Continuous long fiber reinforced thermoplastic composite sheet and preparation method and application thereof

Abstract

The present invention provides a continuous long fiber reinforced thermoplastic composite sheet material and a preparation method and application thereof. The continuous long fiber reinforced thermoplastic composite sheet material comprises m layers of prepreg tape A and n layers of prepreg tape B, and the outer layer is prepreg tape A; wherein, m≥2, n≥1, and m and n are integers; prepreg tape A is a continuous long fiber reinforced long carbon chain polyamide resin unidirectional prepreg tape, which comprises continuous long fibers and long carbon chain polyamide resin; prepreg tape B is a continuous long fiber reinforced short carbon chain polyamide resin unidirectional prepreg tape, which comprises continuous long fibers and short carbon chain polyamide resin. The composite sheet material of the present invention has the advantages of low water absorption, excellent mechanical properties, smooth appearance, reliable performance, and practicality, and the preparation process is simple, time-saving, high production efficiency, and low cost.

Description

Technical Field

[0001] The invention relates to a continuous long fiber reinforced thermoplastic composite plate and a preparation method and application thereof. Background Art

[0002] Continuous fiber reinforced thermoplastic composites (CFRT) are composite materials made by special processes using continuous fibers as reinforcement materials and thermoplastic resin as the matrix. Compared with short glass fiber reinforced thermoplastic composites (SFRT), CFRT is superior in performance, with better mechanical properties, recyclability, light weight and low cost. It is one of the polymer composite materials that has attracted much attention in the past decade. At present, CFRT (such as continuous fiber reinforced thermoplastic composite sheets) is mainly used in automobiles, wind turbine blades, electronics, home appliances, communications, machinery, chemicals, military industry, sports equipment, medical equipment and other fields. Especially in the market of special plastics for automotive parts, the application development potential is huge, the development is relatively rapid, the application is wide, and there are many types. Among them, long glass fiber reinforced polypropylene (PP / LGF) composite materials are the most common. However, the strength of long glass fiber reinforced polypropylene is low, and the secondary molding of composite materials is difficult and cannot be recycled. Continuous fiber reinforced polyamide composite materials have high strength, but because polyamide itself contains a certain amount of amide bonds with polar groups, it is easy to form hydrogen bond structures with water molecules, resulting in a decrease in the hydrogen bond density of the interaction between macromolecular chains, thereby reducing the strength of the material. Therefore, there is an urgent need to prepare a continuous long fiber reinforced thermoplastic composite material that has both high mechanical properties and low water absorption.

[0003] Continuous fiber reinforced thermoplastic prepreg tape is an intermediate used to prepare continuous fiber reinforced thermoplastic composite materials. Its preparation processes mainly include melt impregnation method, solution impregnation method and fiber mixing method.

[0004] At present, the processes for preparing thermoplastic composite materials include injection molding, hot compression molding, pultrusion and other processes. Among them, the injection molding process is the most important molding process for preparing thermoplastic composite materials due to its advantages of high stability, automation and high efficiency. It is also the most widely used molding process. However, the glass fiber retention length of this method is relatively short. The hot compression molding process has the advantages of simple structure, good thermal stability and diversified product appearance. It is one of the more commonly used molding processes for preparing thermoplastic composite materials. The pultrusion process is a molding process for preparing continuous fiber reinforced thermoplastic composites (CFRT) by using fiber roving to be pulled by external force through processes such as impregnation, curing and cutting. The cross-section of the material after molding is fixed and continuous production of the material is achieved. Summary of the invention

[0005] The technical problem to be solved by the present invention is to overcome the defect that the continuous long fiber reinforced thermoplastic composite material in the prior art is difficult to have good mechanical properties and low water absorption at the same time, and to provide a continuous long fiber reinforced thermoplastic composite plate and its preparation method and application. The continuous long fiber reinforced thermoplastic composite plate provided by the present invention has good mechanical properties and low water absorption, and the preparation method is simple and low in cost.

[0006] The present invention solves the above technical problems through the following technical solutions:

[0007] A continuous long fiber reinforced thermoplastic composite plate, comprising m layers of prepreg tape A and n layers of prepreg tape B, and the outer layer is the prepreg tape A; wherein m≥2, n≥1, and m and n are integers;

[0008] The prepreg tape A is a unidirectional prepreg tape of continuous long fibers reinforced with long carbon chain polyamide resin, which comprises continuous long fibers and long carbon chain polyamide resin;

[0009] The prepreg tape B is a continuous long fiber reinforced short carbon chain polyamide resin unidirectional prepreg tape, which includes continuous long fibers and short carbon chain polyamide resin.

[0010] In the present invention, the sum of the values ​​of m and n may be 3-100, such as 4-66 or 20-66.

[0011] In the present invention, n may be 1-98, such as 4, 6, 8 or 10.

[0012] In the present invention, preferably, the continuous long fiber reinforced thermoplastic composite sheet includes m1A-[n1B-m2A-n2B]-m3A, wherein m=m1+m2+m3, m1≥1, m2≥0, m3≥1; n=n1+n2, n1≥0, n2≥0, and n1 and n2 are not 0 at the same time; m1, m2, m3, n1 and n2 are all integers. Among them, "-" indicates that the prepreg tapes are adjacent, for example, "AB" indicates that a layer of prepreg tape A is adjacent to a layer of prepreg tape B.

[0013] For example, the values ​​of m1, m2, m3, n1 and n2 are 1, 0, 1, 3 and 3 respectively, that is, the continuous long fiber reinforced thermoplastic composite sheet includes A-[6B]-A.

[0014] Or, for example, the values ​​of m1, m2, m3, n1 and n2 are 2, 0, 2, 2 and 2 respectively, that is, the continuous long fiber reinforced thermoplastic composite sheet includes 2A-[4B]-A.

[0015] Or, for example, the values ​​of m1, m2, m3, n1 and n2 are 1, 0, 1, 4 and 4 respectively, that is, the continuous long fiber reinforced thermoplastic composite sheet includes A-[8B]-A.

[0016] Or, for example, the values ​​of m1, m2, m3, n1 and n2 are 2, 0, 2, 3 and 3 respectively, that is, the continuous long fiber reinforced thermoplastic composite sheet includes 2A-[6B]-2A.

[0017] In the present invention, preferably, the prepreg tapes B are independently selected from the same or different continuous long fiber reinforced short carbon chain polyamide resin unidirectional prepreg tapes, and the prepreg tapes A are independently selected from the same or different continuous long fiber reinforced long carbon chain polyamide resin unidirectional prepreg tapes.

[0018] In the present invention, the thickness of the prepreg tape A is preferably 0.15-0.5 mm, and further 0.21-0.33 mm, such as 0.23 mm, 0.27 mm, 0.28 mm, 0.31 mm, 0.32 mm or 0.33 mm.

[0019] In the present invention, the thickness of the prepreg tape B is preferably 0.15-0.5 mm, further 0.21-0.33 mm, for example 0.24 mm, 0.31 mm, 0.32 mm or 0.33 mm.

[0020] In the present invention, the total thickness of the continuous long fiber reinforced thermoplastic composite sheet is preferably greater than 0.5 mm, such as 10 mm, and the thickness can be molded and composited according to the specific product.

[0021] In the present invention, the plying method between the layers in the continuous long fiber reinforced thermoplastic composite sheet can be parallel plying or cross plying. Parallel plying means that the plying directions between the layers are the same; cross plying means that the layers are cross-plying at a certain angle.

[0022] The cross-laying method of the cross-ply can be 0°-90°, for example, 45° or 90°.

[0023] In the present invention, the long carbon chain polyamide resin generally refers to a polyamide obtained by polymerizing a diamine (mainly pentamethylenediamine) with a dibasic acid having 10 or more carbon atoms in the methylene group between two carboxyl groups. The short carbon chain polyamide resin generally refers to a polyamide obtained by polymerizing a diamine (mainly pentamethylenediamine) with a dibasic acid having less than 10 carbon atoms in the methylene group between two carboxyl groups.

[0024] In the present invention, the short-chain polyamide resin can be a short-chain polyamide resin conventionally available in the market in the art, preferably purchased from Cathay (Jinxiang) Biomaterials Co., Ltd.

[0025] In the present invention, the short carbon chain polyamide resin is preferably a short carbon chain bio-based polyamide resin.

[0026] Bio-based polyamide resin generally refers to a polyamide resin obtained by using renewable resources such as corn, castor, etc. as raw materials, preparing diamine by microbial method, and then polymerizing with dibasic acid. Preferably, the dibasic acid is also prepared by microbial method.

