A long glass fiber reinforced nylon composite material and its preparation method and application

Abstract

The present invention relates to a long glass fiber reinforced nylon composite material in the field of polymer material technology, and its preparation method and application. The long glass fiber reinforced nylon composite material comprises the following components in parts by weight: nylon, 100 parts by weight; maleic anhydride-styrene alternating copolymer microspheres with dispersed fumed silica, 1 to 40 parts by weight; compatibilizer, 3 to 30 parts by weight; glass fiber, 30 to 60 parts by weight. The nylon reinforced composite material has higher comprehensive mechanical properties, better dimensional stability, and lower water absorption, and has broad application prospects in automobile manufacturing, machinery industry, stationery and sports goods, and home appliances.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer materials, and more particularly to a long glass fiber reinforced nylon composite material and a preparation method and application thereof. Background Art

[0002] Long glass fiber reinforced nylon composites are gaining more and more attention in the automotive industry. Compared with short fiber reinforced polypropylene, they have higher tensile strength, flexural strength and modulus, which helps to realize the widespread application of general-purpose polypropylene plastics in load-bearing parts in the automotive industry, and also helps to achieve the goal of low cost and high efficiency.

[0003] After thermoplastic resin is reinforced with glass fiber, its strength, modulus, impact resistance and heat resistance are comprehensively improved. Glass fiber length is not the only factor that determines the performance of fiber composite materials. The resin impregnation condition of the fiber, the distribution of the fiber in the matrix, the fiber content and the interface bonding strength between the fiber and the matrix all have an important influence on the performance of the composite material. Glass fiber plays a role of reinforcing the skeleton structure in nylon. When subjected to load, due to the axial transmission of glass fiber, the stress is rapidly diffused to prevent the growth of cracks. Therefore, the increase in glass fiber content improves the mechanical properties of nylon. Its addition increases the hindrance to the movement of polymer macromolecular segments in the interface layer between the fiber and the matrix resin, increases the glass transition temperature of the material, and is manifested as an increase in the heat deformation temperature on a macroscopic scale.

[0004] In addition, as the glass fiber content increases, the melt flow rate and elongation at break of the composite material decrease, while the density and hardness increase. This also shows that the compressive performance of the material is improved. Compared with the short glass fiber reinforcement method, the strength, modulus, impact resistance, creep resistance, fatigue resistance, wear resistance, heat resistance, etc. of long glass fiber reinforced nylon are improved, thereby further broadening its application range. Long glass fiber reinforced PA6 has huge development potential in the fields of automobiles, machinery, electrical appliances, military industry, etc.

[0005] This material has become one of the hottest materials for lightweight automobiles. In practical applications, plastic can replace steel and reinforced engineering plastics to meet the requirements of packaging boxes, automobiles, home appliances and other fields. However, after adding glass fiber, the shrinkage rate along the flow direction and the vertical direction will be inconsistent on the parts. This is caused by the different orientations of long glass fibers in the resin matrix during the processing and molding process. This restricts the application of long glass fiber reinforced nylon composites in large parts and complex precision parts in the automotive industry. In addition, there are hydrogen bonds in the molecular structure of nylon. This part of the intermolecular force contributes to the excellent performance of nylon. On the other hand, the existence of hydrogen bonds makes nylon extremely susceptible to moisture absorption, and the rigidity and toughness show completely different physical properties in the dry and wet states.

[0006] In Chinese patent CN106479167B, nylon 6, 0.2-0.8 parts by weight of high temperature heat stabilizer, 0.1-0.8 parts by weight of anhydrous calcium chloride, and 0.1-0.8 parts by weight of silane coupling agent are mixed with the molten material by side feeding. Chinese patent CN110527284A reports a nylon plastic material for automobile electroplating and a preparation method, in which a layer of weakly alkaline porous aluminum hydroxide is coated on the surface of silica microspheres by hydrothermal reaction, which not only achieves the effect of lightweight, but also increases the specific surface area and improves the adsorption capacity of the surface aluminum hydroxide to the acid solution. By compounding with nylon, the nylon material is more easily etched in the acid solution, which is conducive to improving the etching effect, thereby significantly improving the electroplating performance of the nylon material.

