JP2022052983A - Heat-dissipation adhesive sheet and laminate - Google Patents

Abstract

To provide a heat-dissipation adhesive sheet which is particularly excellent in the thinness and heat-dissipation performance and also excellent in the bonding workability and anti-repulsion; and a laminate formed by bonding the heat-dissipation adhesive sheet and a heat dissipation sheet together.SOLUTION: A heat-dissipation adhesive sheet has: a heat-radiating layer (B) containing a heat-radiating filler on one face side of a metal substrate (A); and an adhesive layer (C) on the other face side of the metal substrate (A). The heat-radiating layer (B) is in direct contact with the one face of the metal substrate (A). The thickness of the metal substrate (A) is 10 μm to 38 μm. The thermal emittance of the sheet is 80% or more.SELECTED DRAWING: None

Description

The present invention relates to a heat-dissipating adhesive sheet that can be attached to, for example, a heat-generating component and used. In particular, the present invention relates to a heat-dissipating adhesive sheet suitable for laminating with a heat-dissipating sheet such as a graphite sheet, a graphene sheet, or a silicon rubber sheet.

In recent years, various heat-generating members are mounted on electronic devices such as information display devices. Examples of the heat generating member include electronic devices such as game devices, smartphones, and GPUs (Graphics Processing Units) in the case of personal computers.

In general, the heat generating member is often arranged without a gap in a limited space inside an electronic device. Therefore, the heat generated from the heat generating member tends to be trapped inside the electronic device, and a part of the electronic device is locally heated to a high temperature, which may cause a failure or malfunction of the electronic device. In particular, in the GPU of the above-mentioned device, the temperature rise of the above-mentioned device may cause a malfunction or a failure.

As a method of preventing the inside of an electronic device from becoming hot by efficiently dissipating the heat generated from the heat generating member, for example, there is a method of attaching a heat radiating adhesive sheet to or near the heat generating component. As the heat-dissipating pressure-sensitive adhesive sheet, for example, a heat-dissipating pressure-sensitive adhesive sheet having a predetermined heat-conducting pressure-sensitive adhesive layer on at least one surface of a heat-conducting layer such as copper foil or aluminum foil is known (see, for example, Patent Document 1).

Further, when a graphite sheet, graphene sheet, silicon rubber sheet or the like is used as a heat dissipation sheet, the graphite sheet or the like is fragile and easily damaged, and in order to prevent performance deterioration due to the damage, the above-mentioned aluminum foil is applied to the surface of the graphite sheet or the like. A heat radiating sheet provided with a heat conductive layer such as graphite or copper foil is used.

Japanese Unexamined Patent Publication No. 2017-8262

As the amount of heat generated from electronic devices tends to increase, the heat-dissipating adhesive sheet and the heat-dissipating sheet are required to be able to dissipate heat even more effectively.

With the miniaturization of the space for arranging the heat-generating member, the heat-dissipating adhesive sheet attached to the heat-generating member is required to be thin and have excellent heat-dissipating properties. In addition, if the heat-dissipating adhesive sheet is wrinkled or broken, or if it floats or peels off between the heat-dissipating adhesive sheet and the heat-generating member, and air bubbles are mixed in at the bonding interface, heat is conducted from the heat-dissipating member to the heat-dissipating adhesive sheet. However, it becomes difficult to obtain a sufficient heat dissipation effect due to a decrease in the heat radiation function of the heat dissipation adhesive sheet. Therefore, the heat-dissipating adhesive sheet is required to have excellent sticking workability and resilience resistance.

Similarly, the heat dissipation sheet is also required to be thin and have excellent heat dissipation. However, when the heat dissipation adhesive sheet is attached to the heat dissipation sheet in order to improve the heat dissipation of the heat dissipation sheet, if the heat dissipation adhesive sheet is thick, Although the heat dissipation can be improved, there is a problem that the requirement for thinning the heat dissipation sheet cannot be achieved because the total thickness of the heat dissipation sheet with the heat dissipation adhesive sheet becomes large. Therefore, there is a demand for a heat-dissipating adhesive sheet that is thin and has excellent heat-dissipating properties, even for application to a heat-dissipating sheet. In addition, when the heat-dissipating adhesive sheet is attached to the heat-dissipating adhesive sheet, wrinkles or breaks may occur in the heat-dissipating adhesive sheet, floating or peeling may occur between the heat-dissipating adhesive sheet and the heat-dissipating sheet, and air bubbles may be mixed at the bonding interface. Depending on the laminated structure, the heat dissipation of the heat dissipation sheet cannot be sufficiently exhibited, and there is a problem that the desired heat dissipation performance cannot be achieved. Therefore, there is a demand for a heat-dissipating adhesive sheet that is excellent not only in high heat-dissipating characteristics but also in sticking workability and resilience resistance in the application of bonding to a heat-dissipating sheet.

The present invention provides a heat-dissipating adhesive sheet that is thin and has particularly excellent heat dissipation performance, and is also excellent in sticking workability and resilience resistance, and a laminate obtained by laminating the heat-dissipating adhesive sheet and the heat-dissipating sheet.

The present invention that solves the above problems has a thermal radiation layer (B) containing a thermal radiation filler on one surface side of the metal substrate (A), and the thermal radiation layer (B) is the metal substrate. A radiant pressure-sensitive adhesive sheet that is in direct contact with one surface of (A) and has an adhesive layer (C) on the other surface side of the metal substrate (A), and is the thickness of the metal substrate (A). The present invention relates to a heat-dissipating adhesive sheet having a temperature of 10 μm to 38 μm and a heat radiation coefficient of the sheet of 80% or more.

Although the heat-dissipating adhesive sheet of the present invention is thin, it has particularly excellent heat-dissipating performance, and is also excellent in resilience resistance and sticking workability when it is attached to an adherend. Further, since the heat-dissipating adhesive sheet of the present invention is excellent in sticking workability and resilience resistance when it is bonded to a heat-dissipating sheet such as a graphite sheet, it can be sufficiently adhered to the heat-dissipating sheet and adhered to the heat-dissipating sheet. It is possible to further improve the heat dissipation of the heat dissipation sheet while suppressing the increase in thickness due to the bonding of the sheets.

