JP7242984B2 - Portable information terminal housing and manufacturing method thereof - Google Patents

Description

TECHNICAL FIELD The present invention relates to a mobile information terminal housing typified by smart phones and a manufacturing method thereof.

In this specification and claims, the term "aluminum" is used to mean both pure aluminum and aluminum alloys, unless otherwise specified.

A mobile information terminal typified by a smart phone is generally a flat rectangular parallelepiped, and has four surfaces: a front surface having a touch panel function, a rear surface facing a display screen, and an edge called a bezel. A portable information terminal has electronic components, an antenna, and a battery inside a housing consisting of a bezel and a back surface.

In Patent Document 1 listed below, polycarbonate is used as the material of the housing.

In addition, there are also known housings that use metal as the material for the bezel, use resin plates for the front and back surfaces, and fasten each with screws, or have a structure in which each is joined with an adhesive. there is

JP 2017-145385 A

In Patent Document 1, since the housing is made of polycarbonate, it is difficult to ensure high mechanical strength compared to the case where a metal bezel is employed.

On the other hand, even if a metal bezel is used, if the metal bezel and the front and back resin plates are fastened with screws, assembly will be troublesome and the manufacturing cost will increase.

Moreover, when the metal bezel and the front and back resin plates are joined with an adhesive, there is a problem that sufficient joint strength cannot be obtained unless a specific kind of resin is used.

SUMMARY OF THE INVENTION An object of the present invention is to provide a portable information terminal housing that can ensure high mechanical strength.

The present invention provides the following means.

1) A bezel in which one or more resin coating layers are laminated on at least a part of the surface of an aluminum base material, and a resin surface member and/or bonded to the surface of the bezel on the resin coating layer side and a back surface member,
The resin coating layer is laminated on the surface-treated surface of the bezel,
A portable information terminal housing, wherein at least one of the resin coating layers is formed from a resin composition containing an in-situ polymerizable phenoxy resin.

2) The personal digital assistant housing according to the preceding item 1, wherein the material of the surface member and/or the back member is polycarbonate or polybutylene terephthalate.

3) the resin coating layer has a plurality of layers, at least one layer of which is formed from a resin composition containing a thermosetting resin;
3. The portable information terminal housing according to item 1 or 2, wherein the thermosetting resin is at least one selected from the group consisting of urethane resin, epoxy resin, vinyl ester resin and unsaturated polyester resin.

4) having a functional group attachment layer between the surface-treated surface of the bezel and the resin coating layer;
4. The portable information terminal housing according to any one of the preceding items 1 to 3, wherein the functional group-adhering layer has a functional group introduced from at least one selected from the group consisting of silane coupling agents, isocyanate compounds and thiol compounds.

5) The portable information terminal housing according to any one of items 1 to 4, wherein the surface treatment is at least one selected from the group consisting of blasting, polishing, etching and chemical conversion.

6) The portable information terminal housing according to any one of the preceding items 1 to 5, wherein the coating layer is a primer layer.

7) A method for manufacturing a portable information terminal housing according to any one of 1 to 6 above, comprising:
When molding the resin surface or resin back surface by injection molding, transfer molding, press molding, filament winding molding, or hand lay-up molding, a resin surface member on the resin coating layer side of the bezel and/or a method for manufacturing a portable information terminal housing that joins a back surface member.

The present invention has the following effects.

In the above item 1, the personal digital assistant housing can obtain high mechanical strength because the bezel is made of aluminum.

In addition, the resin front member and/or the back member are bonded to the surface of the aluminum bezel on the resin coating layer side, and the resin coating layer is laminated on the surface-treated surface of the aluminum base, Moreover, since at least one of the resin coating layers is formed from a resin composition containing an in-situ polymerization type phenoxy resin, the bonding strength between the bezel and the surface member and/or the back member is high, and the housing has high mechanical strength. can get.

In the above item 2, since the mechanical strength of the surface member or the back member made of resin is high, a higher mechanical strength can be obtained for the housing as a whole.

In the above items 3 to 6, the bonding strength between the aluminum bezel and the resin front member and/or back member can be reliably increased.

In the above item 7, the number of manufacturing steps of the portable information terminal housing can be reduced.

FIG. 1 is a schematic cross-sectional view of a mobile information terminal provided with a mobile information terminal housing according to one embodiment of the present invention. FIG. 2 is a schematic cross-sectional view of the mobile information terminal housing. FIG. 3 is a perspective view of a bezel of the mobile information terminal housing. FIG. 4 is a schematic cross-sectional view showing a state in which the aluminum member is arranged in a mold when molding the resin member by injection molding. FIG. 5 is a schematic cross-sectional view showing a state in which a resin coating layer is laminated on the surface-treated surface of the aluminum base material of the same aluminum member. FIG. 6 is a schematic cross-sectional view of a state in which the aluminum member and the resin member are joined together. FIG. 7 is a schematic cross-sectional view of a state in which the aluminum member and the resin member are joined via an adhesive layer.

Several embodiments of the invention will now be described below with reference to the drawings.

As shown in FIG. 1, a portable information terminal 20 according to an embodiment of the present invention is generally a flat rectangular parallelepiped, such as a smart phone or a tablet terminal.

The mobile information terminal 20 includes a front surface member 11A having a touch panel function, a rear surface member 11B facing the display screen, and a bezel 21A forming four side edges.

As shown in FIG. 2, the back member 11B and the bezel 21A constitute a portable information terminal housing 21. As shown in FIG. The mobile information terminal housing 21 of the present invention may be a combination of the bezel 21A, the surface member 11A and the back surface member 11B, or a combination of the bezel 21A and the surface member 11A.

Inside the mobile information terminal housing 21, internal devices 22 such as electronic parts, an antenna, and a battery are provided.

The bezel 21A of the mobile information terminal housing 21 is made of the aluminum member 1, and the surface member 11A and the back member 11B are made of the resin member 11. As shown in FIG.

FIG. 2 shows a portable information terminal housing 21 in which a back member 11B, which is a resin member 11, is joined to a bezel 21A, which is an aluminum member 1. As shown in FIG.

As shown in FIG. 3, the bezel 21A is in the shape of a square frame, and one side of the bezel 21A serves as a bonding surface 21z for bonding the back member 11B, which is the resin member 11, as indicated by hatching.

In the portable information terminal 20, the bezel 21A receives the most force when held by hand. Mechanical strength can be secured. Moreover, the thickness of the bezel 21A can be made as small as possible, the volume of the portable information terminal 20 can be made small, or the internal volume of the portable information terminal 20 can be secured large.

Next, the structure of the bezel 21A, which is the aluminum member 1, and the surface member 11A and the back member 11B, which are the resin members 11, of the portable information terminal housing 20 and the manufacturing method thereof will be described in detail.

[Aluminum member]
The bezel 21A, which is an aluminum member 1, has an aluminum base 2 and one or more resin coating layers 4 laminated on the surface of the aluminum base 2, as shown in FIG.

Specifically, the resin coating layer 4 is laminated on the surface-treated surface of the aluminum substrate 2, and at least one layer of the resin coating layer 4 is formed from a resin composition containing an in-situ polymerizable phenoxy resin. there is

The surface-treated surface of the aluminum base material 2 is, as shown in FIG. It is a contact portion with at least the resin member 11 on the surface of the substrate 2).

Specifically, it is a surface parallel to the front or back surface of the aluminum bezel.

Since the resin coating layer 4 is laminated on the aluminum substrate 2 , the aluminum member 1 is provided with excellent bondability (adhesiveness) to the resin member 11 . Therefore, the resin coating layer 4 is the primer layer 5 of the aluminum substrate 2 .

Here, the primer layer 5 is interposed between the aluminum base material 2 and the resin member 11 when the aluminum member 1 and the resin member 11 are bonded, and the bondability of the aluminum base material 2 to the resin member 11 ( It means that it is a layer that improves adhesion).

The aluminum member 1 will be further detailed.

