JP2013173942A - Adhesive tape - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an adhesive tape having excellent thermal conductivity.SOLUTION: An adhesive tape includes a base material layer formed of a plastic material or the like, and an adhesive layer formed at least on one-side surface of the base material layer. In the adhesive tape, the value of thermal resistance at 80°C is <2.00 [cm*K/W], and the total thickness of the base material layer and the adhesive layer is <10 μm. The adhesive layer may be formed on both the surfaces of the base material layer. The total thickness of the base material layer and the adhesive layer may be <6 μm.

Description

  The present invention relates to an adhesive tape, and more particularly, to an adhesive tape that is suitably used at a joint portion between various components that generate heat and a heat conductive sheet when manufacturing (assembling) various OA devices, portable devices, and electronic components.

  In recent years, portable devices such as mobile phones, digital cameras, and PDAs (Personal Digital Assistants) have been downsized. For this reason, various electronic components to be mounted are also reduced in size and thickness. For example, a mobile phone, which is a representative device as a mobile device, tends to be thinned in each of the main components. Usually, the display part of a portable device is mainly composed of an LCD module and a backlight unit, and various sheet-like components are laminated in order to develop functions such as light emission, reflection, light shielding, and light guide. Thus, a double-sided adhesive tape has been devised for use in assembling (joining) these components (see Patent Document 1).

JP 2005-105212 A

  By the way, with the progress of miniaturization and thinning of mobile devices such as the above-described mobile phones, the degree of integration of various mounted electronic components will increase, and further improvement in heat dissipation is required. Yes. Therefore, it has been studied to use a heat conductive sheet in order to efficiently dissipate heat generated by various electronic components to the outside.

  However, when the conventional double-sided adhesive tape is used to join the heat conductive sheet to the electronic component, there is room for further improvement from the viewpoint of transferring the heat generated by the electronic component to the heat conductive sheet.

  The present invention has been made in view of such circumstances, and an object thereof is to provide an adhesive tape having good thermal conductivity.

In order to solve the above problems, an adhesive tape according to an aspect of the present invention includes a base material layer and a pressure-sensitive adhesive layer provided on at least one surface of the base material layer. The adhesive tape has a thermal resistance value at 80 ° C. of less than 2.00 [cm ² · K / W], and the total thickness of the base material layer and the pressure-sensitive adhesive layer is less than 10 μm.

  According to this aspect, the thermal resistance value is low and the thermal conductivity is good. Moreover, since the layer thickness is thin, it contributes to the thinning of parts and devices in which adhesive tape is used.

  The pressure-sensitive adhesive layer may be provided on both surfaces of the base material layer.

The value of the thermal resistance at 80 ° C. may be less than 1.50 [cm ² · K / W].

  The total thickness of the base material layer and the pressure-sensitive adhesive layer may be less than 6 μm.

  It may be usable in a temperature environment of 60 ° C. or higher.

  You may use for adhesion | attachment of a heat-emitting component and a heat conductive sheet.

  The pressure-sensitive adhesive layer may contain less than 20 parts by weight of a thermally conductive filler per 100 parts by weight of the polymer main component constituting the pressure-sensitive adhesive layer.

  The base material layer may be colored.

  According to the present invention, an adhesive tape having good thermal conductivity can be provided.

It is the schematic which shows an example of the double-sided adhesive tape or sheet | seat of this Embodiment. FIG. 2A is a schematic front view showing an apparatus used when measuring thermal resistance in the embodiment, and FIG. 2B is a schematic side view of the apparatus shown in FIG. It is the graph which showed the relationship between tape total thickness and a thermal resistance value.

  Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings and tables. In the following embodiments, a double-sided adhesive tape or sheet having an adhesive layer on both sides will be described as an example, but an adhesive tape or sheet having an adhesive layer on one side may be used depending on the application.

