Continuous fiber reinforced thermoplastic prepreg tape and preparation method and device thereof

Abstract

The invention provides a continuous fiber reinforced thermoplastic prepreg tape and a preparation method and device thereof. The continuous fiber reinforced thermoplastic prepreg tape comprises a thermoplastic prepreg tape base layer and organic barrier layers covering the upper surface and the lower surface of the thermoplastic prepreg tape base layer. The organic barrier layer comprises graphene oxide and sulfonated polyvinylidene fluoride. The continuous fiber reinforced thermoplastic prepreg tape provided by the invention can effectively obstruct gas and has excellent mechanical properties, and the application scene of the continuous fiber reinforced thermoplastic prepreg tape is widened.

Description

TECHNICAL FIELD

[0001] The present application relates to a continuous fiber reinforced thermoplastic prepreg tape and its preparation method and device, belonging to the technical field of polymer composites. BACKGROUND

[0002] Thermoplastic prepreg tape is an important intermediate substrate for the preparation of composite materials, with the advantages of easy use, environmentally friendly molding process, precise resin content control, controllable thickness, and adjustable specifications according to different sizes and processes. The use of thermoplastic prepreg tape to prepare composite materials can effectively improve the strength, corrosion resistance, fatigue life, impact resistance, designability, and lightweight level of the product. Thermoplastic prepreg tape is mainly composed of thermoplastic resin and reinforcing fibers. The thermoplastic resin includes polyether ether ketone, polyether ketone ketone, polyamide, polypropylene, and polyphenylene sulfide, etc. The reinforcing fibers include glass fiber, carbon fiber, basalt fiber, and aramid fiber, etc. Due to its long storage period, high molding efficiency, and easy recycling, thermoplastic prepreg tape has been widely used in the fields of aviation, aerospace, weapon equipment, transportation, and automobile manufacturing.

[0003] Currently, thermoplastic prepreg tape mainly serves as a structural reinforcement, but as its use in high-end equipment in various fields increases, it is developing towards larger size, integration, and complexity. The single structural reinforcement function cannot meet the application requirements. For example, when thermoplastic composites are applied to oil and gas gathering and transportation related components, they can better meet the requirements of corrosion resistance and mechanical properties, but there are still some deficiencies in gas barrier performance. Compared to metal materials, high molecular materials (such as plastics) have better "permeability" at the molecular level. Under the action of pressure, gas molecules will penetrate into the high molecular material body and gradually penetrate to the low pressure area outside, thereby penetrating the high molecular material and causing gas to escape.

[0004] Chinese patent document CN202110095987.X discloses a high-barrier thermoplastic composite plate, which comprises an isolation layer, a functional surface layer, a buffer layer, a reinforcing layer, a barrier layer and a medium layer which are hot-pressed and combined. The isolation layer is a full-transparent or semi-transparent BOPET film. The reinforcing layer is a multi-layer continuous fiber reinforced thermoplastic composite prepreg. The barrier layer is an aluminum-plastic composite film. The continuous fiber reinforced thermoplastic composite prepreg is processed by fully impregnating the reinforcing fiber with the molten base resin, mainly playing a role in structural reinforcement, and does not have barrier properties. Chinese patent document CN202110956483.2 discloses a high-barrier thermoplastic unidirectional prepreg, as well as a preparation method and equipment thereof. The prepreg material is a three-layer structure, the upper and lower layers are multi-layer thermoplastic composite barrier films, and the middle layer is a continuous fiber reinforced thermoplastic unidirectional prepreg. The multi-layer thermoplastic composite barrier film structure in the invention is complex, the preparation process conditions are harsh, and the welding effect is not easy to control when hot-pressed and combined with the prepreg.

[0005] It is a technical problem to be solved to explore a continuous fiber reinforced thermoplastic prepreg with simple process conditions, high barrier properties and tensile properties. SUMMARY

[0006] The present application provides a continuous fiber reinforced thermoplastic prepreg, which has excellent barrier properties and mechanical properties.

[0007] The present application also provides a preparation method of a continuous fiber reinforced thermoplastic prepreg, which has simple process and can prepare a continuous fiber reinforced thermoplastic prepreg with excellent barrier properties and mechanical properties.

[0008] The present application also provides a device for preparing a continuous fiber reinforced thermoplastic prepreg, which can be used to prepare the above-mentioned continuous fiber reinforced thermoplastic prepreg.

[0009] In one aspect, the present application provides a continuous fiber reinforced thermoplastic prepreg, which comprises a thermoplastic prepreg base layer and an organic barrier layer covering the upper and lower surfaces of the thermoplastic prepreg base layer.

[0010] The organic barrier layer comprises graphene oxide and sulfonated polyvinylidene fluoride.

[0011] The continuous fiber reinforced thermoplastic prepreg as described above, the mass percentage of the graphene oxide in the organic barrier layer is 0.5%-3.0%, and the mass percentage of the sulfonated polyvinylidene fluoride in the organic barrier layer is 85%-95%.

[0012] The continuous fiber reinforced thermoplastic prepreg as described above, the oxygen content of the oxygen-containing groups of the graphene oxide is 30%-50%.

[0013] The continuous fiber reinforced thermoplastic prepreg tape as described above, wherein the graphene oxide has a flake diameter of 3-10 microns and a thickness of 0.5-3 nanometers.

[0014] The continuous fiber reinforced thermoplastic prepreg tape as described above, wherein the sulfonated polyvinylidene fluoride is prepared by a method comprising the following steps:

[0015] 1) adding PVDF powder into a methanol solution, ultrasonic soaking for 30 minutes, and then taking out and drying at 60-80 DEG C to obtain dried PVDF powder;

[0016] 2) adding chlorosulfonic acid into the dried PVDF powder, stirring at room temperature for 24-36 hours to obtain sulfonated PVDF powder;

[0017] 3) pouring the sulfonated PVDF powder into a dioxane solution for cleaning, and then washing with water and drying to obtain the sulfonated polyvinylidene fluoride;

[0018] Wherein, the mass-volume ratio of the PVDF powder to the chlorosulfonic acid is 1g:(10-15)ml.

