Flame-retardant antistatic polyamide and preparation method thereof

Abstract

The invention relates to the technical field of polyamide, and particularly provides flame-retardant antistatic polyamide and a preparation method thereof. The flame-retardant antistatic polyamide is characterized in that the limit oxygen index of the flame-retardant antistatic polyamide is 29%-33%, the surface resistance of the flame-retardant antistatic polyamide is 105-109 omega, and the tensile strength of the flame-retardant antistatic polyamide is 70-90 MPa. The preparation method is used for preparing the flame-retardant antistatic polyamide. The polyamide and the preparation method provided by the invention are used for realizing direct extrusion granulation after blending components are mixed while tackifying, and the preparation process is simplified.

Description

Technical Field

[0001] The present invention relates to the technical field of polyamides, and in particular to a flame retardant and antistatic polyamide and a preparation method thereof. Background Art

[0002] Polyamide (PA, commonly known as nylon) has good wear resistance, heat resistance, oil resistance and chemical resistance. It is widely used in textile, automobile, mechanical processing, electronic and electrical fields. It is the basic resin with the largest output, the most varieties, the widest application and excellent comprehensive performance among the five general engineering plastics.

[0003] The fields of electronics, aerospace, etc. all require polyamide materials to have high flame retardancy, antistatic properties, mechanical strength, etc. Therefore, the development of multifunctional nylon with excellent mechanical properties has become a hot research direction at home and abroad.

[0004] At present, the flame retardant and antistatic modification of high-temperature nylon requires the synthesis of prepolymers, followed by screw viscosity enhancement or solid phase viscosity enhancement, and then the preparation of high-temperature nylon materials with comprehensive properties through blending modification. In this process, the process is long, which not only increases labor and production costs, but also due to the high processing temperature of high-temperature nylon, the material is easily decomposed when heated for a long time, causing performance degradation. Summary of the invention

[0005] The present disclosure is proposed in view of the above problems. The present disclosure provides a flame retardant antistatic polyamide and a preparation method, which can make the polyamide material have good flame retardancy and antistatic properties, and realize direct extrusion granulation after mixing the blending components while increasing viscosity, thus simplifying the preparation process.

[0006] According to one aspect of the present disclosure, a flame retardant antistatic polyamide is provided, wherein the limiting oxygen index of the flame retardant antistatic polyamide is 29% to 33%, and the surface resistance of the flame retardant antistatic polyamide is 10 5 Ω~10 9 Ω, the tensile strength of the flame retardant antistatic polyamide is 70MPa to 90MPa.

[0007] Compared with the prior art, the flame retardant antistatic polyamide provided by the present disclosure has the following advantages:

[0008] The flame retardant and antistatic polyamide disclosed in the present invention is not easy to accumulate charge to generate static electricity and arc during use, and in the field of electronic appliances, it can avoid the problems of distortion of precision instruments, scrapping of electronic components, and fire or explosion. At the same time, the flame retardant and antistatic polyamide disclosed in the present invention has a high limiting oxygen index, is not easy to burn, has high flame retardant performance, antistatic performance, and mechanical strength, and has a high fireproof grade and excellent performance in many aspects in the fields of electronic appliances, aerospace, etc.

[0009] According to another aspect of the present disclosure, there is provided a method for preparing a flame retardant and antistatic polyamide, comprising:

[0010] preparing a polyamide prepolymer using a polyamide salt solution;

[0011] The polyamide prepolymer is mixed with a flame retardant, an antistatic agent, a dispersant, a compatibilizer and an antioxidant to obtain a premix;

[0012] The premix is ​​subjected to a viscosity increasing reaction by a twin-screw extruder, and is melt-granulated to obtain a flame-retardant antistatic polyamide.

[0013] Compared with the prior art, the preparation method of the flame retardant and antistatic polyamide provided by the present disclosure has the following advantages:

[0014] In the preparation method of the flame-retardant and antistatic polyamide provided in the embodiment of the present disclosure, after synthesizing the polyamide prepolymer using the polyamide salt solution, the additive components such as flame retardant, antistatic agent, dispersant, compatibilizer and antioxidant are added to the polyamide prepolymer to obtain a premix, and then the premix is ​​directly thickened using a twin-screw extruder, and the blended components are mixed and directly extruded and granulated while the thickening is being carried out. Therefore, the preparation process is simplified, and the steps of blending and modification are omitted, which not only saves energy consumption but also enables the additives to be fully mixed and embedded into the grid structure of the polyamide prepolymer, and will not weaken the mechanical strength and performance of the polyamide prepolymer, while saving a lot of manpower and material costs. At the same time, it can be seen from the experimental results of the embodiment of the present disclosure that the flame-retardant and antistatic polyamide prepared by the method provided by the present disclosure has mechanical properties close to those of unmodified polyamide, and the UL-94 flame retardant grade of the flame-retardant and antistatic polyamide prepared by the method provided by the present disclosure can reach the V-0 level, the limiting oxygen index is 29% to 33%, and the surface resistance is 10 5 Ω~10 9 Ω, tensile strength is 70-90MPa, and the molten drop property is that the dripping does not ignite or there is no dripping.

[0015] It can be seen from the above that the method for preparing the flame-retardant and antistatic polyamide provided in the embodiments of the present disclosure realizes direct extrusion granulation after mixing the blending components while increasing viscosity, thereby simplifying the preparation process.

[0016] It is to be understood that both the foregoing general description and the following detailed description are exemplary, and are intended to provide further explanation of the technology as claimed. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The above and other purposes, features and advantages of the present disclosure will become more apparent by describing the embodiments of the present disclosure in more detail in conjunction with the accompanying drawings. The accompanying drawings are used to provide a further understanding of the embodiments of the present disclosure and constitute a part of the specification. Together with the embodiments of the present disclosure, they are used to explain the present disclosure and do not constitute a limitation of the present disclosure. In the accompanying drawings, the same reference numerals generally represent the same components or steps.

[0018] Figure 1 The present invention is a flow chart of the preparation of the flame retardant and antistatic polyamide according to an embodiment of the present invention;

[0019] Figure 2 is a flow chart for preparing a polyamide prepolymer according to an embodiment of the present disclosure;

[0020] Figure 3 The present invention is a flow chart of the preparation of the polyamide salt solution according to an embodiment of the present invention. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solution and advantages of the present disclosure more obvious, the exemplary embodiments according to the present disclosure will be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present disclosure, rather than all the embodiments of the present disclosure, and it should be understood that the present disclosure is not limited to the exemplary embodiments described here.

[0022] Polyamide (PA), commonly known as nylon, has good wear resistance, heat resistance, oil resistance and chemical resistance. It is widely used in textiles, automobiles, mechanical processing, electronics and electrical fields. It is the base resin with the largest output, the most varieties, the widest application and excellent comprehensive performance among the five general engineering plastics. Semi-aromatic polyamide, also known as high-temperature nylon, is a type of polymer with excellent performance. It can be used at a temperature of more than 150°C for a long time and is an important variety of nylon resin. The currently industrialized high-temperature resistant nylon varieties include PA6T, PA9T, PA10T, etc.

