JP4301487B2 - Manufacturing method of gasket for hard disk device and gasket for hard disk device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a manufacturing method (hereinafter also simply referred to as “manufacturing method”) of a gasket for a hard disk device (hereinafter also referred to as “HDD gasket”) and a gasket for a hard disk device. The present invention relates to a method of manufacturing a hard disk device gasket for sealing a joint surface with a main body in a desired shape by a simple process, and a small hard disk device gasket manufactured thereby.
[0002]
[Prior art]
In recent years, computer hard disk drives have become more sophisticated and smaller in size and have a complicated circuit configuration, and even a small amount of dust can cause damage, increasing the need for dust protection in practice. It is common practice to use a gasket to prevent dust from entering.
[0003]
Conventionally, gaskets for hard disk drives are: (1) a method of attaching a punched urethane foam sheet or solid rubber sheet to the cover plate, and (2) bridging the solid rubber on both sides of the plate by transfer molding or injection molding, and integrating with the plate (3) Dispensing method in which molten resin or solution resin is extruded using a dispenser and extruded into a gasket shape by one stroke on the plate surface, and (4) thermoplastic elastomer compounded with adhesive resin Is manufactured by a method such as injection molding on a plate surface and integration. In addition, as a technique related to the improvement of the gasket material, a technique using an ultraviolet curable material (see Patent Document 1) and a technique using a material having high thixotropy that is cured by irradiation with active energy rays (see Patent Document 2). Etc. are also proposed.
[0004]
Among these manufacturing methods, the dispensing method (1) is a method that draws a gasket shape directly on the cover plate (1) which does not require a mold that requires a long lead time to manufacture and an initial cost. Therefore, there is a merit that a process such as an attaching process is unnecessary. This dispensing method is widely used industrially, and the HDD gasket has already been applied to the manufacture of gaskets for large devices such as 3.5 inch (88.9 mm) HDDs. Most of 5 inch HDD gaskets are manufactured by this method.
[0005]
On the other hand, due to advances in HDD miniaturization technology, 2.5-inch (63.5 mm) HDDs are now becoming mainstream, and 1.8 inches (45.7 mm) and 1 inch (25.4 mm). Small HDDs have also been commercialized. The HDD gasket used for these small HDDs requires a wall-like gasket having a narrower line width and a higher height.
[0006]
[Patent Document 1]
No. 96/010594 (claims, etc.)
[Patent Document 2]
JP 2001-225392 A (Claims etc.)
[0007]
[Problems to be solved by the invention]
However, in the above dispensing method, the gasket material pushed out from the dispenser is made into a gasket shape by one stroke, so that the cross-sectional shape of the gasket is such that the semicircle is crushed by its own weight. For this reason, it is difficult to form a gasket having a narrow line width and a high height, and the accuracy of the height and width of the gasket cannot be obtained. The dispensing method is not applicable to the production of 2.5 inch HDD gaskets or smaller HDD gaskets, and in fact, such products are not on the market.
[0008]
Accordingly, an object of the present invention is to provide a method for manufacturing a gasket for a hard disk device capable of forming a gasket having a narrow line width and a high height on the cover body under such circumstances, and a small size manufactured by this manufacturing method. It is to provide a hard disk device gasket.
[0009]
[Means for Solving the Problems]
As a result of intensive studies to solve the above-described problems, the inventors of the present invention formed a gasket with a molding die using a predetermined gasket material, and also integrated the gasket and the cover body on the molding die. As a result, it was found that a gasket having a desired shape with a narrow line width and a high height can be obtained on the cover body, and the present invention has been completed.
[0010]
The method for manufacturing a gasket for a hard disk device of the present invention includes an injection step of injecting a gasket material having active energy ray curability into a mold using a three-dimensional automatic coating control device, and the injected gasket material, In the curing step of curing by irradiation with active energy rays and the integration step of transferring the obtained gasket from the mold to the cover body to form a gasket for a hard disk device, on the gasket surface in the mold or the above After the adhesive is applied on the surface of the cover body, the transfer is performed by covering the surface of the gasket with the cover body and bonding the gasket and the cover body.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail.
In the method for manufacturing a gasket for a hard disk device of the present invention, after using a gasket material having active energy ray curability, and injecting it into a mold using a three-dimensional automatic coating control device (injection step), The gasket material is cured by irradiation with active energy rays (curing process), and the obtained gasket is transferred from the mold to the cover body to obtain a gasket for a hard disk device (integration process). That is, in order to determine the gasket shape using a mold, it is possible to easily obtain a gasket having a desired line width and height, and to integrate the gasket and the cover body on the same mold. Therefore, it can also contribute to the facilitation of the manufacturing process.
