A carbon nanotube film and a continuous preparation device system and method thereof

Abstract

The application provides a carbon nanotube film and a continuous preparation device system and method thereof, the continuous preparation device system comprises a first unwinding roller, a vacuum forming system, a pressing roller, a drying device and a first winding roller connected in sequence; a mortar spraying device is arranged above the vacuum forming system; the mortar spraying device is connected with a mortar distribution system, a defoaming device and a carbon nanotube dispersion liquid storage tank in sequence; the pressing roller is independently connected with a second unwinding roller and a second winding roller respectively; the vacuum forming system is used for suction filtration forming of the carbon nanotube dispersion liquid to form a porous substrate-carbon nanotube film; the pressing roller is used for lamination of the lamination of the substrate and the porous substrate-carbon nanotube film, and the carbon nanotube film is transferred from the porous substrate to the lamination substrate. The continuous preparation device system and method provided by the application realize continuous preparation of the carbon nanotube film which is coiled, self-supporting and excellent in performance.

Description

Technical Field

[0001] This invention belongs to the field of carbon nanotube membrane preparation technology, and particularly relates to a carbon nanotube membrane and its continuous preparation apparatus system and preparation method. Background Technology

[0002] Due to their excellent mechanical, electrical, and thermal properties, carbon nanotubes have been the subject of in-depth research in recent years by scientists, universities, and industry professionals in fields such as materials reinforcement, electronic devices, smart sensing, and energy conversion. However, because carbon nanotubes are nanomaterials, processing them into macroscopic forms has greater practical application value, such as carbon nanotube films. Carbon nanotube film materials offer significant advantages in areas such as electrical conductivity, electric heating, lightning protection, electromagnetic shielding, and composite material reinforcement.

[0003] Currently, carbon nanotube, graphene, or other carbon nanomaterial films have been prepared using CVD deposition, coating, and filtration methods. While CVD deposition can produce high-performance films, its complex equipment and high cost limit large-scale production and fail to meet market demand. Coating / casting methods are simple and can be used on a large scale, but the resulting films have a relatively porous structure, low strength, and are difficult to separate from the substrate when the thickness is small. Filtration is simple to operate, but requires frequent replacement of filter materials and has limitations in product size.

[0004] CN102877367A discloses a carbon nanotube / short fiber composite carbon nanopaper and its continuous preparation method. The method involves dispersing carbon nanotubes in a solvent to form a dispersion, then mixing and dispersing short fibers to form a slurry. An initial film is prepared by vacuum-assisted casting, followed by subsequent processing to remove the polymer and obtain the target product. While this method continuously prepares the composite film, it does not consider the uniformity of slurry distribution in the filter membrane or the issue of film detachment from the substrate. Furthermore, the addition of short fibers reduces the electrical and thermal properties of the membrane material. CN102561109A and CN104098084A both disclose a method for preparing carbon nanotube paper through dispersion filtration. Although this provides a simple and rapid method for preparing carbon nanotube paper, it still results in a sheet structure.

[0005] Although papermaking and filtration processes are similar in their preparation methods and can achieve the industrial production of membrane / paper materials, traditional papermaking processes use forming wires of around 40-120 mesh, making it difficult for nanomaterials to adhere to their surface and ultimately form a membrane structure. If even finer forming wires are used, for example, with pore sizes below 1 μm, continuous use in large quantities can lead to nanomaterials clogging the pores, resulting in membrane uniformity and reduced efficiency. This necessitates frequent downtime for maintenance and screen replacement, making it unsuitable for large-scale, low-cost production.

[0006] CN102173406A discloses a method for preparing carbon nanotube or graphene ultrathin films. This method involves filtration of a carbon nanotube or graphene dispersion to form a film, at least separating the surface layer of the film from the filter membrane. However, the separation process involves immersing the filter membrane carrying the film in a membrane-taking solution, causing the surface layer to automatically detach from the filter membrane. The membrane-taking solution contains one of the following: acid, alkali, or salt. This could affect the quality of the film, and the method for preparing the film in rolls is not mentioned. CN103015256A discloses a carbon nanofiber paper and its preparation method. The method involves dispersing carbon nanofibers after back-grafting hydroxyl and carboxyl functional groups onto their surface, adding a flocculant to the dispersion, and finally filtering and drying. While the flocculation process ensures the retention of carbon nanofibers during filtration to some extent and reduces the pore size requirements of the filter screen, the flocculant and surface modification of the carbon nanofibers significantly reduce the material's electrical conductivity, thermal conductivity, and shielding properties.

[0007] Therefore, it is of great significance to provide a continuous, large-scale high-performance carbon nanotube thin film material and its preparation method. Summary of the Invention

[0008] The purpose of this invention is to provide a carbon nanotube membrane and its continuous preparation device system and preparation method. The continuous preparation device system and preparation method solve the problems of carbon nanotube retention without introducing new impurities and the difficulty of separating the carbon nanotube membrane from the porous substrate, and realize the continuous preparation of rolled, self-supporting carbon nanotube membranes with controllable membrane thickness and quality.

[0009] To achieve this objective, the present invention adopts the following technical solution:

[0010] In a first aspect, the present invention provides a continuous preparation apparatus system for carbon nanotube films, the continuous preparation apparatus system comprising a first unwinding roller, a vacuum forming system, a pressing roller, a drying device, and a first winding roller connected in sequence;

[0011] A spraying device is installed above the vacuum forming system;

[0012] The spraying device is connected in sequence to the slurry distribution system, the defoaming device, and the carbon nanotube dispersion storage tank.

[0013] The pressing rollers are independently connected to the second unwinding roller and the second winding roller, respectively;

[0014] The vacuum forming system is used for the filtration and forming of carbon nanotube dispersions to form porous substrate-carbon nanotube membranes.

[0015] The pressing roller is used to bond the substrate and the porous substrate-carbon nanotube membrane, and to transfer the carbon nanotube membrane from the porous substrate to the bonding substrate.