[0019] The continuous fiber reinforced thermoplastic prepreg tape as described above, wherein the organic barrier layer has a thickness of 0.02-0.08mm;

[0020] And / or, the thickness of the thermoplastic prepreg tape base layer is 0.25-0.35mm.

[0021] The continuous fiber reinforced thermoplastic prepreg tape as described above, wherein the thermoplastic prepreg tape base layer comprises fibers, thermoplastic resin.

[0022] The continuous fiber reinforced thermoplastic prepreg tape as described above, wherein the fibers comprise at least one of glass fibers, carbon fibers, aramid fibers;

[0023] And / or, the thermoplastic resin comprises at least one of HDPE, PP, PA, PET.

[0024] The continuous fiber reinforced thermoplastic prepreg tape as described above, wherein the mass percentage content of the fibers is 60%-70%.

[0025] In still another aspect, the application provides a preparation method of the continuous fiber reinforced thermoplastic prepreg tape as described above, comprising the following steps:

[0026] 1) using positive corona to perform corona treatment on the thermoplastic prepreg tape base layer at 5-30kw to obtain a prepreg tape base layer with positive charges on the surface;

[0027] 2) Subsequently, the prepreg tape base layer is coated with a coating including graphene oxide and sulfonated polyvinylidene fluoride to obtain a continuous fiber reinforced thermoplastic prepreg tape.

[0028] The coating, prepared by the method described above, further includes a solvent, a leveling agent, and a surfactant.

[0029] In the preparation method described above, the solvent includes at least one of N-methyl-2-pyrrolidone, dimethylformamide, dimethylacetamide, and dimethyl sulfoxide;

[0030] And / or, the leveling agent includes at least one of polyester-modified polydimethylsiloxane, polyether-modified organosiloxane, and alkyl-modified organosiloxane;

[0031] And / or, the surfactant includes at least one of polyvinylpyrrolidone, polyoxyethylene alkylamide, fatty alcohol polyoxyethylene ether, and alkylphenol polyoxyethylene ether.

[0032] According to the preparation method described above, the coating comprises, by weight, 0.3-0.8 parts of graphene oxide, 10-20 parts of sulfonated polyvinylidene fluoride, 0.2-1 parts of polyester-modified polydimethylsiloxane, 3-6 parts of polyvinylpyrrolidone, and 75-85 parts of N-methyl-2-pyrrolidone.

[0033] In another aspect, the present invention provides an apparatus for preparing a continuous fiber reinforced thermoplastic prepreg tape, the apparatus being used to perform the preparation method described above;

[0034] Includes a corona unit, a coating unit, and a traction unit;

[0035] The traction unit is used to sequentially pass the thermoplastic prepreg tape base layer through the corona unit and the coating unit.

[0036] The continuous fiber reinforced thermoplastic prepreg tape provided by the present invention includes a thermoplastic prepreg tape base layer and an organic barrier layer including graphene oxide and sulfonated polyvinylidene fluoride. Under the synergistic effect of graphene oxide and sulfonated polyvinylidene fluoride, the gas is effectively blocked, while the mechanical properties of the continuous fiber reinforced thermoplastic prepreg tape are improved. Attached Figure Description

[0037] Figure 1 A schematic diagram of a partial cross-sectional structure of the continuous fiber reinforced thermoplastic prepreg tape provided by the present invention;

[0038] Figure 2 This is a simplified structural diagram of a preparation apparatus provided in a specific embodiment of the present invention. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions in the embodiments of this invention will be clearly and completely described below in conjunction with the embodiments of this invention. Obviously, the described embodiments are only some embodiments of this invention, not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0040] This invention provides, in one aspect, a continuous fiber-reinforced thermoplastic prepreg tape, such as... Figure 1 As shown, it includes a thermoplastic prepreg tape base layer 1 and an organic barrier layer 2 covering the upper and lower surfaces of the thermoplastic prepreg tape base layer; the organic barrier layer 2 includes graphene oxide and sulfonated polyvinylidene fluoride.

[0041] Among them, the thermoplastic prepreg tape base layer 1 is a strip material mainly composed of thermoplastic resin and reinforcing fibers. The upper and lower surfaces of the thermoplastic prepreg tape base layer 1 refer to the two opposite surfaces with the largest area.

[0042] For ease of distinction, the organic barrier layer covering the upper surface of the thermoplastic prepreg tape base layer can be called the first organic barrier layer, the surface opposite the upper surface is called the lower surface, and the organic barrier layer covering the lower surface is called the second organic barrier layer. The composition of the first organic barrier layer and the second organic barrier layer can be completely identical or have slight differences. These differences may be reflected in the component types and the mass relationship between the components, as long as both the first organic barrier layer and the second organic barrier layer include graphene oxide and sulfonated polyvinylidene fluoride.

[0043] The present invention does not limit the molecular weight of sulfonated polyvinylidene fluoride. Sulfonated polyvinylidene fluoride with a suitable molecular weight can be selected according to actual needs. In one specific embodiment, the weight average molecular weight of sulfonated polyvinylidene fluoride is 300,000-400,000.

[0044] The present invention does not limit the width of the continuous fiber reinforced thermoplastic prepreg tape, and the width of the continuous fiber reinforced thermoplastic prepreg tape can be adjusted according to the actual application needs.

