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CN-122011369-A - Semi-aromatic polyamide resin and synthesis method thereof

CN122011369ACN 122011369 ACN122011369 ACN 122011369ACN-122011369-A

Abstract

The invention discloses a semi-aromatic polyamide resin and a synthesis method thereof, wherein the semi-aromatic polyamide resin is synthesized from the following raw materials of decanediamine, terephthalic acid, phosphoric acid amide salt, caprolactam, 2' - (1, 3-phenylene) -bisoxazoline, organized carbon nano-tubes, benzoic acid and high-temperature resistant antioxidant. The semi-aromatic polyamide resin has excellent mechanical property, flame retardant property and electromagnetic shielding property, and can be widely applied to the field of communication devices needing flame retardance and electromagnetic shielding.

Inventors

  • WANG ZHONGQIANG
  • Lin Shaoze
  • LIU YULING
  • LIU XIANYONG
  • YANG DONGFANG

Assignees

  • 广东中塑新材料股份有限公司

Dates

Publication Date
20260512
Application Date
20260302

Claims (9)

  1. 1. The semi-aromatic polyamide resin is characterized by being prepared from the following raw materials in parts by weight: 172 parts of decamethylene diamine, 166 Parts of terephthalic acid, which is used for preparing the catalyst, 40-80 Parts of phosphoramide salt, 12-24 Parts of caprolactam, 4-8 Parts of 2,2' - (1, 3-phenylene) -bisoxazoline, 22-42 Parts of organic carbon nano-tubes, 2-4 Parts of benzoic acid, 1.3-2.7 Parts of high-temperature-resistant antioxidant; The phosphorus-containing amide salt is obtained by salifying 2-carboxyethyl phenyl hypophosphorous acid and decanediamine, the organic carbon nano tube is obtained by organically modifying carbon nano tube by gamma-aminopropyl triethoxysilane, and the high-temperature-resistant antioxidant is N, N' -bis (2, 6-tetramethyl-4-piperidyl) -1, 3-benzene dicarboxamide.
  2. 2. The semiaromatic polyamide resin according to claim 1, which is prepared from the following raw materials in parts by weight: 172 parts of decamethylene diamine, 166 Parts of terephthalic acid, which is used for preparing the catalyst, 45-75 Parts of phosphoramide salt, 14-22 Parts of caprolactam, 4.5 To 7.5 parts of 2,2' - (1, 3-phenylene) -bisoxazoline, 25-39 Parts of organic carbon nano tube, 2.3-3.7 Parts of benzoic acid, 1.5-2.5 Parts of high-temperature-resistant antioxidant.
  3. 3. The semiaromatic polyamide resin according to claim 2, characterized by being prepared from the following raw materials in parts by weight: 172 parts of decamethylene diamine, 166 Parts of terephthalic acid, which is used for preparing the catalyst, 50-70 Parts of phosphoramide salt, 16-20 Parts of caprolactam, 5.5 To 6.5 parts of 2,2' - (1, 3-phenylene) -bisoxazoline, 28-36 Parts of organic carbon nano tube, 2.6-3.4 Parts of benzoic acid, 1.7-2.3 Parts of high-temperature-resistant antioxidant.
  4. 4. The semiaromatic polyamide resin according to any one of claims 1 to 3, wherein the preparation method of the phosphorus-containing amide salt comprises the steps of adding 214.16 ‌ g of 2-carboxyethylphenyl hypophosphorous acid and 172.31 g decanediamine into a stirred polymerization reactor, then adding 150-200 mL of deionized water, vacuumizing for 2-6 min, introducing nitrogen for 2-6 min, circulating for 3-5 times, controlling the system pressure in the stirred polymerization reactor to be 0.1-0.3 MPa, sealing and heating the stirred polymerization reactor to 85-95 ℃ within 0.5-1.5 hours, controlling the stirring speed to be 50-r/min-100 r/min, carrying out salt formation reaction for 1-2 hours, and then reducing the pressure in the reactor to 0.1-MPa, discharging and vacuum drying.
  5. 5. The semi-aromatic polyamide resin according to any one of claims 1 to 3, wherein the preparation method of the organized carbon nanotubes comprises the steps of adding 100 g carbon nanotubes and 2 g to 3g of gamma-aminopropyl triethoxysilane into a high-speed stirrer, and stirring at room temperature for 7 min to 11 min to obtain the organized carbon nanotubes.
  6. 6. The semiaromatic polyamide resin according to any of claims 1 to 3, wherein the average diameter of the carbon nanotubes in the organized carbon nanotubes is 8 nm to 10 nm, and the structure thereof is an array type.
  7. 7. The method for producing a semiaromatic polyamide resin according to any one of claims 1 to 6, comprising the steps of: (1) Adding the vacuum-dried decanediamine and terephthalic acid into a stirring type polymerization reactor, simultaneously adding phosphorus-containing amide salt, caprolactam, 2' - (1, 3-phenylene) -bisoxazoline, organic carbon nano tube, benzoic acid, high-temperature-resistant antioxidant and a proper amount of water, vacuumizing for 2-6 min, introducing nitrogen for 2-6 min, and circulating for 3-5 times, wherein the system pressure in the stirring type polymerization reactor is controlled to be 0.1-0.3 MPa; (2) Regulating the stirring speed of the stirring type polymerization reactor to 20 r/min-40 r/min, heating the stirring type polymerization reactor to 274-278 ℃ in a sealed and uniform manner within 2-4 hours, deflating to 1.8 MPa when the temperature of the stirring type polymerization reactor reaches 209 ℃, maintaining the pressure at 1.8 MPa, deflating to normal pressure after reacting for 1-2 hours, simultaneously heating to 310-316 ℃ and continuing to react for 1-2 hours, continuously vacuumizing at constant temperature for 15-45 minutes, finishing the reaction, and supplementing nitrogen when discharging to obtain the catalyst.
  8. 8. The method for preparing a semiaromatic polyamide resin according to claim 7, wherein in the step (1), the vacuum is applied for 3 to 5 minutes, nitrogen is introduced for 3 to 5 minutes, the circulation is performed for 3 to 5 times, and the system pressure in the stirred polymerization reactor is controlled to be 0.15 MPa~0.25 MPa.
  9. 9. The method for producing a semiaromatic polyamide resin according to claim 7, wherein in the step (2), the stirring speed of the stirring type polymerization reactor is adjusted to 25 r/min-35 r/min, the stirring type polymerization reactor is heated to 275 ℃ to 277 ℃ at a constant speed in a sealed state within 2.5 hours-3.5 hours, when the temperature of the stirring type polymerization reactor reaches 209 ℃, the stirring type polymerization reactor is deflated to 1.8 MPa, the pressure is maintained at 1.8 MPa, after the reaction is carried out for 1.2 hours-1.8 hours, the deflation is carried out to normal pressure, the temperature is raised to 312 ℃ to 314 ℃ at the same time, the reaction is continued for 1.2 hours-1.8 hours, the constant temperature is continuously evacuated for 20 min-40 min, and after the reaction is finished, nitrogen is supplemented during the discharging, the semiaromatic polyamide resin is obtained.

