Injection molding grade flame retardant metal polymer composite material, and preparation method and application thereof

Abstract

The application discloses an injection molding grade flame-retardant metal polymer composite material and a preparation method and application thereof. The composite material comprises the following components in parts by weight: 28-42 parts of polyolefin resin; 20-30 parts of metal iron powder; 15-25 parts of bromine flame retardant; 5-10 parts of inorganic magnesium compound; and 1-5 parts of interface modifier. The interface modifier is maleic anhydride graft and / or acrylic acid graft. In the application, the polyolefin resin is used as the base resin, the metal iron powder is added, the bromine flame retardant and the inorganic magnesium compound are used in cooperation, the good flame-retardant effect can be achieved, and the good magnetic strength and metal luster are also achieved.

Description

Technical Field

[0001] This invention belongs to the technical field of injection molding grade polyolefin materials, and more specifically, relates to an injection molding grade flame retardant metal polymer composite material, its preparation method and application. Background Technology

[0002] Metal polymer materials are a new type of composite material that combines the advantages of polymer materials (easy to mold and process) and metal materials (high specific gravity and high rigidity). However, traditional metal polymer composite materials generally use polymer resins combined with metal sheets or metal fibers, which is relatively complex to process and difficult to mold. Therefore, easily processed and manufactured injection-molded metal polymer composite materials have gradually become the focus of research.

[0003] Injectable metal polymer composites are usually in the form of metal powder to avoid affecting the thermoplasticity of the resin. However, conventional metal powders are flammable, making the production of injection-grade flame-retardant metal polymer composites a major challenge. Summary of the Invention

[0004] The purpose of this invention is to overcome the defects or shortcomings of existing injection-molded metal polymer composite materials in achieving good flame retardant effects, and to provide an injection-molded flame-retardant metal polymer composite material.

[0005] Another object of the present invention is to provide a method for preparing the injection-molded flame-retardant metal polymer composite material.

[0006] Another object of the present invention is to provide the application of the injection-molded flame-retardant metal polymer composite material.

[0007] To achieve the above objectives, the present invention employs the following technical solution:

[0008] An injection-molding grade flame-retardant metal polymer composite material, comprising the following components in parts by weight:

[0009] 28-42 parts of polyolefin resin;

[0010] 20-30 parts of metallic iron powder;

[0011] 15-25 parts of brominated flame retardant;

[0012] 5-10 parts of inorganic magnesium compounds;

[0013] 1-5 parts of interface improver;

[0014] The interface modifier is a maleic anhydride graft and / or an acrylic acid graft.

[0015] This invention provides an injection-grade flame-retardant metal polymer composite material. By using polyolefin resin as the matrix resin and adding metal iron powder in synergy with bromine-based flame retardants and inorganic magnesium compounds, it can achieve good flame retardant effect while having good magnetic strength and metallic luster.

[0016] Specifically: The interface modifier selected in this invention can ensure that the metallic iron powder is evenly distributed in the resin system, thus ensuring the material's melt plasticizing and flowability; the interface modifier can condense with the active hydroxyl groups on the surface of the iron powder, enhancing the compatibility between the iron powder and the matrix resin; in addition, the molecular chain segments of the interface modifier used in this invention provide lubrication between the flame retardant system and the matrix resin molecular chains, enhancing the interfacial bonding strength; the metallic iron powder can absorb a large amount of heat during combustion, promoting the rapid decomposition of the brominated flame retardant and producing a large amount of metallic bromide, and the metallic iron powder has a strong adsorption effect, the produced bromide reacts rapidly with the metallic iron powder at high temperature, depositing on the surface of the composite material to reduce the oxygen concentration of the ignition source and better achieve the flame retardant effect; and the magnesium halide and magnesium oxide produced during the combustion of inorganic magnesium compounds cover the surface of the material, achieving a solid-phase flame retardant effect that isolates the flame and oxygen.

[0017] It should be noted that in the injection-molded flame-retardant metal polymer composite material of the present invention, the polyolefin resin content is not less than 25 wt.%.

