JPH1125653A - Resin coating aluminum material for hard disk drive case, hard disk/drive case using the resin coating aluminum material and hard disk driving device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin coating aluminum material for hard disk case drive which is light in weight and is excellent in a molding workability and does not gener ate gas from resin coating films under a more strict use condition and moreover to provide a lightweight hard disk drive case having high corrosion resistance of material in which this resin coating aluminum material is used and the risk of a malfunction and a failure due to the generating of gas from organic resin coating films is not present and a hard disk driving device in which this hard disk drive case is used. SOLUTION: This resin coating aluminum material is constituted by forming a coating film which is to be formed with a coating compound in which a polyester resin having a hydroxyl group, an aminoplast resin and an epoxy resin are contained and whose thickness is equal to or thicker than 1 μm as a first layer on the primary coating film of the one side of an aluminum alloy plate on which a primary coating film is formed and by forming a coating film which is to be formed with a coating compound in which the polyester resin having the hydroxyl group and the aminoplast resin are contained and whose thickness is equal to or thicker than 5 μm as a second layer on the first layer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a resin-coated aluminum material used for a case of a hard disk drive (HDD) device, a hard disk drive case using the resin-coated aluminum material, and a hard disk drive device using the case.

[0002]

2. Description of the Related Art Computers and word processors have a built-in hard disk drive (HDD) as a storage medium, and an aluminum die-cast material has conventionally been used for a case member of the hard disk drive. However, since the aluminum die-cast material is heavy, it is not preferable to use it for a portable, lightweight and miniaturized device. Further, since the anticorrosion treatment and the coloring treatment of the aluminum die-cast material are performed individually by painting or alumite treatment, there are also problems in terms of productivity and cost. Meanwhile, there has been proposed an aluminum alloy plate material in which a chromate film is formed on an aluminum alloy plate, and an organic resin film containing a lubricant is formed thereon to improve the general formability (Japanese Patent Laid-Open No. 6-55137). ). However, the formability of this aluminum alloy sheet material was insufficient for processing into a hard disk drive case having a high degree of processing. Also,
An organic resin film is formed on both sides of this aluminum alloy plate, and when used as a case for a hard disk drive, gas is generated from the organic resin film due to the temperature rise due to the rotation of the disk, which may cause malfunction or failure. There was a problem. Further, for a floppy disk drive case, a lightweight aluminum plate material having a high electromagnetic wave shielding property in which an organic resin film is formed on one surface of an aluminum alloy plate has been proposed (Japanese Patent Publication No. 6-70870).
issue). However, the hard disk drive has a higher rotation speed of the disk than the floppy disk drive, and the entire apparatus is complicated, and the processing of the hard disk drive case is performed at a high degree of processing such as deep drawing during molding. For this reason, such an aluminum plate material for a floppy disk can be formed by bending but is broken by deep drawing, and it is difficult to form it into a hard disk drive case, and strict requirements cannot be satisfied.

[0003]

Accordingly, the present invention provides
An object of the present invention is to provide a resin-coated aluminum material for a hard disk drive case that is lightweight, has excellent moldability, and does not generate gas from a resin film under more severe use conditions. Further, the present invention provides a light-weight hard disk drive case which can withstand long-term use without fear of malfunction or failure due to generation of gas from an organic resin film using the above resin-coated aluminum material, and a hard disk drive device using the same The purpose is to provide.

[0004]

