Halogen-free flame-retardant antistatic high-temperature-resistant nylon composite material and preparation method thereof

Abstract

The invention relates to the technical field of halogen-free flame-retardant antistatic high polymer materials, and discloses a halogen-free flame-retardant antistatic high-temperature-resistant nylon composite material and a preparation method of the halogen-free flame-retardant antistatic high-temperature-resistant nylon composite material. Comprising 50-68.4 parts of high-temperature-resistant nylon resin, 20-40 parts of reinforced fibers, 5-10 parts of a flame retardant, 0.5-1 part of a carbon forming catalyst, 1-3 parts of a synergist and 0.1-1 part of an antioxidant. The reinforcing fiber is a mixture of carbon fiber and glass fiber. The formula composition and the preparation process of the composite material are integrally optimized, so that the halogen-free flame-retardant antistatic high-temperature-resistant nylon composite material has good antistatic performance, and the fire safety and flame retardance of the composite material are greatly improved through a compact carbon layer.

Description

Technical Field

[0001] The invention relates to the technical field of halogen-free flame-retardant antistatic polymer materials, and in particular to a halogen-free flame-retardant antistatic high-temperature resistant nylon composite material and a preparation method thereof. Background Art

[0002] As an engineering plastic, nylon is widely used in industrial fields such as machinery, instruments, and automobiles. Especially after being reinforced with glass fiber, its mechanical strength, wear resistance, and heat resistance can be greatly improved. However, for high-temperature scenes such as continuous working mechanical devices, heating appliances, automobile engine compartments, and integrated circuits, ordinary aliphatic nylons such as PA66 and PA6 have low glass transition temperatures and melting points, which are difficult to meet long-term use requirements. PA6T / 66, PA6T / 6I, PA6T / 6I / 66 and other high-temperature resistant nylon resins (PPA) introduce copolymer units such as terephthalic acid and isophthalic acid into the aliphatic nylon molecular chain. The aromatic structure restricts the movement of the polymer chain segments, which greatly improves its heat resistance. It has extremely good application prospects in high-temperature fields such as electronics, electrical appliances, and automobile engine compartments.

[0003] After the PPA resin is reinforced with glass fiber, its mechanical and heat resistance properties can be greatly improved. However, the molecular chain of PPA resin is composed of carbon-carbon bonds and polyamide groups, which cannot effectively transfer charges. Static electricity is easily accumulated on the surface, and the volume resistivity is as high as 1015Ω. In addition, glass fiber reinforced PPA composites are flammable, the carbon formation of the resin matrix itself is very limited, and the glass fiber will also produce a "wick effect". A large amount of toxic and harmful gases and smoke will be released during the combustion process, and the fire hazard is extremely high. Therefore, there is an urgent need for flame-retardant and antistatic PPA composites in high-temperature application scenarios such as electronics, electrical appliances, and automobile engine compartments. The melting point of PPA resin is as high as 310°C. When reinforced with glass fiber, its processing temperature is as high as 330°C. However, the halogen-free flame retardant system for ordinary aliphatic nylons such as PA66 and PA6 is not heat-resistant enough and cannot withstand the processing temperature of glass fiber reinforced PPA composites, resulting in glass fiber reinforced PPA composites. It is difficult to achieve good flame retardancy and fire safety. In addition, the melt viscosity of PPA resin is relatively high. When electrostatic modification is performed using conductive agents such as carbon black and carbon nanotubes, the melt viscosity will be further increased, resulting in difficulties in melt extrusion and granulation. As a result, halogen-free flame-retardant, antistatic, and high-temperature resistant nylon composite materials are difficult to be widely used in engineering applications.

[0004] Chinese patent CN104419198A reports a flame retardant and antistatic continuous long glass fiber reinforced high temperature resistant nylon composite material and its preparation method. By using zinc oxide whiskers, flame retardants, auxiliary flame retardants and other additives, the continuous long fiber reinforced thermoplastic material impregnation coating equipment is used to successfully achieve the flame retardant and antistatic function of the long glass fiber reinforced high temperature resistant nylon composite material. However, the amount of flame retardant added is high and a halogen-containing flame retardant is used.

