JP5419176B2 - Adhesive label for hard disk drive and method for reducing sound generated when driving hard disk drive using the adhesive label - Google Patents

Description

  The present invention relates to an adhesive label for a hard disk drive that is used by being affixed to the outer surface of a housing of the hard disk drive. More specifically, the present invention relates to various functions such as various display functions and an airtightness maintaining function as an adhesive label, and hard disk drive driving. The present invention relates to a pressure-sensitive adhesive label for a hard disk drive capable of reducing sound generated at the time and a method for reducing sound generated when a hard disk drive is driven by the pressure-sensitive adhesive label.

  In recent years, the demand for hard disk drives for consumer computers and other personal computers has greatly increased. As a result, the hard disk drive itself has been downsized and the noise generated during driving (to ensure quietness) has been increased. It has become an important characteristic along with the increase in

  As a means for reducing the sound generated when the hard disk drive is driven, it is generally performed by using a damping steel plate for a part of the housing of the hard disk drive (for example, a cover).

  Hard disk drives are also equipped with many holes (holes) for incorporating various parts and writing data, and many adhesive labels are used to close these holes and ensure airtightness. It is used. In addition, on the outer surface of the hard disk drive housing to display various information (for example, “Precautions for Use”, “Connection Method”, “Recognition and Identification of Product Name / Manufacturer Name”, etc.) The adhesion level to be applied is also widely used.

  However, the method using the vibration-damping steel sheet is still sufficient from the viewpoints of miniaturization and weight reduction, noise reduction, or productivity and cost of the hard disk drive whose recording disk diameter is 2.5 inches or less. It cannot be said that it is an effective measure, and further improvement is demanded.

  The present invention has been made in view of the above-mentioned problems, and the object of the present invention is to replace the generated noise reduction during driving using a conventional vibration-damping steel plate, or further to a method using a conventional vibration-damping steel plate. The object is to provide a new means for reducing noise generated during driving of a hard disk drive, which further improves noise reduction.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors can reduce sound generated when the hard disk drive is driven to an adhesive label for airtightness maintenance and information display that is adhered to the hard disk drive. It has been found that there is a possibility that the above problems can be solved by providing a function, and the present invention has been completed.

That is, the present invention has a pressure-sensitive adhesive layer on one side of a base material, and can be reduced in sound generated when a hard disk drive is driven by being attached to the outer surface of a hard disk drive housing. And the said base material consists of a laminated body by which metal foil and the resin film layer were laminated | stacked, it has an adhesive layer in the metal foil side of the said base material, and the said adhesive label is 0.18 ( It is an adhesive label for a hard disk drive characterized by having an areal density of kg / m ² ) or more.

In this invention, the base material may consist of the laminated body on which metal foil and the resin film layer were laminated | stacked through the adhesive. Moreover, the layer formed by the acrylic adhesive may be sufficient as the adhesive layer laminated | stacked on the metal foil side of the base material. The thickness of the resin film layer constituting the substrate is preferably 50 to 200 μm. The thickness of the metal foil constituting the substrate is preferably 5 μm or more. The resin film layer constituting the base material may be a polyethylene terephthalate film. The metal foil constituting the substrate may be an aluminum foil, iron foil, stainless steel foil, nickel foil, or copper foil.

The pressure-sensitive adhesive layer of the pressure-sensitive adhesive label is preferably protected by a release liner that does not use a silicone release agent as a release agent .

In the present specification, in a hard disk drive configured by a box-shaped housing main body that accommodates a recording disk and a top cover that is paired with the housing main body, the top cover and / or the outer surface of the housing main body or the top cover and Also described is a method for reducing sound generated during driving of a hard disk drive, wherein the hard disk drive adhesive label is attached to a hole (hole) formed in the housing body.

The pressure-sensitive adhesive label of the present invention has the above-described configuration, so that various information display functions and / or airtightness maintaining functions as the pressure-sensitive adhesive label can be made compatible with a function that can reduce sound generated when the hard disk drive is driven. It becomes possible.
Therefore, in the adhesive label of the present invention and the method for reducing the noise generated during driving of a hard disk drive using the adhesive label, in the measures for reducing the noise generated during driving of the hard disk drive, which has been especially emphasized in recent years, It is possible to satisfy the information display function and / or the airtightness maintaining function and the noise reduction function at the time of driving as a soundproofing / damping material at the same time. As an adhesive member for a hard disk drive having the function (effect) of two kinds of members such as a vibration damping material, it can contribute to the improvement of economy and work efficiency.

