JP2009298144A - Bonded composite article of a plurality of metallic shaped bodies, and method for production thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a bonded composite article of a plurality of metallic shaped bodies which are integrated by injecting a resin composition to the metallic shaped bodies to bond them. <P>SOLUTION: The surface of the bonding parts of a plurality of metallic shaped bodies 11 and 12 has a roughness of a micron order formed by chemical etching, a superfine uneven shape including partition projections or grooved recesses of 10-500 nm in height or depth and width when viewed by an electron microscope and of ≥10 nm in length in a period of 10 to several hundreds nm over the whole surface are formed, and a thin layer is provided with a metal oxide or a metallic phosphorus oxide on the edge part of the above uneven shape. A sealed space 19 between the opposed faces of the metallic shaped bodies is sealed by a frame 15. A resin composition 4 is injected into the sealed space to bond the metallic shaped bodies to form the bonded composite article 26. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a joined composite of a plurality of metal shapes used for transportation machinery, electrical equipment, medical equipment, general machinery, other equipment, and the like. In particular, the present invention relates to a bonded composite of a plurality of metal shapes such as structural parts and cases used in mobile machines such as bicycles, automobiles, airplanes, and mobile robots, medical equipment, and electronic devices, and a manufacturing method thereof. More specifically, regarding a basic metal part, a bonded composite of a plurality of metal shapes obtained by injection-bonding a plurality of metal shapes including different kinds of metals with a crystalline resin composition having high mechanical strength, and production thereof Regarding the method.

  Technology for integrating metal and synthetic resin is required from a wide range of industrial fields such as automobiles, home appliances, parts manufacturing industries such as industrial equipment, and many adhesives have been developed for this purpose. Among these, very good adhesives have been proposed. For example, an adhesive that exhibits a function at room temperature or by heating is used for joining to integrate a metal and a synthetic resin, and this joining method is now a common joining technique.

  However, more rational joining methods that do not use an adhesive have been studied. An example is a method of integrating a high-strength engineering resin into magnesium, aluminum, light metals such as alloys thereof, and iron alloys such as stainless steel without using an adhesive. For example, the present inventors inject a molten resin into an etched metal shape previously inserted into an injection mold and mold the resin portion. Proposed a method (hereinafter referred to as “injection joining”) for joining (adhering) to each other.

  This joining technique is an integrated technique in which, for example, polybutylene terephthalate resin (hereinafter referred to as “PBT”) or polyphenylene sulfide resin (hereinafter referred to as “PPS”) is injection-bonded to an aluminum alloy (for example, , See Patent Document 1). In addition, there is also disclosed a technique in which a large hole is provided in an anodized film of an aluminum material and a synthetic resin body is bitten into the hole and bonded (see, for example, Patent Document 2).

  The principle of this injection joining in the proposal of Patent Document 1 is as shown below. The aluminum alloy shaped product is immersed in a dilute aqueous solution of a water-soluble amine compound, that is, the aluminum alloy shaped product is finely etched by a weak base of the aqueous solution. Further, it has been found that in this immersion treatment, adsorption of amine compound molecules occurs simultaneously on the surface of the aluminum alloy shaped article. The aluminum alloy shaped article subjected to this treatment is inserted into an injection mold, and a molten thermoplastic resin is injected at a high pressure.

  At this time, heat is generated by encountering the thermoplastic resin and amine compound molecules adsorbed on the surface of the aluminum alloy shaped article. Almost simultaneously with this heat generation, this thermoplastic resin is rapidly cooled in contact with the aluminum alloy shape maintained at a low mold temperature, but since a heat generation phenomenon occurs, the resin to be solidified while crystallizing for this reason As a result, solidification is delayed and the molten state is maintained, and the material enters the recess on the surface of the ultrafine aluminum alloy shaped article. The molten resin is solidified after entering the recess. Thus, the aluminum alloy shaped article and the thermoplastic resin are firmly joined (hereinafter also referred to as fixation) without the resin being peeled off from the surface of the aluminum alloy shaped article.

  That is, since the exothermic reaction between the amine compound molecules and the molten resin occurs, strong injection joining can be performed. In fact, it has been confirmed that PBT, PPS, and the like that can react exothermically with amine compounds can be injection-bonded with the aluminum alloy. In addition, a technique of inserting a metal part that has been chemically etched in advance into an injection mold of an injection molding machine and injection molding using a thermoplastic resin material is also known (see, for example, Patent Document 3). ). Although this includes shape conditions, it is still one of the techniques related to injection joining. Further, surface treatment techniques relating to various metals are described in detail in Patent Documents 8 to 13, which are the prior inventions of the present applicant.

JP 2004-216425 A WO2004-055248 A1 JP 2001-225352 A PCT / JP2007 / 073526 PCT / JP2007 / 070205 PCT / JP2007 / 0774749 PCT / JP2007 / 075287 PCT / JP2008 / 54539 PCT / JP2008 / 57309 PCT / JP2008 / 056820 PCT / JP2008 / 57131 PCT / JP2008 / 57922 Japanese Patent Application No. 2007-140072

  The technical principle of Patent Document 1 by the present inventors shows a clear effect in aluminum alloys, but it has been confirmed that there is a certain effect also in metals other than aluminum alloys (Patent Documents 8 to 13). reference). The inventors of the present invention have found a new technique in the course of research and development and improvement of injection joining of a hard resin to an aluminum alloy. In other words, we found the conditions that enable injection joining that shows strong adhesion without chemisorption of amine compounds on the surface of metal parts, in other words, without obtaining the assistance of any specific chemical reaction such as a special exothermic reaction. It was.

  This requires at least two conditions. One is to use a hard, highly crystalline resin, that is, to use PPS, PBT, aromatic polyamide, etc., but this is not sufficient, and these are further improved in composition for injection joining. It is necessary to use it. The other conditions are those required on the metal alloy side, in which the surface layer of the metal part has an appropriate roughness (surface roughness) shape and the surface is hard. An outline of the roughness shape is as follows. There are irregularities with a period of 1 to 10 μm (referred to as “micron order period” in the present invention), and at least on the inner wall surface of the concave part, a period of several tens to several hundreds of nm. This is a double concavo-convex roughness structure with fine irregularities. And the surface which makes this roughness is that it is a thin layer of a metal oxide or a metal phosphate, that is, it is a high-hardness ceramic material.

  The thickness of this thin layer is sufficient if it is 10 to several tens of nanometers, and it is preferable that the metal species having a corrosion resistance in the natural oxide layer is thicker than the natural oxide layer. In addition, in the case of a metal species that does not have sufficient corrosion resistance in the natural oxide layer, such as magnesium alloy and general steel material, the surface layer is made of an oxide or phosphor oxide of a metal species different from the base metal by performing a chemical conversion treatment or the like. It is preferable. In short, it is a necessary condition that the surface layer is made of a ceramic material having a hardness higher than that of the metal. For example, when using a shape based on a copper alloy to make a high-hardness ceramic material, when immersed in an aqueous hydrogen peroxide solution made acidic, copper is oxidized to copper ions, resulting in immersion If the conditions are appropriate, the base material is chemically etched to a roughness of several μm.

  Next, when the chemically etched copper alloy shaped product is immersed in a strongly basic sodium chlorite aqueous solution, copper is oxidized but copper ions cannot be dissolved. Therefore, the surface is covered with a thin cupric oxide layer. Is called. When this surface was observed with an electron microscope, it was found that recesses (openings) having a diameter of several tens to several hundreds of nanometers were covered with fine uneven surfaces having a period of several hundred nanometers. Since the thin layer of cupric oxide is ceramic, the copper alloy shape after this treatment satisfies the above-mentioned conditions.

  Next, assuming the case where this copper alloy shaped article is inserted into an injection mold and resin is injected, the state of injection joining will be described. The temperature of the injection mold at the time of injection joining is set to about 120 to 140 ° C. The shape of the copper alloy inserted in the injection mold is maintained at a temperature 100 ° C. or more lower than the melting point of the resin to be injected (temperature of about 250 ° C. for PBT and temperature of about 300 ° C. for PPS). The molten resin that has entered the flow path of the sprue, runner, etc. in the injection mold is rapidly cooled and is likely to be below the melting point when it comes into contact with the copper alloy part.

  However, in any crystalline resin, when it is rapidly cooled from the molten state and becomes below the melting point, it does not crystallize and solidify immediately after the temperature becomes below the melting point, that is, in zero hours. There is a time for a molten state below the melting point, that is, a supercooled state. When the roughness on the surface of the alloy shape is on the order of microns, that is, when the inner diameter of the recess is about 1 to 10 μm, within a limited time from the supercooling to the formation of the first crystal, that is, the microcrystal, If the depth of the recess is about half of the diameter of the recess, the resin flow to the bottom of the recess even if microcrystals are generated after entering the recess and the viscosity rapidly increases. May reach. In other words, if the number density of the resulting polymer microcrystal group is still small, the resin sufficiently penetrates into the concave portion if the concave portion has a large inner diameter of several μm.

  Furthermore, fine irregularities having a diameter of several tens to several hundreds of nanometers are formed on the inner walls of the micron-order concave portions on the metal alloy. For example, to say exactly about pure copper-based copper alloy, rather than having fine unevenness, a unique fine uneven surface having innumerable hole-like recesses with a diameter of about 100 nm is observed. It is considered that the resin flow that has entered the micron-order concave portion can also enter this fine opening having a diameter of about 100 nm. After that, the resin that has entered the inside of the recess is completely solidified with an amorphous solid that fills the gap between the crystallites and the grown crystals and the crystal group.

  In short, it is presumed that the resin crystallized and solidified in the micron-order recesses has a shape with a slight root protruding into the fine opening on the inner wall surface, and the metal surface layer forming the fine opening is made of copper oxide, that is, ceramic. If it is a hard surface layer, it will be in the form which was firmly joined by the catch of the resin formed in the recessed part, and will not be easily peeled off. Since both the resin side and the metal side have high hardness, even when the solidified resin portion is forced to be peeled off from the metal alloy portion, the solidified resin is difficult to escape from the recess. That is, the injection joining force is increased.

  In the present invention, improvement of the resin composition to be injected is also an important factor. That is, the resin composition used in the present invention is a resin composition that slows the crystallization rate when it is injection molded and rapidly cooled from the molten state to a temperature below the melting point. By using this resin composition, a stronger injection joining force is produced. When the molten resin is cooled and crystallized, a resin composition having a function of delaying the crystallization is a condition of a resin composition suitable for injection joining. In consideration of the above-mentioned conditions, the present inventors chemically etched the copper alloy shaped material as described above, and further converted the surface layer into a ceramic material by surface treatment such as oxidation treatment. It has been found that a crystalline resin is injection-bonded to increase the bonding force and obtain high bondability (see Patent Document 5).

  There is no content that restricts the type of metal in the theoretical description of the injection joining described above. This means that, at least for all metals and metal alloys, if there is a similar surface shape and surface layer properties, injection bonding can be performed using a crystalline resin such as PBT or PPS improved for injection bonding. Is shown. Therefore, the present inventors have demonstrated that the same injection joining can be performed on a titanium alloy, a stainless steel, and a general steel material following a copper alloy. In Patent Document 3, a chemically etched copper wire is inserted into an injection mold, PPS is injected, and a lead wire having a shape in which several copper wires penetrate through the center of a PPS disk-shaped object is provided. A method of making a battery lid is described.

  It is described as a feature that even if the internal pressure of the gas generated in the battery rises due to the formation of irregularities (roughness) on the surface of the copper wire by this chemical etching, the gas does not leak from the lead wire portion. . At first glance, the technique described in Patent Document 3 seems to be similar to the above-described injection joining, but this technique is not an injection joining technique described in detail by the present inventors, but a general injection molding technique. The metal surface is not processed to obtain the surface state and shape as recognized in the present invention. It is a technology that simply uses the difference between the linear expansion coefficient of the metal and the molding shrinkage ratio of the resin, and in order to minimize gas leakage, the unevenness between the metal and the resin is increased to produce a labyrinth effect. Is.

When resin is injection-molded around the metal rod-like substance, the metal rod part is tightened from the resin molded part when the molded product is released from the injection mold and allowed to cool. . This is because even if the linear expansion coefficient of the metal is large, it is 1.7 to 2.5 × 10 ⁻⁵ ° C. ⁻¹ of aluminum alloy, magnesium alloy, copper, copper alloy, etc. Even if it cools, the degree of shrinkage is only 0.2 to 0.3% at a linear expansion coefficient x a few tens of degrees Celsius. However, one of the resins has a molding shrinkage of about 1% for PPS and 0.5% for PPS with glass fiber, and even with a resin with an increased filler, the resin part is always better than the metal part after injection molding. The heat shrinks more.

  Therefore, if a metal part is arranged at the center and a shape that penetrates the resin part is manufactured by injection molding with an insert, the metal part is difficult to come off due to the tightening effect due to thermal shrinkage after molding of the resin part. Chemical products can be manufactured. As described above, a method for producing an integrated product of metal and resin using heat shrinkage is a conventionally known method, and there is a handle of an oil stove as a similar molded product. A thick iron wire having a circular cross section of about 2 mm in diameter is inserted into an injection mold to inject a heat resistant resin or the like.

  The wire is formed with knurled irregularities (knurling) so that the resin is fixed to this and does not move. Patent Document 3 discloses that the uneven processing is made smart by replacing the physical processing method with the chemical processing method by knurling, etc., and the unevenness is made slightly fine, and the resin side is hard and has crystallinity. It is characterized by the effect of gripping by using a lot of resin. The invention group relating to injection joining performed by the present inventors does not require the resin hugging effect, that is, the effect of tightening the wire from the outer periphery.

The present invention enables integration of each of the above-mentioned plurality of metal shapes by injection molding of a hard resin. For example, the linear expansion coefficient of a general steel material is about 1.0 to 1.1 × 10 ⁻⁵ ° C.− ^1, which is about half that of the aluminum alloy and copper alloy described above. Steel materials are not lightweight metals compared to aluminum alloys and the like, but if they are integrated with resin in the same way as light alloys, the range of use of the composites associated with the joining is wide. Considering this, the technique related to the present invention can be applied to steel materials.