As shown in FIG. 5, the aluminum member 1 is provided with the functional group adhesion layer 3 on the surface of the surface treatment portion 2a formed on the surface of the aluminum base material 2, and the surface of the functional group adhesion layer 3 is coated with a resin. It comprises a structure in which a layer 4 is formed. Therefore, the functional group adhering layer 3 is formed between the surface-treated portion 2 a of the aluminum substrate 2 and the resin coating layer 4 .

In the present invention, the functional group adhering layer 3 may not necessarily be formed between the surface-treated portion 2a of the aluminum substrate 2 and the resin coating layer 4. That is, the resin coating layer 4 may be directly laminated on the surface of the surface-treated portion 2a of the aluminum base material 2 .

<Aluminum base material 2>
The type of aluminum material of the aluminum base material 2 is not limited, and for example, the aluminum content is 50% by mass or more. A6110), A4000 series alloys, A7000 series alloys, etc., among aluminum alloys, those with higher strength are preferable.

The method of manufacturing the aluminum substrate 2 is preferably a die casting method, a gravity casting method, or a forging method, and the surface to be joined with the resin member 11 is finished by machining (eg, cutting), which is inexpensive and preferable.

<Surface treatment (part)>
A surface-treated portion 2 a is formed at least on the surface of the aluminum base material 2 to be bonded to the resin member 11 . Note that the surface-treated portion 2 a is regarded as part of the aluminum base material 2 .

Examples of the surface treatment include cleaning/degreasing treatment with a solvent or the like, blasting treatment, polishing treatment, etching treatment, chemical conversion treatment (eg, boehmite treatment, zirconium treatment), and the like. Treatment is preferred. Only one type of these treatments may be used, or two or more types may be applied. As specific methods for these surface treatments, known methods can be used.

The surface treatment is to clean the surface of the aluminum substrate 2 and to roughen the surface of the aluminum substrate 2 by forming fine irregularities for the purpose of anchoring effect. Therefore, the surface treatment can improve the bondability (adhesiveness) between the surface of the aluminum base 2 and the resin coating layer 4, and can also contribute to the improvement of the bondability with the resin member 11.

Therefore, when the aluminum member 1 is produced, the surface treatment of the aluminum substrate 2 is performed before the resin coating layer 4 is formed. As the surface treatment, at least one selected from the group consisting of blasting, polishing, etching and chemical conversion is particularly preferred.

[Cleaning and degreasing]
Examples of the cleaning or degreasing treatment with a solvent or the like include a method of degreasing the surface of the aluminum base material 2 by cleaning or wiping with an organic solvent such as acetone or toluene. A cleaning or degreasing treatment is preferably performed before any other surface treatment.

[Blasting]
Examples of blasting include shot blasting and sandblasting.

[Polishing]
Examples of the polishing treatment include buffing using an abrasive cloth, roll polishing using abrasive paper (sandpaper), electropolishing, and the like.

[Etching process]
Examples of the etching treatment include chemical etching treatments such as an alkali method, a phosphoric acid-sulfuric acid method, a fluoride method, a chromic acid-sulfuric acid method, and an iron salt method, and electrochemical etching treatments such as an electrolytic etching method. mentioned.

In particular, the etching treatment is preferably an alkali method using an aqueous sodium hydroxide solution or an aqueous potassium hydroxide solution, and more preferably a caustic soda method using an aqueous sodium hydroxide solution.

As the alkaline method, for example, the aluminum substrate 2 is immersed in an aqueous solution (etching solution) of sodium hydroxide or potassium hydroxide having a concentration of 3 to 20% by mass at 20 to 70° C. for 1 to 15 minutes. can be done. As additives, a chelating agent, an oxidizing agent, a phosphate, or the like may be added to the etching solution. After the immersion, it is preferable to neutralize (desmut) with a 5 to 20 mass % nitric acid aqueous solution or the like, wash with water, and dry.

[Chemical treatment]
The chemical conversion treatment is to form a chemical conversion coating mainly on the surface of the aluminum base material 2 as the surface treated portion 2a.

Examples of the chemical conversion treatment include boehmite treatment and zirconium treatment, and boehmite treatment is particularly preferred.

In the boehmite treatment, a boehmite film is formed on the surface of the aluminum base material 2 by subjecting the aluminum base material 2 to a hot water treatment. As a reaction accelerator, ammonia, triethanolamine, or the like may be added to water. In particular, it is preferable to immerse the aluminum substrate 2 in hot water of 90 to 100° C. containing triethanolamine at a concentration of 0.1 to 5.0% by mass for 3 seconds to 5 minutes.

In the zirconium treatment, a film of a zirconium compound is formed on the surface of the aluminum substrate 2 by immersing the aluminum substrate 2 in a solution containing a zirconium salt such as zirconium phosphate. In particular, the aluminum substrate 2 is immersed for 0.5 to 3 minutes in a chemical agent for zirconium treatment (for example, "Palcoat 3762", "Palcoat 3796", etc. manufactured by Nihon Parkerizing Co., Ltd.) at 45 to 70°C. It is preferable to Zirconium treatment is preferably performed after etching treatment by the caustic soda method.

<Functional group adhesion layer 3>
The functional group adhering layer 3 is laminated between the surface-treated surface of the aluminum substrate 2 and the resin coating layer 4 in contact with both. The functional group-adhering layer 3 is a layer having a functional group introduced from at least one selected from the group consisting of silane coupling agents, isocyanate compounds and thiol compounds.

Since the layer having the functional group is formed between the surface-treated surface of the aluminum substrate 2 and the resin coating layer 4, the chemical bond formed by the reaction of the functional group causes the aluminum substrate 2 to and the resin coating layer 4, and can also contribute to the improvement of the bondability with the resin member 11.

Therefore, when manufacturing the aluminum member 1, before forming the resin coating layer 4, the surface-treated surface of the aluminum substrate 2 is coated with at least one selected from the group consisting of silane coupling agents, isocyanate compounds and thiol compounds. It is preferable to form the functional group adhesion layer 3 on the surface-treated surface of the aluminum substrate 2 by treating with seeds.

Since the surface-treated portion 2a is formed on the aluminum base material 2, the synergistic effect of the anchor effect due to the fine unevenness of the surface-treated portion 2a and the chemical bond formed by the reaction of the functional group of the functional group adhesion layer 3 is formed. As a result, the bondability between the surface of the aluminum base material 2 and the resin coating layer 4 and the bondability with the resin member 11 can be improved.

A method for forming the functional group-adhering layer 3 with a silane coupling agent, an isocyanate compound, or a thiol compound is not particularly limited, but examples thereof include a spray coating method and an immersion method. Specifically, the aluminum substrate 2 is immersed in a solution of a silane coupling agent or the like having a concentration of 5 to 50% by mass at room temperature to 100° C. for 1 minute to 5 days, and then at room temperature to 100° C. for 1 minute to 5 days. It can be carried out by a method such as time drying.

〔Silane coupling agent〕
As the silane coupling agent, for example, a known agent used for surface treatment of glass fibers can be used. A silanol group produced by hydrolyzing a silane coupling agent or an oligomerized silanol group reacts with a hydroxyl group present on the surface-treated surface of the aluminum substrate 2 to form a resin coating layer 4. A functional group based on the structure of the silane coupling agent that can chemically bond with the resin member 11 can be imparted (introduced) to the aluminum substrate 2 .

Examples of the silane coupling agent include, but are not limited to, vinyltrimethoxysilane, vinyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropylmethyl. dimethoxysilane, 3-glycidoxypropylmethyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, p-styryltri Methoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, N -2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3 -triethoxysilyl-N-(1,3-dimethyl-butylidene)propylamine, N-phenyl-3-aminopropyltrimethoxysilane, N-(vinylbenzyl)-2-aminopropyltrimethoxysilane hydrochloride, tris -(trimethoxysilylpropyl)isocyanurate, 3-ureidopropyltrialkoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-isocyanatopropyltriethoxysilane, dithioltriazinepropyltriethoxysilane and the like. These may be used individually by 1 type, or may use 2 or more types together.

[Isocyanate compound]
According to the isocyanate compound, the isocyanate group in the isocyanate compound reacts with and bonds with the hydroxyl groups present on the surface-treated surface of the aluminum base material 2, so that it can chemically bond with the resin coating layer 4 and the resin member 11. A functional group based on the structure of the isocyanate compound can be imparted (introduced) to the aluminum substrate 2 .