It is a schematic sectional drawing which shows the one aspect | mode of the adhesive label for hard disk drives of this invention. It is the schematic which shows the hard disk drive to which the adhesive label for hard disk drives of this invention was affixed.

  Hereinafter, the present invention will be described with reference to the drawings. FIG. 1 is a schematic cross-sectional view showing one embodiment of an adhesive label for a hard disk drive of the present invention. In FIG. 1, 1 is an adhesive label for hard disk drives (HDD adhesive label), 2 is a substrate, 2a is a resin film layer in the substrate 2, 2b is a metal foil in the substrate 2, and 3 is an adhesive layer. Reference numeral 4 denotes an information display section in the HDD adhesive label 1. FIG. 2 is a schematic view showing a hard disk drive to which the hard disk drive adhesive label of the present invention is attached. In FIG. 2, reference numerals 1 and 4 are the same as those in FIG. 1, and specifically, 1 is an adhesive label for HDD, and 4 is an information display unit. A is a housing body and B is a top cover. In FIG. 2, an information display section is provided on the outer surface of the top cover B of the hard disk device composed of a housing main body A in which a recording disk, a magnetic head, a spindle motor and the like are accommodated, and a top cover B. The adhesive label 1 for HDD which has 4 is affixed.

  In the present invention, the adhesive label 1 for HDD is affixed to the outer surface of a hard disk drive housing (for example, the top cover B or the housing main body A in FIG. 2), thereby generating sound (hereinafter referred to as “hard disk drive”). It may be necessary to be able to reduce (sometimes simply referred to as “generated sound during driving”). Here, “it is possible to reduce the sound generated during the drive of the hard disk drive” means that the sound generated during the drive can be reduced (reduced) by 1 dB or more by applying the HDD adhesive label of the present invention. .

  Further, as shown in FIGS. 1 and 2, the HDD adhesive label 1 has, for example, “use precautions”, “connection method”, “product name / manufacturer” on the base surface (rear surface). An information display section 4 such as “recognition / identification items such as name” may be provided. By adopting such a configuration, it is possible to add a function to reduce noise generated during driving by using an adhesive label for HDD, which conventionally has only an airtight holding function to close holes (holes) and maintain airtightness. In addition, the information display function can be provided. Alternatively, an HDD adhesive label that has only an information display function can be used to add a function for reducing noise generated during driving, and further noise reduction of the hard disk drive can be achieved. Furthermore, it is possible to achieve the configuration achieved by the two members of the damping steel plate and the adhesive label with the same member.

  The HDD pressure-sensitive adhesive label of the present invention is not particularly limited as long as it has the above functions and the like, but the HDD pressure-sensitive adhesive label 1 as shown in FIG. 1 is preferably used. it can. In FIG. 1, an adhesive label 1 for HDD has an information display section 4 on one side (rear surface) of a laminated base material composed of at least three layers in which a resin film layer 2a is laminated on both sides of a metal foil 2b as a base material 2. And the pressure-sensitive adhesive layer 3 is formed on the other surface.

The HDD pressure-sensitive adhesive label 1 needs to have a surface density of 0.18 (kg / m ² ) or more. When the surface density is 0.18 (kg / m ² ) or more, it is possible to further reduce the sound generated during driving. More specifically, the surface density of the pressure-sensitive adhesive label for HDD is, for example, 0.18 (kg / m ² ) or more, preferably 0.20 (kg / m ² ) or more, and more preferably 0.40 (kg). / M ² ) or more can be selected.

In addition, if the surface density of the adhesive label for HDD is 0.18 (kg / m ² ) or more, the upper limit is not particularly limited, but since the effect of the function of reducing generated sound during driving becomes saturated when it is increased to some extent, In consideration of the noise reduction function at the time of driving, costs, workability of pasting, and the like, the upper limit of the surface density of the adhesive label for HDD is, for example, 1.0 (kg / m ² ) or less, preferably 0. It can be selected from the range of 80 (kg / m ² ) or less, more preferably 0.75 (kg / m ² ) or less.