[0007] Chinese patent CN107254163B mentions a nylon / silicon dioxide composite microsphere, preparation method and application, which is composed of a porous nylon microsphere matrix and silicon dioxide uniformly dispersed in the pores and / or surface of the porous nylon microsphere. The composite microsphere is obtained by in-situ hydrolysis of silicon dioxide in a porous nylon microsphere dispersion. The addition of silicon dioxide can effectively reduce the water absorption rate of the porous nylon composite microsphere, and improve thermal stability, crystallization performance and mechanical strength.

[0008] Chinese patent CN110467812A is a method for manufacturing composite modified nylon 12 for laser 3D printing. The raw material polylaurolactam is initially grafted with silica through a coupling agent, then melt-mixed with polypropylene to form an alloy modification, and finally grafted with methyl methacrylate again through swelling and expansion. A total of three compatible composite modifications are finally obtained.

[0009] Chinese patent CN106832907B discloses a high shrinkage biaxially stretched nylon 6 film and its production method, comprising nylon, special nylon in 17-21 parts, and an anti-adhesive agent, wherein the anti-adhesive agent is silicon dioxide or calcium carbonate or magnesium carbonate. The high shrinkage film with a heat shrinkage rate of 8-10% is produced by using nylon.

[0010] How to overcome the water absorption and high shrinkage of nylon is the key and focus of nylon research and application. Summary of the invention

[0011] In order to solve the above problems existing in the prior art, the present invention provides a long glass fiber reinforced nylon composite material, specifically, a long glass fiber reinforced nylon composite material and a preparation method and application thereof.

[0012] One of the objects of the present invention is to provide a long glass fiber reinforced nylon composite material, which may include the following components in parts by weight:

[0013] Nylon, 100 parts by weight;

[0014] Maleic anhydride-styrene alternating copolymer microspheres dispersed with fumed silica, 1 to 40 parts by weight, preferably 5 to 25 parts by weight;

[0015] Compatibilizer, 3 to 30 parts by weight, preferably 5 to 15 parts by weight;

[0016] Glass fiber, 30-60 parts by weight.

[0017] in,

[0018] The viscosity of the nylon may be 1.0 to 3.0; and / or,

[0019] The nylon can be selected from at least one of nylon 6, nylon 66, nylon 1010, nylon 12, nylon 11, and aromatic nylon.

[0020] The maleic anhydride-styrene alternating copolymer microspheres dispersed with fumed silica can be prepared by a method comprising the following steps:

[0021] The fumed silica and maleic anhydride-styrene alternating copolymer microspheres are blended and dispersed uniformly to obtain the product.

[0022] The blending temperature can be room temperature, specifically 20 to 50° C.; specifically, a cooling device can be used during operation to keep the blending temperature at 20 to 50° C. If the blending stirring time is long, the system temperature increases, and the fumed silica may precipitate, resulting in a poor final dispersion effect. The blending time of the present invention can be 5 to 40 minutes, preferably 5 to 25 minutes.

[0023] The blending device may be a stirrer, such as a high-speed stirrer or other commonly used stirring equipment in the art; the motor speed may be set to 20 to 500 rpm, preferably 50 to 150 rpm; the blending device may also be a dispersing device, such as a high-speed disperser, or an ultrasonic disperser or a similar dispersing device or a dispersing device with a stirring blade; the blade linear speed of the dispersing device may be 5 to 50 m / s;

[0024] The amount of the fumed silica can be 0.5-10%wt, preferably 0.5-5%wt, of the weight of the maleic anhydride-styrene alternating copolymer microspheres. Within this range, the fumed silica can be well dispersed on the surface of the maleic anhydride-styrene alternating copolymer microspheres.

[0025] in,

[0026] The maleic anhydride-styrene alternating copolymer microspheres are prepared according to the copolymerization method in the Chinese patent CN101235117A (application number CN200810101948.0). Specifically, under nitrogen protection, monomers Man and St, initiator organic peroxide or azo compound, are dissolved in a mixed solution medium of organic acid alkyl ester or ketone and alkane, and reacted at 60-90°C for 1 / 4-12h to obtain a dispersed system of polymer microspheres. The average particle size of the microspheres in the dispersed system is 90-1715nm, the dispersion coefficient is 1.04-1.004, and the number average molecular weight ranges from 8000 to 300000g / mol. The polymer microspheres of nanometer to micrometer scale have large specific surface area, strong adsorption, large cohesion, and strong surface reaction ability. The purpose of dispersing silica in the polymer dispersed microspheres is to disperse the silica agglomerates into very small aggregates, which can be evenly distributed in the resin. Silica and polymer dispersed microspheres are combined through intermolecular interactions, making it easy to add to the polymer resin matrix.

