KR102391712B1 - Gas storage tank having enhanced bonding property and method for manufacturing the same - Google Patents

Abstract

The present invention relates to a gas storage tank for storing hydrogen for fuel cells and a method for manufacturing the same, comprising a container body (10) and a metal boss (20) installed at the end of the container body (10), the container body (10) provides a gas storage tank including a plastic liner 12 made of a plastic material, wherein a bonding film 15 is formed on the contact surface of the plastic material liner 12 and the metal boss 20, and a method for manufacturing the same do. According to an embodiment of the present invention, the bonding film 15 may include an oxide film formed by anodizing the surface of the metal boss 20; and a sulfur compound film formed between the oxide film and the plastic liner 12 . According to the present invention, the bonding film 15 has excellent bonding properties and airtightness at the contact surface between the plastic material liner 12 and the metal material boss 20 .

Description

Gas storage tank with excellent bonding properties and manufacturing method thereof

The present invention relates to a gas storage tank for storing hydrogen (H ₂ ), etc. for fuel cells and a method for manufacturing the same, and according to an embodiment, between a plastic material liner and a metal material boss constituting the gas storage tank It relates to a gas storage tank having excellent at least bonding properties and airtightness at a contact surface, and a method for manufacturing the same.

A gas storage tank (high-pressure vessel) is mounted on a fuel cell vehicle or a natural gas vehicle by compressing and storing gaseous fuel at a high pressure. For example, a fuel cell vehicle is equipped with one or two or more hydrogen storage tanks in which high-pressure hydrogen (H ₂ ) gas used as a fuel of the stack is stored.

1 shows a gas storage tank according to the prior art. Referring to FIG. 1 , in general, a gas storage tank includes an internal liner 1 for storing hydrogen, etc., an external composite layer 2 formed on the liner 1 , and the liner 1 . Includes a boss (3) joined to the. In most cases, the liner 1 is made of a plastic material, and the composite material layer 2 is formed by coating a carbon fiber composite material including carbon fibers and a binder resin (epoxy resin, etc.) on the surface of the liner 1 . do. In addition, the boss 3 is made of a metal material, and a regulator or a valve made of a metal material is coupled thereto.

For example, Korean Patent No. 10-1619630, Korean Patent No. 10-2006330, Korean Patent Publication No. 10-2013-0032186, Japanese Patent Application Laid-Open No. JP2009-174700 and Japanese Patent Application Laid-Open No. JP2012-180892 A technique related to the above is presented.

The plastic liner 1 and the metal boss 3 are difficult to achieve strong bonding and airtightness due to the characteristics of different materials. Maintaining the bondability and airtightness between the plastic liner 1 and the metal boss 3 is an important factor influencing the performance and safety of the gas storage tank. When the bonding and airtightness between the plastic liner 1 and the metal boss 3 is poor, the stored gas leaks to the outside, and in particular, an accident may occur as the boss 3 is separated from the liner 1 by the high-pressure gas. There are concerns.

Accordingly, a technique for separately installing the sealing member 4 and the fastening member 5 for bonding and airtightness between the plastic liner 1 and the metal boss 3 has been proposed. However, the sealing member 4 is a rubber material, which has a disadvantage in that durability is reduced when continuously subjected to the pressure of the high-pressure gas, and thus cannot completely block the external leakage of the high-pressure gas. In addition, the fastening member 5 is made of a metal material for solid fastening with the metal boss 3, and since it is also of a different material from the plastic liner 1, the plastic liner 1 and the metal fastening member ( 5), there is a problem in that airtightness is deteriorated because a gap is generated at the contact interface.

Korean Patent Registration No. 10-1619630 Korean Patent Registration No. 10-2006330 Korean Patent Publication No. 10-2013-0032186 Japanese Patent Laid-Open No. JP2009-174700 Japanese Patent Laid-Open No. JP2012-180892

Accordingly, an object of the present invention is to provide a gas storage tank excellent in bonding properties and airtightness at least on the contact surface between the plastic material liner and the metal material boss, and a method for manufacturing the same.

In order to achieve the above object, the present invention

container body,

It includes a metal boss installed at the end of the container body,

The container body includes a plastic liner made of a plastic material,

It provides a gas storage tank in which a bonding film is formed on the contact surface of the plastic liner and the metal boss.

According to an embodiment of the present invention, the bonding film may include an oxide film formed by anodizing the surface of the metal boss; and a sulfur compound film formed between the oxide film and the plastic liner. In this case, the sulfur compound film includes, for example, triazinethiol and/or a derivative thereof.

