JP4903881B2 - Joined body of metal alloy and adherend and method for producing the same - Google Patents

Description

  The present invention relates to the general field of manufacturing home appliances, general machinery, housing equipment, air conditioning equipment, other equipment and machines. TECHNICAL FIELD The present invention relates to a method for producing a new basic part. Metal alloys or between metal alloys and glass fiber reinforced plastics (hereinafter referred to as “GFRP”) is an unsaturated polyester type. The present invention relates to a bonded body firmly bonded and integrated with an adhesive and its manufacturing technology.

  Technology for integrating metal alloys and resins is required from various parts and materials manufacturing industries such as aircraft, automobiles, home appliances, and industrial equipment, and many adhesives have been developed for this purpose. Among these are very good adhesives. For example, an adhesive exhibiting a function at room temperature or by heating is used for joining to integrate a metal alloy and a synthetic resin, and this method is now a common bonding technique.

  On the other hand, bonding methods that do not use an adhesive have also been studied. An example is a method in which a high-strength thermoplastic engineering resin is integrated by injection or the like without using an adhesive to light metals such as magnesium, aluminum, and alloys thereof, and iron alloys such as stainless steel. For example, as a method of joining simultaneously with resin molding by a method such as injection (hereinafter referred to as “injection joining”), polybutylene terephthalate resin (hereinafter referred to as “PBT”) or polyphenylene sulfide resin which is a thermoplastic resin for an aluminum alloy Manufacturing techniques for injection joining (hereinafter referred to as “PPS”) have been developed (see, for example, Patent Documents 1 and 2). In addition, it has been demonstrated that magnesium alloy, copper alloy, titanium alloy, stainless steel, and the like can be injection-bonded by using the same type of resin (see Patent Documents 3, 4, 5, and 6).

  The principle of injection joining in Patent Documents 1 and 2 is shown below. The aluminum alloy is immersed in a dilute aqueous solution of a water-soluble amine compound, and the aluminum alloy is finely etched by the weak basicity of the aqueous solution. In this immersion treatment, ultrafine irregularities are formed on the surface of the aluminum alloy, and at the same time, adsorption of amine compound molecules on the surface of the aluminum alloy occurs. The surface-treated aluminum alloy is inserted into an injection mold, and the molten thermoplastic resin is injected at a high pressure. At this time, a chemical reaction occurs when the thermoplastic resin and the amine compound molecules adsorbed on the aluminum alloy surface are encountered. This chemical reaction suppresses a physical reaction in which the thermoplastic resin is rapidly cooled in contact with an aluminum alloy maintained at a low mold temperature to crystallize and solidify. As a result, the resin is delayed in crystallization and solidification, and in the meantime, enters the ultra-fine irregularities on the surface of the aluminum alloy. This makes it difficult for the thermoplastic resin to peel off from the aluminum alloy surface even when subjected to external force. That is, the resin molded product formed with the aluminum alloy is firmly bonded. In other words, the chemical reaction and the physical reaction are in a competitive relationship, and in this case, the chemical reaction is prioritized, so it can be said that strong injection joining occurs. In fact, it has been confirmed that PBT and PPS that can chemically react with an amine compound can be injection-bonded with the aluminum alloy. The inventors called this injection joining mechanism the “NMT” (abbreviation of Nano molding technology) theory.

  In addition, as shown in Patent Documents 3, 4, 5, and 6, the present inventors obtain special exothermic reaction or assistance of some chemical reaction without chemical adsorption of the amine compound to the metal alloy surface. We have found a condition that enables injection joining without any problem. In other words, for metal alloys other than aluminum alloys, we discovered a condition that allows the metal alloy and thermoplastic resin to be firmly joined by injection joining. The mechanism of injection joining based on this condition is described as “New NMT (Nano molding technology). Abbreviated) ”theory.

  All of these inventions are by the inventors, but they are based on a relatively simple joining theory. The present inventors refer to the joining theory relating to the aluminum alloy as “NMT” (abbreviation of Nano molding technology) theory and the “new NMT” theory as regards the injection joining of metal alloys in general. The hypothesis of the “new NMT” theory that can be used more widely is as follows. That is, in order to obtain injection bonding with strong bonding strength, there are conditions on both the metal alloy side and the injection resin side. First, the following three conditions are necessary on the metal side.

[Conditions on the metal alloy side in the new NMT theory]
The first condition is that the metal alloy surface has irregularities with a period of 1 to 10 μm by a chemical etching method, and the irregularity height difference is about half of the period, that is, a rough rough surface of 0.5 to 5 μm. It is. However, in actuality, it is difficult to accurately cover the entire surface with the rough surface, and it is difficult to perform a chemical reaction that is not constant. Specifically, when viewed with a roughness meter, it is not within the range of 0.2 to 20 μm. Draw a roughness curve with regular periodic irregularities and a maximum height difference in the range of 0.2-5 μm, or scan with the latest dynamic mode scanning probe microscope to meet JIS standards ( JISB0601: 2001) The average period, that is, the roughness surface having a peak-valley average interval (RSm) of 0.8 to 10 μm and a maximum height roughness (Rz) of 0.2 to 5 μm, is shown above. It is considered that the roughness condition was substantially satisfied. The inventors of the present invention called the “surface having a micron-order roughness” as an easy-to-understand word because the ideal rough surface irregularity period is approximately 1 to 10 μm as described above.

  The second condition is that ultrafine irregularities of 5 nm or more are further formed on the surface of the metal alloy having a roughness on the order of microns. In other words, it needs to be rough when viewed with microscopic eyes. In order to satisfy these conditions, the surface of the metal alloy is subjected to fine etching, oxidation treatment, chemical conversion treatment, etc., and the inner wall surface of the concave portion having the above-mentioned micron-order roughness is 5 to 500 nm, preferably 10 to 300 nm. Preferably, ultrafine irregularities with a period of 30 to 100 nm are formed.

  Describing the ultra-fine irregularities, if the irregular period is a period of 10 nm or less, it is clearly difficult to enter the resin component. Further, in this case, since the unevenness height difference is usually small, it looks smooth as viewed from the resin side. As a result, it no longer serves as a spike. Also, if the period is about 300 to 500 nm or longer (in that case, the diameter and period of the concave part having a micron order roughness is estimated to be close to 10 μm), the spike in the micron order concave part Because the number of slashes, the effect becomes difficult to work. Therefore, in principle, it is necessary that the period of the ultra fine irregularities is in the range of 10 to 300 nm. However, depending on the shape of the ultra-fine irregularities, the resin may enter between them even if it has a period of 5 nm to 10 nm. For example, this is the case when rod-like crystals having a diameter of 5 to 10 nm are complicated. Even with a period of 300 nm to 500 nm, the shape of the ultra-fine irregularities may easily cause an anchor effect. For example, this corresponds to a shape like a pearlite structure in which steps having a height and depth of several hundred to 500 nm and a width of several hundred to several thousand nm are infinitely continuous. Including such a case, the required period of ultra fine irregularities was specified to be 5 nm to 500 nm.

  Here, conventionally, regarding the first condition, the range of Rsm was defined as 1 to 10 μm and the range of Rz was defined as 0.5 to 5 μm, but Rsm was 0.8 to 1 μm and Rz was 0.2 to 0.2 μm. Even if it is the range of 0.5 micrometer, if the uneven | corrugated period of an ultra fine unevenness | corrugation exists in the especially preferable range (generally 30-100 nm), joining force can be maintained highly. Therefore, the Rsm range was slightly expanded to a smaller value. That is, Rsm was in the range of 0.8 to 10 μm and Rz was in the range of 0.2 to 5 μm.

  Furthermore, the third condition is that the surface layer of the metal alloy is ceramic. Specifically, with respect to the metal alloy type that originally has corrosion resistance, the surface layer needs to be a metal oxide layer having a thickness equal to or greater than that of the natural oxide layer, and the metal alloy type having relatively low corrosion resistance ( For example, in the case of a magnesium alloy or a general steel material, the third condition is that the surface layer is a thin layer of metal oxide or metal phosphorous oxide generated by chemical conversion treatment or the like.

  These are schematically illustrated as shown in FIG. A concave portion (C) having a micron-order roughness is formed on the surface of the metal alloy phase 30, and an ultrafine irregularity (A) is formed on the inner wall of the concave portion, and the surface layer becomes a ceramic layer 31. A part of the cured adhesive phase 32 has infiltrated into the ultra-fine irregularities. When the liquid resin composition penetrates into the surface of the metal alloy thus formed and is cured after the penetration, the metal alloy and the cured resin composition are joined together very firmly.

[Conditions on the resin side in the new NMT theory]
Next, the conditions on the resin side will be described. As the resin, it is possible to use a hard, highly crystalline thermoplastic resin that has a reduced crystallization rate during quenching by compounding another polymer suitable for this. Actually, a resin composition compounded with another polymer suitable for PBT or PPS, which is a crystalline hard resin, and glass fiber can be used.

[Injection joining based on the new NMT theory]
The above metal alloy and resin can be used for injection joining with a general injection molding machine or injection mold. This process will be described according to the above-mentioned “new NMT” theoretical hypothesis. The injected molten resin is introduced into a mold having a temperature of about 150 ° C. lower than the melting point, but is cooled in this flow path, and is considered to be a temperature below the melting point. That is, when the molten crystalline resin is rapidly cooled, even if the melting point is lower than the melting point, crystals are formed in zero time and do not change to a solid. In short, a melted state below the melting point, that is, a supercooled state exists for a very short time. As described above, this supercooling time can be lengthened a little by applying a special compound to PBT or PPS. This was used to allow the microcrystals to penetrate into the concave portions of the metal surface having a roughness on the order of microns before the viscosity rapidly increased due to the generation of a large amount of microcrystals. Since it continues to cool after intrusion, the number of microcrystals increases rapidly with this, and the viscosity increases rapidly. However, whether the resin can reach the depth of the recess depends on the size and shape of the recess.

  In the experimental results of the present inventors, the metal type is not selected, and the concave portion having a diameter of 1 to 10 μm according to the roughness of the micron order, and if the depth is up to about half of the period, the concave portion is quite deep. It was estimated that microcrystals invaded. Furthermore, if the inner wall surface of the recess is rough when viewed with a microscopic eye as in the second condition described above, a part of the resin also penetrates into the ultra-fine irregularities, and as a result, a pulling force is exerted on the resin side. It is presumed that even if it is added, it will be caught and difficult to come off. And if this rough surface is covered with metal oxide or metal phosphorous oxide as shown in the third condition, the hardness is high, and the catch between the resin and the concave portion related to the ultra fine unevenness is effective as a spike. Become.

  A specific example is shown. For example, in the case of a magnesium alloy, the corrosion resistance of a magnesium alloy that is still covered with a natural oxide layer is low, so by converting this into a metal oxide, metal carbonate, or metal phosphate, The surface can be covered with a ceramic material having high hardness. When the surface-treated magnesium alloy is inserted into an injection mold, the mold and the inserted magnesium alloy are kept at a temperature lower than the melting point of the resin to be injected by at least 100 ° C. As soon as it enters the flow path in the mold, it is rapidly cooled, and when it approaches the magnesium alloy, there is a high possibility that it is below the melting point.

  When the diameter of the concave portion on the surface of the magnesium alloy is relatively large, such as about 1 to 10 μm, the resin can enter within a limited time during which microcrystals are generated by supercooling. Further, even when the number density of the generated polymer microcrystal group is still small, the resin can penetrate if it is the concave portion. Because the size of a microcrystal, that is, a crystallite having a shape when an alignment state occurs from a molecular chain that has been moving irregularly to a molecular chain, is estimated to be a size of several to 10 nm when estimated from a molecular model. It is. Therefore, it is difficult to say that microcrystals can easily penetrate into ultrafine irregularities with a diameter of 10 nm. However, if the ultrafine irregularities have a period of several tens of nm, there is a possibility that the tip of the resin flow slightly enters. However, since innumerable microcrystals are generated at the same time, the viscosity of the resin flow rapidly rises at the point where it is in contact with the tip of the injection resin or the metal surface of the mold. When the surface of the magnesium alloy that has been subjected to chemical conversion treatment is observed with an electron microscope, an ultrafine uneven surface with a period of 10 to 50 nm is observed, and if this is an ultrafine unevenness with a period of this level, the head is thrust before the viscosity of the resin flow suddenly rises. obtain.

  In addition, when the surface of a metal alloy such as a copper alloy, titanium alloy, or steel material is oxidized or subjected to chemical conversion treatment to form a ceramic crystallite group such as a metal oxide or an amorphous layer, a PPS resin (rapidly cooled) When injection bonding of a PPS resin compound that was able to reduce the PPS molecular crystallization speed at the time, a considerably strong bonding force was generated.

Here, the bonding itself is a problem of the resin component and the surface of the metal alloy, but if the resin composition contains reinforcing fibers or inorganic fillers, the linear expansion coefficient of the entire resin can be brought close to that of the metal alloy, so It becomes easy to maintain the bonding force. In accordance with such a hypothesis, for example, a composite obtained by injection-bonding PBT or PPS resin to magnesium alloy, copper alloy, titanium alloy, stainless steel or the like has a shear breaking force of 20 to 30 MPa (about 200 to 300 kgf / cm ² ) or more, and a tensile breaking force of 30 to 40 MPa (about 300 to 400 kgf / cm ² ) or more, which is confirmed to be a strong composite.

[NAT theory (adhesive bonding)]
The present inventors considered that the “new NMT” theoretical hypothesis can be applied to adhesive bonding, and confirmed whether high-strength bonding based on a similar theory is possible. And it tried to obtain the joined body with higher adhesive force by using the commercially available general-purpose one-component epoxy adhesive and devising the surface structure of the metal alloy.

  The procedure regarding the experimental method of adhesive bonding is shown below. Based on the “new NMT” theory, a metal alloy having the same surface as that used in the injection joining experiment (that is, a metal alloy satisfying the above three conditions) was prepared. Then, a liquid one-component epoxy adhesive is applied to a predetermined range of the metal alloy, put into a desiccator, temporarily put under vacuum, and then returned to normal pressure, etc. Intrude. Thereafter, the adherend is bonded to the predetermined range and heated to be cured.

  In such a case, an epoxy adhesive having a certain viscosity can penetrate into the concave portion (roughness concave portion in the first condition) on the surface of the metal alloy having a roughness on the micron order because it is liquid. And the epoxy adhesive which penetrate | invaded hardens | cures in this recessed part by subsequent heating. Actually, an ultrafine unevenness is further formed on the inner wall surface of the recess (the second condition), and the ultrafine unevenness is a thin ceramic-like thin film (the third condition). Since it is covered, the epoxy resin that has entered the inside of the recess and solidified is difficult to come out by being gripped by ultra-fine irregularities such as spikes.

  By applying the “new NMT” theory, the present inventors can bond metal alloys to each other and metal alloys to CFRP (abbreviation of carbon fiber reinforced plastics) with high strength. Proved that. As an example, as a result of joining A7075 aluminum alloys with an adhesive composed only of a commercially available general-purpose epoxy adhesive, a joined body having an intense shear breaking force and tensile breaking force as high as 70 MPa could be obtained.

  In fact, such high-strength adhesive bonding is performed by the present inventors on magnesium alloys, copper alloys, titanium alloys, stainless steel, general steel materials, aluminum plated steel plates, and zinc-based plated steel plates after aluminum alloys. (See Patent Documents 7, 8, 9, 10, 11, 12, 13, and 14). In any case, various metal alloys could be bonded with unprecedented strength by controlling the state of the metal alloy surface. The present inventors have applied the “new NMT” theory for such adhesive bonding as “NAT (abbreviation of nano adhesion technology)”.

WO 03/064150 A1 (aluminum alloy) WO 2004/041532 A1 (Aluminum alloy) WO 2008/069252 A1 (magnesium alloy) WO 2008/047811 A1 (copper alloy) WO 2008/078714 A1 (titanium alloy) WO 2008/081933 A1 (stainless steel) WO 2008/114669 A1 (aluminum alloy) WO 2008/133096 A1 (magnesium alloy) WO 2008/126812 A1 (copper alloy) WO 2008/133030 A1 (titanium alloy) WO 2008/133296 A1 (stainless steel) WO 2008/146833 A1 (general steel) PCT / JP2008 / 073769 (Aluminum plated steel plate) Japanese Patent Application No. 2008-67313 (galvanized steel sheet) PCT / JP2008 / 072755 (CNT)

  Initially, the “NAT” theory was based on the use of a one-part epoxy adhesive. This is because it is appropriate that the one-component epoxy adhesive is basically a solvent-free type and that the active adhesive component is not gelled at the time of application. In the case of a liquid adhesive, the adhesive penetrates into a concave portion having a roughness on the order of microns at a pressure of about 1 atm, and a concave portion with an ultra fine unevenness of the order of several tens of nm formed on the inner wall surface of the concave portion. This is because it was estimated that there was a certain amount of intrusion. In fact, it is possible to adjust the environmental temperature to make the adhesive viscosity a liquid of several tens of Pa seconds, and if the gelation speed under that temperature condition is very low, it is stable by intrusion into the above ultra-fine irregularities As a result, it was confirmed that strong adhesive strength was exhibited. In that sense, two-component adhesives and resins, for example, two-component epoxy adhesives and two-component unsaturated polyester-based cured resins, can not fully utilize the technical features of "NAT" Not included in the adhesive type to be used.

  Here, the above-described composite in which the aluminum alloy or titanium alloy and CFRP are firmly bonded with an adhesive is effective for reducing the weight of a moving machine such as an aircraft or an automobile, but is very expensive. There is. Under such circumstances, particularly in the field of mobile machines and materials, as well as the above-mentioned strong adhesive bonding between aluminum alloy, titanium alloy, etc. and CFRP, general steel or stainless steel and glass fiber reinforced plastic ( Hereinafter, there is a strong demand for a technique for firmly bonding “GFRP” (abbreviation of “Glass-fiber reinforced plastics”). This is because GFRP is used in a wide range of industries at a low price, unlike CFRP, which is attracting attention as a high-performance composite material or advanced composite material. Therefore, if it is possible to easily manufacture GFRP and metal alloys, particularly those that are strongly bonded to inexpensive general steel materials, they can be used in a wide range of fields such as building materials.

  However, unlike CFRP, GFRP often has a reinforcing fiber impregnated with an unsaturated polyester resin. That is, while the matrix of CFRP is an epoxy resin, the matrix of GFRP is an unsaturated polyester resin, and naturally, an adhesive suitable for this is an unsaturated polyester adhesive. Although the term “unsaturated polyester adhesive” is used here, no such adhesive is actually produced. This is a name created by the present inventors for convenience.

  “Unsaturated polyester adhesive” means, of course, an organic peroxide added to an unsaturated polyester resin as a polymerization initiator (referred to as “curing agent” in the GFRP industry), and a material that exhibits adhesive strength when cured. That is. The “unsaturated polyester adhesive” includes those mainly composed of a vinyl ester resin. That is, the “vinyl ester resin” is a resin obtained by bonding an acrylic ester or a methacrylic ester to the end of the epoxy resin and is also referred to as an “unsaturated epoxy resin”. It is a compound containing several unsaturated bonds. This vinyl ester resin is very similar to unsaturated polyester resin in polymerizability and may be used as part of the raw material of GFRP, and FRP traders are a group of compounds that are treated in the same way as unsaturated polyester. is there. Therefore, it is substantially the same as the unsaturated polyester resin, and the same name "unsaturated polyester adhesive" is used for the name of the adhesive. When the present inventors added an organic oxide as a curing agent to a vinyl ester resin and used it as an adhesive, the performance was not inferior to that using an unsaturated polyester resin.

  An unsaturated polyester adhesive is a two-component thermosetting resin composition that requires the addition of an organic peroxide as a polymerization initiator (“curing agent”) for curing. Peroxide is a naturally degradable substance with a half-life. Organized oxides need to be refrigerated at all times in order to suppress natural decomposition, and with the exception of some of them, the start of gelation immediately after addition at room temperature starts, making it difficult to develop as a commercial adhesive. In addition, there are circumstances where there was no reason to develop an unsaturated polyester-based adhesive because there are epoxy adhesives that have strong adhesive strength and are easy to handle.

  In general, a solidified product of an unsaturated polyester resin has an advantage that its water absorption is lower than that of a solidified epoxy resin, and has excellent durability in outdoor use. However, on the other hand, as described above, the unsaturated polyester adhesive is a two-component thermosetting adhesive. Therefore, even if it is a metal alloy that has been surface-treated so as to satisfy the three conditions in the NAT theory described above, GFRP, metal alloy, etc. can be obtained via an unsaturated polyester adhesive of a two-component thermosetting adhesive. It is difficult to firmly bond and bond to the adherend.

  The present invention has been made based on such a background, and an object of the present invention is to provide a joined body in which a metal alloy and an adherend are firmly joined via an unsaturated polyester adhesive, and a method for producing the joined body. It is to provide.

  First, the present inventors use a two-component epoxy adhesive having an acid anhydride as a curing agent, and even when a metal alloy and an adherend are adhesively bonded based on the “NAT” theory. It was confirmed that excellent adhesion performance was obtained. An epoxy resin containing an acid anhydride as a curing agent is slow to gel at room temperature even after mixing with the curing agent. Therefore, although it may be referred to as one-component, since the gelation rate at room temperature is not zero, it is also officially referred to as two-component. That is, when a product with a hardener mixed therein is marketed, it may be used after being left for several months, and this cannot guarantee performance. Therefore, it is sold as two-component. From this, the present inventors estimated that even unsaturated polyester adhesives can be used for joining based on the “NAT” theory as long as the gelation rate is low. It was developed to enable use of unsatisfactory “unsaturated polyester adhesives”. And the said objective was achieved by the means shown below.

Etching the surface of the metal alloy produces a roughness on the order of microns with an average interval between peaks and valleys (RSm) of 0.8 to 10 μm and a maximum height roughness (Rz) of 0.2 to 5 μm, and In the surface having the roughness, ultrafine irregularities with a period of 5 to 500 nm are formed, and the surface layer is a thin layer of metal oxide or metal phosphate. A state in which an unsaturated polyester-based adhesive mainly composed of an unsaturated polyester resin or a vinyl ester resin is applied to the surface, the adherend is fixed in the application range, and the applied adhesive is allowed to enter the ultra-fine irregularities Cured with.
Hereafter, each element which comprises this invention is demonstrated in detail.

[Metal alloy]
The type of metal alloy in the present invention, that is, a metal alloy having a surface structure based on the above-mentioned “NAT” theory is not particularly limited in theory. All metal species may be used, but what is actually meaningful is a hard and practical metal species or alloy species. That is, since mercury is naturally liquid, it is not relevant to the present invention, but soft metal species such as lead are also excluded from the metal species considered by the present inventors. Of course, alkali metal species and alkaline earth metal species (except for magnesium) that exist chemically but react actively in the atmosphere are also basically excluded.

  The present inventors consider that the metal alloy species to which the “NAT” theory can be applied substantially is an alloy species mainly composed of aluminum, magnesium, copper, titanium, and iron. Hereinafter, these will be described. However, the “NAT” theory does not limit the metal species, and moreover, it does not limit the metal itself. It is not easy to simultaneously provide the three conditions of making a non-metal a condition of “NAT”, such as a micron-order roughness, an ultra fine uneven surface, and a high hardness surface layer. In short, “NAT” defines only the surface shape and the surface layer hardness and discusses the adhesion by the anchor effect theory, and is not limited to at least the following metal alloy types. Patent Document 7 describes an aluminum alloy. Patent Document 8 describes a magnesium alloy. Patent Document 9 describes a copper alloy. Patent Document 10 describes a titanium alloy. Patent Document 11 described stainless steel. Patent Document 12 describes general steel materials. Patent Document 14 describes a zinc-based plated steel sheet. These various metal alloys will be described in detail.

(Aluminum alloy)
The aluminum alloy that can be used in the present invention is not limited as long as it is an aluminum alloy. Specifically, all alloys such as A1000 series to 7000 series aluminum alloys for extension defined by Japanese Industrial Standards (JIS) (corrosion resistant aluminum alloy, high strength aluminum alloy, heat resistant aluminum alloy, etc.), and ADC1 Cast aluminum alloys such as ˜12 types (aluminum alloys for die casting) can be used. As the shape, if it is an alloy for casting or the like, it is possible to use a part shaped by a die-cast method, or a part that is further machined to adjust its shape. Moreover, in the alloy for extending | stretching, the board | plate material which is an intermediate material, etc., and the parts which shape | molded them by applying mechanical processing, such as hot press processing, can also be used.

(Magnesium alloy)
Magnesium alloys used in the present invention include aluminum alloy AZ31B alloy for stipulation defined by International Organization for Standardization (ISO), Japanese Industrial Standards (JIS), American Society for Testing Materials (ASTM), and castings such as AZ91D Magnesium alloy can be used. If it is a magnesium alloy for castings, it uses parts shaped by sand, mold or die casting, and parts and structures that have been shaped by machining such as cutting and grinding. it can. Moreover, in the magnesium alloy for extending | stretching, the board | plate material etc. which are intermediate materials, and the components and structures which shape | molded them by applying plastic processing, such as warm press processing, can be used.

(Copper alloy)
The copper alloy used in the present invention refers to copper, brass, phosphor bronze, Western night, aluminum bronze and the like. Copper developed for various uses including pure copper alloys such as C1020 and C1100, C2600 brass alloys, C5600 copper white alloys, and other iron-based connectors for connectors specified in Japanese Industrial Standards (JIS H 3000 series) All copper alloys etc., such as alloys, are the targets. These are intermediate parts such as plates, strips, pipes, bars, wires, etc., and parts that have been shaped by applying machining such as cutting and pressing, and forged parts.

(Titanium alloy)
The titanium alloy used in the present invention is a pure titanium alloy, α-type titanium alloy, β-type titanium alloy, α-β-type titanium alloy, etc. defined by the International Organization for Standardization (ISO), Japanese Industrial Standards (JIS), etc. All titanium alloys are targeted. Plates, rods, pipes, etc., which are intermediate materials of this titanium alloy, and those formed by machining such as cutting / grinding and pressing are used for parts and structures of various machines and devices. it can.

(Stainless steel)
The stainless steel referred to in the present invention is a Cr-based stainless steel obtained by adding chromium (Cr) to iron, a Cr-Ni-based stainless steel added by combining nickel (Ni) with chromium (Cr), and the like. A known corrosion-resistant iron alloy called stainless steel is the object. SUS405, SUS429, SUS403 and other Cr-based stainless steels standardized by the International Organization for Standardization (ISO), Japanese Industrial Standards (JIS), American Material Testing Association (ASTM), etc., SUS301, SUS304, SUS305, SUS316, etc. Cr-Ni type stainless steel.

(Steel)
The steel materials used in the present invention refer to steel materials such as carbon steels (so-called general steel materials) such as general structural rolled steel materials, high-tensile steels (high-tension steels), low-temperature steels, and reactor steel plates. Specifically, cold rolled steel (hereinafter referred to as “SPCC”), hot rolled steel (hereinafter referred to as “SPHC”), and hot rolled steel sheet for automobile structure (hereinafter referred to as “SAPH”). Used in the body and parts of various machines, such as hot-rolled high-tensile steel plates for automobile processing (hereinafter referred to as “SPFH”) and steel materials mainly used for machining (hereinafter referred to as “SS material”). Structural steel materials that are used are included. Since many of these steel materials can be pressed and cut, the structure and shape can be freely selected when they are used as parts and main bodies. The steel materials referred to in the present invention are not limited to the above steel materials, but include all steel materials standardized by Japanese Industrial Standards (JIS), International Organization for Standardization (ISO), and the like.

