Electromagnetically shielded thermoplastic composite material and method of manufacture and use thereof

Abstract

The present invention discloses a thermoplastic composite material for electromagnetic shielding, and its preparation method and application. The electromagnetic shielding thermoplastic composite material comprises an inner layer material and at least one outer layer material, wherein the inner layer material is a core layer comprising a fiber bundle, a first thermoplastic resin and a first auxiliary agent, and the at least one outer layer material wraps the core layer and is a resin layer comprising a second thermoplastic resin, an electromagnetic shielding filler and an optional second auxiliary agent, wherein the fiber bundle extends continuously from one end of the core layer to the opposite end thereof. The electromagnetic shielding thermoplastic composite material of the present invention is designed based on a multi-component material system, which can achieve a synergistic effect of performance between the components and has good electromagnetic shielding performance.

Description

Technical Field

[0001] This invention belongs to the field of polymer composite materials, specifically relating to an electromagnetic shielding thermoplastic composite material, its preparation method, and its application. Background Technology

[0002] Long fiber reinforced thermoplastic composites are a common type of thermoplastic composite material and one of the fastest-growing materials in the composite materials market today. As both semi-structural and structural materials, long fiber reinforced thermoplastic composites are being developed for various industrial and civilian applications, including automotive, machinery, entertainment, food processing, communications, electronics, power tools, and horticulture.

[0003] Long fiber reinforced thermoplastic materials have fiber lengths equal to particle lengths and highly consistent fiber orientation, resulting in low density, ease of molding, high specific strength, high modulus, good fatigue resistance, and non-absorbency. Furthermore, these materials exhibit good dimensional stability, excellent impact resistance, chemical stability (resistance to salt, oil, and fuels), and recyclability, making them particularly suitable for applications with frequent high and low temperature fluctuations. They can be injection molded on conventional injection molding machines or compression molded, making them ideal candidates for metal replacement. Automotive materials account for 80%-90% of the total usage of long fiber reinforced thermoplastic composites.

[0004] However, with the rapid development of the electronics and information industry, the number of electronic products generating electromagnetic interference has increased dramatically, and electromagnetic interference has become a public nuisance. At the same time, precision electronic equipment and components are easily damaged by electromagnetic interference. Electromagnetic shielding materials, as an effective means of electromagnetic protection, have received widespread attention and application. For large and complex automotive parts and high-precision electronic components, the materials used must possess high flowability, ease of molding, high dimensional stability, high surface quality, electromagnetic shielding capabilities, and be suitable for processing and molding. Therefore, it is necessary to develop a composite material for electromagnetic shielding with excellent mechanical properties. CN109664577A discloses a multilayer electromagnetic shielding composite material and its preparation method, but the layers require an adhesive, making the processing method relatively complex. CN105164192A also discloses a prepreg and its manufacturing method, using epoxy resin as the matrix resin, but its production efficiency is insufficient to meet the requirements of high-efficiency continuous processing.

[0005] The existing technology is far from meeting the needs of practical applications in addressing the aforementioned problems. Summary of the Invention

[0006] To address the aforementioned problems in existing technologies, this invention provides an electromagnetic shielding thermoplastic composite material, its preparation method, and its applications. The electromagnetic shielding thermoplastic composite material of this invention is designed based on a multi-component material system, enabling synergistic performance among the components and resulting in excellent electromagnetic shielding performance. Furthermore, the electromagnetic shielding thermoplastic composite material of this invention significantly improves the flowability of fibers in the resin melt, greatly enhancing the surface properties of the composite material and expanding its application range.

[0007] The first aspect of the present invention provides an electromagnetic shielding thermoplastic composite material, comprising an inner layer material and at least one outer layer material, wherein the inner layer material is a core layer comprising fiber bundles, a first thermoplastic resin and a first additive, and the at least one outer layer material encapsulates the core layer and is a resin layer comprising a second thermoplastic resin, an electromagnetic shielding filler and optionally a second additive, wherein the fiber bundles extend continuously from one end of the core layer to its opposite end.

[0008] The inventors of this application have discovered that by impregnating a continuous fiber bundle with a first component comprising a first thermoplastic resin and a first additive to form a core layer, and uniformly coating the outside of the core layer with a second component comprising a second thermoplastic resin and an electromagnetic shielding filler, an electromagnetic shielding thermoplastic composite material is formed, with a continuous fiber-reinforced resin as the core layer (inner layer material) and a resin layer surrounding the core layer as the outer layer material. Such an electromagnetic shielding thermoplastic composite material exhibits excellent electromagnetic shielding performance. Furthermore, by adjusting the properties and functions of the first thermoplastic resin in the core layer and the second thermoplastic resin in the resin layer, the electromagnetic shielding thermoplastic composite material can be made to have different properties and functions.

[0009] In some embodiments of the electromagnetic shielding thermoplastic composite material according to the present invention, the outer layer material (resin layer) may substantially continuously cover the inner layer material (core layer). Although not preferred, in the electromagnetic shielding thermoplastic composite material of the present invention, the outer layer material (resin layer) covers at least 80% of the inner layer material (core layer), for example, 80-99% or 85-95% of the inner layer material (core layer).

[0010] In this invention, the terms "one end" and / or "opposite end" are generally used in relation to the longitudinal direction of the electromagnetic shielding thermoplastic composite material.

[0011] According to some embodiments of the electromagnetic shielding thermoplastic composite material of the present invention, the electromagnetic shielding thermoplastic composite material can be in the form of strips, rods, or granules. Of course, the electromagnetic shielding thermoplastic composite material of the present invention can also be in other shapes, such as continuous filaments. In the present invention, the strip-shaped, rod-shaped, or granular electromagnetic shielding thermoplastic composite material can be cut from the continuous filament electromagnetic shielding thermoplastic composite material.

[0012] In some embodiments, the thermoplastic composite material for electromagnetic shielding is in the form of strips, rods, or granules. The length (longitudinal dimension) of the thermoplastic composite material for strip, rod, or granular electromagnetic shielding can be 5-30 mm, preferably 5-25 mm, and more preferably 6-15 mm.

[0013] In other embodiments, although not preferred, the electromagnetic shielding thermoplastic composite material may also have a relatively small length dimension. For example, the electromagnetic shielding thermoplastic composite material is granular, and the particle size (length) of the granular electromagnetic shielding thermoplastic composite material may be 2-5 mm, preferably 3-4 mm.

[0014] According to some embodiments of the thermoplastic composite material for electromagnetic shielding described in this invention, the present invention does not have special requirements for the cross-sectional shape of the thermoplastic composite material for electromagnetic shielding. In some embodiments, the cross-section of the thermoplastic composite material for granular or rod-shaped electromagnetic shielding is circular or near-circular. In other embodiments, the cross-section of the thermoplastic composite material for granular or strip-shaped electromagnetic shielding can be rectangular or square.

[0015] According to some embodiments of the electromagnetic shielding thermoplastic composite material of the present invention, in the inner layer material, the amount of the first thermoplastic resin is 1-90 parts by weight, and the amount of the fiber bundle is 10-110 parts by weight.

[0016] In some specific embodiments, the amount of the first thermoplastic resin in the inner layer material can be 1 part by weight, 10 parts by weight, 20 parts by weight, 25 parts by weight, 30 parts by weight, 40 parts by weight, 45 parts by weight, 50 parts by weight, 55 parts by weight, 60 parts by weight, 70 parts by weight, 80 parts by weight, 90 parts by weight, or a range thereof; and in some specific embodiments, the amount of the fiber bundle can be 1 part by weight, 10 parts by weight, 20 parts by weight, 25 parts by weight, 30 parts by weight, 40 parts by weight, 50 parts by weight, 60 parts by weight, 70 parts by weight, 80 parts by weight, 90 parts by weight, 100 parts by weight, 110 parts by weight, or a range thereof.

[0017] In some preferred embodiments, the amount of the first thermoplastic resin in the inner layer material can be 20-70 parts by weight, preferably 20-55 parts by weight, more preferably 24-45 parts by weight; and / or the amount of the fiber bundle can be 20-110 parts by weight, more preferably 25-110 parts by weight.

[0018] According to some embodiments of the electromagnetic shielding thermoplastic composite material of the present invention, the amount of the second thermoplastic resin in the outer layer material is 1-110 parts by weight.

[0019] In some specific embodiments, the amount of the second thermoplastic resin in the outer layer material can be 1 part by weight, 10 parts by weight, 20 parts by weight, 30 parts by weight, 40 parts by weight, 45 parts by weight, 50 parts by weight, 60 parts by weight, 65 parts by weight, 70 parts by weight, 75 parts by weight, 80 parts by weight, 85 parts by weight, 90 parts by weight, 95 parts by weight, 100 parts by weight, 105 parts by weight, 110 parts by weight, or a range thereof.

[0020] In some preferred embodiments, the amount of the second thermoplastic resin in the outer layer material can be 10-99 parts by weight, more preferably 10-90 parts by weight, and more preferably 40-90 parts by weight.

[0021] According to some specific embodiments of the electromagnetic shielding thermoplastic composite material of the present invention, in the inner layer material, the amount of the first thermoplastic resin is 1-90 parts by weight, preferably 20-70 parts by weight, more preferably 20-55 parts by weight, and even more preferably 24-45 parts by weight; and / or the amount of the fiber bundle is 10-99 parts by weight, preferably 20-80 parts by weight, and more preferably 25-50 parts by weight.

[0022] In some specific embodiments of the electromagnetic shielding thermoplastic composite material according to the present invention, in the inner layer material, the amount of the first thermoplastic resin is 50-70 parts by weight, more preferably 50-60 parts by weight; and / or the amount of the fiber bundle is 90-110 parts by weight, preferably 100-110 parts by weight; and / or in the outer layer material, the amount of the second thermoplastic resin is 90-110 parts by weight, more preferably 95-105 parts by weight.

[0023] According to some embodiments of the electromagnetic shielding thermoplastic composite material of the present invention, in the inner layer material, the weight ratio of the fiber bundle to the first thermoplastic resin is 0.25-6:1. For example, in the inner layer material, the weight ratio of the fiber bundle to the first thermoplastic resin is 0.25:1, 0.3:1, 0.35:1, 0.4:1, 0.45:1, 0.5:1, 0.55:1, 0.6:1, 0.65:1, 0.7:1, 0.8:1, 0.9:1, 1:1, 1.2:1, 1.5:1, 1.7:1, 1.8:1, 1.9:1, 2:1, 2.5:1, 3:1, 3.5:1, 4:1, 4.5:1, 5:1, 6:1, or a range thereof.

[0024] In some preferred embodiments, the weight ratio of the fiber bundle to the first thermoplastic resin in the inner layer material can be 0.35-4.5:1, preferably 1.7-4.5:1.

[0025] In this invention, the dosage of the first and second adjuvants is limited in order to achieve the desired effect of the adjuvants.

[0026] In different embodiments of the present invention, the number of outer layer materials is not limited; the outer layer material may be one layer or multiple layers. When the outer layer material is multi-layered, the multi-layered outer layer material may be formed using one type of outer layer material or multiple types of outer layer materials.

[0027] In some embodiments of the electromagnetic shielding thermoplastic composite material according to the present invention, the first thermoplastic resin and the second thermoplastic resin may be the same or different, and each is independently selected from at least one of polypropylene, polyethylene, polystyrene, polyvinyl chloride, polyacrylonitrile-butadiene-styrene copolymer, polyacrylonitrile-styrene copolymer, polyoxymethylene, polyamide, polyethylene terephthalate, polybutylene terephthalate, polymethyl methacrylate, polycarbonate, polyphenylene ether, polyurethane, polyetheretherketone and polyphenylene sulfide, and their alloy polymers.

[0028] According to a preferred embodiment of the electromagnetic shielding thermoplastic composite material of the present invention, the first thermoplastic resin and the second thermoplastic resin are each independently selected from at least one of polypropylene, polyethylene, polyamide (also known as nylon), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyphenylene sulfide, polyurethane and polyetheretherketone (PEEK).

[0029] According to a preferred embodiment of the electromagnetic shielding thermoplastic composite material of the present invention, the first thermoplastic resin and the second thermoplastic resin are each independently selected from at least one of homopolymer polypropylene, copolymer polypropylene, a mixture of homopolymer polypropylene and copolymer polypropylene, nylon 6 (PA6), nylon 66 (PA66), and a mixture of nylon 6 and nylon 66.

[0030] In other embodiments of the electromagnetic shielding thermoplastic composite material according to the present invention, the first thermoplastic resin and the second thermoplastic resin may also be selected from thermoplastic polyurethane elastomer (TPU) and / or high-temperature nylon (PPA).

[0031] According to some embodiments of the electromagnetic shielding thermoplastic composite material of the present invention, the melt flow rate of the first thermoplastic resin at 230°C and a load of 2.16 kg is 60-8000 g / 10 min. For example, the melt flow rate of the first thermoplastic resin at 230°C and a load of 2.16 kg can be 60 g / 10 min, 100 g / 10 min, 200 g / 10 min, 450 g / 10 min, 500 g / 10 min, 1000 g / 10 min, 1500 g / 10 min, 2000 g / 10 min, 3000 g / 10 min, 4000 g / 10 min, 5000 g / 10 min, 6000 g / 10 min, 7000 g / 10 min, 7500 g / 10 min, 8000 g / 10 min, or a range thereof.

