Nylon composite material as well as preparation method and application thereof

Abstract

The invention discloses a nylon composite material as well as a preparation method and application thereof. Belongs to the technical field of high polymer materials. 28-55 parts of an arc extinguishing filler; 0.4 to 2.2 parts of a gas production accelerant; 2.8-11 parts of a rare earth metal oxide; 0-5.2 parts of a flame retardant; 0-16 parts of glass fiber; and 0-5 parts of an auxiliary agent. The nylon composite material disclosed by the invention has excellent flame-retardant, arc-extinguishing and mechanical properties at the same time.

Description

Technical Field

[0001] The present invention belongs to the technical field of polymer engineering plastics, and particularly relates to a nylon composite material, a preparation method thereof, and an application thereof. Background Art

[0002] Modern society cannot do without various facilities in electric power, transportation, and new energy transportation. Therefore, their safety performance has also attracted much attention. Especially for electronic components, such as control switches and circuit breakers. During the use of electronic products, they usually generate heat. Under the combined action of voltage and heat, it is very easy to cause a fire. Therefore, the materials used to prepare electronic components need to have excellent flame retardancy, arc extinguishing performance, and mechanical strength.

[0003] Polyamide is widely used due to its relatively low price and high thermal conductivity coefficient. By adding functional fillers such as flame retardant fillers, arc extinguishing fillers, and reinforcing fillers to its matrix, the flame retardancy, arc extinguishing gas production performance, and mechanical strength can be correspondingly improved. However, a higher content of flame retardant will lead to a decrease in mechanical properties. Adding too much arc extinguishing filler is also likely to cause a decrease in mechanical properties and flame retardancy, unable to meet the high requirements for comprehensive performance of existing products.

[0004] In the polyamide system, in order to improve the gas production and arc extinguishing performance of the material, in addition to adding arc extinguishing fillers, gas production promoters are also added. However, the gas production promoters have poor thermal stability and are prone to decomposition at the high temperature generated by the arc. Moreover, the decomposition rate increases exponentially with temperature. Therefore, at the moment of arc extinguishing, it will decompose and rapidly generate a large amount of gas. The large instantaneous impact force will damage the microstructure of the material, resulting in a decrease in performance.

[0005] In view of this, the present application is proposed. Summary of the Invention

[0006] The purpose of the present invention is to overcome the deficiencies in the prior art that the flame retardancy, arc extinguishing gas production performance, and mechanical properties cannot be further improved simultaneously, and to provide a nylon composite material with excellent flame retardancy, arc extinguishing, and mechanical properties.

[0007] To achieve the above purpose, in the first aspect of the present invention, a nylon composite material is provided. The nylon composite material comprises the following components in parts by mass:

[0008]

[0009] In the above-mentioned flame retardant and arc extinguishing system, rare earth metal oxides are creatively added. On the one hand, the rare earth metal oxides are evenly dispersed in the polyamide matrix, increasing the nucleation points, thus improving the microstructure of the material and enhancing the mechanical strength. More crystalline regions are formed in the composite material, which can also effectively resist the damage of the microstructure caused by the rapid generation of gas. On the other hand, the rare earth metal oxides also have certain catalytic activity, which can reduce the activation energy of the decomposition of the gas generation promoter to a certain extent, improve the decomposition kinetics of the gas generation promoter, and decompose at a lower temperature. This can not only improve the gas generation efficiency and the arc extinguishing efficiency, but also avoid the secondary damage to the microstructure of the material caused by the too rapid gas generation.

[0010] In addition, the rare earth metal oxides can be used as highly efficient flame retardant synergists. When used together with the flame retardant, they can significantly improve the flame retardant performance of polyamide. They form a stable carbon layer at high temperatures, isolating oxygen and heat and reducing the combustion rate of the material.

[0011] Therefore, the addition of rare earth metal oxides can not only improve the thermal stability and gas generation efficiency of the material, but also improve the microstructure of the composite material, enhancing the mechanical strength and flame retardant performance.

[0012] Among them, the dosage of the polyamide resin is 28 to 62 parts, for example, it can be 28 parts, 30 parts, 35 parts, 40 parts, 45 parts, 50 parts, 55 parts, 60 parts, 62 parts or the range composed of any two of these values.