  General steel has a specific gravity of about 7.9. It is a material that is both hard and strong and inexpensive. Although corrosion resistance is not sufficient, if this weakness can be overcome, its applicability is great. Therefore, once the composite technology is established, it can be used in a wide variety of fields as parts and casings for various electronic and electrical equipment, medical equipment, on-vehicle equipment, and other general machines. Next, the invention theory relating to the present invention will be described. All the matters related to the above-mentioned joining technique are based on the present inventors, but the principle of these joining is based on a relatively simple joining theory. An example applied to an aluminum alloy will be described.

  Regarding the injection joining of aluminum alloys, the present inventors named the joining theory as the “NMT” (Nano molding technology) theory hypothesis, and the “new NMT” theory hypothesis for the injection joining of all metal alloys. The theoretical hypothesis advocated by Naoki Ando, one of the inventors of the present invention, about the “new NMT” that can be used in a broader sense is as follows. That is, in order to obtain injection joining with a strong joining force, there are conditions on both the metal alloy side and the injection resin side, and the following conditions are necessary on the metal side. That is, three conditions are necessary on the metal alloy side.

  The first condition is that the unevenness of the unevenness with a period of 1 to 10 μm is rough by chemical etching technique, and the unevenness height difference is about half of the period, that is, 0.5 to 5 μm. However, industrially, it is not easy to form the entire surface with the rough surface (a surface having a certain surface roughness) by a chemical reaction that is uneven and uneven. A specific rough surface, when viewed with a roughness meter (surface roughness meter), has irregular irregularities in the range of 0.2 to 20 μm, and the maximum height difference is in the range of 0.2 to 5 μm. A certain roughness curve can be drawn, or by scanning analysis with a scanning probe microscope, the average period according to “JIS B 0601: 2001 (ISO 4287)” of the Japanese Industrial Standard (JIS), that is, the average of the surface roughness curve If it is a roughness surface (surface having a certain surface roughness) having a length (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, it is described above. It is considered that the roughness condition was substantially satisfied.

  The inventors of the present invention have referred to as “a surface having a roughness on the order of microns” as an easy-to-understand word because the ideal rough surface irregularity period is 1 to 10 μm as described above. Furthermore, the second condition is that an oxidation treatment or the like is added and the inner wall surface of the recess has a fine uneven surface with a period of 10 nm or more, preferably 50 nm. Further, the third condition is that the above-mentioned rough surface of the metal alloy is a ceramic material, specifically, a metal oxide thicker than the natural oxide layer or a thin layer of metal phosphorous oxide.

  On the other hand, the injection resin side has the following conditions. The condition of the resin to be injected is a hard crystalline resin, and a composition that generates a time lag can be used by slowing down the crystallization speed at the time of quenching by compounding another polymer suitable for them. . Actually, in addition to PBT or PPS which is a crystalline hard resin, a resin composition in which an appropriate other polymer and glass fiber are compounded is optimal, and this can be used. These can be used for injection joining with a general injection molding machine or injection mold, and this process will be described according to the above-mentioned “new NMT” hypothesis named by the present inventor.

  The injected molten resin is introduced into an injection mold whose temperature is lower by about 150 ° C. than the melting point, and is cooled in a flow path such as a sprue or runner of the injection mold to a temperature below the melting point. It seems to have become. That is, when the melted crystalline resin is rapidly cooled, even if the melted resin has a melting point or lower, crystals are generated and do not solidify in zero hours. In short, it is in a melted state below the melting point, that is, a supercooled state for a very short time. As described above, PBT or PPS with a special compound thinks that this supercooling time has been made a little longer, and this phenomenon is used to generate a large amount of microcrystals during this supercooling time. Before the viscosity suddenly increases, the microcrystals can penetrate into the recesses on the metal surface of micron order. Since it cools even after intrusion, the number of microcrystals increases rapidly with this, and a viscosity rises rapidly.

  However, it is estimated that whether the resin can reach the bottom of the recess depends on the size and shape of the recess. In the experiment results of the present inventors, the metal type is not selected, and a recess having a diameter of 1 to 10 μm, or a recess having a roughness of 1 to 10 μm, and having a depth or a height difference of about half of the period is fine. It seemed to invade deeper. Furthermore, if the inner wall surface of the recess is rough, as seen from the second condition described above, a part of the resin also enters the gaps between the fine irregularities, and as a result, the pulling force on the resin side It seems that even if it is loaded, it will become difficult to pull out. If the rough surface is a metal oxide as in the third condition, this hardness is high, so that a hook like a spike is effective.

The bonding itself is a problem of the resin component and the surface of the metal alloy. However, if the resin composition contains reinforcing fibers or inorganic fillers, the linear expansion coefficient of the entire resin can be made close to that of the metal alloy, so It becomes easy to maintain the bonding force. According to such a hypothesis, for example, a magnesium alloy, a copper alloy, a titanium alloy, stainless steel or the like obtained by injection-bonding a PBT or PPS resin with a shear breaking force of 200 to 300 kgf / cm ² (about 20 to 30 N / mm ² = 20 to 30 MPa) or more, and even the tensile breaking force is 300 to 400 Kgf / cm ² (30 to 40 MPa) or more, and it has been confirmed that a strong integrated body of metal and resin is obtained.

  The present inventors believe that the “new NMT” theoretical hypothesis is correct because it can be demonstrated by injection joining of many metal alloys, but this hypothesis relates to the basic part of polymer physical chemistry. Inference is the basis, and verification by a large number of chemists and scientists is essential. For example, the melted crystalline resin at the time of rapid cooling is uniquely determined, but from the viewpoint of polymer physics, whether or not the crystallization speed actually decreases has been hardly discussed. The present inventors think that this inference is correct, but it has not been verified from the front.

  That is, this injection joining is a high-speed reaction under high temperature and high pressure and cannot be directly measured. Moreover, the hypothesis advocates a completely physical anchor effect theory about joining, and deviates slightly from conventional common sense. As far as the present inventors know, in various works edited by current bonding experts, there are many descriptions explaining the bonding force when bonded by chemical factors. Again, important conditions for injection joining of metal and resin are summarized from the two hypotheses of the present inventors. That is, this is a condition for obtaining a strong injection joining force.

The first hypothesis (hereinafter referred to as “NMT”) was originally only for aluminum alloys,
(A) The surface has fine irregularities with an irregular period of 20 to 80 nm obtained by chemical etching. The entire surface is covered with the fine recesses.
(B) The surface is covered with a metal oxide layer thicker than the natural oxide layer, and at least one selected from ammonia, hydrazine, and a water-soluble amine compound is chemisorbed.
(C) Crystalline resins such as PBT, PPS, and polyamide-based resins can be used as the resin. Preferably, a composition with an improved composition is used so that the crystallization rate during quenching is reduced. It is a condition.

In the second hypothesis (hereinafter referred to as “new NMT”),
(1) It is a rough surface with unevenness of 1 to 10 μm cycle by chemical etching method, and the unevenness height difference is about half of the cycle, that is, 0.5 to 5 μm. However, in actuality, it is difficult to cover the entire surface with the rough surface by a chemical reaction with variation. Specifically, when viewed with a conventional roughness meter, it is irregular in the range of 0.2 to 20 μm. A roughness curve having a period unevenness and a maximum height difference of 0.2 to 10 μm can be drawn.

  Or, the surface of the surface is scanned and analyzed with the latest scanning probe microscope, and the average period according to “JIS B 0601: 2001 (ISO 4287)” of the Japanese Industrial Standard (JIS), that is, the average length of the roughness curve. A roughness surface with (RSm) of 0.8 to 10 μm and a maximum height roughness (Rz) of 0.2 to 5 μm is considered to substantially satisfy the roughness condition described above. As described above, the present inventors have referred to the “surface having a roughness on the order of microns” as an easy-to-understand term because the ideal rough surface irregularity period is 1 to 10 μm as described above.

(2) The surface is sufficiently hard (chemically) and chemically stable, and has fine irregularities with an irregular period of 10 to 500 nm such as anti-slip. In other words, the inner wall surface of the concave portion with the large unevenness is a rough surface when the unevenness is severe as viewed with an electron microscope.
(3) A crystalline resin composition having a high hardness can be used as the resin, and in particular, a resin composition improved so as to slow down the crystallization rate during rapid cooling is a condition.

The inventor has verified the “NMT” hypothesis for aluminum alloys, and the “new NMT” hypothesis for aluminum alloys, magnesium alloys, copper alloys, titanium alloys, stainless steels, and steel materials. The present invention is considered as a technique based on these technical backgrounds. In other words, the “new NMT” technology has been demonstrated for a plurality of the aforementioned metal shapes. The present invention has been made based on the above technical background and achieves the following object.
SUMMARY OF THE INVENTION An object of the present invention is to provide a bonded composite of a plurality of metal shapes and a method for manufacturing the same, which are obtained by injection-bonding and integrating a resin composition to a plurality of metal shapes to obtain a strong bonding force. There is to do.
Another object of the present invention is to provide a bonded composite of a plurality of metal shapes, which can be mass-produced, and a production method thereof.

The present invention takes the following means in order to achieve the object.
The gist of the joined composite of a plurality of metal shapes as a main component of the present invention is as follows.
A surface having a roughness on the order of microns by chemical etching, and the surface is a convex or concave portion having a height or depth, width, and length, and has an ultra fine uneven shape existing on the entire surface, and A metal space having a thin layer of metal oxide or metal phosphate on the surface and a facing space between the plurality of metal shapes and a sealed space, and a plurality of the metal shapes A structure for positioning and fixing in a fixed position and a crystal in which a molten resin is injected into the sealed space, enters the ultra-fine uneven shape, joins the plurality of metal shapes, and is integrated with each other It consists of a functional resin composition.
In the joined composite, the plurality of metal shapes may be metal shapes of dissimilar metals.

The ultra-fine concavo-convex shape can be said to be almost common to a plurality of metal species, and the height or the depth and the width are 10 to 500 nm and the length is 10 nm or more by electron microscope observation. Or the said recessed part is good in it being a period of 10 to several hundred nm.
Or, the ultra-fine concavo-convex shape can be said to be almost common to a plurality of metal types, and the height or the depth is 10 to 500 nm and the length is 10 to 350 nm as observed with an electron microscope. Or the said recessed part is good in it being a 10-500 nm period.

The gist of the manufacturing method of the joined composite of multiple metal shapes of the present invention is as follows:
The surface of the metal shape has a micron-order roughness by chemical etching, and the surface is a convex or concave portion having a height or depth, width, and length, and an ultra fine irregularity existing on the entire surface. And forming a thin layer of metal oxide or metal phosphate on the surface, and defining a sealed space between the opposing surfaces of the plurality of metal shapes, and a plurality of the metal shapes And a step of injecting a molten resin into the sealed space and joining with a crystalline resin composition that penetrates into the ultra-fine uneven shape and integrates the plurality of metal shapes with each other It is made up of.
In the manufacturing method, the plurality of metal shapes may be metal shapes of different metals.

  The contents of the present invention showing the metal shape for each metal alloy are in accordance with the respective claims of the present invention, and the detailed description of the means related to the claims is to be referred to the respective claims. Description of the contents is omitted. The elements of the means constituting these will be described in detail below.

[Metal alloy parts / Required surface treatment]
The surface shape, state, conditions, etc. of the metal alloy of the adherend used in the present invention are in accordance with the above-mentioned “NAT (Nano Adhesion Technology)” theoretical hypothesis. The “NAT” theory was proposed by Ando, one of the inventors, with a hypothesis. Details are also described in the above-mentioned patent documents. In order to facilitate understanding of the present invention, the essence of the “NAT” theoretical hypothesis, including the definition of “surface with a micron order roughness” related to surface treatment, will be described in more detail below.

  The basic configuration of the metal alloy will be described below with a focus on the example of an aluminum alloy. “NAT” will first describe the “new NMT” theoretical hypothesis that the present inventor has inherited the idea of the invention of injection joining technology using a thermoplastic resin in the past. According to the "new NMT" theoretical hypothesis, the surface state required for the metal alloy as the material to be joined is described as follows: (1) Roughness surface obtained by chemical etching (surface having a certain surface roughness), that is, a period of 1 to 10 μm First, it can be said that it is a rough surface (surface roughness surface) whose unevenness difference is about half of the period, that is, 0.5 to 5 μm. This is because the injection molding is the injection of a high-pressure molten resin of several hundred to 1,000 atmospheres into the injection mold, but it flows into the mold a few tens of degrees Celsius lower than this melting point and is rapidly cooled to crystallize and solidify. It depends on the diameter of the recessed part which can somehow flow in for the resin which is going to be 1-10 micrometers.

  However, in reality, it is difficult to completely cover the surface of the metal alloy with this rough surface by a chemical reaction with variation. Specifically, when measured with a surface roughness measuring instrument, the range is 0.2 to 20 μm. A roughness curve with irregular irregularities and a maximum height difference of 0.2 to 10 μm can be drawn, or it can be automatically analyzed with the latest scanning probe microscope, Japan Industrial Standard (JIS) Roughness in which the average length (RSm) of the roughness curve referred to in “JIS B 0601: 2001 (ISO 4287)” is 0.8 to 10 μm and the maximum height roughness (Rz) is 0.2 to 10 μm. If it is a surface, it is considered that the roughness condition described above was satisfied. As described above, the present inventors define an ideal rough surface unevenness period of 1 to 10 μm, and as an easy-to-understand technical term, this invention defines “a surface having a roughness on the order of microns”. .

  Further, (2) when the surface is enlarged to the electron microscope level, it has a fine uneven surface with a period of 10 to 500 nm, most preferably a fine uneven surface with a period of 40 to 50 nm, and (3) The surface was required to be thicker than the normal natural oxide layer of the metal alloy or covered with a stronger metal oxide, or a thin layer of metal phosphate, ie a ceramic thin layer. As described above, the three conditions necessary for this metal alloy side can be obtained for all of magnesium alloys, titanium alloys, copper alloys, stainless steels, steel materials, etc. including aluminum alloys. By injection joining, a shear breaking force between 20 to 40 MPa, a strong metal and a hard resin, and a tensile breaking force were obtained.