[0032] In some preferred embodiments, the melt flow rate of the first thermoplastic resin at 230°C and a load of 2.16 kg can be 100-8000 g / 10 min, preferably 1000-7500 g / 10 min, and more preferably 1900-7500 g / 10 min.

[0033] According to some embodiments of the electromagnetic shielding thermoplastic composite material of the present invention, the melt flow rate of the second thermoplastic resin at 230°C and a load of 2.16 kg is 0.1-8000 g / 10 min. For example, the melt flow rate of the second thermoplastic resin at 230°C and a load of 2.16 kg can be 0.1 g / 10 min, 1 g / 10 min, 1.5 g / 10 min, 3 g / 10 min, 10 g / 10 min, 20 g / 10 min, 30 g / 10 min, 40 g / 10 min, 45 g / 10 min, 50 g / 10 min, 55 g / 10 min, 60 g / 10 min, 70 g / 10 min, 80 g / 10 min, etc. 90g / 10min, 100g / 10min, 450g / 10min, 500g / 10min, 800g / 10min, 1000g / 10min, 1500g / 10min, 1900g / 10min, 2500g / 10min, 3000g / 10min, 4000g / 10min, 5000g / 10min, 6000g / 10min, 7000g / 10min, 8000g / 10min, or a range thereof.

[0034] In some preferred embodiments, the melt flow rate of the second thermoplastic resin at 230°C and a load of 2.16 kg can be 3-55 g / 10 min or 450-8000 g / 10 min, preferably 3-45 g / 10 min or 1900-8000 g / 10 min.

[0035] In different embodiments of the present invention, the melt flow rates of the first thermoplastic resin and the second thermoplastic resin are not particularly specific, and the melt flow rates of the first thermoplastic resin and the second thermoplastic resin can be selected according to the desired performance.

[0036] In particular, the inventors of this application have discovered that electromagnetic shielding thermoplastic composite materials with high surface quality and overall performance can be prepared using the parameters (e.g., melt flow rate) according to the present invention. For example, if the melt flow rate of the first thermoplastic resin is higher than that of the second thermoplastic resin, the electromagnetic shielding thermoplastic composite material can have improved mechanical properties; conversely, if the melt flow rate of the second thermoplastic resin is higher than that of the first thermoplastic resin, the electromagnetic shielding thermoplastic composite material can have improved gloss.

[0037] In some preferred embodiments of the electromagnetic shielding thermoplastic composite material according to the present invention, the melt flow rate of the first thermoplastic resin at 230°C and a load of 2.16 kg is 60-450 g / 10 min, for example, 60-200 g / 10 min, and the melt flow rate of the second thermoplastic resin at 230°C and a load of 2.16 kg is 3-55 g / 10 min or 450-8000 g / 10 min. In some specific embodiments, the melt flow rate of the first thermoplastic resin at 230°C and a load of 2.16 kg is 60-450 g / 10 min, and the melt flow rate of the second thermoplastic resin at 230°C and a load of 2.16 kg is 800-8000 g / 10 min.

[0038] According to some preferred embodiments of the electromagnetic shielding thermoplastic composite material of the present invention, the melt flow rate of the first thermoplastic resin at 230°C and a load of 2.16 kg is 450 g / 10 min or more, particularly greater than 450 g / 10 min, and the melt flow rate of the second thermoplastic resin at 230°C and a load of 2.16 kg is less than 100 g / 10 min, preferably 1.5-55 g / 10 min, more preferably 3-50 g / 10 min.

[0039] In some embodiments of the electromagnetic shielding thermoplastic composite material according to the present invention, the weight ratio of the second thermoplastic resin to the first thermoplastic resin is 0.05-12.5:1. For example, the weight ratio of the second thermoplastic resin to the first thermoplastic resin can be 0.05:1, 0.1:1, 0.14:1, 0.15:1, 0.18:1, 0.2:1, 0.25:1, 0.3:1, 0.5:1, 0.8:1, 1:1, 1.2:1, 1.3:1, 1.4:1, 1.7:1, 2:1, 2.5:1, 3:1, 3.5:1, 4:1, 5:1, 8:1, 10:1, 12.5:1, or a range thereof.

[0040] In some preferred embodiments, the weight ratio of the second thermoplastic resin to the first thermoplastic resin can be 0.1-4:1, preferably 0.14-3.5:1.

[0041] According to a preferred embodiment of the electromagnetic shielding thermoplastic composite material of the present invention, when the melt flow rate of the second thermoplastic resin is 800-8000 g / 10 min at 230°C and a load of 2.16 kg, the weight ratio of the second thermoplastic resin to the first thermoplastic resin is less than 0.25:1, preferably less than 0.18:1, and more preferably less than 0.15:1.

[0042] In some embodiments of the electromagnetic shielding thermoplastic composite material according to the present invention, when the first thermoplastic resin and the second thermoplastic resin are selected from at least one of nylon 6, nylon 66, and a mixture of nylon 6 and nylon 66, the viscosity of the selected nylon 6 and nylon 66 is 1.8-3.5. Wherein, the viscosity of nylon in the present invention is the relative viscosity measured according to the Engler viscosity determination method GB / T266-88.

[0043] According to a specific embodiment of the electromagnetic shielding thermoplastic composite material of the present invention, the first thermoplastic resin and the second thermoplastic resin can be prepared in-house or commercially available.

[0044] For example, polypropylene resin of grade PPB-M100-GH purchased from Sinopec Yangzi Petrochemical Company, polypropylene resin of grade M60RHC purchased from Sinopec East China Branch, and nylon 6 of grade PA6-BL3200H purchased from Sinopec Baling Branch can be used as the first thermoplastic resin.

[0045] For example, polypropylene resin of grade PPB-M100-GH purchased from Sinopec Yangzi Petrochemical Company, polypropylene resin of grade PPH-T03 purchased from Sinopec Maoming Branch, polypropylene resin of grade M50RH purchased from Sinopec East China Branch, polypropylene resin of grade K8303 purchased from Yanshan Petrochemical Company, polypropylene resin of grade PF1500 purchased from Hunan Shengjin New Materials Co., Ltd., or polypropylene resin of grade PPH-Y450 purchased from Sinopec Shijiazhuang Refining and Chemical Branch, or nylon 6 of grade PA6-BL3200H purchased from Sinopec Baling Branch can be used as the second thermoplastic resin.

[0046] According to some embodiments of the electromagnetic shielding thermoplastic composite material of the present invention, the fiber bundle is selected from at least one of glass fiber, carbon fiber, basalt fiber, aromatic polyamide fiber, stainless steel fiber, synthetic resin fiber and mineral fiber.

[0047] In a preferred embodiment of the electromagnetic shielding thermoplastic composite material according to the present invention, the glass fiber is continuous glass fiber and / or fixed-length glass fiber.

[0048] Suitable fiber bundles for use in this invention may be alkali-free glass fiber of grade SE4805 purchased from Owens Corning (Shanghai) Glass Fiber Co., Ltd., alkali-free glass fiber of grade ER4301H purchased from Chongqing International Composite Materials Co., Ltd., carbon fiber of grade T700SC purchased from Toray Industries, Inc. of Japan, or basalt fiber purchased from Mudanjiang Jinshi Basalt Fiber Co., Ltd.

[0049] According to some embodiments of the electromagnetic shielding thermoplastic composite material of the present invention, in the transverse cross-section of the electromagnetic shielding thermoplastic composite material, there are, from the inside out, a core layer and a resin layer; the fiber bundle is oriented longitudinally along the electromagnetic shielding thermoplastic composite material. Preferably, in the present invention, the length of the fiber bundle is substantially the same as the length (longitudinal dimension) of the electromagnetic shielding thermoplastic composite material, thereby the fiber bundle extends continuously from one end of the core layer in the longitudinal direction to the opposite end in the longitudinal direction.

[0050] In some preferred embodiments, the fiber bundles may be dispersed. Such dispersion methods are known in the art, and the present invention does not specifically limit them.

[0051] According to some embodiments of the electromagnetic shielding thermoplastic composite material of the present invention, the inner layer material does not contain short fibers, especially not non-oriented short fibers.

[0052] In some specific embodiments, the inner layer material is composed of fiber bundles, a first thermoplastic resin, and a first additive.

[0053] In some embodiments of the electromagnetic shielding thermoplastic composite material according to the present invention, the outer layer material is fiber-free. In some preferred embodiments, the outer layer material is composed of a second thermoplastic resin and a second additive.

[0054] In some other embodiments of the electromagnetic shielding thermoplastic composite material according to the present invention, the outer layer material contains fibers, such as short fibers.

[0055] In some specific embodiments, the weight ratio of the fiber to the second thermoplastic resin in the outer layer material is 1-50:100, preferably 5-50:100, and more preferably 20-45:100.

[0056] According to some embodiments of the electromagnetic shielding thermoplastic composite material of the present invention, the electromagnetic shielding filler includes conductive metal filler and / or conductive carbon material. The conductive metal filler is conductive metal particles, preferably one or more conductive metal particles selected from silver, aluminum, copper, iron, nickel, and stainless steel. The conductive carbon material may be one or more selected from carbon black, graphite, graphene, and carbon nanotubes.

[0057] According to some embodiments of the electromagnetic shielding thermoplastic composite material of the present invention, based on 100 parts by weight of the second thermoplastic resin, the amount of the electromagnetic shielding filler is 10-40 parts by weight, preferably 10-35 parts by weight.

[0058] According to some embodiments of the electromagnetic shielding thermoplastic composite material of the present invention, with each of the first and second thermoplastic resins being 100 parts by weight, the first and second additives each independently comprise at least one of the following: 0.5-15 parts by weight of a compatibilizer, 0.05-3 parts by weight of an antioxidant, and 0.05-2.5 parts by weight of a lubricant. Preferably, the first and second additives each independently comprise at least one of the following: 1-15 parts by weight, preferably 1-6 parts by weight, more preferably 3-6 parts by weight of a compatibilizer, 0.1-1 parts by weight, preferably 0.1-0.5 parts by weight of an antioxidant, and 0.5-2.5 parts by weight of a lubricant.

[0059] In some embodiments of the electromagnetic shielding thermoplastic composite material according to the present invention, the compatibilizer is selected from at least one of polar monomer grafted modified polymers. Preferably, the polar monomer is selected from at least one of maleic anhydride, maleic anhydride derivatives, acrylic acid, and acrylate derivatives. Preferably, the polymer is selected from at least one of polyethylene, polypropylene, ethylene-α-olefin copolymers, and propylene-α-olefin (α-olefins other than propylene) copolymers.

[0060] In a specific embodiment of the electromagnetic shielding thermoplastic composite material according to the present invention, maleic anhydride-grafted polypropylene (PP-g-MAH) purchased from Pulilong Plastics Industry Co., Ltd., maleic anhydride-grafted ethylene-octene copolymer (POE-g-MAH) purchased from Shanghai Rizhisheng Technology Co., Ltd., titanate coupling agent purchased from Nanjing Shuguang Chemical Group Co., Ltd., or aluminate coupling agent purchased from Nanjing Youpu Chemical Co., Ltd., can be used as the compatibilizer.

[0061] In some embodiments of the electromagnetic shielding thermoplastic composite material according to the present invention, the antioxidant is selected from at least one of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] (antioxidant 1010), tris[2,4-di-tert-butylphenyl] phosphite (antioxidant 168), octadecyl β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate (antioxidant 1076), 2,2'-methylenebis(4-methyl-6-tert-butylphenol) (antioxidant 2246), 1,1,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane (antioxidant CA), and bis(2,4-di-tert-butylphenol) pentaerythritol diphosphite (antioxidant 626).

[0062] In a specific embodiment of the electromagnetic shielding thermoplastic composite material according to the present invention, antioxidant 1010 and / or antioxidant 168 purchased from BASF can be used as the antioxidant.

[0063] In some embodiments of the electromagnetic shielding thermoplastic composite material according to the present invention, the lubricant is selected from at least one of ethylene bis-stearamide, calcium stearate, polyethylene wax, pentaerythritol stearate, silicone, polyethylene glycol and fluorinated resin.

[0064] In a specific embodiment of the electromagnetic shielding thermoplastic composite material according to the present invention, oxidized polyethylene wax with the brand name XH-201 purchased from Xianghe Coatings Group can be used as the lubricant.

[0065] In different embodiments of the present invention, the first additive may further include at least one of slip agent, antistatic agent and plasticizer, and / or the second additive may further include at least one of slip agent, antistatic agent, plasticizer, nucleating agent, scratch-resistant additive, heat stabilizer, color masterbatch, antistatic agent and filler, and the specific types and amounts of these additives are not limited, and a wide range of choices can be made.

[0066] A second aspect of the present invention provides a method for preparing an electromagnetically shielded thermoplastic composite material, the method comprising the following steps:

[0067] Step A: The first thermoplastic resin and the first additive are mixed and melted to obtain the first component melt;

[0068] Step B: The continuous fiber bundle is subjected to a first impregnation treatment with the first component melt to form a filamentous core layer product;

[0069] Step C: The second thermoplastic resin and the second additive are mixed and melted to obtain the second component melt;

[0070] Step D: The filamentous core layer product is subjected to a second impregnation treatment with the second component melt to form a resin layer that continuously encapsulates the core layer.

