Prepreg tape / metal composite plate, battery pack protection plate and electric automobile

Abstract

The utility model relates to a prepreg tape / metal composite plate, a battery pack protection plate and an electric automobile. The composite plate comprises a first surface layer, a middle layer and a second surface layer which are sequentially stacked, each of the first surface layer and the second surface layer comprises one or more layers of continuous fiber reinforced polyamide unidirectional prepreg tapes; the middle layer comprises a metal plate, and the metal plate comprises a first surface and a second surface; wherein the first surface and / or the second surface are / is provided with a plurality of grooves, the depth of the plurality of grooves is 5-30 [mu] m, and the width of the plurality of grooves is 15-300 [mu] m. According to the prepreg tape / metal composite plate provided by the embodiment of the utility model, the plurality of grooves with specific sizes are formed in the metal plate of the middle layer, so that the impact resistance of the composite plate is improved.

Description

Technical Field

[0001] This utility model relates to composite plates, and more particularly to a prepreg tape / metal composite plate that can be used as a battery pack protective plate. Background Technology

[0002] The battery pack is the power source of an electric vehicle. It is typically located under the vehicle's chassis and is largely exposed under the vehicle. This makes the bottom of the battery pack vulnerable to impacts from flying stones and bricks, as well as scrapes from going uphill and over speed bumps during daily driving. These incidents can potentially cause the battery pack to crack, making protection of the bottom of the battery pack crucial. To cope with these complex operating conditions, a protective plate is usually installed at the bottom of the battery pack to protect it.

[0003] Existing battery pack bottom protection plates for electric vehicles are mostly made of stamped steel sheets, which are then subjected to electrophoresis and other processes to prevent corrosion. However, traditional steel has a high density, which is insufficient to meet the lightweight requirements of electric vehicles. Moreover, steel sheets offer virtually no cushioning for the pallet, and combined with vehicle bumps, they are more likely to cause damage to the pallet. To address this, sandwich panels made of fiber-reinforced PP prepreg tape as the surface layer and steel sheet as the core layer are often used as battery pack bottom protection plates instead of traditional steel sheets. However, these sandwich panels are prone to delamination and deformation after impact or scratches due to insufficient interlayer bonding, resulting in poor protection levels. Utility Model Content

[0004] To overcome at least one of the defects of the prior art, in a first aspect, one embodiment of the present invention provides a prepreg tape / metal composite board, comprising a first surface layer, an intermediate layer, and a second surface layer stacked sequentially; the first surface layer and the second surface layer each comprise one or more layers of continuous fiber-reinforced polyamide unidirectional prepreg tape; the intermediate layer comprises a metal plate, the metal plate comprising a first surface and a second surface; a plurality of grooves are provided on the first surface and / or the second surface, the plurality of grooves having a depth of 5 to 30 μm and a width of 15 to 300 μm.

[0005] According to one embodiment of the present invention, the composite board further includes a first adhesive layer, which is disposed between the first surface layer and the intermediate layer; and / or,

[0006] The composite board further includes a second adhesive layer, which is disposed between the second surface layer and the intermediate layer; and / or,

[0007] The continuous fiber reinforced polyamide unidirectional prepreg tape comprises one or more polyamide layers and one or more continuous fibers disposed within the one or more polyamide layers; and / or

[0008] The width-to-depth ratio of the groove is 2 to 9:1; and / or,

[0009] The surface roughness of the metal plate is 2 to 10 μm.

[0010] According to one embodiment of the present invention, the polyamide layer comprises a first polyamide resin, and the first adhesive layer and / or the second adhesive layer comprises a second polyamide resin, wherein the first polyamide resin is different from the second polyamide resin; and / or...

[0011] The thickness of the first adhesive layer and / or the second adhesive layer does not exceed 0.5 mm; and / or,

[0012] The continuous fiber includes one or more of carbon fiber, glass fiber, silicon carbide fiber, basalt fiber, natural flax fiber, aramid fiber, semi-aromatic polyamide fiber, and polyolefin fiber; and / or,

[0013] The metal plate is in contact with the first surface layer or the first adhesive layer through the first surface, and with the second surface layer or the second adhesive layer through the second surface; and / or,

[0014] The included angle between two adjacent layers of continuous fibers is 0 to 90°.

[0015] According to one embodiment of the present invention, the melting point of the second polyamide resin is 190–210°C; and / or,

[0016] The difference between the melting point of the first polyamide resin and the melting point of the second polyamide resin is ≥30℃; and / or,

[0017] The melting point of the first polyamide resin is 240–320°C.

[0018] According to one embodiment of the present invention, the plurality of grooves are arranged in an array; and / or,

[0019] The depth of the plurality of grooves is 10–20 μm; and / or,

[0020] The angle between the depth direction of the plurality of grooves and the thickness direction of the metal plate is greater than or equal to 0° and less than 90°; and / or,

[0021] The thickness of the first surface layer and / or the second surface layer is 0.5–1 mm; and / or,

[0022] Along the thickness direction of the metal plate, the first surface and the second surface are disposed opposite to each other.

[0023] According to one embodiment of this utility model, the angle between the depth direction of the plurality of grooves and the thickness direction of the metal plate is greater than or equal to 0° and less than 45°; and / or,

[0024] The plurality of grooves are all elongated grooves; and / or,

[0025] The width of the plurality of grooves is 40–200 μm; and / or,

[0026] Along the length of the groove, the projection of the groove is a rectangle, trapezoid, triangle, semicircle or irregular quadrilateral; or, the vertical cross section of the groove is a rectangle, trapezoid, triangle, semicircle or irregular quadrilateral.

[0027] According to one embodiment of this utility model, the angle between the depth direction of the plurality of grooves and the thickness direction of the metal plate is greater than or equal to 0° and less than 5°; and / or,

[0028] The spacing between two adjacent grooves is 200–500 μm, whereby the spacing is the distance between the center lines of the widths of the two grooves; and / or,

[0029] The plurality of grooves are all elongated grooves, and the included angle between the plurality of elongated grooves is 0 to 5°.

[0030] According to one embodiment of this utility model, the angle between the depth direction of the plurality of grooves and the thickness direction of the metal plate is greater than or equal to 0° and less than 1°; and / or,

[0031] The included angle between the plurality of said elongated grooves is 0 to 1°; and / or,

[0032] The width of the plurality of grooves is 15–110 μm; and / or,

[0033] The depth of the plurality of grooves is 7–13 μm.

[0034] Secondly, one embodiment of this utility model provides a battery pack protective plate, including the aforementioned composite plate.

[0035] Thirdly, one embodiment of this utility model provides an electric vehicle, including the aforementioned battery pack guard plate.

[0036] One embodiment of the prepreg tape / metal composite board of this utility model improves the impact resistance of the composite board by setting multiple grooves of specific sizes on the metal plate of the middle layer. Attached Figure Description

[0037] The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this invention.

[0038] in:

[0039] Figure 1 This is a schematic diagram of the structure of a composite plate according to one embodiment of the present invention;

[0040] Figure 2 This is a side view of a metal plate with a rectangular vertical cross-section, representing one embodiment of the present invention.

[0041] Figure 3 This is a schematic diagram of the composite plate according to another embodiment of the present invention;

[0042] Figure 4A A side view of a metal plate with a triangular vertical cross-section for a groove, according to one embodiment of this utility model;

[0043] Figure 4B This is a side view of a metal plate with a trapezoidal vertical cross-section for a groove, according to one embodiment of the present invention.

