Polypropylene composite material as well as preparation method and application thereof

Abstract

The invention relates to the technical field of polymer composite materials, and discloses a polypropylene composite material as well as a preparation method and application thereof. The polypropylene composite material is prepared from the following raw materials: polypropylene resin, glass fibers, a compatilizer, an antioxidant, a lubricant, an antibacterial and mildew-proof agent and color master batches, the monofilament diameter of the glass fiber is 11-14 [mu] m, and the length of the glass fiber is 0.3-0.5 mm. According to the polypropylene composite material provided by the invention, the glass fiber with the specific monofilament diameter is used as a reinforcing material, so that the mechanical property of the polypropylene composite material is guaranteed, the phenomenon of fiber floating on the surface of the material can be reduced, and the appearance quality is improved; by adding the antibacterial mildew preventive, the material is endowed with antibacterial performance; the obtained material not only can meet the requirements of automotive trim parts on the mechanical properties of the material, but also can meet the requirements of sanitation and safety.

Description

Technical Field

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

[0002] Polypropylene (PP) is a semi-crystalline material with the advantages of being non-toxic, odorless and having a low density. Its strength, stiffness, hardness and heat resistance are all superior to those of low-pressure polyethylene and it can be used at around 100°C. Polypropylene also has good electrical properties and high-frequency insulation. It is not affected by humidity and is suitable for making general mechanical parts, corrosion-resistant parts and insulating parts. It has been widely used in the automotive industry.

[0003] Although polypropylene has excellent comprehensive properties, its mechanical strength is still insufficient compared to engineering plastics. The existing technology often uses glass fiber as a modified material to enhance the strength of polypropylene materials, but inorganic fibers and polypropylene have poor compatibility, which easily causes floating fibers to appear on the surface of the material. With the rapid development of the automobile industry, consumers have higher and higher requirements for the appearance of automobile materials, and polypropylene materials prone to floating fibers can no longer meet the application requirements of automobile materials. Summary of the invention

[0004] The present invention aims to solve at least one of the above-mentioned technical problems existing in the prior art. To this end, one of the purposes of the present invention is to provide a polypropylene composite material; the second purpose of the present invention is to provide a method for preparing the polypropylene composite material; the third purpose of the present invention is to provide an application of the polypropylene composite material.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is:

[0006] The first aspect of the present invention provides a polypropylene composite material, comprising the following preparation raw materials: polypropylene resin, glass fiber, compatibilizer, antioxidant, lubricant, antibacterial and mildew-proof agent and masterbatch;

[0007] The monofilament diameter of the glass fiber is 11-14 μm and the length is 0.3-0.5 mm.

[0008] In some embodiments of the present invention, the polypropylene composite material includes the following preparation raw materials, measured by weight:

[0009]

[0010]

[0011] In some specific embodiments of the present invention, the polypropylene composite material includes the following preparation raw materials, measured by weight:

[0012]

[0013] In some embodiments of the present invention, the melt index of the polypropylene resin under the test condition of 230° C. / 2.16 kg is 20 g / 10 min-40 g / 10 min.

[0014] In some specific embodiments of the present invention, the melt index of the polypropylene resin under the test condition of 230° C. / 2.16 kg is 23 g / 10 min-35 g / 10 min.

[0015] In some embodiments of the present invention, the polypropylene resin is selected from at least one of homopolypropylene and copolymer polypropylene.

[0016] In some specific embodiments of the present invention, the polypropylene resin is selected from at least one of homopolypropylene and copolymer polypropylene; the melt index of the homopolypropylene under the test condition of 230°C / 2.16kg is 23g / 10min-27g / 10min; the melt index of the copolymer polypropylene under the test condition of 230°C / 2.16kg is 27g / 10min-35g / 10min.

[0017] In some embodiments of the present invention, the average short-side monofilament diameter of the glass fiber is 6-8 μm.

[0018] In some embodiments of the present invention, the glass fiber is an alkali-free glass fiber.

[0019] In some specific embodiments of the present invention, the glass fiber is aluminate glass fiber.

[0020] In the present invention, by limiting the specifications of glass fibers, the floating fiber phenomenon caused by the poor compatibility of glass fibers with polypropylene is reduced, and the appearance of the material is improved.

[0021] In some embodiments of the present invention, the compatibilizer has a melt index of 10 g / 10 min-20 g / 10 min under the test condition of 190° C. / 2.16 kg.

[0022] In some embodiments of the present invention, the compatibilizer includes a maleic anhydride grafted reactive compatibilizer.