[0071] According to some embodiments of the preparation method described in this invention, the preparation method can be carried out online continuously to obtain continuous filamentous products. Such continuous filamentous products can be directly stored and used, or they can be cut into strips, rods, or granules of a certain length.

[0072] According to some embodiments of the preparation method of the present invention, the mixing conditions of step A include: a temperature of 40-60°C and a time of 0.5-20 min, preferably 1-10 min, and more preferably 3-5 min.

[0073] According to some embodiments of the preparation method described in this invention, the melting temperature in step A is 200-380°C. In this invention, the melting time can have a wide range of options, with the aim of ensuring that the first thermoplastic resin and the first additive are fully melted to obtain a melt.

[0074] According to some embodiments of the preparation method of the present invention, preferably, in step B, before subjecting the continuous fibers to the first impregnation treatment with the first component melt, the continuous fibers are further subjected to dispersion treatment and preheating treatment, wherein the preheating treatment temperature is preferably 80-250°C. The dispersion treatment process in the present invention employs conventional fiber dispersion treatment processes in the art.

[0075] According to some embodiments of the preparation method of the present invention, the mixing conditions in step C include: a temperature of 40-60°C and a time of 0.5-20 min, preferably 1-10 min, and more preferably 3-5 min.

[0076] In some embodiments of the preparation method according to the present invention, the melting temperature in step C is 200-380°C. In the present invention, the melting time can have a wide range of selection, with the aim of ensuring sufficient melting of the second thermoplastic resin and optionally the second additive.

[0077] According to some embodiments of the preparation method of the present invention, the first impregnation treatment in step B can be performed in a first impregnation mold. The first impregnation mold is an adjustable impregnation mold, which includes a fiber inlet, a fiber outlet, and a melt flow channel. At least one first guide roller is provided in the mold cavity of the first impregnation mold. The first guide roller is movable between the fiber inlet and the fiber outlet. And / or, the first guide roller is movable along a direction perpendicular to the line connecting the fiber inlet and the fiber outlet.

[0078] According to some embodiments of the preparation method of the present invention, the first impregnation treatment in step B can be performed in a second impregnation mold. The second impregnation mold is a combined impregnation mold, which includes a first module, an intermediate module, and a second module connected in sequence. The first module is provided with a fiber inlet and a first module flow channel, and the second module is provided with a fiber outlet and a second module flow channel. The intermediate module is provided with an intermediate module flow channel. After the first module, the intermediate module, and the second module are connected in sequence, the first module flow channel, the intermediate module flow channel, and the second module flow channel are connected to form a combined flow channel for the fiber to pass through.

[0079] According to some embodiments of the preparation method of the present invention, the first impregnation treatment in step B can also be carried out in a third impregnation mold. The third impregnation mold is a strong turbulent flow impregnation mold. The third impregnation mold includes a fiber inlet channel, an impregnation outlet, and a melt gap flow channel. The fiber inlet channel, the impregnation outlet, and the melt gap flow channel are all connected to the mold cavity inside the third impregnation mold. A second guide roller is provided inside the mold cavity of the third impregnation mold. The second guide roller includes at least one active guide roller, which is driven to rotate by a driving device.

[0080] The first impregnation mold, the second impregnation mold, and the third impregnation mold used in this invention are described in Chinese patent applications CN 202011193483.3, 202011191450.5, and 202011199839.4, the entire contents of which are incorporated herein by reference.

[0081] It should be noted that the first impregnation mold, the second impregnation mold and the third impregnation mold described above in this invention can be applied to any existing manufacturing system and preparation technology for electromagnetically shielded thermoplastic composite materials, and in particular, can be applied to any existing manufacturing system and preparation technology for continuous fiber reinforced expandable flame retardant thermoplastic composite materials.

[0082] According to some embodiments of the preparation method described in this invention, the second impregnation treatment in step D can be performed in a molding die. The molding die consists of a core, an outer jacket, and an outer jacket opening template. The core is located inside the outer jacket, forming a cavity with it. The resin melt can enter the cavity from the bottom, top, or both sides of the outer jacket. The core can move back and forth within the outer jacket, and the pressure of the melt in the cavity is determined by adjusting the size of the formed cavity space. The pressure of the melt in the cavity can also be adjusted by the angle between the core and the outer jacket.

[0083] The working principle of this molding die is as follows: after passing through the impregnation mold, the strip of inner impregnated material is guided through the hole in the middle of the core, and then the composite structure of inner and outer layer materials is formed in the cavity filled with mixed melt formed by the core and the outer jacket. Finally, it is exported through the outer jacket template.

[0084] According to some embodiments of the preparation method of the present invention, after step D, the obtained electromagnetic shielding thermoplastic composite material is further subjected to pulling, stretching, cooling, drying, and pelletizing processes. The process conditions for pulling, stretching, cooling, drying, and pelletizing are not particularly limited and are all within a wide range of selection, with the aim of obtaining electromagnetic shielding thermoplastic composite materials that meet different specification requirements.

[0085] According to some embodiments of the preparation method of the present invention, in the inner layer material, the amount of the first thermoplastic resin is 1-90 parts by weight, and the amount of the fiber bundle is 10-110 parts by weight.

[0086] In some specific embodiments, the amount of the first thermoplastic resin in the inner layer material can be 1 part by weight, 10 parts by weight, 20 parts by weight, 25 parts by weight, 30 parts by weight, 40 parts by weight, 45 parts by weight, 50 parts by weight, 55 parts by weight, 60 parts by weight, 70 parts by weight, 80 parts by weight, 90 parts by weight, or a range thereof; and in some specific embodiments, the amount of the fiber bundle can be 1 part by weight, 10 parts by weight, 20 parts by weight, 25 parts by weight, 30 parts by weight, 40 parts by weight, 50 parts by weight, 60 parts by weight, 70 parts by weight, 80 parts by weight, 90 parts by weight, 100 parts by weight, 110 parts by weight, or a range thereof.

[0087] In some preferred embodiments, the amount of the first thermoplastic resin in the inner layer material can be 20-70 parts by weight, preferably 20-55 parts by weight, more preferably 24-45 parts by weight; and / or the amount of the fiber bundle can be 20-110 parts by weight, preferably 25-110 parts by weight.

[0088] According to some embodiments of the preparation method of the present invention, the amount of the second thermoplastic resin in the outer layer material is 1-110 parts by weight.

[0089] In some specific embodiments, the amount of the second thermoplastic resin in the outer layer material can be 1 part by weight, 10 parts by weight, 20 parts by weight, 30 parts by weight, 40 parts by weight, 45 parts by weight, 50 parts by weight, 60 parts by weight, 65 parts by weight, 70 parts by weight, 75 parts by weight, 80 parts by weight, 85 parts by weight, 90 parts by weight, 95 parts by weight, 100 parts by weight, 105 parts by weight, 110 parts by weight, or a range thereof.

[0090] In some preferred embodiments, the amount of the second thermoplastic resin in the outer layer material can be 10-90 parts by weight, preferably 40-90 parts by weight.

[0091] According to some specific embodiments of the preparation method of the present invention, in the inner layer material, the amount of the first thermoplastic resin is 1-90 parts by weight, preferably 20-70 parts by weight, more preferably 20-55 parts by weight, and even more preferably 24-45 parts by weight; and / or the amount of the fiber bundle is 10-99 parts by weight, preferably 20-80 parts by weight, and more preferably 25-50 parts by weight.

[0092] According to some specific embodiments of the preparation method of the present invention, in the inner layer material, the amount of the first thermoplastic resin is 50-70 parts by weight, more preferably 50-60 parts by weight; and / or the amount of the fiber bundle is 90-110 parts by weight, preferably 100-110 parts by weight; and / or in the outer layer material, the amount of the second thermoplastic resin is 90-110 parts by weight, more preferably 95-105 parts by weight.

[0093] According to some embodiments of the preparation method of the present invention, in the inner layer material, the weight ratio of the fiber to the first thermoplastic resin is 0.25-6:1. For example, in the inner layer material, the weight ratio of the fiber bundle to the first thermoplastic resin is 0.25:1, 0.3:1, 0.35:1, 0.4:1, 0.45:1, 0.5:1, 0.55:1, 0.6:1, 0.65:1, 0.7:1, 0.8:1, 0.9:1, 1:1, 1.2:1, 1.5:1, 1.7:1, 1.8:1, 1.9:1, 2:1, 2.5:1, 3:1, 3.5:1, 4:1, 4.5:1, 5:1, 6:1, or a range thereof.

[0094] In some preferred embodiments, the weight ratio of the fiber bundle to the first thermoplastic resin in the inner layer material can be 0.35-4.5:1, preferably 0.43-4.5:1.

[0095] In different embodiments of the present invention, the number of outer layer materials is not limited; the outer layer material may be one layer or multiple layers. When the outer layer material is multi-layered, the multi-layered outer layer material may be formed using one type of outer layer material or multiple types of outer layer materials.

[0096] According to some embodiments of the preparation method of the present invention, the first thermoplastic resin and the second thermoplastic resin may be the same or different, and each is independently selected from at least one of polypropylene, polyethylene, polystyrene, polyvinyl chloride, polyacrylonitrile-butadiene-styrene copolymer, polyacrylonitrile-styrene copolymer, polyoxymethylene, polyamide, polyethylene terephthalate, polybutylene terephthalate, polymethyl methacrylate, polycarbonate, polyphenylene ether, polyurethane, polyetheretherketone and polyphenylene sulfide, and their alloy polymers.

[0097] According to a preferred embodiment of the preparation method of the present invention, the first thermoplastic resin and the second thermoplastic resin are each independently selected from at least one of polypropylene, polyethylene, polyamide (also known as nylon), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyphenylene sulfide, polyurethane and polyetheretherketone (PEEK).

[0098] According to a preferred embodiment of the preparation method of the present invention, the first thermoplastic resin and the second thermoplastic resin are each independently selected from at least one of homopolymer polypropylene, copolymer polypropylene, a mixture of homopolymer polypropylene and copolymer polypropylene, nylon 6 (PA6), nylon 66 (PA66), and a mixture of nylon 6 and nylon 66.

[0099] In other embodiments of the preparation method according to the present invention, the first thermoplastic resin and the second thermoplastic resin may also be selected from thermoplastic polyurethane elastomer (TPU) and / or high-temperature nylon (PPA).

[0100] According to some embodiments of the preparation method of the present invention, the melt flow rate of the first thermoplastic resin at 230°C and a load of 2.16 kg is 60-8000 g / 10 min. For example, the melt flow rate of the first thermoplastic resin at 230°C and a load of 2.16 kg can be 60 g / 10 min, 100 g / 10 min, 200 g / 10 min, 450 g / 10 min, 500 g / 10 min, 1000 g / 10 min, 1500 g / 10 min, 2000 g / 10 min, 3000 g / 10 min, 4000 g / 10 min, 5000 g / 10 min, 6000 g / 10 min, 7000 g / 10 min, 7500 g / 10 min, 8000 g / 10 min, or a range thereof.

[0101] In some preferred embodiments, the melt flow rate of the first thermoplastic resin at 230°C and a load of 2.16 kg can be 100-8000 g / 10 min, preferably 1000-7500 g / 10 min, and more preferably 1900-7500 g / 10 min.

[0102] According to some embodiments of the preparation method of the present invention, the melt flow rate of the second thermoplastic resin at 230°C and a load of 2.16 kg is 0.1-8000 g / 10 min. For example, the melt flow rate of the second thermoplastic resin at 230°C and a load of 2.16 kg can be 0.1 g / 10 min, 1 g / 10 min, 1.5 g / 10 min, 3 g / 10 min, 10 g / 10 min, 20 g / 10 min, 30 g / 10 min, 40 g / 10 min, 45 g / 10 min, 50 g / 10 min, 55 g / 10 min, 60 g / 10 min, 70 g / 10 min, 80 g / 10 min, etc. 90g / 10min, 100g / 10min, 450g / 10min, 500g / 10min, 800g / 10min, 1000g / 10min, 1500g / 10min, 1900g / 10min, 2500g / 10min, 3000g / 10min, 4000g / 10min, 5000g / 10min, 6000g / 10min, 7000g / 10min, 8000g / 10min, or a range thereof.

[0103] In some preferred embodiments, the melt flow rate of the second thermoplastic resin at 230°C and a load of 2.16 kg can be 3-55 g / 10 min or 450-8000 g / 10 min, preferably 3-45 g / 10 min or 1900-8000 g / 10 min.

[0104] In different embodiments of the present invention, the melt flow rates of the first thermoplastic resin and the second thermoplastic resin are not particularly limited, and the melt flow rates of the first thermoplastic resin and the second thermoplastic resin can be selected according to the desired performance. In particular, the inventors of this application have discovered that electromagnetic shielding thermoplastic composite materials with high surface quality and overall performance can be prepared using the preparation conditions (e.g., melt flow rates) according to the present invention. For example, if the melt flow rate of the first thermoplastic resin is higher than that of the second thermoplastic resin, the electromagnetic shielding thermoplastic composite material can have improved mechanical properties; conversely, if the melt flow rate of the second thermoplastic resin is higher than that of the first thermoplastic resin, the electromagnetic shielding thermoplastic composite material can have improved gloss.