Means for Solving the Problems The inventors of the present invention have made intensive studies in view of the above-mentioned problems, and as a result, have found that an aluminum material formed by coating two specific types of organic resin film layers on one surface and a hard disk drive formed by processing the same. It has been found that the above problem can be solved by a case, and the present invention has been accomplished based on this finding. That is, the present invention provides (1) a method in which the first undercoat is formed on the undercoat on one side of the aluminum alloy plate on which the undercoat is formed.
A layer having a thickness of 1 μm or more formed from a coating composition containing a polyester resin having a hydroxyl group, an aminoplast resin and an epoxy resin as a layer, and a polyester resin having a hydroxyl group and an aminoplast as a second layer thereon A resin-coated aluminum material for a hard disk drive case, wherein a film having a thickness of 5 μm or more is formed from a coating composition containing a resin. (2) The second organic resin film is further lubricated. (1) The resin-coated aluminum material according to (1), which comprises an agent.
(2) The resin-coated aluminum material according to (2), wherein the lubricant is a fluororesin; (4) The organic resin film of the second layer further contains organic resin fine particles having an average particle size of 5 to 100 μm (1), (2) Or (3), the resin-coated aluminum material according to (4), wherein the organic resin fine particles are fine particles of polyamide resin.
A hard disk drive obtained by molding the resin-coated aluminum material according to any one of (1), (2), (3), (4) and (5) so that an organic resin film becomes an outer surface of the case. A hard disk drive device characterized by using the case and the hard disk drive case described in (7) and (6).
The aluminum alloy plate in the present invention includes an aluminum plate.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The resin-coated aluminum material for a hard disk drive case according to the present invention is characterized in that an aluminum alloy plate on which a base film is formed has two types of organic resin film layers on one surface. The undercoat in the present invention,
In order to improve the corrosion resistance of both sides, it is preferable to apply it to both sides of the aluminum alloy plate, but it is not limited to this. The undercoat is formed by a usual method on an aluminum alloy plate which has been subjected to a pretreatment such as a degreasing treatment. The type of the undercoat is not particularly limited, but is preferably a reactive undercoat such as a chromate type. By having an undercoat,
The adhesion and corrosion resistance of the organic resin film to the aluminum alloy plate during and after molding are improved.

[0006] The aluminum material of the present invention has two types of organic resin film layers on one side of a base film. In the present invention, of the two layers, the organic resin film directly formed on the base film is the first layer, and the organic resin film further formed on the first layer is the second layer. The reason that the organic resin film is formed on only one side is that the surface without the organic resin film inside forms the hard disk drive case, which causes the adverse effect of gas generation from the inner surface of the case due to temperature rise when driving the hard disk In order to prevent this. The first organic resin film of the present invention improves the adhesion of the two organic resin films to the alloy plate. The first layer has the function of improving the adhesion and ensuring the overall formability. The first organic resin film is formed from a thermosetting coating composition (hereinafter, referred to as a primer coating) containing a polyester resin having a hydroxyl group, an aminoplast resin, and an epoxy resin. Further, the organic resin film of the second layer in the present invention has an effect of improving the moldability, workability and mold release properties of the resin-coated aluminum material of the present invention, and includes a polyester resin having a hydroxyl group and an aminoplast resin. (Hereinafter, referred to as a top coating).

In the primer coating and top coating used for forming the first and second organic resin films of the present invention, the polyester resin having a hydroxyl group is not particularly limited to the polyester resin usually used for coating. It is preferable to use a flexible polyester resin which is usually used for pre-coated metal. Examples of such a polyester resin include an oil-modified polyester resin and an oil-free polyester resin, and commercially available products can be used without any particular limitation. As the oil-modified polyester resin,
For example, Becolite M-6601-S (trade name, manufactured by Dainippon Ink and Chemicals, Inc.) can be mentioned. As an oil-free polyester resin, for example, Alloplats OP-63
(Trade name, manufactured by Eclipse Arrow Chemical Co., Ltd.), Becco Light M-6
602-60-S, Beccolite M-6401-50,
Beccolite M-6402-50, Beccolight M-6
003-60, Beccolite M-6005-60, Beccolight M-6007-60, Beccolite 48-31
2, Becolite 49-376, Becolite 46-1
69-S, Becolite M-6201-40-IM and Becolite M-6204-50-S (all trade names,
Manufactured by Dainippon Ink and Chemicals, Inc.), Armatex P-64
5, Armatex P-646, Armatex P-6
47, Armatex HMP15, Armatex HM
P25 and Armatex HMP34 (all trade names,
Mitsui Toatsu Chemicals), Byron GK-130 and Byron 630 (all trade names, Toyobo Co., Ltd.), TP-21
7 and TP-290 (both trade names, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) and Espel 1620 and Espel 1615
(Both are trade names, manufactured by Hitachi Chemical Co., Ltd.).
These polyester resins may be the same or different between the primer paint and the top coat. In addition, one kind may be used alone, or two or more kinds may be used in combination. The polyester resin having a hydroxyl group preferably has a number average molecular weight of 5,000 to 30,000,
More preferably, it is 20,000.

