Heat conduction / electromagnetic shielding composite functional master batch as well as preparation method and application thereof

Abstract

The invention provides a heat-conducting and electromagnetic-shielding composite functional master batch as well as a preparation method and application thereof. The heat conduction / electromagnetic shielding composite functional master batch comprises engineering plastic, heat conduction electromagnetic shielding filler and a toughening agent, and the heat conduction electromagnetic shielding filler comprises heat conduction resistance type electromagnetic shielding filler and heat conduction magnetic loss type electromagnetic shielding filler, the heat-conducting resistance type electromagnetic shielding filler comprises a one-dimensional carbon filler and a two-dimensional carbon filler, and comprises engineering plastic, a flexibilizer and a heat-conducting electromagnetic shielding filler. Under the action of the composite force field module under the combined action of stretching and shearing, uniform dispersion of the engineering plastic and the functional filler is realized, and synchronous improvement of heat conduction and electromagnetic shielding performance of the engineering plastic is realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of polymer material processing methods, and in particular to a heat-conducting and electromagnetic shielding composite functional masterbatch, a preparation method thereof, and a composite functional material containing the heat-conducting and electromagnetic shielding composite functional masterbatch. BACKGROUND

[0002] Engineering plastics are widely used in the fields of aerospace, electronics, electrical equipment, and communication equipment due to their high strength, good heat resistance, good flame resistance, good weather resistance, and wide temperature range of use. However, with the development of modern electronic and electrical equipment towards high power density, high frequency, and high integration, problems such as electromagnetic radiation and electromagnetic interference are becoming increasingly prominent, seriously affecting the normal operation of electronic devices and the safe transmission of information, and endangering human health. At the same time, the heat generated by these devices will accumulate rapidly, and high temperature will lead to low working efficiency of the devices, seriously affecting the service life of the devices. In order to suppress electromagnetic wave radiation and interference, corresponding devices usually use components made of conductive materials to shield electromagnetic waves. At present, single heat dissipation materials or electromagnetic shielding materials cannot meet the needs of advanced electronic equipment for heat dissipation and electromagnetic wave shielding performance, so there is an urgent need to manufacture high polymer composite materials with electromagnetic shielding and heat conduction functions.

[0003] Traditional heat-conducting materials are mainly aluminum, copper, and graphite, which have high thermal conductivity, but are limited in applications such as 5G network infrastructure, electric vehicle batteries, and LED lighting due to their high density and difficulty in forming and processing. Heat-conducting polymer materials can improve impact resistance and reduce weight, and are easy to process, reducing the design restrictions for product engineers. However, the intrinsic thermal conductivity of polymer materials is very low, and in order to improve the thermal conductivity of the polymer, a large amount of high-thermal-conductivity filler must be filled. However, a large amount of filler leads to a sharp increase in melt viscosity, making it difficult to process and form, and the heat-conducting filler is difficult to disperse uniformly in the polymer matrix. Even if the heat-conducting performance is improved, it may cause serious deterioration of mechanical properties.

[0004] Metal materials have been widely studied in electromagnetic shielding applications due to their excellent electrical conductivity. Excellent electrical conductivity is beneficial to the generation of an electric field under the action of a high-frequency electromagnetic field to attenuate electromagnetic wave energy. However, the disadvantages of metal materials are also obvious, such as high density, easy corrosion, and poor processability, which greatly limit their applicability. By blending conductive components with polymer components, the easy processability of polymers can be utilized, and a wide range of conductive fillers can be selected according to the application scenario requirements of the shielding material.

[0005] In order to make the material have the functions of heat conduction and electromagnetic shielding at the same time, researchers usually use filler hybridization technology. In order to make the composite material have good heat conduction and shielding performance, the filler content is usually high, which will cause a series of new problems, such as processing difficulty and poor mechanical properties. Therefore, it is necessary to solve the above problems through reasonable preparation technology and optimized structure design.

[0006] Chinese patent CN112592574A discloses a polycarbonate engineering plastic with electromagnetic shielding and heat conduction functions and a preparation method thereof. The composite conductive and heat-conductive filler is obtained by compounding 2-20 parts of conductive filler and 2-20 parts of heat-conductive filler. The conductive filler is selected from one of fibrous carbon powder, expanded graphite, graphene, carbon nanotube and short-cut stainless steel fiber. The heat-conductive filler is selected from one of boron nitride, aluminum nitride, aluminum oxide and silicon carbide. However, the electromagnetic shielding performance in the formula is provided by the conductive filler, but the heat-conductive filler itself does not have electromagnetic shielding effect. After compounding the conductive and heat-conductive fillers, the probability of forming a conductive path by mutual lapping of the conductive fillers is reduced, so the electromagnetic shielding effect will inevitably be affected.

[0007] Chinese patent CN112080137A discloses a heat-conductive, electromagnetic shielding and high-strength nylon 6 composite material and a preparation method thereof. The main body of the nylon 6 composite material is composed of nylon 6 microspheres containing hexagonal boron nitride, and the guest is carbon nanomaterial. The nylon 6 composite material has an isolated double percolation structure. However, the conductive network constructed by only single carbon nanotube cannot effectively realize the electromagnetic shielding performance. In addition, the technology needs to go through steps such as dissolution, vacuumization and etching, which not only produces a large amount of waste liquid, but also is difficult to realize industrialization and large-scale production.

[0008] Chinese patent CN115536998A discloses an electromagnetic shielding and heat-conductive PBT / PET-based composite material and a preparation method thereof. The electromagnetic shielding and heat-conductive PBT / PET-based composite material comprises the following components: PBT, PET, flake graphite, zinc oxide, barium ferrite and the like. In fact, barium ferrite and zinc oxide have low thermal conductivity. As known from the examples, the thermal conductivity of the PBT / PET composite material is only 1 W / m·K at most, which seriously limits its heat dissipation performance.