I. Heat-dissipating adhesive sheet The heat-dissipating adhesive sheet of the present invention has a heat radiating layer (B) containing a heat-radiating filler on one surface side of the metal substrate (A), and the other surface of the metal substrate (A). It has a pressure-sensitive adhesive layer (C) on the side, and the heat radiating layer (B) is in direct contact with one surface of the metal base material (A), and the metal base material (A) is 10 μm. It is characterized in that the heat radiation rate of the sheet is 80% or more while keeping it within the range of about 38 μm.

Like the heat-dissipating adhesive sheet of the present invention, the present inventors have set the thermal conductivity of the entire sheet within a predetermined range, and by having a thick metal base material, they can utilize the high thermal conductivity of the metal base material. By having a heat radiation layer (B) having a high heat radiation rate that is in direct contact with one surface of the metal substrate (A), heat conduction and heat radiation from the adherend are promoted, so that the material is thin yet thin. We have found that it is a heat-dissipating adhesive sheet having excellent heat-dissipating performance, and came up with the above-mentioned invention. In addition, the heat-dissipating adhesive sheet of the present invention can exhibit excellent heat-dissipating performance due to its thinness and high heat radiation and heat conduction by having the above-mentioned layer structure, and at the same time, it can be attached to an adherend and has repulsion resistance. It was possible to fulfill the request of.

The heat radiating adhesive sheet of the present invention may have a heat emissivity of 80% or more, preferably 85% or more, more preferably 90% or more, and particularly preferably 95% or more. When the heat emissivity of the heat radiating adhesive sheet of the present invention is within the above range, high heat radiating property can be realized. The higher the heat emissivity of the heat-dissipating adhesive sheet of the present invention is, the more preferable it is, and the upper limit thereof can be 100% or 99%. In the present specification, the "heat emissivity of the sheet" means the heat emissivity of the heat-dissipating adhesive sheet.

The heat emissivity of the heat-dissipating adhesive sheet means the heat emissivity measured on the surface of the heat-dissipating adhesive sheet on the heat-radiating layer (B) side. In the present specification, the "surface of the heat radiating adhesive sheet on the heat radiating layer (B) side" means that the heat radiating layer (B) is arranged with respect to the metal substrate in the thickness direction of the heat radiating adhesive sheet of the present invention. Refers to the surface on the other side.
For the heat emissivity of the heat radiating adhesive sheet, the heat radiating adhesive sheet cut into a size of 40 mm in width × 50 mm in length is attached to an aluminum plate (40 mm in width × 50 mm in length, 0.7 mm in thickness), and the heat radiating layer ( Using the far-infrared spectral emissivity / FT-IR method with the surface on the B) side as the measurement surface, the integrated measurement wavelength range can be measured at 4 μm to 20 μm and the measurement temperature can be measured at 50 ° C.

In the heat radiating adhesive sheet of the present invention, the lower limit of the maximum height roughness (Rz) of the surface on the heat radiating layer (B) side is preferably 3.8 μm or more, and more preferably 4.1 μm or more. It is preferable that the thickness is 4.5 μm or more in order to obtain a heat-dissipating adhesive sheet having even better heat-dissipating properties. On the other hand, in order to obtain a heat radiating adhesive sheet having even better heat dissipation while maintaining the adhesion (B) between the metal base material (A) and the heat radiating layer, the heat radiating layer of the heat radiating adhesive sheet is obtained. The upper limit of the maximum height roughness (Rz) of the surface on the (B) side is preferably 13 μm or less, more preferably 10.5 μm or less, and further excellently 9.5 μm or less. It is particularly preferable to obtain a heat-dissipating adhesive sheet having heat-dissipating properties.

Further, in the heat radiating adhesive sheet of the present invention, the lower limit of the arithmetic average roughness (Ra) of the surface on the heat radiating layer (B) side is preferably 0.2 μm or more, and preferably 0.5 μm or more. It is more preferable that the thickness is 0.6 μm or more in order to obtain a heat-dissipating adhesive sheet having even better heat-dissipating properties. On the other hand, in order to obtain a heat radiating adhesive sheet having even better heat dissipation while maintaining the adhesion (B) between the metal base material (A) and the heat radiating layer, the heat radiating layer of the heat radiating adhesive sheet is obtained. The upper limit of the arithmetic average roughness (Ra) of the surface on the (B) side is preferably 2.0 μm or less, more preferably 1.9 μm or less, and further excellently 1.6 μm or less. It is particularly preferable to obtain a heat-dissipating adhesive sheet having a heat-dissipating property.

The maximum height roughness (Rz) and arithmetic average roughness (Ra) of the surface of the heat radiation adhesive sheet on the heat radiation layer (B) side refer to the values specified in JIS B0601: 2013, and are referred to as HANDYSURF + manufactured by Tokyo Precision Co., Ltd. Using, surface measurement was performed on any three points (each 50 μm in length × 50 μm in width) on the surface of the heat radiation adhesive sheet on the heat radiation layer (B) side, and the average value of the three points obtained by the measurement was heat radiation adhesion. Let it be the maximum height roughness (Rz) and the arithmetic mean roughness (Ra) of the surface of the sheet on the heat radiation layer (B) side.

The total thickness of the heat-dissipating adhesive sheet of the present invention is preferably 13 μm or more and 49 μm or less, preferably 15 μm or more and 40 μm or less, 18 μm or more and 35 μm or less, and 20 μm or more and 30 μm or less. By setting the total thickness of the heat-dissipating adhesive sheet of the present invention within the above range, both thinness and heat dissipation can be achieved, and sticking workability and resilience can be improved. The total thickness of the heat-dissipating adhesive sheet does not include the thickness of the release liner described later.