[0023] Unmodified high temperature nylon resin is an insulator with high surface resistance (about 10 13 Ω~10 15Ω), poor antistatic performance, easy to accumulate charge to generate static electricity during use, reaching a certain amount of charge may produce arc, in the field of electronic appliances, will cause precision instrument distortion, electronic components scrapped and other consequences. Static electricity may also cause fire or explosion hazards in some occasions, causing irreparable losses to production and life. Pure high-temperature nylon resin, with a low limiting oxygen index, is prone to fire and combustion accompanied by molten dripping. Certain fields of use, such as electronic appliances, aerospace, etc., require materials to have a high fire retardant grade and excellent performance in many aspects, and require the selected materials to have high flame retardant properties, antistatic properties, mechanical strength, etc. Therefore, the development of multifunctional nylon with excellent mechanical properties has become a hot research direction at home and abroad.

[0024] At present, the flame retardant and antistatic modification of high-temperature nylon requires the synthesis of prepolymers first, followed by screw viscosity enhancement or solid phase viscosity enhancement, and then the preparation of high-temperature nylon materials with comprehensive performance through blending modification. In this process, the high-temperature nylon resin after solid phase viscosity enhancement is in powder or block form, which is prone to dust and other environmental pollution during later use, and is also prone to difficult feeding, bonding, bridging and other undesirable phenomena during processing and feeding.

[0025] In view of the above problems, the embodiments of the present disclosure provide a flame retardant antistatic polyamide and a preparation method thereof, so as to realize direct extrusion granulation after mixing the blended components while increasing viscosity, thereby simplifying the preparation process. The problem that the process flow of the flame retardant antistatic polyamide in the prior art is long and the processing temperature is high, which leads to easy decomposition of the polyamide.

[0026] The embodiment of the present disclosure provides a flame retardant antistatic polyamide, wherein the limiting oxygen index of the flame retardant antistatic polyamide is 29% to 33%, and the surface resistance of the flame retardant antistatic polyamide is 10 5 Ω~10 9 Ω, the tensile strength of the flame retardant antistatic polyamide is 70MPa to 90MPa. Preferably, the limiting oxygen index is 30% to 32%, the surface resistance is 10 6 Ω~10 8 Ω, and the tensile strength is 75MPa to 85MPa. It is not easy to accumulate charges to generate static electricity and arcs during use. In the field of electronic appliances, it can avoid problems such as distortion of precision instruments, scrapping of electronic components, and fire or explosion. At the same time, the flame retardant and antistatic polyamide disclosed in the present invention has a high limiting oxygen index, is not easy to burn, has high flame retardant properties, antistatic properties, and mechanical strength, and has a high fire resistance level and excellent performance in many aspects in the fields of electronic appliances, aerospace, etc.

[0027] The embodiments of the present disclosure also provide a method for preparing a flame retardant and antistatic polyamide, which can be used to prepare the flame retardant and antistatic polyamide of the embodiments of the present disclosure. Figure 1The preparation process of the flame retardant antistatic polyamide according to the embodiment of the present disclosure is shown in FIG. Figure 1 As shown, the preparation method of the flame retardant antistatic polyamide of the embodiment of the present disclosure includes:

[0028] Step 100: Prepare a polyamide prepolymer using a polyamide salt solution.

[0029] For example, the polyamide prepolymer may be prepared using a polyamide salt solution having a concentration of 30 wt % to 80 wt %.

[0030] Step 200: The polyamide prepolymer is mixed with a flame retardant, an antistatic agent, a dispersant, a compatibilizer and an antioxidant to obtain a premix.

[0031] For example, the polyamide prepolymer, flame retardant, antistatic agent, dispersant, compatibilizer and antioxidant can be weighed in proportion, put into the same container for mixing, and then put into a high-speed mixer for further mixing to obtain a premix, wherein the speed of the high-speed mixer is 100 rpm to 10000 rpm, and the mixing time is 3 minutes to 3 hours.

[0032] As for the polyamide prepolymer, it may include at least one of polyhexamethylene terephthalamide, polyhexamethylene adipamide, polyhexamethylene dodecanoamide, polyhexamethylene sebacamide, polylaurolactam, and polydecane terephthalate.

[0033] As for the flame retardant, it may include at least one of melamine cyanurate, diethylaluminum hypophosphite, melamine salt, phosphate, red phosphorus, boehmite, aluminum hydroxide, magnesium hydroxide, ammonium polyphosphate, and antimony trioxide.

[0034] As for the antistatic agent, it can include at least one of conductive carbon black, carbon nanotubes, graphite, conductive carbon fibers, quaternary ammonium salts, polyethylene glycol, stearyl dimethyl amyl ammonium chloride, stearyl trimethyl ammonium chloride, 1,3-dimethyl imidazole tetrafluoroborate, N-octyl pyridinium bromide, N-butyl-N-methyl piperidinium bromide, N-butyl-N-methyl pyrrolidine bromide, tributyl methyl ammonium chloride, N-ethyl, methyl morpholine bromide and tributyl ethyl phosphonium bromide ionic liquids.

[0035] As for the dispersant, it may include at least one of polyethylene wax, polypropylene wax, erucamide, oleamide, calcium stearate, lithium stearate, silicone oil, silicone, montan wax, stearamide, and ethylene bis stearamide.

[0036] As for the compatibilizer, it may include at least one of maleic anhydride, polyacrylate, and m-isopropenyl-2,2-dimethylbenzyl isocyanate.

[0037] As for the antioxidant, it may include one of antioxidant 168, antioxidant 619F, antioxidant 1076, antioxidant 1098, antioxidant 1010, antioxidant B215, and antioxidant H10.

[0038] Step 300: using a twin-screw extruder to carry out a viscosity-increasing reaction on the premix, and after melt granulation, a flame-retardant and antistatic polyamide is obtained.

[0039] In one example, before using a twin-screw extruder to perform a viscosity-increasing reaction on the premix, the method further includes: protecting the twin-screw extruder by replacing it with an inert gas or by extracting a vacuum.

[0040] Exemplarily, the twin-screw extruder of the embodiment of the present disclosure has an exhaust port, which can be connected to a vacuum pumping device or connected to the atmosphere for natural exhaust. The oxygen content at 0 cm to 8 cm above the material at each exhaust port is ≤5%v. The method for maintaining the oxygen content may be a vacuum pumping method, an inert gas protection method, or a natural exhaust method, so that the evil water vapor generated during the viscosity increasing process is continuously discharged to the outside, thereby isolating the oxygen in the air and preventing the residual resin from coming into contact with oxygen when heated, causing color change or carbonization to form black spots, and contaminating subsequent materials. Among them, the inert gas includes at least one of nitrogen, argon, helium and carbon dioxide.

[0041] In the preparation method of the flame-retardant antistatic polyamide provided by the embodiment of the present disclosure, after the polyamide prepolymer is synthesized by using the polyamide salt solution, the additive components such as the flame retardant, the antistatic agent, the dispersant, the compatibilizer and the antioxidant are added to the polyamide prepolymer to obtain a premix, and then the premix is ​​directly thickened by using a twin-screw extruder, and the blended components are directly extruded and granulated after being mixed while the premix is ​​thickened. Therefore, the preparation process is simplified, the step of blending and modification is omitted, not only energy consumption is saved, but also the additives can be fully mixed and embedded into the grid structure of the polyamide prepolymer, which will not weaken the mechanical strength and performance of the polyamide prepolymer, and a large amount of manpower and material costs are saved.