[0009] Chinese patent CN115521721A discloses a heat-conductive and wave-absorbing material with electromagnetic shielding function. The heat-conductive and wave-absorbing material with electromagnetic shielding function has a two-layer structure. The upper layer is a heat-conductive and wave-absorbing gel layer, and the lower layer is an aluminum foil layer. The heat-conductive and wave-absorbing gel layer comprises A component and B component. One side of the aluminum foil layer in contact with the heat-conductive and wave-absorbing gel layer is etched. The heat-conductive and wave-absorbing material has good heat conduction and wave absorption performance. However, it is limited to the material components and can only be used for on-site construction. At the same time, it cannot be applied to the heat conduction and electromagnetic protection of special-shaped devices. SUMMARY

[0010] To solve the above technical problems, the application provides a heat-conducting and electromagnetic shielding composite functional masterbatch, which can assist in the synchronous improvement of the heat-conducting and electromagnetic shielding performance of an engineering plastic when the engineering plastic is filled and then processed by a force field (for example, extrusion molding or injection molding).

[0011] One of the objectives of the application is to provide a heat-conducting and electromagnetic shielding composite functional masterbatch, which comprises an engineering plastic, a heat-conducting and electromagnetic shielding filler and a toughening agent, wherein the heat-conducting and electromagnetic shielding filler comprises a heat-conducting and resistance-type electromagnetic shielding filler and a heat-conducting and magnetic loss-type electromagnetic shielding filler, and the heat-conducting and resistance-type electromagnetic shielding filler comprises a one-dimensional carbon-based filler and a two-dimensional carbon-based filler.

[0012] According to the application, in the heat-conducting and electromagnetic shielding composite functional masterbatch:

[0013] The one-dimensional carbon-based filler is selected from at least one of pitch-based carbon fibers, carbon nanofibers and carbon nanotubes;

[0014] The aspect ratio of the one-dimensional carbon-based filler is 5-100, preferably 20-50;

[0015] The two-dimensional carbon-based filler is selected from at least one of flake graphite, expanded graphite and graphene;

[0016] The mass ratio of the one-dimensional carbon-based filler to the two-dimensional carbon-based filler is 1:(5-50), preferably 1:(10-30).

[0017] According to the application, in the heat-conducting and electromagnetic shielding composite functional masterbatch:

[0018] The engineering plastic is selected from at least one of polyesters, polyamides, polyformaldehyde and polyphenyl ethers, and preferably at least one of polycarbonates, nylon-6, nylon-66, polyformaldehyde, polybutylene terephthalate, polyethylene terephthalate and polyphenyl ether;

[0019] The melt index of the engineering plastic is 6-30 g / 10 min, preferably 10-20 g / 10 min;

[0020] The heat-conducting and magnetic loss-type electromagnetic shielding filler is selected from at least one of iron powder, nickel powder, cobalt powder and carbonyl iron powder, and the particle size of the heat-conducting and magnetic loss-type electromagnetic shielding filler is preferably 1-20 μm;

[0021] The toughening agent is selected from at least one of styrene copolymers and ethylene copolymers, and preferably at least one of hydrogenated styrene-butadiene block copolymers, ethylene-octene copolymers, methacrylic-butadiene-styrene terpolymers, ethylene-propylene copolymers and ethylene-alpha olefin block copolymers;

[0022] The particle size of the toughening agent is 50-600 μm, preferably 100-300 μm.

[0023] According to the present application, the heat-conducting / electromagnetic shielding composite functional masterbatch comprises:

[0024] The engineering plastic is 10-95 parts, the heat-conducting electromagnetic shielding filler is 5-120 parts, and the toughening agent is 0-50 parts by weight; preferably, the engineering plastic is 20-70 parts, the heat-conducting electromagnetic shielding filler is 30-100 parts, and the toughening agent is 5-30 parts by weight.

[0025] The mass ratio of the heat-conducting resistance type electromagnetic shielding filler to the heat-conducting magnetic loss type electromagnetic shielding filler is 1:(0.1-5), preferably 1:(0.25-2).

[0026] The second object of the present application is to provide a preparation method of the heat-conducting / electromagnetic shielding composite functional masterbatch, which comprises the step of processing the components comprising the engineering plastic, the heat-conducting electromagnetic shielding filler and the optional toughening agent under the action of a continuous force field; preferably, the continuous force field comprises at least 5 continuous composite force field modules.

[0027] According to the present application, the preparation method of the heat-conducting / electromagnetic shielding composite functional masterbatch comprises the following steps:

[0028] (1) mechanically blending the components comprising the engineering plastic, the heat-conducting electromagnetic shielding filler and the optional toughening agent to obtain a premix;

[0029] (2) adding the premix obtained in step (1) into an extruder, processing in the continuous force field module after extrusion, and then extruding and granulating to obtain the heat-conducting and electromagnetic shielding composite functional masterbatch.

[0030] According to the present application, the preparation method of the heat-conducting / electromagnetic shielding composite functional masterbatch comprises:

[0031] The mechanical blending in step (1) is carried out at a rotation speed of 500-1500 rpm for 2-10 min;

[0032] Step (2) is completed on a uniform dispersion integrated equipment comprising a double-screw extruder, a connector, at least 5 continuous composite force field modules, a granulating port module and a granulator connected in sequence.

[0033] According to the present application, the preparation method of the heat-conducting / electromagnetic shielding composite functional masterbatch comprises:

[0034] The operating conditions of the double screw extruder are: the temperature of the feeding section is 120-180 DEG C, the temperature of the conveying section is 240-290 DEG C, the temperature of the melting section is 240-290 DEG C, and the temperature of the homogenizing section is 240-290 DEG C.

[0035] The operating conditions of the connector are: the temperature is 240-290 DEG C.

[0036] The operating conditions of the continuous force field are: the temperature is 240-290 DEG C, and the extrusion speed is 100-500 rpm.