The aminoplast resin used in the primer coating and the top coating in the present invention functions as a curing agent by reacting with the hydroxyl groups of the polyester resin. The aminoplast resin in the present invention,
A resin obtained by a condensation reaction of a compound containing an amino group or an amide group with an aldehyde, for example, melamine, benzoguanamine, urea, dicyandiamide, glycolyl urea, etc. in methyl alcohol, ethyl alcohol, propyl alcohol, n-butyl alcohol, isobutyl alcohol And resins obtained by dehydration condensation with formaldehyde in the presence of alcohols such as As this aminoplast resin, an aminoplast resin which is usually used as a curing agent in a reaction system with a polyester resin having a hydroxyl group can be used without particular limitation, preferably a melamine resin, more preferably a methyl etherified melamine resin. Or an alkyl etherified melamine resin such as butyl etherified melamine resin. The aminoplast resin may be the same or different between the primer coating and the top coating, and in each use, one type may be used alone, or two or more types may be used in combination. Examples of the melamine resin that can be used in the primer paint and the top coat in the present invention include commercially available Cymel 303 and Cymel 325 (both trade names, manufactured by Mitsui Cyanamid Co., Ltd.), Becamine L-116, Becamine L-117 and Becamine. L-145 (all product names,
Dainippon Ink and Chemicals, Inc.). In addition to the aminoplast resin, a blocked isocyanate compound can be used as a curing agent. As these curing agents, a curing catalyst such as p-toluenesulfonic acid can be used as necessary.

The mixing ratio of the above-mentioned polyester resin and aminoplast resin in the primer coating material and the top coating material used in the present invention is 70/30 to 95/5, preferably 80, in terms of resin solid content weight ratio of polyester resin / aminoplast resin. / 20 to 90/10. If the amount of the aminoplast resin is too large, the processability is reduced. If the amount is too small, curing failure of the coating film may occur.

An epoxy resin is used for the primer coating in the present invention. As the epoxy resin, conventionally known bisphenol-epichlorohydrin type epoxy resin, alicyclic epoxy resin, novolak type epoxy resin, polyalkylene ether type epoxy resin, polycarboxylic acid glycidyl ester type epoxy resin, etc. Commercial products can be used without particular limitation. Commercially available bisphenol-epichlorohydrin type epoxy resins include, for example, Epikote 828 and Epikote 83
4, epicoat 1001, epicoat 1004, epicoat 1007 and epicoat 1009 (all trade names,
Examples of the novolak type epoxy resin include DEN-431 and DEN-438 (both trade names, manufactured by Dow Chemical Company) and EOCN-10.
20 (trade name, manufactured by Nippon Kayaku Co., Ltd.) and examples of alicyclic epoxy resins include ERL-4221 and ERL-4299.
(All are trade names, manufactured by Union Carbide Co., Ltd.), CY-
179 and CY-177 (both are trade names, manufactured by Ciba Geigy). The epoxy resin has a number average molecular weight of 300 to 4000 and an epoxy equivalent of 180 to
900 are preferably used. The compounding amount of the epoxy resin in the primer coating composition used in the present invention is preferably 1 to 20% by weight, more preferably 5 to 15% by weight, based on the total solid content of the coating composition. If the amount of the epoxy resin is too large, the processability may be reduced, and if the amount is too small, the adhesion of the coating film to the alloy plate may be reduced.

[0011] Further, the top coat in the present invention can contain organic resin fine particles for further improving the releasability. The organic resin fine particles preferably have an average particle size of 5 to 100 μm, more preferably 30 to 60 μm.
Range. If the particle size is too small, the effect of improvement is insufficient. On the other hand, if the particle size is too large, the coating itself becomes difficult and the workability of the coating film may decrease. When organic resin fine particles are used for the top coating, the total solid content in the coating is 1%.
It is preferable to mix them so as to be ２５25 wt%. Examples of the organic resin fine particles that can be used in such a top coating include polyamide resin, polyamide imide resin, polyimide resin, acrylic resin, urethane resin, resin fine particles composed of a phenol resin, and the like, and polyamide resin fine particles are particularly preferable. . Specifically, for example, nylon 6, nylon 6,6, nylon 7, nylon 9, nylon 11, nylon 12, nylon 13, nylon 1
Fine particles of 3:13, nylon 6:13, or mixtures thereof.