[0045] The continuous fiber reinforced thermoplastic prepreg tape provided by this invention can effectively block and prevent gas escape, while also exhibiting excellent tensile strength. The inventors analyzed this and believe the reasons may be as follows: Firstly, the graphene oxide in the organic barrier layer forms a sheet-like structure with a high aspect ratio within the sulfonated polyvinylidene fluoride matrix, creating a tortuous path for gas molecule diffusion within the polymer matrix. Gases bypass the interlayer and edges of the graphene oxide sheets, thus significantly slowing down the gas diffusion process and effectively improving the gas barrier performance of the organic barrier layer. Secondly, the hydroxyl and carboxyl groups contained in the graphene oxide can effectively combine with the sulfonic acid groups of the sulfonated polyvinylidene fluoride, exhibiting a good interfacial effect and improving the mechanical strength of the organic barrier layer. Simultaneously, the synergistic effect of the organic barrier layer and the thermoplastic prepreg tape base layer enhances the interfacial tensile strength of the continuous fiber reinforced thermoplastic prepreg tape, thereby improving its mechanical properties.

[0046] Furthermore, in one specific embodiment of the present invention, the mass percentage of graphene oxide is 0.5%-3%, and the mass percentage of sulfonated polyvinylidene fluoride is 85%-95%.

[0047] The mass percentage of graphene oxide refers to the mass fraction of graphene oxide in the organic barrier layer, while the mass percentage of sulfonated polyvinylidene fluoride refers to the mass fraction of sulfonated polyvinylidene fluoride in the organic barrier layer.

[0048] Thermogravimetric analysis can be used to determine the mass percentage of graphene oxide and sulfonated polyvinylidene fluoride.

[0049] In detail, the mass percentage of graphene oxide includes, but is not limited to, a range of 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, or any two of these.

[0050] The mass percentage of sulfonated polyvinylidene fluoride includes, but is not limited to, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, or any combination thereof.

[0051] When the mass percentages of graphene oxide and sulfonated polyvinylidene fluoride are within the above range, the synergistic effect between the two can be better exerted.

[0052] Furthermore, in one specific embodiment of the present invention, the oxygen content of the oxygen-containing groups in the graphene oxide is 30%-50%.

[0053] The oxygen content of oxygen-containing groups in graphene oxide can be detected using X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis, and other methods.

[0054] In detail, the oxygen content of the oxygen-containing groups in graphene oxide includes, but is not limited to, a range of 30%, 32%, 34%, 36%, 38%, 40%, 42%, 44%, 46%, 48%, 50%, or any two of these.

[0055] The oxygen content of oxygen-containing groups in graphene oxide can be controlled by adjusting the parameters of the preparation process, or commercially available graphene oxide that meets the requirements can be purchased.

[0056] When the oxygen content of the oxygen-containing groups in graphene oxide is within the above range, oxygen atoms can provide more active sites, which greatly enhances its reactivity in reacting with functional groups of other compounds.

[0057] Furthermore, in one specific embodiment of the present invention, the graphene oxide sheet has a diameter of 3-10 μm and a thickness of 0.5-3 nm.

[0058] In detail, the sheet diameter of graphene oxide refers to the average diameter of graphene oxide in the planar direction, while the thickness of graphene oxide refers to the average thickness of graphene oxide.

[0059] The size and thickness of graphene oxide sheets can be observed and measured using high-resolution microscopes such as transmission electron microscopy (TEM), scanning electron microscopy (SEM), and atomic force microscopy (AFM).

[0060] The sheet diameter of graphene oxide includes, but is not limited to, a range of 3μm, 4μm, 5μm, 6μm, 7μm, 8μm, 9μm, 10μm or any combination thereof.

[0061] The thickness of graphene oxide includes, but is not limited to, a range of 0.5 nm, 1 nm, 1.5 nm, 2 nm, 2.5 nm, 3 nm, or any combination thereof.

[0062] When the size of graphene oxide is within the above range, gas cannot penetrate the graphene oxide, and larger sheet-like structures can be constructed in sulfonated polyvinylidene fluoride body to hinder the diffusion path of gas and improve the barrier properties of fiber-reinforced thermoplastic prepreg tape.

[0063] Furthermore, in one specific embodiment of the present invention, sulfonated polyvinylidene fluoride is prepared by a method comprising the following process:

[0064] 1) Add PVDF powder to methanol solution and ultrasonically soak for 30 min, then remove and dry at 60-80℃ to obtain dried PVDF powder; 2) Add chlorosulfonic acid to the dried PVDF powder and stir at room temperature for 24-36 h to obtain sulfonated PVDF powder; 3) Pour the sulfonated PVDF powder into dioxane solution for washing, then wash with water and dry to obtain sulfonated polyvinylidene fluoride; wherein the mass-volume ratio of PVDF powder to chlorosulfonic acid is 1 g:(10-15) mL.

[0065] In detail, the mass-volume ratio of PVDF powder to chlorosulfonic acid is 1g:(10-15)mL. For example, the mass-volume ratio of PVDF powder to chlorosulfonic acid includes, but is not limited to, 1g:10mL, 1g:11mL, 1g:12mL, 1g:13mL, 1g:14mL, 1g:15mL, or any combination thereof.

[0066] The sulfonated polyvinylidene fluoride obtained by the above preparation method has a more suitable degree of sulfonation. Under the action of the sulfonation groups, the connection between the organic barrier layer and the thermoplastic prepreg base layer is better realized, thereby improving the tensile strength of the continuous fiber reinforced thermoplastic prepreg and enhancing its mechanical properties.

[0067] Furthermore, in one specific embodiment of the present invention, the thickness of the organic barrier layer is 0.02-0.08 mm; and / or, the thickness of the thermoplastic prepreg tape base layer is 0.25-0.35 mm.

[0068] In detail, the thickness of the organic barrier layer includes, but is not limited to, a range of 0.02 mm, 0.03 mm, 0.04 mm, 0.05 mm, 0.06 mm, 0.07 mm, 0.08 mm, or any combination thereof.

