Automotive parts and their manufacturing methods

Abstract

The present invention provides an automobile component and a preparation method thereof. The automobile component comprises: an outer panel, an inner panel and a cavity arranged between the outer panel and the inner panel, wherein the outer panel is made of a polydicyclopentadiene composite material reinforced by a discontinuous reinforcement, and the inner panel is made of a polydicyclopentadiene composite material reinforced by a continuous reinforcement. In the above automobile component having the structural features of the inner panel, the outer panel and the cavity, the inner panel, as the main load-bearing part, is made of a polydicyclopentadiene composite material reinforced by a continuous fiber, and the outer panel is made of a polydicyclopentadiene composite material reinforced by a discontinuous fiber. Under the premise of ensuring the structural rigidity and mechanical strength of the components, the design goals of high performance of the inner panel and low cost of the outer panel are achieved, and the high performance, low cost, lightweight and short cycle manufacturing of automobile components are realized, which has significant economic and social benefits.

Description

Technical Field

[0001] The present invention relates to the field of composite material preparation, and in particular to an automobile component and a preparation method thereof. Background Art

[0002] In the existing lightweight technology for automobile parts, aluminum alloy, magnesium alloy, and titanium alloy are used instead of steel. Although they can maintain good structural strength and stiffness, they also have many problems such as poor machinability, high material cost, low weight reduction efficiency, and low shock absorption capacity. Although the "plastic-steel" technology uses plastic products and has obvious advantages such as weight reduction and corrosion resistance, the mechanical properties of plastics such as strength, stiffness, and impact resistance are limited and cannot be used for load-bearing structural parts. Fiber-reinforced resin-based composite materials (FRP) have many excellent properties such as light weight, high strength, and corrosion resistance, and are the preferred direction for current automotive lightweight materials.

[0003] When the reinforcement material is the same, the performance of the resin matrix material plays a key role in the overall performance of FRP. Most thermoplastic polymers have high viscosity, high processing temperature, and difficult molding process, and the preparation technology of their composite materials is not yet mature. Among the common automotive thermosetting polymers, polydicyclopentadiene (PDCPD) has good processability and mechanical properties, and is a new star in the field of automotive parts selection.

[0004] The existing PDCPD application technology is mainly used to prepare polydicyclopentadiene modified plastics and short fiber reinforced composites. The structural reinforcement effect of the composite reinforcement has not been fully reflected. Most of the products have problems such as single performance and insufficient mechanical strength. The products are mainly used for appearance parts and interior parts, and are rarely used for load-bearing structural parts, which limits the application scope of PDCPD.

[0005] In the existing technology, when manufacturing automotive parts of this type of structure, both the inner and outer panels are mostly made of short-cut fiber reinforced composite materials. The short fiber reinforcement effect of the inner panel is poor, which cannot meet the requirements of higher mechanical properties of the application end or has low weight reduction benefits. If continuous fiber reinforced composite materials are used to manufacture inner and outer panels, the epoxy resin system used in the existing technology route has defects such as high viscosity, high processing difficulty, high equipment performance requirements, and low production rate, which seriously restricts the development of application technology of this type of fiber reinforced composite parts. Summary of the invention

[0006] The main purpose of the present invention is to provide an automobile component and a preparation method thereof, so as to solve the problem that the existing automobile components cannot meet the requirements of the mechanical properties of the existing high-end products and have low weight reduction efficiency, which greatly limits the application field thereof.

[0007] In order to achieve the above-mentioned purpose, according to one aspect of the present invention, there is provided an automobile component, which includes: an outer panel, an inner panel and a cavity arranged between the outer panel and the inner panel, the outer panel is made of a polydicyclopentadiene composite material reinforced by a discontinuous reinforcement, and the inner panel is made of a polydicyclopentadiene composite material reinforced by a continuous reinforcement.

[0008] Furthermore, the inner panel and the outer panel are connected by adhesive bonding or hybrid bonding; preferably, the hybrid bonding is selected from adhesive-screw bonding and / or adhesive-rivet bonding.

[0009] Furthermore, the structural forms of the discontinuous reinforcements and the continuous reinforcements are selected from one or more of the group consisting of short fibers, long fibers, fiber webs, unidirectional or multi-axial filaments, non-woven felts, non-woven felt fabrics, continuous fiber fabrics and unidirectional fabrics; wherein the continuous fiber fabrics are selected from one or more of the group consisting of woven fabrics, knitted fabrics, mesh cloths and woven fabrics, and their structural forms include plain weave, twill, satin, three-dimensional weaving, mesh cloth or warp and weft weaving; the materials of the discontinuous reinforcements and the continuous reinforcements are selected from glass fiber, carbon fiber, aramid fiber or ramie fiber.