[0044] Figure 4C This is a side view of a metal plate with a semi-circular vertical cross-section for a groove, according to one embodiment of the present invention.

[0045] The annotations in the attached figures are explained as follows:

[0046] 10. First surface layer; 11. First prepreg layer; 12. Second prepreg layer; 13. Third prepreg layer; 20. Second surface layer; 21. Fourth prepreg layer; 22. Fifth prepreg layer; 23. Sixth prepreg layer; 24. Seventh prepreg layer; 25. Eighth prepreg layer; 30. Metal sheet; 31. First surface; 32. Second surface; 33. Groove; 40. First adhesive layer; 50. Second adhesive layer. Detailed Implementation

[0047] Typical embodiments embodying the features and advantages of this utility model will be described in detail in the following description. It should be understood that this utility model can have various variations in different embodiments, all of which do not depart from the scope of this utility model, and the description herein is for illustrative purposes only and not intended to limit this utility model.

[0048] Reference Figure 1 , 2As shown, one embodiment of this utility model provides a prepreg tape / metal composite board, including a first surface layer 10, an intermediate layer, and a second surface layer 20 stacked sequentially; the first surface layer 10 and the second surface layer 20 each include one or more layers of continuous fiber-reinforced polyamide unidirectional prepreg tape (hereinafter referred to as "unidirectional prepreg tape"); the intermediate layer includes a metal plate 30, the metal plate 30 including a first surface 31 and a second surface 32; wherein, a plurality of grooves 33 are provided on the first surface 31 and / or the second surface 32, the depth H of the plurality of grooves 33 being 5 to 30 μm and the width W being 15 to 300 μm.

[0049] In one implementation, reference Figure 1 , 2 As shown, the first surface 31 of the metal plate 30 is in contact with the first surface layer 10, and the second surface 32 is in contact with the second surface layer 20.

[0050] In one implementation, reference Figure 3 As shown, a first adhesive layer 40 is provided between the first surface layer 10 and the intermediate layer (or metal plate 30), and a second adhesive layer 50 is provided between the second surface layer 20 and the intermediate layer (or metal plate 30).

[0051] In one implementation, reference Figure 2 , 3 As shown, the first surface 31 of the metal plate 30 is in contact with the first adhesive layer 40, and the second surface 32 is in contact with the second adhesive layer 50.

[0052] In one embodiment, the unidirectional prepreg tapes of the first surface layer 10 and the second surface layer 20 include one or more polyamide layers and one or more continuous fibers stacked in the one or more polyamide layers, wherein the polyamide layers contain a first polyamide resin.

[0053] In one embodiment, the first adhesive layer 40 and / or the second adhesive layer 50 comprise a second polyamide resin.

[0054] In one embodiment, the arrangement of multiple grooves 33 on the metal plate 30 can increase the contact area between it and adjacent layers, which is beneficial to enhancing the interlayer bonding force. By limiting parameters such as the depth H and width W of the grooves 33, the strength of the composite plate can be further enhanced, making it more suitable for use as, for example, a battery pack protective plate.

[0055] In one embodiment, the first surface 31 and the second surface 32 of the metal plate 30 are disposed opposite to each other along the thickness direction of the metal plate 30 (or the thickness direction of the composite plate).

[0056] In one embodiment, the depth H of the plurality of grooves 33 can be 5 to 30 μm, further can be 7 to 20 μm, even further can be 7 to 13 μm, and still further can be 10 to 13 μm, for example 7 μm, 8 μm, 9 μm, 10 μm, 11 μm, 12 μm, 13 μm, 15 μm, 18 μm, 25 μm.

[0057] In one embodiment, the angle between the depth direction of the plurality of grooves 33 and the thickness direction of the metal plate 30 can be greater than or equal to 0° and less than 90°, and further can be 0 to 45°, for example 0.1°, 0.2°, 0.5°, 0.8°, 1°, 2°, 5°, 10°, 15°, 20°, 25°, 30°, 35°, 40°, 50°, 60°, 70°, and 80°.

[0058] In one embodiment, the angle between the depth direction of the plurality of grooves 33 and the thickness direction of the metal plate 30 can be 0 to 5°, further can be 0 to 1°, and even further, the depth direction of the plurality of grooves 33 is the same as the thickness direction of the metal plate 30.

[0059] In one embodiment, the width W of the plurality of grooves 33 can be 15–300 μm, more specifically 15–200 μm, even more specifically 15–110 μm, and still more specifically 40–110 μm, and even further specifically 40–50 μm, for example 20 μm, 41 μm, 42 μm, 43 μm, 44 μm, 45 μm, 50 μm, 60 μm, 80 μm, 100 μm, 110 μm, 120 μm, 150 μm, 160 μm, 180 μm, 220 μm, 250 μm, and 280 μm. Here, the width is the width of the opening of the groove 33 on the first surface 31 or the second surface 32, and the width dimension of this opening is smaller than its length dimension; the length of the opening is the length of the groove 33. Further, the width direction of the opening of the groove 33 can be perpendicular to the length direction.

[0060] In one embodiment, the ratio of the width W to the depth H of the groove 33, W / H, can be 2 to 9:1, more specifically 2 to 8.5:1, and even more specifically 4 to 5:1, for example 2.1:1, 3:1, 3.5:1, 4:1, 4.3:1, 4.4:1, 4.5:1, 5:1, 6:1, 7:1, 8:1, 8.3:1, 8.5:1, and 8.7:1. By controlling the W / H ratio within the above range, the interface morphology at the groove 33 can be adjusted, giving the surface a certain roughness. This not only improves the adhesion properties of the metal surface but also improves the mechanical interlocking force between the groove 33 and adjacent layers, increasing the bonding strength between the metal plate 30 and adjacent layers, thereby improving the impact resistance and safety of the composite plate.

[0061] In one embodiment, the arrangement of multiple grooves 33 on the surface of the metal plate 30 forms a microstructure, giving the surface of the metal plate 30 a certain roughness. Further, the surface roughness of the metal plate 30 (e.g., the roughness of the first surface 31 and / or the second surface 32) is 2–10 μm, and more specifically, 2–8 μm, for example, 2.4 μm, 2.5 μm, 2.8 μm, 3.0 μm, 3.2 μm, 3.5 μm, 4.0 μm, 4.5 μm, 5.0 μm, 7.0 μm, 7.5 μm, 7.8 μm, and 8.0 μm. Roughness is expressed as the arithmetic mean (Ra) of the absolute values ​​of the distances between points on the profile along the measurement direction within the sampling length and the reference line. The roughness described herein is measured using a surface roughness meter.

[0062] In one implementation, reference Figure 2 , 4A As shown in 4C, along the length of the groove 33, the projection of the groove 33 is a rectangle (e.g., a square), trapezoid, triangle, semicircle, or irregular quadrilateral; or, the vertical section of the groove 33 is a rectangle (e.g., a square), trapezoid, triangle, semicircle, or irregular quadrilateral, and the vertical section refers to the section along the direction perpendicular to the first surface 31 or the second surface 32.

[0063] In one embodiment, the plurality of grooves 33 are all elongated grooves; further, the included angle between the plurality of elongated grooves can be 0 to 5°, and more particularly, it can be 0 to 1°, for example, 0.1°, 0.5°, 1°, or 2°. Even further, the plurality of elongated grooves are arranged in parallel.

[0064] In one embodiment, the angle between the bottom surface of the groove 33 and the first surface 31 or the second surface 32 of the metal plate 30 is greater than or equal to 0° and less than 90°, and further is 0 to 45°, for example 0.1°, 0.5°, 1°, 2°, 5°, 10°, 15°, 20°, 25°, 30°, 35°, 40°, 50°, 60°, 70°, or 80°.