[0069] The thickness of the organic barrier layer within the above range can not only effectively block gas penetration and protect the thermoplastic prepreg tape base layer from the influence of the external environment, but also control manufacturing costs and quality.

[0070] The thickness of the thermoplastic prepreg tape base layer includes, but is not limited to, 0.25mm, 0.26mm, 0.27mm, 0.28mm, 0.29mm, 0.30mm, 0.31mm, 0.32mm, 0.33mm, 0.34mm, 0.35mm, or any combination thereof.

[0071] The thickness of the thermoplastic prepreg base layer within the above range can effectively improve the mechanical properties of continuous fiber reinforced thermoplastic prepreg tape, thus enhancing its mechanical properties.

[0072] Furthermore, in one specific embodiment of the present invention, the thermoplastic prepreg tape base layer includes fibers and thermoplastic resin.

[0073] In detail, the thermoplastic prepreg tape base layer is composed of fibers impregnated with thermoplastic resin.

[0074] The thermoplastic prepreg tape base layer may also include a compatibilizer and an antioxidant. The compatibilizer mainly includes modified resin, and the antioxidant includes, but is not limited to, at least one of phenolic antioxidants and amine antioxidants.

[0075] It is understood that the type of compatibilizer can be adjusted according to the type of thermoplastic resin. In one specific embodiment, the thermoplastic resin is polyethylene and the compatibilizer is polyethylene grafted with maleic anhydride; in another specific embodiment, the thermoplastic resin is polypropylene and the compatibilizer is polypropylene grafted with maleic anhydride.

[0076] The present invention does not limit the mass relationship between thermoplastic resin, compatibilizer and antioxidant. A suitable mass relationship can be selected according to actual needs. In one specific embodiment, the mass part of thermoplastic resin is 100 parts, the mass part of compatibilizer is 3 parts, and the mass part of antioxidant is 0.3 parts.

[0077] The fibers are mainly used to provide strength and rigidity to the thermoplastic prepreg tape base layer, while the thermoplastic resin can be softened and reprocessed at high temperatures, allowing the fibers to bond together to form a thermoplastic prepreg tape base layer with the required shape.

[0078] Furthermore, in one specific embodiment of the present invention, the fiber includes at least one of glass fiber, carbon fiber, and aramid fiber; and / or, the thermoplastic resin includes at least one of HDPE, PP, PA, and PET.

[0079] Furthermore, in one specific embodiment of the present invention, the fiber mass percentage is 60%-70%.

[0080] In this invention, the fiber mass percentage refers to the percentage of fiber mass in the thermoplastic prepreg tape base layer.

[0081] In detail, the fiber mass percentage includes, but is not limited to, a range of 60%, 62%, 64%, 66%, 68%, 70%, or any two of these.

[0082] The aforementioned percentage of fiber content ensures that the thermoplastic prepreg tape base layer has sufficient fiber content to provide the required strength and stiffness properties. The remaining 30%-40% is the content of thermoplastic resin, which binds the fibers together and forms a monolithic structure.

[0083] It not only maintains the lightweight advantage of thermoplastic prepreg tape base, but also provides sufficient flowability and forming ability during manufacturing to achieve complex geometries and details during molding.

[0084] In another aspect, the present invention provides a method for preparing the continuous fiber reinforced thermoplastic prepreg tape as described above, comprising the following steps:

[0085] 1) The thermoplastic prepreg tape base layer is corona treated with positive corona at 5-30kw to obtain a prepreg tape base layer with a positively charged surface;

[0086] 2) Subsequently, the prepreg tape base layer is coated with a coating including graphene oxide and sulfonated polyvinylidene fluoride to obtain a continuous fiber reinforced thermoplastic prepreg tape.

[0087] In detail, step 1) adjusts the treatment area of ​​the corona device based on the width of the thermoplastic prepreg tape base layer, passes through two electrodes according to the running direction of the thermoplastic prepreg tape base layer, adjusts the potentiometer, and applies a positive corona power of 5-30kW to the treatment device to make it corona discharge.

[0088] Positive corona discharge can be selected using methods common in the field, such as corona treatment in an ammonia atmosphere.

[0089] The thermoplastic prepreg tape base layer of this invention can be prepared by a method including the following process:

[0090] 1) Pull multiple continuous fiber bundles out of the fiber bundle, and then perform a combing process to untangle the fibers in the fiber bundle, making them more parallel, and remove impurities and short fibers from the fiber bundle.

[0091] 2) After combing, the fibers are baked to remove residual moisture or volatile components, and then the fibers are subjected to constant temperature spreading treatment to further optimize the uniformity and tensile properties of the fibers.

[0092] 3) The fibers that have undergone constant temperature yarn spreading treatment are immersed in molten thermoplastic resin for impregnation treatment, so that the surface of the fibers is covered with thermoplastic resin. Then, the fibers are continuously hot-pressed by hot rollers to obtain the thermoplastic prepreg tape base layer.

[0093] This invention does not limit the preparation process parameters of thermoplastic prepreg tape base layer; appropriate parameters can be selected according to actual needs.

[0094] In step 2), a coating including graphene oxide and sulfonated polyvinylidene fluoride is used to coat the prepreg substrate, so that the upper and lower surfaces of the prepreg substrate are filled with the coating, resulting in a continuous fiber-reinforced thermoplastic prepreg.

[0095] The coating process also includes heat treatment and shaping and cooling treatment.

[0096] In detail, the heat treatment includes the following steps: drying the prepreg tape base layer covered with coating at 80°C for 0.5 hours to evaporate the solvent in the coating and to shape the graphene oxide and sulfonated polyvinylidene fluoride in the coating.

[0097] The shaping and cooling process includes the following steps: under the action of the traction unit, the nascent continuous fiber reinforced thermoplastic prepreg tape is rolled by the traction unit at 120°C to make the prepreg tape reach a certain thickness.