[0010] Furthermore, in the outer panel, the content of the discontinuous reinforcement is 0.1 to 50 wt%, preferably 2 to 30 wt%, calculated as the weight percentage of the dicyclopentadiene monomer; in the inner panel, the content of the continuous reinforcement is 30 to 80 wt%, preferably 40 to 65 wt%, calculated as the weight percentage of the continuous fiber reinforced polydicyclopentadiene composite material.

[0011] Furthermore, the polydicyclopentadiene composite material reinforced by a discontinuous reinforcement also includes a first functional additive, and the polydicyclopentadiene composite material reinforced by a continuous reinforcement also includes a second functional additive; preferably, the first functional additive and the second functional additive are independently selected from one or more of an inorganic nanofiller, an antioxidant and a flame retardant.

[0012] Furthermore, the preparation method of the outer panel includes: uniformly dispersing a non-continuous reinforcement and an optional first functional additive in a first dicyclopentadiene polymerization system to carry out a first polymerization curing and molding reaction to obtain an outer panel, wherein the first dicyclopentadiene polymerization system includes a dicyclopentadiene monomer, a first catalyst and a first polymerization time regulator; the preparation method of the inner panel includes: injecting a second dicyclopentadiene polymerization system into a continuous reinforcement and an optional second functional additive to carry out a second polymerization curing and molding reaction to obtain an inner panel, wherein the second dicyclopentadiene polymerization system includes a dicyclopentadiene monomer, a second catalyst and a second polymerization time regulator.

[0013] Furthermore, before carrying out the first polymerization curing and molding reaction, the method for preparing the outer panel also includes: performing a first heating process on the dicyclopentadiene monomer under a first protective atmosphere so that the dicyclopentadiene monomer is liquid at room temperature; before carrying out the second polymerization curing and molding reaction, the method for preparing the inner panel also includes: performing a second heating process on the dicyclopentadiene monomer under a second protective atmosphere so that the dicyclopentadiene monomer is liquid at room temperature.

[0014] Furthermore, the first protective atmosphere and the second protective atmosphere are independently selected from nitrogen or inert gas; the temperatures of the first heating process and the second heating process are independently selected from 140 to 180°C, preferably, the temperatures of the first heating process and the second heating process are independently selected from 145 to 160°C, more preferably, the temperatures of the first heating process and the second heating process are independently selected from 150 to 160°C.

[0015] Further, the first polymerization time regulator and the second polymerization time regulator are independently selected from one or more of the group consisting of alcohols, ketones, ethers, aluminum-based compounds and organic phosphines.

[0016] Another aspect of the present application provides a method for preparing an automobile component, wherein the automobile component includes an outer panel and an inner panel, and the preparation method includes: preparing the outer panel and the inner panel using the above preparation method; and connecting the outer panel and the inner panel using the above connection method.

[0017] Another aspect of the present application provides a discontinuous reinforcement-reinforced polydicyclopentadiene composite material, which is prepared by a first polymerization curing molding reaction.

[0018] Another aspect of the present application provides a continuous reinforcement-reinforced polydicyclopentadiene composite material, which is prepared by a second polymerization curing molding reaction.

[0019] Applying the technical scheme of the present invention, the present invention proposes an automobile component with the structural characteristics of an inner panel, an outer panel and a cavity. The inner panel, as the main load-bearing part, is made of a continuous fiber reinforced polydicyclopentadiene composite material, and the outer panel is made of a non-continuous fiber reinforced polydicyclopentadiene composite material. Under the premise of ensuring the structural rigidity and mechanical strength of the component, the design goals of high performance of the inner panel and low cost of the outer panel are achieved, thereby realizing high performance, low cost, lightweight and short cycle manufacturing of automobile components, which has significant economic and social benefits. DETAILED DESCRIPTION

[0020] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below in conjunction with the embodiments.

[0021] As described in the background technology, existing auto parts cannot meet the requirements of existing high-end products for mechanical properties, and the weight reduction efficiency is low, which greatly limits the problem of their application fields. In order to solve the above technical problems, the present application provides an auto part, which includes: an outer panel, an inner panel, and a cavity arranged between the outer panel and the inner panel, the outer panel is made of a polydicyclopentadiene composite material reinforced by a discontinuous reinforcement, and the inner panel is made of a polydicyclopentadiene composite material reinforced by a continuous reinforcement.

[0022] The present invention proposes an automobile component with the structural features of an inner panel, an outer panel and a cavity. The inner panel, as the main load-bearing part, is made of a continuous fiber-reinforced polydicyclopentadiene composite material, and the outer panel is made of a discontinuous fiber-reinforced polydicyclopentadiene composite material. A cavity is set between the inner panel and the outer panel to improve the overall structural rigidity of the component, which is used to install functional components such as glass, locks, pull ropes, and embedded parts, while providing connection holes, process holes and working space. Therefore, the above-mentioned automobile component can achieve the design goals of high performance of the inner panel and low cost of the outer panel under the premise of ensuring the structural rigidity and mechanical strength of the component, and realize the high performance, low cost, lightweight and short cycle manufacturing of automobile components, which has significant economic and social benefits.

