PA6T modified material with high crystallization rate as well as preparation method and application of PA6T modified material

Abstract

The invention provides a PA6T modified material. The PA6T modified material comprises the following components in parts by weight: 50-80 parts of PA6T resin; 5-15 parts of a crystallization promoter; 3-10 parts of a flow modifier; 5-20 parts of a nano reinforcing filler and 0.1-1 part of an antioxidant; 0.5-2 parts of a lubricant and a release agent; the crystallization accelerant is sodium sulfonate and a carbon nano tube. The crystallization temperature of the PA6T modified material is larger than or equal to 240 DEG C, the melt flow index (320 DEG C / 1.2 KG) is larger than or equal to 60 g / 10 min, the heat distortion temperature is larger than or equal to 260 DEG C, and the PA6T modified material is suitable for rapid cold mold forming of a thin-wall multi-mold-cavity LED reflection support. According to the material, the injection molding cooling time can be greatly shortened, the mold sticking risk is reduced, the production efficiency is improved, meanwhile, excellent high-temperature resistance is kept, and the requirement of a reflow soldering process is met.

Description

Technical Field

[0001] This invention relates to the field of materials technology, and in particular to a high crystallization rate PA6T modified material, its preparation method, and its application. Background Technology

[0002] With the rapid development of LED lighting technology, LED devices are moving towards miniaturization, high power density, and high luminous efficacy, which places higher demands on LED packaging materials. As a key component of LED packaging, the reflector bracket not only needs excellent light reflection performance but also must withstand high-temperature reflow soldering processes (typically peak temperatures exceeding 260℃), while simultaneously meeting the requirements for thin-walled and high-precision injection molding. Currently, the mainstream material for LED reflector brackets is semi-aromatic polyamide, such as PA10T, PA9T, and PA6T copolymers. These materials have high heat distortion temperatures (HDT>260℃) and good mechanical strength, meeting the requirements of traditional LED packaging. However, with the upgrading of market demands and the continuous shrinking of LED chip sizes (such as the application of MiniLED and MicroLED), the wall thickness of the reflector bracket has further decreased. Simultaneously, to improve production efficiency, injection molding manufacturers have increased the number of cavities from below 1000 to above 2000, and are gradually adopting cold molding (mold temperature <80℃) instead of high-mold molding (mold temperature >120℃) to reduce energy consumption and production costs.

[0003] However, existing semi-aromatic polyamides (such as PA6T) face the following key problems during cold molding: (1) Low crystallization temperature and slow crystallization rate: The crystallization temperature of PA6T is usually below 220℃, and the cooling rate is insufficient under cold molding conditions, resulting in a longer molding cycle and reduced production efficiency; (2) Incomplete cooling leads to product defects: If the material is demolded before it has fully crystallized, problems such as sticking, warping, and strip pulling are likely to occur, affecting the product yield; (3) Insufficient fluidity: Thin-wall injection molding requires materials with higher melt fluidity (>50g / 10min), but traditional PA6T often fails to meet the fluidity requirements while ensuring high heat resistance. Currently, the industry usually improves moldability by increasing the mold temperature or extending the cooling time, but this increases energy consumption and reduces production efficiency. In addition, some studies have attempted to adjust the crystallization properties of PA6T through copolymerization modification (such as introducing PA66 or PA6 units), but this often comes at the cost of sacrificing heat resistance.

[0004] Therefore, how to improve the crystallization rate, flowability and demolding performance of PA6T while maintaining its high heat resistance, so as to adapt it to the needs of thin-walled, multi-cavity, cold-mold high-speed molding, has become a key challenge in the research and development of LED reflector bracket materials. Summary of the Invention

[0005] In view of this, the technical problem to be solved by the present invention is to provide a PA6T modified material with a high crystallization rate. The composite material provided by the present invention has high crystallization temperature, crystallization rate, and melt flowability. This material can significantly shorten the injection molding cooling time, reduce the risk of mold sticking, and improve production efficiency, while maintaining excellent high-temperature resistance to meet the requirements of reflow soldering processes.