[0042] For example, Figure 2 The preparation flow chart of the polyamide prepolymer of the embodiment of the present disclosure is shown as follows: Figure 2 As shown, the embodiment of the present disclosure uses a polyamide salt solution to prepare a polyamide prepolymer, comprising:

[0043] Step 110: Mix and dissolve the diamine, dibasic acid, antioxidant and water to obtain a polyamide salt solution.

[0044] Exemplarily, the polymerization kettle can be evacuated and protected with nitrogen, and the diamine, dibasic acid, antioxidant and water are mixed, and then heated to dissolve to obtain a polyamide salt solution. The diamine can include at least one of ethylenediamine, propylenediamine, hexamethylenediamine, p-phenylenediamine and other diamines, and the dibasic acid can include at least one of oxalic acid, adipic acid, phthalic acid, glutamic acid, aspartic acid and other dibasic acids, which are not limited here. The concentration of the polyamide salt solution can be 30wt% to 80wt%.

[0045] Step 120: Use diamine and dibasic acid to adjust the pH of the polyamide salt solution to 6-11.

[0046] For example, the polyamide salt solution can be adjusted to 6-11 using a small amount of diamine and dibasic acid.

[0047] Step 130: Treating the polyamide salt solution with a pH of 6 to 11 into a polyamide prepolymer.

[0048] Exemplarily, a polyamide salt solution (30 wt% to 80 wt%) with a pH of 6 to 11 is concentrated and pretreated to obtain a polyamide prepolymer, wherein the water content of the polyamide prepolymer is less than 10 wt%.

[0049] In an alternative approach, Figure 3 The preparation flow chart of the polyamide salt solution of the embodiment of the present disclosure is shown as follows: Figure 3 As shown, the diamine, dibasic acid, antioxidant and water of the embodiment of the present disclosure are mixed and dissolved to obtain a polyamide salt solution, including:

[0050] Step 111: Mix and dissolve the diamine and water to obtain a diamine aqueous solution.

[0051] For example: the polymerization kettle is evacuated and protected with nitrogen, pure water is added thereto, and then diamine is added thereto to obtain a diamine aqueous solution.

[0052] Step 112: Add dibasic acid and antioxidant to the diamine aqueous solution, heat until dissolved, and obtain a polyamide salt solution.

[0053] For example: after obtaining the diamine aqueous solution, turn off the stirring of the polymer, add the dibasic acid, then add the antioxidant, heat and dissolve, and obtain the polyamide salt solution.

[0054] In one achievable manner, the embodiment of the present disclosure processes a polyamide salt solution having a pH of 6 to 11 into a polyamide prepolymer, comprising:

[0055] First, a polyamide salt solution (30 wt% to 80 wt%) with a pH of 6 to 11 is concentrated at a temperature of 170° C. to 190° C. until the mass concentration of the polyamide salt solution is 50% to 95%. Secondly, the polyamide salt solution with a mass concentration of 50% to 95% is reacted at a temperature of 230° C. to 300° C., preferably at a temperature of 250° C. to 280° C., and a pressure of 1.5 MPa to 6 MPa for 0.5 h to 8 h, preferably at 2 MPa to 5 MPa, for 1 h to 6 h, to obtain a reaction product. Next, the reaction product is treated at a pressure of 1.5 MPa to 5 MPa, preferably at 2 MPa to 4 MPa, to obtain a polyamide prepolymer.

[0056] In one example, the aspect ratio of the screw of the twin-screw extruder of the embodiment of the present disclosure is (25:1) to (100:1). The rotation speed of the twin-screw extruder is 100rpm to 500rpm, preferably 100rpm to 300rpm. The twin-screw extruder should be equipped with a main feeding system and a side feeding system. Both the main feeding system and the side feeding system are equipped with a loss-in-weight scale to accurately measure the feed rate. The side feeding system can add glass fiber and flame-retardant and antistatic nylon as needed to prepare glass fiber reinforced flame-retardant and antistatic high-temperature nylon. The high-temperature nylon or enhanced high-temperature nylon prepared by the present disclosure is a granular material, which is cylindrical or approximately cylindrical, and can be formed into a desired shape by injection molding, film molding, melt spinning, blow molding, vacuum molding and other methods.

[0057] In one achievable manner, the twin-screw extruder of the embodiment of the present disclosure includes a main feed port, multiple extrusion zones and a die. When the twin-screw extruder includes eleven extrusion zones, the temperature of the first extrusion zone is 230°C to 250°C, the temperature of the second extrusion zone is 255°C to 270°C, the temperature of the third extrusion zone is 265°C to 280°C, the temperature of the fourth extrusion zone is 275°C to 280°C, the temperature of the fifth extrusion zone is 275°C to 290°C, the temperature of the sixth extrusion zone is 285°C to 290°C, the temperature of the seventh extrusion zone is 285°C to 295°C, the temperature of the eighth extrusion zone is 290°C to 295°C, the temperature of the ninth extrusion zone is 290°C to 300°C, the temperature of the tenth extrusion zone is 290°C to 300°C, the temperature of the eleventh extrusion zone is 295°C to 300°C, and the temperature of the die is 295°C to 300°C. The temperature of the extrusion zone of the twin-screw extruder in the embodiment of the present disclosure is significantly lower than that in the prior art, which can avoid the problem of performance degradation caused by decomposition of the polyamide material after being heated when the temperature is too high.

[0058] In an optional manner, the mass ratio of the polyamide prepolymer, flame retardant, antistatic agent, dispersant, compatibilizer and antioxidant in the embodiment of the present disclosure is (50-99): (0-20): (2-20): (0-10): (0-6): (0-1). Preferably, it is (55-90): (1-18): (3-18): (1-9): (1-5): (0.1-0.9), and more preferably, it is (50-99): (60-90): (2-15): (4-15): (1-3): (0.1-0.8). By controlling the ratio of each component within this range, uniform dispersion of the flame retardant, antistatic agent, dispersant, compatibilizer and antioxidant can be achieved.

[0059] In one example, in the premix, the mass percentage of the polyamide prepolymer in the premix is ​​50% to 99%.

[0060] In the flame-retardant antistatic polyamide and preparation method provided by the embodiments of the present disclosure, after the polyamide prepolymer is synthesized by using a polyamide salt solution, a flame retardant, an antistatic agent, a dispersant, a compatibilizer, an antioxidant and other additive components are added to the polyamide prepolymer to obtain a premix, and then a twin-screw extruder is used to directly increase viscosity, and at the same time, the blended components are mixed and directly extruded and granulated. Therefore, the preparation process is simplified, the step of blending and modification is omitted, not only energy consumption is saved, but also the additives can be fully mixed and embedded into the grid structure of the polyamide prepolymer, which will not weaken the mechanical strength and performance of the polyamide prepolymer, and a large amount of manpower and material costs are saved.

[0061] In order to verify the effect of the flame retardant and antistatic polyamide provided by the embodiments of the present disclosure, the embodiments of the present disclosure are demonstrated by comparing the embodiments with the comparative examples.