[0027] In the present invention, the short carbon chain polyamide resin is preferably polyamide 56, referred to as PA56.

[0028] Among them, the PA56 preferably has the following characteristics:

[0029] Relative viscosity is 1.9-2.7, for example 2.29;

[0030] The terminal amino group content is 42-60 mmol / kg, for example 55 mmol / kg;

[0031] Melting point 252-255°C, for example 253°C;

[0032] The raw monomers are pentamethylenediamine and adipic acid, with a bio-based content of 43%-46%.

[0033] In the present invention, the long carbon chain polyamide resin can be a conventional commercially available long carbon chain polyamide resin in the art, preferably purchased from Cathay (Jinxiang) Biomaterials Co., Ltd.

[0034] In the present invention, the long carbon chain polyamide resin is preferably a long carbon chain bio-based polyamide resin.

[0035] In the present invention, the long carbon chain polyamide resin is preferably selected from one or more of PA510, PA511, PA512, PA513, PA514, PA515, PA516, PA517 and PA518.

[0036] Wherein, the long carbon chain polyamide resin preferably has the following characteristics:

[0037] Relative viscosity 1.8-2.7, preferably 2.1-2.6, such as 2.25, 2.32, 2.38, 2.46 or 2.51;

[0038] Terminal amino content 42-60mmol / kg;

[0039] Melting point 170°C-320°C, preferably 180-230°C, for example 191, 197, 210 or 217°C;

[0040] The biobased content is between 29% and 100%, such as 29.6, 32.3, 33.8 or 45%.

[0041] In the present invention, the relative viscosity is measured by the concentrated sulfuric acid method using an Ubbelohde viscometer. The biobased content is measured by carbon 14, for example, by the biobased content detection standard method ASTM D6866.

[0042] In the present invention, the continuous long fiber generally refers to a fiber whose theoretical value of retention length is consistent with the product, that is, the fiber retention length = the length of the product.

[0043] In the present invention, the continuous long fibers may be conventional commercially available continuous long fibers in the art.

[0044] In the present invention, the type of the continuous long fiber can be conventional in the art, such as carbon fiber, glass fiber, basalt fiber or aramid fiber.

[0045] Preferably, the continuous long fiber is a continuous long glass fiber, and the diameter of the single filament may be 8-15 μm, preferably 8-10 μm. The linear density of the continuous long glass fiber may be 1000-3600 Tex, preferably 1200 Tex or 2400 Tex. The continuous long glass fiber is, for example, a continuous long glass fiber with a specification of 1200 Tex purchased from Owens Corning (OC) or a continuous long glass fiber with a specification of 2400 Tex purchased from Jushi.

[0046] Preferably, the continuous long fiber is a continuous long carbon fiber. The continuous long carbon fiber is preferably a polyacrylonitrile carbon fiber. The number of monofilaments of the continuous long carbon fiber may be 20,000-30,000, preferably 12,000 (12K) or 24,000 (24K). The monofilament diameter of the continuous long carbon fiber may be 5-10 μm, preferably 6-8 μm. The continuous long carbon fiber is, for example, Toray T700 with a specification of 24K, or Guangwei Composites continuous long carbon fiber 700S with a specification of 12K or 24K.

[0047] In the present invention, in the prepreg tape A, the mass percentage of the continuous long fibers is preferably 40-80wt%, more preferably 60-70wt%, for example 50.1wt%, 60.5wt%, 62.1wt%, 62.8wt% or 51.3wt%, and the mass percentage refers to the mass of the continuous long fibers as a percentage of the mass of the prepreg tape A.

[0048] In the present invention, the mass percentage of the continuous long fibers in the prepreg tape B is preferably 40-80%, more preferably 60-70%, for example 50.4wt% or 61.3wt%, where the mass percentage refers to the mass of the continuous long fibers relative to the mass of the prepreg tape B.

[0049] In the present invention, preferably, the water content of the prepreg tape A is lower than 2000 ppm, more preferably lower than 1200 ppm, for example, 100-1200 ppm, or 500-1000 ppm.

[0050] In the present invention, preferably, the water content of the prepreg tape B is lower than 2000 ppm, more preferably lower than 1200 ppm, for example, 100-1200 ppm, or 500-1000 ppm.

[0051] In the present invention, preferably, the short carbon chain polyamide resin is PA56, and the long carbon chain polyamide resin is any one or more of PA510, PA511, PA512, PA513, PA514, PA515 and PA516.

[0052] In the present invention, preferably, the prepreg tape A comprises continuous long glass fiber and long carbon chain polyamide resin, and the long carbon chain polyamide resin is any one or more of PA510, PA511, PA512, PA513, PA514, PA515 and PA516. More preferably, the prepreg tape A is a continuous long glass fiber reinforced long carbon chain polyamide thermoplastic unidirectional prepreg tape.

[0053] In the present invention, preferably, the prepreg tape A comprises continuous long carbon fibers and long carbon chain polyamide resin, and the long carbon chain polyamide resin is any one or more of PA510, PA511, PA512, PA513, PA514, PA515 and PA516. More preferably, the prepreg tape A is a continuous long carbon fiber reinforced long carbon chain polyamide thermoplastic unidirectional prepreg tape.

[0054] In the present invention, preferably, the prepreg tape B comprises continuous long glass fibers and PA56, and more preferably, the prepreg tape B is a continuous long glass fiber reinforced PA56 unidirectional prepreg tape.

[0055] In the present invention, preferably, the prepreg tape B comprises continuous long carbon fibers and PA56, and more preferably, the prepreg tape B is a continuous long carbon fiber reinforced PA56 unidirectional prepreg tape.

[0056] In a preferred embodiment of the present invention, in the continuous long fiber reinforced thermoplastic composite sheet, the prepreg tape A is a continuous long glass fiber reinforced long carbon chain unidirectional prepreg tape, and the prepreg tape B is a continuous long glass fiber reinforced PA56 unidirectional prepreg tape.

[0057] For example, in the continuous long fiber reinforced thermoplastic composite sheet, the prepreg tape A is a continuous long glass fiber reinforced PA513 unidirectional prepreg tape, and the prepreg tape B is a continuous long glass fiber reinforced PA56 unidirectional prepreg tape.

[0058] For example, in the continuous long fiber reinforced thermoplastic composite sheet, the prepreg tape A is a continuous long glass fiber reinforced PA510 unidirectional prepreg tape, and the prepreg tape B is a continuous long glass fiber reinforced PA56 unidirectional prepreg tape.

[0059] For example, in the continuous long fiber reinforced thermoplastic composite sheet, the prepreg tape A is a continuous long glass fiber reinforced PA512 unidirectional prepreg tape, and the prepreg tape B is a continuous long glass fiber reinforced PA56 unidirectional prepreg tape.

[0060] For example, in the continuous long fiber reinforced thermoplastic composite sheet, the prepreg tape A is a continuous long glass fiber reinforced PA515 unidirectional prepreg tape, and the prepreg tape B is a continuous long glass fiber reinforced PA56 unidirectional prepreg tape.

[0061] In a preferred embodiment of the present invention, in the continuous long fiber reinforced thermoplastic composite sheet, the prepreg tape A is a continuous long carbon fiber reinforced long carbon chain unidirectional prepreg tape, and the prepreg tape B is a continuous long carbon fiber reinforced PA56 unidirectional prepreg tape.

[0062] For example, in the continuous long fiber reinforced thermoplastic composite sheet, the prepreg tape A is a continuous long carbon fiber reinforced PA510 unidirectional prepreg tape, and the prepreg tape B is a continuous long carbon fiber reinforced PA56 unidirectional prepreg tape.

[0063] The present invention also provides a method for preparing the aforementioned continuous long fiber reinforced thermoplastic composite sheet, which comprises the following steps: laminating the prepreg tape B and the prepreg tape A, and compression molding them to obtain a composite sheet.

[0064] In the present invention, the plying method may be a conventional plying method in the art, such as cross plying or parallel plying.

[0065] The cross-ply angles may be 0°, 90° or 45°.

[0066] In the present invention, before the layering, it is preferred to further include a step of drying the prepreg tape. Reducing the water content of the material by drying can prevent excessive bubbles from being generated during the molding process.

[0067] The drying operation may be a conventional drying operation in the art, such as vacuum drying.

[0068] The drying temperature is preferably 85-120°C, such as 105°C.

[0069] The drying time is preferably 4-25 hours, further 15-24 hours, for example 15 hours, 20 hours or 24 hours.

