Method for producing high temperature-resistant polyamide, high temperature-resistant polyamide and use thereof

Patent metadata

Field	Value
Publication number	US-12441839-B2
Application number	US-202117566746-A
Country	US
Kind code	B2
Filing date	Dec 31, 2021
Priority date	Nov 2, 2020
Publication date	Oct 14, 2025
Grant date	Oct 14, 2025

Abstract

The present invention provides a process for producing a high temperature resistant polyamide, the high temperature resistant polyamide and the use thereof. The process comprises: optionally concentrating a polyamide salt solution, and then conducting the following operations: heating and pressurizing to a pressure of P1, and maintaining the pressure, wherein the temperature of the system is T1 at the end of the pressure-maintenance; depressurizing to a pressure of P2, wherein the temperature of the system is T2 at the end of the depressurization; and evacuating, whereby a polyamide melt is obtained; wherein P1 is 0.8-4 MPa, T1 is 250-290° C., T1<T2 and (T2−T1)/(P1−P2)=5-75. The process for producing a high temperature resistant polyamide according to the present invention is simple to operate and reduces energy consumption. The obtained high temperature resistant polyamide may be used as a raw material for such injection molded parts, molded articles, or fibers as high temperature resistant attachments for machines, automobiles, household appliances, toys, textiles, sporting goods, mobile phones, computers, laptops, GPS devices, or optical devices.

First claim

What is claimed is:

1. A process for producing a high temperature resistant polyamide, wherein the process comprises the following steps:
concentrating a polyamide salt solution, and then conducting the following operations:
(1) heating and pressurizing to a pressure of P1, and maintaining the pressure, wherein the temperature of the system is T1 at the end of the pressure-maintenance;
(2) depressurizing to a pressure of P2, wherein the temperature of the system is T2 at the end of the depressurization; and
(3) evacuating, whereby a polyamide melt is obtained;
wherein P1 is 0.8-4 MPa, T1 is 250-290° C., T1<T2 and (T2-T1)/(P1-P2)=5-75° C./MPa,
in Step (1), steam is discharged to the outside, and the ratio of the discharged steam (mol) to the water content (mol) in the polyamide salt solution is (60.6-93.9):100.

2. The process for producing a high temperature resistant polyamide according to claim 1 , wherein:
the mass concentration of the polyamide salt solution is 20 wt %, or more; and/or
prior to Step (1), the pH value is 6.5-9.0 when the concentration of the polyamide salt solution is 10 wt %.

3. The process for producing a high temperature resistant polyamide according to claim 1 , wherein:
the polyamide salt comprises a salt produced by the reaction of Component (A) diamine and Component (B) diacid; and/or
the polyamide salt solution comprises at least ions of Component (A) diamine and ions of Component (B) diacid; and/or
the polyamide salt solution comprises:
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.

4. The process for producing a high temperature resistant polyamide according to claim 3 , wherein Component (A) diamine comprises:
any one of (a1) aliphatic linear, or branched diamines having 4 to 16 carbon atoms; (a2) aromatic diamines, or cycloaliphatic diamines; or any combination of two or more thereof; and/or
Component (B) diacid comprises:
any one of (b1) aliphatic diacids 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.

5. The process for producing a high temperature resistant polyamide according to claim 4 , wherein:
Component (a1) comprises one, or more of butane diamine, pentane diamine, hexane diamine, heptane diamine, octane diamine, nonane diamine, decane diamine, undecane diamine, dodecane diamine, tridecane diamine, tetradecane diamine, pentadecane diamine, and hexadecane diamine; and/or
Component (a2) comprises one, or more of cyclopentane diamine, methyl cyclopentane diamine, cyclohexane diamine, p-phenylenediamine, o-phenylenediamine, and m-phenylenediamine; and/or
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; and/or
Component (b2) comprises one, or more of terephthalic acid, isophthalic acid, and phthalic acid.

6. The process for producing a high temperature resistant polyamide according to claim 4 , wherein:
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 Component (a1) to Component (b2) is (0.1-6):1.