[0014]
As a specific integration method, as shown in FIG. 1, the adhesive 2 is applied on the surface of the gasket 1 cured in the mold 10 ((A) in the figure) ((( B)) Thereafter, the cover body 3 is put on the surface of the gasket 1 ((c) in the figure), and the gasket 1 and the cover body 3 are bonded together, whereby the gasket 1 is applied from the mold 10 to the cover body 3. Can be transferred ((D) in the figure). Further, as shown in FIG. 2, the adhesive 2 is applied on the surface of the cover body 3 ((A) in the figure), and the both sides are adhered on the surface of the gasket 1 (( B)), the gasket 1 can also be transferred ((c) in the figure). In this case, there is no particular limitation on the mold 10, and a commonly used material such as cyanoacrylic, urethane-based, epoxy-based, various rubber-based, thermoplastic resin-based, etc. is appropriately selected and used. can do. Moreover, there is no restriction | limiting in particular also about the adhesive agent used for joining of the gasket 1 and the cover body 3, The conventionally used thing can be used suitably.
[0015]
Although not shown, in particular, when an active energy ray transmitting material such as quartz glass or the like is used as the mold 10, it is not from the gasket material surface side, that is, the surface on the opposite side, that is, The active energy ray can also be irradiated from the back side of the mold 10. Therefore, in this case, after the injection process, the cover is put on the surface of the injected gasket material, and the gasket material is cured by irradiating active energy rays from the surface opposite to the gasket forming surface. It is possible to perform the process and the integration process at the same time.
[0016]
Various materials can be used as the gasket material used in the present invention. In particular, a material having a viscosity of 23 Pa at a temperature of 23 ° C. and a shear rate of 1.0 / second is preferably 500 Pa · s or less. The gasket material can be completely and easily poured into the narrow groove of the mold 10 easily and quickly.
[0017]
Further, the gasket material preferably has a hardness according to JIS K 6253 durometer A hardness test of 50 ° or less, particularly 40 ° or less. This is because when the hardness is 50 ° or less, the gasket is easily deformed when the cover with gasket is incorporated into the main body, so that the cover is difficult to bend and the sealing performance is not impaired.
[0018]
In the present invention, a gasket having a narrow line width and a high height can be obtained more easily by using the gasket material having the above specific physical properties. For example, when the line width is 1.0 mm, the height of the gasket can be 0.5 to 2.0 mm.
[0019]
The gasket material used in the present invention is not particularly limited as long as it has the above-mentioned physical properties, but in particular, the main component is at least one selected from urethane, epoxy-based polymer, silicone, and modified ones thereof. It is preferable to use what to do.
[0020]
In the present invention, among these, those having acrylic-modified urethane as a main component are most preferable. Examples of the urethane modified with acrylic include urethane acrylate oligomer of polyether polyol, urethane acrylate oligomer of polyester polyol, or urethane acrylate oligomer having both ether group and ester group in the molecule and urethane acrylate of carbonate diol having carbonate group. An oligomer etc. can be mentioned. Examples of the polyether polyol include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polyhexamethylene glycol and 1,3-butylene glycol, 1,4-butylene glycol, 1,6-hexanediol, neopentyl glycol, cyclohexane. A compound obtained by adding ethylene oxide or propylene oxide to dimethanol, 2,2-bis (4-hydroxycyclohexyl) propane, bisphenol A, or the like can be used. The polyester polyol can be obtained by reacting an alcohol component with an acid component. For example, polyethylene glycol, polypropylene glycol, polytetramethylene glycol and 1,3-butylene glycol, 1,4-butylene glycol, 1,6- Hexanediol, neopentyl glycol, 1,4-cyclohexanedimethanol, 2,2-bis (4-hydroxycyclohexyl) propane, bisphenol A, etc. added with ethylene oxide or propylene oxide, or ε-caprolactone added A compound or the like can be used as an alcohol component, and a dibasic acid such as adipic acid, sebacic acid, azelaic acid, or dodecanedicarboxylic acid and its anhydride can be used as the acid component. A compound obtained by reacting the above-mentioned alcohol component, acid component and ε-caprolactone at the same time can also be used as the polyester polyol. The carbonate diol is, for example, diaryl carbonate such as diphenyl carbonate, bis-chlorophenyl carbonate, dinaphthyl carbonate, phenyl-toluyl carbonate, phenyl-chlorophenyl carbonate, 2-tolyl-4-tolyl-carbonate, dimethyl carbonate, diethyl carbonate and the like. Carbonates or dialkyl carbonates and diols such as 1,6-hexanediol, neopentyl glycol, 1,4-butanediol, 1,8-octanediol, 1,4-cyclohexanedimethanol, 2-methylpropanediol, di Propylene glycol, dibutylene glycol or the above diol compounds and oxalic acid, malonic acid, succinic acid, adipic acid, azelaic acid, hexahydrophthalic acid, etc. It can be obtained by transesterification of a polyester diol that is the reaction product, or ε- caprolactone reaction product of a carboxylic acid. The polycarbonate diol thus obtained is a monocarbonate diol having one carbonate structure in the molecule or a polycarbonate diol having two or more carbonate structures in the molecule. In the gasket material used in the present invention, particularly preferred acrylic-modified urethane is a urethane acrylate oligomer of polyether polyol and polyester polyol, and examples of the organic diisocyanate include isophorone diisocyanate, 4,4′-dicyclohexylmethane diisocyanate and hexamethylene diisocyanate. Is particularly preferred.
