Member for mobile machine, and method of manufacturing the same

Abstract

To provide a board-like object made of a metal-resin integrated object for use in a car roof or the like, to respond to a trend of weight reduction, energy saving, CO2 reduction, and global warming.SOLUTION: As a resin material, a specific polyamide-based resin composition is used. Meanwhile, objects formed by suitably cutting a board material with 0.5 to 1.5 mm of thickness, made of various types of Al alloys treated with NMT type chemical processing are used, and placed in an injection bonding mold as inserts. The aforementioned resin composition is injected, to make a metal-resin integrated composite having a board-like final shape including a curved surface shape. As the resin material, the polyamide-based resin composition is used. Meanwhile, several numbers of square-rod shaped objects with approximately 5 mm square and 100 mm or more of length, made of the various types of Al alloys treated with the NMT type chemical processing are used, simply assembled up, and placed in the injection bonding mold as an insert. The aforementioned resin composition is injected, to create the metal-resin integrated composite with a final shape which is covered with a round-rod shaped resin molding with 15 to 20 mm of diameter and 50 to 150 mm of length, and to the center of which the Al alloy made square-rod has been sunk down.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a mobile machine member and a manufacturing method thereof. More specifically, the mobile machine member of the present invention is a metal-resin composite integral body in which a plate-shaped product using a specific high-strength, high-heat-resistant thermoplastic resin composition is used as a main structural material and an aluminum alloy plate-shaped product is used as a secondary structural material, or an aluminum alloy bar is used as a main structural material and an injection-molded product using a high-strength, high-heat-resistant thermoplastic resin composition is used as a secondary structural material, and the main structural material and secondary structural material are strongly integrated by injection joining technology. It is expected that these will be adopted as a type of structural member to replace thin steel plates for automobiles in the future. Therefore, the invention according to the present invention is related to the automobile industry, and more broadly, to the mobile machine manufacturing industry. [Background technology]

[0002] The mobile machine member of the present invention is a lightweight, high-strength composite integrated product, and is intended to provide a lighter alternative to the roofs, fenders, doors, seats, etc. of automobiles, which have traditionally been made of thin steel plates. In order to address the issue of global warming, automobiles will change from engine vehicles to hybrid vehicles, fuel cell vehicles, electric vehicles, etc., but regardless of the type of vehicle, it is expected that the important structural parts of mobile machines, such as tires, driving parts including electric motors, energy transmission and supply parts such as hydrogen cylinders, fuel cells, and secondary batteries, and the steel chassis parts that support them, will be made using the same mass-produced products and mass-production methods that have been developed so far. In other words, the electric passenger car produced and sold by Tesla, Inc. in the United States, which uses cast aluminum alloys even in the chassis parts, has attracted worldwide attention as a luxury passenger car, but it is expected that the general-purpose electric cars aimed at the global market by major Japanese and German automobile manufacturers will not use aluminum alloy structures, which are too expensive, but will use conventional steel materials in the chassis parts.

[0003] In other words, there is no structural material as excellent as steel. There is a system in place to mass-supply special steels and thin steel sheets with excellent mechanical properties, and steel has excellent weldability. On the other hand, there is a system in place to mass-supply a wide variety of Al alloys with excellent mechanical properties, but the supplies are plate materials and thin plate materials, and the intermediate material for sash materials with high strength, which is a special shaped extrusion material, is a straight bar-like material similar to L-shaped steel or H-shaped steel. The bending process is also not as flexible as steel, and mass production is not easy. In particular, its greatest weakness is its poor weldability. Automobile chassis parts are structural parts that have complex shapes and require the highest mechanical properties, so if welding is avoided and they are assembled from plate materials and bars, mass production would be extremely difficult in terms of cost.

[0004] Therefore, the only way to make a complex-shaped casting is to add a little machining, which was a difficult problem to overcome in making an aluminum alloy chassis. However, Tesla, Inc. of the United States, has invented a new aluminum alloy composition for casting and even developed a high-pressure casting method using this alloy. It is said that this casting can obtain the expected mechanical properties without heat treatment, and Tesla's technology for practical use of aluminum alloy chassis is considered to be a wonderful new technology. However, after high-pressure casting, the sand mold must be broken in order to separate the casting. Naturally, the cost of producing the casting mold at high speed using a high-speed 3D printer is also added. Therefore, it is inevitable that the cost will be much higher than the current method of using steel. Many people believe that this is the reason for the company's electric vehicle sales price of 7 to 8 million yen per unit. In short, these are the reasons why it is expected that the chassis of future electric general-purpose vehicles will use steel as before, as mentioned above.

[0005] On the other hand, the engine block of a gasoline-powered vehicle has been a great success after the change from steel to aluminum alloys. Aluminum alloy engines are already being used around the world, and the weight reduction has a great effect on energy saving. However, in this major competition, electric vehicles do not have engines to begin with, and the current major automakers are faced with the difficulty of having to abolish or reduce their engine manufacturing and engine improvement development departments. It would be nice to convert all parts to aluminum alloys to reduce weight, but in addition to the fact that the chassis structure will likely survive as steel, it is surprisingly difficult to switch from steel to aluminum alloy structures for other parts, such as fenders, roofs, doors, back doors, seats, etc., even though it is expected that a large weight reduction can be achieved. The reason for this is that aluminum alloy sheets are difficult to press. Aluminum alloys have a springback property, so it is not easy to form them into press shapes, and press-formed thin steel sheets are easy to use for curved plate-shaped parts. Aluminum alloy doors are used in some luxury Japanese cars, but there is no sign of this usage spreading to general-purpose cars. Stable production is seen as difficult.

[0006] The major automakers in Japan, Germany, and the United States, as well as the new automakers that have emerged in China, which will undoubtedly become a large market for electric vehicles. All of them will enter into a fierce competition for the global market for general-purpose electric vehicles. Japanese and German automakers have supported their countries' trade surpluses with their export competitiveness, and since automobile exports have supported the economic power of the nation, it is truly a fierce competition between nations. The same can be said for China, a country of national economics. However, the manufacturing technology for electric vehicles was not originally developed by automobile companies, but was acquired thanks to the technological development capabilities of motor manufacturers, secondary battery manufacturers, and chemical manufacturers. In short, all electric vehicles produced and sold in the future will be produced by receiving the motors, batteries, and necessary electronic and electrical machinery from other companies, and the completed electric vehicles themselves will likely have similar bodies in Japan, Germany, the United States, and China. Therefore, it will be an intense competition for survival of new cars, with competitors watching their new cars. It is predicted that the global competition for survival regarding general-purpose electric vehicles will intensify from 2024 to 2025, and the winner will be decided in 2030.

[0007] The inventor has a new perspective that even automotive industry experts would not think of in the massive global automobile production competition that will take place from 2024 onwards, including not only electric vehicles but also fuel cell vehicles, hybrid vehicles, and gasoline vehicles. That is, he believes that all parts of the vehicle body structure except the chassis, i.e. the aforementioned fenders, doors, back doors, seats, etc., could be made to take on the main role of the product of this invention, i.e., a composite integrated material (basically in a plate shape) of metal and thermoplastic resin, instead of the current thin steel plate structures.

[0008] In short, there is no doubt that "global environmental issues" or "CO2 reduction" is a major goal for the entire world, but the main thing that automakers should do is "energy conservation," and it is not as simple as saying that all cars with engines should be eliminated and all cars should be electric. Even engine cars and hybrid cars cannot and should not be banned depending on the country or region in which they are used. In short, regardless of the model, if the weight of the car body is reduced, it will be an effective CO2 reduction. At the same time as increasing the number of electric cars, it is also necessary to change the fuel for thermal power generation, which is the power source, from coal and petroleum to natural gas, and even more so, to use safe nuclear power plants where the cooling of the reactor never stops. This is a technological capability and investment strategy that each country should respond to, and it is not something that automakers should do. What automakers should do is to first develop mass production technology for all cheap electric cars, and in addition, we should make efforts to replace parts that use steel with parts that use aluminum alloys to promote weight reduction, and as an auto manufacturing and assembly company, we should make efforts to reduce CO2 by reducing weight.

[0009] Therefore, the inventor does not expect to use the Al alloy plate material itself for the fender or door member, but to use a composite integrated member made of Al alloy and high-performance resin as a plate material with a curved surface, and to use a steel frame structure to which the plate material is attached using the current technology. What the inventor does not understand well is the specific assembly method of the car body. That is, what method should be used to join the outer periphery of the large-area thick resin plate material reinforced by adding the Al alloy plate material to the steel frame part that supports it? Should lightweight Al or Ti alloy bolts, nuts, or screws be used, or, since thermoplastic resin is not compatible with adhesives, there is also a method of injection-joining an Al alloy thin plate material to the resin side, and then bonding the side to be bonded to the frame material with the Al alloy surface and bonding it with an epoxy adhesive. It is not clear which joining method is preferable as a mass production method.

[0010] Well, these joining and bonding technologies for assembly are important technologies that automakers possess, and I hope they will find the optimal method. In short, I would like to see these technologies added to reduce the weight of cars by about 10%. The inventor believes that it is domestic automakers that have thoroughly streamlined their automobile manufacturing and achieved the world's highest export competitiveness by using this invention to achieve a unique weight reduction of 10% or more in the manufacture of all types of automobiles. The inventor is convinced that companies that have taken a step forward in reducing the weight of automobiles by using this invention will surely survive in the global competition for general-purpose vehicles that is expected to continue from 2024 to 2030, and will be in the winning group in 2030.

[0011] The basic technology on which the present invention is based is a group of inventions by the present inventor (Naoki Ando) on injection joining technology and adhesive joining technology, most of which have already been disclosed in Japan and abroad. First, there are Patent Documents 1 to 17 on injection joining technology that is particularly related to the present invention, and their outlines and theories are described below. On the other hand, the adhesive joining technology "NAT (short for Nano Adhesion Technology)" by the present inventor is an epoxy adhesive joining technology between metal materials related to weight reduction in automobiles, aircraft, drones, etc., and an epoxy adhesive joining technology between CFRP materials and metal materials, and has no direct relationship with the technology for promoting weight reduction in general-purpose vehicles that is the target of the present invention, because the balance between the weight reduction effect and the material price is not right, and there is only an indirect relationship in terms of theory (Reference: Non-Patent Document 1). Therefore, a detailed explanation of NAT will be omitted.