In addition, the present invention,

an anodization process of forming an oxide film on the surface of the metal boss by electrolyzing the metal boss as an anode and using an acid solution at 10° C. to 95° C. at a current density of 0.01 A/dm ² to 3.5 A/dm ² ;

an electrolytic film forming step of forming a sulfur compound film on the surface of the oxide film by electrolysis in an electrolyte containing a sulfur compound using the metal boss on which the oxide film is formed as an anode;

a water washing process of washing the metal boss on which the oxide film and the sulfur compound film are formed with water at 5°C to 80°C; and

It provides a method of manufacturing a gas storage tank comprising a molding process of insert molding a plastic liner on the metal boss after washing with water.

The present invention has an effect of improving at least bonding properties and airtightness at the contact surface between the plastic material liner and the metal material boss by the bonding film. Accordingly, according to the present invention, the plastic liner and the metal boss are firmly joined with excellent bonding strength without installing a separate sealing member or fastening member at the joint portion between the plastic liner and the metal boss, and external leakage of high-pressure gas is prevented. effectively prevented.

1 is a cross-sectional view showing a gas storage tank according to the prior art.
2 is a perspective view showing a gas storage tank according to an embodiment of the present invention.
3 is a cross-sectional view showing a gas storage tank according to an embodiment of the present invention.
4 is an SEM image of a specimen manufactured according to an embodiment of the present invention.
5 is a photograph showing a state in which the tensile strength of a specimen manufactured according to an embodiment of the present invention is measured.

The term "and/or" used in the present invention is used in a sense including at least one or more of the components listed before and after. As used herein, the term “one or more” refers to one or a plurality of two or more.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings illustrate exemplary embodiments of the present invention, which are provided merely to aid understanding of the present invention. In the accompanying drawings, in order to clearly express each layer and region, the thickness may be enlarged, and the scope of the present invention is not limited by the thickness, size, and ratio indicated in the drawings. In addition, in describing the embodiment of the present invention, detailed description of related well-known general-purpose functions and/or configurations will be omitted.

The present invention provides a gas storage tank having improved adhesion and airtightness at least on the contact surface between the plastic material liner 12 and the metal material boss 20 . In addition, the present invention provides a method for manufacturing a gas storage tank according to the present invention. If the gas storage tank according to the present invention is used for the purpose of storing gas, its specific use is not particularly limited. In addition, the type of gas in the present invention is not limited, and includes liquefied gas. The gas storage tank according to the present invention may be used, for example, as a high-pressure container mounted on a fuel cell vehicle or a natural gas vehicle to compress and store gaseous fuel at high pressure. According to a specific embodiment, the gas storage tank according to the present invention is a hydrogen storage tank storing high-pressure hydrogen (H ₂ ) gas, which may be mounted on a fuel cell vehicle or the like.

2 is a perspective view showing a gas storage tank according to an embodiment of the present invention. And FIG. 3 is a cross-sectional view of a main part showing a gas storage tank according to an embodiment of the present invention, which is a cross-sectional view showing a portion A of FIG. 2 .

2 and 3 , the gas storage tank according to the present invention includes a container body 10 and a boss 20 installed at an end of the container body 10 . Gas such as hydrogen is stored in the container body 10, which includes at least a liner 12 made of a plastic material as usual. According to another embodiment of the present invention, the container body 10 may further include a composite layer 14 formed on the liner 12 . Specifically, in the present invention, the container body 10 includes an internal plastic material liner 12 that forms a storage space in which a gas such as hydrogen is stored, and an external composite material layer formed on the plastic material liner 12 ( 14) may be included. Further, according to another embodiment of the present invention, the container body 10 is provided on the inner surface of the plastic material liner 12 , between the plastic material liner 12 and the composite material layer 14 , and/or the composite material layer 14 . ) may further include a separate layer formed on the outer surface.

The liner 12 is not particularly limited as long as it is made of a plastic material, for example, high-density polyethylene, polypropylene, polyester, polyacrylic acid ester, polyamide, polystyrene, polyacetal, polycarbonate, polyphenylene sulfide, One or more resins selected from polyaniline, polyethylene terephthalate and polybutylene terephthalate may be formed through injection molding. The composite material layer 14 is for reinforcing the strength of the liner 12 , and may be formed of, for example, a composite material including fibers and a binder resin. The fibers constituting the composite layer 14 may be selected from carbon fibers and/or glass fibers, and the binder resin may be selected from epoxy resins, polyesters and/or polyethylene terephthalate, etc. is not limited by

In addition, the boss 20 may be formed on either side or both sides of the container body 10 . 2 illustrates a state in which the boss 20 is formed at both ends of the container body 10 . The boss 20 is made of a metal material, for example, aluminum (Al), iron (Fe), nickel (Ni), chromium (Cr), tungsten (W), tin (Sn), magnesium (Mg), It may be composed of zinc (Zn) and/or alloys thereof. As a specific example, the boss 20 may be made of aluminum (Al), an aluminum (Al) alloy, and/or stainless steel. A metal regulator and/or a valve are coupled to the boss 20 as usual.