[0005] Chinese patent CN116426119A reports a carbon fiber reinforced halogen-free flame-retardant high-temperature nylon composite material and its preparation method, and prepares a halogen-free flame-retardant antistatic high-temperature nylon composite material by using nylon 6T resin, nylon 66 resin, chopped carbon fiber, diethyl aluminum hypophosphite flame retardant and 3.5 water zinc borate synergist. However, using a single carbon fiber as a reinforcing material, although the electrical properties are improved at the same time, there is a problem of high cost. In addition, the total addition amount of diethyl aluminum hypophosphite flame retardant and zinc borate synergist is high, resulting in a low bulk density, and a special double-sided feeding extrusion production method is required.

[0006] Conductive agents such as carbon black and carbon nanotubes can improve the antistatic properties of glass fiber reinforced high-temperature nylon, but high content of powder additives will make material preparation difficult. Although carbon fiber can both enhance and improve electrical properties, it has the problem of high cost when used alone. The processing temperature of fiber-reinforced high-temperature nylon composite materials is as high as 330°C or above. The halogen-free flame retardant system for ordinary aliphatic nylon has insufficient temperature resistance. Although diethyl aluminum hypophosphite flame retardant has good temperature resistance, it is mainly gas-phase flame retardant, with low flame retardant efficiency, and a large amount of smoke will be released during combustion. In addition, the addition of a large amount of diethyl aluminum hypophosphite flame retardant will result in a high bulk density of the material, making it difficult to extrude and process. Therefore, it is urgent to develop a high-temperature resistant nylon composite material that can combine processability, antistatic and high-efficiency flame retardancy. Summary of the invention

[0007] The present invention aims to provide a halogen-free flame-retardant antistatic high-temperature resistant nylon composite material and a preparation method thereof, so as to simultaneously take into account the antistatic, flame-retardant and fire safety properties of the high-temperature resistant nylon composite material.

[0008] To achieve the above-mentioned purpose, the present invention adopts the following technical scheme: a halogen-free flame-retardant, antistatic and high-temperature resistant nylon composite material, the raw materials, by mass, include 50-68.4 parts of high-temperature resistant nylon resin, 20-40 parts of reinforcing fiber, 5-10 parts of flame retardant, 0.5-1 part of carbon-forming catalyst, 1-3 parts of synergist, and 0.1-1 part of antioxidant; the reinforcing fiber is a mixture of carbon fiber and glass fiber.

[0009] Preferably, as an improvement, the mass ratio of carbon fiber to glass fiber is 10:10-30.

[0010] Preferably, as an improvement, the length of the carbon fiber is 10±1 mm, the diameter of the glass fiber is 10±1 μm, and the length of the glass fiber is 4.5±1 mm.

[0011] Preferably, as an improvement, the high temperature resistant nylon resin is at least one of PA6I, PA6I / 6T, PA6T / 66, and PA6T / 6I / 66 resins.

[0012] Preferably, as an improvement, the flame retardant is an alkyl aluminum hypophosphite flame retardant; the carbon-forming catalyst is at least one of copper oxide, iron oxide, and nickel oxide; the synergist is at least one of boron nitride and montmorillonite; and the antioxidant is at least one of N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexanediamine and bis(2,4-dicumylphenyl)pentaerythritol diphosphite.

[0013] Preferably, as an improvement, the flame retardant is aluminum diethylphosphinate; the carbon-forming catalyst is nano copper oxide; the synergist is hexagonal boron carbide; and the antioxidant is N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexanediamine.

[0014] Preferably, as an improvement, the particle size of nano copper oxide is ≤50 nm; and the particle size of hexagonal boron nitride is ≤4 μm.

[0015] Preferably, as an improvement, a method for preparing a halogen-free flame-retardant, antistatic and high-temperature resistant nylon composite material comprises the following steps:

[0016] Step 1, drying the high temperature resistant nylon resin, carbon fiber and glass fiber respectively;

[0017] Step 2: weigh the dried carbon fiber and glass fiber and mix them evenly in a mass ratio of 10:10 to 30;

[0018] Step 3, mixing the dried high temperature resistant nylon resin with a flame retardant, a carbon forming catalyst, a synergist, and an antioxidant;

[0019] Step 4: Add the mixed resin and additive mixture from the main feed port of the twin-screw extruder, add the reinforcing fiber from the side feed port of the twin-screw extruder, and obtain a halogen-free flame-retardant, antistatic and high-temperature resistant nylon composite material through melt blending, extrusion granulation and drying.

[0020] Preferably, as an improvement, in step 1, the drying temperature is 100° C. and the drying time is 6 hours.