[Double-sided adhesive tape or sheet]
FIG. 1 is a schematic view showing an example of a double-sided adhesive tape or sheet according to the present embodiment. In the following description, the double-sided adhesive tape or sheet (hereinafter referred to as “double-sided adhesive tape” as appropriate) 10 of the present embodiment is a pressure-sensitive adhesive layer on both sides of the base material layer 12 as shown in FIG. 14 is a double-sided adhesive tape with a base material. The double-sided adhesive tape 10 has a total thickness of 3 μm or more and less than 10 μm including the base material layer 12 and the two pressure-sensitive adhesive layers 14 and 16 formed on both surfaces of the base material layer 12, and was performed by a measurement method described later. The value of the thermal resistance at 80 ° C. is less than 2.00 [cm ² · K / W], more preferably less than 1.50 [cm ² · K / W] (the lower limit is 0.05 [cm ² · K / W] or more). Thus, although the double-sided adhesive tape 10 of this Embodiment has the base material layer 12, the thickness is as thin as less than 10 micrometers, and also the value of heat resistance is low and it is excellent in thermal conductivity.

  Therefore, the double-sided adhesive tape 10 of the present embodiment has a region where the joining means using the double-sided adhesive tape cannot be conventionally used (for example, an adhesive member) because the thickness of the joining part (clearance between joining parts) is small And a uniform bonding operation using the double-sided adhesive tape 10 can be performed. In other words, it is possible to reduce the thickness of the entire apparatus that accommodates a plurality of components joined by the double-sided adhesive tape. For example, there is a high demand for thinning, and the apparatus is suitable for use in portable devices and flat-screen televisions that tend to be hot during use. More specifically, it can be used for bonding a heat generating component such as a backlight unit for liquid crystal of a mobile phone or a semiconductor chip and a heat dissipating component such as a heat conductive sheet. As a result, the heat dissipation characteristics can be improved while realizing a reduction in thickness.

  As shown in FIG. 1, the double-sided adhesive tape 10 has a configuration in which a pressure-sensitive adhesive layer 14 is formed on one surface of a base material layer 12 and a pressure-sensitive adhesive layer 16 is formed on the other surface. In the double-sided adhesive tape 10, the pressure-sensitive adhesive layer 14 is protected by a release liner (separator) 18, and the other surface (the surface opposite to the pressure-sensitive adhesive layer 14) of the pressure-sensitive adhesive layer 16 and the release liner 18 is formed. It is overlapped so as to come into contact and wound into a roll.

  The total thickness (tape thickness) of the double-sided adhesive tape 10 of the present embodiment is not particularly limited as long as it is 3 μm or more and less than 10 μm. For example, it is selected from the range of 3 μm to 6 μm, preferably 3 μm to 5 μm. be able to. Thereby, thickness reduction of the components and apparatus in which the double-sided adhesive tape 10 is used is further achieved.

  In addition, the total thickness (tape thickness) of the double-sided adhesive tape 10 means the thickness of the part utilized at the time of sticking. That is, the total thickness of the double-sided adhesive tape 10 means the thickness (total thickness) from one adhesive surface to the other adhesive surface. Specifically, since the double-sided adhesive tape 10 of this Embodiment has the base material layer 12, it is formed on both surfaces of the base material layer 12 and the base material layer 12 with the total thickness of a double-sided adhesive tape. The thickness includes the two pressure-sensitive adhesive layers 14 and 16, and does not include the thickness of the release liner 18 for protecting the adhesive surface. In the case of a single-sided adhesive tape in which the pressure-sensitive adhesive layer is formed only on one side of the base material layer, the total thickness includes the base material layer and one pressure-sensitive adhesive layer formed on one surface of the base material layer. The thickness of the release liner for protecting the adhesive surface is not included.

(Base material layer)
As the base material layer 12, the total thickness of the double-sided adhesive tape 10 can be 3 μm or more and less than 10 μm, and the thermal resistance value of the double-sided adhesive tape 10 at 80 ° C. is 2.00 [cm ² · K / As long as it can be less than W], the material and thickness thereof are not particularly limited. Examples of the material of the base material layer 12 include plastic materials, paper materials, fiber materials (woven fabric, non-woven fabric, etc.), metal materials, and the like. As a material of the base material layer 12, a plastic material is suitable. That is, as the base material layer 12, a plastic film can be suitably used.