  In short, it has been clarified that the hypothesis that the above-mentioned three conditions are necessary on the metal side regarding injection joining is correct. At that time, the present inventors anticipated that this hypothesis should be effective not only for injection bonding but also for bonding of adhesive (adhesion). Theoretically, the conditions required for the adherend are not limited to metal non-metals, but since only metal alloys have been demonstrated, the adherend is described as a metal alloy in a narrow sense. The metal alloy types that the present inventors have verified based on “NAT” are six types of structural metals and practical metals such as aluminum alloys, magnesium alloys, copper alloys, titanium alloys, stainless steels, and steel materials. These demonstration metals are the main metals actually used, and the present inventors understand that the hypothesis is correct as described above.

  Check again the conditions required for the adherend by “NAT” theory. That is, (1) there is a roughness on the order of microns by chemical etching, and (2) the surface has fine irregularities with a period of 10 nm or more, preferably fine irregularities with a period of about 50 nm as seen by electron microscope observation, and (3) The surface is covered with a thin layer of ceramic material, that is, metal oxide, metal phosphate, or the like. And, it is said that the effect is great when a joining system is made by using a thermosetting adhesive resin (epoxy resin, etc.) for such an adherend, and the reason is that the complete anchor effect as described above. It is based on the theory.

  Further, the above points will be described in concrete terms. First, the roughness on the micron order referred to in (1) is specifically irregular irregularities with a period of 1 to 10 μm, and the depth and height difference of the irregularities is about half or less, that is, 0.5 μm to It is about 5 μm. In the present invention, this is defined as “a surface having a roughness on the order of microns”. This roughness measurement is preferably performed with the latest scanning probe microscope. The recent scanning probe microscope has an average length (RSm) of the roughness curve, as described in “JIS B 0601: '01, ISO 4287: '97 / ISO 1302: '02” of Japanese Industrial Standard (JIS). The height roughness (Rz) and the like are automatically calculated to quantify the roughness.

  The preferable roughness ranges in numerical values when using this scanning probe microscope are as follows: the average length (RSm) of the roughness curve is 0.8 to 10 μm, and the maximum height roughness (Rz) is 0.2 to 5.0 μm. It is. However, in the scanning probe microscope, the uneven period, that is, the interval between the peaks and valleys may show completely different values. The scanning probe microscope is set up to pass an irregular period that is too small in the calculation software, but the average length (RSm) picks up the irregularities finer than the actual condition to improve the sharpness of the probe tip. It may not be represented. In order to find such a case, it is necessary to re-confirm the value of the average length (RSm) by visually inspecting a roughness curve graph that can be obtained by a scanning probe microscope, instead of looking only at the calculated numerical value. is there.

  In addition, when a scanning probe microscope cannot be used and a roughness curve graph is drawn with a conventional roughness meter (surface roughness meter), the graph is visually inspected and the average length of each surface roughness is measured. All of the (valley interval (irregularity period)) is almost occupied by indefinite ones in the range of 0.2 to 20 μm, and the individual mountain valley height differences are almost all contained in the range of 0.2 to 5 μm. If present, it was actually almost the same as described above. This visual inspection method can also be used when it is determined that automatic calculation with a scanning probe microscope is not reliable. In the present invention, the roughness (surface roughness) is represented by the technical term “roughness on the order of microns”.

  Next, “chemical etching” performed to obtain the roughness will be described. In addition to chemical etching, there is a method that can form an ideal surface shape, but in the present invention, “chemical etching” is applied. For example, as an alternative method, if an advanced ultra-fine processing method is applied, such as applying a photochemical resist and using visible light, ultraviolet rays, etc., the desired uneven surface can be realized if the roughness is on the order of microns. It becomes possible. However, chemical etching is an operation that involves simply immersing a metal alloy in an acid-base aqueous solution that has corrosive properties on the entire surface, and then washing the metal alloy with water. It produces a favorable result.

  That is, when chemical etching is performed under appropriate conditions, not only an appropriate uneven period and an appropriate recess depth can be obtained, but the shape of the obtained recess is not a simple shape, and many of the recesses are partly part of them. Under structure. The under structure is a shape in which the inside of the hole is wider than the opening when the recess is viewed on the opening and the hole side. Accordingly, after the liquid to be solidified is sealed and solidified in the hole, the solidified shape becomes larger than the opening due to the solidification of the liquid, so that it cannot be taken out due to a so-called wrinkle effect. This is why the under structure is suitable for bonding (adhesion).

  Next, it is very difficult to express the fine uneven surface in (2) with words and numerical values, but simply speaking, it is “gritty” with the microscopic eyes. If expressed numerically, the unevenness with a period of 10 nm or less is too fine and not smooth, but rather smooth, and if it is 350 nm or more, the unevenness is too coarse and the number of uneven periods is reduced, so that the bonding force is reduced. As described above, from the results obtained from a large number of experiments, with regard to the use of normal bonding, the fine uneven surface with a period of 40 to 50 nm seems to exhibit the anchor effect most. FIG. 3 shows the relationship between the uneven surface with a period of 50 nm and the micron order roughness. FIG. 3 is a partial schematic view of a state in which a crystalline resin composition 22 is injection-bonded to a plurality of metal base material portions 20a and 20b via a metal oxide thin film or a metal phosphate thin film 21 and cured. It is sectional drawing shown.

  A concrete and ideal image of the bonded (adhered) state is drawn and shown in FIG. 3, and the surface has a valley (unevenness) with a period of 50 nm (A) and a height of 20 to 50 nm (B ) A surface having a certain level of wall and protrusions is a fine uneven surface formed repeatedly by forming a plurality of groups of unevenness (C) having a width of 2 to 3 μm. Actually, the theoretical fine uneven surface as shown in FIG. 3 cannot be found by observation with an electron microscope. Its shape is random and complicated, and it has a wide variety. Moreover, it differs depending on the metal type and its alloy type, and also on the surface treatment process used.

  Visually speaking with an electron microscope, it is “a rough surface as seen with a microscopic eye”. In other words, “a partition-like convex part having a height or depth and width of 10 to 500 nm and a length of 10 nm or more. Or a groove-like recess having a period of 10 to several hundreds of nanometers, and an extremely fine uneven shape existing on the entire surface, or “a height or depth of 10 to 500 nm and a diameter of 10 to 500 nm. This is an expression of “ultra-fine concavo-convex shape existing on the entire surface with a period of several hundred nm”. As described above, in the unevenness of 10 nm or less, it is difficult to enter the gap, and in that sense, the surface is not smooth and is not preferable, and in the unevenness with a period of 500 nm or more, the density of the portion to be caught as an anchor is low. Since it is small, the bonding force decreases. Most preferably, although it depends on the diameter and period of the large recess determined by the roughness, fine unevenness with a period of 50 nm is the most preferable result, but it is possible to show a very strong bonding force even at 30 to 350 nm. .

  There are some that deviate from the expressions (1) and (2). This is a part of the titanium alloy, which will be described in detail in the section of titanium alloy. The thin layer such as metal oxide and metal phosphorous oxide referred to in the above (3) may be a surface layer formed by an oxide of the metal itself in many metal alloy types. The theory requires a hard surface layer at the ceramic level. In short, if the rough surface in the electron microscope observation in (2) is made of the hard material in (3), the rough surface penetrates into the large concave portion (rough surface) in (1) and solidifies. Even if the bonding resin is held together by spike protrusions and a pulling force is applied to the bonding resin, the bonding resin cannot be pulled out from the recess.

  This produces a strong bonding (adhesion) force that has not been achieved in the past. When the metal alloy base material is an adherend, it is desirable that the metal be a metal oxide layer that is thicker than the natural oxide film it possesses under normal conditions. Moreover, the thing which performed the oxidation process intentionally if necessary and made the metal oxide layer moderate thickness is also preferable. However, the thickness refers to a nano-order thickness up to several tens of nanometers, and is not at the level of a metal oxide layer having a thickness of several tens to several tens of μm, such as anodic oxidation (alumite) for an aluminum alloy. . Rather, when the oxide crystal is made thick enough to be detected by an XRD (X-ray diffraction analyzer), the bonding force seems to be deteriorated.

  This is because, when a thick metal oxide layer is formed, the bonding force with the metal phase of the substrate is inferior to that of adhesive bonding. Also, especially in the case of magnesium alloy, general steel materials, etc., the metal oxide layer on the surface is not magnesium oxide, iron oxide, etc., but is made of ceramics with manganese oxide, chromium oxide, zinc phosphate, and other corrosion resistance. Preferably there is. This is a protective measure against the fact that natural oxide films such as magnesium and steel do not have strong corrosion resistance, and it is not necessary to cover them with an oxide film of another metal in the case of a metal alloy type whose own oxide film has corrosion resistance.

  The surface treatment method performed for satisfying the above conditions varies depending on each metal species. These surface treatment methods are all for satisfying the NAT conditions (1), (2) and (3). Specific methods performed by the present inventors for aluminum alloys, magnesium alloys, copper alloys, titanium alloys, stainless steel, general steel materials, etc. are shown in the aforementioned Patent Documents 1-6. However, it is possible to satisfy the “NAT” theoretical hypothesis even if the surface treatment method is not disclosed in these patents. Furthermore, even when performing adhesive bonding using non-metals and other than the above metal species, if the surface shape indicated by the “NAT” theoretical hypothesis is used, a very strong bonding force can be obtained. This is because there are already many empirical examples, albeit hypotheses. A description will now be given of the bonding treatment forms of various metal alloys for which specific methods have been developed.

[Aluminum alloy parts]
Aluminum alloys used in the present invention are all alloys such as A1000 series to 7000 series corrosion resistant aluminum alloys, high strength aluminum alloys, heat resistant aluminum alloys, etc. Cast aluminum alloys such as ADC1-12 (die cast aluminum alloy) 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. Further, as the wrought alloy, it is also possible to use a plate material which is an intermediate material, or a part which is formed by applying mechanical processing such as press working.

[Surface treatment / pretreatment of aluminum alloy parts]
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 an aqueous solution obtained by putting a commercially available degreasing material for aluminum alloy into hot water at a concentration as specified by the drug manufacturer is prepared and immersed in this. It is preferable to wash with water. 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 product is immersed for 5 to 10 minutes.

  Subsequent pretreatment steps are handled differently for an alloy containing a relatively large amount of silicon in an aluminum alloy and an alloy containing a small amount 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, after the aluminum alloy part is immersed in an acidic aqueous solution for a short time, it is preferably washed with water and the acid component is adsorbed on the surface layer of the aluminum alloy part 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, after being immersed in a strongly basic aqueous solution, this is washed with water and etched.

  By this etching, fats and oils, dirt, etc. 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 micron level roughness, that is, a roughness curve according to “JIS B 0601: '01 (ISO4287: '97 / ISO1302: '02)” of Japanese Industrial Standards (JIS). The average length (RSm) is 0.8 to 10 μm, and the maximum height roughness (Rz) is 0.2 to 5.0 μm. These numbers are automatically calculated if they are applied to a modern scanning probe microscope. However, in the above automatic calculation method that automatically omits fine irregularities, the calculated average length RSm value of the surface roughness curve may not represent the actual situation.

  More precisely, it is necessary to re-check the value of the average length (RSm) by visually inspecting the roughness of the roughness curve that can be output by the scanning probe microscope. In addition, when the roughness curve 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 actual situation is almost the same as described above. 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, the “surface having a micron-order roughness” is used.

  This surface has a micron order roughness (surface roughness). The working solution is preferably treated by immersing a caustic soda aqueous solution having a concentration of 1% to several percent at a temperature of 30 to 40 ° C. for several minutes. Next, after dipping again in an acidic aqueous solution such as a thin mineral acid aqueous solution, it is preferably washed with water to remove sodium ions and finish the pretreatment. 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, for casting aluminum alloys such as ADC10 and ADC12 having a high silicon content, the following steps are preferably performed.

  That is, after the degreasing step of removing fats and oils from the surface of the aluminum alloy, it is preferable to perform pickling in the same manner as described above, and to etch with a caustic soda aqueous solution, an aqueous hydrogen difluoride ammonium solution, or the like. In this etching, copper, silicon, etc. are not dissolved, but become fine black smut (hereinafter referred to as “smut” in the metal plating industry) and adhere to the aluminum alloy surface. To do. Therefore, in order to melt and remove the smut, it is then preferable to immerse in a nitric acid aqueous solution having a concentration of several percent.

  By this immersion, the copper smut is dissolved, but the silicon smut is not dissolved and floats slightly from the surface of the aluminum alloy. 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 physically peeled off by immersing in a water tank to which ultrasonic waves are applied, and ultrasonically 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 it again in a dilute nitric acid aqueous solution for a short time and then wash it with water. This completes the preprocessing.

[Surface treatment of aluminum alloy parts / Main treatment]
The aluminum alloy part that has undergone the pretreatment is subjected to the following surface treatment, which is the final treatment, that is, the main treatment. The pre-treated aluminum alloy part is immersed in an aqueous solution containing any one or more of hydrated hydrazine, ammonia, and a water-soluble amine compound, then washed with water and further dried at a temperature of 70 ° C. or lower. This treatment is a revival measure against a slight change in the surface due to the sodium removal ion treatment performed in the final treatment of the pretreatment, and the roughness (surface roughness) is maintained, but the surface becomes slightly smoother. But there is.

  In other words, this treatment is performed by immersing in a weakly basic aqueous solution such as a hydrated hydrazine aqueous solution for a short time and performing ultrafine etching, and the surface has a 10-100 nm diameter with an equivalent height or depth of recesses or protrusions. It is intended to cover a fine uneven surface. In other words, it is formed so that a large number of fine irregularities having a period of 40 to 50 nm occupy on the inner wall surface of the concave and convex of micron order. This surface state is preferably finished to a surface having a high roughness when the sensation seen in the electron micrograph is visually stated. Further, when the drying temperature after washing with water is set to a high temperature of 100 ° C. or higher, for example, 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 a strong and preferable surface layer, and it is necessary to prevent boehmite formation. The humidity in the dryer is affected not only by the size and ventilation of the dryer, but also by the amount of aluminum alloy that is introduced. In this sense, in order to prevent boehmite formation on the surface, it is preferable to dry with warm air at 90 ° C. or lower, preferably 70 ° C. or lower, whatever the input conditions, in order to obtain good results with good reproducibility. When dried at 70 ° C. or lower, surface element analysis by XPS can detect only aluminum (trivalent) from the peak of aluminum, and aluminum (zero valent) that can be detected by XPS analysis of commercially available A5052, A7075 aluminum alloy sheet materials, etc. There is no.

