JP2012215215A - Hard disk storage case - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hard disk storage case which has preferable reworking property of a cover plate and base plate and has the sufficient adhesion of the cover plate and base plate to a gasket even when being used in a high wet heat environment.SOLUTION: The hard disk storage case includes the cover plate, the base plate and the gasket for performing the sealing between the cover plate and the base plate, wherein a groove for fixing the gasket is disposed on at least one side of the cover plate or the base plate and the groove is characterized in that a cross-sectional shape of the groove in the direction orthogonal to the extension direction of the gasket is formed as a curved surface.

Description

  The present invention relates to a hard disk storage case including a cover plate, a base plate, and a gasket for sealing between the cover plate and the base plate.

  In recent years, HDDs (hard disk drives) of computers have become more sophisticated and smaller in size and have a complicated circuit configuration, and even a small amount of dust or moisture can cause damage. There is an increasing need to prevent moisture from entering, and it is common practice to use a gasket to prevent dust and moisture from entering.

For example, as shown in FIGS. 1 to 3, the HDD is protected by a hard disk storage case 1 including a cover plate 11, a base plate 12 on which the HDD is arranged, and a gasket 13, and the cover plate 11 and the base plate 12 Sealing (sealing) is performed by sandwiching the gasket 13.
The HDD has a manufacturing yield of about 50%. For defective products, as shown in FIG. 2 or FIG. 3, it is necessary to remove the cover plate 11 from the base plate 12 and adjust the components. The gasket may be formed by adhering to the cover plate as shown in FIG. 2 or may be formed by adhering to the base plate as shown in FIG. 3, but both are adhered to the other plate. A seal is made. When the HDD components are adjusted, when the cover plate 11 is removed from the base plate 12, it is desired that the gasket remains on the cover plate 11 without leaving the gasket on the base plate 12.

  As a gasket corresponding to such a requirement, it is a multi-stage structure gasket composed of different gasket materials, and the adhesion with the cover plate or the base plate with which the lowermost gasket is in contact is the base plate with which the uppermost gasket is in contact. A multi-stage gasket has been proposed that has high adhesion to the cover plate (Patent Document 1).

JP 2009-52632 A

  However, since the multistage gasket described in Patent Document 1 requires the same number of gasket forming steps as the number of stages in manufacturing, it is necessary to adjust the positions of the gaskets in each stage so that they do not deviate from each other. , Takes time to manufacture. Moreover, since each stage is made of different materials, the manufacturing cost is likely to increase. Furthermore, the multistage gasket of Patent Document 1 may be cracked at the boundary portion of each stage, and as a result, the thermal shock durability and reworkability are lowered, so that improvement is desired.

  An object of the present invention is to provide a hard disk storage case in which the reworkability of the cover plate and the base plate is good and the adhesiveness between the cover plate and the base plate and the gasket is sufficient even when used in a high-humidity heat environment. It is what.

  The present inventor has made extensive studies to achieve the above object, and as a result, the bonding surface area of the base plate and the gasket and the bonding surface area of the cover plate and the gasket are different from each other. As a result, it was found that the reworkability of the cover plate and the base plate can be improved, and the present invention has been completed.

（式中、Ｒ¹は、水素原子又はメチル基を表し、Ｒ²は、炭素数４〜１８の鎖式飽和脂肪族炭化水素基を表す。Ｗは、エチレン基又はプロピレン基を表す。また、ｎは、０〜２の整数を表す。）
［５］前記（Ａ）成分と（Ｂ）成分との合計量１００質量部に対して、光重合開始剤を０．１〜１０質量部、無機充填材及び／又は有機系チクソ性付与剤を０．１〜３０質量部含有する、［４］に記載のハードディスク収納ケース。
［６］前記無機充填材がシリカである、［５］に記載のハードディスク収納ケース。
［７］［１］〜［６］のいずれかに記載の材料に活性エネルギー線を照射して得られるハードディスク収納ケース。 That is, the present invention relates to the following [1] to [7].
[1] A hard disk storage case comprising a cover plate, a base plate, and a gasket for sealing between the cover plate and the base plate, and a groove for fixing the gasket to at least one of the cover plate or the base plate A hard disk storage case, wherein the groove has a curved cross-sectional shape in a direction perpendicular to the extending direction of the gasket.
[2] The hard disk storage case according to [1], wherein the groove is provided in the cover plate.
[3] The hard disk storage case according to [1] or [2], wherein the curved surface of the groove is provided with irregularities.
[4] The gasket is made of a material containing (A) an energy ray-curable liquid oligomer having a (meth) acryloyl group and (B) a (meth) acrylate monomer represented by the following general formula (1). Any of [1] to [3], wherein the blending ratio [(A) :( B)] of the component (A) and the component (B) is mass ratio of 97: 3 to 20:80. Hard disk storage case according to Crab.

