V0 flame-retardant PA66 special for glass fiber reinforced energy storage connector and preparation method of V0 flame-retardant PA66

Abstract

The invention discloses special V0 flame-retardant PA66 for a glass fiber reinforced energy storage connector and a preparation method of the special V0 flame-retardant PA66. Organic montmorillonite is utilized to effectively improve the water absorption, temperature resistance and moisture resistance of PA66, so that the special V0 flame-retardant PA66 not only has lower water absorption, but also can obviously reduce the thermal expansion coefficient of the material and improve the stability of the high-temperature-resistant material; the reduction of voltage resistance, the reduction of mechanical properties and the deformation of the material caused by water absorption of the material in the long-term use process are reduced, so that the material has long-term temperature resistance, moisture resistance and dimensional stability, and the weather resistance of the material is enhanced; through the coordination and cooperation effects of the ultraviolet light absorber, the polytetrafluoroethylene and the titanium dioxide, the material can still have good mechanical properties and small color difference after long-time ultraviolet irradiation; through synergistic use of the organic montmorillonite and the polytetrafluoroethylene, the addition amount of the flame retardant can be effectively reduced, and the PA66 material can reach the V0 flame retardant level.

Description

Technical Field

[0001] The present invention relates to the technical field of engineering plastic modification, and in particular to a V0 flame-retardant PA66 specially used for glass fiber reinforced energy storage connectors and a preparation method thereof. Background Art

[0002] Energy storage is an important means to stabilize new energy power generation and reduce the impact of large-scale new energy access on the power grid. With the introduction of my country's "dual carbon" policy and the guidance of the new power system, it has become an indispensable means of regulating new energy. As an indispensable component in the energy storage industry, the market capacity and product requirements of energy storage connectors have also grown and improved with the development of the energy storage industry. Energy storage connectors are required to ensure safe and effective operation for at least 15 years. This places extremely high demands on the mechanical properties, weather resistance and electrical properties of the plastics used to prepare energy storage connectors. At present, the plastic used to prepare energy storage connectors is mainly nylon 66 halogen-free flame retardant 30 glass fiber, which usually has a tensile strength of 130MPa and a notch impact of 9KJ / M 2 , mechanical properties are poor, and currently, when excellent flame retardancy needs to be ensured, especially when V0 level is required, a large amount of flame retardant needs to be added, which will also cause the insulation and mechanical properties of PA66 materials to drop significantly and cannot meet the use requirements. Therefore, it is necessary to use other means to reduce the amount of flame retardant added so that it can reach the V0 flame retardant level; and because PA66 contains a large number of amide bonds on the molecular chain, it has a large water absorption capacity, which will affect the electrical properties and weather resistance of PA66 materials. Therefore, it is necessary to modify the existing PA66 material used in the preparation of energy storage connectors to better meet the application requirements of energy storage connectors. Summary of the invention

[0003] Based on the above background, the present invention provides a V0 flame-retardant PA66 specially used for a glass fiber reinforced energy storage connector and a preparation method thereof.

[0004] The technical solution of the present invention is:

[0005] A V0 flame-retardant PA66 specially used for glass fiber reinforced energy storage connector, which is made of the following raw materials in parts by weight:

[0006]

[0007]

[0008] Preferably, the flame retardant is at least one of triphenylphosphine oxide and melamine cyanurate.

[0009] Preferably, the toughening agent is POE grafted maleic anhydride, and the grafting rate of the POE grafted maleic anhydride is 1.0-1.5%.

[0010] Preferably, the ultraviolet absorber is UV234.

[0011] Preferably, the antioxidant is at least one of antioxidant 1098, antioxidant 1010, and antioxidant 168.

[0012] Based on the same inventive concept, the present invention also provides a method for preparing V0 flame-retardant PA66 for glass fiber reinforced energy storage connector, which comprises the following steps:

[0013] (1) Take nylon 66 according to the amount and dry it at 100-110°C for 4-6 hours;

[0014] (2) taking a toughening agent, organic montmorillonite, a UV absorber, polytetrafluoroethylene, an antioxidant, and titanium dioxide in proportion, and mixing them with nylon 66 at high speed in a high-speed mixer;

[0015] (3) The mixed material in step (2) is added into a twin-screw extruder through the main feed port of the twin-screw extruder, and while being melt-extruded, short-cut glass fibers and a flame retardant are added from the side feed port, mixed and plasticized, and melt-extruded. After the extruded material is cooled, air-dried, pelletized, and dried, a glass fiber reinforced flame-retardant nylon energy storage connector special material is obtained.