(Zinc-based plated steel sheet)
The zinc-based plated steel sheet of the present invention includes a molten galvanized steel sheet, an alloyed molten galvanized steel sheet, an electrogalvanized steel sheet, an electrogalvanized steel sheet, a molten zinc aluminum alloy plated steel sheet (for example, a molten Zn-55% Al alloy plated steel sheet). Galbarium steel sheet, and other materials such as molten Zn-11% Al-3% Mg alloy-plated steel sheet. Most of the products that are actually distributed are those obtained by subjecting the above-described zinc-based plated steel sheets to various chemical conversion treatments and post-treatments. That is, the material group mainly has an internal protection action by oxidation of surface zinc and a carbonate film, and even if this is broken, the zinc itself has a sacrificial corrosion action and can delay the corrosion of the core steel material. Corrosion resistant steel. However, these are rarely used as they are, and in many cases, they are applied with a chemical treatment such as chromate treatment or non-chromate treatment, or an organic coating containing a chromium compound is applied to protect the zinc plating layer itself. is doing. And most of the zinc-based plated steel sheets that have been subjected to chemical conversion treatment are steel materials that are coated with an oil agent to ensure lubricity during press working. In short, various surface-treated products are supplied from major material manufacturers depending on applications and the needs of secondary processing users. In addition, there are many products that are manufactured and marketed by galvanized steel sheet manufacturers themselves to pre-coated steel sheets such as colored steel sheets and colored irons.

  The subject of the present invention is all these zinc-based plated steel sheets, but when using a zinc-based plated steel sheet coated with a paint containing a pre-coated steel sheet or a chromium-based compound, a process of peeling the coating film by some method is required, The material after peeling becomes the material material in the present invention. In other words, all of the basic material zinc-based plated steel sheet (zinc-based plated steel sheet before chemical conversion treatment), the zinc-coated plated steel sheet that has been subjected to chemical conversion treatment, and the zinc-based plated steel sheet coated with an oil agent on these are all present. The subject of the invention.

  In the examples described later, the chromate-treated hot-dip galvanized steel sheet “Z18” (Nippon Sumikin Building Materials Co., Ltd. (Tokyo, Japan), which is considered to be used most frequently in zinc-based plated steel sheets excluding pre-coated steel sheets, is used. ))). “Z18” indicates a plating adhesion amount of 120 g / m 2 according to JIS, and most of the commercially available products range from “Z12” (plating adhesion amount of 90 g / m 2) to “Z27” (plating adhesion amount of 190 g / m 2). It is a thing inside. “Z18” has an average amount of plating and a large circulation. In general, steel materials without oil coating are used for non-press forming applications and press forming applications with low drawability, and have applications for electrical products such as AV products that dislike oil materials, copying machines and printers. In most applications, oil-coated products that are lubricious during pressing and do not break the plating layer are used. The zinc-based plating layer is relatively soft as a metal and is not weak against the diaphragm. Therefore, even if it is an oil material coated product, the amount of oil material applied is very small, and even if the final processing process is a decoration process with various paints, the surface oil material is dissolved by the solvent in the paint, so painting It is said that there is no adverse effect on In short, the present invention is a surface treatment suitable for “NAT” only by chemical treatment for all commercially available zinc-based plated steel sheets, whether or not an oil agent is applied or a chemical conversion treatment layer is provided below. It has been done.

[Chemical etching]
The purpose of the chemical etching in the present invention is to generate a roughness on the order of microns on the surface of the metal alloy. There are various types of corrosion, such as general corrosion, pitting corrosion, and fatigue corrosion, but it is possible to select an appropriate etching agent by selecting a chemical species that causes general corrosion for the metal alloy and performing trial and error. According to literature records (for example, "Chemical Engineering Handbook (edited by Chemical Engineering Association)"), aluminum alloys are basic aqueous solutions, magnesium alloys are acidic aqueous solutions, stainless steel and general steel materials in general are hydrohalic acid such as hydrochloric acid, sulfurous acid, There is a record that the entire surface is corroded by an aqueous solution of sulfuric acid or a salt thereof. In addition, copper alloys with strong corrosion resistance can be totally corroded by oxidizing agents such as hydrogen peroxide that have been made strongly acidic, and titanium alloys can be corroded by special acids such as oxalic acid or hydrofluoric acid. And are often found in patent literature. The metal alloys that are actually sold in the market, such as pure copper-based copper alloys and pure titanium-based titanium alloys, have a purity of 99.9% or more and are hardly called alloys. Included in the alloy. In fact, most of the materials used in the world are mixed with a wide variety of other elements in order to obtain characteristic physical properties, and there are few pure metal materials, and they are substantially alloys.

  That is, most of the target metals alloyed from pure metals have improved corrosion resistance without degrading the original metal properties. Therefore, in the case of an alloy, the target chemical etching is often not possible even when using acid bases or specific chemical substances applied with reference to the literature as described above. In short, the use of the acid-bases and specific chemicals described above is fundamental, and in practice, the concentration of the acid-base aqueous solution to be used, the liquid temperature, the immersion time, and in some cases, appropriate by trial and error while devising the additive Chemical etching is performed. Speaking of chemical etching, Patent Document 7 describes aluminum alloy, Patent Document 8 describes magnesium alloy, Patent Document 9 describes copper alloy, Patent Document 10 describes titanium alloy, Patent Document 11 relates to stainless steel. Description, Patent Document 12 describes general steel materials, and Patent Document 14 describes zinc-based plated steel sheets.

  To explain the points that are generally common as work actually performed, when a metal alloy shaped product is obtained, first, it is immersed in an aqueous solution in which a commercially available degreasing agent for each metal is dissolved and degreased and washed with water. This step is preferred and should always be performed because it removes most of the machine oil and finger grease deposited in the step of obtaining the metal alloy shape. Then, it is preferably immersed in a thinly diluted acid / base aqueous solution and washed with water. This is a process called the preliminary acid cleaning and preliminary base cleaning by the present inventors, and in the case of a metal species that corrodes with an acid such as a general steel material, it is immersed in a basic aqueous solution and washed with water. As described above, in the case of a metal species that is particularly rapidly corroded in a basic aqueous solution, it is immersed in a dilute acid aqueous solution and washed with water. These are processes in which a solution opposite to the aqueous solution used for chemical etching is attached (adsorbed) to the metal alloy in advance, and the subsequent chemical etching starts without an induction period, so that the reproducibility of the process is remarkably improved. . Therefore, the preliminary acid cleaning and preliminary base cleaning steps are not essential, but are preferably employed in practice. A chemical etching step is inserted after these steps.

[Fine etching / Surface hardening]
The purpose of fine etching in the present invention is to form ultra-fine irregularities on the surface of a metal alloy. Moreover, the surface hardening process in this invention aims at making the surface layer of a metal alloy into a thin layer of a metal oxide or a metal phosphate. Depending on the type of metal alloy, nano-order fine etching may be performed at the same time by performing the chemical etching, and ultra-fine irregularities may be formed. Furthermore, depending on the type of metal alloy, the natural oxide layer on the surface may be thicker than the original and the surface hardening process may be completed. For example, a pure titanium-based titanium alloy is only subjected to chemical etching, so that the surface has a roughness on the order of microns and ultra-fine irregularities are also formed. That is, fine etching is performed together with chemical etching. However, in many cases, it is necessary to perform fine etching or surface hardening treatment after forming a large uneven surface on the order of microns by chemical etching.

  Even at this time, we are often hit by unpredictable chemical phenomena. That is, when a metal alloy after chemical etching is reacted with an oxidizing agent or chemical conversion treatment for the purpose of surface hardening treatment or surface stabilization treatment, ultra fine irregularities may be formed on the resulting surface by chance. The surface layer that appears to be manganese oxide formed when a magnesium alloy is subjected to chemical conversion treatment with a potassium permanganate aqueous solution is a complex of rod-like crystals having a diameter of 5 to 10 nm that can be finally identified with a 100,000-fold electron microscope. This sample was analyzed by XRD (X-ray diffractometer), but diffraction lines derived from manganese oxides could not be detected. It is clear by XPS analysis that the surface is covered with manganese oxide. The reason why XRD could not be detected is that the crystal was a thin layer exceeding the detection limit. In short, the magnesium alloy was subjected to a chemical conversion treatment as a surface hardening treatment, so that fine etching was also completed. The same applies to copper alloys. When surface hardening treatment was performed to change the surface to cupric oxide by oxidation under basic conditions, in pure copper-based copper alloys, the surface had hole openings with a circular or distorted shape. It occurs on one surface and becomes a unique ultra-fine uneven surface. A copper alloy that is not a pure copper type is not a concave shape, but is continuous with a particle having a diameter of 10 to 150 nm or an indefinite polygonal shape. Even in this case, most of the surface is covered with cupric oxide, and the hardening of the surface and the formation of ultrafine irregularities occur simultaneously.

  For general steel materials, although further verification is required, ultra-fine irregularities are often formed only by chemical etching to form micron-order roughness, and originally the surface layer (natural oxide layer) However, it was considered that the “NAT” theory can be applied without performing a surface hardening process or a fine etching process again. The problem is that the corrosion resistance of the natural oxide layer is not sufficient, so that corrosion starts before the bonding process, or the adhesive force decreases in a short time depending on the environment after bonding.

  These can be prevented by chemical conversion treatment, but in practice, the durability of the adhesive is tested by performing tests such as applying the adhesive to a thermal shock test, leaving it in a general environment, and applying the coated product to a salt spray device. It is necessary to examine sex. For example, regarding a bonded body obtained by bonding steel materials not subjected to chemical conversion treatment (actually SPCC: cold rolled steel material) with a phenol resin adhesive, the adhesive strength rapidly decreased in a short period of 4 weeks. On the other hand, regarding the joined body in which the general steel materials (SPCC) subjected to the chemical conversion treatment were bonded to each other with the phenol resin-based adhesive, the initial adhesive force did not decrease during the same period.

  In addition, the present inventors have generally confirmed that when the thickness of a film (chemical conversion film) formed on the surface of a metal alloy by chemical conversion treatment is thick, the adhesive force often decreases. A strong adhesive force can be obtained when the thin layer is such that the diffraction line is not detected by XRD, such as the thin layer of manganese oxide adhered to the magnesium alloy. When metal alloys having a thick chemical conversion film are bonded to each other with an epoxy adhesive and subjected to a destructive test, the fracture surface is mostly between the metal phase and the chemical conversion film. In experiments conducted by the present inventors, the bonding force between the thick chemical conversion film and the cured epoxy adhesive was always stronger than the bonding force between the chemical conversion film and the internal metal alloy phase. That is, even with a general steel material, if the chemical conversion treatment time is further increased and the chemical conversion treatment layer is thickened, the durability of the adhesive (that is, the maintenance of adhesive strength) should be improved. However, if the chemical conversion film is thickened, the adhesive strength itself is lowered. Therefore, the degree of balance depends on the purpose of use and application. The surface treatment method for various metal alloy parts will be described in detail below.

[Specific examples of surface treatment]
(Surface treatment of aluminum alloy)
It is preferable that the aluminum alloy part is first immersed in a degreasing tank to remove oils and oils adhered by machining. Specifically, the degreasing treatment unique to the present invention is not necessary, and a warm aqueous solution in which a commercially available degreasing material for aluminum alloy is poured into hot water at a concentration specified by the drug manufacturer is prepared, immersed in this, and washed with water. It is preferable to do this. In short, a conventional degreasing treatment performed with an aluminum alloy may be used. Although it differs depending on the product of the degreasing material, in a general commercial product, the concentration is 5 to 10%, the liquid temperature is 50 to 80 ° C., and the immersion is performed for 5 to 10 minutes.

  Subsequent pretreatment steps differ in the treatment method between an alloy containing a relatively large amount of silicon in an aluminum alloy and an alloy containing few of these components. For alloys with low silicon content, ie, aluminum alloys for drawing such as A1050, A1100, A2014, A2024, A3003, A5052, and A7075, the following treatment methods are preferred. That is, it is preferable that the aluminum alloy is immersed in an acidic aqueous solution for a short time and washed with water, and the acid component is adsorbed on the surface layer of the aluminum alloy in order to proceed the next alkali etching with good reproducibility. This treatment may be referred to as a preliminary pickling step, but a dilute aqueous solution having a concentration of 1% to several percent of an inexpensive mineral acid such as nitric acid, hydrochloric acid, sulfuric acid or the like can be used. Next, it is immersed in a strongly basic aqueous solution, washed with water, and etched.

  By this etching, fats and oils remaining on the surface of the aluminum alloy are peeled off together with the surface layer of the aluminum alloy. Simultaneously with this peeling, the surface has a roughness on the micron level. That is, according to the JIS standard (JIS B 0601: '01, ISO 4287: '97 / ISO 1302: '02), the average interval between the valleys and valleys (RSm) is 0.8 to 10 μm, and the maximum height roughness (Rz) is The uneven surface is 0.2 to 5.0 μm. These numerical values are automatically calculated and output if applied to a recent scanning probe microscope. However, the numerical value when the fine unevenness is expressed by automatic output may not be the actual value of the calculated RSm value. In order to obtain a more accurate numerical value, it is necessary to reconfirm the RSm value by visually inspecting the roughness curve graph output by the scanning probe microscope with respect to the unevenness.

  If the roughness curve graph is visually inspected and the roughness is in the range of 0.2 to 5 μm with irregular intervals in the range of 0.2 to 20 μm, the average interval between the peaks and valleys (RSm = 0. 8 to 10 μm) and the maximum height roughness (Rz: 0.2 to 5.0 μm). This visual inspection method is preferable because it can be easily determined by visual inspection when it is determined that automatic calculation is not reliable. In short, in terms of technical terms defined in the present invention, a “surface with a roughness on the order of microns”. The working solution is preferably immersed in an aqueous caustic soda solution having a concentration of 1% to several percent at 30 to 40 ° C. for several minutes. Next, it is preferable to finish the pretreatment by removing the sodium ions by immersing again in an acidic aqueous solution and washing with water. The inventors refer to this as a neutralization step. As this acidic aqueous solution, a nitric acid aqueous solution having a concentration of several percent is particularly preferable.

  On the other hand, it is preferable to go through the following steps in casting aluminum alloys such as ADC10 and ADC12. That is, after the degreasing step of removing fats and oils from the surface of the aluminum alloy, it is preferable to carry out preliminary pickling and etching in the same manner as the above-described step. This etching results in a black smut in which the copper and silicon components that do not dissolve under strong basicity are fine particles (hereinafter, this contaminant is referred to as “smut” in the plating industry, and this expression is followed). Therefore, it is preferable to immerse the smut in an aqueous nitric acid solution having a concentration of several percent in order to dissolve and remove the smut. By immersion in an aqueous nitric acid solution, the copper smut is dissolved and the silicon smut floats from the aluminum alloy surface.

  In particular, if the alloy used is an alloy containing a large amount of silicon, such as ADC12, the silicon smut continues to adhere to the surface of the aluminum alloy substrate simply by dipping in an aqueous nitric acid solution, which cannot be completely peeled off. . Therefore, it is preferable that the silicon smut is then physically peeled off by immersing in an ultrasonic bath and ultrasonic cleaning. This does not remove all the smut, but it is sufficient for practical use. The pretreatment may be completed with this, but it is preferable to immerse again in a dilute nitric acid aqueous solution for a short time and wash with water. This completes the pretreatment. Since the pretreatment is completed by immersion in an acidic aqueous solution and washing with water, no sodium ions remain. Hereinafter, sodium ions will be described.

  According to the experimental results, the bonding strength when bonding two pieces of aluminum alloy using an epoxy adhesive is almost due to the roughness on the micron order and the shape characteristics of the nano-scale ultra-fine irregularities on the surface. It is determined. Therefore, in the etching with an aqueous caustic soda solution, if a suitable dipping condition or the like is found and the above-mentioned “NAT” theory condition can be satisfied in shape, a strong adhesive force can be obtained. However, if the surface treatment is completed only by etching with caustic soda, sodium ions remain on the surface layer of the aluminum alloy even after sufficient washing with water. Sodium ions are easy to move because of their small particle size, and even after being painted or adhered, when the whole becomes wet, the remaining sodium ions are accompanied by water molecules penetrating the resin layer. Somehow, it gathers at the metal / resin interface and advances the oxidation of the aluminum surface.

  That is, corrosion of the aluminum alloy surface occurs, and as a result, peeling between the substrate and the coating film or adhesive is promoted. Under such circumstances, there is still no reason to perform etching with an aqueous caustic soda solution as an aluminum alloy pretreatment performed before bonding. Therefore, even today, it is strongly bonded to an aluminum alloy soaked in an aqueous solution of potassium dichromate or hexavalent chromium compound of chromic anhydride, or anodized and used unsealed. It is regarded as a standard pretreatment method for agent bonding. In short, before focusing on improving the adhesion by etching, the main focus was on preventing corrosion and alteration of the aluminum alloy surface.

  However, a method of etching an aluminum alloy with an aqueous caustic soda solution is not completely used, and is often used in a pretreatment for painting. Normally, the coating does not require an extreme adhesive force, and it is based on the judgment that it will not be immersed in water unless it is used outdoors for wind and rain. In addition, this pre-painting method is not unreasonable unless the product has a coating film guarantee of 10 years. The present invention does not presuppose such an easy way of thinking and makes long-term bonding stability an important issue. Therefore, the elimination of sodium ions is of paramount importance.

  The sodium (Na) contained in the aluminum alloy is also described. In the production method of aluminum metal, high purity aluminum compound is obtained by dissolving bauxite with an aqueous caustic soda solution, and aluminum ingot is produced by electrolytic reduction thereof. In this manufacturing method, it is inevitable that sodium is contained as an impurity in the aluminum metal. However, the current metallurgical technology can suppress the sodium content in the aluminum alloy to the limit. Therefore, in a normal environment where there is no acid-base mist, in the recent commercial aluminum alloys, corrosion does not proceed unless direct wetting (liquid water) coexists. In fact, corrosion proceeds at high speed when there is wetting, salt from the sea breeze (sodium chloride), and heating by sunlight. That is, when a commercially available aluminum alloy is used outdoors in a bad environment area, for example, a city located near the coast, in a strong sea breeze and in a high temperature area, the corrosion rate is high.

  As a countermeasure against corrosion, generally, the entire surface is coated with a paint, an adhesive or the like. At that time, it is necessary that cracks or the like are not generated in the coating film or adhesive layer, and it is important that salt-containing water does not enter the surface of the aluminum alloy from the cracks or the like. When such countermeasures are taken, it is not always necessary to use a general chromate treatment as a surface treatment for an aluminum alloy. If the coating film has good weather resistance and adhesion between the coating film and the substrate is good, coating It will last long enough even in a bad environment. In particular, recently, the use of hexavalent chromium is being rejected all over the world, and chromate treatment is not already a preferable aluminum alloy surface treatment method. On the other hand, at present, many paints excellent in weather resistance and adhesives excellent in moisture resistance and heat resistance are commercially available. Under these circumstances, the present inventors have attempted to optimize and theorize the conditions required on the aluminum alloy side in order to maintain a strong bond between the paint or adhesive and the aluminum alloy substrate for a long period of time. did.

  Specifically, the preferred roughness of the aluminum alloy surface is basically obtained by a strongly basic aqueous solution such as caustic soda, and thereafter sodium ions are removed by immersion in an acidic aqueous solution and sufficient water washing. However, when observed with an electron microscope, the microstructure of the surface of the aluminum alloy obtained by etching with a caustic soda solution has ultra-fine irregularities with a period of several tens of nanometers, and the surface on which the hardened adhesive is unlikely to escape from the concave portions of the substrate. In other words, the surface after the aluminum alloy was immersed in an aqueous nitric acid solution and washed with water was reduced in the quality level of the ultra-fine unevenness (the unevenness level). . In short, the immersion operation in an acidic aqueous solution for removing sodium ions is a kind of chemical polishing. Looking at the electron micrograph of the surface of the aluminum alloy after etching with an aqueous solution of caustic soda, it is a rough surface when viewed with microscopic eyes in terms of sensory expression. This rough surface is immersed in an acidic aqueous solution. In this case, the degree of roughness was reduced by chemical polishing, which had an adverse effect on adhesive bonding.

  Therefore, the roughness is recovered by fine etching described below. In short, the background, thought, and theory that the present inventors have made the present invention are based on the fact that a high-performance electron microscope capable of obtaining a high resolution of several nanometers can be easily used. In the present invention, the weather resistance and corrosion resistance of the aluminum alloy can be obtained by making the final aluminum alloy surface the aluminum oxide surface layer and by increasing the bonding strength of the adhesive to the alloy base to the maximum. It is the idea of trying.

  The aluminum alloy part that has undergone the pretreatment is subjected to the following surface treatment, that is, fine etching, which is the final treatment. The pretreated aluminum alloy part is preferably immersed in an aqueous solution containing one or more of hydrated hydrazine, ammonia, and a water-soluble amine compound, then washed with water and dried at 70 ° C. or lower. This is also a revival measure for the rough surface when the surface is slightly changed by the sodium removal ion treatment performed in the final treatment of the pretreatment and the roughness is maintained, but the surface becomes slightly smooth. It is immersed in a weakly basic aqueous solution such as a hydrated hydrazine aqueous solution for a short time and finely etched so that the surface is covered with an ultrafine uneven surface having a recess or protrusion having a diameter of 10 to 100 nm and an equivalent height or depth. To be precise, it is formed so that a large number of ultrafine irregularities with a period of 40 to 50 nm occupy on the inner wall surface of concaves and convexes on the order of microns. It is preferable to finish on a high surface.

  If the drying temperature after washing with water is, for example, 100 ° C. or higher, if the inside of the dryer is sealed, a hydroxylation reaction occurs between boiling water and aluminum, and the surface changes to form a boehmite layer. . This is not preferable because it cannot be said to be a strong surface layer. The humidity condition in the dryer is related not only to the size of the dryer and the state of ventilation, but also to the amount of aluminum alloy to be introduced. In that sense, hot air drying at 90 ° C. or lower, preferably 70 ° C. or lower, is preferred for obtaining good results with good reproducibility under any charging conditions to prevent surface boehmite formation. When dried at 70 ° C. or lower, only aluminum (trivalent) can be detected from the aluminum peak by surface elemental analysis by XPS, and aluminum (zero valent) that can be detected by XPS analysis of commercially available A5052, A7075 aluminum alloy sheet, etc. disappears. .

  The XPS analysis can detect elements present at a depth of 1 to 2 nm from the metal surface. From this result, it is immersed in an aqueous solution of hydrated hydrazine or an amine compound, and then washed with water and dried with warm air to obtain aluminum. It was found that the original natural oxide layer (a thin aluminum oxide layer having a thickness of about 1 nm) that the alloy had became thicker by fine etching. Since it was found that the layer had a thickness of 2 nm or more unlike at least the natural oxide layer, it was not further elucidated. That is, if XPS analysis is performed after etching with an argon ion beam or the like, analysis at a deeper position of about 10 to 100 nm is possible, but the valence of aluminum atoms in the deep layer may change due to the influence of the beam itself. The present inventors considered this analysis difficult at this time, and the present inventors stopped this consideration.

  The formation of an aluminum oxide layer on the surface of an aluminum alloy by another surface treatment method will be described. One surface treatment method for improving the weather resistance of aluminum alloys is an anodic oxidation method. When anodizing is performed on an aluminum alloy, an aluminum oxide layer having a thickness of several μm to several tens of μm can be formed, and weather resistance is greatly improved. An infinite number of holes having a diameter of about 20 to 40 nm are left in the aluminum oxide layer immediately after the anodizing treatment. In this state, that is, when the adhesive is joined or paint is applied in the unsealed alumite state, the adhesive or paint slightly enters the hole from the opening and solidifies, and exhibits a strong anchor effect. It is said that a strong bonding force is produced in the bonding. In fact, in assembling an aircraft, it is known that an anodized aluminum alloy is coated with an adhesive to join different materials.

However, the inventors have questioned this theory. That is, when a shear fracture test of an integrated product in which anodized aluminum alloys are firmly bonded with an epoxy adhesive is performed, according to the fracture test by the present inventors, a strong force of 40 MPa (40 N / mm ² ) or more is used. There was no broken sample, and when the fractured surface was viewed, the adhesive was not broken, and most of the anodized layer (aluminum oxide layer) was peeled off from the aluminum alloy substrate. According to the present inventors' consideration, "The metal side surface required for strong bonding must be a high-hardness layer of ceramic such as metal oxide, but its thickness should not be too thick. ". Although the surface layer of the anodic oxide is aluminum oxide and is an oxide of the base aluminum itself, the surface layer is ceramic and the base material is a metal, so they are foreign matter.

  If the ceramic material is thick, a difference in physical properties will always appear in the extreme state and it should break. Therefore, it is preferable that the metal oxide layer is thin, and based on common sense, it was considered that the metal oxide layer should be preferably bonded to the base material if it is an amorphous or microcrystalline ceramic material. That is, in order to increase the shear breaking force of the adhesive, the metal oxide layer should not be thickened unnecessarily, and the use of unsealed anodized anodized is not preferable.

  Hereinafter, the fine etching referred to in the present invention will be described in more detail. When immersed in an aqueous solution of hydrated hydrazine, ammonia, water-soluble amine or the like in a weakly basic aqueous solution with a pH of 9 to 10 for an appropriate temperature and for an appropriate period of time, the entire surface is an ultra-fine irregular shape with a diameter of 10 to 100 nm. It will be covered. The number average diameter is about 50 nm. In other words, the optimum pH, temperature, and time may be selected in order to obtain an ultra fine uneven shape with a diameter of 10 to 100 nm on the surface. It is empirically considered that the most preferable period of the ultra-fine irregularities predicted by the present inventors or the diameter of the ultra-fine irregularities is about 50 to 100 nm, particularly about 50 to 70 nm. The reason is that if the unevenness has a period of 10 nm, the unevenness is finer than the rough surface, and it is a smooth surface for the viscous adhesive, and if it is 100 nm or more, it is too rough for the rough surface to get caught. This is because the expression is not appropriate and the number of irregularities itself is small. The “number average” in the present invention is not a total average that can be statistically verified, but an average value that is obtained by extracting up to 20 samples.

  The above-mentioned range of 50 to 70 nm is a numerical value estimated from many experimental results through trial and error. However, simply aiming for a period of 50 to 70 nm cannot be made such a disciplined chemical reaction and will vary. There is no choice but to digitize it by looking at a photograph taken with an electron microscope. According to the result, almost the entire surface is a concave portion having a diameter of 10 to 100 nm and an equivalent depth, or a convex portion having a diameter of 10 to 100 nm and an equivalent height. What is necessary is just to be the covered super fine uneven shape. As a result of the experiment, when the unevenness having a diameter of 10 to 20 nm occupies most of the surface, or conversely, the unevenness having a diameter of 100 nm or more occupies many, the bonding force was inferior. In the example described later, an example in which A7075 material or A5052 material is etched with an aqueous solution of hydrated hydrazine will be described.

  That is, in order to cover the aluminum alloy with the concave and convex portions having such a size, it is necessary to search for immersion conditions by trial and error experiments. Speaking of a 60% aqueous solution of hydrazine monohydrate at a concentration of 3.5%, it is optimal to immerse the A5052 and A7075 materials at an immersion time of about 2 minutes, and the surface by this immersion time has a diameter of 10 to 100 nm. In average, the entire surface is covered with a recess having a diameter of 40 to 50 nm. However, when immersed for 4 minutes, the diameter of the recesses expands to 80 to 200 nm, the number average value of the diameters of these recesses rapidly expands to exceed 100 nm diameter, and there are further recesses at the bottom of the recesses. Occurs and the structure becomes complicated. Further, when immersed for 8 minutes, the erosion of the horizontal hole progresses to become slightly sponge-like, and deeper recesses are connected to change into a valley or a canyon shape. When immersed for 16 minutes, it can be seen by visual observation that the aluminum alloy is slightly browned from the original metal color and the absorption of visible light begins to change.

  By the way, when the immersion time was 1 minute under the conditions described above, concave portions having a diameter of 10 to 40 nm were observed in the electron micrograph, and these number average diameters were concave portions having a diameter of 25 to 30 nm. Furthermore, when the immersion is performed for 0.5 minutes, the diameter of the concave portion covering the surface is 10 to 30 nm, and the number average diameter is about 25 nm, which is not much different from the case of the immersion time of 1 minute. And if you look closely at the electron micrographs of the immersion time of 0.5 minutes and the immersion time of 1 minute, the depth of the recess is clearly shallower than the one immersed for 1 minute. It was a state. In short, in A5052 and A7075 in weakly basic aqueous solution, for some reason, erosion started with a period of 20 to 25 nm. First, this formed a recess with a diameter of about 20 nm, and when the depth of this recess became the same level as the diameter, It was found that the edge of the recess was eroded to increase the diameter of the recess, and erosion in the indefinite direction inside the recess started. When so eroded, the simple and strong erosion condition most suitable for adhesive bonding is approximately 2 minutes when A7075 and A5052 are immersed in a 3-5% monohydric hydrazine aqueous solution (60 ° C.). Met.

