Use of array carbon nanotube / polymer composite reinforced sheet in polymer foaming process and injection-molded foamed molded body

Abstract

The application belongs to the technical field of high polymer materials, and relates to application of array carbon nanotube / high polymer composite reinforcing sheet in polymer foaming process and injection molding foaming forming body. In the polymer foaming process, the array carbon nanotube / high polymer composite reinforcing sheet is used as a preset sheet; the reinforcing sheet comprises array carbon nanotube film material and high polymer, and the array carbon nanotube film material comprises array carbon nanotube and low surface energy polymer; and the thickness of the reinforcing sheet is 2 microns to 2 millimeters. The array carbon nanotube / high polymer composite reinforcing sheet is used as a preset sheet, the preset sheet has excellent rigidity and impact toughness, and compared with the preset reinforcing sheet of non-thermoplastic resin material in the market, the compatibility is greatly improved, and the array carbon nanotube / high polymer composite reinforcing sheet has wide market prospect in the field of polymer foaming technology.

Description

Technical Field

[0001] This invention belongs to the field of polymer materials technology, specifically relating to the application of an arrayed carbon nanotube / polymer composite reinforced sheet as a pre-formed sheet in a polymer foaming process, and a thermoplastic resin injection-molded foamed body and its preparation method. Background Technology

[0002] As is well known, thermoplastic resins (PP, PE, PS, PA, POE, PET, PBT, PLA, PBAT, and thermoplastic elastomers, etc.) foaming currently mainly involves four processes: autoclaving, compression molding, extrusion, and injection molding. Autoclaving, compression molding, and extrusion produce foamed materials with a very thin skin and a continuous honeycomb cell structure. Common product ratios range from 5 to 60 times. The resulting autoclaved foam, compression molded foam, and extruded foam sheets all require secondary processing to obtain the final part. Injection molding, on the other hand, has a unique "sandwich" core-skin structure. It has a relatively thick and dense skin layer, and the cell structure consists of intermittently distributed "island-like cells." Currently, the common weight reduction ratio is between 3% and 8%. Parts can be formed in a single molding process. Because injection-molded foam products have better mechanical properties, they can be used in some structural load-bearing components, hence the name "structural foam."

[0003] Injection foaming technology creates a unique "sandwich" core-skin structure, resulting in excellent appearance quality, ease of painting and coloring, and minimal loss of physical properties. The presence of uniform micropores not only reduces weight but also helps eliminate internal stress, significantly reducing shrinkage and warpage, and greatly improving dimensional accuracy. Furthermore, the presence of gas within the melt during injection molding eliminates the need for holding pressure during molding, effectively shortening the production cycle, increasing efficiency, and reducing clamping force. Compared to pre-forming sheets before conventional injection molding, the foaming agent gas escaping from the mold during foaming has a plasticizing effect on the surface of the pre-formed sheet, allowing for the creation of more layers of sheet material and achieving more ideal mechanical properties.

[0004] To further improve the production efficiency and physical properties of thermoplastic resin injection-molded foam products, a new process has emerged: first placing inorganic or organic reinforcing sheets into the mold, and then injecting and foaming them. This method is particularly suitable for applications in automotive structural parts and other fields. Existing technologies that pre-place organic sheets primarily use composite materials such as glass fiber reinforced nylon due to the high mechanical performance requirements; these materials have high density and long molding times.

[0005] Carbon nanotubes can be specifically divided into powdered carbon nanotubes and arrayed carbon nanotubes. Due to their high aspect ratio, powdered carbon nanotubes tend to aggregate and are difficult to disperse uniformly in polymers, significantly reducing their effectiveness in reinforcing composite materials. In contrast, arrayed carbon nanotubes possess ordered directional arrangement and a perfect structure, resulting in physicochemical properties closer to their intrinsic characteristics. If effective composites of arrayed carbon nanotubes with polymer materials can be achieved, their aspect ratio advantage can construct multiple tightly bound network structures within the polymer, not only enhancing the mechanical properties of the composite material but also endowing the material with the inherent thermal, electrical, and chemical stability of carbon nanotubes. However, in current technologies, the preparation of arrayed carbon nanotubes requires a substrate, limiting their transfer and application, and hindering their integration with existing composite processes, thus greatly restricting the development of arrayed carbon nanotubes in the field of composite materials.

[0006] If an array of carbon nanotube composite materials that is easy to prepare, has excellent physical properties, good thermal conductivity, is thin and light, and has specific functions can be developed for use as pre-formed sheets, the application fields of thermoplastic resin injection-molded foams can be greatly expanded, and their added value can be increased. Summary of the Invention

[0007] To address the shortcomings of the prior art, this invention provides an application of arrayed carbon nanotube / polymer composite reinforced sheets in polymer foaming processes, and further provides a thermoplastic resin injection-molded foamed body and its preparation method.

[0008] A first aspect of the present invention provides an application of an arrayed carbon nanotube / polymer composite reinforced sheet in a polymer foaming process, wherein the arrayed carbon nanotube / polymer composite reinforced sheet is used as a pre-formed sheet; the reinforced sheet comprises an arrayed carbon nanotube film material and a polymer composite, wherein the arrayed carbon nanotube film material comprises arrayed carbon nanotubes and a low surface energy polymer; the thickness of the reinforced sheet is 2 μm to 2 mm, preferably 20 μm to 1 mm.

[0009] A second aspect of the present invention provides a thermoplastic resin injection-molded foamed body, the body comprising an injection-molded thermoplastic resin and a pre-set reinforcing sheet, wherein the pre-set reinforcing sheet is the aforementioned arrayed carbon nanotube / polymer composite reinforcing sheet; the content of the pre-set reinforcing sheet in the body is 0.1 to 6.0% by weight, preferably 0.2 to 4.0% by weight.

[0010] A third aspect of the present invention provides a method for preparing the above-described thermoplastic resin injection-molded foam, comprising the following steps:

[0011] (1) The arrayed carbon nanotube / polymer composite reinforced sheet is pre-set in the mold of the injection molding machine as a pre-set sheet;

[0012] (2) The thermoplastic resin composition is melted and homogenized, and then mixed with a foaming agent to form a single-phase melt; the single-phase melt is injected into the mold in step (1) for injection foaming to obtain the thermoplastic resin injection foamed molded body.

[0013] Compared with the prior art, the present invention has the following beneficial effects:

[0014] (1) The present invention uses an array of carbon nanotubes / polymer composite reinforced sheet as a pre-formed sheet. The pre-formed sheet has excellent rigidity and impact toughness, and its compatibility is greatly improved compared with the pre-formed reinforced sheet made of non-thermoplastic resin material on the market. It has a broad market prospect in the field of polymer foaming technology.

[0015] (2) In the preparation of the thermoplastic resin injection foamed body provided by the present invention, an array of carbon nanotubes / polymer composite reinforced sheet is pre-placed in the injection molding mold, and the thermoplastic resin composition is formed in the injection mold in one step by the injection foaming process.