[0013] Among them, the dosage of the arc extinguishing filler is 28 to 55 parts, for example, it can be 25 parts, 28 parts, 30 parts, 35 parts, 40 parts, 45 parts, 50 parts, 5 or the range composed of any two of these values.

[0014] Among them, the dosage of the gas generation promoter is 0.4 to 2.2 parts, for example, it can be 0.4 parts, 0.5 parts, 0.8 parts, 1 part, 1.5 parts, 2 parts, 2.2 parts or the range composed of any two of these values.

[0015] Among them, the dosage of the rare earth metal oxides is 2.8 to 11 parts, for example, it can be 2.8 parts, 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts, 11 parts or the range composed of any two of these values.

[0016] Among them, the dosage of the flame retardant is 0 to 5.2 parts, for example, it can be 0 parts, 0.5 parts, 1 part, 2 parts, 3 parts, 4 parts, 5 parts, 5.2 parts or the range composed of any two of these values.

[0017] Among them, the dosage of the glass fiber is 0 to 16 parts, for example, it can be 0 part, 1 part, 2 parts, 4 parts, 5 parts, 6 parts, 8 parts, 10 parts, 12 parts, 15 parts, 16 parts or the range composed of any two of these values.

[0018] Among them, the dosage of the auxiliary agent is 0 to 5 parts, for example, it can be 0 part, 0.5 part, 1 part, 2 parts, 3 parts, 4 parts, 5 parts or the range composed of any two of these values.

[0019] Based on the total mass of the nylon composite material, the mass percentage of the polyamide resin ≥ 20%.

[0020] Preferably, based on the total mass of the nylon composite material, the mass percentage of the polyamide resin is 28 - 65%.

[0021] As a preferred embodiment of the present invention, the nylon composite material comprises the following components in parts by mass:

[0022]

[0023] As a preferred embodiment of the present invention, the relative viscosity of the polyamide resin ≤ 2.5, preferably 2 - 2.5, for example, it can be 2.0, 2.1, 2.2, 2.3, 2.4, 2.5 or the range composed of any two of them. The relative resin viscosity of the polyamide resin is obtained by testing according to ISO 307:2007.

[0024] As a preferred embodiment of the present invention, the polyamide resin comprises at least one of PA6 resin, PA66 resin, PA66 / 6T resin, MXD6 resin; preferably, the polyamide resin comprises PA6 resin and MXD6 resin; more preferably, the mass ratio of the PA6 resin to the MXD6 resin is (40 - 50) : (5 - 15).

[0025] In the present invention, the arc extinguishing filler comprises at least one of magnesium hydroxide, aluminum hydroxide, boron nitride, silicon nitride.

[0026] As a preferred embodiment of the present invention, the gas generation promoter comprises at least one of potassium nitrate, ammonium nitrate, zinc nitrate, potassium perchlorate, sebacic acid, terephthalic acid, suberic acid.

[0027] As a preferred embodiment of the present invention, the gas generation promoter comprises at least one of potassium nitrate, ammonium nitrate, zinc nitrate. As a preferred embodiment of the present invention, the average particle size of the arc extinguishing filler is 1 - 3 μm, for example, it can be 1 μm, 2 μm, 3 μm or the range composed of any two of them. The arc extinguishing filler with a larger particle size can quickly conduct the high heat generated during arc extinguishing. When the particle size of the arc extinguishing filler is within the above - suitable range, it can ensure its uniform dispersion in the polyamide matrix.

[0028] As a preferred embodiment of the present invention, the rare earth metal oxide includes at least one of yttrium oxide, cerium oxide, and lanthanum oxide.

[0029] As a preferred embodiment of the present invention, the average particle size of the rare earth metal oxide is 10-200 nm, for example, it can be 10 nm, 20 nm, 30 nm, 50 nm, 80 nm, 100 nm, 120 nm, 150 nm, 200 nm, or the range composed of any two of them.

[0030] As a preferred embodiment of the present invention, the average particle size of the rare earth metal oxide is 30-100 nm.

[0031] Among them, the average particle size of the rare earth metal oxide is measured by the laser diffraction method according to GB / T19077.