The isocyanate compound is not particularly limited. 2-isocyanatoethyl methacrylate (e.g., Showa Denko KK "Karenzu MOI (registered trademark)"), which is an isocyanate compound having a radical reactive group, 2-isocyanatoethyl acrylate (e.g., Showa Denko KK "Karenzu AOI ( registered trademark)”, the same “AOI-VM (registered trademark)”), 1,1-(bisacryloyloxyethyl) ethyl isocyanate (for example, “Karenzu BEI (registered trademark)” manufactured by Showa Denko K.K.) and the like. .

[thiol compound]
According to the thiol compound, the mercapto group (thiol group) in the thiol compound reacts with and bonds with the hydroxyl group present on the surface-treated surface of the aluminum substrate 2, thereby forming the resin coating layer 4 and the resin member 11. A functional group based on the structure of the thiol compound that can chemically bond with can be imparted (introduced) to the aluminum substrate 2 .

The thiol compound is not particularly limited, but for example, pentaerythritol tetrakis (3-mercaptopropionate) (eg, "QX40" manufactured by Mitsubishi Chemical Corporation, "QE-340M" manufactured by Toray Fine Chemicals Co., Ltd.) ), ether-based primary thiol (e.g., Cognis "Cup Cure 3-800"), 1,4-bis (3-mercaptobutyryloxy) butane (e.g., Showa Denko K.K. "Karenzu MT ( registered trademark) BD1”), pentaerythritol tetrakis (3-mercaptobutyrate) (for example, Showa Denko Co., Ltd. “Kalenz MT (registered trademark) PE1”), 1,3,5-tris(3-mercaptobutyloxyethyl )-1,3,5-triazine-2,4,6(1H,3H,5H)-trione (eg, “Karenzu MT (registered trademark) NR1” manufactured by Showa Denko KK) and the like.

<Resin coating layer 4>
The resin coating layer 4 is laminated on the surface-treated surface of the aluminum substrate 2 , that is, on the surface of the surface-treated portion 2 a of the aluminum substrate 2 . Alternatively, it may be laminated on the surface of the functional group adhesion layer 3 as described above.

Moreover, the resin coating layer 4 may be composed of a single layer, or may be composed of a plurality of layers of two or more layers.

The resin coating layer 4 is formed on the surface-treated surface of the aluminum substrate 2 with excellent bondability (adhesiveness), protects the surface of the aluminum substrate 2, and protects the surface of the aluminum substrate 2. Deterioration such as adhesion of dirt and oxidation can be suppressed.

Moreover, the resin coating layer 4 can provide the surface of the aluminum base material 2 with excellent bondability with the resin member 11 . Furthermore, with the surface of the aluminum base 2 protected as described above, it is also possible to obtain the aluminum member 1 capable of maintaining excellent bondability over a long period of several months.

As described above, in the aluminum member 1, the resin coating layer 4 can provide the aluminum base material 2 with excellent bondability to the resin member 11. Therefore, the resin coating layer 4 serves as a primer for the aluminum base material 2 as described above. layer 5;

(On-site polymerization type phenoxy resin)
At least one layer of the resin coating layer 4 is a layer formed from a resin composition containing an in-situ polymerizable phenoxy resin (hereinafter also referred to as an in-situ polymerizable phenoxy resin layer).

In-situ polymerizable phenoxy resins are resins that are also called thermoplastic epoxy resins, in-situ curable phenoxy resins, in-situ curable epoxy resins, etc. A bifunctional epoxy resin and a bifunctional phenol compound undergo a polyaddition reaction in the presence of a catalyst. to form a thermoplastic structure, ie a linear polymer structure. That is, unlike a thermosetting resin that forms a three-dimensional network with a crosslinked structure, it is possible to form a resin coating layer 4 having thermoplasticity.

Since the in-situ polymerization type phenoxy resin has such characteristics, it is possible to form the resin coating layer 4 having excellent bonding properties with the aluminum substrate 2 by in-situ polymerization, and the resin coating The layer 4 can be made excellent in bondability with the resin member 11 .

Therefore, when manufacturing the aluminum member 1, at least one layer of the resin coating layer 4 is formed by subjecting the resin composition containing the in-situ polymerizable phenoxy resin to a polyaddition reaction on the surface-treated surface of the aluminum substrate 2. preferably formed.

The polyaddition reaction of the resin composition containing the in-situ polymerizable phenoxy resin is preferably carried out on the surface of the functional group-attached layer 3, and may also be carried out on the surface of the resin coating layer 4 other than the in-situ polymerizable phenoxy resin layer. is also preferred. The resin coating layer including the in-situ polymerization type phenoxy resin layer formed in this manner has excellent bondability with the aluminum substrate 2 and excellent bondability with the resin member 11 .

A coating method for forming the resin coating layer 4 with the resin composition is not particularly limited, but examples thereof include a spray coating method and an immersion method.

In order to allow the polyaddition reaction of the in-situ polymerizable phenoxy resin to proceed sufficiently and form the desired resin coating layer 4, the resin composition may contain a solvent and, if necessary, an additive such as a coloring agent. good. In this case, among the components other than the solvent of the resin composition, it is preferable that the in-situ polymerization type phenoxy resin is the main component. The main component means that the content of the in-situ polymerizable phenoxy resin is 50 to 100% by mass. This content is preferably 60% by mass or more, and more preferably 80% by mass or more.

A combination of a bifunctional epoxy resin and a bifunctional phenolic compound is preferred as the polyaddition-reactive compound for obtaining the in-situ polymerizable phenoxy resin.

Bifunctional epoxy resins include bisphenol-type epoxy resins, biphenyl-type epoxy resins, and the like. Among these, one type may be used alone, or two or more types may be used in combination. Specifically, Mitsubishi Chemical Corporation "jER (registered trademark) 828", "jER (registered trademark) 834", "jER (registered trademark) 1001", "jER (registered trademark) 1004", "jER (registered trademark) YX-4000" and the like.

Bifunctional phenol compounds include bisphenol, biphenol and the like. Among these, one type may be used alone, or two or more types may be used in combination.

Combinations of these include bisphenol A type epoxy resin and bisphenol A, bisphenol A type epoxy resin and bisphenol F, biphenyl type epoxy resin and 4,4'-biphenol, and the like. Also, for example, a combination of "WPE190" and "EX-991L" manufactured by Nagase ChemteX Corporation can be mentioned.

Suitable catalysts for the polyaddition reaction of the in-situ polymerization type phenoxy resin include, for example, tertiary amines such as triethylamine and 2,4,6-tris(dimethylaminomethyl)phenol; phosphorous compounds such as triphenylphosphine; used for

The polyaddition reaction is preferably carried out by heating at 120 to 200° C. for 5 to 90 minutes, depending on the type of reaction compound. Specifically, the in-situ polymerization type phenoxy resin layer can be formed by coating the resin composition, appropriately volatilizing the solvent, and then performing a polyaddition reaction by heating.

(Thermosetting resin)
When the resin coating layer 4 is composed of multiple layers, at least one of the layers is preferably a layer formed from a resin composition containing a thermosetting resin (hereinafter also referred to as a thermosetting resin layer). . Thermosetting resins include urethane resins, epoxy resins, vinyl ester resins, unsaturated polyester resins, and the like.

Each layer of the thermosetting resin layer may be formed of one of these resins alone, or may be formed of a mixture of two or more of these resins. Alternatively, two or more layers may be different types of thermosetting resin layers.

The resin coating layer 4 has a laminated structure of an in-situ polymerization type phenoxy resin layer and a thermosetting resin layer, so that the resin coating layer has various properties such as strength and impact resistance based on the thermosetting resin. can constitute an aluminum member coated with

The order of lamination of the thermosetting resin layer and the on-site polymerization type phenoxy resin layer is not particularly limited, but from the viewpoint of obtaining excellent bonding with the resin member 11, the on-site polymerization type phenoxy resin layer is , the outermost surface of the resin coating layer 4 is preferably laminated.