  XPS analysis can detect elements existing at a depth of 1 to 2 nm from the metal surface. From this result, after immersing in an aqueous solution of hydrated hydrazine, amine compound, etc., this is washed with water and further dried with warm air Thus, it was confirmed that the original natural oxide layer (a thin aluminum oxide layer having a thickness of about 1 nm) that the aluminum alloy had became thicker by this treatment. It has been found that, unlike at least the natural oxide layer, it has a thickness of 2 nm or more. In other words, 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 analysis was not performed after this.

  If the ceramic material is thick, it may break due to a difference in physical properties in the extreme state. Therefore, it is preferable that the metal oxide layer is thin, and further, the metal oxide is preferably bonded to the substrate if it is an amorphous or microcrystalline ceramic material. That is, in order to obtain a shear fracture strength of the bonded product at a level of 50 to 100 MPa, it is better not to make the metal oxide layer thicker than necessary. Therefore, it is not preferable to use unsealed alumite.

Ultrafine etching Hereinafter, the ultrafine etching referred to in the present invention will be described in more detail. When immersed in an aqueous solution of hydrated hydrazine, ammonia, or a water-soluble amine in a weakly basic aqueous solution having a pH of 9 to 10 for an appropriate temperature and for an appropriate time, the entire surface is covered with an ultra-fine irregular shape with a diameter of 10 to 100 nm. It will be broken. In terms of the diameter of the number average (average value of the range observed by electron microscope observation), it is about 50 nm. In other words, it can be easily understood that 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 has been empirically considered that the most preferable period of the ultra-fine irregularities predicted by the present inventors and the diameter of the ultra-fine irregularities will be about 50 nm. The reason for this is that if the irregularity has a period of 10 nm, it is a smooth surface for an adhesive that has a fine irregularity and is viscous rather than a rough surface (referred to by electron microscope observation). In other words, there is no image that is too rough. 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 20 or less samples.

  About 50 nm is a numerical value from an empirical feeling obtained from the experimental results. However, even if aiming for a 50 nm period, such a disciplined chemical reaction cannot be made, and it will vary. If an electron microscopic observation photograph is seen and converted into a numerical value, the result indicates that the surface is an ultra-fine uneven shape with almost 100% of the entire surface covered with a concave or convex portion having a diameter of 10 to 100 nm and an equivalent depth or height. It will be. Actually, when the unevenness having a diameter of 10 to 20 nm occupies most of the surface, and conversely, the unevenness having a diameter of 100 nm or more occupies a large amount, the bonding strength was inferior.

In order to cover an aluminum alloy with a concave or convex portion having such a size, that is, an ultrafine etching experimental example , it is necessary to search for immersion conditions based on trial and error experiments. Speaking of an aqueous solution of monohydric hydrazine of 3.5% concentration at 60 ° C., the immersion time of about 2 minutes is optimal for the immersion of A5052 and A7075 material, and the surface by this immersion time has a diameter of 10 to 100 nm, number average Then, 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 that the aluminum alloy is slightly brownish from the original metallic color, and the absorption of visible light has begun to change. By the way, when the immersion time was 1 minute under the above-mentioned conditions, concave portions having a diameter of 10 to 40 nm were observed in an electron micrograph, and these number average diameters were concave portions 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. In terms of these number average diameters, the immersion time 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. Met. In short, in aluminum alloys A5052 and A7075 in a weakly basic aqueous solution, for some reason, erosion begins with a period of 20 to 25 nm, and first, this creates a recess with a diameter of about 20 nm, and the depth of this recess becomes as deep as the diameter. Thereafter, the edge of the recess was eroded and the diameter of the recess was enlarged, and it was found that erosion in an indefinite direction inside the recess started.

  When so eroded, the simple and strong erosion suitable for adhesive bonding is 3-5% monohydric hydrazine aqueous solution (60 ° C.) immersion in aluminum alloys A7075 and A5052. It was almost 2 minutes. In the case of ammonia water, the pH is lower than that of the hydrazine aqueous solution, and when the aqueous solution is heated from room temperature (15 ° C. to 25 ° C.), the volatilization of ammonia becomes intense. Therefore, the ammonia water is immersed at a high concentration and a low temperature, and even when the most concentrated ammonia water of about 25% concentration is used at room temperature, an immersion time of 15 to 20 minutes is required. On the contrary, many water-soluble amines become a basic aqueous solution stronger than the hydrazine aqueous solution, so that the treatment is performed in a shorter time.

  In mass production processing, the stability of work is lost when the immersion time is too long or too short. In that sense, it can be said that hydrated hydrazine, which can have an optimum immersion time of several minutes, is suitable for practical use as a fine etching aqueous solution. In either case, there was an alloy type 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. Although it is assumed that the thickness of the metal oxide layer on the surface is large, analysis is difficult and difficult for thicknesses of 2 nm or more.

[Magnesium alloy parts]
As the magnesium alloy used in the present invention, an alloy such as AZ31B, which is a magnesium alloy for extension specified in Japanese Industrial Standard (JIS), a magnesium alloy for casting such as AZ91D, or the like can be used. If it is a magnesium alloy for casting, the part shape | molded by the sand mold, the metal mold | die, the die-casting method, etc., and the part which machined it further and adjusted the shape can be used. Further, with the wrought alloy, it is possible to use intermediate materials such as plates, rods, pipes, etc. by applying mechanical processing such as pressing, cutting, grinding, etc. to shaped parts, frames, and the like.

[Surface treatment / chemical etching of magnesium alloy parts]
It is preferable that the magnesium alloy parts are first immersed in a degreasing tank to remove oils, finger grease and the like 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 a normal commercial product, the liquid temperature is 50 to 80 ° C. with a concentration of 5 to 10%, and the liquid is immersed in this liquid for 5 to 10 minutes.

  Next, the magnesium alloy is chemically etched by being immersed in an acidic aqueous solution for a short time and washed with water. The surface layer of this magnesium alloy, including dirt that could not be removed in the degreasing process, was peeled off, and at the same time the roughness on the order of microns, that is, Japanese Industrial Standard (JIS) “JIS B 0601: 2001” measured by scanning probe microscope observation measurement. In terms of roughness, the average length (RSm) of the roughness curve is 1 to 10 μm, the maximum roughness height (Rz) of the roughness curve element is 0.2 to 5 μm, and the conventional roughness In terms of measurement methods that do not involve computer calculations using a meter, the roughness (surface) has a roughness (roughness) curve with a height difference of 0.2 to 5 μm at irregular intervals in the range of 0.5 to 20 μm. (Roughness).

  The working solution is preferably an aqueous solution of carboxylic acid, mineral acid or the like 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 this etching, aluminum, zinc, and the like usually contained in the magnesium alloy do not dissolve and remain on the surface of the magnesium alloy as black smut. Accordingly, it is preferable to immerse in a weakly basic aqueous solution to dissolve and remove the aluminum smut, and then soak in a strong basic aqueous solution to dissolve and remove the zinc smut. This completes the preprocessing.

[Surface treatment of magnesium alloy parts / main treatment]
The magnesium alloy part that has been pretreated is subjected to chemical conversion treatment. That is, since magnesium is a metal having a very high ionization tendency, the oxidation rate by moisture and oxygen in air is faster than other metals. Although a natural oxide film is formed on the magnesium alloy, it is not strong enough from the viewpoint of corrosion resistance. Even under normal circumstances, oxidative corrosion proceeds due to water molecules, oxygen, etc. diffused from the natural oxide film. Therefore, ordinary magnesium alloy parts are immersed in an aqueous solution of chromic acid, potassium dichromate or the like, and this surface is covered with a thin layer of chromium oxide (called chromate treatment) or contains phosphoric acid. It is immersed in an aqueous solution of a manganese salt, and a treatment for covering the entire surface with a manganese phosphate compound is performed to prevent corrosion. 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. Recently, the chromate-type chemical conversion treatment using a hexavalent chromium compound has been difficult due to problems such as environmental contamination of the chromium compound, and this chemical conversion treatment has not been performed. A chemical conversion treatment using a metal salt other than chromium, referred to as a non-chromate treatment, in fact, the above-described manganese phosphate chemical conversion treatment or silicon chemical conversion treatment is performed. In the present invention, it is particularly preferable to use a weakly acidic potassium permanganate aqueous solution as the chemical conversion treatment aqueous solution. In this case, a coating covering the surface (referred to as a chemical conversion coating) is manganese dioxide.

  Specifically, this treatment method involves immersing the pre-treated magnesium alloy part in a very dilute acidic aqueous solution for a short time, and then washing it with water, so that the remaining sodium ions remain unwashed in the pre-treatment. It is preferable to neutralize and remove, and then immerse it in an aqueous solution for chemical conversion treatment and then wash it with water. As the dilute acidic aqueous solution, a 0.1 to 0.3% aqueous solution such as citric acid or malonic acid is preferable, and it is preferable to immerse the aqueous solution in the vicinity of room temperature for about 1 minute. As an aqueous solution for chemical conversion treatment, an aqueous solution containing potassium permanganate 1.5 to 3%, acetic acid about 1% and sodium acetate about 0.5% is preferably used at a temperature of 40 to 50 ° C. The time is preferably about 1 minute. By these immersion treatments, the magnesium alloy is covered with a chemical conversion film of manganese dioxide, and the surface shape has a large roughness on the order of microns, and when observed with an electron microscope, there are nano-order ultra-fine irregularities. It will be a thing.

[Copper alloy parts]
The copper alloys used in the present invention are pure copper alloys such as C1020 and C1100, C2600 brass alloys, C5600 copper white alloys, and other iron alloys for connectors specified in Japanese Industrial Standards (JIS 3000 series). All copper alloys, etc., such as copper alloys developed for various uses are included. In addition, plastic products such as intermediate plates, strips, tubes, rods, wires, etc., and other parts that have been shaped by machining such as cutting, warm pressing, forging, etc. It is.

[Surface treatment / pretreatment / chemical etching of copper alloy parts]
It is preferable that the copper alloy part is first immersed in a degreasing tank to remove oils and finger grease adhered by machining. Specifically, a commercially available degreasing material for copper alloy is poured into water at a concentration specified by the drug manufacturer to prepare an aqueous solution, immersed in this aqueous solution, and then washed with water. Rather than using a degreasing solution for copper alloys, it is preferable to use an aqueous solution in which a commercially available degreasing agent for iron, stainless steel, aluminum and the like, and industrial and general household neutral detergents are dissolved. . A specific degreasing treatment involves dissolving a commercially available degreasing agent, neutral detergent, etc. in water at a concentration of several to 5%, setting the temperature of this aqueous solution to 50 to 70 ° C., and immersing it in this aqueous solution for 5 to 10 minutes. This is preferably washed with water. The reason for avoiding commercially available degreasing agents for copper alloys is that the components for copper alloys already contain a component that oxidizes and dissolves the copper content, and the process adjustment is complicated by overlapping with the etching process to be performed later. Because it becomes.

  Next, after immersing in a several percent concentration aqueous caustic soda solution kept at a temperature of around 40 ° C. for a short time, it is preferably washed with water and pre-base washed. Next, a treatment method in which the copper alloy part is immersed in an aqueous solution containing hydrogen peroxide and sulfuric acid kept at about room temperature or about 25 ° C. and then washed with water to perform chemical etching is preferable. An aqueous solution containing several percent of both sulfuric acid and hydrogen peroxide at a temperature of 20 ° C. to normal temperature (15 ° C. to 25 ° C.) is preferable. Although the immersion time varies depending on the alloy type, it is several minutes to 20 minutes. Most copper alloys in these processes have a roughness on the order of microns as described above, that is, periodic irregularities of 0.2 to 20 μm, and the maximum height of the irregularities is about 0.2 to 10 μm. In addition, when analyzed with a scanning probe microscope, the average length (RSm) of the roughness curve referred to as “JIS B 0601: 2001 (ISO 4287)” of Japanese Industrial Standard (JIS) is 0.8 to 10 μm, the maximum A copper alloy having a roughness surface with a height roughness (Rz) of 0.2 to 10 μm is obtained.

  However, especially when pure copper-based copper alloy parts are chemically etched, the uneven period is generally large, and the rough surface may have an uneven period exceeding 10 μm. The reason for this seems to be that the metal crystal is large and etching starting from the crystal grain boundary creates rough recesses. One countermeasure in such a case is to perform the chemical etching at a high temperature of about 50 ° C. The reaction rate is rapidly increased, and portions other than the crystal grain boundaries are etched to obtain the desired micron-order roughness.

  However, in this chemical etching method, if the reaction is intense and a large amount of copper alloy is added to the liquid, heat generation becomes intense and temperature control becomes difficult, and the copper content dissolves into the etching liquid. When ions increase, it is not clear whether this copper ion will be a catalyst, but there is a risk that decomposition of hydrogen peroxide proceeds even if the immersion material, which is a copper alloy part, is removed. Therefore, other methods for pure copper-based copper alloy parts will be described later. In addition, in copper alloy parts other than pure copper type | system | group, a metal crystal grain diameter is small and it can process safely by keeping etching liquid temperature around 25 degreeC. For this reason, considering the summertime when the temperature is high and the amount of immersion material increases, it is safe to install a cooling line in the chemical etching tank in order to keep the temperature stable.

[Surface treatment / surface hardening treatment for copper alloy parts]
The pre-treated copper alloy part is oxidized. In the electronic component industry, there is a method called blackening treatment. Although the oxidation performed in the present invention is different in its purpose and degree of oxidation, the process itself is the same. Chemically speaking, the surface layer of the copper alloy is oxidized with an oxidizing agent under strong basicity. If copper atoms are ionized with an oxidizing agent and the surroundings are strongly basic, they will not be dissolved in the aqueous solution and will become black cupric oxide. When copper alloy parts are used as heat sinks, heat generating material parts, etc., 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 copper alloy component of the present invention. However, as described above, the purpose of the blackening treatment method of the present invention is to form a hard and nano-sized surface with ultra-fine irregularities on a copper alloy part having a certain roughness. It is not intended to blacken for heat dissipation, heat absorption, and the like. However, a special one is not necessary, and a commercially available blackening agent can be used at a concentration and temperature specified by the commercial manufacturer. The soaking time required in this case is the so-called blackening described above. It takes less time than processing. Actually, the surface of the obtained copper alloy part is observed with an electron microscope, and the immersion time is adjusted. The present inventors preferred to use an aqueous solution containing about 5% sodium chlorite and about 10% caustic soda at a temperature of 60 to 70 ° C. In this case, the immersion time is preferably about 0.5 to 1 minute. By these operations, the copper alloy is covered with a thin layer of cupric oxide.

