A red phosphorus flame-retardant nylon composite material with a high glow-wire ignition temperature and low acid evolution, and a preparation method thereof

Abstract

A red phosphorus flame-retardant nylon composite material with a high glow wire ignition temperature and low acid precipitation, and a preparation method thereof. The composite material is characterized in that it contains the following raw materials in parts by mass: 30-70 parts of nylon resin, 5-40 parts of glass fiber, 5-15 parts of red phosphorus flame-retardant masterbatch, 1-10 parts of flame-retardant synergist, 1-20 parts of filling filler, and 0.1-5 parts of phosphine inhibitor. By introducing the filling filler and the phosphine inhibitor, and combining with the double-sided feeding extrusion processing method, the synergistic effect is further realized, and the glow wire ignition temperature and acid precipitation resistance of the material are improved.

Description

Technical Field

[0001] The present invention relates to a red phosphorus flame-retardant nylon composite material with a high glow wire ignition temperature and low acid precipitation, and a preparation method thereof. Background Art

[0002] With the continuous innovation of new energy vehicle technology, the power distribution system, the three-electric control system and the battery system need to withstand higher voltages and currents. During their operation, high temperatures or high-energy discharge phenomena will occur. In particular, the arcing phenomenon formed is likely to cause safety problems such as fires. Therefore, it is required that the materials used for each component must have better flame retardancy and electrical properties.

[0003] Red phosphorus flame-retardant nylon is widely used in components such as new energy vehicle charging gun heads and battery components due to its excellent comprehensive performance and high cost performance. The glow wire non-ignition temperature of traditional red phosphorus flame-retardant nylon materials is basically around 750°C. When the glow wire temperature is slightly higher (>750°C), open flames will appear, easily causing component burnout and malfunctions, and even fires. In addition, most electrical accessories of new energy vehicles are in contact with metal parts. Due to the structure of the red phosphorus flame retardant itself, the red phosphorus flame-retardant nylon material is prone to acid precipitation in a high humidity and heat environment. This acid precipitation has a corrosive effect on metal parts, easily causing an increase in the surface resistance of the metal, resulting in component temperature rise and abnormal operation. Therefore, how to improve the glow wire flame retardancy and acid precipitation control of red phosphorus flame-retardant nylon materials is the key research direction of future materials.

[0004] At present, there is certain research on the high glow wire performance of red phosphorus flame-retardant nylon in China, but there are few research reports on achieving both high glow wire and low acid precipitation performance. The patent CN103304992A discloses an invention of a flame-retardant nylon composition with a high glow wire ignition temperature. This composition mainly realizes high glow wire flame retardancy by adding a multi-component composite flame retardant, a dripping inhibitor, a charring promoter, and a glow wire ignition temperature enhancer. The compounding of the flame retardant types is complex, and the influence of the addition of the composition on the acid precipitation and insulation performance of the material is not mentioned in the article. The patent CN115304913A discloses an invention of a reinforced flame-retardant hypophosphite / nylon composite material with a high glow wire ignition temperature and a preparation method thereof. This method uses a self-made modified hypophosphite (hexachlorocyclodiphosphazene, silanol compound and hypophosphite) masterbatch as a flame retardant to achieve a high glow wire ignition temperature of the material by adding a flame retardant synergist; the article mainly mentions the role of the modified phosphate, which has no relevance to the red phosphorus flame retardant, and the electrical properties of the material are not mentioned in the article. Summary of the Invention

[0005] The object of the present invention is to develop a red phosphorus flame-retardant nylon composite material with a high glow-wire ignition temperature and low acid evolution. In the present invention, nylon is used as the base resin, and an organopolysiloxane / carbonizing agent compounded flame-retardant synergist is used in synergistic flame retardancy with a red phosphorus flame-retardant masterbatch. A filler, a phosphine inhibitor and a processing aid are introduced, and a red phosphorus flame-retardant nylon composite material with a high glow-wire ignition temperature and low acid evolution is prepared by a double-sided feeding extrusion processing method. This material can achieve non-ignition of the material at a high glow wire (800 °C), and at the same time endow the material with low acid evolution and high insulation performance.