[0016] The continuous preparation apparatus system provided by this invention, through a first unwinding roller, a vacuum forming system, a pressing roller, a drying device, and a first winding roller connected in sequence, and in conjunction with a spraying device, a slurry distribution system, and a degassing device arranged above the vacuum forming system, can form carbon nanotubes to form a porous substrate-carbon nanotube membrane. Then, the pressing roller is used to bond the bonding substrate and the porous substrate-carbon nanotube membrane, and the carbon nanotube membrane is transferred from the porous substrate to the bonding substrate. This allows for the continuous production of carbon nanotube membranes, solving the problems of carbon nanotube retention and difficulty in separating the carbon nanotube membrane from the porous substrate without introducing new impurities. The continuous preparation apparatus system realizes the continuous preparation of rolled, self-supporting carbon nanotube membranes with controllable membrane thickness and quality.

[0017] It is worth noting that the degassing device makes the overlap between carbon nanotubes denser; the pressing roller separates the carbon nanotube film from the porous substrate and transfers it to the bonding substrate with less centrifugal force, facilitating subsequent separation of the carbon nanotube film. This invention, by introducing the degassing device and pressing roller, makes the carbon nanotube film stronger and provides superior electrical conductivity, thermal conductivity, and electromagnetic shielding performance.

[0018] As a preferred embodiment of the present invention, the first unwinding roller is used to wind a porous substrate.

[0019] Preferably, the second unwinding roller is used to wind the bonding substrate.

[0020] Preferably, the first take-up roller is used to take up the carbon nanotube membrane.

[0021] Preferably, the second take-up roller is used to take up the porous substrate.

[0022] As a preferred embodiment of the present invention, the vacuum forming system includes at least 3 vacuum pumping modules, preferably at least 5 vacuum pumping modules.

[0023] In this invention, the vacuum forming system is provided with a forming mesh.

[0024] It is worth noting that the vacuum forming system of this invention adopts a modular design, with at least three vacuum modules, the purpose of which is to control different vacuum levels. The first vacuum module is used to moderate the dehydration rate of the carbon nanotube dispersion and reduce the instability of the slurry on the filter membrane surface; the second vacuum module continues to remove excess water; and the third vacuum module is used to improve the density of the film through a high vacuum.

[0025] Preferably, the slurry distribution system includes a homogenizing device and a rectifying device connected in sequence.

[0026] The carbon nanotube slurry of this invention is homogenized and rectified to ensure uniform distribution during the transverse forming process, thereby ensuring the consistency of the thickness of the resulting carbon nanotube film.

[0027] Preferably, a dispersion device is provided between the carbon nanotube storage tank and the degassing device;

[0028] Preferably, the pressing roller is made of stainless steel and / or rubber.

[0029] As a preferred embodiment of the present invention, a top mesh forming device is provided above the vacuum forming system.

[0030] Preferably, the top mesh forming device is disposed between the spraying device and the pressing roller.

[0031] It is worth noting that the carbon nanotube membrane formed by vacuum forming system is further dehydrated and formed using a top mesh forming device. Due to dehydration on both sides, the surface difference of the carbon nanotube membrane is reduced, thus improving the uniformity of the carbon nanotube membrane.

[0032] Preferably, a spraying device is provided above the vacuum forming system.

[0033] It is worth noting that the present invention sprays alcohol solvents onto carbon nanotube membranes formed by vacuum forming system filtration, utilizing the rapid evaporation of low-boiling-point solvents to accelerate the removal of moisture from the carbon nanotube membrane and the subsequent drying speed of the membrane; or sprays organic / inorganic materials to improve the strength of the carbon nanotube membrane and the interfacial bonding force with other materials.

[0034] Preferably, the spraying device is disposed between the spraying device and the pressing roller.

[0035] Preferably, a third take-up roller is provided after the drying device, the third take-up roller being used to take up the bonding substrate.

[0036] Secondly, the present invention provides a method for preparing carbon nanotube membranes, wherein the preparation method is performed continuously using the continuous preparation apparatus system described in the first aspect, and the preparation method includes the following steps:

[0037] (1) The porous substrate is conveyed to the vacuum forming system via the first unwinding roller. Then, the carbon nanotube dispersion is degassed by the degassing device, homogenized and rectified by the slurry distribution system, and then the carbon nanotube slurry is coated onto the porous substrate by the spraying device. After that, it is filtered and formed by the vacuum forming system to form a porous substrate-carbon nanotube membrane.

[0038] (2) The bonding substrate is conveyed to the pressing roller via the second unwinding roller, and then bonded with the porous substrate-carbon nanotube membrane described in step (1) using the pressing roller, and the carbon nanotube membrane is transferred from the porous substrate to the bonding substrate to form a carbon nanotube membrane-bonding substrate.

[0039] (3) The carbon nanotube film-adhesive substrate described in step (2) is dried by a drying device and then the carbon nanotube film is wound up by a first winding roller.

[0040] The carbon nanotube membrane of this invention can also be composited with other materials during the roller-to-roll transfer process using a pressing roller, thereby achieving wet composite and improving the bonding strength between composite materials.

[0041] The carbon nanotube membrane obtained by this invention can be a self-supporting structure, or it can be combined with other materials before drying to form a composite structure, thereby improving the bonding force when combined with other materials. At the same time, it is not excluded that it can be combined with other materials after drying.

[0042] The present invention does not specifically limit the drying temperature in step (3), and those skilled in the art can select it according to the actual situation.

[0043] The preparation method provided by this invention solves the problems of carbon nanotube retention and carbon nanotube detachment from the substrate without introducing new impurities in the prior art, and enables the industrial-scale, stable and continuous production of carbon nanotube membranes.