[0012] (About injection joining technology) "NMT (short for Nano Molding Technology)" requires a process of preparing an aluminum alloy by subjecting it to a chemical treatment called NMT treatment, which results in a surface shape and chemical properties that are covered entirely with ultrafine uneven surfaces with a period of at least 10 to 100 nm, and hydrazine hydrate is chemically adsorbed on the surface. On the other hand, a resin for injection bonding is prepared with a highly crystalline thermoplastic resin (e.g., PBT, PPS, polyamide resin, or PAEK resin including PEEK) as the main component, and a resin different from the main component resin and compatible with the main component resin if possible is prepared as a secondary component resin, and if the compatibility between these two polymers is weak, a third component resin that helps compatibility even if the compatibility between these two polymers is incomplete is added to make the total resin component, which is then melt-mixed to make the resin component. Specifically, 100 parts by mass of the total resin contains 70 to 90 parts of the main component resin, 30 to 10 parts of the secondary component resin, and 0 to 2 parts of the third component resin. In addition, GF (short glass fiber) or inorganic powder is added as a filler or reinforcing material in an amount of 0 to 35 mass % based on the total amount, and melt-mixed to form a crystalline thermoplastic resin composition for injection molding (for injection joining).

[0013] The purpose of this resin composition with a complex composition is to induce a favorable large change in the physical and chemical properties of the resin part during the time when the resin is injected into the injection mold from the injection port of the injection molding machine, the molten resin passes through the passage in the mold while being cooled, and collides with the above-mentioned NMT-treated Al alloy piece that has been inserted in the mold beforehand, and suddenly stops from the flowing state. In short, the resin moving through the passage in the mold is in a molten state, but the liquid temperature of the main component resin in it is cooled below the melting point of the main component resin. In other words, the resin part in the flow is cooled in the passage, but is in a supercooled state where it remains liquid. Then, the proceeding liquid finally gets blocked by the inserted Al alloy piece and the flow suddenly stops. In other words, it receives a large physical impact and the supercooled state is broken and crystallization begins. Immediately, microcrystals are generated simultaneously in multiple places, and first the viscosity (liquid viscosity) of the liquid material rises sharply. The normal process is that near the entrance of the ultra-fine recesses on the surface of the insert metal piece, the viscosity of the liquid rises suddenly, preventing the resin from flowing deep into the ultra-fine recesses, and crystal growth continues, eventually resulting in the resin solidifying.

[0014] In short, what the inventors aimed to achieve with the resin composition was to significantly reduce the rate of crystallization that begins immediately after the supercooled state is broken when the molten resin is rapidly cooled and its flow is suddenly stopped, as compared to normal times when the main component resin content is 100%, (significantly suppressing the crystallization rate), thereby suppressing a sudden rise in the liquid viscosity of the resin composition and enabling the resin composition flow to flow to the very bottom of the ultrafine recesses on the aluminum alloy in which it was inserted. Although the crystallization rate of the main component resin differs depending on the shape, length, and intramolecular composition of the polymer, it was an empirical rule that, for all crystalline polymers, the rate will always be slower if there is at least a small amount of impurities (different polymers) mixed in. Therefore, even if the tip of the injected resin collides with the Al alloy piece inserted in the mold and crystallization of the main component resin in the resin begins, if the crystallization rate is slow as intended by the inventors, the resin will penetrate close to the bottom of the ultra-fine recesses on the Al alloy as described above, and the numerous microcrystals that have already been generated simultaneously will grow to their limit and solidify, resulting in a strong bond between the Al alloy piece and the injection-molded resin composition part.

[0015] Furthermore, amine molecules (hydrazine hydrate in NMT treatment) are chemically adsorbed on the surface of the inserted Al alloy piece, and these amine molecules collide with the main component resin (PBT, PPS, polyamide, etc.) that is about to crystallize. When these main component resins collide with amine molecules at high temperatures, they always react, causing the polymer to break apart, and molecular motion occurs instantaneously, generating heat and hindering the movement toward crystallization. The intention of chemically adsorbing amine molecules on the metal piece that is inserted in advance is the same as the purpose of suppressing the crystallization rate of the main component resin that occurs when a different polymer is mixed into the injected highly crystalline thermoplastic resin and the molten resin is rapidly cooled. With these two strategies, the injection joining operation using an injection molding machine of the NMT-treated Al alloy piece and a resin composition containing a highly crystalline thermoplastic resin as the main component, adjusted for injection joining, can successfully create a strong integrated product between the Al alloy piece and the resin molding.

[0016] To measure whether the injection joining was really successful, the injection joints in the shapes of Figures 1 and 2 were created, and the shear joint strength and tensile joint strength of each were measured to obtain a large amount of data to make a judgment. In addition, durability tests were conducted on the obtained Figure 1 shape in various environments for a long period of time, for example, in a normal temperature environment for one year in spring, summer, autumn, and winter, and for 5, 10, or 15 years, or in an extremely harsh environment that cannot actually be found, for 1,000 to 8,000 hours, to see how the shear joint strength deteriorates and whether the joint obtained is close to a perfect joint. Including the results, "NMT" had achieved more than sufficient results as a basic technology for manufacturing parts and components for mobile machines at the time of filing this patent (end of 2022).

[0017] "New NMT (short for New Nano Molding Technology)" refers to a process in which all metals and metal alloys, including Al alloys, are subjected to a chemical treatment called New NMT treatment to give them a surface shape with a fine uneven surface with a period of 0.8 to 10 μm, and then further subjected to an appropriate chemical treatment to prepare an ultra-fine uneven surface shape that is covered entirely with a double complex overlapping surface in which an ultra-fine uneven surface with a period of 10 to 100 nm is placed on the fine uneven surface. On the other hand, the resin composition prepared for injection joining is exactly the same as the resin composition used in the NMT described above. The New NMT method does not include the process of chemically adsorbing amine molecules to metal alloy pieces, which was used in NMT. ​​The reason is that the adsorption reaction of amine molecules itself does not work well with anything other than Al alloys. Therefore, the shear joint strength of the injection joint obtained between the metal pieces and the crystalline thermoplastic resin composition as shown in Figure 1 was always inferior to that of the NMT product. However, for non-aluminum metals such as stainless steel, copper, and some Ti alloys, if the surface treatment method (new NMT treatment method) is performed very well and is compatible with the injected resin, the shear joint strength of the resulting injection joint can be at a satisfactorily high level, that is, about 40 MPa when the injected resin is PBT or PPS resin, and 55 to 60 MPa when the injected resin is a special nylon resin, which is close to the level of injection joints produced by NMT when various Al alloys are used.

[0018] "SNMT (short for Special Nano Molding Technology)" refers to a process in which the latest new NMT treatment is applied to all metals including Al alloys and their metal alloys to roughen the surface shape to a period of 20 to 50 μm, and then a fine uneven surface with a period of 0.8 to 10 μm is placed on the rough surface, and then an appropriate chemical treatment is applied to prepare an ultra-fine uneven surface shape that covers the entire surface with a complex overlapping surface of two or three layers, in which an ultra-fine uneven surface with a period of 10 to 100 nm is placed on the fine uneven surface. In addition, the material is immersed in an aqueous solution of amine molecules or amine molecular salts for a long time to physically adsorb them, and after pulling it out of the aqueous solution, it is washed with a very diluted aqueous solution of amine molecules or amine molecular salts and dried with hot air. In short, metal materials other than aluminum alloys do not chemically adsorb to amine compounds, so NMT cannot be used, but we predicted that all metals and metal alloys could be physically adsorbed by immersing them in a somewhat highly concentrated aqueous solution of amine compounds for a long period of time, and came up with a somewhat aggressive processing method and underwent trial and error. As a result, we found systems that showed good results with non-aluminum metals and their alloys. However, copper, a non-aluminum metal, does not originally chemically adsorb amine compounds, and in the presence of oxygen it even reacts with amine compounds (more precisely, it reacts with the copper oxide thin film that forms on the copper surface and turns into copper nitrite). For this reason, NMT cannot be used with non-aluminum metal materials, and of course SNMT also gives poor results. To be more specific, this means that we were able to discover systems in which SNMT shows higher injection joining strength than the new NMT for non-aluminum metals other than copper and copper alloys.

[0019] A specific example is shown in Patent Document 16. We were surprised to discover that when using PPS resin or polyamide resin for injection bonding with Ti alloys or some stainless steels, the maximum shear bonding strength of 40 MPa or 55 to 60 MPa, which is the maximum bonding strength value of each resin, can be stably obtained. The amine molecule used for the purpose of physical adsorption is triethanolamine, which often works well. Also, it was found that Ti alloys showed surprisingly high injection bonding strength when the metal alloy type was selected with 4Na salt of EDTA. In short, it was added to the new injection bonding technology as SNMT for special cases. Details of this technology are described in Patent Document 16.

[0020] (Injection joining technology application technology, etc.) "NMT", "New NMT" and "SNMT" are the basic technologies of injection joining technology. In order to make these basic technologies practical, especially for mobile machines, many development technologies were necessary. Simply put, it is excellent in the durability of the injection joining force. The first is the durability against humidity and heat, and it was predicted that the shear joining strength would definitely decrease if the injection joining product was placed in a high temperature and high humidity environment for several thousand hours. However, if the microstructure of the joining surface of the metal alloy piece and the resin molded product is a so-called perfect joining product, with no water play area where water molecules and oxygen molecules can enter and gather to form a molecular group of several thousand and tens of thousands, then it was predicted that there would be no rust (metal hydroxide) layer on the surface layer of the metal material side, and the joining structure would not change even after 1,000 or tens of thousands of hours have passed after the injection joining product was made, and the shear joining strength and tensile joining strength of the injection joining product would not change. That is, when injection-bonded metal / resin products with the shape shown in Fig. 1 were placed in a high-temperature and high-humidity environment (85°C and 85% humidity) for 3,000 to 8,000 hours and then returned to a room temperature environment, their durability was examined by repeated measurements of shear bond strength, and many products were found to have had almost no decrease from their initial values. These are considered to be products where a complete bonding operation was performed, and basically the micro-irregular combination shape of the metal material surface layer and resin material surface layer that make up the bonding surface, as well as its microstructure, are durable, and there is almost no rust (metal hydroxide) on the metal material side due to the intrusion of water molecules or oxygen molecules, or degradation due to hydrolysis on the resin side.

[0021] (Perfect bonding image and gas sealability) As described above, for the items where a complete joining operation was felt, it was understood that the resin penetrated and solidified during the injection joining operation to the bottom of the concave portion of the ultrafine uneven surface with a period of 10 to 100 nm created by chemical operation on the metal piece surface, and it was predicted that this joining surface would be difficult for not only water molecules, oxygen molecules, and nitrogen molecules, but also hydrogen molecules and He gas to pass through. A pressurized gas leakage test using He gas was performed on the injection joining surface of A5052Al alloy and PPS-based resin "SGX120 (Tosoh Corporation)" and it was confirmed that the sealing degree was several hundred times better than that of rubber O-ring sealing. Similarly, a pressurized leakage test using He gas was performed on the injection joining surface of C1100 copper and PPS-based resin "SGX120 (Tosoh Corporation)" and it was confirmed that the sealing degree was several tens of times better than that of rubber O-ring sealing (Patent Document 8).