[0062] Embodiment 1

[0063] The present disclosure provides a flame retardant antistatic polyamide, and the preparation method thereof comprises the following steps:

[0064] The first step is to prepare a polyamide prepolymer: evacuate a 20-liter polymerization kettle and protect it with nitrogen, add 7kg of pure water, then add 1.83kg of hexamethylenediamine, start stirring, add 1.26kg of terephthalic acid and 1.19kg of adipic acid, and then add 2g of an antioxidant, sodium hypophosphite, and heat to 70°C to dissolve to obtain a nylon salt solution. Use a small amount of hexamethylenediamine or adipic acid to adjust the pH value of the nylon salt solution to 6.50 when the concentration is 10%. Set the 20-liter polymerization kettle oil bath to 180°C to evaporate and concentrate the water. After the system concentration is increased to 75%, continue to heat the oil bath to 290°C, wait until the pressure in the kettle rises to 2.0MPa, start exhausting, and when the temperature in the kettle reaches 245°C, discharge the material to a crushing kettle, crush the prepolymer, and obtain a polyamide prepolymer.

[0065] Step 2: prepare a premix: accurately weigh 3.352 kg of prepolymer, 400 g of melamine cyanurate, 240 g of carbon black, and 80 g of antioxidant (1098), and place the above components in a clean stainless steel container with a total weight of 4 kg. Then transfer to a high-speed mixer, stir at a speed of 1000 rpm, and mix for 0.5 hours to obtain a premix.

[0066] The third step is to prepare flame retardant and antistatic polyamide: the premix is ​​transferred to a twin-screw extruder with a diameter of 26 mm, the temperature of zone 1 is 230°C, the temperature of zone 2 is 255°C, the temperature of zone 3 is 265°C, the temperature of zone 4 is 275°C, the temperature of zone 5 is 275°C, the temperature of zone 6 is 285°C, the temperature of zone 7 is 285°C, the temperature of zone 8 is 290°C, the temperature of zone 9 is 290°C, the temperature of zone 10 is 290°C, the temperature of zone 11 is 295°C, the temperature of the die head is 295°C, it is equipped with 2 exhaust ports and 2 vacuum ports (the exhaust port is in the front and in the back after vacuum, and the specific position can be adjusted according to the viscosity-increasing effect), the exhaust port is protected by nitrogen, the main speed of the extruder is 200rpm, the feeding rate is 10kg / h, the melt is cooled underwater, blown dry by a fan and then pelletized to obtain flame retardant and antistatic polyamide.

[0067] The flame retardant antistatic polyamide was dried at 100° C. in vacuum for 8 hours and then tested for various properties. The results are shown in Table 1.

[0068] Embodiment 2

[0069] The present disclosure provides a flame retardant antistatic polyamide, and the preparation method thereof comprises the following steps:

[0070] The first step is to prepare a polyamide prepolymer: evacuate a 20-liter polymerization kettle and protect it with nitrogen, add 7kg of pure water, then add 1.83kg of hexamethylenediamine, start stirring, add 1.26kg of terephthalic acid and 1.19kg of adipic acid, and then add 2g of an antioxidant, sodium hypophosphite, and heat to 70°C to dissolve to obtain a nylon salt solution. Use a small amount of hexamethylenediamine or adipic acid to adjust the pH value of the nylon salt solution to 6.50 when the concentration is 10%. Set the 20-liter polymerization kettle oil bath to 180°C to evaporate and concentrate the water. After the system concentration is increased to 75%, continue to heat the oil bath to 290°C, wait until the pressure in the kettle rises to 2.0MPa, start exhausting, and when the temperature in the kettle reaches 245°C, discharge the material to a crushing kettle, crush the prepolymer, and obtain a polyamide prepolymer.

[0071] The second step is to prepare a premix: accurately weigh 3.268 kg of prepolymer, 320 g of diethyl aluminum hypophosphite, 400 g of carbon black, and 12 g of antioxidant (1010), and place the above components in a clean stainless steel container with a total weight of 4 kg. Then transfer to a high-speed mixer, stir at a speed of 1000 rpm, and mix for 0.5 hours to obtain a premix.

[0072] The third step is to prepare flame retardant and antistatic polyamide: the premix is ​​transferred to a twin-screw extruder with a diameter of 26 mm, the temperature of zone 1 is 230°C, the temperature of zone 2 is 255°C, the temperature of zone 3 is 265°C, the temperature of zone 4 is 275°C, the temperature of zone 5 is 275°C, the temperature of zone 6 is 285°C, the temperature of zone 7 is 285°C, the temperature of zone 8 is 290°C, the temperature of zone 9 is 290°C, the temperature of zone 10 is 290°C, the temperature of zone 11 is 295°C, the temperature of the die head is 295°C, it is equipped with 2 exhaust ports and 2 vacuum ports (the exhaust port is in the front and in the back after vacuum, and the specific position can be adjusted according to the viscosity-increasing effect), the exhaust port is protected by nitrogen, the main speed of the extruder is 200rpm, the feeding rate is 10kg / h, the melt is cooled underwater, blown dry by a fan and then pelletized to obtain flame retardant and antistatic polyamide.

[0073] The flame retardant antistatic polyamide was dried at 100° C. in vacuum for 8 hours and then tested for various properties. The results are shown in Table 1.

[0074] Embodiment 3

[0075] The present disclosure provides a flame retardant and antistatic polyamide, and a preparation method thereof comprises the following steps:

[0076] The first step is to prepare a polyamide prepolymer: evacuate a 20-liter polymerization kettle and protect it with nitrogen, add 1.05 kg of hexamethylenediamine and 1.05 kg of 2-methylpentamethylenediamine, start stirring, add 3.0 kg of terephthalic acid, and then add 1.5 g of antioxidant H10, heat to 80 ° C to dissolve to obtain a nylon salt solution, and use a small amount of hexamethylenediamine or adipic acid to adjust the pH value of the nylon salt solution to 6.88 when the concentration is 10%. Set the 20-liter polymerization kettle oil bath to heat up and evaporate and concentrate the water. After the system concentration is increased to 75%, continue to heat the oil bath to 290 ° C, wait until the pressure in the kettle rises to 2.0 MPa, start exhausting, and when the temperature in the kettle reaches 255 ° C, discharge the material to a crushing kettle, crush the prepolymer, and obtain a polyamide prepolymer.

[0077] The second step is to prepare a premix: accurately weigh 3.6 kg of prepolymer, 200 g of melamine cyanurate, 160 g of stearyl trimethyl ammonium chloride, 20 g of antioxidant (1010), and 20 g of lithium stearate, and place the above components in a clean stainless steel container with a total weight of 4 kg. Then transfer to a high-speed mixer, stir at a speed of 2000 rpm, and mix for 10 minutes to obtain a premix.