[0070] In the present invention, the equipment used for the compression molding can be equipment conventionally used for compression molding in the art, such as a compression molding machine, and the compression molding machine can be a double steel belt compression molding composite machine.

[0071] In the present invention, the temperature of the compression molding is preferably 5-10°C higher than the melting point of the short carbon chain polyamide resin, preferably 190-310°C, more preferably 250-310°C, such as 260°C or 278°C.

[0072] In the present invention, the compression molding pressure is preferably 1-5 MPa, such as 2-3 MPa.

[0073] In the present invention, the compression molding method may be a conventional compression molding method in the art, such as continuous compression molding or direct compression molding.

[0074] Wherein, when the compression molding method is continuous compression molding, it may include a step of continuous automatic layering according to the conventional method in the art.

[0075] Wherein, when the compression molding method is direct compression molding, the direct compression molding may include the steps of preheating, exhausting, pressure holding, and cooling according to the conventional techniques in the art.

[0076] The preheating time is preferably 3-8 minutes, such as 5 minutes.

[0077] The number of exhausts is preferably 3-6 times, for example 3 times.

[0078] The pressure holding time is preferably 5-10 minutes, for example 8 minutes.

[0079] The cooling rate is preferably 5-20°C / min, such as 15°C / min. The temperature after cooling is preferably room temperature. In the present invention, the room temperature generally refers to 20±5°C.

[0080] In the present invention, the prepreg tape A and the prepreg tape B are preferably prepared by a melt impregnation method.

[0081] The melt impregnation method may be a conventional melt impregnation method in the art.

[0082] Preferably, the melt impregnation method comprises the following steps:

[0083] S1, extruding a polyamide resin composition, and allowing the melt to enter an impregnation die; wherein the polyamide resin composition comprises the long carbon chain polyamide resin or the short carbon chain polyamide resin;

[0084] S2, introducing the continuous long fiber into the impregnation die head, and impregnating the melt and the continuous long fiber;

[0085] S3, molding, cooling, pulling and winding the impregnated continuous long fibers to obtain the prepreg tape A or the prepreg tape B.

[0086] The mass percentage of the continuous long fibers in the prepreg tape is controlled by adjusting the extrusion speed and the winding speed.

[0087] Preferably, the polyamide resin composition further comprises additives.

[0088] The additives preferably include one or more of an antioxidant, a lubricant, a compatibilizer and a coupling agent.

[0089] The antioxidant is preferably selected from one or more of antioxidant 168, antioxidant 1098, antioxidant 1010 and antioxidant S9228. Wherein, the lubricant preferably includes WAXC and WAXE. Wherein, the compatibilizer can be selected from one or more of PP-g-MAH, POE-g-MAH, POE-g-GMA and EPDM-g-MAH. Wherein, the coupling agent can be selected from one or more of coupling agent KH550, coupling agent KH560 and coupling agent KH570.

[0090] Among them, more preferably, the polyamide resin composition includes the following components in parts by weight: 81.8-99.8 parts of the long carbon chain polyamide resin or the short carbon chain polyamide resin, 0.2-1.6 parts of antioxidant, 0-0.8 parts of lubricant, 0-15 parts of compatibilizer and 0-0.8 parts of coupling agent.

[0091] In certain embodiments, the polyamide resin composition comprises the following components in parts by weight: 90-95 parts of the long carbon chain polyamide resin, 0.4-0.6 parts of an antioxidant, 0.3-0.5 parts of a lubricant, 4-8 parts of a compatibilizer, and 0.4-0.5 parts of a coupling agent.

[0092] For example: the polyamide resin composition includes the following components in parts by weight: the long carbon chain polyamide resin: 94.5 parts, antioxidant 1098: 0.3 parts, antioxidant 168: 0.3 parts, internal lubricant WAXE: 0.2 parts, external lubricant WAXC: 0.2 parts, compatibilizer POE-g-MAH: 4 parts, coupling agent KH550: 0.5 parts.

[0093] In certain embodiments, the polyamide resin composition includes the following components in parts by weight: 90.5-93 parts of the short carbon chain polyamide resin, 0.2-0.4 parts of antioxidant 1098, 0.2-0.4 parts of antioxidant 168, 0.2-0.3 parts of internal lubricant WAXE, 0.2-0.3 parts of external lubricant WAXC, 6-8 parts of compatibilizer and 0.3-0.6 parts of silane coupling agent.

[0094] For example, the polyamide resin composition raw material includes the following components in parts by weight: PA56: 90.5 parts, antioxidant 1098: 0.4 parts, antioxidant 168: 0.4 parts, internal lubricant WAXE: 0.2 parts, external lubricant WAXC: 0.2 parts, compatibilizer POE-g-MAH: 8 parts, coupling agent KH560: 0.3 parts.

[0095] For another example, the raw material of the polyamide resin composition includes the following components in parts by weight: PA56: 90.5 parts, antioxidant 1098: 0.3 parts, antioxidant 168: 0.3 parts, internal lubricant WAXE: 0.2 parts, external lubricant WAXC: 0.2 parts, compatibilizer POE-g-MAH: 8 parts, coupling agent KH560: 0.5 parts.

[0096] Wherein, in step S1, before extruding the polyamide resin composition, preferably, the following step is further included: mixing the polyamide resin composition. The mixing may be stirring and mixing; and the stirring and mixing equipment may be a high-speed stirrer.

[0097] In step S1, the extrusion can be performed using a conventional twin-screw extruder or a single-screw extruder in the art, preferably a twin-screw extruder. The aspect ratio of the twin-screw extruder is preferably 1:36.

[0098] In step S1, the extrusion temperature may be 170-340°C.

[0099] When a twin-screw extruder is used, the twin-screw extruder adopts an eight-zone heating mode. Preferably, the temperatures of zones one to eight (feeding to the die) are 195-260°C, 255-305°C, 255-325°C, 255-325°C, 255-325°C, 255-325°C, 255-325°C, 255-325°C, and 255-325°C, respectively.

[0100] In some specific embodiments, the temperatures of zones one to eight (feeding to die head) are 240°C, 290°C, 300°C, 300°C, 300°C, 300°C, 300°C, and 300°C, respectively.

[0101] In some specific embodiments, the temperatures of zones one to eight (feeding to die head) are 210°C, 270°C, 270°C, 270°C, 270°C, 270°C, 270°C, and 280°C, respectively.

[0102] Wherein, in step S1, expressed as screw speed, the extrusion speed is 200-600 rpm / min, for example, 400 rpm / min.

[0103] Wherein, in step S1, preferably, a filtering step is further included after the extrusion. The filtering can be performed using a conventional melt filter in the art. Preferably, when a twin-screw extruder is used, the temperature of the melt filter is within the range of 0-15°C above and below the eight-zone temperature of the twin-screw extruder.

[0104] Wherein, in step S1, the impregnation die head can be a conventional die head in the art. The width of the impregnation die head is preferably 100-650 mm.

[0105] The temperature of the impregnation die head may be 240-335° C., such as 295 or 300° C. Preferably, when a twin-screw extruder is used, the temperature of the impregnation die head is within the range of 0-15° C. above and below the eight-zone temperature of the twin-screw extruder.

[0106] In step S2, the introduction preferably includes the following process: the continuous long fiber is unwound from the creel through the tension controller, passes through the yarn splitting frame, enters the yarn spreading system, so that each filament bundle is fully spread, then enters the yarn drying device for preheating, and then enters the impregnation die head to impregnate the continuous long fiber with the melt. The temperature of the yarn drying device is preferably 70-400°C.

[0107] In step S3, the molding and cooling can be performed by a conventional roller press in the art, preferably a four-roller press. The temperature of the internal circulating water of the four-roller press can be 60-90°C. The traction can be performed by a conventional traction device in the art, and further cooling and trimming are performed in the traction device. The traction speed of the traction can be 5-15m / min. The winding can be performed by a conventional winding device in the art, preferably an automatic winder.

[0108] The present invention also provides an application of the above-mentioned continuous long fiber reinforced thermoplastic composite sheet in plastic products, wherein the plastic products preferably include plastic products in automobile parts.

[0109] The positive progressive effect of the present invention is that the present invention uses continuous long fiber reinforced polyamide prepreg tape as a molded interlayer, fully utilizing the performance characteristics of bio-based polyamide, and uses polyamide as a resin matrix to connect continuous long fibers with excellent performance to each other, thereby preparing a continuous long fiber reinforced thermoplastic composite plate with low water absorption, excellent mechanical properties, smooth appearance, reliable performance, and practicality.