  As such a plastic material (material of the plastic film), various engineering plastic materials can be suitably used. Specifically, as a plastic material, for example, polyester [polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polybutylene terephthalate (PBT), etc.], olefin resin [polyethylene (PE), polypropylene (PP), Olefin resins containing α-olefin as monomer component such as ethylene-propylene copolymer, ethylene-vinyl acetate copolymer (EVA)], polyethersulfone (PES) (polyethersulfone), polysulfone, polychlorinated Vinyl (PVC), polyphenylene sulfide (PPS), amide resins [polyamide (nylon), wholly aromatic polyamide (aramid), etc.], polyimide (PI), polyamideimide, polyetherimide (PEI), polyesterimide, methacrylate Rate resins [polymethyl methacrylate (PMMA), etc.], styrene resins [polystyrene, acrylonitrile-styrene copolymer (AS resin), acrylonitrile-butadiene-styrene copolymer (ABS resin), etc.], polycarbonate (PC), Polyacetal, polyarylene ether (such as polyphenylene ether), polyphenylene sulfide, polyarylate, polyaryl, polyurethanes, polyether ketones [polyether ether ketone (PEEK), polyether ketone ketone, etc.], polyacrylic acid esters (polyacrylic) Acid butyl, polyethyl acrylate, etc.) and epoxy resins. These materials (plastic materials) can be used alone or in combination of two or more.

  As the plastic material, polyester (particularly, polyethylene terephthalate) can be particularly preferably used from the viewpoint of thickness accuracy, tensile strength, workability, and the like. That is, a polyester film (in particular, a polyethylene terephthalate film) can be suitably used as the base material layer.

  In addition, the base material layer may have any form of a single layer or a laminate, and is not subject to structural restrictions. The thickness of the base material layer can be selected from the range of, for example, 1 μm or more and less than 10 μm (preferably 1.5 μm or more and less than 8 μm, more preferably 2 μm or more and less than 6 μm).

  In addition, the surface of the base material layer (particularly, the base material layer made of a plastic material) is a conventional surface treatment, for example, chromic acid treatment, in order to improve the adhesion with the pressure-sensitive adhesive layer formed on the base material layer. Oxidation treatment by chemical or physical methods such as ozone exposure, flame exposure, high-voltage impact exposure, ionizing radiation treatment, etc. may be applied, and coating treatment with a primer may be applied.

  Moreover, the base material layer may be colored. Examples of the coloring type include black and white. Moreover, as a coloring method, you may provide a black or white part on the surface of a base material layer by printing. In this case, the colored portion may be formed on one side of the base material layer, or may be formed on both sides. Moreover, you may contain a black or white pigment and dye in the inside of a base material layer. Here, “the base material layer is colored” is not only the case where a pigment or dye is contained inside the base material layer, but also a colored portion is formed (printed) on the surface of the base material layer. The case where it is done is also included. Thus, the design property can be imparted to the adhesive tape by coloring the base material layer.

  When forming the colored part on the surface of a base material layer by printing, the said colored part can be formed by apply | coating an ink composition, for example. Here, the colored part may be formed by applying the ink composition once, or the colored part may be formed by applying twice or more. In addition, from the viewpoint of enhancing the adhesion between the uncolored portion and the colored portion in the base material layer, the region that is in contact with the colored portion on the surface of the uncolored portion is subjected to an undercoating treatment such as a corona treatment or a primer. Various processes such as these may be performed.

