Phosphorus-nitrogen synergistic flame-retardant high-temperature-resistant nylon material and preparation method thereof

Abstract

The application discloses a phosphorus-nitrogen synergistic flame-retardant high-temperature-resistant nylon material and a preparation method thereof, relates to the technical field of nylon materials, and comprises the following steps: (1) adding a catalyst, an antioxidant, a molecular weight regulator and deionized water into a mixture of a binary amine and a binary acid monomer, and performing a salt formation reaction under the condition that the temperature is 90-100 DEG C and the pressure is 0.1-0.2 MPa to obtain a prepolymer; (2) adding a phosphorus-based flame retardant into the prepolymer, increasing the temperature to 220-230 DEG C and the pressure to 2.4-2.6 MPa, and continuing to react to obtain nylon prepolymer powder; and (3) mixing a nitrogen-based flame retardant with the dried nylon prepolymer powder, and then performing melt viscosity increase to obtain the high-temperature-resistant nylon material. The nylon material prepared by the method not only has long-term flame retardation, but also has the advantages of simple process, low production cost, green environmental protection and suitability for industrialized production of the flame-retardant nylon.

Description

Technical Field

[0001] This invention relates to the field of nylon materials technology, specifically to a high-temperature resistant nylon material with phosphorus and nitrogen synergistic flame retardancy and its preparation method. Background Technology

[0002] Nylon, professionally known as polyamide, possesses excellent properties such as wear resistance, impact resistance, fatigue resistance, and corrosion resistance. In recent years, various high-value-added modified products of this material have emerged, and it is now widely used in electronics, transportation, aerospace, textile equipment, military equipment, and medical devices. With the growing awareness of environmental protection and the implementation of a series of domestic and international environmental regulations, safe and environmentally friendly high-performance materials are receiving increasing attention, especially in the field of flame-retardant polymer materials. We all know that polymer materials are generally flammable, spread rapidly, and are difficult to extinguish. Statistics show that more than 30% of fires worldwide each year are related to the combustion of polymer materials. Therefore, flame-retardant polymer materials with excellent flame-retardant effects and no toxic pollution are very important and necessary in applications such as electronic equipment, new energy vehicles, and construction.

[0003] Currently, commonly used aliphatic polyamides such as PA1010, PA66, and PA6 generally have an oxygen index of less than 23 vol%, making them unsuitable for equipment or components that are exposed to high temperatures for extended periods. Although aromatic and semi-aromatic polyamides have introduced highly heat-resistant aromatic ring structures into their molecular chains, improving their flame retardancy, they still cannot effectively self-extinguish and require modification when used in high-temperature environments.

[0004] Currently, high-temperature flame-retardant nylon materials on the market are mainly divided into two types. One type involves directly adding flame retardants to nylon resin through physical blending. Due to its simple process and high production efficiency, this is currently the most commonly used method in industrial production. However, this method requires very strict and careful control of the amount of flame retardant added, otherwise it can easily have an adverse effect on the mechanical properties of the nylon material. The other type involves grafting or inserting flame-retardant monomers into the nylon molecular chain through a chemical reaction. Because this method has high design flexibility, a small amount of flame retardant can be used to prepare nylon materials with high flame retardant properties, and it has little impact on the mechanical strength of the material itself. This has become one of the hot topics in academic research, but due to its high cost, it is not suitable for industrial production.

[0005] Patent document CN119823570A discloses a halogen-free flame-retardant nylon material and its preparation method. This invention belongs to the field of additive flame-retardant nylon materials. The nylon composite material prepared by this invention exhibits excellent flame-retardant properties, but its mechanical strength is somewhat reduced. Patent document CN115894903A discloses a method for preparing intrinsically flame-retardant nylon. The nylon material obtained has excellent flame-retardant properties, but the preparation process is complex and cumbersome.

[0006] Therefore, in existing flame-retardant nylon preparation technologies, single flame retardant systems are insufficient to achieve effective flame retardancy, while intrinsic flame-retardant schemes using multiple systems are complex, costly, and unsuitable for industrial production. Furthermore, additive flame-retardant schemes often adversely affect the material's inherent properties, leading to difficulties in the development and application of downstream products. Summary of the Invention

[0007] The existing flame-retardant nylon preparation process suffers from poor flame retardant effect and high cost. The purpose of this invention is to provide a high-temperature resistant nylon material with phosphorus and nitrogen synergistic flame retardancy and its preparation method. The nylon material prepared by this method can not only achieve long-term flame retardancy, but also has a simple process, low production cost, and is environmentally friendly, making it suitable for the industrial production of flame-retardant nylon.

[0008] This invention is achieved through the following technical solution:

[0009] In a first aspect, this application provides a method for preparing a high-temperature resistant nylon material with synergistic phosphorus and nitrogen flame retardancy, comprising the following steps:

[0010] (1) Add catalyst, antioxidant, molecular weight regulator and deionized water to a mixture of diamine and diacid monomers, and carry out salt formation reaction at a temperature of 90℃~100℃ and a pressure of 0.1MPa~0.2MPa to obtain prepolymer;

[0011] (2) Add phosphorus-based flame retardant to the prepolymer, raise the temperature to 220℃~230℃, raise the pressure to 2.4MPa~2.6MPa, and continue the reaction to obtain nylon prepolymer powder;

[0012] (3) The nitrogen-based flame retardant is mixed with the dried nylon prepolymer powder and then melt-bonded to obtain high-temperature resistant nylon material.

[0013] Among them, the high-temperature nylon prepolymer preparation method is suitable for semi-aromatic polyamides, including PA6T / X, PA9T, PA10T, PA12T, MXD6, and MXD10.

[0014] The preparation method of this invention employs a stepwise in-situ polymerization approach. First, a salt-forming reaction is carried out at 90℃~100℃ and 0.1MPa~0.2MPa to obtain a low-viscosity aqueous solution, ensuring uniform reaction. Then, the temperature is raised to 220℃~230℃ and 2.4MPa~2.6MPa, and a phosphorus-based flame retardant is simultaneously added for prepolymerization. This allows the flame retardant to be chemically anchored during molecular chain growth. Because the product precipitates in powder form, the common industry problems of difficult discharge, sticking to the reactor, and residue in pipelines associated with high-viscosity nylon melts are completely avoided. Finally, a screw-type melt thickening process is used. At this stage, a nitrogen-based flame retardant is introduced, precisely controlling the molecular weight and preventing premature decomposition of the flame retardant.