[0110] The preparation method of the present invention adopts a compression molding composite process, which has a simple process, short time consumption, high production efficiency and low cost. The present invention can also prepare a unidirectional prepreg tape by a melt impregnation method, so that each monofilament can be impregnated with resin, and the impregnation is uniform and has a good effect; the prepared unidirectional prepreg tape with a thickness of 0.15-0.5 mm can be molded or wound, which can provide more freedom for production design. In addition, the present invention can also change the orientation of the long fibers in the composite board by adjusting the different placement directions of the prepreg tape, thereby improving the impact resistance of the composite board to forces in different directions. Adjusting the number of layers of the prepreg tape can also adjust the thickness of the composite board to suit different applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0111] Figure 1 It is a schematic diagram of the structure of the continuous long fiber reinforced thermoplastic composite plate 2A-[4B]-2A prepared in Example 2.

[0112] Figure 2 It is a schematic diagram of the structure of the continuous long fiber reinforced thermoplastic composite plate A-[6B]-A prepared in Example 4.

[0113] Reference numerals:

[0114] 1-2A, A is continuous long glass fiber reinforced PA513 unidirectional prepreg tape;

[0115] 2-4B, B is continuous long glass fiber reinforced PA56 unidirectional prepreg tape;

[0116] 3-A, A is continuous long glass fiber reinforced PA512 unidirectional prepreg tape;

[0117] 4-6B, B is continuous long glass fiber reinforced PA56 unidirectional prepreg tape. DETAILED DESCRIPTION

[0118] The present invention is further described below by way of examples, but the present invention is not limited to the scope of the examples.

[0119] In the following examples, the raw materials were purchased from the following sources: bio-based polyamide resins PA56, PA510, PA512, PA513 and PA515 were purchased from Cathay (Jinxiang) Biomaterials Co., Ltd. PA6 was purchased from Guangzhou Xinhui Meida Nylon Co., Ltd. Continuous long glass fiber was purchased from Owens Corning (OC) with a specification of 1200Tex. Continuous carbon fiber was purchased from Toray Group T700 with a specification of 24K.

[0120] Among them, the characteristics of each polyamide resin are as follows:

[0121] PA56 has a relative viscosity of 2.29, an amino terminal content of 55 mmol / kg, a melting point of 253°C, and a biobased content of 45%;

[0122] PA510 has a relative viscosity of 2.51, an amino terminal content of 54 mmol / kg, a melting point of 217°C, and a biobased content of 100%;

[0123] PA512 has a relative viscosity of 2.32, an amino terminal content of 56 mmol / kg, a melting point of 210°C, and a biobased content of 33.8%;

[0124] PA513 has a relative viscosity of 2.38, an amino terminal content of 41 mmol / kg, a melting point of 197°C, and a biobased content of 32.3%;

[0125] PA515 has a relative viscosity of 2.25, an amino terminal content of 51 mmol / kg, a melting point of 191°C, and a biobased content of 29.6%;

[0126] The relative viscosity of PA6 is 2.46, the terminal amino content is 54 mmol / kg, the melting point is 223°C, and it does not contain any bio-based materials.

[0127] The relative viscosity is measured by the concentrated sulfuric acid method using an Ubbelohde viscometer. The biobased content is measured by carbon 14, for example, by the biobased content test standard method ASTM D6866.

[0128] The release paper was purchased from Shandong Shenghe Paper and Plastic Packaging Co., Ltd.; the release cloth was purchased from Taiwei New Composite Materials Co., Ltd.

[0129] The unidirectional prepregs in the following examples and comparative examples are prepared by melt impregnation method, and the preparation method refers to the following Preparation Examples 1-4.

[0130] Preparation Example 1 Preparation of continuous long glass fiber reinforced PA56 unidirectional prepreg tape:

[0131] 1. A polyamide 56 resin composition is extruded by a twin-screw extruder, and the extruded melt is filtered by a melt filter and enters an impregnation die; wherein:

[0132] The raw material of the polyamide 56 resin composition includes the following components in parts by weight: PA56: 90.5 parts, antioxidant 1098: 0.4 parts, antioxidant 168: 0.4 parts, internal lubricant WAXE: 0.2 parts, external lubricant WAXC: 0.2 parts, compatibilizer POE-g-MAH: 8 parts, coupling agent KH560: 0.3 parts, the above components are added into a high-speed mixer and mixed to obtain a polyamide 56 resin composition;

[0133] The twin-screw extruder adopts an eight-zone heating mode, and the temperatures of zones 1 to 8 (feeding to the die) are 240°C, 290°C, 300°C, 300°C, 300°C, 300°C, 300°C, 300°C, 300°C, respectively;

[0134] The screw speed is 400r / min; the length-to-diameter ratio of the twin-screw extruder is 1:36;

[0135] The temperature of the melt filter was 300°C; the temperature of the die was 300°C.

[0136] 2. The continuous long glass fiber passes through the tension controller, unwinds from the creel, passes through the yarn splitting frame, and enters the yarn spreading system to fully unfold each tow, and then enters the yarn drying device for preheating. The temperature of the yarn drying device is set to 85°C, and then enters the impregnation die head, where the continuous long glass fiber is impregnated with the melt;

[0137] 3. The impregnated continuous long glass fiber is shaped and cooled by a four-roller machine, wherein the temperature of the circulating water in the four-roller machine is set to 80°C;

[0138] Then it enters the traction device for further cooling and edge trimming, with a traction speed of 8m / min;

[0139] Finally, it enters the automatic winder and is wound into a roll at a speed of 8m / min.

[0140] During the preparation process, the screw speed of the twin-screw extruder and the winding speed of the automatic winder are controlled to ensure that the weight fraction ratio of the continuous long glass fiber and the polyamide 56 resin composition is 65:35, thereby obtaining a continuous long glass fiber reinforced PA56 unidirectional prepreg tape.

[0141] 4. Prepreg treatment: The prepreg obtained in step 3 was placed in a vacuum drying oven at 105° C. for 15 hours to reduce the moisture content of the prepreg to 500 ppm.

[0142] Preparation Example 2 Preparation of continuous long carbon fiber reinforced PA56 unidirectional prepreg tape:

[0143] 1. A polyamide 56 resin composition is extruded by a twin-screw extruder, and the extruded melt is filtered by a melt filter and enters an impregnation die; wherein:

[0144] The weight proportions of the raw materials of the polyamide 56 resin composition include the following components: PA56: 90.5 parts, antioxidant 1098: 0.3 parts, antioxidant 168: 0.3 parts, internal lubricant WAXE: 0.2 parts, external lubricant WAXC: 0.2 parts, compatibilizer POE-g-MAH: 8 parts, coupling agent KH560: 0.5 parts. The above components are added into a high-speed mixer and mixed to obtain a polyamide 56 resin composition;

[0145] The twin-screw extruder adopts an eight-zone heating mode, and the temperatures of zones 1 to 8 (feeding to the die) are 240°C, 290°C, 300°C, 300°C, 300°C, 300°C, 300°C, 300°C, 300°C, respectively;

[0146] The screw speed is 400r / min; the length-to-diameter ratio of the twin-screw extruder is 1:36;

[0147] The temperature of the melt filter was 300°C; the temperature of the die was 300°C.

[0148] 2. The continuous long carbon fiber is unwound from the creel through the tension controller, passes through the yarn splitting frame, and enters the yarn spreading system to fully unfold each tow, and then enters the yarn drying device for preheating. The temperature of the yarn drying device is set to 250°C, and then enters the impregnation die head, where the continuous long carbon fiber is impregnated with the melt;

[0149] 3. The impregnated continuous long carbon fiber is molded and cooled by a four-roller machine, wherein the temperature of the circulating water in the four-roller machine is set to 80°C;

[0150] Then it enters the traction device for further cooling and edge trimming, with a traction speed of 8m / min;

[0151] Finally, it enters the automatic winder and is wound into a roll at a speed of 8m / min.

[0152] During the preparation process, the screw speed of the twin-screw extruder and the winding speed of the automatic winder were controlled to ensure that the weight fraction ratio of the continuous long carbon fiber and the polyamide 56 resin composition was 65:35, thereby obtaining a continuous long carbon fiber reinforced PA56 unidirectional prepreg tape.

[0153] 4. Prepreg treatment: The prepreg obtained in step 3 was placed in a vacuum drying oven at 105° C. for 15 hours to reduce the moisture content of the prepreg to 500 ppm.

