Cuprous salt antioxidant containing phosphite structure as well as preparation method and application of cuprous salt antioxidant

Abstract

The invention relates to a cuprous salt antioxidant containing a phosphite structure and a preparation method and application thereof.The preparation method comprises the steps that firstly, diethyl malonate reacts in the presence of ammonia gas to obtain an intermediate A, then the intermediate A and 3-amino-2, 5-di-tert-butylphenol are subjected to condensation cyclization to obtain an intermediate B, finally, after the intermediate B and a phosphite derivative react, the cuprous salt antioxidant containing the phosphite structure is obtained, and the cuprous salt antioxidant containing the phosphite structure is obtained. And coordinating with cuprous salt to obtain a final product. The invention also provides a nylon composition containing the antioxidant. The antioxidant disclosed by the invention has the characteristics of high-efficiency oxidation resistance, hydrolysis resistance and good compatibility with nylon through the synergistic effect of a plurality of intramolecular stable mechanisms, and can be used for remarkably improving the thermal oxidation stability of a nylon material, inhibiting degradation in the processing and using processes and effectively keeping the mechanical properties, appearance and color of the material.

Description

Technical Field

[0001] This invention relates to the field of polymer antioxidant auxiliaries, specifically to a cuprous salt antioxidant containing a phosphite structure, its preparation method, and its application. Background Technology

[0002] During processing, storage, and use, nylon is inevitably exposed to environmental factors such as heat, oxygen, and light, resulting in oxidative degradation. Oxidative degradation leads to a severe decline in material properties, manifested as discoloration, embrittlement, cracking, and decreased strength, significantly shortening the material's service life.

[0003] To inhibit the oxidative degradation of polymers, antioxidants are typically added. Commonly used antioxidant systems include phenolic primary antioxidants (such as Antioxidant 1010), phosphite secondary antioxidants (such as Antioxidant 168), and thioester secondary antioxidants. Phosphite antioxidants effectively decompose hydroperoxides and block the auto-oxidation chain reaction; however, they are extremely sensitive to moisture and easily hydrolyze to form acidic substances, losing their antioxidant activity and potentially corroding processing equipment and catalyzing polymer degradation. On the other hand, copper ions (Cu⁺ / Cu²⁺) have been found to have excellent thermal stabilizing effects on nylon, catalyzing the decomposition of hydroperoxides through redox reactions. However, inorganic copper salts have poor dispersibility in the polymer matrix and are prone to migration and precipitation, affecting not only the appearance of the product but also limiting the durability of their stabilizing effect.

[0004] In existing technologies, antioxidants with different mechanisms are typically used in combination through physical compounding to achieve a synergistic effect. However, physical compounding is merely a simple superposition of the functions of each component and cannot fundamentally solve the problems of phosphite hydrolysis and copper salt migration and dispersion. Therefore, there is an urgent need in the field to develop a novel antioxidant that can integrate multiple stabilizing mechanisms within a single molecule, possessing characteristics of high efficiency, durability, hydrolysis resistance, and good compatibility. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the first aspect of this invention is to provide a cuprous salt antioxidant containing a phosphite structure, the structure of which is shown in formula (I): (I).

[0006] The second aspect of this invention is to provide a method for preparing a cuprous salt antioxidant containing a phosphite structure, the specific process of which is as follows: Step 1: In a dry, clean reflux condenser, add a certain amount of diethyl malonate and solvent, stir to mix thoroughly, and continuously purge with ammonia gas. React at a certain temperature for a certain time. After the reaction is complete, cool to room temperature, and then perform vacuum distillation to remove most of the solvent, obtaining the crude product. Dissolve the crude product in an ethanol-water mixture, heat and then cool, recrystallize the product for further purification, and obtain intermediate product A.

[0007] Preferably, in step one, the solvent is toluene, and the mass ratio of toluene to diethyl malonate is ≥3:1. The reaction temperature is 40-50 °C, optimally 40 °C, and the reaction time is 15-25 h, optimally 20 h. The vacuum distillation temperature is 80-100 °C, optimally 80 °C. The recrystallization temperature is 60-100 °C, optimally 80 °C.

[0008] Step 2: Dissolve the tert-butyl-substituted benzoxazole compound, intermediate product A prepared in step (1), and catalyst in a solvent and stir until dissolved. After reacting for a certain time under a certain temperature and inert gas protection, cool to room temperature, adjust the pH to neutral with saturated sodium carbonate solution, extract with an organic solvent, combine the organic phases, dry with anhydrous sodium sulfate, and remove the solvent by vacuum distillation to obtain the crude product. Dissolve the crude product in petroleum ether and recrystallize after cooling to obtain intermediate product B.