[0021] Preferably, as an improvement, in step 4, the temperature of the twin-screw extruder is 280°C-330°C, the screw speed is 350rpm / min; the drying temperature is 120°C, and the drying time is 4h.

[0022] The principles and advantages of this solution are as follows: This technical solution aims at the problems existing in flame-retardant nylon in the prior art, and optimizes the formula composition and preparation process of the composite material as a whole: First, in the selection of reinforcing fibers, the surface resistivity of the material can be reduced to below 109Ω by mixing carbon fibers with glass fibers, so that the material has good antistatic function, and the mixing of carbon fibers and glass fibers can also play a synergistic reinforcement role, with the advantages of low cost and easy processing; second, nano copper oxide plays an early catalytic carbonization role, and cooperates with the flame retardant diethyl aluminum hypophosphite to quickly form a carbon layer in the early stage of combustion, thereby improving the flame retardant efficiency; third, this technical solution In the optimization of the synergist, hexagonal boron carbide is used. Hexagonal boron nitride has a special two-dimensional flaky structure and outstanding temperature resistance. It can directly enter the carbon layer during the combustion process, blocking the entry of external oxygen, thereby improving the quality of the carbon layer and the flame retardant efficiency. The dense carbon layer can also reduce the heat release and smoke release during the combustion process, reducing the fire hazard of the material; Fourthly, nano copper oxide and hexagonal boron nitride play a good synergistic role, greatly reducing the addition of diethyl aluminum hypophosphite flame retardant, resulting in a reduction in the total powder additive content, which is beneficial to improving the processing performance of the material and reducing the influence of high content of flame retardant on the mechanical properties of the composite material. In addition, the two-dimensional layered structure of boron nitride also has a certain lubricating effect and improves the heat resistance of the resin matrix. The addition of boron nitride improves the processing performance of the material, making it easy to extrude the tie rod, and improving the processing performance and heat deformation temperature of the material. High-temperature nylon has a high processing temperature, and currently it is mainly flame-retardant modified by ADP flame retardant, but ADP flame retardant usually requires a high addition amount to achieve a good flame retardant effect. When reinforced by fiber, high content of ADP flame retardant and reinforcing fiber will make material processing difficult. During the technical research and development stage, the inventor verified through a large number of experiments that many synergists could not achieve good results and would also lead to a decrease in processing performance. Finally, it was found that the combination of copper oxide and boron nitride can achieve excellent flame retardancy and fire safety of the material while taking into account the processing performance of the material.

[0023] In summary, this technical solution, through the synergistic effect of mixed reinforcing fibers (a mixed system of carbon fibers and glass fibers) and nano-copper oxide, hexagonal boron nitride, and diethyl aluminum hypophosphite, makes the halogen-free flame retardant, antistatic, and high-temperature resistant nylon composite material have good antistatic properties, and the dense carbon layer greatly improves the fire safety and flame retardant efficiency of the composite material. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a microscopic morphology of the combustion carbon residue of Example 2 of the present invention.

[0025] Figure 2 This is a microscopic morphology of the combustion carbon residue of Example 3 of the present invention.

[0026] Figure 3This is a microscopic morphology of the combustion carbon residue of Example 4 of the present invention.

[0027] Figure 4 This is a microscopic morphology of the combustion carbon residue of Comparative Example 6 of the present invention. DETAILED DESCRIPTION

[0028] The following is further described in detail through specific implementations, but the implementation of the present invention is not limited thereto. Unless otherwise specified, the technical means used in the following implementations are conventional means well known to those skilled in the art; the experimental methods used are all conventional methods; the materials, reagents, etc. used can all be obtained from commercial channels.

[0029] Program Overview:

[0030] A halogen-free flame-retardant, antistatic and high-temperature resistant nylon composite material comprises, by weight, 50-68.4 parts of high-temperature resistant nylon resin, 20-40 parts of reinforcing fiber, 5-10 parts of flame retardant, 0.5-1 part of carbon-forming catalyst, 1-3 parts of synergist and 0.1-1 part of antioxidant.

[0031] Among them, the high temperature resistant nylon resin is at least one of PA6I, PA6I / 6T, PA6T / 66, and PA6T / 6I / 66 resins, preferably PA6T / 6I / 66 resin, which is a copolymer of terephthalic acid, hexamethylenediamine, isophthalic acid, and adipic acid, with the brand name N200 and the manufacturer is Zhejiang Xinhecheng.