[0078] The third step is to prepare flame-retardant antistatic polyamide: the premix is ​​transferred to a twin-screw extruder with a diameter of 26 mm, the temperature of zone 1 is 240°C, the temperature of zone 2 is 260°C, the temperature of zone 3 is 270°C, the temperature of zone 4 is 270, the temperature of zone 5 is 280°C, the temperature of zone 6 is 280°C, the temperature of zone 7 is 290°C, the temperature of zone 8 is 295°C, the temperature of zone 9 is 295°C, the temperature of zone 10 is 300°C, the temperature of zone 11 is 300°C, and the temperature of die head is 295°C. It is equipped with 2 exhaust ports and 2 vacuum ports (the exhaust port is in the front and in the back after vacuum, and the specific position can be adjusted according to the viscosity-increasing effect). The exhaust port is protected by nitrogen, the main speed of the extruder is 300rpm, the feeding rate is 8kg / h, the melt is cooled underwater, and the pellets are cut after being blown dry by a fan to obtain flame-retardant antistatic polyamide.

[0079] The flame retardant antistatic polyamide was dried at 100° C. in vacuum for 8 hours and then tested for various properties. The results are shown in Table 1.

[0080] Embodiment 4

[0081] The present disclosure provides a flame retardant and antistatic polyamide, and a preparation method thereof comprises the following steps:

[0082] The first step is to prepare a polyamide prepolymer: evacuate a 20-liter polymerization kettle and protect it with nitrogen, add 7kg of pure water, then add 1.05kg of hexamethylenediamine and 1.05kg of 2-methylpentamethylenediamine, start stirring, add 3.0kg of terephthalic acid, and then add 1.5g of antioxidant H10, heat to 80°C to dissolve to obtain a nylon salt solution, and use a small amount of hexamethylenediamine or adipic acid to adjust the pH value of the nylon salt solution to 6.88 when the concentration is 10%. Heat the 20-liter polymerization kettle in an oil bath to evaporate and concentrate the water. After the system concentration is increased to 75%, continue to heat the oil bath to 290°C, wait until the pressure in the kettle rises to 2.0MPa, start exhausting, and when the temperature in the kettle reaches 255°C, discharge the material to a crushing kettle, crush the prepolymer, and obtain a polyamide prepolymer.

[0083] The second step is to prepare a premix: accurately weigh 3.408 kg of prepolymer, 320 g of diethylaluminum hypophosphite, 80 g of antimony trioxide, 160 g of carbon black, 12 g of antioxidant (1098), and 20 g of lithium stearate, and place the above components in a clean stainless steel container with a total weight of 4 kg. Then transfer the mixture to a high-speed mixer, stir at a speed of 2000 rpm, and mix for 20 minutes to obtain a premix.

[0084] The third step is to prepare flame retardant and antistatic polyamide: the premix is ​​transferred to a twin-screw extruder with a diameter of 26 mm, the temperature of zone 1 is 240°C, the temperature of zone 2 is 260°C, the temperature of zone 3 is 270°C, the temperature of zone 4 is 270, the temperature of zone 5 is 280°C, the temperature of zone 6 is 280°C, the temperature of zone 7 is 290°C, the temperature of zone 8 is 295°C, the temperature of zone 9 is 295°C, the temperature of zone 10 is 300°C, the temperature of zone 11 is 300°C, the temperature of the die head is 295°C, there are 2 exhaust ports and 2 vacuum ports (the exhaust port is in the front and in the back after vacuum, and the specific position can be adjusted according to the viscosity increasing effect), the exhaust port is protected by nitrogen, the main speed of the extruder is 300rpm, the feeding rate is 8kg / h, the melt is cooled underwater, dried by a fan and pelletized to obtain flame retardant and antistatic polyamide.

[0085] The flame retardant antistatic polyamide was dried at 100° C. in vacuum for 8 hours and then tested for various properties. The results are shown in Table 1.

[0086] Embodiment 5

[0087] The present disclosure provides a glass fiber reinforced flame retardant antistatic polyamide, and the preparation method thereof comprises the following steps:

[0088] The first step is to prepare a polyamide prepolymer: evacuate a 20-liter polymerization kettle and protect it with nitrogen, add 7kg of pure water, then add 1.83kg of hexamethylenediamine, start stirring, add 1.26kg of terephthalic acid and 1.19kg of adipic acid, and then add 2g of an antioxidant, sodium hypophosphite, and heat to 70°C to dissolve to obtain a nylon salt solution. Use a small amount of hexamethylenediamine or adipic acid to adjust the pH value of the nylon salt solution to 6.50 when the concentration is 10%. Set the 20-liter polymerization kettle oil bath to 180°C to evaporate and concentrate the water. After the system concentration is increased to 75%, continue to heat the oil bath to 290°C, wait until the pressure in the kettle rises to 2.0MPa, start exhausting, and when the temperature in the kettle reaches 245°C, discharge the material to a crushing kettle, crush the prepolymer, and obtain a polyamide prepolymer.

[0089] Step 2: prepare a premix: accurately weigh 3.52 kg of prepolymer, 400 g of melamine cyanurate, 240 g of carbon black, and 8 g of antioxidant (1098), and place the above components in a clean stainless steel container with a total weight of 4 kg. Then transfer to a high-speed mixer, stir at a speed of 1000 rpm, and mix for 0.5 hours to obtain a premix.

[0090] The third step is to prepare flame retardant antistatic polyamide: the premix is ​​transferred to a twin-screw extruder with a diameter of 26 mm, the temperature of zone 1 is 230°C, the temperature of zone 2 is 255°C, the temperature of zone 3 is 265°C, the temperature of zone 4 is 275°C, the temperature of zone 5 is 275°C, the temperature of zone 6 is 285°C, the temperature of zone 7 is 285°C, the temperature of zone 8 is 290°C, the temperature of zone 9 is 290°C, the temperature of zone 10 is 290°C, the temperature of zone 11 is 295°C, the temperature of die head is 295°C, equipped with 2 exhaust ports, 2 vacuum ports (the exhaust port is in front, and in the back after vacuum, and the specific position can be adjusted according to the viscosity increase effect), the exhaust port is protected by nitrogen, the main speed of the extruder is 200rpm, the feeding rate is 10kg / h, short glass fiber (Jiushi 568H) is added to the extruder side feeding, the feeding rate is 4.29kg / h, and the glass fiber content of the product is 30%wt. The melt is cooled underwater, blown dry by a fan and pelletized to obtain flame retardant antistatic polyamide.

[0091] The glass fiber reinforced flame retardant antistatic polyamide was dried at 100° C. in vacuum for 8 hours and then various properties were tested. The results are shown in Table 1.

[0092] Embodiment 6

[0093] The present disclosure provides a glass fiber reinforced flame retardant antistatic polyamide, and the preparation method thereof comprises the following steps:

[0094] The first step is to prepare a polyamide prepolymer: evacuate a 20-liter polymerization kettle and protect it with nitrogen, add 1.05 kg of hexamethylenediamine and 1.05 kg of 2-methylpentamethylenediamine, start stirring, add 3.0 kg of terephthalic acid, and then add 1.5 g of antioxidant H10, heat to 80 ° C to dissolve to obtain a nylon salt solution, and use a small amount of 2-methylpentamethylenediamine or terephthalic acid to adjust the pH value of the nylon salt solution to 6.88 when the concentration is 10%. Heat the 20-liter polymerization kettle in an oil bath to evaporate and concentrate the water. After the system concentration is increased to 75%, continue to heat the oil bath to 290 ° C, wait until the pressure in the kettle rises to 2.0 MPa, start exhausting, and when the temperature in the kettle reaches 255 ° C, discharge the material to a crushing kettle, crush the prepolymer, and obtain a polyamide prepolymer.

