A nylon material, its preparation method and use

Abstract

The application relates to the technical field of high polymer materials, and discloses a nylon material and a preparation method and application thereof. The nylon material comprises the following preparation raw materials in percentage by mass: 70-85% of nylon resin, 8-15% of nitrogen-based flame retardant, 2-8% of phosphorus-based flame retardant and 1-8% of synergistic flame retardant. The nylon material provided by the application adds the phosphorus-based flame retardant and the synergistic flame retardant in a traditional nitrogen-based flame retardant system, so that the ignition temperature of the material is increased, the dropping speed and the dropping ignition probability are reduced, and the flame retardant performance of the material is improved. The ignition temperature of the material can reach 745 DEG C, the DSC crystallization temperature can reach 187 DEG C, the demolding effect is good, the dropping speed is slow, the dropping ignition probability is low, the performance requirements of a battery assembly product on the material can be met, and the nylon material can be used in the preparation of electronic connectors, battery compartments, low-voltage switches, housings or terminal blocks of power distribution systems of electronic and electrical equipment.

Description

Technical Field

[0001] This invention relates to the field of polymer materials technology, and in particular to a nylon material, its preparation method, and its applications. Background Technology

[0002] With the comprehensive expansion of the new energy vehicle industry market, the demand for connectors for current distribution in its power systems and electronic control systems is growing rapidly. These components require high safety, and the materials must have a high glow wire ignition temperature, and after ignition at a higher temperature, they should extinguish rapidly. Materials with traditional brominated flame retardants cannot meet environmental protection requirements, so it is necessary to develop flame retardant materials with high flame retardant performance and greater environmental friendliness.

[0003] Nylon materials have advantages such as good processability, chemical resistance, and mechanical properties, and are widely used in the market. However, nylon is a flammable material, which releases a large amount of smoke and toxic gases when burning, accompanied by dripping and ignition phenomena, and cannot meet the high flame retardant requirements of household appliances and electronic appliances.

[0004] Flame retardant modification systems for nylon materials mainly include halogen-based flame retardant modification and halogen-free flame retardant modification. Among them, halogen-based flame retardant modified nylon has good flame retardant effect and simple preparation process, but it produces a large amount of toxic halogen gas when burning. After escaping into the air, it easily combines with moisture to form a highly corrosive liquid, which can seriously endanger human health and also hinder escape in case of fire. In contrast, halogen-free flame retardants, mainly nitrogen-based and phosphorus-based, have better safety and are more environmentally friendly.

[0005] The most commonly used flame retardant for halogen-free flame-retardant modified nylon is melamine cyanurate (MCA). MCA is a nitrogen-based flame retardant, and its bulk is an oily powder with a certain lubricating effect. Its flame-retardant mechanism mainly includes the following: ① The MCA flame retardant molecule has a large-area hydrogen bond network, which has good heat resistance. When the material is heated and decomposed, it helps the nylon substrate absorb a large amount of heat, reducing the overall temperature; ② During combustion, the MCA flame retardant can quickly carbonize to form a dense, non-combustible, honeycomb-like carbon layer. These foam-like carbon layers effectively limit heat diffusion and block oxygen; ③ After thermal decomposition, the MCA flame retardant releases nitrogen gas to form an inert atmosphere, diluting surface oxygen and thus reducing the combustion reaction; ④ Halogen-free flame-retardant nylon can carry away heat by dripping the softened portion during combustion.

[0006] However, nylon materials modified with MCA alone have the following drawbacks: ① The ignition temperature of nylon on glow wire is not ideal; ② MCA has poor dispersibility in nylon materials, which can easily lead to insufficient flame retardant properties; ③ Small molecules are prone to precipitation during the injection molding process, which can shorten the time interval for cleaning the mold; ④ MCA can reduce the crystallization rate of nylon, which can prolong the molding time. Summary of the Invention

[0007] The present invention aims to at least solve one of the aforementioned technical problems existing in the prior art. Therefore, one objective of the present invention is to provide a nylon material; a second objective is to provide a method for preparing this nylon material; and a third objective is to provide applications of this nylon material.