[0023] Preferably, the above-mentioned automobile parts include but are not limited to engine hood, car doors, tailgate, etc.

[0024] The outer panel and the inner panel can be connected by a common method in the art. In a preferred embodiment, the inner panel and the outer panel are connected by adhesive bonding or hybrid bonding; preferably, the hybrid bonding is selected from adhesive-screw bonding and / or adhesive-rivet bonding.

[0025] Generally, the outer panels and inner panels can be improved in surface morphology by spraying in-mold paint, coloring the substrate, etc., to achieve customized manufacturing.

[0026] According to the application requirements, the reinforcement body made of continuous fiber or discontinuous fiber can be structurally designed to obtain a three-dimensional mesh structure within or between layers, realize the structural reinforcement of the composite material, and significantly improve the mechanical properties of the PDCPD resin-based composite material. Its manufacturing process can adopt high-performance composite material manufacturing processes such as VARI, RTM, autoclave, and molding. It has fewer defects, stable product performance, and high mechanical strength. It can meet the application end's requirements for higher performance, give full play to the excellent weight reduction benefits of carbon fiber composite materials, and realize lightweight and thin-walled parts. In a preferred embodiment, the structural form of the discontinuous reinforcement body and the continuous reinforcement body is selected from one or more of the group consisting of short fibers, long fibers, fiber meshes, unidirectional or multi-axial filaments, non-woven felt materials, non-woven felt fabrics, continuous fiber fabrics, and unidirectional fabrics.

[0027] The continuous fiber fabric is selected from one or more of the group consisting of woven fabrics, knitted fabrics, mesh cloths and braided fabrics, and its structural forms include plain weave, twill, satin weave, three-dimensional weave, mesh cloth or warp and weft weave.

[0028] The material of the discontinuous reinforcement and the continuous reinforcement is selected from glass fiber, carbon fiber, aramid fiber or ramie fiber.

[0029] In order to further improve the comprehensive properties of the outer plate, such as strength and toughness, more preferably, in the outer plate, the content of the discontinuous reinforcement is 0.1 to 50 wt %, preferably 2 to 30 wt %, calculated on the basis of the weight percentage of the dicyclopentadiene monomer.

[0030] The manufacturing process of discontinuous fiber reinforced PDCPD resin-based composite materials can be matched with rapid prototyping equipment such as hand lay-up, injection molding, spraying, and compression molding, on the premise of meeting application requirements, which can significantly improve production efficiency and reduce manufacturing costs.

[0031] The inner panel uses a continuous fiber reinforced PDCPD resin-based composite material as the weighing structure of the component. Adding continuous fiber reinforcement material is beneficial to improving the stiffness of the composite material. In order to further improve the load-bearing performance of the inner panel, the content of the continuous reinforcement in the inner panel is 30-80wt%, preferably 40-65wt%, based on the weight percentage of the continuous fiber reinforced polydicyclopentadiene composite material.

[0032] In order to improve the comprehensive performance of the composite material, some functional additives are usually added during the polymerization process. In a preferred embodiment, the polydicyclopentadiene composite material reinforced by the discontinuous reinforcement body further includes a first functional additive, and the polydicyclopentadiene composite material reinforced by the continuous reinforcement body further includes a second functional additive; preferably, the first functional additive and the second functional additive are independently selected from one or more of inorganic nanofillers, antioxidants and flame retardants.

[0033] Adding nanometer-sized inorganic fillers is beneficial to improving the uniformity of dispersion in the polymerization system. In a preferred embodiment, the inorganic nanofillers include but are not limited to nanoclay and / or carbon nanotubes. More preferably, the amount of the inorganic nanofiller added is 0.2-10 wt %, more preferably 0.5-5 wt %, and further preferably 1-2 wt %, based on the weight percentage of the dicyclopentadiene monomer.

[0034] The inner plate and outer plate can be prepared by a method commonly used in the art. In a preferred embodiment, the outer plate preparation method includes: uniformly dispersing a discontinuous reinforcement and an optional first functional additive in a first dicyclopentadiene polymerization system to perform a first polymerization curing reaction to obtain an outer plate, wherein the first dicyclopentadiene polymerization system includes a dicyclopentadiene monomer, a first catalyst, and a first polymerization time regulator; the inner plate preparation method includes: injecting a second dicyclopentadiene polymerization system into a continuous reinforcement and an optional second functional additive to perform a second polymerization curing reaction to obtain an inner plate, wherein the second dicyclopentadiene polymerization system includes a dicyclopentadiene monomer, a second catalyst, and a second polymerization time regulator.