[0065] In one embodiment, the spacing L between two adjacent grooves 33 is 200–500 μm, and more specifically, 250–450 μm, such as 280 μm, 300 μm, 320 μm, 350 μm, 360 μm, 380 μm, 400 μm, 420 μm, or 430 μm. Further, the spacing L is the distance between the center lines C of the widths of the two grooves 33, which are perpendicular to the first surface 31 or the second surface 32 and divide the width W of the groove 33 into two equal segments.

[0066] In one embodiment, the width W of the groove 33 is 15-300 μm, the depth H is 5-30 μm, the W / H ratio is 2-9:1, the distance L between two adjacent grooves 33 is 200-500 μm, and the surface roughness of the metal plate 30 is 2-10 μm.

[0067] In one embodiment, the width W of the groove 33 is 15-110 μm, the depth H is 7-13 μm, the W / H ratio is 2.0-8.5:1, the distance L between two adjacent grooves 33 is 250-450 μm, and the surface roughness of the metal plate 30 is 2-8 μm.

[0068] In one embodiment, the projection of the groove 33 along the direction perpendicular to the first surface 31 or the second surface 32 is a straight strip (i.e., a rectangle), a broken strip, or a curved strip.

[0069] In one embodiment, the projection of the groove 33 along a direction perpendicular to the first surface 31 or the second surface 32 is a rectangle (first rectangle), the length of the first rectangle being equal to the length of the groove 33, and the width of the first rectangle being equal to the width W of the groove 33. Further, the included angle between the multiple first rectangles of the plurality of grooves 33 along their length direction is 0–5°, and more specifically 0–1°, for example 0.1°, 0.2°, 0.5°, 0.8°, 1°, or 2°.

[0070] In one implementation, reference Figure 2 As shown, the projection of the groove 33 along its length direction or the vertical cross-section of the groove 33 is a rectangle (second rectangle). The width of the second rectangle is the same as the width W (or depth H) of the groove 33, and the length of the second rectangle is the same as the depth H (or width W) of the groove 33. Further, the angle between the centerline of the second rectangle along its length direction (or width direction) and the first surface 31 or the second surface 32 is 0 to 90°, and more specifically 0 to 45°, for example, 0.1°, 0.5°, 1°, 2°, 5°, 10°, 15°, 20°, 25°, 30°, 35°, 40°, 50°, 60°, 70°, and 80°.

[0071] In one embodiment, the plurality of grooves 33 are arranged in a regular or irregular array. For example, the plurality of grooves 33 may be arranged in parallel; or some of the grooves 33 may be arranged in parallel along a first direction, and the remaining grooves 33 may be arranged in parallel along a second direction, with the grooves 33 arranged in the two directions intersecting to form a grid. The included angle between the first direction and the second direction may be greater than 0° and less than or equal to 90°.

[0072] In one embodiment, the plurality of grooves 33 have the same shape and size.

[0073] In one embodiment, the thickness of the first surface layer 10 and / or the second surface layer 20 is 0.5 to 1 mm, for example 0.6 mm, 0.7 mm, 0.8 mm, or 0.9 mm.

[0074] In one embodiment, the first surface layer 10 and / or the second surface layer 20 include multiple layers of continuous fiber-reinforced polyamide unidirectional prepreg tape (hereinafter referred to as "unidirectional prepreg tape") or are formed by compression molding of multiple layers of unidirectional prepreg tape, wherein the unidirectional prepreg tape comprises a first polyamide resin and continuous fibers.

[0075] In one embodiment, the thickness of the unidirectional prepreg tape is 0.15 to 0.5 mm, and can be further 0.2 to 0.33 mm, for example 0.25 mm, 0.28 mm, 0.3 mm, 0.31 mm, 0.32 mm, 0.35 mm, 0.38 mm, 0.4 mm, or 0.45 mm.

[0076] In one embodiment, the first surface layer 10 and / or the second surface layer 20 comprise multiple layers of continuous fibers, such as 2, 3, 4, or 5 layers. Further, the included angle between adjacent layers of continuous fibers can be 0–90°, for example, 10°, 30°, 45°, or 60°.

[0077] In one implementation, reference Figure 1 , 3 As shown, the first surface layer 10 includes a first prepreg tape layer 11, a second prepreg tape layer 12, and a third prepreg tape layer 13 stacked sequentially. Further, the fiber direction of the second prepreg tape layer 12 forms an angle of 90° with the fiber direction of the first prepreg tape layer 11 and the third prepreg tape layer 13, that is, the fibers in adjacent unidirectional prepreg tape layers are arranged perpendicularly.

[0078] In one implementation, reference Figure 1 , 3 As shown, the second surface layer 20 includes a fourth prepreg tape layer 21, a fifth prepreg tape layer 22, a sixth prepreg tape layer 23, a seventh prepreg tape layer 24, and an eighth prepreg tape layer 25 stacked sequentially. Further, in the above five unidirectional prepreg tape layers, the fiber directions of adjacent prepreg tape layers are at 90° (vertically arranged).

[0079] In one embodiment, the unidirectional prepreg tape is prepared by impregnating a first polyamide resin with continuous fibers. Further, the unidirectional prepreg tape is a strip-shaped prepreg made by impregnating mutually parallel continuous fibers with a first polyamide resin, which can be prepared using existing technologies such as solution impregnation, melt coating, suspension impregnation, powder impregnation, or melt impregnation.

[0080] In one embodiment, the unidirectional prepreg tape is prepared by melt impregnation, for example, by impregnating a fiber bundle by pulling it out of molten resin under tension through a specific impregnation mold. For details, refer to the melt impregnation process disclosed in patent application CN115536876A.

[0081] In one embodiment, the mass content of continuous fibers in the unidirectional prepreg tape can be 50-80%, more preferably 60-70%, for example 55%, 63%, 65%, 67%, or 75%.

[0082] In one embodiment, the mass content of the first polyamide resin in the unidirectional prepreg tape can be 14% to 45%, for example 20%, 23%, 24%, 25%, 30%, 31%, 32%, 35%, or 40%.

[0083] In one embodiment, the unidirectional prepreg tape comprises one or more of a flame retardant, a flow modifier, a lubricant, and an antioxidant. Further, the mass content of the flame retardant in the unidirectional prepreg tape can be 0-15%, for example, 0.1%, 0.5%, 1%, 5%, 7%, 8%, 9%, 10%, or 12%; the mass content of the flow modifier in the unidirectional prepreg tape can be 0.4-3%, for example, 1%, 1.5%, 1.8%, 2%, 2.5%, or 2.7%; the mass content of the lubricant in the unidirectional prepreg tape can be 0-2%, for example, 0.1%, 0.3%, 0.4%, 0.5%, 0.6%, 1%, or 1.5%; and the mass content of the antioxidant in the unidirectional prepreg tape can be 0.2-1%, for example, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, or 0.9%.

[0084] In one embodiment, the raw materials used to prepare the unidirectional prepreg tape may include a first polyamide resin, continuous fibers, and one or more of a flame retardant, flow modifier, lubricant, and antioxidant. Further, the raw materials used to prepare the unidirectional prepreg tape include: 14–45 wt% of the first polyamide resin, 50–80 wt% of the continuous fibers, 0–15 wt% of the flame retardant, 0.4–3 wt% of the flow modifier, 0–2 wt% of the lubricant, and 0.2–1 wt% of the antioxidant; wherein the above-mentioned mass contents are based on the total mass of the raw materials.