[0105] According to some preferred embodiments of the preparation method of the present invention, the melt flow rate of the first thermoplastic resin at 230°C and a load of 2.16 kg is 60-450 g / 10 min, for example, 60-200 g / 10 min, and the melt flow rate of the second thermoplastic resin at 230°C and a load of 2.16 kg is 3-55 g / 10 min or 450-8000 g / 10 min. In some specific embodiments, the melt flow rate of the first thermoplastic resin at 230°C and a load of 2.16 kg is 60-450 g / 10 min, and the melt flow rate of the second thermoplastic resin at 230°C and a load of 2.16 kg is 800-8000 g / 10 min.

[0106] According to some preferred embodiments of the preparation method of the present invention, the melt flow rate of the first thermoplastic resin at 230°C and a load of 2.16 kg is 450 g / 10 min or more, particularly greater than 450 g / 10 min, and the melt flow rate of the second thermoplastic resin at 230°C and a load of 2.16 kg is less than 100 g / 10 min, preferably 1.5-55 g / 10 min, more preferably 3-50 g / 10 min.

[0107] According to some embodiments of the preparation method of the present invention, the weight ratio of the second thermoplastic resin to the first thermoplastic resin is 0.05-12.5:1. For example, the weight ratio of the second thermoplastic resin to the first thermoplastic resin can be 0.05:1, 0.1:1, 0.14:1, 0.15:1, 0.18:1, 0.2:1, 0.25:1, 0.3:1, 0.5:1, 0.8:1, 1:1, 1.2:1, 1.3:1, 1.4:1, 1.7:1, 2:1, 2.5:1, 3:1, 3.5:1, 4:1, 5:1, 8:1, 10:1, 12.5:1, or a range thereof.

[0108] In some preferred embodiments, the weight ratio of the second thermoplastic resin to the first thermoplastic resin can be 0.14-4:1, preferably 0.14-3.5:1.

[0109] According to a preferred embodiment of the preparation method of the present invention, when the melt flow rate of the second thermoplastic resin is 800-8000 g / 10 min at 230°C and a load of 2.16 kg, the weight ratio of the second thermoplastic resin to the first thermoplastic resin is less than 0.25:1, preferably less than 0.18:1, and more preferably less than 0.15:1.

[0110] According to some embodiments of the preparation method of the present invention, when the first thermoplastic resin and the second thermoplastic resin are selected from at least one of nylon 6, nylon 66, and a mixture of nylon 6 and nylon 66, the viscosity of the selected nylon 6 and nylon 66 is 1.8-3.5.

[0111] According to a specific embodiment of the preparation method of the present invention, the first thermoplastic resin and the second thermoplastic resin can be prepared in-house or commercially available.

[0112] For example, polypropylene resin of grade PPB-M100-GH purchased from Sinopec Yangzi Petrochemical Company, polypropylene resin of grade M60RHC purchased from Sinopec East China Branch, and nylon 6 of grade PA6-BL3200H purchased from Sinopec Baling Branch can be used as the first thermoplastic resin.

[0113] For example, polypropylene resin of grade PPB-M100-GH purchased from Sinopec Yangzi Petrochemical Company, polypropylene resin of grade PPH-T03 purchased from Sinopec Maoming Branch, polypropylene resin of grade M50RH purchased from Sinopec East China Branch, polypropylene resin of grade K8303 purchased from Yanshan Petrochemical Company, polypropylene resin of grade PF1500 purchased from Hunan Shengjin New Materials Co., Ltd., or polypropylene resin of grade PPH-Y450 purchased from Sinopec Shijiazhuang Refining and Chemical Branch, or nylon 6 of grade PA6-BL3200H purchased from Sinopec Baling Branch can be used as the second thermoplastic resin.

[0114] According to some embodiments of the preparation method of the present invention, the fiber bundle is selected from at least one of glass fiber, carbon fiber, basalt fiber, aromatic polyamide fiber, stainless steel fiber, synthetic resin fiber and mineral fiber.

[0115] In a preferred embodiment of the preparation method according to the present invention, the glass fiber is a continuous glass fiber and / or a fixed-length glass fiber.

[0116] According to some embodiments of the preparation method of the present invention, with each of the first thermoplastic resin and the second thermoplastic resin being 100 parts by weight, the first and second additives each independently comprise at least one of the following: 0.5-15 parts by weight of a compatibilizer, 0.05-3 parts by weight of an antioxidant, and 0.05-2.5 parts by weight of a lubricant. Preferably, the first and second additives each independently comprise at least one of the following: 1-15 parts by weight, preferably 1-6 parts by weight, more preferably 3-6 parts by weight of a compatibilizer, 0.1-1 parts by weight, preferably 0.1-0.5 parts by weight of an antioxidant, and 0.5-2.5 parts by weight of a lubricant.

[0117] According to some embodiments of the preparation method of the present invention, the compatibilizer is selected from at least one of polar monomer grafted modified polymers. Preferably, the polar monomer is selected from at least one of maleic anhydride, maleic anhydride derivatives, acrylic acid, and acrylate derivatives. Preferably, the polymer is selected from at least one of polyethylene, polypropylene, ethylene-α-olefin copolymers, and propylene-α-olefins (α-olefins other than propylene).

[0118] According to some embodiments of the preparation method of the present invention, the lubricant is selected from at least one of ethylene bis-stearamide, calcium stearate, polyethylene wax, pentaerythritol stearate, silicone, polyethylene glycol and fluorinated resin.

[0119] In different embodiments of the present invention, the first additive may further include at least one of slip agent, antistatic agent and plasticizer, and the second additive may further include at least one of slip agent, antistatic agent, plasticizer, nucleating agent, scratch-resistant additive, flame retardant, heat stabilizer, color masterbatch, antistatic agent and filler, and the specific types and amounts of these additives are not limited, and the amounts can be selected within a wide range.

[0120] In some embodiments of the present invention, the preparation method of the present invention is as follows: Figure 2 or Figure 3 The manufacturing process is carried out in the electromagnetic shielding thermoplastic composite material manufacturing system shown. The specific structure and connection method of the electromagnetic shielding thermoplastic composite material manufacturing system are described in the detailed implementation section.

[0121] A third aspect of this invention provides the application of the above-described electromagnetic shielding thermoplastic composite material and the electromagnetic shielding thermoplastic composite material prepared by the above-described method in the automotive industry, machinery manufacturing, electronics and electrical appliances, chemical and environmental protection, aerospace and communications, and construction industries. Preferably, it is used in large automotive parts and / or high-precision electronic and electrical components, more preferably in automotive front-end modules and / or all-plastic tailgate inner panels. However, it is not limited thereto.

[0122] The beneficial effects of this invention are:

[0123] 1. The electromagnetic shielding thermoplastic composite material prepared by this invention has a core layer and an outer layer composite structure. Based on the design of this multi-material composite system, the performance synergy between different components of the inner and outer layer materials can be achieved. This can effectively improve the processing performance of the electromagnetic shielding thermoplastic composite material and the lubricity between the fiber and the resin matrix during injection molding, and enhance the flowability of the fiber in the resin matrix melt. This improves the bonding state between the two and reduces the separation state between them, thereby improving the flowability of the entire material system. As a result, the comprehensive performance and surface quality of the prepared electromagnetic shielding thermoplastic composite material are greatly improved. At the same time, the requirements of the injection molding process are reduced, expanding the application range of the electromagnetic shielding thermoplastic composite material, which has broad application prospects and economic significance.

[0124] 2. The thermoplastic composite material of the present invention has excellent mechanical properties as well as excellent electromagnetic shielding performance, thus expanding the application of thermoplastic materials in the field of electromagnetic shielding.

[0125] 3. The electromagnetic shielding thermoplastic composite material of the present invention has the advantages of low cost, short injection molding cycle, high part dimensional stability, high material strength, no need for secondary mixing during use, and the ability to add functional materials to the first component and / or the second component, especially the second component (resin layer), making it widely applicable. Furthermore, the outer layer material of the electromagnetic shielding thermoplastic composite material of the present invention can be fiber-free, with good surface quality performance, no floating fibers on the surface, and improved gloss. Attached Figure Description

[0126] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the following detailed description to explain the invention, but do not constitute a limitation thereof. In the drawings:

[0127] Figure 1 This is a schematic diagram of a thermoplastic composite material structure for electromagnetic shielding according to one embodiment of the present invention;

[0128] Figure 2 This is a schematic diagram of a thermoplastic composite material manufacturing system for electromagnetic shielding according to one embodiment of the present invention;

[0129] Figure 3 This is a schematic diagram of the electromagnetic shielding thermoplastic composite material manufacturing system in another embodiment of the present invention;

[0130] Figure 4 This is a cross-sectional view of the first impregnation mold in one embodiment of the present invention;

[0131] Figure 5 This is a cross-sectional view of the second impregnation mold in one embodiment of the present invention;

[0132] Figure 6 This is a cross-sectional view of the third impregnation mold in one embodiment of the present invention;

[0133] Figure 7 This is a schematic diagram of the second impregnation treatment in one embodiment of the present invention;

[0134] Figure 8 This is a cross-sectional view of the molding die used in the second impregnation process according to one embodiment of the present invention.

[0135] Explanation of reference numerals in the attached figures:

[0136] 0-1, Core layer; 0-2, Fiber bundle; 0-3, Resin layer;

[0137] 1. Fiber rack and fiber guiding device; 2. Fiber pretreatment device; 3. First impregnation mold; 4. Melting and plasticizing feeding device; 5. Molding mold; 6. Cooling water tank; 7. Dryer; 8. Traction machine; 9. Pelletizer; 10. Collection box;

[0138] A300, First impregnation die head; A1, Fiber inlet; A2, Second chute; A3, Melt flow channel; A4, First chute; A5, Upper die cover; A6, Fiber outlet; A7, Impregnation die body; A8, First guide roller;

[0139] B300, Second impregnation die head; B1, Fiber inlet; B2, Melt channel; B3, First module; B31, First module channel; B4, Combined channel; B5, Standardized connector; B6, Intermediate module; B61, Intermediate module channel; B7, Second module; B71, Second module channel; B8, Fiber outlet;

[0140] C300, Third impregnation die head; C1, Melt flow channel; C2, Impregnation die body; C3, Fiber inlet channel; C4, Active guide roller; C5, Driven guide roller; C6, Impregnation outlet;

[0141] 4-1. Extruder I; 4-2. Extruder II;

[0142] 5-1 Core; 5-2 Outer shell; 5-3 Outer shell opening template; 5-4 Material strip; 5-5 Second resin inlet. Detailed Implementation

[0143] To make the present invention easier to understand, the present invention will be described in detail below with reference to embodiments. These embodiments are for illustrative purposes only and are not limited to the scope of application of the present invention.

[0144] The testing method and equipment used in this invention are as follows:

[0145] (1) Tensile strength test was conducted in accordance with ISO527-2 standard, with a tensile speed of 5 mm / min.

[0146] (2) The bending strength test was conducted in accordance with ISO178 standard, with a bending speed of 2 mm / min.

[0147] (3) The notched impact strength test shall be conducted in accordance with ISO179 standard.

[0148] (4) Surface gloss test shall be conducted in accordance with ISO2813 standard.

[0149] (5) The electromagnetic shielding effectiveness shall be tested in accordance with the SJ20524 standard.

[0150] Some of the reagents used in this invention are from the following sources:

[0151] (1) PPB-M100-GH, melt flow rate of 100g / 10min, test conditions of 230℃ and 2.16Kg load, produced by Sinopec Yangzi Petrochemical Company.

[0152] (2) PF1500, melt flow rate 1500g / 10min, produced by Hunan Shengjin New Materials Co., Ltd.

[0153] (3) PPH-Y450, melt flow rate 450g / 10min, produced by Sinopec Shijiazhuang Refining & Chemical Branch.

[0154] (4) BL3200H, viscosity 1.8, produced by Sinopec Baling Branch.

[0155] (5) SE4805, alkali-free glass fiber, with a diameter of 17μm and a linear density of 2400tex, is produced by Owens Corning (Shanghai) Glass Fiber Co., Ltd.

[0156] (6)ER4301H, alkali-free glass fiber, with a diameter of 17μm and a linear density of 2400tex, is produced by Chongqing International Composite Materials Co., Ltd.

[0157] (7) T700SC, carbon fiber, filament 1200-50C, manufactured by Toray Industries, Inc. of Japan.

[0158] (8) Basalt fiber, single fiber diameter 12μm, produced by Mudanjiang Jinshi Basalt Fiber Co., Ltd.

[0159] (9) PP-g-MAH grade is BONDYRAM 1001, produced by Pulilang Plastics Industry Co., Ltd.

[0160] (10) POE-g-MAH grade is CMG9805, produced by Shanghai Rizhisheng Technology Co., Ltd.

[0161] (11)NDZ12, produced by Nanjing Shuguang Chemical Group Co., Ltd.

[0162] (12)XHY-501, produced by Nanjing Youpu Chemical Co., Ltd.

[0163] (13) Antioxidant 1010, manufactured by BASF.

[0164] (14) Antioxidant 168, manufactured by BASF.

[0165] (15) Stainless steel fiber, 6-8μm in diameter, commercially available.

[0166] (16) Conductive graphite, commercially available

[0167] (17) Fe powder, 1000 mesh, commercially available

[0168] (18)XH-201, produced by Xianghe Coatings Group.

[0169] The invention will now be further described with reference to the accompanying drawings.