  For example, a case where a one-component high-temperature curing type epoxy adhesive “EP106 (manufactured by Cemedine Co., Ltd. (Tokyo, Japan)) having a viscosity of 40 Pa · sec at a temperature of 23 ° C. will be described. According to the results of the adhesion experiment shown in the examples, in the case of an aluminum alloy material such as A7075 soaked in a hydrated hydrazine aqueous solution for 1 minute under the above conditions, the diameter of the ultrafine recesses was too small as about 25 nm on the number average, and epoxy. It seems that the resin hardly penetrates into the ultrafine recesses, and the adhesive strength when the immersion time is 2 minutes seems to be maximized. When A7075 or the like was immersed for 2 minutes under the above-mentioned conditions, the diameter of the ultrafine recess was about 40 nm in terms of number average diameter. It was estimated that it would be possible to pierce the head.

  In short, when the inner surface of the concave portion of the micron order is a rough surface having irregularities with a period of several tens of nanometers, the bonding force is increased. In addition, when the immersion time is longer than 2 minutes, for example, 4 minutes or 8 minutes, not only the diameter of the recesses is increased, but also recesses are formed in the recesses. Not only does the strength of the alloy surface layer itself weaken, but the adhesive cannot penetrate deeply into the complex holes. As a result, voids increase at the bonding boundary of the bonded article, and as a result, the bonding force decreases from the maximum value. In short, when the epoxy adhesive is used for an aluminum alloy such as A7075, in order to maximize the bonding force, in addition to setting the surface to a suitable roughness on the order of microns, the surface has a number average value of 40 to 40. It is preferable to cover with an ultrafine recess having a diameter of 50 nm, and it can be understood that the optimum immersion time range for making this ultrafine recess is very narrow. This is because the best joining result was obtained when the immersion time was around 2 minutes (approximately 1.5 to 3 minutes) as described above.

  When the same epoxy adhesive is used for the A5052 aluminum alloy, the dipping conditions during etching with an aqueous caustic soda solution are slightly different from those for A7075. This is probably because the erosion condition and the physical properties of the eroded surface are different.

  Ammonia water has a lower pH than an aqueous hydrazine solution, and when the aqueous solution is heated to a temperature higher than room temperature, volatilization of ammonia becomes intense. Therefore, the immersion treatment is performed at a high concentration and a low temperature, and the immersion time of 15 to 20 minutes is required even when the most concentrated ammonia water having a concentration of about 25% is used at room temperature. On the contrary, many water-soluble amines become a basic aqueous solution stronger than the hydrazine aqueous solution, so that the treatment takes a shorter time. In mass production processing, the stability of the work is lost if the immersion time is too long or too short. In that sense, hydrated hydrazine, which can have an optimum soaking time of several minutes, seems to be suitable for practical use.

  In any case, there was an alloy species that improved the bonding strength when immersed in an aqueous solution of hydrogen peroxide having a concentration of several percent after immersion in an aqueous solution of hydrated hydrazine, ammonia, or a water-soluble amine. The thickness of the metal oxide layer on the surface may have increased, but it was difficult to analyze for thicknesses of 2 nm or more and could not be solved theoretically.

(Surface treatment of magnesium alloy)
The magnesium alloy is preferably first immersed in a degreasing bath to remove oils and finger grease adhered by machining. Specifically, it is preferable that a commercially available degreased material for magnesium alloy is poured into hot water at a concentration specified by the drug manufacturer to prepare an aqueous solution and immersed in it, and then washed with water. In an ordinary commercial product, the concentration is generally 5 to 10%, the liquid temperature is 50 to 80 ° C., and the product is immersed in this for 5 to 10 minutes. Next, chemical etching in which the magnesium alloy is immersed in an acidic aqueous solution for a short time is performed and washed with water. The surface of the magnesium alloy is peeled off, including dirt that could not be removed in the degreasing process, and at the same time, the roughness on the order of microns, that is, the roughness according to the JIS standard (JISB0601: 2001 (ISO 4287)) measured by scanning probe microscopy. The surface has an uneven surface with an average length (RSm) of the curve of 0.8 to 10 μm and a maximum height roughness (Rz) of the roughness curve of 0.2 to 5 μm.

  The use solution for chemical etching performed above is preferably an aqueous solution of carboxylic acid or mineral acid having a concentration of 1% to several percent, particularly an aqueous solution of citric acid, malonic acid, acetic acid, nitric acid or the like. In chemical etching, aluminum and zinc contained in a magnesium alloy usually do not dissolve and remain on the surface of the magnesium alloy as a black smut. Then, the aluminum smut is removed by soaking in a weakly basic aqueous solution. It is preferable to dissolve the zinc smut by immersing it in a strong base aqueous solution.

  Thus, the so-called chemical conversion treatment is performed on the magnesium alloy from which the smut is dissolved and eliminated. That is, since magnesium is a metal with a very high ionization tendency, the oxidation rate due to moisture and oxygen in air is faster than other metals. Magnesium alloys have a natural oxide film, but are not strong enough in terms of corrosion resistance, and oxidative corrosion proceeds with water molecules and oxygen diffused through the natural oxide film even in a normal environment. Therefore, ordinary magnesium alloys are either immersed in an aqueous solution of chromic acid or potassium dichromate and covered with a thin layer of chromium oxide (called chromate treatment), or in an aqueous solution of manganese salt containing phosphoric acid. Immersion is performed, and the entire surface is covered with a manganese phosphate compound to perform corrosion prevention treatment. These treatments are called chemical treatments in the magnesium industry.

  In short, the chemical conversion treatment performed on the magnesium alloy is a treatment in which the magnesium alloy is immersed in an aqueous solution containing a metal salt and the surface thereof is covered with a thin layer of metal oxide and / or metal phosphate. At present, the chromate type chemical conversion treatment using a hexavalent chromium compound is avoided from the viewpoint of environmental pollution, and the chemical conversion treatment using a metal salt other than chromium, which is called non-chromate treatment, Manganese phosphate chemical conversion treatment or silicon chemical conversion treatment is performed. In the present invention, unlike these methods, it is particularly preferable to use a weakly acidic aqueous solution of potassium permanganate as an aqueous solution for chemical conversion treatment. In this case, a coating covering the surface (referred to as a chemical conversion coating) is manganese dioxide.

  As a specific treatment method, the magnesium alloy in which the smut is melted as described above is dipped in a very dilute acidic aqueous solution for a short time, and then washed with water to remove the basic component on the surface layer. The method of immersing in the aqueous solution for chemical conversion treatment after that, washing with water, and drying is preferable. As the dilute acidic aqueous solution, it is preferable to use a 0.1 to 0.3% aqueous solution of citric acid or malonic acid, and it is preferable to immerse at about room temperature for about 1 minute. As the chemical conversion treatment aqueous solution, it is preferable to use an aqueous solution containing 1.5 to 3% potassium permanganate, about 1% acetic acid and about 0.5% sodium acetate at a temperature of 40 to 50 ° C. In this aqueous solution, the immersion time is preferably about 1 minute. By these operations, the magnesium alloy is covered with a chemical conversion film of manganese dioxide, and the surface shape has a large roughness (roughness surface) on the order of microns, and when observed with an electron microscope, it is on the order of nanometers. There will be ultra-fine irregularities.

  7 and 8 are electron micrographs of ultra-fine irregularities with a magnification of 100,000 times, respectively. Although it is difficult to express these ultra-fine irregularities in a sentence expression, from an electron micrograph of FIG. 7, a rod-like or spherical object having a diameter of 5 to 20 nm and a length of 20 to 200 nm is used. It can be said that the surface is covered with an infinite number of complex irregularities. From the electron micrograph shown in FIG. 8, this ultra fine irregular shape is in the form of a rod having a diameter of 5 to 20 nm and a length of 10 to 30 nm, or a sphere having a diameter of 80 to 120 nm with numerous spherical protrusions. The surface is shaped like a regular stack. It should be said that the rod-like (needle-like) substance having a diameter of about 10 nm is completely crystalline in terms of electron microscope observation, but the diffraction line seen in the manganese oxide was not observed from the X-ray diffractometer (XRD). .

  Since an X-ray diffractometer (XRD) cannot detect if the amount of crystals is small, it cannot be determined whether these are crystals at present. At least, they are too shaped to be amorphous (non-crystalline), which cannot be said to be amorphous. From XPS analysis, large peaks of manganese (which is an ion and not zero-valent manganese) and oxygen are recognized, and there is no doubt that the surface layer is a manganese oxide. This surface has a dark color and is a manganese oxide mainly composed of manganese dioxide.

  Also, as an ultra-fine uneven shape that is completely different from the above, an ultra-fine uneven shape like a crumb-like ground on a slope of a lava plateau, that is, a shape in which particles with a diameter of 20 to 40 nm or indefinite polygonal shapes are stacked In some cases, the entire surface is covered. In short, when a rod-like material having a diameter of 5 to 20 nm is not recognized, the shape is often like the surface of such a lava plateau, and the composition has a high aluminum content. A photograph of an example of this surface is shown in FIG. 9, which is a processing example of AZ91D, which is a magnesium alloy for casting.

(Surface treatment of copper alloy)
It is preferable that the copper alloy is first immersed in a degreasing tank to remove oils and finger grease adhering by machining from the surface. Specifically, it is preferable that a commercially available defatted material for copper alloy is poured into water at a concentration specified by the drug manufacturer to prepare an aqueous solution, which is then immersed in and washed with water. Moreover, commercially available degreasing agents for iron, stainless steel, aluminum and the like, and aqueous solutions in which neutral detergents for industrial use and general household use are dissolved can also be used. Specifically, it is preferable to dissolve a commercially available degreasing agent or a neutral detergent in water at a concentration of several% to 5%, immerse at 50 to 70 ° C. for 5 to 10 minutes and wash with water.

  Next, it is preferable to perform preliminary base washing in which the copper alloy is immersed in an aqueous solution of several percent caustic soda kept at around 40 ° C. and then washed with water. Further, chemical etching is performed by immersing the copper alloy in an aqueous solution containing hydrogen peroxide and sulfuric acid, followed by washing with water. This chemical etching is preferably an aqueous solution containing several percent of both sulfuric acid and hydrogen peroxide at 20 ° C. to around room temperature. Although the immersion time at this time changes with alloy types, it is several minutes-20 minutes. In this chemical etching process, a preferable roughness of the order of microns for most copper alloys, that is, an average length of a roughness curve according to JIS standard (JIS B 0601: 2001 (ISO 4287)) analyzed by a scanning probe microscope ( RSm) is 0.8 to 10 μm, and the maximum height roughness (Rz) is 0.2 to 10 μm. Preferably, the maximum height roughness (Rz) is 0.2 to 5 μm.

  However, as can be said particularly with pure copper-based copper alloys, the rough surface obtained as a result of the above-mentioned chemical etching often has an irregularity period of 10 μm or more, and the average value, RSm, is a copper alloy other than pure copper-based. Big in comparison. On the other hand, the unevenness height difference is small for the large RSm. In particular, it is obvious that the metal crystal grain size is large, such as C1020 (oxygen-free copper) having a high copper content, and clearly gives a large roughness curve as described above. It was estimated that there was a direct correlation between the crystal grain size and the metal crystal grain size. It is presumed that not only pure copper-based alloys but also chemical etching performed with various alloys are mostly caused by erosion starting from the grain boundaries. In any case, even if there are irregularities with a micron order period, if the height difference of the irregularities is small for the period, the effect of the present invention is hardly exhibited. Therefore, although it will be described later, it is preferable to carry out an appropriate treatment method for those that feel that the roughness of the large unevenness is insufficient.

  The copper alloy that has undergone the chemical etching step is oxidized. A method called blackening treatment is known in the electronic component industry, but the oxidation performed in the present invention is the same in the process itself although the purpose and the degree of oxidation are different. Chemically speaking, the surface layer of the copper alloy is oxidized with an oxidizing agent under strong basicity. When copper atoms are ionized with an oxidizing agent, if the surroundings are strongly basic, they are not dissolved in an aqueous solution and become black cupric oxide. When copper alloy parts are used as heat sinks or heat-generating parts, the surface is blackened to increase the efficiency of heat dissipation and heat absorption, but this process is used in the electronic parts industry that uses copper. This is called blackening treatment. This blackening treatment method can also be used for the surface treatment of the present invention. However, the purpose of this blackening treatment is to form nano-order ultra-fine irregularities on the surface of a copper alloy having a certain roughness and to harden the surface layer (that is, to perform fine etching and surface hardening treatment). Therefore, it is not literally blackening.

  Commercially available blackening agents can be used at concentrations and temperatures specified by commercial manufacturers, but the immersion time in that case is much shorter than during so-called blackening. Actually, the immersion time is adjusted by observing the obtained alloy with an electron microscope. As a specific example, it is preferable to use an aqueous solution containing about 5% sodium chlorite and 5 to 10% caustic soda at 60 to 70 ° C, and the immersion time in this case is about 0.5 to 1.0 minutes. Is preferred. By these operations, the copper alloy is covered with a thin layer of cupric oxide, the surface has a roughness on the order of microns, and when observed with an electron microscope, the rough surface has a diameter of 10 A circular hole having a diameter of ˜150 nm or an elliptical hole having a major axis or a minor axis of 10 to 150 nm is formed.

  And the hole opening part which is this circular hole or an elliptical hole becomes the ultra fine uneven | corrugated shape which exists in the whole surface with a 30-300 nm period (this example was shown with the photograph of FIG. 10). In short, when this surface hardening treatment is performed, both the formation of ultra-fine irregularities and the surface hardened layer can be obtained simultaneously. In addition, it has been found that the surface hardening treatment is excessively performed by increasing the immersion time in the above-described treatment solution by 2 to 3 minutes, but it is not preferable because the bonding force is weakened.

  In the etching of the pure copper-based copper alloy described above, it is a sure pattern that copper erosion occurs from the metal crystal grain boundary based on the observation results, and as described above, a particularly large crystal grain size, that is, oxygen-free copper (C1020 ), It was not possible to exert a strong bonding force only by performing the above-described chemical etching and surface hardening treatment. In short, the most important size of the recess is not as expected.

  The present inventors have discovered a treatment method in such a case. The result is a very simple method, but once the surface hardening treatment (blackening) has been completed, it is again immersed in an etching solution for a short time to re-etch and then blackened again. is there. As a result, the period of roughness on the order of microns becomes as expected as it can be reduced to about 10 μm or less, and the appearance of ultra-fine irregularities is different from the case of no repeated treatment according to electron microscope observation. Absent.

(Titanium alloy surface treatment)
It is preferable that the titanium alloy part is first immersed in a degreasing tank to remove oils and finger grease adhered by machining. No special products are required. Specifically, general degreasing agents such as commercially available iron degreasing agents, stainless steel degreasing agents, aluminum alloy degreasing materials, magnesium alloy degreasing agents, etc. are designated by the drug manufacturer. It is preferable to prepare an aqueous solution by pouring it into hot water at a normal concentration, and immerse in this to wash. Furthermore, it is also preferable to prepare an aqueous solution with a concentration of several percent with a commercially available industrial neutral detergent, soak it at a temperature of about 60 ° C., and then wash it with water. Next, it is preferable to immerse in a basic aqueous solution and wash with water, followed by preliminary base cleaning.

  Next, it is preferable to perform chemical etching by dipping in an aqueous solution of a reducing acid. Specifically, oxalic acid, sulfuric acid, hydrofluoric acid, and the like can be said to be reducing acids that can corrode titanium alloys entirely, and these can be used. In terms of efficiency, hydrofluoric acid has the highest etching rate. However, hydrofluoric acid may invade human skin and lead to bones, and deep pain may continue for several days. In short, there are problems different from hydrochloric acid and the like, and it is preferable to avoid using this acid from the viewpoint of the working environment.

  Preference is given to ammonium hydrofluoride, a half-neutralized product of hydrofluoric acid which can be handled much more safely than hydrofluoric acid. A treatment method in which an aqueous solution of about 1% of 1 hydrogen difluoride ammonium is immersed in this solution at a temperature of 50 to 60 ° C. for several minutes and then washed with water is preferable. Chemical etching with 1 hydrogen difluoride ammonium aqueous solution was performed to obtain micron-order roughness (roughness surface), but in electron microscope observation and observation with the latest analytical equipment, titanium was washed and dried after chemical etching. It was found that the surface of the alloy became a mysteriously shaped ultra-fine uneven shape, and the surface was covered with a thin titanium oxide layer. In short, it seems that surface treatments such as a special fine etching process and a surface oxidation process are unnecessary and need not be performed.

  An analysis example of a titanium alloy etched with an aqueous solution of 1 hydrogen difluoride ammonium, washed with water, and then dried is shown. First, the scanning analysis result by the scanning probe microscope was obtained. Here, scanning within a square area of 20 μm square, the average length of the roughness curve (average length of the contour curve element) RSm is 1.8 μm, and the maximum height roughness (maximum height of the contour curve) Rz. 0.9μ was obtained. Moreover, the example of the 10,000 times and 100,000 times electron micrograph of the thing which carried out the same process was shown in FIG. 14 (upper 10,000 times, lower: 100,000 times). Here, a very unique and mysterious ultra-fine concavo-convex shape having a height or width of 10 to 300 nm and a length of 10 nm or more, or a mountain or mountain range (mountain) -like convex part having a period of 10 to 350 nm and existing on the entire surface. It has been shown.

  According to XPS analysis, large oxygen and titanium peaks were obtained, and the surface compound was clearly titanium oxide. However, the surface color tone was dark brown, and it was seen as a thin film of titanium (trivalent) oxide or a mixed oxide of titanium (trivalent) and titanium (tetravalent). That is, the surface was a metal color before etching, and this surface was a natural oxidation layer of titanium, but after etching with an aqueous hydrogen bifluoride solution, it changed to a dark titanium oxide layer that was not a natural oxidation layer. This titanium oxide layer was etched by 10 to several tens of nm with an argon ion beam, and the etched surface was subjected to XPS analysis. This XPS analysis revealed the thickness of the titanium oxide layer, which is clearly thicker than that of the natural oxide layer, and more than 50 nm for pure titanium-based titanium alloy etched products using an aqueous 1 hydrogen difluoride ammonium fluoride solution. It was seen.

  Moreover, the valence of titanium ions decreases from the surface to the inside, the divalence increases from the tetravalent or trivalent and tetravalent mixed state of the surface toward the inside, and further the divalent decreases to zero. It turns out that it leads to metal. In short, the oxide film that is titanium oxide is not a simple titanium oxide layer, but a continuously changing layer in which the titanium valence continuously decreases from the surface and reaches zero. It can be seen that the surface is an interesting continuously changing layer that becomes darker and thinner towards the interior, as if penetrated from the surface. In such a metal oxide film, there is no clear boundary between the metal phase, so the bonding force between the oxide film layer and the metal substrate is very strong, and there is no concern about its peel-off resistance (stress). You can expect nothing to do.

  The specific treatment method for titanium alloys other than pure titanium alloys is the same as the treatment method described above, but is included as a small amount of additive by the nascent hydrogen gas generated during etching with a reducing strong acid aqueous solution. Other metals may be reduced to produce insoluble matter, so-called smut. Most of the smut can be dissolved and removed by immersing in a nitric acid aqueous solution having a concentration of several percent. However, depending on the alloy, a smut that does not dissolve in the nitric acid aqueous solution may also be generated. In such a case, it is preferable to wash by applying ultrasonic waves when washing with water.

  The surface shape of an alloy other than a pure titanium-based titanium alloy etched with ammonium monohydrogen difluoride and smut-removed is a surface shape whose surface shape is difficult to express in language compared to the above-mentioned photograph of FIG. become. An example of an α-β type titanium alloy containing aluminum is shown in the photograph of FIG. Here, a beautiful slope of a mountain or hill with no ultra-fine irregularities (similar to FIG. 14), which is typical of a titanium alloy, is observed, but a mysterious shape like a dead leaf of a plant was observed. The entire surface is not covered with ultrafine irregularities having a period of 10 to 300 nm, which is preferable as the second condition described above, but a surface with a longer period (called “fine irregularities”) is observed. The unevenness itself was smooth.

  However, apart from the smooth dome-shaped portion in this surface, the dead leaf shape portion is thin and curved, and if it has hardness, it becomes a strong spike shape. The surface of the α-β type titanium alloy has almost no portion that does not meet the above-mentioned second condition (ultra-fine irregularities with a period of 5 nm to 500 nm) in the NAT theory. It is thought that it can play the role of unevenness. Since the surface spike shape is large, it is also related to the micron-order roughness (surface roughness) required under the first condition required by NAT. Roughness satisfying the first condition (mountain valley average interval (RSm): 0.8 to 10 μm, maximum height roughness (Rz): 0.2 to 5 μm) as seen with a scanning probe microscope by this spike shape. A surface is formed. In addition, since it slightly deviates from the second condition and the concavo-convex period is large, the whole surface image cannot be grasped with an electron micrograph of 100,000 times. The surface was observed by taking a magnification photograph of 10,000 times or less. That is, as shown in FIG. 15, an area of at least 10 μm square or more is observed with a 10,000 × electron microscope. By doing so, a fine uneven shape in which both a smooth dome shape and a curved dead leaf shape are present is observed.

(Stainless steel surface treatment)
Since various stainless steels have been developed to improve corrosion resistance, chemical resistance is clearly recorded. There are various types of corrosion, such as general corrosion, pitting corrosion, fatigue corrosion, etc., but it is possible to select an appropriate etching agent by selecting a chemical species that causes general corrosion and performing trial and error. According to literature records (eg "Chemical Engineering Handbook", 6th edition, edited by Chemical Engineering Society, Maruzen (1999)), stainless steel in general is hydrohalic acid such as hydrochloric acid, sulfurous acid, sulfuric acid, metal halide salts, etc. There is a record that the entire surface is corroded with an aqueous solution of The remaining weakness of stainless steel, which is corrosion resistant to many chemicals, is that it is corroded by halides, but the weakness is reduced in stainless steel with reduced carbon content, stainless steel with molybdenum added, etc. Yes.

  However, basically, the above-mentioned aqueous solution causes overall corrosion, so the immersion conditions may be changed depending on the type of stainless steel. Furthermore, a structure whose hardness is reduced by annealing or the like and structurally speaking has a large metal crystal grain size has fewer crystal grain boundaries, and it is difficult to corrode the entire surface to obtain unevenness on the order of microns. In such a case, it is necessary to devise such as adding some additive without changing the immersion condition to a level where the corrosion proceeds, and the etching does not progress to the intended level. In any case, chemical etching is performed for the purpose of occupying most of the roughness surface on the order of microns.

  Specifically, a special degreasing agent is not required, and a commercially available general stainless steel degreasing agent, iron degreasing agent, aluminum alloy degreasing agent, or a commercially available neutral detergent is generally used. Obtain and make an aqueous solution at a temperature of 40-70 ° C. at a concentration of several percent or as indicated in the instructions of the degreasing agent manufacturer, and immerse the stainless steel to be treated for 5-10 minutes. To do. This is a degreasing process. Next, it is preferable to immerse this stainless steel in a caustic soda aqueous solution having a concentration of several percent for a short time, and then wash it with water to adsorb basic ions on this surface. This is because the next chemical etching proceeds with good reproducibility by this operation. This is a so-called preliminary base washing step. Next, the etching process is started.

  In the case of SUS304, a method in which an aqueous sulfuric acid solution having a concentration of about 10% is set to a temperature of 60 to 70 ° C. and immersed in the solution for several minutes is preferable, and this processing method can obtain a micron order roughness required in the present invention. In SUS316, it is preferable to immerse an aqueous sulfuric acid solution having a concentration of about 10% at a temperature of 60 to 70 ° C. for 5 to 10 minutes. Hydrohalic acid, such as aqueous hydrochloric acid, is also suitable for etching, but if this aqueous solution is heated to high temperatures, part of the acid may volatilize and corrode surrounding iron structures. Some processing is necessary. In that sense, use of a sulfuric acid aqueous solution is preferable in terms of cost. However, depending on the steel material, the progress of overall corrosion may be too slow with an aqueous solution of sulfuric acid alone. In such a case, it is effective to add hydrohalic acid to the sulfuric acid aqueous solution for etching.

  After the chemical etching, the surface of the stainless steel is naturally oxidized by sufficiently washing with water, and returns to the surface layer that can withstand corrosion. However, in order to make the metal oxide layer on the stainless steel surface thick and strong, an oxidizing acid, for example, an oxidizing agent such as nitric acid, that is, nitric acid, hydrogen peroxide, potassium permanganate, sodium chlorate, etc. After being immersed in an aqueous solution, it is preferably washed with water.

  It is preferable to conduct an epoxy-based adhesive bonding test to select a material having a high bonding strength, and observe this with an electron microscope to confirm the existence of an ultrafine uneven shape and its shape. Of course, the joining test may be performed after observation with an electron microscope. In any case, a stainless steel having a microstructural surface in which ultra-fine irregularities with a period of several tens to hundreds of nanometers, preferably an ultrafine irregularity with a period of about 50 nm are surely present, should have a high bonding force. is there.

  An example in which stainless steel is actually chemically etched with a sulfuric acid aqueous solution is shown. The above-mentioned roughness surface (surface roughness surface) is obtained by appropriate etching, and this roughness surface can be confirmed by observation using a roughness meter (surface roughness meter), a scanning probe microscope, etc. Furthermore, when the surface is observed with an electron microscope, it can be seen that the surface is covered with a very interesting surface having an extremely fine uneven shape. In short, in stainless steel, fine etching can be achieved at the same time by only chemical etching as described above. This surface will be described with an electron micrograph. In FIG. 16, a shape in which particles having a diameter of 20 to 70 nm, indefinite polygonal shapes, and the like are stacked is recognized, and observation images of the 10,000 times photograph (upper part of FIG. 16) and 100,000 times photograph (lower part of FIG. 16). However, it was very similar to the gala field on the slope of the lava plateau formed by lava flowing around the volcano.

  In addition, when XPS analysis was performed on stainless steel covered with the ultra-fine irregularities on the etched surface, large peaks of oxygen and iron and small peaks of nickel, chromium, carbon, and molybdenum were recognized. In short, the surface was an oxide of a metal having exactly the same composition as that of ordinary stainless steel, and was considered to be covered with a similar corrosion-resistant surface. Here, the importance of taking a chemical etching method will be described. Whatever method is used, it is sufficient that the surface shape is as described above, but that is why chemical etching is performed. It is thought that the designed ultra-fine concavo-convex shape surface can be realized by using a recent ultra-fine processing method applied with a photochemical resist and using visible light, ultraviolet light, or the like.

  However, chemical etching is particularly preferred for injection bonding and adhesive bonding, except that it is simple to operate. In other words, when chemical etching is performed under appropriate conditions, not only can an appropriate concavo-convex cycle and an appropriate depth of the recess be obtained, but the fine shape of the resulting recess is not a simple shape, and many of the recesses are understructured. Because it becomes. The under structure as used in the present invention means that there is a surface that cannot be seen when the concave portion is viewed from the vertical plane, and an overhang portion is visible when it is assumed that the concave portion is viewed with a microscopic eye. That's what it means. It will be readily understood that the under structure is required for injection bonding and adhesive bonding.

  In addition, after the etching with the reducing acid aqueous solution, additional treatment was performed to immerse in a nitric acid aqueous solution, a hydrogen peroxide aqueous solution, etc. to make a metal oxide layer firmly. There was no clear difference in the joining force when joining by the addition of this additional treatment. Long-term weather resistance tests may result in differences in bonding strength.