[0016] (3) Compared with commonly used injection-molded foamed products, the present invention can significantly improve the physical properties of the product by pre-reinforcing the sheet material; the compatibility between the pre-reinforcing sheet material and the matrix resin is greatly improved, which can effectively reduce the weight of the product and improve production efficiency.

[0017] (4) The thermoplastic resin injection foamed molded body of the present invention can be prepared by various existing injection foaming processes, and different process methods and different types of foaming agents can be used to prepare thermoplastic resin injection foamed molded bodies with different properties according to the needs of downstream applications.

[0018] Other features and advantages of the present invention will be described in detail in the following detailed description section. Detailed Implementation

[0019] The following provides a detailed description of specific embodiments of the present invention. It should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the scope of the invention.

[0020] This invention provides an application of an arrayed carbon nanotube / polymer composite reinforced sheet in a polymer foaming process, wherein the arrayed carbon nanotube / polymer composite reinforced sheet is used as a pre-formed sheet; the reinforced sheet comprises an arrayed carbon nanotube film material and a polymer composite, wherein the arrayed carbon nanotube film material comprises arrayed carbon nanotubes and a low surface energy polymer; the thickness of the reinforced sheet is 2μm to 2mm, preferably 20μm to 1mm.

[0021] The thickness of the reinforcing sheet described in this invention can be any one of the following values, or a value within the range of any two of the above: 2μm, 5μm, 10μm, 20μm, 50μm, 80μm, 100μm, 200μm, 500μm, 800μm, 1mm, 1.5mm, and 2mm.

[0022] Because carbon nanotubes are uniformly distributed in the reinforcing sheet, a relatively small amount of arrayed carbon nanotubes is sufficient to give the reinforcing sheet good mechanical and thermal properties. Preferably, based on the weight of the reinforcing sheet, the content of arrayed carbon nanotubes in the reinforcing sheet is 0.01–20% by weight, more preferably 0.1–10% by weight. The content of arrayed carbon nanotubes in the reinforcing sheet can be listed as any one of 0.01% by weight, 0.05% by weight, 0.1% by weight, 0.2% by weight, 0.5% by weight, 1% by weight, 3% by weight, 5% by weight, 8% by weight, 10% by weight, 13% by weight, 15% by weight, 18% by weight, and 20% by weight, or a value within the range of any two of the above values.

[0023] According to the present invention, the relative contents of arrayed carbon nanotubes and low surface energy polymers can be adjusted within a wide range. To obtain a better exfoliation effect, based on the weight of the arrayed carbon nanotube film material, the content of arrayed carbon nanotubes in the arrayed carbon nanotube film material is 0.1-50% by weight, preferably 1-50% by weight; the content of low surface energy polymers is 50-99.9% by weight, preferably 50-99% by weight.

[0024] Specifically, the content of the arrayed carbon nanotubes can be listed as any one of the following values ​​or a range of any two of the above: 0.1 wt%, 0.5 wt%, 1 wt%, 3 wt%, 5 wt%, 8 wt%, 10 wt%, 13 wt%, 15 wt%, 18 wt%, 20 wt%, 23 wt%, 25 wt%, 28 wt%, 30 wt%, 33 wt%, 35 wt%, 38 wt%, 40 wt%, 43 wt%, 45 wt%, 48 wt%, and 50 wt%. The content of the low surface energy polymer can be listed as any one of the following values, or a range of any two of the above values: 50 wt%, 52 wt%, 55 wt%, 57 wt%, 60 wt%, 62 wt%, 65 wt%, 67 wt%, 70 wt%, 72 wt%, 75 wt%, 77 wt%, 80 wt%, 82 wt%, 85 wt%, 87 wt%, 90 wt%, 92 wt%, 95 wt%, 97 wt%, 99 wt%, 99.5 wt%, 99.9 wt%.

[0025] Low surface energy polymers can be used to achieve the exfoliation and composite of arrayed carbon nanotubes. Preferably, the surface energy of the low surface energy polymer is less than 30 mN / m, more preferably less than 25 mN / m.

[0026] This invention can use any polymer that meets the above-mentioned surface energy standard. Preferably, the low surface energy polymer is selected from at least one of fluorocarbon resins, silicone resins, and polyolefins; more preferably, it is selected from at least one of polytetrafluoroethylene, polyvinylidene fluoride, polyvinyl fluoride, polychlorotrifluoroethylene, copolymers of ethylene and trifluoroethylene, copolymers of ethylene and tetrafluoroethylene, copolymers of ethylene and chlorotrifluoroethylene, perfluoroethylene propylene, polyfluoroacrylates, polysiloxanes, polystyrene, polyethylene, and polypropylene. Considering all aspects of performance and ease of application, polytetrafluoroethylene is a preferred choice.

[0027] According to the present invention, from an application perspective, the low surface energy polymer is in the form of a micro powder with a particle size of 0.01–30 μm, preferably 0.02–20 μm. The particle size can be any value selected from 0.05 μm, 0.1 μm, 0.5 μm, 1 μm, 5 μm, 10 μm, 15 μm, and 20 μm, or a value within a range of any two of the above.

[0028] The carbon nanotubes used in this invention are arrayed carbon nanotubes, preferably horizontally arrayed carbon nanotubes; the arrayed carbon nanotubes can be single-walled or multi-walled; the length of the arrayed carbon nanotubes is preferably in the range of 1 μm to 1 m. The length of the arrayed carbon nanotubes can be any one of the following values: 1 μm, 10 μm, 50 μm, 100 μm, 500 μm, 800 μm, 1 mm, 5 mm, 1 cm, 10 cm, 50 cm, 1 m, or a value within the range of any two of the above values.

[0029] According to a preferred embodiment of the present invention, the arrayed carbon nanotube film material is a single-layer or multi-layer stacked arrayed carbon nanotube composite film, and the arrayed carbon nanotube composite film is obtained by directly peeling the arrayed carbon nanotubes on the substrate using the low surface energy polymer.

[0030] This invention does not impose a particular limitation on the number of stacked layers; the number of layers can be determined according to the required thickness. Generally, the number of layers in the multilayer stacked array of carbon nanotube composite film is 2 to 20. The thickness of the film material is 1 μm to 0.1 mm, preferably 10 μm to 0.05 mm. The thickness of the film material can be any value from 1 μm, 5 μm, 10 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, and 100 μm, or a value within the range of any two of the above values.

[0031] The present invention does not particularly limit the specific form of stacking, but from the perspective of increasing strength, the stacking is preferably cross-stacking.

[0032] According to a preferred embodiment of the present invention, the preparation method of the arrayed carbon nanotube / polymer composite reinforced sheet includes the following steps:

[0033] (1) The array of carbon nanotubes was prepared on a substrate by chemical vapor deposition.

[0034] (2) The arrayed carbon nanotubes are peeled off from the substrate using a low surface energy polymer to obtain an arrayed carbon nanotube composite film.

[0035] (3) The arrayed carbon nanotube film material is combined with the polymer to obtain the reinforced sheet; the arrayed carbon nanotube film material is a single-layer arrayed carbon nanotube composite film or a multi-layer stacked and hot-pressed arrayed carbon nanotube composite film.