[0015] In terms of flame retardant mechanism, phosphorus-based components exert their effects through a dual channel of condensed-phase char formation and gas-phase free radical quenching. Piperazine pyrophosphate promotes the formation of an expanded char layer, while bisphenol A-bis(diphenyl phosphate) decomposes to produce phosphoric acid, catalyzing carbonization and releasing phosphorus-containing free radicals to capture the combustion chain. Nitrogen-based flame retardants, on the other hand, undergo endothermic decomposition during combustion, releasing ammonia and water vapor to dilute combustible gases, while simultaneously catalyzing the heat transfer of nylon droplets. The stepwise introduction allows phosphorus-based flame retardants to form a molecularly uniformly distributed "flame retardant skeleton" within the nylon matrix, while nitrogen-based flame retardants are subsequently assembled and filled into the gaps in the skeleton, constructing a phosphorus-nitrogen interpenetrating network. This achieves a sequential relay and functional complementarity of the three functions: solid-phase char formation, gas-phase quenching, and endothermic dilution.

[0016] In the preparation method of this invention, the powdered prepolymer enables continuous screw thickening, and the later addition of nitrogen-based flame retardants does not interfere with the earlier polymerization, ensuring maximum flame retardant efficiency. The synergy between phosphorus-based anchoring and nitrogen-based filling results in a limiting oxygen index of over 30% and a UL 94 V-0 rating, with no migration or precipitation of the flame retardant. Compared to existing melt blending methods, this solution simultaneously solves problems such as high-viscosity discharge, poor flame retardant durability, and high production costs, achieving a balance between long-lasting flame retardancy and green industrial production.

[0017] Furthermore, the molar ratio of the diamine to the diacid is (1.01~1.02):1, preferably 1.01:1.

[0018] Further, the catalyst includes at least one selected from sodium hypophosphite, potassium hypophosphite, calcium hypophosphite, n-butyl titanate, propyl titanate, and isopropyl titanate. The amount of catalyst added is 0.1 wt% to 0.2 wt% of the total mass of the monomer raw materials, preferably 0.1 wt%.

[0019] Further, the molecular weight regulator includes at least one selected from acetic acid, propionic acid, hexanoic acid, benzoic acid, and cyclohexanecarboxylic acid. Benzoic acid is preferred. The molar fraction is 1.0% to 2.0%, preferably 1.0%.

[0020] Furthermore, the mass of the deionized water is 1.0 to 1.1 times the total mass of the diamine and diacid monomers.

[0021] Furthermore, in step (1), nitrogen needs to be introduced to replace the air in the reactor, and the reaction processes in both steps (1) and (2) need to be isolated from air.

[0022] Furthermore, the phosphorus-based flame retardant is a mixture of piperazine pyrophosphate and bisphenol A-bis(diphenyl phosphate), and the amount added is 6 wt% to 12 wt% of the total mass of the diamine and diacid monomers. Preferably, it is 9.0 wt%.

[0023] Furthermore, the nitrogen-based flame retardant is melamine cyanurate, and the amount added is 4wt% to 8wt% of the total mass of the diamine and diacid monomers. Preferably, it is 6.0wt%.

[0024] Furthermore, in step (3), the screw devourer is used for melt thickening. During the melt thickening process, the temperature of each heating section of the screw devourer should be controlled at 280~320 ℃, and the screw speed should be controlled at 60~80 r / min.

[0025] Secondly, this application provides a high-temperature resistant nylon material with synergistic phosphorus and nitrogen flame retardancy, prepared using the above-mentioned method. The resulting high-temperature resistant nylon material has a limiting oxygen index of over 30 vol% and a flame retardancy rating of UL 94-V0.

[0026] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0027] (1) This invention uses phosphorus-based flame retardants to chemically anchor in situ during the polymerization stage, and constructs a triple synergistic network of "solid-phase char formation, gas-phase quenching, and endothermic dilution" with nitrogen-based flame retardants introduced later. The prepared high-temperature resistant nylon material has a limiting oxygen index of over 30 vol%, a flame retardancy rating of UL 94-V0, and the flame retardants are uniformly dispersed in the matrix at the molecular level, effectively avoiding migration and precipitation, and achieving long-lasting flame retardancy.

[0028] (2) This invention enables the prepolymer to precipitate directly in solid powder form by precisely controlling the prepolymer temperature and pressure (220~230℃, 2.4~2.6 MPa). This morphological transformation completely avoids the problems of difficult discharge and uneven feeding of traditional high-temperature nylon high-viscosity melt, greatly simplifies the discharge process, effectively avoids polymer adhesion and residue in the reactor and pipeline, and significantly improves production stability.

[0029] (3) This invention uses a screw devourer for melt thickening. By controlling the screw speed and temperature of each section, it not only achieves continuous production of polymer and greatly improves production efficiency, but also enables precise control of the molecular weight of the final product according to process requirements, ensuring the consistency of performance between batches.

[0030] (4) The preparation method of the present invention uses deionized water as a medium and does not use organic solvents throughout the process. Furthermore, the production process is simplified through a short process design of "in-situ polymerization followed by screw thickening". The powdered prepolymer can be directly introduced into the downstream thickening process without complex crushing treatment, which greatly reduces equipment investment, energy consumption and manual cleaning costs. Moreover, the emissions of waste are minimal, which fully meets the requirements of green and industrialized production.

[0031] (5) The preparation method of the present invention is not only applicable to a single specific nylon system, but is also widely applicable to various semi-aromatic high-temperature resistant nylons such as PA6T / X, PA9T, PA10T, PA12T, MXD6 and MXD10. Flame retardant modification of different products can be achieved through the same process route, the production line has high compatibility, and it is convenient for enterprises to efficiently switch and develop diversified products according to market demand. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the embodiments. The illustrative embodiments and descriptions of this invention are only used to explain this invention and are not intended to limit this invention.

[0033] In the following description, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be apparent to those skilled in the art that these specific details are not necessary to practice the invention. In other embodiments, well-known materials or methods have not been specifically described in order to avoid obscuring the invention.

