Nylon composite material and preparation method and application thereof

Abstract

The application discloses a nylon composite material, which comprises the following components in parts by weight: aliphatic nylon 60-80 parts; MCA flame retardant 15-35 parts; polyethylene glycol 5-10 parts; and polyether block amide 4-10 parts. The MCA with specific free cyanuric acid content is used in the application, and the MCA generates inert gas due to the high temperature generated by an electric arc in the IPT test, which is beneficial to the rapid outward diffusion of the electric arc. Meanwhile, the polyether block amide as a charge dissipating agent can reduce the electric arc energy and guide the rapid diffusion of the electric arc. Meanwhile, the introduction of the polyethylene glycol can improve the water absorption of the nylon composite material, and the electric arc diffusion is synergized, so that the IPT is further improved. Meanwhile, the nylon composite material has a flame retardancy of 0.8mm V-0.

Description

Technical Field

[0001] This invention relates to the field of polymer materials technology, and in particular to a nylon composite material, its preparation method, and its application. Background Technology

[0002] Polyamide resins possess excellent comprehensive properties, including mechanical properties, barrier properties, heat resistance, abrasion resistance, and chemical corrosion resistance. Their composite materials are widely used in machinery manufacturing, home appliances, power tools, electronics, and transportation. In these diverse applications, the requirements for flame retardant properties and IPT (Intense Pulsed Temperature) performance of these composite materials are becoming increasingly stringent.

[0003] Nitrogen-based flame retardant melamine cyanurate (MCA) possesses advantages such as being environmentally friendly, having low smoke density, excellent electrical properties, light weight, easy coloring, and high cost-effectiveness. It is widely used in the flame-retardant modification of nylon, and its modified products are extensively applied in connectors, low-voltage electrical appliances, contactors, and general electrical appliance housings. Current technology mainly focuses on the flame-retardant stability of MCA composite materials. For example, Chinese patent CN 103408750 A involves adding melamine cyanurate (MCA) as a flame retardant during the polymerization of polyamide monomers, with nano-SiO2 and metal oxides acting as synergistic flame retardants, to prepare flame-retardant polyamides through in-situ polymerization. While this method can produce flame-retardant, stable composite materials with excellent mechanical properties, it is not suitable for large-scale industrial production.

[0004] On the other hand, research on improving the IPT (Intensity Tolerance) of flame-retardant nylon mainly focuses on non-nitrogen-based systems. For example, CN114456593 B uses an aromatic polyamide and inorganic hydroxide scheme in an organophosphorus system to achieve high IPT performance; CN114672160 B uses an inorganic hydroxide and toughening agent scheme in a red phosphorus system to achieve an IPT of 1.5 kV. However, in halogen-free nitrogen-based flame-retardant systems, these currently disclosed substances all severely affect the flame-retardant properties of the composite nylon, causing it to change from V-0 to V-2 flame retardancy. Therefore, there is currently very little work on how to obtain high IPT and V0 flame-retardant halogen-free nitrogen-based flame-retardant nylon composites. Summary of the Invention

[0005] The purpose of this invention is to overcome the above-mentioned technical defects and provide a nitrogen-based 0.8mm V-0 flame-retardant nylon composite material with IP greater than or equal to 2.5kV, as well as its preparation method and application.

[0006] This invention is achieved through the following technical solution:

[0007] A nylon composite material, by weight, comprises the following components:

[0008] 60-80 parts aliphatic nylon;

[0009] 15-35 parts of MCA flame retardant;

[0010] 5-10 parts of polyethylene glycol;

[0011] 4-10 parts of polyether block amide.

[0012] The number-average molecular weight range of the polyethylene glycol is 1000-4000.

[0013] Preferably, the number average molecular weight of the polyethylene glycol is in the range of 2000-3000.

[0014] The number-average molecular weight of polyethylene glycol (PEG) can be obtained by gel permeation chromatography-multi-angle laser scattering (SEC-MALLS), as follows: Weigh a certain amount of PEG (accurate to 0.01 mg) and tetrahydrofuran (accurate to 0.1 mL), prepare a PEG dilute solution, let it stand for 24 h, filter the sample solution through a 0.45 μm semi-permeable membrane, and then inject it into the SEC-MALLS testing system for measurement to obtain the corresponding data.