[0095] The second step is to prepare a premix: accurately weigh 3.248 kg of prepolymer, 320 g of diethylaluminum hypophosphite, 80 g of antimony trioxide, 320 g of carbon black, 12 g of antioxidant (1098), and 20 g of lithium stearate, and place the above components in a clean stainless steel container with a total weight of 4 kg. Then transfer the mixture to a high-speed mixer, stir at a speed of 2000 rpm, and mix for 20 minutes to obtain a premix.

[0096] The third step is to prepare flame retardant antistatic polyamide: the premix is ​​transferred to a twin-screw extruder with a diameter of 26 mm, the temperature of zone 1 is 250°C, the temperature of zone 2 is 270°C, the temperature of zone 3 is 280°C, the temperature of zone 4 is 280°C, the temperature of zone 5 is 290°C, the temperature of zone 6 is 290°C, the temperature of zone 7 is 295°C, the temperature of zone 8 is 295°C, the temperature of zone 9 is 300°C, the temperature of zone 10 is 300°C, the temperature of zone 11 is 300°C, the temperature of die head is 300°C, equipped with 2 exhaust ports, 2 vacuum ports (the exhaust port is in front, and in the back after vacuum, and the specific position can be adjusted according to the viscosity enhancement effect), the exhaust port is protected by nitrogen, the main speed of the extruder is 300rpm, the feeding rate is 8kg / h, short glass fiber (Jiushi 568H) is added to the extruder side feeding, the feeding rate is 3.43kg / h, and the glass fiber content of the product is 30%wt. The melt is cooled underwater, blown dry by a fan and pelletized to obtain glass fiber reinforced flame retardant antistatic polyamide.

[0097] The glass fiber reinforced flame retardant antistatic polyamide was dried at 100° C. in vacuum for 8 hours and then various properties were tested. The results are shown in Table 1.

[0098] Comparative Example 1

[0099] Comparative Example 1 of the present disclosure provides a polyamide, and the preparation method thereof comprises the following steps:

[0100] The first step is to prepare a polyamide prepolymer: evacuate a 20-liter polymerization kettle and protect it with nitrogen, add 7kg of pure water, then add 1.83kg of hexamethylenediamine, start stirring, add 1.26kg of terephthalic acid and 1.19kg of adipic acid, and then add 2g of an antioxidant, sodium hypophosphite, and heat to 70°C to dissolve to obtain a nylon salt solution. Use a small amount of hexamethylenediamine or adipic acid to adjust the pH value of the nylon salt solution to 6.50 when the concentration is 10%. Set the 20-liter polymerization kettle oil bath to 180°C to evaporate and concentrate the water. After the system concentration is increased to 75%, continue to heat the oil bath to 290°C, wait until the pressure in the kettle rises to 2.0MPa, start exhausting, and when the temperature in the kettle reaches 245°C, discharge the material to a crushing kettle, crush the prepolymer, and obtain a polyamide prepolymer.

[0101] Step 2: prepare a premix: accurately weigh 2.985 kg of prepolymer and 15 g of antioxidant (1098), place the above components in a clean stainless steel container with a total weight of 3 kg, and then transfer to a high-speed mixer with a stirring speed of 1000 rpm and mix for 0.5 hours to obtain a premix.

[0102] The third step is to prepare polyamide: the premix is ​​transferred to a twin-screw extruder with a diameter of 26 mm, the temperature of zone 1 is 230°C, the temperature of zone 2 is 255°C, the temperature of zone 3 is 265°C, the temperature of zone 4 is 275°C, the temperature of zone 5 is 275°C, the temperature of zone 6 is 285°C, the temperature of zone 7 is 285°C, the temperature of zone 8 is 290°C, the temperature of zone 9 is 290°C, the temperature of zone 10 is 290°C, the temperature of zone 11 is 295°C, the temperature of the die head is 295°C, it is equipped with 2 exhaust ports and 2 vacuum ports, the exhaust ports are protected by nitrogen, the main speed of the extruder is 200rpm, the feeding rate is 10kg / h, the melt is cooled underwater, blown dry by a fan and then pelletized to obtain polyamide.

[0103] The polyamide was vacuum dried at 100°C for 8 hours and then tested for various properties. The results are shown in Table 1.

[0104] Comparative Example 2

[0105] Comparative Example 2 of the present disclosure provides a polyamide, and the preparation method thereof comprises the following steps:

[0106] The first step is to prepare a polyamide prepolymer: evacuate a 20-liter polymerization kettle and protect it with nitrogen, add 1.05 kg of hexamethylenediamine and 1.05 kg of 2-methylpentamethylenediamine, start stirring, add 3.0 kg of terephthalic acid, and then add 1.5 g of antioxidant H10, heat to 80 ° C to dissolve to obtain a nylon salt solution, and use a small amount of 2-methylpentamethylenediamine or terephthalic acid to adjust the pH value of the nylon salt solution to 6.88 when the concentration is 10%. Heat the 20-liter polymerization kettle in an oil bath to evaporate and concentrate the water. After the system concentration is increased to 75%, continue to heat the oil bath to 290 ° C, wait until the pressure in the kettle rises to 2.0 MPa, start exhausting, and when the temperature in the kettle reaches 255 ° C, discharge the material to a crushing kettle, crush the prepolymer, and obtain a polyamide prepolymer.

[0107] The second step is to prepare a premix: accurately weigh 2.985 kg of prepolymer, 15 g of antioxidant (1098), and 300 g of carbon black, and place the above components in a clean stainless steel container with a total weight of 3.3 kg. Then transfer to a high-speed mixer, stir at a speed of 2000 rpm, and mix for 0.5 hours to obtain a premix.

[0108] The third step is to prepare polyamide: the premix is ​​transferred to a twin-screw extruder with a diameter of 26 mm, the temperature of zone 1 is 240°C, the temperature of zone 2 is 260°C, the temperature of zone 3 is 270°C, the temperature of zone 4 is 270, the temperature of zone 5 is 280°C, the temperature of zone 6 is 280°C, the temperature of zone 7 is 290°C, the temperature of zone 8 is 295°C, the temperature of zone 9 is 295°C, the temperature of zone 10 is 300°C, the temperature of zone 11 is 300°C, the temperature of the die head is 295°C, it is equipped with 2 exhaust ports and 2 vacuum ports, the exhaust port is protected by nitrogen, the main speed of the extruder is 300rpm, the feeding rate is 8kg / h, the melt is cooled underwater, blown dry by a fan and then pelletized to obtain polyamide.

[0109] The polyamide was vacuum dried at 100°C for 8 hours and then tested for various properties. The results are shown in Table 1.