[0034] Throughout this specification, references to "an embodiment," "an example," or "an example" mean that a particular feature, structure, or characteristic described in connection with that embodiment or example is included in at least one embodiment of the invention. Therefore, the phrases "an embodiment," "an example," "an example," or "an example" appearing in various places throughout the specification do not necessarily refer to the same embodiment or example. Furthermore, specific features, structures, or characteristics can be combined in one or more embodiments or examples in any suitable combination and / or sub-combination. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described herein, as well as the features of those different embodiments or examples.

[0035] The "range" disclosed in this application is defined by a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, which define the boundaries of a particular range. Ranges defined in this way can include or exclude endpoints and can be arbitrarily combined; that is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60–120 and 80–110 are listed for a specific parameter, it is understood that ranges of 60–110 and 80–120 are also expected. Furthermore, if minimum range values ​​of 1 and 2 are listed, and if maximum range values ​​of 3, 4, and 5 are listed, then the following ranges are all expected: 1–3, 1–4, 1–5, 2–3, 2–4, and 2–5. In this application, unless otherwise stated, the numerical range "a–b" represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0~5" indicates that all real numbers between "0~5" have been listed in this article; "0~5" is simply a shortened representation of these numerical combinations. Furthermore, when a parameter is stated as an integer ≥2, it is equivalent to disclosing that the parameter is, for example, an integer such as 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0036] Unless otherwise specified, all steps in this application may be performed sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), indicating that the method may include steps (a) and (b) performed sequentially, or it may include steps (b) and (a) performed sequentially. For example, the method may also include step (c), indicating that step (c) may be added to the method in any order. For example, the method may include steps (a), (b), and (c), or it may include steps (a), (c), and (b), or it may include steps (c), (a), and (b), etc.

[0037] Example 1

[0038] This embodiment provides a method for preparing a high-temperature resistant nylon material with synergistic phosphorus and nitrogen flame retardancy. The specific method is as follows:

[0039] S1. Add 1329.05g terephthalic acid, 1378.50g decanediamine, 9.77g benzoic acid, 2.71g sodium hypophosphite, and 2707g deionized water to the reactor in sequence. Close the reactor and purge with nitrogen to 2.6MPa to check for air tightness. After confirming that there is no leakage, open the valve and slowly release the gas in the reactor. Then purge with nitrogen to 0.5MPa and release. Repeat this process 3 times to replace the air in the reactor. Finally, purge with a small amount of nitrogen to maintain the pressure at 0.1~0.2 MPa.

[0040] S2. Set the temperature inside the vessel to 90℃, the temperature of the heat transfer oil to 110℃, and the stirring rod speed to 60r / min. Start heating. After the temperature inside the vessel reaches the set value, start the salt formation reaction for 1.5 hours.

[0041] S3. After the salt formation reaction is completed, directly open the feed port and add 243.63g of phosphorus-based flame retardant (a mixture of piperazine pyrophosphate and bisphenol A-bis(diphenyl phosphate), with a mass ratio of 1:2; piperazine pyrophosphate, purity 99%, Shanghai Titan Technology Co., Ltd.; bisphenol A-bis(diphenyl phosphate): purity 99%, Guangzhou Yuanda New Materials Co., Ltd.), close the feed port, purge with nitrogen to 0.5MPa and then discharge, repeat 3 times to replace the air in the reactor, and finally purge with a small amount of nitrogen to maintain the pressure at 0.1~0.2MPa;

[0042] S4. Set the reactor temperature to 230℃ and the heat transfer oil temperature to 280℃, and start heating. When the reactor temperature reaches the set value and the pressure reaches 2.5MPa, fine-tune the opening and closing degree of the pressure relief valve to maintain the reactor pressure at 2.4~2.6MPa and start the prepolymerization reaction for 3.0 h.

[0043] S5. After the prepolymerization stage is completed, increase the opening degree of the pressure relief valve appropriately to start depressurization. When the pressure inside the reactor reaches below 1.0 MPa, open the discharge valve, filter and collect the prepolymer slurry, and dry it at 100 ℃ for 8 h.

[0044] S6. Take a certain mass of dried nylon prepolymer powder and add 6 wt% nitrogen-based flame retardant (melamine cyanurate: 99% purity, Shanghai Titan Technology Co., Ltd.). After mixing evenly with a mixer, extrude and pelletize the mixture through a screw devourer to obtain high-temperature resistant nylon material. Set the temperature of the two sections near the extruder inlet to 280℃, and the temperature of the remaining sections to 320℃. Set the screw speed to 60 r / min.

[0045] Example 2

[0046] This embodiment provides a method for preparing a high-temperature resistant nylon material with phosphorus and nitrogen synergistic flame retardancy. The difference from Embodiment 1 is that in step S2 of this embodiment, the temperature inside the reactor is controlled at 95°C, and the temperature of the heat transfer oil is 120°C. Everything else is the same as in Embodiment 1.

[0047] The specific method is as follows:

[0048] S1. Add 1329.05g terephthalic acid, 1378.50g decanediamine, 9.77g benzoic acid, 2.71g sodium hypophosphite, and 2707g deionized water to the reactor in sequence. Close the reactor and purge with nitrogen to 2.6MPa to check for air tightness. After confirming that there is no leakage, open the valve and slowly release the gas in the reactor. Then purge with nitrogen to 0.5MPa and release. Repeat this process 3 times to replace the air in the reactor. Finally, purge with a small amount of nitrogen to maintain the pressure at 0.1~0.2MPa.

[0049] S2. Set the temperature inside the vessel to 95℃, the temperature of the heat transfer oil to 120℃, and the stirring rod speed to 60r / min. Start heating. After the temperature inside the vessel reaches the set value, start the salt formation reaction for 1.5 hours.

[0050] S3. After the salt formation reaction is completed, directly open the feed port and add 243.63g of phosphorus-based flame retardant (a mixture of piperazine pyrophosphate and bisphenol A-bis(diphenyl phosphate), with a mass ratio of 1:2; piperazine pyrophosphate, purity 99%, Shanghai Titan Technology Co., Ltd.; bisphenol A-bis(diphenyl phosphate), purity 99%, Guangzhou Yuanda New Materials Co., Ltd.). Close the feed port, purge with nitrogen to 0.5MPa and then purge. Repeat this process 3 times to replace the air in the reactor. Finally, purge the reactor with a small amount of nitrogen to maintain the pressure at 0.1~0.2MPa.