[0037] The composite force field module adopts an inclined flow channel, the front section of the flow channel comprises at least 4 sub-flow regions, the middle section of the flow channel is narrowed, and then the flow channel is gradually widened to the width of the front section of the flow channel; preferably, the included angle between the flow channel and the horizontal line is 120-150 DEG; the width of the middle section of the flow channel is 1 / 2-1 / 8 of the width of the two end sections of the flow channel, and more preferably 1 / 3-1 / 6.

[0038] In the composite force field module, a special flow channel design is adopted, when the engineering plastic / functional filler fluid preliminarily mixed by the double screw extruder enters a composite force field module, the fluid is divided into multiple streams, then the thickness of each stream is reduced and the width is increased, and the fluid volume change rate is greatly increased (for example, when the fluid is divided into 4 streams, the thickness of each stream is reduced to 1 / 4 of the original thickness, and the width is increased to 4 times of the original width, and the fluid volume change rate is 16 times), which will generate a very strong tensile and shear composite force field, and promote the high-efficiency dispersion of the polymer / functional filler fluid; in particular, when the number of the composite force field modules is increased, the above process is synchronously increased, and the force acting on the engineering plastic / functional filler fluid will be enhanced, and the dispersion of the components will be promoted.

[0039] The third object of the present application is to provide an engineering plastic-based heat-conducting / electromagnetic shielding composite functional material, which comprises engineering plastic and the heat-conducting / electromagnetic shielding composite functional masterbatch of the first object of the present application or the heat-conducting / electromagnetic shielding composite functional masterbatch obtained by the preparation method of the second object of the present application. The engineering plastic and the heat-conducting / electromagnetic shielding composite functional masterbatch are uniformly mixed by using a common mixing device to obtain the composite functional material.

[0040] According to the present application, in the engineering plastic-based heat-conducting / electromagnetic shielding composite functional material:

[0041] The engineering plastic is selected from at least one of polyester, polyamide, polyformaldehyde and polyphenyl ether, and preferably at least one of polycarbonate, nylon-6, nylon-66, polyformaldehyde, polybutylene terephthalate, polyethylene terephthalate and polyphenyl ether; the engineering plastic in the above engineering plastic and the engineering plastic in the heat-conducting / electromagnetic shielding composite functional masterbatch are the same or different;

[0042] The content of the heat-conducting / electromagnetic shielding composite functional masterbatch is 40-99%, preferably 60-90%, based on the total weight of the composite functional material.

[0043] The engineering plastic-based heat-conducting / electromagnetic shielding composite functional material can also be added with other auxiliary materials commonly used in the art, such as commonly used flame retardants, antistatic agents, antioxidants, etc.

[0044] The heat-conducting / electromagnetic shielding composite functional masterbatch provided by the application is obtained by premixing components including the engineering plastic, the heat-conducting electromagnetic shielding filler and the optional toughening agent, and then processing under the action of a continuous force field. The composite force field module in the continuous force field adopts a special flow channel design, utilizes the continuous tensile and shear composite force field, promotes the engineering plastic to have a huge volume deformation rate during the flow process, makes the high-filled filler uniformly dispersed in the matrix, and improves the performance of the masterbatch.

[0045] Compared with the prior art, the application has the following advantages:

[0046] 1. The tensile and shear composite force field module in the uniform dispersion integrated equipment can realize the uniform dispersion of each component in the high-filled engineering plastic system, and fully play the role of each functional component. In addition, the uniform dispersion integrated equipment can realize continuous, solvent-free and large-scale production.

[0047] 2. The heat-conducting resistance type electromagnetic shielding filler and the heat-conducting magnetic loss type electromagnetic shielding filler are used in the application, which can increase the electromagnetic shielding effect through resistance loss and magnetic loss. In addition, the one-dimensional and two-dimensional heat-conducting resistance type electromagnetic shielding filler belongs to carbon filler and has extremely high intrinsic thermal conductivity. At the same time, the one-dimensional and two-dimensional filler has a large aspect ratio and is easy to overlap to form a heat-conducting network, effectively improving the thermal conductivity. Therefore, the combination of the heat-conducting resistance type electromagnetic shielding filler and the heat-conducting magnetic loss type electromagnetic shielding filler can obtain the heat-conducting and electromagnetic shielding composite functional masterbatch.

[0048] 3. The functional masterbatch prepared by the application can be diluted in different proportions in the engineering plastic according to the use requirements, so as to realize the significant improvement of the heat-conducting and electromagnetic shielding performance of the target engineering plastic. BRIEF DESCRIPTION OF DRAWINGS

[0049] Figure 1 It is the uniform dispersion integrated equipment used in the embodiment of the application. Figure 1 In the figure, 1-1 is a twin-screw extruder, 1-2 is a connector, 1-3 is a tensile and shear composite force field module, 1-4 is a granulating port module, and 1-5 is a granulator.

[0050] Figure 2 It is a schematic diagram of the fluid flow channel in the tensile and shear composite force field module used in the embodiment of the application.

[0051] Figure 3 Figure 1 is a schematic diagram of the fluid evolution in the process of the polymer melt flowing through the stretching and shearing complex force field module in the present application. DETAILED DESCRIPTION

[0052] The following specific embodiments of the present application will be described in detail, it is necessary to point out that the following examples are only used to further illustrate the present application, can not be understood as limiting the scope of protection of the present application, the skilled in the art according to the content of the present application to make some non-essential improvements and adjustment of the present application still belongs to the scope of protection of the present application.

[0053] The test instruments and test conditions used in the examples are as follows:

[0054] Thermal conductivity test: hot-disk (2500-OT, Sweden) was used to characterize the thermal conductivity of the composite material.

[0055] Electromagnetic shielding efficiency test: vector network analyzer (Agilent, N5247, USA) was used to test the electromagnetic shielding efficiency of the composite material. Coaxial method was used. The measurement was carried out at room temperature in the frequency range of 8.2-12.4 GHz (X-band).