[0032] As a preferred embodiment of the present invention, the weight ratio of the arc extinguishing filler to the rare earth metal oxide is (3.2-13):1, for example, it can be 3.2:1, 3.5:1, 5:1, 6:1, 8:1, 10:1, 12:1, 13:1, or the range composed of any two of these values. When the dosage ratio of the arc extinguishing filler to the rare earth metal oxide is within this range, the arc extinguishing efficiency, flame retardant performance, and mechanical properties of the nylon composite material can be further improved.

[0033] As a preferred embodiment of the present invention, the weight ratio of the arc extinguishing filler to the rare earth metal oxide is (5-7.4):1.

[0034] As a preferred embodiment of the present invention, the flame retardant includes melamine cyanurate, phosphate flame retardants, and aromatic secondary amine flame retardant synergists; preferably, it includes melamine cyanurate, phosphate flame retardants, and aromatic secondary amine flame retardant synergists with a mass ratio of (4-6):1:(0.4-0.8).

[0035] As a preferred embodiment of the present invention, the phosphate flame retardants include at least one of bisphenol A bis(diphenyl phosphate) and hydroquinone bis(diphenyl phosphate).

[0036] As a preferred embodiment of the present invention, the aromatic secondary amine flame retardant synergists include at least one of 4,4'-bis(phenylisopropyl)diphenylamine, N,N'-diphenyl-p-phenylenediamine, and N-phenyl-1-naphthylamine.

[0037] As a preferred embodiment of the present invention, the glass fiber is preferably an alkali-free and arsenic-free chopped glass fiber, the length of the glass fiber is 3.0-4.5 mm, and the average diameter is 8-10 μm.

[0038] In the present invention, the test method for the length and diameter of glass fibers is obtained by microscopic measurement: 100 glass fiber samples are placed under a microscope for observation, and the diameters and lengths of all glass fibers in the samples are calculated, and the average value is calculated to obtain the average diameter and length of the glass fibers.

[0039] The present invention has no special requirements for the type, length, and average diameter of glass fibers, and the effects of the present invention can be achieved within the above ranges.

[0040] In the present invention, the types of additives are not particularly limited, and common functional additives in the art can be used in the present invention to bring corresponding properties without affecting the flame retardancy, arc extinguishing performance, and mechanical properties of the material. The additives can be added according to requirements.

[0041] The additive can be at least one of an antioxidant and a lubricant.

[0042] Exemplarily, the antioxidant includes at least one of phenolic antioxidants, hindered amine antioxidants, thioester antioxidants, phosphite antioxidants, and inorganic phosphate antioxidants.

[0043] Exemplarily, the lubricant includes but is not limited to at least one of silicone masterbatch, polyethylene wax, stearate, ethylene bis-fatty acid amide, and montan ester.

[0044] The additive can also be a marking agent.

[0045] In the second aspect of the present invention, the present invention also provides a method for preparing the nylon composite material described in the first aspect of the present invention, and the preparation method includes the following steps:

[0046] According to the weight parts, polyamide resin, arc extinguishing filler, gas generation promoter, rare earth metal oxide, flame retardant, glass fiber, and additive are mixed, and the nylon composite material is obtained after extrusion and granulation.

[0047] Preferably, the method for preparing the nylon composite material includes the following steps:

[0048] (1) Weigh the raw materials according to the weight parts;

[0049] (2) Mix the flame retardant and the additive, and then mix them with the polyamide resin in a high-speed mixer evenly, and the mixing time is 3-5 minutes, denoted as component A;

[0050] (3) Denote the reinforcing filler as component B and the arc extinguishing filler as component C;

[0051] (4) Add the component A prepared in step (2) to the main feeding system of the twin-screw extruder, and add the component B and component C in step (3) to the bilateral feeding systems of the twin-screw extruder respectively, and perform melt blending and extrusion granulation to obtain the flame-retardant nylon arc extinguishing material; the length-diameter ratio of the screw of the twin-screw extruder is 36-48∶1, the screw speed is 250-450 rpm, and the extrusion temperature is 220-300 °C.

[0052] The preparation method of the product of the present invention has simple operation steps and can realize industrial-scale production.