[0051] S4. Set the reactor temperature to 230℃ and the heat transfer oil temperature to 280℃, and start heating. When the reactor temperature reaches the set value and the pressure reaches 2.5MPa, fine-tune the opening and closing degree of the pressure relief valve to maintain the reactor pressure at 2.4~2.6MPa and start the prepolymerization reaction for 3.0h.

[0052] S5. After the prepolymerization stage is completed, increase the opening degree of the pressure relief valve appropriately to start depressurization. When the pressure inside the reactor reaches below 1.0 MPa, open the discharge valve, filter and collect the prepolymer slurry, and dry it at 100℃ for 8 hours.

[0053] S6. Take a certain mass of dried nylon prepolymer powder and add 6 wt% nitrogen-based flame retardant (melamine cyanurate: 99% purity, Shanghai Titan Technology Co., Ltd.). After mixing evenly with a mixer, extrude and pelletize the mixture through a screw devourer to obtain high-temperature resistant nylon material. Set the temperature of the two sections near the extruder inlet to 280℃, and the temperature of the remaining sections to 320℃. Set the screw speed to 60 r / min.

[0054] Example 3

[0055] This embodiment provides a method for preparing a high-temperature resistant nylon material with synergistic phosphorus and nitrogen flame retardancy. The difference from Embodiment 1 is that in step S2 of this embodiment, the temperature inside the reactor is controlled at 100°C, and the temperature of the heat transfer oil is controlled at 130°C. Everything else is the same as in Embodiment 1.

[0056] The specific method is as follows:

[0057] S1. Add 1329.05g terephthalic acid, 1378.50g decanediamine, 9.77g benzoic acid, 2.71g sodium hypophosphite, and 2707g deionized water to the reactor in sequence. Close the reactor and purge with nitrogen to 2.6MPa to check for air tightness. After confirming that there is no leakage, open the valve and slowly release the gas in the reactor. Then purge with nitrogen to 0.5MPa and release. Repeat this process 3 times to replace the air in the reactor. Finally, purge with a small amount of nitrogen to maintain the pressure at 0.1~0.2MPa.

[0058] S2. Set the temperature inside the vessel to 100℃, the temperature of the heat transfer oil to 130℃, and the stirring rod speed to 60r / min. Start heating. After the temperature inside the vessel reaches the set value, start the salt formation reaction for 1.5 hours.

[0059] S3. After the salt formation reaction is completed, directly open the feed port and add 243.63g of phosphorus-based flame retardant (a mixture of piperazine pyrophosphate and bisphenol A-bis(diphenyl phosphate), with a mass ratio of 1:2; piperazine pyrophosphate, purity 99%, Shanghai Titan Technology Co., Ltd.; bisphenol A-bis(diphenyl phosphate), purity 99%, Guangzhou Yuanda New Materials Co., Ltd.). Close the feed port, purge with nitrogen to 0.5MPa and then purge. Repeat this process 3 times to replace the air in the reactor. Finally, purge the reactor with a small amount of nitrogen to maintain the pressure at 0.1~0.2MPa.

[0060] S4. Set the reactor temperature to 230℃ and the heat transfer oil temperature to 280℃, and start heating. When the reactor temperature reaches the set value and the pressure reaches 2.5MPa, fine-tune the opening and closing degree of the pressure relief valve to maintain the reactor pressure at 2.4~2.6MPa and start the prepolymerization reaction for 3.0h.

[0061] S5. After the prepolymerization stage is completed, increase the opening degree of the pressure relief valve appropriately to start depressurization. When the pressure inside the reactor reaches below 1.0 MPa, open the discharge valve, filter and collect the prepolymer slurry, and dry it at 100℃ for 8 hours.

[0062] S6. Take a certain mass of dried nylon prepolymer powder and add 6 wt% nitrogen-based flame retardant (melamine cyanurate: 99% purity, Shanghai Titan Technology Co., Ltd.). After mixing evenly with a mixer, extrude and pelletize the mixture through a screw devourer to obtain high-temperature resistant nylon material. Set the temperature of the two sections near the extruder inlet to 280℃, and the temperature of the remaining sections to 320℃. Set the screw speed to 60 r / min.

[0063] Example 4

[0064] This embodiment provides a method for preparing a high-temperature resistant nylon material with phosphorus and nitrogen synergistic flame retardancy. The difference from Embodiment 1 is that in step S4 of this embodiment, the temperature inside the reactor is 220°C and the temperature of the heat transfer oil is 260°C. Everything else is the same as in Embodiment 1.

[0065] The specific method is as follows:

[0066] S1. Add 1329.05g terephthalic acid, 1378.50g decanediamine, 9.77g benzoic acid, 2.71g sodium hypophosphite, and 2707g deionized water to the reactor in sequence. Close the reactor and purge with nitrogen to 2.6MPa to check for air tightness. After confirming that there is no leakage, open the valve and slowly release the gas in the reactor. Then purge with nitrogen to 0.5MPa and release. Repeat this process 3 times to replace the air in the reactor. Finally, purge with a small amount of nitrogen to maintain the pressure at 0.1~0.2MPa.

[0067] S2. Set the temperature inside the vessel to 90℃, the temperature of the heat transfer oil to 110℃, and the stirring rod speed to 60r / min. Start heating. After the temperature inside the vessel reaches the set value, start the salt formation reaction for 1.5 hours.

[0068] S3. After the salt formation reaction is completed, directly open the feed port and add 243.63g of phosphorus-based flame retardant (a mixture of piperazine pyrophosphate and bisphenol A-bis(diphenyl phosphate), with a mass ratio of 1:2; piperazine pyrophosphate, purity 99%, Shanghai Titan Technology Co., Ltd.; bisphenol A-bis(diphenyl phosphate), purity 99%, Guangzhou Yuanda New Materials Co., Ltd.). Close the feed port, purge with nitrogen to 0.5MPa and then purge. Repeat this process 3 times to replace the air in the reactor. Finally, purge the reactor with a small amount of nitrogen to maintain the pressure at 0.1~0.2MPa.

[0069] S4. Set the reactor temperature to 220℃ and the heat transfer oil temperature to 260℃, and start heating. When the reactor temperature reaches the set value and the pressure reaches 2.5MPa, fine-tune the opening and closing degree of the pressure relief valve to maintain the reactor pressure at 2.4~2.6MPa and start the prepolymerization reaction for 3.0h.