[0036] Arrayed carbon nanotube composite films can be directly composited with polymers as arrayed carbon nanotube film materials, or they can be first stacked in multiple layers to obtain a shaped body, and then hot-pressed to obtain arrayed carbon nanotube film materials, and finally composited with polymers.

[0037] The array of carbon nanotubes can be prepared by chemical vapor deposition using methods known in the art. Specifically, step (1) includes: placing a substrate in a horizontal resistance furnace, introducing a carbon source and a carrier gas, and having the carbon source react on the substrate to prepare the array of carbon nanotubes.

[0038] Preferably, the carbon source is a mixture of C1-C in any proportion. 10 Alkanes, C2-C 10 Olefins and C2-C 10 One or more alkynes; the carrier gas is one or more of hydrogen, nitrogen and argon mixed in any proportion; the substrate is a silicon substrate, a silicon oxide substrate or a silicon / silicon oxide substrate; the reaction temperature is 800-1200℃ and the pressure is 0.1-1MPa.

[0039] The key to the exfoliation of arrayed carbon nanotubes in this invention lies in the second step. According to one specific embodiment, step (2) includes:

[0040] Low surface energy polymer powder is sprinkled onto the substrate on which the array of carbon nanotubes is prepared;

[0041] The substrate containing the arrayed carbon nanotubes, which is sprinkled with the low surface energy polymer powder, is heated, and the arrayed carbon nanotubes and the low surface energy polymer are initially combined to obtain the arrayed carbon nanotube composite film.

[0042] The arrayed carbon nanotube composite film is peeled off from the surface of the substrate.

[0043] The heating can be performed using infrared heating. Preferably, the parameters for infrared heating include: the power of infrared heating is 200-2000W; and the duration of infrared heating is 0.5-10h.

[0044] The present invention can use conventional hot pressing conditions. Specifically, the hot pressing conditions include: a temperature of 50 to 500°C, preferably 140 to 450°C; a pressure of 0.1 to 30 MPa, preferably 0.5 to 20 MPa; and a heat preservation and pressurization time of 0.1 to 10 hours, preferably 0.2 to 5 hours.

[0045] According to a preferred embodiment of the present invention, in step (3), the composite method includes the following steps: processing the film material with a polymer to obtain the reinforced sheet. The processing is carried out under certain temperature and pressure conditions; preferably, the processing temperature is 40-500℃, more preferably 50-350℃; the processing pressure is 0.05-20MPa, more preferably 0.1-10MPa; and the processing time is 0.5min-10h, more preferably 1min-3h.

[0046] This invention does not impose special requirements on the polymer used in the composite; it can be one or more of polyethylene, polypropylene, polyvinyl chloride, polystyrene, nylon, polyester, acrylic, vinylon, styrene-butadiene rubber, butadiene rubber, isoprene rubber, and ethylene propylene rubber mixed in any proportion. Any polymer can achieve a reinforcing effect by being composited with the arrayed carbon nanotube film material of this invention. The arrayed carbon nanotube / polymer composite reinforced sheet can increase the strength by 15% to 300% compared to the polymer itself.

[0047] The method of this invention is applicable to various polymer foaming processes, including but not limited to injection molding foaming, compression molding foaming, or foamed bead molding. Depending on the characteristics of the foaming process, the arrayed carbon nanotube / polymer composite reinforced sheet can be pre-placed in a mold before foaming, or it can be stacked with other materials before foaming. Regardless of the method, it can achieve reinforcement of the polymer and improvement of other properties.

[0048] This invention does not particularly limit the arrangement of the pre-placed sheets; conventional arrangements in the art can be used, such as parallel arrangement within the mold. Typically, multiple pre-placed sheets are provided. To achieve better physical properties, the pre-placed sheets are preferably placed on the outer surface of the molded body. Therefore, the maximum distance between the pre-placed sheets is preferably the farthest distance between two points on the outer surface of the molded body. The pre-placed sheets inside the molded body are preferably evenly distributed. The number of pre-placed sheets can be determined based on the size of the molded body combined with the above-mentioned preferred arrangement. According to a preferred embodiment of the invention, at least two pre-placed sheets are attached to the inner wall of the mold, and the remaining optional pre-placed sheets are evenly distributed inside the molded body. In the formed molded body, at least two reinforcing sheets are located on the outer surface of the molded body, and the remaining optional reinforcing sheets are evenly distributed inside the molded body. According to a specific embodiment of the invention, using a 500mm*500mm*24mm mold, the distance between the reinforcing sheets inside the molded body can be 1-20mm, preferably 2-10mm.

[0049] Furthermore, the present invention provides a thermoplastic resin injection-molded foamed article; however, those skilled in the art will recognize that the method of the present invention is not limited to the injection molding foaming process.

[0050] The molded body of the present invention comprises injection-molded thermoplastic resin and a pre-set reinforcing sheet, wherein the pre-set reinforcing sheet is the aforementioned arrayed carbon nanotube / polymer composite reinforcing sheet; the content of the pre-set reinforcing sheet in the molded body is 0.1-6.0% by weight, preferably 0.2-4.0% by weight.

[0051] The content of the pre-set reinforcing sheet in the molded body can be listed as any one of 0.1 wt%, 0.5 wt%, 1 wt%, 3 wt%, 5 wt%, 6 wt%, or a value within the range of any two of the above values.

[0052] Specifically, the molded body is made from a thermoplastic resin composition and a pre-set reinforcing sheet through an injection molding foaming process, and can be formed in one step in an injection mold; the thermoplastic resin composition includes thermoplastic resin and additives.

[0053] The thermoplastic resin may be a single thermoplastic resin or a composition of several resins in free proportions, including but not limited to one or more of PP, PE, PS, PA, POE, PET, PBT, PLA, PBAT and thermoplastic elastomers.

[0054] In addition to thermoplastic resin, the thermoplastic resin composition may also contain various additives. This invention does not particularly limit the additives, which can be various processing aids and / or functionalized additives commonly used in injection molding processes. The processing aids include, but are not limited to, at least one of antioxidants, antistatic agents, cell nucleating agents, and lubricants. The functionalized additives include, but are not limited to, at least one of flame retardants, conductive fillers, light stabilizers, anti-aging agents, antibacterial agents, and color masterbatches / color powders. The specific substances and amounts of the above-mentioned additives can be conventionally selected in the art.

[0055] This invention also provides a method for preparing the aforementioned thermoplastic resin injection-molded foam, comprising the following steps:

[0056] (1) The arrayed carbon nanotube / polymer composite reinforced sheet is pre-set in the mold of the injection molding machine as a pre-set sheet;

[0057] (2) The thermoplastic resin composition is melted and homogenized, and then mixed with a foaming agent to form a single-phase melt; the single-phase melt is injected into the mold in step (1) for injection foaming to obtain the thermoplastic resin injection foamed molded body.

[0058] This invention does not impose any particular limitations on the injection molding foaming process steps and conditions, all of which can be conventional choices in the field. The specific process is well known to those skilled in the art and will not be described in detail here.