[0016] Furthermore, the temperature setting range of the twin-screw extruder in step (3) is 235-270° C., the screw speed is 200-500 rpm, and the vacuum degree is -0.6-1.0 Kgf / cm2.

[0017] Further, the temperature of each zone of the twin-screw extruder is:

[0018] Zone 1 temperature: 245-250°C;

[0019] Zone 2 temperature: 265-270°C;

[0020] Temperature in zone 3: 265-270°C;

[0021] Temperature in zone 4: 270-265°C;

[0022] Zone 5 temperature: 265~260℃;

[0023] Temperature of zone 6: 260~255℃;

[0024] Temperature of zone 7: 255~250℃;

[0025] Zone 8 temperature: 240-245°C;

[0026] Temperature in zone 9: 235-240°C;

[0027] Zone 10 temperature: 255~250℃;

[0028] Machine head temperature: 260~265℃.

[0029] The beneficial effects achieved by the present invention are:

[0030] 1) Organic montmorillonite is a modified montmorillonite with a layered one-dimensional nanostructure. Its strong adsorption can effectively reduce the water absorption rate of the nylon substrate, significantly reducing the water absorption rate of the material as a whole. Therefore, the present invention uses organic montmorillonite to effectively improve the water absorption and temperature and moisture resistance of PA66, so that it not only has a lower water absorption rate, but also can significantly reduce the thermal expansion coefficient of the material, improve the stability of its high-temperature resistant material, so as to reduce the reduction of voltage resistance, mechanical properties and deformation of the material caused by water absorption of the material during long-term use, so that it has long-term temperature and moisture resistant dimensional stability and enhances its weather resistance;

[0031] The principle of adding organic montmorillonite to reduce the water absorption of PA66 is as follows:

[0032] ① Organic montmorillonite significantly affects the material properties by inserting organic molecules or ions between montmorillonite layers to expand the interlayer distance. The interlayer distance of organically modified montmorillonite increases, and the interlayer force weakens, resulting in improved interlayer sliding and reduced water absorption of the material; ② The interaction between organic molecules and montmorillonite is also an important factor in reducing the water absorption of the material. Organic molecules interact with the silicon-aluminum layer of montmorillonite, such as covalent bonding and ionic bonding, which makes the organic molecules and montmorillonite more tightly bound, thereby reducing the adsorption of water by the material; ③ Organic montmorillonite also has unique adsorption characteristics for water molecules. Due to the polar effect of organic molecules on water, the adsorption capacity of organic montmorillonite for water is weakened. In addition, the organic modification between the organic montmorillonite layers also increases the repulsion of water molecules, further reducing the water absorption of the material. ④ The introduction of organic montmorillonite enhances the stability of the material structure. The interaction between organic molecules and montmorillonite and the increase in the interlayer distance after organic modification make the microstructure of the material more stable and less susceptible to environmental factors, thereby reducing the water absorption rate of the material. ⑤ The insertion of organic montmorillonite changes the microstructure of the material. Due to the insertion of organic molecules between montmorillonite layers, the pore size and specific surface area of ​​the material change. These changes in the microstructure affect the material's adsorption performance for water. When the content of organic montmorillonite increases, the pore size of the material decreases, the specific surface area decreases, the adsorption capacity for water weakens, and the water absorption rate decreases.

[0033] 2) The present invention can make the material still have good mechanical properties and small color difference after long-term ultraviolet irradiation through the coordinated cooperation of the ultraviolet absorber and polytetrafluoroethylene and titanium dioxide;

[0034] The polytetrafluoroethylene and titanium dioxide added in the present invention can absorb photons in ultraviolet rays, reduce the damage of ultraviolet rays to polymer bonds, and further improve the anti-ultraviolet ability of PA66 materials.

[0035] 3) The present invention uses organic montmorillonite and polytetrafluoroethylene in a coordinated manner, which can effectively reduce the amount of flame retardant added, so that the PA66 material can reach the V0 flame retardant level. DETAILED DESCRIPTION

[0036] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with its embodiments; it should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0037] Example 1: In this example 1, PA66 plastic was prepared according to the material ratio in Table 1 and relevant characterizations including mechanical properties and water absorption properties were performed.