[0006] The technical solution of the present invention is as follows:

[0007] A red phosphorus flame-retardant nylon composite material with a high glow-wire ignition temperature and low acid evolution and a preparation method thereof, characterized in that the composite material comprises the following raw materials in parts by mass:

[0008] Nylon resin 30 - 70 parts

[0009] Glass fiber 5 - 40 parts

[0010] Red phosphorus flame-retardant masterbatch 5 - 15 parts

[0011] Flame-retardant synergist 1 - 10 parts

[0012] Filler 1 - 20 parts

[0013] Phosphine inhibitor 0.1 - 5 parts.

[0014] A red phosphorus flame-retardant nylon composite material with a high glow-wire ignition temperature and low acid evolution and a preparation method thereof, characterized in that the composite material comprises the following raw materials in parts by mass:

[0015] Nylon resin 37 - 50 parts

[0016] Glass fiber 30 - 40 parts

[0017] Red phosphorus flame-retardant masterbatch 5 - 13 parts

[0018] Flame-retardant synergist 5 - 9 parts

[0019] Filler 3 - 7 parts

[0020] Phosphine inhibitor 0.1 - 1 part

[0021] Coupling agent 0.1 - 0.3 part

[0022] Lubricant 0.3 - 0.8 part

[0023] Antioxidant 0.2 - 0.4 part

[0024] Black masterbatch 2 - 3 parts.

[0025] The nylon resin described above is one or a mixture of more than one of PA6, PA66, copolyamide, PA56, PA612, and PA1012.

[0026] The red phosphorus flame retardant masterbatch described above is a red phosphorus masterbatch with PA6 as the carrier, and further preferably a red phosphorus flame retardant masterbatch coated with melamine, which is commercially available.

[0027] The flame retardant synergist described above is a compound of semi-doubled polysiloxane with a POS structure and a triazine-based hyperbranched charring agent, and further preferably the compounding ratio is 20:1.

[0028] The filling filler described above is one or a mixture of more than one of wollastonite, talcum powder, montmorillonite, and kaolin, and further preferably montmorillonite.

[0029] The phosphine inhibitor described above is a mixture of two or more of copper oxide, aluminum oxide, magnesium oxide, and zinc oxide and / or a Cu-Zn-Al composite salt, and further preferably the Cu-Zn-Al composite salt of model CZ-D08A20.

[0030] The coupling agent described above is a silane coupling agent; further preferably KH550.

[0031] The lubricant described above is one or a mixture of more than one of ethylene bis-stearamide modifier, calcium stearate, and ethylene acrylic copolymer.

[0032] The antioxidant described above is one or a mixture of more than one of hindered amines, phosphite esters, and thioesters.

[0033] The black masterbatch described above is prepared by mixing carbon black and / or organic black with PA6 as the carrier, and is commercially available.

[0034] A red phosphorus flame retardant nylon composite material with a high glow wire ignition temperature and low acid evolution and a preparation method thereof are characterized in that the preparation steps of the method are as follows:

[0035] First step: First, uniformly stir the nylon resin and the silane coupling agent at a rotation speed of 35 rpm, and then add the flame retardant synergist, the filling filler, the phosphine inhibitor, the lubricant, the antioxidant, and the black masterbatch and stir evenly at a rotation speed of 25 rpm to obtain a mixed material;

[0036] Second step: Use a twin-screw extruder with a bilateral feeding and loss-in-weight feeder discharging method. There are 2 side feeding ports: mainly used for non-alkali short glass fibers and red phosphorus flame retardants, located in the 5th zone and the 7th zone respectively; set the screw rotation speed to 340 rpm, and set the process temperature according to the processing temperature of the polyamide resin. By extrusion granulation, a red phosphorus flame retardant nylon composite material with a high glow wire ignition temperature and low acid evolution can be obtained.

[0037] Compared with the prior art, the advantages of the present invention are as follows:

[0038] The innovation points of the present invention: Using an organic polysiloxane / carbonizing agent compounded flame retardant synergist and a red phosphorus flame retardant masterbatch for synergistic flame retardancy can not only reduce the dosage of the red phosphorus flame retardant, but also reduce the risk of acid precipitation; By introducing filler fillers, phosphine inhibitors, and combining with a double-sided feeding extrusion processing method, the synergistic effect is further achieved, improving the glow wire ignition temperature and acid precipitation resistance of the material. Specific embodiments

[0039] The technical solutions of the present invention will be further described below in conjunction with specific Comparative Examples 1-4 and Examples 1-8.