[0059] According to some specific embodiments of the present invention, the injection molding foaming apparatus used consists of a KraussMaffei KMGX650-4300 injection molding foaming machine and a TREXEL T-300L supercritical gas controller. The conditions for using the injection molding foaming apparatus in this invention are all conventional choices in the art, and the specific processes are well known to those skilled in the art and will not be elaborated upon here.

[0060] According to some specific embodiments of the present invention, the injection mold used can produce a square plate of 500mm*500mm*24mm. The conditions for the injection foam molding mold used in the present invention are all conventional choices in the art, and the specific process is known to those skilled in the art, and will not be described in detail here.

[0061] When forming an injection-molded foamed article from a thermoplastic resin composition, a foaming agent is typically added. The foaming agent can be a chemical foaming agent or a physical foaming agent. Physical foaming agents can be organic or inorganic. Examples of chemical foaming agents include, but are not limited to, at least one of azoformamide (AC foaming agent), p-toluenesulfonyl hydrazine, aminoureas, tetrazolium, sodium bicarbonate, and sodium citrate. Examples of organic physical foaming agents include, but are not limited to, at least one of aliphatic hydrocarbons such as propane, butane, pentane, hexane, and heptane; alicyclic hydrocarbons such as cyclobutane and / or cyclohexane; and at least one of halogenated hydrocarbons such as chlorofluoromethane, trifluoromethane, 1,2-difluoroethane, 1,2,2,2-tetrafluoroethane, methyl chloride, ethyl chloride, and dichloromethane. Examples of inorganic physical foaming agents include, but are not limited to, at least one of air, nitrogen, carbon dioxide, oxygen, and water.

[0062] Compared with conventional injection-molded foamed articles of the same shape and base resin, the single-mold production time of the injection-molded foamed articles of the present invention can be reduced by more than 15%, preferably more than 30%.

[0063] Compared with conventional injection-molded foams of the same shape and base resin, the injection pressure of the injection-molded foam of the present invention can be reduced by more than 15%, preferably more than 30%.

[0064] Compared with injection-molded foamed articles of the same matrix resin, shape, and weight reduction ratio, the injection-molded foamed articles of the present invention exhibit significantly improved impact resistance. Tested according to the GB4857.5 drop test method for packaging and transport, the articles show no deformation or breakage after a drop height of up to 1200mm, preferably up to 1500mm.

[0065] Compared with injection molded articles of the same volume based on the same matrix resin, the weight reduction ratio of the injection molded foamed articles of the present invention is ≥5%, preferably ≥10%.

[0066] The present invention will be further described below with reference to the embodiments, but the scope of the present invention is not limited to these embodiments.

[0067] Drop impact resistance: Tested according to the drop test method specified in GB4857.5 Packaging and Transport Packaging. The drop heights tested are 500mm, 600mm, 800mm, 1000mm, 1200mm, and 1500mm, increasing in 300mm increments starting from 1500mm.

[0068] The thermoplastic resin composition used is as follows.

[0069] PP1: Using 100 parts by weight of Sinopec Zhenhai Refining & Chemical PPB-M09 as raw material, add 0.3 parts by weight of BASF antioxidant 1010, 3.0 parts by weight of Changzhou Masterbatch Plant graphite masterbatch G25, 0.3 parts by weight of Sinopec Beijing Research Institute of Chemical Industry β-crystal nucleating agent VP101B, and 2 parts by Changzhou Huanju Technology Co., Ltd. flame retardant HJ740. After uniform mixing in a twin-screw extruder at 200°C, granulate by die extrusion at 190°C.

[0070] PA1: Using 100 parts by weight of Sinopec Baling Petrochemical PA6 YH-800 as raw material, add 0.3 parts by weight of ADK antioxidant PEP-36 and 1.0 part by weight of American Minerals talc AG609. After uniform mixing in a twin-screw extruder at 250°C, granulate by die extrusion at 230°C.

[0071] PLA1: 100 parts by weight of Zhejiang Haizheng polylactic acid REVODE213 as raw material, with 0.3 parts by weight of ADK antioxidant PEP-36 and 1.0 part by weight of American mining company talc AG609 added. After uniform mixing in a twin-screw extruder at 190°C, the mixture is extruded and granulated at 180°C using a die.

[0072] PP2: Using 80 parts by weight of Sinopec Yanshan Petrochemical PPH-K1008 and 20 parts by weight of ExxonMobil polyolefin elastomer Vistamaxx 3000 as raw materials, 0.3 parts by weight of BASF antioxidant 1010, 0.3 parts by weight of American Minerals talc AG609, and 4 parts by weight of Cabot Corporation black masterbatch 6204 were added. After uniform mixing in a twin-screw extruder at 200°C, the mixture was extruded and granulated at 190°C using a die.

[0073] PTFE ultrafine powder: TPD-603S from Taipuda New Materials, surface energy 20-25 mN / m, particle size distribution: D50 < 3.0 μm.

[0074] Polypropylene powder: Zhongyuan Petrochemical polypropylene FC03, surface energy 28-30 mN / m, sieve particle size 15-20 μm.

[0075] Polysiloxane powder: Shenzhen Xinyongsheng XYS-9223, surface energy 20~25mN / m, particle size 1~2μm.

[0076] Poly(fluoroethylene propylene) powder: Daikin NC-1500, Japan, surface energy 23-27 mN / m, particle size 30 μm.

[0077] Example 1

[0078] This embodiment is used to illustrate the thermoplastic resin injection-molded foamed body and its preparation method provided by the present invention.

[0079] (1) Preparation of arrayed carbon nanotube / polymer composite reinforced sheets:

[0080] S101. Arrayed carbon nanotubes were prepared using chemical vapor deposition.

[0081] In the specific implementation, a silicon substrate was placed in a horizontal resistance furnace, and methane and hydrogen were introduced. The reaction was carried out on the silicon substrate in a hydrogen atmosphere. The reaction temperature was set to 1200℃, and the reaction pressure was set to 0.1MPa. Multi-walled horizontal array carbon nanotubes with a length of 1m were prepared.

[0082] S102. Sprinkle PTFE ultrafine powder onto the arrayed carbon nanotubes and heat with infrared to obtain an arrayed carbon nanotube-PTFE composite film.

[0083] In practice, a certain proportion of PTFE ultrafine powder is sprinkled onto a silicon substrate on which the aforementioned arrayed carbon nanotubes are prepared. Then, the substrate with the PTFE ultrafine powder and arrayed carbon nanotubes is subjected to infrared heating, with the infrared heating power controlled at 2000W and the heating time at 0.5h, to allow the arrayed carbon nanotubes and PTFE to initially bond, resulting in an arrayed carbon nanotube-PTFE composite film. The obtained arrayed carbon nanotube-PTFE composite film is then peeled off from the substrate surface.

[0084] S103. The arrayed carbon nanotube-PTFE composite film is prepared into a carbon nanotube-PTFE macroscopic body, and then hot-pressed into a film material.