[0098] Corona treatment can introduce positive charges onto the surface of thermoplastic prepreg substrates, altering their surface properties. After coatings containing graphene oxide and sulfonated polyvinylidene fluoride (PVDF) are applied to the prepreg substrate, the interaction between the sulfonated groups in PVDF and the positive charges on the prepreg substrate enhances the adhesion between the thermoplastic prepreg substrate and the organic barrier layer on the surface, thereby improving the performance and stability of continuous fiber reinforced thermoplastic prepregs.

[0099] Furthermore, in one specific embodiment of the present invention, the coating further includes a solvent, a leveling agent, and a surfactant.

[0100] The main role of solvents in coatings is to dilute solid particles (such as resins or polymers) and adjust the viscosity and flowability of the coatings to make them easy to apply.

[0101] Leveling agents can improve the smoothness and flatness of the coating surface, reduce unevenness, and improve the appearance and feel of the coating film.

[0102] Surfactants are mainly used in coatings to adjust the surface tension and wettability of the coating, which helps the coating adhere well to the substrate and distribute evenly.

[0103] Furthermore, in a specific embodiment of the present invention, the solvent includes at least one of N-methyl-2-pyrrolidone, dimethylformamide, dimethylacetamide, and dimethyl sulfoxide; and / or, the leveling agent includes at least one of polyester-modified polydimethylsiloxane, polyether-modified organosiloxane, and alkyl-modified organosiloxane; and / or, the surfactant includes at least one of polyvinylpyrrolidone, polyoxyethylene alkylamide, fatty alcohol polyoxyethylene ether, and alkylphenol polyoxyethylene ether.

[0104] Furthermore, in a specific embodiment of the present invention, the coating comprises, by weight, 0.3-0.8 parts of graphene oxide, 10-20 parts of sulfonated polyvinylidene fluoride, 0.2-1 parts of polyester-modified polydimethylsiloxane, 3-6 parts of polyvinylpyrrolidone, and 75-85 parts of N-methyl-2-pyrrolidone.

[0105] When the coating includes the components mentioned above by mass, the resulting solution has good stability and appropriate viscosity, which can be effectively applied to the surface of the prepreg tape during the coating process and form a certain coating thickness. It can also promote the formation of a smooth, uniform coating during the drying process.

[0106] like Figure 2 As shown, another aspect of the present invention provides an apparatus for preparing a continuous fiber reinforced thermoplastic prepreg tape, the apparatus being used to perform the preparation method described above; it includes a corona unit 8, a coating unit 9, and a traction unit 11; the traction unit 11 is used to sequentially pass the thermoplastic prepreg tape base layer through the corona unit 8 and the coating unit 9.

[0107] The corona unit 8 is used to perform corona treatment on the thermoplastic prepreg tape base layer to obtain a prepreg tape base layer with a positively charged surface, while the coating unit 9 is used to coat the surface of the prepreg tape base layer with a coating including graphene oxide and sulfonated polyvinylidene fluoride.

[0108] In one specific implementation, such as Figure 2 As shown, the preparation device also includes a yarn feeding unit 1, a yarn combing unit 2, a baking unit 3, a yarn spreading unit 4, a wetting unit 5, a glue extrusion unit 6, a roller pressing unit 7, a drying unit 10, an online detection unit 12, and a winding unit 13.

[0109] In this process, under the action of the traction unit 11, the fibers are drawn out through the yarn feeding unit 1 and enter the yarn combing unit 2 for combing treatment, making the fibers more uniform. Then, they enter the baking unit 3 for baking treatment to remove moisture and other volatile impurities from the fiber surface. The baked fibers then enter the spreading unit 4 for spreading treatment, which orients the fibers, increases their surface energy, and prepares them for subsequent processing. The spread fibers then enter the impregnation unit 5, where molten thermoplastic resin is extruded through the extrusion unit 6. The fibers are impregnated in the impregnation unit 5, with their surface coated with thermoplastic resin. The impregnated fibers then enter the rolling unit for rolling treatment, obtaining a shaped thermoplastic impregnated tape base layer. Subsequently, under the action of the traction unit 11, the thermoplastic impregnated tape base layer passes sequentially through the corona treatment unit 8, the coating unit 9, and the drying unit 10 to obtain a shaped continuous fiber-reinforced thermoplastic prepreg tape.

[0110] The online detection unit 12 can detect the appearance of the upper and lower surface coatings in real time, while the winding unit 13 can store the continuous fiber reinforced thermoplastic prepreg tape.

[0111] The present invention does not limit the device type and quantity of each unit, and can be adjusted according to actual needs.

[0112] In one specific embodiment, the yarn feeding unit 1 includes a yarn frame, the yarn spreading unit 4 uses heated ceramic rollers, the extrusion unit 6 uses a twin-screw extruder, and the roller pressing unit 7 includes several stages of hot-pressing rollers. The combing unit 2 includes a ceramic eye plate and steel buckles, the baking unit 3 uses an infrared heater, the impregnation unit 5 uses an "I"-shaped impregnation mold, the corona treatment unit 8 uses a plastic film corona treatment machine, the coating unit 9 includes a solution tank and guide rollers, the drying unit 10 uses a multi-stage continuous dryer, the traction unit 11 uses hot-pressing rollers, the online detection unit 12 uses an online surface defect detection system, and the winding unit 13 uses a fully automatic winding machine.

[0113] The preparation apparatus provided by the present invention can perform the above preparation method to prepare a continuous fiber-reinforced thermoplastic prepreg tape with high barrier properties and mechanical properties.

[0114] The following describes the continuous fiber reinforced thermoplastic prepreg tape provided by the present invention through specific embodiments.

