METHOD FOR PRODUCING HIGH TEMPERATURE RESISTANT POLYAMIDE, HIGH TEMPERATURE RESISTANT POLYAMIDE AND USE THEREOF

Abstract

The present invention provides a method for producing a high-temperature resistant polyamide, the high-temperature resistant polyamide, and its use. The method optionally concentrates a polyamide salt solution and then performs the following operations: heating and pressurizing to a pressure of P1 and maintaining that pressure, where the temperature of the system is T1 at the end of the pressure maintenance; depressurizing to a pressure of P2, where the temperature of the system is T2 at the end of the depressurization; and exhausting, thereby obtaining a polyamide melt. Here, P1 is 0.8 to 4 MPa, T1 is 250 to 290 °C, T1 < T2, and (T2 - T1) / (P1 - P2) = 5 to 75. The method for producing a high-temperature resistant polyamide according to the present invention is simple in operation and reduces energy consumption. The obtained high-temperature resistant polyamide can be used as a raw material for injection-molded parts, molded articles, or fibers, such as high-temperature resistant attachments for machines, automobiles, household electrical appliances, toys, textile products, sports goods, mobile phones, computers, laptops, GPS devices, or optical devices.

Description

[Technical Field]

[0001] The present invention relates to a method for producing a high temperature resistant polyamide, a high temperature resistant polyamide and uses thereof. [Background technology]

[0002] High-temperature-resistant polyamides generally refer to polyamide engineering plastics that can be used for long periods at temperatures above 150°C. High-temperature-resistant polyamides have good abrasion resistance, heat resistance, oil resistance, and chemical resistance. They also significantly reduce moisture absorption and shrinkage of raw materials, while also possessing excellent dimensional stability and mechanical strength. Compared to aliphatic polyamides, semi-aromatic polyamides generally have superior heat resistance. High-temperature-resistant polyamides are increasingly being used in fields where high heat resistance is desired, such as the automotive, construction, military, and aerospace industries. Industrially produced high-temperature-resistant polyamides primarily include PA46, PA6T, and PA9T. At the same time, new high-temperature-resistant materials, such as PA10T, PA4T, and PA12T, have begun to emerge.

[0003] Currently, industrial production of semi-aromatic polyamides is conventionally carried out via a solution polycondensation process, which generally involves two steps: first, polymerization in an autoclave to obtain a semi-aromatic polyamide prepolymer, and then melt polycondensation or solid-state polymerization to increase the molecular weight and thereby obtain a polyamide polymer. Therefore, such a process is generally referred to as a two-stage process. For example, Chinese Patent Application Publication No. 102372920A discloses a partially aromatic polyamide molding composition and its use. First, polyamide compounding ingredients, along with a catalyst, regulator, and water, were placed in a 20-liter autoclave. The reaction mixture was heated to a temperature of 260°C over 50 to 80 minutes and maintained at a pressure of 32 bar for 1 hour. Subsequently, the precondensate was discharged through a nozzle. The precondensate was dried under reduced pressure and post-condensed in a twin-screw extruder. The product was then extruded through a nozzle and pelletized. Summary of the Invention

Problems to be Solved by the Invention

[0004] Existing processes use water as a solvent and are thus cost - efficient and environmentally friendly. However, the prepolymers produced have a relatively low molecular weight, making it difficult to use them directly. Further melt polycondensation or solid - phase polymerization is required to increase the molecular weight, which also lengthens the manufacturing cycle and increases costs.

Means for Solving the Problems

[0005] In one embodiment according to the present invention, a method for producing a high - temperature - resistant polyamide is provided. The method optionally concentrates a polyamide salt solution and then performs the following operations: (1) A step of heating and pressurizing to a pressure of P1 and maintaining that pressure, where the temperature of the system is T1 at the end of the pressure maintenance; (2) A step of depressurizing to a pressure of P2, where the temperature of the system is T2 at the end of the depressurization; and (3) A step of evacuating, whereby a polyamide melt is obtained including performing, where P1 is 0.8 - 4 MPa, T1 is 250 - 290 °C, T1 < T2, and (T2 - T1) / (P1 - P2)=5 - 75.

[0006] In one embodiment according to the present invention, a high - temperature - resistant polyamide is provided. The high - temperature - resistant polyamide includes at least a polyamide produced from component (A) diamine and component (B) diacid as raw materials, and the molar ratio of component (A) to component (B) is (0.5 - 5):1.

[0007] Component (A) diamine is (a1) an aliphatic straight - chain or branched - chain diamine having 4 - 1十六条個の炭素原子を有する脂肪族直鎖若しくは分枝鎖ジアミン、(a2)芳香族ジアミン若しくは脂環式ジアミンのうちのいずれか1つ、又はこれらのうちの2つ以上の任意の組合せを含み;及び / 又は It should be noted that there seems to be an error in the original text where "十六条個の炭素原子を有する脂肪族直鎖若しくは分枝鎖ジアミン" should probably be "16個の炭素原子を有する脂肪族直鎖若しくは分枝鎖ジアミン". The translation is done as accurately as possible based on the provided text.Component (B) diacid is (b1) an aliphatic diacid having 2 to 18 carbon atoms, or (b2) a benzene ring-containing diacid having 8 or more carbon atoms, or any combination of two or more of these.

[0008] In one embodiment according to the present invention, there is provided a high temperature resistant polyamide, characterized in that the high temperature resistant polyamide comprises at least a polyamide produced from a solution of component (C) polyamide salt as a raw material.

[0009] In one embodiment according to the present invention, a high temperature resistant polyamide is provided, wherein the structural units of the high temperature resistant polyamide are represented by the following formula: [ka] (wherein n=4 to 16 and m=2 to 18) Includes:

[0010] In one embodiment, n is preferably 4-7.

[0011] In one embodiment, m is preferably 4-16.

[0012] The high temperature resistant polyamide has a melting point of 280 to 328°C, preferably 286 to 328°C.

[0013] High temperature resistant polyamides have a relative viscosity of 1.80 to 2.70.

[0014] High temperature resistant polyamide: 5~12KJ / cm 2 , preferably 6.5 to 10 KJ / cm 2 It has a notched impact strength of

[0015] The high temperature resistant polyamide has a tensile strength of 95 to 140 MPa, preferably 105 to 134 MPa.

[0016] The high temperature resistant polyamide has a flexural strength of 135 to 190 MPa, preferably 155 to 183 MPa.

[0017] High temperature resistant polyamide 2,800 to 4,400 MPa, preferably 2,800 to 4,050 MPa, more preferably 3,500~4,400MPa , and even more preferably 3,500 to 4,050 MPa It has a flexural modulus of elasticity of .