(Surface treatment of steel materials)
There are known types of corrosion of steel materials such as general corrosion, pitting corrosion, fatigue corrosion, and the like, but it is possible to select an appropriate etching agent by selecting a chemical type that causes general corrosion and trial and error. According to the records of various documents (for example, “Chemical Engineering Handbook (edited by the Chemical Engineering Association)”), all steel materials are corroded by an aqueous solution of hydrohalic acid such as hydrochloric acid, sulfurous acid, sulfuric acid, and their salts. Is described. Depending on the amount of carbon, chromium, vanadium, molybdenum, and other small additives added, the corrosion rate and form of corrosion change, but basically the above-mentioned aqueous solution causes general corrosion. Therefore, basically, the immersion conditions may be changed depending on the type of steel material.

  Specifically, in the steel materials that are commercially available and often used such as SPCC, SPHC, SAPH, SPFH, SS material, etc., a degreasing agent that is commercially available for this steel material, degreasing for stainless steel Agents, aluminum alloy degreasing agents, and further commercially available neutral detergents, and the concentration of aqueous solution as indicated in the instructions of these degreasing agent manufacturers, or an aqueous solution of several percent concentration, After this temperature is set to 40 to 70 ° C. and immersed for 5 to 10 minutes, this is washed with water (degreasing step). Next, in order to improve etching reproducibility, it is preferable to immerse in a dilute caustic soda aqueous solution for a short time, and then wash it with water. This processing step is, so to speak, a preliminary base washing step.

  Next, in the case of SPCC, it is preferable to etch by immersing the sulfuric acid aqueous solution of about 10% concentration at 50 ° C. for several minutes. This is an etching process for obtaining a micron-order roughness. For SPHC, SAPH, SPFH, and SS materials, it is preferable that the temperature of the sulfuric acid aqueous solution is increased by 10 to 20 ° C. from the former. Hydrohalic acid, such as aqueous hydrochloric acid, is also suitable for etching, but if this aqueous solution is used, part of the acid may volatilize and corrode surrounding iron structures, and even if it is exhausted locally, it will be exhausted. Some processing is required. In that sense, use of a sulfuric acid aqueous solution is preferable in terms of cost.

[Surface Treatment Method I: Method of Forced Drying after Washing with Water]
After the chemical etching described above, it is washed with water, dried, and observed with an electron micrograph. Ultra fine irregularities with a height and depth of 50 to 500 nm and a width of several hundred to several thousand nm followed by infinite steps. Often, the shape covers almost the entire surface. This seems to have exposed the pearlite structure that steel materials generally have. Specifically, when an aqueous sulfuric acid solution is used in the above chemical etching process under appropriate conditions, an uneven surface corresponding to a large undulation is obtained, and at the same time, a surface having a fine and mysterious step-like ultra-fine uneven shape is also obtained. Often formed simultaneously. Thus, when the roughness of micron order and the creation of ultra-fine irregularities are made at once, the water after the etching is sufficiently washed and then drained and rapidly dried at a temperature of 90-100 ° C. or higher. You can use it as it is. Rust on the surface does not appear and it becomes a beautiful natural oxide layer.

  However, the natural oxidation layer alone is considered to have insufficient corrosion resistance in a general environment, particularly in a high humidity and warm environment as in Japan. Perhaps it is necessary to store it under dry conditions for the bonding process, and it is questionable whether the bonded composite can maintain the bonding strength (adhesive strength) for a sufficient amount of time. In fact, after being left for a month in a place with a roof but practically close to the outdoors (Suehiro-cho, Ota City, Gunma Prefecture, Japan, December 2006-January 2007), when a fracture test was performed, the bonding strength was slightly reduced. Was. In practice, it seems that a clear surface stabilization treatment is necessary.

[Surface Treatment Method II: Method Utilizing Adsorption of Amine-Based Molecules]
After the above chemical etching, the substrate is washed with water, and subsequently immersed in an aqueous solution of ammonia, hydrazine, or a water-soluble amine compound, washed with water, and dried. It has been found that amine-based substances in a broad sense such as ammonia remain in the steel material after the etching process. Strictly speaking, nitrogen atoms are confirmed when the steel material after drying is analyzed by XPS. Therefore, we understood that amines in a broad sense, including ammonia and hydrazine, were chemically adsorbed on the surface of steel materials. Since it appears to be attached, an iron-based complex of iron may have occurred.

  More specifically, the 100,000 times electron micrographs of the steel material immersed in aqueous ammonia and the steel material immersed in the hydrazine aqueous solution appear to differ in the shape of the thin skin substance adhering to the staircase. Looks like. In any case, the adsorption or reaction of these amines seems to prevail over the adsorption of water molecules or the iron hydroxide formation reaction. In that sense, at least for several days to several weeks until the joining operation with the epoxy adhesive is performed, generation of rust due to moisture adsorption and reaction thereof can be suppressed. In addition, it is expected that the adhesion strength after adhesion is superior to the above-mentioned “Surface Treatment Method I”. There was no decrease in bonding strength when the bonded article was left for 4 weeks.

  The concentration and temperature of the aqueous ammonia, the aqueous hydrazine solution, or the aqueous solution of the water-soluble amine to be used need almost no strict conditions. Specifically, an effect can be obtained by using an aqueous solution having a concentration of 0.5 to several percent at room temperature, immersing for 0.5 to several minutes, washing with water, and drying. Industrially, a 1% to several percent aqueous solution of hydrated hydrazine having a slight odor but inexpensive and having a concentration of about 1%, or a low odor and stable effect is preferable.

[Surface treatment method III: method by chemical conversion treatment]
After the chemical etching described above, the surface of the steel material is subjected to chromium oxidation by rinsing with an aqueous solution of an acid or salt containing a hexavalent chromium compound, a permanganate, or a zinc phosphate-based compound. It is known that corrosion resistance is improved by being covered with metal oxides such as metal oxides, manganese oxides and zinc phosphorus oxides, and metal phosphorus oxides. This is a well-known method for improving the corrosion resistance of iron alloys and steel materials, and this method can also be used. However, the true purpose is not to ensure corrosion resistance that can be said to be perfect in practical use, and at least there will be no hindrance until the bonding process. If this is done, the level should be such that it is difficult to cause trouble over time in the bonded portion. In short, when the chemical conversion film is thickened, it may be preferable from the viewpoint of corrosion resistance, but it is not preferable in terms of bonding strength. Although the chemical conversion film is necessary, it is the view of the present inventors that the bonding force is weakened if it is too thick.

  The specific methods for implementing corrosion resistance can be extended. When immersed in a dilute aqueous solution of chromium trioxide in a chemical conversion treatment solution, washed with water and dried, the surface appears to be covered with chromium (III) oxide. The surface was not covered with a uniform film-like object, and protrusions having a diameter of 10 to 30 nm and an equivalent height were generated at a distance of about 100 nm. Further, an aqueous solution of potassium permanganate having a concentration of several percent adjusted to weak acidity could be preferably used.

  The surface subjected to chemical conversion treatment in which SPCC was immersed in a zinc phosphate aqueous solution was observed with an electron microscope. The shape was such that foreign matter mainly adhered to the vicinity of the stepped corner, and the flat portion of the step was dotted with small protrusions having a diameter of 10 to 30 nm although the density was low. In any case, it is preferable to obtain an aqueous solution at a temperature of 45 to 60 ° C., soak the SPCC for 0.5 to several minutes, wash with water, and dry to obtain a high bonding strength. Therefore, the chemical conversion film is thin. The change due to the chemical conversion treatment agent described above was not something that could be confirmed by a 10,000 × low electron micrograph.

[Surface Treatment Method IV: Silane Coupling Agent]
Numerous inventions have been made and proposed as treatment methods for imparting corrosion resistance and weather resistance to steel materials, and methods for adsorbing a silane coupling agent therein are known. A silane coupling agent is a compound having a hydrophilic group and a water repellent group in its molecule. When a steel material is immersed in a dilute aqueous solution, washed with water and dried, a silane cup is formed on the surface of the hydrophilic steel material. The hydrophilic base side of the ring agent is adsorbed, and as a result, the entire steel material is covered with the water repellent base side of the silane coupling agent. When an epoxy adhesive is allowed to act with the silane coupling agent adsorbed, even if water molecules enter the very thin gap of several tens of nanometers created by the hardened adhesive and the steel material surface, The water-repellent group of the silane coupling agent covering the water may suppress the water molecules from approaching the steel material.

  These can be expected to have better corrosion resistance than the surface treatment method I as in the surface treatment method II and surface treatment method III described above, but a long-term test is necessary to demonstrate this. The present inventors, for each steel material using each of the above-mentioned surface treatment method I, surface treatment method II, surface treatment method III, and surface treatment method IV, after joining with the same steel material by an adhesive, about Shear breaking force was measured after one week (January 2007: a covered building in Ota City, Gunma Prefecture, Japan). As a result, the strength was almost the same as the initial level. However, when about 4 weeks passed after joining, the shear rupture force deteriorated when the surface treatment method I was used. It is thought that which method is most practical will be found if a long-term neglect test is performed. However, from a practical point of view, steel materials are generally used after being coated, so it is necessary to select candidates by a non-painted material test, and further paint these candidates to conduct a long-term environmental test.

(Surface treatment of galvanized steel sheet)
There are practically four types of galvanized steel sheets in Japan, including hot-dip galvanized steel sheets, electrogalvanized steel sheets, zinc-55% aluminum alloy steel sheets (galvalume steel sheets), zinc-11% aluminum-3% magnesium alloy steel sheets. It is. Among these, first, the surface treatment method of the hot dip galvanized steel sheet with oil coating chromate treatment, which is most often handled by secondary processors, will be described.

  In this steel plate, the surface layer that seems to be the original oil layer or grease layer disappears by immersing it in a degreasing agent aqueous solution at a particularly high temperature for a long time, and then washing and drying. A surface layer appeared (observation with an electron microscope). In the XPS analysis of this new surface layer, chromium was observed, and it was found that this surface layer was a layer obtained by chromate treatment. That is, the surface is covered with a thin layer of a hard phase. If the surface roughness is in the range of 0.8 to 10 μm with RSm and Rz is in the range of 0.2 to 5.0 μm in this state excluding the oil layer, results can be obtained by injection bonding or adhesive bonding as it is. Should be. In that case, the processing performed by the present inventors is the shortest so far, and the degreasing treatment is combined with all of chemical etching, fine etching, and surface hardening treatment.

  Of course, the chemical conversion treatment (here, chromate treatment) performed by the material manufacturer on the hot dip galvanized steel sheet is an appropriate level for the present invention, and the roughness level of the original hot dip galvanized layer coincides with the requirements of the present invention. It was because it was in the range to do. Furthermore, it is effective that the degreasing agent used in the degreasing treatment by the present inventors is a product that dissolves only the oil and does not adversely affect the chromate layer. In such a degreasing process, a commercially available industrial degreasing agent for steel and aluminum materials can be used as a degreasing agent. Particularly, a degreasing agent for aluminum materials is preferable, and a grease-like oil agent that adheres strongly as a usage method or For the purpose of desorbing the special organic polymer material for lubrication, it is desirable to set the temperature of the degreasing aqueous solution to a high temperature, for example, 70 ° C. or higher. The immersion time is preferably 5 minutes or more, but this should be determined by considering the situation after degreasing of the steel sheet used. An immersion time can be shortened by attaching an ultrasonic oscillation end to the degreasing tank and degreasing while adding ultrasonic waves.

  It is not particularly difficult to carry out without being bound by the chemical conversion treatment method of the steel plate manufacturer. After degreasing, the chemical conversion treatment layer is peeled off by dipping in an acidic aqueous solution such as a thin sulfuric acid aqueous solution, and the process proceeds to chemical etching of the zinc plating layer, so that the etching level is adjusted to obtain a micron-order roughness, then chromate treatment, An ultrafine uneven surface can be formed by thinly adding a zinc phosphate type chemical conversion treatment or a zinc calcium phosphate type chemical conversion treatment. That is, chemical etching and surface hardening treatment are performed after the degreasing treatment. The surface hardening treatment in this case is a chemical conversion treatment itself, but also serves as fine etching.

  Actually, when experiments were repeated with this idea, it could be further omitted, and it was found that the chemical conversion treatment, which is a surface hardening treatment, also serves as chemical etching. That is, all the treatment liquids of the chromate treatment, zinc phosphate type chemical conversion treatment, and zinc calcium phosphate chemical conversion treatment, which are chemical conversion treatments, are acidic aqueous solutions of PH1 to 3, in which zinc plating with chromate treatment after the degreasing step is performed. When the steel plate was immersed, hydrogen was emitted and the entire surface was corroded. Therefore, it was judged that this process can also serve as chemical etching if the immersion conditions and the like are adjusted. In short, if the conditions are selected, the entire process can be completed only by degreasing and surface hardening treatment.

  However, in the case of zinc-aluminum alloy-plated steel sheets, the above-described abbreviated processing often does not achieve the surface required by the “NAT” theory. In these, as a chemical etching, a step of etching a zinc aluminum alloy phase by immersing in an acidic aqueous solution of PH1 to 3, specifically, a dilute aqueous solution of sulfuric acid, hydrochloric acid or the like that is inexpensive and easy to dispose of is added. Is preferred. That is, the galvalume steel sheet requires steps of degreasing, chemical etching, and surface hardening treatment. Even in this steel sheet, the surface hardening treatment is a so-called chemical conversion treatment, and since the chemical conversion treatment also creates an ultra fine uneven surface, fine etching can be omitted.

  The chemical conversion treatment method as the surface hardening treatment will be specifically described. Although it was stated that chromate treatment, zinc phosphate type treatment, or zinc calcium phosphate type treatment can be used, as a result, the zinc phase is covered with a ceramic thin film and has an ultra fine uneven surface, and if added, a thin film layer It is necessary that the bonding force between the zinc phase and the zinc phase is sufficiently strong. As such a chemical conversion treatment method, the present inventors have shown that at least a chromate treatment, a zinc phosphate type treatment, and a zinc calcium phosphate type treatment can be used. If the above requirements are satisfied, other chemical treatment methods can be used. It can be used.

  Each chemical conversion treatment will be described in more detail. Many methods are known as a chromate treatment solution, and an aqueous phosphoric acid solution containing trivalent chromium and hexavalent chromium is particularly preferable. Also, it is unclear whether it is catalytically effective for the formation of the chromate layer, but when a small amount of nickel ions coexists, the surface became preferable by immersion at a low temperature. More specifically, chromium nitrate is 1 to 1.5%, chromic anhydride is about 0.3%, phosphoric acid is 1.5 to 2%, and basic nickel carbonate is 0.01 to 0.05%. It is preferable to use an aqueous solution containing about 40 ° C.

  In addition, the zinc phosphate type chemical conversion treatment solution preferably contains a small amount of nickel ions in addition to phosphoric acid and divalent zinc, and is also effective for exhibiting good coexistence of silicofluoride ions. preferable. More specifically, it is preferable to use an aqueous solution containing 1 to 1.5% phosphoric acid, zinc oxide, basic nickel carbonate, and sodium silicofluoride at about 0.2% each at 50 to 60 ° C. .

  As the zinc phosphate calcium type chemical conversion treatment solution, it is preferable that a small amount of nickel ions coexist in addition to phosphoric acid, divalent zinc and calcium. Furthermore, although the zinc phosphate calcium chemical conversion treatment solution that is excellent as a chemical conversion treatment solution for steel materials is usually not effective unless it is at a high temperature of 80 ° C. or higher, when used in the present invention, 60 to Excellent results were obtained at 65 ° C. The example of the photograph obtained by electron microscope observation was shown in the Example mentioned later. Specifically, regarding the liquid composition, it is preferable to use an aqueous solution containing 1 to 1.5% phosphoric acid, zinc oxide, basic nickel carbonate, and calcium nitrate about 0.2% each.

  Finally, as a result of scanning a rough surface using a scanning probe microscope, RSm is in a range of 0.8 to 10 μm, Rz is in a range of 0.2 to 5 μm, and an ultrafine uneven surface having a period of 5 to 500 nm, More preferably, it is necessary in the “NAT” theory that the surface is covered with an ultrafine irregular surface with a period of 30 to 100 nm. If Rsm is smaller than about 0.8 μm, the concave / convex period is too small, and it is difficult to firmly enter the resin component in either injection bonding or adhesive bonding. On the other hand, even if RSm is 10 μm or more, the bonding force is greatly reduced. In this case, since the recess period and the hole diameter are too large and the absolute number of recesses is reduced, the anchor effect is rapidly reduced and the joining force is reduced.

  In addition, the value of Rz in injection joining is about half of Rsm, if the recess has a depth up to about half of the concave-convex cycle, the resin used by the present inventors for injection joining, ie, improved This is because the PBT resin composition, the PPS resin composition, and the aromatic polyamide resin composition thus formed are considered to be able to penetrate to the bottom of the recess. This is also true for liquid one-component adhesives that can enter with a pressure difference of up to about 1 atmosphere. When Rz is larger, that is, when the bottom of the unevenness is deep, the above-described resin cannot be fully penetrated, and the bottom of the micron-order concave portion remains as a void after the joining process, and becomes the weakest phase against destruction. In short, high bonding strength cannot be obtained. On the other hand, if Rz is too small, most of the role of maintaining the bonding force will be borne by the ultra-fine irregularities, and eventually the bonding force will be reduced.

  In the observation result of the surface obtained by subjecting the above-described hot-dip galvanized steel sheet “Z18” with oil treatment and chromate treatment to the high temperature degreasing process, Rsm is 0.8 to 3 μm by 10 times of roughness measurement with a scanning probe microscope, Rz = 0.3-1 μm, and speaking of the rough surface described in the general theory of “NAT”, both Rsm and Rz were close to the lower limit. On the other hand, the irregularity period of the ultrafine irregularities by electron microscope observation was 80 to 150 nm, which was a preferable ultrafine irregularity period. Further, the shape of the ultra-fine unevenness itself is a shape that easily causes an anchor effect, and a sufficiently high bonding force can be obtained even if the unevenness period in the micron order is near the lower limit of the range defined in the “NAT” theory.

[Unsaturated polyester adhesive]
For metal alloys such as aluminum alloy, magnesium alloy, copper alloy, titanium alloy, stainless steel, general steel material, aluminum plated steel plate, and galvanized steel plate, a one-component epoxy adhesive is used to adhere to the adherend. When a joined body is obtained, very high adhesive strength is exhibited (Patent Documents 7 to 14). The present invention shows that such high adhesive strength is not limited to epoxy adhesives. Specifically, an unsaturated polyester-based composition adjusted so that the gelation rate at room temperature was zero or very small, and the existing fracture theory was applied to “NAT” to devise a filler. Details will be described below.

  The composition of the thermosetting unsaturated polyester composition is usually (1) an unsaturated polyester resin and / or vinyl ester resin, (2) a liquid vinyl monomer, (3) an organic peroxide of a curing agent, and (4 ) A hardening accelerator such as a cobalt compound is included. Actually, it is used as a two-component type, and (1) and (2) are mixed in the main solution, and (3) a curing agent is added to this and mixed and used. A curing accelerator (4) is often used during normal GFRP production.

  Regarding the unsaturated polyester resin composition for GFRP, since many manuals have been published, only the main points are shown here. (1) Unsaturated polyester resin is a mixture of unsaturated dibasic acids such as maleic anhydride and fumaric acid, saturated dibasic acids such as phthalic anhydride, isophthalic acid, adipic acid and endo acid and various glycols. It is a group called alkyd resin obtained. The vinyl ester resin is a group of products obtained by reacting methacrylic acid or the like with the terminal or intermediate part of an epoxy resin or a phenol resin to form an ester.

  Both alkyd resins and vinyl ester resins are solids or high-viscosity liquids having a molecular weight of about several thousand, and are dissolved in (2) liquid vinyl monomers (actually styrene or α-methylstyrene is used in many cases) (1 ) The so-called “unsaturated polyester main liquid” comprising (2) is a slightly viscous liquid.

  Basically, the basic components for making a cured product are (1) and (2) mixtures as the main liquid, and (3) an organic catalyst as a curing agent (in terms of polymer chemistry, it is a “polymerization initiator”). It is an oxide. There are various organic peroxides such as methyl ethyl ketone peroxide and benzoyl peroxide, and these are decomposed by raising the temperature or (4) addition of a curing accelerator to generate radicals and start polymerization. When polymerization is initiated, heat of polymerization is generated, which further accelerates the decomposition of the organic peroxide and the polymerization reaction itself. When building on-site by superposing glass mats or glass cloths at room temperature, as in the case of FRP ship production, a high-speed reaction that solidifies within a few hours is required. A combination of low organic peroxide and cure accelerator is used.

  In the present invention, the polymerization is basically very slow, and as a result, the gel (macromolecule) is reduced in the adhesive composition in the coating process to the metal alloy. It is required that the microscopic irregularities formed on the wall surface of the concave portion having a roughness of 1 can be penetrated at a pressure of about 1 atm. In short, the basic idea of “new NMT” and “NAT” is that the liquid resin solidifies with high hardness after intruding into the ultra-fine irregularities as described above, so that strong adhesive bonding is produced. The early gelation of the components weakens the adhesive strength.

  Therefore, it is preferable to use a curing agent system in which the unsaturated polyester resin and vinyl ester resin do not substantially initiate the polymerization reaction at around room temperature. Specifically, (3) kick-off temperature (thermal decomposition) as an organic peroxide. High starting temperature), for example, bis (1-hydroxycyclohexyl) peroxide, hydrohexyl heptyl peroxide, t-butyl hydroperoxide, cumene hydroperoxide, t-butyl perbenzoate, t-butyl peracenate Di-t-butyl peroxide, dicumyl peroxide, t-butyl-peroxyisopropyl monocarbonate, t-hexyl-peroxyisopropyl monocarbonate, t-butyl peroxybenzoate, and the like are candidate curing agents.

  Among these, reference data are shown below when selecting a particularly preferable organic peroxide. That is, GFRP has a molding method via SMC and BMC, which will be described later. These are usually (1) (2) main liquid component, (3) curing agent, and (5) reinforcing fibers (SMC, BMC). In this case, it is often a short glass fiber), and (6) a compound containing other filler is formed into a sheet.

  In many cases, SMC and BMC are not formed immediately after being compounded and formed into a sheet, so that the gelation is progressed only slightly when stored at room temperature for a short time. The organic oxides used for SMC and BMC are usually t-butyl-peroxyisopropyl monocarbonate, t-hexyl-peroxyisopropyl monocarbonate, and t-butyl peroxybenzoate. Therefore, their use is particularly preferred in the present invention. Other than these, in other words, after mixing the curing agent with the main liquid, gelation does not start at least at room temperature for 1 hour, preferably 3 hours. Those that do not rise are suitable. Of course, since the gelation starts when the temperature of the mixture is raised to 50 to 80 ° C., it is necessary to strictly control the temperature as compared with the one-component epoxy adhesive and the phenol resin adhesive.

  In summary, the unsaturated polyester adhesive requires a mixture of the above (1), (2) and (3). The curing accelerator (4) is not always necessary. The reinforcing fiber (5) is not necessarily required. The “other filler” of (6) in BMC is a substance for increasing the viscosity of the main liquid consisting of (1) and (2) to make it difficult to separate from the glass fiber. This refers to the use of oxide / hydroxide powders, but these are not necessarily required. A mixture of unsaturated polyester and vinyl monomer comprising the above (1) and (2) is commercially available as an unsaturated polyester solution for GFRP, and any of them can be used. The curing agent of (3) is also selected from those described above, and (1) (2) 100 parts of main liquid is mixed with 0.5 to 2 parts of (3) organic peroxide at room temperature.

[Filler]
The composition is merely a thermosetting resin essential for an adhesive, and a component necessary for obtaining high adhesive strength is a powder filler. That is, unsaturated polyester-based adhesives are not commercially available, but a variety of epoxy-based adhesives are commercially available. These always include an inorganic filler and play an important role. According to the current fracture theory, a local fracture first occurs at a minute portion of the stress concentration point before the object is broken, and this increases the stress concentration in the immediate vicinity to generate a chain of local fractures. Then, the stress concentration in the surrounding area is further increased, and the breakage occurs at a minute part slightly away from it, the chain of the original breakage points continues, and the breakage area spreads one after another, eventually leading to clear breakage This is the idea. According to this theory, the idea is that the presence of a lump that does not break, that is, the presence of a filler, is effective even if the local breakage of the initial minute portion is not chained and stopped once. The commercially available epoxy adhesives include inorganic fillers having a diameter of several μm to several tens of μm, and these are selected as a result of many trials and errors. It would be useful to incorporate the same idea into unsaturated polyester adhesives.

  In addition, the present invention is an adhesive for “NAT”. In addition to the parts learned from past adhesives, the conditions required for adhesive fillers were considered, assuming the metal surface condition in “NAT”. That is, two locations where mutations are first generated when the junction by “NAT” is destroyed are estimated and set as hypotheses. One is in the vicinity of the entrance of a micron-order recess already mentioned in the “NAT” theory. If it breaks here, it can be strengthened by adding carbon nanotubes (hereinafter referred to as “CNT (abbreviation of Carbon nano-tube)”) as already proved by the experimental results using an epoxy adhesive (Patent Document 15). The amount of CNT added is preferably 0.2% by mass or less, particularly preferably 0.06 to 0.1% by mass in view of the experimental value at this time, although CNT is very expensive, so GFRP and zinc plating are preferred. It should not be an indispensable filler for low-cost and general-purpose bonding, such as considering the bonding of steel sheets, so it was also important how far the adhesive strength could be improved without CNTs.

  The other is that the cured adhesive near the spike (super fine irregularities with a period of several tens to several hundreds of nanometers) in the concave part of the micron order can slip out for some reason, that is, the part in contact with the spike. It was estimated that the shape collapsed somewhere, causing microfracture and slippage. If the breakage and peeling at the minute interface proceed in a chain manner along the interface, the spike effect disappears and the anchor effect of the micron-order recess becomes zero. As a result, the degree of stress concentration in the recesses around the recesses increases, and the same thing occurs in the recesses next. Thus, when the resin part which a spike hold | suppresses loosens, the fall of adhesive force is promoted. It is conceivable to use a filler as a method of making it difficult to break the cured adhesive portion where the spike contacts. However, since the irregularity period of the spike portion is on the order of several tens of nanometers, an ultrafine filler of several nanometers is required to sufficiently penetrate the spike, and a very high level of uniform dispersion is required. Unfortunately, there is no ultrafine powder with a diameter of several nanometers that can achieve such high dispersion.

  Therefore, it is assumed that fine breakage and sliding progress in a chain around the spike, the effect of the spike disappears, and the cured adhesive in the micron-order recess is in a state where it floats about several tens of nanometers from the inner surface of the recess. .

  In this case, in order to prevent the chain from being transmitted to the surrounding micron-order concavo-convex portions, the floated distance does not become more than several tens of nanometers and stops at the looseness. The stopping conditions are as follows: (I) The concave shape is an under shape and the opening is narrower than the internal diameter, or the direction in which the opening of the concave portion faces is tilted by several tens of degrees from the direction in which the force is applied. And (II) that the center part of the adhesive cured product (convex part) contained in the concave part does not collapse and does not break. Based on this, the present inventors have proposed the hypothesis of the following destruction mechanism.

  In other words, since the recesses on the surface of the metal alloy are obtained by a chemical etching method, the recesses are not simple hemispherical shapes, that is, bowl-shaped recesses whose openings are narrower than the inside, and the recess opening direction is not vertical but oblique There is a so-called under-shaped recess having a high probability. When an adhesive in which a filler having a particle size of several tens to several hundreds of nanometers penetrates into such under-shaped recesses and solidifies, the cured adhesive present in these recesses is easily shattered. It is thought that it will not be destroyed. For example, when a strong peeling force in the direction of an arrow is applied, it is assumed that there is a concave portion where the effectiveness of the spike has fallen, and the concave portion where the effectiveness of the spike has fallen is an under-shaped concave portion as described above.