Further, a lubricant can be used in the top coat according to the present invention, if necessary, for the purpose of improving the releasability and abrasion resistance of the coating film. The amount of the lubricant to be used is preferably 0.5 to 10% by weight based on the total solid content of the top coat. When the lubricant is used, if the amount is too small, the abrasion resistance is not improved, and if it is too large, the appearance of the coating film may be deteriorated. Examples of the lubricant that can be used at this time include a fluororesin and a wax lubricant, and a fluororesin is preferable. When a fluororesin is used, those having a number average molecular weight of 10,000 to 600,000 are preferred, and those having a number average molecular weight of 50,000 to 400,000 are more preferred. Specifically, for example, monofluoroethylene,
A homopolymer of ethylene difluoride, chlorotrifluoroethylene, or tetrafluoroethylene, or a copolymer thereof, or a copolymer thereof with another fluorine-containing unsaturated monomer or a fluorine-free unsaturated monomer. There are polymers and the like. These fluororesins can be appropriately selected in consideration of the compatibility with the polyester resin and the aminoplast resin used in the top coating material, the workability of the formed film, the releasability, the anti-scratch property and the like. Particularly preferred is a fine powder of polytetrafluoroethylene resin (hereinafter referred to as PTFE) which is a homopolymer of ethylene tetrafluoride. Among them, PTFE having a number average molecular weight of 40,000 to 400,000 and a heat resistance temperature of 200 ° C. or more is preferable.

[0013] In addition to the above components, organic solvents (eg, xylene, butyl acetate, etc.) commonly used in coatings are used in the primer coating and the top coating in the present invention. Further, for the purpose of adjusting the properties of the paint and the coating such as the viscosity of the paint and the flexibility of the coating, an organic resin (for example, a polyester resin other than the above, a polyisocyanate resin, a vinyl chloride-acetic acid) may be further added as necessary. Vinyl copolymer resins); additives such as leveling agents, flow regulators, ultraviolet stabilizers, ultraviolet absorbers, defoamers; organic pigments (eg, quinacridone, cyanine green, cyanine blue, etc.), inorganic pigments (eg, Titanium oxide, carbon black, iron oxide, lead chromate, zinc chromate, strontium chromate, calcium carbonate, etc., rust preventive pigments (for example, strontium chromate, zinc chromate,
Aluminum dihydrogen tripolyphosphate, barium metaborate, zinc borate, barium borate, calcium molybdate, etc., extender pigments (eg, talc, silica, etc.), metal powders (eg, aluminum powder, pearl mica, etc.), organic fibers (eg, , Carbon fibers, aramid fibers, etc.), inorganic fibers, metal fibers, and the like.
Of these, it is particularly effective to mix the rust-preventive pigment in the primer coating and to include it in the first layer. Aluminum phosphate-based white rust preventive pigments or chromate-based rust preventive pigments are preferably used.

The first organic resin film of the aluminum material of the present invention can be obtained by applying the above primer coating to only one side of the aluminum alloy material on which the base film is formed, and then heating and hardening. Heat curing conditions can be appropriately selected depending on the types of the polyester resin and aminoplast resin used in the coating material.
Bake for 5 to 90 seconds. The thickness of the first organic resin film is 1 μm or more in dry film thickness, preferably 3 to 15 μm.
m. If the thickness is less than 1 μm, the adhesion of the two organic resin films to the aluminum alloy material will be poor, and the first
The role as a layer cannot be fulfilled.

In the aluminum material of the present invention, a second organic resin film is formed on the first organic film.
It can be obtained by further applying the above-mentioned top coating and heating and curing. The heat-curing conditions can be appropriately selected depending on the types of the polyester resin and the aminoplast resin used for the coating material, but usually baking is performed at 180 to 300 ° C. for 15 to 90 seconds. The thickness of the organic resin film of the second layer is 5 μm or more, preferably 5 to 30 μm, more preferably 10 to 20 μm as a dry film thickness. If the thickness is less than 5 μm, the workability of the obtained aluminum material will be poor. On the other hand, if it is too thick, the appearance of the painted surface may deteriorate. For forming the first layer and the second layer, the coating of the primer coating and the top coating is all curtain coating, roll coating,
It can be performed by a usual method such as spray coating.