[0008] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0009] A first aspect of the present invention provides a nylon material comprising the following raw materials by weight percentage: 70%-85% nylon resin, 8%-15% nitrogen-based flame retardant, 2%-8% phosphorus-based flame retardant and 1%-8% synergistic flame retardant.

[0010] In this invention, to address the problem of poor flame retardant effect when using nitrogen-based flame retardants alone, a combination of nitrogen-based and phosphorus-based flame retardants is used. Nitrogen-based flame retardants can release nitrogen gas upon decomposition, forming an inert gas phase and reducing oxygen concentration, thereby inhibiting combustion. Phosphorus-based flame retardants can form solid and gaseous flame retardant barriers by releasing substances such as phosphoric acid and phosphorus pentoxide. When used in combination, the two flame retardants can complement each other's flame retardant mechanisms, improving the flame retardancy of the material.

[0011] In some embodiments of the present invention, the nylon resin is selected from at least one of polycaprolactam (nylon 6) and polyhexamethylene adipamide (nylon 66).

[0012] In some embodiments of the present invention, the nitrogen-based flame retardant includes melamine cyanurate (MCA).

[0013] In some embodiments of the present invention, the phosphorus-based flame retardant is selected from at least one of melamine pyrophosphate and zinc inositol hexaphosphate.

[0014] In some specific embodiments of the present invention, the phosphorus-based flame retardant is a compound phosphorus-based flame retardant composed of melamine pyrophosphate and zinc inositol hexaphosphate in any proportion.

[0015] In this invention, the selected phosphorus-based flame retardants, melamine pyrophosphate and zinc inositol hexaphosphate (zinc phytate), both have high phosphorus content. When added alone, they can improve the flame retardancy of the material. Compared with melamine pyrophosphate, zinc inositol hexaphosphate has a higher phosphorus content. When used together with melamine pyrophosphate, it can release more phosphoric acid components when the material is heated, thereby improving the flame retardancy efficiency of the material. In addition, zinc inositol hexaphosphate is a bio-based material, which is more environmentally friendly.

[0016] In some embodiments of the present invention, the synergistic flame retardant is selected from at least one of zinc borate and glass powder.

[0017] In some embodiments of the present invention, the melting point of the glass powder is less than 800°C.

[0018] In some embodiments of the present invention, the synergistic flame retardant is a compound of zinc borate and glass powder in a mass ratio of 1:(1-5).

[0019] In this invention, the addition of zinc borate and glass powder as synergistic flame retardants enables the material to form a dense vitrified coating during combustion, which blocks the diffusion of heat and the escape of combustible gases, while promoting char formation and improving flame retardant efficiency.

[0020] In some embodiments of the present invention, the nylon material further includes the following preparation raw materials: 0.1%-2% nucleating agent.

[0021] In some embodiments of the present invention, the nucleating agent is selected from talc, and at least one of calcium stearate and glyceryl monostearate.

[0022] In some embodiments of the present invention, the talc powder accounts for 70%-80% of the mass of the nucleating agent.

[0023] In some embodiments of the present invention, the particle size of the talc powder is 8000-12000 mesh.

[0024] In this invention, the nucleating agent includes both organic and inorganic nucleating agents, with the inorganic nucleating agent accounting for a larger proportion. When nano-sized talc powder is used as the nucleating agent, compared with organic nucleating agents, it can reduce costs and resource dependence, improve the crystallinity of the material, shorten the molding cycle, and improve molding efficiency. Furthermore, the addition of calcium stearate and / or glyceryl monostearate organic nucleating agents can improve the dispersibility of talc powder during processing and improve the demolding effect during material injection molding.

[0025] In some embodiments of the present invention, the nylon material further includes the following raw materials: 0.1%-1% antioxidant and 0.01%-0.2% surface modifier.

[0026] In some embodiments of the present invention, the antioxidant is selected from at least one of hindered phenolic antioxidants, thioester antioxidants, and phosphite antioxidants.

[0027] In some specific embodiments of the present invention, the antioxidant is a compound of hindered phenolic antioxidants and phosphite antioxidants.