[0170] Figure 1 The structure of the electromagnetic shielding thermoplastic composite material of the present invention is shown. For example... Figure 1 As shown, the cross-section of the electromagnetic shielding thermoplastic composite material of the present invention is circular, and from the inside out, it includes a core layer 0-1 and a resin layer 0-3. Fiber bundles 0-2 are distributed in the core layer 0-1 along the longitudinal direction, and the fiber bundles 0-2 are uniformly dispersed in the core layer 0-1.

[0171] like Figure 2 and Figure 3 As shown, the manufacturing system of the present invention includes a fiber rack and fiber guiding device 1, a fiber pretreatment device 2, a first impregnation mold 3, a melt plasticizing feeding device 4, a molding mold 5, a cooling water tank 6, a dryer 7, a traction machine 8, a pelletizer 9, a collection box 10, and an electrical control system (not shown in the figure), which are connected in sequence.

[0172] In the manufacturing system, molding die 5 is used for molding the inner and outer layer composite material, and its structure is as follows: Figure 8 As shown.

[0173] In the manufacturing system, the first impregnation mold 3 is used for impregnating the fiber with the resin melt.

[0174] like Figure 4 As shown, in one embodiment, the first impregnation mold is an impregnation device with an adjustable guide roller position, including a first impregnation mold head A300. The first impregnation mold head A300 includes an impregnation mold body A7, a fiber inlet A1, a fiber outlet A6, and a melt flow channel A3. At least one first guide roller A8 is provided in the mold cavity, wherein the first guide roller A8 is movable between the fiber inlet A1 and the fiber outlet A6, or the first guide roller A8 is movable along a direction perpendicular to the line connecting the fiber inlet A1 and the fiber outlet A6; or, the first guide roller A8 is movable both between the fiber inlet A1 and the fiber outlet A6 and along a direction perpendicular to the line connecting the fiber inlet A1 and the fiber outlet A6.

[0175] Taking a rectangular first impregnation mold head A300 as an example, the first impregnation mold head A300 is provided with a plurality of first guide rollers A8. The axial direction of each first guide roller A8 is the width direction of the first impregnation mold head A300. Therefore, each first guide roller A8 can move along the length direction of the first impregnation mold head A300 or along the height direction, thereby changing the position of the first guide roller A8 within the first impregnation mold head A300.

[0176] Understandably, the axial direction of the first guide roller A8 can also be the length direction of the first impregnation mold head A300. In this case, each first guide roller A8 can move along the width direction of the first impregnation mold head A300 or along the height direction of the first impregnation mold head A300, thereby changing the position of the first guide roller A8 within the first impregnation mold head A300.

[0177] Since the fiber (fiber bundle) needs to pass around the first guide roller A8 in sequence within the mold cavity of the first impregnation mold head A300, the fiber's path within the mold cavity can be altered by changing the position of the first guide roller A8 within the first impregnation mold head A300 (horizontal position, longitudinal position, etc.). Therefore, when the required impregnation conditions change, it is not necessary to replace the mold; only the position of the first guide roller A8 within the first impregnation mold head A300 needs to be adjusted. This improves production efficiency and continuity. It also reduces the number of first impregnation mold heads A300, saving production costs.

[0178] Specifically, the inventive concept of this invention is to achieve the purpose of adjusting the position of the first guide roller A8 by slotting the inner wall of the mold cavity of the first impregnation mold head A300.

[0179] A first groove A4 is provided on the first inner wall of the first impregnation mold head A300, and the first groove A4 extends between the fiber inlet A1 and the fiber outlet A6 (i.e., Figure 4 (As shown in the X-axis direction), the first guide roller A8 moves along the first groove A4 to change its horizontal position within the first impregnation mold head A300.

[0180] Furthermore, a second groove A2 is also provided on the first inner wall of the first impregnation mold head A300, and the second groove extends in a direction perpendicular to the first groove A4 (i.e. Figure 4 (As shown in the Y-axis direction), the first guide roller A8 moves along the second slide groove A2 to change its vertical position in the die head.

[0181] It should be noted that the first groove A4 and the second groove A2 can be connected. Therefore, the first guide roller A8 can move arbitrarily in the longitudinal or transverse direction, thereby changing its position.

[0182] The cross-sections of the first groove A4 and the second groove A2 can be trapezoidal, circular, arc-shaped, or rectangular, etc., and the present invention does not limit them.

[0183] Both ends of the first guide roller A8 are provided with adjustment devices (not shown in the figure). The adjustment devices are used to adjust the axial length of the first guide roller A8. The minimum axial length of the first guide roller A8 is less than the distance between the first inner wall and the second inner wall, and the maximum axial length of the first guide roller A8 is greater than the distance between the first inner wall and the second inner wall.

[0184] like Figure 5 As shown, in another embodiment of the present invention, the second impregnation mold is a combined impregnation mold, including a second impregnation mold head B300. The second impregnation mold head B300 includes a first module B3, an intermediate module B6, and a second module B7 connected in sequence. The first module B3 is provided with a fiber inlet B1 and a first module flow channel B31, the second module B7 is provided with a fiber outlet B8 and a second module flow channel B71, and the intermediate module B6 is provided with an intermediate module flow channel B61.

[0185] After sequentially connecting the first module B3, intermediate module B6, and second module B7, the first module flow channel B31, intermediate module flow channel B61, and second module flow channel B71 are connected to form a combined flow channel B4 for the fiber to pass through. The number of intermediate modules B6 is at least one. That is, the first module B3 is the head module, the second module B7 is the tail module, and there are one or more intermediate modules B6 between them. It should be noted that these intermediate modules B6 are also sequentially connected.

[0186] In other words, the number of intermediate modules B6 can be increased or decreased as needed, so that when the impregnation requirements change, different intermediate modules B6 can be combined to form a combined second impregnation mold head B300, thereby improving production continuity and efficiency and saving the cost of additional mold opening.

[0187] Furthermore, by selecting different intermediate modules B6, the shape parameters (such as curvature) of the formed combined flow channel B4 can be changed, thereby altering the flow path of the fiber and melt. This allows for changes in the impregnation angle and fiber tension at different stations in the mold, ultimately achieving the goal of adjusting and optimizing the entire fiber impregnation process and improving the adaptability of the second impregnation mold head B300 to different resin matrices and fibers.

[0188] The first module B3, the intermediate module B6, and the second module B7 are placed in the mold frame. The mold frame provides a constraint, ensuring that they are in close contact with each other and thus guaranteeing the sealing of the combined flow channel B4.

[0189] like Figure 5 As shown, an implementation with two intermediate modules B6 is illustrated. Figure 5 In the embodiment shown, the downstream end of the first module flow channel B31 is connected to the upstream end of one of the intermediate module flow channels B61, the two intermediate module flow channels B61 are connected to each other, and the downstream section of the other intermediate module flow channel B61 is connected to the upstream end of the second intermediate module flow channel B71, thereby forming a combined flow channel B4 extending from the fiber inlet B1 to the fiber outlet B8.

[0190] Understandably, different combinations of flow channels B4 can be obtained by selecting different intermediate modules B6.

[0191] like Figure 5 As shown, the downstream end of the first module flow channel B31, the upstream end of the second module flow channel B71, and both ends of the intermediate module flow channel B61 are all located in the same plane and are constructed with standardized connectors B5. In other words, the connections between the first module flow channel B31, the intermediate module flow channel B61, and the second module B71 are made through standardized connectors B5. Since the standardized connectors B5 are all located in the same plane and have the same shape and size, it facilitates the combination and connection between different modules.

[0192] like Figure 6 As shown, in another embodiment of the present invention, the third impregnation mold is a strong turbulent impregnation mold, including a third impregnation mold head C300. The third impregnation mold head C300 includes an impregnation mold outer body C2. The impregnation mold outer body C2 is provided with a fiber inlet channel C3, an impregnation outlet C6, and a melt gap flow channel C1. The fiber inlet channel C3, the impregnation outlet C6, and the melt gap flow channel C1 are all connected to the mold cavity inside the impregnation mold outer body C2.

[0193] The impregnation mold outer body C2 has a second guide roller inside its cavity. This second guide roller includes at least one active guide roller C4, which is driven to rotate by a drive device (not shown in the figure). Since the rotation of the active guide roller C4 is driven by the drive device, rather than by the fiber's traction, the actively rotating active guide roller C4 helps reduce the fiber's traction tension and the friction between the fiber and the active guide roller C4 as the fiber passes through it. This reduces fiber breakage, ensures fiber integrity, and prevents fiber breakage, thereby improving the material's mechanical properties. Preferably, the second guide roller also includes at least one driven guide roller C5, which is driven by the fiber passing through the active guide roller C4; or the driven guide roller C5 and the active guide roller C4 are connected via a belt mechanism, gear mechanism, or chain mechanism. Figure 6The diagram illustrates an example with one active guide roller C4 and two driven guide rollers C5, wherein the two driven guide rollers C5 are arranged one above the other to extend the impregnation path of the fibers passing through them. The active guide roller C4 and the driven guide rollers C5 may be at the same or different heights within the die cavity.

[0194] Furthermore, the driving device can be a motor, hydraulic mechanism, or gearbox, or any device capable of driving the active guide roller C4 to rotate.

[0195] Based on the fiber's traveling speed v1 in the mold cavity of the impregnation mold body C2, the corresponding tangential speed v2 of the active guide roller C4 can be selected. For example, the tangential speed v2 of the active guide roller C4 can be made the same as the fiber's traveling speed v1, i.e., v1 = v2. This reduces fiber breakage and wear, thus ensuring fiber integrity, promoting the degree of fiber impregnation, shortening impregnation time, and improving production efficiency.

[0196] like Figure 2 As shown, the melt plasticizing feeding device 4 consists of a twin-screw extruder used for melting and plasticizing materials. The twin-screw extruder is a co-rotating twin-screw extruder with a screw diameter of 25mm-95mm and a length-to-diameter ratio of 36:1-65:1. When the melt plasticizing feeding device 4 consists of a single extruder 4, the melt plasticizing material in the extruder is divided by a melt distributor and fed into the impregnation die and the forming die respectively, and the flow rate of each die is controlled by a melt flow control valve.

[0197] like Figure 3 As shown, when the melt plasticizing feeding device 4 consists of two extruders 4-1 and 4-2, the molten plasticized melts from extruder I 4-1 and extruder II 4-2 are respectively fed into the impregnation mold and the forming mold. In this embodiment, the melt plasticizing feeding device consists of two extruders, namely extruder I 4-1 and extruder II 4-2, which respectively feed the molten plasticized melts from extruder I 4-1 and extruder II 4-2 into the first impregnation mold 3 and the forming mold 5. Extruder I 4-1 and extruder II 4-2 can be fed with the same or different materials, thus enabling the preparation of composite materials with the same or different materials for the inner and outer layers.

[0198] The fiber pretreatment device 2 consists of a tension roller and a hot drying tunnel. This combination allows for some release of tension on the fibers as they enter the hot drying tunnel, thus accommodating fibers of different strengths and preventing fibers with lower strength from breaking before entering the impregnation die. The surface of the tension roller in the fiber pretreatment device 2 needs to be ceramic-coated to increase surface roughness and reduce friction on the fibers.

[0199] In the manufacturing system, the fiber frame and fiber guiding device 1 are used for fiber output and untwisting. The device is equipped with an automatic control untwisting device, which is linked with the traction machine 8 and electrically connected to the electrical control system (such as a PLC control device).

[0200] In the manufacturing system, the cooling water tank 6, dryer 7, traction machine 8, pelletizer 9, and collection box 10 are conventional equipment or devices known to those skilled in the art, and will not be described in detail here.

[0201] Figure 7 A schematic diagram showing the second impregnation process using a molding die is shown. Figure 8 A cross-sectional view of the molding die used in the second impregnation process is shown.

[0202] like Figure 8 As shown, in one embodiment, the molding die 5 consists of a core 5-1, an outer sleeve 5-2, and an outer sleeve opening template 5-3. The core 5-1 is located inside the outer sleeve 5-2, forming a cavity with the outer sleeve 5-2. The resin melt can enter the cavity from the bottom, top, or both sides of the outer sleeve 5-2. The core 5-1 can move back and forth within the outer sleeve 5-2, and the pressure of the melt in the cavity is determined by adjusting the size of the formed cavity space. The pressure of the melt in the cavity can also be adjusted by the angle between the core 5-1 and the outer sleeve 5-2. The working principle of the molding die 5 is as follows: the strip of inner impregnated material formed after passing through the impregnation mold 3 is guided through the hole in the middle of the core 5-1, and then the composite structure of the inner and outer layer materials is formed in the cavity filled with mixed melt formed by the core 5-1 and the outer sleeve 5-2. Finally, it is discharged through the outer sleeve opening template 5-3.

[0203] like Figure 7 As shown, the strip 5-4 enters the cavity filled with the second component melt formed by the core (not shown) and the outer sleeve 5-2 for processing, wherein the second component melt is fed into the cavity from the second resin inlet 5-5.

[0204] In the following embodiments and comparative examples, the following methods are employed: Figure 3 The manufacturing system shown prepares electromagnetically shielded thermoplastic composite materials, wherein the first impregnation treatment is selected from... Figure 4 The first immersion mold shown, the second immersion treatment adopts Figure 8 The molding die shown.