[0038] Table 1: Proportions of materials in Examples and Comparative Examples

[0039]

[0040] The PA66 of each embodiment and comparative example in Table 1 was prepared by the following steps:

[0041] (1) Dry the required nylon 66 at 100-110°C for 4-6 hours.

[0042] (2) Mixing with nylon 66, toughening agent, organic montmorillonite, UV234, polytetrafluoroethylene, antioxidant, titanium dioxide, etc. in a high-speed mixer at a high speed for 5-10 minutes;

[0043] (3) Add the material into the twin-screw extruder through the main feed port of the twin-screw extruder, and add chopped glass fibers and flame retardants from the side feed port while melt extruding, mix and plasticize, and melt extrude. After the extruded material is cooled, air-dried, pelletized, and dried, a glass fiber reinforced flame-retardant nylon energy storage connector special material is obtained.

[0044] The temperature setting range of the twin-screw extruder is 235-270°C, the screw speed is 200-500rpm, and the vacuum degree is -0.6-1.0Kgf / cm2.

[0045] The temperature of each zone of the twin-screw extruder is:

[0046] Zone 1 temperature: 245~250℃,

[0047] Zone 2 temperature: 265~270℃,

[0048] Temperature in zone 3: 265~270℃,

[0049] Temperature in zone 4: 270~265℃,

[0050] Zone 5 temperature: 265~260℃,

[0051] Temperature of zone 6: 260~255℃,

[0052] Temperature of zone seven: 255~250℃.

[0053] Temperature of zone eight: 240~245℃.

[0054] Temperature in zone nine: 235-240℃.

[0055] Temperature of zone 10: 255~250℃.

[0056] Machine head temperature: 260~265℃.

[0057] In the above steps, the embodiments or comparative examples may not contain organic montmorillonite, UV234, polytetrafluoroethylene, etc., and the operation of each step can be adjusted during the preparation process.

[0058] The relevant materials used in this embodiment are selected as follows:

[0059] PA66 Shenma EPR27; toughening agent POE-g-MAH (POE grafted with maleic anhydride, grafting rate 1.1);

[0060] Chopped glass fiber Jushi ECS10-03-568H; UV absorber UV234, which can convert the energy of ultraviolet rays into other forms of energy, thereby reducing the damage of ultraviolet rays to the material itself; polytetrafluoroethylene (PTFE); titanium dioxide (TiO2); antioxidant 1098; flame retardant is a composite flame retardant of triphenylphosphine oxide and melamine cyanurate in a mass ratio of 3:1.

[0061] The organic montmorillonite in this embodiment is homemade and prepared by a dry method. The specific preparation method refers to the invention patent "A dry preparation method of organic montmorillonite" with application number 201910207586, and more specifically refers to Example 3 disclosed in its specification for preparation, see the following steps:

[0062] Step 1, emulsification: dissolve 10g of polyvinyl alcohol into 50ml solution and stir evenly; stir 1000g of calcium montmorillonite in a stirred tank, add 15ml of polyvinyl alcohol emulsion, and stir at a speed of 100 rpm for 25min;

[0063] Step 2, sodiumization: dissolve 20 g of sodium phosphate in 100 ml of water to form a solution, gradually heat the stirred kettle to 65°C, add 100 ml of sodium phosphate solution, and stir at 200 rpm for 60 min.

[0064] Step 3, drying: continue heating to 100°C and stirring at 100 rpm for 5 hours until the moisture content is 8%;

[0065] Step 4, crushing: take out the dried product and crush it in a mechanical crusher with a fineness of 300 mesh;

[0066] Step 5, organic treatment and acidification: add 15g KH570 silane coupling agent to 70ml deionized water, stir evenly, add 10g ammonium phosphate to the solution, and continue stirring until uniform; take the powder of step 4 in a high-speed stirring kettle, stir at high speed, add to the mixture of silane coupling agent and ammonium phosphate solution, stir for 15min, add 3ml acetic acid, and continue stirring at high speed for 30min;

[0067] Step 6, refinement: Take out the evenly stirred powder, place it in a jet mill and grind it to a fineness of 2500 mesh, add it into a sealed plastic bag, and store it in a sealed bag for 7 days to obtain the organic montmorillonite prepared by the dry method.

[0068] The mechanical properties, water absorption, flame retardancy, etc. of the PA66 of each embodiment and comparative example in Table 1 were tested, and the test results are shown in Table 2.