[0028] In some specific embodiments of the present invention, the mass ratio of the hindered phenolic antioxidant to the phosphite antioxidant is (2-3):1.

[0029] In some specific embodiments of the present invention, the hindered phenolic antioxidant is selected from at least one of N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexamethylenediamine (antioxidant 1098), 2,6-di-tert-butyl-p-methylphenol (BHT), octadecyl β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate (antioxidant 1076), pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] (antioxidant 1010), and triethylene glycol bis[β-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate] (antioxidant 245).

[0030] In some specific embodiments of the present invention, the phosphite antioxidant is selected from at least one of tris[2,4-di-tert-butylphenyl] phosphite (antioxidant 168), bisphenol A phosphite, triphenyl phosphite (TPP), and diphenyl isooctyl phosphite (ODPP).

[0031] In some embodiments of the present invention, the surfactant is selected from at least one of aminosilane coupling agents and epoxysilane coupling agents.

[0032] In some specific embodiments of the present invention, the surfactant is selected from at least one of γ-aminopropyltriethoxysilane and γ-glycidoxypropyltrimethoxysilane.

[0033] In some embodiments of the present invention, the nylon material comprises the following raw materials by weight percentage:

[0034] Nylon resin 70%-85%;

[0035] Nitrogen-based flame retardants: 8%-15%;

[0036] Phosphorus-based flame retardants 2%-8%;

[0037]

[0038] In some specific embodiments of the present invention, the nylon material comprises the following raw materials by weight percentage:

[0039]

[0040] In some specific embodiments of the present invention, the density of the nylon material is 1.1-1.3 g / cm³. 3 .

[0041] In some specific embodiments of the present invention, the glow wire ignition temperature of the nylon material is ≥725°C.

[0042] A second aspect of the present invention provides a method for preparing the nylon material described in the first aspect of the present invention, comprising the following steps:

[0043] All raw materials except for the phosphorus-based flame retardant are mixed to obtain a premix; the premix is ​​added from the main feed port of a twin-screw extruder for melt mixing; the phosphorus-based flame retardant is added from the side feed port of the twin-screw extruder for melt extrusion granulation to obtain the nylon material.

[0044] In some embodiments of the present invention, the preparation method specifically includes the following steps:

[0045] First, nylon resin, nucleating agent, synergistic flame retardant and surface modifier are mixed, then nitrogen-based flame retardant and antioxidant are added and mixed to obtain a premix; the premix is ​​added from the main feed port of a twin-screw extruder for melt mixing; the phosphorus-based flame retardant is added from the side feed port of the twin-screw extruder for melt extrusion granulation to obtain the nylon material.

[0046] In some embodiments of the present invention, the mixing speed of the premix is ​​800-1500 r / min.

[0047] In some embodiments of the present invention, the mixing temperature of the premix is ​​40-50°C.

[0048] In some embodiments of the present invention, the mixing time of the premix is ​​3-5 minutes.

[0049] In some embodiments of the present invention, the temperatures of the various sections of the twin-screw extruder from the hopper to the die are as follows: first section: 170-190℃, second section: 220-240℃, third section: 230-250℃, fourth section: 240-260℃, fifth section: 250-270℃, sixth section: 250-270℃, seventh section: 220-240℃, eighth section: 210-230℃, and ninth section: 210-230℃.

[0050] In some embodiments of the present invention, the side feed port is located in the fifth section of the twin-screw extruder.

[0051] In some embodiments of the present invention, the die head temperature of the twin-screw extruder is 240-260°C.

[0052] In some embodiments of the present invention, the screw speed of the twin-screw extruder is 300-600 r / min.

[0053] In this invention, given the poor temperature resistance of phosphorus-based flame retardants, they are added from the side feed port during the preparation process. This reduces degradation losses and unstable foaming during processing, maximizing the role of the flame retardant and improving the flame retardant performance of the material.

[0054] The third aspect of the present invention provides the application of the nylon material described in the first aspect of the present invention in the preparation of battery component articles.