(Adhesive layer)
The pressure-sensitive adhesive forming the pressure-sensitive adhesive layer is not particularly limited. For example, acrylic pressure-sensitive adhesive, rubber pressure-sensitive adhesive, silicone pressure-sensitive adhesive, urethane pressure-sensitive adhesive, polyester pressure-sensitive adhesive, styrene-diene block copolymer system It can be appropriately selected from known pressure-sensitive adhesives such as pressure-sensitive adhesives, vinyl alkyl ether pressure-sensitive adhesives, polyamide-based pressure-sensitive adhesives, fluorine-based pressure-sensitive adhesives, creep property-improving pressure-sensitive adhesives, and radiation curable pressure-sensitive adhesives. An adhesive can be used individually or in combination of 2 or more types.

As the pressure-sensitive adhesive, an acrylic pressure-sensitive adhesive can be particularly preferably used from the viewpoint of reliability of adhesion. The acrylic pressure-sensitive adhesive comprises an acrylic polymer as a pressure-sensitive adhesive component (base polymer) or main ingredient, and a crosslinking agent, a tackifier, a softener, a plasticizer, a filler, an anti-aging agent, and a colorant as necessary. Appropriate additives such as are included. The acrylic polymer is composed of a monomer (copolymerizable monomer) that has (meth) acrylic acid alkyl ester as a main monomer component and can be copolymerized with the (meth) alkyl ester as necessary. Body). Examples of the (meth) acrylic acid alkyl ester include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, (meth ) Isobutyl acrylate, s-butyl (meth) acrylate, t-butyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, octyl (meth) acrylate , 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, nonyl (meth) acrylate, isononyl (meth) acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, (meth) acrylic acid Undecyl, dodecyl (meth) acrylate, tridecyl (meth) acrylate, Such as tetradecyl (meth) acrylate, pentadecyl (meth) acrylate, hexadecyl (meth) acrylate, heptadecyl (meth) acrylate, octadecyl (meth) acrylate, nonadecyl (meth) acrylate, eicosyl (meth) acrylate ( And (meth) acrylic acid C _1-20 alkyl ester [preferably (meth) acrylic acid C _4-18 alkyl (straight or branched alkyl) ester]. The (meth) acrylic acid alkyl ester can be appropriately selected according to the intended tackiness and the like. The (meth) acrylic acid alkyl ester can be used alone or in combination of two or more.

  Examples of the copolymerizable monomer include (meth) acrylic acid, itaconic acid, maleic acid, fumaric acid, crotonic acid, isocrotonic acid and other carboxyl group-containing monomers or anhydrides thereof; vinyl sulfonic acid Sulfonic acid group-containing monomers such as sodium; aromatic vinyl compounds such as styrene and substituted styrene; cyano group-containing monomers such as acrylonitrile; olefins such as ethylene, propylene and butadiene; vinyl esters such as vinyl acetate; Amide group-containing monomers such as vinyl chloride; acrylamide, methacrylamide, N-vinylpyrrolidone, N, N-dimethyl (meth) acrylamide; Hydroxyl group-containing monomers such as hydroxyalkyl (meth) acrylate and glycerol dimethacrylate Aminoethyl (meth) acrylate, (meth ) Amino group-containing monomers such as acryloylmorpholine; Imido group-containing monomers such as cyclohexylmaleimide and isopropylmaleimide; Epoxy group-containing monomers such as glycidyl (meth) acrylate and methyl glycidyl (meth) acrylate; 2 -In addition to isocyanate group-containing monomers such as methacryloyloxyethyl isocyanate, triethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, ethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, neo Pentyl glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate Dipentaerythritol hexa (meth) acrylate, a polyfunctional copolymerizable monomer (polyfunctional monomer) such as divinylbenzene, and the like. A copolymerizable monomer can be used individually or in combination of 2 or more types. As the copolymerizable monomer, a modifying monomer having a functional group such as a carboxyl group can be suitably used.

  The acrylic polymer can be prepared by a conventional polymerization method such as a solution polymerization method, an emulsion polymerization method, or an ultraviolet irradiation polymerization method.