  In the present invention, the surface density of the pressure-sensitive adhesive label (the pressure-sensitive adhesive label composed of the base material and the pressure-sensitive adhesive layer) can be calculated as, for example, the sum of the density and the thickness of each layer. Therefore, in the present invention, the surface density of the pressure-sensitive adhesive label can be controlled by adjusting the density (material) and thickness of the base material and the density (material) and thickness of the pressure-sensitive adhesive layer.

  Of course, it is also possible to calculate by dividing (dividing) the weight (total weight) of the pressure-sensitive adhesive label (the pressure-sensitive adhesive label comprising the base material and the pressure-sensitive adhesive layer) by the area of the surface on the pressure-sensitive adhesive layer side.

  In the present invention, the surface density of the pressure-sensitive adhesive label means the surface density of the pressure-sensitive adhesive label when attached to a hard disk drive. That is, the pressure-sensitive adhesive label for calculating the surface density is a pressure-sensitive adhesive label in a state where the release liner is peeled off.

[Base material]
As shown in FIG. 1, the base material for the HDD pressure-sensitive adhesive label is a base material (laminated base material) 2 composed of at least three layers in which resin film layers 2a are laminated on both surfaces of a metal foil 2b. It is preferable to use it. Here, as the resin film layer 2a, for example, a resin film made of polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyimide (PI), polyethylene (PE), polypropylene (PP), or the like can be used. Among these, polyethylene terephthalate is particularly preferable from the viewpoint of economy and durability. Moreover, as the metal foil 2b, for example, a metal foil made of aluminum foil, iron foil, stainless steel foil, nickel foil, copper foil or the like can be used. Among these, aluminum foil is particularly preferable from the viewpoint of workability and economy.

The pressure-sensitive adhesive label of the present invention has rigidity capable of exhibiting vibration damping properties, and satisfies the pasting workability as a pressure-sensitive adhesive label, and each of the resin film layer / metal foil / resin film layer in the base material For example, the following thicknesses or configurations can be exemplified as the thickness or configuration of.
(1) The thickness of the resin film layer on the back side of the pressure-sensitive adhesive label on which the information display section is formed is usually 6 μm to 200 μm (6 μm to 150 μm), preferably 25 μm to 150 μm (25 μm to 150 μm). When the resin film layer is thinner than 6 μm, the entire substrate is governed by the properties of the metal foil, and wrinkles are easily formed, and since it is very thin, it is very difficult to stably laminate.
In addition, by setting the thickness of the resin film layer to 25 μm or more, when the information display portion is formed on the resin film layer surface on the back side of the pressure-sensitive adhesive label by a thermal transfer printing means, the heat at the time of ink transfer is a metal It is possible to further improve the problem of printing defects that are considered to occur due to dissipation through the foil.
In addition, when printing a barcode etc. as an information display part, it was excellent in the readability, such as barcode, by using the resin film (for example, white polyethylene terephthalate film etc.) colored in particular white etc. for the said resin film layer. Characteristics are obtained.

  (2) The thickness of the metal foil is preferably 5 μm or more (for example, 5 to 250 μm), preferably 10 to 200 μm from the viewpoint of maintaining the rigidity as the base material. If the thickness of the metal foil is less than 5 μm, the purpose of increasing the rigidity of the substrate may not be achieved. Also, in order to increase the rigidity of the base material, the thicker the better, but if it is too thick, it will become too thick as an adhesive label, which will affect the product thickness of the hard disk drive, so as a metal foil, The thickness is preferably 250 μm or less.

  (3) The resin film layer on the side forming the pressure-sensitive adhesive layer is laminated mainly for the purpose of suppressing the curling of the pressure-sensitive adhesive label. In order to reduce the overall thickness of the pressure-sensitive adhesive label, the thickness of the metal foil layer Although it is preferable that the thickness is as thin as possible, for example, it may be 6 μm to 200 μm (preferably 25 to 150 μm).