[0018] High temperature resistant polyamides are those with a temperature range of 240 to 320°C, preferably 250 to 300°C, more preferably 250 to 290°C, or It has a heat distortion temperature of 260 to 300°C.

[0019] In one embodiment according to the present invention there is provided the use of a high temperature resistant polyamide, which is a raw material for injection molded parts, molded articles or fibers.

[0020] This method for producing high-temperature-resistant polyamides has the advantages of being simpler and consuming less energy than existing polymerization processes. By utilizing the correlation between pressure and temperature, it solves the problem of high sample residues in autoclaves and overcomes the difficulties of continuous multi-batch production. This method is suitable for producing high-temperature-resistant polyamides with good product quality. DETAILED DESCRIPTION OF THE INVENTION

[0021] Exemplary embodiments embodying the features and advantages of the present invention are described in detail in the following description. It should be understood that the present invention may have various modifications in different embodiments without departing from the scope of the present invention. The description set forth herein is intended to be illustrative in nature and should not be used to limit the present invention.

[0022] In one embodiment according to the present invention, there is provided a method for producing high temperature resistant polyamides, the method comprising optionally concentrating a polyamide salt solution, followed by the following operations: (1) heating and pressurizing to a pressure P1 and maintaining that pressure, whereby at the end of the pressure maintenance, the system has a temperature T1; (2) reducing the pressure to a pressure of P2, where at the end of the reduction the system has a temperature of T2; and (3) evacuating, thereby obtaining a polyamide melt; This includes performing the following.

[0023] Preferably, the method comprises the following steps: Optionally, concentrating the polyamide salt solution to a mass concentration of 20-90 wt %, followed by the following operation: (1) heating and pressurizing to a pressure P1 and maintaining that pressure, whereby at the end of the pressure maintenance, the system has a temperature T1; (2) reducing the pressure to a pressure of P2, where at the end of the reduction the system has a temperature of T2; and (3) evacuating, thereby obtaining a polyamide melt; and performing the steps of:

[0024] In one embodiment, the method comprises the steps of: mixing component (A) a diamine, component (B) a diacid, and water to produce a polyamide salt solution having a mass concentration of 20 to 90 wt %, and optionally concentrating the polyamide salt solution, followed by: (1) heating and pressurizing to a pressure P1 and maintaining that pressure, whereby at the end of the pressure maintenance, the system has a temperature T1; (2) reducing the pressure to a pressure of P2, where at the end of the reduction the system has a temperature of T2; and (3) evacuating, thereby obtaining a polyamide melt; and performing the steps of:

[0025] In one embodiment, when the polyamide salt solution has a mass concentration of 10 wt %, the pH value is 6.5 to 9.0, preferably 7.6 to 8.4, for example, 7.2, 7.4, 7.6, 7.8, 8.0, 8.1, 8.2, 8.3, 8.5, or 8.7. In this specification, the concentration in "the polyamide salt solution has a mass concentration of 10 wt %" can refer to the mass concentration of the unconcentrated polyamide salt solution itself, or the mass concentration obtained after sampling and diluting the concentrated or unconcentrated polyamide salt solution. In one embodiment, the polyamide salt solution has a mass concentration of 20 wt% or more, preferably 20 to 90 wt%, for example, 25 wt%, 30 wt%, 35 wt%, 40 wt%, 45 wt%, 48 wt%, 55 wt%, 57 wt%, 60 wt%, 62 wt%, 65 wt%, 68 wt%, 70 wt%, 72 wt%, 75 wt%, 77 wt%, 80 wt%, or 85 wt%. In this specification, the mass concentration of the polyamide salt solution may be the mass concentration of the unconcentrated polyamide salt solution itself or the mass concentration of a concentrated polyamide salt solution.

[0026] In one embodiment, the polyamide salt comprises a salt formed by the reaction of component (A) a diamine with component (B) a diacid. The molar ratio of component (A) to component (B) is (0.5-5):1, preferably (0.6-3):1, more preferably (0.6-1.6):1, even more preferably (0.9-1.3):1, and even more preferably (1.01-1.3):1. The pH value of the polyamide salt solution can be adjusted by controlling the molar ratio of diamine to diacid. For example, the pH of the polyamide salt can be made alkaline by providing a stoichiometric excess of diamine relative to diacid.

[0027] The polyamide salt solution contains at least ions of component (A) a diamine and ions of component (B) a diacid.

[0028] In one embodiment, the polyamide salt solution comprises The composition includes any one of (1) a solution obtained by mixing component (A) diamine, component (B) diacid, and a solvent, (2) a solution obtained by mixing component (C) polyamide salt, and a solvent, and (3) a solution obtained by mixing component (C) polyamide salt, component (A) diamine and / or component (B) diacid, and a solvent, or any combination of two or more thereof.

[0029] Solvents include, but are not limited to, water.

[0030] The salt produced by the reaction of diamine and diacid is a polyamide salt, also known as a "nylon salt." Polyamide is obtained by polycondensation of the polyamide salt. During the polycondensation in steps (1) to (3), carboxyl groups and amino groups in the polyamide salt are bonded, and water is eliminated.

[0031] In one embodiment, the diamine or diacid may be produced by a fermentation process or an enzymatic conversion process.

[0032] In one embodiment, P1 is 0.8 to 4 MPa and T1 is 250 to 290°C.

[0033] In one embodiment, P1 is 3 to 4 MPa.

[0034] In one embodiment, T1 is 275 to 290°C.

[0035] In some embodiments, P1 is, for example, 1 MPa, 1.2 MPa, 1.5 MPa, 1.8 MPa, 2 MPa, 2.1 MPa, 2.2 MPa, 2.5 MPa, 3 MPa, 3.5 MPa, or 3.8 MPa.

[0036] In some embodiments, T1 is, for example, 255°C, 260°C, 262°C, 265°C, 268°C, 270°C, 272°C, 275°C, 277°C, 280°C, 283°C, or 286°C.

[0037] In one embodiment, T <T2であり、(T2-T1) / (P1-P2)=5~75である。

[0038] In one embodiment, T <T2であり、(T2-T1) / (P1-P2)=5~55である。

[0039] In one embodiment, T <T2であり、(T2-T1) / (P1-P2)=10~45である。

[0040] In one embodiment, T <T2であり、(T2-T1) / (P1-P2)=10~23である。

[0041] In one embodiment, T <T2であり、(T2-T1) / (P1-P2)=10~16である。

[0042] In one embodiment, (T2-T1) / (P1-P2) can be, for example, 10, 12, 14, 15, 18, 20, 22, 25, 28, 30, 35, 40, 42, 46, 50, 55, 57, 63, 66, or 68.