A coating method for forming at least one layer of the resin coating layer 4 with a resin composition containing a thermosetting resin is not particularly limited, but examples thereof include a spray coating method and an immersion method.

The resin composition may contain a solvent and, if necessary, an additive such as a coloring agent in order to allow the curing reaction of the thermosetting resin to proceed sufficiently to form a desired resin coating layer. In this case, it is preferable that the thermosetting resin is the main component among the components other than the solvent of the resin composition. A main component means that the content of the thermosetting resin is 50 to 100% by mass. This content is preferably 60% by mass or more, and more preferably 80% by mass or more.

The thermosetting resin referred to in the present invention broadly means a resin that forms a crosslinked structure when cured, and is not limited to the heat-curing type, and includes room-temperature curing type and light-curing type. The photo-curing type can be cured in a short time by irradiation with visible light or ultraviolet rays. The photo-curing type may be used in combination with the heat-curing type and/or the room temperature-curing type. Examples of the photo-curing type include vinyl ester resins such as “Lipoxy (registered trademark) LC-760” and “Lipoxy (registered trademark) LC-720” manufactured by Showa Denko K.K.

[Urethane resin]
A urethane resin is usually a resin obtained by a reaction between an isocyanato group and a hydroxyl group, and is preferably a urethane resin that corresponds to what is defined in ASTM D16 as "a coating material containing polyisocyanate with a non-volatile content of 10 wt% or more in a vehicle". . The urethane resin may be of a one-component type or a two-component type.

One-liquid type urethane resins include oil-modified type (cured by oxidation polymerization of unsaturated fatty acid groups), moisture-cured type (cured by reaction of isocyanato group with water in the air), block type (blocking agent is dissociated and regenerated by heating and cures by reacting with hydroxyl groups), lacquer type (cures by evaporation of the solvent and drying), and the like. Among these, moisture-curable one-liquid urethane resins are preferably used from the viewpoint of ease of handling and the like. Specifically, "UM-50P" manufactured by Showa Denko K.K.

Two-component urethane resins include catalyst-curing type (which cures by reacting isocyanato groups with water in the air in the presence of a catalyst), and polyol-curing type (which cures by reaction between isocyanato groups and hydroxyl groups of polyol compounds). what to do), etc.

Polyester polyols, polyether polyols, phenol resins, and the like are examples of polyol compounds in the polyol curing type.

Further, the isocyanate compound having an isocyanato group in the polyol curing type includes aliphatic isocyanates such as hexamethylene diisocyanate (HDI), tetramethylene diisocyanate, and dimer acid diisocyanate; 2,4- or 2,6-tolylene diisocyanate (TDI). or mixtures thereof, p-phenylene diisocyanate, xylylene diisocyanate, diphenylmethane diisocyanate (MDI) and aromatic isocyanates such as polymeric MDI which is a polynuclear mixture thereof; alicyclic isocyanates such as isophorone diisocyanate (IPDI), etc. .

As for the compounding ratio of the polyol compound and the isocyanate compound in the polyol-curable two-component urethane resin, the hydroxyl group/isocyanate group molar equivalent ratio is preferably in the range of 0.7 to 1.5.

Urethane catalysts used in two-component urethane resins include triethylenediamine, tetramethylguanidine, N,N,N',N'-tetramethylhexane-1,6-diamine, dimethyl etheramine, N,N,N ',N'',N''-Pentamethyldipropylene-triamine, N-methylmorpholine, bis(2-dimethylaminoethyl)ether, dimethylaminoethoxyethanol, triethylamine and other amine-based catalysts; dibutyltin diacetate, dibutyl Organic tin-based catalysts such as tin dilaurate, dibutyltinthiocarboxylate, dibutyltindimaleate, and the like are included.

In the polyol curing type, it is generally preferable to blend 0.01 to 10 parts by mass of the urethanization catalyst with respect to 100 parts by mass of the polyol compound.

〔Epoxy resin〕
Epoxy resins are resins having at least two epoxy groups in one molecule.

Prepolymers of epoxy resins before curing include ether-based bisphenol-type epoxy resins, novolac-type epoxy resins, polyphenol-type epoxy resins, aliphatic-type epoxy resins, ester-type aromatic epoxy resins, cycloaliphatic epoxy resins, ether-type epoxy resins, Examples thereof include ester-based epoxy resins, and among these, bisphenol A-type epoxy resins are preferably used. Among these, one type may be used alone, or two or more types may be used in combination.

Specific examples of the bisphenol A epoxy resin include "jER (registered trademark) 828" and "jER (registered trademark) 1001" manufactured by Mitsubishi Chemical Corporation.

Specific examples of the novolak-type epoxy resin include "D.E.N. (registered trademark) 438 (registered trademark)" manufactured by The Dow Chemical Company.

Curing agents used for epoxy resins include known curing agents such as aliphatic amines, aromatic amines, acid anhydrides, phenol resins, thiols, imidazoles, and cationic catalysts. When the curing agent is used in combination with a long-chain aliphatic amine and/or thiols, effects such as high elongation and excellent impact resistance can be obtained.

Specific examples of thiols include the same compounds as those exemplified as the thiol compounds in the surface treatment described above. Among these, pentaerythritol tetrakis(3-mercaptobutyrate) (for example, "Karenzu MT (registered trademark) PE1" manufactured by Showa Denko KK) is preferable from the viewpoint of elongation and impact resistance.

[Vinyl ester resin]
A vinyl ester resin is obtained by dissolving a vinyl ester compound in a polymerizable monomer (such as styrene). Also called epoxy (meth)acrylate resin, vinyl ester resin includes urethane (meth)acrylate resin.

As the vinyl ester resin, those described in "Polyester Resin Handbook" (Nikkan Kogyo Shimbun, 1988), "Paint Glossary" (Shikizai Kyokai, 1993), etc. can also be used. Specific examples include "Lipoxy (registered trademark) R-802", "Lipoxy (registered trademark) R-804", and "Lipoxy (registered trademark) R-806" manufactured by Showa Denko K.K. .

The urethane (meth)acrylate resin is obtained, for example, by reacting an isocyanate compound with a polyol compound and then reacting with a hydroxyl group-containing (meth)acrylic monomer (and, if necessary, a hydroxyl group-containing allyl ether monomer). Radically polymerizable unsaturated group-containing oligomers can be mentioned. Specific examples include "Lipoxy (registered trademark) R-6545" manufactured by Showa Denko K.K.

A vinyl ester resin can be cured by radical polymerization by heating in the presence of a catalyst such as an organic peroxide.

Examples of organic peroxides include, but are not limited to, ketone peroxides, peroxyketals, hydroperoxides, diallyl peroxides, diacyl peroxides, peroxyesters, peroxy and dicarbonates. By combining these with a cobalt metal salt or the like, curing at room temperature is also possible.

Examples of the cobalt metal salt include, but are not particularly limited to, cobalt naphthenate, cobalt octylate, cobalt hydroxide, and the like. Among these, cobalt naphthenate and/or cobalt octylate are preferred.

[Unsaturated polyester resin]
Unsaturated polyester resin is a condensation product (unsaturated polyester) obtained by an esterification reaction between a polyol compound and an unsaturated polybasic acid (and saturated polybasic acid if necessary) and a polymerizable monomer (such as styrene). dissolved in

As the unsaturated polyester resin, those described in "Polyester Resin Handbook" (Nikkan Kogyo Shimbun, 1988), "Paint Glossary" (Shikizai Kyokai, 1993), etc. can also be used. , and, more specifically, "Rigolac (registered trademark)" manufactured by Showa Denko K.K.

Unsaturated polyester resins can be cured by radical polymerization by heating in the presence of catalysts as for vinyl ester resins.

[Portable information terminal housing 21]
As shown in FIG. 6, in the portable information terminal housing 21, the surface 4a of the aluminum base material 2 of the aluminum member 1 on the side of the resin coating layer 4 and the resin member 11 are joined and integrated. The resin coating layer 4 is the primer layer 5 of the aluminum substrate 2 as described above.