[0205]

Example 1

[0206] (1) Weigh 50 parts by weight of dry PPB-M100-GH polypropylene resin (melt flow rate of 100g / 10min), 3 parts by weight of BONDYRAM 1001, 0.1 parts by weight of antioxidant 1010, and 0.5 parts by weight of XH-201. Stir in a high-speed mixer at 50°C for 3min to obtain the first component melt, and send it into the first impregnation mold.

[0207] (2) 30 parts by weight of glass fiber SE4805 enter the first impregnation mold under the action of the traction machine, where it is impregnated and dispersed with the first component melt to form a strip, which is used as the inner layer material.

[0208] (3) Weigh 49 parts by weight of dried PPH-Y450 polypropylene resin (melt flow rate of 450 g / 10 min), 10 parts by weight of conductive graphite, 2.5 parts by weight of BONDYRAM 1001, 0.1 parts by weight of antioxidant 1010, and 0.5 parts by weight of XH-201. Stir them in a high-speed mixer at 50°C for 3 min. Use this as the outer layer material and feed it into a twin-screw extruder connected to the molding die to obtain the second component melt.

[0209] (4) The inner layer material enters the molding die under the action of the traction machine, is guided through the hole in the middle of the core, and is formed in the cavity filled with the second component melt formed by the core and the outer jacket to realize the molding of the composite structure of the inner and outer layer materials. Finally, it is exported through the mold outlet.

[0210] (5) The coating amount of the outer layer material is adjusted by adjusting the extrusion rate of the extruder used for the outer layer material and the die exit diameter, so that it coats the material according to the amount specified in step (3). The cutting speed of the pelletizer is adjusted so that the pellet length of the prepared electromagnetic shielded thermoplastic composite material is controlled to be 61.1 mm. In the composite material, the proportion of glass fiber SE4805 is 21% by weight.

[0211] (6) The polypropylene composite material obtained by the above method was injection molded into standard specimens and its performance was tested. The test results are shown in Table 1.

[0212]

Example 2

[0213] (1) Weigh 20 parts by weight of dried self-made high-flow polypropylene (melt flow rate of 1000g / 10min), 0.6 parts by weight of BONDYRAM 1001, 0.1 parts by weight of antioxidant 1010 and 0.5 parts by weight of XH-201, stir in a high-speed mixer at 50°C for 3min to obtain the first component melt, and send it into the first impregnation mold.

[0214] (2) 50 parts by weight of glass fiber SE4805 enter the first impregnation mold under the action of the traction machine, where it is impregnated and dispersed with the melt to form a strip, which is used as the inner layer material.

[0215] (3) Weigh 59 parts by weight of dried PPH-T03 polypropylene resin (melt flow rate 3g / 10min), 23.6 parts by weight of Fe powder, 3 parts by weight of BONDYRAM 1001, 0.5 parts by weight of NDZ12, 0.1 parts by weight of antioxidant 1010, and 0.5 parts by weight of XH-201. Stir them in a high-speed mixer at 50°C for 3min. Use this as the outer layer material and feed it into a twin-screw extruder connected to the molding die to obtain the second component melt.

[0216] (4) The inner layer material enters the molding die under the action of the traction machine, is guided through the hole in the middle of the core, and is formed in the cavity filled with the second component melt formed by the core and the outer jacket to realize the molding of the composite structure of the inner and outer layer materials. Finally, it is exported through the mold outlet.

[0217] (5) Adjust the coating amount of the outer layer material by adjusting the extrusion rate of the extruder used for the outer layer material and the die exit diameter, so that it coats the material according to the amount specified in step (3). Adjust the cutting speed of the pelletizer so that the pellet length of the prepared electromagnetic shielded thermoplastic composite material is controlled to be 15 mm. In the composite material, the proportion of glass fiber SE4805 is 31.3% by weight.

[0218] (6) The polypropylene composite material obtained by the above method was injection molded into standard specimens and its performance was tested. The test results are shown in Table 1.

[0219]

Example 3

[0220] (1) Weigh 20 parts by weight of dried self-made high-flow polypropylene (melt flow rate 7500g / 10min), 0.6 parts by weight of BONDYRAM 1001, 0.5 parts by weight of NDZ12, 0.1 parts by weight of antioxidant 1010 and 0.5 parts by weight of XH-201, stir them in a high-speed mixer at 50°C for 3min to obtain the first component melt, and send it into the first impregnation mold.

[0221] (2) 60 parts by weight of glass fiber SE4805 and 20 parts by weight of stainless steel fiber enter the first impregnation mold under the action of the traction machine, where they are impregnated and dispersed with the melt to form a strip, which is used as the inner layer material.

[0222] (3) Weigh 69 parts by weight of dried K8303 polypropylene resin (melt flow rate 1.5 g / 10 min), 13.8 parts by weight of Fe powder, 3 parts by weight of BONDYRAM 1001, 0.5 parts by weight of NDZ12, 0.1 parts by weight of antioxidant 1010, and 0.5 parts by weight of XH-201. Stir them in a high-speed mixer at 50°C for 3 min. Use this as the outer layer material and feed it into a twin-screw extruder connected to the molding die to obtain the second component melt.

[0223] (4) The inner layer material enters the molding die under the action of the traction machine, is guided through the hole in the middle of the core, and is formed in the cavity filled with the second component melt formed by the core and the outer jacket to realize the molding of the composite structure of the inner and outer layer materials. Finally, it is exported through the mold outlet.

[0224] (5) Adjust the coating amount of the outer layer material by adjusting the extrusion rate of the extruder used for the outer layer material and the die exit diameter, so that it coats the material according to the amount specified in step (3). Adjust the cutting speed of the pelletizer so that the pellet length of the prepared electromagnetic shielded thermoplastic composite material is controlled to be 18 mm. The fiber content in the composite material is 42.5% by weight.

[0225] (6) The polypropylene composite material obtained by the above method was injection molded into standard specimens and its performance was tested. The test results are shown in Table 1.

[0226]

Example 4

[0227] (1) Weigh 70 parts by weight of dried PPB-M100-GH (melt flow rate 100g / 10min), 3 parts by weight of BONDYRAM 1001, 0.5 parts by weight of NDZ12, 0.1 parts by weight of antioxidant 1010, and 0.5 parts by weight of XH-201. Stir them in a high-speed mixer at 50°C for 3min to obtain the first component melt, and then send it into the first impregnation mold.

[0228] (2) 30 parts by weight of stainless steel fiber enter the first impregnation mold under the action of the traction machine, where it is impregnated and dispersed with the melt to form a strip, which is used as the inner layer material.

[0229] (3) Weigh 10 parts by weight of dried self-made high-flow polypropylene (melt flow rate 1900g / 10min), 1.5 parts by weight of conductive carbon black, 0.5 parts by weight of BONDYRAM 1001, 0.05 parts by weight of antioxidant 1010 and 0.25 parts by weight of XH-201, stir them in a high-speed mixer at 50°C for 3min, use them as the outer layer material, and feed them into a twin-screw extruder connected to the molding die to obtain the second component melt.

[0230] (4) The inner layer material enters the molding die under the action of the traction machine, is guided through the hole in the middle of the core, and is formed in the cavity filled with the second component melt formed by the core and the outer jacket to realize the molding of the composite structure of the inner and outer layer materials. Finally, it is exported through the mold outlet.

[0231] (5) Adjust the coating amount of the outer layer material by adjusting the extrusion rate of the extruder used for the outer layer material and the die exit diameter, so that it coats the material according to the amount specified in step (3). Adjust the cutting speed of the pelletizer so that the pellet length of the prepared electromagnetic shielded thermoplastic composite material is controlled to be 5 mm. In the composite material, the proportion of stainless steel fiber is 25.9% by weight.

[0232] (6) The polypropylene composite material obtained by the above method was injection molded into standard specimens and its performance was tested. The test results are shown in Table 1.

[0233]

Example 5

[0234] (1) Weigh 57 parts by weight of dried M60RHC polypropylene resin (melt flow rate 60g / 10min), 2.5 parts by weight of BONDYRAM 1001, 0.5 parts by weight of NDZ12, 0.1 parts by weight of antioxidant 168 and 0.25 parts by weight of XH-201, stir them in a high-speed mixer at 50°C for 3min to obtain the first component melt, and send it into the first impregnation mold.

[0235] (2) 40 parts by weight of carbon fiber enter the first impregnation mold under the action of the traction machine, where it is impregnated and dispersed with the melt to form a strip, which is used as the inner layer material.

[0236] (3) Weigh 85 parts by weight of dried M50RH polypropylene resin (melt flow rate 50g / 10min), 12 parts by weight of conductive carbon black, 4 parts by weight of BONDYRAM 1001, 0.8 parts by weight of NDZ12, 0.1 parts by weight of antioxidant 168, and 0.8 parts by weight of XH-201. Stir them in a high-speed mixer at 50°C for 3min. Use this as the outer layer material and feed it into a twin-screw extruder connected to the molding die to obtain the second component melt.

[0237] (4) The inner layer material enters the molding die under the action of the traction machine, is guided through the hole in the middle of the core, and is formed in the cavity filled with the second component melt formed by the core and the outer jacket to realize the molding of the composite structure of the inner and outer layer materials. Finally, it is exported through the mold outlet.

[0238] (5) Adjust the coating amount of the outer layer material by adjusting the extrusion rate of the extruder used for the outer layer material and the die outlet diameter, so that it coats the material according to the amount specified in step (3). Adjust the cutting speed of the pelletizer so that the pellet length of the prepared electromagnetic shielding thermoplastic composite material is controlled to be 10 mm. In the composite material, the carbon fiber accounts for 18.6% by weight.

[0239] (6) The polypropylene composite material obtained by the above method was injection molded into standard specimens and its performance was tested. The test results are shown in Table 1.

[0240]

Example 6

[0241] (1) Weigh 57 parts by weight of dried PA6-BL3200H, 3 parts by weight of CMG9805, 0.1 parts by weight of antioxidant 1010 and 0.5 parts by weight of XH-201, stir them in a high-speed mixer at 50°C for 3 minutes to obtain the first component melt, and send it into the first impregnation mold.

[0242] (2) ER4301H enters the first impregnation mold under the action of the traction machine, where it is impregnated and dispersed with the first component melt to form a strip, which is used as the inner layer material.

[0243] (3) Weigh 85 parts by weight of dried PA6-BL3200H, 12 parts by weight of conductive carbon black, 3 parts by weight of CMG9805, 0.1 parts by weight of antioxidant 1010 and 0.5 parts by weight of XH-201, stir them in a high-speed mixer at 50°C for 3 minutes, use them as the outer layer material, and feed them into a twin-screw extruder connected to the molding die to obtain the second component melt.

[0244] (4) The inner layer material enters the molding die under the action of the traction machine, is guided through the hole in the middle of the core, and is formed in the cavity filled with the second component melt formed by the core and the outer jacket to realize the molding of the composite structure of the inner and outer layer materials. Finally, it is exported through the mold outlet.

[0245] (5) Adjust the coating amount of the outer layer material by adjusting the extrusion rate of the extruder used for the outer layer material and the die exit diameter, so that it coats the material according to the amount specified in step (3). Adjust the cutting speed of the pelletizer so that the pellet length of the prepared electromagnetic shielded thermoplastic composite material is controlled to be 12 mm. In the composite material, ER4301H accounts for 40% by weight.

[0246] (6) The long glass fiber reinforced PA6 composite material prepared by the above method was injection molded into standard specimens and its performance was tested. The test results are shown in Table 1.

[0247]

Example 7

[0248] (1) Weigh 57 parts by weight of dried PPB-M100-GH, 3 parts by weight of BONDYRAM 1001, 0.5 parts by weight of XHY-501, 0.1 parts by weight of antioxidant 1010, and 0.5 parts by weight of XH-201. Stir them in a high-speed mixer at 50°C for 3 minutes to obtain the first component melt, and send it into the first impregnation mold.

[0249] (2) Continuous basalt fibers enter the first impregnation mold under the action of the traction machine, where they are impregnated and dispersed with the first component melt to form strips, which are used as inner layer materials.

[0250] (3) Weigh 85 parts by weight of dried PPB-M100-GH, 12 parts by weight of conductive carbon black, 3 parts by weight of BONDYRAM1001, 0.5 parts by weight of XHY-501, 0.1 parts by weight of antioxidant 1010, and 0.5 parts by weight of XH-201. Stir them in a high-speed mixer at 50°C for 3 minutes. Use them as the outer layer material and feed them into a twin-screw extruder connected to the molding die to obtain the second component melt.

[0251] (4) The inner layer material enters the molding die under the action of the traction machine, is guided through the hole in the middle of the core, and is formed in the cavity filled with the second component melt formed by the core and the outer jacket to realize the molding of the composite structure of the inner and outer layer materials. Finally, it is exported through the mold outlet.

[0252] (5) Adjust the coating amount of the outer layer material by adjusting the extrusion rate of the extruder used for the outer layer material and the die outlet diameter, so that it coats the material according to the amount specified in step (3). Adjust the cutting speed of the pelletizer so that the pellet length of the prepared electromagnetic shielded thermoplastic composite material is controlled to be 12 mm. In the composite material, the proportion of continuous basalt fiber is 40% by weight.

[0253] (6) The basalt fiber reinforced PP composite material prepared by the above method was injection molded into standard specimens and its performance was tested. The test results are shown in Table 1.