[0055] In some embodiments of the present invention, the battery component article includes electronic connectors, battery compartments, low-voltage switches, housings, and power distribution system terminals for new energy electric vehicles and / or other electronic and electrical equipment.

[0056] Compared with the prior art, the beneficial effects of the present invention are:

[0057] 1) The nylon material provided by the present invention adds phosphorus flame retardant and synergistic flame retardant to the traditional nitrogen-based flame retardant system, which increases the ignition temperature of the material on a hot wire, reduces the dripping speed and the probability of dripping ignition, and improves the flame retardant performance of the material.

[0058] 2) The nylon material provided by this invention, with the addition of a nucleating agent, increases the crystallization temperature of the material, shortens the molding cycle, and improves the demolding effect;

[0059] 3) The method for preparing nylon material provided by the present invention has simple steps and mild process conditions. The side-feeding method of phosphorus flame retardant reduces the degradation and decomposition of flame retardant during processing and ensures the effectiveness of flame retardant.

[0060] 4) The nylon material provided by this invention has a glow wire ignition temperature of up to 745°C and a DSC crystallization temperature of up to 187°C. It has good demolding effect, slow dripping speed, and low probability of dripping ignition. It can meet the performance requirements of battery component products for materials and can be used in the preparation of electronic connectors, battery compartments, low-voltage switches, housings or power distribution system terminals of electronic and electrical equipment. Detailed Implementation

[0061] The present invention will be further described in detail below through specific embodiments. Unless otherwise specified, the raw materials, reagents, or apparatus used in the embodiments and comparative examples are all available from conventional commercial sources or can be obtained by existing technical methods. Unless otherwise specified, the test or experimental methods are conventional methods in the art.

[0062] The raw material information used in the following examples and comparative examples is shown in Table 1 below:

[0063] Table 1. Information on raw materials used in the examples and comparative examples.

[0064]

[0065]

[0066] Example 1

[0067] This embodiment prepares a nylon material, and the raw materials are shown in Table 2:

[0068] Table 2. Raw material composition of nylon material in Example 1.

[0069]

[0070] The preparation method of nylon material includes the following steps:

[0071] At 60°C, nylon resin, synergistic flame retardant and surface modifier are first mixed at a high speed of 1000 r / min for 5 min, then nitrogen-based flame retardant and antioxidant are added and mixed for another 3 min to obtain premix.

[0072] The premixed material is added from the main feed port of the twin-screw extruder for melt mixing, and the phosphorus-based flame retardant is added from the side feed port of the twin-screw extruder for melt extrusion granulation to obtain nylon material.

[0073] The side feed port is located in the fifth section of the twin-screw extruder. The temperatures of each section of the twin-screw extruder from the hopper to the die are as follows: first section: 180℃, second section: 230℃, third section: 245℃, fourth section: 250℃, fifth section: 260℃, sixth section: 250℃, seventh section: 230℃, eighth section: 220℃, ninth section: 220℃; the die head temperature is 250℃, and the screw speed is 450 r / min.

[0074] Example 2

[0075] This embodiment prepares a nylon material, and the raw materials are shown in Table 3:

[0076] Table 3. Raw material composition of nylon material in Example 2.

[0077]

[0078] The preparation method of nylon material includes the following steps:

[0079] At 60°C, nylon resin, synergistic flame retardant and surface modifier are first mixed at a high speed of 1000 r / min for 5 min, then nitrogen-based flame retardant and antioxidant are added and mixed for another 3 min to obtain premix.

[0080] The premixed material is added from the main feed port of the twin-screw extruder for melt mixing, and the phosphorus-based flame retardant is added from the side feed port of the twin-screw extruder for melt extrusion granulation to obtain nylon material.

[0081] The side feed port is located in the fifth section of the twin-screw extruder. The temperatures of each section of the twin-screw extruder from the hopper to the die are as follows: first section: 180℃, second section: 230℃, third section: 245℃, fourth section: 250℃, fifth section: 260℃, sixth section: 250℃, seventh section: 230℃, eighth section: 220℃, ninth section: 220℃; the die head temperature is 250℃, and the screw speed is 450 r / min.