[0006] To address the aforementioned problems, this invention develops a high-crystallization-rate PA6T modified material by optimizing the synergistic system of nucleating agents, flow modifiers, and nanofillers. This material can achieve rapid molding under cold molding conditions while maintaining excellent heat resistance and mechanical properties, meeting the industrial production needs of next-generation LED reflector brackets.

[0007] This invention provides a PA6T modified material, comprising the following components in parts by weight:

[0008] 50-80 parts of PA6T resin;

[0009] 5-15 parts of crystallization accelerator;

[0010] 3-10 parts of flow improver;

[0011] 5-20 parts of nano-reinforced filler

[0012] Antioxidant 0.1 to 1 part;

[0013] 0.5 to 2 parts of lubricant and release agent;

[0014] The crystallization promoter is sodium sulfonate and carbon nanotubes.

[0015] The high crystallization rate PA6T modified material provided by this invention comprises 50 to 80 parts by weight of PA6T resin; specifically, it can be 50 parts, 51 parts, 52 parts, 53 parts, 54 parts, 55 parts, 56 parts, 57 parts, 58 parts, 59 parts, 60 parts, 61 parts, 62 parts, 63 parts, 64 parts, 65 parts, 66 parts, 67 parts, 68 parts, 69 parts, 70 parts, 71 parts, 72 parts, 73 parts, 74 parts, 75 parts, 76 parts, 77 parts, 78 parts, 79 parts, or 80 parts.

[0016] The high crystallization rate PA6T modified material provided by the present invention includes 5 to 15 parts by weight of crystallization promoter; specifically, it can be 5 parts by weight, 6 parts by weight, 7 parts by weight, 8 parts by weight, 9 parts by weight, 10 parts by weight, 11 parts by weight, 12 parts by weight, 13 parts by weight, 14 parts by weight, or 15 parts by weight.

[0017] The crystallization promoter is sodium sulfonate and carbon nanotubes.

[0018] According to the present invention, the mass ratio of the sodium sulfonate salt to the carbon nanotubes is 1:1 to 1:3.

[0019] In some specific embodiments, the mass ratio of the sodium sulfonate salt to the carbon nanotubes is 1:1, 1:2, or 1:3.

[0020] The sodium sulfonate salt of the present invention is selected from one or more combinations of sodium p-toluenesulfonate, sodium benzenesulfonate, sodium dodecylbenzenesulfonate or sodium 2-naphthalenesulfonate, preferably sodium p-toluenesulfonate or sodium benzenesulfonate;

[0021] The carbon nanotubes are selected from single-walled carbon nanotubes or multi-walled carbon nanotubes, with multi-walled carbon nanotubes being preferred. The high crystallization rate PA6T modified material provided by the present invention includes 3 to 10 parts by weight of flow modifier; specifically, it can be 3 parts by weight, 4 parts by weight, 5 parts by weight, 6 parts by weight, 7 parts by weight, 8 parts by weight, 9 parts by weight, or 10 parts by weight.

[0022] The flowability improver of this invention is selected from low molecular weight polysiloxane, maleic anhydride-grafted polyolefin, or a combination thereof; wherein, the low molecular weight polysiloxane may be one or more of methyl silicone oil, phenyl silicone oil, or amino-modified silicone oil; the maleic anhydride-grafted polyolefin is selected from one or more of maleic anhydride-grafted polyethylene, maleic anhydride-grafted polypropylene, or maleic anhydride-grafted ethylene-octene copolymer.

[0023] The high crystallization rate PA6T modified material provided by this invention includes 5 to 20 parts by weight of nano-reinforced filler; specifically, it can be 5 parts by weight, 6 parts by weight, 7 parts by weight, 8 parts by weight, 9 parts by weight, 10 parts by weight, 11 parts by weight, 12 parts by weight, 13 parts by weight, 14 parts by weight, 15 parts by weight, 16 parts by weight, 17 parts by weight, 18 parts by weight, 19 parts by weight, or 20 parts by weight.

[0024] The nano-reinforced filler described in this invention is one or both of nano-silica or boron nitride that have been surface-modified with a silane coupling agent.

[0025] The particle size of the nano-reinforced filler is 20–50 nm. Specifically, it can be 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, 45 nm, or 50 nm.