[0009] Preferably, in step two, the tert-butyl-substituted benzoxazole compound is 3-amino-2,5-di-tert-butylphenol, the catalyst is polyphosphoric acid, and the solvent is formic acid. The mass ratio of 3-amino-2,5-di-tert-butylphenol to intermediate A is 1:2-1:3, with an optimal ratio of 1:2.5. The amount of catalyst used is 0.4%-0.8% of the sum of the masses of 3-amino-2,5-di-tert-butylphenol and intermediate A. The mass ratio of formic acid to 3-amino-2,5-di-tert-butylphenol is ≥4:1. The inert gas in step (2) is nitrogen or argon, the reaction temperature is 120-140℃, with an optimal temperature of 130℃. The reaction time is 3-6 h, with an optimal time of 4 h. The organic solvent for extraction is ethyl acetate, and extraction is performed three times. The vacuum distillation temperature is 80-100℃, with an optimal temperature of 80℃. The recrystallization temperature is 80-100℃, with the optimal temperature being 90℃.

[0010] Step 3: Add intermediate product B prepared in Step 2 and the phosphite derivative to a three-necked flask equipped with a stirrer, condenser, and thermometer at a certain molar ratio. Add an appropriate amount of organic solvent and stir the mixture at a certain temperature for a certain time to obtain intermediate product C. Then, slowly add monovalent copper salt and continue the reaction at a higher temperature for a certain time. After the reaction is complete, cool to room temperature, rotary evaporate, and vacuum dry to obtain a cuprous salt antioxidant containing a phosphite ester structure.

[0011] Preferably, the organic solvent in step three is toluene. The phosphite derivative is one or more combinations of trimethyl phosphite and triethyl phosphite. The molar ratio of intermediate product B to the phosphite derivative is 1.5:1-2.5:1, preferably 2:1. The mass ratio of toluene to the phosphite derivative is ≥6:1. The reaction temperature of intermediate product B with the phosphite derivative is 60-100℃, preferably 80℃, and the reaction time is 2-4h, preferably 3h. The monovalent copper salt is CuCl, the molar ratio of intermediate product C to the monovalent copper salt is 2:1-6:1, preferably 4:1, the reaction temperature of intermediate product C with the monovalent copper salt is 120℃, and the reaction time is 8-12h, preferably 10h. The rotary evaporation temperature is 40-80℃, preferably 60℃. The vacuum drying temperature is 60℃, and the time is 8-12h, preferably 10h.

[0012] A third aspect of the present invention is to provide a nylon composition comprising a nylon resin and the aforementioned cuprous salt antioxidant containing a phosphite structure, wherein the specific method is as follows: After drying the nylon resin in an oven, the antioxidant, lubricant and inorganic filler prepared in this invention are added to the nylon in a certain mass fraction and mixed evenly in a high-speed mixer to complete the premix. Under certain temperature, speed and vacuum conditions, the premix is ​​extruded and granulated using a twin-screw extruder to obtain the antioxidant-stabilized nylon material of this invention.

[0013] Preferably, the nylon resin used in this invention is PA66, the oven temperature is 60-120℃, and the drying time is 4-10 hours; the high-speed mixer speed is 1500 rpm, and the mixing time is 5 minutes. In this invention, the antioxidant is added at 0.6-1.0 wt%, the lubricant is pentaerythritol stearate (PETS) at 0.4 wt%, and the inorganic filler is glass fiber (GF) at 30 wt%. The temperature range of the twin-screw extruder is ±20℃ of the nylon melting point. The screw speed of the twin-screw extruder is 200 rpm. The vacuum degree of the twin-screw extruder is -0.6 bar.

[0014] This invention designs and synthesizes a cuprous salt antioxidant containing a phosphite structure. The phosphite structure provides lone pair electrons on the phosphorus atom to participate in free radical scavenging reactions and decompose hydrogen peroxide; the cuprous ion Cu + It can achieve electron transfer through redox reactions and inhibit oxidation chain reactions; the benzoxazole group containing tert-butyl can protect the active sites in the molecule by means of the steric hindrance effect of tert-butyl, and the conjugated structure of benzoxazole can stabilize free radicals, thus synergistically enhancing the antioxidant effect and helping to improve the compatibility between antioxidants and nylon.