Description

Semi-aromatic polyamide resin and synthesis method thereof Technical Field The invention belongs to the field of materials, and particularly relates to a semi-aromatic polyamide resin and a synthesis method thereof. Background Polyamide (PA) resins can be prepared by self-polymerization of lactams or polycondensation of diamines/diacids and can be classified into aliphatic PA, semiaromatic PA and wholly aromatic PA according to the main chain structure. Although the aliphatic PA6/PA66 with the largest dosage has excellent mechanical property, wear resistance and self-lubricating property, the flame retardant property is poor (UL 94 vertical burning only reaches V-2 level), and the electromagnetic shielding function is completely absent. With the development of SMT technology (the heat resistance requirement is more than or equal to 270 ℃) and the improvement of the comprehensive performance requirement of the material in the aerospace field, the defects that the traditional PA is easy to thermally decompose at high temperature (the initial temperature of thermal weight loss is less than 300 ℃) and generates molten drops during combustion are increasingly prominent. Although the wholly aromatic PA has excellent heat resistance, the wholly aromatic PA has the fundamental defects of difficult melt processing, high flame retardant modification cost (15% -30% of flame retardant is needed) and incapability of realizing electromagnetic shielding function. Although the semi-aromatic PA improves heat resistance by introducing a benzene ring structure, the flame retardant property (about 27% of oxygen index) of the semi-aromatic PA is still obviously lower than the flame retardant requirement of engineering plastics, and the electromagnetic shielding effectiveness can not meet the protection requirement of electronic devices. Common modification methods for improving the flame retardant property of the polyamide comprise ‌ adding type flame retardant ‌ (such as halogen-antimony synergistic system, phosphorus flame retardant, inorganic hydroxide and the like), ‌ reactive type flame retardant ‌ (flame retardant elements are introduced into a molecular chain in a copolymerization mode), and ‌ composite flame retardant system ‌ (such as glass fiber reinforcement and flame retardant synergistic, nano composite material and the like). The halogen flame retardant (such as decabromodiphenyl ethane) and antimony oxide are compounded to obviously improve the flame retardant efficiency, but have the environmental protection problem, the phosphorus flame retardant (such as ammonium polyphosphate) can form a carbon layer during combustion to inhibit flame propagation, and inorganic hydroxide (such as aluminum hydroxide and magnesium hydroxide) is environment-friendly, but takes effect only by high addition (more than 50 percent) and often influences the mechanical property of the material. In addition, the incorporation of phosphorus or nitrogen containing monomers such as bis (hydroxyethyl) methylphosphine by copolymerization can improve the flame retardance durability, but the process is more complicated. Nanocomposite flame retardant technologies (e.g., carbon nanotubes and layered silicate) are receiving attention for flame retardant enhancement and mechanical property optimization. At present, some researches are carried out on a copolymerization flame-retardant polyamide material in the prior art, for example, china patent CN 112048061A discloses a copolymerization flame-retardant polyamide and a preparation method thereof, wherein the preparation method comprises the steps of mixing a flame retardant salt with polyamide 66 oligomer and/or polyamide 6 oligomer, and then carrying out polycondensation reaction to obtain the copolymerization flame-retardant polyamide, and the flame retardant salt is prepared by carrying out high-temperature high-pressure reaction on N, N-di (6-aminohexyl) phenyl phosphoryl diamine and dibasic acid HOOCR1 COOH. Chinese patent CN 104231262a discloses a method for preparing an organophosphorus copolymerized flame-retardant polyamide material for textile, engineering plastics and films. the preparation method of the organophosphorus copolymerized flame-retardant polyamide material specifically comprises the following steps of (1) reacting a flame retardant with diamine monomers in advance to prepare a prepolymer, and (2) adding the polymerized monomers, a catalyst and the prepolymer into a reaction kettle to prepare the organophosphorus copolymerized flame-retardant polyamide material. Chinese patent CN 112144141A discloses a copolymerization flame-retardant polyamide fiber and a preparation method thereof, wherein the preparation method comprises the steps of taking a flame-retardant polyamide copolymer as a whole or part of spinning raw materials to spin so as to prepare the copolymerization flame-retardant polyamide fiber, the flame-retardant polyamide copolymer is prepared by mixing flame