[0027] The fumed silica is a highly dispersed, amorphous, high-purity silica particle, which is obtained by high-temperature hydrolysis of silicon tetrachloride in a hydrogen-oxygen flame. The average diameter of the primary particles of the fumed silica can be 7 to 40 nm, and the corresponding specific surface area can be 50 to 380 m 2 / g, different products have different particle sizes. Siloxane and silanol groups are distributed on the surface of these particles. Fumed silica can be surface-modified by reacting the surface silanol groups with suitable substances, such as silane compounds. The surface of this product is covered with chemically bonded dimethyl silyl groups, so that it cannot be wetted by water, that is, it shows hydrophobicity. The present invention adopts maleic anhydride-styrene alternating copolymer microspheres to disperse fumed silica. The silanol groups on the surface of fumed silica interact with the anhydride bonds of the maleic anhydride-styrene alternating copolymer microspheres, and the fumed silica changes from hydrophilicity to hydrophobicity. Maleic anhydride-styrene alternating copolymer microspheres have good compatibility with nylon, so fumed silica can be more evenly dispersed in nylon.

[0028] The compatibilizer of the present invention can be a maleic anhydride grafted copolymer, preferably at least one of polypropylene grafted maleic anhydride, polyethylene grafted maleic anhydride, maleic anhydride grafted polyolefin elastomer, and maleic anhydride grafted methyl methacrylate copolymer.

[0029] Specifically, the compatibilizer may be maleic anhydride grafted POE, and the density may be 0.89-0.91 g / cm 3 The melting point can be 160-180°C, the melt flow rate (230°C, 2.16Kg) can be 100-200g / 10min, and the grafting rate of maleic anhydride can be 0.8-1.2%.

[0030] The glass fiber may be an alkali-free continuous glass fiber, may have a diameter of 10 to 24 um, and may have a linear density of 1200 to 4800 TEX.

[0031] In some specific implementations of the present invention,

[0032] The long glass fiber reinforced nylon composite material may contain a lubricant; based on 100 parts by weight of the nylon, the amount of the lubricant may be 0.1 to 1 part by weight, preferably 0.5 to 1 part by weight; and / or, the lubricant may be selected from one or more of oxidized polyethylene wax, microcrystalline wax, ethylene amide, and stearic acid amide.

[0033] In some specific implementations of the present invention,

[0034] The long glass fiber reinforced nylon composite material may contain a surface modifier; based on 100 parts by weight of the nylon, the amount of the surface modifier is 5 to 10 parts by weight. The surface modifier may be one or more combinations of ultra-high melt index polypropylene; the melt flow rate of the ultra-high melt index polypropylene may be 400 to 3800 g / 10 min.

[0035] In some specific implementations of the present invention,

[0036] The long glass fiber reinforced nylon composite material may contain an antioxidant; based on 100 parts by weight of the nylon, the amount of the antioxidant is 0.1 to 3 parts by weight. The antioxidant is at least one or two of antioxidant 1010, antioxidant 1076, antioxidant 2246, antioxidant 168, antioxidant CA, antioxidant 626 or antioxidant 636.

[0037] The second object of the present invention is to provide a method for preparing the long glass fiber reinforced nylon composite material, which may include the following steps:

[0038] (1) uniformly blending the components including the nylon, maleic anhydride-styrene alternating copolymer microspheres dispersed with fumed silica, a compatibilizer, a lubricant, and an antioxidant to obtain a nylon mixed resin;

[0039] (2) Melting the nylon mixed resin and impregnating and coating it with glass fibers to obtain the long glass fiber reinforced nylon composite material.