[0015] The free cyanuric acid content of the MCA flame retardant is 0.08-0.16 wt%, preferably 0.10-0.13 wt%.

[0016] The preparation method of MCA flame retardant is as follows: Melamine monomer and cyanuric acid are added to a high-pressure reactor in a molar ratio of 1:1.03, using deionized water as the medium. The reaction temperature is controlled at 105℃, and the reaction time is 2 hours. The mixture is then cooled to a constant temperature of 30℃. The reactants are filtered, washed with deionized water, and filtered again. This process is repeated several times. The reactants are then dried in a 100℃ oven to obtain the MCA flame retardant. The mixture is then repeatedly washed with deionized water at 80℃ until the desired free cyanuric acid is obtained.

[0017] The test method for free cyanuric acid in MCA flame retardant is as follows: Determination is performed by gravimetric method according to industry standard HG / T 5341-2018. Specifically: Add 10g of sample to 100mL of water, heat to boiling, and while hot, filter through a Buchner funnel using three layers of slow-moving quantitative filter paper. Transfer the filtrate to a 150mL beaker and heat to near boiling. Add 10mL of melamine solution (10g / L) dropwise while stirring continuously. After boiling, let stand at room temperature for 1 hour, then transfer to cold water and let stand for 10mL. Filter using a pre-weighed glass frit crucible, and wash the precipitate with melamine solution (0.3g / L). Transfer the glass frit crucible to a 105℃±2℃ electric thermostatic drying oven and dry for 2 hours. Remove the precipitate, cool, and weigh. Calculate the precipitate using the following formula:

[0018] W5=(m1×0.5058 / m0)×100=m1×50.58 / m0

[0019] m1 is the mass value of the precipitate, in grams;

[0020] m0 is the mass of the sample, in grams;

[0021] 0.5058 is the conversion factor for melamine cyanurate to cyanuric acid.

[0022] The aliphatic nylon is a polyamide obtained by polycondensation of at least one aliphatic dicarboxylic acid with an aliphatic diamine or a cyclic diamine; the aliphatic nylon is selected from one or more of PA6, PA66, PA610, PA612, and PA1212.

[0023] The relative viscosity range of aliphatic nylon, as measured according to ISO 307-2007, is 2.0–2.8 L / g.

[0024] Polyether block amides have a large number of ether and amide bonds in their molecular structure, which readily form hydrogen bonds with water molecules in the air, greatly improving the water absorption of the material. On the other hand, because they have the same amide bond structure as nylon, they do not require additional compatibilizers to have good compatibility with nylon resin.

[0025] Polyether block amides can be selected from Arkema Chemicals' Pebax series or Sanyo Chemicals' PELESTAT series, etc.

[0026] Depending on actual needs, 0-2 parts of additives may be added, wherein the additives are selected from at least one of antioxidants and lubricants.

[0027] The method for preparing the nylon composite material of the present invention includes the following steps: mixing the components evenly, extruding and granulating them through a twin-screw extruder to obtain the nylon composite material.

[0028] The nylon composite material of the present invention is used to manufacture high-voltage connectors and flame-retardant connectors.

[0029] The present invention has the following beneficial effects:

[0030] This invention utilizes the instantaneous high temperature generated by the electric arc during IPT testing of MCA with a specific free cyanuric acid content, which causes the MCA to generate an inert gas, facilitating the rapid outward diffusion of the arc. Simultaneously, polyether block amide acts as a charge dissipation agent, reducing arc energy and guiding rapid arc diffusion. Furthermore, the introduction of polyethylene glycol enhances the water absorption of the nylon composite material, synergistically promoting arc diffusion and further improving the IPT. Additionally, the nylon composite material of this invention exhibits a flame retardancy of 0.8 mmV-0. Detailed Implementation

[0031] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention. These all fall within the scope of protection of the present invention.

