JP2017043845A - Metal material surface treatment agent, metal joint body and method for bonding metal material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a surface treatment agent capable of providing high bond strength and bond durability and having a low environmental load.SOLUTION: The surface treatment agent consists of a solution including an azole silane compound, such as an imidazole silane and an amino based silane coupling agent. The concentration of the azole silane compound in the solution is 0.1 mass% or more and 4.2 mass% or less, and the concentration of the amino based silane coupling agent in the solution is 0.1 mass% or more and 0.5 mass% or less. After the surface treatment agent is applied to the bonding surfaces of both metal materials to form ground layers, the metal materials are preferably bonded with a modified acrylic or epoxy adhesive.SELECTED DRAWING: None

Description

  The present invention relates to a surface treatment agent for a metal material, a metal joined body, and a method for bonding a metal material. More specifically, the present invention improves the affinity for an adhesive on the surface of a metal member and enables strong bonding with the adhesive. The present invention relates to a surface treatment agent, a method for bonding a metal material with an adhesive using the surface treatment agent, and a metal joined body obtained by joining a metal material treated with the surface treatment agent with an adhesive.

  Various metal materials such as stainless steel, cold-rolled steel, nickel, aluminum, aluminum alloy, copper, and galvanized steel are widely used in many fields such as building materials and electronic devices utilizing their excellent corrosion resistance and surface appearance. When these metal materials are used as structural materials or various parts, it is required to join metal members such as metal plates to each other or to join metal plates to other parts or members. Many. In such cases, conventionally, metal members are often joined together by welding or brazing.

  However, for example, when joining metal plates by welding, welding marks remain on the surface of the welded metal plates, so that the excellent surface appearance unique to the metal plates is likely to be damaged. It can be a problem that the properties are significantly impaired. In addition, when welding is performed on a metal member, welding distortion may be a problem. In the case of a galvanized steel sheet, the zinc layer of the welded part may be alloyed with the base iron layer to reduce the corrosion resistance. Although welding marks and welding distortion can be removed by sheet metal processing, sheet metal processing requires a lot of labor and long work, and also has problems in working environment such as generation of noise. For this reason, it has been avoided by the local residents as well as the workers.

  Therefore, in recent years, an adhesion method using an adhesive has attracted attention as a method for joining metal materials instead of welding. The bonding method using an adhesive has an advantage that the above-described sheet metal processing becomes unnecessary because the surface appearance of the metal member is hardly impaired. However, in general, the surface of a metal material is often covered with a stable oxide film. In particular, the oxide film of stainless steel is excellent in corrosion resistance, but has a very low affinity with an adhesive and is inferior in adhesive strength. There was a problem.

  In addition, when attaching a heat sink member to the heat generating part of an electronic device, it is important for heat dissipation to adhere TIM (Thermal Interface Material) to nickel-plated stainless steel. Since the surface is inactive, the affinity with the silicone polymer, which is the TIM material, is low, and sufficient heat dissipation may not be obtained. Furthermore, since a metal plate such as nickel is inferior in water resistance at the adhesive bonding interface, there has been a problem that when the bonded portion of the metal plate is exposed to a high-temperature and high-humidity atmosphere, the adhesive strength is remarkably reduced in a short period of time.

  The affinity of such a metal material for an adhesive, particularly the affinity for an epoxy or acrylic adhesive, can be improved by previously activating the surface of the metal material with an acid. For example, a method of treating the surface of a stainless steel plate with a mixed aqueous solution of sulfuric acid and oxalic acid is known. In addition, a method is also known in which an aluminum plate or an aluminum alloy plate is immersed in a phosphoric acid aqueous solution or a dichromic acid aqueous solution, or is electrically oxidized at the anode while being immersed. These processing methods are known to exhibit excellent adhesiveness and have been put into practical use in aircraft assembly processes and the like. Moreover, in the galvanized steel sheet, phosphoric acid treatment and chromate treatment are performed for improving rust prevention power, and these treatments also contribute to improvement of adhesiveness.