  The cured adhesive in the recess is not fixed and can no longer function as an anchor, but does not come off completely and is caught by the mouth of the recess and floats only tens of nanometers. That is, when the concave portion has an under structure, it stops without coming off unless the central portion of the cured adhesive in the concave portion is largely broken. For example, even if an ultra-fine concave part in a specific micron-order concave part is in a situation where the anchor does not work and it has a shape that floats several tens of nanometers, the entire cured adhesive is somewhat elastic, so the surrounding micron order The concave portion does not float by being pulled by the destruction in the specific micron-order concave portion. In other words, it is a hypothesis that even if the effect of spikes disappears and a destruction phenomenon occurs, it is difficult to proceed to chain destruction once it stops at this level of destruction. In other words, it is also an idea that momentary strong force can be absorbed by the occurrence of floating (backlash) of about several tens of nanometers in a part of innumerable micron-order recesses. A filler to be added was selected according to this hypothesis and a verification test was conducted.

  In view of the structure of the metal alloy surface, the combined use of an inorganic filler having a diameter of 1 μm to several μm and an ultrafine inorganic filler having a diameter of 100 nm or less is preferable. That is, the former penetrates into irregularities forming a micron-order roughness, and the latter penetrates into ultrafine irregularities to prevent destruction of the cured adhesive.

  Here, fumed silica is easily available from the market as an ultrafine inorganic filler having a particle size of 100 nm or less. There are two types of fumed silica, one is ultra-fine fused silica recovered from the exhaust gas of the reduction process to obtain metallic silicon from silica (silicon oxide), and another is supplied by European companies. Is a material which is vaporized silicon tetrachloride and burned to form ultrafine fused silica, which is usually referred to as Aerosil. The latter is higher in purity and more stable in product, and a spherical product having a diameter of 15 to 25 nm is usually obtained. If the diameter of the aerosil is as described above, it is difficult to sufficiently penetrate into the ultra-fine irregularities having a period of several tens of nanometers, but some of them can penetrate, and if the period is larger (approximately 50 nm or more) ) Enough invasion can be expected. Moreover, even if the penetration is insufficient, it is useful for maintaining the central portion of the cured adhesive (convex portion) together with the inorganic filler having a diameter of 1 μm to several μm.

  Fine powders smaller than the micron order are usually agglomerated, and the actual state of ultrafine powders such as Aerosil is also an agglomerated product. Therefore, an expected dispersion state cannot be obtained by mixing with an adhesive and mixing and kneading in an automatic mortar. After mixing, it must be applied to a full-fledged dispersing machine. This will be described later. Further, the effect of addition became clear when the filling rate (composition ratio) of the ultrafine inorganic filler was 0.1% by mass or more. On the other hand, when the addition rate of the ultrafine inorganic filler is 1% by mass or more, the reason is not known, but the adhesive force may be saturated and warped to decrease.

  On the other hand, examples of the inorganic filler having a diameter of 1 μm or more include talc, calcium carbonate, clay, glass flake, glass balloon, magnesium carbonate, silica and the like. The effect of addition of this inorganic filler became clear by adding 1.0% by mass or more. In addition, it is also preferable to add an elastomer component. This is because the elastomer component can be a relaxation agent when subjected to temperature impact or mechanical impact. As the elastomer component, uncured rubber, polyolefin resin, polyamide resin, powders of other thermoplastic resins, and the like can be used in addition to powders of cured products of thermosetting resins such as powder rubber. In order not to lower the adhesive strength by the addition of the elastomer component, the addition amount is preferably 10% by mass or less. In particular, it is preferable to add 5% by mass or less of a thermoplastic resin from the viewpoint of maintaining at least adhesive strength.

  In addition, addition of a filler is also preferable from the following viewpoints. When the thickness of the adhesive layer after solidification is very thin, that is, in the case of adhesion between metal alloy plates, adhesion between the metal alloy plate and uncured FRP, etc., the linear expansion coefficient of the adhesive layer is the final product. Does not significantly affect durability. However, when the thickness of the adhesive layer after curing is thick, for example, when bonding between metal alloys but there is a gap between the metal alloys, or bonding between the metal alloy and already hardened FRP or other hard adherends In the case of performing the above, if the linear expansion coefficient of the adhesive layer is too different from the surroundings, the durability with time after bonding tends to deteriorate. It is preferable to reduce the linear expansion coefficient by adding a filler to the adhesive used in such a case.

  From the above, the adhesive composition is summarized. That is, the unsaturated polyester adhesive used in the present invention requires (1) an unsaturated polyester resin and / or vinyl ester resin, (2) a vinyl monomer, and (3) an organic peroxide. In order to further improve the adhesive force, it is preferable to add (6) a filler. An essential component as the filler is that the inorganic filler having a diameter of 1 μm or more is contained 1% by mass or more and 0.1 to 1.0% by mass of the ultrafine inorganic filler having a diameter of 100 nm or less. Furthermore, (6) as described above, it is preferable that CNT is contained in an amount of 0.2% by mass or less, particularly 0.06 to 0.1% by mass, and the elastomer component is 10% by mass or less, preferably heat. You may make it add 5 mass% or less of plastic resins.

[Dispersing method of filler]
When the composition of the unsaturated polyester adhesive is (1) unsaturated polyester resin and / or vinyl ester resin, (2) vinyl monomer, (3) organic peroxide, and (6) filler. (6) Dispersion of the filler is required.

  The present inventors have already practiced the addition and dispersion of commonly used inorganic fillers with epoxy adhesives. However, it is actually not easy to add and disperse the inorganic filler with the unsaturated polyester resin. This is because the liquid mixture of the unsaturated polyester resin and the monomer, or the liquid mixture of the vinyl ester resin and the monomer, which is the main liquid of the unsaturated polyester adhesive, has a lower viscosity than the epoxy resin. Even when an inorganic filler was blended into the main liquid and kneaded thoroughly, the inorganic filler settled after standing for several days.

  Epoxy resins that do not contain low-viscosity monomers are relatively easy to mix and disperse inorganic fillers. Specifically, automatic mortars are used, but automatic mortar techniques are commonly used in unsaturated polyester main liquids. I did not. Therefore, difficulties were felt from the formulation of common-sense inorganic fillers. This could be overcome using the latest high speed disperser, the sand grind mill, the latest wet grinder. Actually, the unsaturated polyester main liquid in which fine talc having a particle size center of about 10 μm was dispersed using this wet pulverizer was a transparent material that did not cause sedimentation and remained cloudy even when left at room temperature for 1 month. . Using this sand grind mill, an improvement in adhesive strength was confirmed using an unsaturated polyester main liquid containing an inorganic filler.

  Moreover, since the ultrafine inorganic filler with a diameter of 10 to 100 nm is also used in combination as described above, dispersion of this becomes a problem. Ultrafine inorganic fillers such as fumed silica are usually agglomerated into particles with a diameter of several μm, which definitely needs to be dispersed using a state-of-the-art wet pulverizer. Since the unsaturated polyester adhesive itself is not common, it can be said that it is a new attempt to disperse these ultrafine powders in the unsaturated polyester adhesive and see the effect. According to the results, both the addition of the inorganic filler having a particle size of 1 μm or more and the newly added ultrafine particles having a particle size of 100 nm or less had the effect of improving the adhesive force.

  The method for dispersing the filler will be described in detail below. The latest media mill, for example, a sand grind mill that uses zirconia beads with a particle size of 0.5 mm or less and zirconia for the case is prepared, and the liquid outlet of this mill is poured into a release container from a pipe. A conduit from the bottom of the vessel is connected to the mill inlet via a small volume pump to form a circulation line. The capacity of the open container is about the same as or larger than the mill capacity, and the stirring blades are submerged to allow low-speed stirring. After that, the inside of the mill is filled with the liquid, and the liquid is filled in the open container so that the liquid can be sufficiently stirred by the stirring blade. Thereafter, when the small capacity pump is driven and the liquid fills the circulation line, the mill and the agitator are driven. If the mill outlet liquid disappears and becomes a transparent liquid, it is evidence that the air in the mill has escaped. Then, the powder is poured into an open container and the wet grinding and circulation are continued. Since the mill generates heat, the mill mantle is water-cooled as necessary while monitoring the temperature.

  In the present invention, the main liquid (there are many commercially available products) which is a mixture of the above-mentioned (1) unsaturated polyester resin and / or vinyl ester resin and (2) vinyl monomer is initially filled as a liquid, 6) The filling material is poured into the open container. When inorganic powder is used as the filler, it can be visually observed that the liquid in the open container becomes transparent and the dispersion progresses while the circulating pulverization is progressed for several tens of minutes.

  There is a method of measuring how far the dispersion has progressed based on the theory of dynamic light diffusion or light diffusion of laser light, and various analyzers are commercially available. If you know the dispersion state well, you can tell if the powder in the liquid has been released from aggregation or in the middle. These analyzers were also used by the present inventors, but in a thin dispersion having a concentration in the liquid of 0.5% or less, a titanium white (usually, titanium oxide powder having a particle size of 20 to 40 μm) dispersion is A certain particle size distribution was detected, but I knew that Aerosil had a problem in generality of measurement, such as not detecting the presence of fine particles at all. On the other hand, the dispersion state of fine talc and fine clay having a concentration in the liquid of several percent and an average particle diameter of several tens μm could be detected by the analyzer. Eventually, the inventors stopped relying on the dispersity measuring device. The operating conditions of the sand grind mill (bead diameter used, bead input amount, rotor peripheral speed, liquid temperature, flow rate of the small capacity pump for circulation) were fixed, and both inorganic filler and ultrafine inorganic filler were added. Wet pulverization is continued for a certain period of time, and a certain amount of a predetermined curing agent is added to the obtained sample to create an adhesive, a predetermined sample (made NAT-processed A7075 pieces) is joined, and it is broken. We decided to compare the breaking force and see the effect. In short, an attempt was made to see whether or not there was an effect in the result theory after determining the processing conditions.

  In any case, fine talc or fine clay with an average particle diameter of 10 to 20 μm and unsaturated polyester resin main liquid can be treated for 30 minutes with an average operation of a sand grind mill, and can be made into a transparent liquid. However, no sediment was observed. It is not known whether or not the agglutination of Aerosil was solved under the same conditions, but the present inventors assumed that the same operating conditions as described above were extended by 30 minutes and dispersed as much as possible to 60 minutes. When the elastomer filler is also used, the inventors put the ultrafine inorganic filler (Aerosil), the inorganic filler, and the pre-filler of the elastomer filler into the sand grind mill and drive the grinding chamber for about 1 hour. Mixed and dispersed. Using a wet pulverizer, etc., once obtain a liquid that does not cause sediment, and store in a container. By being able to do this, the liquid is taken out from the storage container when necessary, and an adhesive is obtained by adding and mixing a curing agent which is an organic peroxide. Since the addition and mixing of the curing agent has a low liquid viscosity, it is not necessary to use a kneader. It can be used by mixing for several tens of seconds with a glass rod.

[Adhesive application and pretreatment]
The unsaturated polyester-based adhesive composition obtained by the above-described method is applied to a necessary portion of the metal alloy piece. Brush painting or spatula painting may be used. The coated metal alloy piece is put into a vacuum vessel or a pressure vessel, and the pressure is reduced to about 50 mmHg for several seconds. Thereafter, it is preferable that air is introduced to return to normal pressure, or the pressure is set to several atmospheric pressure or several tens of atmospheric pressure. Furthermore, it is preferable to repeat the cycle of pressure reduction and pressure increase. The air between the adhesive and the metal alloy escapes under reduced pressure, and the adhesive easily penetrates into the ultra-fine irregularities on the surface of the metal alloy when returned to normal pressure. In actual mass production, using high-pressure air using a pressure vessel leads to increased costs both in terms of equipment and costs. Therefore, use a bag or vacuum vessel that is more airtight than that. It is economical to perform the return several times. Then, it is preferable to take out the metal alloy from the bag or container, place it in a storage place at a temperature below room temperature, and enter the next step within a short time.

[Substrate]
A metal alloy can be used as the adherend, and the metal alloys can be bonded to each other. An FRP prepreg having an unsaturated polyester resin or vinyl ester resin as a matrix can also be used as the adherend. In the following example, an example in which an unsaturated polyester resin is used as a matrix will be described. Naturally, a vinyl ester resin can also be used. FRP molding methods include hand lay-up method, spraying method, vacuum bag method, pressure bag method, cold press method, resin injection method, matched die molding method, SMC molding method, BMC molding method, prepreg molding method, filament winding There are a wide variety of laws and others. If the molding method does not use a mold, such as a hand lay-up method, spraying method, or fermentation winding method, apply the adhesive before applying the FRP composition (ie, unsaturated polyester resin) to the reinforcing fiber. By fixing the finished metal alloy pieces and the reinforcing fibers in advance, both can be easily joined after application of the FRP composition.

  In the case of a fast curing room temperature curing molding method such as a hand lay-up method, even if FRP is cured, the unsaturated polyester content (adhesive layer) on the metal alloy piece has not yet been sufficiently cured. Therefore, since the adhesive force is also weak, it is preferable to post-cure the adhesive part by at least partially heating after releasing the mold well so as not to peel off from the inner mold. Other molding methods are a method using a mold and an airtight sheet in combination, and are also a heat curing method. By inserting a metal alloy piece coated with an adhesive in the mold in advance, the adhesive and the FRP are inserted. Can be cured together. However, when comparing the adhesive composition and the unsaturated polyester resin composition of FRP as the adherend, the latter is more easily cured. Even under conditions where the FRP side is sufficiently cured, the adhesive composition is often insufficiently cured. Therefore, it is desirable to subject the obtained metal alloy and FRP integrated product to a post-curing treatment such as heating in a hot air dryer at about 100 ° C. for 24 hours.

  The SMC molding method and the prepreg molding method are methods for creating SMC or prepreg as an uncured or slightly cured FRP. SMC and prepreg are intermediate products and can be stored in a refrigerator or the like. That is, an intermediate product in an uncured state or a slightly cured state needs to be obtained in a stable state. Among the compositions for SMC and prepreg, among (1) to (6) described in the previous section, (1) unsaturated polyester resin, (2) vinyl monomer, (3) curing agent, (5) glass fiber Etc. are included at least.

  SMC (5) is a product in which short glass fibers are usually used as reinforcing fibers, and a component in which these (1) to (5) are mixed is sandwiched between upper and lower polyolefin films to form a sheet. The necessary components are contained in a film, and the sticky tactile sensation and odor of styrene are sealed, so that SMC is easy to transport and store. On the other hand, (5) glass fiber nonwoven fabric or woven fabric is usually used as the prepreg. Although it is often transported and stored by being covered with a polyethylene film, the stickiness itself is originally composed of a small amount.

  That is, both SMC and prepreg (1) Use a high melting point material for unsaturated polyester, (2) As a vinyl monomer, in the case of prepreg, reduce styrene and use many high boiling point monomers such as diallyl phthalate, Furthermore, (6) a method of using an oxide or hydroxide of a divalent metal such as magnesium or calcium as a filler and linking the unsaturated polyester molecule end carboxylic acids together to reduce stickiness is frequently used. Since SMC and prepreg are in sheet form, in order to obtain an adherend with the desired dimensions and structure, first cut it into an appropriate shape, peel off the cover film, stack the contents, adjust the thickness, Close and heat cure.

  While it is preferred to use FRP composition sets that are recipe-tuned for each molding method from many companies, it is preferred to use them, but it should be noted that with respect to the present invention, it is already mixed with the commercially available FRP composition. It is an internal mold release agent. In mass production molding of FRP, there is always an interest in how to release the mold smoothly, and the mold release agent is an important molding factor. That is, the mold release agent includes an external mold release agent that is applied to the mold surface before molding and an internal mold release agent that is added in advance to the composition itself.

  When adopting the FRP molding joining method in which the metal alloy piece is inserted into the mold, it is natural that the metal alloy piece is inserted after spraying the release agent into the mold. In addition, when using a commercially available FRP composition set that contains an internal mold release agent in advance, it is better to prepare an FRP composition set that does not contain an internal mold release agent and perform a comparison test with this. The present inventors believe that the internal mold release agent should be used in the smallest possible amount.

  As described above in detail, the present invention can bond and bond the same kind of metal alloys, different metal alloys, or a metal alloy material and GFRP via an unsaturated polyester-based adhesive. It is possible to provide the joined body. In addition, since the metal alloy and the GFRP can be firmly bonded with an adhesive, the excellent characteristics of the metal alloy and the GFRP can be achieved in terms of the strength and physical properties of the entire component. For example, by increasing the volume ratio of GFRP in a part, it is possible to reduce the weight of the part as a whole. By using a metal alloy for the end part or coupling part of the part, Welding is possible and assembly can be facilitated. If the design is devised, it will open the way to common parts that can be mass-produced.

  In other words, the design control of the metal alloy surface is precisely controlled, and the content of the unsaturated polyester-based thermosetting resin composition is devised to give the reaction properties similar to those of a one-component thermosetting adhesive. As a result, the adhesive strength between the metal alloy and the GFRP could be dramatically increased. Regarding a method for producing a similar metal alloy-resin bonded body, the present inventors have already disclosed a new adhesion technique between a metal alloy and CFRP, that is, FRP using an epoxy resin as a matrix. In the present invention, the technique is further developed for adhesion to FRP using an unsaturated polyester resin as a matrix.

  By changing the resin type from an epoxy type to an unsaturated polyester type, it has become possible to use GFRP, which is cheaper than CFRP, as an adherend. GFRP is not a high-performance material because it is weaker and has a higher specific gravity than CFRP, but it is used in a much wider range than CFRP and is inexpensive. That is, it is possible to bond an adhesive between a relatively inexpensive metal alloy and an inexpensive GFRP, such as a general steel material and GFRP, and a stainless steel and GFRP. As described above, since the solidified product of unsaturated polyester resin has an advantage of excellent durability, the joined body obtained by this is inexpensive and can be used in outdoor facilities, outdoor buildings, or disasters. It becomes very useful as a part such as a temporary structure. Specific examples are likely to be useful in the production of canopies, outdoor fences, outdoor benches and exterior products. In addition, a joined body of titanium alloy, stainless steel, or aluminum alloy and GFRP is lighter than an all-metal part, and is also useful as a structural part for trains, ships, bicycles, and other mobile machines. As described above, the present invention is a basic technology that greatly contributes to the improvement of versatility and economy in the field of manufacturing structural parts, and can be expected to be applied to various uses.

FIG. 1 is a cross-sectional view schematically showing a firing jig for bonding a metal piece and an FRP uncured product with an unsaturated polyester adhesive and curing them in a hot air dryer. FIG. 2 is an external view showing an adhesive composite in which a metal piece and GFRP are joined with an unsaturated polyester adhesive. FIG. 3 is an external view showing an adhesive composite in which metal pieces are bonded to each other with an unsaturated polyester adhesive. FIG. 4 is a schematic partial cross-sectional view showing a theoretical configuration (NAT theory) to be bonded by using a thermosetting adhesive. FIG. 5 is a 10,000 times and 100,000 times electron micrograph of an A7075 aluminum alloy piece etched with a caustic soda solution and finely etched with a hydrated hydrazine solution. FIG. 6 is a 10,000 times and 100,000 times electron micrograph of an A5052 aluminum alloy piece etched with a caustic soda aqueous solution and finely etched with a hydrated hydrazine aqueous solution. FIG. 7 is a 100,000 times electron micrograph of an AZ31B magnesium alloy piece etched with an organic carboxylic acid aqueous solution and subjected to chemical conversion treatment with a potassium permanganate aqueous solution. FIG. 8 is a 100,000 times electron micrograph of an AZ31B magnesium alloy piece etched with an organic carboxylic acid aqueous solution and subjected to chemical conversion treatment with a potassium permanganate aqueous solution. FIG. 9 is a 10,000 times and 100,000 times electron micrograph of an AZ91D magnesium alloy piece etched with an organic carboxylic acid aqueous solution and subjected to chemical conversion treatment with a potassium permanganate aqueous solution. FIG. 10 is a 10,000 times and 100,000 times electron micrograph of a C1100 tough pitch copper piece etched with sulfuric acid / hydrogen peroxide aqueous solution and oxidized with sodium chlorite aqueous solution. FIG. 11 is a 10,000 times and 100,000 times electron micrograph of a C5191 phosphor bronze piece etched with sulfuric acid / hydrogen peroxide aqueous solution and oxidized with sodium chlorite aqueous solution. FIG. 12 is a 10,000 times and 100,000 times electron micrograph of a KFC copper alloy piece etched with sulfuric acid / hydrogen peroxide aqueous solution and oxidized with sodium chlorite aqueous solution. FIG. 13 is a 10,000 times and 100,000 times electron micrograph of a KLF5 copper alloy piece etched with a sulfuric acid / hydrogen peroxide aqueous solution and oxidized with a sodium chlorite aqueous solution. FIG. 14 is a 10,000 times and 100,000 times electron micrograph of a KS-40 titanium alloy piece etched with an aqueous solution of 1 hydrogen ammonium difluoride. FIG. 15 is a 10,000 times and 100,000 times electron micrograph of a KSTi-9 titanium alloy piece etched with an aqueous solution of 1 hydrogen ammonium difluoride. FIG. 16 is a 10,000 times and 100,000 times electron micrograph of a SUS304 stainless steel piece etched with a sulfuric acid aqueous solution. FIG. 17 is a 10,000 times and 100,000 times electron micrograph of SPCC cold-rolled steel pieces etched with a sulfuric acid aqueous solution and subjected to chemical conversion treatment with a potassium permanganate aqueous solution. FIG. 18 is a 10,000 times electron micrograph of a Z18 galvanized steel sheet piece etched with a sulfuric acid aqueous solution and subjected to chemical conversion treatment with a zinc phosphate aqueous solution. FIG. 19 is a 100,000 times electron micrograph of a Z18 galvanized steel sheet piece etched with a sulfuric acid aqueous solution and subjected to chemical conversion treatment with a zinc phosphate aqueous solution. FIG. 20 is a 10,000 times electron micrograph of a Z18 galvanized steel sheet piece etched with a sulfuric acid aqueous solution and subjected to chemical conversion treatment with a zinc calcium phosphate aqueous solution. FIG. 21 is a 100,000 times electron micrograph of a Z18 galvanized steel sheet piece etched with a sulfuric acid aqueous solution and subjected to chemical conversion treatment with a zinc calcium phosphate-based aqueous solution. FIG. 22 is a 10,000 times electron micrograph of a Z18 galvanized steel sheet piece etched with a sulfuric acid aqueous solution and subjected to a chromate conversion treatment. FIG. 23 is a 100,000 times electron micrograph of a Z18 galvanized steel sheet piece etched with a sulfuric acid aqueous solution and subjected to chromate conversion treatment.

  Hereinafter, embodiments of the present invention will be described by way of examples. FIG. 1 is a cross-sectional view showing a firing jig 1 for bonding a metal alloy piece and FRP. FIG. 2 is an external view showing the metal alloy / resin composite 10 produced by firing the metal alloy piece 11 and the GFRP plate 12 with the firing jig 1. FIG. 2 is also a diagram showing an example of the structure of a test piece for measuring the shear breaking strength by applying both ends to a tensile tester.

  A firing jig 1 shown in FIG. 1 is a fixing jig for firing a metal alloy piece 11 and a GFRP plate material 12. The mold body 2 has an open upper surface and a mold recess 3 formed in a rectangular shape. A mold through hole 4 is formed at the bottom.

  A bottom plate protrusion 6 of a mold bottom plate 5 is inserted into the mold through hole 4. The bottom plate protrusion 6 protrudes from the mold bottom surface 7 of the mold body 2. The bottom surface of the mold body 2 is mounted on the mold base 8. With the mold bottom plate 5 inserted and placed in the mold recess 3 of the mold body 2, the metal alloy / resin composite 10 in which the metal alloy piece 11 and the GFRP plate 12 are joined as shown in FIG. To manufacture. In general, the metal alloy / resin composite 10 is manufactured by the following procedure. First, a release film 17 is laid on the entire upper surface of the mold bottom plate 5. The metal alloy piece 11 and the plate-like spacer 16 are placed on the release film 17. A required GFRP plate 12 is laminated on the spacer 16 and the end of the metal alloy piece 11. The GFRP plate 12 is obtained by cutting and stacking the prepreg described above into a predetermined shape.

  After the lamination of the GFRP plate 12, a release film 13 is further laminated on the metal alloy piece 11 and the GFRP plate 12. On top of this, PTFE (polytetrafluoroethylene resin) PTFE blocks 14 and 15 are placed as weights. Furthermore, if necessary, a several hundred g weight (not shown) is placed thereon. In this state, the GFRP is allowed to cool by allowing it to cool, and after removing the weight, the pedestal 8 and the like and pressing the lower end of the bottom plate projection 6 against the floor surface, the bottom plate projection 6 is brought to the floor surface. Only the mold body is pressed down, and the metal alloy / resin composite 10 (see FIG. 2) in which the metal alloy pieces and GFRP are joined together with the release films 13 and 17 can be taken out. Since the spacer 16 and the release films 13 and 17 are non-adhesive materials, they can be easily peeled off from the GFRP.

  In this example, 0.05 mm polyethylene film was cut into strips to form the release films 13 and 17 described above. In addition, PTFE blocks 14 and 15 were placed as pressers, and an iron weight was placed thereon. Then, the entire mold was put into a hot air dryer and energized, and the temperature was raised to 90 ° C. The mixture was heated at 90 ° C. for 1 hour, further heated to 150 ° C. over 5 minutes, held at 150 ° C. for 30 minutes, and then the entire mold was taken out of the hot air dryer and allowed to cool. The molded product was released from the mold the next day, and the release films 13 and 17 were peeled off to obtain the metal alloy / resin composite 10 shown in FIG. This composite was again placed in a hot air dryer and allowed to cure at 100 ° C. for 24 hours.

  FIG. 3 is a view showing an example of the structure of the adhesive composite 20 which is a test piece for measuring the adhesive force obtained by joining the metal alloy pieces 21 and 22 with the unsaturated polyester adhesive and joining the joint 23.

  FIG. 4 schematically shows a cross-sectional view of the surface of the metal alloy and the cured adhesive in NAT. 30 is a metal alloy phase, 31 is the surface, and is a ceramic metal oxide or metal. It is a hardened surface thin film layer mainly composed of phosphorous oxide. And 32 is the hardened | cured material phase of an adhesive agent, and is a hardened | cured material of an unsaturated polyester type composition in this invention.

Next, an experimental example relating to adhesion between a metal alloy and an adherend will be described. The equipment used is shown below.
[X-ray surface observation (XPS observation)]
ESCA “AXIS-Nova (Kraitos (USA) / Shimadzu Corporation (Kyoto Prefecture, Japan))” in the form of observing constituent elements on a surface having a diameter of several μm in a depth range of 1 to 2 nm was used.
[Electron beam surface observation (EPMA observation)]
An electron beam microanalyzer “EPMA 1600 (manufactured by Shimadzu Corporation)” in the form of observing constituent elements in a range of several μm diameter to a depth of several μm was used.
[Electron microscope observation]
An SEM type electron microscope “JSM-6700F (manufactured by JEOL Ltd., Tokyo, Japan)” was used and observed at 1 to 2 KV.
[Scanning probe microscope observation]
“SPM-9600 (manufactured by Shimadzu Corporation)” was used. This is a dynamic force mode scanning probe microscope.
[Measurement of bonding strength of composite]
Using a tensile tester “MODEL-1323 (manufactured by Aiko Engineering Co., Ltd. (Osaka, Japan))”, the shear breaking force was measured at a pulling speed of 10 mm / min.
[Dispersion of filler (use of wet pulverizer)]
A sand grind mill “Tsuair (manufactured by Ashizawa Finetech Co., Ltd., Tokyo, Japan)” using zirconia beads having a diameter of 0.1 to 0.5 mm as a sand was used.
[Measurement of inorganic powder dispersion in liquid]
A “Microtrack particle size distribution measuring device MT330II (manufactured by Nikkiso Co., Ltd., Tokyo, Japan)” in the form of measuring particle size distribution by laser diffraction / scattering method (microtrack method) using a plurality of lasers was used.

Next, each experimental example will be described for each type of metal piece.
[Experimental Example 1] (A7075 aluminum alloy piece surface treatment)
A commercially available 3 mm thick A7075 plate was obtained and cut to produce a large number of 45 mm × 18 mm rectangular A7075 pieces. Water was prepared in a tank, and a commercially available aluminum alloy degreasing agent “NE-6 (manufactured by Meltex Co., Ltd., Tokyo, Japan)” was added to form an aqueous solution at 60 ° C. and a concentration of 7.5%. The A7075 pieces were immersed in this for 7 minutes and washed thoroughly with water. Subsequently, a 1% concentration hydrochloric acid aqueous solution at 40 ° C. was prepared in another tank, and the A7075 piece was immersed in it for 1 minute and washed with water.