[0254]

Example 8

[0255] (1) Weigh 57 parts by weight of dried PA6-BL3200H, 3 parts by weight of BONDYRAM 1001, 0.5 parts by weight of NDZ12, 0.1 parts by weight of antioxidant 1010, and 0.5 parts by weight of XH-201. Stir them in a high-speed mixer at 50°C for 3 minutes to obtain the first component melt, and then send it into the first impregnation mold.

[0256] (2) Continuous carbon fiber enters the first impregnation mold under the action of the traction machine, where it is impregnated and dispersed with the first component melt to form a strip, which is used as the inner layer material.

[0257] (3) Weigh 85 parts of dry PA6-BL3200H, 12 parts of conductive carbon black, 3 parts of BONDYRAM 1001, 0.5 parts of NDZ12, 0.1 parts of antioxidant 1010, and 0.5 parts of XH-201. Stir them in a high-speed mixer at 50°C for 3 minutes. Use them as the outer layer material and feed them into a twin-screw extruder connected to the molding die to obtain the second component melt.

[0258] (4) The inner layer material enters the molding die under the action of the traction machine, is guided through the hole in the middle of the core, and is formed in the cavity filled with the second component melt formed by the core and the outer jacket to realize the molding of the composite structure of the inner and outer layer materials. Finally, it is exported through the mold outlet.

[0259] (5) Adjust the coating amount of the outer layer material by adjusting the extrusion rate of the extruder used for the outer layer material and the die outlet diameter, so that it coats the material according to the amount specified in step (3). Adjust the cutting speed of the pelletizer so that the pellet length of the prepared electromagnetic shielded thermoplastic composite material is controlled to be 12 mm. In the composite material, the proportion of continuous carbon fiber is 40% by weight.

[0260] (6) The long carbon fiber reinforced PA6 composite material obtained by the above method was injection molded into standard specimens and its performance was tested. The test results are shown in Table 1.

[0261]

Example 9

[0262] The preparation process is the same as in Example 1, except that 70 parts by weight of PPB-M100-GH are weighed in step (1) and 85 parts by weight of PPH-Y450 are weighed in step (3). The performance of the prepared composite material was tested, and the results are shown in Table 1. In the composite material, the proportion of glass fiber SE4805 is 15% by weight.

[0263]

Example 10

[0264] The preparation process is the same as in Example 1, except that: in step (1), 45 parts by weight of PPB-M100-GH, 2.5 parts by weight of BONDYRAM 1001, 0.08 parts by weight of antioxidant 1010, and 0.4 parts by weight of XH-201 are weighed; and in step (3), 65 parts by weight of PPH-Y450 are weighed. The performance of the prepared composite material was tested, and the results are shown in Table 1. In the composite material, the proportion of glass fiber SE4805 is 19.3% by weight.

[0265]

Example 11

[0266] The preparation process is the same as in Example 1, except that: in step (1), 25 parts by weight of PPB-M100-GH, 1.5 parts by weight of BONDYRAM 1001, 0.05 parts by weight of antioxidant 1010, and 0.25 parts by weight of XH-201 are weighed; and in step (3), 45 parts by weight of PPH-Y450 are weighed. The performance of the prepared composite material was tested, and the test results are shown in Table 1. In the composite material, the proportion of glass fiber SE4805 is 26% by weight.

[0267]

Example 12

[0268] The preparation process was the same as in Example 1, except that 55 parts by weight of PPB-M100-GH were weighed in step (1) and 70 parts by weight of PPH-Y450 were weighed in step (3). The performance of the prepared composite material was tested, and the results are shown in Table 1. In the composite material, the proportion of glass fiber SE4805 was 17.6% by weight.

[0269]

Example 13

[0270] (1) Weigh 50 parts by weight of dry PPB-M100-GH polypropylene resin (melt flow rate of 100g / 10min), 3 parts by weight of BONDYRAM 1001, 0.1 parts by weight of antioxidant 1010, and 0.5 parts by weight of XH-201. Stir in a high-speed mixer at 50°C for 3min to obtain the first component melt, and send it into the first impregnation mold.

[0271] (2) 30 parts by weight of glass fiber SE4805 enter the first impregnation mold under the action of the traction machine, where it is impregnated and dispersed with the first component melt to form a strip, which is used as the inner layer material.

[0272] (3) Weigh 49 parts by weight of dried M60RHC polypropylene resin (melt flow rate of 60g / 10min), 8.5 parts by weight of conductive graphite, 20 parts by weight of short glass fibers cut from SE4805 glass fiber with a length of 3mm, 2.5 parts by weight of BONDYRAM 1001, 0.1 parts by weight of antioxidant 1010, and 0.5 parts by weight of XH-201. Stir them in a high-speed mixer at 50°C for 3min. Use this as the outer layer material and feed it into a twin-screw extruder connected to the molding die to obtain the second component melt.

[0273] (4) The inner layer material enters the molding die under the action of the traction machine, is guided through the hole in the middle of the core, and is formed in the cavity filled with the second component melt formed by the core and the outer jacket to realize the molding of the composite structure of the inner and outer layer materials. Finally, it is exported through the mold outlet.

[0274] (5) Adjust the coating amount of the outer layer material by adjusting the extrusion rate of the extruder used for the outer layer material and the die exit diameter, so that it coats the material according to the amount specified in step (3). Adjust the cutting speed of the pelletizer so that the pellet length of the prepared electromagnetic shielded thermoplastic composite material is controlled to be 6.1 mm. In the composite material, the proportion of glass fiber SE4805 is 30% by weight.

[0275] (6) The polypropylene composite material obtained by the above method was injection molded into standard specimens and its performance was tested. The test results are shown in Table 1.

[0276] Comparative Example 1

[0277] (1) Weigh 57 parts by weight of dried PPB-M100-GH, 3 parts by weight of BONDYRAM 1001, 0.1 parts by weight of antioxidant 1010 and 0.5 parts by weight of XH-201, stir them in a high-speed mixer at 50°C for 3 minutes to obtain a melt, and send it into an impregnation mold.

[0278] (2) SE4805 enters the impregnation mold under the action of the traction machine, where it is impregnated and dispersed with the melt. The content of SE4805 in the composite material is adjusted by selecting the size of the mold plate (6mm) of the impregnation mold. The content of SE4805 is controlled to be 22% by weight. The cutting speed of the pelletizer is adjusted so that the pellet length of the prepared polypropylene composite material is controlled to be 12mm.

[0279] (3) The polypropylene composite material obtained by the above method was injection molded into standard specimens and its performance was tested. The test results are shown in Table 1.

[0280] Comparative Example 2

[0281] (1) Weigh 50 parts by weight of dried PPB-M100-GH polypropylene resin (melt flow rate of 100g / 10min), 30 parts by weight of short glass fiber cut from stainless steel fiber with a length of 3mm, 3 parts by weight of BONDYRAM 1001, 0.5 parts by weight of NDZ12, 0.1 parts by weight of antioxidant 1010, and 0.5 parts by weight of XH-201. Stir them in a high-speed mixer at 50°C for 3min to obtain the inner layer resin.

[0282] (2) Weigh 49 parts by weight of dried M60RHC polypropylene resin (melt flow rate of 60g / 10min), 20 parts by weight of short glass fiber cut from stainless steel fiber with a length of 3mm, 3 parts by weight of BONDYRAM 1001, 0.5 parts by weight of NDZ12, 0.1 parts by weight of antioxidant 1010, and 0.5 parts by weight of XH-201. Stir them in a high-speed mixer at 50°C for 3min and use them as the outer layer material.

[0283] (3) The inner layer material was added to extruder No. 1, and the outer layer material was added to extruder No. 2. The two extruders simultaneously extruded the raw materials, and the materials were extruded through a die with an inner and outer layer structure to obtain a continuous filament material with an inner layer containing short glass fiber resin and an outer layer containing short glass fiber resin. The filament material was then pelletized to obtain the comparative raw material. Performance tests are shown in Table 1.

[0284] Table 1

[0285] Tensile strength (MPa) Flexural modulus (GPa) <![CDATA[Notched impact of simply supported beam (KJ / m 2 )]]> Shielding effectiveness (dB) D1 107 4.7 14.8 -- D2 106 5.9 14.0 32 S1 130 5.2 15.6 38 S2 132 7.0 23.2 25 S3 135 8.8 30.3 36 S4 118 4.8 14.8 38 S5 115 4.7 15.2 52 S6 180 8.9 30.1 34 S7 110 8.0 43.6 33 S8 195 12 56.2 33 S9 119 5.0 17.2 -- S10 131 5.5 17.3 -- S11 142 6.7 23.4 -- S12 128 5.2 17.9 -- S13 135 6.5 28.1 38

[0286] Note: In Table 1, D1 and D2 are Comparative Example 1 and Comparative Example 2, respectively, and S1-S13 are Examples 1-13.

[0287] By comparing Examples 1-5 and Examples 9-13 with Comparative Examples 1-2, it was found that the tensile strength, flexural strength, notched beam impact strength, and surface gloss of the long glass fiber reinforced polypropylene material prepared by the present invention are significantly higher than those of the material prepared in Comparative Example 1, and the surface quality of the parts is also higher.

[0288] As can be seen from Examples 6-8 of the present invention, the preparation method proposed in this invention is not only applicable to long glass fiber reinforced polypropylene composites, but also applicable to the preparation of continuous glass fiber reinforced PA6, continuous basalt fiber reinforced polypropylene, and continuous carbon fiber reinforced PA6 composites.

[0289] Furthermore, as can be seen from the data in Table 1, the thermoplastic composite material of the present invention has good electromagnetic shielding performance. By selecting the melt flow rate of the thermoplastic resin of the inner and outer layer materials, the prepared composite material can have an ideal surface gloss.

[0290] The preparation method of the present invention is simple to operate, can realize online continuous production, can ensure high production capacity and low energy consumption, and is suitable for industrial production and application.

[0291] The above description is merely a preferred embodiment of the present invention. It should be noted that, for those skilled in the art, based on the technical teachings provided by the present invention and as common knowledge in the field, other equivalent modifications and improvements can be made, and these should also be considered within the scope of protection of the present invention.

Claims

1. An electromagnetic shielding thermoplastic composite material, comprising an inner layer material and at least one outer layer material, wherein the inner layer material is a core layer comprising fiber bundles, a first thermoplastic resin, and a first additive, and the at least one outer layer material encapsulates the core layer, and wherein the at least one outer layer material is a resin layer composed of a second thermoplastic resin, an electromagnetic shielding filler, and optionally a second additive, or a resin layer composed of a second thermoplastic resin, an electromagnetic shielding filler, fibers, and optionally a second additive, wherein... The fiber bundle extends continuously from one end of the core layer to its opposite end, and the second additive is selected from at least one of compatibilizer, antioxidant, lubricant, slip agent, antistatic agent, plasticizer, nucleating agent, scratch-resistant additive, flame retardant, heat stabilizer, color masterbatch and filler; In the transverse cross section of the electromagnetic shielding thermoplastic composite material, from the inside out, there are a core layer and a resin layer, and the first thermoplastic resin and the second thermoplastic resin are of the same type. The melt flow rate of the first thermoplastic resin at 230°C and a load of 2.16 kg is 60-8000 g / 10 min. The melt flow rate of the second thermoplastic resin at 230°C and a load of 2.16 kg is 480-8000 g / 10 min; The melt flow rate of the first thermoplastic resin is higher than the melt flow rate of the second thermoplastic resin, or the melt flow rate of the second thermoplastic resin is higher than the melt flow rate of the first thermoplastic resin. In the inner layer material, the amount of the first thermoplastic resin is 1-90 parts by weight, and the amount of the fiber bundle is 10-110 parts by weight; in the outer layer material, the amount of the second thermoplastic resin is 1-110 parts by weight.

2. The thermoplastic composite material for electromagnetic shielding according to claim 1, characterized in that, The thermoplastic composite material used for electromagnetic shielding is in the form of strips, rods, or granules.

3. The electromagnetic shielding thermoplastic composite material according to claim 2, characterized in that, The length of the thermoplastic composite material used for electromagnetic shielding is 5-30 mm.

4. The electromagnetic shielding thermoplastic composite material according to claim 2, characterized in that, The length of the thermoplastic composite material used for electromagnetic shielding is 5-25 mm.

5. The thermoplastic composite material for electromagnetic shielding according to claim 2, characterized in that, The length of the thermoplastic composite material used for electromagnetic shielding is 6-15 mm.

6. The thermoplastic composite material for electromagnetic shielding according to claim 1, characterized in that, In the inner layer material, the amount of the first thermoplastic resin is 20-70 parts by weight; the amount of the fiber bundle is 20-110 parts by weight; and / or, In the inner layer material, the weight ratio of the fiber bundle to the first thermoplastic resin is 0.25-6:1; and / or, In the outer layer material, the amount of the second thermoplastic resin is 10-99 parts by weight.

7. The electromagnetic shielding thermoplastic composite material according to claim 6, characterized in that, In the inner layer material, the amount of the first thermoplastic resin is 20-55 parts by weight; the amount of the fiber bundle is 25-110 parts by weight; and / or, In the inner layer material, the weight ratio of the fiber bundle to the first thermoplastic resin is 0.35-4.5:1; and / or, In the outer layer material, the amount of the second thermoplastic resin is 40-90 parts by weight.