(In the formula, R ¹ represents a hydrogen atom or a methyl group, R ² represents a chain saturated aliphatic hydrocarbon group having 4 to 18 carbon atoms, and W represents an ethylene group or a propylene group. n represents an integer of 0 to 2.)
[5] 0.1 to 10 parts by mass of a photopolymerization initiator, an inorganic filler and / or an organic thixotropic agent with respect to 100 parts by mass of the total amount of the component (A) and the component (B). The hard disk storage case according to [4], containing 0.1 to 30 parts by mass.
[6] The hard disk storage case according to [5], wherein the inorganic filler is silica.
[7] A hard disk storage case obtained by irradiating the material according to any one of [1] to [6] with active energy rays.

  According to the present invention, there is provided a hard disk storage case in which the reworkability of the cover plate and the base plate is good and the adhesiveness between the cover plate and the base plate and the gasket is sufficient even when used in a high-humidity heat environment. be able to.

It is a conceptual diagram which shows the hard disk storage case which protects HDD. It is the figure which removed the cover plate from the base plate, and is a figure which shows the case where a gasket is adhere | attached on the cover plate. It is the figure which removed the cover plate from the base plate, and is a figure which shows the case where a gasket is adhere | attached on the base plate. (A) is a sectional view of a groove according to an embodiment of the present invention, and (b) is a sectional view when a gasket is held between a cover plate and a base plate.

[Hard disk storage case]
The hard disk storage case of the present invention comprises a cover plate, a base plate, and a gasket for sealing between the cover plate and the base plate, and the gasket is fixed to at least one of the cover plate or the base plate. A groove is provided, and the groove has a curved cross section in a direction perpendicular to the extending direction of the gasket.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 4 (a) is a cross-sectional view of a groove showing an embodiment of the present invention. In the present embodiment, the groove 14 is provided in the cover plate 11. The gasket 13 extends along the groove 14 and is sandwiched between the cover plate 11 and the base plate 12 to seal between them. In the present embodiment, the groove width (w) is larger than the groove depth (d), but the groove depth (d) is increased with respect to the groove width (w). Also good. However, if the depth of the groove is too large compared to the width of the groove, the surface pressure of the gasket sandwiched between the cover plate and the base plate increases, which may cause deformation of each plate. The ratio (d / w) between the depth (d) and the groove width (w) is preferably 0.01 to 0.5, more preferably 0.23 to 0.5. In the present invention, the depth of the groove refers to the length from the bottom of the groove to the flat portion of the plate, and the width of the groove refers to the length of the groove perpendicular to the extending direction of the groove. .
As described above, by extending the curved groove at the position where the gasket 13 is provided, the bonding area between the cover plate 11 and the gasket 13 can be increased. As a result, the adhesive force on the cover plate 11 side of the gasket is greater than the adhesive force on the base plate 12 side, and as a result, only the adhesive surface on the base plate side of the gasket is peeled cleanly during rework. Further, by providing the groove, the gasket 13 can be surely fixed to the desired positions of the cover plate 11 and the base plate 12, so that it is possible to prevent a problem that the gasket is displaced at the time of mounting. .
In addition, when it is set as the groove | channel provided with a corner part without making the side surface of a groove | channel into a curved surface, the surface pressure of a gasket becomes high and the said malfunction that each plate deform | transforms arises. In addition, when the gasket is manufactured from a UV curable resin, it becomes difficult to irradiate the resin existing in the corner portion with UV, so that there is a manufacturing problem that an uncured resin partially remains. Arise.

The width (w) of the groove 14 is preferably 0.5 to 2.4 mm, more preferably 0.8 to 2.0 mm, from the viewpoint of improving reworkability and fixing the gasket to the groove. More preferably, -1.8 mm. Further, from the same viewpoint, the depth (d) of the groove 14 is preferably 0.01 to 0.8 mm, more preferably 0.015 to 0.7 mm, and still more preferably 0.02 to 0.6 mm.
The cross-sectional shape of the groove is preferably a curved surface having the same shape as a curve drawn by a circle having a radius (R) of 0.6 to 10 mm. The radius (R) is more preferably 0.6 to 0.75 mm. When the radius (R) is within the above range, the contact width on the cover plate side of the gasket becomes larger. Further, when the groove shape is a curved surface shape having the radius, the UV irradiation described later can be performed uniformly on the gasket material as compared with the case where the groove shape is provided with a corner portion. This is preferable because it is possible.

  The cross-sectional shape of the gasket formed in such a groove is preferably circular, elliptical, semicircular, or the like. The width of the gasket is preferably 75 to 95%, more preferably 85 to 90% of the width of the groove from the viewpoint of fixing to the groove.

  In the present invention, from the viewpoint of improving the reworkability of the cover plate and the base plate, the line width (B) of the bonding surface between the gasket and the base plate, and the line width (K) of the bonding surface between the gasket and the cover plate. )) ((B) / (K)) is preferably 0.33 to 0.70, and more preferably 0.33 to 0.66. By setting this ratio ((B) / (K)) within the above range, the adhesive force on the base plate side of the adhesive surface of the gasket becomes weak, so that the adhesive surface between the gasket and the base plate can be peeled cleanly during rework. become. In addition, the line width in this specification points out the line width of the part which the gasket in the cross section orthogonal to the extension direction of a groove | channel and the cover plate or the base plate is contacting.