  Next, a 1.5% strength aqueous solution of caustic soda at 40 ° C. was prepared in another tank, and the A7075 piece was dipped for 4 minutes and washed with water. Subsequently, a 3% concentration nitric acid aqueous solution at 40 ° C. was prepared in another tank, and the A7075 piece was immersed in this for 1 minute and washed with water. Next, an aqueous solution containing 3.5% monohydric hydrazine at 60 ° C. was prepared in another tank, and the A7075 pieces were immersed in the solution for 2 minutes and washed with water. Further, a 5% hydrogen peroxide aqueous solution was set to 40 ° C., and the A7075 pieces were immersed in this for 5 minutes and washed with water.

  Next, the A7075 piece was put in a hot air dryer at 67 ° C. for 15 minutes and dried. After drying, the A7075 pieces were wrapped together with aluminum foil, and further sealed in a plastic bag for storage. When one of the stored ones was observed with an electron microscope, it was found to be covered with a recess having a diameter of 40 to 100 nm. An electron micrograph is shown in FIG. 5 (top: 10,000 times, bottom: 100,000 times). The roughness data was obtained by scanning probe microscope. According to this, the peak / valley average interval (RSm) was 3 to 4 μm, and the maximum height roughness (Rz) was 1 to 2 μm.

[Experimental Example 2] (Surface treatment of A5052 aluminum alloy piece)
A commercially available 1.6 mm thick A5052 plate was obtained and cut to create a large number of 45 mm × 18 mm rectangular A5052 pieces. Water was prepared in a tank, and a commercially available aluminum alloy degreasing agent “NE-6 (manufactured by Meltex Co., Ltd.)” was added to form an aqueous solution at 60 ° C. and a concentration of 7.5%. The A5052 piece was immersed in this for 7 minutes and washed thoroughly with water. Subsequently, a 1% hydrochloric acid aqueous solution adjusted to 40 ° C. was prepared in another tank, and the A5052 pieces were immersed in this for 1 minute and washed with water.

  Next, a 1.5% strength aqueous solution of caustic soda at 40 ° C. was prepared in a separate tank, and the A5052 piece was dipped for 2 minutes and washed with water. Subsequently, a 3% nitric acid aqueous solution with a temperature of 40 ° C. was prepared in another tank, and the A5052 pieces were immersed in this for 1 minute and washed with water. Next, an aqueous solution containing 3.5% monohydric hydrazine at 60 ° C. was prepared in another tank, and the A5052 pieces were immersed in this for 2 minutes and washed with water.

  Next, the A5052 piece was put in a hot air dryer at 67 ° C. for 15 minutes and dried. After drying, the A5052 pieces were wrapped together with aluminum foil, and further sealed in a plastic bag for storage. When one of the stored ones was observed with an electron microscope, it was found that the surface was covered with a recess having a diameter of 30 to 100 nm. An electron micrograph is shown in FIG. 6 (top: 10,000 times, bottom: 100,000 times). . The roughness data was obtained by scanning probe microscope. According to this, the peak / valley mean interval (RSm) was 1-2 μm, and the maximum height roughness (Rz) was 0.3-0.5 μm.

[Experimental Example 3] (Surface treatment of AZ31B magnesium alloy piece)
A commercially available 1 mm-thick AZ31B plate was obtained and cut to create a large number of 45 mm × 18 mm rectangular AZ31B pieces. Water was prepared in a tank, and a commercially available magnesium alloy degreasing agent “Cleaner 160 (manufactured by Meltex Co., Ltd.)” was added to prepare an aqueous solution at 65 ° C. and a concentration of 7.5%. The AZ31B piece was immersed in this for 5 minutes and washed thoroughly with water. Subsequently, a 1% concentration hydrated citric acid aqueous solution at 40 ° C. was prepared in another tank, and the AZ31B piece was immersed in this for 6 minutes and washed with water.

  Next, an aqueous solution containing 1% concentration sodium carbonate and 1% concentration sodium hydrogen carbonate at 65 ° C. was prepared in another tank, and the above AZ31B piece was immersed in this for 5 minutes and washed with water. Subsequently, a 15% caustic soda aqueous solution at 65 ° C. was prepared in another tank, and the AZ31B piece was immersed in this for 5 minutes and washed with water. Next, a 0.25% strength hydrated citric acid aqueous solution at 40 ° C. was prepared in another tank, and the AZ31B piece was immersed in it for 1 minute and washed with water. Next, an aqueous solution containing 2% potassium permanganate at 45 ° C., 1% acetic acid and 0.5% hydrated sodium acetate was prepared, and the AZ31B piece was immersed in this for 1 minute and washed with water for 15 seconds.

  Next, the AZ31B piece was put in a warm air dryer at 90 ° C. for 15 minutes and dried. After drying, the AZ31B pieces were wrapped together with aluminum foil, and further sealed in a plastic bag for storage. Observation of one piece that had been stored using an electron microscope revealed that 5 to 10 nm diameter rod-shaped crystals were intertwined in a complex manner, and their lumps were gathered together with a diameter of about 100 nm, and these gatherings formed a surface. There was a part covered with an uneven shape. Electron micrographs (100,000 times) are shown in FIGS. Further, when the roughness was observed by scanning with a scanning probe microscope, the average interval between peaks and valleys as defined by JIS, that is, the average value (RSm) of the uneven period was 2 to 3 μm, and the maximum height roughness (Rz) was 1 to 1. It was 1.5 μm.

[Experimental Example 4] (Surface treatment of AZ91D magnesium alloy piece)
A rectangular AZ91D piece of 1 mm × 45 mm × 18 mm was machined out from a die-cast product of a magnesium alloy AZ91D for casting, and a number of AZ91D pieces were produced. Water was prepared in a tank, and a commercially available magnesium alloy degreasing agent “Cleaner 160 (manufactured by Meltex Co., Ltd.)” was added to prepare an aqueous solution at 65 ° C. and a concentration of 7.5%. The AZ91D piece was immersed in this for 5 minutes and washed thoroughly with water. Subsequently, a 1% -concentrated malonic acid aqueous solution at 40 ° C. was prepared in a separate tank, and the AZ91D piece was immersed in this for 2.25 minutes and washed with water.

  Next, an aqueous solution containing 1% sodium carbonate and 1% sodium hydrogen carbonate at 65 ° C. was prepared in another tank, and the AZ91D piece was immersed in this for 5 minutes and washed thoroughly with water. Subsequently, a 15% caustic soda aqueous solution at 65 ° C. was prepared in another tank, and the AZ91D piece was immersed in this for 5 minutes and washed with water. Next, a 0.25% concentration hydrated citric acid aqueous solution at 40 ° C. was prepared in another tank, and the AZ91D piece was immersed in this for 1 minute and washed with water. Next, an aqueous solution containing 2% potassium permanganate at 45 ° C., 1% acetic acid and 0.5% hydrated sodium acetate was prepared, and the AZ91D piece was immersed in this for 1 minute and washed with water for 15 seconds.

  Next, the AZ91D piece was put in a hot air dryer set at 90 ° C. for 15 minutes and dried. After drying, the AZ91D pieces were wrapped together with aluminum foil, and further sealed in a plastic bag for storage. When one of the pieces was observed with an electron microscope, it was covered with an ultra-fine irregular surface of lava plateau slopes that were stacked with 20-40 nm particle size and indefinite polygonal shapes by 100,000 times observation. It turned out to be a broken shape. The photograph is shown in FIG. 9 (top: 10,000 times, bottom: 100,000 times). Further, when the roughness was observed by scanning with a scanning probe microscope, the average interval between peaks and valleys as defined in JIS, that is, the average value (RSm) of the uneven period was 3 to 5 μm, and the maximum height roughness (Rz) was 1. It was 5 to 2.5 μm.

[Experimental Example 5] (Surface treatment of C1100 copper alloy piece)
A tough pitch copper (C1100) plate material, which is a commercially available 1 mm-thick pure copper-based copper alloy, was obtained and cut to produce a large number of 45 mm × 18 mm rectangular C1100 pieces. Water was prepared in a tank, and a commercially available aluminum alloy degreasing agent “NE-6 (manufactured by Meltex Co., Ltd.)” was added to form an aqueous solution at 60 ° C. and a concentration of 7.5%. The C1100 piece was immersed in this for 5 minutes and washed with water. Next, preliminary base washing was performed by immersing the C1100 piece in a 1.5% strength caustic soda solution at 40 ° C. for 1 minute and washing with water. Next, an aqueous solution containing 20% of an etching material for copper alloy “CB-5002 (MEC Co., Ltd. (Hyogo, Japan))” at 25 ° C. and 18% of 30% hydrogen peroxide was prepared. Was immersed for 10 minutes and washed with water.

  Next, an aqueous solution containing 10% of caustic soda at 65 ° C. and 5% of sodium chlorite was prepared as an oxidizing aqueous solution in another tank, and the C1100 piece was immersed for 1 minute and washed thoroughly with water. Next, it was immersed in the etching tank for 1 minute and washed with water, and then immersed in the oxidation treatment tank for 1 minute and washed with water. Subsequently, it put into the warm air dryer which was 90 degreeC for 15 minutes, and dried. After drying, the C1100 pieces were wrapped together with aluminum foil, which was then sealed in a plastic bag and stored.

  One piece stored was applied to a scanning probe microscope. As a result, the mean valley interval (RSm) in JIS was 3-7 μm, and the maximum height roughness (Rz) was 3-5 μm. Also, when observed with an electron microscope at 100,000 times, the average diameter or major axis and minor axis averaged 10-150 nm hole openings or recesses on the entire surface with irregular intervals of 30-300 nm. Was covered. The electron micrograph is shown in FIG. 10 (top: 10,000 times, bottom: 100,000 times).

[Experimental Example 6] (Surface treatment of C5191 copper alloy piece)
A commercially available phosphor bronze (C5191) plate material having a thickness of 0.8 mm was purchased and cut to produce a large number of 45 mm × 18 mm rectangular C5191 pieces. Water was prepared in the tank, and a commercially available aluminum alloy degreasing agent “NE-6 (manufactured by Meltex Co., Ltd.)” was added to prepare a degreasing aqueous solution at 60 ° C. and a concentration of 7.5%. The C5191 piece was immersed in this for 5 minutes for degreasing and thoroughly washed with water. Subsequently, an aqueous solution containing 20% of an etching agent for copper alloy “CB-5002 (made by MEC Co., Ltd.)” at 25 ° C. and 18% of 30% hydrogen peroxide was prepared in a separate tank, and the C5191 piece was added to this. It was immersed for 15 minutes and washed with water.

  Next, an aqueous solution containing 10% caustic soda and 5% sodium chlorite was prepared as an oxidizing aqueous solution in another tank, and the temperature of 65 ° C. was immersed in the C5191 piece for 1 minute and washed thoroughly with water. Next, it was again immersed in the previous etching solution for 1 minute and washed with water. Subsequently, it was immersed again in the aqueous solution for oxidation for 1 minute and washed with water. Next, the C5191 piece was placed in a hot air dryer at 90 ° C. for 15 minutes and dried. Further, after drying, the C5191 piece was wrapped in aluminum foil and stored.

  FIG. 11 shows a photograph of one piece that was stored with an electron microscope (upper 10,000 times, lower: 100,000 times). It is an ultra-fine concavo-convex shape in which projections with an average diameter or major axis and minor axis of 10 to 200 nm are mixed and present on the entire surface when observed at a magnification of 100,000 times, which is completely different from the microstructure of tough pitch copper, which is pure copper It was a shape. Moreover, when it applied to the scanning probe microscope, the mean interval (RSm) of the valleys and valleys said by JIS was 1-3 micrometers, and the maximum height roughness (Rz) was 0.3-0.4 micrometer.

[Experimental Example 7] (Surface treatment of KFC copper alloy piece)
A commercially available 0.7 mm thick iron-containing copper alloy “KFC (Kobe Steel Works, Japan)” plate was obtained and cut to produce a large number of 45 mm × 18 mm rectangular KFC pieces. An aqueous solution containing 7.5% of a commercially available aluminum alloy degreasing agent “NE-6 (manufactured by Meltex Co., Ltd.)” was prepared in a tank, and this was set to 60 ° C. The KFC pieces were immersed in this for 5 minutes and washed with water. Next, the KFC pieces were immersed in a 1.5% strength aqueous caustic soda solution at 40 ° C. for 1 minute and washed with water to perform preliminary base washing.

  Next, an aqueous solution containing 20% of an etching material for copper alloy “CB5002 (MEC Co., Ltd.)” at 25 ° C. and 18% of 30% hydrogen peroxide was prepared, and the KFC piece was immersed in this for 8 minutes and washed with water. . Next, an aqueous solution containing 10% caustic soda at 65 ° C. and 5% sodium chlorite was prepared as an oxidizing aqueous solution in another tank, and the KFC pieces were immersed in this for 1 minute and washed thoroughly with water. Next, the KFC piece was immersed in the etching tank for 1 minute and washed with water, and the KFC piece was immersed in the oxidation tank for 1 minute and washed with water. Next, the KFC pieces were placed in a warm air dryer at 90 ° C. for 15 minutes and dried. After drying, the KFC pieces were wrapped together with aluminum foil, which was then sealed in a plastic bag and stored.

  As a result of subjecting one of the stored samples to a scanning probe microscope, the mean valley interval (RSm) in JIS was 1 to 3 μm, and the maximum height roughness (Rz) was 0.3 to 0.5 μm. Further, when observed with an electron microscope at a magnification of 100,000, the entire surface was covered with an ultra-fine uneven shape existing on the entire surface by mixing convex portions having an average diameter or major axis and minor axis of 10 to 200 nm. An electron micrograph is shown in FIG. 12 (top: 10,000 times, bottom: 100,000 times).

[Experimental Example 8] (Surface treatment of KLF5 copper alloy piece)
A commercially available 0.7 mm-thick special copper alloy “KLF5 (manufactured by Kobe Steel, Ltd.)” plate material was obtained and cut to produce a large number of 45 mm × 18 mm rectangular KLF5 pieces. An aqueous solution containing 7.5% of a commercially available aluminum alloy degreasing agent “NE-6 (manufactured by Meltex Co., Ltd.)” was prepared in a tank, and this was set to 60 ° C. The KLF5 piece was immersed in this for 5 minutes and washed with water. Next, the KLF5 piece was immersed in a 1.5% strength aqueous caustic soda solution at 40 ° C. for 1 minute and washed with water to perform preliminary base washing.

  Next, an aqueous solution containing 20% of an etching material for copper alloy “CB5002 (MEC Co., Ltd.)” at 25 ° C. and 18% of 30% hydrogen peroxide was prepared, and the KLF5 pieces were immersed in this for 8 minutes and washed with water. . Next, an aqueous solution containing 10% caustic soda at 65 ° C. and 5% sodium chlorite was prepared as an aqueous solution for oxidation in another tank, and the KLF5 pieces were immersed in this for 1 minute and washed with water. Next, the KLF5 piece was immersed in the previous etching bath for 1 minute and washed with water, and the KLF5 piece was then immersed in the previous oxidation treatment bath for 1 minute and washed with water. Next, the KLF5 pieces were placed in a warm air dryer at 90 ° C. for 15 minutes and dried. After drying, the KLF5 pieces were wrapped together with aluminum foil, which was then sealed in a plastic bag and stored.

  One piece stored was applied to a scanning probe microscope. As a result, the mean valley interval (RSm) in JIS was 1 to 3 μm, and the maximum height roughness (Rz) was 0.3 to 0.5 μm. In addition, when observed with an electron microscope at a magnification of 100,000 times, a shape in which a particle having a diameter of 10 to 20 nm and an indefinite polygon having a diameter of 50 to 150 nm are mixed and stacked, so to speak, a lava plateau slope-like ultra-fine uneven shape It was almost entirely covered. An electron micrograph is shown in FIG. 13 (top: 10,000 times, bottom: 100,000 times).

[Experimental Example 9] (Surface treatment of KS40 titanium alloy piece)
A commercially available pure titanium type titanium alloy JIS type 1 “KS40 (manufactured by Kobe Steel, Ltd.)” 1 mm thick plate material was obtained and cut to produce a large number of 45 mm × 18 mm rectangular KS40 pieces. An aqueous solution containing 7.5% of a commercially available aluminum alloy degreasing agent “NE-6 (manufactured by Meltex Co., Ltd.)” was prepared in a tank, and this was adjusted to 60 ° C. to obtain a degreasing aqueous solution. The KS40 pieces were immersed in this degreasing aqueous solution for 5 minutes to degrease and washed thoroughly with water.

  Subsequently, in a separate tank, an aqueous solution containing 2% of a universal etching material “KA-3 (manufactured by Metallurgy Engineering Laboratory, Tokyo, Japan)” containing 40% of ammonium difluoride at 60 ° C. The KS40 pieces were dipped in this for 3 minutes and washed thoroughly with ion-exchanged water. Next, the KS40 pieces were immersed in a 3% concentration nitric acid aqueous solution for 1 minute and washed with water. Next, the KS40 pieces were placed in a warm air dryer at 90 ° C. for 15 minutes and dried. After drying, the KS40 pieces were wrapped together with aluminum foil, which was then sealed in a plastic bag and stored.

  One stored was observed with an electron microscope and a scanning probe microscope. From observations with an electron microscope, a shape in which curved continuous mountain-shaped protrusions having a width and height of 10 to several hundred nm and a length of several hundred to several μm stand on the surface with an interval period of 10 to several hundred nm. It was found to have an ultrafine uneven surface. This electron micrograph is shown in FIG. 14 (top: 10,000 times, bottom: 100,000 times). Moreover, by observation with a scanning probe microscope, the mean valley interval (RSm) was 1 to 3 μm, and the maximum height roughness (Rz) was 0.8 to 1.5 μm. Further, from the analysis by XPS, a large amount of oxygen and titanium were observed on the surface, and a small amount of carbon was observed. From these, it was found that the surface layer was composed mainly of titanium oxide, and because it was dark, it was estimated to be a trivalent titanium oxide.

[Experimental Example 10] (Surface treatment of KSTi-9 titanium alloy piece)
A 1 mm thick plate material of a commercially available α-β type titanium alloy “KSTi-9 (manufactured by Kobe Steel, Ltd.)” was cut to prepare a large number of 45 mm × 18 mm rectangular KSTi-9 pieces. An aqueous solution containing 7.5% of a commercially available aluminum alloy degreasing agent “NE-6 (manufactured by Meltex Co., Ltd.)” was prepared in a tank, and this was adjusted to 60 ° C. to obtain a degreasing aqueous solution. The KSTi-9 pieces were immersed in this degreasing aqueous solution for 5 minutes for degreasing and thoroughly washed with water.

  Next, an aqueous solution of 1.5% concentration of caustic soda at 40 ° C. was prepared in another tank, and the KSTi-9 piece was immersed in this for 1 minute and washed with water. Next, in another tank, an aqueous solution in which 2% by weight of a commercially available general-purpose etching reagent “KA-3 (manufactured by Metal Chemical Engineering Laboratory Co., Ltd.)” was dissolved was prepared at 60 ° C., and the KSTi-9 piece was added to this for 3 minutes. It was immersed and washed thoroughly with ion exchange water. Since the black smut was adhered to the KSTi-9 piece after washing with water, the smut was immersed in 3% nitric acid aqueous solution at 40 ° C. for 3 minutes and then immersed in ion-exchanged water subjected to ultrasonic waves for 5 minutes. Was again immersed in a 3% nitric acid aqueous solution for 0.5 minutes and washed with water. Next, the KSTi-9 pieces were placed in a hot air dryer at 90 ° C. for 15 minutes and dried. The KSTi-9 pieces after drying had no metallic luster and were dark brown. After drying, the KSTi-9 pieces were wrapped together with aluminum foil, which was then sealed in a plastic bag and stored.

  One piece stored was observed with an electron microscope and a scanning probe microscope. The results observed with an electron microscope are shown in FIG. 15 (top: 10,000 times, bottom: 100,000 times). In addition to the portion very similar to the electron microscopic observation photograph FIG. 14 of Experimental Example 9, many complex leaf-like portions were observed. Further, according to the scanning analysis by the scanning probe microscope, the average interval between peaks and valleys RSm was 4 to 6 μm, and the maximum height roughness Rz was 1 to 2 μm.

[Experimental Example 11] (Surface treatment of SUS304 stainless steel piece)
A commercially available 1 mm thick plate material of stainless steel SUS304 was obtained and cut to produce a large number of 45 mm × 18 mm rectangular SUS304 pieces. An aqueous solution containing 7.5% of a commercially available aluminum alloy degreasing agent “NE-6 (manufactured by Meltex Co., Ltd.)” was prepared in a tank, and this was adjusted to 60 ° C. to obtain a degreasing aqueous solution. The SUS304 piece was immersed in this degreasing aqueous solution for 5 minutes to degrease and washed thoroughly with water.

  Subsequently, an aqueous solution containing 10% of 98% sulfuric acid at 60 ° C. was prepared in another tank, and the SUS304 pieces were immersed in this for 5 minutes and washed thoroughly with ion-exchanged water. Next, the SUS304 piece was immersed in a 5% hydrogen peroxide aqueous solution at 40 ° C. for 5 minutes and washed with water. Thereafter, the SUS304 pieces were placed in a warm air dryer at 90 ° C. for 15 minutes and dried. After drying, the SUS304 pieces were wrapped together with aluminum foil, which was then sealed in a plastic bag and stored.

  One stored was observed with an electron microscope and a scanning probe microscope. From observation with an electron microscope, it is covered with a shape in which particles having a particle diameter of 20 to 70 nm and indefinite polygonal shapes are stacked, in other words, an ultra-fine uneven shape such as a lava plateau slope galley field, and the coverage is about 90 %Met. An electron micrograph is shown in FIG. 16 (top: 10,000 times, bottom: 100,000 times).

  At the same time, in the scanning analysis of the scanning probe microscope, the average interval between the valleys and valleys (RSm) was 1-2 μm, and the maximum height roughness (Rz) was 0.3-0.4 μm. Another one was subjected to XPS analysis. In XPS, element information of a portion shallower than the surface depth of about 1 nm can be obtained. From this XPS analysis, a large amount of oxygen and iron was observed on the surface, and a small amount of nickel, chromium, carbon, a very small amount of molybdenum and silicon were observed. From these, it was found that the metal oxide was the main component of the surface layer. This analysis pattern was almost the same as SUS304 before etching.

[Experiment 12] (Surface treatment of SPCC cold-rolled steel piece)
A commercially available 1.6 mm-thick cold-rolled steel “SPCC” plate was purchased and cut to produce a large number of 45 mm × 18 mm rectangular SPCC pieces. An aqueous solution containing 7.5% of a degreasing agent for aluminum alloy “NE-6 (manufactured by Meltex Co., Ltd.)” was prepared in a tank, and this was set to 60 ° C. SPCC pieces were immersed in this for 5 minutes and washed with tap water (Ota City, Gunma Prefecture).

  Next, a 1.5% aqueous solution of caustic soda at 40 ° C. was prepared in another tank, and the SPCC pieces were immersed in this for 1 minute and washed with water. Next, an aqueous solution containing 10% of 98% sulfuric acid at 50 ° C. was prepared in another tank, and the SPCC pieces were immersed in this for 6 minutes and sufficiently washed with ion-exchanged water. Then, the SPCC piece was immersed in 1% ammonia water at 25 ° C. for 1 minute and washed with water, and then at 45 ° C. 2% potassium permanganate, 1% acetic acid, 0.5% concentration It was immersed in an aqueous solution containing hydrated sodium acetate for 1 minute and thoroughly washed with water. Thereafter, the SPCC piece was placed in a warm air dryer at 90 ° C. for 15 minutes and dried.

  From the observation result of the SPCC piece with a 100,000 times electron microscope, the entire surface is covered with an ultra fine uneven shape having a height and depth of 80 to 200 nm and a width of several hundred to several thousand nm and followed innumerably. You can see that It can be seen that the pearlite structure is exposed and the chemical conversion treatment layer is very thin. An electron micrograph is shown in FIG. 17 (top: 10,000 times, bottom: 100,000 times). On the other hand, in the scanning analysis using the scanning probe microscope, roughness having a peak-valley average interval RSm of 1 to 3 μm and a maximum height roughness Rz of 0.3 to 1.0 μm was observed.

[Experimental Example 13] (Surface treatment of SPHC hot-rolled steel piece)
A commercially available 1.6 mm thick hot rolled steel “SPHC” plate was purchased and cut to produce a large number of 45 mm × 18 mm rectangular SPHC pieces. An aqueous solution containing 7.5% of a degreasing agent for aluminum alloy “NE-6 (manufactured by Meltex Co., Ltd.)” was prepared in a tank, and this was set to 60 ° C. SPHC pieces were immersed in this for 5 minutes and washed with tap water (Ota City, Gunma Prefecture).

  Next, a 1.5% aqueous solution of caustic soda at 40 ° C. was prepared in another tank, and the SPHC pieces were immersed in this for 1 minute and washed with water. Next, an aqueous solution containing 10% 98% sulfuric acid at 65 ° C. and 1% ammonium hydrogen fluoride and 1% was prepared in another tank, and the SPHC pieces were immersed in this for 2 minutes and washed thoroughly with ion-exchanged water. . Next, the SPHC piece was immersed in 1% aqueous ammonia at 25 ° C. for 1 minute and washed with water, and then at 55 ° C., 80% normal phosphoric acid was 1.5%, zinc white was 0.21%, silica fluoride. It was immersed in an aqueous solution containing 0.16% sodium chloride and 0.23% basic nickel carbonate for 1 minute and thoroughly washed with water. Thereafter, the SPHC pieces were placed in a warm air dryer at 90 ° C. for 15 minutes and dried.

  According to the observation result of the SPHC piece with a 100,000 times electron microscope, almost the entire surface is covered with an ultra fine concavo-convex shape having a height and depth of 80 to 500 nm and a width of several hundred to several tens of thousands of stairs. This was also a pearlite structure. On the other hand, in the scanning analysis using the scanning probe microscope, roughness having a peak-valley average interval RSm of 1 to 3 μm and a maximum height roughness Rz of 0.3 to 1.0 μm was observed.

[Experimental Example 14] (Surface treatment of Z18 galvanized steel sheet piece (1))
Obtain a 0.4 mm thick oil-coated hot-dip galvanized steel sheet “Z18 (manufactured by Nippon Steel & Sumikin Construction Co., Ltd.)”, cut it into 45 mm × 18 mm rectangular pieces, and obtain a number of Z18 pieces (1 )created. An aqueous solution containing 7.5% of an aluminum degreasing agent “NE-6 (manufactured by Meltex Co., Ltd.)” was prepared in a tank to a liquid temperature of 75 ° C., and this aqueous solution was used as a degreasing aqueous solution. In another tank, phosphoric acid containing 1.2% normal phosphoric acid at 55 ° C., 0.21% zinc white, 0.16% sodium silicofluoride, and 0.23% basic nickel carbonate. A zinc-based chemical conversion treatment solution was prepared. The Z18 piece (1) was first immersed in a degreasing tank for 5 minutes and washed with water. Subsequently, it was immersed in the chemical conversion treatment tank for 1 minute. Here, foaming of fine hydrogen bubbles was observed, and it was found that the zinc phase was dissolved and ionized with phosphoric acid. Therefore, it was found that this chemical conversion treatment serves as both “chemical etching” and “surface hardening treatment” by chemical conversion treatment. Dry at 90 ° C. for 15 minutes.