In this embodiment, more specifically, the surface 4a of the aluminum base material 2 of the aluminum member 1 on the side of the resin coating layer 4 and the resin member 11 are joined and integrated so as to be in direct contact with each other.

As described above, since the surface 4a of the resin coating layer 4 has excellent bondability with the resin member 11, the portable information terminal housing 21 in which the aluminum member 1 and the resin member 11 are bonded with high bonding strength can be manufactured. can do.

The thickness of the resin coating layer 4 (thickness after drying) depends on the type of resin of the resin member 11 and the bonding area, but excellent bondability with the resin member 11 on the surface 4a on the resin coating layer 4 side is obtained. From the point of view, it is preferably 1 μm to 10 mm, more preferably 2 μm to 8 mm, still more preferably 3 μm to 5 mm.

Specifically, when joining and integrating the aluminum member 1 and the carbon fiber reinforced resin member (CFRP member) as the resin member 11, the aluminum member 1 and the glass fiber reinforced resin member (GFRP member) as the resin member 11 , the thickness of the resin coating layer 4 is preferably 0.1 to 10 mm, more preferably 0.2 to 8 mm, still more preferably 0.5 to 5 mm.

The type of resin of the resin member 11 is not limited, and general synthetic resin may be used. Examples thereof include polycarbonate resins, polybutylene terephthalate resins, polyester resins, modified polyphenylene ether resins, polyetherimide resins, and the like.

Also, the resin of the resin member 11 may be a resin molding containing reinforcing fibers (eg, carbon fiber, glass fiber). Examples of such resin moldings include carbon fiber reinforced resin moldings (CFRP), glass fiber reinforced resin moldings (GFRP), etc. Further, molding such as sheet molding compounds (SMC), bulk molding compounds (BMC), etc. A sheet-like molded body molded from a material may also be used.

SMC is a mixture of unsaturated polyester resin and / or vinyl ester resin, polymerizable unsaturated monomer, curing agent, low shrinkage agent and filler, etc. It is a sheet-shaped molding material obtained by impregnating a fiber).

As a method for manufacturing the portable information terminal housing 21, there is a method in which the aluminum member 1 and the resin member 11 are separately produced and then joined (adhered) to be integrated.

In particular, as a method of manufacturing the housing 21, a method of forming the resin member 11 and at the same time joining the aluminum member 1 and the resin member 11 together is preferable. Specifically, when molding the resin member 11 by a method such as an injection molding method (including an insert molding method), a transfer molding method, a press molding method, or a hand lay-up molding method, the aluminum base material 2 of the aluminum member 1 By joining the resin member 11 to the surface 4a on the resin coating layer 4 side of the aluminum member 1 and the resin member 11, the housing 21 can be obtained. In this case, the number of manufacturing steps for the housing 21 can be reduced.

Specifically, as shown in FIG. 4, when the resin member 11 is molded by, for example, an injection molding method, the aluminum member 1 is placed in an injection mold 30, and the resin is injected by an injection device (not shown). is injected into the cavity 31 of the mold 30 (its injection direction 35) to mold the resin member 11, and at the same time, the aluminum member 1 and the resin member 11 are joined.

Note that reference numeral "34" in the figure denotes a knockout pin.

Next, another embodiment of the invention will be described below.

As shown in FIG. 7 , in the housing 21 , the surface 4 a of the aluminum base 2 of the aluminum member 1 on the resin coating layer 4 side and the resin member 11 may be integrally bonded via the adhesive layer 10 .

As described above, depending on the type of resin of the resin member 11, by using an adhesive, it is possible to obtain the housing 21 in which the aluminum member 1 and the resin member 11 are joined with a higher joint strength.

The adhesive for the adhesive layer 10 is appropriately selected according to the type of resin of the resin member 11. For example, known adhesives such as epoxy resin, urethane resin, and vinyl ester resin may be used. can.

Depending on the heating temperature during bonding (bonding), the housing 21A may be thermally deformed due to the difference in thermal expansion coefficient between the aluminum base material 2 and the resin member 11 in the process of cooling to room temperature after bonding (bonding). more likely to occur. From the viewpoint of suppressing and alleviating such thermal deformation, the thickness of the adhesive layer 10 is set so that the total thickness of the resin coating layer 4 and the adhesive layer 10 is 0.5 mm or more. It is desirable to provide a portion having a large elongation rate with a predetermined thickness between the resin member 11 and the resin member 11 . The above-mentioned total thickness can be determined by taking into account the physical properties such as the elongation rate of the resin coating layer 4 and the adhesive layer 10 when the temperature changes during bonding (temperature changes from the heating temperature during bonding to room temperature cooling). preferable. A preferred upper limit for the total thickness is 10 mm.

Here, when the aluminum member 1 and the resin member 11 are joined together, the layer that joins the two members 1 and 11 is called a joint layer, and the thickness thereof is called the thickness of the joint layer. Therefore, when the adhesive layer 10 is formed on the surface 4a of the resin coating layer 4 of the aluminum member 1, both layers 4 and 10 of the resin coating layer 4 and the adhesive layer 10 are bonding layers. The total thickness of 4 and 10 is the thickness of the joining layer. Further, when the adhesive layer 10 is not formed on the surface 4a of the resin coating layer 4 of the aluminum member 1, the resin coating layer 4 is the bonding layer, and the thickness of the resin coating layer 4 is the thickness of the bonding layer. be.

According to the portable information terminal housing 21 according to the embodiment of the present invention described above, since the bezel 21A is made of the aluminum member 1, high mechanical strength can be obtained.

Further, the back member 11B, which is the resin member 11, is joined to the surface of the aluminum bezel 21A on the side of the resin coating layer 4, and the resin coating layer 4 is laminated on the surface-treated surface of the aluminum base 2. Moreover, since at least one layer of the resin coating layer 4 is formed from a resin composition containing an in-situ polymerization type phenoxy resin, the bonding strength between the bezel 21A and the back surface member 11B is high, and the housing 21 has high mechanical strength. is obtained.

Moreover, since the housing 21 is formed by joining the bezel 21A and the back surface member 11B, the labor for assembly is reduced compared to the case of fastening with screws, and the manufacturing cost can be suppressed.

In addition, since the resin coating layer 4 is laminated on the surface-treated surface of the aluminum base material 2, and at least one layer thereof is formed from a resin composition containing an in-situ polymerization type phenoxy resin, it can be compared with a conventional metal bezel. Compared to the case where resin plates on the front and back surfaces are joined with an adhesive, there are many types of resins that can obtain a predetermined joint strength, and it is possible to secure many choices of resins according to the required properties.

Although several embodiments of the present invention have been described above, it goes without saying that the present invention is not limited to the above-described embodiments and can be variously modified without departing from the gist of the present invention.

For example, in the above description, the mobile information terminal housing 21 is formed by joining the bezel 21A and the back surface member 11B together. It is good also as a housing which joined the back surface member 11B.

Even when the bezel 21A is joined to the surface member 11A and/or the back member 11B, partial screwing may be used together.

Hereinafter, practical test examples and comparative test examples related to the present invention will be described. However, the present invention is not limited to the following practical test examples.

<Test Example 1>
An aluminum plate as an aluminum substrate was molded by hot die forging. Then, the surface of the aluminum plate was smoothed by machining.

The aluminum material of the aluminum plate is an aluminum alloy "AHS (registered trademark)-1" manufactured by Showa Denko K.K. Fe: 0.23% by mass, Cu: 2.0% by mass, Mg: 0.6% by mass, the balance being Al and inevitable impurities It has a chemical composition, its tensile strength is 400 MPa, and its Young The modulus was 78 MPa.

The dimensions of the aluminum plate were 100 mm long, 25 mm wide and 1.6 mm thick.