[0040] Preferably, the preparation method may include the following steps:

[0041] (1) Adding the components including the nylon, maleic anhydride-styrene alternating copolymer microspheres of dispersed fumed silica, a compatibilizer, a lubricant, and an antioxidant into a high-speed mixer and blending them uniformly to obtain a nylon mixed resin; preferably, the blending temperature is controlled to be 20 to 60° C., and the mixing time is 1 to 5 minutes, and then the mixed nylon mixed resin is added to the hopper of the extruder for standby use.

[0042] (2) Using a continuous fiber reinforced thermoplastic material impregnation device, the mixed nylon mixed resin obtained in step (1) is melted and plasticized by an extruder and then enters a melt impregnation die connected to the extruder head. The continuous glass fiber bundle is led out from the fiber guide frame, enters the glass fiber dispersion roller system and preheating unit to preheat and disperse the glass fiber, and then enters the melt impregnation die head and is impregnated and coated with the molten nylon mixed resin. The impregnated and coated composite material strip is pulled out through a shaping plate and a die plate, and then is stretched, cooled, blown dry, and pelletized to prepare a long glass fiber reinforced nylon composite material. The content of continuous glass fiber in the composite material is adjusted to 30 to 60 parts by weight by selecting the size of the die plate; and long glass fiber reinforced nylon pellets with a pelletizing length of 6 to 25 mm are obtained by adjusting the cutting speed of the pelletizer.

[0043] Furthermore, the preparation method of the long glass fiber reinforced nylon composite material may include the following steps:

[0044] (1) Maleic anhydride-styrene alternating copolymer microspheres are prepared according to the method of patent CN101235117A (application number CN200810101948.0), which is to dissolve monomers Man and St and initiator organic peroxide or azo compound in a mixed solution medium of organic acid alkyl ester or ketone and alkane under nitrogen protection, and react at 60-90°C for 1 / 4-12h to obtain a dispersed system of polymer microspheres. The average particle size of the microspheres in the dispersed system is 90-1715nm, the dispersion coefficient is 1.04-1.004, and the number average molecular weight ranges from 8000 to 300000g / mol.

[0045] (2) Blending the maleic anhydride-styrene alternating copolymer microspheres with fumed silica to obtain the maleic anhydride-styrene alternating copolymer microspheres dispersed with fumed silica, wherein the amount of fumed silica used is 0.5-10%wt of the weight of the maleic anhydride-styrene alternating copolymer microspheres.

[0046] (3) Adding the components including the nylon, compatibilizer, maleic anhydride-styrene alternating copolymer microspheres dispersed with fumed silica, antioxidant, lubricant, and surface modifier into a high-speed mixer, controlling the mixing temperature to 20-60° C. for 1-5 minutes, and then adding the mixed nylon mixed resin into the hopper of the extruder for standby use.

[0047] (4) Using a continuous fiber reinforced thermoplastic material impregnation device, the nylon mixed resin mixed in step (3) is melted and plasticized through an extruder and then enters a melt impregnation mold connected to the extruder head.

[0048] (5) The continuous glass fiber bundle is guided out from the fiber guide frame, enters the glass fiber dispersion roller system and preheating unit to preheat and disperse the glass fiber, and then enters the melt impregnation die head to be impregnated and coated with the molten nylon mixed resin.

[0049] (6) The impregnated and coated composite material strip is pulled out through a shaping plate and a die plate, and then subjected to strip drawing, cooling, drying, and pelletizing to prepare a long glass fiber reinforced nylon composite material. The content of the continuous glass fiber in the composite material is adjusted to 30 to 60 parts by weight by selecting the size of the die plate; and the long glass fiber reinforced nylon pellets with a pelletizing length of 6 to 25 mm are obtained by adjusting the cutting speed of the pelletizer.

[0050] The extruder can be a twin-screw extruder, the screw diameter can be 40-55mm, the screw aspect ratio can be 40:1, the processing temperature can be 240-300℃, the melt temperature can be 240-280℃, and the die temperature can be 240-280℃.

[0051] The temperature of the impregnation equipment can be 260-280°C.

[0052] The temperature of the dispersion roller system and the preheating unit can be 130-170°C.

[0053] The diameter of the shaping die can be 3.0-5.0 mm, corresponding to 100 parts by weight of the nylon, the content of the glass fiber in the composite material can be 30-60 parts by weight.