  The Z18 piece (1) was observed with an electron microscope and a scanning probe microscope. The observation results with a 10,000 times and 100,000 times electron microscope are shown in FIGS. From FIG. 19, it was found that the surface had an ultra-fine uneven shape covering the entire surface with overlapping convex portions of an indefinite polygonal shape having a diameter of 20 to 150 nm. In addition, the measurement results obtained by scanning the length of 20 μm with a scanning probe microscope 10 times were as follows. The mean valley interval RSm was 1.5 to 2.3 μm, and the maximum height roughness Rz was 0.5 to 1.5 μm. . Thus, the electron microscope observation results also show that the ultra-fine irregularities required by “NAT” have been achieved. In fact, “chemical etching”, “fine etching” and “surface hardening treatment” It was found that he played three roles at once. That is, since the first condition to the third condition are satisfied, there is no need to separately perform chemical etching and fine etching, and the surface treatment method contributes to process shortening and cost reduction.

[Experimental Example 15] (Surface treatment of Z18 galvanized steel sheet piece (2))
Obtain a 0.4 mm thick oil-coated hot-dip galvanized steel sheet “Z18 (manufactured by Nippon Steel & Sumikin Construction Co., Ltd.)” and cut it into 45 mm × 18 mm rectangular pieces to obtain a number of Z18 pieces (2 )created. An aqueous solution containing 7.5% of an aluminum degreasing agent “NE-6 (manufactured by Meltex Co., Ltd.)” was prepared in a tank to a liquid temperature of 75 ° C., and this aqueous solution was used as a degreasing aqueous solution. In another tank, a commercially available zinc calcium phosphate chemical conversion solution “Palbond 880 (manufactured by Nippon Parkerizing Co., Ltd. (Tokyo, Japan))” was used. The normal use conditions of Palbond 880 (use conditions during the chemical conversion treatment of steel materials) are to immerse the steel materials for about 2 minutes at a liquid temperature of 80 to 90 ° C, but in the present invention, they are used under much milder conditions. did. Specifically, the immersion time was 1 minute at a liquid temperature of 65 ° C. That is, the steel piece (2) was immersed in a degreasing bath for 5 minutes and thoroughly washed with tap water, then immersed in a chemical conversion treatment bath as described above, and then thoroughly washed with ion-exchanged water.

  The Z18 piece (2) was observed with an electron microscope and a scanning probe microscope. Observation results with an electron microscope of 10,000 times and 100,000 times are shown in FIGS. It turns out that it is the super fine uneven | corrugated shape which covered the whole surface, the flat-shaped indefinite polygonal thing of a major axis and a minor axis 80-200 nm overlapping. In the measurement with a scanning probe microscope, the surface was rough, the average irregularity period RSm was 2.8 to 3.6 μm, and the maximum height roughness Rz was 0.4 to 1.3 μm.

[Experimental example 16] (Surface treatment of Z18 galvanized steel sheet piece (3))
An experiment similar to Experimental Example 15 was performed. However, the chemical conversion treatment is different, and instead of the zinc phosphate chemical conversion treatment solution used in Experimental Example 15, 1.2% hydrated chromium nitrate is 1.2%, chromium trioxide is 0.3%, A chromate-treated aqueous solution containing 1.5% orthophosphoric acid and 0.033% basic nickel carbonate was used at 40 ° C. However, the treatment liquid of this system is a relatively recently developed solution for general steel materials (for iron alloys), and the feature is that it contains trivalent and hexavalent chromium. It is considered as one of the excellent chemical conversion solutions. As in Experimental Examples 14 and 15, the Z18 piece (3) was degreased, washed with water, and immediately subjected to chemical conversion treatment. After the chemical conversion treatment, it was thoroughly washed with ion exchange water and then dried at 90 ° C. for 15 minutes.

  The Z18 piece (3) was observed with an electron microscope and a scanning probe microscope. The observation results with a 10,000 times and 100,000 times electron microscope are shown in FIGS. It can be seen that the entire surface is covered with ultrafine irregularities with an irregular period of 10 to 200 nm. Further, in the measurement with a scanning probe microscope, the surface was rough, the peak / valley average interval RSm was 1.3 to 2.5 μm, and the maximum height roughness Rz was 0.3 to 1.5 μm.

[Experimental Example 17] (Preparation of adhesive (1))
Commercially available styrene-diluted FRP unsaturated polyester resin “Rigolac 258BQT (manufactured by Showa Polymer Co., Ltd., Tokyo, Japan)”, commercially available t-butyl peroxybenzoate “Perbutyl Z (Nippon Co., Ltd. (Japan) Tokyo Metropolitan Government)) ”. In a container, 100 parts of “Rigolac 258BQT” and 0.5 part of “Perbutyl Z” were taken and mixed well, and this was used as the adhesive (1).

[Experiment 18] (Preparation of adhesive (2))
100 parts of “Rigolac 258BQT” and 1 part of “Perbutyl Z” were mixed well and used as an adhesive (2).

[Experimental Example 19] (Preparation of adhesive (3))
100 parts of “Rigolac 258BQT” and 2 parts of “Perbutyl Z” were mixed well and used as an adhesive (3).

  Each of the adhesives (1), (2), and (3) was mixed and subjected to the application work for each of the following experiments within 1 hour, but the remaining mixture increased in viscosity after 3 hours of mixing. The liquid temperature did not rise. “Rigolac” is an alkyd resin unsaturated polyester and styrene compound.

[Experiment 20] (Preparation of adhesive (4))
A commercially available styrene-diluted FRP unsaturated polyester resin “Lipoxy R802 (Showa Polymer Co., Ltd.)” and a commercially available t-butyl peroxybenzoate “Perbutyl Z” were obtained. In a container, 100 parts of “Lipoxy R802” and 1 part of “Perbutyl Z” were taken and mixed well to obtain an adhesive (4). Within 1 hour after mixing, it was subjected to the application work of each of the following experiments, but the remaining mixture did not show an increase in viscosity even after 3 hours of mixing, and the liquid temperature did not rise. “Lipoxy” is a compound of vinyl ester resin and styrene monomer.

[Experimental example 21] (Preparation of adhesive (5))
Commercially available main solution for FRP “Lipoxy R802”, commercially available t-butyl peroxybenzoate “Perbutyl Z”, fine talc “Himicron HE5 (manufactured by Takehara Chemical Co., Ltd. (Hyogo, Japan))” were obtained. The “Hi-micron HE5” is a classified product of talc powder obtained by mechanical pulverization with an average particle size of several tens of μm. In a container, 100 parts of “Lipoxy R802” and 2 parts of “Hymicron HE5” were thoroughly mixed and mixed. The container was covered with wrapping material, and further covered with aluminum foil and allowed to stand. One week later, when the cover was removed, it was clear that a cloudy substance had precipitated at the bottom and the degree of dispersion was insufficient. Thereafter, 1 part of t-butyl peroxybenzoate “perbutyl Z” was added and kneaded and mixed for about 15 seconds. This is designated as adhesive (5). The adhesive (5) and the adhesives (6) to (12) shown below were mixed and subjected to the application work of each of the following experiments within 1 hour, but the remaining mixture was mixed. Even after 3 hours, the viscosity did not increase.

[Experimental example 22] (Preparation of adhesive (6))
The same raw materials as in Experimental Example 21 were prepared. Then, a sand grind mill “Tuea (manufactured by Ashizawa Finetech Co., Ltd.)” filled with 80% by volume of 0.3 mm diameter zirconia beads and 400 g of an unsaturated polyester resin “Lipoxy R802” are filled in an open container. The small capacity pump was driven in the full range to evacuate the air. The rotor was driven to a peripheral speed of 11 to 13 m / sec, and 8 g of fine powder talc “HIMICRON HE5” was charged into the open container, and stirring in the open container was also started. The crushing chamber mantle was cooled by running tap water, and the crushing chamber temperature was kept at 45 ° C. or lower. This wet grinding was continued for 30 minutes, and the liquid flowing out from the outlet of the grinding chamber was collected in a polyethylene bottle. It was a lightly colored transparent liquid that was completely different from the production of the adhesive (5). The polyethylene bottle was allowed to stand for one month and then the inside was observed, but no precipitate was confirmed as it was at the beginning. 10 g of the content liquid was taken, 0.1 g of t-butyl peroxybenzoate “Perbutyl Z” was added and mixed well. This was designated as an adhesive (6).

[Experimental example 23] (Preparation of adhesive (7))
A fired clay “Satinton 5 (manufactured by Takehara Chemical Co., Ltd.)” was used as the inorganic filler instead of “Hi-micron HE5”. This was a calcined hard clay made in Georgia with high kaolin purity, and the average particle size was about 10 μm. That is, 400 g of unsaturated polyester resin “Lipoxy R802” is filled in an open container associated with a sand grind mill “Tuea (manufactured by Ashizawa Finetech Co., Ltd.)” filled with 80% by volume of 0.3 mm zirconia beads and used for circulation. The small capacity pump was driven in the full range to evacuate the air. The rotor was driven to a peripheral speed of 11 to 13 m / sec, 8 g of clay “Satinton 5” was put into the open container, and stirring in the open container was also started. The crushing chamber mantle was cooled by running tap water, and the crushing chamber temperature was kept at 45 ° C. or lower. This wet grinding was continued for 30 minutes, and the liquid flowing out from the outlet of the grinding chamber was collected in a polyethylene bottle. It was a lightly colored transparent liquid and was the same as the adhesive (6). The polyethylene bottle was allowed to stand for one month and then the inside was observed, but no precipitate was confirmed as it was at the beginning. 10 g of the content liquid was taken, 0.1 g of t-butyl peroxybenzoate “Perbutyl Z” was added and mixed well. This was designated as an adhesive (7).

[Experimental Example 24] (Preparation of adhesive (8))
Instead of Experimental Examples 22 and 23, a so-called inorganic filler was not used, and fumed silica “Aerosil R805” (manufactured by Nippon Aerosil Co., Ltd. (Tokyo, Japan)), which is an ultrafine inorganic filler, was used. That is, 400 g of unsaturated polyester resin “Lipoxy R802” is filled in an open container associated with a sand grind mill “Tuea (manufactured by Ashizawa Finetech Co., Ltd.)” filled with 80% by volume of 0.3 mm zirconia beads and used for circulation. The small-capacity pump was fully driven to remove air. The rotor was driven to a peripheral speed of 11 to 13 m / sec, 0.8 g of fused silica “Aerosil R805” was charged into the open container, and stirring in the open container was also started. The crushing chamber mantle was cooled by running tap water, and the crushing chamber temperature was kept at 45 ° C. or lower. This wet grinding was continued for 30 minutes, and the liquid flowing out from the outlet of the grinding chamber was collected in a polyethylene bottle. It was a lightly colored transparent liquid and looked the same as adhesives (6) and (7). The polyethylene bottle was allowed to stand for one month and then the inside was observed, but no precipitate was confirmed as it was at the beginning. 10 g of the content liquid was taken, 0.1 g of t-butyl peroxybenzoate “Perbutyl Z” was added and mixed well. This was designated as adhesive (8).

[Experimental example 25] (Preparation of adhesive (9))
“Lipoxy R805”, “Himicron HE5” and “Aerosil R805” were prepared. Then, a sand grind mill “Tuea (manufactured by Ashizawa Finetech Co., Ltd.)” filled with 80% by volume of 0.3 mm diameter zirconia beads and 400 g of an unsaturated polyester resin “Lipoxy R802” are filled in an open container. The small-capacity pump was fully driven to remove air. The rotor was driven to a peripheral speed of 11 to 13 m / sec, and 8 g of fine talc “HYMICRON HE5” and 0.8 g of fused silica “Aerosil R805” were charged into the open container, and stirring in the open container was started. The crushing chamber mantle was cooled by running tap water, and the crushing chamber temperature was kept at 45 ° C. or lower. This wet grinding was continued for 30 minutes, and the liquid flowing out from the outlet of the grinding chamber was collected in a polyethylene bottle. It was a lightly colored transparent liquid and looked the same as adhesives (6), (7) and (8). The polyethylene bottle was allowed to stand for one month and then the inside was observed, but no precipitate was confirmed as it was at the beginning. 10 g of the content liquid was taken, 0.1 g of t-butyl peroxybenzoate “Perbutyl Z” was added and mixed well. This was designated as an adhesive (9).

[Experiment 26] (Preparation of adhesive (10))
In addition to the thing prepared in Experimental Example 25, multilayer CNT “MCNT (manufactured by Nanocarbon Technologies Inc. (Tokyo, Japan))” was obtained. When this CNT was observed with a 30,000-fold electron microscope, the average diameter was about 50 nm. In exactly the same way as in Experimental Example 25, using a sand grind mill “Tuea (manufactured by Ashizawa Finetech Co., Ltd.)”, 100 parts of unsaturated polyester resin “Lipoxy R802”, 2 parts of fine talc “Himicron HE5”, fuse A black liquid in which 0.2 part of silica gel “Aerosil R805” and 0.06 part of CNT “MCNT” were mixed and dispersed was obtained and recovered in a polyethylene bottle. After the polyethylene bottle was allowed to stand for 1 month, 10 g of the content solution was taken, 0.1 g of t-butyl peroxybenzoate “Perbutyl Z” was added, and kneaded and mixed well. This was designated as an adhesive (10).

[Experiment 27] (Preparation of adhesive (11))
In addition to the product prepared in Experimental Example 25, a polyethersulfone resin (hereinafter referred to as “PES”) finely pulverized product “PES4100MP (manufactured by Sumitomo Chemical Co., Ltd., Japan)”, which is a thermoplastic resin, was obtained. This “PES4100MP” had an average particle size of about 10 μm according to the manufacturer's analysis. In exactly the same way as in Experimental Example 22, using a sand grind mill “Tuea (manufactured by Ashizawa Finetech Co., Ltd.)”, 100 parts of unsaturated polyester resin “Lipoxy R802”, 2 parts of fine talc “Himicron HE5”, fuse A liquid in which 0.2 part of dosilica “Aerosil R805” and 3 parts of PES “PES4100MP” were mixed and dispersed was obtained and recovered in a polyethylene bottle. After the polyethylene bottle was allowed to stand for 1 month, 10 g of the content solution was taken, 0.1 g of t-butyl peroxybenzoate “Perbutyl Z” was added, and kneaded and mixed well. This was designated as an adhesive (11).

[Experiment 28] (Preparation of adhesive (12))
Commercially available FRP main liquids “Rigolac 258BQTM”, “Himicron HE5”, and “Aerosil R805”, which are a mixture of unsaturated polyester resin and styrene, were prepared. A sand grind mill “Tuea (manufactured by Ashizawa Finetech Co., Ltd.)” filled with 80% by volume of 0.3 mm zirconia beads and 400 g of an unsaturated polyester resin “Rigolac 258BQTM” are filled in an open container. The small-capacity pump was fully driven to remove air. The rotor was driven to a peripheral speed of 11 to 13 m / sec, and 8 g of fine talc “HYMICRON HE5” and 0.8 g of fused silica “Aerosil R805” were charged into the open container, and stirring in the open container was started. The crushing chamber mantle was cooled by running tap water, and the crushing chamber temperature was kept at 45 ° C. or lower. This wet grinding was continued for 30 minutes, and the liquid flowing out from the outlet of the grinding chamber was collected in a polyethylene bottle. It was a lightly colored transparent liquid and looked the same as the adhesive (9). The polyethylene bottle was allowed to stand for one month and then the inside was observed, but no precipitate was confirmed as it was at the beginning. 10 g of the content liquid was taken, 0.1 g of t-butyl peroxybenzoate “Perbutyl Z” was added and mixed well. This was designated as an adhesive (12).

  Next, an adhesion experiment will be described. Hereinafter, Experimental Examples 29 to 66 are adhesion experiments using any of the adhesives (1) to (4). That is, this is an adhesion experiment when no filler is used.

[Experimental example 29] (Adhesion between A5052 pieces)
Of 18 pieces of A5052 pieces prepared in Experimental Example 2, the adhesive (1) prepared in Experimental Example 17 was applied to each of six ends with a brush. Similarly, the adhesive (2) was applied to another 6 pieces, and the adhesive (3) was applied to the remaining 6 pieces with a brush. A5052 pieces coated with these adhesives were placed in a large desiccator and depressurized with a vacuum pump. When the pressure reached 50 mmHg, the pieces were placed for 10 seconds to return to normal pressure. The cycle of returning to normal pressure and allowing to stand for 0.5 minutes, reducing pressure again and returning to the same normal pressure was repeated three times.

Next, the A5052 piece was taken out from the desiccator, and a pair in which the surfaces to which the adhesive was applied was brought into contact with each other was placed between clips to prepare for bonding. The adhesive area of both A5052 pieces was 0.5 to 0.7 cm ² . As a result, three pairs of A5052 pieces were obtained for each of the three types of adhesives (adhesives (1), (2), and (3)). A total of 3 types of 9 pairs of A5052 pieces sandwiched between 2 small clips placed in a hot air dryer set at 90 ° C and left for 1 hour, further raised to 120 ° C and left at 120 ° C for 1 hour to cure. It was.

After that, after one week from the dryer, each of the 9 pairs was broken by a tensile tester, and the shear breaking strength was measured. And three pairs of average values were calculated for each of the three types of adhesives. As a result, the adhesive (1) was 25 MPa (252 Kgf / cm ² ), the adhesive (2) was 25 MPa (255 Kgf / cm ² ), and the adhesive (3) was 22 MPa (226 Kgf / cm ² ). In conclusion, under the above-mentioned curing conditions, the strongest joining force was obtained when about 1 part of t-butyl peroxybenzoate “perbutyl Z” was used with respect to 100 parts of “Rigolac 258BQT”.

[Experiment 30] (Adhesion between A5052 pieces: Comparative example)
A commercially available 1.6 mm thick A5052 plate was obtained and cut to produce a large number of 45 mm × 18 mm rectangular A5052 pieces. Water was prepared in a tank, and a commercially available aluminum alloy degreasing agent “NE-6 (manufactured by Meltex)” was added to prepare an aqueous solution at 60 ° C. and a concentration of 7.5%. The A5052 piece was immersed in this for 7 minutes and washed thoroughly with water. The process so far is the same as in Experimental Example 2 described above, but six pieces of A5052 pieces that were subjected only to the above degreasing step were prepared without performing subsequent chemical etching. From these six pieces, three pairs of A5052 pieces were bonded with the adhesive (2) prepared in Experimental Example 18 in the same manner as described above. Further, the sample was broken by a tensile tester in the same manner as described above, and the shear breaking force was measured. The average of the three pairs was 7 MPa (75 Kgf / cm ² ). This was significantly lower than Experimental Example 29.

[Experimental examples 31 to 41] (Adhesion between various metal alloy pieces)
A7075 pieces, AZ31B pieces, AZ91D pieces, C1100 pieces, C5191 pieces, KFC pieces, KLF5 pieces, KS40 pieces prepared in Experimental Examples 1, 3, 4, 5, 6, 7, 8, 9, 10, 11, and 12. , KSTi-9 pieces, SUS304 pieces, and SPCC pieces were each prepared in six pieces (that is, for various three pairs), and the adhesive (2) prepared in Experimental Example 18 was applied to each end with a brush. Thereafter, in the same manner as in Experimental Example 29, two pieces of the same kind of metal alloy were bonded and cured, and as a result, a joined body of 11 kinds of a total of 33 pairs of the same kind of metal alloy pieces was obtained. The 33 pairs were broken by a tensile tester after one week, and three pairs of shear breaking forces were measured for each of the 11 types. Table 1 shows the average value of shear breaking force of each metal alloy type.

[Experimental Examples 42, 45-51] (Adhesion between various metal alloy pieces: Comparative example)
A7075 pieces, AZ31B pieces, AZ91D pieces, C1100 pieces, C5191 pieces, KFC pieces, KLF5 pieces, KS40 pieces prepared in Experimental Examples 1, 3, 4, 5, 6, 7, 8, 9, 10, 11, and 12. , KSTi-9 pieces, SUS304 pieces, and SPCC pieces were prepared for each six pieces (that is, for various three pairs). Among these, only the degreasing process was performed except for the magnesium alloy piece of AZ31B piece, the AZ91D piece, and the SPCC steel piece. Specifically, it was immersed in each degreasing solution for 7 minutes, washed with water and dried. Then, similarly to Experimental Examples 31 to 41, the two homogeneous metal alloy pieces are bonded and cured with the adhesive (2) created in Experimental Example 18, and as a result, a total of 24 pairs of homogeneous metal alloy pieces are in contact with each other. A joined body was obtained. Furthermore, it fractured | ruptured with the tension test machine similarly to Experimental example 31-41, and the shear fracture | rupture force was measured. The results are shown in Table 1.

[Experimental Examples 43 and 44] (Adhesion between various metal alloy pieces: Comparative example)
On the other hand, about AZ31B piece and AZ91D piece which are magnesium alloy pieces, not only a degreasing process but normal chemical conversion treatment was also performed. Specifically, the following processing was performed for the AZ31B piece. That is, a commercially available magnesium alloy degreasing agent “Cleaner 160 (manufactured by Meltex)” was added to water prepared in the tank to obtain an aqueous solution at 65 ° C. and a concentration of 7.5%. The AZ31B piece was immersed in this for 5 minutes and washed thoroughly with water. Subsequently, a 10-fold diluted solution of a commercially available magnesium alloy etching material “magtreat E5109 (Meltex Co., Ltd.)” at 40 ° C. was prepared in a separate tank, and the AZ31B piece was immersed in this for 6 minutes and washed thoroughly with water. did.

  Next, prepare a 7.5% aqueous solution of the commercially available first smut treating agent “NE-6 (manufactured by Meltex)” at 65 ° C. in another tank, and immerse the AZ31B piece in the previous 5 minutes. And washed well with water. Subsequently, a 15% caustic soda aqueous solution at 65 ° C. was prepared in another tank, and the AZ31B piece was immersed in this for 5 minutes and washed with water. Next, a 10-fold diluted aqueous solution of a commercially available manganese phosphate chemical conversion treatment agent “Magtreat MG5565 (manufactured by Meltex)” at 45 ° C. was prepared in another tank, and the AZ31B piece was immersed in this for 2 minutes. Washed with water for 2 seconds. Thereafter, the AZ31B piece was placed in a warm air dryer at 90 ° C. for 15 minutes and dried.

  The entire chemical conversion treatment method described above was a standard formulation of a treatment agent manufacturer (Meltex Co., Ltd.), and was followed. After drying, the AZ31B pieces were wrapped together with aluminum foil, which was then placed in a plastic bag and sealed. Here, the processing of the AZ31B piece has been described, but the same processing is also performed for the AZ91D piece. Using the AZ31B piece and the AZ91D piece that have been subjected to the above-described treatment, the two AZ31B pieces and the two AZ91D pieces are made with the adhesive (2) created in Experimental Example 18 in the same manner as in Experimental Examples 32 and 33. As a result, a joined body of two pairs of the same kind of metal alloy pieces of 6 pairs was obtained. The six pairs were broken with a tensile tester, and the shear breaking force was measured (Experimental Examples 43 and 44). The results are shown in Table 1.

[Experimental Example 52] (Adhesion between various metal alloys: Comparative example)
Moreover, about the SPCC piece, not only the degreasing process but normal chemical conversion treatment was also performed. A commercially available 1.6 mm-thick cold-rolled steel “SPCC Bright” plate was purchased and cut to produce a large number of rectangular SPCC pieces having a size of 18 mm × 45 mm. An aqueous solution containing 7.5% of an aluminum alloy degreasing agent “NE-6 (manufactured by Meltex)” was prepared in a tank, and the temperature was set to 60 ° C. The SPCC piece was immersed in this aqueous solution for 5 minutes and washed with tap water (Ota City, Gunma Prefecture).

  Next, an aqueous solution in which 1.2% of orthophosphoric acid, 0.21% of zinc oxide, 0.23% of basic nickel carbonate and 0.16% of sodium silicofluoride were dissolved in 55 ° C. was prepared. The SPCC piece was immersed in 2 minutes and washed with water. This is a standard method of zinc phosphate processing used to prevent rusting of steel materials. Using this SPCC piece, the two SPCC pieces were bonded and cured with the adhesive (2) produced in Experimental Example 18 in exactly the same manner as in Example 41. As a result, a joined body of three pairs of SPCC pieces was obtained. Obtained. The three pairs were broken with a tensile tester, and the shear breaking force was measured (Experimental Example 52). The results are shown in Table 1.

  As a result of applying the present invention, as is apparent from Table 1, all showed high adhesive strength as compared with the conventional standard treatment before adhesion. The shear breaking force was as high as 35 MPa for SPCC pieces, about 20 to 25 MPa for most other metal alloy pieces, and as low as 10 or more MPa for AZ31B pieces, C5191 pieces, and KS40 pieces. The reason for this is that in the case of the AZ31B piece, the ultra fine irregularities are only fine as seen from the surface photographs (FIGS. 7 and 8), while in the case of the KS40 piece, it is ultra fine as seen from the surface photograph (FIG. 14). It is estimated that the unevenness is too rough.

  From Table 1, the bonded product obtained by applying the present invention generally has a bonding strength of 20 to 30 MPa in terms of shear breaking force, which is greatly different from 50 to 70 MPa in the case of an epoxy adhesive. There is also some literature description that the cured resin itself has a strength of about 70 MPa for epoxy resin, but 30 to 40 MPa for the cured alkyd resin-based unsaturated polyester, which is parallel to the strength of the adhesive itself. It seemed to be a result. Among these, although the numerical value is high in general steel materials such as SPCC, such a phenomenon is similarly observed in the phenol resin adhesive. As shown in FIG. 17, it is considered that innumerable stairs with a pearlite structure are suitable as spike shapes. On the other hand, compared to SPCC, the surface of A7075 or SUS304 may not be suitable as a spike shape.

  However, in the NAT theory, it is considered that if the surface shape satisfies the necessary conditions, the joining force will be at the same level. Therefore, it can be said that the expected fracture occurred only in the steel material in the theory. That is, in the joined body having a joining force of 20 to 30 MPa, it is estimated that a considerable part of the resin is finely broken in the vicinity of the spike, and there are many parts where the resin is completely removed from the micron-order recesses. In particular, with magnesium alloys and phosphor bronze of 20 MPa or less, the size and shape of the spikes are not effective, and it seems that there are many more resins that have come out of the recesses. It can be considered that the above can be confirmed if the resin portion after fracture can be carefully observed with an electron microscope. In any case, the cured product of the unsaturated polyester resin is hard, but on the other hand, it is brittle and inferior in adhesive strength as compared with an epoxy resin having higher toughness. In other words, if it is possible to improve the toughness of the solidified product by some kind of composition improvement, the result can be improved, and the improvement of the joining force is considered to be on the adhesive side rather than the metal side.

[Experimental Examples 53 to 63] (Adhesion of various metal alloys)
A5052 piece, A7075 piece, AZ31B piece, C1100 piece, KFC piece, KLF5 piece, KS40 piece, KSTi- created in Experimental Examples 2, 1, 3, 5, 7, 8, 9, 10, 11, 12, and 13 Nine pieces, SUS304 pieces, SPCC pieces, and SPHC pieces were prepared in a variety of 6 pieces, that is, 66 pieces for 11 kinds. The adhesive (4) prepared in Experimental Example 20 was applied to each end of six metal alloy pieces (3 pairs) with a brush. Thereafter, adhesion and curing were carried out in exactly the same manner as in Experimental Example 29. As a result, a total of 33 pairs of the same kind of metal alloy pieces were obtained.

  The obtained bonded body was subjected to a tensile tester after one week, and the shear breaking strength was measured (Experimental Examples 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, and 63). Table 2 shows the average value of three pairs of shear fracture forces for each metal type. Comparing Table 2 and Table 1, it can be said that the results of Table 2 are generally excellent in bonding strength. That is, it has been found that a vinyl ester resin as a main component exhibits a stronger bonding force. At the same time, the excellent results in Table 2 indicate that the fracture site is mainly generated inside the cured adhesive, and vinyl ester resin is used as a raw material as a means for further improving the adhesive strength. It shows that trial and error with the adhesive used is desirable.