[0032] The reinforcing fiber is at least one of carbon fiber, glass fiber, aramid fiber, and basalt fiber, preferably a mixture of chopped carbon fiber and chopped glass fiber, the mass ratio of chopped carbon fiber to chopped glass fiber is 10:10-30; the chopped carbon fiber brand is CT-T300P, the carbon fiber length is 10±1mm, the manufacturer is Jiangsu Chuangyu Carbon Fiber, the chopped glass fiber brand is ECS301HG-3 / 4.5, the glass fiber diameter is 10±1μm, the length is 4.5±1mm, the manufacturer is Chongqing International Composite Materials.

[0033] The flame retardant is an alkyl aluminum hypophosphite flame retardant, preferably diethyl aluminum phosphite, with a brand name of OP1230 and a manufacturer of Klein of Germany.

[0034] The carbon-forming catalyst is at least one of copper oxide, iron oxide, and nickel oxide, preferably nano copper oxide with a particle size of ≤50nm, and the manufacturer is Suzhou Sailonan New Materials.

[0035] The synergist is at least one of boron nitride and montmorillonite, preferably hexagonal boron nitride, with a particle size of ≤4 μm, a brand of H-BN-A, and a manufacturer of Tianyuan Aerospace Materials.

[0036] The antioxidant is at least one of N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexanediamine and bis(2,4-dicumylphenyl)pentaerythritol diphosphite, preferably N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexanediamine antioxidant, and the manufacturer is BASF Chemical.

[0037] A method for preparing a halogen-free flame-retardant, antistatic and high-temperature resistant nylon composite material comprises the following steps:

[0038] Step 1: Place the high temperature resistant nylon resin, chopped carbon fiber and chopped glass fiber in an oven at 100°C for drying for 6 hours;

[0039] Step 2: weigh the dried chopped carbon fibers and chopped glass fibers, and mechanically mix 10 parts of carbon fibers and 0-40 parts of glass fibers evenly;

[0040] Step 3: weigh the dried high temperature resistant nylon resin, flame retardant, carbon forming catalyst, synergist and antioxidant according to a certain proportion, and mix the weighed materials in a high speed mixer for 3 minutes at a speed of 1000 rpm / min;

[0041] Step 4: Add the mixed resin and additive mixture from the main feed port of the twin-screw extruder, add the reinforcing fiber from the side feed port of the twin-screw extruder, and obtain a halogen-free, flame-retardant, antistatic and high-temperature resistant nylon composite material through melt blending, extrusion granulation and drying; the twin-screw extruder temperature is 280°C-330°C, the screw speed is 350rpm / min; the drying temperature is 120°C, and the drying time is 4h.

[0042] Example 1

[0043] A method for preparing a halogen-free flame-retardant, antistatic and high-temperature resistant nylon composite material comprises the following steps:

[0044] 69.9 parts of high-temperature nylon resin (PA6T / 6I / 66 resin) and 0.1 parts of antioxidant (N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionyl) hexanediamine) were added to a high-speed mixer and mixed for 3 minutes, and the resulting mixture was added from the main feed port of a twin-screw extruder. 20 parts of chopped glass fibers and 10 parts of chopped carbon fibers were mechanically mixed and added from the side feed port of the third section of the twin-screw extruder. Extrusion, cooling, and pelletizing were performed at an extruder temperature of 270-330°C and a screw speed of 350rpm / min, and the mixture was dried at 120°C for 4 hours in a blast drying oven to obtain a high-temperature resistant nylon composite material.

[0045] Example 2

[0046] The difference between this embodiment and embodiment 1 is that in this embodiment, the mixture added from the main feeding port of the twin-screw extruder consists of 59.9 parts of high-temperature nylon resin, 0.1 parts of antioxidant, 8 parts of diethyl aluminum phosphite flame retardant, and 2 parts of hexagonal boron nitride synergist.

[0047] Example 3

[0048] The difference between this embodiment and embodiment 1 is that in this embodiment, the mixture added from the main feeding port of the twin-screw extruder consists of: 61.4 parts of high-temperature nylon resin, 0.1 parts of antioxidant, 8 parts of diethyl aluminum phosphinate flame retardant, and 0.5 parts of nano copper oxide catalyst.