[0015] Compared with the prior art, the present invention has the following beneficial effects: 1) Compared with traditional antioxidants (such as 1010, 168, etc.), the antioxidant of the present invention can significantly improve the thermal oxidation stability of nylon, reduce the decrease in oxidation induction time, reduce the change in melt index, and effectively inhibit the oxidative degradation of plastics during processing and use. 2) The antioxidant of this invention has good compatibility with nylon and will not cause a decrease in the mechanical properties of plastic due to phase separation. On the contrary, it can synergistically improve the mechanical properties of plastic to a certain extent through intermolecular interactions. 3) Nylon with the antioxidant of this invention exhibits minimal color change after processing. The antioxidant continues to exert its antioxidant effect at high processing temperatures, effectively inhibiting thermo-oxidative degradation during plastic processing. Attached Figure Description

[0016] Figure 1 This is a flowchart illustrating the preparation process of the antioxidant of this invention. Detailed Implementation

[0017] The present invention will be further described below with reference to specific embodiments in order to better understand the technical solution. Example

[0018] Preparation of cuprous salt antioxidants: (1) In a 100 mL three-necked flask, add 1.6 g (0.01 mol) of diethyl malonate and 10 mL of toluene, and stir until fully dissolved. Ammonia gas is continuously introduced, and the reaction is carried out at 40 °C for 20 h. After the reaction is complete, cool to room temperature, and then remove the solvent by vacuum distillation at 80 °C to obtain the crude product. The crude product is recrystallized with an ethanol-water mixture and further purified at 80 °C to obtain intermediate product A.

[0019] (2) In a 100 mL three-necked flask, add 3.54 g (0.016 mol) of 3-amino-2,5-di-tert-butylphenol, 15 mL of formic acid, and 7.5 g of polyphosphoric acid, and stir until homogeneous. Heat in an oil bath to 130 °C and reflux for 4 h. After the reaction is complete, cool to room temperature, slowly pour the reaction solution into 50 mL of ice water, stir for 10 min, adjust the pH to approximately 7-8 with saturated sodium carbonate solution; extract with ethyl acetate (3 × 30 mL), combine the organic phases, remove the solvent by vacuum distillation at 80 °C to obtain the crude product, recrystallize the crude product with petroleum ether at 90 °C to obtain intermediate product B.

[0020] (3) Under nitrogen protection, intermediate B (10.0 g, 0.03 mol) and triethyl phosphite (2.49 g, 0.015 mol) were added to a three-necked flask containing 80 mL of toluene. The mixture was heated to 80 °C and stirred for 3 hours to obtain intermediate C. Then, CuCl (0.37 g, 0.00375 mol) was slowly added, and the mixture was heated to 120 °C and the reaction was continued for 10 hours. After the reaction was completed, the mixture was cooled to room temperature, rotary evaporated at 60 °C, and then vacuum dried at 60 °C for 10 h to obtain a cuprous salt antioxidant containing a phosphite structure.

[0021] Preparation of PA66 / GF composite material: PA66 was dried in an oven at 80℃ for 8 hours. PA66 (1376g), glass fiber GF (600g), cuprous salt antioxidant containing phosphite structure (16g), and lubricant PETS (8g) were then uniformly mixed in a high-speed mixer at 1500 rpm for 5 minutes. The extrusion temperatures were set as follows: Zone 1 200℃, Zone 2 260℃, Zone 3 260℃, Zone 4 260℃, Zone 5 255℃, Zone 6 250℃, Zone 7 240℃, Zone 8 250℃, Zone 9 260℃, and the die head 260℃. The screw speed was 200 rpm. Example

[0022] Preparation of cuprous salt antioxidants: (1) In a 100 mL three-necked flask, add 1.6 g (0.01 mol) of diethyl malonate and 10 mL of toluene, and stir until fully dissolved. Ammonia gas is continuously introduced, and the reaction is carried out at 40 °C for 20 h. After the reaction is complete, cool to room temperature, and then remove the solvent by vacuum distillation at 80 °C to obtain the crude product. The crude product is recrystallized with an ethanol-water mixture and further purified at 80 °C to obtain intermediate product A.