[Metal base material (A)]
The metal base material (A) in the heat-dissipating adhesive sheet of the present invention has a thickness in the range of 10 μm to 38 μm. From the viewpoint of promoting heat conduction and heat radiation from the adherend by utilizing heat conduction by the metal base material, the thickness of the metal base material (A) may be 10 μm or more, preferably 12 μm or more. , 15 μm or more is particularly preferable for obtaining further excellent heat dissipation and workability for attaching the heat dissipation adhesive sheet to, for example, a curved surface portion of a heat generating component. On the other hand, in order to obtain a heat-dissipating adhesive sheet that has excellent heat-dissipating properties, for example, excellent sticking workability to curved surfaces of heat-generating parts, and is less likely to cause peeling due to repulsive force of the curved surfaces, etc., the metal substrate (A) is used. The thickness may be 38 μm or less, more preferably 30 μm or less, and 25 μm or less is a heat-dissipating adhesive sheet having even better heat dissipation, sticking workability and resilience. It is particularly preferable to obtain.

The metal base material (A) is not particularly limited as long as it is a foil made of a desired metal material, and examples thereof include copper foil, aluminum foil, nickel foil, and stainless steel foil. Of these, copper foil is most preferable because it has excellent thermal conductivity.

The copper foil may be an electrolytic copper foil or a rolled copper foil, but an electrolytic copper foil is preferable from the viewpoint of adhesive strength when the heat-dissipating adhesive sheet is used.

As the base material made of the electrolytic copper foil, a base material made of hard copper can be generally used, and for example, it can be produced by precipitating copper on an electrode by electrolysis from an aqueous solution of copper sulfate.

As the metal base material (A), it is preferable to use one that has been subjected to a rust preventive treatment. Examples of the rust preventive treatment include an organic rust preventive treatment and an inorganic rust preventive treatment, and an inorganic rust preventive treatment by chromate treatment is preferable.

The metal substrate (A) preferably has a thermal conductivity of 100 W / m · K or more, more preferably 150 W / m · K or more, and even more preferably 200 W / m · K or more. By using the metal base material (A) having the above-mentioned predetermined thermal conductivity, a heat-dissipating adhesive sheet having excellent heat-dissipating properties can be obtained. The upper limit of the thermal conductivity of the metal substrate (A) is not particularly limited, but may be 450 W / m · K or less. The thermal conductivity of the metal substrate can be measured by a laser flash method based on JIS R1611.

4. The lower limit of the maximum height roughness (Rz) of the surface of the metal substrate (A) on the thermal radiation layer side is preferably 0.6 μm or more, more preferably 0.7 μm or more. It is preferable that the thickness is 0 μm or more in order to obtain a heat-dissipating adhesive sheet having even better heat-dissipating properties. On the other hand, in addition to excellent heat dissipation, high heat dissipation is exhibited by forming a homogeneous heat radiation layer that is less likely to cause printing defects of the heat radiation layer on the metal substrate (A) and suppresses printing unevenness. Since it can be maintained, the upper limit of the maximum height roughness (Rz) of the surface of the metal substrate (A) on the heat radiating zone (B) side is preferably 12 μm or less, more preferably 11 μm or less. It is preferable that the thickness is 10.5 μm or less, which is particularly preferable for obtaining a heat-dissipating pressure-sensitive adhesive sheet having even better heat-dissipating properties. In addition, when the printing defect of the thermal radiation layer (B) occurs, the emissivity is likely to be lowered due to the printing unevenness, and the heat dissipation property is likely to be lowered accordingly.

The lower limit of the arithmetic mean roughness (Ra) of the surface of the metal substrate (A) on the thermal radiation zone side is preferably 0.1 μm or more, more preferably 0.3 μm or more, and more preferably 0.5 μm. The above is preferable in order to obtain a heat-dissipating adhesive sheet having even better heat-dissipating properties. On the other hand, in addition to excellent heat dissipation, high heat dissipation is exhibited by forming a homogeneous heat radiation layer that is less likely to cause printing defects of the heat radiation layer on the metal substrate (A) and suppresses printing unevenness. Since it can be maintained, the upper limit of the arithmetic surface roughness (Ra) of the surface of the metal substrate (A) on the heat radiating zone (B) side is preferably 2.0 μm or less, preferably 1.8 μm or less. It is more preferable, and it is particularly preferable that the thickness is 1.7 μm or less in order to obtain a heat-dissipating adhesive sheet having even better heat-dissipating properties.

The lower limit of the maximum height roughness (Rz) of the surface of the metal substrate (A) opposite to the thermal radiation layer is preferably 0.5 μm or more, more preferably 0.8 μm or more. , 1.0 μm or more is preferable in order to obtain more excellent adhesion between the metal base material (A) and the adhesive layer provided on the metal base material (A). On the other hand, the upper limit of the maximum height roughness (Rz) of the surface of the metal substrate (A) opposite to the thermal radiation layer is preferably 2.0 μm or less, and more preferably 1.7 μm or less. It is preferable that the thickness is 1.5 μm or less, which is particularly preferable for obtaining a heat-dissipating pressure-sensitive adhesive sheet having even better adhesiveness.

The lower limit of the arithmetic mean roughness (Ra) of the surface of the metal substrate (A) opposite to the thermal radiation layer is preferably 0.1 μm or more, more preferably 0.13 μm or more. It is preferable that the thickness is 0.15 μm or more in order to obtain more excellent adhesion between the metal base material (A) and the adhesive layer provided on the metal base material (A). On the other hand, the upper limit of the arithmetic mean roughness (Ra) of the surface of the metal substrate (A) opposite to the thermal radiation layer is preferably 1.0 μm or less, and more preferably 0.4 μm or less. It is preferable that the thickness is 0.35 μm or less, which is particularly preferable for obtaining a heat-dissipating pressure-sensitive adhesive sheet having even better adhesiveness. The surface of the metal substrate (A) opposite to the heat radiant layer is the surface of the metal substrate (A) on the pressure-sensitive adhesive layer (C) side.

The maximum height roughness (Rz) and arithmetic mean roughness (Ra) of the metal substrate (A) refer to the values specified in JIS B0601: 2013, and the surface of the metal substrate is surfaced using HANDYSURF + manufactured by Tokyo Seimitsu Co., Ltd. Surface measurement was performed on any three points (length 50 μm × width 50 μm, respectively), and the average value of the three points obtained by the measurement was used as the maximum height roughness (Rz) of (A) of the metal substrate and arithmetic. Let it be the average roughness (Ra). If the thermal radiation layer can be removed with a desired solvent, the thermal radiation layer can be removed with a solvent to expose the surface of the metal substrate on the thermal radiation layer side for measurement.