[0043] (T2-T1) is the difference between T2 (°C) and T1 (°C), and (P1-P2) is the difference between P1 (MPa) and P2 (MPa).

[0044] In one embodiment, component (A) diamine comprises any one of (a1) an aliphatic straight-chain or branched-chain diamine having 4 to 16 carbon atoms, (a2) an aromatic diamine or an alicyclic diamine, or any combination of two or more thereof.

[0045] In one embodiment, the component (B) diacid comprises any one of (b1) an aliphatic diacid having 2 to 18 carbon atoms, (b2) a benzene ring-containing diacid having 8 or more carbon atoms, or any combination of two or more thereof.

[0046] In some embodiments, component (a1) is an aliphatic straight or branched chain diamine having 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, or 16 carbon atoms.

[0047] In some embodiments, component (a2) has 5 to 10, preferably 5 to 6, for example, 5, 6, 7, 8, 9, or 10, carbon atoms.

[0048] In some embodiments, the number of carbon atoms in component (b1) can be 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, or 18.

[0049] In one embodiment, the number of carbon atoms in component (b2) may be 8 to 12, preferably 8 to 10.

[0050] In some embodiments, the number of carbon atoms in component (b2) can be, for example, 8, 9, 10, 11, or 12.

[0051] In one embodiment, component (a1) comprises one or more of butanediamine, pentanediamine, hexanediamine, heptanediamine, octanediamine, nonanediamine, decanediamine, undecanediamine, dodecanediamine, tridecanediamine, tetradecanediamine, pentadecanediamine, and hexadecanediamine.

[0052] In one embodiment, component (a2) comprises one or more of cyclopentanediamine, methylcyclopentanediamine, cyclohexanediamine, p-phenylenediamine, o-phenylenediamine, and m-phenylenediamine.

[0053] In one embodiment, component (b1) comprises one or more of oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, tridecanedioic acid, tetradecanedioic acid, pentadecanedioic acid, hexadecanedioic acid, heptadecanedioic acid, and octadecanedioic acid.

[0054] In one embodiment, component (b2) comprises one or more of terephthalic acid, isophthalic acid, and phthalic acid.

[0055] In one embodiment, the polyamide salt solution is a solution obtained by mixing at least component (A) a diamine, component (B) a diacid, and a solvent.

[0056] In one embodiment, the component (A) diamine comprises (a1) an aliphatic straight-chain or branched-chain diamine having from 4 to 16 carbon atoms, and the component (B) diacid comprises (b1) an aliphatic diacid having from 2 to 18 carbon atoms and (b2) one or more of terephthalic acid, isophthalic acid, and phthalic acid.

[0057] In one embodiment, the molar ratio of component (A) to component (B) is (0.5-5):1, preferably (0.6-3):1, more preferably (0.6-1.6):1, even more preferably (0.9-1.3):1, and even more preferably (1.01-1.3):1, for example, 1:1, 1.1:1, 1.15:1, 1.2:1, 1.3:1, 1.5:1, 1.8:1, 2:1, 2.3:1, 2.5:1, 3:1, 3.5:1, or 4:1.

[0058] In one embodiment, the molar ratio of component (a1) to component (b1) is (0.5-12):1, preferably (1-10):1, more preferably (1-8):1, even more preferably (2-5):1, and even more preferably (2.3-3.3):1, for example, 0.8:1, 1.2:1, 1.4:1, 1.5:1, 1.8:1, 2:1, 2.2:1, 2.5:1, 2.7:1, 3:1, 3.2:1, 3.5:1, 4.5:1, 5:1, 6:1, 8:1, or 9:1.

[0059] In one embodiment, the molar ratio of component (a1) to component (b2) is (0.1-6):1, preferably (0.5-5):1, more preferably (0.5-4):1, even more preferably (1-4):1, more preferably (1-2):1, even more preferably (1-1.7):1, and even more preferably (1.4-1.7):1, for example, 0.2:1, 0.3:1, 0.7:1, 1.0:1, 1.3:1, 1.5:1, 1.6:1, 1.8:1, 2:1, 2.3:1, 2.5:1, 2.6:1, 2.8:1, 3:1, 3.5:1, 3.8:1, 4:1, or 4.6:1.

[0060] In one embodiment, parameters such as tensile strength, flexural strength, and / or flexural modulus of the polyamide product may be improved by controlling the relationship, particularly the type, content, and / or relative ratio, of the diamine and diacid components.

[0061] In one embodiment, the content of component (b2) is within the above reasonable range, and the parameters such as tensile strength, flexural strength, flexural modulus, etc. of the polyamide product are improved.

[0062] In one embodiment, the flexibility of the polyamide product is improved by incorporating long chain diacids / diamines.

[0063] In one embodiment, in step (1), the pressure is maintained for 1 to 4 hours, preferably 1.5 to 3 hours.

[0064] In one embodiment, in step (1), the method of maintaining pressure is degassing to maintain pressure.

[0065] In one embodiment, during the step (2) of reducing the pressure to P2, the pressure P and the temperature T satisfy the following conditions: when P is 0.4 to 0.65 times of P1, for example, when P is 0.4 to 0.6 times of P1, or when P is 0.4 to 0.55 times of P1, T = (1.01 to 1.18) × T1, for example, 1.095T1, 1.097T1, 1.101T1, 1.102T1, 1.11T1, 1.115T1, 1.12T1, 1.13T1, 1.14T1, 1.145T1, 1.15T1, 1.16T1, or 1.17T1, where P2 < P < P1 and T1 < T < T2.

[0066] In one embodiment, during the step (2) of reducing the pressure to P2, the pressure P and the temperature T satisfy the following conditions: when P is 0.4 to 0.65 times of P1, for example, when P is 0.4 to 0.6 times of P1, or when P is 0.4 to 0.55 times of P1, T is (1.03 to 1.18) × T1, more preferably (1.04 to 1.18) × T1, still more preferably (1.04 to 1.16) × T1, even more preferably (1.04 to 1.15) × T1, still more preferably (1.06 to 1.15) × T1, even more preferably (1.095 to 1.14) × T1, and yet even more preferably (1.095 to 1.13) × T1, where P2 < P < P1 and T1 < T < T2.

[0067] In one embodiment, during the step (2) of reducing the pressure to P2, the pressure P and the temperature T satisfy the following conditions: when P is 0.1 to 0.3 times of P1, for example, when P is 0.12 to 0.3 times of P1, or when P is 0.14 to 0.3 times of P1, T satisfies (1.132 to 1.26) × T1, for example, 1.15T1, 1.17T1, 1.22T1, 1.23T1, 1.24T1, 1.25T1, or 1.27T1, where P2 < P < P1 and T1 < T < T2.