  The base material can be produced by using a known lamination means such as a dry lamination method, for example, a metal foil and a resin film layer.

  Furthermore, the substrate can be subjected to surface treatment on one or both sides of the resin film using a known means such as corona treatment or easy adhesion treatment to improve the printability and the anchoring property of the adhesive.

  In this invention, the base material may consist only of metal foil, for example, and may consist of the laminated body on which 2 layers, metal foil and a resin film layer, were laminated | stacked. When it consists only of metal foil, as thickness of metal foil, what is necessary is just 5 micrometers or more, but selecting from the range of about 100-200 micrometers is preferable. Moreover, when it consists of two layers of metal foil and a resin film layer, as thickness of metal foil, what is necessary is just 5 micrometers or more, The thinner one of about 5-50 micrometers is preferable, On the other hand, The thickness is preferably selected from a range of about 50 to 200 μm.

[Information display section]
An information display unit 4 is formed on one side (back side) of a base material (such as a laminated base material in which a resin film layer 2a is laminated on both sides of a metal foil 2b) 2 of an adhesive label for HDD. For example, “notes on use”, “connection method”, “recognition / identification items such as product name / manufacturer name” and the like can be formed by ordinary printing means.

  The information display unit 4 can be provided as necessary. For example, when the adhesive label for HDD is an adhesive label having a function of maintaining airtightness and a function of reducing sound generated during driving, the information display unit may be provided, but not provided. May be.

[Adhesive layer]
In the HDD pressure-sensitive adhesive label 1, the pressure-sensitive adhesive layer 3 is formed on the surface (other surface) opposite to the surface on which the information display portion 4 of the base material (laminated base material in FIG. 1) 2 is formed. . The pressure-sensitive adhesive layer 3 can be formed of a pressure-sensitive adhesive composition made of a pressure-sensitive adhesive for imparting pressure-sensitive adhesiveness.

  In the pressure-sensitive adhesive composition forming the pressure-sensitive adhesive layer 3, as the pressure-sensitive adhesive, a conventional or known pressure-sensitive adhesive such as a synthetic rubber pressure-sensitive adhesive, a natural rubber pressure-sensitive adhesive, or an acrylic pressure-sensitive adhesive is appropriately selected and used. can do. An adhesive can be used individually or in combination of 2 or more types.

  As the pressure-sensitive adhesive, an acrylic pressure-sensitive adhesive is preferable from the viewpoint of durability. More specifically, a pressure-sensitive adhesive composed of a polymer (base polymer) whose main component is a (meth) acrylate having an alkyl group having 4 to 14 carbon atoms is desirable. Here, examples of the (meth) acrylate having an alkyl group having 4 to 14 carbon atoms include a butyl group, 2-ethylhexyl group, octyl group, isononyl group, hexyl group, isoamyl group, lauryl group, and isomyristyl group. Examples include alkyl esters of (meth) acrylic acid having an alkyl group.

  In particular, in the present invention, as the acrylic pressure-sensitive adhesive, (meth) acrylate having an alkyl group having 7 to 10 carbon atoms that easily achieves both a glass transition temperature and a pressure-sensitive adhesive characteristic that greatly contributes to vibration damping performance, and acrylic acid An acrylic pressure-sensitive adhesive composed of a polymer having as a copolymerization component can be suitably used.

  The damping performance of the adhesive layer is greatly influenced by the glass transition temperature of the adhesive, and its characteristics are effectively exhibited at the operating temperature (specifically, the operating temperature of the hard disk drive, which is usually above room temperature). Therefore, the loss factor of the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer is 0.5 to 5.0 (0.5 to 5.0), preferably 0.7 to 5.0 (0. 7 to 5.0) is desirable. Moreover, it is preferable that it is -10 degreeC or more and 50 degrees C or less as a peak temperature of the loss coefficient of the said adhesive. By setting the loss factor and / or the peak of the loss factor of the pressure-sensitive adhesive within the above range, the vibration damping performance and pressure-sensitive adhesive properties of the pressure-sensitive adhesive can be achieved at an excellent level.