[0032] The raw materials used in the embodiments and comparative examples of this invention are as follows:

[0033] Nylon 66: PA66 EP-158, Huafeng Group Co., Ltd.;

[0034] Nylon 6: PA6 HY-2500A, Haiyang Technology Co., Ltd.;

[0035] MCA-1: Free cyanuric acid content is 0.08 wt%, prepared in-house;

[0036] MCA-2: Free cyanuric acid content is 0.10 wt%, prepared in-house;

[0037] MCA-3: Free cyanuric acid content is 0.13wt%, prepared in-house;

[0038] MCA-4: Free cyanuric acid content is 0.16wt%, prepared in-house;

[0039] MCA-5: Free cyanuric acid content is 0.05wt%, prepared in-house;

[0040] MCA-6: Free cyanuric acid content is 0.20 wt%, prepared in-house;

[0041] Polyethylene glycol-1, PEG-1000, with a number average molecular weight of 1000, is manufactured by Lotte Chemicals, South Korea.

[0042] Polyethylene glycol-2, PEG-1500, with a number average molecular weight of 1500, is manufactured by Lotte Chemicals, South Korea.

[0043] Polyethylene glycol-3, PEG-2000, with a number average molecular weight of 2000, is manufactured by Lotte Chemicals, South Korea.

[0044] Polyethylene glycol-4, PEG-3000, with a number average molecular weight of 3000, is manufactured by Lotte Chemicals, South Korea.

[0045] Polyethylene glycol-5, PEG-4000, with a number average molecular weight of 4000, is manufactured by Lotte Chemicals in South Korea.

[0046] Polyethylene glycol-6: PEG-800, with a number average molecular weight of 800, is manufactured by Lotte Chemicals in South Korea;

[0047] Polyethylene glycol-7: PEG-6000, with a number average molecular weight of 6000, is manufactured by Lotte Chemicals in South Korea;

[0048] Polyether block amide A: Pebax® 2533 SD 01, Arkema Chemicals Ltd.;

[0049] Polyether block amide B: Pebax® 3533 SD 01, Arkema Chemicals Ltd.;

[0050] Polyether block amide C: PELESTAT® 300, Sanyo Chemical Co., Ltd., Japan;

[0051] Polyether block amide D: PELESTAT® 2450, Sanyo Chemical Co., Ltd., Japan;

[0052] Antioxidant: N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexamethylenediamine (IRGANOX 1098), BASF;

[0053] Lubricant: Ethylene bis-stearamide, EBS HI-LUBE, Shinwon, South Korea.

[0054] Preparation method of nylon composite material in the examples and comparative examples: The components were mixed evenly and granulated by extrusion through a twin-screw extruder to obtain the nylon composite material. The barrel temperature was set as follows: Zone 1: 80℃, Zone 2: 180℃, Zone 3: 270℃, Zone 4: 270℃, Zone 5: 250℃, Zone 6: 250℃, Zone 7: 250℃, Zone 8: 250℃, Zone 9: 250℃, Zone 10: 260℃, and the main extruder speed was 300~500 r / min.

[0055] Test methods:

[0056] (1) IPT: Referring to ASTM D2303, the sample is placed at a 45° angle, the test liquid conduit is installed on the upper part of the sample and the liquid is continuously added at a certain flow rate. The two electrodes are made of stainless steel and the distance between them is 50 mm. The high voltage end is placed on the upper part of the sample and the ground end is placed on the lower part of the sample. The AC frequency is 48-62 Hz. The test is carried out under the specified voltage and liquid flow rate. The time taken for the tracking failure to occur is recorded to characterize the tracking resistance of the sample. The test voltage is in the range of 1-5 kV. If the arc of the material does not exceed 25 mm for 1 hour, it means that the material has passed the IPT of this voltage.

[0057] (2) Flame retardant rating: Refer to UL94 standard, the test strip size is 125mm*13mm*0.8mm.

[0058] Table 1: Weight parts and test results of each component of the nylon composite material in Examples 1-7

[0059] Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Nylon 66 60 70 80 70 70 70 Nylon 6 70 MCA-1 15 25 35 25 MCA-2 25 MCA-3 25 MCA-4 25 Polyethylene glycol-1 5 7 10 7 7 7 7 Polyether block amide A 4 7 10 7 7 7 7 antioxidants 0.3 0.3 lubricant 0.2 IPT, V 1500 1800 2000 1900 2000 2000 1900 Flame retardant rating V-0 V-0 V-0 V-0 V-0 V-0 V-0

[0060] As can be seen from Examples 2 / 5-7, the IPT is higher when the MCA with the preferred cyanuric acid content is selected.