[0040] The raw materials and their ratios used in the present invention are shown in Table 1, but are not limited to the raw materials and ratios used in the comparative examples and examples.

[0041] The flame retardant synergist is a half-fold polysiloxane with a POS structure compounded with a triazine-based hyperbranched carbonizing agent, and the compounding ratio is preferably 20:1; The red phosphorus flame retardant masterbatch is a red phosphorus flame retardant masterbatch coated with melamine using PA6 as the carrier, with a red phosphorus content of 50%, commercially available; Talc powder 1250 mesh; Montmorillonite 800 mesh; The phosphine inhibitor is a Cu-Zn-Al composite salt, model CZ-D08A20; Copper oxide, zinc oxide, and aluminum oxide are of chemical purity, commercially available; Antioxidants, lubricants, and color masterbatches are all commercially available.

[0042] According to the ratio of raw materials in Table 1, high-speed stirring and premixing are carried out, and granulation is carried out by using a double-sided feeding, multi-loss weighing twin-screw extrusion method to obtain a red phosphorus flame retardant nylon composite material with a high glow wire ignition temperature and low acid precipitation.

[0043] Performance characterization and testing methods:

[0044] The tensile strength of the composite materials prepared in the above comparative examples and examples was measured using a universal mechanical testing machine with reference to the GB / T 1040.2-2022 standard; The notched impact strength was measured using a simple beam impact testing machine with reference to the GB / T 1043.1-2008 standard; Vertical combustion flame retardancy was measured using a vertical-horizontal combustion measuring instrument with reference to the GB / T 2408-2008 standard; Glow wire flame retardancy was measured using a glow wire tester with reference to the GB / T5169.11-2017 standard; The comparative tracking index (CTI) was measured using a comparative tracking index tester with reference to the GB / T4207-2003 standard; High humidity and heat phosphine (PH3): Take 5g of the sample and place it in a sealed environment at 70°C / 100%RH for 168h, and measure it using a phosphine tester.

[0045] The raw material ratios and performance test results of Comparative Examples 1 to 4 are shown in Table 1. Among them, Comparative Examples 1-4 are conventional red phosphorus flame-retardant nylon materials and preparation methods. Comparative 1 is a normal red phosphorus flame-retardant reinforced nylon material. Comparative 2 adds a mineral synergist on the basis of Comparative 1 to increase the glow wire ignition temperature. Comparative 3 further adds a compound oxide on the basis of Comparative 2 to further reduce the release of phosphine, but has no effect on the glow wire ignition temperature. Comparative 4 further adds a phosphine inhibitor on the basis of Comparative 2, which further reduces the release of phosphine and significantly increases the glow wire ignition temperature and CTI value. Generally speaking, however, the glow wire ignition temperatures of Comparative 1-Comparative 3 are relatively low, the release of phosphine is relatively high, and the CTI is about 525V.

[0046] The raw material ratios and performance test results of Examples 1-9 are shown in Table 1. Through formula optimization and combined with a special extrusion method, the glow wire ignition temperature and CTI of the material are significantly increased, and the release of phosphine is significantly reduced.

[0047] Compared with Comparative Example 3, in Example 1, the customized red phosphorus flame-retardant masterbatch is fed from the side feeding port, which reduces the shearing effect of the screw on the coating layer of the red phosphorus flame retardant, thereby reducing the release of phosphine from the material.