[0023] (2) In a 100 mL three-necked flask, add 3.54 g (0.016 mol) of 3-amino-2,5-di-tert-butylphenol, 10 mL of formic acid, and 6.5 g of polyphosphoric acid, and stir until homogeneous. Heat in an oil bath to 120 °C and reflux for 6 h. After the reaction is complete, cool to room temperature, slowly pour the reaction solution into 50 mL of ice water, stir for 10 min, adjust the pH to approximately 7-8 with saturated sodium carbonate solution; extract with ethyl acetate (3 × 30 mL), combine the organic phases, and remove most of the solvent by vacuum distillation at 80 °C to obtain the crude product. Recrystallize the crude product with petroleum ether at 80 °C to obtain intermediate product B.

[0024] (3) Under nitrogen protection, intermediate B (10.0 g, 0.03 mol) and triethyl phosphite (3.32 g, 0.02 mol) were added to a three-necked flask containing 80 mL of toluene. The mixture was heated to 60 °C and stirred for 4 hours to obtain intermediate C. Then, CuCl (0.792 g, 0.008 mol) was slowly added, and the mixture was heated to 120 °C and reacted for another 8 hours. After the reaction was completed, the mixture was cooled to room temperature, rotary evaporated at 60 °C, and then vacuum dried at 60 °C for 8 hours to obtain a cuprous salt antioxidant containing a phosphite structure.

[0025] Preparation of PA66 / GF composite material: PA66 was dried in an oven at 80℃ for 8 hours. PA66 (1380g), glass fiber GF (600g), cuprous salt antioxidant containing phosphite structure (12g), and lubricant PETS (8g) were then uniformly mixed in a high-speed mixer at 1500 rpm for 5 minutes. The extrusion temperatures were set as follows: Zone 1 200℃, Zone 2 260℃, Zone 3 260℃, Zone 4 260℃, Zone 5 255℃, Zone 6 250℃, Zone 7 240℃, Zone 8 250℃, Zone 9 260℃, and the die head 260℃. The screw speed was 200 rpm. Example

[0026] Preparation of cuprous salt antioxidants: (1) In a 100 mL three-necked flask, add 1.6 g (0.01 mol) of diethyl malonate and 10 mL of toluene, and stir until fully dissolved. Ammonia gas is continuously introduced, and the reaction is carried out at 40 °C for 20 h. After the reaction is complete, cool to room temperature, and then remove the solvent by vacuum distillation at 80 °C to obtain the crude product. The crude product is recrystallized with an ethanol-water mixture and further purified at 90 °C to obtain intermediate product A.

[0027] (2) In a 100 mL three-necked flask, add 3.54 g (0.016 mol) of 3-amino-2,5-di-tert-butylphenol, 20 mL of formic acid, and 9 g of polyphosphoric acid, and stir until homogeneous. Heat in an oil bath to 140 °C and reflux for 3 h. After the reaction is complete, cool to room temperature, slowly pour the reaction solution into 50 mL of ice water, stir for 10 min, adjust the pH to approximately 7-8 with saturated sodium carbonate solution; extract with ethyl acetate (3 × 30 mL), combine the organic phases, remove the solvent by vacuum distillation at 90 °C to obtain the crude product, recrystallize the crude product with petroleum ether at 100 °C to obtain intermediate product B.

[0028] (3) Under nitrogen protection, intermediate B (10.0 g, 0.03 mol) and triethyl phosphite (1.992 g, 0.012 mol) were added to a three-necked flask containing 80 mL of toluene. The mixture was heated to 100 °C and stirred for 2 hours to obtain intermediate C. Then, CuCl (0.0495 g, 0.005 mol) was slowly added, and the mixture was heated to 120 °C and the reaction was continued for 12 hours. After the reaction was completed, the mixture was cooled to room temperature, rotary evaporated at 80 °C, and then vacuum dried at 60 °C for 12 h to obtain a cuprous salt antioxidant containing a phosphite structure.

[0029] Preparation of PA66 / GF composite material: PA66 was dried in an oven at 80℃ for 8 hours. PA66 (1372g), glass fiber GF (600g), cuprous salt antioxidant containing phosphite structure (20g), and lubricant (8g) were then uniformly mixed in a high-speed mixer at 1500 rpm for 5 minutes. The extrusion temperatures were set as follows: Zone 1 200℃, Zone 2 260℃, Zone 3 260℃, Zone 4 260℃, Zone 5 255℃, Zone 6 250℃, Zone 7 240℃, Zone 8 250℃, Zone 9 260℃, and the die head 260℃. The screw speed was 200 rpm. Example

[0030] Preparation of cuprous salt antioxidants: (1) In a 100 mL three-necked flask, add 1.6 g (0.01 mol) of diethyl malonate and 10 mL of toluene, and stir until fully dissolved. Ammonia gas is continuously introduced, and the reaction is carried out at 500 °C for 18 h. After the reaction is complete, cool to room temperature, and then remove the solvent by vacuum distillation at 80 °C to obtain the crude product. The crude product is recrystallized with an ethanol-water mixture and further purified at 80 °C to obtain intermediate product A.