[0022] These two gas sealing technologies mentioned above far exceed the level of technology currently used to completely prevent water molecules from penetrating into the electrode solution in current LIBs (Li-ion batteries) that use two types of electrode lead materials, Al alloy and copper, and PPS-based resin for the battery box. The current product uses a rubber O-ring seal, which is sufficient for practical use of LIBs for 5 years, and the above-mentioned complete sealing method recommended by the inventor has not yet been adopted in practice. However, if the complete sealing technology could extend the LIB life to 10 years or more, it would halve the consumption rate of Li resources. The inventor would like to be aware of this, but at present, electrical machinery and battery manufacturers are greatly expanding LIB manufacturing plants in preparation for the rapid increase in electric vehicles, while trading companies are approaching Li resource countries other than China and Russia, and they have not yet shown any enthusiasm for the complete sealing technology for LIB battery boxes. This is unfortunate.

[0023] In any case, NMT, New NMT, and SNMT are technologies that can improve the bond between metal pieces and resin molded products to a perfect bond. In short, with any of the technologies, NMT, New NMT, and SNMT, if the most ideal injection bonding is performed and a sample for measuring shear bond strength as shown in Figure 1 is used, and in testing it shows 40 MPa when PPS resin is used, and 55 MPa when polyamide resin is used, then I believe it will show the same gas sealing properties as above. This is because I believe this is close to perfect bonding. Therefore, even in injection bonded products with extremely high gas sealing properties, if the main component resin itself is not hydrolyzable, then they should basically be durable in high temperature and high humidity tests.

[0024] (Metal and resin materials have a large difference in linear expansion coefficient. What are the countermeasures?) Even if an ideal injection joint is created by joining metal materials and thermoplastic resin materials using the injection joining technology described above, the shape of the practical product will not be as simple as the shapes shown in Figures 1 and 2. Furthermore, as for the usage environment, for example, for automobile parts and components for mobile machinery, the temperatures can range from -30°C in eastern and central Hokkaido in winter to 40°C in inland Honshu in summer, even within Japan. If it is exported and used in Alaska or Siberia, it can be as high as -50°C in winter and +50°C in the salt plains of Ethiopia. In addition, automobiles have not only temperature, but also heat-generating devices such as engines, electric motors, and lights, and the exterior parts such as fenders and doors exposed to sunlight can reach nearly 100°C for a few hours in the sun when parked in a windless area, depending on the location of use. In short, since the linear expansion coefficients of metal materials and resin molding materials differ, even if the injection joint that has been completed is OK in a durability test at around room temperature, that alone is not sufficient. Taking into consideration the difference in linear expansion coefficient between the metal material and the resin (injection molded product), the inventors have also conducted research and experiments into a joint structure and joint shape that will not be affected at all by temperature shocks of at least 3,000 cycles of +150°C and -50°C, and have clarified the basic technology (Patent Document 14).

[0025] (Relationship between complete bonding of metal and resin materials and linear expansion coefficient of integrated composite) One example of this is related to physical chemistry, and is what happens to the linear expansion coefficient of a composite material when a metal sheet material and a thick resin injection molded product are integrated by injection bonding the plate surfaces together to form a thick composite material. In short, the resin material contains GF (short glass fiber) at, for example, 30-35% by mass, and is quite hard, has high tensile strength, is durable, and has a melting point of about 250°C (for example, a special polyamide composition "CM3506G50 (manufactured by Toray Industries, Inc. (headquarters: Tokyo, Japan)" containing 33.3% by mass of GF), and the resin plate is 5 mm thick and is an injection molded product in the shape of a rectangular thick plate measuring 45 mm x 18 mm. The metal piece in this case is SUS304 stainless steel obtained by chemical treatment for injection bonding, and is a thin plate measuring 45 mm x 18 mm and 0.28 mm thick. This describes the case where these two materials are surface-bonded (close to perfect bonding) using the highest level of injection bonding technology to form a composite plate. The linear expansion coefficient of the resin molding itself is (3~3.5)×10 -5 K -1 The linear expansion coefficient of SUS304 steel itself is 1.6×10 -5 K -1 So the difference is quite large.

[0026] In this case, the linear expansion coefficient of the plate surface of the 5.3 mm thick special steel / resin composite plate obtained by injection joining technology is approximately 3×10 -5 K -1 It was found that the linear expansion coefficient of the integrated material was close to that of the resin material. In this case, both the metal and resin materials have high rigidity, and when comparing the metal and resin materials with the product of the longitudinal elastic modulus and thickness as the longitudinal elastic modulus including thickness, the resin material is clearly superior to the metal material, as in this case. In other words, the linear expansion coefficient of the composite material follows the inherent value of the resin material, and the linear expansion coefficient of the metal material is subordinate to the other and its own value disappears. Of course, this is only possible if the bonding strength between the two materials is extremely strong, at around 55 MPa. The completed composite plate is ultimately like a thick resin plate plated with stainless steel, and is lighter than a single thin steel plate.

[0027] (Relationship between perfect bonding of metal and resin materials and linear expansion coefficient of integrated composite, Part 2) On the other hand, suppose an injection molded product is planned using the same special polyamide composition "CM3506G50" as above for the resin material, with the resin plate being 1.5 mm thick, and one of the metals is made of A5052 Al alloy, two thin plates with a thickness of 0.75 mm. All three of these materials are inserted into an injection mold, and then the resin is injected into the middle of the two plates to be injection bonded, and the three plates are completely bonded (close to perfect bonding) using the most advanced injection bonding technology to form a 3 mm thick three-layered integrated composite thick plate. What will be the linear expansion coefficient of the resulting composite plate? The linear expansion coefficient of the resin molded product itself is (3~3.5) x 10 -5 K -1 The linear expansion coefficient of A5052Al alloy itself is 2.4×10 -5 K -1 Therefore, the difference in linear expansion coefficient between the two is quite small. In this case, the resin side will yield and have a linear expansion coefficient of 2.5×10 -5 K -1 It is likely to be a number close to

[0028] It is the job of a physicist to show a formula and establish a theory, but the inventor is an engineer, and if he can make it into a practical product, he has done his job well. In fact, to theorize it, he must make a 1.5mm thick plate-shaped molded product of the special polyamide resin composition "CM3506G50" containing 33.3% by weight of GF, and use the obtained plate-shaped product to precisely measure the change in length due to temperature change in various directions. In fact, this measurement is surprisingly difficult. He learned that the linear expansion coefficient changes depending on the direction and location of the measurement line depending on where the resin was injected from using a pin gate, whether a side gate was used instead of a pin gate, and so on, and he began to think that a more complicated theory is needed to organize the data. Furthermore, he learned that the large amount of GF, an average of 33.3% by weight, in the resin causes large changes even in measurements of the simplest rectangular plate-shaped injection molded product made by pouring resin into the side of the short side.

[0029] For example, if you measure the linear expansion coefficient using a line parallel to the long side, the difference in the year of purchase of the "CM3506G50" is 3.2 x 10 -5 K -1 ~3.8×10 -5 K -1The linear expansion coefficient of the injection molded product varies depending on the fiber thickness, fiber length, and even the short fiber manufacturing conditions, when the GF content is 25% or more. Considering this, even though a large amount of GF is added to the resin "CM3506G50", the resin manufacturer (Toray Industries, Inc.) claims in the product catalog that "Despite the large amount of GF contained in this resin molded product, the GF fiber tips do not protrude from the surface, and the molded product has a smooth and beautiful feel to the touch." This is a characteristic of molded products obtained by injection molding or extrusion molding of amorphous thermoplastic resins that generally contain up to 35% inorganic powder or other fillers, and refers to the fact that only a small amount of solid filler is added to the surface layer up to a depth of about 10 μm from the surface.

[0030] Resin processing engineers say that the surface thin layer of such thermoplastic resin moldings contains almost no so-called fillers such as solid powders or short reinforcing fibers, and that there is a "skin layer." In the above example, it would be expressed as having a skin layer of about 10 μm thickness. However, the resin "CM3506G50" is mainly a highly crystalline thermoplastic resin to which a large amount of filler, 33.3% by weight of the total, has been added, and generally speaking, the molded product will always have areas where the tips of the filler GF are exposed, so the injection molded product will not be smooth and beautiful to the touch. However, the surface layer of the molded product of the polyamide resin "CM3506G50" is as beautiful as a mirror, and the finish of the mold is realized as it is. The reason why this is the case is that the resin composition contained in this resin composition is a crystalline resin that crystallizes very slowly when cooled rapidly, and as a result, it resembles an injection molded product of an amorphous resin.

[0031] The detailed explanation is related to the details of the resin composition itself, i.e., what kind of polyamide resin is the polyamide resin in the polyamide resin "CM3506G50". In this regard, roughly speaking, the true identity of the polyamide resin referred to here is a composition in which aliphatic nylons such as PA6 (6 nylon) and PA66 (66 nylon), which have a very fast crystallization speed when quenched, and semi-aromatic nylons such as PA6I (alternating copolymer of hexamethylenediamine and isophthalic acid) and PA6T (alternating copolymer of hexamethylenediamine and terephthalic acid), which have an abnormally slow crystallization speed when quenched, are mixed in an appropriate ratio. By mixing multiple polyamides like this, the crystallization speed when quenched is adjusted to a resin level with injection bonding properties, which is somewhat slow, and this itself has the same effect as improving the mold transferability when manufacturing normal injection molded products.

[0032] In other words, if there is a metal material that has been NMT-treated, new NMT-treated, or SNMT-treated inserted into the mold, the injected "CM3506G50" will penetrate deep into the ultra-fine recesses on the surface of the metal material, and then crystallization will be completed, producing the highest level of metal-resin bonding and integration. Similarly, if normal injection molding is performed, a clear skin layer will be easily formed, and if the mold is well polished and has been mirror-finished, the molded product obtained will have good transferability and a beautiful molded product with a mirror finish. In other words, the resin flow, which is in a turbulent state as it proceeds through the passages in the mold and is cooled to a liquid temperature below the melting point, but crystallization has not yet begun, and the resin flow, which is in a supercooled state, will suddenly stop at the passage stopper and crystallization will begin due to the physical impact, and at the most rapidly cooling tip surface, the polymers will gather together and the liquid viscosity will begin to increase.