[0110] Comparative Example 3

[0111] Comparative Example 3 of the present disclosure provides a glass fiber reinforced polyamide, and the preparation method thereof comprises the following steps:

[0112] The first step is to prepare a polyamide prepolymer: evacuate a 20-liter polymerization kettle and protect it with nitrogen, add 7kg of pure water, then add 1.83kg of hexamethylenediamine, start stirring, add 1.26kg of terephthalic acid and 1.19kg of adipic acid, and then add 2g of an antioxidant, sodium hypophosphite, and heat to 70°C to dissolve to obtain a nylon salt solution. Use a small amount of hexamethylenediamine or adipic acid to adjust the pH value of the nylon salt solution to 6.50 when the concentration is 10%. Heat the 20-liter polymerization kettle in an oil bath to evaporate and concentrate the water. After the system concentration is increased to 75%, continue to heat the oil bath to 290°C, wait until the pressure in the kettle rises to 2.0MPa, start exhausting, and when the temperature in the kettle reaches 245°C, discharge the material to a crushing kettle, crush the prepolymer, and obtain a polyamide prepolymer.

[0113] Step 2: prepare a premix: accurately weigh 2.985 kg of prepolymer and 15 g of antioxidant (1098), place the above components in a clean stainless steel container with a total weight of 3 kg, and then transfer to a high-speed mixer with a stirring speed of 1000 rpm and mix for 0.5 hours to obtain a premix.

[0114] The third step is to prepare polyamide: the premix is ​​transferred to a twin-screw extruder with a diameter of 26 mm, the temperature of zone 1 is 230°C, the temperature of zone 2 is 255°C, the temperature of zone 3 is 265°C, the temperature of zone 4 is 275°C, the temperature of zone 5 is 275°C, the temperature of zone 6 is 285°C, the temperature of zone 7 is 285°C, the temperature of zone 8 is 290°C, the temperature of zone 9 is 290°C, the temperature of zone 10 is 290°C, the temperature of zone 11 is 295°C, the temperature of die head is 295°C, equipped with 2 exhaust ports, 2 vacuum ports, the exhaust port is protected by nitrogen, the main speed of the extruder is 200rpm, the feeding rate is 10kg / h, short glass fiber (Jiushi 568H) is added to the side feed of the extruder, the feeding rate is 4.29kg / h, and the glass fiber content of the product is 30%wt. The melt is cooled underwater, blown dry by a fan and pelletized to obtain glass fiber reinforced polyamide.

[0115] The glass fiber reinforced polyamide was dried at 100° C. in vacuum for 8 hours and then various properties were tested. The results are shown in Table 1.

[0116] Comparative Example 4

[0117] Comparative Example 4 of the present disclosure provides an extruded flame-retardant antistatic polyamide, and a preparation method thereof comprises the following steps:

[0118] The first step is to prepare a premix: accurately weigh 2.985 kg of nylon 6T, 30 g of antioxidant (1010), 320 g of diethyl aluminum hypophosphite, and 400 g of carbon black, place the above components in a high-speed mixer, stir at a speed of 1000 rpm, mix for 0.5 hours, and obtain a premix.

[0119] The second step is to prepare polyamide: the premix is ​​transferred to a twin-screw extruder with a diameter of 26 mm, the temperature of zone 1 is 230°C, the temperature of zone 2 is 255°C, the temperature of zone 3 is 265°C, the temperature of zone 4 is 275°C, the temperature of zone 5 is 275°C, the temperature of zone 6 is 285°C, the temperature of zone 7 is 285°C, the temperature of zone 8 is 290°C, the temperature of zone 9 is 290°C, the temperature of zone 10 is 290°C, the temperature of zone 11 is 295°C, the temperature of the die head is 295°C, it is equipped with 2 exhaust ports and 2 vacuum ports, the exhaust port is protected by nitrogen, the main speed of the extruder is 300rpm, the feeding rate is 8kg / h, the melt is cooled underwater, blown dry by a fan and then pelletized to obtain extruded flame-retardant and antistatic polyamide.

[0120] The extruded flame-retardant antistatic polyamide was dried at 100° C. in vacuum for 8 hours and then tested for various properties. The results are shown in Table 1.

[0121] Comparative Example 5

[0122] Comparative Example 5 of the present disclosure provides a glass fiber reinforced polyamide, and the preparation method thereof comprises the following steps:

[0123] The first step is to prepare a premix: accurately weigh 3 kg of nylon 6T, 30 g of antioxidant (1010), 320 g of diethyl aluminum hypophosphite, and 400 g of carbon black, place the above components in a high-speed mixer, stir at a speed of 1000 rpm, mix for 0.5 hours, and obtain a premix.

[0124] The second step is to prepare polyamide: the premix is ​​transferred to a twin-screw extruder with a diameter of 26 mm, the temperature of zone 1 is 240°C, the temperature of zone 2 is 295°C, the temperature of zone 3 is 295°C, the temperature of zone 4 is 300, the temperature of zone 5 is 300°C, the temperature of zone 6 is 305°C, the temperature of zone 7 is 305°C, the temperature of zone 8 is 310°C, the temperature of zone 9 is 310°C, the temperature of zone 10 is 310°C, the temperature of zone 11 is 315°C, and the head temperature is 315°C. It is equipped with 2 exhaust ports and 2 vacuum ports (the exhaust port is in the front and in the back after vacuum. The specific position can be adjusted according to the viscosity-increasing effect). The exhaust port is protected by nitrogen. The main speed of the extruder is 200rpm, the feeding rate is 10kg / h, and short glass fiber (Jiushi 568H) is added to the side feeding of the extruder. The feeding rate is 4.29kg / h, and the glass fiber content of the product is 30%wt. The melt is cooled underwater, blown dry by a fan, and pelletized to obtain glass fiber reinforced polyamide.

[0125] The glass fiber reinforced polyamide was dried at 100° C. in vacuum for 8 hours and then various properties were tested. The results are shown in Table 1.

[0126] The tensile strength of the polyamide prepared in the examples and comparative examples of the present disclosure was tested for various properties after being dried in vacuum at 100° C. for 8 hours. The results are shown in Table 1:

[0127] Table 1: Polyamide performance test data table

[0128]

[0129]

[0130] As can be seen from the above table, the flame retardant antistatic polyamide prepared in Examples 1 to 4 of the present disclosure and the polyamide prepared in Comparative Examples 1 to 2 have significantly better tensile strength and surface resistance than the polyamide prepared in Comparative Examples 1 to 2. The glass fiber reinforced flame retardant antistatic polyamide prepared in Examples 5 and 6 of the present disclosure and the glass fiber reinforced polyamide prepared in Comparative Examples 3 and 5 have significantly better tensile strength and surface resistance than the glass fiber reinforced polyamide prepared in Comparative Examples 3 and 5.

[0131] On this basis, the polyamide prepared in Examples 1 to 6 of the present disclosure adopts a polyamide prepolymer prepared by diamine, dibasic acid, and antioxidant, and the prepared polyamide has better data on tensile strength and surface resistance than the nylon 6T prepolymer used in Comparative Examples 4 and 5. The basic principles of the present disclosure are described above in conjunction with specific embodiments, but it should be pointed out that the advantages, advantages, effects, etc. mentioned in the present disclosure are only examples and not limitations, and it cannot be considered that these advantages, advantages, effects, etc. are necessary for each embodiment of the present disclosure. In addition, the specific details disclosed above are only for the purpose of illustration and the purpose of facilitating understanding, rather than limitation, and the above details do not limit the present disclosure to the use of the above specific details to be implemented.