In the present embodiment, the groove is provided in the cover plate, but may be provided in the base plate, or may be provided in both the cover plate and the base plate. In the case where the groove is provided in both the cover plate and the base plate, the fixing stability of the gasket is further enhanced. However, in the case where the groove is provided in both the cover plate and the base plate, it is preferable that a groove having a shape satisfying the ratio of the line widths ((B) / (K)) is provided in each plate.
When the groove is provided on the base plate side and the adhesive force on the cover plate side is weakened, the ratio of the line widths is set to ((K) / (B)) and the ratio is adjusted to satisfy the above range. Is preferred.

In the present invention, the adhesion area between the gasket 13 and the groove 14 may be adjusted by providing irregularities on the curved surface of the groove 14. As the irregularities, wavy irregularities in which concave and convex stripes are alternately provided in the same direction as the groove extending direction are preferable. In this case, the height difference between the bottom of the groove and the top of the protrusion is preferably 0.01 to 0.05 mm, and more preferably 0.02 to 0.04 mm. Moreover, 0.01-0.09 mm is preferable and, as for the space | interval of the bottom part of a groove and the top part of a protrusion, 0.05-0.08 mm is more preferable. Such wavy irregularities may be provided in all parts in the extending direction of the groove, or may be provided only in the middle part in the extending direction of the groove. However, from the viewpoint of improving the adhesion area, the area of the concavo-convex portion with respect to the total area of the groove is preferably 20 to 100%, and more preferably 50 to 100%. The wavy irregularities may be provided in a direction orthogonal to the extending direction of the grooves.
As the unevenness provided on the curved surface of the groove 14, a cylindrical concave portion and a cylindrical convex portion may be provided alternately. In this case, the columnar diameter is preferably 0.05 to 0.2 mm. The height difference between the cylindrical concave and convex portions is preferably 0.01 to 0.05 mm, and more preferably 0.02 to 0.04 mm. It is preferable to provide 1-10, and more preferably 2-5, of such cylindrical convex portions and concave portions per 1 mm ^{2 of} the groove area.
Furthermore, in this invention, an unevenness | corrugation may be formed by making the curved surface of a groove | channel rough, and the said wavy unevenness | corrugation, a cylindrical unevenness | corrugation, etc. may be combined.

[gasket]
The gasket used in the present invention includes an energy ray-curable liquid oligomer having a (meth) acryloyl group as the component (A), and a (meth) acrylate monomer represented by the general formula (1) described later as the component (B). It is preferable to use a gasket material that is contained.

((A) Energy ray curable liquid oligomer)
The energy ray-curable liquid oligomer having a (meth) acryloyl group constituting the component (A) has at least two (meth) acryloyl groups in the molecule from the viewpoint of the performance and processability of the obtained gasket. An oligomer can be suitably used. The number of (meth) acryloyl groups in one molecule is usually preferably 2-6, more preferably 2-4, and even more preferably 2.
The (meth) acryloyl group refers to an acryloyl group or a methacryloyl group.

There is no restriction | limiting in particular as an energy-beam curable oligomer which has a (meth) acryloyl group, For example, a urethane type (meth) acrylate oligomer, a polyester type (meth) acrylate oligomer, a polyether type (meth) acrylate oligomer, a polycarbonate type (meta ) Acrylate oligomers, epoxy (meth) acrylate oligomers, conjugated diene polymer (meth) acrylate oligomers and hydrogenated products thereof.
Here, the urethane-based (meth) acrylate oligomer is obtained by esterifying, for example, a polyurethane oligomer obtained by a reaction of polyether polyol, polyester polyol, carbonate diol and the like with polyisocyanate with (meth) acrylic acid. Can do.
Polyester (meth) acrylate oligomers can be obtained by, for example, esterifying the hydroxyl groups of polyester oligomers having hydroxyl groups at both ends obtained by condensation of polyvalent carboxylic acids and polyhydric alcohols with (meth) acrylic acid, It can be obtained by esterifying the terminal hydroxyl group of an oligomer obtained by adding alkylene oxide to carboxylic acid with (meth) acrylic acid.