[0069] Table 2: PA66 sample performance table

[0070]

[0071]

[0072] The test conditions in the above table are: tensile strength, test condition 50mm / min; flexural strength, flexural modulus, test condition 5mm / min; flame retardancy, test condition 1.6mm; elongation, test condition 50mm / min; cantilever beam notch impact, test condition 23℃ / 5.5kj; thermal linear expansion coefficient, test condition is from 0℃ to 100℃ at a rate of 5℃ / min in N2 environment.

[0073] According to the results in Table 1 and Table 2, it can be seen that the synergistic use of organic montmorillonite and polytetrafluoroethylene can effectively reduce the amount of flame retardant added, so that PA66 can reach V0 flame retardant level.

[0074] Example 2: After the PA66 of Comparative Example 1 and Examples 3 to 6 prepared in Example 1 were irradiated with a UV-340 lamp for 500 hours, the mechanical properties of each PA66 sample were tested. The test results are shown in Table 3.

[0075] Table 3: Mechanical properties after UV-340 irradiation for 500 hours

[0076]

[0077] The color difference of the PA66 samples of Comparative Example 1 and Examples 3 to 6 before and after UV-340 irradiation was detected by a portable colorimeter. The color difference symbol is △E. The results show that the △E of Comparative Example 1 is 37.5, the △E of Example 3 is 21.5, the color difference △E of Example 4 is 18.7, the △E of Example 5 is 29.9, and the △E of Example 6 is 30.6.

[0078] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A V0 flame retardant PA66 specially made for glass fiber reinforced energy storage connector, characterized in that: It is made of the following raw materials in parts by weight:

2. The V0 flame retardant PA66 for glass fiber reinforced energy storage connector according to claim 1, characterized in that: The flame retardant is at least one of triphenylphosphine oxide and melamine cyanurate.

3. The V0 flame retardant PA66 for glass fiber reinforced energy storage connector according to claim 1, characterized in that: The toughening agent is POE grafted maleic anhydride, and the grafting rate of the POE grafted maleic anhydride is 1.0-1.5%.

4. The V0 flame retardant PA66 for glass fiber reinforced energy storage connector according to claim 1, characterized in that: The ultraviolet absorber is UV234.

5. The V0 flame retardant PA66 for glass fiber reinforced energy storage connector according to claim 1, characterized in that: The antioxidant is at least one of antioxidant 1098, antioxidant 1010, and antioxidant 168.

6. Use of a glass fiber reinforced V0 flame retardant PA66 specially used for energy storage connectors as claimed in any one of claims 1 to 5 in the preparation of energy storage connectors.

7. A method for preparing a glass fiber reinforced V0 flame retardant PA66 for energy storage connectors according to any one of claims 1 to 5, characterized in that: It includes the following steps: (1) Take nylon 66 according to the amount and dry it at 100-110°C for 4-6 hours; (2) taking a toughening agent, organic montmorillonite, a UV absorber, polytetrafluoroethylene, an antioxidant, and titanium dioxide in proportion, and mixing them with nylon 66 at high speed in a high-speed mixer; (3) The mixed material in step (2) is added into a twin-screw extruder through the main feed port of the twin-screw extruder, and while being melt-extruded, short-cut glass fibers and a flame retardant are added from the side feed port, mixed and plasticized, and melt-extruded. After the extruded material is cooled, air-dried, pelletized, and dried, a glass fiber reinforced flame-retardant nylon energy storage connector special material is obtained.

8. The method for preparing V0 flame-retardant PA66 for glass fiber reinforced energy storage connector according to claim 7, characterized in that: The temperature setting range of the twin-screw extruder in step (3) is 235-270° C., the screw speed is 200-500 rpm, and the vacuum degree is -0.6-1.0 Kgf / cm2.

9. The method for preparing V0 flame-retardant PA66 for glass fiber reinforced energy storage connector according to claim 7, characterized in that: The temperature of each zone of the twin-screw extruder is: Zone 1 temperature: 245-250°C; Zone 2 temperature: 265-270°C; Temperature in zone 3: 265-270°C; Temperature in zone 4: 270-265°C; Zone 5 temperature: 265-260°C; Temperature of zone 6: 260~255℃; Temperature of zone 7: 255~250℃; Zone 8 temperature: 240-245°C; Temperature in zone 9: 235-240°C; Zone 10 temperature: 255~250℃; Machine head temperature: 260~265℃.

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