(Surface treatment process)
An aluminum plate (that is, an aluminum substrate) is immersed in an aqueous sodium hydroxide solution with a concentration of 5% by mass for 1.5 minutes, neutralized with an aqueous nitric acid solution with a concentration of 5% by mass, washed with water, and dried to perform an etching treatment. did

Next, the aluminum plate after the etching treatment is boiled for 3 minutes in an aqueous solution containing 0.3% by mass of triethanolamine to perform a boehmite treatment. A boehmite film having

(Functional group adhesion layer forming step)
Next, 3-methacryloxypropyltrimethoxysilane (“KBM-503” manufactured by Shin-Etsu Silicone Co., Ltd.; silane coupling agent) 2.48 g (0.01 mol) was dissolved in 1000 g of industrial ethanol at 80 ° C. The boehmite-treated aluminum plate was immersed in the solution containing the coupling agent for 3 minutes. After that, the aluminum plate was taken out and dried to form a functional group adhering layer on the surface of the boehmite film (surface treatment portion).

(Resin coating layer forming step)
Next, a one-component urethane resin (“UM-50P” manufactured by Showa Denko K.K.) was applied to the surface of the functional group adhesion layer of the aluminum plate by a spray method so that the thickness after drying was 15 μm. . Then, the solvent was volatilized and cured by leaving it in the air at normal temperature for 24 hours to form a first resin coating layer (thermosetting resin layer).

Furthermore, on the surface of the thermosetting resin layer, 100 g of epoxy resin (“jER (registered trademark) 1004” manufactured by Mitsubishi Chemical Corporation), 12.6 g of bisphenol A, and 0.45 g of triethylamine are dissolved in 209 g of acetone. The in-situ polymerization type phenoxy resin composition was applied by a spray method so that the thickness after drying was 10 μm. After the solvent is volatilized by leaving it in the air at normal temperature for 30 minutes, it is left in a furnace at 150° C. for 30 minutes for a polyaddition reaction and allowed to cool to normal temperature, thereby forming the second layer resin. A coating layer (in-situ polymerization type phenoxy resin layer) was formed.

A plate having a resin coating layer consisting of two layers, a thermosetting resin layer with a thickness of 15 μm and an in-situ polymerizable phenoxy resin layer with a thickness of 10 μm, formed on the surface of the functional group-attached layer of the aluminum plate by the above method. A shaped aluminum member was produced.

(Joining process)
Next, the aluminum member is placed in a mold for injection molding, and a bulk molding compound (BMC) (“Rigolac (registered trademark) RNC-980” manufactured by Showa Denko Co., Ltd.) is applied to the surface of the resin coating layer of the aluminum member. ) is injection-molded by an injection molding machine (“α-S100iA” manufactured by Fanuc Corporation; mold temperature 160 ° C., molding pressure 100 MPa, molding time 3 minutes) to form an aluminum member and resin The members were joined together to produce an aluminum-resin joined body A.

The dimensions of the resin member were 45 mm in length, 10 mm in width and 3 mm in thickness. Also, the bonding area between the aluminum member and the resin member was 50 mm ² .

Also, the aluminum member was stored in the air at room temperature for 3 months, and then the aluminum member and the resin member were joined in the same manner as described above, whereby an aluminum-resin joined body B was produced.

<Comparative Test Example 1>
An aluminum member (without a resin coating layer) was prepared by sequentially performing a surface treatment step and a functional group adhesion layer forming step in the same manner as in Test Example 1. Then, an attempt was made to join the aluminum member and the resin member by injection-molding a plate-like resin member made of BMC in the same manner as in Example 1 on the surface of the functional group adhering layer of the aluminum member. After molding the resin member, when both members were removed from the mold, the aluminum member and the resin member were not joined and the resin member fell off.

<Test Example 2>
(Surface treatment process)
The same aluminum plate as in Experimental Example 1 was prepared. Then, the aluminum plate was subjected to a surface treatment step in the same manner as in Experimental Example 1, thereby forming a surface-treated portion (boehmite film having surface unevenness) on the surface of the aluminum plate.

(Functional group adhesion layer forming step)
Next, instead of 3-methacryloxypropyltrimethoxysilane, 3-acryloxypropyltrimethoxysilane (manufactured by Shin-Etsu Silicone Co., Ltd. "KBM-5103"; silane cup A functional group adhering layer was formed in the same manner as in Experimental Example 1, except that 2.34 g (0.01 mol) of ring agent) was used.

(Resin coating layer forming step)
Next, a visible light-curable vinyl ester resin (“Lipoxy (registered trademark) LC-720” manufactured by Showa Denko KK) was applied to the surface of the functional group adhesion layer of the aluminum plate so that the thickness after drying was 15 μm. After coating the surface of the aluminum plate by a spray method, the first resin coating layer (thermal A curable resin (photocurable type) layer) was formed.

Further, on the surface of the thermosetting resin layer, 100 g of epoxy resin (“jER (registered trademark) 1004” manufactured by Mitsubishi Chemical Corporation), 12.6 g of bisphenol A, and 0.45 g of triethylamine were dissolved in 209 g of acetone. The in-situ polymerization type phenoxy resin composition was applied by a spray method so that the thickness after drying was 10 μm. After the solvent is volatilized by leaving it in the air at normal temperature for 30 minutes, it is left in a furnace at 150° C. for 30 minutes for a polyaddition reaction and allowed to cool to normal temperature, thereby forming the second layer resin. A coating layer (in-situ polymerization type phenoxy resin layer) was formed.

By the above method, a plate-shaped resin coating layer consisting of two layers of a thermosetting resin layer with a thickness of 15 μm and an in-situ polymerization type phenoxy resin with a thickness of 10 μm was formed on the surface of the functional group adhesion layer of the aluminum plate. An aluminum member was produced.

(Adhesive layer forming step)
Next, on the surface of the resin coating layer of the aluminum member, a room-temperature curing adhesive was applied in a layered manner so as to have a thickness of 30 μm. Then, the adhesive layer was cured by being left in the air at room temperature for 24 hours.

In addition, as the room temperature curing adhesive, 100 g of bisphenol A type epoxy resin (“jER (registered trademark) 828” manufactured by Mitsubishi Chemical Corporation), pentaerythritol tetrakis (3-mercaptobutyrate) (manufactured by Showa Denko K.K. “Karenzu MT (Registered Trademark) PE1”; curing agent) and 10 g of 2,4,6-tris(dimethylaminomethyl)phenol were mixed to form a room-temperature curing adhesive.

(Joining process)
Next, on the surface of the adhesive layer of the aluminum member, by injection molding a plate-shaped resin member made of BMC in the same manner as in Example 1, the aluminum member and the resin member are joined, thereby aluminum-resin joining. Body A was produced.

Also, the aluminum member was stored in the air at room temperature for 3 months, and then the aluminum member and the resin member were joined in the same manner as described above, whereby an aluminum-resin joined body B was produced.

<Comparative Test Example 2>
An aluminum member (without a resin coating layer) was prepared by sequentially performing the surface treatment step and the functional group adhesion layer forming step in the same manner as in Test Example 2. On the surface of the functional group adhering layer of this aluminum member, a room temperature curing adhesive was applied in a layered manner in the same manner as in Example 2. Then, the adhesive layer was cured by being left in the air at room temperature for 24 hours. Next, the aluminum member and the resin member were joined in the same manner as in Example 2, thereby producing an aluminum-resin joined body A.

Also, an aluminum member (without a resin coating layer) was stored in air at room temperature for 3 months, and then the aluminum member and the resin member were joined in the same manner as described above, thereby producing an aluminum-resin joined body B.

[Evaluation of bonding properties]
The aluminum-resin joints produced in Examples 1 and 2 and Comparative Examples 1 and 2 were subjected to a tensile shear bond strength test as a joint strength test to evaluate the joint strength. These results are shown in Table 1. The tensile shear bond strength test was conducted according to JIS K6850 (1999).

The meanings of the symbols in the "joining strength evaluation" column in Table 1 are as follows.

○: Bonding strength is 20 MPa or more ×: Bonding strength is less than 20 MPa -: The aluminum member and the resin member are not bonded.

<Test Example 3>
(Surface treatment process)
The same aluminum plate as in Experimental Example 1 was prepared. Then, the aluminum plate was subjected to a surface treatment step in the same manner as in Experimental Example 1, thereby forming a surface-treated portion (boehmite film having surface unevenness) on the surface of the aluminum plate.