[0023] In some specific embodiments of the present invention, the compatibilizer is selected from at least one of maleic anhydride grafted polypropylene (PP-g-MAH), maleic anhydride grafted polyolefin elastomer (POE-g-MAH), and maleic anhydride grafted ethylene propylene diene monomer rubber (EPDM-g-MAH).

[0024] In some embodiments of the present invention, the antioxidant is a composite antioxidant of a hindered phenol antioxidant and a phosphite antioxidant in a mass ratio of 1:(1-2).

[0025] In some specific embodiments of the present invention, the antioxidant is a composite antioxidant of a hindered phenol antioxidant and a phosphite antioxidant in a mass ratio of 1:(1-1.2).

[0026] In some embodiments of the present invention, the hindered phenol antioxidant is selected from at least one of 2,6-di-tert-butyl-p-methylphenol (BHT), β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate (antioxidant 1076), pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate (antioxidant 1010), N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionyl) hexanediamine (antioxidant 1098), and triethylene glycol bis[β-(3-tert-butyl-4-hydroxy-5-methylphenyl) propionate] (antioxidant 245).

[0027] In some embodiments of the present invention, the phosphite antioxidant includes at least one of diphenyl isooctyl phosphite (ODPP), tris[2,4-di-tert-butylphenyl]phosphite (antioxidant 168), bisphenol A phosphite, and triphenyl phosphite (TPP).

[0028] In some embodiments of the present invention, the lubricant is selected from at least one of ethylene bisstearamide (EBS) and pentaerythritol stearate (PETS).

[0029] In some embodiments of the present invention, the active ingredient of the antibacterial and antifungal agent includes a nitrogen-containing heterocyclic phenol alcohol compound.

[0030] In the present invention, an environmentally friendly antibacterial and mildew-proof agent with a nitrogen-containing heterocyclic phenol alcohol compound as an active ingredient is selected, which can effectively inhibit the growth and reproduction of molds such as Aspergillus niger, Aspergillus terreus, Paecilomyces variotii and Chaetomium globosum, and improve the antibacterial property of the material.

[0031] In some embodiments of the present invention, the carbon black content of the masterbatch is 40wt%-50wt%.

[0032] In some embodiments of the present invention, the masterbatch is a masterbatch with polypropylene resin as a carrier.

[0033] The second aspect of the present invention provides a method for preparing the polypropylene composite material according to the first aspect of the present invention, comprising the following steps:

[0034] A mixture of polypropylene resin, compatibilizer, antioxidant, lubricant, masterbatch and antibacterial and mildewproof agent is added into a twin-screw extruder, glass fiber is added from the side feed port of the twin-screw extruder, melt-mixed, extruded and granulated to obtain the polypropylene composite material.

[0035] In some embodiments of the present invention, the mixture of polypropylene resin, compatibilizer, antioxidant, lubricant, masterbatch and antibacterial and mildew-proof agent comprises stirring the polypropylene resin, compatibilizer, antioxidant, lubricant, masterbatch and antibacterial and mildew-proof agent at a speed of 150-300 r / min for 3-5 minutes.

[0036] In some embodiments of the present invention, the temperatures of each feeding section of the twin-screw extruder from the hopper to the die head are: first zone temperature: 170-190°C, second zone temperature: 210-220°C, third zone temperature: 210-230°C, fourth zone temperature: 210-230°C, fifth zone temperature: 210-230°C, sixth zone temperature: 210-230°C, seventh zone temperature: 210-230°C, eighth zone temperature: 210-230°C, ninth zone temperature: 210-230°C, tenth zone temperature: 210-230°C, eleventh zone temperature: 210-230°C.

[0037] In some embodiments of the present invention, the feeding speed of the twin-screw extruder is 15-20r / min.

[0038] In some embodiments of the present invention, the main engine speed of the twin-screw extruder is 300-450r / min.

[0039] The third aspect of the present invention provides application of the polypropylene composite material described in the first aspect of the present invention in the automotive industry.