[0033] In this case, crystallization refers to the liquid polymers starting to align with each other, so they will align and gather, and therefore fillers such as GF and inorganic powders that were evenly distributed in the polymer group will be pushed backwards if the crystallization is slow. This entropic physicochemical change of polymer crystallization is the reason why the skin layer is created, but if the crystallization speed is very fast, the speed at which large powders and short GF fibers with a length of about 1 mm escape cannot keep up with the speed of crystallization of the resin part, resulting in a thin skin layer and an uneven surface shape with the GF ends slightly exposed on the molded product. Also, in injection molded products made of amorphous resin, the liquid viscosity increases as the liquid temperature decreases, so the solidification speed of the resin is much slower, so the polymers lower their thermal motion level and gather and entangle with the intermolecular forces between the polymers, slowly increasing the liquid viscosity and heading towards solidification. There, the dispersed fillers are expelled from the group of polymers that are gathering together, but because the rate at which the polymers gather together is slow (usually slower than the rate of crystallization), the fillers are pushed out slowly accordingly, resulting in the formation of a distinct skin layer.

[0034] In the end, it is very interesting that the plates, rods, and other shapes of the chito-special polyamide resin "CM3506G50" obtained by injection molding contain 33% or more of GF, so the molded products are somewhat hard and rigid, but are an extremely special resin material that does not suffer from the poor transferability and dimensional stability that tend to occur when a large amount of GF is used. In short, the inventor thought that the injection molded products of this resin are beautiful, have good dimensional stability, and are somewhat hard, so it is a material that can be used for structural materials. And since it is a resin that is compatible with NMT, new NMT, and SNMT injection joining technologies even though it contains 33% or more of CF, he thought that if it is used as a composite material with metal, it can be used in place of steel depending on the location of use.

[0035] (Is it possible to standardize the linear expansion coefficient of an integrated composite of metal and resin materials?) Let us consider the theory behind this. First, regarding the linear expansion coefficient of the "CM3506G50" resin itself, the linear expansion coefficient of the glass itself, which is the raw material for glass fiber, is (0.6~0.7)×10 -5 K-1 Naturally, the linear expansion coefficient of the GF itself is the same. On the other hand, the linear expansion coefficient of the resin component itself is (5~6)×10 if it is an amorphous resin. -5 K -1 For crystalline resin, it is about 10 x 10 -5 K -1 It is well known that the crystallinity of the resin is close to 10×10 because a highly crystalline resin is used here. -5 K -1 However, in reality, 33.3% GF is included, and the linear expansion coefficient decreases as the filler content increases, as mentioned above: (3~3.5) x 10 -5 K -1 On the other hand, all aluminum alloys had a melting point of 2.4×10 -5 K -1 SUS304 steel is 1.6×10 -5 K -1 SUS430 steel and general steel are 1.1 x 10 -5 K -1 Ti and Ti alloys are about 0.8×10 -5 K -1 That's about it.

[0036] As such, all metals have a smaller linear expansion coefficient than resin materials, and even if a metal material and a resin material are completely joined at room temperature using injection joining technology to create an integrated product, there will inherently be a difference in length between the two materials on either side of the joining surface whether the environmental temperature rises or falls, so internal shear stress will inevitably occur in both materials near the adhesive surface. However, the linear expansion coefficient of the molded product made from the above-mentioned "CM3506G50" resin is 10 x 10 -5 K -1 The linear expansion coefficient is close to (0.6~0.7)×10 -5 K -1 By mixing more GF, the -5 K -1 This shows that the resin material itself is basically soft, and when it is mixed with a hard material with a low linear expansion coefficient, it is easily pulled by the mechanical properties of the material.

[0037] Therefore, if the integrated product of metal and resin materials joined by injection joining technology, for example the joint shown in Figure 1, shows a strong joining force with a shear joining strength of 40 to 60 MPa, it seems that problems due to the difference in linear expansion coefficients do not occur unexpectedly if the product is a composite rod plate in which the metal material is a 10 mm diameter rod and the resin material containing GF is surrounded by a thick plate cover material with an inner diameter of 10 mm and an outer diameter of 15 mm. For example, if the temperature rises to +150°C, the linear expansion coefficient of the resin side is higher than that of the metal side, so it seems that the resin side will stretch and try to peel off from the central metal rod, but the resin itself has a very high linear expansion coefficient, so the tendency to peel off is the same even under room temperature conditions. It was a large amount of GF that constantly suppressed the internal stress of the resin that tried to peel off.

[0038] The GF itself has a linear expansion coefficient of 0.6 x 10 -5 K -1 This is about the same as the coefficient of linear expansion, and is actually smaller than that of metal materials. Therefore, in the case of a composite shape like this, if we consider that the soft resin is held in place by both the GF group, which has a low linear expansion coefficient and is hard, and the metal rod at the center, it seems that spontaneous destruction or breakage between the two materials due to the difference in linear expansion coefficient is surprisingly unlikely to occur. After all, the condition for everything is that the joint structure between the metal part and the resin part is close to a perfect joint structure, and that the injection joining technology is carried out correctly. Therefore, if the metal side is an Al alloy, the linear expansion coefficient is 2.3 x 10 -5 K -1 If the resin composition is an injection-bonded resin containing GF33.3%, such as "CM3506G50", the linear expansion coefficient of the injection-bonded resin composition is probably (3 to 4) x 10 -5 K -1 Therefore, it can be said that the difference in linear expansion coefficient between metal and resin materials is small, so it is believed that the above-mentioned integrated thick-walled material can withstand the temperature shock cycle test. In other words, in such a case, the difference in linear expansion coefficient between the two materials disappears and the aluminum alloy's (2.4~2.5) x 10 -5 K -1 The two materials will not separate due to temperature changes. [Prior art documents] [Patent documents]

[0039] [Patent Document 1] JP2004-050488(NMT PBT) [Patent Document 2] Patent Publication 2007-050630 (NMT PPS) [Patent Document 3] Patent Publication 2007-182071 (NMT Nylon) [Patent Document 4] JP2010-064498 (NMT PPS anodizing) [Patent Document 5] WO2021 / 070654(NMT2) [Patent Document 6] WO2008 / 281933 (New NMT SUS) [Patent Document 7] WO2008 / 047811 (New NMT copper) [Patent Document 8] Patent Publication 2017-132243 (New NMT copper sealed LIB) [Patent Document 9] WO2008 / 078714 (New NMT Ti) [Patent Document 10] Patent Publication 2010-064397 (New NMT Ti alloy) [Patent Document 11] WO2009 / 011398 (new NMT steel) [Patent Document 12] JP2018-111277(NMT PEEK) [Patent Document 13] Patent Publication 2017-132243 (New NMT Copper Whiskers) [Patent Document 14] Patent Publication 2019-217704 (NMT injection joining product shape) [Patent Document 15] Patent Publication 2022-071227 (NMT Semi-aromatic polyamide) [Patent Document 16] Patent Publication 2021-095385 (SNMT) [Patent Document 17] Patent Publication 2020-100248 (New NMT copper LIB viscosity) [Non-patent literature]

[0040] [Non-Patent Document 1] "High specific strength composite material made by laminating aluminum and CFRP; jointly developed by Taiseiplas and Toray" Nikkei Crosstech Mechanical Components Technology Exhibition 2009,06,24 Summary of the Invention [Problem to be solved by the invention]

[0041] What the inventor aimed to achieve is a method or means for Japanese automobile manufacturers to win the huge automobile manufacturing and sales competition that is expected to begin around the world in 2023 or 2024. From the inventor's point of view, the inventor intends to replace the current steel materials and thin steel sheets in automobile components, i.e., roof panels, fenders, doors, tailgates, front and rear seats, in other words, the steel chassis and the parts that are not the main structural parts placed on it, with three-dimensional structures using shaped plates made of a composite integrated metal-resin material using a highly crystalline thermoplastic resin composition. This matter is publicly known from the above-mentioned Patent Documents 1 to 17, and from the inventor's point of view, it has already been communicated to many people, including engineers and strategic planners at domestic automobile manufacturers and automobile component manufacturers, but unfortunately it has not been well noticed, which is why the present invention was made.

[0042] The idea of ​​changing materials to similar non-ferrous metal structural materials or resin structural materials has been under consideration for half a century, and in the United States, a sporty car called the Mustang (manufactured by Ford Motor Company (headquartered in Deer Park, Michigan, USA)) was made with FRP plates made of long glass fiber and unsaturated polyester resin installed in several places other than the chassis, and this car became very popular. Although there was no intention to reduce the weight of the car body, it is certain that the use of resin materials in relatively large automotive parts gained popularity, and historically this is considered to be the first time that resin materials were used at least in structural parts. Also, with the advancement of petrochemicals, an injection-molded ABS resin was attached to the meter panel in front of the driver's seat, and the use of ABS resin in non-structural materials began.

[0043] However, it was later discovered that ABS resin would continue to burn if ignited by the flame of a cigarette lighter, and as a countermeasure, development of flame-retardant ABS progressed, and it was made heat-resistant and used as a cover material for headlights and backlights. Around the time this movement towards flame-retardant ABS resin began, GE in the US developed POM (poly oxy-methylene) resin, which is flame-retardant even without additives, and established a mass production method. The company decided that POM was not only a sales channel for home appliances that already used ABS resin, but also a groundbreaking new resin that could be used as a structural material for a wide range of applications, from single-family homes to automobiles, and created prototype POM roofing and exterior wall materials based on the image of a POM house, and also built a prototype car using POM automotive parts (fenders, doors, etc.) to challenge the public.

[0044] As a result of this, two types of small passenger cars were manufactured and sold in Japan, using fenders made from injection-molded flame-retardant thermoplastic resin. The inventor himself visited the automobile production factory at the time and spoke with a worker who was installing the plastic fenders. He said, "The mounting hole positions, which were consistent in winter, started to shift significantly in summer, making adjustments troublesome. I hate this work because it takes a lot of time." The reason for the misalignment is that when attaching a plastic plate to a steel part, if the environmental temperature changes, the linear expansion coefficients of the two parts differ greatly, so it is natural that this will occur, and the measures taken to anticipate this were insufficient. However, although I do not think that this additional work caused a slight deterioration in automobile production efficiency, no successors were produced for these two models. Also, during the same period, the only products that adopted the POM resin invented by GE were office appliances such as printers and copy machines, and housing materials and automobile parts were never made into POM products.