[0056] In the following examples and comparative examples, the engineering plastic polycarbonate (PC) was PC-1100 from Lotte, South Korea; the hydrogenated styrene-butadiene block copolymer was 8048 from SINOPEC Group, China; the pitch-based carbon fiber was XN-100-25M from Fujian Joint New Material Co., Ltd.; the flake graphite was from Qingdao Xingyuan Graphite Co., Ltd., with an average particle size of 10-15 μm; and the carbonyl iron powder was purchased from Jiangxi Yuean New Material Co., Ltd., with a particle size of 1-20 μm.

[0057] Comparative Example 1

[0058] (1) The polycarbonate (melt index 15 g / 10 min) and the hydrogenated styrene-butadiene block copolymer were mechanically blended in proportion, with a rotation speed of 1500 rpm and a mixing time of 10 min; the mass fraction of the hydrogenated styrene-butadiene block copolymer was 5 wt%.

[0059] (2) The premix obtained in step (1) was added to the high filler content uniform dispersion integrated equipment (see Figure 1) consisting of a twin-screw extruder (1-1), a connector (1-2), five stretching and shearing complex force field modules (1-3), a pelletizing port die (1-4) and a pelletizer (1-5) for extrusion and pelletization, to obtain a polycarbonate-based thermal conductive and electromagnetic shielding composite functional masterbatch. Figure 1

[0060] ​The temperature of the feeding section, conveying section, melting section and homogenizing section of the twin-screw extruder in step (2) is 160°C, 240°C, 260°C and 260°C respectively. The temperature of the connector is 260°C. The temperature of the stretching and shearing compound force field generator is 260°C. The extrusion speed is 500 rpm.

[0061] The obtained masterbatch is applied with a shearing force field by injection molding (plastic injection molding machine, MA600 II / 130) to obtain a sample. The thickness of the sample is 2 mm. The electromagnetic shielding effect of the sample in the frequency range of 8.2-12.4 GHz is tested by using a vector network analyzer instrument. The in-plane and out-of-plane thermal conductivity of the sample is tested by using the instantaneous plane heat source method. The results are shown in Table 1.

[0062] Comparative Example 2

[0063] (1) Polycarbonate (melt index 15 g / 10 min), hydrogenated styrene-butadiene block copolymer and thermally conductive electromagnetic shielding filler are mechanically blended in proportion. The rotation speed is 1500 rpm and the mixing time is 10 min. The polycarbonate is 30 parts, the hydrogenated styrene-butadiene block copolymer is 10 parts, the thermally conductive resistance type electromagnetic shielding filler is 80 parts, which is composed of pitch-based carbon fiber and flake graphite in a mass ratio of 1:30, and the pitch-based carbon fiber has an aspect ratio of 50. The thermally conductive magnetic loss type filler is carbonyl iron powder, the content is 20 parts, and the particle size is 1 μm.

[0064] (2) The pre-mixture obtained in step (1) is added to a twin-screw extruder for extrusion and granulation to obtain a polycarbonate-based thermally conductive and electromagnetic shielding composite functional masterbatch.

[0065] The temperature of the feeding section, conveying section, melting section and homogenizing section of the twin-screw extruder in step (2) is 160°C, 240°C, 260°C and 260°C respectively. The extrusion speed is 500 rpm.

[0066] Preparation and testing of polycarbonate thermally conductive and electromagnetic shielding composite material:

[0067] The obtained masterbatch is blended and diluted with pure polycarbonate to obtain a polycarbonate thermally conductive and electromagnetic shielding composite material. In this example, the mass fraction of the thermally conductive and electromagnetic shielding filler after dilution of the masterbatch is 50 wt%, and the mass fraction of the hydrogenated styrene-butadiene block copolymer is 5%. A sample is obtained by applying a shearing force field by injection molding. The thickness of the sample is 2 mm. The electromagnetic shielding effect of the sample in the frequency range of 8.2-12.4 GHz is tested by using a vector network analyzer instrument. The in-plane and out-of-plane thermal conductivity of the sample is tested by using the instantaneous plane heat source method. The results are shown in Table 1.

[0068] Comparative Example 3

[0069] Preparation of thermally conductive / electromagnetic shielding composite functional masterbatch:

[0070] (1) Mechanical blending of polycarbonate (melt index 15 g / 10 min), hydrogenated styrene-butadiene block copolymer and thermally conductive electromagnetic shielding filler at a ratio of 30 parts of polycarbonate, 10 parts of hydrogenated styrene-butadiene block copolymer, 80 parts of pitch-based carbon fiber with a length-diameter ratio of 50, and 20 parts of carbonyl iron powder as thermally conductive magnetic loss type filler with a particle size of 1 μm at a rotation speed of 1500 rpm for 10 min.

[0071] (2) The premix obtained in step (1) is added to a high filler content uniform dispersion integrated device (see Figure 1 ) consisting of a twin-screw extruder (1-1), a connector (1-2), five stretch and shear composite force field modules (1-3), a pelletizing port module (1-4) and a pelletizer (1-5) for extrusion and pelletization to obtain a polycarbonate-based thermally conductive and electromagnetic shielding composite functional masterbatch.

[0072] The temperatures of the feeding section, conveying section, melting section and homogenizing section of the twin-screw extruder in step 2 are 160°C, 240°C, 260°C and 260°C, respectively; the temperature of the connector is 260°C; and the temperature of the stretch and shear composite force field generator is 260°C and the extrusion speed is 500 rpm.

[0073] Preparation and testing of polycarbonate thermally conductive / electromagnetic shielding composite material:

[0074] The obtained thermally conductive / electromagnetic shielding composite functional masterbatch is blended and diluted with pure polycarbonate to obtain a polycarbonate thermally conductive / electromagnetic shielding composite material, wherein the mass fraction of the thermally conductive / electromagnetic shielding composite functional masterbatch is 70 wt%, the mass fraction of the thermally conductive electromagnetic shielding filler is 50 wt%, and the mass fraction of the hydrogenated styrene-butadiene block copolymer is 5%. The sample is obtained by using injection molding to apply a shear force field, the sample thickness is 2 mm, the electromagnetic shielding effect of the sample in the frequency range of 8.2-12.4 GHz is tested by using a vector network analyzer instrument, and the in-plane and out-of-plane thermal conductivities of the sample are tested by using the instantaneous plane heat source method. The results are shown in Table 1.