  In the case of a pure copper system, the fine surface shape, when observed with an electron microscope, is a diameter or an average value of a major axis and a minor axis of 20 to 150 nm, and pore openings having an irregular interval of 100 to 300 nm on the entire surface. It has an ultra-fine uneven shape. In short, when this surface hardening treatment is performed, both formation of fine irregularities and surface hardening can be obtained simultaneously. Further, if the immersion time in the treatment liquid is increased to 2 to 3 minutes, the surface hardening treatment becomes longer, and the joining force is weakened. On the other hand, in a copper alloy that is not pure copper-based, convex portions having an average value of 10 to 200 nm in diameter or major axis and minor axis are mixed, and the ultra fine irregular shape existing on the entire surface is a particle having a diameter of 10 to 150 nm or indefinite. It becomes a shape in which almost the entire surface is covered with ultra-fine irregularities of a shape in which polygonal objects and the like are joined together and partially stacked.

[Surface treatment / repeated treatment of copper alloy parts]
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, and as described above, those having a particularly large crystal grain size, that is, oxygen-free copper (C1020), tough pitch, etc. With copper (C1100), it is not possible to stably exert a strong bonding force only by performing the chemical etching and surface hardening treatment. In short, since the roughness on the order of microns is difficult to achieve as expected, the treatment method in such a case was performed as follows.

  In this method, once the surface hardening treatment (blackening) is finished, the surface is again immersed in an etching solution for a short time and reetched, and then blackened again. As a result, the micron-order roughness cycle obtained by this processing method is almost expected to be close to 10 μm or less, and the appearance of fine irregularities is not repeatedly processed according to observation with an electron microscope. It became the same as the case.

[Titanium alloy parts]
Titanium alloys used in the present invention are all titanium alloys such as pure titanium alloys, α-type titanium alloys, β-type titanium alloys, α-β-type titanium alloys and the like specified by Japanese Industrial Standards (JIS). . Titanium alloy parts include intermediate materials such as plate materials, pipe materials, and square materials, which are intermediate materials of mechanical materials, and these are machined by methods such as cold pressing, warm pressing, forging, cutting and grinding. In addition, it can be used for shaped parts, cases and the like obtained by shaping.

[Surface treatment of titanium alloy parts]
It is preferable that the titanium alloy part is first immersed in a degreasing tank to remove oils, finger grease and the like adhered by machining. Specifically, commercially available iron degreasing agents, stainless steel degreasing agents, aluminum alloy degreasing agents, magnesium alloy degreasing agents, etc., are poured into hot water at concentrations specified by the drug manufacturer. It is preferable to prepare the warm aqueous solution and immerse it in this, and then wash it with water. 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 around 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 or the like can be used as a reducing acid capable of corroding the titanium alloy entirely. Of these, hydrofluoric acid has the highest etching rate. However, hydrofluoric acid may lead to bone when touched, and deep pain may continue for several days. From such problems, it is preferable not to use this acid. Preference is given to ammonium hydrofluoride, a half-neutralized hydrofluoric acid which can be handled safely. It is preferable to use an aqueous solution of about 1% ammonium difluoride at a temperature of 50 to 65 ° C. and immerse it for several minutes, and then wash it with water. Further, an aqueous solution containing about 1% ammonium difluoride and several percent to tens of percent sulfuric acid is used at a temperature of 40 to 65 ° C., immersed in this for several minutes, and then washed with water. preferable.

  Chemical etching with 1 hydrogen difluoride ammonium fluoride solution was performed to obtain micron-order roughness. However, in the observation with an electron microscope and the latest analytical equipment, the surface of the titanium alloy was washed and dried after chemical etching. It turned out that it became the micro uneven | corrugated shape of a unique shape, and the whole surface was covered with the titanium oxide thin layer. In short, special fine etching processes, surface oxidation processes, and the like can be eliminated. Next, an analysis example of a pure titanium-based titanium alloy “KS40 (manufactured by Kobe Steel, Ltd., Hyogo Prefecture, Japan)” that has been etched with an aqueous solution of ammonium difluoride and washed with water and dried will be shown.

  In the example of the scanning analysis result by the scanning probe microscope, the average length of the roughness curve (RSm, average uneven period) is 1.5 to 3 μm by scanning a 20 μm square area on the titanium alloy surface. A maximum height roughness (Rz) of about 0.5 to 1.5 μm was obtained. Here, a very unique and unique ultra-fine concavo-convex shape present on the entire surface with a period of 10 to 350 nm in height and width of 10 to 300 nm and a length of 10 nm or more is shown. It was. 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 was judged to be a titanium (trivalent) oxide or a mixed oxide thin film of titanium (trivalent) and titanium (tetravalent).

  That is, before etching, it was a metal color and the surface was a natural oxidation layer of titanium, but after etching with an aqueous solution of 1 hydrogen difluoride ammonium, 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 thickness of the titanium oxide layer was confirmed by XPS analysis of the etched surface. This thickness was clearly greater than the thickness of the natural oxide layer, and it was found to be 50 nm or more in a pure titanium-based titanium alloy etched product with an aqueous solution of 1 hydrogen difluoride ammonium fluoride.

  In addition, the valence of titanium ions decreases from the surface of the formed titanium oxide layer to the inside, and the divalence from the tetravalent state of the surface or a mixed state of trivalent and tetravalent to the inside is reduced. It was found that the divalent value further increased, leading to a zero-valent metal. The formed oxide film 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. In other words, the surface is a continuously changing layer that becomes thicker and thinner towards the interior, as oxygen penetrates from the surface. In such a metal oxide film, since there is no clear boundary between the metal phase, the bonding force between the oxide film layer and the metal substrate is very strong, and there is no concern about peeling and breaking at the boundary. I can expect that.

  Other than the pure titanium-based titanium alloy, the specific treatment method of the titanium alloy is the same as described above, but other metals contained as a small amount of additive by the nascent hydrogen gas generated during etching with a reducing strong acid aqueous solution. 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, since the silicon smut is not dissolved in the aqueous nitric acid solution and is only released, it is preferably peeled off in ultrasonic water.

  According to an electron micrograph, a beautiful slope of a mountain or hill without fine irregularities like a titanium alloy is observed here, but a unique shape like a dead leaf was observed. The overall image of these surfaces is not the image of the fine irregular surface having an irregularity period of 10 nm or more, preferably the irregular surface having a period of 50 nm, which is the condition (2) claimed in the NAT hypothesis described above. However, the fine uneven surface itself is smooth. However, apart from the dome-shaped portion having a smooth surface, the dead leaf-shaped portion is thin and curved, and if it has a predetermined hardness, it becomes the spike shape itself intended by the present inventors.

  In the NAT hypothesis described above, although it is slightly different from the condition (2) claimed by the present inventor, it can be said that the shape matches the role required by the condition (2). However, this spike shape is large and relates to the micron-order roughness of the condition (1) required by NAT, so it is easier to understand if the roughness is clearly defined. That is, as viewed with a scanning probe microscope, it is preferable that the roughness curve has an average length (RSm) of 1 to 10 [mu] m and a maximum height roughness (Rz) of 1 to 5 [mu] m.

  Further, since the fine irregularity period is slightly out of the NAT condition (2), the whole surface image cannot be grasped with an electron micrograph of 100,000 times. The entire surface was observed by taking a magnification photograph of 10,000 times or less. That is, it is to see an area of at least 10 to 20 μm square when viewed with a 10,000 times electron micrograph. According to this, both a smooth dome shape and a curved dead leaf shape can be observed. Further, a titanium alloy containing titanium and aluminum is formed by chemical etching, and when viewed with a scanning probe microscope, the average length (RSm) of the roughness curve is 0.8 to 10 μm, and the maximum height roughness (Rz). Is a surface having a roughness of 0.2 to 5 μm, and this surface has both a smooth dome-like shape within a 10 μm square area and a complex shape of a dead leaf shape as viewed with a 10,000 × electron microscope. A metal shape made of an α-β type titanium alloy having a fine irregular shape in which the surface is observed and a surface of which is a metal oxide thin layer mainly containing titanium and aluminum is preferable.

[Stainless steel alloy parts]
The stainless steel in the present invention is a Cr-based stainless steel obtained by adding chromium (Cr) to iron, or a Cr-Ni-based stainless steel added by combining nickel (Ni) with chromium (Cr). A known corrosion-resistant iron alloy called stainless steel is the object. Cr-based stainless steels such as SUS405, SUS429, and SUS403, and Cr—Ni-based stainless steels such as SUS301, SUS304, SUS305, and SUS316 that are standardized by Japanese Industrial Standards (JIS) and the like.

[Chemical etching of stainless steel]
Since various stainless steels have been developed to improve corrosion resistance, chemical resistance is clearly recorded. There are known types of corrosion of stainless steel, such as general corrosion, pitting corrosion, fatigue corrosion, etc., 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 literature records (for example, “Chemical Engineering Handbook (edited by the Chemical Engineering Society)”), stainless steel in general is corroded entirely with aqueous solutions of hydrohalic acid such as hydrochloric acid, sulfurous acid, sulfuric acid, and metal halides. There is a record. The remaining weakness of stainless steel that 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. .

  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, when the hardness is lowered by annealing or the like, and structurally speaking, the metal crystal grain size is increased, the crystal grain boundary is reduced, and it is difficult to intentionally corrode the entire surface. In such a case, it is necessary to devise such as adding some additive without changing the immersion condition to a level at which the corrosion progresses by simply changing the immersion condition so that the corrosion proceeds. In any case, as described above, as a pretreatment, there is unevenness of 1 to 10 μm in periodic units, and chemical etching is performed for the purpose of occupying most of the roughness surface where the unevenness height difference is about half of the period. To do.

  Specifically, first, obtain a commercially available general degreasing agent for stainless steel, a degreasing agent for iron, a degreasing agent for aluminum alloy, or a commercially available neutral detergent, and add it to the manufacturer's instructions. The aqueous solution has a concentration of several percent as indicated, or an aqueous solution having a concentration of several percent, and is immersed for 5 to 10 minutes at a temperature of 40 to 70 ° C., and then washed with water. This is a degreasing process. Next, it is preferable that basic ions are adsorbed on the surface by immersing in a caustic soda aqueous solution of several percent concentration for a short time and washing with water. 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, it is preferable to immerse a sulfuric acid aqueous solution of about 10% concentration at a temperature of 60 to 70 ° C. for several minutes, thereby obtaining a micron-order roughness. Moreover, in SUS316, it is preferable to immerse a sulfuric acid aqueous solution of about 10% concentration 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 treatment is required for the exhaust gas. In that sense, the use of an aqueous sulfuric acid solution is preferable in terms of cost. However, depending on the stainless 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 perform chemical etching by adding hydrohalic acid or a derivative thereof to a sulfuric acid aqueous solution.

[Surface hardening of stainless steel]
After the chemical etching, the surface is naturally oxidized by sufficiently washing with water and returns to the surface layer that is resistant to corrosion. Therefore, it is not necessary to perform a separate curing process. However, in order to make the metal oxide layer on the surface thick and firm, an oxidizing acid such as nitric acid such as nitric acid, that is, an aqueous solution of nitric acid, hydrogen peroxide, potassium permanganate, sodium chlorate, etc. It is preferable to immerse and wash with water. It is preferable to select an adhesive having a high bonding strength through an epoxy adhesive bonding test, and then observe the same with an electron microscope to confirm the presence of fine irregularities and its shape.

  Of course, the bonding test may be performed after first observing with an electron microscope. In any case, fine irregularities with a period of several tens to hundreds of nanometers, particularly preferably stainless steel having a fine structure surface on which fine irregularities with a period of about 50 nm are firmly formed have high bonding strength. An example in which SUS304 stainless steel is actually chemically etched with a sulfuric acid aqueous solution is shown. By the appropriate chemical etching, the roughness surface as described above can be obtained. This can be confirmed by observation with a roughness meter (surface roughness meter), a scanning probe microscope, etc. When observed with a microscope, it can be seen that the surface is covered with a very unique ultra-fine irregular shape. In short, in stainless steel, fine etching is simultaneously performed only by chemical etching as described above.

  Further, when XPS analysis was performed on the stainless steel covered with the ultra-fine irregularities, 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 the same composition metal as that of ordinary stainless steel, and it was considered that the surface was covered with the same corrosion-resistant surface. In addition, after etching with the reducing acid aqueous solution, additional treatment was performed to immerse in a nitric acid aqueous solution, hydrogen peroxide aqueous solution, etc. to form a metal oxide layer firmly, but the appearance was observed with an electron micrograph. Even in the test of the bonding strength with an adhesive, no clear difference was observed even with the addition of this treatment.

[General steel parts]
The general steel materials referred to in the present invention are cold rolled steel materials (hereinafter referred to as “SPCC”), hot rolled steel materials (hereinafter referred to as “SPHC”), hot rolled steel plates for automobile structures (hereinafter referred to as “SAPH”). ”), Hot-rolled high-tensile steel plate material for automobile processing (hereinafter referred to as“ SPFH ”) and the like, which are used in large quantities for machine parts. Many of these are also steel plates for press working. Further, general structural steel materials used as structural members for machining in the narrow sense such as cutting and grinding are also included. The Japanese Industrial Standard (JIS) “SS400” is one example. Other casting iron materials, general-purpose soft iron materials, and the like can also be used.

[Chemical etching of steel materials]
There are various types of corrosion, such as general corrosion, pitting corrosion, fatigue corrosion, etc., but it is possible to select an appropriate chemical etching agent through trial and error of corrosion by selecting a chemical type that causes general corrosion. According to records in the literature (for example, “Chemical Engineering Handbook (edited by the Chemical Engineering Society)”), iron and steel materials are generally corroded with aqueous solutions of hydrohalic acid such as hydrochloric acid, sulfurous acid, sulfuric acid, and their salts. There is a record. Depending on the amount of addition of carbon, chromium, vanadium, molybdenum, and other minor additives, the corrosion rate and the form of corrosion change, but basically, the above-mentioned aqueous solution can cause overall corrosion. Therefore, what is necessary is just to change the immersion conditions with the kind of steel materials.