7. The process for producing a high temperature resistant polyamide according to claim 3 , wherein the polyamide salt solution further comprises Component (D) additive(s);
Component (D) comprises one, or more of antioxidants, defoamers, 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 quantity of Component (D) is 0.001% to 1% of the molar quantity of Component (A) and/or Component (C).

8. The process for producing a high temperature resistant polyamide according to claim 7 , wherein the molar quantity of Component (D) is 0.01% to 0.8% of the molar quantity of Component (A) and/or Component (C).

9. The process for producing a high temperature resistant polyamide according to claim 1 , wherein:
during Step (2) of depressurizing to a pressure of P2, the pressure P and the temperature T satisfy the following conditions: when P is 0.4-0.65 times of P1, T=(1.01-1.18)×T1; and/or
during Step (2) of depressurizing to a pressure of P2, the pressure P and the temperature T satisfy the following conditions: when P is 0.1-0.3 times of P1, T=(1.132-1.26)×T1;
wherein P2<P<P1, and T1<T<T2.

10. The process for producing a high temperature resistant polyamide according to claim 1 , wherein:
in Step (2), steam is discharged to the outside, and the ratio of the discharged steam (mol) to the water content (mol) in the polyamide salt solution is (93.9-118.2):100.

11. The process for producing a high temperature resistant polyamide according to claim 1 , wherein:
prior to Step (1), the polyamide salt solution is concentrated to a concentration of 50-85 wt %; and/or
adding Component (D) additive(s) in any stage of Step (1) to Step (3); and/or
T2 is 295-340° C., and T1<T2; and/or
P2 is 0-0.05 MPa, and P1>P2; and/or
in Step (3), evacuating to a pressure of −0.09 to −0.005 MPa; and/or
in Step (3), the temperature of the system is 310-340° C. at the end of the evacuation; and/or
the process further comprises Step (4): discharging and pelletizing the polyamide melt, whereby a polyamide resin is obtained.

12. A high temperature resistant polyamide prepared by the process of claim 1 , wherein the high temperature resistant polyamide comprises at least a polyamide produced from Component (A) diamine and Component (B) diacid as raw materials,
the molar ratio of Component (A) to Component (B) is (0.5-5):1; and/or
Component (A) diamine comprises:
any one of (a1) aliphatic linear, or branched diamines having 4 to 16 carbon atoms; (a2) aromatic diamines, or cycloaliphatic diamines; or any combination of two or more thereof; and/or
Component (B) diacid comprises:
any one of (b1) aliphatic diacids having 2 to 18 carbon atoms; (b2) a benzene ring-containing diacid having 8 carbon atoms, or more; or any combination of two or more thereof,
the high temperature resistant polyamide has a melting point of 280-328° C.; and
the high temperature resistant polyamide has a relative viscosity of 1.80-2.70; and
the high temperature resistant polyamide has a notched impact strength of 5-12 KJ/cm 2 ; and
the high temperature resistant polyamide has a tensile strength of 95-140 MPa; and
the high temperature resistant polyamide has a flexural strength of 135-190 MPa; and
the high temperature resistant polyamide has a flexural modulus of 3,500-4,400 MPa; and
the high temperature resistant polyamide has a heat deflection temperature of 240-320° C.

13. A high temperature resistant polyamide according to claim 12 , wherein a structural unit of the high temperature resistant polyamide includes the following formula:

wherein n=4-16, and m=2-18.

14. The high temperature resistant polyamide according to claim 12 , where

Assignees

• Cathay Biotech Inc
• Cibt America Inc
• Shanxi Synthetic Biology Inst Co Ltd

Inventors

• Zhao Yuanbo
• Qin Bingbing
• Liu Xiucai

Classifications

• C08G69/265 Primary

  from at least two different diamines or at least two different dicarboxylic acids · CPC title

• C08G69/28 Primary

  Preparatory processes · CPC title

• C08G69/26 Primary

  derived from polyamines and polycarboxylic acids · CPC title