[0082] Example 3

[0083] This embodiment prepares a nylon material, and the raw materials are shown in Table 4:

[0084] Table 4. Raw material composition of nylon material in Example 3.

[0085]

[0086]

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

[0088] At 60°C, nylon resin, synergistic flame retardant and surface modifier are first mixed at a high speed of 1000 r / min for 5 min, then nitrogen-based flame retardant and antioxidant are added and mixed for another 3 min to obtain premix.

[0089] The premixed material is added from the main feed port of the twin-screw extruder for melt mixing, and the phosphorus-based flame retardant is added from the side feed port of the twin-screw extruder for melt extrusion granulation to obtain nylon material.

[0090] The side feed port is located in the fifth section of the twin-screw extruder. The temperatures of each section of the twin-screw extruder from the hopper to the die are as follows: first section: 180℃, second section: 230℃, third section: 245℃, fourth section: 250℃, fifth section: 260℃, sixth section: 250℃, seventh section: 230℃, eighth section: 220℃, ninth section: 220℃; the die head temperature is 250℃, and the screw speed is 450 r / min.

[0091] Example 4

[0092] This embodiment prepares a nylon material, and the raw materials are shown in Table 5:

[0093] Table 5. Raw material composition of nylon material in Example 4

[0094]

[0095] The preparation method of nylon material includes the following steps:

[0096] At 60°C, nylon resin, synergistic flame retardant and surface modifier are first mixed at a high speed of 1000 r / min for 5 min, then nitrogen-based flame retardant and antioxidant are added and mixed for another 3 min to obtain premix.

[0097] The premixed material is added from the main feed port of the twin-screw extruder for melt mixing, and the phosphorus-based flame retardant is added from the side feed port of the twin-screw extruder for melt extrusion granulation to obtain nylon material.

[0098] The side feed port is located in the fifth section of the twin-screw extruder. The temperatures of each section of the twin-screw extruder from the hopper to the die are as follows: first section: 180℃, second section: 230℃, third section: 245℃, fourth section: 250℃, fifth section: 260℃, sixth section: 250℃, seventh section: 230℃, eighth section: 220℃, ninth section: 220℃; the die head temperature is 250℃, and the screw speed is 450 r / min.

[0099] Example 5

[0100] This embodiment prepares a nylon material, and the raw materials are shown in Table 6:

[0101] Table 6. Raw material composition of nylon material in Example 5.

[0102]

[0103] The preparation method of nylon material includes the following steps:

[0104] At 60°C, nylon resin, synergistic flame retardant and surface modifier are first mixed at a high speed of 1000 r / min for 5 min, then nitrogen-based flame retardant and antioxidant are added and mixed for another 3 min to obtain premix.

[0105] The premixed material is added from the main feed port of the twin-screw extruder for melt mixing, and the phosphorus-based flame retardant is added from the side feed port of the twin-screw extruder for melt extrusion granulation to obtain nylon material.

[0106] The side feed port is located in the fifth section of the twin-screw extruder. The temperatures of each section of the twin-screw extruder from the hopper to the die are as follows: first section: 180℃, second section: 230℃, third section: 245℃, fourth section: 250℃, fifth section: 260℃, sixth section: 250℃, seventh section: 230℃, eighth section: 220℃, ninth section: 220℃; the die head temperature is 250℃, and the screw speed is 450 r / min.

[0107] Example 6

[0108] This embodiment prepares a nylon material, and the raw materials are shown in Table 7:

[0109] Table 7. Raw material composition of nylon material in Example 6

[0110]

[0111] The preparation method of nylon material includes the following steps:

[0112] At 60℃, nylon resin, nucleating agent, synergistic flame retardant and surface modifier are first mixed at a high speed of 1000r / min for 5min, then nitrogen-based flame retardant and antioxidant are added and mixed for another 3min to obtain premix;

[0113] The premixed material is added from the main feed port of the twin-screw extruder for melt mixing, and the phosphorus-based flame retardant is added from the side feed port of the twin-screw extruder for melt extrusion granulation to obtain nylon material.