The polyether-based (meth) acrylate oligomer can be obtained by esterifying the hydroxyl groups at both ends of the polyether polyol oligomer with (meth) acrylic acid. The polycarbonate (meth) acrylate oligomer can be obtained by esterifying the hydroxyl groups at both ends of the polycarbonate polyol oligomer with (meth) acrylic acid. The epoxy-based (meth) acrylate oligomer can be obtained, for example, by reacting (meth) acrylic acid with an oxirane ring of a relatively low molecular weight bisphenol-type epoxy resin or novolak-type epoxy resin and esterifying it. A carboxyl-modified epoxy acrylate oligomer obtained by partially modifying this epoxy-based (meth) acrylate oligomer with a dibasic carboxylic acid anhydride can also be used.
Examples of the conjugated diene polymer (meth) acrylate oligomer include SBR diacrylate obtained by acrylic modification of liquid styrene-butadiene copolymer, and polyisoprene acrylate obtained by acrylic modification of polyisoprene. It is done. The hydrogenated conjugated diene polymer (meth) acrylate oligomer can be obtained, for example, by esterifying the hydroxyl group of hydrogenated polybutadiene or hydrogenated polyisoprene having hydroxyl groups at both ends with (meth) acrylic acid.
In addition, (meth) acrylate refers to acrylate or methacrylate, and (meth) acrylic acid refers to acrylic acid or methacrylic acid.

The energy ray-curable liquid oligomer having the (meth) acryloyl group may be used alone or in combination of two or more, but from the viewpoint of the performance and workability of the resulting gasket. A bifunctional urethane-based (meth) acrylate oligomer is preferred. The bifunctional urethane-based (meth) acrylate oligomer means that two (meth) acryloyl groups are contained in one molecule of the urethane-based (meth) acrylate oligomer.
The bifunctional urethane-based (meth) acrylate oligomer can be obtained by reacting a polyether polyol, polyester polyol, carbonate diol, or the like having two hydroxy groups in the molecule with a polyisocyanate.

Examples of the polyether polyol having two hydroxy groups include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polyhexamethylene glycol and 1,3-butylene glycol, 1,4-butylene glycol, neopentyl glycol, A compound obtained by adding ethylene oxide or propylene oxide to cyclohexanedimethanol, 2,2-bis (4-hydroxycyclohexyl) propane, bisphenol A, or the like can be used.
The polyester polyol having two hydroxy groups can be obtained by reacting an alcohol component and an acid component. For example, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, 1,3-butylene glycol, 1,4 A compound in which ethylene oxide or propylene oxide is added to butylene glycol, 1,6-hexanediol, neopentyl glycol, 1,4-cyclohexanedimethanol, 2,2-bis (4-hydroxycyclohexyl) propane, bisphenol A, Alternatively, a compound or the like to which ε-caprolactone is added can be used as an alcohol component, and a dibasic acid such as adipic acid, sebacic acid, azelaic acid, or dodecanedicarboxylic acid, and an anhydride thereof 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.

Examples of the carbonate diol include diaryls such as diphenyl carbonate, bis-chlorophenyl carbonate, dinaphthyl carbonate, phenyl-toluyl carbonate, phenyl-chlorophenyl carbonate, 2-tolyl-4-tolyl-carbonate, dimethyl carbonate, and diethyl carbonate. Carbonates or dialkyl carbonates and diols such as 1,6-hexanediol, neopentyl glycol, 1,4-butanediol, 1,8-octanediol, 1,4-cyclohexanedimethanol, 2-methylpropanediol , Dipropylene glycol, dibutylene glycol or the above diol compounds and oxalic acid, malonic acid, succinic acid, adipic acid, azelaic acid, hexahydrophthalic acid, etc. Reaction products of carboxylic acids, or can be obtained by transesterification of the polyester diol is the reaction product of ε- caprolactone.
The carbonate diol thus obtained is a polycarbonate diol having two or more carbonate structures in the molecule.

As the bifunctional urethane-based (meth) acrylate oligomer, a compound obtained by reacting the above-described polyether polyol or polyester polyol with an organic diisocyanate is preferable. As the organic diisocyanate, for example, cycloaliphatic and aliphatic diisocyanates such as isophorone diisocyanate, 4,4′-dicyclohexylmethane diisocyanate and hexamethylene diisocyanate are preferably used.
As the bifunctional urethane-based (meth) acrylate oligomer, an oligomer having a number average molecular weight of about 4,000 to 8,000 is preferable from the viewpoint of handling properties. The number average molecular weight is a value in terms of standard polystyrene measured by a gel permeation chromatography (GPC) method.

((B) (Meth) acrylate monomer)
As the component (B), a specific (meth) acrylate monomer represented by the following general formula (1) is used. By blending the component (B) with the gasket material, the surface after the gasket is placed in a high temperature environment while the surface tackiness at room temperature (about 15 to 30 ° C.) is moderate and the leakage resistance is excellent. An increase in adhesiveness can be suppressed, and a gasket that can sufficiently withstand a heat shock test for an HDD gasket can be manufactured.