Referring to FIG. 3 , the metal boss 20 includes a flange part 22 extending and formed along the outer periphery, and the flange part 22 is the distal end 12a of the plastic liner 12 . ) may have an embedded structure. As described above, as the flange portion 22 is embedded in the distal end 12a of the plastic material liner 12 , the bonding force between the metal material boss 20 and the plastic material liner 12 may be improved. The embedded structure of the flange portion 22 may be formed by insert injection molding as usual.

In addition, according to another embodiment of the present invention, the contact surface of the metal boss 20 and the plastic liner 12 may have a concave-convex structure and/or an interlocking structure for improving bonding force between the two. The concave-convex structure may be formed through, for example, a hair line treatment using an acid treatment, an etching treatment, and/or a grinding process on the surface of the metal boss 20 . there is. The concave-convex structure is random and irregular, and for example, may have a shape such as a wave shape or a sawtooth shape.

The gas storage tank according to the present invention includes a bonding film (15). Specifically, according to the present invention, a bonding film 15 is formed on the contact surface between the plastic material liner 12 and the metal material boss 20 . The bonding film 15 improves bonding and airtightness between the plastic material liner 12 and the metal material boss 20 . The bonding film 15 is preferably formed on all contact interfaces where the plastic liner 12 and the metal boss 20 come into contact with each other.

According to an embodiment of the present invention, the bonding film 15 includes an oxide film and/or a sulfur compound film. Preferably, the bonding film 15 includes both an oxide film and a sulfur compound film. The oxide film is formed by anodizing the surface of the metal boss 20 , and is formed over at least the entire surface of the flange portion 22 . The sulfur compound film is a film formed by interposing a sulfur compound between the oxide film and the plastic liner 12, and contains at least a sulfur compound. According to the present invention, the oxide film and the sulfur compound film as the bonding film 15 effectively improve the bondability and airtightness between the metal boss 20 and the plastic liner 12 . In this case, the oxide film may have a thickness of, for example, 5 nm to 30 µm, specifically, a film thickness of 10 nm to 25 µm. In addition, the sulfur compound film, for example, may have a thickness of 1nm ~ 15㎛, specifically, may have a film thickness of 2nm ~ 10㎛.

Hereinafter, a specific embodiment of the bonding film 15 will be described while describing a method for manufacturing a gas storage tank according to the present invention.

The method for manufacturing a gas storage tank according to the present invention, according to the first aspect of the present invention, with the metal boss 20 as an anode, 0.01 A/dm ² to 3.5 A using an acidic solution at 10° C. to 95° C. an anodic oxidation process of forming an oxide film on the surface of the metal boss 20 by electrolysis at a current density of /dm ² ; a water washing process of washing the metal boss 20 on which the oxide film is formed with water at 5° C. to 80° C.; and a molding process of insert molding the plastic liner 12 into the metal boss 20 after washing with water. At this time, in the molding process, as usual, the metal boss 20 is first charged into the molding mold, and then the plastic material (thermoplastic resin) constituting the liner 12 is put in the molding mold to insert molding (blow molding). can proceed. By this manufacturing process, a microporous oxide film is formed as a bonding film 15 on the contact surface of the metal boss 20 and the plastic liner 12, and the metal boss 20 and the plastic material liner ( 12) The bonding and airtightness between the two is improved.

According to the second aspect of the present invention, the method for manufacturing a gas storage tank according to the present invention uses the metal boss 20 as an anode, and 0.01 A/dm ² to 3.5 A using an acidic solution at 10° C. to 95° C. an anodic oxidation process of forming an oxide film on the surface of the metal boss 20 by electrolysis at a current density of /dm ² ; an electrolytic film forming step of forming a sulfur compound film on the surface of the oxide film by using the metal boss 20 on which the oxide film is formed as an anode and performing electrolysis in an electrolyte containing a sulfur compound; a water washing process of washing the metal boss 20 on which the oxide film and the sulfur compound film are formed with water at 5° C. to 80° C.; and a molding process of insert molding the plastic liner 12 into the metal boss 20 after washing with water. At this time, in the electrolytic film formation process, as the sulfur compound is coated on the surface of the oxide film, the sulfur compound penetrates into the microporous oxide film at the same time, and the sulfur compound penetrates into the surface of the oxide film and the internal pores of the oxide film to be formed. can By this manufacturing process, an oxide film and a sulfur compound film are formed as the bonding film 15 on the contact surface of the metal boss 20 and the plastic liner 12, and the metal boss 20 and the plastic are formed by the oxide film and the sulfur compound film. Bonding and airtightness between the ash liners 12 are further improved.