[0085] In one embodiment, the continuous fiber includes one or more of carbon fiber, glass fiber, silicon carbide fiber, basalt fiber, natural flax fiber, aramid fiber, semi-aromatic polyamide fiber, and polyolefin fiber.

[0086] In one embodiment, the continuous fiber is a continuous glass fiber.

[0087] In one embodiment, the diameter of the monofilament of the continuous fiber can be 5 to 20 μm, and the linear density can be 1000 to 3600 TeX.

[0088] In one embodiment, the first polyamide resin or the second polyamide resin is obtained by copolymerization of a diamine and a diacid, wherein the diamine includes pentanediamine.

[0089] In one embodiment, the first polyamide resin is different from the second polyamide resin.

[0090] In one embodiment, the first polyamide resin and / or the second polyamide resin can be bio-based polyamides. For example, the raw material for its preparation, pentanediamine, can be obtained through bio-fermentation, thereby effectively reducing the use of fossil fuels and thus reducing carbon emissions. Further, bio-based pentanediamine refers to pentanediamine synthesized from compounds derived from biomass, such as glucose and lysine, through enzymatic reactions, yeast reactions, or fermentation reactions during the monomer synthesis process.

[0091] In one embodiment, the diamine used to prepare the first polyamide resin and / or the second polyamide resin includes pentanediamine and other diamines, the other diamines including aliphatic diamines having 4 to 16 carbon atoms other than pentanediamine, such as one or more of butanediamine, hexanediamine, heptadecanediamine, octanediamine, nonanediamine, decanedanediamine, undecanediamine, dodecanediamine, tridecanediamine, tetradecanediamine, pentadecanediamine, and hexadecanediamine.

[0092] In one embodiment, the diacid used to prepare the first polyamide resin and / or the second polyamide resin includes one or more aliphatic diacids and aromatic diacids, such as aliphatic diacids with 4 to 18 carbon atoms and aromatic diacids with 8 to 10 carbon atoms. Further, the aliphatic diacids with 4 to 18 carbon atoms may include one or more of oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, octanoic acid, azelaic acid, sebacic acid, undecanoic acid, dodecanoic acid, tridecanoic acid, tetradecanoic acid, pentadecanoic acid, hexadecanoic acid, heptadecanoic acid, and octadecanoic acid. The aromatic diacids with 8 to 10 carbon atoms may include one or more of terephthalic acid, isophthalic acid, and phthalic acid.

[0093] In one embodiment, the melting point of the first polyamide resin can be 240-320°C, more specifically 260-320°C, and even further 270-320°C, for example 240°C, 250°C, 260°C, 270°C, 280°C, 290°C, 295°C, 298°C, 299°C, or 300°C.

[0094] In one embodiment, the relative viscosity of the first polyamide resin and / or the second polyamide resin can be 1.2 to 6.0, more further, 2.0 to 5.2, even further, 2.0 to 3.2, and still further, 2.0 to 2.7, for example, 2.05, 2.2, 2.3, 2.4, 2.5, 2.6, 2.65, 2.8, or 3.0. The relative viscosity is measured using the Ubbelohde viscometer concentrated sulfuric acid method at a test temperature of 25 ± 0.02 °C.

[0095] In one embodiment, the first polyamide resin is obtained by copolymerization of pentanediamine, adipic acid and terephthalic acid, and has a melting point of 240–320°C.

[0096] In one embodiment, the first polyamide resin is obtained by copolymerization of pentanediamine, hexamethylenediamine, adipic acid and terephthalic acid, and has a melting point of 240–320°C.

[0097] In one embodiment, the first polyamide resin is obtained by copolymerization of pentanediamine, dodecanoic acid and terephthalic acid, and has a melting point of 270-320°C.

[0098] In one embodiment, the second polyamide resin has a melting point of 190–210°C. Using a second polyamide resin with a lower melting point results in lower film preparation costs and reduces energy consumption by melting and bonding the substrate at a lower temperature.

[0099] In one embodiment, the enthalpy of crystallization of the second polyamide resin is below 20 J / g, more specifically 8 to 20 J / g, for example 10 J / g, 15 J / g, or 18 J / g. The enthalpy of crystallization is measured using a differential scanning calorimeter (DSC).

[0100] In one embodiment, the melting point of the first polyamide resin is higher than that of the second polyamide resin.

[0101] In one embodiment, the difference between the melting point of the first polyamide resin and the melting point of the second polyamide resin is ≥30°C, further ≥60°C, and even further ≥80°C.

[0102] In one embodiment, the thickness of the first adhesive layer 40 and / or the second adhesive layer 50 is no more than 0.5 mm, and may further be 0.05 to 0.15 mm, for example 0.06 mm, 0.07 mm, 0.1 mm, 0.12 mm, 0.15 mm, 0.2 mm, 0.3 mm, or 0.4 mm.

[0103] In one embodiment, the thickness of the metal plate 30 is 0.4 to 1.0 mm.

[0104] In one embodiment, the thickness of the prepreg tape / metal composite plate is 2 to 4 mm.

[0105] One embodiment of this utility model provides a method for preparing the above-mentioned prepreg tape / metal composite plate, comprising the following steps:

[0106] S1: Provide a metal plate 30 (or a metal plate with a microstructure) with a plurality of grooves 33 on its surface;

[0107] S2: One or more layers of continuous fiber reinforced polyamide unidirectional prepreg tape, metal plate 30, and one or more layers of continuous fiber reinforced polyamide unidirectional prepreg tape are sequentially laid up, and then molded to obtain a prepreg tape / metal composite plate.

[0108] Another embodiment of this utility model provides a method for preparing the above-mentioned prepreg tape / metal composite plate, comprising the following steps:

[0109] S1: Provide a metal plate 30 (or a metal plate 30 with microstructure) with a plurality of grooves 33 on its surface;

[0110] S2: The first polyamide / fiber composite board, the first polyamide film, the metal plate 30, the second polyamide film, and the second polyamide / fiber composite board are sequentially laid out, and then molded to obtain the composite board.

[0111] In one embodiment, the first polyamide / fiber composite board and / or the second polyamide / fiber composite board comprises one or more polyamide layers and one or more continuous fibers stacked within the one or more polyamide layers. Further, the first polyamide / fiber composite board and / or the second polyamide / fiber composite board are obtained by compression molding of multiple unidirectional prepreg tapes, the unidirectional prepreg tapes comprising a first polyamide resin and continuous fibers.

[0112] In one embodiment, the first polyamide / fiber composite board and / or the second polyamide / fiber composite board are obtained by compression molding after alternating layers of continuous fiber-reinforced bio-based polyamide unidirectional prepreg tape.

[0113] In one embodiment, after molding, the first polyamide film and the second polyamide film form a first adhesive layer 40 and a second adhesive layer 50.

[0114] In one embodiment, step S1 includes: forming a plurality of grooves 33 on one or two surfaces of a metal plate with a smooth surface to form the aforementioned metal plate 30 with a microstructure. Further, the surface of the metal plate may be polished before forming the grooves 33.

[0115] In one embodiment, a plurality of grooves 33 are formed on the surface of the metal plate by sandblasting, laser etching, or plasma etching. Further, the grooves 33 can be formed on the surface of the metal plate by laser etching.

[0116] In one embodiment, in step S2, molding can be performed using a double steel strip molding composite machine or a flat vulcanizing machine.

[0117] One embodiment of this utility model provides the application of the above-mentioned composite plate as a battery pack protective plate.