[0154] Preparation Example 3 Preparation of continuous long glass fiber reinforced long carbon chain bio-based polyamide unidirectional prepreg tape:

[0155] The long carbon chain bio-based polyamide includes PA513, PA510, PA512 or PA515.

[0156] 1. A long carbon chain bio-based polyamide resin composition is extruded by a twin-screw extruder, and the extruded melt is filtered by a melt filter and enters an impregnation die; wherein:

[0157] The weight proportions of the raw materials of the long carbon chain bio-based polyamide composition include the following components: 94.5 parts of long carbon chain bio-based polyamide, 0.3 parts of antioxidant 1098, 0.3 parts of antioxidant 168, 0.2 parts of internal lubricant WAXE, 0.2 parts of external lubricant WAXC, 4 parts of compatibilizer POE-g-MAH, and 0.5 parts of coupling agent KH550. The above components are added into a high-speed mixer and mixed to obtain a long carbon chain bio-based polyamide composition;

[0158] The twin-screw extruder adopts an eight-zone heating mode, and the temperatures of zones 1 to 8 (feeding to the die) are 210°C, 270°C, 270°C, 270°C, 270°C, 270°C, 270°C, 280°C respectively;

[0159] The screw speed is 400r / min; the length-to-diameter ratio of the twin-screw extruder is 1:36;

[0160] The temperature of the melt filter was 290°C; the die temperature was 295°C.

[0161] 2. The continuous long glass fiber passes through the tension controller, unwinds from the creel, passes through the yarn splitting frame, and enters the yarn spreading system to fully unfold each tow, and then enters the yarn drying device for preheating. The temperature of the yarn drying device is set to 85°C, and then enters the impregnation die head, where the continuous long glass fiber is impregnated with the melt;

[0162] 3. The impregnated continuous long glass fiber is molded and cooled by a four-roller machine, wherein the temperature of the circulating water in the four-roller machine is set to 80°C;

[0163] Then it enters the traction device for further cooling and edge trimming, with a traction speed of 8m / min;

[0164] Finally, it enters the automatic winder and is wound into a roll at a speed of 8m / min.

[0165] During the preparation process, the screw speed of the twin-screw extruder and the winding speed of the automatic winder are controlled to ensure that the weight fraction ratio of the continuous long glass fiber and the long carbon chain bio-based polyamide resin composition is 65:35, thereby obtaining a continuous long glass fiber reinforced long carbon chain bio-based polyamide unidirectional prepreg tape.

[0166] 4. Prepreg treatment: The prepreg obtained in step 3 was placed in a vacuum drying oven at 105° C. for 15 hours to reduce the moisture content of the prepreg to 500 ppm.

[0167] Preparation Example 4 Preparation of continuous long carbon fiber reinforced bio-based long carbon chain polyamide unidirectional prepreg tape:

[0168] The long carbon chain bio-based polyamide includes PA513, PA510, PA512 or PA515.

[0169] 1. A long carbon chain bio-based polyamide resin composition is extruded by a twin-screw extruder, and the extruded melt is filtered by a melt filter and enters an impregnation die; wherein:

[0170] The raw materials of the long carbon chain bio-based polyamide resin composition include the following components in weight parts: 94.5 parts of long carbon chain bio-based polyamide, 0.3 parts of antioxidant 1098, 0.3 parts of antioxidant 168, 0.2 parts of internal lubricant WAXE, 0.2 parts of external lubricant WAXC, 4 parts of compatibilizer POE-g-MAH, and 0.5 parts of coupling agent KH560. The above components are added into a high-speed mixer and mixed to obtain a long carbon chain bio-based polyamide resin composition;

[0171] The twin-screw extruder adopts an eight-zone heating mode, and the temperatures of zones 1 to 8 (feeding to the die) are 210°C, 270°C, 270°C, 270°C, 270°C, 270°C, 270°C, 280°C respectively;

[0172] The screw speed is 400r / min; the length-to-diameter ratio of the twin-screw extruder is 1:36;

[0173] The temperature of the melt filter was 290°C; the die temperature was 295°C.

[0174] 2. The continuous long carbon fiber is unwound from the creel through the tension controller, passes through the yarn splitting frame, and enters the yarn spreading system to fully unfold each tow, and then enters the yarn drying device for preheating. The temperature of the yarn drying device is set to 250°C, and then enters the impregnation die head, where the continuous long carbon fiber is impregnated with the melt;

[0175] 3. The impregnated continuous long carbon fiber is molded and cooled by a four-roller machine, wherein the temperature of the circulating water in the four-roller machine is set to 80°C;

[0176] Then it enters the traction device for further cooling and edge trimming, with a traction speed of 8m / min;

[0177] Finally, it enters the automatic winder and is wound into a roll at a speed of 8m / min.

[0178] During the preparation process, the screw speed of the twin-screw extruder and the winding speed of the automatic winder are controlled to ensure that the weight fraction ratio of the continuous long carbon fiber and the long carbon chain bio-based polyamide resin composition is 65:35, thereby obtaining a continuous long carbon fiber reinforced long carbon chain bio-based polyamide unidirectional prepreg tape.

[0179] 4. Prepreg treatment: The prepreg obtained in step 3 was placed in a vacuum drying oven at 105° C. for 15 hours to reduce the moisture content of the prepreg to 500 ppm.

[0180] Example 1

[0181] Prepreg tape A: Continuous long glass fiber reinforced PA513 unidirectional prepreg tape, prepared as in Preparation Example 3, with a thickness of 0.28 mm and a fiber content of 60.5 wt%

[0182] Prepreg tape B: Continuous long glass fiber reinforced PA56 unidirectional prepreg tape, prepared as in Preparation Example 1, with a thickness of 0.32 mm and a fiber content of 61.3 wt%

[0183] Cut the prepreg tape into the size of the template, place a layer of release cloth or release paper on the upper and lower layers of the template, place different layers of prepreg tape in the middle, and perform compression molding. Specifically:

[0184] The temperature of the molding machine was set to 260°C, and 6 layers of prepreg tape B were laid crosswise at 0° and 90°. Then, one layer of prepreg tape A was laid crosswise at 90° relative to the adjacent prepreg tape B on the top and bottom. The pressure of the molding machine was controlled at 3 MPa. The machine was preheated for 5 minutes, vented 3 times, and maintained at pressure for 8 minutes. Then, the machine was moved to the cooling layer and cooled at a cooling rate of 15°C / min to prepare a continuous long fiber reinforced thermoplastic composite sheet A-[6B]-A with a thickness of 2.31 mm.

[0185] Example 2

[0186] Prepreg tape A: Continuous long glass fiber reinforced PA513 unidirectional prepreg tape, prepared as in Preparation Example 3, with a thickness of 0.28 mm and a fiber content of 60.5 wt%

[0187] Prepreg tape B: Continuous long glass fiber reinforced PA56 unidirectional prepreg tape, prepared as in Preparation Example 1, with a thickness of 0.32 mm and a fiber content of 61.3 wt%

[0188] Cut the prepreg tape into the size of the template, place a layer of release cloth or release paper on the upper and lower layers of the template, place different layers of prepreg tape in the middle, and perform compression molding. Specifically:

[0189] The temperature of the molding machine was set to 260°C, and four layers of prepreg tape B were laid crosswise at 0° and 90°, and two layers of prepreg tape A were laid crosswise at 0° and 90° respectively. The pressure of the molding machine was controlled at 3MPa, and the preheating was performed for 5 minutes, the exhaust was performed 3 times, the pressure was maintained for 8 minutes, and then the preheating was performed on the cooling layer and the temperature was cooled at a rate of 15°C / min to prepare a continuous long fiber reinforced thermoplastic composite sheet 2A-[4B]-2A with a thickness of 2.28 mm. The schematic diagram of its structure is shown in Figure 1 , Figure 1 The 1 in the figure represents 2A, and A is continuous long glass fiber reinforced PA513 unidirectional prepreg tape. Figure 1 The 2 in the figure represents 4B, and B is a continuous long glass fiber reinforced PA56 unidirectional prepreg tape.