  The thickness of each pressure-sensitive adhesive layer can be appropriately selected in consideration of the pressure-sensitive adhesive properties and the total thickness of the double-sided adhesive tape or sheet. The thickness of each pressure-sensitive adhesive layer can be selected from the range of, for example, 0.5 μm or more and less than 4 μm (preferably 1 μm or more and less than 3 μm, more preferably 1.2 μm or more and less than 2 μm). In addition, in the two pressure-sensitive adhesive layers formed on both surfaces of the base material layer, the thickness of each pressure-sensitive adhesive layer (the pressure-sensitive adhesive layer on the front surface side and the pressure-sensitive adhesive layer on the back surface side) is not particularly defined, It can be appropriately selected depending on the case. Moreover, although the thickness of the two adhesive layers formed on both surfaces of the base material layer may be the same or different, the same or substantially the same thickness is often selected.

(Release liner)
In the double-sided adhesive tape or sheet according to the present embodiment, a release liner for protecting the adhesive surface of the adhesive layer can be provided until use. Such a release liner is not particularly defined and can be appropriately selected from known release liners. Specifically, as the release liner, for example, a plastic film having high peelability itself [eg, ethylene such as polyethylene (low density polyethylene, linear low density polyethylene, etc.), polypropylene, ethylene-propylene copolymer, etc. In addition to the α-olefin copolymer (block copolymer or random copolymer), it may be a release liner made of a polyolefin-based resin made of a mixture of these, a polyolefin-based film; a fluororesin film, etc.] A release liner having a configuration in which a release treatment layer is formed on the surface (one side or both sides) of various base material layers (base materials) can be suitably used.

  A plastic film is preferably used as the base material of the release liner, but paper (for example, Japanese paper, western paper, glassine paper, etc.), non-woven fabric or cloth, foam, metal foil, composite base material made of various base materials (for example, It may be a metal-deposited plastic film or the like. Although the thickness of a base material can be suitably selected according to the objective, generally it is about 10-500 micrometers. Examples of the material of the release liner base plastic film include polyesters such as polyethylene terephthalate; polyolefins such as polypropylene, polyethylene and ethylene-propylene copolymers; polyvinyl chloride; polyimides; thermoplastic resins such as polycarbonate. It is done. The plastic film may be either an unstretched film or a stretched (uniaxially stretched or biaxially stretched) film.

  The release treatment layer is a known or commonly used release treatment agent for forming the release treatment layer in the release liner (for example, a silicone release agent, a fluorine release agent, a long-chain alkyl release agent, etc.). Can be formed. The release treatment layer is a polyolefin film made of a polyolefin resin such as an ethylene-α-olefin copolymer such as polyethylene, polypropylene, or an ethylene-propylene copolymer; a fluororesin film; It may be formed by laminating or coating. In the release liner, the release treatment layer can be provided on one side or both sides of the substrate as described above.

  As the release liner, the deformation of the double-sided adhesive tape or sheet can be suppressed or prevented during the bonding operation (peeling operation of the release liner) by adjusting the peeling force to the pressure-sensitive adhesive layer to be 1 N / 50 mm or less. And workability can be improved. The release liner and its peeling force can be appropriately selected or adjusted according to the use and the like, and are not particularly limited.

  As the double-sided adhesive tape or sheet of the present embodiment, it may have a form of a laminated body in which sheet-like ones are laminated, and has a form of a wound body wound in a roll shape. Also good. For example, as a release liner, one long strip-shaped release liner whose both surfaces are release treatment surfaces is used, and one release treatment surface of the release liner is attached to one of the long strip-like double-sided adhesive tape or sheet. The adhesive layer of the pressure-sensitive adhesive layer is overlapped and laminated, and the other release treatment surface of the release liner is overlapped with the pressure-sensitive adhesive surface of the other pressure-sensitive adhesive layer and wound into a roll shape to be wound into a roll shape. A double-sided adhesive tape or sheet having a formed form can be produced. In addition, as the release liner, two long strip-shaped release liners whose only one surface is a release treatment surface are used, and one of the pressure-sensitive adhesive layers of the long-band double-sided adhesive tape or sheet is formed by one release liner. A double-sided adhesive tape or sheet having a form wound in a roll shape by protecting the pressure-sensitive adhesive surface and winding it in a roll shape with the other release liner protecting the pressure-sensitive adhesive surface of the other pressure-sensitive adhesive layer Can be produced.