[0048] In Examples 2-4, on the basis of Example 1, a flame-retardant synergist composed of a polysiloxane / carbonizing agent compound, montmorillonite, and a silane coupling agent are introduced respectively. It can be seen from Table 1 that the introduction of the flame-retardant synergist reduces the dosage of the red phosphorus flame retardant, greatly increases the glow wire ignition temperature of the material, and reduces the release of phosphine from the material; after montmorillonite replaces talc powder, the glow wire ignition temperature is further increased from 765 °C to 800 °C, and the phosphine is reduced from 7.9 to 3.9 ppm; the addition of the silane coupling agent KH550 improves the dispersion of the flame-retardant synergist and the filled minerals, which is beneficial to the improvement of the overall performance. When Examples 5-6 change to use a Cu-Zn-Al composite salt phosphine inhibitor to replace the ordinary oxide, the release of phosphine from the material is further reduced to 1.5 ppm, and the comprehensive mechanical properties are improved. It is further shown that the ordinary oxide has no effect on the glow wire ignition temperature, while the composite salt phosphine inhibitor not only reduces the release of phosphine but also can increase the glow wire ignition temperature.

[0049] Increasing the dosage of the flame-retardant synergist composed of a polysiloxane / carbonizing agent compound in Example 7 can further increase the glow wire ignition temperature and CTI performance of the material, while reducing the release of phosphine from the material and achieving the best comprehensive mechanical properties. It can also be shown here that the compound carbonizing agent does not affect the electrical properties of the material and is beneficial to the carbonization of the material during combustion. In Example 8, compared with Example 7, the addition amount of the flame-retardant synergist is reduced. Due to the low addition amount of the flame retardant, the carbonization is not dense, and a single-sided burning phenomenon (the second combustion is 10-20 s) appears at the edge of the sample bar, affecting the flame-retardant performance of the material.

[0050] The results of various performance tests are shown in Table 1

[0051] Table 1 Comparison of the results of Comparative Examples 1-4 and Examples 1-8

[0052] Raw material quality parts / Test performance Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 Juhe Shun J2400 46.3 41.3 40.3 41.1 40.3 42.3 42.3 42.1 42.9 42.7 42.9 44.9 Jushi short fiber 560A 35 35 35 35 35 35 35 35 35 35 35 35 Silane coupling agent KH550 / / / / / / / 0.2 0.2 0.2 0.2 0.2 Red phosphorus masterbatch main feed 12 12 12 12 / / / / / / / / Red phosphorus masterbatch side feed / / / / 12 7 7 7 7 7 5.5 5.5 Flame retardant synergist / / / / / 6.5 6.5 6.5 6.5 6.5 8 6 Zinc borate 3.5 3.5 3.5 3.5 3.5 / / / / / / / Talc powder / 5 5 5 5 5 / / / / / / Montmorillonite / / / / / / 5 5 5 5 5 5 Copper oxide / / 0.1 part / 0.1 part 0.1 part 0.1 part 0.1 part / / / / Zinc oxide / / 0.5 part / 0.5 part 0.5 part 0.5 part 0.5 part / / / / Aluminum oxide / / 0.4 part / 0.4 part 0.4 part 0.4 part 0.4 part / / / / Phosphine inhibitor / / / 0.2 / / / / 0.2 part 0.4 part 0.2 part 0.2 part 1010 antioxidant 0.1 part 0.1 part 0.1 part 0.1 part 0.1 part 0.1 part 0.1 part 0.1 part 0.1 part 0.1 part 0.1 part 0.1 part 168 antioxidant 0.2 part 0.2 part 0.2 part 0.2 part 0.2 part 0.2 part 0.2 part 0.2 part 0.2 part 0.2 part 0.2 part 0.2 part TAF lubricant 0.4 part 0.4 part 0.4 part 0.4 part 0.4 part 0.4 part 0.4 part 0.4 part 0.4 part 0.4 part 0.4 part 0.4 part Black masterbatch 2.5 parts 2.5 parts 2.5 parts 2.5 parts 2.5 parts 2.5 parts 2.5 parts 2.5 parts 2.5 parts 2.5 parts 2.5 parts 2.5 parts Tensile strength (MPa) 161 136 132 135 133 139 141 143 147 146 150 149 <![CDATA[Notched impact of simply supported beam (KJ / m 2 )]]> 9.4 7.9 7.3 7.6 7.2 7.8 8.0 8.3 8.6 8.5 8.9 8.9 Vertical burning (1.6 mm) V-0 V-0 V-0 V-0 V-0 V-0 V-0 V-0 V-0 V-0 V-0 V-1 Glow wire ignition temperature (1.6 mm) 750 760 760 770 765 785 800 800 810 810 820 770 CTI (V) 500 525 525 550 525 575 575 575 600 600 625 575 High humidity and heat PH3 (ppm) 17.9 15.8 12.4 6.0 7.9 4.4 4.3 3.9 1.8 1.5 1.4 1.4

[0053] It should be understood that the application of the present invention is not limited to the above examples. For those of ordinary skill in the art, improvements or modifications can be made according to the above description. All such improvements and modifications should fall within the protection scope of the appended claims of the present invention.