  However, the method of activating the stainless steel surface by the acid treatment has a problem of generating smut on the stainless steel surface. This smut can be removed by a desmutting treatment in which the stainless steel surface is treated with a mixed aqueous solution of dichromic acid and sulfuric acid. However, the desmutting treatment generates chrome-containing wastewater, and is severely restricted from the viewpoint of environmental destruction. In addition, in the phosphoric acid treatment and chromate treatment for galvanized steel sheets, it may be necessary to consider waste liquid treatment and the like because the waste liquid may cause environmental pollution.

  Recently, as a joining method that does not require such desmutting treatment, a method has been attempted in which adhesion is improved by previously applying a primer to the surface of a stainless steel plate to form an organic thin film (primer layer). . For example, Patent Document 1 describes a method of treating a stainless steel plate using an aqueous primer containing an acidic phosphate ester and / or a salt thereof and water in order to improve the adhesion of the stainless steel plate. Moreover, the technique which provides adhesiveness to a stainless steel plate using a silane coupling agent is known, for example, in patent document 2, by processing the surface of stainless steel using a silane coupling agent, A method for improving the adhesion with a fluorine-based coating film is described.

JP-A-6-93211 Japanese Patent Publication No. 6-57872

  As described above, in Patent Document 1 and Patent Document 2, an epoxy-based adhesive for a metal plate such as a stainless steel plate is obtained by surface-treating the metal plate using an acidic phosphate ester or a silane coupling agent. It is described to improve the affinity for. However, the adhesive strength and durability of the stainless steel plates bonded after being treated by these surface treatment methods cannot be said to be practically sufficient, and cannot be stably used as a bonded structure for a long time.

  Therefore, in some cases, the adhesive force of the metal surface may be increased by a physical (mechanical) method such as surface roughening by sandpaper or sandblasting instead of the chemical bonding method. In this case, the apparent adhesion force is increased because the adhesion area is increased by roughening the metal surface, but the adhesion force may be greatly reduced in an exposure test in a high temperature and high humidity atmosphere.

  The present invention has been made in view of the above-described conventional problems, and an object of the present invention is to provide a surface treatment agent capable of forming a base layer having excellent adhesion to an adhesive on the surface of a metal material. . In particular, an object of the present invention is to provide a surface treatment agent with a low environmental load that can impart high adhesive strength and adhesion durability when a metal material is bonded by an epoxy or acrylic adhesive.

  In order to achieve the above object, the present inventors conducted extensive research on the adhesion method of metal materials, and as a result, surface-treated a solution obtained by blending an azole silane compound and an amino silane coupling agent at a predetermined ratio. It is applied to the surface of metal, etc. as an agent, and by applying an epoxy or acrylic adhesive on the coating film as the underlayer formed thereby, the durability of the adhesive strength is greatly improved. The present inventors have found that this can be done and have completed the present invention.

  That is, the surface treatment agent provided by the present invention is a surface treatment agent comprising a solution containing an azole silane compound and an amino silane coupling agent, and the concentration of the azole silane compound in the solution is 0.1 mass. % To 4.2% by mass, and the concentration of the amino silane coupling agent in the solution is from 0.1% by mass to 0.5% by mass.

  Further, the metal joined body provided by the present invention is a metal joined body in which metal materials are joined with an adhesive, and the surface of the present invention is provided on at least one of both facing joint surfaces of the metal materials. A surface treatment agent layer made of a treatment agent is formed.

  The metal material bonding method provided by the present invention is a metal material bonding method in which metal materials are bonded to each other using an adhesive, and the present invention is applied to at least one of the bonding surfaces of both metal materials. After the surface treatment agent is applied to form a base layer, the substrate is bonded with an acrylic adhesive or an epoxy adhesive.

  According to the present invention, since the base layer having excellent adhesion to the adhesive can be formed on the surface of the metal material, high adhesion strength and adhesion durability can be obtained when the metal material is adhered by the adhesive.