[0054] The third object of the present invention is to provide the application of the long glass fiber reinforced nylon composite material or the long glass fiber reinforced nylon composite material prepared according to the preparation method in the fields of automobile manufacturing, machinery industry, stationery and sports goods, and household appliances.

[0055] The long glass fiber reinforced nylon composite material comprises nylon, compatibilizer, glass fiber, maleic anhydride-styrene alternating copolymer microspheres dispersed with fumed silica, antioxidant, lubricant, surface modifier, etc. The nylon reinforced composite material has higher comprehensive mechanical properties, better dimensional stability, and lower water absorption, and is widely used in automobile manufacturing, machinery industry, stationery and sports goods, home appliances and other fields. DETAILED DESCRIPTION

[0056] The present invention is described in detail below in conjunction with specific embodiments. It is necessary to point out that the following embodiments are only used to further illustrate the present invention and cannot be understood as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made to the present invention by those skilled in the art based on the contents of the present invention still fall within the scope of protection of the present invention.

[0057] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0058] Source of raw materials

[0059] Nylon 6, BL2000, viscosity 2.0, produced by Sinopec Baling Petrochemical Company.

[0060] Glass fiber: alkali-free glass fiber, ER4301, diameter 17μm, linear density 2400tex, Chongqing International Composite Materials.

[0061] Maleic anhydride grafted polyolefin elastomer (MAH-g-POE), brand EB-3008, grafting rate 1.2%, Guangzhou Chuanju Chemical Technology Co., Ltd.

[0062] Fumed silica, average primary particle size 12nm, corresponding specific surface area 200±25m 2 / g, 200, purchased from Evonik Corporation, USA;

[0063] Antioxidant 1010, produced by BASF;

[0064] Antioxidant 168, produced by BASF;

[0065] Lubricant Incromold T, produced by Croda, UK;

[0066] Surface modifier, PP PF1500, melt index 1800g / 10min, Hunan Shengjin New Materials Co., Ltd.;

[0067] The maleic anhydride-styrene alternating copolymer microsphere sample was prepared according to Example 1 of patent CN200810101948.0, with a molar ratio of MAn and St of 1:1, wherein Man 0.3001g, St 0.330g; the initiator was azobisisobutyronitrile AIBN, 0.05g; the medium was isoamyl acetate, 45mL. The reaction was carried out at a temperature of 70°C for 6 hours by heating in a water bath to obtain maleic anhydride / styrene alternating copolymer PMS microspheres, with an average particle size (Dn) of 341nm, a dispersion coefficient (U) of 1.031, a polymerization yield (Cp) of 85%, and a polymer number average molecular weight (Mn) of 120365.

[0068] Preparation of maleic anhydride-styrene alternating copolymer microspheres dispersed with fumed silica :

[0069] The maleic anhydride-styrene alternating copolymer microspheres and fumed silica were mixed in a high-speed disperser for 25 minutes, and a cooling device was used to keep the temperature of the high-speed disperser at 30° C. The blade linear speed was 25 m / s. The amount of fumed silica was 3 wt % of the weight of the maleic anhydride-styrene alternating copolymer microspheres.

[0070] In addition, the preparation method of maleic anhydride-styrene alternating copolymer microspheres 1 was adopted, except that the amount of the fumed silica was 5 wt % of the amount of the maleic anhydride-styrene alternating copolymer microspheres, to obtain maleic anhydride-styrene alternating copolymer microspheres 2 dispersed with fumed silica.

[0071] Examples 1 to 5

[0072] (1) Mix nylon, maleic anhydride grafted polyolefin elastomer as a compatibilizer, maleic anhydride-styrene alternating copolymer microspheres with dispersed fumed silica, and antioxidant in a high-speed mixer at 25°C for 3 minutes, with the motor speed set at 150 rpm; then add the mixed nylon mixed resin into the hopper of the extruder for later use. The mass fraction of nylon 6 is 100 mass fractions, and the mass fractions of other components are shown in Table 1 below.

[0073] (2) Using continuous fiber reinforced thermoplastic material impregnation equipment, the mixed nylon mixed resin is melted and plasticized through an extruder and then enters a melt impregnation mold connected to the extruder head.

[0074] (3) The continuous glass fiber bundle is guided out from the fiber guide frame, enters the glass fiber dispersion roller system and preheating unit to preheat and disperse the glass fiber, and then enters the melt impregnation die head to be impregnated and coated with the molten nylon mixed resin.