In the general formula (1), R ¹ represents a hydrogen atom or a methyl group, and R ² represents a chain saturated aliphatic hydrocarbon group having 4 to 18 carbon atoms. W represents an ethylene group or a propylene group. Moreover, n represents the integer of 0-2.
R ¹ is preferably a hydrogen atom from the viewpoint of availability.
The chain saturated aliphatic hydrocarbon group having 4 to 18 carbon atoms represented by R ² is not particularly limited as long as it is a chain saturated aliphatic hydrocarbon group having a total carbon number of 4 to 18, for example, n-butyl group (C4), isobutyl group (C4), s-butyl group (C4), n-hexyl group (C6), ethylhexyl group (C8), n-octyl group (C8), isooctyl group (C8), Various decyl groups (C10) ("various" means including straight chain and all branched chains. The same applies hereinafter), various dodecyl groups (C12), various tridecyl groups (C13), various hexadecyl groups (C16), various octadecyl groups (C18) and the like. Among these, a branched chain saturated aliphatic hydrocarbon group having 7 to 18 carbon atoms is preferable from the viewpoint of suppressing an increase in surface adhesion after placing the gasket in a high temperature environment, and an ethylhexyl group, an isooctyl group (6 -Methylheptyl group), n-dodecyl group (lauryl group), isomyristyl group, and isostearyl group are more preferable.
When the carbon number of R ² is within the above range, a gasket that can sufficiently withstand the heat shock test for the HDD gasket can be obtained.
W is preferably an ethylene group from the viewpoint of availability.
If n is an integer of 0 to 2, it does not affect the effect of suppressing the increase in adhesiveness of the gasket in a high temperature environment.
(B) component (meth) acrylate monomer may be used individually by 1 type, and may be used in combination of 2 or more type.

  The blending ratio of the component (A) and the component (B) is a mass ratio from the viewpoint of suppressing an increase in adhesiveness after placing the gasket in a high temperature environment, and (A) :( B) = 97: 3 -20: 80 is preferable, 95: 5-20: 80 is more preferable, 90: 10-40: 60 is more preferable, and 80: 20-70: 30 is still more preferable.

  The gasket material is an active energy ray curable type, and as the active energy ray, ultraviolet rays; electron rays; ionizing radiation such as α rays, β rays, and γ rays can be used. From the viewpoints of economy and the like, it is preferable to use ultraviolet rays. When ultraviolet rays are used, the gasket material preferably contains a photopolymerization initiator described later. In addition, when ionizing radiation like an electron beam or a gamma ray is used, curing can proceed promptly without the inclusion of a photopolymerization initiator.

(Photopolymerization initiator)
As the photopolymerization initiator that is a component, known ones can be widely used, and are not particularly limited.
For example, intramolecular cleavage type photopolymerization initiators may be mentioned, and benzoin alkyl ether photopolymerization initiators such as benzoin ethyl ether, benzoin isobutyl ether and benzoin isopropyl ether; 2,2-diethoxyacetophenone, 4′-phenoxy-2 , 2-dichloroacetophenone and other acetophenone photopolymerization initiators; 2-hydroxy-2-methylpropiophenone, 4′-isopropyl-2-hydroxy-2-methylpropiophenone, 4′-dodecyl-2-hydroxy- Propiophenone photopolymerization initiators such as 2-methylpropiophenone; anthraquinone photopolymerization initiators such as benzyldimethyl ketal, 1-hydroxycyclohexyl phenyl ketone and 2-ethylanthraquinone, 2-chloroanthraquinone; acylphosphine Side-based photopolymerization initiators, and the like. Among these, propiophenone-based photopolymerization initiators are preferable, and 2-hydroxy-2-methylpropiophenone is more preferable.
Other hydrogen abstraction type photopolymerization initiators include benzophenone / amine photopolymerization initiators, Michler ketone / benzophenone photopolymerization initiators, and thioxanthone / amine photopolymerization initiators.
In order to avoid migration of the unreacted photopolymerization initiator, a non-extractable photopolymerization initiator can be used. For example, there are those obtained by polymerizing an acetophenone-based initiator and those obtained by adding a double bond of an acrylic group to benzophenone.
These photoinitiators may be used individually by 1 type, and may be used in combination of 2 or more type.
When the photopolymerization initiator is blended in the gasket material, the blending amount is usually preferably 0 with respect to 100 parts by mass of the total amount of the component (A) and the component (B) contained in the gasket material. About 1 to 10 parts by mass, more preferably 0.5 to 5 parts by mass, and still more preferably 0.5 to 3 parts by mass. Moreover, a well-known photosensitizer can also be used together with the said photoinitiator.

(Optional component)
In the gasket material used in the present invention, as optional components, for example, (meth) acrylic monomers other than the component (B), inorganic fillers, organic thixotropic agents, coupling agents, antioxidants ( Anti-aging agent), light stabilizers, carbodiimides, and the like. The gasket material is basically solvent-free, but various solvents may be blended as necessary.
In particular, by adding an inorganic filler or an organic thixotropic agent to the gasket material, it is possible to impart thickening and thixotropic properties to the material, thereby improving the moldability of the gasket material. it can.
Hereinafter, these optional components will be described.