The manufacturing method of the gas storage tank according to the present invention, according to the third aspect of the present invention, with the metal boss 20 as an anode, 0.01 A/dm ² a film forming process of forming an oxide film and a sulfur compound film on the surface of the metal boss 20 by electrolysis at a current density of ~ 3.5 A/dm ² ; a water washing process of washing the metal boss 20 on which the oxide film and the sulfur compound film are formed with water at 5° C. to 80° C.; and a molding process of insert molding the plastic liner 12 into the metal boss 20 after washing with water. At this time, in the film forming process, an oxide film and a sulfur compound film are formed at the same time, and the sulfur compound may penetrate into the microporous oxide film together with the oxide film while being filmed on the surface of the oxide film. By this manufacturing process, an oxide film and a sulfur compound film are formed as the bonding film 15 on the contact surface of the metal boss 20 and the plastic liner 12, and the metal boss 20 and the plastic are formed by the oxide film and the sulfur compound film. Bonding and airtightness between the ash liners 12 are further improved. In addition, in the manufacturing process according to the third aspect, the oxide film and the sulfur compound film are simultaneously formed by the film forming process, so that the manufacturing process can be shortened.

According to the fourth aspect of the present invention, the method for manufacturing a gas storage tank according to the present invention uses the metal boss 20 as an anode, and 0.01 A/dm ² to 3.5 A using an acidic solution at 10° C. to 95° C. an anodic oxidation process of forming an oxide film on the surface of the metal boss 20 by electrolysis at a current density of /dm ² ; an immersion step of immersing the metal boss 20 on which the oxide film is formed in an immersion solution containing a sulfur compound to form a sulfur compound film on the surface of the oxide film; a water washing process of washing the metal boss 20 on which the oxide film and the sulfur compound film are formed with water at 5° C. to 80° C.; and a molding process of insert molding the plastic liner 12 into the metal boss 20 after washing with water. At this time, in the immersion process, the sulfur compound is coated on the surface of the oxide film, and at the same time, the sulfur compound penetrates into the microporous oxide film, and the sulfur compound penetrates into the surface of the oxide film and the internal pores of the oxide film. Can be formed. . By this manufacturing process, an oxide film and a sulfur compound film are formed as the bonding film 15 on the contact surface of the metal boss 20 and the plastic liner 12, and the metal boss 20 and the plastic are formed by the oxide film and the sulfur compound film. Bonding and airtightness between the ash liners 12 are further improved.

In the present invention, the sulfur compound is not particularly limited as long as it is a sulfur (S)-containing compound capable of having a bond between the oxide film and M-S (where M is a metal constituting the oxide film). The sulfur compound preferably includes a thiol-based sulfur compound having one or more thiol groups (-SH) in the molecule. The sulfur compound is more preferably a thiol-based sulfur compound and may be selected from triazinethiol and/or derivatives thereof (such as a salt of triazinethiol), for example, 1,3,5-triazine-2, 4,6-trithiol, 1,3,5-triazine-2,4,6-trithiol monosodium, 1,3,5-triazine-2,4,6-trithiol triethanolamine, 6-anyl Rhino-1,3,5-triazine-2,4-dithiol, 6-anilino-1,3,5-triazine-2,4-dithiol monosodium, 6-dilauryl amino-1,3 ,5-triazine-2,4-dithiol monosodium, 6-stearyl amino-1,3,5-triazine-2,4-dithiol monopotassium, 6-oleyl amino-1,3,5 -triazine-2,4-dithiol and/or 6-oleyl amino-1,3,5-triazine-2,4-dithiol monopotassium and the like.

According to the present invention, a microporous oxide film is formed on the surface of the metal boss 20 through anodization, so that the fine concavo-convex structure of the oxide film and the plastic of the liner 12 are anchored to provide strong bonding and airtightness. have For example, when the metal boss 20 is aluminum (Al) or an aluminum (Al) alloy, Al ₂ O ₃ present on the surface of the oxide film in the insert molding process is a plastic (thermoplastic resin) constituting the liner 12 . ) anchor-bonded with the main skeleton, and acid-base bonding proceeds with it, so that it has excellent bonding and airtightness.