[0085] In practice, the stripped arrayed carbon nanotube-PTFE composite film is cross-stacked in 5 layers to form an arrayed carbon nanotube-PTFE macrostructure. The formed arrayed carbon nanotube-PTFE macrostructure is then fed into a hot press to obtain a film material with a thickness of 100 μm. The hot pressing conditions include: temperature of 365℃, pressure of 20 MPa, and holding time of 3 hours.

[0086] S104. Composite the film material with a polymer to obtain an array of carbon nanotubes / polymer composite reinforced sheet.

[0087] In practice, the obtained film-like material is processed and molded with polyethylene material at a temperature of 150°C, a pressure of 5 MPa, and a processing time of 0.5 h, resulting in a uniformly distributed array of carbon nanotubes / polymer composite reinforced sheets with a thickness of 0.75 mm. The mass fraction of carbon nanotubes is 0.1%, and the mass fraction of PTFE is 1%.

[0088] (2) Preparation of thermoplastic resin injection-molded foam:

[0089] On a dedicated injection molding machine for physical microfoaming, PP1 is used as the base resin, and the arrayed carbon nanotube / polymer composite reinforcing sheet obtained in step (1) above is used as the pre-placed reinforcing sheet. Specifically, six square sheets with a side length of 100mm are hung parallel to each other in the center of the mold (size 500mm×500mm×24mm), with a spacing of 4.2mm between the sheets. The two outermost sheets are placed close to the inner wall of the mold. The injection molding machine is turned on to feed PP1 into the injection screw and melt and homogenize it. Then, 99.99% nitrogen is injected into the homogenization zone of the screw as a supercritical physical foaming agent. Under the shearing of the screw, the supercritical nitrogen and PP1 are mixed into a single-phase melt. The single-phase melt is injected into the mold cavity through a self-locking nozzle. The mold is opened and the pressure is released, and the gas escapes to obtain a thermoplastic resin injection-molded foamed body, in which the content of the reinforcing sheet is 2.5% by weight. The weight and drop height of the molded part were measured, and the production time and injection pressure were recorded. The results are shown in Table 1.

[0090] Example 2

[0091] This embodiment is used to illustrate the thermoplastic resin injection-molded foamed body and its preparation method provided by the present invention.

[0092] (1) Preparation of arrayed carbon nanotube / polymer composite reinforced sheets:

[0093] S101. Arrayed carbon nanotubes were prepared using chemical vapor deposition.

[0094] In the specific implementation, a silicon substrate was placed in a horizontal resistance furnace, and a mixture of C2-C5 alkanes and olefins (ethane, 1-butene, and n-pentane mixed in equal weight ratios) and a mixed carrier gas of hydrogen and argon (1:1, v / v) was introduced. The reaction was carried out on the silicon substrate in the mixed carrier atmosphere of hydrogen and argon, with the reaction temperature set at 800℃ and the reaction pressure set at 0.1 MPa. Single-walled horizontal array carbon nanotubes with a length of 1 μm were prepared.

[0095] S102. Sprinkle PTFE ultrafine powder onto the arrayed carbon nanotubes and heat with infrared to obtain an arrayed carbon nanotube-PTFE composite film.

[0096] In practice, a certain proportion of PTFE ultrafine powder is sprinkled onto a silicon substrate on which the aforementioned arrayed carbon nanotubes are prepared. The substrate with the PTFE ultrafine powder and arrayed carbon nanotubes is then subjected to infrared heating. The infrared heating power is controlled at 200W, and the infrared heating time is 10 hours, allowing the arrayed carbon nanotubes and PTFE to initially bond, resulting in an arrayed carbon nanotube-PTFE composite film with a thickness of 10 μm. The obtained arrayed carbon nanotube-PTFE composite film is then peeled off from the substrate surface.

[0097] S103. Composite the arrayed carbon nanotube-PTFE composite film with a polymer material to obtain an arrayed carbon nanotube / polymer composite reinforced sheet.

[0098] In specific implementation, the arrayed carbon nanotube-PTFE composite film obtained above is processed and molded with a mixture of polypropylene and polyethylene. The molding temperature is 200℃, the molding pressure is 5MPa, and the molding time is 0.5h, resulting in a uniformly distributed arrayed carbon nanotube / polymer composite reinforced sheet with a thickness of 0.02mm. The mass fraction of carbon nanotubes is 10%, and the mass fraction of PTFE is 10%.

[0099] (2) Preparation of thermoplastic resin injection-molded foam:

[0100] The process is the same as step (2) of Example 1, to obtain a thermoplastic resin injection-molded foamed body, the difference being that the reinforcing sheet prepared in step (1) of Example 2 is used. The content of the reinforcing sheet is 0.25% by weight. The weight and drop height of the molded body are measured, and the production time and injection pressure are recorded. The results are shown in Table 1.

[0101] Example 3

[0102] This embodiment is used to illustrate the thermoplastic resin injection-molded foamed body and its preparation method provided by the present invention.

[0103] (1) Preparation of arrayed carbon nanotube / polymer composite reinforced sheets:

[0104] S101. Arrayed carbon nanotubes were prepared using chemical vapor deposition.

[0105] In the specific implementation, a silicon substrate was placed in a horizontal resistance furnace, and methane and hydrogen were introduced. The reaction was carried out on the silicon substrate in a hydrogen atmosphere. The reaction temperature was set to 1000℃, and the reaction pressure was set to 0.1MPa. Multi-walled horizontal array carbon nanotubes with a length of 0.5m were prepared.

[0106] S102. Sprinkle PTFE ultrafine powder onto the arrayed carbon nanotubes and heat with infrared to obtain an arrayed carbon nanotube-PTFE composite film.

[0107] In practice, a certain proportion of PTFE ultrafine powder is sprinkled onto a silicon substrate on which the above-mentioned arrayed carbon nanotubes are prepared. Then, the substrate with the PTFE ultrafine powder and arrayed carbon nanotubes is subjected to infrared heating, with the infrared heating power controlled at 1000W and the heating time at 5 hours, to allow the arrayed carbon nanotubes and PTFE to initially bond, thus obtaining an arrayed carbon nanotube-PTFE composite film. The obtained arrayed carbon nanotube-PTFE composite film is then peeled off from the substrate surface.

[0108] S103. The arrayed carbon nanotube-PTFE composite film is prepared into a carbon nanotube-PTFE macroscopic body, and then hot-pressed into a film material.

[0109] In practice, the peeled arrayed carbon nanotube-PTFE composite film is cross-stacked in three layers to form a macroscopic arrayed carbon nanotube-PTFE body. The formed macroscopic arrayed carbon nanotube-PTFE body is then fed into a hot press to obtain a film material with a thickness of 0.05 mm. The hot pressing conditions include: temperature of 350℃, pressure of 20 MPa, and holding time of 3 hours.

[0110] S104. Composite the film material with a polymer to obtain an array of carbon nanotubes / polymer composite reinforced sheet.