[0190] Example 3

[0191] Prepreg tape A: continuous long glass fiber reinforced PA510 unidirectional prepreg tape, prepared as in Preparation Example 3, with a thickness of 0.31 mm and a fiber content of 62.8 wt%;

[0192] Prepreg tape B: continuous long glass fiber reinforced PA56 unidirectional prepreg tape, prepared as in Preparation Example 1, with a thickness of 0.32 mm and a fiber content of 61.3 wt%;

[0193] Cut the prepreg tape into the size of the template, place a layer of release cloth or release paper on the upper and lower layers of the template, place different layers of prepreg tape in the middle, and perform compression molding. Specifically:

[0194] The temperature of the molding machine was set to 260°C, and four layers of prepreg tape B were cross-laid at 0° and 90°. Two layers of prepreg tape A were cross-laid at 0° and 90° on the top and bottom, respectively. The pressure of the molding machine was controlled at 3 MPa. The machine was preheated for 5 minutes, vented three times, and maintained at pressure for 8 minutes. The machine was then moved to the cooling layer and cooled at a cooling rate of 15°C / min to produce a continuous long fiber reinforced thermoplastic composite sheet 2A-[4B]-2A with a thickness of 2.39 mm.

[0195] Example 4

[0196] Prepreg tape A: continuous long glass fiber reinforced PA512 unidirectional prepreg tape, prepared as in Preparation 3, with a thickness of 0.28 mm and a fiber content of 62.1 wt%;

[0197] Prepreg tape B: continuous long glass fiber reinforced PA56 unidirectional prepreg tape, prepared as in Preparation Example 1, with a thickness of 0.32 mm and a fiber content of 61.3 wt%;

[0198] Cut the prepreg tape into the size of the template, place a layer of release cloth or release paper on the upper and lower layers of the template, place different layers of prepreg tape in the middle, and perform compression molding. Specifically:

[0199] The temperature of the molding machine was set to 260°C, and 6 layers of prepreg tape B were laid crosswise at 0° and 90°. Then, a layer of prepreg tape A was laid crosswise at 90° relative to the adjacent prepreg tape B. The pressure of the molding machine was controlled at 3 MPa. The machine was preheated for 5 min, vented 3 times, and kept at pressure for 8 min. Then, the machine was moved to the cooling layer and cooled at a cooling rate of 15°C / min to prepare a continuous long fiber reinforced thermoplastic composite sheet A-[6B]-A with a thickness of 2.31 mm. The schematic diagram of its structure is shown in Figure 2 , Figure 2 The 3 in the figure represents A, which is a continuous long glass fiber reinforced PA512 unidirectional prepreg tape. Figure 2 The 4 in the figure represents 6B, and B is a continuous long glass fiber reinforced PA56 unidirectional prepreg tape.

[0200] Example 5

[0201] Prepreg tape A: continuous long glass fiber reinforced PA515 unidirectional prepreg tape, prepared as in Preparation Example 3, with a thickness of 0.27 mm and a fiber content of 62.8 wt%;

[0202] Prepreg tape B: continuous long glass fiber reinforced PA56 unidirectional prepreg tape, prepared as in Preparation Example 1, with a thickness of 0.32 mm and a fiber content of 61.3 wt%;

[0203] Cut the prepreg tape into the size of the template, place a layer of release cloth or release paper on the upper and lower layers of the template, place different layers of prepreg tape in the middle, and perform compression molding. Specifically:

[0204] The temperature of the molding machine was set to 260°C, and 6 layers of prepreg tape B were laid crosswise at 0° and 90°. Then, one layer of prepreg tape A was laid crosswise at 90° relative to the adjacent prepreg tape B on the top and bottom. The pressure of the molding machine was controlled at 3 MPa. The machine was preheated for 5 minutes, vented 3 times, and maintained at pressure for 8 minutes. Then, the machine was moved to the cooling layer and cooled at a cooling rate of 15°C / min to prepare a continuous long fiber reinforced thermoplastic composite sheet A-[6B]-A with a thickness of 2.26 mm.

[0205] Example 6

[0206] Prepreg tape A: continuous long carbon fiber reinforced PA513 unidirectional prepreg tape, prepared as in Preparation Example 4, with a thickness of 0.21 mm and a fiber content of 51.3 wt%;

[0207] Prepreg tape B: continuous long carbon fiber reinforced PA56 unidirectional prepreg tape, prepared as in Preparation Example 2, with a thickness of 0.24 mm and a fiber content of 50.4 wt%;

[0208] Cut the prepreg tape into the size of the template, place a layer of release cloth or release paper on the upper and lower layers of the template, place different layers of prepreg tape in the middle, and perform compression molding. Specifically:

[0209] The temperature of the molding machine was set to 260°C, and 8 layers of prepreg tape B were cross-laid at 0° and 90°. Then, a layer of prepreg tape A was cross-laid at 90° relative to the adjacent prepreg tape B on the top and bottom. The pressure of the molding machine was controlled at 3 MPa. The machine was preheated for 5 minutes, vented 3 times, and maintained at pressure for 8 minutes. Then, the machine was moved to the cooling layer and cooled at a cooling rate of 15°C / min to prepare a continuous long fiber reinforced thermoplastic composite sheet A-[8B]-A with a thickness of 2.23 mm.

[0210] Example 7

[0211] Prepreg tape A: continuous long carbon fiber reinforced PA513 unidirectional prepreg tape, prepared as in Preparation Example 4, with a thickness of 0.21 mm and a fiber content of 51.3 wt%;

[0212] Prepreg tape B: continuous long carbon fiber reinforced PA56 unidirectional prepreg tape, prepared as in Preparation Example 2, with a thickness of 0.24 mm and a fiber content of 50.4 wt%;

[0213] Cut the prepreg tape into the size of the template, place a layer of release cloth or release paper on the upper and lower layers of the template, place different layers of prepreg tape in the middle, and perform compression molding. Specifically:

[0214] The temperature of the molding machine was set to 260°C, and 6 layers of prepreg tape B were cross-laid at 0° and 90°. Two layers of prepreg tape A were cross-laid at 0° and 90° on the top and bottom respectively. The pressure of the molding machine was controlled at 3 MPa. It was preheated for 5 minutes, vented 3 times, and maintained at pressure for 8 minutes. Then it was moved to the cooling layer and cooled at a cooling rate of 15°C / min to prepare a continuous long fiber reinforced thermoplastic composite sheet 2A-[6B]-2A with a thickness of 2.25 mm.

[0215] Example 8

[0216] Prepreg tape A: continuous long carbon fiber reinforced PA510 unidirectional prepreg tape, prepared as in Preparation Example 4, with a thickness of 0.23 mm and a fiber content of 50.1 wt%;

[0217] Prepreg tape B: continuous long carbon fiber reinforced PA56 unidirectional prepreg tape, prepared as in Preparation Example 2, with a thickness of 0.24 mm and a fiber content of 50.4 wt%;

[0218] Cut the prepreg tape into the size of the template, place a layer of release cloth or release paper on the upper and lower layers of the template, place different layers of prepreg tape in the middle, and perform compression molding. Specifically:

[0219] The temperature of the molding machine was set to 260°C, and 8 layers of prepreg tape B were cross-laid at 0° and 90°. Then, a layer of prepreg tape A was cross-laid at 90° relative to the adjacent prepreg tape B on the top and bottom. The pressure of the molding machine was controlled at 3 MPa. The machine was preheated for 5 minutes, vented 3 times, and maintained at pressure for 8 minutes. Then, the machine was moved to the cooling layer and cooled at a cooling rate of 15°C / min to prepare a continuous long fiber reinforced thermoplastic composite sheet A-[8B]-A with a thickness of 2.39 mm.

[0220] Comparative Example 1

[0221] Prepreg tape: continuous long glass fiber reinforced PA6 unidirectional prepreg tape, the process preparation method refers to Preparation Example 3 (only the raw material long carbon chain bio-based polyamide of the resin composition is replaced by PA6), the thickness is 0.31mm, and the fiber content is 61.8wt%;

[0222] Cut the prepreg tape into the size of the template, place a layer of release cloth or release paper on the upper and lower layers of the template, place the prepreg tape in the middle, and perform compression molding. Specifically:

[0223] The temperature of the molding machine was set to 228°C, and the above-mentioned prepreg tape was cross-laid with 8 layers at 0° and 90°. The molding machine pressure was controlled at 3MPa. It was preheated for 5 minutes, vented 3 times, and kept at pressure for 8 minutes. Then it was moved to the cooling layer and cooled at a cooling rate of 15°C / min to prepare a continuous long fiber reinforced thermoplastic composite sheet with a thickness of 2.24 mm.