[0070] S5. After the prepolymerization stage is completed, increase the opening degree of the pressure relief valve appropriately to start depressurization. When the pressure inside the reactor reaches below 1.0 MPa, open the discharge valve, filter and collect the prepolymer slurry, and dry it at 100℃ for 8 hours.

[0071] S6. Take a certain mass of dried nylon prepolymer powder and add 6 wt% nitrogen-based flame retardant (melamine cyanurate: 99% purity, Shanghai Titan Technology Co., Ltd.). After mixing evenly with a mixer, extrude and pelletize the mixture through a screw devourer to obtain high-temperature resistant nylon material. Set the temperature of the two sections near the extruder inlet to 280℃, and the temperature of the remaining sections to 320℃. Set the screw speed to 60 r / min.

[0072] Example 5

[0073] This embodiment provides a method for preparing a high-temperature resistant nylon material with phosphorus and nitrogen synergistic flame retardancy. The difference from Embodiment 1 is that in step S4 of this embodiment, the temperature inside the reactor is 225°C and the temperature of the heat transfer oil is 270°C. Everything else is the same as in Embodiment 1.

[0074] The specific method is as follows:

[0075] S1. Add 1329.05g terephthalic acid, 1378.50g decanediamine, 9.77g benzoic acid, 2.71g sodium hypophosphite, and 2707g deionized water to the reactor in sequence. Close the reactor and purge with nitrogen to 2.6MPa to check for air tightness. After confirming that there is no leakage, open the valve and slowly release the gas in the reactor. Then purge with nitrogen to 0.5MPa and release. Repeat this process 3 times to replace the air in the reactor. Finally, purge with a small amount of nitrogen to maintain the pressure at 0.1~0.2MPa.

[0076] S2. Set the temperature inside the vessel to 90℃, the temperature of the heat transfer oil to 110℃, and the stirring rod speed to 60r / min. Start heating. After the temperature inside the vessel reaches the set value, start the salt formation reaction for 1.5 hours.

[0077] S3. After the salt formation reaction is completed, directly open the feed port and add 243.63g of phosphorus-based flame retardant (a mixture of piperazine pyrophosphate and bisphenol A-bis(diphenyl phosphate), with a mass ratio of 1:2; piperazine pyrophosphate, purity 99%, Shanghai Titan Technology Co., Ltd.; bisphenol A-bis(diphenyl phosphate), purity 99%, Guangzhou Yuanda New Materials Co., Ltd.). Close the feed port, purge with nitrogen to 0.5MPa and then purge. Repeat this process 3 times to replace the air in the reactor. Finally, purge the reactor with a small amount of nitrogen to maintain the pressure at 0.1~0.2MPa.

[0078] S4. Set the reactor temperature to 225℃ and the heat transfer oil temperature to 270℃, and start heating. When the reactor temperature reaches the set value and the pressure reaches 2.5MPa, fine-tune the opening and closing of the pressure relief valve to maintain the reactor pressure at 2.4~2.6MPa and start the prepolymerization reaction for 3.0h.

[0079] S5. After the prepolymerization stage is completed, increase the opening degree of the pressure relief valve appropriately to start depressurization. When the pressure inside the reactor reaches below 1.0 MPa, open the discharge valve, filter and collect the prepolymer slurry, and dry it at 100℃ for 8 hours.

[0080] S6. Take a certain mass of dried nylon prepolymer powder and add 6 wt% nitrogen-based flame retardant (melamine cyanurate: 99% purity, Shanghai Titan Technology Co., Ltd.). After mixing evenly with a mixer, extrude and pelletize the mixture through a screw devourer to obtain high-temperature resistant nylon material. Set the temperature of the two sections near the extruder inlet to 280℃, and the temperature of the remaining sections to 320℃. Set the screw speed to 60 r / min.

[0081] Comparative Example 1

[0082] This comparative example provides a method for preparing nylon material. Unlike Example 1, in step S2 of this example, the temperature inside the reactor is controlled at 85°C, the temperature of the heat transfer oil is 110°C, and the pressure is controlled below 0.1 MPa, which represents a lower temperature and lower pressure. Everything else is the same as in Example 1.

[0083] The specific method is as follows:

[0084] S1. Add 1329.05g terephthalic acid, 1378.50g decanediamine, 9.77g benzoic acid, 2.71g sodium hypophosphite, and 2707g deionized water to the reactor in sequence. Close the reactor and purge with nitrogen to 2.6MPa to check for air tightness. After confirming that there is no leakage, open the valve and slowly release the gas in the reactor. Then purge with nitrogen to 0.5MPa and release. Repeat this process 3 times to replace the air in the reactor. Finally, purge with a small amount of nitrogen to maintain the pressure below 0.1MPa.

[0085] S2. Set the temperature inside the vessel to 85℃, the temperature of the heat transfer oil to 110℃, and the stirring rod speed to 60r / min. Start heating. After the temperature inside the vessel reaches the set value, start the salt formation reaction for 1.5 hours.

[0086] S3. After the salt formation reaction is completed, directly open the feed port and add 243.63g of phosphorus-based flame retardant (a mixture of piperazine pyrophosphate and bisphenol A-bis(diphenyl phosphate), with a mass ratio of 1:2; piperazine pyrophosphate, purity 99%, Shanghai Titan Technology Co., Ltd.; bisphenol A-bis(diphenyl phosphate), purity 99%, Guangzhou Yuanda New Materials Co., Ltd.). Close the feed port, purge with nitrogen to 0.5MPa and then purge. Repeat this process 3 times to replace the air in the reactor. Finally, purge the reactor with a small amount of nitrogen to maintain the pressure at 0.1~0.2MPa.

[0087] S4. Set the reactor temperature to 230℃ and the heat transfer oil temperature to 280℃, and start heating. When the reactor temperature reaches the set value and the pressure reaches 2.5MPa, fine-tune the opening and closing degree of the pressure relief valve to maintain the reactor pressure at 2.4~2.6MPa and start the prepolymerization reaction for 3.0h.

[0088] S5. After the prepolymerization stage is completed, increase the opening degree of the pressure relief valve appropriately to start depressurization. When the pressure inside the reactor reaches below 1.0 MPa, open the discharge valve, filter and collect the prepolymer slurry, and dry it at 100℃ for 8 hours.