Claims

1. A red phosphorus flame retardant nylon composite material with a high glow wire ignition temperature and low acid evolution, characterized in that The composite material comprises raw materials in the following parts by mass: Nylon resin: 30 - 70 parts Glass fiber: 5 - 40 parts Red phosphorus flame retardant masterbatch: 5 - 15 parts Flame retardant synergist: 1 - 10 parts Filler: 1 - 20 parts Phosphine inhibitor: 0.1 - 5 parts; The flame retardant synergist is a mixture of polysiloxane and triazine-based hyperbranched charring agent; The filler is one or more mixtures of wollastonite, talcum powder, montmorillonite, kaolin; The phosphine inhibitor is a Cu-Zn-Al composite salt.

2. A red phosphorus flame-retardant nylon composite material with a high glow wire ignition temperature and low acid evolution, characterized in that The composite material comprises raw materials in the following parts by mass: Nylon resin: 37 - 50 parts Glass fiber: 30 - 40 parts Red phosphorus flame retardant masterbatch: 5 - 13 parts Flame retardant synergist: 5 - 9 parts Filler: 3 - 7 parts Phosphine inhibitor: 0.1 - 1 part Coupling agent: 0.1 - 0.3 part Lubricant: 0.3 - 0.8 part Antioxidant: 0.2 - 0.4 part Black masterbatch: 2 - 3 parts; The flame retardant synergist is a mixture of polysiloxane and triazine-based hyperbranched charring agent; The filler is one or more mixtures of wollastonite, talcum powder, montmorillonite, kaolin; The phosphine inhibitor is a Cu-Zn-Al composite salt.

3. A red phosphorus flame retardant nylon composite material with a high glow wire ignition temperature and low acid evolution, according to claim 1 or 2, characterized in that, The nylon resin is one or more mixtures of PA6, PA66, copolyamide, PA56, PA612, PA1012.

4. A red phosphorus flame retardant nylon composite material with a high glow wire ignition temperature and low acid evolution, according to claim 1 or 2, characterized in that, The red phosphorus flame retardant masterbatch is a red phosphorus flame retardant masterbatch with PA6 as the carrier.

5. A red phosphorus flame retardant nylon composite material with a high glow wire ignition temperature and low acid evolution, as claimed in claim 2, characterized in that The coupling agent is a silane coupling agent; the lubricant is one or more mixtures of ethylene bis stearamide modifier, calcium stearate, ethylene acrylic acid copolymer; the antioxidant is one or more mixtures of hindered amines, phosphite esters and thioesters.

6. A red phosphorus flame retardant nylon composite material with a high glow wire ignition temperature and low acid evolution, characterized in that, The black masterbatch is prepared by mixing carbon black and / or organic black with PA6 as the carrier.

7. The preparation method of a red phosphorus flame-retardant nylon composite material with a high glow wire ignition temperature and low acid evolution as described in claim 1 or 2, characterized in that, The preparation steps of this method are as follows: First step: First, stir the nylon resin and the silane coupling agent evenly at a rotation speed of 35 rpm, then add the flame retardant synergist, filler, phosphine inhibitor, lubricant, antioxidant and black masterbatch and stir evenly at a rotation speed of 25 rpm to obtain a mixed material; Second step: Use a twin-screw extruder with a double-sided feeding and loss-in-weight weighing feeding method. There are 2 side feeding ports: mainly used for non-alkali short glass fiber and red phosphorus flame retardant, located in the 5th zone and the 7th zone respectively; set the screw rotation speed to 340 rpm, and set the process temperature according to the processing temperature of polyamide resin. Through extrusion granulation, a red phosphorus flame retardant nylon composite material with a high glow wire ignition temperature and low acid evolution can be obtained.