[0026] Silicon dioxide modification steps:

[0027] 1. Dry 100g of SiO2 at 120℃ for 4 hours to remove adsorbed water.

[0028] Add 2.5g KH-560 to an ethanol / water mixture (500mL, volume ratio 8:2), adjust the pH to 4-5 with acetic acid, and stir for 30min to hydrolyze.

[0029] 3. Add SiO2 to the hydrolysate from step 2 and stir at 80°C for 4 hours.

[0030] 4. Centrifugation → Washing with ethanol 3 times → Vacuum drying at 80℃ for 12 hours → Sieving (particle size 20-50 nm)

[0031] Boron nitride modification steps:

[0032] 1. Immerse 100g of boron nitride in a concentrated H2SO4 / HNO3 (3:1) mixed acid solution and treat at 80℃ for 2h to introduce surface -OH groups.

[0033] Dissolve 2.8g KH-560 in ethanol (500mL), add 25mL water, and hydrolyze for 30min.

[0034] 3. Add the hydroxylated BN obtained in step 1 to the hydrolysate obtained in step 2, and reflux at 85°C for 5 hours.

[0035] 4. The product is obtained by washing with ethanol, filtering, vacuum drying at 100℃, grinding and sieving (particle size 20-50 nm).

[0036] The high crystallization rate PA6T modified material provided by the present invention includes 0.1 to 1 part of antioxidant; specifically, it can be 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, or 1.0 parts by weight.

[0037] The antioxidant described in this invention is selected from one or more of the following: pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, N,N'-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl]hexamethylenediamine, tris[2,4-di-tert-butylphenyl]phosphite, or bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite;

[0038] The high crystallization rate PA6T modified material provided by this invention includes 0.5 to 2 parts of lubricant and release agent; specifically, it can be 0.5 parts, 0.6 parts, 0.7 parts, 0.8 parts, 0.9 parts, 1.0 parts, 1.1 parts, 1.2 parts, 1.3 parts, 1.4 parts, 1.5 parts, 1.6 parts, 1.7 parts, 1.8 parts, 1.9 parts, or 2.0 parts.

[0039] The lubricant and release agent of this invention are compounded at a mass ratio of 2:1.

[0040] The lubricant of this invention is selected from one or more combinations of stearic acid, zinc / calcium stearate, lignite wax, glyceryl monostearate, pentaerythritol stearate, polydimethylsiloxane, and silicone masterbatch; the mold release agent is selected from one or more combinations of zinc / magnesium stearate, ethylene bis-stearamide, fluorinated mold release agent, and polyether modified silicone oil.

[0041] The PA6T modified material prepared by this invention has a crystallization temperature ≥240℃, a melt flow index ≥60g / 10min, and a heat distortion temperature ≥260℃.

[0042] This invention provides a method for preparing the PA6T modified material described in the above technical solution, comprising:

[0043] A) PA6T resin, crystallization accelerator, flowability improver, nano-reinforcing filler, antioxidant, lubricant and release agent are premixed to obtain a premix;

[0044] C) Melt-blend the premix, extrude and granulate, and dry to obtain the final product.

[0045] This invention premixes PA6T resin, crystallization accelerator, flowability improver, nano-reinforcing filler, antioxidant, lubricant and release agent to obtain a premix.

[0046] The components and proportions described above have been clearly described in this invention and will not be repeated here.

[0047] The premixing time described in this invention is 10 minutes.

[0048] The premix is ​​melt-blended, extruded and granulated to obtain the final product.

[0049] The melt blending described in this invention is carried out using a twin-screw extruder in a temperature range of 290 to 320°C, specifically 290°C, 295°C, 300°C, 305°C, 310°C, 315°C, and 320°C.

[0050] The screw speed is 300 rpm.

[0051] The granulation method described in this invention is underwater pelletizing.

[0052] No drying is required after extrusion granulation; the granules can be collected directly.

[0053] This invention provides an LED reflector bracket, comprising the high crystallization rate PA6T modified material described in the above technical solution.

[0054] This invention provides an application of the PA6T modified material described in any one of the above technical solutions in the preparation of LED reflector brackets.

[0055] The PA6T modified material described in this invention is suitable for rapid cold molding of thin-walled, multi-cavity LED reflector brackets.