[0114] The side feed port is located in the fifth section of the twin-screw extruder. The temperatures of each section of the twin-screw extruder from the hopper to the die are as follows: first section: 180℃, second section: 230℃, third section: 245℃, fourth section: 250℃, fifth section: 260℃, sixth section: 250℃, seventh section: 230℃, eighth section: 220℃, ninth section: 220℃; the die head temperature is 250℃, and the screw speed is 450 r / min.

[0115] Comparative Example 1

[0116] This comparative example prepares a nylon material, and the raw materials are shown in Table 8:

[0117] Table 8. Raw material composition of nylon material in Comparative Example 1

[0118]

[0119]

[0120] The preparation method of nylon material includes the following steps:

[0121] At 60℃, nylon resin and surface modifier are first mixed at a high speed of 1000r / min for 5min, then nitrogen-based flame retardant and antioxidant are added and mixed for another 3min to obtain premix.

[0122] The premixed material is added from the main feed port of the twin-screw extruder, melt-mixed, extruded and granulated to obtain nylon material.

[0123] The temperatures of each section of the twin-screw extruder barrel from the hopper to the die are as follows: first section: 180℃, second section: 230℃, third section: 245℃, fourth section: 250℃, fifth section: 260℃, sixth section: 250℃, seventh section: 230℃, eighth section: 220℃, and ninth section: 220℃; the die head temperature is 250℃, and the screw speed is 450 r / min.

[0124] Comparative Example 2

[0125] This comparative example prepares a nylon material, and the raw materials are shown in Table 9:

[0126] Table 9. Raw material composition of nylon material in Comparative Example 2

[0127]

[0128] The preparation method of nylon material includes the following steps:

[0129] At 60℃, nylon resin and surface modifier are first mixed at a high speed of 1000r / min for 5min, then nitrogen-based flame retardant and antioxidant are added and mixed for another 3min to obtain premix.

[0130] The premixed material is added from the main feed port of the twin-screw extruder for melt mixing, and the phosphorus-based flame retardant is added from the side feed port of the twin-screw extruder for melt extrusion granulation to obtain nylon material.

[0131] The side feed port is located in the fifth section of the twin-screw extruder. The temperatures of each section of the twin-screw extruder from the hopper to the die are as follows: first section: 180℃, second section: 230℃, third section: 245℃, fourth section: 250℃, fifth section: 260℃, sixth section: 250℃, seventh section: 230℃, eighth section: 220℃, ninth section: 220℃; the die head temperature is 250℃, and the screw speed is 450 r / min.

[0132] Comparative Example 3

[0133] This comparative example prepares a nylon material, and the raw materials are shown in Table 10:

[0134] Table 10 Raw material composition of nylon material in Comparative Example 3

[0135]

[0136] The preparation method of nylon material includes the following steps:

[0137] At 60℃, nylon resin and surface modifier are first mixed at a high speed of 1000r / min for 5min, then nitrogen-based flame retardant and antioxidant are added and mixed for another 3min to obtain premix.

[0138] The premixed material is added from the main feed port of the twin-screw extruder for melt mixing, and the phosphorus-based flame retardant is added from the side feed port of the twin-screw extruder for melt extrusion granulation to obtain nylon material.

[0139] The side feed port is located in the fifth section of the twin-screw extruder. The temperatures of each section of the twin-screw extruder from the hopper to the die are as follows: first section: 180℃, second section: 230℃, third section: 245℃, fourth section: 250℃, fifth section: 260℃, sixth section: 250℃, seventh section: 230℃, eighth section: 220℃, ninth section: 220℃; the die head temperature is 250℃, and the screw speed is 450 r / min.

[0140] Comparative Example 4

[0141] This comparative example prepares a nylon material, and the raw materials are shown in Table 11:

[0142] Table 11 Raw material composition of nylon material in Comparative Example 4

[0143]

[0144] The preparation method of nylon material includes the following steps:

[0145] At 60℃, nylon resin and surface modifier are first mixed at a high speed of 1000r / min for 5min, then nitrogen-based flame retardant and antioxidant are added and mixed for another 3min to obtain premix.