[0068] In one embodiment, during the step (2) of reducing the pressure to P2, the pressure P and the temperature T satisfy the following conditions: when P is 0.1 to 0.3 times of P1, for example, when P is 0.12 to 0.3 times of P1, or when P is 0.14 to 0.3 times of P1, T satisfies (1.132 to 1.20)×T1, more preferably (1.132 to 1.17)×T1, still more preferably (1.132 to 1.16)×T1, preferably (1.132 to 1.155)×T1, where P2 < P < P1 and T1 < T < T2.

[0069] In one embodiment, the yield of the process is improved by controlling the course step (2) of reducing the pressure.

[0070] In one embodiment, the relative viscosity of the obtained polyamide product becomes relatively high by controlling the progress of the step (2) of reducing the pressure.

[0071] In one embodiment, during the pressure reduction in step (2), the temperature of the system continues to rise.

[0072] In one embodiment, the period of pressure reduction in step (2) is 0.5 to 3 hours, preferably 0.8 to 1.5 hours.

[0073] In one embodiment, T2 is 295 to 340°C, preferably 305 to 335°C, more preferably 325 to 335°C. For example, T2 is 300°C, 310°C, 315°C, 320°C, or 330°C.

[0074] In one embodiment, P2 is 0 to 0.05 MPa, preferably 0 to 0.02 MPa. For example, P2 is 0.01 MPa, 0.02 MPa, 0.03 MPa, 0.035 MPa, or 0.04 MPa.

[0075] In one embodiment, P1 > P2.

[0076] In one embodiment, during polycondensation, in addition to the water originally contained in the polyamide salt solution, the water present in the system also includes water generated during polycondensation.

[0077] In one embodiment, water vapor is vented during polycondensation, thereby adjusting the reaction process and, in particular, reducing the pressure of the system.

[0078] In one embodiment, between steps (1) and (2), water vapor is vented to reduce the pressure in the system.

[0079] In one embodiment, water vapor is discharged to the outside during step (1), and the ratio of the discharged water vapor (moles) to the water content (moles) in the polyamide salt solution (abbreviated as dehydration ratio) is (60.6 to 93.9):100, preferably (75.4 to 90.9):100, more preferably (80 to 90.9):100, even more preferably (87 to 90.9):100, for example, 65:100, 70:100, 72:100, 75:100, 78:100, 82:100, 84:100, 85:100, 86:100, 88:100, 90:100, or 91:100.

[0080] In one embodiment, water vapor is discharged to the outside during step (1), and the ratio of the discharged water vapor (moles) to the water content (moles) in the polyamide salt solution (abbreviated as dehydration ratio) is (60.6 to 93.9):100, preferably (75.4 to 93.9):100, more preferably (80 to 93.9):100, and even more preferably (87 to 93.9):100.

[0081] In one embodiment, water vapor is discharged during step (2), and the ratio of the discharged water vapor (moles) to the water content (moles) in the polyamide salt solution (abbreviated as dehydration ratio) is (93.9-118.2):100, preferably (93.9-114):100, preferably (98.7-113.9):100, for example, 94:100, 95:100, 96:100, 97:100, 98:100, 99:100, 100:100, 102:100, 103:100, 105:100, 107:100, 110:100, or 112:100.

[0082] In one embodiment, water vapor is discharged during step (2), and the ratio of the discharged water vapor (moles) to the water content (moles) in the polyamide salt solution (abbreviated as dehydration ratio) is (93.9-118.2):100, more preferably (104-117):100, more preferably (110-117):100, and even more preferably (110-114):100.

[0083] In one embodiment, the polyamide salt solution is concentrated prior to the reaction in step (1), and the dehydration rates in step (1) and step (2) are based on the concentrated polyamide salt solution.

[0084] In one embodiment, prior to reacting in step (1), the polyamide salt solution is concentrated to a concentration of 50% to 85 wt%, more preferably 55 to 70 wt%, even more preferably 60 to 70 wt%, for example, 52 wt%, 55 wt%, 57 wt%, 60 wt%, 62 wt%, 65 wt%, 68 wt%, 70 wt%, 72 wt%, 75 wt%, 77 wt%, 80 wt%, and 85 wt%.

[0085] In one embodiment, in step (3), evacuation is carried out to a pressure of −0.09 to −0.005 MPa, more preferably −0.09 to −0.01 MPa, more preferably −0.09 to −0.02 MPa, and even more preferably −0.065 to −0.04 MPa.

[0086] In one embodiment, at the end of the evacuation step (3), the temperature of the system is 310-340°C, preferably 315-335°C, for example, 312°C, 318°C, 320°C, 325°C, 328°C, 330°C, or 333°C.

[0087] In one embodiment, the evacuation time in step (3) is 1 to 40 minutes, preferably 4 to 20 minutes.

[0088] In one embodiment, the method further comprises step (4) of discharging and pelletizing the polyamide melt, thereby obtaining a polyamide resin.

[0089] In one embodiment, the pelletization may be water-cooled pelletization, and the temperature of the cooling water is 10-30°C.

[0090] In one embodiment, the polyamide salt solution further comprises component (D) an additive.

[0091] In one embodiment, the component (D) additive is added at any stage of steps (1) to (3).

[0092] In one embodiment, component (D) comprises one or more of antioxidants, antifoaming agents, UV stabilizers, heat stabilizers, crystallization accelerators, free radical scavengers, lubricants, plasticizers, impact modifiers, inorganic fillers, brighteners, dyes, flame retardants, and minerals.

[0093] In one embodiment, the molar amount of component (D) is (0.001 to 1)%, preferably (0.01 to 0.8)%, preferably (0.02 to 0.4)%, of the molar amount of component (A) and / or component (C), for example, 0.03%, 0.05%, 0.07%, 0.1%, 0.12%, 0.15%, 0.2%, 0.24%, 0.27%, 0.30%, 0.33%, 0.38%, 0.45%, 0.5%, or 0.6%.

[0094] In one embodiment, the heat stabilizer further comprises one or more of phosphoric acid, phosphorous acid, trimethyl phosphite, triphenyl phosphite, trimethyl phosphate, triphenyl phosphate, sodium hypophosphite, zinc hypophosphite, and potassium hypophosphite.

[0095] In one embodiment, the crystallization promoter further comprises a metal salt of a long carbon chain carboxylic acid, preferably having 10 to 30 carbon atoms, and the metal preferably comprising one or more of calcium, magnesium, and zinc.