[0056] This invention discloses a high-crystallization-rate PA6T modified material and its application in LED reflector brackets. The modified material comprises PA6T resin, a crystallization promoter, a flowability improver, and nano-reinforcing fillers. Through optimized component formulation, the material's crystallization temperature, crystallization rate, and melt flowability are significantly improved. This invention, through innovative material formulation design, successfully solves a series of technical challenges faced by traditional PA6T materials in LED reflector bracket applications, providing an ideal material solution for the LED industry's development towards smaller sizes and higher efficiency.

[0057] This invention provides a modified PA6T material, comprising the following components by weight: 50-80 parts PA6T resin; 5-15 parts crystallization accelerator; 3-10 parts flow modifier; 5-20 parts nano-reinforcing filler; 0.1-1 parts antioxidant; and 0.5-2 parts lubricant and release agent. The crystallization accelerator is sodium sulfonate and carbon nanotubes. The modified PA6T material of this invention has a crystallization temperature ≥240℃, a melt flow index (320℃ / 1.2KG) ≥60g / 10min, and a heat distortion temperature ≥260℃, making it suitable for rapid cold molding of thin-walled, multi-cavity LED reflector brackets. This material can significantly shorten injection molding cooling time, reduce the risk of mold sticking, and improve production efficiency, while maintaining excellent high-temperature resistance to meet reflow soldering process requirements. Detailed Implementation

[0058] This invention provides a high-crystallization-rate PA6T modified material, its preparation method, and its applications. Those skilled in the art can refer to the content of this document and appropriately modify the process parameters to achieve the desired result. It should be particularly noted that all similar substitutions and modifications are obvious to those skilled in the art and fall within the scope of this invention. The methods and applications of this invention have been described through preferred embodiments. Those skilled in the art can clearly modify or appropriately change and combine the methods and applications described herein without departing from the content, spirit, and scope of this invention to realize and apply the technology of this invention.

[0059] It should be understood that the expression “one or more of…” individually includes each of the objects described after the expression, as well as various different combinations of two or more of the described objects, unless otherwise understood from the context and usage. The expression “and / or” combined with three or more described objects should be understood to have the same meaning, unless otherwise understood from the context.

[0060] The terms “including,” “having,” or “containing,” including the use of their grammatical synonyms, should generally be understood as open-ended and non-restrictive, for example, not excluding other unstated elements or steps, unless otherwise specifically stated or understood from the context.

[0061] In this application, the term "and / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. A and B can be singular or plural.

[0062] In this application, "at least one" means one or more, and "more than one" means two or more. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or multiple items.

[0063] It should be understood that the order of the steps or the order in which certain actions are performed is not important as long as the invention remains operational. Furthermore, two or more steps or actions can be performed simultaneously.

[0064] The use of any and all instances or exemplary language such as “e.g.” or “including” in this document is merely intended to better illustrate the invention and is not intended to limit the scope of the invention unless the claims are made. No language in this specification should be construed as indicating that any unclaimed element is essential to the practice of the invention.

[0065] Furthermore, the numerical ranges and parameters used to define the present invention are approximate values, and the relevant values ​​in the specific embodiments have been presented as precisely as possible. However, any value inevitably contains standard deviations due to individual test methods. Therefore, unless explicitly stated otherwise, it should be understood that all ranges, quantities, values, and percentages used in this disclosure are modified with the word "approximately." Here, "approximately" generally means an actual value within plus or minus 10%, 5%, 1%, or 0.5% of a particular value or range.

[0066] It should be understood that in the various embodiments of this application, the order of the above processes does not imply the order of execution. Some or all steps may be executed in parallel or sequentially. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0067] The embodiments and comparative examples of this invention describe some examples, in which the embodiments illustrate certain implementations of the invention. However, this does not mean that the effects of the invention can only be achieved in these examples.

[0068] To further illustrate the present invention, the following detailed description, in conjunction with embodiments, provides a high crystallization rate PA6T modified material, its preparation method, and its applications.

[0069] In this embodiment of the invention:

[0070] Silicon dioxide modification steps:

[0071] 5. Dry 100g of SiO2 at 120℃ for 4 hours to remove adsorbed water.