In addition, when the bonding film 15 is coated on the surface of the oxide film and further includes a sulfur compound penetrating into the oxide film, M-S (where M is a metal constituting the oxide film) between the oxide film and the sulfur compound A chemical bond is formed, and a covalent bond is formed between a sulfur compound (eg, triazinethiol and/or a derivative thereof) and a terminal functional group of the plastic (thermoplastic resin) constituting the liner 12, and addition For example, an anchor bond is also formed between the sulfur compound film and the surface of the plastic material liner 12 due to fine irregularities, so that it has very good bonding properties and airtightness.

Meanwhile, in the anodization process, the metal boss 20 is used as an anode, and an insoluble electrode, for example, carbon or platinum, may be used as a cathode as the cathode. The electrolysis time in the anodization process may be carried out for 5 minutes or more, and it is preferable to proceed with the anodization (electrolysis reaction) for 10 minutes or more for good bonding properties. Specifically, it is preferable to perform anodization at a current density of 0.05 A/dm ² to 2.5 A/dm ² for 10 minutes to 2 hours.

In addition, in the present invention, the acidic solution may be an acidic aqueous solution containing an inorganic acid and/or an organic acid, for example. The inorganic acid may include at least one selected from sulfuric acid, hydrochloric acid and/or nitric acid, and the organic acid may include carboxylic acid. In this case, the carboxylic acid is dicarboxylic acid (oxalic acid), aminocarboxylic acid, hydroxycarboxylic acid, imidazole-5-carboxylic acid, 1,2,3-thiadiazolecarboxylic acid, cyclohexane polycarboxylic acid, heteroarylcarboxylic acid, benzene polycarboxylic acid, benzoic acid Indole carboxylic acid, pyrazole carboxylic acid, quinoline carboxylic acid, polyfluorocarboxylic acid, isothiazole carboxylic acid, pyridone carboxylic acid, aminothiophene carboxylic acid, benzophenone tetracarboxylic acid, 3-carbamoylpyrazine-2-carboxylic acid, 3-carboxy-1- It may include at least one selected from adamantane acetic acid, naphthalene acetic acid, tetraacetic acid and/or indole acetic acid.

In the electrolytic film forming process, a sulfur compound film is formed on the oxide film of the metal boss 20 by electrolysis in an electrolyte containing a sulfur compound (eg, triazinethiol and/or a derivative thereof, etc.), but the electrolyte is, for example For example, an electrolyte including an electrolyte selected from NaOH, NaNO ₂ , NaNO ₃ , Na ₂ CO ₃ , KNO ₂ , Na ₂ SO ₄ and/or CH ₃ COONa may be used. In addition, the solvent constituting the electrolyte solution is, for example, water, methanol, ethanol, isopropyl alcohol, acetone, toluene, diethylene glycol monobutyl ether, ethylene glycol monoethyl ether, dimethylformamide, methylpyrrolidone and / or acrylonitrile and the like. The temperature of the electrolyte may be 10 °C to 90 °C, preferably 20 °C to 60 °C. And the current density during the electrolysis is 0.005 ~ 50 mA / cm ² , preferably 0.05 ~ 5 mA / cm ² may be, the electrolysis time may be 2 seconds ~ 10 minutes, preferably 5 seconds ~ 2 minutes .

In addition, in the immersion process, the metal boss 20 on which the oxide film is formed is immersed in an immersion solution containing a sulfur compound to form a sulfur compound film on the surface of the oxide film, and the immersion solution may be an aqueous solution or an organic solution. Specifically, the immersion solution includes a sulfur compound and a solvent, wherein the solvent is from water, alcohol, isopropyl alcohol, acetone, toluene, ethylene glycol monoethyl ether, dimethylformaldehyde, tetrahydrofuran and/or methyl ethyl ketone. can be selected. This immersion process, for example, 5 ℃ ~ 95 ℃, preferably 40 ℃ ~ 80 ℃ temperature in an immersion solution of about 1 minute to 2 hours, preferably 5 minutes to 1 hour It can proceed by a method of immersion. .

According to another embodiment of the present invention, the sulfur compound film may further include phenylenediamine and acrylic acid alkyl ester. Specifically, the sulfur compound film is formed between the oxide film and the plastic liner 12, and as an active ingredient constituting the film, a thiol-based sulfur compound (for example, triazinethiol and/or a derivative thereof), phenylenediamine And it is good to further include an acrylic acid alkyl ester. To this end, the film forming process and the immersion process may be prepared by further adding phenylenediamine and an acrylic acid alkyl ester to each solution when preparing the electrolyte solution, acidic solution or immersion solution.