[0044] As a preferred technical solution of the present invention, the porous substrate in step (1) includes any one or a combination of at least two of the following: cellulose derivative membranes, polytetrafluoroethylene membranes, polyvinylidene fluoride membranes, PP membranes, glass fiber membranes, nylon membranes, polyethersulfone membranes, polyamide membranes, polyimide membranes, polyester membranes, polyolefin membranes, or glass fiber filter membranes. Typical but non-limiting examples of such combinations include: a combination of polytetrafluoroethylene membrane and polyvinylidene fluoride membrane, a combination of PP membrane and glass fiber membrane, or a combination of nylon membrane and polyethersulfone membrane, etc.

[0045] The porous substrate in step (1) of the present invention comprises a hydrophobic or hydrophilic polymer synthesized by weaving or meshing, including an organic membrane or an inorganic membrane, or an inorganic membrane loaded on an organic membrane, or an organic membrane loaded on an inorganic membrane.

[0046] Preferably, the pore size of the porous substrate in step (1) is 0.05-100μm, for example, it can be 0.1μm, 0.5μm, 1μm, 3μm, 5μm, 10μm, 15μm, 20μm, 25μm, 30μm, 35μm, 40μm, 50μm, 60μm, 70μm, 80μm or 90μm, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable. Preferably, it is 0.1-60μm, more preferably 0.2-30μm, and even more preferably 0.5-10μm.

[0047] Preferably, the carbon nanotubes in step (1) include single-walled carbon nanotubes and / or multi-walled carbon nanotubes.

[0048] In this invention, other carbon-based materials or fiber materials may be added to the carbon nanotube dispersion in step (1). The carbon-based materials include carbon fibers, graphene, graphene oxide, inorganic fibers (such as glass fibers and aramid fibers) or organic fibers (PI fibers and PP fibers).

[0049] Preferably, the median length of the carbon nanotubes in step (1) is 0.1 μm-10 mm, for example, it can be 0.5 μm, 1 μm, 5 μm, 10 μm, 20 μm, 50 μm, 70 μm, 100 μm, 150 μm, 200 μm, 300 μm, 400 μm, 500 μm, 700 μm, 900 μm, 1 mm, 1.5 mm, 2 mm, 3 mm, 4 mm, 5 mm, 7 mm or 9 mm, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable. Preferably, it is 1 μm-2 mm, and more preferably, it is 10 μm-500 μm.

[0050] Preferably, the coating method in step (1) includes any one of casting, spraying, or scraping.

[0051] Preferably, the carbon nanotube dispersion in step (1) further includes dispersion by a dispersion device before entering the degassing device.

[0052] Preferably, the dispersion method includes any one or a combination of at least two of mechanical stirring, ultrasonication, homogenization, sand milling, or emulsification.

[0053] In this invention, the dispersant used for dispersion includes ionic surfactants and / or nonionic surfactants. The dispersant includes any one or a combination of at least two of sodium dodecyl sulfonate, sodium dodecylbenzene sulfonate, polyvinylpyrrolidone, sodium carboxymethyl cellulose, or Triton. Typical but non-limiting examples of such combinations include combinations of sodium dodecyl sulfonate and sodium dodecylbenzene sulfonate, combinations of polyvinylpyrrolidone and sodium carboxymethyl cellulose, or combinations of sodium carboxymethyl cellulose and Triton, etc.

[0054] This invention does not specify the specific materials or amount of dispersant used, as long as the carbon nanotubes are uniformly dispersed to form a carbon nanotube dispersion. Those skilled in the art can choose to add the dispersant according to the actual situation.

[0055] As a preferred technical solution of the present invention, the vacuum forming system in step (1) includes a first vacuum module, a second vacuum module and a third vacuum module connected in sequence.

[0056] Preferably, the first vacuum module is equipped with a water baffle.

[0057] Preferably, the height of the water baffle is ≥2cm, for example, it can be 2.2cm, 2.5cm, 2.7cm, 3cm or 3.5cm, etc., but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0058] The present invention provides a baffle plate at the contact point between the carbon nanotube slurry and the forming mesh to prevent the carbon nanotube dispersion from overflowing due to a high liquid level.

[0059] Preferably, the vacuum degree of the first vacuum module is -0.06 to -0.04 MPa, for example, it can be -0.06 MPa, -0.055 MPa, -0.05 MPa or -0.045 MPa, etc., but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0060] Preferably, the vacuum degree of the second vacuum module is -0.08 to -0.06 MPa, for example, it can be -0.075 MPa, -0.07 MPa, -0.065 MPa or -0.06 MPa, but it is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0061] The present invention controls the vacuum degree of the second vacuum module within the range of -0.08 to -0.06 MPa to continue removing moisture.

[0062] Preferably, the vacuum degree of the third vacuum module is -0.1 to -0.08 MPa, for example, it can be -0.095 MPa, -0.09 MPa, -0.085 MPa, or -0.08 MPa, but it is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0063] This invention controls the vacuum level of the third vacuum module within the range of -0.1 to -0.08 MPa, thereby improving the wet strength of the carbon nanotube film and also increasing the density of the film.

[0064] After being formed by the vacuum forming system, the dryness of the carbon nanotube film is 5-70%, for example, it can be 7%, 9%, 10%, 12%, 15%, 17%, 20%, 22%, 25%, 27%, 30%, 32%, 35%, 37%, 40%, 45%, 50%, 60% or 65%, etc., but is not limited to the listed values. Other unlisted values ​​within the range are also applicable. Preferably, it is 10-50%, more preferably 10-30%.

[0065] As a preferred technical solution of the present invention, after the filtration and molding in step (1), the method further includes: using a top mesh molding device for dehydration molding.

[0066] Preferably, after the filtration and molding process described in step (1), the process further includes spraying using a spraying device.

[0067] Preferably, the spraying material includes any one or a combination of at least two of alcohol solvents, organic materials, or inorganic materials.

[0068] Preferably, the alcohol solvent includes low-boiling-point alcohol solvents.

[0069] As a preferred technical solution of the present invention, the bonding substrate in step (2) includes a continuous substrate or a porous substrate.