  Specifically, the above-mentioned SPCC, SPHC, SAPH, SPFH, SS, etc., for each of them, are commercially available degreasing agents for steel materials, degreasing agents for stainless steel, degreasing agents for aluminum alloys, , Obtain a commercially available neutral detergent, change the concentration of the aqueous solution as indicated in the instructions of the degreasing agent manufacturer, or an aqueous solution with a concentration of several percent, and set the temperature to 40 to 70 ° C. After being immersed in 5-10 minutes, this is washed with water (degreasing process). Next, in order to improve the reproducibility of the next chemical etching, it is preferable to immerse it in a dilute caustic soda aqueous solution for a short time and then wash it with water. This step is a preliminary base washing step.

  Next, in the case of SPCC, it is preferable to etch by immersing a sulfuric acid aqueous solution of about 10% concentration at a temperature of 50 ° C. for several minutes. This is an etching process for obtaining a micron-order roughness. In SPHC, SAPH, SPFH, and SS, it is preferable to increase the temperature of the sulfuric acid aqueous solution 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, corrode surrounding iron structures, and even if locally exhausted Some treatment is required for the exhaust gas. In that sense, the use of an aqueous solution mainly composed of sulfuric acid is preferable in terms of cost.

  By the etching alone, fine unevenness of several tens nm to several hundreds nm is simultaneously achieved. Moreover, although the surface is only a natural oxide layer, it is quite hard, and a strong bonding force can be obtained even if it is bonded (fixed) with an adhesive as it is. However, this bond is still weak to the environment. Probably, oxygen and water vapor enter from the edge of the interface and change (rust) the joining surface of the steel material. On the other hand, it is a first countermeasure that the etching is followed by washing with water, then immersing in a thin aqueous solution of ammonia, hydrazine, or water-soluble amines for several minutes and then washing with water. It has been found that these broadly defined amines are chemisorbed on the surface of the steel material to suppress the oxidation reaction of the steel material and are useful for maintaining the joining force of the joint.

[Surface treatment of steel materials 2: Method by chemical conversion treatment]
Washing with water after the chemical etching, and then immersing in an aqueous solution of acid or salt containing chromium, manganese, zinc, etc. and washing with water, the steel material surface is made of metal oxides such as chromium, manganese, or zinc phosphate. Corrosion resistance can be improved by covering with metal phosphorous oxide. This is a well-known method for improving the corrosion resistance of iron alloys and steel materials, and can be used in the present invention. It can be determined that the bonding life can be kept longer than at least the amine adsorption method described above.

  The true purpose of the chemical conversion treatment referred to in the present invention is not to ensure complete corrosion resistance, but to strengthen the bondability, so it differs slightly from existing methods. In other words, at least there is no problem in the period up to the joining step, and after joining, appropriate corrosion resistance measures are applied to the integrated product. For example, by painting or the like, it is possible to make a level at which it is difficult to cause a trouble with time at the joint portion. In short, when the chemical conversion film is made thick, it is preferable from the viewpoint of corrosion resistance, but not preferable from the viewpoint of bondability. The present inventors believe that the chemical conversion film is necessary, but if it is too thick, the bonding force is warped and decreases.

  Speaking of specific implementation methods, the chemical conversion solution is an aqueous solution of chromium trioxide having a concentration of several percent, an aqueous solution of potassium permanganate having a weak acidity adjusted to weak acidity, and an aqueous solution of zinc salt adjusted to weak phosphoric acidity. Can be preferably used. A treatment method in which the temperature of the aqueous solution is 45 to 60 ° C., the steel material is immersed for 0.5 to several minutes, washed with water, and dried is preferable.

[Surface treatment of steel material 3: Silane coupling agent]
Many patents have been filed as treatment methods for imparting corrosion resistance and weather resistance to steel materials, and methods for adsorbing a silane coupling agent are disclosed therein. 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 a very thin gap of several tens of nanometers created by the hardened adhesive and the steel surface, the silane cup covers the steel. The water repellent group of the ring agent may suppress water molecules from approaching the steel material. Whether the bonding force is maintained over a long period of time cannot be confirmed unless the test is performed over a long period of time, but at least the chemical conversion treatment described above is performed, and in addition, the silane coupling agent is used for the immersion treatment. There was no adverse effect on the bonding strength even when the test was performed. Therefore, it is judged that it is preferable to perform the silane coupling treatment in addition to the chemical conversion treatment.

[Crystalline resin composition / PPS]
The PPS resin composition will be described. When the resin composition is composed of a resin composition containing 70 to 97% by mass of PPS and 3 to 30% by mass of polyolefin resin, a composite having particularly excellent bonding strength can be obtained. When the polyolefin resin is 3% by mass or less, the effect of improving the injection joining force due to the inclusion of the polyolefin resin is uncertain. On the other hand, the same applies when the polyolefin resin is 30% by mass or more. In addition, PPS resin to which more than 30% by mass of polyolefin resin is added is affected by the thermal decomposition of the polyolefin resin in the injection cylinder of the injection molding machine, resulting in an abnormally large gas generation amount, making injection molding itself difficult. Become.

  Any PPS component may be used as long as it belongs to a category called PPS. Among them, a high-kneading type equipped with a die having a diameter of 1 mm and a length of 2 mm because of excellent molding processability when making a resin composition part. It is preferable that the melt viscosity measured by a flow tester is 100 to 30000 poise under the conditions of a measurement temperature of 315 ° C. and a load of 98 N (10 Kgf). PPS may be substituted with an amino group, a carboxyl group or the like, or may be copolymerized with trichlorobenzene or the like during polymerization. Furthermore, the PPS may be linear, introduced with a branched structure, or heat-treated in an inert gas.

  Furthermore, PPS is a product in which impurities such as ions and oligomers are reduced by performing a deionization process (such as acid cleaning or hot water cleaning) before or after heat curing or a cleaning process using an organic solvent such as acetone. Alternatively, it may be one that has been cured by heat treatment in an oxidizing gas after completion of the polymerization reaction. Examples of the polyolefin resin include ethylene resins and propylene resins that are generally known as polyolefin resins, and may be commercially available. Among them, since it becomes possible to obtain a composite having particularly excellent bonding properties, maleic anhydride modified ethylene copolymer, glycidyl methacrylate modified ethylene copolymer, glycidyl ether modified ethylene copolymer, ethylene alkyl An acrylate copolymer or the like is preferable.

  Examples of the maleic anhydride-modified ethylene copolymer include maleic anhydride graft-modified ethylene polymer, maleic anhydride-ethylene copolymer, ethylene-acrylic acid ester-maleic anhydride terpolymer. Among them, an ethylene-acrylic acid ester-maleic anhydride terpolymer is preferable because a particularly excellent composite can be obtained. Specific examples of the ethylene-acrylic acid ester-maleic anhydride terpolymer include “Bondyne (manufactured by Arkema (France))” and the like.

  Examples of the glycidyl methacrylate-modified ethylene copolymer include glycidyl methacrylate graft-modified ethylene polymer and glycidyl methacrylate-ethylene copolymer, and among them, particularly excellent composites can be obtained. A copolymer is preferred. Specific examples of the glycidyl methacrylate-ethylene copolymer include “Bond First” (manufactured by Sumitomo Chemical Co., Ltd.). Examples of the glycidyl ether-modified ethylene copolymer include glycidyl ether graft-modified ethylene copolymer and glycidyl ether-ethylene copolymer. Specific examples of the ethylene alkyl acrylate copolymer include “Lotryl (Arkema Co., Ltd.). Manufactured) ”and the like.

  In the composite of the present invention, considering that the bonding property with the resin composition is more excellent with respect to the metal shape, the resin composition has a PPS of 70 to 97% by mass and a polyolefin resin of 3 to 30. What mix | blends 0.1-6 mass% of polyfunctional isocyanate compounds and / or 1-25 mass% of epoxy resins with respect to the resin part total 100 mass% containing mass% is preferable. As the polyfunctional isocyanate compound, commercially available non-block type and block type compounds can be used.

  Examples of this polyfunctional non-blocked isocyanate compound include 4,4'-diphenylmethane diisocyanate, 4,4'-diphenylpropane diisocyanate, toluene diisocyanate, phenylene diisocyanate, bis (4-isocyanatophenyl) sulfone, and the like. Examples of the polyfunctional block type isocyanate compound include those having two or more isocyanate groups in the molecule and inactive at room temperature by reacting the isocyanate group with a volatile active hydrogen compound. The

  The type of the polyfunctional blocked isocyanate compound is not particularly specified, and generally the isocyanate group is masked by a blocking agent such as alcohols, phenols, ε-caprolactam, oximes, and active methylene compounds. It has a structure. As this polyfunctional block type isocyanate, for example, “Takenate (manufactured by Mitsui Takeda Chemical Co., Ltd., Tokyo, Japan)” and the like can be mentioned. As the epoxy resin, an epoxy resin generally known as a bisphenol A type, a cresol novolak type or the like can be used. As the bisphenol A type epoxy resin, for example, “Epicoat (Japan Epoxy Resin Co., Ltd. (Tokyo, Japan)” Manufactured) ”and the like. Examples of the cresol novolac type epoxy resin include “Epiclon” (manufactured by DIC Corporation (Tokyo, Japan)).

[Crystalline resin composition / PBT]
Next, the PBT resin composition will be described. More preferably, not only the above-described filler but also 3 to 30% by mass of PET and / or polyolefin-based resin as a resin component composition, which has a composition of 70 to 97% by mass of PBT. A PBT resin composition containing PBT as a main component and PET and / or polyolefin resin as a subsidiary component is excellent in injection joining force. The polyolefin resin here is the same as that described in the section of PPS.

  When the PET and / or polyolefin-based resin component is 5 to 20% by mass, the bonding force is the highest, but the bonding force is not significantly reduced even at 3 to 5% by mass and 20 to 30% by mass. However, if it is 30% by mass or more, the effect on the bonding force is low, and if the PET component is 25% by mass or more, the transesterification reaction between the PBTs easily proceeds at a high temperature in the injection molding machine, and the resin There exists a possibility that the intensity | strength of itself may fall. Further, when the polyolefin resin component is 30% by mass or more, the generation of gas increases and the moldability tends to deteriorate.

[Manufacture of composite / injection bonding]
The manufacturing method of the composite of the present invention is basically an injection molding method in which a metal shape is inserted into an injection mold and a resin composition is injected to manufacture the composite, and is performed as follows. An injection mold is prepared, this injection mold is opened, and a metal shape obtained by the above-described processing is inserted into one of the molds. In addition, when the configuration is simple, a hole that constitutes an injection gate is provided in one of the plurality of metal-shaped objects, and when the plurality of metal-shaped objects are positioned to face each other, resin is directly passed through the hole to the internal space. It may be in the form of injection. In this case, the injection molding nozzle body is pressed against the metal shape to inject the resin composition. In a normal case, after the metal shape is inserted into the injection mold, the injection mold is closed, a thermoplastic resin composition such as PBT or PPS is injected and solidified, and then the injection mold is opened, that is, separated. Mold to remove the complex.

  Next, the injection conditions will be described. As the temperature of the injection mold, the temperature is preferably 100 ° C. or more, more preferably PBT resin, PPS resin, etc., because there is little influence on the resin strength after solidification and the composite production efficiency is excellent. It is good that it is 120 degreeC or more. Although the injection temperature, injection pressure, and injection speed are not particularly different from those of ordinary injection molding, it is preferable to increase the injection speed and injection pressure.

〔Apply〕
By applying the present invention to various fields, it is possible to improve bondability to parts that have been difficult to join in the past, improve efficiency, expand the scope of application, and the like. This will improve the corrosion resistance of parts, and enable mass production of automobile-related parts, leading to streamlined manufacturing. The joining of the plurality of metal shaped objects may be the same kind of metals or different kinds of metals. In particular, a bonded composite of dissimilar metals has a wide range of applications in all fields. As a result, it can greatly contribute to the improvement of the performance of the case and parts and the improvement of productivity in electronic and electrical equipment and many other fields.

  As described in detail above, the bonded composite according to the present invention is obtained by firmly integrating a plurality of metal shaped objects without being easily peeled off via the resin composition. With respect to various metal shapes used as industrial base materials, that is, a metal shape processed into a predetermined shape and subjected to a predetermined surface treatment is positioned at a fixed position, PBT is 70 to 97% by mass, Thermoplastic resin composition having a resin composition containing 30 to 3% by mass of a polyolefin resin, or thermoplastic resin having a resin composition containing 70 to 97% by mass of PPS and 3 to 30% by mass of a polyolefin resin By strongly injecting the resin composition, it is possible to produce a joint composite in which both have strong bonding properties. As a result, the applicable industrial field has become widespread, and in particular, it has become a bonded composite that is very effective for mass production in fields where composites bonded with dissimilar metals are required.

  Moreover, in the manufacturing method of the joining composite body of a multiple metal shape thing, it becomes possible to join a several metal shape object by the injection | emission joining method, and can manufacture the joining composite body of a multiple metal shape object easily. became. In particular, it has become possible to produce a bonded composite in a field that requires a composite bonded with dissimilar metals so that it can be mass-produced.

FIG. 1 is a configuration diagram schematically showing an injection mold for injection molding a single metal piece and a crystalline resin composition. FIG. 2 is a configuration diagram schematically showing a composite obtained by injection molding a single metal piece and a crystalline resin composition. FIG. 3 is a schematic partial cross-sectional view showing a theoretical configuration (NAT theory) in which a crystalline resin composition is applied to a plurality of metal shaped objects by surface treatment of the present invention and bonded. FIG. 4 is a cross-sectional view showing a configuration in which a steel part is joined to an aluminum alloy plate with a resin through a frame. FIG. 5 is a plan view of FIG. FIG. 6 is a partial external view showing a joined composite in which a steel part and an aluminum alloy plate are joined by a resin. FIG. 7 is a cross-sectional view showing an example in which the joining surface of the steel part is in a convex state in the modification of FIG. FIG. 8 is a cross-sectional view showing a configuration in which a groove is formed in an aluminum alloy plate, positioned by a frame, and steel parts are joined by a resin. FIG. 9 is a cross-sectional view showing a configuration in which a groove is provided in an aluminum alloy plate, a frame having a step is inserted, and steel parts are joined by resin. FIG. 10 is a cross-sectional view showing a configuration in which a stepped groove is provided in an aluminum alloy plate and steel parts are directly joined by resin. FIG. 11 is a partial external view showing a bonded composite body made of a copper part and an aluminum alloy part. FIG. 12 is a cross-sectional view showing a configuration in which a copper part is bonded to an aluminum alloy part with a resin.