[0018] Furthermore, the injection-molding grade flame-retardant metal polymer composite material comprises the following components calculated in parts by weight:

[0019] 30-40 parts of polyolefin resin;

[0020] 22-28 parts of metallic iron powder;

[0021] 18-22 parts of brominated flame retardant;

[0022] 6-8 parts of inorganic magnesium compounds;

[0023] 1 to 5 parts of interface improver.

[0024] Furthermore, the polyolefin resin includes one or more of polyethylene resin, polypropylene resin, ethylene-vinyl acetate copolymer, or ethylene-octene copolymer.

[0025] Specifically, the polyethylene resin includes one or more of high-density polyethylene resin, low-density polyethylene resin, and linear low-density polyethylene resin.

[0026] Specifically, the polypropylene resin includes one or more of homopolymer polypropylene, block copolymer polypropylene, or random copolymer polypropylene.

[0027] In some preferred embodiments, the polypropylene resin has a melt flow rate of 0.1 to 40 g / 10 min at 230°C and 2.16 kg.

[0028] In some preferred embodiments, the melt flow rate of the ethylene-vinyl acetate copolymer or ethylene-octene copolymer at 230°C and 2.16 kg is 1–20 g / 10 min.

[0029] In some preferred embodiments, the polyethylene resin has a melt flow rate of 0.1 to 10 g / 10 min at 190°C and 2.16 kg.

[0030] Specifically, the test standard for the melt flow rate is ISO 1133-1:2011.

[0031] Furthermore, the average particle size D50 of the iron powder is 10–55 μm.

[0032] Specifically, the average particle size D50 was obtained by using a laser particle size analyzer in an aqueous ethanol solution with a mass concentration of 50%.

[0033] Specifically, the iron powder is prepared by reduction or atomization.

[0034] Furthermore, the maleic anhydride graft comprises maleic anhydride-grafted polyolefin, and the acrylic acid graft comprises acrylic acid-grafted polyolefin.

[0035] Furthermore, the maleic anhydride grafting rate in the maleic anhydride graft is 0.8–1.5 wt%; and the acrylic acid grafting rate in the acrylic acid graft is 0.8–1.5 wt%.

[0036] Specifically, the grafting rate is tested by acid-base titration.

[0037] Specifically, the maleic anhydride-grafted polyolefin includes maleic anhydride-grafted polypropylene and / or maleic anhydride-grafted polyethylene.

[0038] The acrylic-grafted polyolefins include acrylic-grafted polypropylene and / or acrylic-grafted polyethylene.

[0039] Furthermore, the brominated flame retardant includes one or more of the following: decabromodiphenyl ethane, tris(tribromoneopentyl) phosphate, tris(2,3-dibromopropyl)isocyanurate, tetrabromobisphenol A bis(2,3-dibromopropyl) ether, tetrabromobisphenol S bis(2,3-dibromopropyl) ether, or ethyl-bis(tetrabromophenyl o-dicarboximide).

[0040] Furthermore, the brominated flame retardant is one or more of decabromodiphenyl ethane and / or ethyl-bis(tetrabromophenyl o-dicarboximide).

[0041] Furthermore, the inorganic magnesium compound includes one or more of magnesium hydroxide, magnesium sulfate, magnesium carbonate, magnesium borate, or magnesium nitrate.

[0042] Furthermore, the injection-molded flame-retardant metal polymer composite material also includes 0.1 to 2 parts of additives without affecting the overall performance of the composite material.

[0043] Specifically, the additives include one or more of antioxidants, lubricants, weathering agents, or colorants.

[0044] The antioxidants described in this invention can be selected with reference to existing technologies, such as, but not limited to, one or more of phenolic antioxidants, phosphite antioxidants, divalent sulfur antioxidants, or hindered amine antioxidants.

[0045] Specifically, the phenolic antioxidants include one or more of antioxidant 264, antioxidant 1010, antioxidant 1076, antioxidant SP, antioxidant 2246, antioxidant CA, antioxidant 330, Irganox 1890, or antioxidant 3114; the phosphite antioxidants include one or more of antioxidant TNP, antioxidant ODP, antioxidant 168, Irganox 1093, or Irganox 1222; the divalent sulfur antioxidants include dilaurate thiodipropionate (DLTP) and / or distearate thiodipropionate (DSTP); and the hindered amine antioxidants include one or more of LS-744, LS-770, GW-540, or Flamstab NOR116.