The hard disk drive case of the present invention is characterized in that the resin-coated aluminum material of the present invention is formed by processing so that the resin-coated surface is outside the case, and there is no particular limitation other than that. Since the resin film of aluminum material is not inside the case, no gas is generated from the film due to temperature rise due to driving of the internal magnetic disk and reading device when used for hard disk drive device,
Malfunctions and failures can be prevented. In addition, since the outer surface of the case is coated with a resin film, fingerprints and stains are unlikely to adhere during handling after molding. The molding method is
Press molding by drawing or the like can be performed to form a hard disk drive case, but specific press molding is not particularly limited as long as it is a conventional press molding.

There are various shapes of such a hard disk drive case depending on the use and capacity, etc., but in the present invention, any shape may be used. No restrictions. In particular, since the case of the present invention is lightweight, it can be suitably used for a word processor, a personal computer, and the like that want to reduce the weight. Also, the hard disk drive of the present invention is not particularly limited except that the hard disk drive case of the present invention is used. The present invention can be applied to any commonly used hard disk drive. Next, FIG. 1 shows an exploded perspective view of one embodiment of the hard disk drive case of the present invention. In the drawing, reference numeral 1 denotes a base of a hard disk drive case, 2 denotes a cover of the hard disk drive case, 3 denotes disks and the like accommodated in the case, and 4 denotes a DC motor attached to the base. The hard disk drive of the present invention has other components and members of a normal hard disk drive such as a print board, an air filter, a head stack assembly, and a read / write amplifier, but these are omitted in FIG. The hard disk drive case shown in FIG. 1 has a concave portion for accommodating a disk or the like provided with a curved surface step or the like, as shown at A in the figure, and such a shape is formed by deep drawing. Have been.

[0018]

Next, the present invention will be described in more detail with reference to examples. In the examples, "parts" are parts by weight and "%".
Is% by weight. Production Example 1 (Preparation of Base Dispersion) A mixture having the composition shown in the following Table 1 was charged into a paint shaker, and dispersed until the particle size of the dispersed particles became 10 μm or less, to obtain Base Dispersions A and B.

[0019]

[Table 1]

Production Example 2 (Production of a primer paint) 100 parts of the dispersion A obtained in Production Example 1 was added to Epotote YD-
011X70 (trade name, manufactured by Toto Kasei Co., Ltd., bisphenol A-epichlorohydrin type epoxy resin, nonvolatile content 70)
%) And 0.15 part of a 10% solution of p-toluenesulfonic acid in isopropanol as a curing catalyst were added and stirred to obtain a primer coating material P. The epoxy resin (solid content) content in the total solid content of the primer paint P is 10.3
%Met. Further, a primer paint P ′ was obtained in exactly the same manner as the primer paint P except that no epoxy resin was used.

Production Example 3 (Production of Top Coating Paint) To 100 parts of the dispersion B obtained in Production Example 1 were added 0.15 parts of a 10% solution of p-toluenesulfonic acid in isopropanol as a curing catalyst, and Daiamide 1118 (trade name, Daicel) Nylon resin particles having an average particle size of 30 μm manufactured by Huls Co.) 5
, Lubron L-2 (trade name, manufactured by Daikin Industries, Ltd., PT
(FE resin) 3 parts were added and mixed with stirring to obtain a top coat T6. The content of nylon resin particles in the total solid content of the top coating material T6 was 10.2%, and the content of PTFE resin was 6.1.
%Met.

Production Examples 4 to 16 (Production of Top Coating Coatings) The top coatings T1 to T5 were prepared in exactly the same manner as in Production Example 3 except that the type and amount of the organic resin particles and the type and amount of the lubricant were changed. And T7 to T14. This top coat is shown in Table 2 in the column of "Top coat" in the second layer. The nylon resin particles having an average particle size of 10 μm used were Diamide 2159, those having an average particle size of 60 μm used Diamide 2157, and those having an average particle size of 120 μm used Daiamide 1111 (all trade names, manufactured by Daicel Huls). Production Example 17 An acrylic resin (Almatex 748-16AE, instead of the polyester resin and the melamine resin of the base dispersion B)
200 parts of melamine resin (trade name, manufactured by Mitsui Toatsu Chemicals Co., Ltd.)
A top coat paint T was prepared in exactly the same manner as in Production Example 3 except that p-toluenesulfonic acid was removed using a dispersion liquid containing 42 parts.
15 was obtained.