[Thermal radiation zone (B)]
The heat-dissipating pressure-sensitive adhesive sheet of the present invention has a structure in which the heat-radiating layer (B) containing the heat-radiating filler is provided on one surface side of the metal base material (A). Used as a material).
In the heat radiating adhesive sheet of the present invention, the heat radiating layer (B) is in direct contact with the one surface of the metal base material (A). The fact that the thermal radiation layer (B) is in direct contact with one of the above surfaces of the metal substrate (A) means that no other layer is interposed between the thermal radiation layer (B) and the metal substrate (A). .. That is, the thermal radiation layer (B) is directly formed on one surface of the metal substrate (A). By not providing another layer between the metal base material (A) and the heat radiating layer (B), it is thin and has excellent sticking workability to curved surfaces and the like, causing peeling due to the repulsive force of the curved surfaces and the like. A difficult heat dissipation adhesive sheet can be realized.
Above all, the thermal radiation layer (B) is preferably a printed layer directly printed on one surface of the metal substrate (A). The heat radiant layer (B) can be made thinner, can be made even thinner, has excellent sticking workability to curved surfaces, etc., and is a heat-dissipating adhesive sheet that does not easily peel off due to the repulsive force of the curved surface, etc. Can be realized.

The heat emissivity of the heat radiation layer (B) may be any size as long as the heat radiation adhesive sheet of the present invention can exhibit a predetermined heat radiation emissivity, and is preferably 80% or more, preferably 83% or more. Is preferable, and 85% or more is particularly preferable. Further, the higher the heat emissivity of the heat radiation layer (B) is, the more preferable it is, and the upper limit thereof can be 100% or 99%. By setting the heat radiation coefficient of the heat radiation layer (B) in the above range, the heat radiation rate of the entire heat radiation adhesive sheet can be increased by synergistic effect with the heat conductivity of the metal substrate.

The thickness of the heat radiant layer (B) is not particularly limited as long as it can exhibit the desired heat dissipation, but is preferably 2 μm or more, more preferably 3 μm or more, still more preferably 4 μm or more. Can be done. The thickness can be preferably 10 μm or less, more preferably 8 μm or less, still more preferably 6 μm or less. This is because when the heat radiant layer (B) is within the above range, it is easy to achieve both thinness and high heat dissipation.

The thermal radiant layer (B) is a layer containing at least a thermal radiant filler, and preferably contains at least a thermal radiant filler and a binder resin. The thermal radiation layer (B) is formed by a resin liquid in which a known thermal radiation filler is dispersed in a resin varnish.

The heat radioactive filler can be used alone or in combination of two or more.

As the heat radioactive filler, a known material having a heat radiation performance, in other words, a function of promoting heat absorption / radiation can be used, and it may be an organic filler or an inorganic filler.

Examples of the organic filler include garbon black, graphite, carbon fiber, melamine cyanurate, acrylic beads, urethane beads, silicon beads and the like. Of these, carbon black is preferable from the viewpoints of price, availability, and printability.

Specific examples of the inorganic filler include fillers made of inorganic materials such as alumina, titania, zirconia, ferrite, silica, zinc oxide, magnesium oxide, noble aluminum, silicon carbide, aluminum nitride, boron nitride, calcium carbonate, calcium phosphate, and talc. Can be mentioned. Among them, oxidation of a metal selected from the group consisting of aluminum (Al), titanium (Ti), magnesium (Mg), silicon (Si) and calcium (Ca) because of its high thermal radiation, availability and stability. It is preferable to contain at least one kind of substance, hydroxide or carbonate, and among these, at least one kind of metal oxide selected from the above group because of its excellent thermal radiation and thermal conductivity. It is more preferable to include the above.

The thermally radioactive filler may be surface-modified with a coupling agent or the like. For example, an inorganic filler surface-modified with a silane-based and / or titanate-based coupling agent or the like can be used.

The thermally radioactive filler preferably contains at least one of carbon black and an inorganic oxide, and preferably contains carbon black and one or more kinds of inorganic oxides. This is because the high thermal radioactivity of carbon black and the high thermal conductivity of inorganic oxides can be compatible with each other. When the thermally radioactive filler contains carbon black and one or more kinds of inorganic oxides, the mixing ratio of carbon black and the inorganic oxides is preferably 1: 3 to 10: 1 in terms of mass ratio. The ratio of 1: 2 to 8: 1 is more preferable for the reason of achieving both thermal radiation and thermal conductivity. As the inorganic oxide, among the above-mentioned materials for the inorganic filler, for example, metal oxides such as alumina, zinc oxide, magnesium oxide, and silica are preferably mentioned. Of these, alumina is preferable in that it improves the efficiency of heat conduction and heat radiation.

The thermally radioactive filler preferably has a small particle size in order to have uniform dispersibility and to improve printability with the metal substrate (A). For example, the volume average particle size of the heat radiation filler by the Coulter counter method is preferably 20 μm or less, and more preferably 10 μm or less. The lower limit of the volume average particle size is preferably 0.1 μm from the viewpoint of workability and availability.

The content of the heat-radiating filler in the heat-radiating layer (B) may be an amount that can sufficiently coat the metal base material (A), for example, the total amount (100% by mass) of the heat-radiating layer (B). Of the above, 5% by mass or more is preferable, 10% by mass or more is preferable, 20% by mass or more is further preferable, and 30% by mass or more is more preferable. The content of the heat radiant filler is preferably 80% by mass or less, more preferably 75% by mass or less, preferably 70% by mass or less, and 65% by mass, based on the total amount (100% by mass) of the heat radiation layer (B). % Or less is more preferable, and 60% by mass or less is more preferable. By setting the content of the heat-radiating filler in the above range, the dispersibility of the heat-radiating filler is improved, the heat-radiating layer (B) exhibits high heat radiation, and the heat radiation rate of the heat-dissipating adhesive sheet is determined. This is because it can be in the range of. If the content of the heat-radiating filler is less than the above lower limit, a sufficient film cannot be formed, and the emissivity of the heat-dissipating adhesive sheet cannot be expected to be significantly improved. On the other hand, when the content of the thermal radiation filler exceeds the above upper limit, the printability of the thermal radiation layer (B) for the metal substrate (A) is rapidly deteriorated, and as a result, a uniform coating is not provided. It becomes difficult for the heat-dissipating adhesive sheet to exhibit a predetermined heat emissivity.