[0045] For such automotive structural materials other than the chassis, there is a history of resin materials not working very well in the past. Therefore, even if the technology executives of automotive manufacturers, who are busy dealing with the upcoming shift to electric vehicles, obtained information on the excellent physical properties of the integrated composite of metal and thermoplastic resin using the injection joining technology developed by our company (Taisei Plus Co., Ltd.), they felt that it would be similar to past failures, and did not proactively try to start collaborative research with the inventor or our company (Taisei Plus Co., Ltd.) on automotive applications. In other words, the inventor (Ando Naoki) thought that the above-mentioned Patent Documents 1 to 17 were all basic technologies, and that the specific mass production technologies should be developed and acquired mainly by automobile manufacturers and automobile part manufacturers, and that automobile manufacturers and automobile part manufacturers should apply for and acquire them as new patents. Therefore, the inventor changed his strategy.

[0046] That is, this invention even includes the shape of the automobile parts and shows an example of how to put them to practical use. The inventor, who was a technical officer at a petrochemical company and had never done any assembly work or research on the methods, even in areas that should have been developed by automobile manufacturers or automobile component manufacturers, predicted the site of an automobile parts manufacturing factory, illustrated and explained the component structure, and thought about how to connect it to other materials and what method a designer would use to fix it. This invention is a kind of application invention that includes such content. In fact, the content itself is just a list of the injection joining technology inventions made by the inventor, but the execution of the strategy of making it an application invention and incorporating it into a specific automobile manufacturing method is the very "problem that the inventor is trying to solve," and this was carried out in the application and disclosure of this invention. [Means for solving the problem]

[0047] The present invention 1 uses a crystalline thermoplastic resin composition containing 50 to 90 mass % of an aliphatic polyamide and 50 to 10 mass % of a semi-aromatic polyamide as a resin material, and containing 30 to 35 mass % of short glass fibers as a whole, On the other hand, NMT-type chemically treated thin plate material of A5052, A5083, A6061, or A2024 Al alloy with a thickness of 0.5 to 0.9 mm is cut into suitable rectangular pieces, and each piece is inserted into a mold for injection joining at a determined insert position. The mold is then closed and the crystalline thermoplastic resin composition is injected, and the shape after release is basically 2.5 mm or more in thickness and 500 cm in area. 2 The above-mentioned plate-shaped resin molding including the curved surface is a composite integrated product in which each aluminum alloy thin plate is surface-bonded mainly to its outer periphery, and the overall shape of the product is in accordance with the example shown in FIG. 4, and The area of ​​use of this integrated composite product is as a plate-like member used for roofs, fenders, outer surfaces of doors, undersides of seats, backs of seats, etc. of moving machines including automobiles. A metal-resin composite integrated product characterized by the above and a method for using the same.

[0048] The present invention 2 uses a crystalline thermoplastic resin composition containing 50 to 90 mass % of an aliphatic polyamide and 50 to 10 mass % of a semi-aromatic polyamide as a resin material, and containing 30 to 35 mass % of short glass fibers as a whole, On the other hand, one or more long sheets of NMT-type chemically treated A5052, A5083, A6061, or A2024 aluminum alloy with a thickness of 1.0 to 1.5 mm are placed in the injection joining mold at the respective insert positions. The mold is then closed and the crystalline thermoplastic resin composition is injected into the mold, so that the shape of the mold is basically 2.5 mm or more in thickness and 400 cm in area. 2 The above plate-shaped resin molding has a long aluminum alloy plate mainly in the center, and when there are multiple plates, they are lined up in the long direction and surface-bonded to form a composite integrated product, and the overall shape of the product is in accordance with the examples shown in Figures 5 to 9, and The area of ​​use of this integrated composite material is as a plate-like member for roofs, fenders, outer door surfaces, etc. of moving machines including automobiles. A metal-resin composite integrated product characterized by the above and a method for using the same.

[0049] The present invention 3 uses a crystalline thermoplastic resin composition containing 50 to 90 mass % of an aliphatic polyamide and 50 to 10 mass % of a semi-aromatic polyamide as a resin material, and containing 30 to 35 mass % of short glass fibers as a whole, On the other hand, a square bar-shaped material of about 5 mm square and 100 mm or more in length obtained by machining a heat-treated square bar material obtained by extruding an Al alloy for casting, such as A5083, A6061, or A2024, is used, and the like. The insert position is determined and placed in an injection joining mold, Next, the mold is closed and the crystalline thermoplastic resin composition is injected, and the shape is basically a rod-like resin molding having a diameter of 15 to 20 mm and a length of 50 to 150 mm, and the aluminum alloy square bar is sunk into the center of the rod and contained therein, so that the rods are bonded almost entirely to each other to form a composite integrated product, and the overall shape of the product is in accordance with the example shown in FIG. 10, and The area of ​​use of this composite integrated product is as a component for the pillar parts of the driver's seat and passenger seat of moving machines including automobiles. A metal-resin composite integrated product characterized by the above and a method for using the same.

[0050] (Highly crystalline thermoplastic resin composition important for carrying out the present invention) Obtaining this type of resin was the greatest discovery made during the development of injection joining technology. That is, according to Patent Document 3 (JP 2007-182071) and Patent Document 15 (JP 2022-071227), the resin contains 10% or more of semi-aromatic polyamide components, and the rest is composed of aliphatic polyamide components mainly consisting of PA6 and PA66 aliphatic polyamide components, and a resin composition in which 50 parts by mass of GF is added to 100 parts by mass of the resin is a highly crystalline thermoplastic resin composition that can be used.

[0051] A representative resin of the resin composition is "CM3506G50 (manufactured by Toray Industries, Inc. (Head Office: Tokyo, Japan))". This resin composition was selected because it was found to have an astonishingly high value of over 55 MPa in the shear strength data of the injection joints shown in Figure 1, which were obtained by combining nearly 100 types of crystalline thermoplastic resin compositions with more than 300 types of metal pieces treated with chemical processing methods based on injection joining technology called NMT, new NMT, or SNMT of more than 100 types of commonly available metal alloys. After that, it was confirmed that the injection joints have excellent durability over time, durability in high temperature and high humidity environments, and durability tests of 3,000 cycles of severe temperature shock between high and low temperatures. Furthermore, the physicochemical considerations of why this resin composition is strong in such durability tests make sense, so it was chosen as the resin composition.

[0052] In short, if it contains a large amount of GF and is injection molded into a plate several mm thick, it will have a strength close to that of cypress boards, and the surface can be made to have a mirror-like or matte finish. However, compared to thin steel plates and hard wood boards, its hardness is low, so its rigidity is inferior, and its rigidity is also inferior to lauan wood. Therefore, when made into a large-area plate, its weak bending rigidity may be a problem when used for the exterior panels of automobiles. On the other hand, when used as a small-area plate, it is fully durable for use as an exterior panel. The source of its favorable physical properties is the large amount of GF it contains, and the crystallization speed during quenching is quite slow, so the injection molded product has a clear skin layer, and it has the ability to be strongly injection bonded to metal pieces that have been treated to have an ultra-fine uneven surface. A resin with exactly these characteristics, "CM3506G50 (manufactured by Toray Industries, Inc.)," ​​was discovered early on in a joint research project between Taiseiplas Co., Ltd. and Toray Industries, Inc. (Patent Document 2), and it was significant that the NMT processing method was further improved and SNMT was also achieved, resulting in the highest injection joining strength of this resin, 55 to 60 MPa (Patent Document 15).

[0053] The interesting and mysterious physical properties of the polyamide resin composition "CM3506G50" are that it gives beautiful injection molded products even though it contains 33.3% by mass of CF (short glass fiber). This shows that the injection molded product has a skin layer that does not contain CF, which also shows that it is optimal as a resin for injection bonding with metal materials. And the reason why a strong bonding strength (shear bonding strength) of 55 MPa can be produced when a good injection bond is obtained using the latest injection bonding technology, i.e. the latest NMT, new NMT, and SNMT, is that the elongation deformation of the crystallized thermoplastic resin with a high GF content deviates from the straight line starting from the origin on the graph showing the tensile strength / strain relationship at around 55 MPa of tensile strength and enters the plastic deformation region, causing the resin elongation to suddenly increase, causing simultaneous multiple breaks near the base of the resin side of the bonding surface, leading to a sudden fracture.

[0054] In other words, the upper limit of the reversible deformation region in the tensile deformation of the resin part is considered to be around 55 MPa, and it is clear that the source of this high bonding strength is the GF content of 33.3%. This high GF content is the low linear expansion coefficient of the resin composition, about 3 × 10 -5 K -1 This value corresponds to the linear expansion coefficient of Al alloy, 2.4×10 -5 K -1 The fact that the GF content is close to 35% or 38% also supports the stability of the product of the present invention against temperature changes. We would like to see what would happen if the GF content was further increased to 35% or 38%, but if the present invention is fully examined by automobile manufacturers, for example, resin manufacturers such as Toray Industries, Inc. can conduct additional comprehensive studies. As explained in the previous section, when a thermoplastic resin composition containing a large amount of GF and a metal piece are strongly injection-bonded using injection bonding technology such as NMT, we know that the linear expansion coefficient of the thermoplastic resin composition itself will approach the linear expansion coefficient of the metal piece if the difference in the linear expansion coefficient between the two is not too great.

[0055] In short, if we consider only the resin component, it is originally 10 x 10 -5 K -1 The closest linear expansion coefficient is 0.6×10 -5 K -1 GF is now in abundance and is close at hand, so the-5 K -1 The thermal expansion coefficient of the thermoplastic resin composition is 2.4×10. -5 K -1 When completely joined to the Al alloy, the resin, which does not strongly assert its own linear expansion coefficient, accepts the linear expansion coefficient of the Al alloy after the GF and becomes 2.4 x 10 -5 K -1 This means that the resistance should drop to . At least when an aluminum alloy plate and a resin plate using "CM3506G50" are surface-bonded using the best injection bonding technology to form a single integrated composite plate, the resin composition and metal pieces will not assert themselves against each other and break between the two materials in a temperature shock cycle test with a temperature difference of about 150°C.

[0056] (The important thing in implementing this invention is the vehicle body assembly method) If the mobile machine member of the present invention is used for the roof, fender, door exterior, seat bottom, seat back, etc. of an automobile, what the inventor does not know is the specific assembly technique and method to finish the automobile using the product of the present invention. In the process of attaching a plastic fender to a car body that I once visited at an automobile company, I was told that "the holes are getting misaligned in the summer and we are having a hard time," so I thought it was a screw or a hook fastener, but I was not shown the work itself, so I did not know. If it is not a simple screw fastener, the outer circumference of the fender itself is fitted, and after fitting it, it may be fixed with a screw at several points. I wonder if adhesive is also used. In any case, I thought that selecting such a final joining method, conducting tests, and putting it together is the specialized technology of an automobile manufacturer, and I wondered if there was a method to help with this, but I thought that this is impossible only for an engineer who knows the field, and that it is truly the job of an automobile manufacturer with a long history.