[0053] In the third aspect of the present invention, an electronic component is provided. The raw materials for preparing the electronic component include the nylon composite material described in the first aspect of the present application, and the electronic component can be at least one of a control switch and a circuit breaker.

[0054] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0055] By further adding rare earth metal oxides to the flame-retardant and arc-extinguishing polyamide system, the present invention can not only improve the thermal stability and gas generation efficiency of the material, but also improve the microstructure of the composite material, and enhance the mechanical strength and flame-retardant performance. The flame-retardant grade of the nylon composite material prepared by the present invention is V-0, and it can pass the glow wire performance test of the IEC 60695-2 standard, the notch impact strength ≥ 8 MPa, the smoke density ≤ 80 mg / cm 3 , the air pressure increase value ≥ 0.08 kPa, and the current breaking life ≥ 1100 times. Specific Embodiments

[0056] To better illustrate the purpose, technical solution and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments.

[0057] The reagents, methods and equipment used in the present invention are all conventional reagents, methods and equipment in the art unless otherwise specified.

[0058] PA1: PA6, HY-2500A, relative resin viscosity 2.5, Haiyang Chemical Fiber;

[0059] PA2: PA6, PA6 J2000, relative resin viscosity 2, Polymerization Shun;

[0060] PA 3: Composed of PA6 and MXD6, the mass ratio of PA6 resin and MXD6 resin is 40:5, PA6 is HY-2500A, MXD6 is ZYMX5001, relative viscosity is 2.0, Sinochem Technology.

[0061] PA 4: Consisting of PA6 and MXD6, the mass ratio of PA6 resin to MXD6 resin is 50:15, PA6 is PA6 J2000, MXD6 is PAMXD6, relative viscosity is 2.5, supplied by Shanghai Yinggu Chemical Industry

[0062] PA 5: PA66, PA66 U3600 NC01, relative resin viscosity 2.4, Invista;

[0063] PA 6: PA66 / 6T, NPD-652, relative resin viscosity 2.4, Invista;

[0064] Magnesium hydroxide: MH-01, average particle size is 2μm, purchased from Luoyang Zhongchao;

[0065] Aluminum hydroxide: AH008, average particle size is 1μm, purchased from Luoyang Zhongchao;

[0066] Boron nitride: PN02, average particle size is 2.5μm, purchased from Zibo Jingyi;

[0067] Gas generation promoter 1: Zinc nitrate, commercially available;

[0068] Gas generation promoter 2: Terephthalic acid, commercially available;

[0069] Yttrium oxide 1: Average particle size 100nm, commercially available;

[0070] Yttrium oxide 2: Average particle size 30nm, commercially available;

[0071] Yttrium oxide 3: Average particle size 10nm, commercially available;

[0072] Yttrium oxide 4: Average particle size 200nm, commercially available;

[0073] Lanthanum oxide: Average particle size is 100nm, commercially available;

[0074] Cerium oxide: Average particle size is 100nm, commercially available;

[0075] Silicon oxide: Average particle size is 100nm, commercially available;

[0076] Flame retardant 1: Melamine cyanurate MCA, purchased from Shouguang Weidong;

[0077] Flame retardant 2: A compound of melamine cyanurate MCA, bisphenol A bis(diphenyl phosphate) and 4,4'-bis(phenylisopropyl)diphenylamine, the mass ratio of melamine cyanurate MCA, bisphenol A bis(diphenyl phosphate) and 4,4'-bis(phenylisopropyl)diphenylamine is 4:1:0.8, bisphenol A bis(diphenyl phosphate) and 4,4'-bis(phenylisopropyl)diphenylamine are commercially available products;

[0078] Flame retardant 3: A compound of melamine cyanurate (MCA), bisphenol A bis(diphenyl phosphate), and 4,4'-bis(phenylisopropyl)diphenylamine. The mass ratio of melamine cyanurate (MCA), bisphenol A bis(diphenyl phosphate), and 4,4'-bis(phenylisopropyl)diphenylamine is 6:1:0.4. Bisphenol A bis(diphenyl phosphate) and 4,4'-bis(phenylisopropyl)diphenylamine are commercially available products;