[0118] One embodiment of this utility model provides a battery pack protective plate (e.g., a battery pack bottom protective plate), which includes the composite plate described above.

[0119] One embodiment of this utility model provides an electric vehicle, including the aforementioned battery pack guard plate.

[0120] The composite plate of this utility model improves the interlayer bonding strength between the surface layer and the intermediate layer and the impact resistance of the composite plate by setting multiple grooves of specific size on the surface of the metal plate and further setting an adhesive layer, which is more conducive to its application in battery pack protective plates.

[0121] The following description, in conjunction with the accompanying drawings and specific embodiments, further illustrates one embodiment of the composite plate of this utility model and its preparation. The raw materials and testing methods involved in each embodiment and comparative example are as follows.

[0122] raw material

[0123] Bio-based pentanediamine, adipic acid, dodecanoic acid, and tridecanoic acid were purchased from Kaisai (Jinxiang) Biomaterials Co., Ltd., and other raw materials not explicitly stated were commercially available.

[0124] The steel plate (grade DP780) was purchased from Shanghai Baosteel; the PP was purchased from LG Chem in South Korea.

[0125] Test methods

[0126] 1. Relative viscosity η of polyamide resin r Test (Ubbelohde viscometer concentrated sulfuric acid method)

[0127] Accurately weigh 0.5 ± 0.0002 g of the dried polyamide sample, dissolve it in 50 mL of concentrated sulfuric acid (96%), and measure and record the flow time t0 of the concentrated sulfuric acid and the flow time t of the polyamide solution in a constant temperature water bath at 25 ± 0.02 °C. Calculate the relative viscosity η according to the following formula. r :

[0128] η r =t / t0

[0129] Where: t: solution flow time; t0: solvent flow time.

[0130] 2. Test of the enthalpy of crystallization of polyamide resin

[0131] The crystallization enthalpy of polyamide resin was tested using a DSC-600S differential scanning calorimeter. The test temperature range was from room temperature to 600℃, and the heating rate was 10℃ / min.

[0132] 3. Steel plate roughness test

[0133] Roughness is expressed as the arithmetic mean (Ra) of the absolute values ​​of the distances between points on the profile along the measurement direction within the sampling length and the baseline. The surface roughness of an etched steel plate (sampling length: 12.5 mm) was measured using a DR300 portable surface roughness meter from Beijing Taicona Technology Co., Ltd.

[0134] 4. Peel performance test of composite board

[0135] The composite panel was subjected to a peel test according to the test method for roller peel strength of sandwich structures (GB / T 1457-2022). The peel strength of the adhesive bond between the panel and the core was determined by peeling the panel from the sandwich structure using a flanged cylinder. One end of the panel was attached to the cylinder, and the other end was attached to a clamp. A loading strip was connected to the flange. When the loading strip was stretched, the cylinder rolled upward, thus peeling the panel from the sandwich structure. The loading strip on the flange and the panel on the cylinder were separated by a certain distance. The roller peel strength of the sandwich structure is actually the peel torque per unit width at which the panel and core separate.

[0136] 5. Impact performance test of composite panels

[0137] (1) A sphere is used as an impact head to impact the composite plate to simulate the working condition of the bottom of the vehicle being hit by a foreign object. The diameter of the sphere is 25mm, the weight is 10kg, the impact energy is 300J, and the impact speed is 8.5m / s. The center point of the composite plate and four points around the center point are selected as impact points and five impacts are performed. The surface of the composite plate should not have any penetration cracks, and the internal aluminum plate should not have any cracks and the amount of dent deformation should be <4mm.

[0138] The diameter of the delamination and hollow areas of the composite board after impact was measured using vernier calipers. Measurements were repeated three times for each impact point to determine the average value. The impact point with the largest hollow area diameter was selected and recorded as the hollow size of the composite board. The degree of hollowness was determined according to the following grading standards:

[0139] R1: No layering;

[0140] R2: Slight delamination, hollow area diameter <4mm;

[0141] R3: Slight delamination, hollow area diameter <8mm;

[0142] R4: Layered, hollow area diameter > 8mm.

[0143] (2) A 50mm extrusion head is used to extrude the weakest part at the bottom of the power battery assembly at a speed of 1mm / s; when the outer shell deformation reaches Amm, the supporting force should exceed BkN. A is the maximum effective deformation space from the bottom of the power battery assembly outer shell to the cell, and B = 30kN. The composite plate is fixed on the lower clamp with grooves, and the 50mm extrusion ball head is used to extrude the composite plate at a speed of 1mm / s. The force-displacement curve is recorded by a universal tensile testing machine, and the deformation and supporting force are read from the curve.

[0144] Preparation Example 1

[0145] Preparation of unidirectional prepreg tape

[0146] A unidirectional prepreg tape with a thickness of 0.2 mm was prepared according to the method of Example 4 in patent application CN115536876A. The mass percentage of continuous long glass fibers in the unidirectional prepreg tape was 65%. The raw materials used to prepare the unidirectional prepreg tape are as follows:

[0147] 31.2 wt% bio-based polyamide (PA5T / 512), 65 wt% continuous long glass fiber, 2.5 wt% flow modifier dodecanoic acid, 0.5 wt% lubricant silicone powder, and 0.8 wt% antioxidant (antioxidants 1098 and 608, mass ratio 1:1).

[0148] The bio-based polyamide (PA5T / 512) was prepared using bio-based pentanediamine, dodecanoic acid, and terephthalic acid as comonomers, following the method described in patent application CN112029090A. The molar ratio of amino acids was 1:1, and the molar ratio of dodecanoic acid to terephthalic acid was 0.3:0.7. PA5T / 512 had a relative viscosity of 2.5 and a melting point of 300℃. The continuous long glass fiber had a monofilament diameter of 17μm and a linear density of 2400Tex, and was purchased from Taishan Glass Fiber Co., Ltd.

[0149] Preparation Example 2

[0150] Preparation of polyamide films

[0151] Bio-based polyamide PA56I was heated and melted, and the melt was cast through a T-die onto a cooling roller with a surface temperature of 36°C. The resulting film was then drawn and wound to obtain a bio-based polyamide PA56I film. Bio-based polyamide PA56I films with thicknesses of 30μm, 60μm, 100μm, 120μm, and 200μm were prepared using this process.

[0152] Among them, the bio-based polyamide PA56I is obtained by copolymerization of bio-based pentanediamine, adipic acid and isophthalic acid, with an amino acid molar ratio of 1:1 and an adipic acid to isophthalic acid molar ratio of 0.9:0.1. Its melting point is 198℃ and its crystallization enthalpy is 10J / g.

[0153] Preparation Example 3

[0154] Preparation of unidirectional prepreg tape

[0155] A unidirectional prepreg tape with a thickness of 0.2 mm was prepared according to the method of Example 4 in patent application CN115536876A. The mass percentage of continuous long glass fibers in the unidirectional prepreg tape was 65%. The raw materials used to prepare the unidirectional prepreg tape are as follows:

[0156] 31.2 wt% bio-based polyamide (PA56 / 5T), 65 wt% continuous long glass fiber, 2.5 wt% flow modifier dodecanoic acid, 0.5 wt% lubricant silicone powder, and 0.8 wt% antioxidant (antioxidants 1098 and 608, mass ratio 1:1).

[0157] The bio-based polyamide (PA56 / 5T) used is the bio-based copolyamide C from patent application CN115536876A, with a relative viscosity of 2.24 and a melting point of 300℃. The continuous long glass fiber has a single filament diameter of 17μm and a linear density of 2400Tex, and was purchased from Taishan Glass Fiber Co., Ltd.