[0031] (2) In a 100 mL three-necked flask, add 3.54 g (0.016 mol) of 3-amino-2,5-di-tert-butylphenol, 10 mL of formic acid, and 7.5 g of polyphosphoric acid, and stir until homogeneous. Heat in an oil bath to 130 °C and reflux for 4 h. After the reaction is complete, cool to room temperature, slowly pour the reaction solution into 50 mL of ice water, stir for 10 min, adjust the pH to approximately 7-8 with saturated sodium carbonate solution; extract with ethyl acetate (3 × 30 mL), combine the organic phases, remove the solvent by vacuum distillation at 90 °C, recrystallize the crude product with petroleum ether at 90 °C to obtain intermediate product B.

[0032] (3) Under nitrogen protection, intermediate B (10.0 g, 0.03 mol) and triethyl phosphite (2.49 g, 0.015 mol) were added to a three-necked flask containing 80 mL of toluene. The mixture was heated to 80 °C and stirred for 3 hours to obtain intermediate C. Then, CuCl (0.37 g, 0.00375 mol) was slowly added, and the mixture was heated to 120 °C and the reaction was continued for 10 hours. After the reaction was completed, the mixture was cooled to room temperature, rotary evaporated at 60 °C, and then vacuum dried at 60 °C for 10 h to obtain a cuprous salt antioxidant containing a phosphite structure.

[0033] Preparation of PA66 / GF composite material: PA66 was dried in an oven at 80℃ for 8 hours. PA66 (1376g), glass fiber GF (600g), cuprous salt antioxidant containing phosphite structure (16g), and lubricant PETS (8g) were then uniformly mixed in a high-speed mixer at 1500 rpm for 5 minutes. The extrusion temperatures were set as follows: Zone 1 200℃, Zone 2 260℃, Zone 3 260℃, Zone 4 260℃, Zone 5 255℃, Zone 6 250℃, Zone 7 240℃, Zone 8 250℃, Zone 9 260℃, and the die head 260℃. The screw speed was 200 rpm. Example

[0034] Preparation of cuprous salt antioxidants: (1) In a 100 mL three-necked flask, add 1.6 g (0.01 mol) of diethyl malonate and 10 mL of toluene, and stir until fully dissolved. Ammonia gas is continuously introduced, and the reaction is carried out at 45 °C for 20 h. After the reaction is complete, cool to room temperature, and then remove the solvent by vacuum distillation at 80 °C to obtain the crude product. The crude product is recrystallized with an ethanol-water mixture and further purified at 100 °C to obtain intermediate product A.

[0035] (2) In a 100 mL three-necked flask, add 3.54 g (0.016 mol) of 3-amino-2,5-di-tert-butylphenol, 10 mL of formic acid, and 7.5 g of polyphosphoric acid, and stir until homogeneous. Heat in an oil bath to 130 °C and reflux for 4 h. After the reaction is complete, cool to room temperature, slowly pour the reaction solution into 50 mL of ice water, stir for 10 min, adjust the pH to approximately 7-8 with saturated sodium carbonate solution; extract with ethyl acetate (3 × 30 mL), combine the organic phases, remove the solvent by vacuum distillation at 100 °C, recrystallize the crude product with petroleum ether at 90 °C to obtain intermediate product B.

[0036] (3) Under nitrogen protection, intermediate B (10.0 g, 0.03 mol) and trimethyl phosphite (1.86 g, 0.015 mol) were added to a three-necked flask containing 80 mL of toluene. The mixture was heated to 80 °C and stirred for 3 hours to obtain intermediate C. Then, CuCl (0.37 g, 0.00375 mol) was slowly added, and the mixture was heated to 120 °C and reacted for another 10 hours. After the reaction was completed, the mixture was cooled to room temperature, rotary evaporated at 60 °C, and then vacuum dried at 60 °C for 10 h to obtain a cuprous salt antioxidant containing a phosphite structure.