  Hereinafter, a specific example of the surface treatment agent for a metal material of the present invention will be described. The surface treating agent of one specific example of the present invention is a solution containing both an azole silane compound and an amino silane coupling agent as essential components, stainless steel, ordinary steel, nickel, aluminum, aluminum alloy, copper, It can be applied to various metal materials such as galvanized steel, and among these, it can be suitably applied particularly to stainless steel, ordinary steel, and nickel. The metals to be joined together may be the same type of metal material or a combination of different types of metal materials. The shape of the metal material to be applied is not particularly limited, and can be applied to various forms of members such as plate materials and metal parts. Moreover, you may apply when joining metal materials with materials other than metals, such as resin and a plastics.

  Water or an organic solvent can be used as the solvent for the surface treatment agent for dissolving the two essential components described above, but water is preferably used as the solvent. Hereinafter, the case of an aqueous surface treatment agent using water as a solvent will be described. One azole silane compound of the above two types of essential components preferably has a structure having an azole ring or a condensed ring of an azole ring and a benzene ring and an alkoxysilyl group in the molecule. In particular, the azole silane compound is preferably at least one selected from the group consisting of imidazole silane, benzimidazole silane, benzotriazole silane, and derivatives thereof.

  It is important that the concentration of the azolesilane compound in the aqueous solution as the surface treatment agent is 0.1% by mass or more and 4.2% by mass or less. If the concentration is less than 0.1% by mass, it is difficult to coat the surface of the metal material with the base layer substantially uniformly, and an untreated part is likely to be formed, which is not preferable. On the other hand, if it exceeds 4.2% by mass, the azolesilane layer becomes bulky and is liable to cohesive failure.

  The azolesilane compound is commercially available, for example, as a metal surface treatment agent in the form of a 10% aqueous solution (trade name: PA-2, manufactured by Nikko Metal Co., Ltd.), and the surface treatment agent may be prepared using this. . The azole silane compound of this commercial product (PA-2) is produced in an oligomerized state and thus has excellent film-forming properties. Also, due to its high polarity derived from its azole structure, stainless steel, ordinary It has high affinity with metal surfaces such as steel and nickel, and has excellent properties as an underlayer. Note that additives such as a boron compound as a catalyst and an aliphatic carboxylic acid as a surfactant may be added to the azolesilane as necessary.

  As described above, the azole silane compound is widely used as a metal surface treatment agent. However, since the bonding durability is slightly insufficient for bonding a structural material, improvement has been demanded. Therefore, in the surface treating agent of one specific example of the present invention, the other essential component, a silane coupling agent having an amino group (hereinafter also referred to as an amino-based silane coupling agent) is contained in an aqueous solution together with an azolesilane compound. Yes. Thereby, the adhesiveness of the surface treatment agent is greatly improved, and excellent adhesive strength and adhesive durability are exhibited.

  As described above, the reason why the adhesion is improved by adding the amino silane coupling agent to the azole silane compound is that the amino group of the amino silane coupling agent has a very strong polarity. This is thought to be due to strong adsorption to a metal layer such as a nickel layer. For example, the chromium oxide layer on the surface of stainless steel is partly hydrated by moisture in the atmosphere, and its isoelectric point is near 7, which makes it easy for basic amino groups to be adsorbed. Yes. Moreover, since the ethoxy group and methoxy group present in the azolesilane compound are bonded to the ethoxy group and methoxy group present in the amino silane coupling agent by dehydration condensation, an extremely strong hybrid film is formed. For the above reasons, it is considered that the surface treatment agent exhibits excellent adhesion performance.

  As amino-based silane coupling agents having such characteristics, silane coupling agents having various amino groups can be used, such as 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, N-2, and the like. -(Aminoethyl) -3-aminopropylmethoxysilane, 3-triethoxyl-N- (1,3-dimethyl-butylidene) propylamine, and N-phenyl-3-aminopropyltrimethoxysilane are preferred. Among these, 3-aminopropyltriethoxysilane is more preferable.

  In the surface treating agent of one specific example of the present invention, the concentration of the amino-based silane coupling agent in the aqueous solution is 0.1 mass% or more and 0.5 mass% or less so that the above-described effects can be stably obtained. It is important to make it. If this concentration is less than 0.1% by mass, the effect obtained by the combined use with azolesilane may be insufficient. Conversely, if it exceeds 0.5% by mass, the dehydration condensation reaction of the amino silane coupling agent itself. Is preferentially advanced, and the effect obtained by the combined use with the azole-based silane is hardly exhibited.