[0075] Comparative Example 4

[0076] Preparation of thermally conductive / electromagnetic shielding composite functional masterbatch:

[0077] (1) Mechanical blending of polycarbonate (melt index 15 g / 10 min), hydrogenated styrene-butadiene block copolymer and thermally conductive electromagnetic shielding filler at a ratio of 30 parts of polycarbonate, 10 parts of hydrogenated styrene-butadiene block copolymer, 80 parts of flaky graphite, and 20 parts of carbonyl iron powder as thermally conductive magnetic loss type filler with a particle size of 1 μm at a rotation speed of 1500 rpm for 10 min.

[0078] (2) The premix obtained in step (1) is added to a high filler content uniform dispersion integrated device (see Figure 1 ) composed of a twin-screw extruder (1-1), a connector (1-2), five stretch and shear composite force field modules (1-3), a pelletizing die (1-4), and a pelletizer (1-5) to perform extrusion and pelletization, obtaining a polycarbonate-based heat-conducting and electromagnetic shielding composite functional masterbatch.

[0079] In step 2, the temperatures of the feeding section, conveying section, melting section, and homogenizing section of the twin-screw extruder are 160°C, 240°C, 260°C, and 260°C, respectively; the temperature of the connector is 260°C; and the temperature of the stretch and shear composite force field generator is 260°C, and the extrusion speed is 500 rpm.

[0080] Preparation and testing of polycarbonate heat-conducting / electromagnetic shielding composite material:

[0081] The obtained heat-conducting / electromagnetic shielding composite functional masterbatch is blended and diluted with pure polycarbonate to obtain a polycarbonate heat-conducting / electromagnetic shielding composite material, wherein the mass fraction of the heat-conducting / electromagnetic shielding composite functional masterbatch is 70wt%, the mass fraction of the heat-conducting electromagnetic shielding filler is 50wt%, and the mass fraction of the hydrogenated styrene-butadiene block copolymer is 5%. A sample is obtained by applying a shear force field using injection molding, and the sample thickness is 2mm. The electromagnetic shielding effect of the sample in the frequency range of 8.2-12.4GHz is tested using a vector network analyzer instrument, and the in-plane and out-of-plane thermal conductivity of the sample is tested using the instantaneous plane heat source method. The results are shown in Table 1.

[0082] Example 1

[0083] Preparation of heat-conducting / electromagnetic shielding composite functional masterbatch:

[0084] (1) Polycarbonate (melt index 15g / 10min), hydrogenated styrene-butadiene block copolymer, and heat-conducting electromagnetic shielding filler are mechanically blended in proportion, with a rotation speed of 1500rpm and a mixing time of 10min; wherein the polycarbonate is 30 parts, the hydrogenated styrene-butadiene block copolymer is 10 parts; the heat-conducting electromagnetic shielding filler is 80 parts, composed of pitch-based carbon fiber and flake graphite in a mass ratio of 1:30, and the pitch-based carbon fiber has an aspect ratio of 50; the heat-conducting magnetic loss type filler is carbonyl iron powder, and the amount used is 20 parts with a particle size of 1μm.

[0085] (2) The premix obtained in step (1) is added to a high filler content uniform dispersion integrated device (see Figure 1 ) composed of a twin-screw extruder (1-1), a connector (1-2), five stretch and shear composite force field modules (1-3), a pelletizing die (1-4), and a pelletizer (1-5) to perform extrusion and pelletization, obtaining a polycarbonate-based heat-conducting and electromagnetic shielding composite functional masterbatch.

[0086] The temperature of the feeding section, conveying section, melting section and homogenizing section of the double screw extruder in step 2 is 160℃, 240℃, 260℃ and 260℃ respectively; the temperature of the connector is 260℃; the temperature of the tensile and shear combined force field generator is 260℃, and the extrusion speed is 500 rpm.

[0087] Preparation and testing of polycarbonate heat-conducting / electromagnetic shielding composite material:

[0088] The obtained heat-conducting / electromagnetic shielding composite functional masterbatch is blended and diluted with pure polycarbonate to obtain a polycarbonate heat-conducting / electromagnetic shielding composite material, wherein the mass fraction of the heat-conducting / electromagnetic shielding composite functional masterbatch is 70wt%, the mass fraction of the heat-conducting electromagnetic shielding filler is 50wt%, and the mass fraction of the hydrogenated styrene-butadiene block copolymer is 5%. The sample is obtained by using injection molding to apply a shear force field, the sample thickness is 2mm, the electromagnetic shielding effect of the sample in the frequency range of 8.2-12.4GHz is tested by using a vector network analyzer instrument, and the in-plane and out-of-plane thermal conductivities of the sample are tested by using the instantaneous plane heat source method. The results are shown in Table 1.

[0089] Example 2

[0090] Preparation of heat-conducting / electromagnetic shielding composite functional masterbatch:

[0091] (1) The polycarbonate (melt index 15g / 10min), hydrogenated styrene-butadiene block copolymer and heat-conducting electromagnetic shielding filler are mechanically blended in proportion, the rotating speed is 500 rpm, and the mixing time is 2 min; wherein the polycarbonate is 70 parts, the hydrogenated styrene-butadiene block copolymer is 30 parts; the heat-conducting electromagnetic shielding filler is 20 parts, which is composed of pitch-based carbon fiber and flake graphite in a mass ratio of 1:10, and the pitch-based carbon fiber has an aspect ratio of 20; the heat-conducting magnetic loss type filler is carbonyl iron powder, and the amount used is 20 parts, and the particle size is 20μm.