[0035] Adding catalysts and polymerization time regulators during the polymerization of dicyclopentadiene is beneficial to making the polymerization system have the advantages of low viscosity, wide process applicability, low cost and adjustable curing rate, thereby greatly reducing the use threshold of polydicyclopentadiene and broadening the scope of application.

[0036] Since the dicyclopentadiene monomer is solid at room temperature, it is difficult to process it, which greatly limits its application field. In order to solve the above problems, in a preferred embodiment, before the first polymerization curing reaction, the preparation method of the outer plate further includes: performing a first heating process on the dicyclopentadiene monomer under a first protective atmosphere to make the dicyclopentadiene monomer liquid at room temperature; before the second polymerization curing reaction, the preparation method of the inner plate further includes: performing a second heating process on the dicyclopentadiene monomer under a second protective atmosphere to make the dicyclopentadiene monomer liquid at room temperature.

[0037] Heating the dicyclopentadiene monomer under a protective atmosphere can prevent the dicyclopentadiene monomer from being oxidized and affecting the performance of subsequent products. At the same time, before the polymerization reaction, the raw materials are pretreated to convert the dicyclopentadiene monomer from solid to liquid at room temperature, which is conducive to improving the convenience of dicyclopentadiene monomer in composite material processing, reducing the difficulty of its processing technology, and broadening the scope of application.

[0038] Preferably, the first protective atmosphere and the second protective atmosphere are independently selected from nitrogen or an inert gas; the temperature of the first heating process and the second heating process are independently selected from 140 to 180°C. The heating temperature includes but is not limited to the above range, and limiting it within the above range is beneficial to improving the liquefaction process of the dicyclopentadiene monomer. Preferably, the temperature of the first heating process and the second heating process are independently selected from 145 to 160°C, more preferably, the temperature of the first heating process and the second heating process are independently selected from 150 to 160°C.

[0039] The addition of the first polymerization time regulator and the second polymerization time regulator can regulate the curing rate of the first dicyclopentadiene polymerization system and the second dicyclopentadiene polymerization system. In a preferred embodiment, the first polymerization time regulator and the second polymerization time regulator are independently selected from one or more of the group consisting of alcohol, ketone, ether, aluminum-based compound and organic phosphine.

[0040] The catalyst used in the above polymerization reaction includes but is not limited to a single-component metal carbene catalyst or a two-component transition metal catalyst. Preferably, the single-component metal carbene catalyst is a transition metal carbene catalyst; preferably, the two-component transition metal catalyst includes a transition metal complex catalyst and a co-catalyst, the transition metal atom in the transition metal complex catalyst includes but is not limited to Ru, Ti, Ni or Mo, preferably Ru, and the co-catalyst is a Lewis base.

[0041] When the first catalyst is a system using a single-component catalytic system, the first polymerization time regulator is preferably an organic phosphorus; when the second catalyst is a system using a single-component catalytic system, the second polymerization time regulator is preferably an organic phosphorus. When the first catalyst is a system using a two-component catalytic system, the first polymerization time regulator is preferably one or more of the group consisting of alcohols, ethers and aluminum-based compounds; when the second catalyst is a system using a two-component catalytic system, the second polymerization time regulator is preferably one or more of the group consisting of alcohols, ethers and aluminum-based compounds. According to different catalysts, the use of different polymerization time regulators is conducive to adjusting the curing time of the dicyclopentadiene monomer in the polymerization reaction to a more appropriate range, so as to facilitate its processing and modification.

[0042] In a preferred embodiment, when a single-component catalyst is used, the weight ratio of the first catalyst, the first polymerization time regulator and the dicyclopentadiene monomer and the weight ratio of the second catalyst, the second polymerization time regulator and the dicyclopentadiene monomer are independently selected from (0.01-5): (0.5-20): 100. The weight ratio of the catalyst, the polymerization time regulator and the dicyclopentadiene monomer includes but is not limited to the above range, and limiting it within the above range is conducive to improving the reaction rate of the polymerization reaction and the comprehensive performance of the composite material.

[0043] On the other hand, the present application also provides a method for preparing an automobile component, the automobile component includes an outer panel and an inner panel, and the preparation method includes: preparing the outer panel and the inner panel using the above-mentioned preparation method; and connecting the outer panel and the inner panel using the above-mentioned connection method.