  Next, a method for adhering metal materials to each other using the surface treating agent of one specific example of the present invention described above will be described. In addition, the adhesion method of the metal material using the surface treating agent of one specific example of the present invention can be applied to various metal materials such as stainless steel, ordinary steel, nickel, aluminum, aluminum alloy, copper, and galvanized steel as described above. Although applicable, the following description demonstrates the case where it applies to stainless steel.

  First, preferably, an azole silane compound and an amino-based silane coupling agent are added to pure water so as to be within the above-described predetermined concentration ranges and mixed with a stirrer. Thereby, the aqueous solution as a surface treating agent is prepared. Next, the prepared aqueous solution as a surface treatment agent is applied to each bonding surface of the two stainless steel plates to be bonded to each other. There is no particular limitation on the coating method, and known means such as a method of immersing a metal material in an aqueous solution as a surface treating agent or a method of coating the surface of the metal material with a brush or the like can be used. In the case of immersion, the immersion time may be about 1 second to 10 minutes, preferably 1 second to 60 seconds. After application of the surface treatment agent, it is dried at a temperature of 100 to 150 ° C.

  In this way, an adhesive is applied on one or both of the two stainless steel plates on which the base layer is formed, and the two plate materials are overlapped and bonded so that the two base layer sides face each other. . Thereby, the joined body which has high adhesive strength and adhesive durability is obtained. The adhesive used for adhesion is not particularly limited as long as it forms a chemical bond (covalent bond) with the silane coupling agent. For example, a commercially available one-component or two-component epoxy adhesive, isocyanate and a curing agent are used. And urethane-type adhesives, radical-curing modified acrylic adhesives, heat-curing silicone adhesives, and the like. Among these, radical curable modified acrylic adhesives and two-component epoxy adhesives that are excellent in oil surface adhesion are preferable for stainless steel sheets. For example, a modified acrylic adhesive may include 3M Scotchweld EPX metal grip, and a two-component epoxy adhesive may include 3M Scotchweld EP190.

  As described above, by using the surface treatment agent of the present invention to form a base layer, a simple construction in which the same kind of metal material or a different kind of metal material is bonded using an adhesive, a conventional acid is used. Hazardous pollution to metal joints such as building materials and other structural materials with high adhesive strength and excellent durability almost equal to or higher than when surface treatment with mixed aqueous solution or chemical treatment such as silane coupling agent It can be produced without producing a substance. In particular, the bonded portion of the metal joined body is excellent in moisture resistance at high temperatures, and can maintain high adhesive strength over a long period of time even when exposed to a high temperature and high humidity environment such as immersion in boiling water.

  Moreover, it can be used conveniently also as a surface treating agent in the case of applying TIM to metal materials, such as nickel. That is, since the nickel surface is very inactive, it is difficult to increase the adhesion to organic materials, and the adhesive force with the TIM adhered to the surface may be significantly reduced by the thermal load. By treating the surface of the nickel plate with an agent, adhesion to the TIM material, for example, an organic / inorganic composite thin film, while maintaining a smooth surface of nickel without roughening the surface such as sandblasting It can be increased very simply.

  Furthermore, the surface treating agent of the present invention can also be used for adhesion of electrically insulating materials. That is, the surface treatment agent of the present invention can maintain a stable adhesive property even under severe use conditions such as a high temperature strong acid or strong alkali aqueous solution, and the cross-linking density of the coating film is very high. In addition, new developments such as application to various electrochemical processes such as insulating films for metals used in strong acid and strong basic aqueous solutions are possible.

[Example A]
Hereinafter, the metal plates surface-treated using the surface treating agents of Examples and Comparative Examples were bonded with an adhesive, and the adhesive strength and durability were evaluated. The present invention is not limited by the following examples and comparative examples. First, as an azole silane compound and an amino-based silane coupling agent, respectively, an azole silane polymer (trade name PA-2: 10% by mass aqueous solution) manufactured by Nikko Shoji and 3-aminopropyltriethoxysilane (trade name) manufactured by Shin-Etsu Silicone. KBE-903) was prepared.