However, in the above production examples, the lubricant in the above top coat was polyethylene wax (HIFLAT 2352, trade name, manufactured by Gifu Shellac Mfg. Co., Ltd.) only for T3, and other T2, T6 to T15 Lubron L-2 was used. The organic resin fine particles are T5 only acrylic beads (Tech Polymer MBX-30, trade name,
T4, T6 to T15
Is a nylon resin fine particle represented by diamide. Example 1 Organic resin films a to o including a first layer and a second layer shown in Table 2 were formed only on one surface of an aluminum alloy plate subjected to a base treatment shown in Table 3 below. First, the primer coating obtained in Production Example 2 was applied using a bar coater after the base treatment, and baked at 240 ° C. for 50 seconds to form a first organic resin film. Next, the top coat obtained in Production Examples 3 to 15 is applied on the organic resin film of the first layer using a bar coater, and baked under the same conditions as in the case of the primer paint to form the organic layer of the second layer. A resin film was formed. As described above, only the first layer and the second layer
A resin-coated aluminum material having a coating film composed of layers was obtained. Tables 2 and 4 show the thickness and composition of the coating film of the obtained resin-coated aluminum material. The moldability, number of scratches, outgas resistance, coating film adhesion and corrosion resistance of the obtained aluminum material were tested by the following methods. Table 4 shows the results. (Test method) Formability Volatile lubricating oil G-6 was applied to the obtained resin-coated aluminum material.
216FA (trade name, manufactured by Nippon Kogyo Oil Co., Ltd.) was applied, and deep drawing was performed to form a 33φ cylinder so that the organic resin film surface was on the outside, and the critical drawing ratio (LDR) was determined. In addition,
L. D. R. Is a value represented by the following formula,
A higher value indicates better moldability.

[0024]

(Equation 1)

Number of scratches (releasability) The same volatile lubricating oil as that used for the obtained resin-coated aluminum material was applied, and 10,000 hard disk drive cases were formed so that the organic resin film surface was on the outside. Then, the number of damaged coating films was counted. Outgas resistance The outgas resistance of the surface on which the organic resin film was not formed (the surface serving as the inner surface of the case) was examined. The test method is such that the organic resin coating-formed surface of the sample is sealed, left in a closed container kept at 80 ° C. for 24 hours, and then the container is returned to room temperature.
The gas released from the sample is aggregated on the inner surface of the container, and then the inner surface of the container is washed with a solvent (isopropylene) to dissolve the aggregated gas in the solvent.
Gas analysis was performed by IR (Fourier transform infrared spectroscopy).
For comparison, an organic resin film formed on both surfaces of the aluminum alloy plate was also tested, but only one surface was sealed, and the other surface was left with the organic resin film exposed.

The organic resin-coated surface on the side of the cup formed in the test of coating film adhesion was cut with a cutter so as to reach an aluminum base, 100 squares of 1 mm square were formed, and then a cellophane tape was attached and peeled off. The state of peeling of the resin coating film was observed. The evaluation was (number of remaining coating films / number of initial preparations).
I went in. Corrosion resistance A salt spray test according to JIS-Z-2731 was performed for 500 hours, and the state of occurrence of corrosion was evaluated using a rating number (R.
N. ). In addition, R. N. The higher the value, the better the corrosion resistance.

Comparative Example An organic resin film h or p to v shown in Table 2 was formed on both surfaces or only one surface of an aluminum alloy plate in the same manner as in Example 1 to obtain a resin-coated aluminum material. Tables 2, 3 and 5 show the base treatment of the alloy plate and the thickness and constitution of the coating film of the obtained resin-coated aluminum material. The moldability, the number of scratches, the outgas resistance, the coating film adhesion and the corrosion resistance of the obtained aluminum material were tested in the same manner as in Example 1. Table 5 shows the results.