[0037] Preparation of PA66 / GF composite material: PA66 was dried in an oven at 80℃ for 8 hours. PA66 (1376g), glass fiber GF (600g), cuprous salt antioxidant containing phosphite structure (16g), and lubricant PETS (8g) were then uniformly mixed in a high-speed mixer at 1500 rpm for 5 minutes. The extrusion temperatures were set as follows: Zone 1 200℃, Zone 2 260℃, Zone 3 260℃, Zone 4 260℃, Zone 5 255℃, Zone 6 250℃, Zone 7 240℃, Zone 8 250℃, Zone 9 260℃, and the die head 260℃. The screw speed was 200 rpm. Example

[0038] Preparation of cuprous salt antioxidants: (1) In a 100 mL three-necked flask, add 1.6 g (0.01 mol) of diethyl malonate and 10 mL of toluene, and stir until fully dissolved. Ammonia gas is continuously introduced, and the reaction is carried out at 40 °C for 20 h. After the reaction is complete, cool to room temperature, and then remove the solvent by vacuum distillation at 80 °C to obtain the crude product. The crude product is recrystallized with an ethanol-water mixture and further purified at 80 °C to obtain intermediate product A.

[0039] (2) In a 100 mL three-necked flask, add 3.54 g (0.016 mol) of 3-amino-2,5-di-tert-butylphenol, 10 mL of formic acid, and 7.5 g of polyphosphoric acid, and stir until homogeneous. Heat in an oil bath to 130 °C and reflux for 4 h. After the reaction is complete, cool to room temperature, slowly pour the reaction solution into 50 mL of ice water, stir for 10 min, adjust the pH to approximately 7-8 with saturated sodium carbonate solution; extract with ethyl acetate (3 × 30 mL), combine the organic phases, remove the solvent by vacuum distillation at 80 °C, and recrystallize the crude product with petroleum ether at 90 °C to obtain intermediate product B.

[0040] (3) Under nitrogen protection, intermediate B (10.0 g, 0.03 mol) and trimethyl phosphite (1.86 g, 0.015 mol) were added to a three-necked flask containing 80 mL of toluene. The mixture was heated to 80 °C and stirred for 3 hours to obtain intermediate C. Then, CuCl (0.2475 g, 0.0025 mol) was slowly added, and the mixture was heated to 120 °C and the reaction was continued for 10 hours. After the reaction was completed, the mixture was cooled to room temperature, rotary evaporated at 60 °C, and then vacuum dried at 60 °C for 10 h to obtain a cuprous salt antioxidant containing a phosphite structure.

[0041] Preparation of PA66 / GF composite material: PA66 was dried in an oven at 80℃ for 8 hours. PA66 (1376g), glass fiber GF (600g), cuprous salt antioxidant containing phosphite structure (16g), and lubricant PETS (8g) were then uniformly mixed in a high-speed mixer at 1500 rpm for 5 minutes. The extrusion temperatures were set as follows: Zone 1 200℃, Zone 2 260℃, Zone 3 260℃, Zone 4 260℃, Zone 5 255℃, Zone 6 250℃, Zone 7 240℃, Zone 8 250℃, Zone 9 260℃, and the die head 260℃. The screw speed was 200 rpm.

[0042] The flowcharts for preparing cuprous salt antioxidants in the above embodiments are as follows: Figure 1 As shown.

[0043] Comparative Example 1 The formulation of this comparative example is as follows (by mass fraction): PA66 resin 68.8 wt%, glass fiber GF 30%, antioxidant 1010 0.8 wt%, and lubricant PETS 0.4 wt%. The preparation process is the same as in Example 1. Comparative Example 2 The formulation of this comparative example is as follows: by mass fraction, PA66 resin 68.8 wt%, glass fiber GF 30%, antioxidant 168 0.8 wt%, and lubricant PETS 0.4 wt%. The preparation process is the same as that of the example.