As the binder resin, a known resin used for ink can be applied, and one type may be used alone or two or more types may be used in combination. Examples of the binder resin include polyurethane resin, polyester resin, acrylic resin, vinyl chloride-vinyl acetate copolymer resin, nitrocellulose resin and the like. Among them, polyurethane resin or polyester resin is preferable because it has excellent adhesion, and polyurethane resin is more preferable because it has good flexibility and adhesion to the metal substrate (A).

The polyurethane resin is a resin that is obtained by a polycondensation reaction of a diisocyanate compound, a polyol compound, a low molecular weight chain extender and the like, and has a large number of urethane bonds in the molecule and is rich in flexibility and elasticity. The polyurethane resin used as the binder resin preferably has a weight average molecular weight in the range of 1,000 to 500,000, more preferably in the range of 3,000 to 300,000, and even more preferably. Is preferably in the range of 20,000 to 100,000. The weight average molecular weight of the polyurethane resin can be measured by the method for measuring the weight average molecular weight described in the section [Adhesive Layer (C)] described later.

Examples of the diisocyanate compound for forming the polyurethane resin include methylene diisocyanate, isopropylene diisocyanate, butane-1,4-diisocyanate, hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, and carboxyl groups of dimer acid. Chain aliphatic diisocyanate such as dimerge diisocyanate substituted with isocyanate group; cyclohexane-1,4-diisocyanate, isophorone diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, 1,3-di (isocyanatemethyl) cyclohexane, methylcyclohexanediisocyanate Cyclic aliphatic diisocyanates such as; dialkyldiphenylmethane diisocyanates such as 4,4'-diphenyldimethylmethane diisocyanate, tetraalkyldiphenylmethane diisocyanates such as 4,4'-diphenyltetramethylmethane diisocyanate, 1,5-naphthylene diisocyanate, 4,4. '-Diphenylmethane diisocyanate, 4,4'-diphenyldimethylmethane diisocyanate, 4,4'-dibenzylisocyanate, 1,3-phenylenediocyanate, 1,4-phenylenediocyanate, tolylene diisocyanate, xylylene diisocyanate, m-tetramethyl Aromatic diisocyanates such as xylylene diisocyanate; amino acid diisocyanates such as lysine diisocyanates and the like can be mentioned. The above polyisocyanate compounds including these diisocyanate compounds are used alone or in combination of two or more.

Examples of the polyol compound for forming the polyurethane resin include polyether polyols, polyester polyols, polycarbonate polyols, polybutadiene polyols and the like. Examples of the polyether polyols include polyethylene glycol obtained by ring-opening polymerization of ethylene oxide, propylene oxide and tetrahydrofuran, polypropylene glycol, polyoxytetramethylene ether glycol and the like. Examples of polyester polyols include ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, neopentyl glycol, and pentanediol. Saturated or unsaturated low molecular weight glycols such as 3-methyl-1,5-pentanediol, 1,6-hexanediol, octanediol, 1,4-butindiol, dipropylene glycol, bisphenol A, hydrogenated bisphenol A, etc. And adipic acid, maleic acid, fumaric acid, phthalic anhydride, isophthalic acid, terephthalic acid, succinic acid, oxalic acid, malonic acid, glutaric acid, pimelic acid, azelaic acid, sebacic acid, suberic acid and other dibasic acids or these. Examples thereof include compounds obtained by dehydration condensation of the acid anhydride or the like corresponding to the above.

On the other hand, when the binder resin is not a polyurethane resin, for example, when it is an acrylic resin or a polyester resin, it is preferable that the binder resin has the following weight average molecular weight. In the case of the acrylic resin, the weight average molecular weight is preferably in the range of 1,000 to 500,000, more preferably in the range of 2,000 to 300,000, and further preferably in the range of 3,. It is preferably 000 to 200,000. In the case of the polyester resin, the weight average molecular weight is preferably 200 to 100,000, more preferably 500 to 80,000, still more preferably in the range of 1,000 to 40,000. It is preferable to have. The weight average molecular weight of the acrylic resin and the polyester resin can be measured by the method for measuring the weight average molecular weight described in the section [Adhesive Layer (C)] described later.

In addition to the above-mentioned thermal radiation filler and binder resin, the thermal radiation layer (B) can contain known materials used in general-purpose ink compositions. Known materials include, for example, blocking prevention of dispersants such as cellulose-based resins, various isocyanate-based curing agents, polyethylene wax (PE wax), fatty acid amides, fatty acid esters, and organic compound-based blocking inhibitors such as higher fatty acids. Agents and the like can be mentioned.

[Adhesive layer (C)]
The pressure-sensitive adhesive layer (C) in the present invention is arranged on the surface of the metal base material (A) opposite to the heat radiation layer (B) side, and the heat-dissipating pressure-sensitive adhesive sheet and the adherend are bonded to each other. It is a layer.

The pressure-sensitive adhesive layer (C) can be formed by using a conventionally known pressure-sensitive adhesive. The pressure-sensitive adhesive component contained in the pressure-sensitive adhesive is not particularly limited, and for example, an acrylic pressure-sensitive adhesive composition, a rubber-based pressure-sensitive adhesive composition, a silicone-based pressure-sensitive adhesive composition, a urethane-based pressure-sensitive adhesive composition, and a polyester-based pressure-sensitive adhesive composition. , Styrene-diene block copolymerized adhesive, vinyl alkyl ether adhesive composition, polyamide adhesive composition, fluorine adhesive composition, creep property improved adhesive composition, radiation curable adhesive A known pressure-sensitive adhesive composition such as a composition can be appropriately selected and used. The pressure-sensitive adhesive component can be used alone or in combination of two or more.