[0158] Comparative Preparation Example 1

[0159] Preparation of unidirectional prepreg tape

[0160] The raw materials used to prepare continuous fiber reinforced PP unidirectional prepreg tape are as follows: 30 wt% PP (polypropylene), 65 wt% continuous long glass fiber (monofilament diameter of 17 μm, linear density of 2400 Tex, purchased from Taishan Glass Fiber Co., Ltd.), 0.3 wt% antioxidant 1010, 0.3 wt% antioxidant 168, 0.4 wt% lubricant (calcium stearate) and 4 wt% compatibilizer (PP-g-MAH).

[0161] The preparation method of continuous fiber reinforced PP unidirectional prepreg tape is as follows:

[0162] (1) Mix the raw materials except for the continuous long glass fiber, and melt-extrude them through a twin-screw extruder; filter the extruded melt through a melt filter, and then enter the impregnation die; wherein, the twin-screw extruder is an eight-zone heating mode, and the temperatures of zones one to eight (from feeding to the die head) are 130℃, 150℃, 190℃, 230℃, 230℃, 230℃, 230℃, 230℃ respectively; the screw speed is 400r / min; the die head temperature is 230℃; the length-to-diameter ratio of the twin-screw extruder is 36:1; the temperature of the melt filter is 230℃;

[0163] (2) The continuous long glass fiber is unwound from the yarn frame by the tension controller, enters the yarn spreading system through the yarn splitting frame, so that each filament bundle is fully spread, and then enters the yarn drying device for preheating (the temperature of the yarn drying device is set at 85℃), and finally enters the impregnation die head, where the continuous long glass fiber is impregnated with the melt.

[0164] (3) The impregnated continuous long glass fibers are molded and cooled using a four-roll mill; the temperature of the circulating water in the four-roll mill is set to 40℃; then, the shaped fibers enter a traction device for further cooling and edge trimming, with a traction speed of 8m / min; finally, they enter an automatic winding machine to be wound into rolls at a winding speed of 8m / min, resulting in a unidirectional prepreg tape with a thickness of 0.2mm. During the preparation process, the screw speed of the twin-screw extruder and the winding speed of the automatic winding machine are controlled to ensure that the content of continuous long glass fibers in the unidirectional prepreg tape is 65wt%.

[0165] Example 1A

[0166] S1: A steel plate with a thickness of 0.8 mm is polished, and then a laser etching machine is used to laser etch the polished steel plate. The laser power is controlled at 40 kW, the scanning speed is 200 mm / s, and the scanning frequency is 30 kHz to prepare a steel plate with surface microstructures on two opposite surfaces. After that, the steel plate with surface microstructures is wiped with ethanol or acetone to thoroughly remove surface contaminants.

[0167] The surface microstructure of the steel plate is formed by several parallel grooves 33. Each groove 33 is rectangular and has a rectangular vertical cross section. The depth H of the groove 33 is 7μm, the width W is 15μm, the spacing L between adjacent grooves 33 is 250μm, the depth direction of the groove 33 is perpendicular to the surface of the steel plate, and the surface roughness of the steel plate is 2.4μm.

[0168] S2: Cut the unidirectional prepreg tape obtained in Preparation Example 1 to the size of the template. Place a layer of release cloth or release paper on the upper and lower layers of the template. Lay three layers of unidirectional prepreg tape at 90° between the upper and lower layers. Then place the steel plate with the surface microstructure mentioned above as the intermediate layer. On the intermediate layer, lay five layers of unidirectional prepreg tape at 90°. Mold the resulting structure on a flat vulcanizing machine. The specific process is as follows:

[0169] The molding press temperature was controlled at 310℃, preheated for 6 minutes at 1.5MPa, and then vented. The pressure was maintained at 3MPa for 20 minutes to obtain a prepreg tape / metal composite board with a thickness of 2.4mm. Its structure is described in [reference needed]. Figure 1 .

[0170] Example 2A

[0171] S1: A steel plate with a thickness of 0.8 mm is polished, and then a laser etching machine is used to laser etch the polished steel plate. The laser power is controlled at 50 kW, the scanning speed is 500 mm / s, and the scanning frequency is 30 kHz to prepare a steel plate with surface microstructures on two opposite surfaces. After that, the steel plate with surface microstructures is wiped with ethanol or acetone to thoroughly remove surface contaminants.

[0172] The surface microstructure of the steel plate is formed by several parallel grooves 33. Each groove 33 is rectangular and has a rectangular vertical cross section. The depth H of the groove 33 is 10 μm, the width W is 44 μm, the spacing L between adjacent grooves 33 is 250 μm, the depth direction of the groove 33 is perpendicular to the surface of the steel plate, and the surface roughness of the steel plate is 3.2 μm.

[0173] S2: Cut the unidirectional prepreg tape obtained in Preparation Example 3 to the size of the template. Place a layer of release cloth or release paper on the upper and lower layers of the template. Lay three layers of unidirectional prepreg tape at 90° between the upper and lower layers. Then place the steel plate with the surface microstructure mentioned above as the intermediate layer. On the intermediate layer, lay five layers of unidirectional prepreg tape at 90°. Mold the resulting structure on a flat vulcanizing machine. The specific process is as follows:

[0174] The molding press temperature was controlled at 310℃, preheated for 6 minutes at 1.5MPa, and then vented. The pressure was maintained at 3MPa for 20 minutes to obtain a prepreg tape / metal composite board with a thickness of 2.4mm. Its structure is described in [reference needed]. Figure 1 .

[0175] Example 3A

[0176] The prepreg tape / metal composite plate was prepared using essentially the same raw materials and processes as in Example 1A, with the difference being: the laser power was controlled at 80kW, the scanning speed at 200mm / s, and the scanning frequency at 30kHz, resulting in a groove depth H of 13μm, a groove width W of 110μm, a spacing L between adjacent grooves 33 of 250μm, and a surface roughness of 7.8μm for the steel plate. For the specific structure of the composite plate, please refer to [link to relevant documentation]. Figure 1 .

[0177] Example 4A

[0178] The prepreg tape / metal composite plate was prepared using essentially the same raw materials and processes as in Example 2A, with the following differences: the depth H of the groove 33 in the steel plate is 10 μm, the width W is 44 μm, the spacing L between adjacent grooves 33 is 450 μm, and the surface roughness of the steel plate is 2.8 μm. For the specific structure of the composite plate, please refer to [link to relevant documentation]. Figure 1 .

[0179] Comparative Example 1A

[0180] The prepreg tape / metal composite plate was prepared using essentially the same raw materials and processes as in Example 2A, with the following differences: the depth H of the groove 33 in the steel plate is 6 μm, the width W is 10 μm, the spacing L between adjacent grooves 33 is 250 μm, and the surface roughness of the steel plate is 1.1 μm. For the specific structure of the composite plate, please refer to [link to example 2]. Figure 1 .

[0181] Comparative Example 2A

[0182] The prepreg tape / metal composite plate was prepared using essentially the same raw materials and processes as in Example 2A, with the following differences: the depth H of the groove 33 in the steel plate is 15 μm, the width W is 163 μm, the spacing L between adjacent grooves 33 is 250 μm, and the surface roughness of the steel plate is 11.8 μm. For the specific structure of the composite plate, please refer to [link to relevant documentation]. Figure 1 .