According to one embodiment, in the electrolytic film forming process, phenylenediamine and acrylic acid alkyl ester are further added to an electrolyte containing a thiol-based sulfur compound, and then, the metal boss 20 on which the oxide film is formed is used as an anode and an insoluble electrode is used As a cathode, it is possible to form a sulfur compound film including a thiol-based sulfur compound, phenylenediamine and an acrylic acid alkyl ester on the surface of the oxide film by electrolysis in the electrolyte solution.

When phenylenediamine and acrylic acid alkyl ester are further included in the sulfur compound film, bondability and airtightness are improved, and high reliability (durability) can be achieved. For example, when triazinethiol and/or a derivative thereof is used as the sulfur compound, the phenylenediamine is combined with triazinethiol, and the acrylic acid alkylester is a plastic (thermoplastic resin) constituting the liner 12 and phenyl. By crosslinking rendiamine, it has excellent bonding strength and airtightness, and it can also have high reliability (durability) by maintaining excellent bonding strength and airtightness even under high temperature/high humidity conditions. In this case, the acrylic acid alkyl ester may be, for example, methyl acrylate ester and/or ethyl acrylate ester.

According to the present invention described above, the bonding film 15 selected from the oxide film and/or the sulfur compound film improves at least bonding properties and airtightness at the contact surface between the plastic material liner 12 and the metal material boss 20 . Accordingly, without installing a separate sealing member 4 or fastening member 5 at the joint between the plastic liner 12 and the metal boss 20 as in the prior art, the plastic liner 12 and the metal boss 20 ) is firmly joined with excellent bonding strength, effectively preventing external leakage of high-pressure gas.

Hereinafter, Examples and Comparative Examples of the present invention are exemplified. The following examples are provided only by way of illustration to help the understanding of the present invention, and the technical scope of the present invention is not limited thereby. In addition, the following comparative examples do not mean the prior art, and are provided only for comparison with the examples.

[Example 1]

First, an aluminum plate (Al 6063) having a thickness of 3 mm, a width of 12 mm, and a length of 50 mm was prepared, which was ultrasonically cleaned in acetone and alcohol solution for 5 minutes, respectively, and then washed with deionized water. Thereafter, it was degreased by immersion in a sulfuric acid aqueous solution having a sulfuric acid concentration of 0.2 mol/L for about 2 minutes, followed by washing again with deionized water.

Next, the degreased and water-washed aluminum plate is placed in an electrolytic cell containing an acidic solution at about 50° C. (a sulfuric acid aqueous solution with a sulfuric acid concentration of 0.5 mol/L), and the aluminum plate is used as an anode, and the carbon plate is used as a cathode, Electrolysis was performed for about 30 minutes at a current density of about 1.2 A/dm ² to form an oxide film on the surface of the aluminum plate. (anodic oxidation process)

Then, an aqueous solution in which sodium nitrate is dissolved at a concentration of 0.2 mol/L as an electrolyte is prepared, and 1,3,5-triazine-2,4,6-trithiol (hereinafter referred to as “TRI”) as a sulfur compound is prepared. A TRI solution was prepared with a concentration of about 0.6 mmol/L. Then, put the aluminum plate on which the oxide film is formed in the electrolytic cell containing the TRI solution, use the aluminum plate as the anode and the carbon plate as the cathode, and proceed with anode electrolysis at about 8 V for 10 minutes, and the oxide film formed on the aluminum plate A TRI bonding layer was formed as a sulfur compound film on the inside and on the surface of the oxide film. (Sulfur compound film formation process through electrolysis)

Next, the aluminum plate on which the oxide film and the TRI bonding layer were formed was washed with water at 50° C., and then dried to completely remove moisture. Thereafter, the water-washed and dried aluminum plate is put into an insert injection molding machine, polyphenylene sulfide (PPS) is injected as a resin therein, and injection molded (insert injection molding process) at a temperature of 140 ° C. and a pressure of 180 MPa (insert injection molding process), the aluminum plate ( An Al-PPS bonding specimen in which a resin (PPS) was bonded to Al) was prepared. At this time, it was found that, in the Al-PPS bonding specimen, an Al oxide film and a TRI bonding layer (sulfur compound film) were formed as bonding films at the bonding interface between the aluminum plate (Al) and the resin (PPS). The accompanying FIG. 4 shows the surface SEM image of the Al oxide film and the SEM image of the bonding interface of the Al-PPS bonding specimen according to the present embodiment.

[Examples 2 and 3]

It was carried out in the same manner as in Example 1, except that the type of resin was changed during insert injection molding. Specifically, in Example 2, polybutylene terephthalate (PBT) was used as the resin, and in Example 3, the same procedure as in Example 1 was used except that polyamide (PA) was used as the resin. Thus, Al-resin bonding specimens according to each Example were prepared.