[0044] The present invention proposes an automobile component with the structural features of an inner panel, an outer panel and a cavity. The inner panel, as the main load-bearing part, is made of a continuous fiber-reinforced polydicyclopentadiene composite material, and the outer panel is made of a discontinuous fiber-reinforced polydicyclopentadiene composite material. A cavity is set between the inner panel and the outer panel to improve the overall structural rigidity of the component, which is used to install functional components such as glass, locks, pull ropes, and embedded parts, while providing connection holes, process holes and working space. Therefore, the above-mentioned automobile component can achieve the design goals of high performance of the inner panel and low cost of the outer panel under the premise of ensuring the structural rigidity and mechanical strength of the component, and realize the high performance, low cost, lightweight and short cycle manufacturing of automobile components, which has significant economic and social benefits.

[0045] In another aspect, the present application provides a discontinuous reinforcement reinforced polydicyclopentadiene composite material, which is prepared by a first polymerization curing reaction. The discontinuous reinforcement reinforced polydicyclopentadiene composite material prepared by the above method has excellent strength and toughness.

[0046] In another aspect, the present application provides a continuous reinforcement reinforced polydicyclopentadiene composite material, which is prepared by a second polymerization curing reaction. The continuous reinforcement reinforced polydicyclopentadiene composite material prepared by the above method has high rigidity and good load-bearing performance.

[0047] The above-mentioned discontinuous reinforcement reinforced polydicyclopentadiene composite materials and continuous reinforcement reinforced polydicyclopentadiene composite materials both have the characteristics of low viscosity and fast curing, are suitable for molding complex structural parts, can realize the optimized design of cavity layout, and integrally mold complex structures, such as integrally molded wire troughs, positioning points, embedded metal parts, etc. during outer panel manufacturing, which can be quickly installed and avoid complex welding or stamping processes of metal components, thereby reducing manufacturing costs and improving production efficiency.

[0048] The present application is further described in detail below in conjunction with specific embodiments. These embodiments should not be construed as limiting the scope of protection claimed in the present application.

[0049] The relevant properties of the materials were characterized by the following methods.

[0050] The tensile properties of composite materials were tested according to GB / T 1447-2005.

[0051] The impact resistance of the material is characterized by using CAI, which is the combined effect of two independent phenomena: impact damage resistance and damage tolerance. The post-impact compressive strength (CAI value) of the composite material is tested according to the ASTM D7130 standard. The larger the CAI value, the higher the toughness of the composite material.

[0052] The viscosity of the composites was characterized by the viscosity measurement method of GB / T 10247-2008.

[0053] The coating adhesion test of composite materials is evaluated by the ISO 2409 cross-cut test.

[0054] Example 1

[0055] Under the protection of nitrogen, the dicyclopentadiene monomer is heated to 150° C. and then restored to room temperature so as to remain in a liquid state at room temperature.

[0056] The outer panel of the automobile engine cover is made of a PDCPD composite material reinforced with a discontinuous reinforcement. In the production process, firstly, the polymerization time regulator triphenylphosphine is added to the treated liquid dicyclopentadiene monomer, and the addition amount is 2% of the weight fraction of the DCPD monomer, and then the above-mentioned mixed system is stirred for 1 hour. Then, during the stirring process, the catalyst Grubbs catalyst is added to the system, and the addition amount is 0.017% of the weight fraction of the dicyclopentadiene monomer. After the mixed system is quickly stirred for 3 minutes, the LFI process (reaction injection molding) is used to add 2mm short chopped carbon fiber, and the addition amount is 50% of the weight fraction of the DCPD monomer to prepare the composite automobile engine cover outer panel.

[0057] The inner panel of the automobile engine hood adopts a continuous reinforcement reinforced PDCPD composite material. In the production process, firstly, the preform of the engine hood inner panel prepared by carbon fiber twill fabric and unidirectional fabric is placed on the mold with a layer ratio of 1:1, and the DCPD polymerization system is injected after the mold is closed. The polymerization system contains dicyclopentadiene monomer, polymerization time regulator and catalyst, and its ratio is consistent with the composition of the dicyclopentadiene polymerization system used in the preparation process of the outer panel. Afterwards, the RTM process (resin transfer molding) is used to prepare the engine hood inner panel, in which the weight of the composite material continuous reinforcement (carbon fiber twill fabric and unidirectional fabric) in the engine hood inner panel accounts for 80wt% of the total weight of the composite material.

[0058] Subsequently, the inner and outer panels were assembled using a hybrid glue-screw connection method to produce a lightweight automobile engine cover that weighs only 8Kg, has high structural strength and is light in weight.

[0059] The mechanical properties of the prepared products are shown in Table 1.