[0092] (2) The premix obtained in step (1) is added to the high filler content dispersion integrated equipment (see Figure 1 ) composed of a double screw extruder (1-1), a connector (1-2), 5 tensile and shear combined force field modules (1-3), a granulating port module (1-4) and a granulator (1-5) for extrusion and granulation to obtain a polycarbonate-based heat-conducting and electromagnetic shielding composite functional masterbatch.

[0093] The temperature of the feeding section, conveying section, melting section and homogenizing section of the double screw extruder in step 2 is 160℃, 240℃, 260℃ and 260℃ respectively; the temperature of the connector is 260℃; the temperature of the tensile and shear combined force field generator is 260℃, and the extrusion speed is 500 rpm.

[0094] Preparation and testing of polycarbonate thermally conductive / electromagnetic shielding composite:

[0095] The obtained thermally conductive / electromagnetic shielding composite functional masterbatch is blended and diluted with pure polycarbonate to obtain a polycarbonate thermally conductive / electromagnetic shielding composite, wherein the mass fraction of the thermally conductive / electromagnetic shielding composite functional masterbatch is 70wt%, the mass fraction of the thermally conductive electromagnetic shielding filler is 20wt%, and the mass fraction of the hydrogenated styrene-butadiene block copolymer is 15%. The sample is obtained by using injection molding to apply a shear field, the sample thickness is 2mm, the electromagnetic shielding effect of the sample in the frequency range of 8.2-12.4GHz is tested by using a vector network analyzer instrument, and the in-plane and out-of-plane thermal conductivities of the sample are tested by using the instantaneous plane heat source method. The results are shown in Table 1.

[0096] Example 3

[0097] Preparation of thermally conductive / electromagnetic shielding composite functional masterbatch:

[0098] (1) The polycarbonate (melt index 15g / 10min), hydrogenated styrene-butadiene block copolymer and thermally conductive electromagnetic shielding filler are mechanically blended in proportion, the rotation speed is 1500rpm, and the mixing time is 10min; wherein the polycarbonate is 40 parts, the hydrogenated styrene-butadiene block copolymer is 20 parts; the thermally conductive electromagnetic shielding filler is 30 parts, which is composed of pitch-based carbon fiber and flake graphite in a mass ratio of 1:20, and the aspect ratio of the pitch-based carbon fiber is 30; the thermally conductive magnetic loss type filler is carbonyl iron powder, and the amount used is 30 parts, and the particle size is 5μm.

[0099] (2) The premix obtained in step (1) is added to a high filler content uniform dispersion integrated equipment (see Figure 1 ) composed of a twin-screw extruder (1-1), a connector (1-2), five stretching and shearing composite force field modules (1-3), a pelletizing port module (1-4) and a pelletizer (1-5) for extrusion and pelletization, to obtain a polycarbonate-based thermally conductive and electromagnetic shielding composite functional masterbatch.

[0100] Among them, the temperatures of the feeding section, the conveying section, the melting section and the homogenizing section of the twin-screw extruder in step (2) are 160℃, 240℃, 260℃ and 260℃ respectively; the temperature of the connector is 260℃; the temperature of the stretching and shearing composite force field generator is 260℃, and the extrusion speed is 500rpm.

[0101] Preparation and testing of polycarbonate thermally conductive / electromagnetic shielding composite:

[0102] The obtained heat-conducting / electromagnetic shielding composite functional masterbatch is blended and diluted with pure polycarbonate to obtain a polycarbonate heat-conducting / electromagnetic shielding composite material, wherein the mass fraction of the heat-conducting / electromagnetic shielding composite functional masterbatch is 90 wt%, the mass fraction of the heat-conducting electromagnetic shielding filler is 45 wt%, and the mass fraction of the hydrogenated styrene-butadiene block copolymer is 15%. A sample is obtained by using injection molding to apply a shear field, the sample has a thickness of 2 mm, a vector network analyzer instrument is used to test the electromagnetic shielding effect of the sample in a frequency range of 8.2-12.4 GHz, and the in-plane and out-of-plane thermal conductivities of the sample are tested by using the instantaneous plane heat source method. The results are shown in Table 1.

[0103] Example 4

[0104] Preparation of the heat-conducting / electromagnetic shielding composite functional masterbatch:

[0105] (1) The polycarbonate (melt index 15 g / 10 min), hydrogenated styrene-butadiene block copolymer and heat-conducting electromagnetic shielding filler are mechanically blended in proportion at a rotation speed of 1500 rpm for 10 min; wherein the polycarbonate is 30 parts, the hydrogenated styrene-butadiene block copolymer is 10 parts; the heat-conducting resistance type electromagnetic shielding filler is 60 parts, which is composed of pitch-based carbon fiber and flake graphite in a mass ratio of 1:30, and the pitch-based carbon fiber has an aspect ratio of 50; the heat-conducting magnetic loss type filler is carbonyl iron powder, and the amount used is 40 parts with a particle size of 1 μm.

[0106] (2) The premix obtained in step (1) is added to a high filler content uniform dispersion integrated equipment (see Figure 1 ) composed of a twin-screw extruder (1-1), a connector (1-2), five stretching and shearing composite force field modules (1-3), a granulating port module (1-4) and a granulator (1-5) for extrusion and granulation to obtain a polycarbonate-based heat-conducting and electromagnetic shielding composite functional masterbatch.

[0107] In step (2), the temperatures of the feeding section, the conveying section, the melting section and the homogenizing section of the twin-screw extruder are 160℃, 240℃, 260℃ and 260℃ respectively; the temperature of the connector is 260℃; the temperature of the stretching and shearing composite force field generator is 260℃, and the extrusion speed is 500 rpm.