[Examples 4 and 5]

It was carried out in the same manner as in Example 1, except that the process for forming a sulfur compound film was not carried out in the same manner as in Example 1. Specifically, an oxide film was formed as a bonding film through an anodization process, and a TRI bonding layer (sulfur compound film) was not formed thereafter. In addition, in the case of Example 5, the anodization process was performed for 20 seconds, and the electrolysis time of the anodization was shorter than that of Example 4.

[Example 6]

It was carried out in the same manner as in Example 1, except that phenylenediamine and acrylic acid alkylester were further added to the TRI solution in the sulfur compound film formation process. Specifically, in forming the sulfur compound film, 1,3,5-triazine-2,4,6- as a sulfur compound in the electrolyte (aqueous solution in which sodium nitrate is dissolved at a concentration of 0.2 mol/L) as in Example 1 A TRI solution containing trithiol (TRI) was prepared. And separately, a phenylenediamine-acrylic acid ethyl ester solution in which para-phenylenediamine and acrylic acid ethyl ester (CH ₂ = CHCO ₂ Et) are mixed in a solvent methyl ethyl ketone (MEK) was prepared. In addition, sodium borohydride (NaBH ₄ ), palladium acetate (Pd(O ₂ CCH ₃ )) and triethylamine (TEA) for reactivity were further added to the phenylenediamine-ethyl acrylate solution.

Next, the phenylenediamine-ethyl acrylate ester solution is added to the electrolytic cell containing the TRI solution and thoroughly mixed, and then an aluminum plate with an oxide film is put into the electrolytic cell, the aluminum plate as the anode and the carbon plate as the cathode, Anode electrolysis was performed at about 8 V for 10 minutes to form a sulfur compound film containing TRI and phenylenediamine-ethyl acrylate ester on the inside of the oxide film formed on the aluminum plate and on the surface of the oxide film. Thereafter, the insert injection molding process was performed in the same manner as in Example 1 to prepare an Al-PPS bonding specimen in which a resin (PPS) was bonded to an aluminum plate (Al). In the Al-PPS bonding specimen according to this embodiment, an Al oxide film and a sulfur compound film are formed as a bonding film at the bonding interface between the aluminum plate (Al) and the resin (PPS), and the sulfur compound film is TRI and phenyl bonded to the TRI Contains rendiamine, which specifically has a chemical bonding structure of Al-TRI-phenylenediamine-acrylic acid ethyl ester-PPS.

[Comparative Example 1]

An aluminum plate (thickness 3mm, width 12mm, and length 50mm) of the same standard used in Example 1 and a PPS resin plate (thickness 3mm, width 12mm, and length 40mm) were prepared, and then their contact surfaces were bonded with an epoxy resin adhesive. A PPS bonded specimen was used as a specimen according to this comparative example.

For the Al-resin bonded specimens according to Examples 1 to 6 and Comparative Example 1, tensile strength (bonding strength) and gas leakage tests were performed, and the results are shown in [Table 1] below. At this time, the tensile strength (bonding strength) was measured using a tensile tester, and FIG. 5 is a photograph showing the state in which the tensile strength is measured for an Al-resin bonded specimen. In addition, the gas leak test was performed as a helium leak test using helium (He) gas, and in the case of a specimen with a helium (He) leakage of 9x10 ^-10 Pa·m ³ /sec or less, "○", In the case of a specimen exceeding 9x10 ^-10 Pa·m ³ /sec, it was evaluated as “X” and is shown in [Table 1].

On the other hand, the tensile strength (bonding strength) after applying high temperature/high humidity to the reliability (durability) of the Al-resin bonded specimens according to Examples 1 and 6 was evaluated. Specifically, the initial tensile strength of each Al-resin bonding specimen was measured, and then stored for about 200 hours in a constant temperature/humidity bath maintained at a temperature of 80° C. and a humidity of 95%, and then the tensile strength (bonding strength) was measured. . The results are shown in [Table 1].