((Meth) acrylic monomer other than component (B))
The gasket material used in the present invention may contain a (meth) acrylic monomer other than the component (B). As the (meth) acrylic monomer other than the component (B), a (meth) acrylic monomer having a molecular weight of less than 1,000 is preferable. For example, cyclohexyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyl ( (Meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, diethylene glycol monoethyl ether (meth) acrylate, dimethylaminoethyl (meth) acrylate, dipropylene glycol mono (meth) acrylate, ethoxydiethylene glycol (meth) acrylate, ethoxylated phenyl (Meth) acrylate, ethyl (meth) acrylate, isoamyl (meth) acrylate, isobornyl (meth) acrylate, isobutyl (meth) acrylate, isodecyl (meth) Chryrate, isooctyl (meth) acrylate, isostearyl (meth) acrylate, isomyristyl (meth) acrylate, lauroxy polyethylene glycol (meth) acrylate, lauryl (meth) acrylate, methoxydipropylene glycol (meth) acrylate, methoxytripropylene glycol And monofunctional (meth) acrylate monomers such as (meth) acrylate, methoxypolyethylene glycol (meth) acrylate and methoxytriethylene glycol (meth) acrylate.
When the (meth) acrylic monomer other than the component (B) is blended in the gasket material, the blending amount may be a level that does not significantly impair the effect. For example, the (A) component and the (B) component Preferably it is 20 mass parts or less with respect to 100 mass parts of total amounts, More preferably, it is 10 mass parts or less, More preferably, it is 5 mass parts or less, Most preferably, it is 3 mass parts or less.

(Inorganic filler)
Examples of the inorganic filler include silica (SiO ₂ ), alumina, titania, and viscosity mineral. Among these, silica is preferable. More specifically, silica fine powder [for example, product name: Aerosil 300 manufactured by Nippon Aerosil Co., Ltd.] and the like finely powdered by a dry method may be used.
The average particle diameter of the inorganic filler is preferably 5 to 50 μm, more preferably 5 to 12 μm, from the viewpoint of thickening and thixotropy.
When the inorganic filler is blended in the gasket material, the blending amount is 100 parts by mass of the total amount of the component (A) and the component (B) contained in the gasket material from the viewpoint of thickening and thixotropy. The amount is preferably about 0.1 to 30 parts by mass, more preferably 1 to 15 parts by mass, and further preferably 5 to 15 parts by mass.

(Organic thixotropic agent)
As the organic thixotropic agent, hydrogenated castor oil, amide wax or a mixture thereof is preferable. Specifically, hydrogenated castor oil which is a hydrogenated product of castor oil (non-drying oil whose main component is ricinoleic acid) [for example, product name: ADVITROL100, manufactured by Enomoto Kasei Co., Ltd., product name : Dispalon 305 etc.] and high-grade amide wax which is a compound obtained by substituting hydrogen of ammonia with an acyl group [for example, trade name: Disparon 6500, manufactured by Enomoto Kasei Co., Ltd.].
These may be used alone or in combination of two or more, or may be used in combination with the inorganic filler.
When the organic thixotropic agent is blended with the gasket material, the blending amount is 100 parts by mass of the total amount of the component (A) and the component (B) contained in the gasket material from the viewpoint of imparting thixotropy. The amount is preferably about 0.1 to 30 parts by mass, more preferably 1 to 15 parts by mass, and still more preferably 5 to 15 parts by mass. In addition, when using together an organic type thixotropic agent and an inorganic filler, it is preferable that the total amount is the said range.

(Coupling agent)
When producing a member with a gasket, the coupling agent may be used in an appropriate amount as necessary in order to improve the adhesion between the gasket and the substrate. As this coupling agent, there are a silane coupling agent, a titanate coupling agent, an aluminum coupling agent, and the like, among which a silane coupling agent is preferable.
In the case where a coupling agent is blended in the gasket material, the blending amount thereof is usually preferably 0.00 with respect to 100 parts by mass of the total amount of the component (A) and the component (B) contained in the gasket material. About 1-20 mass parts, More preferably, it is 1-15 mass parts, More preferably, it is 3-15 mass parts.

(Antioxidant)
Examples of the antioxidant include phenolic antioxidants, sulfur antioxidants, and phosphorus antioxidants.
Examples of the sulfur antioxidant include dilauryl 3,3′-thiodipropionate, dimyristyl 3,3′-thiodipropionate, distearyl 3,3′-thiodipropionate, and the like.
Examples of phosphorus antioxidants include triphenyl phosphite, diphenylisodecyl phosphite, phenylisodecyl phosphite, tris (nonylphenyl) phosphite, tris (2,4-di-t-butylphenyl) phosphite, 2,2'-methylenebis (4,6-di-t-butylphenyl) octyl phosphite and the like can be mentioned.
These antioxidants may be used individually by 1 type, and may be used in combination of 2 or more type.
When the antioxidant is blended in the gasket material, the blending amount is appropriately selected according to the type, and is usually preferable with respect to 100 parts by mass of the total amount of the component (A) and the component (B). Is 0.01-5 parts by mass, more preferably 0.1-5 parts by mass.

(Light stabilizer)
Examples of the light stabilizer include benzophenone-based, benzotriazole-based, benzoate-based or triazine-based ultraviolet absorbers, hindered amine-based light stabilizers, and the like. Among these, hindered amine-based light stabilizers are preferable.