[0070] In this invention, an adhesive can also be coated on the bonding substrate to facilitate better transfer of the carbon nanotube membrane from the porous substrate to the bonding substrate.

[0071] Preferably, the continuous substrate comprises any one or a combination of at least two of PET, PP, PI, or release film.

[0072] Preferably, in step (2), the bonding substrate is conveyed to the pressing roller via the second unwinding roller to form a bonding substrate-carbon nanotube membrane-porous substrate structure.

[0073] Preferably, the bonding pressure in step (2) is 0.01-50 MPa, for example, it can be 0.05 MPa, 0.1 MPa, 0.5 MPa, 1 MPa, 2 MPa, 5 MPa, 7 MPa, 10 MPa, 15 MPa, 20 MPa, 25 MPa, 30 MPa, 35 MPa, 40 MPa, 45 MPa or 47 MPa, etc., but is not limited to the listed values. Other unlisted values ​​within the range are also applicable. Preferably, it is 0.1-30 MPa, more preferably 1-20 MPa.

[0074] Preferably, the contact angle in step (2) is 10°-80°, for example, it can be 15°, 20°, 25°, 30°, 35°, 40°, 45°, 50°, 55°, 60°, 65°, 70° or 75°, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable. Preferably, it is 20°-70°, and more preferably, it is 30°-50°.

[0075] This invention controls the pressure and angle range of the pressing roller during bonding, enabling the carbon nanotube membrane to transfer from a porous substrate to a bonding substrate with low centrifugal force, and the porous substrate to separate automatically, thus solving the problem of the difficulty in detaching the carbon nanotube membrane formed by vacuum filtration from the porous substrate.

[0076] Preferably, step (2) further includes: winding the separated porous substrate by a second take-up roller after bonding.

[0077] Preferably, after drying in step (3), the process further includes: winding the separated bonding substrate by a third take-up roller.

[0078] Thirdly, the present invention provides a carbon nanotube membrane, which is prepared by the preparation method described in the second aspect.

[0079] Preferably, the thickness of the carbon nanotube film is 0.05-500 μm, for example, it can be 0.1 μm, 0.5 μm, 1 μm, 3 μm, 5 μm, 10 μm, 20 μm, 30 μm, 40 μm, 50 μm, 70 μm, 90 μm, 100 μm, 120 μm, 150 μm, 170 μm, 200 μm, 250 μm, 300 μm, 350 μm, 400 μm or 450 μm, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable. Preferably, it is 3-200 μm, more preferably 5-50 μm, and even more preferably 10-30 μm.

[0080] Preferably, the areal density of the carbon nanotube membrane is 0.05-300 g / m³. 2 For example, it could be 0.1g / m 2 0.5g / m 2 1g / m 2 2g / m 2 4g / m 2 5g / m 2 7g / m 2 10g / m 2 15g / m 2 20g / m 2 25g / m 2 30g / m 2 50g / m 2 70g / m2 90g / m 2 100g / m 2 120g / m 2 150g / m 2 170g / m 2 190g / m 2 200g / m 2 220g / m 2 250g / m 2 270g / m 2 Or 290g / m 2 The values ​​may include, but are not limited to, the listed values; other unlisted values ​​within the range are also applicable, with 1.5-120 g / m³ being preferred. 2 More preferably 6-30g / m 2 Further preferred is 6-18 g / m 2 .

[0081] The numerical range described in this invention includes not only the point values ​​listed above, but also any point values ​​within the numerical ranges not listed above. Due to space limitations and for the sake of brevity, this invention will not exhaustively list all the specific point values ​​included in the range.

[0082] Compared with the prior art, the present invention has the following beneficial effects:

[0083] (1) The continuous preparation device system provided by the present invention, through the first unwinding roller, vacuum forming system, pressing roller, drying device and first winding roller connected in sequence, and in conjunction with the spraying device, slurry distribution system and degassing device set above the vacuum forming system, can form carbon nanotubes to form a porous substrate-carbon nanotube membrane. Then, the pressing roller is used to bond the bonding substrate and the porous substrate-carbon nanotube membrane, and the carbon nanotube membrane is transferred from the porous substrate to the bonding substrate, so that carbon nanotube membrane can be continuously produced.

[0084] (2) The continuous preparation device system and preparation method provided by the present invention solve the problems of carbon nanotube retention and carbon nanotube membrane separation from porous substrate without introducing new impurities, and realize the continuous preparation of rolled, self-supporting carbon nanotube membranes with controllable membrane thickness and quality.

[0085] (3) The carbon nanotube film prepared by the present invention has controllable thickness and areal density, and has excellent electrical conductivity, thermal conductivity and electromagnetic shielding properties. Attached Figure Description

[0086] Figure 1 This is a schematic diagram of the continuous preparation apparatus system for carbon nanotube films provided in Example 1;

[0087] Figure 2This is a schematic diagram of the continuous preparation apparatus system for carbon nanotube films provided in Example 2;

[0088] Figure 3 This is a schematic diagram of the continuous preparation apparatus system for carbon nanotube films provided in Example 3;

[0089] Among them, 1-first unwinding roller, 2-vacuum forming system, 3-pressing roller, 4-drying device, 5-first winding roller, 6-dispersing device, 7-defoaming device, 8-slurry storage device, 9-slurry distribution system, 10-slurry spraying device, 11-second unwinding roller, 12-second winding roller, 13-third winding roller, 14-top mesh forming device, 15-spraying device, 16-porous substrate, 17-bonding substrate, 18-carbon nanotube membrane. Detailed Implementation

[0090] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0091] Example 1

[0092] This embodiment provides a continuous preparation device system for carbon nanotube films, the schematic diagram of which is shown below. Figure 1 As shown; the continuous preparation device system includes a first unwinding roller 1, a vacuum forming system 2, a pressing roller 3, a drying device 4, and a first winding roller 5 connected in sequence;

[0093] The vacuum forming system 2 includes a first vacuum module, a second vacuum module, and a third vacuum module connected in sequence.