[0072] Add 6.5g of KH-560 to an ethanol / water mixture (500mL, volume ratio 8:2), adjust the pH to 4-5 with acetic acid, and stir for 30 minutes to hydrolyze.

[0073] 7. Add SiO2 to the hydrolysate from step 2 and stir at 80°C for 4 hours.

[0074] 8. Centrifugation → Washing with ethanol 3 times → Vacuum drying at 80℃ for 12 hours → Sieving (particle size 20-50 nm)

[0075] Boron nitride modification steps:

[0076] 5. Immerse 100g of boron nitride in a concentrated H2SO4 / HNO3 (3:1) mixed acid solution and treat at 80℃ for 2h to introduce surface -OH groups.

[0077] Dissolve 6.8g KH-560 in ethanol (500mL), add 25mL water, and hydrolyze for 30min.

[0078] 7. Add the hydroxylated BN obtained in step 1 to the hydrolysate obtained in step 2, and reflux at 85°C for 5 hours.

[0079] 8. The product is obtained by washing with ethanol, filtering, vacuum drying at 100℃, grinding and sieving (particle size 20-50 nm).

[0080] Example 1:

[0081] The preparation method of the PA6T modified material includes the following steps:

[0082] (1) Vacuum dry 60 kg of PA6T resin matrix at 100 °C for 5 hours;

[0083] (2) 10 kg of crystallization promoter (obtained by compounding sodium p-toluenesulfonate and multi-walled carbon nanotubes in a mass ratio of 1:2), 13 kg of flow modifier (obtained by compounding low molecular weight phenyl silicone oil and maleic anhydride grafted ethylene-octene copolymer in a mass ratio of 1:1), 15 kg of nano-reinforcing filler (obtained by compounding nano-silica modified by silane coupling agent KH-560 and boron nitride modified by silane coupling agent KH-560 in a mass ratio of 2:1), 0.5 kg of antioxidant (obtained by compounding N,N'-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl]hexamethylenediamine and tris[2,4-di-tert-butylphenyl]phosphite in a mass ratio of 4:3) and 1.5 kg of lubricant and release agent (obtained by compounding calcium stearate and ethylene bis-stearamide in a mass ratio of 2:1) are premixed in a high-speed mixer for 10 minutes;

[0084] (3) Add the dried PA6T resin matrix from step (1) and the premix from step (2) to a twin-screw extruder, set the temperature of zone 1 to 300°C, zone 2 to 310°C, zone 3 to 310°C, and the die temperature to 290°C for melt blending, and the screw speed to 300 rpm.

[0085] (4) Extrusion granulation to obtain modified PA6T material;

[0086] Example 2:

[0087] The preparation method of the PA6T modified material includes the following steps:

[0088] (1) Vacuum dry 70 kg of PA6T resin matrix at 100 °C for 5 hours;

[0089] (2) 8 kg of crystallization promoter (obtained by compounding sodium p-toluenesulfonate and multi-walled carbon nanotubes in a mass ratio of 1:2), 10 kg of flowability improver (obtained by compounding low molecular weight phenyl silicone oil and maleic anhydride grafted ethylene-octene copolymer in a mass ratio of 1:1), 10 kg of nano-reinforcing filler (obtained by compounding nano-silica modified by silane coupling agent KH-560 and boron nitride modified by silane coupling agent KH-560 in a mass ratio of 2:1), 0.5 kg of antioxidant (obtained by compounding N,N'-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl]hexamethylenediamine and tris[2,4-di-tert-butylphenyl]phosphite in a mass ratio of 4:3), and 1.5 kg of lubricant and release agent (obtained by compounding calcium stearate and ethylene bis-stearamide in a mass ratio of 2:1) were premixed in a high-speed mixer for 10 minutes.

[0090] (3) Add the dried PA6T resin matrix from step (1) and the premix from step (2) to a twin-screw extruder, set the temperature of zone 1 to 300°C, zone 2 to 310°C, zone 3 to 310°C, and the die temperature to 290°C for melt blending, and the screw speed to 300 rpm.