[0049] Example 4

[0050] The difference between this embodiment and embodiment 1 is that in this embodiment, the mixture added from the main feeding port of the twin-screw extruder consists of: 60.4 parts of high-temperature nylon resin, 0.1 parts of antioxidant, 8 parts of diethyl aluminum phosphinate flame retardant, 1 part of boron nitride synergist, and 0.5 parts of nano copper oxide catalyst.

[0051] Example 5

[0052] The difference between this embodiment and embodiment 4 is that in this embodiment, the mixture added from the main feed port of the twin-screw extruder is composed of: 68.4 parts of high-temperature nylon resin, 0.1 parts of antioxidant, 10 parts of aluminum diethylphosphinate flame retardant, 1 part of boron nitride synergist, and 0.5 parts of nano copper oxide catalyst. The reinforcing fiber added from the side feed port of the twin-screw extruder is a mixture of 10 parts of chopped glass fiber and 10 parts of chopped carbon fiber.

[0053] Example 6

[0054] The difference between this embodiment and embodiment 4 is that in this embodiment, the mixture added from the main feed port of the twin-screw extruder is composed of 50 parts of high-temperature nylon resin, 1 part of antioxidant, 5 parts of aluminum diethylphosphinate flame retardant, 3 parts of boron nitride synergist, and 1 part of nano copper oxide catalyst. The reinforcing fiber added from the side feed port of the twin-screw extruder is a mixture of 30 parts of chopped glass fiber and 10 parts of chopped carbon fiber.

[0055] Comparative Example 1

[0056] The difference between this comparative example and Example 1 is that in this comparative example, the reinforcing fiber added from the side feed port of the twin-screw extruder is: 30 parts of chopped glass fiber, and the remaining raw material composition and processing technology are the same as those in Example 1.

[0057] Comparative Example 2

[0058] The difference between this comparative example and Example 1 is that in this comparative example, the mixture added from the main feed port of the twin-screw extruder is composed of 71.9 parts of high-temperature nylon resin and 0.1 parts of antioxidant. The reinforcing fiber added from the side feed port of the twin-screw extruder is a mixture of 20 parts of chopped glass fiber and 8 parts of chopped carbon fiber. The rest of the processing technology is the same as Example 1.

[0059] Comparative Example 3

[0060] The difference between this comparative example and Example 1 is that in this comparative example, the mixture added from the main feed port of the twin-screw extruder is composed of 67.9 parts of high-temperature nylon resin and 0.1 parts of antioxidant. The reinforcing fiber added from the side feed port of the twin-screw extruder is a mixture of 20 parts of chopped glass fiber and 12 parts of chopped carbon fiber. The rest of the processing technology is the same as Example 1.

[0061] Comparative Example 4

[0062] The difference between this comparative example and Example 4 is that in this comparative example, the mixture added from the main feeding port of the twin-screw extruder consists of 61.9 parts of high-temperature nylon resin, 0.1 parts of antioxidant, and 8 parts of diethyl aluminum phosphinate flame retardant.

[0063] Comparative Example 5

[0064] The difference between this comparative example and Example 4 is that in this comparative example, the mixture added from the main feeding port of the twin-screw extruder consists of 57.9 parts of high-temperature nylon resin, 0.1 parts of antioxidant, and 12 parts of diethyl aluminum phosphinate flame retardant.

[0065] Comparative Example 6

[0066] The difference between this comparative example and Example 4 is that in this comparative example, the mixture added from the main feeding port of the twin-screw extruder consists of 56.9 parts of high-temperature nylon resin, 0.1 parts of antioxidant, and 13 parts of diethyl aluminum phosphinate flame retardant.

[0067] Comparative Example 7

[0068] The difference between this comparative example and Example 4 is that in this comparative example, the mixture added from the main feeding port of the twin-screw extruder consists of 55.9 parts of high-temperature nylon resin, 0.1 parts of antioxidant, and 14 parts of diethyl aluminum phosphinate flame retardant.

[0069] Comparative Example 8

[0070] The difference between this comparative example and Example 5 is that in this comparative example, the mixture added from the main feed port of the twin-screw extruder is composed of 65.9 parts of high-temperature nylon resin, 0.1 parts of antioxidant, and 14 parts of diethyl phosphinate aluminum flame retardant. The reinforcing fiber added from the side feed port of the twin-screw extruder is a mixture of 10 parts of chopped glass fiber and 10 parts of chopped carbon fiber.