[0089] S6. Take a certain mass of dried nylon prepolymer powder and add 6 wt% nitrogen-based flame retardant (melamine cyanurate: 99% purity, Shanghai Titan Technology Co., Ltd.). After mixing evenly with a mixer, extrude and pelletize the mixture through a screw devourer to obtain nylon material. Set the temperature of the two sections near the extruder inlet to 280℃, and the temperature of the remaining sections to 320℃. Set the screw speed to 60 r / min.

[0090] Comparative Example 2

[0091] This comparative example provides a method for preparing nylon material. Unlike Example 1, in step S2 of this example, the temperature inside the reactor is controlled at 105°C, the temperature of the heat transfer oil is 140°C, and the pressure is controlled above 0.2 MPa, which is a case of relatively high temperature and pressure. Everything else is the same as in Example 1.

[0092] The specific method is as follows:

[0093] S1. Add 1329.05g terephthalic acid, 1378.50g decanediamine, 9.77g benzoic acid, 2.71g sodium hypophosphite, and 2707g deionized water to the reactor in sequence. Close the reactor and purge with nitrogen to 2.6MPa to check for air tightness. After confirming that there is no leakage, open the valve and slowly release the gas in the reactor. Then purge with nitrogen to 0.5MPa and release. Repeat this process 3 times to replace the air in the reactor. Finally, purge with a small amount of nitrogen to maintain the pressure at 0.1~0.2MPa.

[0094] S2. Set the temperature inside the vessel to 105℃, the temperature of the heat transfer oil to 140℃, and the stirring rod speed to 60r / min. Start heating. After the temperature inside the vessel reaches the set value, start the salt formation reaction for 1.5 hours.

[0095] S3. After the salt formation reaction is completed, directly open the feed port and add 243.63g of phosphorus-based flame retardant (a mixture of piperazine pyrophosphate and bisphenol A-bis(diphenyl phosphate), with a mass ratio of 1:2; piperazine pyrophosphate, purity 99%, Shanghai Titan Technology Co., Ltd.; bisphenol A-bis(diphenyl phosphate), purity 99%, Guangzhou Yuanda New Materials Co., Ltd.). Close the feed port, purge with nitrogen to 0.5MPa and then purge. Repeat this process 3 times to replace the air in the reactor. Finally, purge the reactor with a small amount of nitrogen to maintain the pressure at 0.1~0.2MPa.

[0096] S4. Set the reactor temperature to 230℃ and the heat transfer oil temperature to 280℃, and start heating. When the reactor temperature reaches the set value and the pressure reaches 2.5MPa, fine-tune the opening and closing degree of the pressure relief valve to maintain the reactor pressure at 2.4~2.6MPa and start the prepolymerization reaction for 3.0h.

[0097] S5. After the prepolymerization stage is completed, increase the opening degree of the pressure relief valve appropriately to start depressurization. When the pressure inside the reactor reaches below 1.0 MPa, open the discharge valve, filter and collect the prepolymer slurry, and dry it at 100℃ for 8 hours.

[0098] S6. Take a certain mass of dried nylon prepolymer powder and add 6 wt% nitrogen-based flame retardant (melamine cyanurate: 99% purity, Shanghai Titan Technology Co., Ltd.). After mixing evenly with a mixer, extrude and pelletize the mixture through a screw devourer to obtain nylon material. Set the temperature of the two sections near the extruder inlet to 280℃, and the temperature of the remaining sections to 320℃. Set the screw speed to 60 r / min.

[0099] Comparative Example 3

[0100] This embodiment provides a method for preparing nylon material. Unlike Embodiment 1, in step S4 of this embodiment, the temperature inside the reactor is 210°C, the temperature of the heat transfer oil is 250°C, and the pressure is controlled below 2.4 MPa, which represents a relatively low temperature and low pressure. Other aspects are the same as in Embodiment 1.

[0101] The specific method is as follows:

[0102] S1. Add 1329.05g terephthalic acid, 1378.50g decanediamine, 9.77g benzoic acid, 2.71g sodium hypophosphite, and 2707g deionized water to the reactor in sequence. Close the reactor and purge with nitrogen to 2.6MPa to check for air tightness. After confirming that there is no leakage, open the valve and slowly release the gas in the reactor. Then purge with nitrogen to 0.5MPa and release. Repeat this process 3 times to replace the air in the reactor. Finally, purge with a small amount of nitrogen to maintain the pressure at 0.1~0.2MPa.

[0103] S2. Set the temperature inside the vessel to 90℃, the temperature of the heat transfer oil to 110℃, and the stirring rod speed to 60r / min. Start heating. After the temperature inside the vessel reaches the set value, start the salt formation reaction for 1.5 hours.

[0104] S3. After the salt formation reaction is completed, directly open the feed port and add 243.63g of phosphorus-based flame retardant (a mixture of piperazine pyrophosphate and bisphenol A-bis(diphenyl phosphate), with a mass ratio of 1:2; piperazine pyrophosphate, purity 99%, Shanghai Titan Technology Co., Ltd.; bisphenol A-bis(diphenyl phosphate): purity 99%, Guangzhou Yuanda New Materials Co., Ltd.), close the feed port, purge with nitrogen to 0.5MPa and then discharge, repeat 3 times to replace the air in the reactor, and finally purge with a small amount of nitrogen to maintain the pressure at 0.1~0.2MPa;

[0105] S4. Set the reactor temperature to 210℃ and the heat transfer oil temperature to 250℃, and start heating. When the reactor temperature reaches the set value, fine-tune the opening and closing of the pressure relief valve to maintain the reactor pressure below 2.4MPa. The prepolymerization reaction is timed for 3.0h.

[0106] S5. After the prepolymerization stage is completed, increase the opening degree of the pressure relief valve appropriately to start depressurization. When the pressure inside the reactor reaches below 1.0 MPa, open the discharge valve, filter and collect the prepolymer slurry, and dry it at 100 ℃ for 8 hours.

[0107] S6. Take a certain mass of dried nylon prepolymer powder and add 6 wt% nitrogen-based flame retardant (melamine cyanurate: 99% purity, Shanghai Titan Technology Co., Ltd.). After mixing evenly with a mixer, extrude and pelletize the mixture through a screw devourer to obtain nylon material. Set the temperature of the two sections near the extruder inlet to 280℃, and the temperature of the remaining sections to 320℃. Set the screw speed to 60 r / min.