[0115] Example 1

[0116] The apparatus for preparing continuous fiber reinforced thermoplastic prepreg tape provided in this embodiment is as follows: Figure 2 As shown, the preparation method includes the following steps:

[0117] 1) 144 rolls of continuous fiber are loaded onto the yarn feeding unit 1, and then each fiber is pulled to the fixed-length carding unit 2 to form a row of continuous fibers. Then, they enter the baking unit 3 and are baked at 380°C to bake off the sizing agent on the fiber surface used to bond the fiber bundles. After the fibers come out of the baking unit 3, they enter the yarn spreading unit 4. The fibers are fully spread out by left and right circulating yarn spreading. Thermoplastic resin is extruded into the impregnation unit 5 through a twin-screw extruder (extrusion unit 6). The fibers are impregnated with molten thermoplastic resin in the impregnation unit 5 to obtain a fiber and resin molten product. Then, the fiber is hot-pressed and impregnated by a single set of hot pressing device (roller pressing unit 7). The gap between the pressure rollers is adjusted to control the uniformity of the resin coating on the surface of the tape. The upper and lower resins are pressed into the glass fiber to prevent the tape from drying out, and the formed thermoplastic prepreg tape base layer is obtained.

[0118] 2) The formed thermoplastic prepreg tape base layer is introduced into the corona unit 8, and NH3 gas is used at 20kW to corona treat the thermoplastic prepreg tape base layer so that its surface is positively charged, thus obtaining a prepreg tape base layer with a positively charged surface.

[0119] 3) The prepreg tape base layer enters the coating unit 9 under the action of the guide roller, so that the upper and lower surfaces of the prepreg tape base layer are fully coated with paint. Then, it enters the drying unit 10 to heat and blow air to treat the prepreg tape base layer coated with paint, so that the solvent in the coating evaporates, resulting in a continuous fiber reinforced thermoplastic prepreg tape. Finally, it is continuously conveyed forward under the action of the traction unit 11. The online monitoring unit 12 detects the appearance quality of the coating on the upper and lower surfaces in real time. The winding unit 13 winds and stores the continuous fiber reinforced thermoplastic prepreg tape.

[0120] In this embodiment, the fiber used is 1200TEX untwisted continuous glass fiber, with a fiber mass percentage of 62%. The main material of the thermoplastic resin is high-density polyethylene (HDPE) with a melt index of 60 g / 10 min. The thermoplastic resin also includes a compatibilizer, which is high-density polyethylene grafted with maleic anhydride, with a compatibilizer-to-thermoplastic resin mass ratio of 3%. Additionally, 0.3% antioxidant (antioxidant 1010) is added. The coating comprises 20 parts sulfonated polyvinylidene fluoride powder, 0.3 parts graphene oxide, 0.5 parts polyester-modified polydimethylsiloxane, 5 parts polyvinylpyrrolidone, and 75 parts N-methyl-2-pyrrolidone solvent.

[0121] The graphene oxide in this invention has a sheet diameter of 6 μm, a thickness of 1.4 nm, and an oxygen content of 45% containing oxygen groups. The sulfonated polyvinylidene fluoride is prepared by a method comprising the following steps:

[0122] A certain weight of PVDF powder was added to a methanol solution and ultrasonically soaked for 30 minutes. After soaking, the powder was dried at 60°C. Chlorosulfonic acid was added to the dried PVDF powder and stirred at room temperature for 24 hours. The sulfonated PVDF powder was then poured into a dioxane solution and rinsed repeatedly with deionized water to remove excess chlorosulfonic acid. Finally, the sulfonated PVDF powder was dried. The mass-volume ratio of PVDF powder to chlorosulfonic acid was 1 g: 10 mL.

[0123] The continuous fiber reinforced thermoplastic prepreg tape provided by the present invention was tested. The thickness of the organic barrier layer was 0.06 mm, the thickness of the thermoplastic prepreg tape base layer was 0.31 mm, the mass percentage of graphene oxide in the organic barrier layer was 1%, and the mass percentage of sulfonated polyvinylidene fluoride was 90%.

[0124] Example 2

[0125] The preparation apparatus used in this embodiment is the same as that in Embodiment 1, and the preparation method of the continuous fiber reinforced thermoplastic prepreg tape provided in this embodiment is basically the same as that in Embodiment 1, except that:

[0126] The main material of the thermoplastic resin is polypropylene with a melt index of 100 g / 10 min, and the compatibilizer is polypropylene grafted with maleic anhydride.

[0127] The continuous fiber reinforced thermoplastic prepreg tape provided by the present invention was tested. The thickness of the organic barrier layer was 0.06 mm, the thickness of the thermoplastic prepreg tape base layer was 0.27 mm, the mass percentage of graphene oxide in the organic barrier layer was 1%, and the mass percentage of sulfonated polyvinylidene fluoride was 90%.

[0128] Example 3

[0129] The preparation apparatus used in this embodiment is the same as that in Embodiment 1, and the preparation method of the continuous fiber reinforced thermoplastic prepreg tape provided in this embodiment is basically the same as that in Embodiment 1, except that:

[0130] The coating comprises 15 parts sulfonated polyvinylidene fluoride powder, 0.5 parts graphene oxide, 1 part polyester-modified polydimethylsiloxane, 6 parts polyvinylpyrrolidone, and 77.5 parts N-methyl-2-pyrrolidone solvent.

[0131] The continuous fiber reinforced thermoplastic prepreg tape provided by the present invention was tested. The thickness of the organic barrier layer was 0.05 mm, the thickness of the thermoplastic prepreg tape base layer was 0.32 mm, the mass percentage of graphene oxide in the organic barrier layer was 3%, and the mass percentage of sulfonated polyvinylidene fluoride was 88%.

[0132] Example 4

[0133] The preparation apparatus used in this embodiment is the same as that in Embodiment 1, and the preparation method of the continuous fiber reinforced thermoplastic prepreg tape provided in this embodiment is basically the same as that in Embodiment 1, except that:

[0134] The oxygen content of the oxygen-containing groups in graphene oxide is 10%.