[0071] Comparative Example 9

[0072] The difference between this comparative example and Example 6 is that in this comparative example, the mixture added from the main feed port of the twin-screw extruder is composed of 45 parts of high-temperature nylon resin, 1 part of antioxidant, and 14 parts of diethyl phosphinate aluminum flame retardant. The reinforcing fiber added from the side feed port of the twin-screw extruder is a mixture of 30 parts of chopped glass fiber and 10 parts of chopped carbon fiber. The results show that the comparative example has poor processing performance and cannot complete the preparation of flame-retardant and antistatic high-temperature nylon composite materials.

[0073] Experimental Example 1

[0074] The materials of Examples 2, 3, 4 and Comparative Example 6 were subjected to microscopic morphology testing of the combustion residues. The results were as follows: Figure 1-4 As shown, the results show that the density and thickness of the carbon layer in the embodiment of the present invention are significantly improved compared with the comparative example.

[0075] Experimental Example 2

[0076] The materials prepared in the above embodiments and comparative examples were characterized in terms of performance. The tensile strength was tested according to GB / T1040-2022; the notched impact strength was tested according to GB / T 1843-2008; the flexural strength was tested according to GB / T9341-2008; the heat deformation temperature was tested according to GB / T 1634-2019; the surface resistivity was tested according to GB / T31838-2019; the flame retardant grade was tested according to GB / T 2408-2008; the limiting oxygen index was tested according to GB / T2406.2-2009; and the total heat release and total smoke release were tested according to ISO-5660. The test results are shown in Table 1.

[0077] Table 1

[0078]

[0079]

[0080] In Example 1, 20wt% glass fiber and 10wt% carbon fiber are added; in Example 2, 8wt% aluminum diethylphosphinate flame retardant and 2wt% boron nitride synergist are added on the basis of Example 1; in Example 3, 8wt% aluminum diethylphosphinate flame retardant and 0.5wt% nano copper oxide are added on the basis of Example 1; in Example 4, 8wt% aluminum diethylphosphinate flame retardant, 1wt% boron nitride synergist and 0.5wt% nano copper oxide are added on the basis of Example 1. In Example 5, based on Example 4, the composition of the reinforcing fiber is adjusted to a mixture of 10wt% glass fiber and 10wt% carbon fiber. In Example 6, based on Example 4, the composition of the reinforcing fiber is adjusted to a mixture of 30wt% glass fiber and 10wt% carbon fiber. In Comparative Example 1, only a single glass fiber is added; in Comparative Examples 2-3, 8wt% and 12% of carbon fibers are respectively added on the basis of 20wt% of glass fibers; in Comparative Examples 4-7, 8wt%, 12wt%, 13wt% and 14wt% of diethyl aluminum phosphinate flame retardant are respectively added on the basis of Example 1; in Comparative Example 8, the addition amount of diethyl aluminum phosphinate flame retardant is adjusted to 14wt% on the basis of Example 5; in Comparative Example 9, the addition amount of diethyl aluminum phosphinate flame retardant is adjusted to 14wt% on the basis of Example 6.

[0081] It can be seen from the data in Table 1 that, compared with Comparative Examples 1-3, when a single glass fiber is added in Example 1, the composite material does not have antistatic properties, when the carbon fiber content is 8wt%, the composite material does not have antistatic function, and when the carbon fiber content is 12wt%, the surface resistance of the composite material further decreases, but at this time the composite material is not as economical as Example 1, so 10wt% of carbon fiber has good antistatic function and economy.

[0082] Compared with Comparative Examples 4-7, Example 2 shows good synergistic effect of boron nitride, reduces the amount of diethyl aluminum phosphite flame retardant, greatly improves the oxygen index of the material, reduces the total heat release and total smoke release of the material, and boron nitride greatly increases the thermal deformation temperature of the composite material and reduces the difficulty of extruding the tie rod, thereby improving the heat resistance and processing performance of the material.

[0083] Compared with comparative examples 4-7, Example 3 can form a carbon layer at the initial stage of combustion under the early catalytic carbonization of copper oxide, thereby improving the flame retardant efficiency, reducing the amount of diethyl aluminum phosphinate flame retardant, slightly increasing the oxygen index of the material, and reducing the total heat release and total smoke release of the material.

[0084] Compared with Comparative Examples 4-7, under the combined effect of boron nitride and copper oxide, the composite material of Example 4 exhibits extremely excellent flame retardant properties, and has extremely low total heat release and total smoke release, showing higher fire safety.