[0096] In one embodiment, the inorganic filler further comprises one or more of glass fibers, glass beads, carbon fibers, carbon black, and graphite.

[0097] In one embodiment, the minerals further include one or more of titanium dioxide, calcium carbonate, and barium sulfate.

[0098] In one embodiment, the component (D) additive comprises at least an antioxidant.

[0099] In one embodiment, the component (D) additive comprises at least an antifoaming agent.

[0100] In one embodiment, the component (D) additive comprises at least a heat stabilizer.

[0101] In one embodiment, the component (D) additives include at least an antioxidant, an antifoaming agent, and a heat stabilizer.

[0102] In one embodiment, the entire process for producing high temperature resistant polyamide is carried out under an inert gas atmosphere.

[0103] In one embodiment, step (1) and / or step (2) and / or step (3) and / or step (4) are carried out under an inert gas atmosphere.

[0104] Inert gases include nitrogen, argon, or helium.

[0105] One embodiment of the present invention provides a high-temperature resistant polyamide, comprising a polyamide produced from component (A) diamine and component (B) diacid as raw materials, wherein the molar ratio of component (A) to component (B) is (0.5-5):1.

[0106] In one embodiment, component (A) the diamine is (a1) an aliphatic straight-chain or branched-chain diamine having 4 to 16 carbon atoms, (a2) any one of an aromatic diamine or an alicyclic diamine, or any combination of two or more thereof.

[0107] In one embodiment, the component (B) diacid is (b1) an aliphatic diacid having 2 to 18 carbon atoms, or (b2) a benzene ring-containing diacid having 8 or more carbon atoms, or any combination of two or more of these.

[0108] In one embodiment, the high temperature resistant polyamide comprises at least a polyamide produced from a solution of component (C) a polyamide salt as a raw material.

[0109] In one embodiment, the structural units of the high temperature resistant polyamide have the following formula: [ka] (In the formula, n=4 to 16, preferably 4 to 10, and preferably 4 to 8, for example, n is 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, or 16; m=2 to 18, preferably 4 to 16, for example, m is 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, or 16. Includes:

[0110] In one embodiment, a high temperature resistant polyamide is provided. The high temperature resistant polyamide has a melting point of 280 to 328°C, preferably 286 to 328°C, preferably 293 to 320°C, for example, 290, 294, 298, 301, 304, 307, 309, 312, 315, 317, 321, or 325°C.

[0111] The high temperature resistant polyamide has a relative viscosity of 1.80 to 2.70, preferably 2.0 to 2.5, for example, 1.85, 1.9, 1.95, 2.1, 2.2, 2.3, 2.4, 2.55, 2.6, 2.67, or 2.7.

[0112] High temperature resistant polyamide: 5~12KJ / cm 2 , preferably 7.0 to 10 KJ / cm 2 , more preferably 6.5 to 10 KJ / cm 2 , for example, 5.5, 6.5, 7.5, 8.0, 8.2, 8.5, 8.7, 9.3, 9.6, 9.8, 10.2, or 10.5 KJ / cm 2 It has a notched impact strength of

[0113] The high temperature resistant polyamide has a tensile strength of 95 to 140 MPa, preferably 105 to 134 MPa, more preferably 105 to 131 MPa, for example, 100, 110, 112, 116, 119, 121, 125, 132, 135, or 138 MPa.

[0114] The high temperature resistant polyamide has a flexural strength of 135 to 190 MPa, preferably 155 to 183 MPa, more preferably 155 to 173 MPa, for example, 140, 145, 150, 154, 157, 161, 164, 169, 172, 175, 178, 183, or 185 MPa.

[0115] High temperature resistant polyamide 2,800 to 4,400 MPa, preferably 2,800 to 4,050 MPa, more preferably 3500~4400MPa , and even more preferably 3,500 to 4,050 MPa or The flexural modulus is 3700 to 4200 MPa, for example, 3600, 3650, 3750, 3800, 3850, 3890, 3920, 3950, 3995, 4050, 4130, 4200, or 4300 MPa.

[0116] The high temperature resistant polyamide has a temperature of 240 to 320°C, preferably 270 to 310°C, more preferably 250~300℃、 260~300℃, or 250 to 290°C, For example, having a heat deflection temperature of 249, 250, 251, 252, 253, 254, 255, 256, 257, 258, 259, 260, 261, 262, 263, 264, 265, 266, 267, 268, 269, 270, 271, 272, 273, 274, 275, 276, or 277°C.

[0117] In one embodiment, there is provided the use of a high temperature resistant polyamide, wherein the high temperature resistant polyamide is a raw material for injection molded parts, molded articles, or fibers.

[0118] In one embodiment, the high temperature resistant polyamide is used as a raw material for injection molded parts, molded articles, or fibers, such as high temperature resistant attachments for machines, automobiles, consumer electronics, toys, textiles, sporting goods, mobile phones, computers, laptops, GPS devices, or optical devices.

[0119] The high temperature resistant polyamide and its preparation method according to one embodiment of the present invention are further described below with specific examples. The relevant tests involved are as follows:

[0120] 1) Flexural strength and flexural modulus test: The test is performed according to the standard ISO178-2010 at a rate of 2 mm / min. The sample bar size is 10 mm. * 4mm * It is 80mm.

[0121] 2) Tensile strength test: The test is carried out according to the standard ISO572-2-2012 at 50 mm / min.

[0122] 3) Notched impact strength test: The notched impact strength test is a cantilever beam notched impact test in accordance with measurement standard ISO180 / 1A under test conditions of 23°C.

[0123] 4) Relative viscosity: The relative viscosity is tested by using concentrated sulfuric acid and an Ubbelohde viscometer in the following manner: 0.25±0.0002 g of dry polyamide resin chips are accurately weighed, and 50 mL of concentrated sulfuric acid (96 wt%) is added to dissolve the polyamide resin chips, thereby obtaining a polyamide sample solution; and in a constant temperature water bath at 25°C, the flow time t0 of the concentrated sulfuric acid and the flow time of the polyamide sample solution are measured and recorded. The relative viscosity is calculated according to the following formula: Relative viscosity=t / t0 t represents the flow time of the polyamide sample solution; t0 represents the flow time of the concentrated sulfuric acid solvent.

[0124] 5) Heat Deflection Temperature (HDT): The polyamide produced in the examples is blended with 30 wt% glass fiber to obtain a glass fiber reinforced polyamide. Then, the heat deflection temperature is tested according to the national standard GB / T1634.2-2004. Here, the sample size is 120 mm. * 10mm * 4mm (length * width * thickness) and the applied bending stress is 1.8 MPa.