[0040] Compared with the prior art, the present invention has the following beneficial effects:

[0041] The polypropylene composite material provided by the present invention uses glass fiber with a specific single filament diameter as a reinforcing material, which can reduce the floating fiber phenomenon on the surface of the material and improve the appearance quality while ensuring the mechanical properties of the polypropylene composite material; by adding an antibacterial and mildew-proof agent, the material is given antibacterial properties; the obtained material can meet the requirements of automotive interior parts for material mechanical properties and meet the hygiene and safety requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 This is a physical picture of the spiral plate made of the polypropylene composite material in Example 1;

[0043] Figure 2 This is a physical picture of the spiral plate made of the polypropylene composite material in Example 2;

[0044] Figure 3 This is a physical picture of the spiral plate made of the polypropylene composite material in Comparative Example 1;

[0045] Figure 4 This is a physical picture of the spiral plate made of the polypropylene composite material in Comparative Example 2;

[0046] Figure 5 This is a physical picture of a standard combustion plate for automobiles made from the polypropylene composite material in Example 1;

[0047] Figure 6 This is a physical picture of a standard combustion plate for automobiles made from the polypropylene composite material in Example 2;

[0048] Figure 7 This is a physical picture of a standard combustion plate for automobiles made from the polypropylene composite material in Comparative Example 1;

[0049] Figure 8 This is a physical picture of the standard combustion plate for automobiles made from the polypropylene composite material in Comparative Example 2. DETAILED DESCRIPTION

[0050] The present invention is further described in detail below by specific examples. Unless otherwise specified, the raw materials, reagents or devices used in the examples and comparative examples can be obtained from conventional commercial sources or can be obtained by prior art methods. Unless otherwise specified, the experiments or test methods are conventional methods in the art.

[0051] The raw material information used in the following examples and comparative examples is shown in Table 1 below:

[0052] Table 1 Information of raw materials used in the examples and comparative examples

[0053]

[0054]

[0055] in:

[0056] 1) The melt index of homopolymer polypropylene PP Z30S under the test conditions of 230℃ / 2.16kg is 26g / 10min;

[0057] 2) The melt index of homopolymer polypropylene EP548R-Z under the test conditions of 230°C / 2.16kg is 28g / 10min;

[0058] 3) The melt index of the compatibilizer under the test conditions of 190°C / 2.16kg is 12g / 10min;

[0059] 4) The monofilament diameter of glass fiber 248AF-13P is 11-14 μm, the average short-side monofilament diameter is 6-8 μm, and the length is 0.3-0.5 mm;

[0060] 5) ECS4F-03-508A is a flat glass fiber with a flatness ratio of 4:1, a cross-sectional long side of 28 μm, a short side of 7 μm, and a short cut length of 3 mm;

[0061] 6) The active ingredient of the antibacterial and antifungal agent AM117 is a nitrogen-containing heterocyclic phenol alcohol compound;

[0062] 7) The masterbatch is a masterbatch with polypropylene resin as a carrier and a carbon black content of 40wt%-50wt%.

[0063] Example 1

[0064] This example prepares a polypropylene composite material, and the raw materials are shown in Table 2:

[0065] Table 2 Composition of raw materials of polypropylene composite material in Example 1

[0066]

[0067]

[0068] The preparation method of the polypropylene composite material comprises the following steps:

[0069] The polypropylene resin, the compatibilizer, the antioxidant, the lubricant, the masterbatch and the antibacterial and mildew-proof agent are stirred at a speed of 200 r / min for 5 minutes to obtain a mixed material;

[0070] The mixed material is put into a twin-screw extruder, and the glass fiber is added from the side feeding port of the twin-screw extruder. The temperatures of 11 temperature zones of the twin-screw extruder are set to 170°C, 215°C, 225°C, 230°C, 230°C, 220°C, 220°C, 220°C, 220°C, 225°C and 220°C, respectively. The feeding speed is 15r / min, the main engine speed is 350r / min, and the materials are blended and melted and extruded;

[0071] The pellets coming out of the extruder die are cooled in a water trough, dried by a fan, and then enter a pelletizer for pelletizing to obtain a polypropylene composite material.

[0072] Example 2

[0073] This example prepares a polypropylene composite material, and the raw materials are shown in Table 3:

[0074] Table 3 Composition of raw materials of polypropylene composite material in Example 2

[0075]

[0076] The preparation method of the polypropylene composite material comprises the following steps:

[0077] The polypropylene resin, the compatibilizer, the antioxidant, the lubricant, the masterbatch and the antibacterial and mildew-proof agent are stirred at a speed of 200 r / min for 5 minutes to obtain a mixed material;

[0078] The mixed material is put into a twin-screw extruder, and the glass fiber is added from the side feeding port of the twin-screw extruder. The temperatures of 11 temperature zones of the twin-screw extruder are set to 170°C, 215°C, 225°C, 230°C, 230°C, 220°C, 220°C, 220°C, 220°C, 225°C and 220°C, respectively. The feeding speed is 15r / min, the main engine speed is 350r / min, and the materials are blended and melted and extruded;

[0079] The pellets coming out of the extruder die are cooled in a water trough, dried by a fan, and then enter a pelletizer for pelletizing to obtain a polypropylene composite material.