[0224] Comparative Example 2

[0225] Prepreg tape: Continuous long carbon fiber reinforced PA6 unidirectional prepreg tape, the process preparation method refers to Preparation Example 4 (only the raw material of the resin composition, the long carbon chain bio-based polyamide, is replaced by PA6), the thickness is 0.23mm, and the fiber content is 50.9wt%

[0226] Cut the prepreg tape into the size of the template, place a layer of release cloth or release paper on the upper and lower layers of the template, place the prepreg tape in the middle, and perform compression molding. Specifically:

[0227] The temperature of the molding machine was set to 228°C, and the above-mentioned prepreg tape was laid crosswise at 0° and 90° for 10 layers. The pressure of the molding machine was controlled at 3 MPa. It was preheated for 5 minutes, vented 3 times, and kept at pressure for 8 minutes. Then it was moved to the cooling layer and cooled at a cooling rate of 15°C / min to prepare a continuous long fiber reinforced thermoplastic composite sheet with a thickness of 2.12 mm.

[0228] Comparative Example 3

[0229] Prepreg tape A: Continuous long glass fiber reinforced PA513 unidirectional prepreg tape, prepared as in Preparation Example 3, with a thickness of 0.28 mm and a fiber content of 60.5 wt%

[0230] Prepreg tape: Continuous long glass fiber reinforced PA6 unidirectional prepreg tape, the process preparation method refers to Preparation Example 3 (only the raw material of the resin composition, the long carbon chain bio-based polyamide, is replaced by PA6), the thickness is 0.31 mm, and the fiber content is 61.8 wt%

[0231] Cut the prepreg tape into the size of the template, place a layer of release cloth or release paper on the upper and lower layers of the template, place different layers of prepreg tape in the middle, and perform compression molding. Specifically:

[0232] The temperature of the molding machine was set to 228°C, and 6 layers of prepreg tape B were cross-laid at 0° and 90°. Then, a layer of prepreg tape A was cross-laid at 90° relative to the adjacent prepreg tape B on the top and bottom. The pressure of the molding machine was controlled at 3 MPa. The machine was preheated for 5 minutes, vented 3 times, and maintained at pressure for 8 minutes. Then, the machine was moved to the cooling layer and cooled at a cooling rate of 15°C / min to prepare a continuous long fiber reinforced thermoplastic composite sheet 1A-[6B]-1A with a thickness of 2.31 mm.

[0233] Comparative Example 4

[0234] Prepreg tape A: continuous long carbon fiber reinforced PA513 unidirectional prepreg tape, prepared as in Preparation Example 4, with a thickness of 0.21 mm and a fiber content of 51.3 wt%;

[0235] Prepreg tape B: continuous long carbon fiber reinforced PA6 unidirectional prepreg tape, the process preparation method is the same as that of Preparation Example 4 (only the raw material of the resin composition, the long carbon chain bio-based polyamide, is replaced by PA6), the thickness is 0.23 mm, and the fiber content is 50.9 wt%;

[0236] Cut the prepreg tape into the size of the template, place a layer of release cloth or release paper on the upper and lower layers of the template, place different layers of prepreg tape in the middle, and perform compression molding. Specifically:

[0237] The temperature of the molding machine was set to 228°C, and 8 layers of prepreg tape B were cross-laid at 0° and 90°. Then, a layer of prepreg tape A was cross-laid at 90° relative to the adjacent prepreg tape B on the top and bottom. The pressure of the molding machine was controlled at 3 MPa. The machine was preheated for 5 minutes, vented 3 times, and maintained at pressure for 8 minutes. Then, the machine was moved to the cooling layer and cooled at a cooling rate of 15°C / min to prepare a continuous long fiber reinforced thermoplastic composite sheet A-[8B]-A with a thickness of 2.23 mm.

[0238] The samples prepared in the above Examples 1-8 and Comparative Examples 1-4 were subjected to bending test, HDT test and water absorption test respectively. The test methods are as follows and the test results are shown in Table 1 below.

[0239] (1) Bending test: According to the ISO 14125 standard, a sample with a length of 80 mm, a width of 10 mm, and a thickness of 2 mm was cut for the bending test.

[0240] (2) Heat deformation temperature (HDT) test: The test was conducted in accordance with the national standard GB / T 1634.2-2004. A sample with a length of 120 mm, a width of 10 mm, and a thickness of 2 mm was prepared. The bending stress applied was 1.8 MPa for the HDT test.

[0241] (3) Water absorption test: A 2 mm thick composite board was prepared using the same process. The test was conducted according to the ASTM-D570-2005 standard. A 60 mm long, 60 mm wide, and 2 mm thick water-absorbing board was first prepared. The test was conducted according to the plastic water absorption test method. The test time was 24 h.

[0242] Table 1 Performance test results of composite boards prepared in Examples 1-8 and Comparative Examples 1-4

[0243]

[0244]

[0245] From Table 1, we can see that:

[0246] By comparing Examples 1-5 with Comparative Examples 1 and 3, it can be found that the strength and modulus of the continuous long glass fiber reinforced bio-based polyamide composite sheet are significantly improved compared with the corresponding properties of the continuous long glass fiber reinforced PA6 composite sheet, and the heat resistance is also significantly better than the continuous long glass fiber reinforced PA6 composite sheet, and the water absorption performance is lower than that of the continuous long glass fiber reinforced PA6 composite sheet;

[0247] By comparing Examples 6-8 with Comparative Examples 1 and 3, it can be found that the strength and modulus of the continuous long carbon fiber reinforced bio-based polyamide composite sheet are significantly improved compared with the corresponding performance of the continuous long carbon fiber reinforced PA6 composite sheet, and the heat resistance is also significantly better than the continuous carbon fiber reinforced PA6 composite sheet, and the water absorption performance is lower than that of the continuous carbon fiber reinforced PA6 composite sheet.

[0248] Although the specific embodiments of the present invention are described above, it should be understood by those skilled in the art that this is only for illustration and the protection scope of the present invention is defined by the appended claims. Those skilled in the art may make various changes or modifications to these embodiments without departing from the principles and essence of the present invention, but these changes and modifications all fall within the protection scope of the present invention.

Claims

1. A continuous long fiber reinforced thermoplastic composite sheet, characterized in that: It comprises m layers of prepreg tape A and n layers of prepreg tape B, and the outer layer is the prepreg tape A; wherein m≥2, n≥1, and m and n are integers; The prepreg tape A is a unidirectional prepreg tape of continuous long fiber reinforced long carbon chain polyamide resin, which comprises continuous long fibers and long carbon chain polyamide resin; the long carbon chain polyamide resin is selected from one or more of PA510, PA511, PA512, PA513, PA514, PA515, PA516, PA517 and PA518; The prepreg tape B is a unidirectional prepreg tape of continuous long fiber reinforced short carbon chain polyamide resin, which includes continuous long fibers and short carbon chain polyamide resin; the short carbon chain polyamide resin is obtained by polymerizing pentamethylenediamine and a dibasic acid, and the total number of carbon atoms of the methylene groups between the two carboxyl groups of the dibasic acid is less than 10.

2. The continuous long fiber reinforced thermoplastic composite sheet according to claim 1, characterized in that: The continuous long fiber reinforced thermoplastic composite plate includes m1A-[n1B-m2A-n2B]-m3A, wherein m=m1+m2+m3, m1≥1, m2≥0, m3≥1; n=n1+n2, n1≥0, n2≥0, and n1 and n2 are not 0 at the same time; m1, m2, m3, n1 and n2 are all integers.

3. The continuous long fiber reinforced thermoplastic composite sheet according to claim 1, characterized in that: The sum of the values ​​of m and n is 3-100; And / or, said n is 1-98; And / or, the prepreg tapes A are independently selected from the same or different continuous long fiber reinforced long carbon chain polyamide resin unidirectional prepreg tapes; the prepreg tapes B are independently selected from the same or different continuous long fiber reinforced short carbon chain polyamide resin unidirectional prepreg tapes; And / or, the thickness of the prepreg tape A is 0.15-0.5 mm; And / or, the thickness of the prepreg tape B is 0.15-0.5 mm; And / or, the total thickness of the continuous long fiber reinforced thermoplastic composite sheet is greater than 0.5 mm; And / or, the plying method between the layers in the continuous long fiber reinforced thermoplastic composite sheet is parallel plying or cross plying; the crossing method of the cross plying is greater than 0° and less than or equal to 90°; And / or, the short carbon chain polyamide resin is a short carbon chain bio-based polyamide resin; And / or, the long carbon chain polyamide resin is a long carbon chain bio-based polyamide resin; and / or, in the prepreg tape A, the mass percentage of the continuous long fibers is 40-80%, where the mass percentage refers to the mass of the continuous long fibers accounting for the mass of the prepreg tape A; and / or, the mass percentage of the continuous long fibers in the prepreg tape B is 40-80%, where the mass percentage refers to the mass of the continuous long fibers accounting for the mass of the prepreg tape B; And / or, the water content of the prepreg tape A is less than 2000 ppm; And / or, the water content of the prepreg tape B is lower than 2000 ppm.