[0046] The lubricant described in this invention can be selected with reference to existing technologies, such as, but not limited to, one or more of low molecular weight esters, metal soaps, stearic acid complex esters, and amides.

[0047] Specifically, the low-molecular-weight lipids include one or more of solid paraffin, liquid paraffin, or low-molecular-weight polyolefin waxes; the metal soaps include one or more of calcium stearate, magnesium stearate, zinc stearate, or barium stearate; the stearic acid complex esters include one or more of ethylene glycol stearate, glyceryl stearate, or pentaerythritol stearate; and the amides include one or more of erucamide, methylene bis-stearamide, or N,N-ethylene bis-stearamide.

[0048] In this invention, commonly used weathering agents can be selected according to existing technology, such as, but not limited to, hindered amine light stabilizers and benzotriazole ultraviolet absorbers.

[0049] Specifically, the hindered amine light stabilizer is at least one of UV-3808, LA-402XP, and LA-402AF.

[0050] This invention also protects a method for preparing the above-mentioned injection-molding grade flame-retardant metal polymer composite material, comprising the following steps:

[0051] The components are mixed evenly and added to an extruder. The mixture is then melt-extruded and granulated to obtain an injection-grade flame-retardant metal polymer composite material.

[0052] Specifically, the extruder is a twin-screw extruder.

[0053] Specifically, the extrusion temperature is 190–230°C.

[0054] Specifically, the screw speed of the twin-screw extruder is 300-600 rpm.

[0055] Specifically, the length-to-diameter ratio of the twin-screw extruder is 40:1.

[0056] This invention also provides the use of the above-mentioned injection-molded flame-retardant metallic polymer composite material in the manufacture of household goods, electronic components, household appliances, gardening equipment, medical technology equipment, motor vehicle parts, and vehicle body parts. In particular, the above-mentioned injection-molded flame-retardant metallic polymer composite material can be used to manufacture parts with good flame-retardant properties, magnetic strength, and metallic luster. Specifically, it can be used to manufacture automotive parts and home appliance parts, and is particularly suitable for applications such as automotive power battery covers and washing machine control boxes.

[0057] Compared with the prior art, the present invention has the following beneficial effects:

[0058] This invention provides an injection-molded flame-retardant metal polymer composite material, which uses polyolefin resin as the matrix resin, and adds iron powder, bromine flame retardant and inorganic magnesium compound, and adds interface modifier to achieve a better flame retardant effect, while also having good magnetic strength and metallic luster. Detailed Implementation

[0059] The present invention will be further described in detail below with reference to specific embodiments. These embodiments are only used to explain the present invention and are not intended to limit the scope of the present invention. Unless otherwise specified, the experimental methods used in the following embodiments are conventional methods; the materials and reagents used are commercially available unless otherwise specified.

[0060] Raw materials used in each embodiment and comparative example:

[0061] Polyolefin resin:

[0062] Polyolefin resin 1: Polypropylene resin, PP N-Z30S, purchased from Sinopec;

[0063] Polyolefin resin 2: Polyethylene resin, HDPE HSGC7260, purchased from Sinopec;

[0064] Polyolefin resin 3: Ethylene-vinyl acetate copolymer, EVA 14-2, purchased from PetroChina;

[0065] Metallic iron powder:

[0066] Metallic iron powder 1: average particle size D50 is 15μm, reduction method;

[0067] Metallic iron powder 2: average particle size D50 is 30μm, reduction method;

[0068] Metallic iron powder 3: average particle size D50 is 50μm, reduction method, commercially available;

[0069] Iron powder 1 and 2 are obtained by grinding and sieving iron powder 3.

[0070] Metallic iron powder 4: average particle size D50 is 30μm, atomized, commercially available;

[0071] Metal powder: Aluminum powder, average particle size D50 is 30μm; commercially available;

[0072] Brominated flame retardants:

[0073] Bromine-based flame retardant 1: Decabromodiphenyl ethane, FR-102WE, purchased from Shandong Haiwang Chemical Co., Ltd.

[0074] Bromine-based flame retardant 2: Tetrabromobisphenol A bis(2,3-dibromopropyl) ether, XZ-6800, purchased from Shandong Xiongdi Chemical Co., Ltd.