[0094] A spraying device 10 is provided above the vacuum forming system 2; the spraying device 10 is connected in sequence to the slurry distribution system 9, the slurry storage device 8, the degassing device 7, the dispersion device 6, and the carbon nanotube dispersion storage tank; the slurry distribution system 9 includes a homogenizing device and a rectifying device connected in sequence.

[0095] The pressing roller 3 is independently connected to the second unwinding roller 11 and the second winding roller 12; the pressing roller 3 is made of stainless steel and rubber.

[0096] The first unwinding roller 1 is used to wind the porous substrate 16;

[0097] The vacuum forming system 2 is used for the filtration and forming of carbon nanotube dispersion to form a porous substrate-carbon nanotube membrane.

[0098] The second unwinding roller 11 is used to wind the bonding substrate 17;

[0099] The pressing roller 3 is used to bond the substrate 17 and the porous substrate-carbon nanotube membrane, and to transfer the carbon nanotube membrane 18 from the porous substrate 16 to the bonding substrate 17.

[0100] The first take-up roller 5 is used to take up the carbon nanotube membrane 18;

[0101] The second take-up roller 12 is used to take up the porous substrate 16;

[0102] A third take-up roller 13 is provided after the drying device 4, and the third take-up roller 13 is used to take up the bonding substrate 17.

[0103] Example 2

[0104] This embodiment provides a continuous preparation device system for carbon nanotube films, the schematic diagram of which is shown below. Figure 2 As shown; based on the continuous preparation device system provided in Example 1, it further includes: a top mesh forming device 14 is provided above the vacuum forming system 2; the top mesh forming device 14 is located between the spraying device 10 and the pressing roller 3.

[0105] Example 3

[0106] This embodiment provides a continuous preparation device system for carbon nanotube films, the schematic diagram of which is shown below. Figure 3 As shown; based on the continuous preparation device system provided in Example 1, it further includes: a spraying device 15 is provided above the vacuum forming system 2; the spraying device 15 is located between the spraying device 10 and the pressing roller 3.

[0107] Example 4

[0108] This embodiment provides a continuous preparation device system for carbon nanotube films. Except that the vacuum forming system 2 only includes the first vacuum pumping module, all other conditions are the same as in Embodiment 1.

[0109] Example 5

[0110] This embodiment provides a continuous preparation device system for carbon nanotube films. Except that the vacuum forming system 2 only includes a first vacuum module and a second vacuum module connected in sequence, all other conditions are the same as in Embodiment 1.

[0111] Comparative Example 1

[0112] This comparative example provides a continuous preparation apparatus system for carbon nanotube films. Except for the absence of the degassing device 7, all other conditions are the same as in Example 1.

[0113] Comparative Example 2

[0114] This comparative example provides a continuous preparation apparatus system for carbon nanotube films. Except for the absence of the second unwinding roller 11, the bonding substrate 17, and the pressing roller 3, all other conditions are the same as in Example 1.

[0115] Comparative Example 3

[0116] This comparative example provides a continuous preparation apparatus system for carbon nanotube films. Except for the absence of the slurry application system 9 and the slurry spraying device 10, all other conditions are the same as in Example 1.

[0117] Application Example 1

[0118] This application example provides a method for preparing carbon nanotube films. The preparation method uses the continuous preparation apparatus system provided in Example 1 for continuous preparation, and the preparation method includes the following steps:

[0119] (1) A porous substrate 16 with a pore size of 1 μm is conveyed to a vacuum forming system 2 via a first unwinding roller 1. Then, a single-walled carbon nanotube with a median length of 100 μm is ultrasonically dispersed by a dispersion device 6, degassed by a degassing device 7, homogenized and rectified by a slurry distribution system 9, and then the carbon nanotube slurry is uniformly sprayed onto the porous substrate 16 by a spraying device 10. After that, it is filtered and formed by the vacuum forming system 2 to form a porous substrate-carbon nanotube membrane.

[0120] The porous substrate 16 is a polytetrafluoroethylene membrane;

[0121] The dispersant used in the ultrasonic dispersion is SDS;

[0122] The vacuum forming system 2 includes a first vacuum module, a second vacuum module, and a third vacuum module connected in sequence.

[0123] The first vacuum module is equipped with a baffle plate with a height of ≥2cm; the vacuum degree of the first vacuum module is -0.06MPa; the vacuum degree of the second vacuum module is 0.08MPa; and the vacuum degree of the third vacuum module is -0.09MPa.

[0124] (2) The bonding substrate 17 is conveyed to the pressing roller 3 via the second unwinding roller 11 to form a bonding substrate-carbon nanotube film-porous substrate structure. Then, the pressing roller 3 is used to bond the carbon nanotube film 18 from the porous substrate 16 to the bonding substrate 17 to form a carbon nanotube film-bonded substrate. At the same time, the separated porous substrate 16 is wound up via the second winding roller 12.

[0125] The bonding substrate 17 is a PP film;

[0126] The bonding pressure is 40 MPa and the angle is 40°;

[0127] (3) The carbon nanotube film-adhesive substrate described in step (2) is dried by the drying device 4, the separated adhesive substrate 17 is wound up by the third winding roller 13, and the carbon nanotube film is wound up by the first winding roller 5.

[0128] Application Example 2

[0129] This application example provides a method for preparing carbon nanotube films. The preparation method uses the continuous preparation apparatus system provided in Example 1 for continuous preparation, and the preparation method includes the following steps:

[0130] (1) A porous substrate 16 with a pore size of 20 μm is conveyed to a vacuum forming system 2 via a first unwinding roller 1. Then, a single-walled carbon nanotube with a median length of 600 μm is ultrasonically dispersed by a dispersion device 6, degassed by a degassing device 7, homogenized and rectified by a slurry distribution system 9, and then the carbon nanotube slurry is uniformly sprayed onto the porous substrate 16 by a spraying device 10. After that, it is filtered and formed by the vacuum forming system 2 to form a porous substrate-carbon nanotube membrane.