[0108] Comparative Example 4

[0109] This embodiment provides a method for preparing nylon material. Unlike Embodiment 1, in step S4 of this embodiment, the temperature inside the reactor is 240°C, the temperature of the heat transfer oil is 280°C, and the pressure is controlled above 2.6 MPa, which is a case of high temperature and high pressure. Everything else is the same as in Embodiment 1.

[0110] The specific method is as follows:

[0111] S1. Add 1329.05g terephthalic acid, 1378.50g decanediamine, 9.77g benzoic acid, 2.71g sodium hypophosphite, and 2707g deionized water to the reactor in sequence. Close the reactor and purge with nitrogen to 2.6MPa to check for air tightness. After confirming that there is no leakage, open the valve and slowly release the gas in the reactor. Then purge with nitrogen to 0.5MPa and release. Repeat this process 3 times to replace the air in the reactor. Finally, purge with a small amount of nitrogen to maintain the pressure at 0.1~0.2MPa.

[0112] S2. Set the temperature inside the vessel to 90℃, the temperature of the heat transfer oil to 110℃, and the stirring rod speed to 60r / min. Start heating. After the temperature inside the vessel reaches the set value, start the salt formation reaction for 1.5 hours.

[0113] S3. After the salt formation reaction is completed, directly open the feed port and add 243.63g of phosphorus-based flame retardant (a mixture of piperazine pyrophosphate and bisphenol A-bis(diphenyl phosphate), with a mass ratio of 1:2; piperazine pyrophosphate, purity 99%, Shanghai Titan Technology Co., Ltd.; bisphenol A-bis(diphenyl phosphate): purity 99%, Guangzhou Yuanda New Materials Co., Ltd.), close the feed port, purge with nitrogen to 0.5MPa and then discharge, repeat 3 times to replace the air in the reactor, and finally purge with a small amount of nitrogen to maintain the pressure at 0.1~0.2MPa;

[0114] S4. Set the reactor temperature to 240℃ and the heat transfer oil temperature to 280℃, and start heating. When the reactor temperature reaches the set value, fine-tune the opening and closing of the pressure relief valve to maintain the reactor pressure above 2.6MPa. The prepolymerization reaction is timed for 3.0h.

[0115] S5. After the prepolymerization stage is completed, increase the opening degree of the pressure relief valve appropriately to start depressurization. When the pressure inside the reactor reaches below 1.0 MPa, open the discharge valve, filter and collect the prepolymer slurry, and dry it at 100 ℃ for 8 h.

[0116] S6. Take a certain mass of dried nylon prepolymer powder and add 6 wt% nitrogen-based flame retardant (melamine cyanurate: 99% purity, Shanghai Titan Technology Co., Ltd.). After mixing evenly with a mixer, extrude and pelletize the mixture through a screw devourer to obtain nylon material. Set the temperature of the two sections near the extruder inlet to 280℃, and the temperature of the remaining sections to 320℃. Set the screw speed to 60 r / min.

[0117] Comparative Example 5

[0118] This embodiment provides a method for preparing nylon material. Unlike Example 1, no phosphorus-based flame retardant is added in this comparative example. Otherwise, it is the same as Example 1.

[0119] The specific method is as follows:

[0120] S1. Add 1329.05g terephthalic acid, 1378.50g decanediamine, 9.77g benzoic acid, 2.71g sodium hypophosphite, and 2707g deionized water to the reactor in sequence. Close the reactor and purge with nitrogen to 2.6MPa to check for air tightness. After confirming that there is no leakage, open the valve and slowly release the gas in the reactor. Then purge with nitrogen to 0.5MPa and release. Repeat this process 3 times to replace the air in the reactor. Finally, purge with a small amount of nitrogen to maintain the pressure at 0.1~0.2MPa.

[0121] S2. Set the temperature inside the vessel to 90℃, the temperature of the heat transfer oil to 110℃, and the stirring rod speed to 60r / min. Start heating. After the temperature inside the vessel reaches the set value, start the salt formation reaction for 1.5 hours.

[0122] S3. After the salt formation reaction is completed, increase the opening degree of the pressure relief valve appropriately to start pressure relief. When the pressure inside the reactor reaches below 1.0 MPa, open the discharge valve, filter and collect the prepolymer slurry, and dry it at 100℃ for 8 hours.

[0123] S4. Take a certain mass of dried nylon prepolymer powder and add 6 wt% nitrogen-based flame retardant (melamine cyanurate: 99% purity, Shanghai Titan Technology Co., Ltd.). After mixing evenly with a mixer, extrude and pelletize the mixture through a screw devourer to obtain nylon material. Set the temperature of the two sections near the extruder inlet to 280℃, and the temperature of the remaining sections to 320℃. Set the screw speed to 60 r / min.

[0124] Comparative Example 6

[0125] This embodiment provides a method for preparing nylon material. Unlike Example 1, this comparative example does not include a nitrogen-based flame retardant. Everything else is the same as in Example 1.

[0126] The specific method is as follows:

[0127] S1. Add 1329.05g terephthalic acid, 1378.50g decanediamine, 9.77g benzoic acid, 2.71g sodium hypophosphite, and 2707g deionized water to the reactor in sequence. Close the reactor and purge with nitrogen to 2.6MPa to check for air tightness. After confirming that there is no leakage, open the valve and slowly release the gas in the reactor. Then purge with nitrogen to 0.5MPa and release. Repeat this process 3 times to replace the air in the reactor. Finally, purge with a small amount of nitrogen to maintain the pressure at 0.1~0.2MPa.

[0128] S2. Set the temperature inside the vessel to 90℃, the temperature of the heat transfer oil to 110℃, and the stirring rod speed to 60r / min. Start heating. After the temperature inside the vessel reaches the set value, start the salt formation reaction for 1.5 hours.