  Although the thickness of an adhesive layer is not specifically limited, From the point of the reduction effect of the sound generated at the time of a drive, it is 15 micrometers or more, Preferably it is 20-100 micrometers. From the viewpoint of sealing properties and adhesive properties, the thickness of the adhesive layer may be 20 μm or more, preferably about 50 to 350 μm. Therefore, in the present invention, the thickness of the pressure-sensitive adhesive layer is preferably selected from a range of 20 to 100 μm, for example.

[Peeling liner]
In the pressure-sensitive adhesive label for HDD of the present invention, a release liner for protecting the pressure-sensitive adhesive layer until use may be used. As this release liner, in order to prevent problems such as contact failure based on silicone components in precision electronic devices such as hard disk drives, release liners with a small amount of silicone component transferred (transferred) to the adhesive layer surface, especially It is preferable to use a release liner that does not use a silicone release agent as the release agent. As a release liner in which no silicone release agent is used as a release agent, for example, a release agent layer made of a release agent other than a silicone release agent such as a fluorine release agent or a long-chain alkyl release agent is used as a substrate surface. Or a release film, a plastic film having high releasability such as a polyethylene film (such as a linear low density polyethylene film) or an ethylene-α-olefin copolymer film.

  When a release liner with a small amount of silicone component transferred (transferred) to the surface of the adhesive layer or a release liner that does not use a silicone release agent as a release agent is used, compared to a release liner that uses a silicone release agent In general, the peeling force tends to increase. As a result, when the HDD pressure-sensitive adhesive label of the present invention is peeled off from the release liner, the HDD pressure-sensitive adhesive label may be curled. For this reason, it is preferable to use the laminated base material comprised from the at least 3 layer by which the resin film layer was laminated | stacked on both surfaces of metal foil as a base material of the adhesive label for HDD. By combining a HDD pressure-sensitive adhesive label using a substrate having such a structure with a release liner that does not use a silicone-based release agent as a release agent, curl when peeling from the release liner when using an HDD pressure-sensitive adhesive label Generation | occurrence | production can be prevented and the sticking workability | operativity of the adhesive label for HDD after that improves.

  The adhesive label for HDD of the present invention peels off the release liner when a release liner is used. For example, as shown in FIG. 2, a housing main body in which a recording disk, a magnetic head, a spindle motor, etc. are accommodated. The adhesive label for HDD can be affixed and used on the outer surface of the top cover and / or the housing body (housing) of the hard disk device composed of A and the top cover B. By attaching the HDD adhesive label, it is possible to reduce the sound generated when the hard disk drive is driven, and to exhibit the information display function and / or the airtightness maintaining function. In the present invention, the adhesive label for HDD may be attached to at least a part of the housing of the hard disk drive. However, in order to further reduce the noise generated during driving, the adhesive area of the adhesive label should be increased. Most preferably, it is affixed to the outer surface of the top cover of the hard disk drive so that the total area of the top cover is 20% or more, preferably 25 to 100%.

  In order to maintain airtightness, it is necessary to stick an HDD adhesive label so as to close a hole (hole) formed in the outer surface of the top cover and / or housing body (housing) of the hard disk device. There is. Therefore, it is preferable that the sticking part of the HDD adhesive label is a part that closes at least the hole formed in the outer surface of the hard disk drive.

  In the present invention, the HDD adhesive label to be attached to the outer surface of the hard disk drive may be single or plural. For example, when there are a plurality of holes formed on the outer surface of the hard disk drive, (a) a single HDD adhesive label can be affixed so that all the holes are closed by a single HDD adhesive label; Alternatively, (b) a plurality of HDD pressure-sensitive adhesive labels are used so that one or more holes are closed by each HDD pressure-sensitive adhesive label, and as a result all holes are closed. Can be affixed.

EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated more concretely, this invention is not limited only to an Example. Examples 3 and 4 are described as reference examples.

Example 1
The following base material A was used as the base material.
Substrate A: Substrate A composed of an aluminum foil (thickness: 7 μm) / polyethylene terephthalate film layer (thickness: 100 μm) was prepared by a lamination method using dry lamination.