[0135] The continuous fiber reinforced thermoplastic prepreg tape provided by the present invention was tested. The thickness of the organic barrier layer was 0.06 mm, the thickness of the thermoplastic prepreg tape base layer was 0.31 mm, the mass percentage of graphene oxide in the organic barrier layer was 1%, and the mass percentage of sulfonated polyvinylidene fluoride was 90%.

[0136] Example 5

[0137] The preparation apparatus used in this embodiment is the same as that in Embodiment 1, and the preparation method of the continuous fiber reinforced thermoplastic prepreg tape provided in this embodiment is basically the same as that in Embodiment 1, except that:

[0138] The graphene oxide has a sheet diameter of 0.8 μm and a thickness of 0.3 nm.

[0139] The continuous fiber reinforced thermoplastic prepreg tape provided by the present invention was tested. The thickness of the organic barrier layer was 0.06 mm, the thickness of the thermoplastic prepreg tape base layer was 0.31 mm, the mass percentage of graphene oxide in the organic barrier layer was 1%, and the mass percentage of sulfonated polyvinylidene fluoride was 90%.

[0140] Example 6

[0141] The preparation apparatus used in this embodiment is the same as that in Embodiment 1, and the preparation method of the continuous fiber reinforced thermoplastic prepreg tape provided in this embodiment is basically the same as that in Embodiment 1, except that:

[0142] The fiber content is 55% by weight.

[0143] The continuous fiber reinforced thermoplastic prepreg tape provided by the present invention was tested. The thickness of the organic barrier layer was 0.06 mm, the thickness of the thermoplastic prepreg tape base layer was 0.37 mm, the mass percentage of graphene oxide in the organic barrier layer was 1%, and the mass percentage of sulfonated polyvinylidene fluoride was 90%.

[0144] Example 7

[0145] The preparation apparatus used in this embodiment is the same as that in Embodiment 1, and the preparation method of the continuous fiber reinforced thermoplastic prepreg tape provided in this embodiment is basically the same as that in Embodiment 1, except that:

[0146] The coating comprises 6 parts sulfonated polyvinylidene fluoride powder, 0.04 parts graphene oxide, 0.1 parts polyester-modified polydimethylsiloxane, 1 part polyvinylpyrrolidone, and 90 parts N-methyl-2-pyrrolidone solvent.

[0147] The continuous fiber reinforced thermoplastic prepreg tape provided by the present invention was tested. The thickness of the organic barrier layer was 0.01 mm, the thickness of the thermoplastic prepreg tape base layer was 0.31 mm, the mass percentage of graphene oxide in the organic barrier layer was 0.03%, and the mass percentage of sulfonated polyvinylidene fluoride was 98%.

[0148] Comparative Example 1

[0149] The method for preparing the continuous fiber reinforced thermoplastic prepreg tape provided in this comparative example includes the following steps:

[0150] 1) 144 rolls of continuous fiber are loaded onto the yarn feeding unit 1, and then each fiber is pulled to the fixed-length carding unit 2 to form a row of continuous fibers. The fibers are then baked at 380℃ in the baking unit 3 to remove some of the sizing agent used to bind the fiber bundles, facilitating further yarn unfolding. After exiting the oven, the continuous fibers enter the unfolding unit 4, where they are fully unfolded through left-right circulating yarn spreading. Thermoplastic resin is extruded through a twin-screw extruder (extrusion unit 6), and the continuous fibers are impregnated with hot-melt resin in the impregnation unit 5 to obtain a molten product of continuous fibers and resin. This product is then hot-pressed and impregnated by a single-set hot-pressing device (roller pressing unit 7). The gap between the pressure rollers is adjusted to control the uniformity of resin coating on the tape surface, pressing the upper and lower resins into the glass fiber to prevent the tape from drying out, resulting in a formed thermoplastic prepreg tape base layer.

[0151] In this comparative example, the continuous fiber used was 1200TEX untwisted continuous fiber, with a fiber mass fraction of 62%. The main material of the thermoplastic resin was high-density polyethylene (HDPE) with a melt index of 60g / 10min. 3% compatibilizer was added to the HDPE to increase the bonding strength between the HDPE and the glass fiber. The compatibilizer's main component was HDPE grafted with maleic anhydride, and 0.3% antioxidant (antioxidant 1010) was also added.

[0152] Comparative Example 2

[0153] The preparation apparatus used in this comparative example is the same as that in Example 1, and the preparation method of the continuous fiber reinforced thermoplastic prepreg tape provided in this comparative example is basically the same as that in Example 1, except that:

[0154] The coating comprises 20 parts sulfonated polyvinylidene fluoride powder, 0.5 parts polyester-modified polydimethylsiloxane, 5 parts polyvinylpyrrolidone, and 75 parts N-methyl-2-pyrrolidone solvent.

[0155] Comparative Example 3

[0156] The preparation apparatus used in this comparative example is the same as that in Example 1, and the preparation method of the continuous fiber reinforced thermoplastic prepreg tape provided in this comparative example is basically the same as that in Example 1, except that:

[0157] The coating comprises 10 parts sulfonated polyvinylidene fluoride powder, 0.5 parts polyester-modified polydimethylsiloxane, 5 parts polyvinylpyrrolidone, and 85 parts N-methyl-2-pyrrolidone solvent.

[0158] Comparative Example 4

[0159] The preparation apparatus used in this comparative example is the same as that in Example 1, and the preparation method of the continuous fiber reinforced thermoplastic prepreg tape provided in this comparative example is basically the same as that in Example 1, except that:

[0160] The sulfonated polyvinylidene fluoride in the coating is replaced with unmodified polyvinylidene fluoride.

[0161] Test case

[0162] The continuous fiber reinforced thermoplastic prepreg tapes provided in all embodiments and comparative examples were tested.