[0125] 6) Melting Point Test: The test is carried out in a differential scanning calorimeter.

[0126] Unless otherwise specified, all temperatures in this invention are in °C, all pressures are gauge pressures, and pressures are in MPa. Unless otherwise specified, the antioxidant H10 used in the examples is BRUGGOLEN H10 antioxidant, and the antifoaming agent used in the examples is Dow Corning Defoamer 3168. [Example]

[0127] Example 1 The method for producing high temperature resistant polyamide included the following steps: 3838.73 moles of 1,5-pentanediamine, 1411.03 moles of adipic acid, 2423.04 moles of terephthalic acid, and water were uniformly mixed under a nitrogen atmosphere to produce a 50 wt% polyamide salt solution. A sample was taken from the polyamide salt solution. When the sample was diluted to a concentration of 10 wt%, the pH value was 8.10. Sodium hypophosphite (120 ppm), antioxidant H10 (2000 ppm), and Dow Corning Defoamer 3168 (50 ppm) were added to the polyamide salt solution and mixed uniformly.

[0128] The polyamide salt solution was heated to 138°C so as to be concentrated to a concentration of 65 wt% and then subjected to the following steps:

[0129] Step (1): The polyamide salt solution was heated and pressurized. The pressure in the reaction system was increased to 3.5 MPa (P1) and maintained by degassing. At the end of the pressure maintenance, the temperature (T1) of the reaction system was 279°C.

[0130] Step (2): While continuing to increase the temperature, the pressure in the reaction system began to decrease until it reached 0 MPa (P2, gauge pressure). At this point, the temperature (T2) of the reaction system was 330°C. During the decrease in pressure, when the pressure (P) was 1.8 MPa, the temperature (T) of the system was 303°C. When the pressure (P) was 0.7 MPa, the temperature (T) of the system was 319°C.

[0131] Step (3): The pressure was maintained at -0.06 MPa by evacuation. The evacuation time was 15 minutes. At the end of evacuation, the temperature of the system was 335°C, and a polyamide melt was obtained.

[0132] Step (4): The melt was discharged and pelletized by water cooling to obtain a polyamide resin.

[0133] Here, the ratio of the water vapor (moles) discharged in step (1) to the water content (moles) in the concentrated polyamide salt solution (65 wt%) (abbreviated as dehydration rate) was 90.2:100. The ratio of the water vapor (moles) discharged in step (2) to the water content (moles) in the concentrated polyamide salt solution (65 wt%) (abbreviated as dehydration rate) was 113.1:100.

[0134] Example 2 The method for producing high temperature resistant polyamide included the following steps: 3,875 moles of 1,5-pentanediamine, 1,894.80 moles of adipic acid, 1,975.02 moles of terephthalic acid, and water were uniformly mixed under a nitrogen atmosphere to produce a 50 wt% polyamide salt solution. A sample was taken from the polyamide salt solution. When the sample was diluted to a concentration of 10 wt%, the pH value was 8.20. Sodium hypophosphite (120 ppm), antioxidant H10 (2,000 ppm), and Dow Corning Defoamer 3168 (50 ppm) were added to the polyamide salt solution and mixed uniformly.

[0135] The polyamide salt solution was heated to 130° C. so as to be concentrated to a concentration of 68 wt %, and then subjected to the following steps:

[0136] Step (1): The polyamide salt solution was heated and pressurized. The pressure in the reaction system was increased to 2.5 MPa (P1) and maintained by degassing. At the end of the pressure maintenance, the temperature (T1) of the reaction system was 267°C.

[0137] Step (2): While continuing to increase the temperature, the pressure in the reaction system began to decrease until it reached 0 MPa (P2, gauge pressure). At this point, the temperature (T2) of the reaction system was 315°C. During the decrease in pressure, when the pressure (P) was 1.2 MPa, the temperature (T) of the system was 295°C. When the pressure (P) was 0.4 MPa, the temperature (T) of the system was 308°C.

[0138] Step (3): The pressure was maintained at -0.04 MPa by evacuation. The evacuation time was 10 minutes. At the end of evacuation, the temperature of the system was 321°C, and a polyamide melt was obtained.

[0139] Step (4): The melt was discharged and pelletized by water cooling to obtain a polyamide resin.

[0140] Here, the ratio of the water vapor (moles) discharged in step (1) to the water content (moles) in the concentrated polyamide salt solution (68 wt%) (abbreviated as dehydration rate) was 83.3:100. The ratio of the water vapor (moles) discharged in step (2) to the water content (moles) in the concentrated polyamide salt solution (68 wt%) (abbreviated as dehydration rate) was 106.9:100.

[0141] Example 3 The method for producing high temperature resistant polyamide included the following steps: 3913.92 moles of 1,5-pentanediamine, 2418.56 moles of adipic acid, 1490.82 moles of terephthalic acid, and water were uniformly mixed under a nitrogen atmosphere to produce a 50 wt% polyamide salt solution. A sample was taken from the polyamide salt solution. When the sample was diluted to a concentration of 10 wt%, the pH value was 8.20. Sodium hypophosphite (120 ppm), antioxidant H10 (2000 ppm), and Dow Corning Defoamer 3168 (50 ppm) were added to the polyamide salt solution and mixed uniformly.

[0142] The polyamide salt solution was heated to 122°C so as to be concentrated to a concentration of 62 wt% and then subjected to the following steps:

[0143] Step (1): The polyamide salt solution was heated and pressurized. The pressure in the reaction system was increased to 1.4 MPa (P1) and maintained by degassing. At the end of the pressure maintenance, the temperature (T1) of the reaction system was 255°C.

[0144] Step (2): While continuing to increase the temperature, the pressure in the reaction system began to decrease until it reached 0 MPa (P2, gauge pressure). At this point, the temperature (T2) of the reaction system was 299°C. During the decrease in pressure, when the pressure (P) was 0.7 MPa, the temperature (T) of the system was 287°C. When the pressure (P) was 0.2 MPa, the temperature (T) of the system was 298°C.

[0145] Step (3): The pressure was maintained at -0.02 MPa by evacuation. The evacuation time was 5 minutes. At the end of evacuation, the temperature of the system was 313°C, and a polyamide melt was obtained.

[0146] Step (4): The melt was discharged and pelletized by water cooling to obtain a polyamide resin.

[0147] Here, the ratio of the water vapor (moles) discharged in step (1) to the water content (moles) in the concentrated polyamide salt solution (62 wt%) (abbreviated as dehydration rate) was 77.6:100. The ratio of the water vapor (moles) discharged in step (2) to the water content (moles) in the concentrated polyamide salt solution (62 wt%) (abbreviated as dehydration rate) was 99.8:100.