Above all, it is preferable to include an acrylic pressure-sensitive adhesive composition as a pressure-sensitive adhesive component, and it is preferable that the acrylic pressure-sensitive adhesive composition contains at least a (meth) acrylic polymer (acrylic copolymer) as a base polymer.

The (meth) acrylic polymer is a polymer containing a (meth) acrylic acid alkyl ester monomer as a main component, and is a monomer capable of copolymerizing with the (meth) alkyl acid alkyl ester monomer, if necessary. Prepared by using (copolymerizable monomer). The acrylic polymer may be a homopolymer or a copolymer.

Examples of the (meth) acrylic acid alkyl ester constituting the (meth) acrylic polymer include methyl (meth) acrylic acid, ethyl (meth) acrylic acid, propyl (meth) acrylic acid, and isopropyl (meth) acrylic acid. N-butyl (meth) acrylate, isobutyl (meth) acrylate, s-butyl (meth) acrylate, t-butyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, (meth) Heptyl acrylate, (meth) octyl acrylate, (meth) 2-ethylhexyl acrylate, (meth) isooctyl acrylate, (meth) nonyl acrylate, (meth) isononyl acrylate, (meth) decyl acrylate, (meth) ) Isodecyl acrylate, (meth) undecyl acrylate, (meth) dodecyl acrylate, (meth) tridecyl acrylate, (meth) tetradecyl acrylate, (meth) pentadecyl acrylate, (meth) hexadecyl acrylate, (meth) Examples thereof include (meth) acrylic acid C1-20 alkyl esters such as heptadecyl acrylate, octadecyl (meth) acrylate, nonadecil (meth) acrylate, and eicocil (meth) acrylate, preferably (meth) acrylate C4-18. Acrylic (linear or branched alkyl) ester. The (meth) acrylic acid alkyl ester can be appropriately selected depending on the desired adhesiveness and the like. The (meth) acrylic acid alkyl ester can be used alone or in combination of two or more. Above all, as the (meth) acrylic acid alkyl ester, it is preferable to contain butyl acrylate in an amount of 30% or more in the total amount of the monomers constituting the (meth) acrylic polymer because it is excellent in adhesiveness and heat resistance.

Examples of the copolymerizable monomer copolymerizable with the above (meth) alkyl ester include carboxyl groups such as (meth) acrylic acid, itaconic acid, maleic acid, fumaric acid, crotonic acid, and isocrotonic acid. Containing monomer or its anhydride; Sulphonic acid group-containing monomer such as sodium vinyl sulfonate; Aromatic vinyl compound such as styrene and substituted styrene; Cyano group-containing monomer such as acrylonitrile; Ethylene, propylene, butadiene and the like Olefins; Vinyl esters such as vinyl acetate; Vinyl chloride; Amido group-containing monomers such as acrylamide, metaacrylamide, N-vinylpyrrolidone, N, N-dimethyl (meth) acrylamide; hydroxyalkyl (meth) acrylate. , A hydroxyl group-containing monomers such as glycerin dimethacrylate; amino group-containing monomers such as (meth) aminoethyl acrylate, (meth) acryloylmorpholine; and imide group-containing monomers such as cyclohexylmaleimide and isopropylmaleimide; Epoxy group-containing monomers such as glycidyl acrylate and methyl glycidyl (meth) acrylate; isocyanate group-containing monomers such as 2-methacryloyloxyethyl isocyanate, as well as triethylene glycol di (meth) acrylate and diethylene glycol di. (Meta) acrylate, ethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, trimerol propantri (meth) Examples thereof include polyfunctional copolymerizable monomers (polyfunctional monomers) such as acrylates, pentaerythritol tri (meth) acrylates, dipentaerythritol hexa (meth) acrylates, and divinylbenzene. The copolymerizable monomer may be used alone or in combination of two or more. As the copolymerizable monomer, a modifying monomer having a functional group such as a carboxyl group can be preferably used. Among them, it is preferable that acrylic acid is contained as a copolymerizable monomer in an amount of 0.5 to 4.0% in the total amount of the monomers constituting the polymer forming the (meth) acrylic polymer because of excellent adhesiveness and heat resistance. ..

The weight average molecular weight (Mw) of the (meth) acrylic polymer is preferably 300,000 or more, 500,000 or more, 600,000 or more, and the weight average molecular weight (Mw) is preferably 1.2 million or less, 1 million or more. Below, it is 900,000 or less. More specifically, the weight average molecular weight (Mw) of the (meth) acrylic polymer is preferably in the range of 300,000 to 1.2 million, more preferably in the range of 500,000 to 1,000,000, and 600,000 to 900,000. Within the range is more preferred. When the weight average molecular weight (Mw) of the (meth) acrylic polymer is in the above range, the pressure-sensitive adhesive layer has good adhesiveness to the metal substrate (A) and the adherend even if it is thin. And heat resistance can be exhibited.

The weight average molecular weight (Mw) can be measured by gel permeation chromatography (GPC). More specifically, it can be obtained by measuring with the following GPC measuring conditions by the polystyrene conversion value using "SC8020" manufactured by Tosoh Corporation as a GPC measuring device.
(GPC measurement conditions)
-Sample concentration: 0.5% by weight (tetrahydrofuran solution)
-Sample injection amount: 100 μL
-Eluent: Tetrahydrofuran (THF)
・ Flow velocity: 1.0 mL / min
-Column temperature (measurement temperature): 40 ° C
-Column: "TSKgel GMHR-H" manufactured by Tosoh Corporation
・ Detector: Differential refractometer

The weight average molecular weight (Mw) in the present specification is a value measured by the above method and conditions unless otherwise specified.

The (meth) 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.

From the viewpoint of improving the adhesive reliability, the (meth) acrylic pressure-sensitive adhesive composition preferably contains an additive, if necessary, in addition to the above-mentioned (meth) acrylic polymer. In other words, the pressure-sensitive adhesive layer (C) preferably contains an additive, if necessary. Examples of the additive include a cross-linking agent, a tackifier, a softener, a plasticizer, a filler, an antiaging agent, a coloring agent and the like.