[0075] Inorganic magnesium compounds:

[0076] Inorganic magnesium compound 1: Magnesium hydroxide, JLH-M3G, purchased from Huizhou Jinhaohui Industrial Development Co., Ltd.;

[0077] Inorganic magnesium compound 2: Magnesium sulfate, NP-YW2, purchased from Jiangxi Fengzhu New Material Technology Co., Ltd.;

[0078] Interface improvers:

[0079] Interface improver 1: Polypropylene grafted with maleic anhydride, grafting rate 0.7wt%, GPM200A, purchased from Ningbo Nengzhiguang.

[0080] Interface improver 2: Polypropylene grafted with maleic anhydride, grafting rate 0.9wt%, GPM200AL, purchased from Ningbo Nengzhiguang.

[0081] Interface improver 3: Polypropylene grafted with maleic anhydride, grafting rate 1.5wt%, QF551, purchased from Mitsui, Japan;

[0082] Interface improver 4: Polypropylene grafted with acrylic acid, grafting rate 1.0 wt%, 5980L, purchased from Dow Chemical;

[0083] Interface improver 5: Polypropylene grafted with glycidyl methacrylate, grafting rate 0.8 wt%, SOG-03, purchased from Shanghai Jiayirong Company;

[0084] Additives:

[0085] Antioxidant: A compound of antioxidant 1010 and antioxidant 168 in a mass ratio of 1:1;

[0086] Lubricant: calcium stearate; all additives are commercially available.

[0087] It should be noted that the same raw materials were used in the parallel experiments of the embodiments and comparative examples of the present invention;

[0088] 2. Performance Testing:

[0089] (1) Magnetic force test: The polymer composite materials prepared in each example and comparative example were tested for attractive force using a permanent magnet in accordance with ISO 9934-2015;

[0090] (2) Flame retardant performance test: The polymer composite materials prepared in each example and comparative example were tested for flame retardant performance using a vertical burning tester and an oxygen index meter in accordance with GB / T10707-2008; the oxygen index requirement for interior plastic parts in the passenger car interior combustion standard GB 38262-2019 is not less than 24%;

[0091] (3) Surface metallic luster test: The polymer composite materials prepared in each example and comparative example are visually measured and evaluated based on the flashing effect of the surface metallic powder. The more uniform the dispersion of the metallic powder and the more flashing points there are, the better the metallic luster.

[0092] 3. The polymer composite materials in each embodiment and comparative example were prepared according to the formulations in Tables 1-2 by the following method, including the following steps:

[0093] The components are mixed evenly in proportion and fed into a twin-screw extruder. The polymer composite material is obtained by melt extrusion granulation. The extrusion temperature of the twin-screw extruder is 190-230℃. The screw speed of the twin-screw extruder is 300-600 rpm. The length-to-diameter ratio of the twin-screw extruder is 40:1.

[0094] Examples 1-12 and Comparative Examples 1-5

[0095] Table 1. Formulations (parts by weight) and properties of injection-molded flame-retardant metal polymer composites in Examples 1-12

[0096]

[0097]

[0098] Table 2. Formulations (parts by weight) and properties of polymer composite materials in each comparative example.

[0099] Comparative Example 1 2 3 4 5 Polyolefin resin 1 35 35 35 35 35 Metallic iron powder 1 / 25 10 40 25 Metal powder 25 / / / / Bromine-based flame retardant 1 20 20 20 20 20 Inorganic magnesium compound 1 7 7 7 7 / Interface improver 1 3 / 3 3 3 Interface improver 5 / 3 / / / antioxidants 0.2 0.2 0.2 0.2 0.2 lubricant 0.2 0.2 0.2 0.2 0.2 Magnetic force intensity (N) 0 10 7 20 16 Oxygen index (%) 21 23 24 21 20 1.5mm UL-94 vertical burning V-2 V-1 V-1 V-2 V-1 metallic luster on the surface high middle Low high high

[0100] As can be seen from Table 1, the injection-grade flame-retardant metal polymer composite materials prepared in the various embodiments of the present invention have good flame-retardant properties, magnetic strength and metallic luster. Specifically, the magnetic strength is not less than 14N, the oxygen index is not less than 24%, the flame retardant rating can reach V-0, and the surface has good metallic luster.