[0057] However, when using this "CM3506G50" resin, or an improved resin composition with further adjustments to the GF shape (short fiber length) and content relative to the entire resin composition, if a 1mm thick plate of A5052Al alloy is placed on the outer periphery of the injection joined product, that part will become a composite plate of Al alloy and high-strength resin, so I think that the screw tightening to the steel frame will be firm. Such a product of the present invention is shown in Figures 4, 5, and 7.

[0058] (Specific injection joining technology used in the present invention) The injection resin is "CM3506G50" or other polyamide resin composition selected from the composition conditions of a crystalline thermoplastic resin composition containing 50-90% by mass of aliphatic polyamide, 50-10% by mass of semi-aromatic polyamide, and 30-35% by mass of short glass fiber. On the other hand, metals and metal alloys are chemically treated by NMT, new NMT, or SNMT type, but these chemical treatment methods have been improved from the initial method to the present, and in practice they have changed year by year. The most clear is the NMT treatment method, and the name of the treatment method has changed as follows so that it is possible to know the specific level of NMT treatment. That is, the order is NMT treatment → NMT2 treatment → NMT5 treatment → NMT7 treatment → NMT8 treatment. There are about 20 types of JIS aluminum alloys that are commonly used, and the original NMT treatment method was the same for all of them, but after NMT2 treatment, the treatment method was different for each aluminum alloy type. The Al alloy treatment method used in the present invention is NMT5 or NMT8 treatment method.

[0059] The new NMT processing method is a processing method for each metal and metal alloy piece of non-aluminum metal material, and naturally, the specific processing method for each metal and alloy is completely different from the beginning of development. Of course, the newer the processing method, the more improved it is, and there is a record table in the company (Taisei Plus Co., Ltd.), but the specific processing method is not named. Furthermore, although the SNMT processing method has been improved for each metal and metal alloy type, it is not named. In the examples in the present invention, the chemical processing method for several types of Al alloys is disclosed in detail.

[0060] (Injection joining and annealing) The injection joining operation is the same as the injection molding operation, and there is no special technique that needs to be explained. However, there are mold temperature and dwell time. The mold temperature has a temperature range specified by the resin manufacturer, but it is basically set to a high temperature. Specifically, when using "CM3506G50", the mold temperature is preferably around 140°C. If the insert is large, weighing more than 1 kg, it is necessary to wait 30 to 90 seconds when the insert temperature is almost equal to the mold temperature, rather than inserting it and closing the mold and immediately moving to the injection operation. The reason is the same as for setting the mold temperature. As for the dwell time after that, it seems that the crystallization speed of "CM3506G50" is slow when it is rapidly cooled, so it seems better to set the time from the start of injection to the end of dwell time to about 30 seconds.

[0061] Of course, the injection-bonded product obtained is not simply left to cool and become the final product, but is heat-treated (annealed) at 150-170℃ for 1 hour within a few hours to fully crystallize the resin, and then the entire injection-bonding process is completed. In the previous section, it was said that the injection-bonded product should be obtained by keeping the time from resin injection to the end of dwelling pressure close to 30 seconds, and it is the injection-bonded product that is annealed after this process.

[0062] (Measurement of shear bond strength) ISO19095 describes the method of measuring the tensile lap-shear strength and tensile strength between the metal part and the resin molded part in the injection-bonded product, and describes a method of measuring the shear bond strength by tensile breaking the product in the shape of FIG. 1 with a tensile tester, and a method of measuring the tensile bond strength by tensile breaking the product in the shape of FIG. 2 with a tensile tester. This method of measuring the shear bond strength using the product in the shape of FIG. 1 is the one used by the inventors in all of Patent Documents 1 to 17, and the method of measuring the tensile bond strength using the product in the shape of FIG. 2 is the one that the inventors started to use around 2015 after various experiences. Neither of these methods can be measured by the methods specified in JISK6849 and 6850, which were the conventional methods for measuring adhesive strength and bond strength, so our company (Taisei Plus Co., Ltd.) proposed a new regulation, which was approved as ISO19095 after being examined by a Japanese government agency and by ISO-related government agencies in various countries.

[0063] (Injection joints that can withstand temperature shock cycle tests) Automobiles are used all over the world. They are used in tropical desert regions such as Alaska, and the temperature range is from -50℃ to +50℃. Furthermore, the temperature around the engine and the parts around the lights can reach +150℃ regardless of summer or winter, and even in cold regions, it can reach +30℃ indoors when driving. The most severe temperature shock cycle is in the winter in Alaska, Russia, and Northern Europe, and the engine parts around the engine vehicles are thought to be about 300 cycles / year of temperature shock of -50℃ / +150℃. Therefore, it is understood that a temperature shock test of 3,000 cycles of -50℃ / +150℃ is used as a durability test for automobiles, anticipating 10 years of use. The product of the present invention was also evaluated using this temperature shock cycle test (1,000 to 3,000).

[0064] The first test to carry out this -50℃ / +150℃ temperature shock 3,000 cycle test was conducted on a PPS resin "SGX120 (manufactured by Tosoh Corporation (head office: Tokyo, Japan))" different from the product of the present invention, and various metal pieces were injection-bonded, all of which showed a shear bond strength of 40 to 42 MPa, which the inventors consider to be "completely bonded". Then, we started by creating the shape shown in Figure 1. The product of the present invention uses a special polyamide resin composition "CM3506G50", and the shear bond strength of the resulting injection bond with metal is around 55 MPa, so the shear bond strength of the injection bond with this "SGX120" seems to be low at about 40 MPa. However, if both are completely bonded, the bond strength will vary depending on how much reinforcing fiber GF is contained in the resin composition, and there will be this much difference in shear bond strength between "SGX120" with a GF content of about 20% and "CM3506G50" with a GF content of about 33%. In short, the reason why a completely joined material will fracture in shear during a tensile test is that when its strength is exceeded, one of the two materials will no longer be able to undergo rigid deformation (reversible deformation) and will transition to plasticity (irreversible deformation). Naturally, this will result in small fractures near the joint surface of the material that has undergone plastic deformation, and stress will immediately concentrate in the surrounding area, leading to complete fracture.

[0065] Metal materials are generally harder than resin materials, so it is the resin material that breaks. Therefore, if the metal side of the injection joint is an Al alloy, steel, copper, or Ti alloy, it will break at about 40 MPa when using "SGX120" and 55 MPa when using "CM3506G50". There are some injection joints that do not meet this expectation at all, and that is the case when the metal is a soft metal material that is closer to a pure metal than an alloy, such as A1050 Al alloy. This is the case when the injection joint uses a metal material that can change from rigid deformation to composition deformation before the resin material in the tensile tester. In the case of injection joints where the metal is an Al alloy such as A1085, A1080, or A1050 and is completely joined with "SGX120" or "CM3506G50", the shear joint strength is 35 to 38 MPa, and a shear joint strength of 40 MPa or more is not observed. This is because plastic deformation on the metal side begins at this tensile strength.

[0066] Let's go back to the original point. The following is what was described in Patent Document 14, but I will introduce it again. First, about 30 injection-bonded objects of the shape shown in FIG. 1 were made using the PPS resin composition "SGX120" as the resin. Next, the resin part of the object of the shape shown in FIG. 1 was mechanically polished to remove the thickness of the resin part on the bonding surface of the object with the thickness of the resin part (originally 3 mm thick), and objects with a thickness of 2 mm were made, and objects with a thickness of 1 mm were made by further polishing. In short, 10 objects of the shape shown in FIG. 1 were left, and 10 objects with a thickness of 2 mm only on the resin part were made, and 10 objects with a thickness of 1 mm only on the resin part were made. After that, all 30 objects were painted with rust-preventive paint and baked at 100°C. Then, they were subjected to a temperature shock test of 2,000 cycles at -50°C / +150°C, and left at room temperature for one week, after which the bonding surface was broken.

[0067] Only the resin part with a thickness of 3 mm was broken using the tensile tester and the shear joint strength was obtained using the method described in ISO19096. The other parts were broken using tools such as pliers because the joints could not be broken using the tensile tester. The evaluation method is that the shear joint strength is obtained for the product in the shape shown in Figure 1, so it can be immediately determined, but the other parts were evaluated by observing the joint surface marks of the obtained metal pieces. In other words, since the resin "SGX120" used for injection joining is blackened with carbon black, colored resin powder is attached to the joint surface marks on the metal side after breaking. The parts without resin adhesion are the parts where the joint strength was reduced by the temperature shock test and the resin part was pulled out from the fine recesses on the metal surface, so if such parts exist, there is no black resin adhesion and the joint strength is zero. If you understand it like this, you can understand the parts where the joint strength was lost due to the temperature shock and the parts where the joint strength was maintained.

[0068] This 2,000 cycle temperature shock test was performed on the metal material with a thickness of 3 to 6 mm (3 mm or more for steel and hard Al alloy, 4.5 to 6 mm for soft Al alloy) in the shape shown in Figure 1, and when multiple temperature shocks were applied, the difference in linear expansion coefficient between the two materials directly damaged the joint surface. The joint surface was less likely to be damaged in samples with a thin resin part that made it flexible in expansion and contraction. In fact, in samples with a resin part thickness of 3 mm (injection joint with the shape shown in Figure 1), the shear joint strength decreased in all cases, even if it was small or large, and when both materials were thick and strong, the complete joint surface clearly shrank due to repeated temperature shocks. On the other hand, in samples with a resin part thickness of 1 mm, the Al alloy was completely undamaged, the SUS304 steel had very slight peeling at one or one or two corners of the joint surface trace, and the Ti alloy had slight peeling at two corners of the joint surface trace. In the sample with a resin part 2mm thick, peeling was observed somewhere between the 3mm and 1mm thick specimens, with varying degrees of peeling observed at two and four corners of the bonded surface. In conclusion, if the metal material is an Al alloy, even if it is thick, it will be resistant to temperature shock if the resin part is about 1mm thick, and paradoxically, if the resin part is 3mm thick, the completely bonded object will be able to withstand temperature shock by making the metal piece thinner.

[0069] Returning to the injection joint using "CM3506G50", if an injection joint as shown in Fig. 1 is made using thick plates of A5052Al alloy, A5082Al alloy, and A6061Al alloy with "CM3506G50", and the injection joint is subjected to a temperature shock test of several thousand cycles at -50℃ / +150℃ and the joining strength between the metal and resin is examined, if the resin in the previous section is 1mm thick, which occupies the widest joining area, as in the case of "SGX120", it will not be adversely affected by the temperature shock at all, and the design policy of the injection joint that can withstand the severe temperature shock test of several thousand cycles can be the same as that shown in the attached diagram of Patent Document 14. Of course, the type of resin used is different and the physical properties of the resin composition are different, so it is not appropriate to irresponsibly conclude that if the resin part of the injection joint is as thin as 1mm, it will withstand the same high temperature shock cycle test.