[0148] Example 4 The method for producing high temperature resistant polyamide included the following steps: 2977.99 moles of decanediamine, 625 moles of adipic acid, 2351.05 moles of terephthalic acid, and water were uniformly mixed under a nitrogen atmosphere to produce a 50 wt% polyamide salt solution. A sample was taken from the polyamide salt solution. When the sample was diluted to a concentration of 10 wt%, the pH value was 8.20. Sodium hypophosphite (120 ppm), antioxidant H10 (2000 ppm), and Dow Corning Defoamer 3168 (50 ppm) were added to the polyamide salt solution and mixed uniformly.

[0149] The polyamide salt solution was heated to 130° C. so as to be concentrated to a concentration of 65 wt %, and then subjected to the following steps:

[0150] Step (1): The polyamide salt solution was heated and pressurized. The pressure in the reaction system was increased to 2.5 MPa (P1) and maintained by degassing. At the end of the pressure maintenance, the temperature (T1) of the reaction system was 270°C.

[0151] Step (2): While continuing to increase the temperature, the pressure in the reaction system began to decrease until it reached 0 MPa (P2, gauge pressure). At this point, the temperature (T2) of the reaction system was 320°C. During the decrease in pressure, when the pressure (P) was 1.1 MPa, the temperature (T) of the system was 305°C. When the pressure (P) was 0.8 MPa, the temperature (T) of the system was 318°C.

[0152] Step (3): The pressure was maintained at -0.04 MPa by evacuation. The evacuation time was 10 minutes. At the end of evacuation, the temperature of the system was 320°C, and a polyamide melt was obtained.

[0153] Step (4): The melt was discharged and pelletized by water cooling to obtain a polyamide resin.

[0154] Here, the ratio of the water vapor (moles) discharged in step (1) to the water content (moles) in the concentrated polyamide salt solution (65 wt%) (abbreviated as dehydration rate) was 83.1:100. The ratio of the water vapor (moles) discharged in step (2) to the water content (moles) in the concentrated polyamide salt solution (65 wt%) (abbreviated as dehydration rate) was 106.9:100.

[0155] Example 5 The method for producing high temperature resistant polyamide included the following steps: 3587.55 moles of 1,5-pentanediamine, 602.39 moles of dodecanedioic acid, 2982.72 moles of terephthalic acid, and water were uniformly mixed under a nitrogen atmosphere to produce a 50 wt% polyamide salt solution. A sample was taken from the polyamide salt solution. When the sample was diluted to a concentration of 10 wt%, the pH value was 8.20. Sodium hypophosphite (120 ppm), antioxidant H10 (2000 ppm), and Dow Corning Defoamer 3168 (50 ppm) were added to the polyamide salt solution and mixed uniformly.

[0156] The polyamide salt solution was heated to 130° C. so as to be concentrated to a concentration of 65 wt %, and then subjected to the following steps:

[0157] Step (1): The polyamide salt solution was heated and pressurized. The pressure in the reaction system was increased to 2.5 MPa (P1) and maintained by degassing. At the end of the pressure maintenance, the temperature (T1) of the reaction system was 275°C.

[0158] Step (2): While continuing to increase the temperature, the pressure in the reaction system began to decrease until it reached 0 MPa (P2, gauge pressure). At this point, the temperature (T2) of the reaction system was 315°C. During the decrease in pressure, when the pressure (P) was 1.3 MPa, the temperature (T) of the system was 300°C. When the pressure (P) was 0.7 MPa, the temperature (T) of the system was 314°C.

[0159] Step (3): The pressure was maintained at -0.04 MPa by evacuation. The evacuation time was 10 minutes. At the end of evacuation, the temperature of the system was 318°C, and a polyamide melt was obtained.

[0160] Step (4): The melt was discharged and pelletized by water cooling to obtain a polyamide resin.

[0161] Here, the ratio of the water vapor (moles) discharged in step (1) to the water content (moles) in the concentrated polyamide salt solution (65 wt%) (abbreviated as dehydration rate) was 81.0:100. The ratio of the water vapor (moles) discharged in step (2) to the water content (moles) in the concentrated polyamide salt solution (65 wt%) (abbreviated as dehydration rate) was 110.5:100.

[0162] Example 6 The steps and conditions for preparing a high-temperature resistant polyamide were the same as those in Example 1, except that in step (2), while continuing to increase the temperature, the pressure in the reaction system began to decrease until it reached 0 MPa (P2, gauge pressure); at this point, the temperature (T2) of the reaction system was 330°C; during the reduction in pressure, the temperature (T) of the system was 283°C when the pressure (P) was 1.5 MPa, and the temperature (T) of the system was 319°C when the pressure (P) was 0.7 MPa.

[0163] Example 7 The steps and conditions for preparing the high-temperature resistant polyamide were the same as those in Example 1, except that in step (2), while continuing to increase the temperature, the pressure in the reaction system began to decrease until it reached 0 MPa (P2, gauge pressure); at this point, the temperature (T2) of the reaction system was 330°C; during the reduction in pressure, when the pressure (P) was 1.8 MPa, the temperature (T) of the system was 303°C; and when the pressure (P) was 0.6 MPa, the temperature (T) of the system was 330°C.

[0164] Example 8 The steps and conditions for preparing the high-temperature resistant polyamide were the same as those in Example 1, except that in step (2), while continuing to increase the temperature, the pressure in the reaction system began to decrease until it reached 0 MPa (P2, gauge pressure); at this point, the temperature (T2) of the reaction system was 330°C; during the reduction in pressure, when the pressure (P) was 1.5 MPa, the temperature (T) of the system was 283°C; and when the pressure (P) was 0.6 MPa, the temperature (T) of the system was 330°C.

[0165] Example 9 The steps and conditions for preparing the high-temperature resistant polyamide were the same as those in Example 1, except that the ratio of the water vapor (moles) discharged in step (1) to the water content (moles) in the concentrated polyamide salt solution (65 wt%) (abbreviated as dehydration rate) was 69.5:100; and the ratio of the water vapor (moles) discharged in step (2) to the water content (moles) in the concentrated polyamide salt solution (65 wt%) (abbreviated as dehydration rate) was 113.1:100.