  The length of the double-sided adhesive tape or sheet having a form wound in such a roll shape is not particularly limited as long as it is a long belt-like length, but is usually 5 m or more (preferably 10 m or more, more preferably Is 20 m or more).

  Hereinafter, examples according to the present invention will be described in more detail. In the following, “part” means part by weight, and “%” means weight%.

(Adhesive Preparation Example 1)
N-butyl acrylate: 97 parts, acrylic acid: 3 parts, 2-hydroxyethyl acrylate: 0.1 part, azobisisobutyronitrile: 0.2 part as a polymerization initiator, toluene and ethyl acetate In a mixed solution of [Toluene / ethyl acetate (weight ratio) = 1/1], solution polymerization was performed for 6 hours to obtain an acrylic polymer having a weight average molecular weight of 500,000. The acrylic polymer: 100 parts, a terpene-phenol resin (trade name “YS Polystar T 130” manufactured by Yasuhara Chemical Co., Ltd .; softening point: 130 ° C.): 30 parts and an isocyanate cross-linking agent (trade name “Coronate L” Japan) Polyurethane Kogyo Co., Ltd.): 2 parts was added, and the mixture was stirred and mixed uniformly to prepare a pressure-sensitive adhesive (pressure-sensitive adhesive composition; sometimes referred to as “pressure-sensitive adhesive A”). .

Example 1
As a base material layer, the pressure-sensitive adhesive having a thickness of 1.5 μm using the above-mentioned pressure-sensitive adhesive A on both sides of a polyester film (trade name “C660-2.0W” manufactured by Mitsubishi Chemical Polyester Co., Ltd .; thickness: 2 μm). Each layer was formed and the adhesive tape (double-sided adhesive tape) based on Example 1 whose total thickness was 5 micrometers was produced.

(Example 1 ')
As a base material layer, a pressure-sensitive adhesive layer having a thickness of 4 μm is formed on both sides of a polyester film (trade name “C660-2.0W” manufactured by Mitsubishi Chemical Polyester; thickness: 2 μm) using the above-mentioned pressure-sensitive adhesive A. Each was formed to prepare an adhesive tape (double-sided adhesive tape) having a total thickness of 10 μm.

(Comparative Example 1)
As a base material layer, a pressure-sensitive adhesive layer having a thickness of 13 μm is formed on both sides of a polyester film (trade name “K880-4.5W” manufactured by Mitsubishi Chemical Polyester; thickness: 4 μm) using the above-mentioned pressure-sensitive adhesive A. Each was formed to produce an adhesive tape (double-sided adhesive tape) having a total thickness of 30 μm.

(Comparative Example 2)
As a base material layer, a pressure-sensitive adhesive layer having a thickness of 44 μm is formed on both sides of a polyester film (trade name “Lumirror # 12” manufactured by Toray Industries Inc .; thickness: 12 μm) using the above-mentioned pressure-sensitive adhesive A, respectively. An adhesive tape (double-sided adhesive tape) having a total thickness of 100 μm was produced.

(Example 2)
Black by gravure printing using a black ink composition containing carbon black as a black color material on one side of a polyester film (trade name “C660-2.0W” manufactured by Mitsubishi Chemical Polyester; thickness: 2 μm) A layer (total thickness of the black layer: 1.5 μm) was formed, and a base material layer having a thickness of 3.5 μm was produced. A pressure-sensitive adhesive layer having a thickness of 1.5 μm is formed on the other surface of the base material layer (the surface opposite to the surface on which the black layer is printed) using the above-mentioned pressure-sensitive adhesive A. Produced an adhesive tape (single-sided adhesive tape) according to Example 2 having a thickness of 5 μm. In the adhesive tape which concerns on Example 2, the base material layer is comprised by the polyester film and the black layer (printing layer). That is, the base material layer of the adhesive tape according to Example 2 is colored black.