[0070] However, if the resin material was changed from "SGX120" to "CM3506G50" and the same experimental method was used to obtain the same results, it would be a waste of time. Therefore, in conclusion, in the test experiment using "SGX120", the metal material (linear expansion coefficient 2.4 x 10 -5 K -1 ) If the metal material in the injection-bonded product is an Al alloy, then even if it is thick, if the thickness of the resin part is thinned to around 1mm, it will be fine with temperature shock, and paradoxically, if the resin part is 3mm thick, then conversely, it is known that the fully bonded product can withstand temperature shock by making the metal piece thinner, so the part to be corrected by replacing "SGX120" with "CM3506G50" is the 1mm-thick part in "If the metal material in the injection-bonded product is an Al alloy, then even if it is thick, if the thickness of the resin part is thinned to 1mm, it will be fine with temperature shock" - whether this part is 1.2mm, 1.0mm, or 0.8mm. In this case, instead of making many pieces with the shape shown in Figure 1 and carrying out troublesome experiments again to reach a conclusion, we can create a mold for the final product from the beginning, create a mold that can make final injection-bonded products with the example part having thicknesses of 1.2 mm, 1.0 mm, or 0.8 mm, injection-bond several pieces for the three final shapes, and subject all of these to a temperature shock test with several thousand cycles to find usable products all at once. After all, the good thing about injection bonding technology is that the shape can be easily changed by nesting the molds and inserting and removing spacers. If you understand the theory, inspection and testing can also be simplified. Effect of the Invention

[0071] The intention of disclosing this invention is to inform related engineers that the current thin steel plate structures for the roof, fender, door exterior, seat bottom, seat back, etc., other than the drive system and chassis of mobile machines, first of all, general-purpose vehicles, will be converted to metal-resin integrated composite plates with resin as the main structure and metal as the auxiliary structure, and that the conversion from this steel structure to a structure using metal-resin integrated composites will lead to a 10% or more weight reduction of the vehicle body, which will have the most clear effect on "CO2 reduction". Fortunately, the key technology of this invention is the successful production of an injection joint that shows the highest shear joint technology of 55MPa by using the latest injection joining technology developed in Japan for special polyamide resin composition "CM3506G50" obtained by the joint research between the present inventor and the research laboratory of Toray Industries, Inc., and metals, especially Al alloys, and that this invention is easy to understand for engineers and scholars related to material technology. Many automobile manufacturing engineers who have struggled to replace steel with aluminum alloys in order to reduce the weight of automobiles and have now given up on using all-aluminum alloys for general-purpose automobiles will likely realize that there is still a completely new resinification method available. The inventor believes that this is the greatest benefit of this invention.

[0072] Furthermore, if this invention progresses in the direction of adoption, the present invention, which relies on the resin "CM3506G50", can also proceed with research into further improving the resin performance. For example, regarding the GF content, if the injection joining capacity is not reduced, the GF content of 33.3% can be increased to 36% or 40%, and a demonstration test of the present invention product will be conducted, and if the performance of the final product does not deteriorate, a composition with an injection joining strength of 60 MPa or more will be created. Furthermore, in order to ensure clear flame retardancy, an appropriate flame retardant should be added to prevent the spread of fire in the event of a fire caused by a collision accident. In fact, there is a possibility that the battery LIB storage box may be damaged in a collision accident, leading to a fire accident, and therefore many engineers believe that the LIB storage box should be made of strong steel for general-purpose electric vehicles that aim to be sold in large quantities around the world, and they believe that this will eventually become a rule. In that case, the weight of the vehicle will increase, and this invention can also contribute to eliminating this increase in vehicle weight. [Brief description of the drawings]

[0073] [Figure 1] FIG. 1 is a diagram showing the shape of an injection-molded product for measuring the shear bonding strength between the metal part and the resin part in a metal-resin integrated product described in ISO19095. [Diagram 2] FIG. 2 is a diagram showing the shape of an injection-bonded product for the purpose of measuring the tensile bonding strength between the metal part and the resin part in a metal-resin bonded integrated product described in ISO19095. [Diagram 3] FIG. 3 is a diagram showing the shape of an auxiliary jig used when measuring the shear joint strength of a metal-resin integrated joint described in ISO19095. [Figure 4] 4(a)-(b) are schematic diagrams illustrating the appearance of an injection-joined product obtained by inserting multiple Al alloy sheets that have been subjected to the improved NMT process as metal materials into an injection joining die and injecting a specific polyamide-based resin composition into the die. [Diagram 5] 5(a)-(b) are schematic diagrams illustrating the appearance of an injection-joined product obtained by inserting multiple Al alloy sheets that have been subjected to the improved NMT process as metal materials into an injection joining die and injecting a specific polyamide-based resin composition into the die. [Figure 6] Figures 6(a) and (b) are schematic diagrams of the appearance of an injection-joined product obtained by inserting multiple aluminum alloy sheets that have been subjected to the improved NMT process as metal materials into an injection-joining die and injecting a specific polyamide-based resin composition into them. [Figure 7] Figures 7(a) and (b) are schematic diagrams of the appearance of an injection-joined product obtained by inserting multiple aluminum alloy sheets that had been subjected to the improved NMT process as metal materials into an injection-joining die and injecting a specific polyamide-based resin composition. [Figure 8] Figures 8(a) and (b) are schematic diagrams of the appearance of an injection-joined product obtained by inserting multiple aluminum alloy sheets that had been subjected to the improved NMT process as metal materials into an injection-joining die and injecting a specific polyamide-based resin composition into the die. [Figure 9] FIG. 9 is a schematic diagram of an injection-joined product obtained by inserting multiple aluminum alloy sheets that have been subjected to the improved NMT process as metal materials into an injection-joining die and injecting a specific polyamide-based resin composition into the die. [Figure 10] Figure 10 is a schematic diagram of an injection-jointed product obtained by assembling several rods of aluminum alloy that have been subjected to improved NMT processing as metal materials, inserting them into an injection-jointing die, and injecting a specific polyamide-based resin composition into the die, the whole of which is covered with resin. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS EXAMPLES

[0074] Experimental examples of the present invention will be described in detail below, and methods for evaluating and measuring the injection-bonded products obtained from the experimental examples will be shown. (a) Measurement of bonding strength The breaking force when the injection joint (Fig. 1, Fig. 2) was pulled to break using a tensile tester was taken as the joint strength (shear joint strength, tensile joint strength). However, the auxiliary jig shown in Fig. 3 was used to measure the shear joint strength. The tensile tester used was the "AG-500N / 1kN (Shimadzu Corporation)," and measurements were taken at a pulling speed of 10mm / min. This measurement method is based on ISO19095.

[0075] [Experimental Example 1] NMT8 treatment of A5052 Al alloy A large number of rectangular pieces measuring 18 mm x 45 mm x 1.5 mm were obtained by machining from commercially available aluminum alloy (A5052) plate material. The aluminum alloy pieces were immersed in a 10% aqueous solution of aluminum degreaser "NA-6" at 60°C in a tank for 5 minutes and rinsed with tap water (Ota City, Gunma Prefecture). Next, a 10% aqueous solution of caustic soda at 40°C was prepared in another tank, and the alloy pieces were immersed in this for 1 minute and rinsed. Next, a 1% aqueous solution of hydrated aluminum chloride and 5% aqueous hydrochloric acid at 40°C was prepared in another tank, and the alloy pieces were immersed in this for 6 minutes and rinsed. Next, a 2% aqueous solution of ammonium difluoride and 10% aqueous sulfuric acid at 40°C was prepared in another tank, and the alloy pieces were immersed in this for 4 minutes and rinsed.

[0076] Next, a 1.5% caustic soda solution at 40°C was prepared in another tank, and the alloy pieces were immersed in this for 1 minute, then immersed in a 3% nitric acid solution at 40°C in another tank for 1.5 minutes and washed with water. Next, a 3.5% hydrazine hydrate solution at 60°C was prepared in another tank, and the alloy pieces were immersed in this for 1 minute, then immersed in a 0.5% hydrazine hydrate solution at 33°C in another tank for 6 minutes and washed with water. Next, the alloy pieces were immersed in a 0.5% hydrogen peroxide solution for 1 minute, and a 0.2% triethanolamine solution was prepared, and the alloy pieces were immersed in it for 5 minutes. Although the alloy pieces were washed with water, they were not washed with pure water, but with a 25 ppm triethanolamine solution. The obtained alloy pieces were dried in a hot air dryer set at 67°C for 15 minutes, and then wrapped in aluminum foil and stored.

[0077] [Experimental Example 2] NMT8 treatment of A6061Al alloy A6061Al alloy pieces of 18mm x 45mm x 1.5mm were obtained. Next, an aqueous solution containing 10% aluminum degreaser "NA-6" was placed in a tank at 60°C, and the aluminum alloy pieces were immersed for 5 minutes and washed with tap water (Ota City, Gunma Prefecture). Next, a 10% caustic soda aqueous solution at 40°C was prepared in another tank, and the alloy pieces were immersed for 1 minute and washed. Next, an aqueous solution containing 1% aluminum chloride hydrate and 5% hydrochloric acid at 40°C was prepared in another tank, and the alloy pieces were immersed for 1 minute and washed. Next, an aqueous solution containing 2% ammonium difluoride and 10% sulfuric acid at 40°C was prepared in another tank, and the alloy pieces were immersed for 1 minute and washed.

[0078] Next, a 1.5% caustic soda solution at 40°C was prepared in another tank, and the alloy pieces were immersed in this for 2 minutes, then immersed in a 3% nitric acid solution at 40°C in another tank for 1.5 minutes and washed with water. Next, a 3.5% hydrazine hydrate solution at 60°C was prepared in another tank, and the alloy pieces were immersed in this for 1 minute, then immersed in a 0.5% hydrazine hydrate solution at 33°C in another tank for 4.5 minutes and washed with water. Next, the alloy pieces were immersed in a 0.5% hydrogen peroxide solution for 1 minute, and a 0.2% triethanolamine solution was prepared, and the alloy pieces were immersed in it for 5 minutes, and then washed with water, but not with pure water, but with a 25 ppm triethanolamine solution, and the obtained alloy pieces were dried in a hot air dryer set at 67°C for 15 minutes, and wrapped in aluminum foil for storage.