The pressure-sensitive adhesive layer (C) preferably contains a pressure-sensitive adhesive in order to improve the pressure-sensitive adhesive strength. Since the pressure-sensitive adhesive layer (C) contains the pressure-sensitive adhesive resin, the tensile strength and the tensile breaking strength can be increased. Therefore, by appropriately adding the pressure-sensitive adhesive resin according to the (meth) acrylic polymer used, the present invention The tensile strength and tensile breaking strength of the heat-dissipating adhesive sheet of the present invention can be adjusted. Examples of the tackifier include rosin-based resins such as rosin and rosin ester compounds; terpene-based resins such as diterpene polymers and α-pinene-phenol copolymers; aliphatic (C5) and aromatic (C5) and aromatic (C5). Petroleum resins such as C9); In addition, styrene-based resins, phenol-based resins, xylene resins and the like can be mentioned. The tackifier may be used alone or in combination of two or more.

In particular, when the pressure-sensitive adhesive layer (C) contains a (meth) acrylic polymer containing n-butyl (meth) acrylate (in other words, n-butyl (meth) acrylate) as a main monomer component, rosin. It is preferable to mix and contain the based resin and the styrene based resin. This is because by using these two types of pressure-sensitive adhesives in combination, it becomes easier to achieve both the thinning of the pressure-sensitive adhesive layer (C) and the adhesive strength.

The pressure-sensitive adhesive layer (C) preferably contains a pressure-sensitive adhesive that is liquid at room temperature in order to increase the initial adhesive strength. Examples of the tackifier that is liquid at room temperature include liquid resins that are solid tackifiers at room temperature, and low molecular weight liquid rubbers such as process oils, polyester-based plasticizers, and polybutenes. In particular, terpene phenol resin is preferable. Commercially available products include YP-90L manufactured by Yasuhara Chemical Co., Ltd.

The tackifier is preferably contained in the range of 10 parts by mass to 70 parts by mass, and more preferably in the range of 20 parts by mass to 60 parts by mass with respect to 100 parts by mass of the (meth) acrylic polymer. By setting the amount of the pressure-sensitive adhesive in the above range, the adhesive strength of the pressure-sensitive adhesive layer can be improved.

The gel fraction of the pressure-sensitive adhesive layer (C) is not particularly limited, but is preferably in the range of 5 to 95% by mass. This is because even if the pressure-sensitive adhesive layer (C) is thin, sufficient adhesiveness is likely to be exhibited. Above all, the gel fraction of the pressure-sensitive adhesive layer (C) is more preferably in the range of 10 to 70% by mass, and further preferably in the range of 15 to 50% by mass.

The gel fraction is expressed as a percentage of the original mass by immersing the pressure-sensitive adhesive layer (C) after curing in toluene and measuring the mass of the insoluble component remaining after being left for 24 hours after drying.
Gel fraction (mass%) = [(mass of the pressure-sensitive adhesive layer after immersion in toluene) / (mass of the pressure-sensitive adhesive layer before immersion in toluene)] × 100

The storage elastic modulus of the pressure-sensitive adhesive layer (C) at 25 ° C. is preferably 1 × 10 ⁴ or more and 5 × 10 ⁵ Pa or less, and preferably 3 × 10 ⁴ or more and 1 × 10 ⁵ Pa or less. More preferred. By setting the storage elastic modulus of the pressure-sensitive adhesive layer (C) within the above range, it becomes easy to achieve both wettability (initial tack) and adhesiveness and processability even if it is a thin film.

The glass transition temperature of the pressure-sensitive adhesive layer (C) is preferably −10 ° C. or higher and 20 ° C. or lower, and more preferably −5 ° C. or higher and 10 ° C. or lower. By setting the glass transition temperature of the pressure-sensitive adhesive layer (C) within the above range, it becomes easy to achieve both wettability (initial tack) and adhesiveness and processability even if the film is thin.

The storage elastic modulus and the glass transition temperature of the pressure-sensitive adhesive layer (C) at 25 ° C. can be measured by a viscoelasticity tester. More specifically, it can be obtained by measuring under the following measurement conditions using a viscoelasticity tester (Ares 2kSTD) manufactured by TA Instruments Japan Co., Ltd. as a viscoelasticity tester.
・ Test piece thickness: 2 mm
・ Frequency: 1Hz
・ Compression load: 40-60g

In the present specification, the storage elastic modulus and the glass transition temperature of the pressure-sensitive adhesive layer (C) are values measured by the above method and conditions unless otherwise specified.

The pressure-sensitive adhesive layer (C) may contain the heat-radioactive filler, but it is preferable that the pressure-sensitive adhesive layer (C) does not contain the heat-radioactive filler. This is to achieve both thinness and adhesiveness. This is because if the thickness of the pressure-sensitive adhesive layer (C) is sufficiently thin, the pressure-sensitive adhesive layer (C) has almost no effect on the heat conductivity, and high heat conductivity and the heat dissipation associated therewith can be maintained.

The thickness of the pressure-sensitive adhesive layer (C) is preferably 1 μm or more and 2 μm or more and 2.5 μm or more, and the thickness is preferably 10 μm or less, 8 μm or less, and 6 μm or less. More specifically, the thickness of the pressure-sensitive adhesive layer (C) is preferably 2.5 μm or more and 6 μm or less, preferably 3 μm or more and 5.5 μm or less, and 3.5 μm or more and 5 μm or less. Is the most preferable. If the thickness of the pressure-sensitive adhesive layer (C) is too large, heat conduction from the adherend may be hindered by the pressure-sensitive adhesive layer (C), and heat dissipation may not be sufficiently exhibited. This is because, by setting it within the above range, it becomes easy to achieve both the adhesive strength, the thinness and the heat dissipation property of the heat dissipation adhesive sheet.