[0131] The porous substrate 16 is a polyethersulfone membrane;

[0132] The dispersant used in the ultrasonic dispersion is PVP;

[0133] The vacuum forming system 2 includes a first vacuum module, a second vacuum module, and a third vacuum module connected in sequence.

[0134] The first vacuum module is equipped with a baffle plate with a height of ≥2cm; the vacuum degree of the first vacuum module is -0.04MPa; the vacuum degree of the second vacuum module is -0.06MPa; and the vacuum degree of the third vacuum module is -0.08MPa.

[0135] (2) The bonding substrate 17 is conveyed to the pressing roller 3 via the second unwinding roller 11 to form a bonding substrate-carbon nanotube film-porous substrate structure. Then, the pressing roller 3 is used to bond the carbon nanotube film 18 from the porous substrate 16 to the bonding substrate 17 to form a carbon nanotube film-bonded substrate. At the same time, the separated porous substrate 16 is wound up via the second winding roller 12.

[0136] The bonding substrate 17 is a PVDF porous membrane;

[0137] The bonding pressure is 20 MPa and the angle is 70°;

[0138] (3) The carbon nanotube film-adhesive substrate described in step (2) is dried by the drying device 4, the separated adhesive substrate 17 is wound up by the third winding roller 13, and the carbon nanotube film is wound up by the first winding roller 5.

[0139] Application Example 3

[0140] This application example provides a method for preparing carbon nanotube films. The preparation method uses the continuous preparation apparatus system provided in Example 1 for continuous preparation, and the preparation method includes the following steps:

[0141] (1) A porous substrate 16 with a pore size of 0.5 μm is conveyed to a vacuum forming system 2 via a first unwinding roller 1. Then, a multi-walled carbon nanotube with a median length of 10 μm is ultrasonically dispersed by a dispersion device 6, degassed by a degassing device 7, homogenized and rectified by a slurry distribution system 9, and then the carbon nanotube slurry is uniformly sprayed onto the porous substrate 16 by a spraying device 10. After that, it is filtered and formed by the vacuum forming system 2 to form a porous substrate-carbon nanotube membrane.

[0142] The porous substrate 16 is a PP membrane;

[0143] The dispersant used in the ultrasonic dispersion is PVP;

[0144] The vacuum forming system 2 includes a first vacuum module, a second vacuum module, and a third vacuum module connected in sequence.

[0145] The first vacuum module is equipped with a baffle plate with a height of ≥2cm; the first vacuum module is equipped with 5 wipers connected in series; the vacuum degree of the first vacuum module is -0.05MPa; the vacuum degree of the second vacuum module is -0.07MPa; the vacuum degree of the third vacuum module is -0.1MPa.

[0146] (2) The bonding substrate 17 is conveyed to the pressing roller 3 via the second unwinding roller 11 to form a bonding substrate-carbon nanotube film-porous substrate structure. Then, the pressing roller 3 is used to bond the carbon nanotube film 18 from the porous substrate 16 to the bonding substrate 17 to form a carbon nanotube film-bonded substrate. At the same time, the separated porous substrate 16 is wound up via the second winding roller 12.

[0147] The bonding substrate 17 is a nylon film;

[0148] The bonding pressure is 1 MPa and the angle is 20°;

[0149] (3) The carbon nanotube film-adhesive substrate described in step (2) is dried by the drying device 4, the separated adhesive substrate 17 is wound up by the third winding roller 13, and the carbon nanotube film is wound up by the first winding roller 5.

[0150] Application Example 4

[0151] This application example provides a method for preparing a carbon nanotube membrane. Except that the preparation method uses the continuous preparation device system provided in Example 2 for continuous preparation, and in step (1) the membrane is first filtered and shaped by the vacuum forming system 2, and then dehydrated and shaped by the top mesh forming device 14 to dehydrate both sides of the carbon nanotube membrane, all other conditions are the same as in Application Example 1.

[0152] Application Example 5

[0153] This application example provides a method for preparing a carbon nanotube membrane. Except that the preparation method uses the continuous preparation device system provided in Example 3 for continuous preparation, and in step (1) after being filtered and formed by vacuum forming system 2, ethanol is sprayed by spraying device 15 to accelerate the removal of water from the carbon nanotube membrane and the drying speed of the membrane in the later stage, all other conditions are the same as in Application Example 1.

[0154] Application Example 6

[0155] This application example provides a method for preparing carbon nanotube films. Except that the preparation method uses the continuous preparation apparatus system provided in Example 4 for continuous preparation, all other conditions are the same as in Application Example 1.

[0156] Application Example 7

[0157] This application example provides a method for preparing carbon nanotube films. Except that the preparation method uses the continuous preparation apparatus system provided in Example 5 for continuous preparation, all other conditions are the same as in Application Example 1.

[0158] Application Example 8

[0159] This application example provides a method for preparing a carbon nanotube membrane. Except for the vacuum degree of the first vacuum module in step (1) being -0.07 MPa, all other conditions are the same as in application example 1.

[0160] Application Example 9

[0161] This application example provides a method for preparing a carbon nanotube membrane. Except for the vacuum degree of the third vacuum module in step (1) being -0.07 MPa, all other conditions are the same as in application example 1.

[0162] Application Example 10

[0163] This application example provides a method for preparing a carbon nanotube membrane. Except for the bonding pressure of 0.002 MPa in step (2), all other conditions are the same as in application example 1.

[0164] Application Example 11

[0165] This application example provides a method for preparing a carbon nanotube membrane. Except for the bonding pressure of 60 MPa in step (2), all other conditions are the same as in application example 1.

[0166] Application Example 12

[0167] This application example provides a method for preparing a carbon nanotube membrane. Except for the bonding angle of 5° in step (2), all other conditions are the same as in application example 1.