[0080] Comparative Example 1

[0081] This comparative example prepares a polypropylene composite material, and the raw materials for preparation are shown in Table 4:

[0082] Table 4 Composition of raw materials of polypropylene composite material in comparative example 1

[0083]

[0084] The preparation method of the polypropylene composite material comprises the following steps:

[0085] The polypropylene resin, the compatibilizer, the antioxidant, the lubricant and the masterbatch were stirred at a speed of 200 r / min for 5 minutes to obtain a mixed material;

[0086] The mixed material is put into a twin-screw extruder, and the glass fiber is added from the side feeding port of the twin-screw extruder. The temperatures of 11 temperature zones of the twin-screw extruder are set to 170°C, 215°C, 225°C, 230°C, 230°C, 220°C, 220°C, 220°C, 220°C, 225°C and 220°C, respectively. The feeding speed is 15r / min, the main engine speed is 350r / min, and the materials are blended and melted and extruded;

[0087] The pellets coming out of the extruder die are cooled in a water trough, dried by a fan, and then enter a pelletizer for pelletizing to obtain a polypropylene composite material.

[0088] Comparative Example 2

[0089] This comparative example prepares a polypropylene composite material, and the raw materials for preparation are shown in Table 5:

[0090] Table 5 Composition of raw materials of polypropylene composite material in comparative example 2

[0091]

[0092] The preparation method of the polypropylene composite material comprises the following steps:

[0093] The polypropylene resin, the compatibilizer, the antioxidant, the lubricant and the masterbatch were stirred at a speed of 200 r / min for 5 minutes to obtain a mixed material;

[0094] The mixed material is put into a twin-screw extruder, and the glass fiber is added from the side feeding port of the twin-screw extruder. The temperatures of 11 temperature zones of the twin-screw extruder are set to 170°C, 215°C, 225°C, 230°C, 230°C, 220°C, 220°C, 220°C, 220°C, 225°C and 220°C, respectively. The feeding speed is 15r / min, the main engine speed is 350r / min, and the materials are blended and melted and extruded;

[0095] The pellets coming out of the extruder die are cooled in a water trough, dried by a fan, and then enter a pelletizer for pelletizing to obtain a polypropylene composite material.

[0096] Performance Testing

[0097] The polypropylene composite materials in Example 1-2 and Comparative Example 1-2 were respectively injection molded into standard specimens, and the following properties were tested after being placed in a standard test box (23°C, 50% humidity) for 24 hours:

[0098] 1. Density: Tested in accordance with GB / T 1033.1-2008 "Determination of density of non-foamed plastics";

[0099] 2. Melt index (MI, 30°C / 2.16kg): Tested with reference to GB / T 3682.1-2018 "Determination of melt mass flow rate MFR and melt volume flow rate MVR of thermoplastic plastics";

[0100] 3. Heat deformation temperature: refer to GB / T 1634.1-2019 "Determination of load deformation temperature of plastics" for testing;

[0101] 4. Tensile strength: Tested in accordance with GB / T 1040-2018 "Determination of tensile properties of plastics";

[0102] 5. Bending strength and bending modulus: refer to GB / T 9341-2008 "Determination of bending properties of plastics" for testing;

[0103] 6. Izod notched impact strength: Tested in accordance with GB / T 1843-2008 “Standard for Determination of Izod Impact Strength of Plastics”.

[0104] The polypropylene composite materials in Example 1-2 and Comparative Example 1-2 were respectively injection molded into spiral sheets and automobile standard combustion plates with a length of 365 mm, a width of 100 mm, and a thickness of 3.0 mm. After being placed in a standard test box (23° C., humidity 50%) for 24 hours, the appearance of the spiral sheets and the automobile standard combustion plates were observed with the naked eye, and the automobile standard combustion plates were used for anti-mold performance testing:

[0105] The antifungal performance was tested with reference to GB 21551.2-2010 "Particular requirements for antibacterial materials with antibacterial, sterilizing and purification functions for household and similar electrical appliances", wherein the strain added in Example 1 and Comparative Example 1 was Aspergillus niger, and the strain added in Example 2 and Comparative Example 2 was Aspergillus terreus, and the test conditions were: 28 days, 90% RH, and 28°C.