  Next, each of a plurality of beakers in which pure water is contained within a range of 30 to 50 g is weighed so that PA-2 as an azolesilane compound has various contents within a range of 0.5 to 21 g. And dissolved by stirring for 3 minutes with a stirrer. Subsequently, KBE-903 as an amino-based silane coupling agent was weighed and added to each of the plurality of beakers so as to have various contents within a range of 0.05 to 0.20 g, and further added for 3 minutes. It was dissolved by stirring. In this manner, aqueous solutions of the surface treatment agents for Samples 1 to 16 were prepared.

  Further, the surface of sample 17 using N-2- (aminoethyl) -3-aminopropyltrimethoxysilane (trade name KBM-603) made by Shin-Etsu Silicone instead of KBE-903 as an amino silane coupling agent. A treating agent was prepared. For comparison, surface treatment agents for Samples 18 and 19 were prepared by adding only the azolesilane polymer to pure water. Table 1 below shows the amounts and concentrations of pure water, azole silane compound, and amino silane coupling agent contained in each of the surface treatment agents of Samples 1 to 19 thus prepared.

  Next, a plurality of rectangular test pieces having a width of 25 mm and a length of 100 mm were cut from a SUS304 stainless steel plate having a thickness of 1.2 mm to be bonded so that the longitudinal direction thereof was in the rolling direction. These test pieces were degreased by immersing them in normal temperature acetone for 3 minutes, then immersed in normal temperature 10% aqueous hydrochloric acid for 3 minutes, pickled, and washed with distilled water. Then, four test pieces were immersed in each of the surface treatment agents of Samples 1 to 19 for 60 seconds. After the immersion, it was dried in a dryer at a temperature of 100 ° C.

  A modified acrylic adhesive (Scotchweld EPX Metal Grip manufactured by 3M) was applied to each of the four treated specimens for each sample of the surface treatment agent thus obtained, and a lap width of 12.5 mm. Glued with. Thus, two bonded bodies of Samples 1A to 19A each treated with the surface treatment agent of Samples 1 to 19 were produced. Further, two samples of the four test pieces subjected to only the degreasing, pickling and water washing described above without performing the surface treatment with the surface treatment agent were similarly adhered with a modified acrylic adhesive to prepare the sample 20A. Two joined bodies were produced.

  Then, after bonding the bonded portion to one of the two bonded bodies of each sample for 7 days at room temperature, the shear bond strength was measured according to JIS K6850, and the initial shear was measured. The strength was examined. Further, in order to investigate the moisture resistance of the bonded portion, the other of the two joined bodies of each sample was exposed to an atmosphere having a relative humidity of 98% or more at a temperature of 80 ° C. for 60 days, and then sheared in the same manner. The adhesive strength was measured and the shear strength was examined after 60 days. The measurement results are shown in Table 2 below.

From the results of Table 2 above, the bonded assemblies of Samples 1A to 17A that were surface-treated with the surface treatment agents of Samples 1 to 17 that satisfy the requirements of the present invention maintain high adhesive durability even under high temperature and high humidity. I understand that. On the other hand, the bonding strengths of the bonded body of Samples 18A to 19A that were surface-treated with only the azolesilane compound of Samples 18 to 19 and the bonded body of Sample 20A that was not subjected to the surface treatment with the surface treatment agent were initial and In any case after 60 days, it was inferior to the joined bodies of Samples 1A to 17A.
[Example B]
Implemented on samples 1B to 20B, which were produced in the same manner as in Example A, except that an epoxy adhesive (Scotch Weld EP-190 manufactured by 3M) was used instead of the modified acrylic adhesive. In the same manner as in Example A, the shear strength at the initial stage and after 60 days was measured. The measurement results are shown in Table 3 below.

  From the results of Table 3 above, the bonded assemblies of Samples 1B to 17B, which were surface-treated with the surface treatment agents of Samples 1 to 17 that satisfy the requirements of the present invention, maintained high adhesive durability even under high temperature and high humidity. I understand that. On the other hand, the bonding strengths of the joined body of Samples 18B to 19B surface-treated with only the azolesilane compound of Samples 18 to 19 and the joined body of Sample 20B not subjected to the surface treatment with the surface treatment agent are initial and In any case after 60 days, it was inferior to the joined bodies of Samples 1B to 17B.