[0021]
A known photopolymerization initiator can be blended in the gasket material used in the present invention. Examples of the photopolymerization initiator include benzoin alkyl ethers such as benzoin ethyl ether, benzoin isobutyl ether and benzoin isopropyl ether; acetophenones such as 2,2-diethoxyacetophenone and 4′-phenoxy-2,2-dichloroacetophenone. A propiophenone system such as 2-hydroxy-2-methylpropiophenone, 4′-isopropyl-2-hydroxy-2-methylpropiophenone, 4′-dodecyl-2-hydroxy-2-methylpropiophenone; Examples include anthraquinone series such as benzyl dimethyl ketal, 1-hydroxycyclohexyl phenyl ketone, 2-ethylanthraquinone, 2-chloroanthraquinone, and other thioxanthone photopolymerization initiators. These photoinitiators can be used individually by 1 type or in combination of 2 or more types. When using a photoinitiator, the compounding quantity is preferably 0.5 to 5 parts by mass, more preferably 1 to 3 parts by mass, per 100 parts by mass of the acrylic-modified urethane as the main component.
The gasket material used in the present invention may contain a photosensitizer, a thermal polymerization inhibitor, a curing accelerator, a pigment, and the like as long as the effects of the present invention are not impaired.
[0022]
The three-dimensional automatic coating control device used for injecting the gasket material into the mold is not particularly limited, and it is necessary to provide an extrusion device such as a pneumatic type, a screw type, a cylinder type, and a tube type.
[0023]
In the present invention, by appropriately setting the shape of the mold, when the line width of the adhesion surface to the cover body of the gasket cross section is w and the height is h (see FIG. 1 (A)), A gasket in which the ratio h / w of the height h to the line width w is 0.8 or more in all portions can be easily formed.
[0024]
Further, the cover body integrated with the gasket formed by extruding and curing the gasket material can be formed of a synthetic resin such as a metal or a thermoplastic resin. Examples of the metal forming the cover body include nickel-plated aluminum, nickel-plated copper, cold-rolled steel, galvanized steel, aluminum / zinc alloy-plated steel, stainless steel, aluminum, aluminum alloy, magnesium, and magnesium alloy. Can be appropriately selected and used. Moreover, what injection-molded magnesium can also be used. From the viewpoint of corrosion resistance, a metal that has been subjected to electroless nickel plating is suitable. In the present invention, nickel-plated aluminum and nickel-plated steel are preferred. As an electroless nickel plating method, a known method conventionally applied to a metal material, for example, nickel sulfate, sodium hypophosphite, lactic acid, propionic acid and the like are contained at an appropriate ratio, and pH 4.0 to 5 A method of immersing a metal plate in an electroless nickel plating bath made of an aqueous solution having a temperature of about 0.0 and a temperature of about 85 to 95 ° C can be used.