[0079] [Experimental Example 3] NMT8 treatment of A2024Al alloy A2024Al alloy pieces of 18mm x 45mm x 1.5mm were obtained. Next, an aqueous solution containing 10% aluminum degreaser "NA-6" was placed in a tank at 60°C, and the aluminum alloy pieces were immersed for 5 minutes and washed with tap water (Ota City, Gunma Prefecture). Next, a 10% caustic soda aqueous solution at 40°C was prepared in another tank, and the alloy pieces were immersed for 1 minute and washed. Next, an aqueous solution containing 1% aluminum chloride hydrate and 5% hydrochloric acid at 40°C was prepared in another tank, and the alloy pieces were immersed for 1 minute and washed. Next, an aqueous solution containing 2% ammonium difluoride and 10% sulfuric acid at 40°C was prepared in another tank, and the alloy pieces were immersed for 3 minutes and washed.

[0080] Next, a 1.5% caustic soda solution at 40°C was prepared in another tank, and the alloy pieces were immersed in this for 2 minutes, then immersed in a 3% nitric acid solution at 40°C in another tank for 2.5 minutes and washed with water. Next, a 3.5% hydrazine hydrate solution at 60°C was prepared in another tank, and the alloy pieces were immersed in this for 1 minute, then immersed in a 0.5% hydrazine hydrate solution at 33°C in another tank for 3 minutes and washed with water. Next, the alloy pieces were immersed in a 0.5% hydrogen peroxide solution for 1 minute, and a 0.2% triethanolamine solution was prepared, and the alloy pieces were immersed in it for 4 minutes. Although the alloy pieces were washed with water, they were not washed with pure water, but with a 25 ppm triethanolamine solution. The obtained alloy pieces were dried in a hot air dryer set at 67°C for 15 minutes, and then wrapped in aluminum foil and stored.

[0081] [Experimental Example 4] NMT5 treatment of ADC12Al alloy ADC12Al alloy pieces measuring 18mm x 45mm x 1.5mm were ordered from an affiliated company and obtained in large quantities. Next, the aluminum alloy pieces were immersed in a 10% aluminum degreaser "NA-6" aqueous solution at 60°C in a tank, and the aluminum alloy pieces were rinsed with tap water (Ota City, Gunma Prefecture). Next, a 1.5% caustic soda aqueous solution at 40°C was prepared in another tank, and the alloy pieces were immersed in this for 4 minutes, and then immersed in a 3% nitric acid aqueous solution at 40°C in another tank for 2 minutes and rinsed with water. Next, the pieces were immersed in a water tank equipped with an ultrasonic oscillator for 5 minutes and washed. Next, a 3.5% hydrazine hydrate aqueous solution at 60°C was prepared in another tank, and the pieces were immersed in this for 1 minute, then immersed in a water tank equipped with an ultrasonic oscillator for 5 minutes and washed again, then immersed in a 0.5% hydrazine hydrate aqueous solution at 33°C in another tank for 1 minute and rinsed with water, and then immersed in a water tank equipped with an ultrasonic oscillator for 5 minutes and washed again. The obtained alloy pieces were dried in a hot air dryer set at 67° C. for 15 minutes, and then wrapped in aluminum foil and stored.

[0082] [Experimental Example 5] Creation of injection-bonded objects and measurement of bonding strength The various surface-treated Al alloy pieces obtained in Experimental Examples 1 to 4 were inserted into an injection molding die, and the polyamide resin for injection bonding "CM3506G50" was injected to obtain injection-bonded products as shown in Fig. 1. The injection temperature was 300°C, and the die temperature was 140°C. The obtained injection-bonded products were annealed for 1 hour in a hot air dryer at 170°C. The shear bond strength of the obtained injection-bonded products at 23°C is shown in Table 1. The measurement method was in accordance with ISO19095, and the injection-bonded products as shown in Fig. 1 were placed in the auxiliary jig shown in Fig. 3 and subjected to a tensile tester at 23°C, with the results being the average of three pieces for each.

[0083] [Table 1] Examples of shapes and characteristics of the resulting injection-bonded products

[0084] [Shape example 1] Shape examples of plate-shaped materials for passenger car ceilings The one shown in Figure 4 is a curved flat plate made of resin with a thickness of 2.5 mm or more, and the ceiling plate material in the shape of Figure 4 is precisely positioned on the vehicle interior structural frame made of steel or cast aluminum alloy frame material by extrusion processing, with multiple long aluminum alloy plate pieces arranged on the outer periphery, and is placed in an injection joining mold to be injection joined as is. The thickness of the aluminum alloy pieces is 0.5 to 0.8 mm, and it seems that it is strong enough to be screwed to the metal frame if the number is increased to a certain extent. Other adhesion methods, such as adhesive + screw fastening, should also be better with a multi-layer material with aluminum alloy than with resin alone.

[0085] [Shape example 2] Shape examples of plate-shaped materials for passenger car ceilings Figure 5 shows an example of the same design as in Example 1, but with two backbone members in the ceiling plate to make the interior structure stronger. In mass-produced SUVs with high interiors, it may be possible to use cut and pasted 1mm thick aluminum alloy plates made of A6061 or A2024 aluminum alloy for the aluminum alloy parts to strengthen the backbone to withstand rough roads.

[0086] [Shape example 3] Shape example for side fender The one shown in Figure 6 is a curved flat plate made of resin with a thickness of 2.5 mm or more, and in order to maintain the shape of the side of the front of the car body, a strong long aluminum alloy flat plate with a thickness of 1.5 mm is joined in the length direction. I don't think this is necessary for a passenger car, but it would be preferable for an SUV.

[0087] [Shape example 4] Shape example for side doors The one shown in Fig. 7 is a curved flat plate made of resin with a thickness of 2.5 mm or more, and the door structure itself is assumed to be a steel frame structure to which a door panel as shown in Fig. 7 is attached. The door panel is fixed to the steel frame, and a 1.5 mm thick aluminum alloy plate is placed at the base of the door panel rotation to prevent misalignment when the door is opened and closed. The area around the door handle is also reinforced.

[0088] [Shape example 5] Seat back shape example The one shown in Fig. 8 is a 3mm thick resin plate with a slight curved surface, with a large 1.5mm thick rectangular aluminum alloy plate placed in the center for reinforcement. I don't think it's necessary to use an aluminum alloy plate as thick as 1.5mm, but since a heavy person weighing 200kg may ride and apply the emergency brakes with full force, this setting should be determined through a fair amount of experimentation.

[0089] [Shape example 6] Seat back panel shape example The device shown in FIG. 9 is a flat resin plate 3 mm thick, with a rectangular aluminum alloy plate 1 mm thick layered on top of the flat plate.

[0090] [Shape example 5] The structure shown in Figure 10 is a core made up of three assembled aluminum alloy square bars, which are completely covered with resin, so the aluminum alloy is basically hidden. In other words, it is made by cutting aluminum alloys such as A5083, A6061, and A2024 for wrought aluminum alloys, or aluminum alloy extrusions for casting into square bars about 5 mm square and 100 mm long or more, and then chemically processing the bars with NMT type treatment, and then assembling these three bars, inserting them into an injection joining die, and then injecting resin into them to join them.

Claims

1. A crystalline thermoplastic resin composition is used as a resin material, the composition containing 50 to 90% by mass of an aliphatic polyamide and 50 to 10% by mass of a semi-aromatic polyamide in the resin content, and containing 30 to 35% by mass of short glass fibers in the total content, On the other hand, a plurality of sheets of NMT-type chemically treated A5052, A5083, A6061, or A2024 aluminum alloy having a thickness of 0.5 to 0.9 mm are cut into suitable rectangular shapes, and the respective insert positions are determined and placed in an injection joining mold; The mold is then closed and the crystalline thermoplastic resin composition is injected into the mold. After release, the mold shape is basically 2.5 mm or more in thickness and 500 cm in area. ２ The above-mentioned plate-shaped resin molding including the curved surface is a composite integrated product in which each Al alloy thin plate is surface-bonded mainly to its outer periphery, and the overall shape of the product is in accordance with the example shown in FIG. In addition, the area of ​​use of this integrated composite product is a plate-like member used for the roof, fender, door outer surface, seat bottom, seat back, etc. of a moving machine including an automobile. The present invention provides a metal-resin composite integrated product characterized by the above-mentioned, and a method for using the same.

2. A crystalline thermoplastic resin composition is used as a resin material, the composition containing 50 to 90% by mass of an aliphatic polyamide and 50 to 10% by mass of a semi-aromatic polyamide in the resin content, and containing 30 to 35% by mass of short glass fibers in the total content, On the other hand, one or more long plates of 1.0 to 1.5 mm thick made of NMT-type chemically treated A5052, A5083, A6061, or A2024 Al alloy are used, and each insert location is determined and placed in an injection joining mold; The mold is then closed and the crystalline thermoplastic resin composition is injected into the mold, so that the shape of the mold is basically 2.5 mm or more in thickness and 400 cm in area. ２ The plate-shaped resin molding has a long aluminum alloy plate mainly in the center, and when there are multiple plates, they are lined up in the long direction and surface-bonded to form a composite integrated product, and the overall shape of the product is in accordance with the examples shown in Figures 5 to 9. In addition, the area of ​​use of this integrated composite product is a plate-shaped member used for the roof, fender, outer surface of door, etc. of a moving machine including an automobile. The present invention provides a metal-resin composite integrated product characterized by the above-mentioned, and a method for using the same.

3. A crystalline thermoplastic resin composition is used as a resin material, the composition containing 50 to 90% by mass of an aliphatic polyamide and 50 to 10% by mass of a semi-aromatic polyamide in the resin content, and containing 30 to 35% by mass of short glass fibers in the total content, On the other hand, a square bar-shaped object of about 5 mm square and 100 mm or more in length obtained by machining a heat-treated square bar material obtained by extruding an Al alloy for casting, such as A5083, A6061, or A2024, is subjected to NMT type chemical treatment, and the insert position is determined and placed in an injection joining mold, Next, the mold is closed and the crystalline thermoplastic resin composition is injected, and the resulting shape is a rod-like resin molding having a diameter of 15 to 20 mm and a length of 50 to 150 mm, and the aluminum alloy square bar sinks into the center of the rod and is contained therein, so that the rods are bonded almost entirely to each other to form a composite integrated product, and the overall shape of the product is in accordance with the example shown in FIG.

10. In addition, the area of ​​use of this composite integrated product is as a member for the pillar parts of the driver's seat and passenger seat of a moving machine including an automobile. The present invention provides a metal-resin composite integrated product characterized by the above-mentioned, and a method for using the same.

Images