[0146] The premixed material is added from the main feed port of the twin-screw extruder for melt mixing, and the phosphorus-based flame retardant is added from the side feed port of the twin-screw extruder for melt extrusion granulation to obtain nylon material.

[0147] The side feed port is located in the fifth section of the twin-screw extruder. The temperatures of each section of the twin-screw extruder from the hopper to the die are as follows: first section: 180℃, second section: 230℃, third section: 245℃, fourth section: 250℃, fifth section: 260℃, sixth section: 250℃, seventh section: 230℃, eighth section: 220℃, ninth section: 220℃; the die head temperature is 250℃, and the screw speed is 450 r / min.

[0148] Comparative Example 5

[0149] This comparative example prepares a nylon material, and the raw materials are shown in Table 12:

[0150] Table 12 Raw material composition of nylon material in Comparative Example 5

[0151]

[0152] The preparation method of nylon material includes the following steps:

[0153] At 60℃, nylon resin and surface modifier are first mixed at a high speed of 1000r / min for 5min, then nitrogen-based flame retardant and antioxidant are added and mixed for another 3min to obtain premix.

[0154] The premixed material is added from the main feed port of the twin-screw extruder for melt mixing. The phosphorus-based flame retardant is added from the main feed port of the twin-screw extruder for melt extrusion granulation to obtain nylon material.

[0155] The temperatures of each section of the twin-screw extruder barrel from the hopper to the die are as follows: first section: 180℃, second section: 230℃, third section: 245℃, fourth section: 250℃, fifth section: 260℃, sixth section: 250℃, seventh section: 230℃, eighth section: 220℃, and ninth section: 220℃; the die head temperature is 250℃, and the screw speed is 450 r / min.

[0156] Performance testing

[0157] The nylon materials prepared in Examples 1-6 and Comparative Examples 1-5 were subjected to performance tests. The test items and standards are as follows:

[0158] 1. Density: Tested according to ISO 1183-1-2019 "Plastics - Determination of density of non-foamed plastics";

[0159] 2. DSC crystallization temperature: Tested according to ISO 11357-1:2023 "Plastics - Differential scanning calorimetry (DSC)".

[0160] 3. Glow wire ignition temperature: Tested according to GB / T 5169.10-2017 "Basic Test Methods for Glow Wire".

[0161] 4. Demolding effect: Use a standard spline mold to make samples and visually inspect the demolding effect. The more "+" signs there are, the better the demolding effect.

[0162] 5. Dropping speed: Visually inspected, the more "+" signs there are, the earlier the first drop of melt falls;

[0163] 6. Probability of ignition by dripping: The average value of the probability of ignition by dripping from 50 UL94 vertical burning tests.

[0164] Table 13 Performance test results of nylon materials in Examples 1-6 and Comparative Examples 1-5

[0165]

[0166] Table 13 shows the performance test results of the nylon materials in Examples 1-6 and Comparative Examples 1-5. As can be seen from Table 13, the nylon material prepared in Comparative Example 1, with only the addition of the nitrogen-based flame retardant MCA, had a glow wire ignition temperature of only 705°C, was difficult to demold, had a fast melt dripping rate, and was easily ignited by dripping. Comparative Examples 2 and 3, based on Comparative Example 1, added melamine pyrophosphate or zinc inositol hexaphosphate as phosphorus-based flame retardants, respectively. The glow wire ignition temperatures of the nylon materials increased to 715°C and 720°C, respectively, and the dripping ignition probability decreased to 96%. The results showed that adding phosphorus-based flame retardants to the nitrogen-based flame retardant system could improve the flame retardant effect to some extent, but the crystallization temperature was not improved at this time. In Comparative Example 4, the addition of melamine pyrophosphate and zinc inositol hexaphosphate as phosphorus-based flame retardants further reduced the drip ignition probability to 90%. The only difference between Comparative Example 5 and Comparative Example 4 was that the phosphorus-based flame retardant was added from the main feed port of the twin-screw extruder. The phosphorus-based flame retardant underwent a longer processing time, which made it easy to foam and decompose, reducing the flame retardant efficiency. The side-feeding method of preparing phosphorus-based flame retardants was significantly more effective.