[Example C]
A cold rolled steel plate with a thickness of 1.6 mm is used for the metal plate instead of the SUS304 stainless steel plate, and an epoxy adhesive (Scotch Weld EP-190 manufactured by 3M) is used for the adhesive instead of the modified acrylic adhesive. Except for the above, for the joined bodies of Samples 1C to 20C produced in the same manner as in Example A, the initial and 60-day shear strengths were measured in the same manner as in Example A. The measurement results are shown in Table 4 below.

  From the results in Table 4 above, the bonded assemblies of Samples 1C to 17C that were surface-treated with the surface treatment agents of Samples 1 to 17 that satisfy the requirements of the present invention maintained high adhesive durability even under high temperature and high humidity. I understand that. In contrast, the bonding strengths of the joined body of Samples 18C to 19C surface-treated with only the azole silane compound of Samples 18 to 19 and the joined body of Sample 20C that was not subjected to the surface treatment with the surface treatment agent were initial and In any case after 60 days, it was inferior to the joined bodies of Samples 1C to 17C.

[Example D]
Instead of the SUS304 stainless steel plate, a 1.6 mm thick aluminum / titanium alloy (2024-T3) is used for the metal plate, and an epoxy adhesive (3M Scotch Weld EP manufactured by 3M) is used instead of the modified acrylic adhesive. With respect to the joined bodies of Samples 1D to 20D prepared in the same manner as in Example A except that -190) was used, the shear strengths at the initial stage and after 60 days were measured in the same manner as in Example A. The measurement results are shown in Table 5 below.

  From the results of Table 5 above, the bonded assemblies of Samples 1D to 17D that were surface-treated with the surface treatment agents of Samples 1 to 17 that satisfy the requirements of the present invention maintained high adhesive durability even under high temperature and high humidity. I understand that. On the other hand, the bonding strengths of the joined body of Samples 18D to 19D surface-treated with only the azolesilane compound of Samples 18 to 19 and the joined body of Sample 20D not subjected to the surface treatment with the surface treatment agent are initial and In any case after 60 days, it was inferior to the joined bodies of Samples 1D to 17D.

[Example E]
Instead of the SUS304 stainless steel plate, a hot-dip galvanized steel plate with a thickness of 1.2 mm is used for the metal plate, and an epoxy adhesive (Scotch Weld EP-190 manufactured by 3M) is used as the adhesive instead of the modified acrylic adhesive. Except that, the shear strengths at the initial stage and after 60 days were measured in the same manner as in Example A for the joined bodies of Samples 1E to 20E prepared in the same manner as in Example A. The measurement results are shown in Table 6 below.

  From the results of Table 6 above, the bonded assemblies of Samples 1E to 17E that were surface-treated with the surface treatment agents of Samples 1 to 17 that satisfy the requirements of the present invention maintained high adhesive durability even under high temperature and high humidity. I understand that. On the other hand, the bonding strengths of the joined body of samples 18E to 19E surface-treated with only the azolesilane compound of samples 18 to 19 and the joined body of sample 20E not subjected to the surface treatment with the surface treatment agent are initial and In any case after 60 days, it was inferior to the joined bodies of Samples 1E to 17E.

[Example F]
Instead of the SUS304 stainless steel plate, a JIS H4551 nickel plate (Standard Test Piece) with a thickness of 1.0 mm is used for the metal plate, and an epoxy adhesive (Scotch Weld made by 3M) is used instead of the modified acrylic adhesive as the adhesive. A joined body of Samples 1F to 20F was produced in the same manner as in Example A except that EP-190) was used. The initial shear strength was tested on the joined bodies of Samples 1F to 20F in the same manner as in Example A. In the moisture resistance test, the joined body was exposed to an atmosphere of 60 ° C. and a relative humidity of 98% or more for 60 days. After that, the shear adhesive strength was measured in the same manner as in Example A. The measurement results are shown in Table 7 below.