[0091] (4) Extrusion granulation to obtain modified PA6T material;

[0092] Example 3:

[0093] The preparation method of the PA6T modified material includes the following steps:

[0094] (1) Vacuum dry 75kg of PA6T resin matrix at 100℃ for 5 hours;

[0095] (2) 7 kg of crystallization promoter (obtained by compounding sodium p-toluenesulfonate and multi-walled carbon nanotubes in a mass ratio of 1:2), 8 kg of flowability improver (obtained by compounding low molecular weight phenyl silicone oil and maleic anhydride grafted ethylene-octene copolymer in a mass ratio of 1:1), 8 kg of nano-reinforcing filler (obtained by compounding nano-silica modified by silane coupling agent KH-560 and boron nitride modified by silane coupling agent KH-560 in a mass ratio of 2:1), 0.5 kg of antioxidant (obtained by compounding N,N'-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl]hexamethylenediamine and tris[2,4-di-tert-butylphenyl]phosphite in a mass ratio of 4:3) and 1.5 kg of lubricant and release agent (obtained by compounding calcium stearate and ethylene bis-stearamide in a mass ratio of 2:1) were premixed in a high-speed mixer for 10 minutes;

[0096] (3) Add the dried PA6T resin matrix from step (1) and the premix from step (2) to a twin-screw extruder, set the temperature of zone 1 to 300°C, zone 2 to 310°C, zone 3 to 310°C, and the die temperature to 290°C for melt blending, and the screw speed to 300 rpm.

[0097] (4) Extrusion granulation to obtain modified PA6T material;

[0098] Comparative Example 1:

[0099] The selected PA6T resin was extruded and pelletized separately under the same extrusion conditions, serving as Comparative Example 1 and Comparative Example 2:

[0100] The preparation method of the PA6T modified material includes the following steps:

[0101] (1) Vacuum dry 60 kg of PA6T resin matrix at 100 °C for 5 hours;

[0102] (2) 10 kg of crystallization accelerator (sodium p-toluenesulfonate), 13 kg of flow modifier (obtained by compounding low molecular weight phenyl silicone oil and maleic anhydride grafted ethylene-octene copolymer in a mass ratio of 1:1), 15 kg of nano-reinforcing filler (obtained by compounding nano-silica modified by silane coupling agent KH-560 and boron nitride modified by silane coupling agent KH-560 in a mass ratio of 2:1), 0.5 kg of antioxidant (obtained by compounding N,N'-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl]hexamethylenediamine and tris[2,4-di-tert-butylphenyl]phosphite in a mass ratio of 4:3), and 1.5 kg of lubricant and release agent (obtained by compounding calcium stearate and ethylene bis-stearamide in a mass ratio of 2:1) are premixed in a high-speed mixer for 10 minutes;

[0103] (3) Add the dried PA6T resin matrix from step (1) and the premix from step (2) to a twin-screw extruder, set the temperature of zone 1 to 300°C, zone 2 to 310°C, zone 3 to 310°C, and the die temperature to 290°C for melt blending, and the screw speed to 300 rpm.

[0104] (4) Extrusion granulation to obtain modified PA6T material;

[0105] Comparative Example 3:

[0106] The preparation method of the PA6T modified material includes the following steps:

[0107] (1) Vacuum dry 60 kg of PA6T resin matrix at 100 °C for 5 hours;

[0108] (2) 10 kg of crystallization promoter (multi-walled carbon nanotubes), 13 kg of flow modifier (obtained by compounding low molecular weight phenyl silicone oil and maleic anhydride grafted ethylene-octene copolymer in a mass ratio of 1:1), 15 kg of nano-reinforcing filler (obtained by compounding nano-silica modified by silane coupling agent KH-560 and boron nitride modified by silane coupling agent KH-560 in a mass ratio of 2:1), 0.5 kg of antioxidant (obtained by compounding N,N'-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl]hexamethylenediamine and tris[2,4-di-tert-butylphenyl]phosphite in a mass ratio of 4:3), and 1.5 kg of lubricant and release agent (obtained by compounding calcium stearate and ethylene bis-stearamide in a mass ratio of 2:1) are premixed in a high-speed mixer for 10 minutes;

[0109] (3) Add the dried PA6T resin matrix from step (1) and the premix from step (2) to a twin-screw extruder, set the temperature of zone 1 to 300°C, zone 2 to 310°C, zone 3 to 310°C, and the die temperature to 290°C for melt blending, and the screw speed to 300 rpm.