[0183] Comparative Example 3A

[0184] The prepreg tape / metal composite plate was prepared using essentially the same raw materials and processes as in Example 2A, with the following differences: the depth H of the groove 33 in the steel plate is 10 μm, the width W is 44 μm, the spacing L between adjacent grooves 33 is 100 μm, and the surface roughness of the steel plate is 7.6 μm. For the specific structure of the composite plate, please refer to [link to relevant documentation]. Figure 1 .

[0185] Comparative Example 4A

[0186] The prepreg tape / metal composite plate was prepared using essentially the same raw materials and processes as in Example 2A, with the following differences: the depth H of the groove 33 in the steel plate is 10 μm, the width W is 44 μm, the spacing L between adjacent grooves 33 is 600 μm, and the surface roughness of the steel plate is 0.8 μm. For the specific structure of the composite plate, please refer to [link to relevant documentation]. Figure 1 .

[0187] Comparative Example 5A

[0188] The continuous fiber-reinforced PP unidirectional prepreg tape prepared in Comparative Preparation Example 1 was cut to the size of a template. A layer of release cloth or release paper was placed on the upper and lower layers of the template. Three layers of PP unidirectional prepreg tape were laid at 90° between the upper and lower layers. Then, a steel plate with a thickness of 0.8 mm (with a smooth surface) was placed as the intermediate layer. Five layers of PP unidirectional prepreg tape were laid at 90° on the intermediate layer. The resulting structure was then molded on a double steel strip molding composite machine. The specific process is as follows:

[0189] The molding press temperature was controlled at 200℃, preheated for 6 minutes at 1.5MPa, vented, and held at 10MPa for 20 minutes to obtain a prepreg tape / metal composite board with a thickness of 2.4mm. Its structure is described in [reference needed]. Figure 1 .

[0190] Example 1B

[0191] (1) The unidirectional prepreg tape prepared in Example 3 was laid in 3 layers at 90° cross-lay and molded in one step. The temperature of the molding machine was controlled at 310°. It was preheated for 6 minutes under 1.5MPa, the air was vented, and it was held under 3MPa pressure for 6 minutes to obtain the first polyamide / fiber composite board with a thickness of 0.6mm.

[0192] (2) The unidirectional prepreg tape prepared in Example 3 was laid in 5 layers at 90° cross-lay and molded in one step. The temperature of the molding machine was controlled at 310°. It was preheated for 6 minutes under 1.5MPa, the air was vented, and it was held under 3MPa pressure for 6 minutes to obtain a second polyamide / fiber composite board with a thickness of 1mm.

[0193] (3) Grind the steel plate with a thickness of 0.8 mm, and then use a laser etching machine to laser etch the ground steel plate. Control the laser power to be 50 kW, the scanning speed to be 500 mm / s, and the scanning frequency to be 30 kHz to prepare a steel plate with surface microstructure on two opposite surfaces. After that, use ethanol or acetone to wipe the steel plate with surface microstructure to thoroughly remove surface contaminants.

[0194] The surface microstructure of the steel plate is formed by several parallel grooves 33. Each groove 33 is rectangular and has a rectangular vertical cross section. The depth H of the groove 33 is 10 μm, the width W is 44 μm, the spacing L between adjacent grooves 33 is 250 μm, the depth direction of the groove 33 is perpendicular to the surface of the steel plate, and the surface roughness of the steel plate is 3.2 μm.

[0195] (4) The first polyamide / fiber composite board and the second polyamide / fiber composite board were preheated to 280°C for 90 seconds. Then, they were laid up in the following order: first polyamide / fiber composite board, first polyamide film, steel plate with surface microstructure, second polyamide film, second polyamide / fiber composite board. The layers were then molded on a flat vulcanizing machine. Both the first and second polyamide films were 100 μm thick bio-based polyamide PA56I films prepared in Preparation Example 2. The specific molding process was as follows:

[0196] The molding press temperature was controlled at 240℃, preheated for 5 minutes at 1.5MPa, and then vented. The pressure was maintained at 3MPa for 10 minutes to obtain a composite board with a thickness of 2.4mm. Its structure is described in [reference needed]. Figure 3 .

[0197] Example 2B

[0198] The composite board was prepared using essentially the same raw materials and processes as in Example 1B, with the only difference being:

[0199] In step (1), the unidirectional prepreg tape prepared in Preparation Example 1 was used for molding to obtain a first polyamide / fiber composite board with a thickness of 0.6 mm;

[0200] In step (2), the unidirectional prepreg tape prepared in Preparation Example 1 is used for molding to obtain a second polyamide / fiber composite board with a thickness of 1 mm;

[0201] The groove 33 of the steel plate obtained in step (3) has a depth H of 13 μm, a width W of 110 μm, a spacing L between adjacent grooves of 250 μm, and a surface roughness of 7.8 μm.

[0202] In step (4), the 120 μm thick bio-based polyamide PA56I film prepared in Preparation Example 2 is used as the first polyamide film and the second polyamide film;

[0203] The preheating temperature in step (4) is 240℃. For the specific structure of the composite panel, please refer to [link / reference needed]. Figure 3 .

[0204] Example 3B

[0205] The composite board was prepared using essentially the same raw materials and processes as in Example 2B, with the only difference being:

[0206] The groove 33 of the steel plate obtained in step (3) has a depth H of 7 μm, a width W of 15 μm, a spacing L between adjacent grooves of 250 μm, and a surface roughness of 2.4 μm.

[0207] In step (4), the 60 μm thick bio-based polyamide PA56I film prepared in Preparation Example 2 was used as the first polyamide film and the second polyamide film.

[0208] Example 4B

[0209] The composite plate was prepared using essentially the same raw materials and processes as in Example 1B, with the only differences being: the spacing L between adjacent grooves 33 was 450 μm, and the surface roughness of the steel plate was 2.8 μm. For the specific structure of the composite plate, please refer to [link to example]. Figure 3 .

[0210] Comparative Example 1B

[0211] The composite plate was prepared using essentially the same raw materials and processes as in Example 1B, with the following differences: the depth H of the groove 33 in the steel plate was 8 μm, the width W was 14 μm, the spacing L between adjacent grooves was 250 μm, and the surface roughness was 1.3 μm. For the specific structure of the composite plate, please refer to [link to example]. Figure 3 .

[0212] Comparative Example 2B

[0213] The composite plate was prepared using essentially the same raw materials and processes as in Example 1B, with the following differences: the depth H of the groove 33 in the steel plate is 24 μm, the width W is 229 μm, the spacing L between adjacent grooves 33 is 250 μm, and the surface roughness is 12.1 μm. For the specific structure of the composite plate, please refer to [link to relevant documentation]. Figure 3 .

[0214] Comparative Example 3B

[0215] The composite plate was prepared using essentially the same raw materials and processes as in Example 1B, with the following differences: the depth H of the groove 33 in the steel plate is 10 μm, the width W is 44 μm, the spacing L between adjacent grooves 33 is 100 μm, and the surface roughness is 7.4 μm. For the specific structure of the composite plate, please refer to [link to relevant documentation]. Figure 3 .

[0216] Comparative Example 4B

[0217] The composite plate was prepared using essentially the same raw materials and processes as in Example 1B, with the following differences: the depth H of the groove 33 in the steel plate is 10 μm, the width W is 44 μm, the spacing L between adjacent grooves 33 is 700 μm, and the surface roughness of the steel plate is 0.8 μm. For the specific structure of the composite plate, please refer to [link to relevant documentation]. Figure 3 .