(Functional group adhesion layer forming step)
Next, 2 g of 3-aminopropyltrimethoxysilane (manufactured by Shin-Etsu Silicone Co., Ltd. "KBM-903"; silane coupling agent) was dissolved in 1000 g of industrial ethanol at 70° C. in a silane coupling agent-containing solution. The treated aluminum plate was immersed for 3 minutes. After that, the aluminum plate was taken out and dried to form a functional group adhering layer on the surface of the boehmite film (surface treatment portion).

(Resin coating layer forming step)
Next, an in situ polymerization type phenoxy resin composition prepared by dissolving 100 g of an epoxy resin (“jER (registered trademark) 1001” manufactured by Mitsubishi Chemical Corporation), 24 g of bisphenol A, and 0.4 g of triethylamine in 250 g of acetone, It was applied to the surface of the functional group adhering layer of the aluminum plate by a spray method so that the thickness after drying was 10 μm. After the solvent is volatilized by leaving it in the air at room temperature for 30 minutes, it is left in a furnace at 150° C. for 30 minutes for a polyaddition reaction and allowed to cool to room temperature, thereby forming the first layer resin. A coating layer (in-situ polymerization type phenoxy resin layer) was formed.

Furthermore, on the surface of the in-situ polymerization type phenoxy resin layer, 100 g of a vinyl ester resin (“Lipoxy (registered trademark) R-6540” manufactured by Showa Denko Co., Ltd.; tensile elongation of 20%), 0.5 g of cobalt octylate, and an organic peroxide A thermosetting resin composition prepared by mixing 1.5 g of an oxide catalyst (“Hardener 328E” manufactured by Kayaku Akzo Co., Ltd.) is applied by a spray method and cured at room temperature by repeating the operation several times. , a second resin coating layer (thermosetting resin (normal temperature curing type) layer) having a thickness of 2 mm was formed.

By the above method, a plate having a resin coating layer consisting of two layers, a 10 μm-thick in-situ polymerizable phenoxy resin layer and a 2 mm-thick thermosetting resin layer, formed on the surface of the functional group-attached layer of the aluminum plate. A shaped aluminum member was produced.

(Adhesive layer forming step)
Next, on the surface of the resin coating layer of the aluminum member, a room-temperature curing adhesive was applied in a layered manner so as to have a thickness of 20 μm. Then, the adhesive layer was cured by being left in the air at room temperature for 24 hours.

In addition, as the room temperature curing adhesive, 100 g of bisphenol A type epoxy resin (“jER (registered trademark) 828” manufactured by Mitsubishi Chemical Corporation), pentaerythritol tetrakis (3-mercaptobutyrate) (manufactured by Showa Denko K.K. “Karenzu MT (Registered Trademark) PE1”; curing agent) and 10 g of 2,4,6-tris(dimethylaminomethyl)phenol were mixed to prepare a room-temperature curing adhesive.

(Joining process)
Next, on the surface of the adhesive layer of the aluminum member, by injection molding a plate-shaped resin member made of BMC in the same manner as in Example 1, the aluminum member and the resin member are joined, thereby aluminum-resin joining. made the body.

<Comparative Test Example 3>
An aluminum member (without a resin coating layer) was prepared by sequentially performing the surface treatment step and the functional group adhesion layer forming step in the same manner as in Test Example 3. On the surface of the functional group adhering layer of this aluminum member, a room temperature curing adhesive was applied in a layered manner in the same manner as in Example 3. Then, the adhesive layer was cured by being left in the air at room temperature for 24 hours. Next, the aluminum member and the resin member were joined in the same manner as in Example 3, thereby producing an aluminum-resin joined body.

<Test Example 4>
(Surface treatment process)
The same aluminum plate as in Experimental Example 1 was prepared. Then, the aluminum plate was immersed in an aqueous sodium hydroxide solution with a concentration of 5% by mass for 1.5 minutes, neutralized with an aqueous nitric acid solution with a concentration of 5% by mass, washed with water, and dried to perform an etching treatment. .

Next, the aluminum plate after the etching treatment is boiled in pure water for 10 minutes and then baked at 250° C. for 10 minutes to perform boehmite treatment. A boehmite film having a

(Functional group adhesion layer forming step)
Next, 2 g of 3-aminopropyltrimethoxysilane (manufactured by Shin-Etsu Silicone Co., Ltd. "KBM-903"; silane coupling agent) was dissolved in 1000 g of industrial ethanol at 70° C. in a silane coupling agent-containing solution. The treated aluminum plate was immersed for 20 minutes. After that, the aluminum plate was taken out and dried to form a functional group adhering layer on the surface of the boehmite film (surface treatment portion).

(Resin coating layer forming step)
Next, an in situ polymerization type phenoxy resin composition prepared by dissolving 100 g of an epoxy resin (“jER (registered trademark) 1001” manufactured by Mitsubishi Chemical Corporation), 24 g of bisphenol A, and 0.4 g of triethylamine in 250 g of acetone, It was applied to the surface of the functional group adhering layer of the aluminum plate by a spray method so that the thickness after drying was 90 μm. Then, after volatilizing the solvent by leaving it in the air at room temperature for 30 minutes, it is left in a furnace at 150 ° C. for 30 minutes to perform a polyaddition reaction, and allowed to cool to room temperature. A polymerized phenoxy resin layer) was formed.

By the above method, a plate-shaped aluminum member was produced in which a resin coating layer of an in-situ polymerizable phenoxy resin layer having a thickness of 90 μm was formed on the surface of the functional group-adhering layer of the aluminum plate.

(Joining process)
Next, the aluminum member is placed in an injection mold, and a plate made of polycarbonate resin (PC resin) ("LEXAN (registered trademark) 121R-111" manufactured by SABIC) is applied to the surface of the resin coating layer of the aluminum member. A shaped resin member is molded by an injection molding machine ("SE100V" manufactured by Sumitomo Heavy Industries, Ltd.; cylinder temperature 300 ° C, tool temperature 110 ° C, injection speed 10 mm / sec, peak / holding pressure 100/80 [MPa / MPa] By injection molding, the aluminum member and the resin member were joined, thereby producing an aluminum-resin joined body.

<Comparative Test Example 4>
An aluminum member (without a resin coating layer) was prepared by sequentially performing the surface treatment step and the functional group-imparting layer forming step in the same manner as in Test Example 4. Then, on the surface of the functional group adhesion layer of the aluminum member, a plate-shaped resin member made of PC resin was injection-molded in the same manner as in Example 4 to try to join the aluminum member and the resin member. The member and the resin member were not joined at all.

<Test Example 5>
An aluminum plate was prepared by sequentially performing a surface treatment step and a functional group adhesion layer forming step in the same manner as in Test Example 4.

(Resin coating layer forming step)
Next, on the surface of the functional group adhesion layer of the aluminum plate, bisphenol A type epoxy resin (“jER (registered trademark) 828” manufactured by Mitsubishi Chemical Corporation) 100 g, pentaerythritol tetrakis (3-mercaptobutyrate) (Showa Denko K.K.) A curable resin composition obtained by dissolving 70 g of Karenz MT (registered trademark) PE1 (manufactured by the company; curing agent) and 10 g of 2,4,6-tris(dimethylaminomethyl)phenol in 344 g of acetone, after drying The coating was applied by a spray method so as to have a thickness of 5 μm. Then, the solvent was volatilized and cured by leaving it in the air at room temperature for 30 minutes to form a first resin coating layer (thermosetting resin layer).

Furthermore, on the surface of the thermosetting resin layer, an in-situ curable phenoxy resin layer having a thickness of 80 μm was formed by the same method as in Example 4 to form a second resin coating layer.

A plate having a resin coating layer consisting of two layers, a thermosetting resin layer with a thickness of 5 μm and an in-situ polymerizable phenoxy resin layer with a thickness of 80 μm, formed on the surface of the functional group-attached layer of the aluminum plate by the above method. A shaped aluminum member was produced.

(Joining process)
Next, on the surface of the resin coating layer (in-situ polymerization type phenoxy resin layer) of the aluminum member, a plate-shaped resin member made of PC resin was injection-molded in the same manner as in Experimental Example 4, thereby separating the aluminum member and the resin member. The aluminum-resin composite was produced by bonding.

