hours and then injection molded at 200°C to obtain the required test specimens.

[0062] (1) Cantilever beam notched impact strength test: The cantilever beam notched impact strength test was conducted using a ZBC1400-B LCD plastic pendulum impact tester (METS Industrial Systems (China) Co., Ltd.). The test standard was ISO180-2019, the test conditions were ambient temperature 23℃ and 0℃, and the sample size was 80mm×10mm×4mm.

[0063] (2) Haze test: The transparency of the material is characterized by the haze index. The lower the haze, the higher the transparency of the material. The test is conducted in accordance with the standard (GB / T 2410-2008). The sample size is 100mm×100mm×1mm. The test equipment is HM-65W and the manufacturer is Murakami Color MCRL of Japan.

[0064] Examples 1-12

[0065] This embodiment provides a series of polypropylene composite materials, the weight parts of each component in the formulation are shown in Table 1.

[0066] Table 1. Formulations (parts) for Examples 1-12

[0067]

[0068] Comparative Examples 1-9

[0069] This comparative example provides a series of polypropylene composite materials, the components of which are shown in Table 2.

[0070] Table 2: Formulations (per serving) for Comparative Examples 1–9

[0071]

[0072]

[0073] The performance test results of the polypropylene composite materials in each embodiment and comparative example according to the methods mentioned above are shown in Table 3.

[0074] Table 3 Performance test results of each embodiment and comparative example

[0075]

[0076]

[0077] As shown in Table 3, the polypropylene composite materials prepared in Examples 1-12 of this invention all possess high impact strength, high transparency, and excellent low-temperature toughness, with Example 1 exhibiting the best overall performance. Comparative Example 1 used a first polypropylene exceeding the melt flow index range. Although its notched impact strength was comparable to Example 1, the composite material showed a significant increase in haze and a decrease in transparency. Comparative Example 4 used a second polypropylene not meeting the melt flow index range. Compared to Example 1, it exhibited poorer toughness, a greater increase in haze, and a marked decrease in transparency. Comparative Example 7 used a toughening agent derived from a polyolefin elastomer. Although its toughness was comparable, the haze increased significantly, indicating that while enhancing toughness, it also substantially reduced transparency. Comparative Examples 8 and 9 used toughening agents outside the range, both increasing haze and failing to achieve a balance between toughness and haze. Other comparative examples, consisting of polypropylene materials with components outside the range, exhibited poor toughness, increased haze, and decreased transparency. The low-temperature toughness of the examples was similar to that of Comparative Example 7, indicating that the toughening agent of this invention improves the low-temperature toughness of the polypropylene composite material.

[0078] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A polypropylene composite material, characterized in that, The components include the following parts by weight: 40-60 parts of first polypropylene, 30-50 parts of second polypropylene, 10-25 parts of toughening agent, and 1-6 parts of processing aid. Wherein, both the first polypropylene and the second polypropylene are ethylene-propylene random copolymers; The melt index of the first polypropylene is 15~35g / 10min at 230℃ and 2.16kg. The melt index of the second polypropylene is 0.3~8.5g / 10min at 230℃ and 2.16kg. The toughening agent is a polypropylene-based elastomer, which is mainly composed of isotactic repeating monomers of propylene and randomly distributed ethylene.

2. The polypropylene composite material according to claim 1, characterized in that, The polypropylene composite material comprises the following components in parts by weight: 45-60 parts of first polypropylene, 30-45 parts of second polypropylene, 15-25 parts of toughening agent, and 1-6 parts of processing aid.

3. The polypropylene composite material according to claim 1, characterized in that, The toughening agent has a melt index of 0.2~10g / 10min at 190℃ and 2.16kg.

4. The polypropylene composite material according to claim 1, characterized in that, The processing aids include lubricants and antioxidants.

5. The polypropylene composite material according to claim 4, characterized in that, The lubricant is an ester-based lubricant.

6. The polypropylene composite material according to claim 4, characterized in that, The antioxidant is at least one of hindered amines, hindered phenols, phosphites, or thioesters.

7. The method for preparing the polypropylene composite material according to any one of claims 1 to 6, characterized in that, Includes the following steps: The first polypropylene, the second polypropylene, the toughening agent, and the processing aid are mixed evenly, melt-extruded, granulated and dried to obtain the polypropylene composite material.

8. The preparation method according to claim 7, characterized in that, The temperature of the melt extrusion is 160~210℃.

9. The use of the polypropylene composite material according to any one of claims 1 to 6 in the preparation of household appliances, medical devices and commodity packaging.

10. The use of the polypropylene composite material according to any one of claims 1 to 6 in the preparation of vacuum cleaner water tanks, floor scrubber water tanks, garment steamer water tanks, and food packaging.

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