  Embodiments of the present invention will be described below with reference to the drawings. The composite that is the subject of the present invention is a bonded composite in which a plurality of metals are bonded to each other by a resin. However, in order to facilitate understanding of the invention, in this embodiment, as a simple example, The joining of the metal shape and the resin composition will be described. FIG. 1 and FIG. 2 are diagrams showing a basic embodiment, and show a joining state of a single metal and a resin as described above. FIG. 1 is a cross-sectional view schematically showing an injection mold 10. FIG. 1 shows a state where the injection mold 10 is closed and injection molding is performed. FIG. 2 is an external view showing a composite 7 of metal and resin molded by the injection mold 10. The injection mold 10 includes a movable side mold plate 2 and a fixed side mold plate 3, and a resin injection portion including a pinpoint gate 5 and a runner is formed on the fixed side mold plate 3 side.

  The composite 7 is molded as follows. First, the movable side mold plate 2 is opened, and the metal piece 1 is inserted into a cavity formed between the movable side mold plate 3 and the fixed side mold plate 3. After the insertion, the movable side template 2 is closed to the state before injection in FIG. Next, the molten resin composition 4 is injected through the pinpoint gate 5 into the cavity in which the metal piece 1 is inserted. When injected, the resin composition 4 is bonded to the metal piece 1 to fill the cavity other than the metal piece 1 and is resin-molded, and the composite 7 in which the metal piece 1 and the resin composition 4 (metal and resin) are integrated is formed. can get.

The composite 7 has a joint surface 6 between the metal piece 1 and the resin composition 4, and the area of the joint surface 6 is 5 mm × 10 mm. That is, the area of the joint surface 6 is 0.5 cm ² . In the embodiment described below, the strength is obtained with the area of the joint surface as the same base. The equipment used for the measurement etc. is shown below. Moreover, although the composite body shown in FIG. 1 and FIG. 2 is made into the shape which is easy to test for confirming joining strength, it cannot be overemphasized that it applies to the thing of all the shapes used in industry.

(A) X-ray surface observation (XPS observation)
An ESCA “AXIS-Nova (Kuratos / Shimadzu Corporation (Kyoto Prefecture, Japan))” that observes constituent elements on a surface with a diameter of several μm in a depth range of 1 to 2 nm was used.
(B) Electron Microscope Observation Using an SEM type electron microscope “JSM-6700F (manufactured by JEOL Ltd. (Tokyo, Japan))”, observation was performed at 1 to 2 KV.
(C) Scanning probe microscope observation “SPM-9600 (manufactured by Shimadzu Corporation)” was used.
(D) Measurement of Bonding Strength of Composite Material Using a tensile tester “Model 1323 (manufactured by Aiko Engineering Co., Ltd. (Osaka, Japan))”, the shear breaking strength was measured at a pulling speed of 10 mm / min.

Next, adjustment examples of the resin composition will be described.
[Preparation Example 1 (Preparation Example of PPS Composition)]
A 50 liter autoclave equipped with a stirrer was charged with 6,214 g of Na ₂ S · 2.9H ₂ O and 17,000 g of N-methyl-2-pyrrolidone, and gradually heated to 205 ° C. while stirring under a nitrogen stream. 1,355 g of water was distilled off. After cooling the system to 140 ° C., 7,160 g of p-dichlorobenzene and 5,000 g of N-methyl-2-pyrrolidone were added, and the system was sealed under a nitrogen stream. This system was heated to 225 ° C. over 2 hours, polymerized at 225 ° C. for 2 hours, then heated to 250 ° C. over 30 minutes, and further polymerized at this temperature of 250 ° C. for 3 hours. After completion of the polymerization, the mixture was cooled to room temperature (atmospheric temperature), and the polymer was separated by a centrifuge. The polymer was washed repeatedly with warm water and dried at 100 ° C. for a whole day and night to obtain a PPS having a melt viscosity of 280 poise (hereinafter referred to as PPS (1)). The PPS is not a special one and may be a commercially available PPS.

  The PPS (1) was further cured at 250 ° C. for 3 hours under a nitrogen atmosphere to obtain PPS (hereinafter referred to as PPS (2)). The resulting PPS (2) had a melt viscosity of 400 poise. 6.0 kg of the obtained PPS (2), 1.5 kg of ethylene-acrylic acid ester-maleic anhydride terpolymer “Bondyne TX8030 (manufactured by Arkema)”, epoxy resin “Epicoat 1004 (Japan Epoxy Resin) 0.5 kg "(manufactured by Tokyo, Japan)" was previously mixed uniformly with a tumbler.

  Then, with a twin screw extruder “TEM-35B (manufactured by Toshiba Machine Co., Ltd. (Shizuoka, Japan))”, glass fiber “RES03-TP91” (Nippon Sheet Glass Co., Ltd. (Japan) with an average fiber diameter of 9 μm and a fiber length of 3 mm was used. PPS composition (1) obtained by melt-kneading and pelletizing at a cylinder temperature of 300 ° C. was fed from a side feeder so that the addition amount was 20% by mass. The obtained PPS composition (1) was dried at a temperature of 175 ° C. for 5 hours.

[Preparation Example 2 (Preparation of PPS composition)]
The PPS (1) obtained in Preparation Example 1 was cured at a temperature of 250 ° C. in an oxygen atmosphere for 3 hours to obtain a PPS composition (hereinafter referred to as PPS (3)). The resulting PPS (3) had a melt viscosity of 1800 poise. 5.98 kg of the obtained PPS (3) and 0.02 kg of polyethylene “Nipolon Hard 8300A (manufactured by Tosoh Corporation (Tokyo, Japan))” were uniformly mixed in advance with a tumbler.

  Thereafter, the glass fiber “RES03-TP91” having an average fiber diameter of 9 μm and a fiber length of 3 mm is supplied from the side feeder with a twin-screw extruder “TEM-35B” while the addition amount is 40% by mass. A PPS composition (2) pelletized by melt-kneading at a temperature of 300 ° C. was obtained. The obtained PPS composition (2) was dried at a temperature of 175 ° C. for 5 hours.

[Preparation Example 3 (Preparation of PPS composition)]
7.2 kg of PPS (2) obtained in Preparation Example 1 and 0.8 kg of glycidyl methacrylate-ethylene copolymer “Bond First E” (manufactured by Sumitomo Chemical Co., Ltd.) were previously mixed uniformly with a tumbler. . Thereafter, the glass fiber “RES03-TP91” having an average fiber diameter of 9 μm and a fiber length of 3 mm is fed from the side feeder with a twin-screw extruder “TEM-35B” while the addition amount is 20% by mass. It was melt-kneaded at a temperature of 300 ° C. to obtain a pelletized PPS composition (3). The obtained PPS composition (3) was dried at a temperature of 175 ° C. for 5 hours.

[Preparation Example 4 (Preparation of PPS composition)]
In a tumbler, 4.0 kg of PPS (2) obtained in Preparation Example 1 and 4.0 kg of ethylene-acrylic acid ester-maleic anhydride terpolymer “Bondyne TX8030 (manufactured by Arkema)” Mix evenly. Thereafter, the glass fiber “RES03-TP91” having an average fiber diameter of 9 μm and a fiber length of 3 mm is fed from the side feeder with a twin-screw extruder “TEM-35B” while the addition amount is 20% by mass. The mixture was melt-kneaded at a temperature of 300 ° C. to obtain a pelletized PPS composition (hereinafter referred to as PPS composition (4)). The obtained PPS composition (4) was dried at a temperature of 175 ° C. for 5 hours.

[Example 5 of adjustment (adjustment of PBT composition)]
4.5 kg of PBT resin “Torcon 1100S (Toray Industries, Inc., Tokyo, Japan)” and 0.5 kg of PET resin “TR-4550BH (Teijin Chemicals, Inc., Tokyo, Japan)”, tumbler And mixed uniformly. Thereafter, in the twin screw extruder “TEM-35B”, while supplying glass fiber “RES03-TP91” having an average fiber diameter of 9 μm and a fiber length of 3 mm from the side feeder so that the addition amount becomes 30% by mass, the cylinder temperature A PBT composition (hereinafter referred to as PBT composition (1)) that was melt-kneaded at 270 ° C. and pelletized was obtained. The obtained PBT composition (1) was dried at 140 ° C. for 3 hours.

[Preparation Example 6 (Preparation of PBT composition)]
6.0 kg of PBT resin “Torcon 1401X31 (manufactured by Toray Industries, Inc.)”, 0.7 kg of ethylene-acrylic acid ester-maleic anhydride terpolymer “Bondyne TX8030 (manufactured by Arkema)”, epoxy resin “Epicoat” 1005 (manufactured by Japan Epoxy Resin Co., Ltd.) "was uniformly mixed with 0.15 kg in advance using a tumbler. Then, in a twin screw extruder “TEM-35B (manufactured by Toshiba Machine Co., Ltd.)”, glass fiber “RES03-TP91 (manufactured by Nippon Sheet Glass Co., Ltd.)” having an average fiber diameter of 9 μm and a fiber length of 3 mm is added from the side feeder. The PBT composition (hereinafter referred to as PBT composition (2)) obtained by melt-kneading and pelletizing at a cylinder temperature of 270 ° C. was supplied. The obtained PBT composition (2) was dried at 150 ° C. for 5 hours.

[Adjustment Example 7 (adjustment of PBT composition)]
6.0 kg of PBT resin “Torcon 1401X31 (Toray Industries, Inc.)”, 0.5 kg of PET resin “TR-4550BH (Teijin Chemicals)”, ethylene-acrylic ester-maleic anhydride 0.5 kg of the combined “Bondyne TX8030 (manufactured by Arkema)” and 0.1 kg of the epoxy resin “Epicoat 1004 (manufactured by Japan Epoxy Resin Co., Ltd.)” were uniformly mixed in advance with a tumbler. Then, glass fiber “RES03-TP91 (manufactured by Nippon Sheet Glass Co., Ltd.)” having an average fiber diameter of 9 μm and a fiber length of 3 mm is added from the side feeder with a twin screw extruder “TEM-35B (manufactured by Toshiba Machine Co., Ltd.)”. A PBT composition (hereinafter referred to as PBT composition (3)) that was melt-kneaded and pelletized at a cylinder temperature of 270 ° C. was obtained while supplying the amount to be 30% by mass. The obtained PBT composition (3) was dried at a temperature of 150 ° C. for 5 hours.

  FIG. 3 is a partial schematic view of the state in which the crystalline resin composition 22 is bonded and cured to the metal base portions 20a and 20b via the metal oxide thin film or the metal phosphate thin film 21, as described above. It is sectional drawing shown. Next, a description will be given of an embodiment of a composite structure by joining a steel material and an aluminum alloy. 4 and 5 show a configuration in which an L-shaped steel material part 12 is joined (fixed) to a base aluminum alloy plate 11 as a joining member of different metals. FIG. 5 is a plan view of FIG. The joint surface 13 of the aluminum alloy plate 11 and the joint surface 14 of the steel material part 12 are subjected to surface treatment as described above. In the configuration of this example, the aluminum alloy plate 11 is a large member, and an L-shaped steel part 12 is joined to a part thereof.

  The bonding is performed by injecting the above-described crystalline resin composition (hereinafter referred to as “resin composition 4”). In the configuration of this example, an injection mold 10 as shown in FIG. 1 is not used. On the joint surface 13 of the aluminum alloy plate 11, a frame 15 is attached at the attachment location of the steel material part 12. The frame body 15 is made of synthetic resin, and the shape of the frame body 15 is a surrounding shape, and is temporarily fixed or locked at a predetermined position of the joining surface 13 of the aluminum alloy plate 11. In the example shown in FIG. 4, a small hole 16 having a through hole or a bottom is provided in the joint surface 13 of the aluminum alloy plate 11, and positioning is performed by inserting a boss 17 of the frame 15 into the small hole 16. Yes.

  A step portion 18 is provided inside the frame body 15, and the joining surface 14 side of the steel material part 12 is placed on the step portion 18. The steel material component 12 is positioned and installed with respect to the frame body 15 via the step portion 18. Is done. Therefore, the steel material part 12 is positioned on the joint surface 13 of the aluminum alloy plate 11 through the frame body 15. When the steel part 12 is installed in the step portion 18 of the frame 15, a space is defined and formed between the steel part 12 and the aluminum alloy plate 11. That is, a space portion 19 is formed between the steel material part 12 and the aluminum alloy plate 11 and sealed with the frame body 15 interposed therebetween. This sealed space 19 becomes a cavity for injection molding.

  Further, the steel material part 12 is provided with a through hole 23 which forms a gate for resin injection. Further, the opening edge 24 on the insertion side of the steel part 12 of the frame 15 is chamfered so that the steel part 12 can be easily inserted. Under such a configuration, for example, the steel part 12 is transported by a robot or the like, and positioned and set at a fixed position of the aluminum alloy plate 11 via the frame 15. When the steel material part 12 is positioned and set, a sealed space 19 is automatically formed between the steel part 12 and the aluminum alloy plate 11.

  Next, the nozzle body 25 for injecting the resin composition is positioned and pressed at the position of the through hole 23 which is a through hole of the steel material part 12. The steel part 12 is fixed to the frame 15 by this pressing. In this state, the above-described resin composition 4 is injected through the nozzle body 25 into the sealed space 19 through the through hole 23 that forms a gate. This resin composition 4 is a crystalline resin composition as described above. When the nozzle body 25 is detached after injection and the resin composition 4 is solidified, the resin composition 4 is bonded (fixed) to the bonding surfaces 13 and 14 of the aluminum alloy plate 11 and the steel material part 12, and these two metals are resin. It is integrated with the composition 4 to form a joined composite 26 shown in FIG. At this time, the frame body 15 is also joined and integrated. However, the frame body 15 may be peeled off and removed, but may be integrated if there is no problem as a composite.