[0108] Preparation and testing of the polycarbonate heat-conducting / electromagnetic shielding composite material:

[0109] The obtained heat-conducting / electromagnetic shielding composite functional masterbatch is blended and diluted with pure polycarbonate to obtain a polycarbonate heat-conducting / electromagnetic shielding composite material, wherein the mass fraction of the heat-conducting / electromagnetic shielding composite functional masterbatch is 70 wt%, the mass fraction of the heat-conducting electromagnetic shielding filler is 50 wt%, and the mass fraction of the hydrogenated styrene-butadiene block copolymer is 5%. A sample is obtained by using injection molding to apply a shear force field, the sample has a thickness of 2 mm, a vector network analyzer instrument is used to test the electromagnetic shielding effect of the sample in a frequency range of 8.2-12.4 GHz, and the in-plane and out-of-plane thermal conductivities of the sample are tested by using the instantaneous plane heat source method. The results are shown in Table 1.

[0110] Example 5

[0111] Preparation of the heat-conducting / electromagnetic shielding composite functional masterbatch:

[0112] (1) The nylon-6 (melt index is 17 g / 10 min), ethylene-propylene copolymer and heat-conducting electromagnetic shielding filler are mechanically blended in proportion at a rotation speed of 1500 rpm for 10 min; wherein the nylon-6 is 30 parts, the ethylene-propylene copolymer is 10 parts; the heat-conducting resistance type electromagnetic shielding filler is 60 parts, which is composed of pitch-based carbon fiber and flake graphite in a mass ratio of 1:30, and the pitch-based carbon fiber has an aspect ratio of 50; the heat-conducting magnetic loss type filler is carbonyl iron powder, and the amount used is 40 parts with a particle size of 1 μm.

[0113] (2) The premix obtained in step (1) is added to a high filler content uniform dispersion integrated equipment (see Figure 1 ) composed of a twin-screw extruder (1-1), a connector (1-2), five stretching and shearing composite force field modules (1-3), a granulating port module (1-4) and a granulator (1-5) for extrusion and granulation to obtain a nylon-6-based heat-conducting and electromagnetic shielding composite functional masterbatch.

[0114] In step (2), the temperatures of the feeding section, the conveying section, the melting section and the homogenizing section of the twin-screw extruder are 160℃, 230℃, 240℃ and 250℃ respectively; the temperature of the connector is 250℃; the temperature of the stretching and shearing composite force field generator is 250℃, and the extrusion speed is 500 rpm.

[0115] Preparation and testing of the nylon-6 heat-conducting / electromagnetic shielding composite material:

[0116] The obtained heat-conducting / electromagnetic shielding composite functional masterbatch is blended and diluted with pure nylon-6 to obtain a nylon-6 heat-conducting / electromagnetic shielding composite material, wherein the mass fraction of the heat-conducting / electromagnetic shielding composite functional masterbatch is 70 wt%, the mass fraction of the heat-conducting electromagnetic shielding filler is 50 wt%, and the mass fraction of the ethylene-propylene copolymer is 5%. A sample is obtained by using injection molding to apply a shear force field, the sample has a thickness of 2 mm, a vector network analyzer instrument is used to test the electromagnetic shielding effect of the sample in a frequency range of 8.2-12.4 GHz, and the in-plane and out-of-plane thermal conductivities of the sample are tested by using the instantaneous plane heat source method. The results are shown in Table 1.

[0117] Example 6

[0118] Preparation of the heat-conducting / electromagnetic shielding composite functional masterbatch:

[0119] (1) The nylon-6 (melt index is 17 g / 10 min), ethylene-propylene copolymer and heat-conducting electromagnetic shielding filler are mechanically blended in proportion at a rotation speed of 1500 rpm for 10 min; wherein the nylon-6 is 30 parts, the ethylene-propylene copolymer is 10 parts; the heat-conducting resistance type electromagnetic shielding filler is 60 parts, which is composed of carbon nanofiber and graphene in a mass ratio of 1:30, and the carbon nanofiber has an aspect ratio of 50; the heat-conducting magnetic loss type filler is nickel powder, and the amount used is 40 parts, and the particle size is 1 μm.

[0120] (2) The premix obtained in step (1) is added to a high filler content uniform dispersion integrated equipment (see Figure 1 ) composed of a twin-screw extruder (1-1), a connector (1-2), five stretching and shearing composite force field modules (1-3), a granulating port module (1-4) and a granulator (1-5) for extrusion and granulation to obtain a nylon-6-based heat-conducting and electromagnetic shielding composite functional masterbatch.

[0121] In step (2), the temperatures of the feeding section, the conveying section, the melting section and the homogenizing section of the twin-screw extruder are 160℃, 230℃, 240℃ and 250℃ respectively; the temperature of the connector is 250℃; the temperature of the stretching and shearing composite force field generator is 250℃, and the extrusion speed is 500 rpm.

[0122] Preparation and testing of the nylon-6 heat-conducting / electromagnetic shielding composite material:

[0123] The obtained heat-conducting / electromagnetic shielding composite functional master batch is blended and diluted with pure nylon-6 to obtain a nylon-6 heat-conducting / electromagnetic shielding composite material, wherein the mass fraction of the heat-conducting / electromagnetic shielding composite functional master batch is 70 wt%, the mass fraction of the heat-conducting electromagnetic shielding filler is 50 wt%, and the mass fraction of the ethylene-propylene copolymer is 5%. A sample is obtained by using injection molding to apply a shear field, the sample has a thickness of 2 mm, a vector network analyzer instrument is used to test the electromagnetic shielding effect of the sample in a frequency range of 8.2-12.4 GHz, and the in-plane and out-of-plane thermal conductivities of the sample are tested by using the instantaneous plane heat source method. The results are shown in Table 1.

[0124] Table 1:

[0125]

[0126] It can be seen from the comparison between the above-mentioned Examples 1, 2, 3, 4 and Comparative Examples 1, 2, 3, 4 that after processing by the continuous force field module, the functional filler has better dispersibility, thereby not only helping to fully exert the performance of each component, but also better bridging the performance heat-conducting network, and the composite heat-conducting and wave-absorbing performance prepared under the same filler content is more excellent. At the same time, by hybridizing the 1D and 2D functional fillers, it is easier to form an efficient heat-conducting and conductive network by bridging each other, and the heat-conducting and electromagnetic shielding performance is better than that of a single heat-conducting filler system. In addition, the test results of Examples 5 and 6 show that the composite material prepared after replacing the matrix and the functional filler still has excellent heat-conducting and wave-absorbing performance.