<Comparative Test Example 5>
An aluminum plate was prepared by sequentially performing a surface treatment step and a functional group adhesion layer forming step in the same manner as in Test Example 4.

(Resin coating layer forming step)
Next, on the surface of the functional group adhesion layer of the aluminum plate, the first resin coating layer (thermosetting resin layer) was formed in the same manner as in Example 5, but on the surface of this thermosetting resin layer A second resin coating layer (that is, an in-situ polymerizable phenoxy resin layer) was not formed.

(Joining process)
Next, on the surface of the resin coating layer (thermosetting resin layer) of the aluminum member, a plate-shaped resin member made of PC resin was injection-molded in the same manner as in Example 4, thereby forming a bond between the aluminum member and the resin member. When an attempt was made to join, the aluminum member and the resin member were not joined at all.

[Evaluation of bonding properties]
The aluminum-resin joints produced in Examples 3 to 5 and Comparative Examples 3 to 5 were subjected to a tensile shear bond strength test as a joint strength test to evaluate the joint strength. These results are shown in Table 2. In addition, the meaning of the code|symbol in the "bonding-strength evaluation" column in Table 2 is the same as that of Table 1.

<Test Example 6>
The same aluminum plate as in Experimental Example 1 was prepared. Then, the aluminum plate was immersed in an aqueous sodium hydroxide solution with a concentration of 5% by mass for 1.5 minutes, neutralized with an aqueous nitric acid solution with a concentration of 5% by mass, washed with water, and dried to perform an etching treatment. .

Next, the aluminum plate after the etching treatment is boiled for 3 minutes in an aqueous solution containing 0.3% by mass of triethanolamine to perform a boehmite treatment. A boehmite film having

(Functional group adhesion layer forming step)
Next, 4 g of N-2-(aminoethyl)-3-aminopropyltrimethoxysilane (manufactured by Shin-Etsu Silicone Co., Ltd. "KBM-603"; silane coupling agent) was dissolved in 1000 g of industrial ethanol at 70°C. The boehmite-treated aluminum plate was immersed in the coupling agent-containing aqueous solution for 20 minutes. After that, the aluminum plate was taken out and dried to form a functional group adhering layer on the surface of the boehmite film (surface treatment portion).

(Resin coating layer forming step)
Next, an in situ polymerization type phenoxy resin composition obtained by dissolving 100 g of an epoxy resin ("jER (registered trademark) 828" manufactured by Mitsubishi Chemical Corporation), 61.6 g of bisphenol A, and 0.6 g of triethylamine in 300 g of acetone. was applied to the surface of the functional group-adhering layer of the aluminum plate by a spray method so that the thickness after drying was 3 μm. Then, after volatilizing the solvent by leaving it in the air at room temperature for 30 minutes, it is left in a furnace at 150 ° C. for 30 minutes to perform a polyaddition reaction, and allowed to cool to room temperature. A polymerized phenoxy resin layer) was formed.

By the above method, a plate-shaped aluminum member was produced in which a resin coating layer of a 3 μm-thick in-situ polymerizable phenoxy resin layer was formed on the surface of the functional group-adhering layer of the aluminum plate.

(Adhesive layer forming step and bonding step)
Next, on the surface of the resin coating layer of the aluminum member, a two-liquid type urethane adhesive was applied in a layer so that the thickness after drying was 2 μm. Then, the adhesive layer was cured by being left in the air at room temperature for 24 hours. In addition, as a two-component urethane adhesive, Showa Denko Co., Ltd. "Vinylol (registered trademark) OLY-5438-6" 100g, "Vinylol (registered trademark) OLX-7872" 5.45g, and "Vinylol (registered trademark) An adhesive obtained by mixing 10 g of "Shokubaieki B" (trademark) was used.

(Joining process)
Next, the aluminum member is placed in a transfer molding die, and a plate-shaped resin member made of PBT-GF30 is formed on the surface of the adhesive layer of the aluminum member by a transfer molding method, whereby the aluminum member and the resin are formed. The members were bonded together to produce an aluminum-resin bonded body. PBT-GF30 is polybutylene terephthalate containing 30% glass fiber (that is, glass fiber reinforced polybutylene terephthalate).

<Comparative Test Example 6>
An aluminum member (without a resin coating layer) was prepared by sequentially performing a surface treatment step and a functional group adhesion layer forming step in the same manner as in Test Example 6. On the surface of the functional group adhesion layer of this aluminum member, a two-liquid type urethane-based adhesive was applied in layers in the same manner as in Example 6. Then, the adhesive layer was cured by being left in the air at room temperature for 24 hours. Next, the aluminum member and the resin member were joined in the same manner as in Example 6, thereby producing an aluminum-resin joined body.

[Evaluation of bonding properties]
A tensile shear bond strength test was conducted as a bonding strength test for each of the aluminum-resin bonded bodies produced in Example 6 of the above practical test and Example 6 of the comparative test, and the bonding strength was evaluated. These results are shown in Table 3. In addition, the meaning of the code|symbol in the "bonding-strength evaluation" column in Table 3 is the same as that of Table 1.

As can be seen from the evaluation results in Tables 1 to 3 above, all of the aluminum-resin bonded bodies of Examples 1 to 6 had high bonding strength.

Also, as the aluminum base material, an aluminum plate made of another aluminum material was molded by hot die forging, and then the surface of the aluminum plate was smoothed by machining. The aluminum material of the aluminum plate is Si: 0.6% by mass, Fe: 0.25% by mass, Cu: 0.3% by mass, Mg: 1.0% by mass, and the balance is Al and unavoidable impurities. have.

Next, the aluminum plate and the resin member were bonded in the same manner as in Examples 1 to 6, thereby producing an aluminum-resin bonded body. Then, each of these bonded bodies was subjected to a tensile shear bond strength test as a bonding strength test to evaluate the bonding strength. As a result, all of these bonded bodies had high bonding strength.

Therefore, according to the present invention, it is considered possible to manufacture a portable information terminal housing in which the aluminum member and the resin member are firmly joined.

INDUSTRIAL APPLICABILITY The present invention is applicable to housings used in mobile information terminals and methods of manufacturing the same.

1: Aluminum member 2: Aluminum substrate 2a: Surface treatment layer 3: Functional group adhesion layer 4: Resin coating layer 5: Primer layer 10: Adhesive layer 11: Resin member 11A: Surface member 11B: Back member 20: Portable information Terminal 21: Personal Digital Assistant Housing 21A: Bezel

Claims (7)

A bezel in which one or more resin coating layers are laminated on at least a part of the surface of an aluminum base material, and a resin front member and/or back member bonded to the surface of the bezel on the resin coating layer side. and
The resin coating layer is laminated on the surface-treated surface of the bezel,
A portable information terminal housing, wherein at least one of the resin coating layers is formed from a resin composition containing an in-situ polymerizable phenoxy resin. 2. The mobile information terminal housing according to claim 1, wherein the material of said surface member and/or said back surface member is polycarbonate or polybutylene terephthalate. The resin coating layer has a plurality of layers, at least one layer of which is formed from a resin composition containing a thermosetting resin,
3. The portable information terminal housing according to claim 1, wherein said thermosetting resin is at least one selected from the group consisting of urethane resin, epoxy resin, vinyl ester resin and unsaturated polyester resin. having a functional group attachment layer between the surface-treated surface of the bezel and the resin coating layer;
The portable information terminal housing according to any one of claims 1 to 3, wherein the functional group-adhering layer has a functional group introduced from at least one selected from the group consisting of silane coupling agents, isocyanate compounds and thiol compounds. 5. The portable information terminal housing according to claim 1, wherein said surface treatment is at least one selected from the group consisting of blasting, polishing, etching and chemical conversion. A mobile information terminal housing according to any one of claims 1 to 5, wherein said coating layer is a primer layer. A method for manufacturing a portable information terminal housing according to any one of claims 1 to 6,
When molding the resin front surface or the resin back surface by injection molding, transfer molding, press molding, or hand lay-up molding, a resin front member and/or back member is placed on the resin coating layer side of the bezel. A method for manufacturing a personal digital assistant housing for joining.

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