[0060] Example 2

[0061] Under the protection of helium, the dicyclopentadiene monomer is heated to 160°C and then returned to room temperature so that it remains in a liquid state at room temperature;

[0062] The production of the door outer panel adopts short-cut fiber toughened PDCPD resin-based composite material. The polymerization time regulator triphenylphosphine is added to the treated liquid dicyclopentadiene monomer in an amount of 2% of the monomer weight fraction, and then the above mixed system is stirred for 1 hour. Subsequently, the catalyst Grubbs catalyst is added to the above mixed system under stirring, and the addition amount is 0.017% of the monomer weight fraction. The mixed system is quickly stirred for 3 minutes to obtain a DCPD polymerization system. Subsequently, the LFI process (reaction injection molding) is used to prepare a 2mm short-cut carbon fiber reinforced composite material. 2mm short-cut carbon fiber is added to the system in an amount of 30% of the monomer addition amount. It is cured and formed in 5 minutes. After shaping, the mold is opened to obtain the door outer panel.

[0063] The inner door panel adopts continuous fiber reinforced PDCPD composite material. During the production process, the inner door panel preform prepared by carbon fiber twill fabric, the weight of carbon fiber twill fabric in the designed product accounts for 65wt% of the total weight, is placed in the lower mold, and the mold is closed to inject the DCPD polymerization system, which contains monomers, polymerization time regulators and catalysts, and its ratio is consistent with the composition of the dicyclopentadiene polymerization system in the outer panel preparation process. The inner door panel is made by RTM process (resin transfer molding). Subsequently, the inner panel and the outer panel are assembled by glue-screw hybrid connection method, glass and door locks are installed in the cavity between the inner panel and the outer panel, and the inner panel and the outer panel are assembled by glue-screw hybrid connection method to obtain a fiber reinforced PDCPD composite door.

[0064] The mechanical properties of the prepared products are shown in Table 1.

[0065] Example 3

[0066] The difference from Example 2 is that under the protection of helium, the dicyclopentadiene monomer is heated to 145° C. and then restored to room temperature, so that it remains in liquid state at room temperature.

[0067] Example 4

[0068] The difference from Example 2 is that under the protection of helium, the dicyclopentadiene monomer is heated to 140° C. and then restored to room temperature, so that it remains in liquid state at room temperature.

[0069] Example 5

[0070] The difference from Example 2 is that in the outer plate, the discontinuous reinforcement is discontinuous long carbon fiber; in the inner plate, the continuous reinforcement is aramid fiber.

[0071] Example 6

[0072] The difference from Example 2 is that in the outer plate, the content of the discontinuous reinforcement is 50wt% based on the weight of the dicyclopentadiene monomer; in the inner plate, the content of the continuous reinforcement is 50wt% based on the total weight of the polydicyclopentadiene composite material reinforced with the continuous reinforcement.

[0073] Example 7

[0074] The difference from Example 2 is that in the outer plate, the content of the discontinuous reinforcement is 0.2wt% based on the weight of the dicyclopentadiene monomer; in the inner plate, the content of the continuous reinforcement is 65wt% based on the total weight of the polydicyclopentadiene composite material reinforced with the continuous reinforcement.

[0075] Comparative Example 1-1

[0076] In order to compare the mechanical properties of the material products before and after fiber reinforcement, a PDCPD car hood with no fiber reinforcement on both the inner and outer panels was prepared. In the production process, firstly, triphenylphosphine, a polymerization time regulator, was added to the treated liquid dicyclopentadiene monomer in an amount of 2% of the monomer weight fraction, and then the mixed system was stirred for 1 hour. Then, during the stirring process, Grubbs catalyst was added to the system in an amount of 0.017% of the monomer weight fraction. After the mixed system was quickly stirred for 3 minutes, a non-fiber-reinforced car hood outer panel was prepared. At the same time, the inner panel of the car hood was made using the same formula as the outer panel. Among them, the dimensions of the inner and outer panels of the hood are the same as those in Example 1.

[0077] The mechanical properties of the prepared products are shown in Table 1.

[0078] Comparative Example 1-2

[0079] In order to compare the effects of different reinforcement forms for inner and outer panels, a PDCPD automobile engine hood with continuous fiber reinforcement for both inner and outer panels was prepared. In the production process, firstly, triphenylphosphine, a polymerization time regulator, was added to the treated liquid dicyclopentadiene monomer in an amount of 2% of the monomer weight fraction, and then the mixed system was stirred for 1 hour, and then Grubbs catalyst was added to the system during the stirring process in an amount of 0.017% of the monomer weight fraction, and the mixed system was quickly stirred for 3 minutes, and then quickly injected into a pre-laid mold with carbon fiber twill fabric and unidirectional fabric, and then the inner and outer panels of the hood were prepared using the RTM process. Among them, the weight of the composite material continuous fiber in the inner and outer panels of the hood accounted for 50wt% of the total weight of the composite material, and the dimensions of the inner and outer panels were the same as those in Example 1.

[0080] The mechanical properties of the prepared products are shown in Table 1.