[0168] Application Example 13

[0169] This application example provides a method for preparing a carbon nanotube membrane. Except for the bonding angle of 85° described in step (2), all other conditions are the same as in application example 1.

[0170] Comparative Application Example 1

[0171] This comparative application example provides a method for preparing a carbon nanotube membrane. Except that the preparation method uses the continuous preparation apparatus system provided in Comparative Example 1 for continuous preparation, all other conditions are the same as in Application Example 1.

[0172] Comparative Application Example 2

[0173] This comparative application example provides a method for preparing a carbon nanotube membrane. Except that the preparation method uses the continuous preparation apparatus system provided in Comparative Example 2 for continuous preparation, all other conditions are the same as in Application Example 2.

[0174] Comparative Application Example 3

[0175] This comparative application example provides a method for preparing a carbon nanotube membrane. Except that the preparation method uses the continuous preparation apparatus system provided in Comparative Example 3 for continuous preparation, all other conditions are the same as in Application Example 1.

[0176] The carbon nanotube films prepared in the above application examples and comparative application examples were tested for thickness, areal density, dryness, thermal conductivity (laser thermal conductivity method) and electromagnetic shielding performance (waveguide method). The test results are shown in Table 1.

[0177] Table 1

[0178]

[0179]

[0180] As shown in Table 1:

[0181] (1) The present invention uses a continuous preparation device system to continuously prepare carbon nanotube films with a thickness of 0.05-500 μm and an areal density of 0.05-300 g / m³. 2It also has excellent electrical conductivity, thermal conductivity and electromagnetic shielding properties;

[0182] (2) By comparing the comprehensive application example 2 and the comparative application example 1, it can be seen that when the degassing device is not introduced, the air bubbles in the carbon nanotube slurry cannot be removed, resulting in looser overlap between carbon nanotubes, which leads to a decrease in the conductivity and electromagnetic shielding effectiveness of the carbon nanotube film.

[0183] (3) Comparing the comprehensive application example 2 and the comparative application example 2, it can be seen that when no bonding substrate is introduced to the surface of the carbon nanotube film, and when the thickness of the carbon nanotube film is small, it is difficult for the carbon nanotube film to separate from the porous substrate, and the continuous preparation of the carbon nanotube film cannot be achieved.

[0184] The applicant declares that the detailed structural features of the present invention are illustrated through the above embodiments, but the present invention is not limited to the above detailed structural features, that is, it does not mean that the present invention must rely on the above detailed structural features to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent substitutions for the components selected in the present invention, additions of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

[0185] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0186] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

[0187] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. A continuous preparation apparatus system for carbon nanotube films, characterized in that, The continuous preparation apparatus system includes a first unwinding roller, a vacuum forming system, a pressing roller, a drying device, and a first winding roller connected in sequence. A spraying device is installed above the vacuum forming system; The spraying device is connected in sequence to the slurry distribution system, the defoaming device, and the carbon nanotube dispersion storage tank. The pressing rollers are independently connected to the second unwinding roller and the second winding roller, respectively; The vacuum forming system is used for the filtration and forming of carbon nanotube dispersions to form porous substrate-carbon nanotube membranes. The pressing roller is used to bond the substrate and the porous substrate-carbon nanotube membrane, and to transfer the carbon nanotube membrane from the porous substrate to the bonding substrate.

2. The continuous preparation apparatus system according to claim 1, characterized in that, The first unwinding roller is used to wind the porous substrate.

3. The continuous preparation apparatus system according to claim 1, characterized in that, The second unwinding roller is used to wind the bonding substrate.

4. The continuous preparation apparatus system according to claim 1, characterized in that, The first take-up roller is used to take up the carbon nanotube film.

5. The continuous preparation apparatus system according to claim 1, characterized in that, The second take-up roller is used to take up the porous substrate.

6. The continuous preparation apparatus system according to claim 1, characterized in that, The vacuum forming system includes at least three vacuum pumping modules.

7. The continuous preparation apparatus system according to claim 1, characterized in that, The vacuum forming system includes at least five vacuum pumping modules.

8. The continuous preparation apparatus system according to claim 1, characterized in that, The slurry distribution system includes a homogenizing device and a rectifier connected in sequence.

9. The continuous preparation apparatus system according to claim 1, characterized in that, A dispersion device is provided between the carbon nanotube dispersion storage tank and the degassing device.

10. The continuous preparation apparatus system according to claim 1, characterized in that, The pressing roller is made of stainless steel and / or rubber.

11. The continuous preparation apparatus system according to claim 1, characterized in that, A top mesh forming device is installed above the vacuum forming system.

12. The continuous preparation apparatus system according to claim 11, characterized in that, The top mesh forming device is located between the spraying device and the pressing roller.

13. The continuous preparation apparatus system according to claim 1, characterized in that, A spraying device is installed above the vacuum forming system.

14. The continuous preparation apparatus system according to claim 13, characterized in that, The spraying device is located between the spraying device and the pressing roller.

15. The continuous preparation apparatus system according to claim 1, characterized in that, A third take-up roller is provided after the drying device, and the third take-up roller is used to take up the substrate.

16. A method for preparing a carbon nanotube membrane, characterized in that, The preparation method is carried out continuously using the continuous preparation apparatus system according to any one of claims 1-15, and the preparation method includes the following steps: (1) The porous substrate is conveyed to the vacuum forming system via the first unwinding roller. Then, the carbon nanotube dispersion is degassed by the degassing device, homogenized and rectified by the slurry distribution system, and then the carbon nanotube slurry is coated onto the porous substrate by the spraying device. After that, it is filtered and formed by the vacuum forming system to form a porous substrate-carbon nanotube membrane. (2) The bonding substrate is conveyed to the pressing roller via the second unwinding roller, and then bonded with the porous substrate-carbon nanotube membrane described in step (1) using the pressing roller, and the carbon nanotube membrane is transferred from the porous substrate to the bonding substrate to form a carbon nanotube membrane-bonding substrate. (3) The carbon nanotube film-adhesive substrate described in step (2) is dried by a drying device and then the carbon nanotube film is wound up by a first winding roller.