  From the results in Table 7 above, the bonded assemblies of Samples 1F to 17F that were surface-treated with the surface treatment agents of Samples 1 to 17 that satisfy the requirements of the present invention maintained high adhesive durability even under high temperature and high humidity. I understand that. On the other hand, the adhesion strength of the joined body of samples 18F to 19F surface-treated with only the azolesilane compound of samples 18 to 19 and the joined body of sample 20F not subjected to the surface treatment with the surface treatment agent was 60 days later. Was inferior to the joined bodies of Samples 1F to 17F.

[Example G]
Implemented on samples 1G to 20G, which were prepared in the same manner as in Example F, except that a modified acrylic adhesive (Scotch Weld EPX Metal Grip manufactured by 3M) was used instead of the epoxy adhesive. In the same manner as in Example F, the shear strength at the initial stage and after 60 days was measured. The measurement results are shown in Table 8 below.

  From the results of Table 8 above, the bonded assemblies of Samples 1G to 17G that were surface-treated with the surface treatment agents of Samples 1 to 17 that satisfy the requirements of the present invention maintained high adhesive durability even under high temperature and high humidity. I understand that. On the other hand, the adhesion strength of the joined body of samples 18G to 19G surface-treated with only the azolesilane compound of samples 18 to 19 and the joined body of sample 20G not subjected to the surface treatment with the surface treatment agent was 60 days later. In comparison with the joined bodies of Samples 1G to 17G.

[Example H]
Two types of joined bodies were prepared under the same conditions as Sample 7 of Example A and Sample 7 of Example B, respectively, except that a copper plate having a thickness of 1.6 mm was used instead of the SUS304 stainless steel plate. In the same manner as in Example A, the shear bond strength at the initial stage and after 60 days was measured. As a result, the former had an initial shear strength of 14 MPa and a shear strength after 60 days of 12 MPa, and the latter had an initial shear strength of 18 MPa and a shear strength after 60 days of 14 MPa. Therefore, it can be seen that high adhesion durability is maintained even at high temperature and high humidity in the copper plate as in the case of the SUS304 stainless steel plate.

[Example I]
Two types of joined bodies were produced under the same conditions as Sample 7 of Example A and Sample 7 of Example B, respectively, except that an aluminum plate having a thickness of 1.6 mm was used instead of the SUS304 stainless steel plate. In the same manner as in Example A, the shear bond strength at the initial stage and after 60 days was measured. As a result, the former had an initial shear strength of 14 MPa and a shear strength after 60 days of 10 MPa, and the latter had an initial shear strength of 18 MPa and a shear strength after 60 days of 14 MPa. Therefore, it can be seen that also in the aluminum plate, high adhesive durability is maintained even under high temperature and high humidity as in the case of the SUS304 stainless steel plate.

Claims (6)

  A surface treatment agent comprising a solution containing an azole silane compound and an amino silane coupling agent, wherein the concentration of the azole silane compound in the solution is 0.1% by mass or more and 4.2% by mass or less, A surface treatment agent for a metal material, wherein the concentration of the amino silane coupling agent in the solution is 0.1% by mass or more and 0.5% by mass or less.   The surface treatment for a metal material according to claim 1, wherein the azole silane compound is at least one selected from the group consisting of imidazole silane, benzimidazole silane, benzotriazole silane, and derivatives thereof. Agent.   The metal material is one or two selected from the group consisting of stainless steel, ordinary steel, nickel, aluminum, aluminum alloy, copper, and galvanized steel. Surface treatment agent for metal materials.   It is a metal joined body formed by joining metal materials with an adhesive, and the surface treatment agent according to any one of claims 1 to 3 is applied to at least one of both facing joint surfaces of the metal materials. A metal joined body characterized in that a surface treatment agent layer is formed.   A method for adhering metal materials using an adhesive, wherein the surface treatment agent according to claim 1 or 2 is applied to at least one of the adhesion surfaces of both metal materials to form an underlayer After the film is formed, the metal material is bonded with an acrylic adhesive or an epoxy adhesive. The metal material adhesion according to claim 3, wherein the metal material is one or two of stainless steel, ordinary steel, nickel, aluminum, aluminum alloy, copper, and galvanized steel. Method.