[0163] 1. Tensile strength test: Samples were taken and tested according to standard GB / T1447-2005 to obtain tensile strength: The prepreg tape was cut with a type II strip cutter. A strip sample with a length of 1000 mm and a width of 20 mm was taken from the middle area. Samples were taken at 100 mm intervals. Five test strips were taken from each group and the average value was recorded. The specific results are shown in Table 1.

[0164] 2. Gas Transmission Rate Test: The gas transmission rate was tested using the differential pressure method according to standard GB / T1038.1-2022. A 40mm*40mm prepreg sample was attached to the permeation chamber, with a gas permeation area diameter of 10mm. The surface of the permeation chamber in contact with the sample should be smooth and flat, and there should be no air leakage after sample loading. Three test strips were taken from each group, and the average value was recorded. Specific results are shown in Table 1.

[0165] Table 1

[0166]

[0167]

[0168] As shown in Table 1, the oxygen permeability of the continuous fiber reinforced thermoplastic prepreg tapes provided in Examples 1-7 of the present invention is no higher than 29 cc / m. 2 •d·atm, hydrogen permeability not higher than 170cc / m 2 With a tensile strength of ·d·atm, it has excellent barrier properties. Meanwhile, the continuous fiber reinforced thermoplastic prepreg tapes provided in Examples 1-7 have relatively excellent mechanical properties. The transverse tensile strength of Example 3 reached 11.6 MPa, and the longitudinal tensile strength reached 903 MPa.

[0169] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A continuous fiber-reinforced thermoplastic prepreg tape, characterized in that, Includes a thermoplastic prepreg tape base layer and an organic barrier layer covering the upper and lower surfaces of the thermoplastic prepreg tape base layer; The organic barrier layer includes graphene oxide and sulfonated polyvinylidene fluoride.

2. The continuous fiber-reinforced thermoplastic prepreg tape according to claim 1, characterized in that, The graphene oxide accounts for 0.5%-3.0% of the organic barrier layer by mass, and the sulfonated polyvinylidene fluoride accounts for 85%-95% of the organic barrier layer by mass.

3. The continuous fiber-reinforced thermoplastic prepreg tape according to claim 1 or 2, characterized in that, The oxygen content of the oxygen-containing groups in the graphene oxide is 30%-50%.

4. The continuous fiber-reinforced thermoplastic prepreg tape according to claim 1 or 2, characterized in that, The graphene oxide has a sheet diameter of 3-10 μm and a thickness of 0.5-3 nm.

5. The continuous fiber-reinforced thermoplastic prepreg tape according to claim 1 or 2, characterized in that, The sulfonated polyvinylidene fluoride is prepared by a method comprising the following process: 1) Add PVDF powder to methanol solution and ultrasonically soak for 30 minutes, then remove and dry at 60-80℃ to obtain dried PVDF powder; 2) Add chlorosulfonic acid to the dried PVDF powder and stir at room temperature for 24-36 hours to obtain sulfonated PVDF powder; 3) The sulfonated PVDF powder is washed in a dioxane solution, then washed with water and dried to obtain the sulfonated polyvinylidene fluoride; The mass-to-volume ratio of the PVDF powder to the chlorosulfonic acid is 1g:(10-15)ml.

6. The continuous fiber-reinforced thermoplastic prepreg tape according to claim 1, characterized in that, The thickness of the organic barrier layer is 0.02-0.08 mm; And / or, the thickness of the thermoplastic prepreg tape base layer is 0.25-0.35 mm.

7. The continuous fiber-reinforced thermoplastic prepreg tape according to claim 1, characterized in that, The thermoplastic prepreg tape base layer includes fibers and thermoplastic resin.

8. The continuous fiber-reinforced thermoplastic prepreg tape according to claim 7, characterized in that, The fiber includes at least one of glass fiber, carbon fiber, and aramid fiber; And / or, the thermoplastic resin includes at least one of HDPE, PP, PA, and PET.

9. The continuous fiber-reinforced thermoplastic prepreg tape according to claim 8, characterized in that, The fiber has a mass percentage content of 60%-70%.

10. A method for preparing a continuous fiber-reinforced thermoplastic prepreg tape according to any one of claims 1-9, characterized in that, Includes the following steps: 1) The thermoplastic prepreg tape base layer is corona treated with positive corona at 5-30kw to obtain a prepreg tape base layer with a positively charged surface; 2) Subsequently, the prepreg tape base layer is coated with a coating including graphene oxide and sulfonated polyvinylidene fluoride to obtain a continuous fiber reinforced thermoplastic prepreg tape.

11. The preparation method according to claim 10, characterized in that, The coating also includes solvents, leveling agents, and surfactants.

12. The preparation method according to claim 11, characterized in that, The solvent includes at least one of N-methyl-2-pyrrolidone, dimethylformamide, dimethylacetamide, and dimethyl sulfoxide; And / or, the leveling agent includes at least one of polyester-modified polydimethylsiloxane, polyether-modified organosiloxane, and alkyl-modified organosiloxane; And / or, the surfactant includes at least one of polyvinylpyrrolidone, polyoxyethylene alkylamide, fatty alcohol polyoxyethylene ether, and alkylphenol polyoxyethylene ether.

13. The preparation method according to claim 12, characterized in that, The coating comprises, by weight, 0.3-0.8 parts graphene oxide, 10-20 parts sulfonated polyvinylidene fluoride, 0.2-1 parts polyester-modified polydimethylsiloxane, 3-6 parts polyvinylpyrrolidone, and 75-85 parts N-methyl-2-pyrrolidone.

14. An apparatus for preparing a continuous fiber-reinforced thermoplastic prepreg tape, characterized in that, The preparation apparatus is used to perform the preparation method according to any one of claims 10-13; Includes a corona unit, a coating unit, and a traction unit; The traction unit is used to sequentially pass the thermoplastic prepreg tape base layer through the corona unit and the coating unit.

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