[0111] In practice, the obtained film material is processed and molded with styrene-butadiene rubber material at a temperature of 130°C, a pressure of 4 MPa, and a processing time of 1 hour, resulting in a uniformly distributed array of carbon nanotubes / polymer composite reinforced sheets with a thickness of 0.5 mm. The mass fraction of carbon nanotubes is 1%, and the mass fraction of PTFE is 4%.

[0112] (2) Preparation of thermoplastic resin injection-molded foam:

[0113] The preparation process is the same as step (2) of Example 2, resulting in a thermoplastic resin injection-molded foam. The content of the reinforcing sheet is 1.2% by weight. The weight and drop height of the molded body were measured, and the production time and injection pressure were recorded. The results are shown in Table 1.

[0114] Example 4

[0115] This embodiment is used to illustrate the thermoplastic resin injection-molded foamed body and its preparation method provided by the present invention.

[0116] (1) Preparation of arrayed carbon nanotube / polymer composite reinforced sheets:

[0117] The preparation process is the same as step (1) in Example 1.

[0118] (2) Preparation of thermoplastic resin injection-molded foam:

[0119] The preparation process is the same as step (2) of Example 1, except that the thermoplastic resin PP1 is replaced with PA1 to obtain a thermoplastic resin injection-molded foam. The weight and drop height of the molded body were measured, and the production time and injection pressure were recorded. The results are shown in Table 1.

[0120] Example 5

[0121] This embodiment is used to illustrate the thermoplastic resin injection-molded foamed body and its preparation method provided by the present invention.

[0122] (1) Preparation of arrayed carbon nanotube / polymer composite reinforced sheets:

[0123] The preparation process is the same as step (1) in Example 1.

[0124] (2) Preparation of thermoplastic resin injection-molded foam:

[0125] The preparation process is the same as step (2) of Example 1, except that the thermoplastic resin PP1 is replaced with PLA1 to obtain a thermoplastic resin injection-molded foam. The weight and drop height of the molded body were measured, and the production time and injection pressure were recorded. The results are shown in Table 1.

[0126] Example 6

[0127] This embodiment is used to illustrate the thermoplastic resin injection-molded foamed body and its preparation method provided by the present invention.

[0128] (1) Preparation of arrayed carbon nanotube / polymer composite reinforced sheets:

[0129] The preparation process is the same as step (1) in Example 2.

[0130] (2) Preparation of thermoplastic resin injection-molded foam:

[0131] The preparation process is the same as step (2) of Example 2, except that the thermoplastic resin PP1 is replaced with PP2 to obtain a thermoplastic resin injection-molded foam. The weight and drop height of the molded body were measured, and the production time and injection pressure were recorded. The results are shown in Table 1.

[0132] Example 7

[0133] This embodiment is used to illustrate the thermoplastic resin injection-molded foamed body and its preparation method provided by the present invention.

[0134] (1) Preparation of arrayed carbon nanotube / polymer composite reinforced sheets:

[0135] The preparation process is the same as step (1) in Example 1.

[0136] (2) Preparation of thermoplastic resin injection-molded foam:

[0137] The preparation process is the same as step (2) of Example 1, except that three square sheets with a side length of 100 mm are hung in the mold with a spacing of 12 mm. The two outermost sheets are placed close to the inner wall of the mold to obtain a thermoplastic resin injection-molded foam body, wherein the content of the reinforcing sheet is 1.2% by weight. The weight and drop height of the molded body are measured, and the production time and injection pressure are recorded. The results are shown in Table 1.

[0138] Example 8

[0139] This embodiment is used to illustrate the thermoplastic resin injection-molded foamed body and its preparation method provided by the present invention.

[0140] (1) Preparation of arrayed carbon nanotube / polymer composite reinforced sheets:

[0141] The preparation process is the same as step (1) in Example 1.

[0142] (2) Preparation of thermoplastic resin injection-molded foam:

[0143] The preparation process is the same as step (2) of Example 1, except that 11 square sheets with a side length of 100 mm are hung in the mold at approximately equal intervals, with the two outermost sheets placed close to the inner wall of the mold to obtain a thermoplastic resin injection-molded foam body, wherein the content of the reinforcing sheet is 4.8% by weight. The weight and drop height of the molded body are measured, and the production time and injection pressure are recorded. The results are shown in Table 1.

[0144] Example 9

[0145] (1) Preparation of arrayed carbon nanotube / polymer composite reinforced sheets:

[0146] The preparation process is the same as step (1) of Example 1, except that polypropylene powder of equal mass is used instead of PTFE for the exfoliation of array carbon nanotubes.

[0147] (2) Preparation of thermoplastic resin injection-molded foam:

[0148] The preparation process is the same as step (2) of Example 1, resulting in a thermoplastic resin injection-molded foam. The weight and drop height of the molded body were measured, and the production time and injection pressure were recorded. The results are shown in Table 1.

[0149] Example 10

[0150] (1) Preparation of arrayed carbon nanotube / polymer composite reinforced sheets:

[0151] The preparation process is the same as step (1) of Example 1, except that an equal mass of polysiloxane powder is used instead of PTFE to exfoliate the arrayed carbon nanotubes.

[0152] (2) Preparation of thermoplastic resin injection-molded foam:

[0153] The preparation process is the same as step (2) of Example 1, resulting in a thermoplastic resin injection-molded foam. The weight and drop height of the molded body were measured, and the production time and injection pressure were recorded. The results are shown in Table 1.

[0154] Example 11

[0155] (1) Preparation of arrayed carbon nanotube / polymer composite reinforced sheets:

[0156] The preparation process is the same as step (1) of Example 1, except that an equal mass of poly(fluoroethylene propylene) powder is used instead of PTFE for the exfoliation of the arrayed carbon nanotubes.

[0157] (2) Preparation of thermoplastic resin injection-molded foam:

[0158] The preparation process is the same as step (2) of Example 1, resulting in a thermoplastic resin injection-molded foam. The weight and drop height of the molded body were measured, and the production time and injection pressure were recorded. The results are shown in Table 1.

[0159] Comparative Example 1

[0160] Commercially available powdered carbon nanotubes (Shanghai Kajite Chemical Technology Co., Ltd., MWCNT-1) were mixed with epoxy resin (OlinEpoxy 121H) and then thermoset to obtain a composite sheet with the same dimensions as the arrayed carbon nanotube / polymer composite reinforced sheet used in Example 1.

[0161] The preparation process of the injection-molded foam is the same as step (2) in Example 1, resulting in a thermoplastic resin injection-molded foam. The weight and drop height of the molded body were measured, and the production time and injection pressure were recorded. The results are shown in Table 1.

[0162] Comparative Example 2

[0163] (1) Preparation of arrayed carbon nanotube / polymer composite reinforced sheets:

[0164] Carbon nanotube / polymer composite reinforced materials were prepared according to the method in Example 1. The exfoliated arrayed carbon nanotube-PTFE composite film was cross-stacked with 42 layers, and after hot pressing and composite polymer, a uniformly distributed arrayed carbon nanotube / polymer composite reinforced sheet with a thickness of 2.1 mm was obtained.