  An adhesive layer (thickness: 50 μm) made of an acrylic adhesive is formed on the aluminum foil surface of the substrate A, and a release liner made of only a low-density polyethylene (LDPE) film is laminated on the adhesive layer. A pressure-sensitive adhesive sheet with a base material (pressure-sensitive adhesive label A) in which the agent layer was protected by a release liner was produced.

It was 0.21 (kg / m < ² >) when the surface density in the said adhesive label A was computed in the state in which the peeling liner was not laminated | stacked.

(Example 2)
The following base material B was used as the base material.
Substrate B: Substrate B made of aluminum foil (thickness: 7 μm) / polyethylene terephthalate film layer (thickness: 100 μm) was produced by a lamination method using dry lamination.

  A pressure-sensitive adhesive layer (thickness: 30 μm) of an acrylic pressure-sensitive adhesive was formed on the aluminum foil surface of the base material B, and three of the laminates were stacked. That is, the laminated body which consists of base material B / adhesive layer / base material B / adhesive layer / base material B / adhesive layer was formed. A base material in which a release liner consisting only of a low density polyethylene (LDPE) film is laminated on the pressure-sensitive adhesive layer located on the surface of the laminate, and the pressure-sensitive adhesive layer located on the surface is protected by the release liner An attached adhesive sheet (adhesive label B) was prepared.

It was 0.58 (kg / m < ² >) when the area density in the said adhesive label B was computed in the state in which the peeling liner was not laminated | stacked. Moreover, the surface density of the laminated body which consists of base material B / adhesive layer was 0.19 (kg / m < ² >).

(Example 3)
The following base material B was used as the base material.
Substrate C: Substrate C consisting only of aluminum foil (thickness: 150 μm) was produced.

  An adhesive layer (thickness: 50 μm) made of an acrylic adhesive is formed on the aluminum foil surface of the substrate C, and a release liner made only of a low-density polyethylene (LDPE) film is laminated on the adhesive layer. A pressure-sensitive adhesive sheet with a base material (pressure-sensitive adhesive label C) in which the agent layer was protected by a release liner was produced.

It was 0.44 (kg / m < ² >) when the surface density in the said adhesive label C was computed in the state in which the peeling liner was not laminated | stacked.

Example 4
The following base material D was used as the base material.
Base material D: A base material D made of only aluminum foil (thickness: 150 μm) was prepared.

  An adhesive layer (thickness: 320 μm) made of an acrylic adhesive is formed on the aluminum foil surface of the substrate D, and a release liner made of a polyethylene terephthalate (PET) film surface-treated with silicone is formed on the adhesive layer. Lamination was performed to prepare a pressure-sensitive adhesive sheet with a base material (pressure-sensitive adhesive label D) in which the pressure-sensitive adhesive layer was protected by a release liner.

It was 0.71 (kg / m < ² >) when the surface density in the said adhesive label D was computed in the state in which the peeling liner was not laminated | stacked.

(Example 5)
The following base material E was used as the base material.
Substrate E: A polyethylene terephthalate film (thickness: 125 μm) and an aluminum foil (thickness: 150 μm) were bonded together with an acrylic pressure-sensitive adhesive to produce a substrate E. In addition, the layer by the acrylic adhesive in this base material E is 50 micrometers in thickness.

  An adhesive layer (thickness: 50 μm) made of an acrylic adhesive is formed on the aluminum foil surface of the substrate E, and a release liner made of only a low-density polyethylene (LDPE) film is laminated on the adhesive layer. A pressure-sensitive adhesive sheet with a base material (pressure-sensitive adhesive label E) in which the agent layer was protected by a release liner was produced.

It was 0.69 (kg / m < ² >) when the surface density in the said adhesive label E was computed in the state in which the peeling liner was not laminated | stacked.

(Evaluation)
The pressure-sensitive adhesive labels obtained in Examples 1 to 5 were cut into the same shape as the display label previously attached to the outer surface of the case of a commercially available 3.5-inch hard disk drive. Next, the display label previously affixed from the commercially available 3.5-inch hard disk drive was peeled off, and cut into the same shape at the same location where the display label was affixed. Each adhesive label was attached. When the release liner was peeled off, the pressure-sensitive adhesive label was not curled, and the workability when peeling the release liner was good.