[0110] (4) Extrusion granulation to obtain modified PA6T material;

[0111] Comparative Example 4

[0112] Melt mass flow rate of the examples and comparative examples: tested according to standard GB / TP 3682.1 2018, at a test temperature of 320°C and a load of 1.2 kg.

[0113] Crystallization temperatures for examples and comparative examples: Refer to ASTM D3418-2003

[0114] Heat distortion temperature of the examples and comparative examples: refer to ASTM D648, load 1.82 MPa

[0115] Table 1 shows the performance test results of the examples and comparative examples.

[0116]

[0117] The performance test results above show that, compared with Comparative Example 1, the melt flow rate and heat distortion temperature of the PA6T modified materials in Examples 1-3 developed according to this technology are increased by more than 2 times, and the crystallization temperature is also further improved. This indicates that by optimizing the component compounding, the crystallization temperature, crystallization rate and melt flowability of PA6T are significantly improved. Compared with Comparative Examples 2 and 3, the component ratios in Examples 1-3 developed according to this technology are better, and their melt flow rate, heat distortion temperature and crystallization temperature are higher, further proving the effectiveness of the method.

[0118] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A PA6T modified material, characterized in that, The components include the following parts by weight: 50-80 parts of PA6T resin; 5-15 parts of crystallization accelerator; 3-10 parts of flow improver; 5-20 parts of nano-reinforced filler; Antioxidant 0.1 to 1 part; 0.5 to 2 parts of lubricant and release agent; The crystallization promoter is sodium sulfonate and carbon nanotubes.

2. The composite material according to claim 1, characterized in that, The mass ratio of the sodium sulfonate salt to the carbon nanotubes is 1:1 to 1:

3.

3. The composite material according to claim 1, characterized in that, The sodium sulfonate salt is selected from one or more of sodium p-toluenesulfonate, sodium benzenesulfonate, sodium dodecylbenzenesulfonate, or sodium 2-naphthalenesulfonate; The carbon nanotubes are selected from single-walled carbon nanotubes or multi-walled carbon nanotubes.

4. The composite material according to claim 1, characterized in that, The flow modifier is selected from low molecular weight polysiloxane or maleic anhydride-grafted polyolefin. The low molecular weight polysiloxane may be one or more of methyl silicone oil, phenyl silicone oil, or amino-modified silicone oil; the maleic anhydride-grafted polyolefin is selected from one or more of maleic anhydride-grafted polyethylene, maleic anhydride-grafted polypropylene, or maleic anhydride-grafted ethylene-octene copolymer.

5. The composite material according to claim 1, characterized in that, The nano-reinforced filler is one or both of nano-silica or boron nitride that have been surface modified with a silane coupling agent. The particle size of the nano-reinforced filler is 20–50 nm.

6. The composite material according to claim 1, characterized in that, The antioxidant is selected from one or more of the following: pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, N,N'-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl]hexamethylenediamine, tris[2,4-di-tert-butylphenyl]phosphite, or bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite; The lubricant is selected from one or more of stearic acid, zinc / calcium stearate, lignite wax, glyceryl monostearate, pentaerythritol stearate, polydimethylsiloxane, or silicone masterbatch; the mold release agent is selected from one or more of zinc / magnesium stearate, ethylene bis-stearamide, fluorinated mold release agent, or polyether modified silicone oil.

7. A method for preparing the PA6T modified material according to any one of claims 1 to 6, characterized in that, include: A) PA6T resin, crystallization accelerator, flowability improver, nano-reinforcing filler, antioxidant, lubricant and release agent are premixed to obtain a premix; C) Melt-blend the premix, extrude and granulate, and dry to obtain the final product.

8. The composite material according to claim 1, characterized in that, The melt blending is performed using a twin-screw extruder in a temperature range of 290–320°C.

9. An LED reflector bracket, characterized in that, It includes a PA6T modified material with a high crystallization rate as described in any one of claims 1 to 6.

10. The application of the PA6T modified material according to any one of claims 1 to 6 in the preparation of LED reflector brackets.

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