[0101] As can be seen from Comparative Example 1, when other metal powders are used instead of the iron powder in this application, the resulting polymer composite material is non-magnetic and has reduced flame retardant properties. This is mainly because, compared with iron powder, the exothermic behavior of other metal powders during combustion cannot match the decomposition of the flame retardant, and the excessively fast exothermic rate will actually intensify combustion.

[0102] As can be seen from Comparative Example 2, the composite material prepared using other types of interface modifiers has poor metallic luster and magnetic properties. This is because other substances are less effective in improving the compatibility between metals and polymers, leading to a decline in the performance of the composite material.

[0103] As can be seen from Comparative Examples 3 and 4, if too little iron powder is added, the magnetic properties and metallic luster of the prepared composite material will decrease. In addition, if there is too little iron powder, the concentrated heat release energy during the combustion process will be insufficient, resulting in poor synergistic flame retardant effect and a decrease in flame retardant grade. If too much iron powder is used, although the magnetic strength and metallic luster of the prepared composite material are good, the flame retardant effect will decrease. This is because iron powder releases heat during combustion, and too much will result in an excessive amount of heat release, which will accelerate the combustion of the matrix resin.

[0104] As can be seen from Comparative Example 5, without the addition of inorganic magnesium compounds, the flame retardant properties of the prepared composite material are significantly reduced, failing to meet the V-0 flame retardant rating.

[0105] 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 flame-retardant metal polymer composite material for injection molding, characterized in that, Includes the following components, calculated in parts by weight: 28-42 parts of polyolefin resin; 20-30 parts of metallic iron powder; 15-25 parts of brominated flame retardant; 5-10 parts of inorganic magnesium compounds; 1-5 parts of interface improver; The interface modifier is a maleic anhydride graft and / or an acrylic acid graft.

2. The injection-molding grade flame-retardant metal polymer composite material according to claim 1, characterized in that, The average particle size of the iron powder is 10–55 μm.

3. The injection-molding grade flame-retardant metal polymer composite material according to claim 1, characterized in that, The maleic anhydride graft comprises maleic anhydride-grafted polyolefin, and the acrylic acid graft comprises acrylic acid-grafted polyolefin.

4. The injection-molded flame-retardant metal polymer composite material according to claim 3, characterized in that, The maleic anhydride-grafted polyolefin includes maleic anhydride-grafted polypropylene and / or maleic anhydride-grafted polyethylene; the acrylic acid-grafted polyolefin includes acrylic acid-grafted polypropylene and / or acrylic acid-grafted polyethylene.

5. The injection-molding grade flame-retardant metal polymer composite material according to claim 1, characterized in that, The polyolefin resin includes one or more of polyethylene resin, polypropylene resin, ethylene-vinyl acetate copolymer, or ethylene-octene copolymer.

6. The injection-molded flame-retardant metal polymer composite material according to claim 1, characterized in that, The bromine-based flame retardant includes one or more of the following: decabromodiphenyl ethane, tris(tribromoneopentyl) phosphate, tris(2,3-dibromopropyl)isocyanurate, tetrabromobisphenol A bis(2,3-dibromopropyl) ether, tetrabromobisphenol S bis(2,3-dibromopropyl) ether, or ethyl-bis(tetrabromophenyl o-dicarboximide).

7. The injection-molding grade flame-retardant metal polymer composite material according to claim 1, characterized in that, The inorganic magnesium compound includes one or more of magnesium hydroxide, magnesium sulfate, magnesium carbonate, magnesium borate, or magnesium nitrate.

8. The injection-molding grade flame-retardant metal polymer composite material according to claim 1, characterized in that, It also includes 0.1 to 2 parts of adjuvants.

9. A method for preparing an injection-molding grade flame-retardant metal polymer composite material according to any one of claims 1 to 8, characterized in that, Includes the following steps: The components are mixed evenly and added to an extruder. The mixture is then melt-extruded and granulated to obtain an injection-grade flame-retardant metal polymer composite material.

10. The application of the injection-molding grade flame-retardant metal polymer composite material according to any one of claims 1 to 8 in the preparation of automotive parts and home appliance parts materials.

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