[0166] Example 10 The steps and conditions for preparing the high-temperature resistant polyamide were the same as those in Example 1, except that the ratio of the water vapor (moles) discharged in step (1) to the water content (moles) in the concentrated polyamide salt solution (65 wt%) (abbreviated as dehydration rate) was 70.2:100; and the ratio of the water vapor (moles) discharged in step (2) to the water content (moles) in the concentrated polyamide salt solution (65 wt%) (abbreviated as dehydration rate) was 116.7:100.

[0167] Example 11 The steps and conditions for preparing the high-temperature resistant polyamide were the same as those in Example 4, except that in step (2), while continuing to increase the temperature, the pressure in the reaction system began to decrease until it reached 0 MPa (P2, gauge pressure); at this point, the temperature (T2) of the reaction system was 330°C; during the reduction in pressure, when the pressure (P) was 1.5 MPa, the temperature (T) of the system was 275°C; and when the pressure (P) was 0.7 MPa, the temperature (T) of the system was 319°C. The ratio of the water vapor (moles) discharged in step (1) to the water content (moles) in the concentrated polyamide salt solution (65 wt%) (abbreviated as the dehydration ratio) was 71.4:100; and the ratio of the water vapor (moles) discharged in step (2) to the water content (moles) in the concentrated polyamide salt solution (65 wt%) (abbreviated as the dehydration ratio) was 113.1:100.

[0168] The test results for the polyamide resins obtained in the above examples are shown in Table 1.

[0169] [Table 1]

[0170] Unless otherwise limited, the terms used herein have the meanings that are commonly understood by those skilled in the art.

[0171] The embodiments described in the present invention are for illustrative purposes only and are not intended to limit the protection scope of the present invention. Those skilled in the art may make various substitutions, modifications and improvements within the scope of the present invention. Therefore, the present invention is not limited to the above embodiments, but is defined only by the claims.

Claims

1. A method for producing a high temperature resistant polyamide, wherein the high temperature resistant polyamide can be used at 150°C or above, Optionally, the polyamide salt solution is concentrated, followed by the following procedure: (1) heating and pressurizing to a pressure P1 and maintaining said pressure, wherein at the end of said pressure maintenance, the system temperature is T1; (2) reducing the pressure to a pressure of P2, at the end of which the system temperature is T2; and (3) Evacuation, thereby obtaining a polyamide melt. performing P1 is 0.8 to 4 MPa, T1 is 250 to 290°C, T1 < T2, and (T2 - T1) / (P1 - P2) = 5 to 75, where P1 and P2 are gauge pressures, In step (1), water vapor is discharged to the outside, and the ratio of the discharged water vapor (mol) to the water content (mol) in the polyamide salt solution is (75.4-93.9):100; In step (2), the water vapor is discharged to the outside, and the ratio of the discharged water vapor (mol) to the water content (mol) in the polyamide salt solution is (98.7-113.9):100; the polyamide salt comprises a salt formed by the reaction of component (A) a diamine with component (B) a diacid; and / or the polyamide salt solution contains at least ions of component (A) a diamine and ions of component (B) a diacid; and / or The polyamide salt solution (1) a solution obtained by mixing a component (A) diamine, a component (B) diacid, and a solvent; (2) a solution obtained by mixing a component (C) polyamide salt, and a solvent; and (3) a solution obtained by mixing a component (C) polyamide salt, a component (A) diamine and / or a component (B) diacid, and a solvent, or any combination of two or more thereof; the component (A) diamine is one or more of component (a1): pentanediamine, hexanediamine, heptanediamine, octanediamine, nonanediamine, decanediamine, undecanediamine, dodecanediamine, tridecanediamine, tetradecanediamine, pentadecanediamine, and hexadecanediamine; and The component (B) diacid is one or more of component (b1): adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, tridecanedioic acid, tetradecanedioic acid, pentadecanedioic acid, hexadecanedioic acid, heptadecanedioic acid, and octadecanedioic acid, and component (b2): terephthalic acid, isophthalic acid, and phthalic acid. A method characterized by:

2. The mass concentration of the polyamide salt solution is 20 wt % or more, preferably 20 to 90 wt %; and / or Before step (1), if the concentration of the polyamide salt solution is 10 wt%, the pH value is 6.5 to 9.

0.

2. The method for producing high-temperature resistant polyamide according to claim 1.

3. component (a1) comprises one of pentanediamine, hexanediamine, heptanediamine, octanediamine, nonanediamine, and decanediamine; and Component (b1) comprises one of adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, and dodecanedioic acid.

3. A method for producing high-temperature resistant polyamide according to claim 1 or 2.

4. Component (a1) is pentanediamine or decanediamine; and 4. The method for producing high-temperature resistant polyamides according to claim 3, wherein component (b1) is adipic acid or dodecanedioic acid.

5. the molar ratio of component (A) to component (B) is (0.5-5):1; and / or the molar ratio of component (a1) to component (b1) is (0.5-12):1; and / or The molar ratio of the component (a1) to the component (b2) is (0.1 to 6):

1.

5. The method for producing high-temperature resistant polyamide according to claim 4.

6. During the step (2) of reducing the pressure to P2, the pressure P and the temperature T satisfy the following condition: T=(1.01-1.18)×T1 when P is 0.4-0.65 times P1; and / or During the step (2) of reducing the pressure to P2, the pressure P and the temperature T satisfy the following condition: T=(1.132-1.26)×T1 when P is 0.1-0.3 times P1; 2. The method for producing high-temperature resistant polyamide according to claim 1, characterized in that P2<P<P1 and T1<T<T2, where P1 and P2 are gauge pressures.

7. Prior to step (1), the polyamide salt solution is concentrated to a concentration of 50 to 85 wt %; and / or Adding component (D) additive at any stage of step (1) to step (3); and / or T2 is 295 to 340°C and T1 < T2; and / or P2 is 0 to 0.05 MPa and P1 > P2; and / or In the step (3), the pressure is evacuated to a gauge pressure of −0.09 to −0.005 MPa; and / or In the step (3), the temperature of the system at the end of the evacuation is 310 to 340°C; and / or The method further comprises the step (4) of discharging and pelletizing the polyamide melt, thereby obtaining a polyamide resin.

2. The method for producing high-temperature resistant polyamide according to claim 1.

8. the polyamide salt solution further comprises component (D) an additive; said component (D) comprising one or more of antioxidants, antifoaming agents, UV stabilizers, heat stabilizers, crystallization accelerators, free radical scavengers, lubricants, plasticizers, impact modifiers, inorganic fillers, brighteners, dyes, flame retardants, and minerals; and / or The molar amount of the component (D) is 0.001% to 1%, preferably 0.01% to 0.8%, of the molar amount of the component (A) and / or the component (C).

2. The method for producing high-temperature resistant polyamide according to claim 1.

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