[0075] (4) After the impregnated and coated composite material strip is pulled out through the shaping plate and the die plate, it is stretched, cooled, blown dry, and pelletized to obtain a long glass fiber reinforced nylon composite material. By adjusting the cutting speed of the pelletizer, a long glass fiber reinforced nylon pellet with a pelletizing length of 12 mm is obtained.

[0076] (5) Long glass fiber reinforced nylon pellets were dried and injection molded to test the mechanical properties.

[0077] The extruder is a twin-screw extruder with a screw diameter of 40-55 mm, a screw length-diameter ratio of 40:1, a processing temperature of 240-300°C, a melt temperature of 240-280°C, and a die head temperature of 240-280°C.

[0078] The temperature of the impregnation equipment is 260-280°C.

[0079] The temperature of the dispersion roller system and the preheating unit is 130-170°C.

[0080] Comparative Example 1

[0081] Except that maleic anhydride-styrene alternating copolymer microspheres with dispersed fumed silica, maleic anhydride grafted polyolefin elastomer (MAH-g-POE), glass fiber, lubricant and surface modifier are not added, the other steps are the same as those in Example 1. The specific amounts of the components are shown in Table 2 below.

[0082] Comparative Example 2

[0083] Except that fumed silica was added instead of maleic anhydride-styrene alternating copolymer microspheres dispersed with fumed silica, the other steps were the same as those in Example 1. The specific amounts of the components are shown in Table 2 below.

[0084] Comparative Example 3

[0085] Except that maleic anhydride-styrene alternating copolymer microspheres dispersed with fumed silica were not added, but MAH-g-St microspheres not modified with fumed silica were added, the other steps were the same as those in Example 1. The specific amounts of the components are shown in Table 2 below.

[0086] Table 1 Recipe

[0087] Example 1 Example 2 Example 3 Example 4 Example 5 MAH-g-POE 10 10 10 15 10 Microsphere 1 5 15 25 0 35 Microsphere 2 0 0 0 25 0 Fiberglass 40 40 40 35 35 Antioxidant 1010 0.20 0.15 0.15 0.2 0.2 Antioxidant 168 0.20 0.25 0.15 0.2 0.2 Incromold T 0.3 0.5 0.5 0.5 0.5 Surface modifier PF1800 5 5 5 5 5

[0088] Table 2 Recipe

[0089] Comparative Example 1 Comparative Example 2 Comparative Example 3 MAH-g-POE 0 10 10 Fumed Silica 0 0.75 0 MAH-g-St microspheres 0 0 25 Fiberglass 0 40 40 Antioxidant 1010 0.15 0.15 0.15 Antioxidant 168 0.15 0.15 0.15 Incromold T 0 0.5 0.5 Surface modifier PF1800 0 5 5

[0090] Product performance testing

[0091] The products prepared in Examples 1 to 5 and Comparative Examples 1 to 3 were subjected to performance tests. The test methods are as follows: tensile strength was measured according to GB / T 1040-2006, with a tensile rate of 5 mm / min; flexural strength was measured according to GB / T 9341-2000, with a test rate of 2 mm / min; simply supported beam notched impact strength was measured according to GB / T 1043-2008; shrinkage was measured according to GB / T15585-1995. Moisture content was tested by weighing method. The test results are shown in Table 3 below.

[0092] Table 3 Material performance test results

[0093]

[0094] Compared with comparative examples 1 to 3, the above-mentioned embodiments 1 to 5 are dispersed in the maleic anhydride-styrene alternating copolymer microspheres, which improves the tensile strength, flexural strength and simply supported beam notched impact strength of the composite material, reduces the shrinkage rate of the composite material, especially reduces the difference in shrinkage rate of the composite material parallel to the flow direction and perpendicular to the flow direction, and greatly reduces the water absorption rate.