[0165] (2) Preparation of thermoplastic resin injection-molded foam:

[0166] The preparation process of the injection-molded foam is the same as step (2) of Example 1, but the thermoplastic resin injection-molded foam cannot be obtained after molding.

[0167] Comparative Example 3

[0168] The preparation process of the thermoplastic resin injection-molded foam is the same as step (2) in Example 1, except that no sheet material is placed inside the mold. The thermoplastic resin injection-molded foam is obtained. The weight and drop height of the molded body are measured, and the production time and injection pressure are recorded. The results are shown in Table 1.

[0169] Comparative Example 4

[0170] The preparation process of the thermoplastic resin injection-molded foam is the same as step (2) in Example 4, except that no sheet material is placed inside the mold. The thermoplastic resin injection-molded foam is obtained. The weight and drop height of the molded body are measured, and the production time and injection pressure are recorded. The results are shown in Table 1.

[0171] Comparative Example 5

[0172] The preparation process of the thermoplastic resin injection-molded foam is the same as step (2) in Example 5, except that no sheet material is placed inside the mold. The thermoplastic resin injection-molded foam is obtained. The weight and drop height of the molded body are measured, and the production time and injection pressure are recorded. The results are shown in Table 1.

[0173] Comparative Example 6

[0174] The preparation process of the thermoplastic resin injection-molded foam is the same as step (2) in Example 6, except that no sheet material is placed inside the mold. The thermoplastic resin injection-molded foam is obtained. The weight and drop height of the molded body are measured, and the production time and injection pressure are recorded. The results are shown in Table 1.

[0175] Comparative Example 7

[0176] Arrayed carbon nanotube / polymer composite reinforced sheets were prepared according to the method of Example 1. The preparation process of the thermoplastic resin injection-molded foam body was the same as step (2) of Example 1, except that 17 square sheets with a side length of 100 mm were hung in the mold at approximately equal intervals, with the two outermost sheets placed close to the inner wall of the mold to obtain the thermoplastic resin injection-molded foam body, wherein the content of the reinforcing sheet was 7.0% by weight. The weight and drop height of the molded body were measured, and the production time and injection pressure were recorded. The results are shown in Table 1.

[0177] Comparative Example 8

[0178] The preparation process of the thermoplastic resin injection-molded foam is the same as step (2) in Example 1, except that five square glass fiber composite sheets with a side length of 100 mm and a thickness of 1.7 mm, purchased from the market, are hung at approximately equal intervals inside the mold. The two outermost sheets are placed close to the inner wall of the mold to obtain the thermoplastic resin injection-molded foam. The weight and drop height of the molded body were measured, and the production time and injection pressure were recorded. The results are shown in Table 1.

[0179] Comparative Example 9

[0180] The preparation process of the thermoplastic resin injection-molded foam is the same as step (2) in Example 1, except that a square stainless steel sheet with a side length of 100 mm and a thickness of 2.5 mm, purchased from the market, is hung in the center of the mold to obtain the thermoplastic resin injection-molded foam. The weight and drop height of the molded body are measured, and the production time and injection pressure are recorded. The results are shown in Table 1.

[0181] Table 1

[0182]

[0183]

[0184] As can be seen from the results of the embodiments in Table 1, the thermoplastic resin injection-molded foam of the present invention has better physical properties and molding and processing performance than the prior art.

[0185] Compared with Comparative Example 3, Examples 1-3, Examples 4, Examples 5, and Examples 6, and Examples 6 respectively, show that, compared with injection-molded foamed bodies prepared by conventional processes, the thermoplastic resin injection-molded foamed bodies prepared by the present invention using arrayed carbon nanotube / polymer composite reinforcing sheets as reinforcing sheets can significantly increase drop height and effectively improve production efficiency, regardless of whether the base resin is a thermoplastic resin such as PP, PA, PLA, or PP polyolefin elastomer blend.

[0186] The foamed molded body prepared by the method in Comparative Example 1 could not significantly increase the drop height, and it would also significantly increase the weight and production efficiency.

[0187] As can be seen from Examples 8 and 9 and Comparative Example 7, the content of arrayed carbon nanotube / polymer composite reinforcing sheet has a significant impact on the final product. As the number of sheets in the molded body increases, the drop height increases and the production efficiency decreases. When the content of reinforcing sheet is too high, it is difficult to obtain a qualified injection-molded foamed body.

[0188] As can be seen from Examples 1-3 and Comparative Example 2, the thickness of the reinforcing sheet has a significant impact on the final product. As the thickness increases, the drop height increases and the production efficiency decreases. When the thickness is too large, it is difficult to obtain a qualified injection-molded foam body.

[0189] As can be seen from Comparative Examples 8-9, although using sheet reinforcement methods commonly used in the industry, such as glass fiber and metal, can also increase the drop height of the molded body to a level close to that of the embodiment, the weight of the product will be much greater than that of Comparative Example 3, and the production efficiency will also decrease significantly.

[0190] The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

[0191] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

Claims

1. An application of an arrayed carbon nanotube / polymer composite reinforced sheet in a polymer foaming process, wherein, The arrayed carbon nanotube / polymer composite reinforced sheet is used as a pre-formed sheet; the reinforced sheet includes an arrayed carbon nanotube film material and a polymer composite, wherein the arrayed carbon nanotube film material includes arrayed carbon nanotubes and a low surface energy polymer; the thickness of the reinforced sheet is 2μm to 2mm, preferably 20μm to 1mm.

2. The application according to claim 1, wherein, Based on the weight of the reinforcing sheet, the content of arrayed carbon nanotubes in the reinforcing sheet is 0.01 to 20% by weight, preferably 0.1 to 10% by weight.

3. The application according to claim 1, wherein, Based on the weight of the arrayed carbon nanotube film material, the content of arrayed carbon nanotubes in the arrayed carbon nanotube film material is 0.1-50% by weight, preferably 1-50% by weight; the content of low surface energy polymer is 50-99.9% by weight, preferably 50-99% by weight.

4. The application according to claim 1, wherein, The surface energy of the low surface energy polymer is less than 30 mN / m, preferably less than 25 mN / m.

5. The application according to claim 4, wherein, The low surface energy polymer is selected from at least one of fluorocarbon resins, silicone resins, and polyolefins; preferably, it is selected from at least one of polytetrafluoroethylene, polyvinylidene fluoride, polyvinyl fluoride, polychlorotrifluoroethylene, copolymers of ethylene and trifluoroethylene, copolymers of ethylene and tetrafluoroethylene, copolymers of ethylene and chlorotrifluoroethylene, perfluoroethylene propylene, polyfluoroacrylate, polysiloxane, polystyrene, polyethylene, and polypropylene.

6. The application according to claim 1, wherein, The low surface energy polymer is in the form of micro powder with a particle size of 0.01–30 μm, preferably 0.02–20 μm.

7. The application according to claim 1, wherein, The arrayed carbon nanotubes are horizontally arrayed carbon nanotubes; the arrayed carbon nanotubes are single-walled or multi-walled; the length of the arrayed carbon nanotubes ranges from 1 μm to 1 m.