[0132] Additionally, as used herein, "or" used in a list of items beginning with "at least one" indicates a separate list, so that, for example, a list of "at least one of A, B, or C" means A or B or C, or AB or AC or BC, or ABC (i.e., A and B and C). Furthermore, the word "exemplary" does not mean that the example described is preferred or better than other examples.

[0133] It should also be noted that in the system and method of the present disclosure, each component or each step can be decomposed and / or recombined. Such decomposition and / or recombination should be regarded as equivalent solutions of the present disclosure.

[0134] Various changes, substitutions, and modifications of the techniques described herein may be made without departing from the teachings defined by the appended claims. Furthermore, the scope of the claims of the present disclosure is not limited to the specific aspects of the processes, machines, manufactures, compositions of events, means, methods, and actions described above. Currently existing or later to be developed processes, machines, manufactures, compositions of events, means, methods, or actions that perform substantially the same functions or achieve substantially the same results as the corresponding aspects described herein may be utilized. Thus, the appended claims include such processes, machines, manufactures, compositions of events, means, methods, or actions within their scope.

[0135] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use the present disclosure. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other aspects without departing from the scope of the present disclosure. Therefore, the present disclosure is not intended to be limited to the aspects shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

[0136] The above description has been given for the purpose of illustration and description. In addition, this description is not intended to limit the embodiments of the present disclosure to the forms disclosed herein. Although multiple example aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, changes, additions and sub-combinations thereof.

Claims

1. A flame retardant antistatic polyamide, characterized in that: The limiting oxygen index of the flame retardant antistatic polyamide is 29% to 33%, and the surface resistance of the flame retardant antistatic polyamide is 10 5 Ω~10 9 Ω, the tensile strength of the flame retardant antistatic polyamide is 70MPa to 90MPa.

2. A method for preparing the flame retardant antistatic polyamide according to claim 1, characterized in that: include: preparing a polyamide prepolymer using a polyamide salt solution; The polyamide prepolymer is mixed with a flame retardant, an antistatic agent, a dispersant, a compatibilizer and an antioxidant to obtain a premix; The premix is ​​subjected to a viscosity increasing reaction by a twin-screw extruder, and is melt-granulated to obtain a flame-retardant antistatic polyamide.

3. The method for preparing the flame retardant antistatic polyamide according to claim 2, characterized in that: The method of preparing a polyamide prepolymer by using a polyamide salt solution comprises: Mix and dissolve a diamine, a dibasic acid, an antioxidant and water to obtain a polyamide salt solution; Using diamine and dibasic acid to adjust the pH of the polyamide salt solution to 6-11; The polyamide salt solution with a pH of 6 to 11 is treated into a polyamide prepolymer.

4. The method for preparing the flame retardant antistatic polyamide according to claim 3, characterized in that: The diamine, dibasic acid, antioxidant and water are mixed and dissolved to obtain a polyamide salt solution, including: Mixing and dissolving a diamine and water to obtain a diamine aqueous solution; Add dibasic acid and antioxidant to the diamine aqueous solution, heat until dissolved, and obtain a polyamide salt solution.

5. The method for preparing the flame retardant and antistatic polyamide according to claim 3, characterized in that: The step of treating the polyamide salt solution having a pH of 6 to 11 into a polyamide prepolymer comprises: At a temperature of 170° C. to 190° C., concentrating the polyamide salt solution having a pH of 6 to 11 until the mass concentration of the polyamide salt solution is 50% to 95%; The polyamide salt solution with a mass concentration of 50% to 95% is reacted at a temperature of 230° C. to 300° C. and a pressure of 1.5 MPa to 6 MPa for 0.5 h to 8 h to obtain a reaction product; The reaction product is treated under a pressure of 1.5 MPa to 5 MPa to obtain a polyamide prepolymer.

6. The method for preparing the flame retardant and antistatic polyamide according to claim 2, characterized in that: Before the premix is ​​subjected to a viscosity increasing reaction by a twin-screw extruder, the method further comprises: The twin-screw extruder is protected by inert gas replacement or vacuum extraction.

7. The method for preparing the flame retardant and antistatic polyamide according to claim 2, characterized in that: The twin-screw extruder comprises a main feeding port, a plurality of extrusion zones and a die. When the twin-screw extruder comprises eleven extrusion zones, the temperature of the first extrusion zone is 230°C to 250°C, the temperature of the second extrusion zone is 255°C to 270°C, the temperature of the third extrusion zone is 265°C to 280°C, the temperature of the fourth extrusion zone is 275°C to 280°C, the temperature of the fifth extrusion zone is 275°C to 290°C, the temperature of the sixth extrusion zone is 285°C to 290°C, the temperature of the seventh extrusion zone is 285°C to 295°C, the temperature of the eighth extrusion zone is 290°C to 295°C, the temperature of the ninth extrusion zone is 290°C to 300°C, the temperature of the tenth extrusion zone is 290°C to 300°C, the temperature of the eleventh extrusion zone is 295°C to 300°C, and the temperature of the die is 295°C to 300°C.

8. The method for preparing the flame retardant antistatic polyamide according to claim 2, characterized in that: The mass ratio of the polyamide prepolymer, the flame retardant, the antistatic agent, the dispersant, the compatibilizer and the antioxidant is (50-99): (0-20): (2-20): (0-10): (0-6): (0-1).

9. The method for preparing the flame retardant antistatic polyamide according to claim 2, characterized in that: In the premix, the mass percentage of the polyamide prepolymer in the premix is ​​50% to 99%.

10. The method for preparing the flame retardant antistatic polyamide according to any one of claims 2 to 9, characterized in that: The polyamide prepolymer includes at least one of polyhexamethylene terephthalamide, polyhexamethylene adipamide, polyhexamethylene dodecanoamide, polyhexamethylene sebacamide, polylaurolactam, and polydecane terephthalate.

11. The method for preparing the flame retardant antistatic polyamide according to any one of claims 2 to 9, characterized in that: The flame retardant comprises at least one of melamine cyanurate, diethyl aluminum hypophosphite, melamine salt, phosphate, red phosphorus, boehmite, aluminum hydroxide, magnesium hydroxide, ammonium polyphosphate, and antimony trioxide; The antistatic agent comprises at least one of conductive carbon black, carbon nanotubes, graphite, conductive carbon fibers, quaternary ammonium salts, polyethylene glycol, stearyl dimethyl amyl ammonium chloride, stearyl trimethyl ammonium chloride, 1,3-dimethyl imidazole tetrafluoroborate, N-octyl pyridinium bromide, N-butyl-N-methyl piperidinium bromide, N-butyl-N-methyl pyrrolidine bromide, tributyl methyl ammonium chloride, N-ethyl, methyl morpholine bromide and tributyl ethyl phosphonium bromide ionic liquids; The dispersant includes at least one of polyethylene wax, polypropylene wax, erucamide, oleamide, calcium stearate, lithium stearate, silicone oil, silicone, montan wax, stearamide, and ethylene bis stearamide; The compatibilizer includes at least one of maleic anhydride, polyacrylate, and m-isopropenyl-2,2-dimethylbenzyl isocyanate; The antioxidant includes one of antioxidant 168, antioxidant 619F, antioxidant 1076, antioxidant 1098, antioxidant 1010, antioxidant B215, and antioxidant H10.

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