[0061] Table 2: Weight parts and test results of each component of the nylon composite material in Examples 8-14

[0062] Example 8 Example 9 Example 10 Example 11 Example 12 Example 13 Example 14 Nylon 66 70 70 70 70 70 70 70 MCA-1 25 25 25 25 25 25 25 Polyethylene glycol label -2 -3 -4 -5 -1 -1 -1 polyethylene glycol content 7 7 7 7 7 7 7 Polyether block amide A 7 7 7 7 Polyether block amide B 7 Polyether block amide C 7 Polyether block amide D 7 IPT, V 1900 2200 2300 1800 1900 1800 1800 Flame retardant rating V-0 V-0 V-0 V-0 V-0 V-0 V-0

[0063] As can be seen from Examples 2 / 8-11, the IPT is higher when polyethylene glycol with a preferred number-average molecular weight.

[0064] Table 3: Weight parts of each component and test results of comparative nylon composite materials

[0065] Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 Comparative Example 7 Comparative Example 8 Nylon 66 70 70 70 70 70 70 70 70 MCA-1 25 25 25 25 25 25 MCA-5 25 MCA-6 25 Polyethylene glycol label -1 -1 -6 -7 / -1 -1 -1 polyethylene glycol content 7 7 7 7 / 15 7 7 Polyether block amide A 7 7 7 7 7 7 0 15 IPT, V 1200 1000 1100 1800 900 1000 800 1500 Flame retardant rating V-0 V-0 V-2 V-2 V-0 V-2 V-0 V-2

[0066] As shown in Comparative Example 1 / 2, IPT is very low when the free cyanuric acid content of MCA is too low or too high.

[0067] As shown in Comparative Example 3, when the number-average molecular weight of polyethylene glycol is too low, the IPT is low and cannot reach V-0.

[0068] As shown in Comparative Example 4, when the number-average molecular weight of polyethylene glycol is too high, V-0 cannot be achieved.

[0069] As shown in Comparative Example 5, the IPT is too low when polyethylene glycol is not present.

[0070] As shown in Comparative Example 6, when the polyethylene glycol content is too high, it will actually reduce the IPT and fail to reach V-0.

[0071] As shown in Comparative Example 7, the IPT is low when polyether block amide is not present.

[0072] As can be seen from Comparative Example 8, when the content of polyether block amide is too high, V-0 cannot be achieved.

Claims

1. A nylon composite material, characterized in that, By weight, it includes the following components: 60-80 parts aliphatic nylon; 15-35 parts of MCA flame retardant; 5-10 parts of polyethylene glycol; 4-10 parts of polyether block amide; The number-average molecular weight range of the polyethylene glycol is 1000-4000; The free cyanuric acid content of the MCA flame retardant is 0.08-0.16 wt%.

2. The nylon composite material according to claim 1, characterized in that, The number-average molecular weight range of the polyethylene glycol is 2000-3000.

3. The nylon composite material according to claim 1, characterized in that, The free cyanuric acid content of the MCA flame retardant is 0.10-0.13 wt%.

4. The nylon composite material according to claim 1, characterized in that, The aliphatic nylon is a polyamide obtained by polycondensation of at least one aliphatic dicarboxylic acid with an aliphatic diamine or a cyclic diamine; the aliphatic nylon is selected from one or more of PA6, PA66, PA610, PA612, and PA1212.

5. The nylon composite material according to any one of claims 1-4, characterized in that, The product also includes 0-2 parts by weight of additives, wherein the additives are selected from at least one of antioxidants and lubricants.

6. The method for preparing the nylon composite material according to any one of claims 1-5, characterized in that, The process includes the following steps: mixing the components evenly, extruding and granulating them using a twin-screw extruder to obtain a nylon composite material.

7. The application of the nylon composite material according to any one of claims 1-5, characterized in that, Used in the manufacture of high-voltage connectors and flame-retardant connectors.