[0028]

[Table 2]

[0029]

[Table 3]

[0030]

[Table 4]

[0031]

[Table 5]

As is evident from the results in Table 4, the resin-coated aluminum material of the present invention has excellent moldability and causes less damage to the molded product. Further, the adhesion of the resin coating film is high, and the coating film does not peel off even when molded into a hard disk drive case having a high degree of processing.

Specimen No. 18 with no underlying treatment
Is insufficient in moldability, coating film adhesion and corrosion resistance, and is insufficient. Specimen No. 19, in which only the first layer was formed and the top coat was not applied, had a number of scratches of 7564, and the mold releasability was significantly inferior to each of the specimens of the present invention and the moldability was low. . In addition, the test material N in which only the second layer was formed without forming the first layer was used.
In the case of o.20, the releasability was good, but the coating film adhesion was very low, and the corrosion resistance and moldability were poor. On the other hand, the test materials of the examples of the present invention were excellent in moldability, releasability, coating film adhesion and corrosion resistance. Sample No. 21 had poor adhesion due to the thin first layer, and also had poor moldability. The test material No. 22 had poor moldability because the second layer was thin. Test material No. 23 had a large particle size of the organic resin particles, and the coated surface was extremely poor. In the test material No. 26 in which the coating film was formed on both surfaces, an organic substance was detected in the outgas resistance test, but no organic substance was detected in any of the examples of the present invention. The test material No. 24, which did not use an epoxy resin for the primer coating, had lower moldability and poorer coating film adhesion than the test material of the present invention. The test material No. 25 using an acrylic resin instead of a polyester resin for the second layer has extremely low moldability.
Further, in the examples of the present invention, it can be seen that the use of a lubricant in the top coat further improves the releasability of the molded product (test materials Nos. 6 and 7). Also, when organic resin fine particles are used as the top coat, the releasability is further improved, and the molded article is not damaged at all (test materials No. 8, 9). Furthermore, in the examples of the present invention, those in which the lubricant and the organic resin fine particles are used in combination for the top coat have not only excellent releasability but also excellent moldability (test materials No. 10 to 17).

[0034]

The resin-coated aluminum material of the present invention has the above-mentioned organic resin film on one side and is coated with an organic resin film having high adhesion, and has excellent moldability and mold release properties. Molding of a high hard disk drive case can be performed favorably, and peeling, flaws, etc. of the film do not occur during and after forming into a complicated shape. Further, with respect to outgas resistance, since no gas is generated from the inner surface of the case and corrosion resistance is high, it can be suitably used for a hard disk drive case, and an excellent hard disk drive case and hard disk drive device can be obtained.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing one embodiment of a hard disk drive case of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Base part of hard disk drive case 2 Cover part of hard disk drive case 3 Disks 4 DC motor

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Kouji Miyabe 1300-7, Okazucho, Izumi-ku, Yokohama-shi, Kanagawa Prefecture (72) Inventor Ryoji Okamura 2-3-38, Enzo, Chigasaki-shi, Kanagawa Prefecture

Claims (7)

[Claims] 1. A film formed from a coating composition comprising a polyester resin having a hydroxyl group, an aminoplast resin and an epoxy resin as a first layer on one surface of an aluminum alloy plate having an undercoat formed thereon. A film having a thickness of 1 μm or more is formed thereon, and a film having a film thickness of 5 μm or more is formed thereon as a second layer from a coating composition comprising a polyester resin having a hydroxyl group and an aminoplast resin. Resin coated aluminum material for hard disk drive cases. 2. The resin-coated aluminum material according to claim 1, wherein the second organic resin film further contains a lubricant. 3. The resin-coated aluminum material according to claim 2, wherein the lubricant is a fluororesin. 4. The resin-coated aluminum material according to claim 1, wherein the second organic resin film further comprises organic resin fine particles having an average particle size of 5 to 100 μm. 5. The resin-coated aluminum material according to claim 4, wherein the organic resin fine particles are fine particles of a polyamide resin. 6. A hard disk drive case, wherein the resin-coated aluminum material according to claim 1, 2, 3, 4, or 5 is formed so that an organic resin film is formed on an outer surface of the case. 7. A hard disk drive device using the hard disk drive case according to claim 6.