< Characteristic evaluation result of bonded specimen > profit bonding film anodic oxidation
time The tensile strength
(Early) The tensile strength
(after high temperature/high humidity) gas leak test Example 1 PPS oxide film + TRI 30 minutes 42.8 MPa 40.1 MPa ○ Example 2 PBT oxide film + TRI 30 minutes 36.1 MPa - ○ Example 3 PA oxide film + TRI 30 minutes 51.4 MPa - ○ Example 4 PPS oxide film 30 minutes 34.6 MPa - ○ Example 5 PPS oxide film 20 seconds 13.7 MPa - X Example 6 PPS Oxide + TRI + PDA 30 minutes 44.7 MPa 44.2 MPa ○ Comparative Example 1 PPS Epoxy Adhesive - 6.8 MPa - X
* PPS: polyphenylene sulfide
* PBT: polybutylene terephthalate
* PA: Polyamide
* TRI: Triazinethiol (1,3,5-triazine-2,4,6-trithiol)
* PDA: phenylenediamine-acrylic acid ethyl ester

As shown in [Table 1], when an oxide film is formed as a bonding film between the aluminum plate and the resin or when an oxide film and a sulfur compound film (TRI bonding layer) are formed (Examples 1 to 6), adhesion through the epoxy resin It was found to have superior bonding properties (tensile strength) and airtightness (low gas leakage) than the case of (Comparative Example 1). In addition, when comparing Examples 1 to 3, it was found that the bondability (tensile strength) was different depending on the type of resin, and when polyamide (PA) was used (Example 3), Example 1 (PPS) and It was found to have higher bonding properties (tensile strength) compared to Example 2 (PBT).

In addition, when comparing Examples 1 to 5, the case in which both the oxide film and the sulfur compound film (TRI bonding layer) are formed (Examples 1 to 3) has superior bonding properties (tensile strength) compared to the case in which it is not (Examples 4 to 5). strength) and airtightness. In addition, it was found that when the electrolysis time in the anodization process was too short (Example 5), the bondability (tensile strength) was somewhat deteriorated.

In addition, in comparison with Examples 1 and 6, an oxide film and a sulfur compound film (TRI bonding layer) are included as a bonding film between the aluminum plate and the resin, but the sulfur compound film (TRI bonding layer) is phenylenediamine -When acrylic acid ethyl ester is further included (Example 6), the bondability (tensile strength) is improved compared to the case where it is not (Example 1), which maintains excellent bondability (tensile strength) even after particularly high temperature/high humidity, resulting in high reliability (durability) was found.

10: container body 12: liner
14: composite material layer 15: bonding film
20: boss 22: flange portion

Claims (5)

A container body (10) and
It includes a metal boss 20 installed at the end of the container body 10,
The container body 10 includes a plastic liner 12 made of a plastic material,
A bonding film 15 is formed on the contact surface of the plastic liner 12 and the metal boss 20,
The bonding film 15 is
an oxide film formed by anodizing the surface of the metal boss 20; and
and a sulfur compound film formed between the oxide film and the plastic material liner 12,
The sulfur compound film is a gas storage tank comprising a thiol-based sulfur compound, phenylenediamine and acrylic acid alkyl ester.
delete delete A method for manufacturing a gas storage tank according to claim 1, comprising:
Using the metal boss 20 as an anode, an acid solution of 10° C. to 95° C. containing a sulfur compound is electrolyzed at a current density of 0.01 A/dm ² to 3.5 A/dm ² in the surface of the metal boss 20 a film forming process of forming an oxide film and a sulfur compound film;
a water washing process of washing the metal boss 20 on which the oxide film and the sulfur compound film are formed with water at 5° C. to 80° C.; and
a molding process of insert molding a plastic liner 12 into the metal boss 20 after washing with water;
In the film forming process, phenylenediamine and an acrylic acid alkyl ester are further added to an acidic solution containing a thiol-based sulfur compound, and then electrolyzed on the surface of the oxide film by a sulfur compound containing a thiol-based sulfur compound, phenylenediamine and an acrylic acid alkyl ester. A method of manufacturing a gas storage tank for forming a film.
A method for manufacturing a gas storage tank according to claim 1, comprising:
An oxide film is formed on the surface of the metal boss 20 by electrolysis at a current density of 0.01 A/dm ² to 3.5 A/dm ² using an acid solution of 10° C. to 95° C. with the metal boss 20 as an anode. anodizing process to form;
an electrolytic film forming step of forming a sulfur compound film on the surface of the oxide film by using the metal boss 20 on which the oxide film is formed as an anode and performing electrolysis in an electrolyte containing a sulfur compound;
a water washing process of washing the metal boss 20 on which the oxide film and the sulfur compound film are formed with water at 5° C. to 80° C.; and
a molding process of insert molding a plastic liner 12 into the metal boss 20 after washing with water;
In the electrolytic film formation process, phenylenediamine and an acrylic acid alkyl ester are further added to an electrolyte containing a thiol-based sulfur compound, and then electrolyzed on the surface of the oxide film by a thiol-based sulfur compound, a phenylenediamine and a sulfur compound containing an acrylic acid alkyl ester A method of manufacturing a gas storage tank for forming a film.

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