  Each hard disk drive to which the adhesive label according to Examples 1 to 5 is attached is powered on and driven, and the noise level during driving (generated sound during driving) is measured as follows: [Measurement of noise level (generated sound during driving)] Method]. The measurement results are shown in Table 1.

At this time, as a comparative example, the sound generated during driving of a commercially available 3.5-inch hard disk drive itself was measured under the same conditions. The measurement is performed in a state where the display label that has been pasted on the outer surface of the housing of the hard disk drive is stuck (state 1: comparative example 1) and in a state where the display label is peeled off (state 2: comparative example 2). went. The display label previously affixed to the commercially available hard disk drive was obtained by depositing aluminum on the surface of a polyethylene terephthalate film, and the surface density of the display label was 0.14 (kg / m ² ). .

<Measurement method of noise level (generated sound during driving)>
The hard disk drive with the pressure-sensitive adhesive label according to the example attached to the top cover was turned on and driven, and the noise level during driving (generated sound during driving) was measured by the following method.

  The noise level was measured in an anechoic room. A test stand was installed in an anechoic chamber, and was placed on a highly sound-insulating rubber foam (thickness: 20 mm) with the surface to be the adhesive label affixing part of the hard disk drive to be measured for noise. (Highly sound-insulating rubber foam is used for the purpose of preventing solid propagation noise on the test bench due to vibration propagation of the hard disk drive and blocking noise from the bottom of the hard disk drive.)

  After the hard disk drive was driven and left until the noise level was stabilized, the noise level was measured with a free sound field type microphone installed 300 mm above the center. The measured value was expressed as an overall value of 20 to 20000 Hz as a frequency range, using A characteristic for auditory sense correction, averaged for 20 seconds.

  As can be seen from Table 1, the adhesive labels according to Examples 1 to 5 can reduce the sound generated during driving by 1 dB or more simply by applying the adhesive label to the display label of the hard disk drive currently on the market. It becomes.

  Furthermore, the pressure-sensitive adhesive label according to the example does not cause curling of the pressure-sensitive adhesive label even when a release liner that does not use a silicone-based release agent is used. Workability was also good.

DESCRIPTION OF SYMBOLS 1 Adhesive label for hard disk drives 2 Base material 2a Resin film layer 2b Metal foil 3 Adhesive layer 4 Information display part A Housing main body B Top cover

Claims (6)

A pressure-sensitive adhesive layer for a hard disk drive that has an adhesive layer on one side of a base material and can be reduced in sound generated when the hard disk drive is driven by being affixed to the outer surface of a hard disk drive housing, The substrate comprises a laminate in which a metal foil and a resin film layer are laminated, has a pressure-sensitive adhesive layer on the metal foil side of the substrate, and the pressure-sensitive adhesive label is 0.18 (kg / m ² ). It has the above surface density ,
The pressure-sensitive adhesive layer laminated on the metal foil side of the substrate is a layer formed with an acrylic pressure-sensitive adhesive,
The thickness of the metal foil constituting the substrate is 5 μm or more,
The resin film layer constituting the substrate is a polyethylene terephthalate film,
The adhesive label for a hard disk drive, wherein the metal foil constituting the substrate is an aluminum foil, an iron foil, a stainless steel foil, a nickel foil, or a copper foil .   The pressure-sensitive adhesive label for a hard disk drive according to claim 1, wherein the substrate comprises a laminate in which a metal foil and a resin film layer are laminated via an adhesive. The pressure-sensitive adhesive label for a hard disk drive according to claim 1 or 2, wherein the resin film layer constituting the substrate has a thickness of 50 to 200 µm. The pressure-sensitive adhesive label is 0.18 to 1.0 (kg / m ² The adhesive label for hard disk drives according to any one of claims 1 to 3, which has a surface density of The pressure-sensitive adhesive label for hard disk drive according to any one of claims 1 to 4, wherein the thickness of the metal foil constituting the substrate is 5 to 250 µm. The pressure-sensitive adhesive label for hard disk drive according to any one of claims 1 to 5, wherein the metal foil constituting the substrate is an aluminum foil.

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