[0044] Performance test results of nylon compositions prepared in each embodiment and comparative example Performance testing: The tensile strength and whiteness of PA66 in the examples and comparative examples before and after heat aging (170℃) were tested in accordance with the national standards GB / T 1040 Determination of tensile properties, GB / T 25278 Determination of flowability of plastics by capillary and slit rheometer, and GB / T 2913-1982 Test method for whiteness of plastics. The results are shown in Table 1 and Table 2. Table 1: Tensile strength test results of PA66 / GF composite materials at different heat aging times at 170℃ (unit: MPa) sample 0h 2h 4h 6h 8h Example 1 170 157 139 113 92 Example 2 168 152 133 107 88 Example 3 166 152 130 106 87 Example 4 162 141 120 98 78 Example 5 166 148 129 107 87 Example 6 162 145 124 103 82 Comparative Example 1 167 133 108 91 71 Comparative Example 2 164 139 117 99 74 Table 2: Whiteness test results of PA66 / GF composite materials at different thermal aging times at 170℃ sample 0h 2h 4h 6h 8h Example 1 88.7 82.6 77.2 71.4 63.2 Example 2 87.9 82.3 76.4 70.1 61.8 Example 3 88.1 81.7 75.8 69.1 60.8 Example 4 88.9 80.6 74.1 66.3 59.2 Example 5 88.7 82.4 76.2 69.8 61.2 Example 6 88.6 81.4 76.1 69.4 60.6 Comparative Example 1 88.3 79.3 73.6 62.1 58.7 Comparative Example 2 88.4 79.9 73.8 61.4 58.1 As can be seen from the results in Tables 1 and 2, by adding the antioxidant provided by this invention, the prepared PA66 / GF composite material has excellent tensile strength and processing fluidity. After heat aging at 170℃ for 8 hours, the tensile strength can reach up to 92 MPa and the whiteness can reach up to 63.2.

Claims

1. A cuprous salt antioxidant containing a phosphite structure, characterized in that, The structure of this antioxidant is shown in formula (Ⅰ): （Ⅰ）。 2. A method for preparing the cuprous salt antioxidant containing a phosphite structure as described in claim 1, characterized in that, Includes the following steps: 1) Diethyl malonate and solvent were reacted in the presence of ammonia. After the reaction was completed, the mixture was cooled to room temperature and the solvent was removed by vacuum distillation to obtain a crude product. The crude product was dissolved in an ethanol-water mixed solvent, heated and then cooled. The product was recrystallized for further purification to obtain intermediate product A. 2) 3-Amino-2,5-di-tert-butylphenol and intermediate A undergo a condensation cyclization reaction in the presence of a catalyst in an acidic solvent to obtain intermediate B; 3) React intermediate B with a phosphite derivative in an organic solvent to generate intermediate C, then add a monovalent copper salt for coordination reaction to obtain a cuprous salt antioxidant containing a phosphite structure.

3. The method for preparing cuprous salt antioxidants containing phosphite structure as described in claim 2, wherein the solvent in step 1) is toluene, the mass ratio of toluene to diethyl malonate is ≥3:1, the reaction temperature is 40-50℃, the reaction time is 15-25h, the vacuum distillation temperature is 80-100℃, and the recrystallization temperature is 60-100℃.

4. The method for preparing a cuprous salt antioxidant containing a phosphite structure as described in claim 2, characterized in that, In step 2), the catalyst is polyphosphoric acid, the acidic solvent is formic acid, the reaction temperature is 120-140℃, and the reaction time is 3-6h.

5. The method for preparing a cuprous salt antioxidant containing a phosphite structure as described in claim 2, characterized in that, In step 3), the phosphite derivative is one or more of trimethyl phosphite and triethyl phosphite, the organic solvent is toluene, the molar ratio of intermediate product B to phosphite derivative is 1.5-2.5:1, and the mass ratio of toluene to phosphite derivative is ≥6:

1.

6. The method for preparing a cuprous salt antioxidant containing a phosphite structure as described in claim 2, characterized in that, In step 3), the reaction temperature of intermediate product B with the phosphite derivative is 60-100℃, and the reaction time is 2-4h.

7. The method for preparing a cuprous salt antioxidant containing a phosphite structure as described in claim 2, characterized in that, In step 3), the monovalent copper salt is CuCl, the molar ratio of intermediate product C to monovalent copper salt is 2-6:1, the reaction temperature of intermediate product C and monovalent copper salt is 120℃, and the reaction time is 8-12h.

8. A nylon composition, characterized in that, Includes nylon resin and cuprous salt antioxidants containing phosphite structures as described in any one of claims 1-7.

9. The nylon composition according to claim 8, characterized in that, The antioxidant is added at an amount of 0.6-1.0 wt% of the nylon composition, the nylon resin is PA66, and the nylon composition also includes glass fiber and lubricant.

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