(Example 3)
One side of a polyester film (trade name “C660-2.0W” manufactured by Mitsubishi Chemical Polyester; thickness: 2 μm) is white by gravure printing using a white ink composition containing titanium oxide as a white color material. A layer (total thickness of the white layer: 1.5 μm) was formed, and a base material layer having a thickness of 3.5 μm was produced. A pressure-sensitive adhesive layer having a thickness of 1.5 μm is formed on the other surface (surface opposite to the surface on which the white layer is printed) of this base material layer using the above-mentioned pressure-sensitive adhesive A, and the total thickness Produced an adhesive tape (single-sided adhesive tape) according to Example 3 having a thickness of 5 μm. In the adhesive tape which concerns on Example 3, the base material layer is comprised by the polyester film and the white layer (printing layer). That is, the base material layer of the adhesive tape according to Example 3 is colored white.

(Evaluation)
About the double-sided adhesive tape which concerns on Examples 1-3 and Comparative Examples 1-2, the thermal resistance in 80 degreeC was measured. The measurement was performed using the thermal characteristic evaluation apparatus shown in FIG. FIG. 2A is a schematic front view showing an apparatus used when measuring thermal resistance in the embodiment, and FIG. 2B is a schematic side view of the apparatus shown in FIG.

  Specifically, a double-sided adhesive tape (20 mm × 20 mm) S between a pair of rods L made of aluminum (A5052, thermal conductivity: 140 W / m · K) formed so as to be a cube having a side of 20 mm. And a pair of rods L were bonded with a double-sided adhesive tape S.

  And it arrange | positioned between the heat generating body (heater block) H and the heat radiating body (cooling base board comprised so that a cooling water may circulate through the inside) C so that a pair of rod L may become up and down. Specifically, the heating element H is disposed on the upper rod L, and the radiator C is disposed below the lower rod L.

  At this time, the pair of rods L bonded with the double-sided adhesive tape S is located between a pair of pressure adjusting screws T penetrating the heating element and the heat radiating body. A load cell R is installed between the pressure adjusting screw T and the heating element H so that the pressure when the pressure adjusting screw T is tightened is measured. Was used as the pressure applied to the double-sided adhesive tape S.

  Further, three probes P (diameter 1 mm) of a contact displacement meter were installed so as to penetrate the lower rod L and the double-sided adhesive tape S from the radiator C side. At this time, the upper end portion of the probe P is in contact with the lower surface of the upper rod L, and the distance between the upper and lower rods L (the thickness of the double-sided adhesive tape S) can be measured.

  A temperature sensor D was attached to the heating element H and the upper and lower rods L (see FIG. 2B). Specifically, the temperature sensor D was attached at one place on the heating element H and five places at intervals of 5 mm in the vertical direction of each rod L.

  First, the pressure adjusting screw T was tightened to apply pressure to the double-sided adhesive tape S, the temperature of the heating element H was set to 80 ° C., and 20 ° C. cooling water was circulated through the radiator C.

After the temperature of the heating element H and the upper and lower rods L is stabilized, the temperature of the upper and lower rods L is measured by each temperature sensor D, and passes through the double-sided adhesive tape S from the thermal conductivity and temperature gradient of the upper and lower rods L. The heat flux to be calculated was calculated, and the temperature at the interface between the upper and lower rods L and the double-sided adhesive tape S was calculated. And the total thermal resistance (cm < ² > * K / W) in the said pressure was computed using these. The pressure applied to the double-sided adhesive tape S was 250 kPa, and the total thermal resistance was measured.