Claims

1. A thermal conductive / electromagnetic shielding composite functional masterbatch, comprising engineering plastics, thermal conductive electromagnetic shielding fillers and toughening agents, wherein the thermal conductive electromagnetic shielding fillers include thermal conductive resistance type electromagnetic shielding fillers and thermal conductive magnetic loss type electromagnetic shielding fillers, wherein: The thermally conductive resistor type electromagnetic shielding filler includes a one-dimensional carbon filler and a two-dimensional carbon filler.

2. The composite functional masterbatch according to claim 1, characterized in that The one-dimensional carbon filler is selected from at least one of pitch-based carbon fibers, carbon nanofibers, and carbon nanotubes; and / or, The aspect ratio of the one-dimensional carbon-based filler is 5 to 100, preferably 20 to 50; and / or, The two-dimensional carbon filler is selected from at least one of flake graphite, expanded graphite, and graphene; and / or, The mass ratio of the one-dimensional carbon filler to the two-dimensional carbon filler is 1:(5-50), preferably 1:(10-30).

3. The composite functional masterbatch according to claim 1, characterized in that The engineering plastic is selected from at least one of polyester, polyamide, polyoxymethylene, and polyphenylene ether, preferably at least one of polycarbonate, nylon-6, nylon-66, polyoxymethylene, polybutylene terephthalate, polyethylene terephthalate, and polyphenylene ether; and / or, The engineering plastic has a melt index of 6 to 30 g / 10 min, preferably 10 to 20 g / 10 min; and / or, The thermal conductive magnetic loss type electromagnetic shielding filler is selected from at least one of iron powder, nickel powder, cobalt powder and carbonyl iron powder, and the particle size of the thermal conductive magnetic loss type electromagnetic shielding filler is preferably 1 to 20 μm; and / or, The toughening agent is selected from at least one of styrene copolymers and ethylene copolymers, preferably at least one of hydrogenated styrene-butadiene block copolymers, ethylene-octene copolymers, methacrylic acid-butadiene-styrene terpolymers, ethylene-propylene copolymers, and ethylene-α-olefin block copolymers; and / or, The particle size of the toughening agent is 50 to 600 μm, preferably 100 to 300 μm.

4. The composite functional masterbatch according to claim 1, characterized in that In parts by weight, the engineering plastic is 10 to 95 parts, the thermal conductive electromagnetic shielding filler is 5 to 120 parts, and the toughening agent is 0 to 50 parts; preferably, in parts by weight, the engineering plastic is 20 to 70 parts, the thermal conductive electromagnetic shielding filler is 30 to 100 parts, and the toughening agent is 5 to 30 parts; and / or, The mass ratio of the thermal conductive resistance type electromagnetic shielding filler to the thermal conductive magnetic loss type electromagnetic shielding filler is 1:(0.1-5), preferably 1:(0.25-2).

5. A method for preparing the thermal conductive / electromagnetic shielding composite functional masterbatch according to any one of claims 1 to 4, comprising the step of processing the components including the engineering plastic, thermal conductive electromagnetic shielding filler and optional toughening agent under the action of a continuous force field. Preferably, the continuous force field comprises at least 5 continuous composite force field modules.

6. The preparation method according to claim 5, characterized in that The preparation method specifically comprises the following steps: (1) mechanically blending the components including the engineering plastic, the thermal conductive electromagnetic shielding filler, and an optional toughening agent to obtain a premix; (2) adding the premix obtained in step (1) into an extruder, extruding it into a continuous force field for processing, and then extruding and granulating it to obtain the thermal conductive and electromagnetic shielding composite functional masterbatch.

7. The preparation method according to claim 6, characterized in that The conditions for mechanical blending in step (1) are: a rotation speed of 500 to 1500 rpm and a time of 2 to 10 minutes; and / or, The step (2) is completed on a uniformly dispersed integrated device comprising an extruder, a continuous force field and a granulator. The uniformly dispersed integrated device preferably comprises a twin-screw extruder, a connector, at least 5 continuous composite force field modules, a granulation die and a granulator connected in sequence.

8. The preparation method according to claim 7, characterized in that The operating conditions of the twin-screw extruder are: the temperature of the feeding section is 120-180°C, the temperature of the conveying section is 240-290°C, the temperature of the melting section is 240-290°C, and the temperature of the homogenizing section is 240-290°C; and / or, The operating conditions of the connector are: temperature 240-290°C; and / or, The operating conditions of the continuous force field are: temperature 240-290° C., extrusion speed 100-500 rpm; and / or, The composite force field module adopts an inclined flow channel, the front section of the flow channel includes at least 4 diversion areas, the middle section of the flow channel narrows, and then the flow channel gradually widens to the width of the front section of the flow channel; preferably, the angle between the flow channel and the horizontal line is 120 to 150°; the width of the middle flow channel is 1 / 2 to 1 / 8 of the width of the flow channels at both ends, and more preferably 1 / 3 to 1 / 6.

9. An engineering plastic-based thermal conductive / electromagnetic shielding composite functional material, comprising engineering plastic and the thermal conductive / electromagnetic shielding composite functional masterbatch according to any one of claims 1 to 4 or the thermal conductive / electromagnetic shielding composite functional masterbatch obtained by the preparation method according to any one of claims 5 to 8.

10. The composite functional material according to claim 9, characterized in that: The engineering plastic is selected from at least one of polyester, polyamide, polyoxymethylene, and polyphenylene ether, preferably at least one of polycarbonate, nylon-6, nylon-66, polyoxymethylene, polybutylene terephthalate, polyethylene terephthalate, and polyphenylene ether; and / or, Based on the total weight of the composite functional material being 100%, the content of the thermal conductive / electromagnetic shielding composite functional masterbatch is 40 to 99%, preferably 60 to 90%.

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