[0079] Flame retardant 4: A compound of melamine cyanurate (MCA), bisphenol A bis(diphenyl phosphate), and 4,4'-bis(phenylisopropyl)diphenylamine. The mass ratio of melamine cyanurate (MCA), bisphenol A bis(diphenyl phosphate), and 4,4'-bis(phenylisopropyl)diphenylamine is 8:1:0.2. Bisphenol A bis(diphenyl phosphate) and 4,4'-bis(phenylisopropyl)diphenylamine are commercially available products;

[0080] Flame retardant 5: A compound of melamine cyanurate (MCA), bisphenol A bis(diphenyl phosphate), and 4,4'-bis(phenylisopropyl)diphenylamine. The mass ratio of melamine cyanurate (MCA), bisphenol A bis(diphenyl phosphate), and 4,4'-bis(phenylisopropyl)diphenylamine is 2:1:1. Bisphenol A bis(diphenyl phosphate) and 4,4'-bis(phenylisopropyl)diphenylamine are commercially available products;

[0081] Glass fiber: ECS10-03-568H, with a length of 3 mm and an average diameter of 10 μm, produced by Jushi Group;

[0082] Antioxidant: A compound formed by IRGANOX 1098 and Revonox 608 in a mass ratio of 1:1, commercially available;

[0083] Lubricant: Montan ester, commercially available.

[0084] Unless otherwise specified, in the parallel experiments of the examples and comparative examples of the present invention, except for the replaced raw materials, the types of other raw materials are kept consistent.

[0085] Examples 1-23, Comparative Examples 1-4

[0086] The examples and comparative examples of the present invention provide a series of nylon composites. The component contents (parts by weight) of the nylon composites are shown in Tables 1, 2, and 3. The preparation method includes the following steps;

[0087] (1) Weigh the raw materials according to the said parts by weight;

[0088] (2) Mix the flame retardant and additives, and then mix them evenly with the polyamide resin in a high-speed mixer for 3-5 minutes, denoted as Component A;

[0089] (3) The reinforcing filler is denoted as component B, and the arc extinguishing filler is denoted as component C;

[0090] (4) Add the component A prepared in step (2) to the main feeding system of a twin-screw extruder, and add the component B and component C in step (3) to the bilateral feeding systems of the twin-screw extruder respectively, melt and blend them, and extrude and pelletize to obtain the flame-retardant nylon arc extinguishing material; the length-diameter ratio of the screw of the twin-screw extruder is 36 - 48∶1, the screw rotation speed is 250 - 450 rpm, and the extrusion temperature is 220 - 300 °C.

[0091] Table 1

[0092]

[0093] Table 2

[0094]

[0095] Table 3

[0096]

[0097] Performance test

[0098] The present invention further tests the performance of the products prepared in the above-mentioned examples and comparative examples. The test items include the following aspects:

[0099] 1. Izod notched impact strength: After drying the obtained nylon composite material in an oven at 120 °C for 4 hours, injection mold ISO standard Izod notched impact specimens, and test the Izod notched impact strength of the nylon composite material according to the ISO 180:2019 standard. The notch type is A, and the notch depth is 2 mm.

[0100] 2. UL94 vertical burning @1.6 mm: After drying the obtained nylon composite material in an oven at 120 °C for 4 hours, injection mold UL flame-retardant specimens with a thickness of 1.6 mm, and test the flame-retardant performance of the nylon composite material according to the UL94 standard.

[0101] 3. Glow wire performance test: After drying the obtained nylon material in an oven at 120 °C for 4 hours, injection mold 100*100*1.0 mm specimens, and test the glow wire performance according to the IEC 60695-2 standard.

[0102] 4. Arc extinguishing performance test: Prepare the above-mentioned flame-retardant gas-producing polyamide arc extinguishing composite material into the gas-producing component (side wall arc extinguishing piece) of a circuit breaker. In the test of the model arc extinguishing chamber, measure the pressure with a pressure sensor, and the gas pressure change is shown in Table 3.

[0103] 5. Current breaking life test: Tested according to IEC 60898-1 standard, test voltage: DC250 V; test current: 63 A; time constant: 2 ms; number of operations: 1500 times; frequency: 120 times / hour.