A light stabilizer may be used individually by 1 type, and may be used in combination of 2 or more type.
When the light stabilizer is blended in the gasket material, the blending amount is appropriately selected according to the type, and is usually based on 100 parts by mass of the total amount of the component (A) and the component (B). Preferably it is 0.01-5 mass parts, More preferably, it is 0.1-3 mass parts.

(Carbodiimides)
As the carbodiimides, for example, commercially available products such as “Elastostab H01” (manufactured by Nisshinbo Industries, Inc.) can be used. By blending carbodiimides, functions such as suppressing hydrolysis in the gasket material can be expected. When blending carbodiimides into the gasket material, the blending amount is appropriately selected according to the type, but is usually preferably 100 parts by weight of the total amount of the component (A) and the component (B). It is 0.01-5 mass parts, More preferably, it is 0.1-3 mass parts.

(Adhesion improver)
Examples of the adhesion improver used as desired include terpene resins, terpene phenol resins, coumarone resins, coumarone-indene resins, petroleum hydrocarbons, rosin derivatives and the like, and these may be used alone. Two or more kinds may be used in combination.

(Other optional ingredients)
Other optional components include fatty acids such as stearic acid, fatty acid metal salts such as calcium stearate, fatty acid amides such as stearic acid amide, and internal mold release agents such as fatty acid esters, polyolefin waxes, and paraffin waxes, Softeners such as process oil, colorants, leveling agents and the like can be used as appropriate.

[Preparation of gasket material]
There is no restriction | limiting in particular in the preparation method of the material for gaskets, A well-known method is applicable. For example, the component (A), the component (B) and the photopolymerization initiator used as required and the optional component can be kneaded with a temperature, for example, a single screw extruder, a twin screw extruder, a planetary mixer, It can be prepared by kneading using a biaxial mixer, a high shear mixer or the like.
The gasket material thus obtained preferably has a viscosity in the range of 1 to 10,000 Pa · s at a temperature of 50 ° C. and a shear rate of 1.0 / second. When the viscosity is in the above range, the gasket material has appropriate fluidity, good handling properties, and can maintain the gasket shape. The viscosity is more preferably 10 to 2,000 Pa · s, still more preferably 30 to 1,000 Pa · s.
The viscosity is a value measured by the following method.
(Viscosity of gasket material at a temperature of 50 ° C. and a shear rate of 1.0 / second)
Rheometer “RS-600” (manufactured by Harke) was used for measurement. Casson in which the material for the gasket was adjusted to 50 ° C., the shear stress was measured while changing the shear rate in the range of ¹ to 10 s ⁻¹ with a gap of 0.2 mm, and the shear rate and the half power of the stress were plotted An approximate line by the least square method was drawn from the plot, and the viscosity at 1 s ⁻¹ was calculated.

The gasket can be obtained by irradiating the above-described gasket material with active energy rays. As the energy ray, it is preferable to use ultraviolet rays from the viewpoints of operability, productivity and economy as described above. When ultraviolet rays are used, the gasket material preferably contains a photopolymerization initiator. Examples of the ultraviolet light source include a xenon lamp, a low-pressure mercury lamp, a high-pressure mercury lamp, a metal halide lamp, and a microwave excimer lamp. The atmosphere for irradiation with ultraviolet rays is preferably an inert gas atmosphere such as nitrogen gas or carbon dioxide gas, or an atmosphere with a reduced oxygen concentration, but can be sufficiently cured even in a normal air atmosphere. The irradiation atmosphere temperature can usually be 10 to 200 ° C. The irradiation time is usually preferably 10 seconds to 60 minutes, and the integrated light quantity is usually preferably 1,000 to 20,000 mJ / cm ² .
The curing method by irradiation of energy of the gasket material, preferably ultraviolet rays, can be appropriately selected according to the use of the obtained gasket.

(Member with gasket)
A gasketed member can be produced by applying a gasket material to an adherend and curing it by irradiation with energy rays, preferably ultraviolet rays. As the adherend, for example, one made of a hard resin can be used, but a metal one is preferable from the viewpoint of workability. There is no particular limitation on the metal, for example, cold-rolled steel sheet, galvanized steel sheet, aluminum / zinc alloy plated steel sheet, stainless steel sheet, aluminum plate, aluminum alloy plate, magnesium plate, magnesium alloy plate, etc. Can be used. Moreover, what injection-molded magnesium can also be used. From the viewpoint of corrosion resistance, a nickel-plated metal is preferred.
Examples of the member with gasket include a gasket for HDD, a seal for ink tank, a seal for liquid crystal device, and the like. Although the thickness of a gasket can be suitably selected according to a use, it is about 0.1-2 mm normally.

  The application of the gasket material to the adherend can be performed by any method using a coating liquid in which the temperature of the material is adjusted as necessary and adjusted to a constant viscosity, such as gravure coating, roll coating, Methods such as spin coating, reverse coating, bar coating, screen coating, blade coating, air knife coating, dipping, and dispensing can be used. After the gasket material is applied and molded, the coating layer is cured by irradiating energy rays, preferably ultraviolet rays, to obtain a member with a gasket.