17. The preparation method according to claim 16, characterized in that, The porous substrate in step (1) includes any one or a combination of at least two of the following: cellulose derivative membranes, polytetrafluoroethylene membranes, polyvinylidene fluoride membranes, PP membranes, glass fiber membranes, nylon membranes, polyethersulfone membranes, polyamide membranes, polyimide membranes, polyester membranes, polyolefin membranes, or glass fiber filter membranes.

18. The preparation method according to claim 16, characterized in that, The pore size of the porous substrate in step (1) is 0.05-100μm.

19. The preparation method according to claim 16, characterized in that, The pore size of the porous substrate in step (1) is 0.1-60 μm.

20. The preparation method according to claim 16, characterized in that, The pore size of the porous substrate in step (1) is 0.2-30 μm.

21. The preparation method according to claim 16, characterized in that, The carbon nanotubes in step (1) include single-walled carbon nanotubes and / or multi-walled carbon nanotubes.

22. The preparation method according to claim 16, characterized in that, The median length of the carbon nanotubes in step (1) is 0.1 μm-10 mm.

23. The preparation method according to claim 16, characterized in that, The median length of the carbon nanotubes in step (1) is 1 μm-2 mm.

24. The preparation method according to claim 16, characterized in that, The median length of the carbon nanotubes in step (1) is 10 μm-500 μm.

25. The preparation method according to claim 16, characterized in that, The coating method described in step (1) includes any one of casting, spraying, or scraping.

26. The preparation method according to claim 16, characterized in that, Before entering the degassing device, the carbon nanotube dispersion in step (1) further includes dispersion by a dispersion device.

27. The preparation method according to claim 26, characterized in that, The dispersion method includes any one or a combination of at least two of mechanical stirring, ultrasonication, homogenization, sand milling, or emulsification.

28. The preparation method according to claim 16, characterized in that, The vacuum forming system in step (1) includes a first vacuum module, a second vacuum module and a third vacuum module connected in sequence.

29. The preparation method according to claim 28, characterized in that, The first vacuum module is equipped with a water baffle.

30. The preparation method according to claim 29, characterized in that, The height of the water baffle is ≥2cm.

31. The preparation method according to claim 28, characterized in that, The vacuum level of the first vacuum module is -0.06 to -0.04 MPa.

32. The preparation method according to claim 28, characterized in that, The vacuum level of the second vacuum module is -0.08 to -0.06 MPa.

33. The preparation method according to claim 28, characterized in that, The vacuum level of the third vacuum module is -0.1 to -0.08 MPa.

34. The preparation method according to claim 16, characterized in that, After being formed by the vacuum forming system, the dryness of the carbon nanotube film is 5-70%.

35. The preparation method according to claim 16, characterized in that, After being formed by the vacuum forming system, the dryness of the carbon nanotube film is 10-50%.

36. The preparation method according to claim 16, characterized in that, After being formed by the vacuum forming system, the dryness of the carbon nanotube film is 10-30%.

37. The preparation method according to claim 16, characterized in that, Step (1) after the filtration and molding process also includes: using a top mesh molding device for dehydration and molding.

38. The preparation method according to claim 16, characterized in that, Step (1) after the filtration and molding process also includes: spraying with a spraying device.

39. The preparation method according to claim 38, characterized in that, The spraying material includes any one or a combination of at least two of the following: alcohol solvents, organic materials, or inorganic materials.

40. The preparation method according to claim 16, characterized in that, The bonding substrate in step (2) includes a continuous substrate or a porous substrate.

41. The preparation method according to claim 40, characterized in that, The continuous substrate includes any one or a combination of at least two of PET, PP, PI, or release film.

42. The preparation method according to claim 16, characterized in that, Step (2) The bonding substrate is conveyed to the pressing roller via the second unwinding roller to form a bonding substrate-carbon nanotube membrane-porous substrate structure.

43. The preparation method according to claim 16, characterized in that, The pressure for bonding in step (2) is 0.01-50 MPa.

44. The preparation method according to claim 16, characterized in that, The pressure for bonding in step (2) is 0.1-30 MPa.

45. The preparation method according to claim 16, characterized in that, The pressure for bonding in step (2) is 1-20 MPa.

46. ​​The preparation method according to claim 16, characterized in that, The fitting angle in step (2) is 10°-80°.

47. The preparation method according to claim 16, characterized in that, The fitting angle in step (2) is 20°-70°.

48. The preparation method according to claim 16, characterized in that, The fitting angle in step (2) is 30°-50°.

49. The preparation method according to claim 16, characterized in that, Step (2) after bonding also includes: winding the separated porous substrate by a second take-up roller.

50. The preparation method according to claim 16, characterized in that, After drying in step (3), the process further includes: winding the separated bonding substrates up using a third take-up roller.

51. A carbon nanotube membrane, characterized in that, The carbon nanotube membrane is prepared by the preparation method according to any one of claims 16-50.

52. The carbon nanotube membrane according to claim 51, characterized in that, The thickness of the carbon nanotube film is 0.05-500 μm.

53. The carbon nanotube membrane according to claim 51, characterized in that, The thickness of the carbon nanotube film is 3-200 μm.

54. The carbon nanotube membrane according to claim 51, characterized in that, The thickness of the carbon nanotube film is 5-50 μm.

55. The carbon nanotube membrane according to claim 51, characterized in that, The areal density of the carbon nanotube film is 0.05-300 g / m³. 2 .

56. The carbon nanotube membrane according to claim 51, characterized in that, The areal density of the carbon nanotube film is 1.5-120 g / m³. 2 .

57. The carbon nanotube membrane according to claim 51, characterized in that, The areal density of the carbon nanotube film is 6-30 g / m³. 2 .

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