[0218] Comparative Example 5B

[0219] The 0.2 mm thick continuous fiber-reinforced PP unidirectional prepreg tape prepared in Comparative Preparation Example 1 was cut to the size of a template. A release cloth or release paper was placed on the upper and lower layers of the template. Three layers of PP unidirectional prepreg tape were laid at 90° between the upper and lower layers. Then, a 100 μm thick EVA film, a 0.8 mm thick steel plate (with a smooth surface), and another 100 μm thick EVA film were placed in sequence. Finally, five layers of PP unidirectional prepreg tape were laid at 90°. The resulting structure was molded on a double steel strip molding composite machine. The specific process is as follows:

[0220] The molding press temperature was controlled at 200℃, preheated for 5 minutes at 1.5MPa, and then vented. The pressure was maintained at 3MPa for 6 minutes to produce a composite plate with a thickness of 2.4mm. Its structure is described in [reference needed]. Figure 3 .

[0221] The composite boards prepared according to the aforementioned methods in each embodiment and comparative example were tested respectively, and the test results are shown in Tables 1 and 2.

[0222]

[0223]

[0224] Comparing Examples 1A to 4A with Comparative Example 5A, the main differences are: the unidirectional prepreg tape used in Examples 1A to 4A is polyamide, while that used in Comparative Example 5A is PP; and the metal plate in Comparative Example 5A does not contain grooves. According to the results in Table 1, the peel strength of the composite plates of Examples 1A to 4A is much greater than that of Comparative Example 5A; the dent depth of the composite plates of Examples 1A to 4A under drop hammer impact is all within 4 mm, while the corresponding dent depth of Comparative Example 5A is 7.5 mm; the hollowness of Examples 1A to 4A is R3 (slight delamination), while that of Comparative Example 5A is R4 (delamination); the deformation size of Examples 1A to 4A under a force of 30 kN is all within 21 mm, while the deformation size of Comparative Example 5A is 23.8 mm.

[0225] Based on the above results, it can be seen that the interlayer bonding strength and impact resistance of the composite panels obtained by embodiments 1A to 4A of this utility model are significantly better than those of the existing composite panel of comparative example 5A.

[0226] Comparing Examples 1B to 4B with Comparative Example 5B, the main difference between them is that the unidirectional prepreg tape of Examples 1B to 4B uses polyamide, while that of Comparative Example 5B uses PP; the metal plate of Comparative Example 5B does not have grooves, and Comparative Example 5B uses EVA film as the adhesive layer.

[0227] According to the results in Table 1, the peel strength of the composite plates of Examples 1B to 4B is greater than that of Comparative Example 5B; the dent depth of the composite plates of Examples 1B to 4B under drop hammer impact is all within 4 mm, while the corresponding dent depth of Comparative Example 5B is 5.2 mm; the deformation size of Examples 1B to 4B under a force of 30 KN is all within 21 mm, while the deformation size of Comparative Example 5B is 23 mm.

[0228] Based on the above results, it can be seen that the interlayer bonding strength and impact resistance of the composite panels obtained by embodiments 1B to 4B of this utility model are significantly better than those of the composite panel of comparative example 5B.

[0229] Unless otherwise specified, the terms used in this utility model have the meanings commonly understood by those skilled in the art.

[0230] The embodiments described in this utility model are for illustrative purposes only and are not intended to limit the scope of protection of this utility model. Those skilled in the art can make various other substitutions, changes and improvements within the scope of this utility model. Therefore, this utility model is not limited to the above embodiments, but is only defined by the claims.

Claims

1. A prepreg tape / metal composite board, characterized in that, It includes a first surface layer, an intermediate layer, and a second surface layer stacked sequentially; both the first surface layer and the second surface layer include one or more layers of continuous fiber-reinforced polyamide unidirectional prepreg tape; the intermediate layer includes a metal plate, the metal plate including a first surface and a second surface; a plurality of grooves are provided on the first surface and / or the second surface, the plurality of grooves having a depth of 5 to 30 μm and a width of 15 to 300 μm.

2. The prepreg tape / metal composite board according to claim 1, characterized in that, The composite board further includes a first adhesive layer, which is disposed between the first surface layer and the intermediate layer; and / or, The composite board further includes a second adhesive layer, which is disposed between the second surface layer and the intermediate layer; and / or, The continuous fiber reinforced polyamide unidirectional prepreg tape comprises one or more polyamide layers and one or more continuous fibers disposed within the one or more polyamide layers; and / or The width-to-depth ratio of the groove is 2 to 9:1; and / or, The surface roughness of the metal plate is 2 to 10 μm.

3. The prepreg tape / metal composite board according to claim 2, characterized in that, The polyamide layer comprises a first polyamide resin, and the first adhesive layer and / or the second adhesive layer comprises a second polyamide resin, wherein the first polyamide resin is different from the second polyamide resin; and / or The thickness of the first adhesive layer and / or the second adhesive layer does not exceed 0.5 mm; and / or, The continuous fiber includes one or more of carbon fiber, glass fiber, silicon carbide fiber, basalt fiber, natural flax fiber, aramid fiber, semi-aromatic polyamide fiber, and polyolefin fiber; and / or, The metal plate is in contact with the first surface layer or the first adhesive layer through the first surface, and with the second surface layer or the second adhesive layer through the second surface; and / or, The included angle between two adjacent layers of continuous fibers is 0 to 90°.

4. The prepreg tape / metal composite board according to claim 3, characterized in that, The melting point of the second polyamide resin is 190–210°C; and / or, The difference between the melting point of the first polyamide resin and the melting point of the second polyamide resin is ≥30℃; and / or, The melting point of the first polyamide resin is 240–320°C.

5. The prepreg tape / metal composite board according to claim 1 or 2, characterized in that, The plurality of grooves are arranged in an array; and / or, The depth of the plurality of grooves is 10–20 μm; and / or, The angle between the depth direction of the plurality of grooves and the thickness direction of the metal plate is greater than or equal to 0° and less than 90°; and / or, The thickness of the first surface layer and / or the second surface layer is 0.5–1 mm; and / or, Along the thickness direction of the metal plate, the first surface and the second surface are disposed opposite to each other.

6. The prepreg tape / metal composite board according to claim 1 or 2, characterized in that, The angle between the depth direction of the plurality of grooves and the thickness direction of the metal plate is greater than or equal to 0° and less than 45°; and / or, The plurality of grooves are all elongated grooves; and / or, The width of the plurality of grooves is 40–200 μm; and / or, Along the length of the groove, the projection of the groove is a rectangle, trapezoid, triangle, semicircle or irregular quadrilateral; or, the vertical cross section of the groove is a rectangle, trapezoid, triangle, semicircle or irregular quadrilateral.

7. The prepreg tape / metal composite board according to claim 1 or 2, characterized in that, The angle between the depth direction of the plurality of grooves and the thickness direction of the metal plate is greater than or equal to 0° and less than 5°; and / or, The spacing between two adjacent grooves is 200–500 μm, whereby the spacing is the distance between the center lines of the widths of the two grooves; and / or, The plurality of grooves are all elongated grooves, and the included angle between the plurality of elongated grooves is 0 to 5°.

8. The prepreg tape / metal composite board according to claim 7, characterized in that, The angle between the depth direction of the plurality of grooves and the thickness direction of the metal plate is greater than or equal to 0° and less than 1°; and / or, The included angle between the plurality of said elongated grooves is 0 to 1°; and / or, The width of the plurality of grooves is 15–110 μm; and / or, The depth of the plurality of grooves is 7–13 μm.

9. A battery pack protective plate, characterized in that, Includes the prepreg tape / metal composite board according to any one of claims 1 to 8.

10. An electric vehicle, characterized in that, Includes the battery pack guard plate as described in claim 9.

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