  In this way, a joined composite 26 of a plurality of metal shaped objects can be easily manufactured. This composite has a structure in which the resin composition 4 has a certain amount of thickness and two metals are opposed to each other and bonded to each other. However, as shown in FIG. Even if the joining surface 14 of the component 12 is not flat and has unevenness, the joining is possible. 7 is a component in which a convex body 27 is provided on the joint surface 14. This convex body 27 protrudes into the space 19.

  The same applies when the convex body is on the aluminum alloy plate 11 side. This means that a process for flattening the bonding surface in accordance with the mating bonding surface as in conventional bonding is unnecessary and can be omitted. If the steel material part 12 is only positioned in the height direction and on the plane and the sealed space 19 is secured, a plurality of metal shaped objects can be easily joined. As described above, since the frame body 15 is provided so that the positioning can be performed accurately, it can be efficiently joined by automatic conveyance by a robot or the like without depending on human hands.

  This configuration greatly contributes to mass production and improves production efficiency. Although the material of the frame 15 is made of resin, its property is not limited. Any device can be used as long as the sealed space portion 19 can be formed. Although the opening edge 24 of the frame 15 has a chamfered shape, if it is an elastomer material, the steel material part 12 can be inserted by being elastically deformed. Next, another embodiment will be described. FIG. 8 is a form in which a groove 31 is provided on the aluminum alloy plate 30 side and the steel part 32 is directly placed in a state of covering the groove 31.

  Also in this case, the positioning frame 33 is installed on the aluminum alloy plate 30. Since the frame body 33 only needs to have a function of determining the position of the steel material part 32, the frame body 33 does not need to be the enclosed frame body 33, and may have a partial shape and be chamfered. In the case of this example, the space 34 is formed only between the steel part 32 and the aluminum alloy plate 30. This is effective when the steel part 32 is large and the joining surface 35 is wide. In this case, the aluminum alloy plate 30 is partially provided with the grooves 31 so that the steel part 32 is partially joined.

  In the example of FIG. 8, the number of the grooves 31 is two. In the case of this example, the position adjustment in the height direction cannot be performed, but even if the joining surface 35 of the steel material part 32 has irregularities, it can be partially allowed to be in the groove position. Further, although the description has been given by providing the joining groove 31 in the aluminum alloy plate 30, the groove may be provided on the joining surface 35 side of the steel part 32. Further, as shown in the drawing, the through hole 36 forming the gate may be provided on the aluminum alloy plate 30 side. In the example of FIG. 8, the resin composition 4 is injected into the space 34 through the through small holes 36 to form a bonded composite.

  FIG. 9 is an example in which a frame body 42 is provided in the groove 41 of the aluminum alloy plate 40. The frame body 42 has a surrounding shape, and a stepped portion 43 is provided on the frame body 42 as in the case of FIG. By providing the stepped portion 43, a space portion 45 is formed between the steel component 44 and the aluminum alloy plate 40 via the frame body 42, and the resin composition 4 is placed in the space portion 45 in the same manner as described above. Inject and join. In the case of this example, it is effective that the steel part 44 is a round member. The height adjustment of the steel material part 44 can be determined by the shape of the stepped portion 43.

  FIG. 10 is a configuration example in which the steel material part 51 is directly inserted into and joined to the step groove provided in the aluminum alloy plate 50. The steel part 51 is placed on the step part 52 of the step part groove, and a space part 55 is formed between the joining surface 53 of the steel part part 51 and the step groove bottom face 54 of the aluminum alloy plate 50, and the resin composition is formed in the space part 55. The object 4 is injected and the two metals are joined and integrated. In the case of this example, a frame body is not required, a sealed space portion 55 without a frame body is formed, and a structure body that positions a plurality of metal shaped objects in a fixed position is a step groove edge portion of the aluminum alloy plate 50. 56. The step groove edge 56 is preferably chamfered.

FIGS. 11 and 12 show a configuration in which a copper part (for example, a heat sink) 72 is joined (fixed) to a case body 71 which is an aluminum alloy part as a joined composite of different kinds of metal shapes. FIG. 11 is a partial external view, and FIG. 12 is a cross-sectional view. The joint surface of the case body 71 and the joint surface of the copper part 72 are subjected to surface treatment as described above.
In this embodiment, a groove is provided on the case body 71 side, and the copper part 72 is directly placed so as to cover the groove. Bonding is performed by injecting the resin composition 4 described above. The case body 71 may be manufactured by bending a plate material, drawing, or the like.

A frame body 75 for positioning is installed on the case body 71. Since the frame 75 only needs to have a function of determining the position of the copper part 72, the frame 75 may be an enclosed frame 75, but may not be enclosed. In the case of this form, a sealed space (groove) is formed between the copper part 72 and the case body 71. There are two spaces in this form. This space becomes a cavity for injection molding.
On the joint surface of the case body 71, a frame body 75 is attached to a place where the copper part 72 is attached. The frame body 75 is made of synthetic resin, and a small hole that is a through hole or a blind hole is provided at a predetermined position, and positioning is performed by inserting a boss of the frame body 75 into the small hole. Further, as shown in the figure, a through hole 76 forming a gate is provided in the case body 71. The resin composition 4 is injected into the space through a small hole 76 that forms a gate through a nozzle body (not shown) to form a bonded composite.

  In addition, although demonstrated by providing the space part (groove) for joining in the case body 71, you may make it provide a groove | channel in the joining surface side of the copper components 72. FIG. The number of grooves may be other than two. When integrated in this way, the copper part (heat sink) 72 can be brought close to the heat source in the case body 71 and heat can be moved therefrom.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to these embodiment. Needless to say, changes can be made without departing from the scope and spirit of the present invention. For example, in the present embodiment, a plurality of metal shapes have been described by taking steel parts and aluminum alloy plates as examples, but in addition to steel materials and aluminum alloys, magnesium alloys, copper alloys, titanium alloys, and stainless steel may be used. Needless to say, it doesn't matter whether it is the same or different. Furthermore, the joined composite of the present invention may be a joined composite obtained by combining three or more kinds of metal shapes and injection joining them.

DESCRIPTION OF SYMBOLS 1 ... Metal piece 2 ... Movable side template 3 ... Fixed side template 4 ... Resin composition 5 ... Pinpoint gate 6 ... Joining surface 7 ... Composite 10 ... Injection molding die 11 ... Aluminum alloy plate 12 ... Steel component 15 ... Frame 19 ... Space 26 ... Joint composite

Claims (22)

A surface having a roughness on the order of microns by chemical etching, and the surface is a convex or concave portion having a height or depth, width, and length, and has an ultra fine uneven shape existing on the entire surface, and A metal shaped article (11, 12) having a thin layer (21) of metal oxide or metal phosphate on the surface;
A structure (15) for partitioning a sealed space (19) between opposing surfaces of the plurality of metal shaped objects, and positioning and fixing the plurality of metal shaped objects in place;
A plurality of metal shaped objects comprising a crystalline resin composition (4) injecting molten resin into the sealed space, intruding into the ultra-fine uneven shape and joining the plurality of metal shaped objects together Bonding complex. In the joined composite of multiple metal shapes according to claim 1,
The plurality of metal shapes are metal shapes of dissimilar metals. A joint composite of a plurality of metal shapes. In the joined composite of multiple metal shapes according to claim 1 or 2,
The ultra-fine concavo-convex shape has an interval of 10 to several hundreds of nanometers when the height or depth and width are 10 to 500 nm and the length is 10 nm or more. A bonded composite of a plurality of metal shaped objects. In the joined composite of multiple metal shapes according to claim 1 or 2,
The ultra-fine uneven shape is characterized in that the height or the depth is 10 to 500 nm and the length or the recess is 10 to 350 nm, and the length or the recess is a cycle of 10 to 500 nm, as observed with an electron microscope. A multi-metal joint composite. In the joined complex of multiple metal shapes according to claim 1 or 2,
One of the metal shapes is made of an aluminum alloy,
The ultra fine uneven shape is
An aqueous solution formed by immersing in a strong basic aqueous solution for chemical etching, and containing at least one selected from hydrazine, ammonia, and a water-soluble amine compound after being immersed in the strong basic aqueous solution Joining a plurality of metal objects having a thin aluminum oxide layer having a thickness of 2 nm or more by being immersed in the surface and covered with a recess having a diameter of 10 to 100 nm Complex. In the joined complex of multiple metal shapes according to claim 1 or 2,
One of the metal shapes is made of a magnesium alloy,
The ultra fine uneven shape is
A thin layer surface of manganese oxide formed by immersing in an acidic aqueous solution for chemical etching, and formed by immersing in an aqueous alkali metal permanganate solution after immersing in the acidic aqueous solution A multi-metal shaped joint composite comprising: a rod-like material having a diameter of 5 to 20 nm and a length of 20 to 200 nm covered with an infinite number of complex shapes. In the joined complex of multiple metal shapes according to claim 1 or 2,
One of the metal shapes is made of copper or a copper alloy,
The ultra fine uneven shape is
It is formed by immersing in a strong acidic aqueous solution containing an oxidizing agent for chemical etching, and formed by immersing in a strongly basic aqueous solution containing an oxidizing agent after being immersed in the strong basic aqueous solution. A multi-metal shape, characterized in that it is a thin layer of cupric oxide that is mainly formed and has hole openings having an average diameter or major axis and minor axis of 20 to 150 nm on the entire surface with a period of 100 to 300 nm. Bonding complex of objects. In the joined complex of multiple metal shapes according to claim 1 or 2,
One of the metal shapes is made of copper or a copper alloy,
The ultra fine uneven shape is
It is formed by immersing in a strong acidic aqueous solution containing an oxidizing agent for chemical etching, and is formed by immersing in a strong basic aqueous solution containing an oxidizing agent after being immersed in the strong basic aqueous solution. In addition, it is a thin layer of cupric oxide, and a convex portion having an average diameter or major axis and minor axis of 10 to 200 nm is mixed and exists on the entire surface. body. In the joined complex of multiple metal shapes according to claim 1 or 2,
One of the metal shapes is made of a titanium alloy,
The ultra fine uneven shape is
It is covered with a thin layer of titanium oxide by being immersed in a strongly acidic aqueous solution containing a hydrogen fluoride compound, and has a mountain shape or a mountain shape having a height and width of 10 to 350 nm and a length of 10 nm or more. A joint composite of multiple metal shapes, wherein the convex portions are present on the entire surface with a period of 10 to 350 nm, and the surface is a tubular titanium alloy part in which the surface is mainly a thin layer of titanium oxide. In the joined complex of multiple metal shapes according to claim 1 or 2,
One of the metal shapes is made of stainless steel,
The ultra fine uneven shape is
Galvanic field on the slope of a lava plateau, which is a thin-layer stainless steel oxide formed by dipping in a reducing strong acid aqueous solution, and is a shape in which particles having a diameter of 20 to 70 nm or indefinite polygonal shapes are stacked. A multi-metal shaped joint composite characterized in that almost the entire surface is covered with an ultra-fine uneven shape such as In the joined complex of multiple metal shapes according to claim 1 or 2,
One of the metal shapes is made of steel,
The ultra fine uneven shape is
A thin-layer natural steel material oxide formed after the chemical etching by dipping in a reducing strong acid aqueous solution, and, when observed by the electron microscope, has a height of 50 to 150 nm, a depth of 80 to 500 nm and a width of several hundred to A bonded composite of multi-metallic objects, characterized in that the surface is almost entirely covered with an ultra-fine concavo-convex shape in which a step of several thousand nm follows an infinite step. In the joint composite of multiple metal shapes according to claim 11,
The natural oxide film thin layer is a natural oxide film thin layer of iron on which one or more kinds selected from ammonia, hydrazine, and water-soluble amine are adsorbed on the surface. body. In the joint composite of multiple metal shapes according to claim 11,
The natural oxide film thin layer is a thin layer of one oxide or phosphor oxide whose surface is selected from chromium, manganese, and zinc. In the joined complex of multiple metal shapes according to claim 1 selected from claims 1 to 13,
The crystalline resin composition is a resin composition containing a polyphenylene sulfide resin as a main component. In the joined complex of multiple metal shapes according to claim 1 selected from claims 1 to 13,
The crystalline resin composition is a resin composition containing a polybutylene terephthalate resin as a main component. A joined composite of multiple metal shapes. The joined composite of multiple metal shapes according to claim 14,
The crystalline resin composition comprises 70 to 97% by mass of the polyphenylene sulfide resin and 3 to 30% by mass of a polyolefin-based resin. The joined composite of multiple metal shapes according to claim 15,
The crystalline resin composition comprises 70 to 97% by mass of the polybutylene terephthalate resin and 3 to 30% by mass of polyethylene terephthalate and / or polyolefin-based resin. In the joining composite_body | complex of the multiple metal shape object of 1 selected from Claims 14 thru | or 17,
The crystalline resin composition is filled with 20 to 60% by mass of at least one selected from glass fiber, carbon fiber, aramid fiber, other reinforcing fiber, calcium carbonate, magnesium carbonate, silica, talc, clay, and glass powder. A bonded composite of multi-metal shapes, characterized by being a resin composition containing a material. The joined composite of multiple metal shapes according to claim 1 selected from claim 1 to claim 18,
The metal shaped article is provided with a gate for injecting the crystalline resin composition in the space. A joined complex of a plurality of metal shaped articles. The joined composite of multiple metal shapes according to claim 1 selected from claims 1 to 19,
The said structure is comprised in the shape of an enclosure, and was comprised between the said some metal shape thing, and was comprised so that the said sealed space might be provided. The joining composite_body | complex of the metal shape thing characterized by the above-mentioned. The metal shape (11, 12) is a surface having a roughness on the order of microns by chemical etching, and the surface is a convex or concave portion having a height or depth, width and length, and is entirely on the surface. A step of forming a thin layer (21) of a metal oxide or metal phosphate, wherein the surface has an ultra-fine uneven shape and the surface is a metal oxide or a metal phosphate;
Partitioning a sealed space (19) between opposing surfaces of the plurality of metal shaped objects, and positioning the plurality of metal shaped objects in place;
Injecting molten resin into the sealed space and joining with a crystalline resin composition that penetrates into the ultra fine uneven shape and integrates the plurality of metal shapes with each other. A method for producing a composite. In the manufacturing method of the joining composite_body | complex of the multiple metal shape object described in Claim 21,
The plurality of metal shapes are metal shapes of dissimilar metals. A method of manufacturing a joined complex of metal shapes.

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