[0081] Table 1

[0082]

[0083] It can be seen from the data in Table 1 that the tensile strength and impact resistance of the PDCPD composite material reinforced by the reinforcement body are significantly increased. Moreover, the scheme of the present invention, that is, the inner plate adopts the continuous fiber reinforced polydicyclopentadiene composite material, and the outer plate adopts the discontinuous fiber reinforced polydicyclopentadiene composite material, can significantly improve the tensile strength and impact resistance, while also reducing weight and cost to a greater extent.

[0084] Example 8

[0085] Under the protection of nitrogen, the dicyclopentadiene monomer is heated to 170° C. and then returned to room temperature so as to remain in a liquid state at room temperature.

[0086] The outer panel of the automobile engine cover is made of non-continuous fiber reinforced PDCPD composite material. In the production process, firstly, triphenylphosphine, a polymerization time regulator, is added to the treated liquid dicyclopentadiene monomer in an amount of 2.2% of the monomer weight fraction, and then the mixed system is stirred for 1 hour. Then, Grubbs catalyst is added to the system during the stirring process in an amount of 0.02% of the monomer weight fraction, and the mixed system is quickly stirred for 3 minutes. Then, 2mm short chopped carbon fiber and nano-silicon dioxide are added to the system using the LFI process, and the weight fractions are 10wt% and 5wt%, respectively. The composite automobile engine cover outer panel is prepared.

[0087] The inner panel of the automobile engine hood is made of continuous fiber reinforced PDCPD composite material. In the production process, the preform of the engine hood inner panel made of aramid fabric is first placed on the mold, and the DCPD polymerization system is injected after the mold is closed. The formula system includes monomers, polymerization time regulators and catalysts, and the ratio is consistent with the above non-continuous fiber reinforcement system ratio. After that, the RTM process is used to make the engine hood inner panel, in which the weight of the composite material continuous fiber in the engine hood inner panel accounts for 70wt% of the total weight of the composite material.

[0088] The 1# paint was applied on the surface of the composite material sheet and baked at 60℃ for 2h.

[0089] Comparative Example 3-1

[0090] The aramid composite material was prepared using the commonly used 935# epoxy system, and the coating was completed using the same process as in Example 8.

[0091] The paint adhesion of different composite materials was tested using the ISO 2409 cross-cut test.

[0092] Table 2

[0093]

[0094] The results show that, under the same other conditions, the paint adhesion of the carbon fiber composite material based on the PDCPD resin system is level 0, which is better than that of the carbon fiber reinforced epoxy resin composite material, indicating that the carbon fiber reinforced PDCPD resin composite material has excellent paintability.

[0095] In summary, the beneficial effects that can be achieved by this application include:

[0096] 1. The present invention proposes an automobile component having the structural features of an inner panel, an outer panel and a cavity. The inner panel, as the main load-bearing part, is made of a polydicyclopentadiene composite material reinforced with a continuous reinforcement, and the outer panel is made of a polydicyclopentadiene composite material reinforced with a discontinuous reinforcement. On the premise of ensuring the structural rigidity and mechanical strength of the component, the design goals of high performance of the inner panel and low cost of the outer panel are achieved, thereby realizing high performance, low cost, lightweight and short cycle manufacturing of automobile components, which has significant economic and social benefits.

[0097] 2. Before polymerization and curing, the dicyclopentadiene monomer is first converted from solid to liquid at room temperature by heating. This is beneficial to improving the convenience of dicyclopentadiene monomer in composite material processing and reducing the difficulty of its processing technology.

[0098] 3. The polymerization system composed of a catalyst, a polymerization time regulator and a liquid dicyclopentadiene monomer has the advantages of low viscosity, wide process applicability and low cost, which greatly reduces the use threshold of polydicyclopentadiene and broadens the scope of application.

[0099] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An automobile component, characterized in that: The automobile component comprises: an outer panel, an inner panel and a cavity arranged between the outer panel and the inner panel, wherein the outer panel is made of a polydicyclopentadiene composite material reinforced by a discontinuous reinforcement, and the inner panel is made of a polydicyclopentadiene composite material reinforced by a continuous reinforcement; In the outer plate, the content of the discontinuous reinforcement is 0.2-50wt% based on the weight percentage of the dicyclopentadiene monomer; In the inner panel, the content of the continuous reinforcement is 50-65wt% based on the total weight of the polydicyclopentadiene composite material reinforced by the continuous reinforcement; The material of the discontinuous reinforcement and the continuous reinforcement is selected from carbon fiber; The inner plate and the outer plate are connected by adhesive bonding or mixed connection; The hybrid connection is selected from glue-screw connection and / or glue-rivet connection; The structural form of the discontinuous reinforcement is chopped carbon fiber; the structural form of the continuous reinforcement is carbon fiber twill fabric.