[0025]
Examples of the thermoplastic resin forming the cover body include styrene resins such as acrylonitrile styrene (AS) resin, acrylonitrile butadiene styrene (ABS) resin, polystyrene, and syndiotactic polystyrene, polyethylene, polypropylene, and ethylene-propylene copolymer. Olefin resins such as polypropylene composites, polyamide resins such as nylon, polyester resins such as polyethylene terephthalate and polybutylene terephthalate, modified polyphenylene ethers, acrylic resins, polyacetals, polycarbonates, liquid crystal polymers, polyphenylene sulfide (PPS) And the like, and may be appropriately selected from these. As the liquid crystal polymer, a thermotropic liquid crystal polymer is preferable, and specific examples include a polycarbonate liquid crystal polymer, a polyurethane liquid crystal polymer, a polyamide liquid crystal polymer, and a polyester liquid crystal polymer. These resins may be used alone or in combination of two or more.
[0026]
In the present invention, the cover body can be surface-treated in advance in order to improve the adhesion between the cover body and the gasket. Examples of the surface treatment include plasma treatment and corona discharge treatment. For example, an apparatus such as a plasma irradiator manufactured by Keyence Corporation can be used for the plasma treatment.
[0027]
The active energy ray used for curing the gasket material refers to ionizing radiation such as ultraviolet rays and electron beams, α rays, β rays, and γ rays. When ultraviolet rays are used, the gasket material preferably contains the above-described photopolymerization initiator and / or photosensitizer. Further, when ionizing radiation such as an electron beam or γ-ray is used, curing can proceed promptly without containing a photopolymerization initiator or a photosensitizer. Examples of the ultraviolet light source include a xenon lamp, a low pressure mercury lamp, a high pressure mercury lamp, and an ultrahigh pressure mercury lamp. As an atmosphere for irradiating ultraviolet rays, an inert gas atmosphere such as nitrogen gas or carbon dioxide gas or an atmosphere with a reduced oxygen concentration is preferable. However, even in a normal air atmosphere, it is sufficiently cured when an ultraviolet curable gasket is used. Can be made. The irradiation atmosphere temperature can usually be 10 to 200 ° C.
[0028]
Since the gasket for a hard disk device of the present invention is manufactured by the above manufacturing method and has a suitable line width and height, it is particularly a small hard disk having a size of less than 3.5 inches (88.9 mm). The present invention can be preferably applied to the apparatus.
[0029]
【The invention's effect】
As described above, according to the present invention, it is possible to realize a manufacturing method of a gasket for a hard disk device that can form a gasket having a narrow line width and a high height on a cover body by a simple process. Thus, a hard disk device gasket suitable for a small hard disk device of less than 3.5 inches can be provided.
[Brief description of the drawings]
FIG. 1 is an explanatory view showing an example of a method for producing a gasket for a hard disk device of the present invention.
FIG. 2 is an explanatory view showing another example of a method for producing a gasket for a hard disk device of the present invention.
[Explanation of symbols]
1 Gasket 2 Adhesive 3 Cover body 10 Mold

Claims (8)

An injection step of injecting a gasket material having active energy ray curability into a mold using a three-dimensional automatic coating control device, a curing step of hardening the injected gasket material by irradiation with active energy rays, In the integration step of transferring the obtained gasket from the mold to the cover body to form a gasket for a hard disk device , after applying an adhesive on the gasket surface in the mold or on the cover body surface, A manufacturing method of a gasket for a hard disk device, wherein the transfer is performed by covering the gasket surface with the cover body and bonding the gasket and the cover body . Wherein as a three-dimensional automatic coating controlling apparatus, pneumatic, screw, cylinder type or method of claim 1, wherein the hard disk drive gasket with those with tube type extruder performs extrusion. The ratio h / w of the height h to the line width w is 0.8 in all parts of the gasket, where w is the line width of the bonding surface to the cover body and h is the height of the gasket cross section. The method for producing a gasket for a hard disk device according to claim 1 or 2, which is as described above. The method for producing a gasket for a hard disk device according to any one of claims 1 to 3 , wherein a material having a viscosity at a temperature of 23 ° C and a shear rate of 1.0 / second of 500 Pa · s or less is used as the gasket material. The method for manufacturing a gasket for a hard disk device according to any one of claims 1 to 4 , wherein the gasket material is one having a hardness of 50 ° or less according to a JIS K 6253 durometer A hardness test. As the gasket material, urethane, epoxy polymer, for a hard disk device according to any one of claims 1-5 for use as a main component at least one selected from among those modified silicone and these Manufacturing method of gasket. The method for manufacturing a gasket for a hard disk device according to claim 6 , wherein acrylic modified urethane is used as the gasket material. Any one hard disk drive gaskets method according one of claims 1-7 using ultraviolet rays as the active energy ray.

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