  Table 1 shows the thickness of the base material layer, the total tape thickness, and the thermal resistance value in each of the adhesive tapes of Examples 1 to 3 and Comparative Examples 1 to 2. FIG. 3 is a graph showing the relationship between the total tape thickness and the thermal resistance value.

As shown in FIG. 3, there is a good correlation between the total tape thickness and the thermal resistance value, and an adhesive tape with a small thermal resistance value can be obtained by reducing the total tape thickness. Specifically, the total thickness of the tape may be less than 10 μm, and more preferably 6 μm or less. The pressure-sensitive adhesive layer may have a thickness of less than 3 μm. This further contributes to the thinning of parts and devices in which the double-sided adhesive tape is used. The double-sided adhesive tape according to Example 1 has a low thermal resistance value of 0.48 [cm ² · K / W], and can fix a plurality of components to each other while exhibiting good thermal conductivity. . Further, the single-sided adhesive tapes according to Examples 2 and 3 have a low thermal resistance value of 0.49 [cm ² · K / W], and are given design properties while exhibiting good thermal conductivity.

  The adhesive tape according to the present embodiment is configured to be usable in a temperature environment of 60 ° C. or higher. Thereby, for example, it is possible to apply to a product such as a portable device or a liquid crystal television which has a high demand for thinness and the temperature inside the apparatus tends to be high.

  In the adhesive tape according to the present embodiment, the pressure-sensitive adhesive layer contains less than 20 parts by weight of a thermally conductive filler per 100 parts by weight of the polymer main component constituting the pressure-sensitive adhesive layer. Here, the “polymer main component constituting the pressure-sensitive adhesive layer” means, for example, an acrylic polymer in the case of an acrylic pressure-sensitive adhesive, and a main polymer such as natural rubber or synthetic rubber in the case of a rubber pressure-sensitive adhesive. .

  The pressure-sensitive adhesive layer preferably contains less than 10 parts by weight (more preferably less than 5 parts by weight) of thermally conductive filler per 100 parts by weight of the polymer main component. Even more preferably, the pressure-sensitive adhesive layer may be substantially free of filler. “Substantially free” of the filler may be taken to mean a case where the filler is contained in such a small amount that it does not function. Generally, a filler contributes to a decrease in the adhesive strength of the pressure-sensitive adhesive layer. Then, the fall of adhesive force can be suppressed by reducing content of a filler. On the other hand, even if the filler content decreases, the thermal resistance value is low, so that good thermal conductivity can be exhibited.

  The present invention has been described based on the embodiments and examples. This embodiment is an exemplification, and it will be understood by those skilled in the art that various modifications can be made to combinations of the respective constituent elements and processing processes, and such modifications are also within the scope of the present invention. is there.

  10 double-sided adhesive tape, 12 substrate layer, 14, 16 adhesive layer, 18 release liner.

Claims (8)

A base material layer;
An adhesive layer provided on at least one surface of the base material layer;
Prepared,
The base material layer is colored,
The value of the thermal resistance at 80 ° C. is less than 2.00 [cm ² · K / W].
Adhesive tape characterized by that.   The adhesive tape according to claim 1, wherein the base material layer is a plastic film. The adhesive tape according to claim 1 or 2, wherein the value of thermal resistance at 80 ° C is less than 1.50 [cm ² · K / W].   The adhesive tape according to any one of claims 1 to 3, wherein the colored portion is formed on one side or both sides of the base material layer.   The adhesive tape according to claim 1, wherein the colored portion is black.   The adhesive tape according to any one of claims 1 to 5, which can be used in a temperature environment of 60 ° C or higher.   The said adhesive layer contains the heat conductive filler of less than 20 weight part per 100 weight part of polymer main components which comprise this adhesive layer, The any one of Claim 1 thru | or 6 characterized by the above-mentioned. Adhesive tape as described in 1.   The adhesive tape according to any one of claims 1 to 7, wherein the adhesive tape is used for bonding a heat-generating component and a heat conductive sheet used in a portable device or a thin television.

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