[0106] Figure 1 This is a physical picture of the spiral plate made of the polypropylene composite material in Example 1. Figure 2 This is a physical picture of the spiral plate made of the polypropylene composite material in Example 2. Figure 3 This is a physical picture of the spiral plate made of the polypropylene composite material in Comparative Example 1. Figure 4 This is a physical picture of the spiral plate made of the polypropylene composite material in Comparative Example 2. Figure 5 This is a physical picture of the standard combustion plate of an automobile made of the polypropylene composite material in Example 1. Figure 6 This is a physical picture of the standard combustion plate of an automobile made of the polypropylene composite material in Example 2. Figure 7 This is a physical picture of the standard combustion plate of an automobile made of the polypropylene composite material in Comparative Example 1. Figure 8 This is a real picture of the standard combustion plate of an automobile made of the polypropylene composite material in Comparative Example 2. Figure 1-Figure 8 It can be seen that the spiral plate and the automobile standard combustion plate made of the polypropylene composite material provided by the present invention have no floating fiber phenomenon. Compared with the polypropylene composite material in Comparative Examples 1 and 2 in which flat glass fibers are added as reinforcing materials, the products obtained have better appearance.

[0107] Table 6 Performance test results and corresponding standards of polypropylene composite materials in Examples 1-2 and Comparative Examples 1-2

[0108] Test items standard Example 1 Example 2 Comparative Example 1 Comparative Example 2 <![CDATA[Density (g / cm 3 )]]> 1.15±0.03 1.130 1.128 1.128 1.122 MI(g / 10min) / 10.1 11.2 8.9 12.5 Tensile strength(MPa) ≥70 93 76 96 73 Bending strength(MPa) ≥100 135 113 140 114 Flexural modulus (MPa) ≥5000 6687 5704 6523 5685 Izod notched impact strength ≥6 8.9 17.6 9.2 17.3 Heat deformation temperature(℃) ≥130 152 148 152 152 Anti-fungal properties / Level 0 Level 0 Level 2 Level 2

[0109] Table 6 shows the performance test results and corresponding standards of the polypropylene composite materials in Examples 1-2 and Comparative Examples 1-2. It can be seen from Table 6 that the polypropylene composite materials provided by the present invention, by adding alkali-free short glass fibers with a specific monofilament diameter, reduce the floating fiber phenomenon on the surface of the material while ensuring the mechanical properties of the material; by adding environmentally friendly antibacterial and mildew-proof agents, the material is given antibacterial properties. In the anti-mildew performance test, no mold growth was observed on the standard combustion plates of automobiles prepared from the polypropylene composite materials in Examples 1 and 2 under a microscope magnified 50 times, while the mold growth coverage area of ​​the standard combustion plates of automobiles prepared from the polypropylene composite materials in Comparative Examples 1 and 2 was greater than 10%.

Claims

1. A polypropylene composite material, characterized in that: The preparation method comprises the following raw materials: polypropylene resin, glass fiber, compatibilizer, antioxidant, lubricant, antibacterial and antifungal agent and masterbatch; The monofilament diameter of the glass fiber is 11-14 μm and the length is 0.3-0.5 mm.

2. The polypropylene composite material according to claim 1, characterized in that: The polypropylene composite material comprises the following raw materials by weight:

3. The polypropylene composite material according to claim 2, characterized in that: The melt index of the polypropylene resin under the test condition of 230°C / 2.16kg is 20g / 10min-40g / 10min; Preferably, the polypropylene resin is selected from at least one of homopolypropylene and copolymer polypropylene.

4. The polypropylene composite material according to claim 2, characterized in that: The average short-side monofilament diameter of the glass fiber is 6-8 μm.

5. The polypropylene composite material according to claim 2, characterized in that: The compatibilizer has a melt index of 10 g / 10 min-20 g / 10 min under the test condition of 190° C. / 2.16 kg; Preferably, the compatibilizer includes a maleic anhydride grafted reactive compatibilizer.

6. The polypropylene composite material according to claim 2, characterized in that: The antioxidant is a composite antioxidant of a hindered phenol antioxidant and a phosphite antioxidant in a mass ratio of 1:(1-2).

7. The polypropylene composite material according to claim 2, characterized in that: The lubricant is selected from at least one of vinyl bisstearamide and pentaerythritol stearate.

8. The polypropylene composite material according to claim 2, characterized in that: The active ingredients of the antibacterial and mildew-proof agent include a nitrogen-containing heterocyclic phenol alcohol compound.

9. The method for preparing the polypropylene composite material according to any one of claims 1 to 8, characterized in that: The following steps are involved: A mixture of polypropylene resin, compatibilizer, antioxidant, lubricant, masterbatch and antibacterial and mildewproof agent is added into a twin-screw extruder, glass fiber is added from the side feed port of the twin-screw extruder, melt-mixed, 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 automobile industry.

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