[0085] In addition, in Comparative Example 7, without adding a synergist and a catalyst, the amount of the flame retardant needs to be increased to 14 wt % to achieve a flame retardant effect.

[0086] The difference between Comparative Example 8 and Example 5 is that no synergist and carbon-forming catalyst are added. The results show that 14wt% of diethylphosphinate aluminum flame retardant is required to achieve the flame retardant effect; Comparative Example 9 has a low resin content, a high fiber content and a high amount of flame retardant added, resulting in poor material processing performance and unable to complete material preparation, so it is impossible to complete the detection of various indicators.

[0087] The above is only an embodiment of the present invention, and the common knowledge such as the known specific technical solutions and / or characteristics in the solution is not described in detail here. It should be pointed out that for those skilled in the art, without departing from the technical solution of the present invention, several modifications and improvements can be made, which should also be regarded as the protection scope of the present invention, and these will not affect the effect of the implementation of the present invention and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims

1. A halogen-free flame-retardant, antistatic and high-temperature resistant nylon composite material, characterized by: The raw materials, calculated by weight, include 50-68.4 parts of high temperature resistant nylon resin, 20-40 parts of reinforcing fiber, 5-10 parts of flame retardant, 0.5-1 parts of carbon forming catalyst, 1-3 parts of synergist, and 0.1-1 parts of antioxidant; The reinforcing fibers are a mixture of carbon fibers and glass fibers.

2. The halogen-free flame-retardant, antistatic and high-temperature resistant nylon composite material according to claim 1, characterized in that: The mass ratio of the carbon fiber to the glass fiber is 10:10-30.

3. The halogen-free flame-retardant, antistatic and high-temperature resistant nylon composite material according to claim 2, characterized in that: The length of the carbon fiber is 10±1 mm, the diameter of the glass fiber is 10±1 μm, and the length of the glass fiber is 4.5±1 mm.

4. The halogen-free flame-retardant, antistatic and high-temperature resistant nylon composite material according to claim 3, characterized in that: The high temperature resistant nylon resin is at least one of PA6I, PA6I / 6T, PA6T / 66, and PA6T / 6I / 66 resins.

5. The halogen-free flame-retardant, antistatic and high-temperature resistant nylon composite material according to claim 4, characterized in that: The flame retardant is an alkyl aluminum hypophosphite flame retardant; the carbon-forming catalyst is at least one of copper oxide, iron oxide, and nickel oxide; the synergist is at least one of boron nitride and montmorillonite; and the antioxidant is at least one of N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexanediamine and bis(2,4-dicumylphenyl)pentaerythritol diphosphite.

6. The halogen-free flame-retardant, antistatic and high-temperature resistant nylon composite material according to claim 5, characterized in that: The flame retardant is aluminum diethylphosphinate; the carbon-forming catalyst is nano copper oxide; the synergist is hexagonal boron carbide; and the antioxidant is N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionyl) hexamethylenediamine.

7. The halogen-free flame-retardant, antistatic and high-temperature resistant nylon composite material according to claim 6, characterized in that: The particle size of the nano copper oxide is ≤50nm; the particle size of the hexagonal boron nitride is ≤4μm.

8. The method for preparing a halogen-free flame-retardant, antistatic and high-temperature resistant nylon composite material according to any one of claims 1 to 7, characterized in that: The steps include: Step 1, drying the high temperature resistant nylon resin, carbon fiber and glass fiber respectively; Step 2: weigh the dried carbon fiber and glass fiber and mix them evenly in a mass ratio of 10:10-30; Step 3, mixing the dried high temperature resistant nylon resin with a flame retardant, a carbon forming catalyst, a synergist, and an antioxidant; Step 4: Add the mixed resin and additive mixture from the main feed port of the twin-screw extruder, add the reinforcing fiber from the side feed port of the twin-screw extruder, and obtain a halogen-free flame-retardant, antistatic and high-temperature resistant nylon composite material through melt blending, extrusion granulation and drying.

9. The method for preparing a halogen-free flame-retardant, antistatic and high-temperature resistant nylon composite material according to claim 8, characterized in that: In step 1, the drying temperature is 100°C and the drying time is 6 hours.

10. The method for preparing a halogen-free flame-retardant, antistatic and high-temperature resistant nylon composite material according to claim 9, characterized in that: In step 4, the temperature of the twin-screw extruder is 280°C-330°C, the screw speed is 350rpm / min; the drying temperature is 120°C, and the drying time is 4h.

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