[0167] In Example 1, anhydrous zinc borate was added as a synergistic flame retardant to Comparative Example 4. The glow wire ignition temperature of the nylon material significantly increased to 740°C, while the dripping rate and the probability of dripping ignition decreased. Example 2 differed from Example 1 in that 650°C glass powder was used instead of anhydrous zinc borate as a synergistic flame retardant. It was found that this also achieved the goal of reducing the dripping rate and the probability of dripping ignition. This is because the addition of the flame retardant synergist generated a high-temperature, dense, glassy layer, blocking the escape of combustible gases and heat erosion, effectively improving the flame retardant effect of the material. Example 3 differed from Example 2 in that the 650°C glass powder was replaced with 800°C glass powder, which significantly affected the material's dripping rate. The effect was unstable, resulting in unstable flame retardant performance. Therefore, when glass powder is used as a flame retardant synergist, its melting point should be below 800℃. The difference between Example 4 and Example 2 is that the amount of glass powder with a melting point of 650℃ was increased. It was found that this seriously affected the dripping effect of the MCA flame retardant system, resulting in poor flame retardant stability. The difference between Example 5 and Example 2 is that anhydrous zinc borate and glass powder with a melting point of 650℃ were added simultaneously as synergistic flame retardants. It can be seen that the glow wire ignition temperature of the material increased to 745℃, the demolding effect was improved, and the dripping speed and dripping ignition probability were reduced. Example 6 added a nucleating agent based on Example 5. It was found that the crystallization temperature of the material was significantly increased, which shortened the material molding cycle and achieved the best demolding effect.

Claims

1. A nylon material, characterized in that, The preparation raw materials include the following percentages by weight: 70%-85% nylon resin, 8%-15% nitrogen-based flame retardant, 2%-8% phosphorus-based flame retardant, 1%-8% synergistic flame retardant and 0.1%-2% nucleating agent; The phosphorus-based flame retardant is a compound phosphorus-based flame retardant composed of melamine pyrophosphate and zinc inositol hexaphosphate in any proportion; the synergistic flame retardant is a compound of zinc borate and glass powder in a mass ratio of 1:(1-5); the melting point of the glass powder is less than 800℃; the nucleating agent includes talc, and at least one of calcium stearate and glyceryl monostearate, wherein the talc accounts for 70%-80% of the mass of the nucleating agent; The nylon material is prepared by a method comprising the following steps: mixing all raw materials except for the phosphorus-based flame retardant to obtain a premix; adding the premix from the main feed port of a twin-screw extruder for melt mixing; adding the phosphorus-based flame retardant from the side feed port of the twin-screw extruder for melt extrusion granulation to obtain the nylon material.

2. The nylon material according to claim 1, characterized in that, The nitrogen-based flame retardant includes melamine cyanurate.

3. The nylon material according to claim 1, characterized in that, The nylon material, by weight percentage, also includes the following raw materials: 0.1%-1% antioxidant and 0.01%-0.2% surface modifier.

4. The method for preparing the nylon material according to any one of claims 1-3, characterized in that, Includes the following steps: All raw materials except for the phosphorus-based flame retardant are mixed to obtain a premix; the premix is ​​added from the main feed port of a twin-screw extruder for melt mixing; the phosphorus-based flame retardant is added from the side feed port of the twin-screw extruder for melt extrusion granulation to obtain the nylon material.

5. The preparation method according to claim 4, characterized in that, The twin-screw extruder has the following temperatures for each section of the barrel from the hopper to the die: first section: 170-190℃, second section: 220-240℃, third section: 230-250℃, fourth section: 240-260℃, fifth section: 250-270℃, sixth section: 250-270℃, seventh section: 220-240℃, eighth section: 210-230℃, and ninth section: 210-230℃. And / or, the side feed port is located in the fifth section of the barrel of the twin-screw extruder.

6. The use of the nylon material according to any one of claims 1-3 in the preparation of battery component articles.

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