2. The automotive component according to claim 1, characterized in that: The polydicyclopentadiene composite material reinforced by the discontinuous reinforcement further comprises a first functional additive, and the polydicyclopentadiene composite material reinforced by the continuous reinforcement further comprises a second functional additive.

3. The automotive component according to claim 2, characterized in that: The first functional additive and the second functional additive are independently selected from one or more of an inorganic nanofiller, an antioxidant and a flame retardant.

4. The automotive component according to claim 2, characterized in that: The preparation method of the outer plate comprises: uniformly dispersing the discontinuous reinforcement and the first functional additive in a first dicyclopentadiene polymerization system to perform a first polymerization curing and molding reaction to obtain the outer plate, wherein the first dicyclopentadiene polymerization system comprises a dicyclopentadiene monomer, a first catalyst and a first polymerization time regulator; The preparation method of the inner plate comprises: injecting a second dicyclopentadiene polymerization system into the continuous reinforcement and a second functional additive to carry out a second polymerization curing and molding reaction to obtain the inner plate, wherein the second dicyclopentadiene polymerization system comprises a dicyclopentadiene monomer, a second catalyst and a second polymerization time regulator.

5. The automobile component according to claim 4, characterized in that: Before performing the first polymerization curing and molding reaction, the outer plate preparation method further includes: performing a first heating process on the dicyclopentadiene monomer under a first protective atmosphere so that the dicyclopentadiene monomer is liquid at room temperature; Before performing the second polymerization curing and molding reaction, the method for preparing the inner plate further includes: performing a second heating process on the dicyclopentadiene monomer under a second protective atmosphere to make the dicyclopentadiene monomer liquid at room temperature.

6. The automobile component according to claim 5, characterized in that: The first protective atmosphere and the second protective atmosphere are independently selected from nitrogen or an inert gas; The temperatures of the first heating process and the second heating process are independently selected from 140 to 180°C.

7. The automobile component according to claim 6, characterized in that: The temperatures of the first heating process and the second heating process are independently selected from 145 to 160°C.

8. The automotive component according to claim 6, characterized in that: The temperatures of the first heating process and the second heating process are independently selected from 150 to 160°C.

9. The automotive component according to claim 4, characterized in that: The first polymerization time regulator and the second polymerization time regulator are independently selected from one or more of the group consisting of alcohols, ketones, ethers, aluminum-based compounds and organic phosphines.

10. A method for preparing an automobile component, characterized in that: The automobile component is an automobile component according to any one of claims 4 to 9, and the preparation method comprises: The preparation method of the outer plate comprises: uniformly dispersing the discontinuous reinforcement and the first functional additive in a first dicyclopentadiene polymerization system to perform a first polymerization curing and molding reaction to obtain the outer plate, wherein the first dicyclopentadiene polymerization system comprises a dicyclopentadiene monomer, a first catalyst and a first polymerization time regulator; The preparation method of the inner plate comprises: injecting a second dicyclopentadiene polymerization system into the continuous reinforcement and the second functional additive to carry out a second polymerization curing and molding reaction to obtain the inner plate, wherein the second dicyclopentadiene polymerization system comprises a dicyclopentadiene monomer, a second catalyst and a second polymerization time regulator; The outer plate and the inner plate are connected by adhesive connection or hybrid connection; wherein the hybrid connection is selected from adhesive-screw connection and / or adhesive-rivet connection.

11. The method for preparing automobile parts according to claim 10, characterized in that: Before performing the first polymerization curing and molding reaction, the outer plate preparation method further includes: performing a first heating process on the dicyclopentadiene monomer under a first protective atmosphere so that the dicyclopentadiene monomer is liquid at room temperature; Before performing the second polymerization curing and molding reaction, the method for preparing the inner plate further includes: performing a second heating process on the dicyclopentadiene monomer under a second protective atmosphere to make the dicyclopentadiene monomer liquid at room temperature.

12. The method for preparing an automobile component according to claim 11, characterized in that: The first protective atmosphere and the second protective atmosphere are independently selected from nitrogen or an inert gas; The temperatures of the first heating process and the second heating process are independently selected from 140 to 180°C.

13. The method for preparing an automobile component according to claim 12, characterized in that: The temperatures of the first heating process and the second heating process are independently selected from 145 to 160°C.

14. The method for preparing an automobile component according to claim 12, characterized in that: The temperatures of the first heating process and the second heating process are independently selected from 150 to 160°C.

15. The method for preparing automobile parts according to claim 10, characterized in that: The first polymerization time regulator and the second polymerization time regulator are independently selected from one or more of the group consisting of alcohols, ketones, ethers, aluminum-based compounds and organic phosphines.

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