Claims

1. A long glass fiber reinforced nylon composite material comprising the following components in parts by weight: Nylon, 100 parts by weight; Maleic anhydride-styrene alternating copolymer microspheres dispersed with fumed silica, 1 to 40 parts by weight; Compatibilizer, 3 to 30 parts by weight; Glass fiber, 30-60 parts by weight; The compatibilizer is a maleic anhydride graft copolymer; The method for preparing maleic anhydride-styrene alternating copolymer microspheres dispersed with fumed silica comprises the following steps: The fumed silica and maleic anhydride-styrene alternating copolymer microspheres are blended to obtain; The amount of the fumed silica is 0.5-10%wt of the weight of the maleic anhydride-styrene alternating copolymer microspheres.

2. The long glass fiber reinforced nylon composite material according to claim 1, characterized in that: The viscosity of the nylon is 1 to 3.0; and / or, The nylon is selected from at least one of nylon 6, nylon 66, nylon 1010 and aromatic nylon.

3. The long glass fiber reinforced nylon composite material according to claim 1, characterized in that: Based on 100 parts by weight of the nylon, the amount of maleic anhydride-styrene alternating copolymer microspheres dispersed with fumed silica is 5 to 25 parts by weight.

4. The long glass fiber reinforced nylon composite material according to claim 1, characterized in that: Taking the amount of the nylon as 100 parts by weight, the amount of the compatibilizer is 5 to 15 parts by weight.

5. The long glass fiber reinforced nylon composite material according to claim 1, characterized in that: The compatibilizer is at least one of polypropylene grafted maleic anhydride, polyethylene grafted maleic anhydride, maleic anhydride grafted polyolefin elastomer, and maleic anhydride grafted methyl methacrylate copolymer.

6. The long glass fiber reinforced nylon composite material according to claim 1, characterized in that Containing a lubricant; based on 100 parts by weight of the nylon, the amount of the lubricant is 0.1 to 1 part by weight; The lubricant is selected from one or more of oxidized polyethylene wax, microcrystalline wax, ethylene amide, and stearic amide.

7. The long glass fiber reinforced nylon composite material according to claim 6, characterized in that: Based on 100 parts by weight of the nylon, the amount of the lubricant is 0.5 to 1 part by weight.

8. The long glass fiber reinforced nylon composite material according to claim 1, characterized in that Contains a surface modifier; based on 100 parts by weight of the nylon, the amount of the surface modifier is 5 to 10 parts by weight; the surface modifier is one or more combinations of ultra-high melt index polypropylene; the melt flow rate of the ultra-high melt index polypropylene is 400-3800g / 10min.

9. The long glass fiber reinforced nylon composite material according to claim 1, characterized in that: The glass fiber is an alkali-free continuous glass fiber with a diameter of 10 to 24 um and a linear density of 1200 to 4800 TEX.

10. A long glass fiber reinforced nylon composite material according to any one of claims 1 to 9, characterized in that: The amount of the fumed silica is 0.5-5%wt of the weight of the maleic anhydride-styrene alternating copolymer microspheres.

11. The long glass fiber reinforced nylon composite material according to claim 10, characterized in that: The blending time is 5 to 40 minutes; the blending temperature is 20 to 50°C.

12. The long glass fiber reinforced nylon composite material according to claim 10, characterized in that: The maleic anhydride-styrene alternating copolymer microspheres have an average particle size of 90 to 1715 nm, a dispersion coefficient of 1.04 to 1.004, and a number average molecular weight range of 8000 to 300000 g / mol.

13. The long glass fiber reinforced nylon composite material according to claim 10, characterized in that: The average diameter of the fumed silica is 7-40 nm, and the corresponding specific surface area is 50-380 m 2 / g.

14. A method for preparing a long glass fiber reinforced nylon composite material according to any one of claims 1 to 13, characterized in that The following steps are involved: (1) uniformly blending the components including the nylon, maleic anhydride-styrene alternating copolymer microspheres dispersed with fumed silica, and a compatibilizer to obtain a nylon mixed resin; (2) Melting the nylon mixed resin and impregnating and coating it with glass fibers to obtain the long glass fiber reinforced nylon composite material.

15. The method for preparing a long glass fiber reinforced nylon composite material according to claim 14, characterized in that: In step (1), the blending temperature is 20 to 60°C.

16. Use of the long glass fiber reinforced nylon composite material according to any one of claims 1 to 13 or the long glass fiber reinforced nylon composite material prepared by the preparation method according to claim 14 in the fields of automobile manufacturing, machinery industry, stationery and sports goods, and household appliances.

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