[0104] 6. Smoke density test @ 3.0 mm: After drying the obtained nylon composite material in an oven at 120 °C for 4 hours, injection mold an ISO standard 3.0 mm smoke density test sample, and test the smoke density data of the nylon composite material according to ISO 5659-2:2017 standard. Test conditions: irradiation intensity 25 kW / m 2 , duration 10 min.

[0105] Table 4

[0106]

[0107] As can be seen from Table 4, the nylon composite material described in the present invention has excellent flame retardancy, arc extinguishing, and mechanical properties. Among them, the flame retardancy grade of the nylon composite material is V-0, and it can pass the glow wire performance test according to IEC 60695-2 standard. The notched impact strength ≥ 8 MPa, the smoke density ≤ 80 mg / cm 3 , the air pressure increase value ≥ 0.08 kPa, and the current breaking life ≥ 1100 times.

[0108] By comparing Example 2 with Comparative Examples 1-4, it can be seen that in the present invention, the arc extinguishing filler, gas generation promoter, and rare earth metal oxide are all indispensable. The lack of any one of them will lead to a significant decrease in performance. In particular, the arc extinguishing filler and rare earth metal oxide have a significant synergistic effect. Under the combined action of the two, the flame retardancy, arc extinguishing, and mechanical properties of the nylon composite material are significantly improved.

[0109] Finally, it should be noted that the above embodiments are used to illustrate the technical solutions of the present invention rather than to limit the protection scope of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A nylon composite material, characterized in that, The nylon composite material comprises the following components in parts by mass:

2. The nylon composite material according to claim 1, wherein The relative viscosity of the polyamide resin is ≤2.5, preferably 2 - 2.

5.

3. The nylon composite material according to claim 1, wherein The polyamide resin includes at least one of PA6 resin, PA66 resin, PA66 / 6T resin, and MXD6 resin; preferably, the polyamide resin includes PA6 resin and MXD6 resin; more preferably, the mass ratio of the PA6 resin to the MXD6 resin is (40 - 50):(5 - 15).

4. The nylon composite material according to claim 1, wherein Meet at least one of the following (a) - (e): (a) The rare earth metal oxide includes at least one of yttrium oxide, cerium oxide, and lanthanum oxide; (b) The average particle size of the rare earth metal oxide is 10 - 200 nm; (c) The gas generation promoter includes at least one of potassium nitrate, ammonium nitrate, zinc nitrate, potassium perchlorate, sebacic acid, terephthalic acid, and suberic acid; (d) The arc extinguishing filler includes at least one of magnesium hydroxide, aluminum hydroxide, boron nitride, and silicon nitride; (e) The average particle size of the arc extinguishing filler is 1 - 3 μm.

5. The nylon composite material according to claim 1, wherein The weight ratio of the arc extinguishing filler to the rare earth metal oxide is (3.2 - 13):

1.

6. The nylon composite material according to claim 1, wherein The flame retardant includes at least one of melamine cyanurate, phosphate flame retardants, and aromatic secondary amine flame retardant synergists; preferably, it includes melamine cyanurate, phosphate flame retardants, and aromatic secondary amine flame retardant synergists with a mass ratio of (4 - 6):1:(0.4 - 0.8).

7. The nylon composite material according to claim 1, characterized in that, The phosphate flame retardant includes at least one of bisphenol A bis(diphenyl phosphate) and hydroquinone bis(diphenyl phosphate); and / or The aromatic secondary amine flame retardant synergist includes at least one of 4,4'-bis(phenylisopropyl)diphenylamine, N,N'-diphenyl-p-phenylenediamine, and N-phenyl-1-naphthylamine.

8. The nylon composite material according to claim 1, wherein The auxiliary agent includes at least one of an antioxidant and a lubricant.

9. The preparation method of the nylon composite material according to any one of claims 1-8, characterized in that, The preparation method includes the following steps: According to the parts by weight, mix the polyamide resin, arc extinguishing filler, gas generation promoter, rare earth metal oxide, flame retardant, glass fiber, and auxiliary agent, and obtain the nylon composite material after extrusion and pelletization.

10. An electronic component, characterized in that, The preparation raw material of the electronic component includes the nylon composite material according to any one of claims 1 - 8, and the electronic component includes at least one of a control switch and a circuit breaker.

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