8. The electromagnetic shielding thermoplastic composite material according to claim 6, characterized in that, In the inner layer material, the amount of the first thermoplastic resin is 24-45 parts by weight; and / or, In the inner layer material, the weight ratio of the fiber bundle to the first thermoplastic resin is 0.43-4.5:

1.

9. The thermoplastic composite material for electromagnetic shielding according to claim 1, characterized in that, In the inner layer material, the amount of the first thermoplastic resin is 1-90 parts by weight; the amount of the fiber bundle is 10-99 parts by weight; or, In the inner layer material, the amount of the first thermoplastic resin is 50-70 parts by weight; the amount of the fiber bundle is 90-110 parts by weight; and / or in the outer layer material, the amount of the second thermoplastic resin is 90-110 parts by weight.

10. The thermoplastic composite material for electromagnetic shielding according to claim 9, characterized in that, In the inner layer material, the amount of the first thermoplastic resin is 20-70 parts by weight; and / or the amount of the fiber bundle is 20-80 parts by weight; or, In the inner layer material, the amount of the first thermoplastic resin is 50-60 parts by weight; and / or the amount of the fiber bundle is 100-110 parts by weight; and / or in the outer layer material, the amount of the second thermoplastic resin is 95-105 parts by weight.

11. The thermoplastic composite material for electromagnetic shielding according to claim 10, characterized in that, In the inner layer material, the amount of the first thermoplastic resin is 20-55 parts by weight; and / or the amount of the fiber bundle is 25-50 parts by weight.

12. The thermoplastic composite material for electromagnetic shielding according to claim 11, characterized in that, In the inner layer material, the amount of the first thermoplastic resin is 24-45 parts by weight.

13. The thermoplastic composite material for electromagnetic shielding according to any one of claims 1-12, characterized in that, The inner layer material does not contain non-oriented short fibers.

14. The thermoplastic composite material for electromagnetic shielding according to any one of claims 1-12, characterized in that, The inner layer material is composed of fiber bundles, a first thermoplastic resin, and a first additive.

15. The thermoplastic composite material for electromagnetic shielding according to any one of claims 1-12, characterized in that, The fibers in the outer layer material are short fibers.

16. The thermoplastic composite material for electromagnetic shielding according to any one of claims 1-12, characterized in that, In the outer layer material, the weight ratio of the fiber to the second thermoplastic resin is 1-50:

100.

17. The thermoplastic composite material for electromagnetic shielding according to any one of claims 1-12, characterized in that, In the outer layer material, the weight ratio of the fiber to the second thermoplastic resin is 5-50:

100.

18. The thermoplastic composite material for electromagnetic shielding according to any one of claims 1-12, characterized in that, In the outer layer material, the weight ratio of the fiber to the second thermoplastic resin is 20-45:

100.

19. The thermoplastic composite material for electromagnetic shielding according to any one of claims 1-12, characterized in that, The first thermoplastic resin and the second thermoplastic resin are selected from at least one of polypropylene, polyethylene, polystyrene, polyvinyl chloride, polyacrylonitrile-butadiene-styrene copolymer, polyacrylonitrile-styrene copolymer, polyoxymethylene, polyamide, polyethylene terephthalate, polybutylene terephthalate, and polymethyl methacrylate, and their alloy polymers; and / or, The fiber bundle is selected from at least one of glass fiber, carbon fiber, stainless steel fiber, synthetic resin fiber, and mineral fiber.

20. The thermoplastic composite material for electromagnetic shielding according to claim 19, characterized in that, The first thermoplastic resin and the second thermoplastic resin are selected from at least one of polypropylene, polyethylene, polyamide, polyethylene terephthalate, polybutylene terephthalate, polyphenylene sulfide, polyurethane, and polyetheretherketone; and / or, The fiber bundle is selected from at least one of basalt fiber and aromatic polyamide fiber.

21. The electromagnetic shielding thermoplastic composite material according to claim 19, characterized in that, The first thermoplastic resin and the second thermoplastic resin are selected from at least one of homopolymer polypropylene, copolymer polypropylene, a mixture of homopolymer polypropylene and copolymer polypropylene, nylon 6, nylon 66, and a mixture of nylon 6 and nylon 66.

22. The thermoplastic composite material for electromagnetic shielding according to any one of claims 1-12, characterized in that, The melt flow rate of the first thermoplastic resin at 230°C and a load of 2.16 kg is 100-8000 g / 10 min. And / or, the weight ratio of the second thermoplastic resin to the first thermoplastic resin is 0.05-12.5:

1.

23. The thermoplastic composite material for electromagnetic shielding according to claim 22, characterized in that, The melt flow rate of the first thermoplastic resin at 230°C and a load of 2.16 kg is 1000-7500 g / 10 min; the melt flow rate of the second thermoplastic resin at 230°C and a load of 2.16 kg is 1900-8000 g / 10 min. And / or, the weight ratio of the second thermoplastic resin to the first thermoplastic resin is 0.1-4:

1.

24. The electromagnetic shielding thermoplastic composite material according to claim 23, characterized in that, The melt flow rate of the first thermoplastic resin at 230°C and a load of 2.16 kg is 1900-7500 g / 10 min. And / or, the weight ratio of the second thermoplastic resin to the first thermoplastic resin is 0.14-3.5:

1.

25. The thermoplastic composite material for electromagnetic shielding according to any one of claims 1-12, characterized in that, The first thermoplastic resin has a melt flow rate of 60-450 g / 10min at 230°C and a load of 2.16 kg, and the second thermoplastic resin has a melt flow rate of 450-8000 g / 10min at 230°C and a load of 2.16 kg.

26. The electromagnetic shielding thermoplastic composite material according to claim 25, characterized in that, The melt flow rate of the first thermoplastic resin at 230°C and a load of 2.16 kg is 60-200 g / 10 min.

27. The electromagnetic shielding thermoplastic composite material according to claim 25, characterized in that, The first thermoplastic resin has a melt flow rate of 60-450 g / 10min at 230°C and a load of 2.16 kg, and the second thermoplastic resin has a melt flow rate of 800-8000 g / 10min at 230°C and a load of 2.16 kg.

28. The electromagnetic shielding thermoplastic composite material according to claim 22, characterized in that, When the melt flow rate of the second thermoplastic resin is 800-8000 g / 10min at 230°C and a load of 2.16 kg, the weight ratio of the second thermoplastic resin to the first thermoplastic resin is less than 0.25:1; and / or, When the first thermoplastic resin and the second thermoplastic resin are selected from at least one of nylon 6, nylon 66, and a mixture of nylon 6 and nylon 66, the viscosity of the nylon 6 and nylon 66 is 1.8-3.

5.

29. The electromagnetic shielding thermoplastic composite material according to claim 22, characterized in that, When the melt flow rate of the second thermoplastic resin is 800-8000 g / 10min under the conditions of 230℃ and a load of 2.16kg, the weight ratio of the second thermoplastic resin to the first thermoplastic resin is less than 0.18:

1.

30. The electromagnetic shielding thermoplastic composite material according to claim 22, characterized in that, When the melt flow rate of the second thermoplastic resin is 800-8000 g / 10min under the conditions of 230℃ and a load of 2.16kg, the weight ratio of the second thermoplastic resin to the first thermoplastic resin is less than 0.15:

1.

31. The electromagnetic shielding thermoplastic composite material according to any one of claims 1-12, characterized in that, The electromagnetic shielding filler includes conductive metal filler and / or conductive carbon material; And / or, based on 100 parts by weight of the second thermoplastic resin, the amount of the electromagnetic shielding filler is 10-40 parts by weight. And / or, based on 100 parts by weight of the first thermoplastic resin and the second thermoplastic resin respectively, the first additive and the second additive each independently include at least one of 0.5-15 parts by weight of compatibilizer, 0.05-3 parts by weight of antioxidant and 0.05-2.5 parts by weight of lubricant.

32. The electromagnetic shielding thermoplastic composite material according to claim 31, characterized in that, The conductive metal filler is conductive metal particles and / or the conductive carbon material is one or more of carbon black, graphite, graphene, and carbon nanotubes. And / or, based on 100 parts by weight of the second thermoplastic resin, the amount of the electromagnetic shielding filler is 10-35 parts by weight. And / or, based on 100 parts by weight of the first thermoplastic resin and the second thermoplastic resin respectively, the first additive and the second additive each independently include 1-15 parts by weight of a compatibilizer. At least one of an antioxidant (0.1-1 parts by weight) and a lubricant (0.5-2.5 parts by weight); and / or, The compatibilizer is selected from at least one of polar monomer-grafted modified polymers; and / or, The antioxidant is selected from at least one of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], tris[2,4-di-tert-butylphenyl] phosphite, octadecyl β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, 2,2'-methylenebis(4-methyl-6-tert-butylphenol), 1,1,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane, and bis(2,4-di-tert-butylphenol) pentaerythritol diphosphite; and / or The lubricant is selected from at least one of ethylene bis-stearamide, calcium stearate, polyethylene wax, pentaerythritol stearate, silicone, polyethylene glycol, and fluorinated resins; and / or, The first additive also includes at least one of slip agent, antistatic agent and plasticizer.

33. The electromagnetic shielding thermoplastic composite material according to claim 32, characterized in that, Based on 100 parts by weight of the first thermoplastic resin and the second thermoplastic resin respectively, the first additive and the second additive each independently comprise at least one of 1-6 parts by weight of a compatibilizer and 0.1-0.5 parts by weight of an antioxidant; and / or, The polar monomer is selected from at least one of maleic anhydride, maleic anhydride derivatives, acrylic acid, and acrylate derivatives.

34. The electromagnetic shielding thermoplastic composite material according to claim 33, characterized in that, Based on 100 parts by weight of the first thermoplastic resin and the second thermoplastic resin respectively, each of the first and second additives independently comprises 3-6 parts by weight of a compatibilizer; and / or, The polymer in the polar monomer grafted modified polymer is selected from at least one of polyethylene, polypropylene, ethylene-α-octene copolymer and propylene-α-olefin copolymer.

35. A method for preparing the electromagnetic shielding thermoplastic composite material according to any one of claims 1-34, characterized in that, The method includes the following steps: Step A: The first thermoplastic resin and the first additive are mixed and melted to obtain the first component melt; Step B: The continuous fiber bundle is subjected to a first impregnation treatment with the first component melt to form a filamentous core layer product; Step C: The second thermoplastic resin and the second additive are mixed and melted to obtain the second component melt; Step D: The filamentous core layer product is subjected to a second impregnation treatment with the second component melt to form a resin layer that encapsulates the core layer.

36. The preparation method according to claim 35, characterized in that, The mixing conditions in step A include: a temperature of 40-60℃ and a time of 0.5-20 min; a melting temperature of 200-380℃ in step A; and / or, The mixing conditions in step C include: a temperature of 40-60℃ and a time of 0.5-20 min; the melting temperature in step C is 200-380℃.

37. The preparation method according to claim 36, characterized in that, The mixing conditions for step A include: a time of 1-10 minutes; and / or, The mixing conditions for step C include a time of 1-10 minutes.

38. The preparation method according to claim 36, characterized in that, The mixing conditions for step A include: a time of 3-5 minutes; and / or, The mixing conditions for step C include a time of 3-5 minutes.

39. The preparation method according to any one of claims 35-38, characterized in that, In step B, the first impregnation process is performed in a first impregnation mold. The first impregnation mold is an adjustable impregnation mold, which includes a fiber inlet, a fiber outlet, and a melt flow channel. At least one first guide roller is provided in the mold cavity of the first impregnation mold. The first guide roller is movable between the fiber inlet and the fiber outlet. And / or, the first guide roller is movable along a direction perpendicular to the line connecting the fiber inlet and the fiber outlet.

40. The preparation method according to any one of claims 35-38, characterized in that, In step B, the first impregnation process is carried out in the second impregnation mold. The second impregnation mold is a combined impregnation mold, which includes a first module, an intermediate module, and a second module connected in sequence. The first module is provided with a fiber inlet and a first module flow channel. The second module is provided with a fiber outlet and a second module flow channel. The intermediate module is provided with an intermediate module flow channel. After the first module, the intermediate module, and the second module are connected in sequence, the first module flow channel, the intermediate module flow channel, and the second module flow channel are connected to form a combined flow channel for the fiber to pass through.

41. The preparation method according to any one of claims 35-38, characterized in that, In step B, the first impregnation process is carried out in a third impregnation mold, which is a strong turbulent impregnation mold. The third impregnation mold includes a fiber inlet channel, an impregnation outlet, and a melt gap channel. The fiber inlet channel, the impregnation outlet, and the melt gap channel are all connected to the mold cavity inside the third impregnation mold. A second guide roller is provided inside the mold cavity of the third impregnation mold. The second guide roller includes at least one active guide roller, which is driven to rotate by a driving device.

42. The application of a thermoplastic composite material for electromagnetic shielding as described in any one of claims 1-34 or a thermoplastic composite material for electromagnetic shielding prepared by any one of claims 35-41 in the fields of automotive industry, machinery manufacturing, electronics and electrical appliances, chemical and environmental protection, aerospace and communications and construction industry.

43. The application according to claim 42, characterized in that, The applications are in large automotive parts and / or high-precision electronic and electrical components.

44. The application according to claim 42, characterized in that, The application is in the automotive front-end module and / or the all-plastic tailgate inner panel.

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