EXAMPLES Next, although an Example demonstrates this invention still in detail, this invention is not limited at all by these examples.
<Example 1>
As the gasket material, a UV curable resin (model number “FS08”) manufactured by Bridgestone Corporation was used. In this UV curable resin, the mixing ratio [(A) :( B)] of the component (A) and the component (B) is 83:17 by mass ratio.
As the base plate and cover plate, an aluminum plate (A5052) having a thickness of 0.4 mm was used. A groove with a depth of 0.23 mm, a width of 1.4 mm, and a radius (R) of 1.0 mm is provided on the cover plate made of this aluminum plate by press-molding the aluminum plate (apparatus: solid frame progressive press). It was.

The UV curable resin was provided along the groove by a liquid precision discharge device. The resin is irradiated with UV at an integrated light quantity of 2000 mJ / cm ² , the gasket is bonded to the base plate with an adhesive force of 0.543 N / mm, and the gasket is bonded to the cover plate with an adhesive force of 0.374 N / mm. Glued.
The UV cured resin had a cured width of 0.76 mm and a height of 0.72 mm.
The gasketed member prepared as described above was evaluated according to the following evaluation method. The results are shown in Table 1.

<Examples 2-3>
A member with a gasket was prepared in the same manner as in Example 1 except that the shape of the groove provided in the cover plate was changed as shown in Table 1. The results are shown in Table 1.
<Examples 4 to 8>
By changing the shape of the groove provided in the cover plate as shown in Table 1 and transferring the mold shape to the entire surface in the extending direction of the groove with a press molding machine at the time of press molding, the wavy unevenness of the following shape is obtained. A member with a gasket was prepared in the same manner as in Example 1 except that it was provided. The results are shown in Table 1.
The shape of the wavy unevenness provided over the entire part in the extending direction of the groove is as follows.
Difference in height between wave bottom and wave top: 0.03mm
Distance between wave bottom and wave top: 0.07 mm

<Comparative Examples 1 and 2>
In Comparative Example 1, a member with a gasket was prepared in the same manner as in Example 1 except that the aluminum plate was not provided with a groove. Further, in Comparative Example 2, a member with a gasket was provided in the same manner as in Comparative Example 1, except that the UV curable resin arrangement surface of the aluminum plate was provided with the same irregularities as the corrugated irregularities provided in the above example. Created. The results are shown in Table 1.

<Evaluation>
(safety ratio)
The safety factor can be obtained as follows. That is, a value obtained by multiplying the adhesive strength (N / mm) of the gasket to the base plate by the contact width (B [mm]) on the base plate side of the gasket is (x), and further, the adhesive strength of the gasket to the cover plate (N / mm) ) Multiplied by the contact width (K [mm]) on the cover plate side of the gasket, and (y) is obtained by dividing (y) by (x) ((y) / (x)). it can.
(effect)
The effect can be obtained as follows. That is, the ratio of the safety factor of each example to the safety factor of Comparative Example 1 (flat) described below was taken as an effect.

  When an experiment was conducted with a groove having a specific shape, both the safety factor and the effect were high. Moreover, when the wavy unevenness was provided on the surface of the groove, the safety factor and the effect were further improved.

1 Hard Disk Storage Case 11 Cover Plate 12 Base Plate 13 Gasket 14 Groove

Claims (7)

  A hard disk storage case comprising a cover plate, a base plate, and a gasket for sealing between the cover plate and the base plate, wherein at least one of the cover plate or the base plate is provided with a groove for fixing the gasket. A hard disk storage case, wherein the groove has a curved cross-sectional shape in a direction orthogonal to the extending direction of the gasket.   The hard disk storage case according to claim 1, wherein the groove is provided in the cover plate.   The hard disk storage case according to claim 1, wherein unevenness is provided on the curved surface of the groove. The gasket is made of a material containing (A) an energy ray-curable liquid oligomer having a (meth) acryloyl group and (B) a (meth) acrylate monomer represented by the following general formula (1), The hard disk according to any one of claims 1 to 3, wherein the mixing ratio [(A) :( B)] of the component (A) and the component (B) is 97: 3 to 20:80 in terms of mass ratio. Storage case.

(In the formula, R ¹ represents a hydrogen atom or a methyl group, R ² represents a chain saturated aliphatic hydrocarbon group having 4 to 18 carbon atoms, and W represents an ethylene group or a propylene group. n represents an integer of 0 to 2.)   0.1 to 10 parts by mass of the photopolymerization initiator, 0.1% of the inorganic filler and / or organic thixotropic agent is added to 100 parts by mass of the total amount of the component (A) and the component (B). The hard disk storage case according to claim 4, containing ˜30 parts by mass.   The hard disk storage case according to claim 5, wherein the inorganic filler is silica.   A hard disk storage case obtained by irradiating the material according to claim 1 with active energy rays.

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