8. The application according to claim 1, wherein, The arrayed carbon nanotube film material is a single-layer or multi-layer stacked arrayed carbon nanotube composite film, which is obtained by directly peeling the arrayed carbon nanotubes off the substrate using the low surface energy polymer.

9. The application according to claim 8, wherein, The number of layers in the multilayer stacked array of carbon nanotube composite film is 2 to 20; the stacking is preferably cross-stacking.

10. The application according to claim 1, wherein, The thickness of the arrayed carbon nanotube film material is 1 μm to 0.1 mm, preferably 10 μm to 0.05 mm.

11. The application according to claim 1, wherein, The preparation method of the arrayed carbon nanotube / polymer composite reinforced sheet includes the following steps: (1) The array of carbon nanotubes was prepared on a substrate by chemical vapor deposition. (2) The arrayed carbon nanotubes are peeled off from the substrate using a low surface energy polymer to obtain an arrayed carbon nanotube composite film. (3) The arrayed carbon nanotube film material is combined with the polymer to obtain the reinforced sheet; the arrayed carbon nanotube film material is a single-layer arrayed carbon nanotube composite film or a multi-layer stacked and hot-pressed arrayed carbon nanotube composite film.

12. The application according to claim 11, wherein, Step (1) includes: placing a substrate in a horizontal resistance furnace, introducing a carbon source and a carrier gas, wherein the carbon source reacts on the substrate to prepare the array of carbon nanotubes; Preferably, the carbon source is a mixture of C1-C in any proportion. 10 Alkanes, C2-C 10 Olefins and C2-C 10 One or more alkynes; the carrier gas is one or more of hydrogen, nitrogen and argon mixed in any proportion; the substrate is a silicon substrate, a silicon oxide substrate or a silicon / silicon oxide substrate; the reaction temperature is 800-1200℃ and the pressure is 0.1-1MPa.

13. The application according to claim 11, wherein, Step (2) includes: Low surface energy polymer powder is sprinkled onto the substrate on which the array of carbon nanotubes is prepared; The substrate containing the arrayed carbon nanotubes, which is sprinkled with the low surface energy polymer powder, is heated, and the arrayed carbon nanotubes and the low surface energy polymer are initially combined to obtain the arrayed carbon nanotube composite film. The arrayed carbon nanotube composite film is peeled off from the surface of the substrate.

14. The application according to claim 13, wherein, The heating is infrared heating. Preferably, the parameters for infrared heating include: the power of infrared heating is 200-2000W; and the duration of infrared heating is 0.5-10h.

15. The application according to claim 11, wherein, In step (3), the hot pressing conditions include: temperature of 50-500℃, preferably 140-450℃; pressure of 0.1-30MPa, preferably 0.5-20MPa; and heat preservation and pressurization time of 0.1-10h, preferably 0.2-5h.

16. The application according to claim 11, wherein, In step (3), the composite method includes the following steps: processing the film material and the polymer to obtain the reinforced sheet.

17. The application according to claim 16, wherein, The processing temperature is 40–500℃, preferably 50–350℃; the processing pressure is 0.05–20MPa, preferably 0.1–10MPa; and the processing time is 0.5 min–10 h, preferably 1 min–3 h.

18. The application according to claim 1, wherein, The polymer is one or more of polyethylene, polypropylene, polyvinyl chloride, polystyrene, nylon, polyester, acrylic, vinylon, styrene-butadiene rubber, butadiene rubber, isoprene rubber, and ethylene propylene rubber, mixed in any proportion.

19. The application according to claim 1, wherein, The polymer foaming process includes injection molding foaming process, compression molding foaming process, or foamed bead molding process.

20. The application according to claim 1, wherein, The arrayed carbon nanotube / polymer composite reinforced sheet is pre-set in the mold as a pre-set sheet; preferably, multiple pre-set sheets are provided; more preferably, at least two pre-set sheets are attached to the inner wall of the mold, and the remaining pre-set sheets are arbitrarily arranged inside the molded body.

21. A thermoplastic resin injection-molded foam, characterized in that, The molded body comprises injection-molded thermoplastic resin and a pre-set reinforcing sheet, wherein the pre-set reinforcing sheet is the arrayed carbon nanotube / polymer composite reinforcing sheet as described in any one of claims 1-18; the content of the pre-set reinforcing sheet in the molded body is 0.1-6.0% by weight, preferably 0.2-4.0% by weight.

22. The thermoplastic resin injection-molded foam according to claim 21, wherein, The preset reinforcing sheet is provided in multiple pieces; preferably, at least two reinforcing sheets are located on the outer surface of the molded body, and the remaining reinforcing sheets are arbitrarily disposed inside the molded body.

23. The thermoplastic resin injection-molded foam according to claim 1, wherein, The molded body is obtained by injection molding and foaming process of thermoplastic resin composition and pre-set reinforcing sheet; the thermoplastic resin composition includes thermoplastic resin and additives.

24. The thermoplastic resin injection-molded foam according to claim 23, wherein, The thermoplastic resin is selected from one or more of PP, PE, PS, PA, POE, PET, PBT, PLA, PBAT and thermoplastic elastomers; The additives are processing aids and / or functional additives; the processing aids are preferably at least one of antioxidants, antistatic agents, cell nucleating agents and lubricants; the functional additives are preferably at least one of flame retardants, conductive fillers, light stabilizers, anti-aging agents, antibacterial agents and color masterbatches.

25. A method for preparing a thermoplastic resin injection-molded foamed article according to any one of claims 21-24, comprising the following steps: (1) The arrayed carbon nanotube / polymer composite reinforced sheet is pre-set in the mold of the injection molding machine as a pre-set sheet; (2) The thermoplastic resin composition is melted and homogenized, and then mixed with a foaming agent to form a single-phase melt; the single-phase melt is injected into the mold in step (1) for injection foaming to obtain the thermoplastic resin injection foamed molded body.

26. The preparation method according to claim 25, wherein, The foaming agent is a chemical foaming agent or a physical foaming agent; The chemical foaming agent is preferably at least one of azodicarbonamide, p-toluenesulfonyl hydrazine, aminourea, tetrazolium, sodium bicarbonate, and sodium citrate. The physical foaming agent is preferably an organic physical foaming agent and / or an inorganic physical foaming agent; the organic physical foaming agent is preferably at least one of aliphatic hydrocarbon foaming agents, alicyclic hydrocarbon foaming agents, and halogenated hydrocarbon foaming agents, the aliphatic hydrocarbon foaming agent is preferably at least one of propane, butane, pentane, hexane, and heptane, the alicyclic hydrocarbon foaming agent is preferably cyclobutane and / or cyclohexane, the halogenated hydrocarbon foaming agent is preferably at least one of chlorofluoromethane, trifluoromethane, 1,2-difluoroethane, 1,2,2,2-tetrafluoroethane, methyl chloride, ethyl chloride, and dichloromethane; the inorganic physical foaming agent is preferably at least one of air, nitrogen, carbon dioxide, oxygen, and water.

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