[0129] S3. After the salt formation reaction is completed, directly open the feed port and add 243.63g of phosphorus-based flame retardant (a mixture of piperazine pyrophosphate and bisphenol A-bis(diphenyl phosphate), with a mass ratio of 1:2; piperazine pyrophosphate, purity 99%, Shanghai Titan Technology Co., Ltd.; bisphenol A-bis(diphenyl phosphate): purity 99%, Guangzhou Yuanda New Materials Co., Ltd.), close the feed port, purge with nitrogen to 0.5MPa and then discharge, repeat 3 times to replace the air in the reactor, and finally purge with a small amount of nitrogen to maintain the pressure at 0.1~0.2MPa;

[0130] S4. Set the reactor temperature to 230℃ and the heat transfer oil temperature to 280℃, and start heating. When the reactor temperature reaches the set value and the pressure reaches 2.5MPa, fine-tune the opening and closing degree of the pressure relief valve to maintain the reactor pressure at 2.4~2.6MPa and start the prepolymerization reaction for 3.0h.

[0131] S5. After the prepolymerization stage is completed, increase the opening degree of the pressure relief valve appropriately to start depressurization. When the pressure inside the reactor reaches below 1.0 MPa, open the discharge valve, filter and collect the prepolymer slurry, and dry it at 100℃ for 8 hours.

[0132] S6. Take a certain mass of dried nylon prepolymer powder and extrude and pelletize it through a screw devolatilizer to obtain nylon material. Set the temperature of the two sections near the extruder feed port to 280℃, and the temperature of the remaining sections to 320℃. Set the screw speed to 60r / min.

[0133] The flame retardant and mechanical properties of the nylon materials prepared in the above embodiments and comparative examples were tested. The tensile test followed the standard GB / T 1040.3-2006; the flexural test followed GB / T 9341-2008; the impact test followed ISO 197-1:2000; the limiting oxygen index (LOI) was tested according to GB / T 2408-84; the UL 94 rating of the samples was tested according to GB / T 2408-2008; and the cone calorimetry test was conducted according to ISO 5600. The test results are shown in Table 1 below.

[0134] Table 1

[0135] Example 1 198.1 426.2 3.91 V0 31.5 74.8 6.05 92.3 2.58 Example 2 195.7 429.1 4.12 V0 31.9 73.2 5.86 94.1 2.71 Example 3 200.4 423.5 3.73 V0 31.1 76.3 6.32 90.6 2.43 Example 4 196.3 424.0 3.82 V0 32.0 75.9 6.21 93.7 2.66 Example 5 201.6 428.7 4.05 V0 31.2 73.6 5.92 91.2 2.49 Comparative Example 1 199.6 427.5 3.84 V0 32.1 71.9 5.81 88.7 2.47 Comparative Example 2 196.5 424.1 4.03 V0 31.8 77.4 6.26 95.5 2.67 Comparative Example 3 192.2 413.4 4.10 V0 32.4 71.1 5.74 87.7 2.45 Comparative Example 4 203.8 435.6 3.76 V0 30.7 77.0 6.22 94.9 2.65 Comparative Example 5 257.5 584.1 2.72 V1 25.7 79.9 6.47 98.6 2.76 Comparative Example 6 227.9 498.8 3.48 V1 28.3 78.2 6.33 96.4 2.70

[0136] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered within the scope of the claims and specification of the present invention.

Claims

1. A method for preparing a high-temperature resistant nylon material with synergistic phosphorus and nitrogen flame retardancy, characterized in that, Includes the following steps: (1) Add catalyst, antioxidant, molecular weight regulator and deionized water to a mixture of diamine and diacid monomers, and carry out salt formation reaction at a temperature of 90℃~100℃ and a pressure of 0.1MPa~0.2MPa to obtain prepolymer; (2) Add phosphorus-based flame retardant to the prepolymer, raise the temperature to 220℃~230℃, raise the pressure to 2.4MPa~2.6MPa, and continue the reaction to obtain nylon prepolymer powder; (3) The nitrogen-based flame retardant is mixed with the dried nylon prepolymer powder and then melt-bonded to obtain high-temperature resistant nylon material.

2. The method for preparing a high-temperature resistant nylon material with synergistic phosphorus and nitrogen flame retardancy according to claim 1, characterized in that, The molar ratio of the diamine to the dicarboxylic acid is (1.01~1.02):

1.

3. The method for preparing a high-temperature resistant nylon material with phosphorus and nitrogen synergistic flame retardancy according to claim 1, characterized in that, The catalyst includes at least one of sodium hypophosphite, potassium hypophosphite, calcium hypophosphite, n-butyl titanate, propyl titanate, and isopropyl titanate.

4. The method for preparing a high-temperature resistant nylon material with synergistic phosphorus and nitrogen flame retardancy according to claim 1, characterized in that, The molecular weight regulator includes at least one of acetic acid, propionic acid, hexanoic acid, benzoic acid, and cyclohexanecarboxylic acid.

5. The method for preparing a high-temperature resistant nylon material with synergistic phosphorus and nitrogen flame retardancy according to claim 1, characterized in that, The mass of the deionized water is 1.0 to 1.1 times the total mass of the diamine and diacid monomers.

6. The method for preparing a high-temperature resistant nylon material with synergistic phosphorus and nitrogen flame retardancy according to claim 1, characterized in that, In step (1), nitrogen needs to be introduced to replace the air in the reactor, and the reaction processes in steps (1) and (2) both need to be isolated from air.

7. The method for preparing a high-temperature resistant nylon material with synergistic phosphorus and nitrogen flame retardancy according to claim 1, characterized in that, The phosphorus-based flame retardant is a mixture of piperazine pyrophosphate and bisphenol A-bis(diphenyl phosphate), and the amount added is 6wt% to 12wt% of the total mass of the diamine and dicarboxylic acid monomers.

8. The method for preparing a high-temperature resistant nylon material with synergistic phosphorus and nitrogen flame retardancy according to claim 1, characterized in that, The nitrogen-based flame retardant is melamine cyanurate, and the amount added is 4wt% to 8wt% of the total mass of the diamine and dicarboxylic acid monomers.

9. The method for preparing a high-temperature resistant nylon material with phosphorus and nitrogen synergistic flame retardancy according to claim 1, characterized in that, In step (3), the screw devourer is used for melt thickening. During the melt thickening process, the temperature of each heating section of the screw devourer should be controlled at 280~320 ℃, and the screw speed should be controlled at 60~80 r / min.

10. A high-temperature resistant nylon material with synergistic phosphorus and nitrogen flame retardancy, characterized in that, It is prepared by the preparation method described in any one of claims 1 to 9.