4. The continuous long fiber reinforced thermoplastic composite sheet according to claim 3, characterized in that: The cross-plying method is 45° cross-plying or 90° cross-plying; and / or, In the prepreg tape A, the mass percentage of the continuous long fibers is 60-70%; and / or, The mass percentage of the continuous long fibers in the prepreg tape B is 60-70%; and / or, The water content of the prepreg tape A is lower than 1200 ppm; and / or, The water content of the prepreg tape B is less than 1200 ppm.

5. The continuous long fiber reinforced thermoplastic composite sheet according to claim 1, characterized in that: The water content of the prepreg tape A is 100-1200 ppm; and / or, The water content of the prepreg tape B is 100-1200 ppm.

6. The continuous long fiber reinforced thermoplastic composite sheet according to any one of claims 1 to 5, characterized in that: The short carbon chain polyamide resin is PA56; the continuous long fiber is continuous long glass fiber, and the linear density of the continuous long glass fiber is 1000-2400 Tex.

7. The continuous long fiber reinforced thermoplastic composite sheet according to claim 6, characterized in that: The PA56 has the following characteristics: relative viscosity of 1.9-2.7, terminal amino content of 42-60 mmol / kg, melting point of 252-255°C; The long carbon chain polyamide resin has the following characteristics: relative viscosity of 1.8-2.7; terminal amino content of 42-60 mmol / kg; melting point of 170°C-320°C; And / or, the continuous long fibers include carbon fibers, glass fibers, basalt fibers or aramid fibers.

8. The continuous long fiber reinforced thermoplastic composite sheet according to claim 6, characterized in that: The bio-based content of the PA56 is 43%-46%, and the bio-based content of the long carbon chain polyamide resin is 29%-100%.

9. The continuous long fiber reinforced thermoplastic composite sheet according to claim 1, characterized in that: The continuous long fiber is a continuous long glass fiber, the monofilament diameter of the continuous long glass fiber is 8-15 μm; the linear density of the continuous long glass fiber is 1000-1200 Tex; Alternatively, the continuous long fibers are continuous long carbon fibers; the continuous long carbon fibers are polyacrylonitrile carbon fibers; the number of single filaments of the continuous long carbon fibers is 20,000-30,000; and the diameter of single filaments of the continuous long carbon fibers is 5-10 μm.

10. The continuous long fiber reinforced thermoplastic composite sheet according to claim 9, characterized in that: The monofilament diameter of the continuous long glass fiber is 8-10 μm; or, The number of the single filaments of the continuous long carbon fiber is 12,000 or 24,000, and the diameter of the single filaments of the continuous long carbon fiber is 6-8 μm.

11. The continuous long fiber reinforced thermoplastic composite sheet according to claim 1, characterized in that: The prepreg tape A comprises continuous long glass fibers and long carbon chain polyamide resin, wherein the long carbon chain polyamide resin is any one or more of PA510, PA511, PA512, PA513, PA514, PA515 and PA516; or, the prepreg tape A comprises continuous long carbon fibers and long carbon chain polyamide resin, wherein the long carbon chain polyamide resin is any one or more of PA510, PA511, PA512, PA513, PA514, PA515 and PA516; And / or, the prepreg tape B comprises continuous long glass fiber and PA56; or, the prepreg tape B comprises continuous long carbon fiber and PA56; and / or, The linear density of the continuous long glass fiber is 1000-3600 Tex.

12. The continuous long fiber reinforced thermoplastic composite sheet according to claim 11, characterized in that: The prepreg tape A is a continuous long glass fiber reinforced long carbon chain polyamide resin thermoplastic unidirectional prepreg tape; or, the prepreg tape A is a continuous long carbon fiber reinforced long carbon chain polyamide resin thermoplastic unidirectional prepreg tape; and / or, The prepreg tape B is a continuous long glass fiber reinforced PA56 unidirectional prepreg tape; or, the prepreg tape B is a continuous long carbon fiber reinforced PA56 unidirectional prepreg tape.

13. The continuous long fiber reinforced thermoplastic composite sheet according to claim 11, characterized in that: In the continuous long fiber reinforced thermoplastic composite sheet, the prepreg tape A is a continuous long glass fiber reinforced long carbon chain unidirectional prepreg tape, and the prepreg tape B is a continuous long glass fiber reinforced PA56 unidirectional prepreg tape; Alternatively, in the continuous long fiber reinforced thermoplastic composite sheet, the prepreg tape A is a continuous long carbon fiber reinforced long carbon chain unidirectional prepreg tape, and the prepreg tape B is a continuous long carbon fiber reinforced PA56 unidirectional prepreg tape.

14. A method for preparing the continuous long fiber reinforced thermoplastic composite sheet according to any one of claims 1 to 13, characterized in that: The method comprises the following steps: plying the prepreg tape B and the prepreg tape A, and performing compression molding.

15. The preparation method according to claim 14, characterized in that: The ply laying method is cross ply laying or parallel ply laying; wherein the cross ply laying method is greater than 0° and less than or equal to 90°; And / or, before the layering, the step of drying the prepreg tape is also included; wherein the drying operation is vacuum drying; And / or, the equipment used for the compression molding is a compression molding machine; And / or, the compression molding temperature is 5-10° C. higher than the melting point of the short carbon chain polyamide resin; And / or, the compression molding pressure is 1-5 MPa; And / or, the compression molding method is continuous compression molding or direct compression molding; And / or, the prepreg tape A and the prepreg tape B are prepared by melt impregnation method.

16. The preparation method according to claim 15, characterized in that: The cross-plying method is 45° cross-plying or 90° cross-plying; and / or, The drying temperature is 85-120° C., and the drying time is 4-25 hours; and / or, The molding machine is a double steel belt molding compound machine; and / or, The compression molding temperature is 190-310°C; and / or, The compression molding method is continuous compression molding, and the continuous compression molding includes the step of continuous automatic layering; or, the compression molding method is direct compression molding, and the direct compression molding includes the steps of preheating, exhausting, holding pressure, and cooling; and / or, The melt impregnation method comprises the following steps: S1, extruding a polyamide resin composition, and allowing the melt to enter an impregnation die; wherein the polyamide resin composition comprises the long carbon chain polyamide resin or the short carbon chain polyamide resin; S2, introducing the continuous long fiber into the impregnation die head, and the melt and the continuous long fiber are impregnated; S3, molding, cooling, pulling and winding the impregnated continuous long fibers to obtain the prepreg tape A or the prepreg tape B.

17. The preparation method according to claim 16, characterized in that The preheating time is 3-8 min; and / or, The number of exhausts is 3-6 times; and / or, The pressure holding time is 5-10 minutes; and / or, The cooling rate is 5-20°C / min; and / or, The temperature after cooling is 20±5°C; and / or, The polyamide resin composition further includes additives.

18. The preparation method according to claim 17, characterized in that: The additives include one or more of an antioxidant, a lubricant, a compatibilizer and a coupling agent.

19. The preparation method according to claim 17, characterized in that: The polyamide resin composition comprises the following components in parts by weight: 81.8-99.8 parts of the long carbon chain polyamide resin or the short carbon chain polyamide resin, 0.2-1.6 parts of an antioxidant, 0-0.8 parts of a lubricant, 0-15 parts of a compatibilizer and 0-0.8 parts of a coupling agent.

20. The preparation method according to claim 18 or 19, characterized in that: The antioxidant is selected from one or more of antioxidant 168, antioxidant 1098, antioxidant 1010 and antioxidant S9228; and / or, The lubricant includes WAXC and WAXE; and / or, The compatibilizer is selected from one or more of PP-g-MAH, POE-g-MAH, POE-g-GMA and EPDM-g-MAH; and / or, The coupling agent is selected from one or more of coupling agent KH550, coupling agent KH560 or coupling agent KH570.

21. Use of the continuous long fiber reinforced thermoplastic composite sheet according to any one of claims 1 to 13 or the continuous long fiber reinforced thermoplastic composite sheet prepared by the preparation method according to any one of claims 14 to 20 in plastic products.

22. The use according to claim 21, characterized in that The plastic products include plastic products in automobile parts.

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