[Experimental Example 64] (Preparation for preparation of GFRP)
Commercially available glass fiber woven fabric “GF plain weave (manufactured by Nitto Kogyo Co., Ltd., Fukushima Prefecture, Japan)”, commercially available unsaturated polyester resin for FRP “Rigolac 258BQT (manufactured by Showa Polymer Co., Ltd.)”, commercially available t-butyl Peroxybenzoate “Perbutyl Z (manufactured by NOF Corporation)” was prepared. 1 part of “Perbutyl Z” and 1 part of magnesium hydroxide powder (manufactured by Showa Chemical Industry Co., Ltd. (Tokyo, Japan)) were added to 100 parts of “Rigolac 258BQT” and mixed well to obtain an FRP matrix resin. On the other hand, a large number of “GF plain weaves” cut into 45 mm × 15 mm with a gold cutter were prepared.

[Experimental Example 65] (A7075 / GFRP complex)
A7075 pieces obtained in the same manner as in Experimental Example 2 were used. The A7075 piece was taken out, coated with the adhesive (4) prepared in Experimental Example 20, placed in a desiccator, reduced to 50 mmHg or less with a vacuum pump, placed for about 15 seconds, and then air was added to return to normal pressure. After returning to normal pressure, the operation of leaving for 30 seconds and then reducing the pressure was repeated three times, and the pressure was returned to normal pressure and taken out from the desiccator.

  On the other hand, the same mold and jig as shown in FIG. 1 were prepared. The cut piece of the sealing tape was laid in the mold cavity as a release film 17 and the A7075 piece taken out from the desiccator was placed as the metal alloy piece 11 with the adhesive-coated surface facing upward. A plate material having a thickness of 3 mm cut out from the block was arranged as a spacer 16 on the side. A cut product of “GF plain weave” prepared in Experimental Example 64 was laid on the spacer 16, and the matrix resin similarly prepared in Experimental Example 64 was applied. Further, a “GF plain weave” cut product was placed, the matrix resin prepared in Experimental Example 64 was applied, and the same thing was repeated to stack four glass fiber woven fabrics. 1.5 cc of matrix resin was used. Thus, the shaped GFRP, that is, the GFRP plate 12 as a metal alloy adherend is completed (corresponding to 12 in FIG. 1).

  A cut piece of the sealing tape was placed as the release film 13 on the metal alloy piece 11 and the GFRP plate member 12, and the PTFE blocks 14 and 15 were placed thereon. It put in the hot air dryer in this form. Further, an aluminum lump of 0.1 kg was placed on the PTFE block 15 as a weight, and the dryer was energized, and the temperature was raised to 90 ° C. It was kept at 90 ° C. for 3 hours, further heated to 120 ° C. and heated for 1 hour, taken out of the dryer and allowed to cool. The molded product was released from the mold on the next day, and the release films 13 and 17 were peeled off to obtain the shape shown in FIG. The obtained shape was further cured by heating at 100 ° C. for 24 hours.

The same operation was repeated to obtain three sets of A7075 / GFRP complexes. After a week or more had elapsed, they were broken by a tensile tester, and each shear breaking force was measured. The average shear breaking strength was 30 MPa (305 Kgf / cm ² ), which was very strong.

[Experimental example 66] (SPCC / GFRP complex)
The SPCC piece obtained by the same method as Experimental Example 12 was used. The SPCC piece was taken out and coated with the adhesive (4) prepared in Experimental Example 20, and three SPCC / GFRP conjugates were obtained in exactly the same manner as in Experimental Example 65. One week later, they were broken by a tensile tester, and each shear breaking force was measured. The average shear breaking strength was 35 MPa (355 Kgf / cm ² ), which was very strong.

  Hereinafter, Experimental Example 67 and subsequent examples are adhesion experiments using any one of the adhesives (4) to (12). That is, this is an adhesion experiment in which a filler is used except when the adhesive (4) is used.

[Experiment 67] (Adhesion between A7075 aluminum alloy pieces)
The adhesives (4) to (11) prepared in Experimental Examples 20 to 27 were applied to each end of the A7075 aluminum alloy piece prepared in Experimental Example 1 with a spatula. The number of tests is 6 per adhesive, and the total number is 48. The aluminum alloy piece coated with the adhesive was placed in a large desiccator and depressurized with a vacuum pump, and when it reached 50 mmHg, it was placed for 10 seconds to return to normal pressure. The cycle of returning to normal pressure and allowing to stand for 0.5 minutes, reducing pressure again and returning to the same normal pressure was repeated three times.

Next, the aluminum alloy piece was taken out from the desiccator, put in a hot air dryer set at 90 ° C. for 10 minutes, taken out, and the pair with the adhesive-coated surfaces in contact with each other was sandwiched between clips and installed as shown in FIG. At this time, the adhesion area of both aluminum alloy pieces was 0.6 to 0.7 cm ² . As a result, there were three pairs of aluminum alloy pieces for each adhesive type. 24 pairs of aluminum alloy pieces sandwiched between two small clips are placed in a hot air dryer set at 90 ° C. for 30 minutes, further raised to 110 ° C. for 30 minutes, and further raised to 135 ° C. for 30 minutes. It was set aside, turned off, and allowed to cool. The next day, the test piece was taken out of the dryer, and after one week, it was broken by a tensile tester and the shear breaking strength was measured.

  The results are shown in Table 3. The adhesives obtained by forcibly dispersing the inorganic filler (adhesives (6), (7), (9), (10), and (11)) showed a significant improvement in adhesive strength of nearly 20 MPa. In addition, even when the ultrafine inorganic filler was blended, the effect was not clear in the case of a single blend that does not contain the inorganic filler (adhesive (8)). When both the inorganic filler and the ultrafine inorganic filler coexist (adhesives (9), (10), and (11)), higher adhesive strength was given than when only the inorganic filler was included.

  When the adhesive (4) is used, the shear breaking force is 33.8 MPa, and since the shear breaking force of the adhesive (5) filled with only the inorganic filler is 39.2 MPa, only the inorganic filler is added. In this case, it can be said that the adhesion can be improved. And when the inorganic filler is disperse | distributed with a sand grind mill (adhesive (6)), a shear fracture | rupture force will be 52.9 Mpa and the effect will improve markedly. Furthermore, when an inorganic filler and an ultrafine inorganic filler are used in combination and dispersed by a sand grind mill (adhesive (9) (10) (11)), only the inorganic filler is dispersed by a sand grind mill ( Compared with the adhesive (6)), the shear breaking strength was improved by about 10 MPa. Since all showed a shear breaking force exceeding 60 MPa, it can be said that a shear breaking force close to that when an epoxy adhesive was used could be obtained. Another point to be noted is that when CNT is added in addition to the inorganic filler and the ultrafine inorganic filler (adhesive (10)), the shear breaking force is improved by about 2 MPa, The effect is not obtained. This means that sufficient adhesive strength can be improved with the inorganic filler and the ultrafine inorganic filler without using expensive CNTs.

[Experimental Examples 68 to 82] (Adhesion between metal alloy pieces: Adhesives (4) and (9))
A5052 aluminum alloy pieces, AZ31B magnesium alloy pieces, AZ91D magnesium alloy pieces, C1100 copper alloy pieces, C5191 phosphor bronze pieces, KFC copper alloy pieces, KLF5 copper alloy pieces, titanium alloy pieces, α-β created in Experimental Examples 2 to 16 A number of type titanium alloy pieces, SUS304 stainless steel pieces, SPCC steel pieces, SPHC steel pieces, Z18 pieces (1), (2), and (3) were prepared. The adhesive (4) prepared in Experimental Example 20 was applied with a spatula onto the surface of each of the various metal alloy pieces. Further, the adhesive (9) prepared in Experimental Example 25 was applied with a spatula onto the surface of the above-mentioned various metal alloy pieces (different from those applied with the adhesive (4)). Thereafter, two identical metal alloy pieces were bonded and cured in exactly the same manner as in Experimental Example 67. As a result, a total of 32 types of samples of 2 types of adhesives and 16 types of metal alloy types were prepared, and 3 pairs of joined bodies were prepared for each sample, so that 96 pairs of joined bodies were obtained in total. The 96 pairs were broken by a tensile tester after one week, and the shear breaking strength at room temperature was measured.

  The results are shown in Table 4. The filler effect of the inorganic filler and the ultrafine inorganic filler was observed for all the metal alloy type samples. However, there was a metal alloy species having a large difference between the adhesive (4) and the adhesive (9), that is, a metal alloy species having a large filling effect and a metal alloy species having a relatively small filling effect. The aluminum alloys (A7075, A5052), some copper alloys (C5191, KLF5), and titanium alloys (KS40, KSTI-9) had a relatively large filling effect, and the shear fracture strength was 50% or more. An improvement was observed. On the other hand, it was magnesium alloys (AZ31B, AZ91D), some copper alloys (C1100), and steel materials (SPCC, SPHC) that had a relatively small filling effect, and the improvement in shear fracture strength was 30% or less. there were.

[Experimental example 83] (Adhesion between metal alloy pieces: Adhesive (12))
The adhesive (12) prepared in Experimental Example 28 was applied to each end of the A7075 aluminum alloy piece prepared in Experimental Example 1 with a spatula. The A7075 piece coated with adhesive was placed in a large desiccator and depressurized with a vacuum pump, and when it reached 50 mmHg, it was placed for 10 seconds to return to normal pressure. The cycle of returning to normal pressure and allowing to stand for 0.5 minutes, reducing pressure again and returning to the same normal pressure was repeated three times. Next, the A7075 piece was taken out from the desiccator, put in a hot air dryer set at 90 ° C. for 10 minutes, taken out, and the pair with the adhesive-coated surfaces in contact with each other was placed between clips and installed as shown in FIG. At this time, the adhesion area of both A7075 pieces was 0.6 to 0.7 cm ² . Three pairs of A7075 pieces sandwiched between two small clips are placed in a hot air dryer set at 90 ° C for 30 minutes, further raised to 110 ° C for 30 minutes, further raised to 135 ° C for 30 minutes. Placed, turned off and allowed to cool. The next day, it was taken out of the dryer and one week later, it was broken by a tensile tester. The obtained average shear breaking strength was 52 MPa, which was slightly lower than the result of the adhesive (9) obtained from the vinyl ester resin, but was sufficiently high.

[Experimental Example 84] (Preparation for preparation of GFRP)
Commercially available glass fiber woven fabric “GF plain weave (manufactured by Nitto Kogyo Co., Ltd.)”, commercially available unsaturated polyester resin for FRP “Rigolac 258BQT (manufactured by Showa Polymer Co., Ltd.)”, commercially available t-butyl peroxybenzoate “perbutyl Z” (Manufactured by NOF Corporation) "and a silane coupling agent" KBM-603 (manufactured by Shin-Etsu Chemical Co., Ltd. (Tokyo, Japan)) "were prepared. The “GF plain weave” cloth was dipped in an aqueous solution of 1% concentration of “KBM-603” for 15 minutes, air-dried, and placed in a hot air dryer at 80 ° C. for 30 minutes for drying. This was cut into 45 mm × 15 mm with a scissors to prepare a large number of them. On the other hand, 5 parts of magnesium hydroxide powder (manufactured by Showa Chemical Industry Co., Ltd. (Tokyo, Japan)) was added to 100 parts of “Rigolac 258BQT” and well kneaded and stored in a plastic bottle. Before starting the adhesion experiment described later, the liquid in the plastic bottle is mixed well again with a glass rod, taken out into a beaker, and 1 part of “Perbutyl Z” is added to 100 parts of the liquid and kneaded well. Resin was used.

[Experimental Example 85] (A7075 / GFRP complex (adhesive (9)))
A7075 aluminum alloy pieces obtained in the same manner as in Experimental Example 1 were used. Take out the stored A7075 aluminum alloy piece, apply the adhesive (9) prepared in Experimental Example 25, put it in a desiccator, depressurize it to 50 mmHg or less with a vacuum pump and leave it for about 15 seconds. Returned to. After returning to normal pressure, the operation of leaving for 30 seconds and then reducing the pressure was repeated three times, and the pressure was returned to normal pressure and taken out from the desiccator.

  On the other hand, the same mold and jig as shown in FIG. 1 were prepared. A cut piece of the sealing tape was laid in the mold cavity as a release film 17, and an A7075 aluminum alloy piece taken out from the desiccator was placed as the metal alloy piece 11 with the adhesive application surface facing upward. A plate material having a thickness of 3 mm cut out from the block was arranged as a spacer 16 on the side. A cut product of “GF plain weave” created in Experimental Example 84 was laid on the spacer 16, and the matrix resin similarly produced in Experimental Example 84 was applied. Further, a “GF plain weave” cut product was placed, the matrix resin prepared in Experimental Example 84 was applied, and the same thing was repeated to stack six glass fiber woven fabrics. About 1.5 cc of matrix resin was used. Thus, the shaped GFRP, that is, the GFRP plate 12 as a metal alloy adherend is completed (corresponding to 12 in FIG. 1).

  A cut piece of the sealing tape was placed as the release film 13 on the metal alloy piece 11 and the GFRP plate member 12, and the PTFE blocks 14 and 15 were placed thereon. It put in the hot air dryer in this form. Further, a 1 kg steel ingot was placed on the PTFE block 15 as a weight, the dryer was energized, and the temperature was raised to 90 ° C. The temperature was maintained at 90 ° C. for 3 hours, further heated to 130 ° C. and heated for 1 hour, and the dryer was turned off and left standing. On the next day, the product was removed from the dryer, the molded product was released from the mold, and the release films 13 and 17 were peeled off to obtain the shaped product shown in FIG. The obtained shape was further cured by heating at 100 ° C. for 24 hours.

  The same operation was repeated, and three sets of A7075 aluminum alloy / GFRP joined bodies were obtained. After one week, these were ruptured by using a tensile tester, and each shear breaking force was measured. The average shear breaking strength was 40.1 MPa, which was very strong. This is because the matrix resin of GFRP is an unsaturated polyester resin and is common with the main component of the adhesive. Further, the shear fracture strength was improved by about 10 MPa compared with Experimental Example 65, and the effect of adding the inorganic filler and the ultrafine inorganic filler was clear.

[Experimental Example 86] (A7075 / GFRP complex (adhesive (11)))
In the same manner as in Experimental Example 85, an A7075 aluminum alloy and GFRP bonded integrated product was obtained, but the adhesive (11) according to Experimental Example 27 was used instead of the adhesive (9). Three sets of A7075 / GFRP joined bodies were obtained, and after one week, they were ruptured by a tensile tester, and the shear breaking strength of each was measured. The average shear breaking strength was 40.5 MPa, which was very strong. The comparison between Experimental Examples 85 and 86 is that the adhesive used does not contain PES which is a thermoplastic resin, but the difference is not clear. It was confirmed that the adhesive strength was not deteriorated at least by the addition of PES.

[Experimental example 87] (Z18 galvanized steel sheet / GFRP composite (adhesive (11)))
A galvanized steel sheet piece (that is, Z18 piece (3)) obtained by the same method as in Experimental Example 16 was used. The adhesive (9) was used in exactly the same manner as in Experimental Example 85 except that this steel plate piece was used, and this was co-cured and bonded to the GFRP prepreg using the matrix resin of Experimental Example 84. Thus, three sets of Z18 galvanized steel sheet / GFRP joined bodies were obtained. After one week, these were ruptured by using a tensile tester, and each shear breaking force was measured. The average shear breaking force was 30.3 MPa, which was very strong.

  The present invention is a technique for firmly bonding metal alloys or metal alloys and GFRP. Adhesive bonding between a metal alloy and an inexpensive GFRP is possible, which is useful for manufacturing parts such as outdoor facilities, outdoor buildings, or temporary structures during disasters. Moreover, the joined body of titanium alloy, stainless steel, or aluminum alloy and GFRP is lightweight, and is also useful as a structural component for trains, ships, bicycles, and other mobile machines.

Claims (40)

A joined body in which the metal alloy and the adherend are joined via an adhesive,
The surface of the metal alloy is etched to have a roughness on the order of microns with an average interval between peaks and valleys (RSm) of 0.8 to 10 μm and a maximum height roughness (Rz) of 0.2 to 5 μm. And in the surface having the roughness, ultrafine irregularities with a period of 5 to 500 nm are formed, and the surface layer is a thin layer of metal oxide or metal phosphate,
The adhesive is mainly composed of unsaturated polyester resin or vinyl ester resin,
A bonded body of a metal alloy and an adherend, wherein the metal alloy and the adherend are firmly joined by the adhesive entering the ultrafine irregularities. A joined body of a metal alloy and an adherend according to claim 1,
The metal alloy and the adherend are joined together, wherein the metal alloy is any one selected from an aluminum alloy, a magnesium alloy, a copper alloy, a titanium alloy, stainless steel, a steel material, and a galvanized steel sheet. . A joined body in which the metal alloy and the adherend are joined via an adhesive,
The metal alloy is an α-β type titanium alloy,
When the surface of the α-β type titanium alloy is etched, an average interval between peaks and valleys (RSm) is 0.8 to 10 μm, and a maximum height roughness (Rz) is 0.2 to 5 μm. A metal oxide that has a roughness of 10 μm and has fine irregularities due to the presence of both a smooth dome shape and a curved dead leaf shape in an area of 10 μm square, and the surface layer is mainly composed of titanium and aluminum. A thin layer of things,
The adhesive is mainly composed of unsaturated polyester resin or vinyl ester resin,
A bonded body of a metal alloy and an adherend, wherein the metal alloy and the adherend are firmly joined by the adhesive entering the fine irregularities. A joined body of a metal alloy and an adherend according to claim 1 selected from claims 1 to 3,
The curing agent used in the adhesive is an organic peroxide, which slows the polymerization reaction around the room temperature of the unsaturated polyester resin or vinyl ester resin that is the main component of the adhesive. A bonded body of metal alloy and adherend. A joined body of a metal alloy and an adherend according to claim 4,
The organic peroxide is one or more selected from t-butyl-peroxyisopropyl monocarbonate, t-hexyl-peroxyisopropyl monocarbonate, and t-butyl peroxybenzoate. And bonded material. A joined body of a metal alloy and an adherend according to claim 1 selected from claims 1 to 5,
The said adhesive agent contains 1 mass% or more of inorganic fillers with a 1 micrometer diameter or more, The joined body of the metal alloy and adherend characterized by the above-mentioned. A joined body of a metal alloy and an adherend according to claim 6,
The said adhesive agent contains 0.1 mass% or more of ultrafine inorganic fillers with a diameter of 100 nm or less, and the joined body of a metal alloy and a to-be-adhered material characterized by the above-mentioned. A joined body of a metal alloy and an adherend according to claim 7,
The said adhesive agent contains 0.1-1.0 mass% of said ultrafine inorganic fillers, The joined body of the metal alloy and adherend characterized by the above-mentioned. A joined body of a metal alloy and an adherend according to claim 7 or 8,
A joined body of a metal alloy and an adherend, wherein the ultrafine inorganic filler is fumed silica. A joined body of a metal alloy and an adherend according to claim 1 selected from claims 1 to 9,
The adhesive may further include a thermoplastic resin in an amount of 5% by mass or less, and the bonded body of the metal alloy and the adherend. A joined body of a metal alloy and an adherend according to claim 1 selected from claims 1 to 10,
The adherend is a metal alloy having the same property as that of the metal part. A joined body of a metal alloy and an adherend according to claim 1 selected from claims 1 to 11,
The adherend is a fiber-reinforced plastic having an unsaturated polyester resin or vinyl ester resin as a matrix resin, and is a bonded body of a metal alloy and an adherend. On the surface of the metal alloy, a roughness on the order of microns having an average interval between valleys and valleys (RSm) of 0.8 to 10 μm and a maximum height roughness (Rz) of 0.2 to 5 μm is generated. A surface treatment step of performing etching for forming ultrafine irregularities with a period of 5 to 500 nm in a plane having a surface layer and forming a surface layer as a thin layer of metal oxide or metal phosphate;
An adhesive preparation step of creating an adhesive mainly composed of unsaturated polyester resin or vinyl ester resin;
An application step of applying the adhesive obtained in the adhesive preparation step to a predetermined range of the surface of the metal alloy that has undergone the surface treatment step;
An integration step of fixing the adherend to the predetermined range on the surface of the metal alloy that has undergone the coating step, and curing the uncured resin by heating to integrate the two,
The manufacturing method of the joined body of the metal alloy and adherend characterized by including these. A method for producing a joined body of a metal alloy and an adherend according to claim 13,
The metal alloy is an aluminum alloy;
The surface treatment step includes a chemical etching step of immersing the aluminum alloy in a strongly basic aqueous solution, a neutralization step of immersing the aluminum alloy in an acidic aqueous solution after the chemical etching step, and after the neutralizing step, the aluminum And a fine etching step of immersing the alloy in an aqueous solution containing at least one selected from hydrated hydrazine, ammonia, and a water-soluble amine compound. A method for producing a joined body of a metal alloy and an adherend according to claim 14,
The manufacturing method according to claim 1, wherein the surface treatment step further includes an oxidation step of immersing the aluminum alloy in a hydrogen peroxide solution after the fine etching step. A method for producing a joined body of a metal alloy and an adherend according to claim 13,
The metal alloy is a magnesium alloy,
The surface treatment step includes a chemical etching step of immersing the magnesium alloy in an acidic aqueous solution, and a chemical conversion treatment step of immersing the magnesium alloy in a permanganate aqueous solution after the chemical etching step. The manufacturing method. A method for producing a joined body of a metal alloy and an adherend according to claim 13,
The metal alloy is a copper alloy;
The surface treatment step includes a chemical etching step of immersing the copper alloy in an acidic aqueous solution containing an oxidizing agent, and a surface hardening step of immersing the copper alloy in a strongly basic aqueous solution containing an oxidizing agent after the chemical etching step, The manufacturing method characterized by including. A method for producing a joined body of a metal alloy and an adherend according to claim 17,
The copper alloy is a pure copper-based copper alloy,
The said manufacturing method characterized by performing the said chemical etching process and the said surface hardening process again with respect to the copper alloy which passed through the said chemical etching process and the said surface hardening process in the said surface treatment process. A method for producing a joined body of a metal alloy and an adherend according to claim 13,
The metal alloy is a pure titanium-based titanium alloy,
The method according to claim 1, wherein the surface treatment step includes a chemical etching step of immersing the titanium alloy in an aqueous solution containing ammonium hydrogen fluoride. A method for producing a joined body of a metal alloy and an adherend according to claim 13,
The metal alloy is stainless steel;
The said surface treatment process includes the chemical etching process of immersing the said stainless steel in sulfuric acid aqueous solution, The said manufacturing method characterized by the above-mentioned. A method for producing a joined body of a metal alloy and an adherend according to claim 13,
The metal alloy is a steel material,
The said surface treatment process includes the chemical etching process which immerses the said steel material in sulfuric acid aqueous solution, The said manufacturing method characterized by the above-mentioned. A method for producing a joined body of a metal alloy and an adherend according to claim 21,
The surface treatment step further includes a step of immersing the steel material that has undergone the chemical etching step in an aqueous solution containing one selected from ammonia, hydrazine, and a water-soluble amine compound. Method. A method for producing a joined body of a metal alloy and an adherend according to claim 21,
The surface treatment step further includes a step of immersing the steel material having undergone the chemical etching step in an aqueous solution containing one selected from hexavalent chromium compounds, permanganates, and zinc phosphate compounds. Said manufacturing method characterized by these. A method for producing a joined body of a metal alloy and an adherend according to claim 13,
The metal alloy is a zinc-based plated steel plate,
The surface treatment step includes a chemical conversion treatment in which the zinc-based plated steel sheet is immersed in an aqueous solution containing trivalent chromium, hexavalent chromium, phosphoric acid, and nickel. A method for producing a joined body of a metal alloy and an adherend according to claim 13,
The metal alloy is a zinc-based plated steel plate,
The method according to claim 1, wherein the surface treatment step includes a chemical conversion treatment in which the zinc-based plated steel sheet is immersed in an aqueous solution containing phosphoric acid, divalent zinc, nickel, and silicofluoride. A method for producing a joined body of a metal alloy and an adherend according to claim 13,
The metal alloy is a zinc-based plated steel plate,
The said surface treatment process includes the chemical conversion treatment which immerses the said zinc-based plated steel plate in the aqueous solution containing phosphoric acid, bivalent zinc, calcium, and nickel. A method for producing a joined body of a metal alloy and an adherend according to one of claims 24 to 26, comprising:
The zinc-based plated steel sheet is a zinc aluminum alloy plated steel sheet,
The manufacturing method according to claim 1, wherein the surface treatment step further includes a chemical etching step of immersing the zinc-aluminum alloy-plated steel sheet in a non-oxidizing acidic aqueous solution before the chemical conversion treatment. On the surface of the α-β type titanium alloy, a roughness on the order of microns having an average interval between peaks and valleys (RSm) of 0.8 to 10 μm and a maximum height roughness (Rz) of 0.2 to 5 μm is generated, and Etching to form fine irregularities due to the presence of both a smooth dome shape and a curved dead leaf shape within an area of 10 μm square, and to make the surface layer a thin layer of metal oxide mainly containing titanium and aluminum A surface treatment step of performing,
An adhesive preparation step of creating an adhesive mainly composed of unsaturated polyester resin or vinyl ester resin;
An application step of applying the adhesive obtained in the adhesive preparation step to a predetermined range of the surface of the α-β type titanium alloy that has undergone the surface treatment step;
An integration step of fixing the adherend to the predetermined range on the surface of the α-β type titanium alloy that has undergone the coating step, and curing the uncured resin by heating to integrate the two,
The manufacturing method of the joined body of the metal alloy and adherend characterized by including these. A method for producing a joined body of a metal alloy and an adherend according to one of claims 13 to 28, comprising:
In the adhesive preparation step, as the curing agent, an organic peroxide that slows the polymerization reaction near normal temperature of the unsaturated polyester resin or vinyl ester resin that is the main component of the adhesive is used. Production method. A method for producing a joined body of a metal alloy and an adherend according to claim 29,
The production method according to claim 1, wherein the organic peroxide is one or more selected from t-butyl-peroxyisopropyl monocarbonate, t-hexyl-peroxyisopropyl monocarbonate, and t-butyl peroxybenzoate. Method. A method for producing a joined body of a metal alloy and an adherend according to claim 29 or 30,
In the adhesive preparation step, the organic peroxide is added after the adhesive is filled with 1% by mass or more of an inorganic filler having a diameter of 1 μm or more. A method for producing a joined body of a metal alloy and an adherend according to claim 31,
In the adhesive preparation step, the organic peroxide is added after the inorganic filler is dispersed in a resin using a wet pulverizer or a wet disperser. A method for producing a joined body of a metal alloy and an adherend according to claim 31 or 32,
In the adhesive preparation step, before the organic peroxide is added, the adhesive is further filled with 0.1 to 1.0% by mass of an ultrafine inorganic filler having a diameter of 100 nm or less. Method. A method for producing a joined body of a metal alloy and an adherend according to claim 33,
The said manufacturing method characterized by the said ultra-fine inorganic filler being fumed silica. A method for producing a joined body of a metal alloy and an adherend according to claim 33 or 34,
In the adhesive preparation step, the organic peroxide is added after the inorganic filler and the ultrafine inorganic filler are dispersed in a resin using a wet pulverizer or a wet disperser. Production method. A method for producing a joined body of a metal alloy and an adherend according to claim 32 or 35,
The method according to claim 1, wherein the wet pulverizer or the wet disperser is a sand grind mill. A method for producing a joined body of a metal alloy and an adherend according to one of claims 13 to 36, comprising:
In the said adhesive preparation process, 5 mass% or less is further filled with a thermoplastic resin, The said manufacturing method characterized by the above-mentioned. A method for producing a joined body of a metal alloy and an adherend according to one of claims 13 to 37, comprising:
After the coating step and before the integration step, the metal alloy is housed in a sealed container, the inside of the sealed container is depressurized, and then the operation of pressurizing is repeated, whereby the adhesive is applied to the surface of the metal alloy. The said manufacturing method characterized by including the process to make it soak. A method for producing a joined body of a metal alloy and an adherend according to one of claims 13 to 38, comprising:
The manufacturing method according to claim 1, wherein the adherend is a metal alloy having the same property as the metal part. 40. A method for producing a joined body of a metal alloy and an adherend according to one of claims 13 to 39, comprising:
The said manufacturing method characterized by the above-mentioned to-be-adhered material being the fiber reinforced plastic which uses unsaturated polyester resin or vinyl ester resin as a matrix resin.