[others]
The heat-dissipating adhesive sheet of the present invention is, for example, a first step of printing an ink containing at least a heat-radiating filler and a binder resin on one surface of a metal base material (A) to form a heat-radiating layer (B), and peeling off. After forming the pressure-sensitive adhesive layer by applying the pressure-sensitive adhesive to the surface of the liner and drying it, it is necessary to bond the metal base material (A) to the surface opposite to the heat-radiating layer (B). The second step of applying the pressure-sensitive adhesive layer directly to the surface of the metal substrate (A) opposite to the heat radiating layer (B), drying it, and curing it as needed. It is preferable that the second step is the step of bonding the latter release liner to the metal base material (A) without damaging the coating head, among the above-mentioned steps.

Examples of the method of applying the adhesive to the surface of the release liner or the metal substrate (A) include a method using a roll coater, a die coater, or the like. The pressure-sensitive adhesive layer formed by the above-mentioned method is preferably heated at a temperature of about 50 ° C. to 120 ° C. and dried in order to remove the solvent contained in the pressure-sensitive adhesive layer.

The curing is preferably performed so that the gel fraction of the pressure-sensitive adhesive layer (C) is within the above range, and is preferably performed at a temperature of, for example, about 15 ° C to 50 ° C for about 48 hours to 168 hours.

Examples of the release liner include paper such as kraft paper, glassin paper, and high-quality paper; resin films such as polyethylene, polypropylene (OPP, CPP), and polyethylene terephthalate; laminated paper obtained by laminating the above paper and the above resin film, and the above paper. It is possible to use a product which has been sealed with clay, polyvinyl alcohol, or the like, and which has been subjected to a peeling treatment such as a silicone resin on one side or both sides.

Since the heat-dissipating adhesive sheet of the present invention obtained by the above method has excellent heat-dissipating properties, for example, by attaching it to a heat-generating member provided in various electronic devices, the heat generated from the heat-generating member can be efficiently dissipated. Can be

The heat-dissipating adhesive sheet may be used alone, but the heat-dissipating adhesive sheet and the heat-dissipating sheet such as a graphite sheet are laminated in order to achieve both excellent heat dissipation and thinness. It is preferable to use it in a state.

II. Laminated body The laminated body of the present invention has a heat radiating sheet on the surface of the heat radiating adhesive sheet described in the section of "I. Heat radiating adhesive sheet" having the pressure-sensitive adhesive layer (C).

According to the laminated body of the present invention, by laminating the above-mentioned heat-dissipating adhesive sheet with the heat-dissipating sheet, the heat-dissipating property of the heat-dissipating sheet is not impaired, and in addition to the heat-dissipating property of the heat-dissipating sheet, the heat-dissipating property of the heat-dissipating adhesive sheet is exhibited. Therefore, it is thin and can exhibit even better heat dissipation.

In particular, the laminate of the heat-dissipating adhesive sheet and the heat-dissipating sheet of the present invention can be suitably used as a heat-dissipating member as a substitute for the vapor chamber used in electronic devices. As a specific specification mode, there is a mode in which the above-mentioned laminate is attached for cooling a device such as a game device, a smartphone, or a GPU of a personal computer. Compared with the existing vapor chamber heat dissipation device, the laminate of the present invention is inexpensive, thin, and can exhibit the same or better heat dissipation performance.

As the heat radiating sheet of the present invention, a sheet having heat radiating property can be used, and examples thereof include a graphite sheet, a graphene sheet, and a silicon rubber sheet. Known sheets can be used as the graphite sheet, graphene sheet, and silicon rubber sheet.

The laminate of the present invention may have a heat-dissipating adhesive sheet on one side of the heat-dissipating sheet, or may have a heat-dissipating adhesive sheet on both sides of the heat-dissipating sheet.

The present disclosure is not limited to the above embodiment. The above embodiment is an example, and any object having substantially the same structure as the technical idea described in the claims of the present disclosure and having the same effect and effect is the present invention. Included in the technical scope of the disclosure.

Examples and comparative examples will be specifically described below.

[Preparation of thermal radiation ink]
(Urethane resin A)
Adipic acid / terephthalic acid = 50/50 acid component and a number average molecular weight obtained from 3-methyl-1,5-pentanediol in a four-polyol flask equipped with a stirrer, a thermometer, a reflux cooler and a nitrogen gas introduction tube (hereinafter referred to as “2”). 192.9 parts by mass of a polyester polyol (called Mn), 15.8 parts by mass of 1,4-butanediol, and 77.9 parts by mass of isophoron diisocyanate were charged and reacted at 90 ° C. for 15 hours under a nitrogen stream. Next, 11.0 parts by mass of isophorone diamine, 2.4 parts by mass of di-n-butylamine, and 700 parts by mass of methyl ethyl ketone were added and reacted at 50 ° C. for 4 hours under a stirring frame to obtain a resin solid content concentration of 30.0% by mass. A polyurethane resin A having a Gardner viscosity U (25 ° C.), an amine value = 0, and a weight average molecular weight of 30,000 was obtained.

(Polyester resin A)
233 parts by mass of ethyl acetate was added to 100 parts by mass of polyester-based thermoplastic resin "ER-1082" (nonvolatile content NV = 100%, weight average molecular weight 30,000) manufactured by Mitsubishi Chemical Corporation, and dissolved under stirring. A polyester resin A having a resin solid content concentration of 30.0% was obtained.

(Acrylic resin A)
Add 66 parts by mass of ethyl acetate to 100 parts by mass of acrylic resin "Acrydic A-804" (nonvolatile content NV = 50%) manufactured by DIC Corporation, dissolve under stirring, and resin solid content concentration is 30%. Acrylic resin A was obtained.

(Heat radiation ink A)
As a thermal radioactive filler, 20 parts by mass of carbon black manufactured by Mitsubishi Chemical Co., Ltd. (average particle size by the Coulter counter method: 0.5 μm) and synthetic silica "Silohobic 704" manufactured by Fuji Silicia Co., Ltd. (silane coupling treatment: Coulter) Using 5 parts by mass of an average particle size of 3.5 μm by the counter method and 2 parts by mass of a spherical silicone resin bead “Tospearl 2000B” (average particle size of 6 μm by the Coulter counter method) manufactured by Momentive Performance Materials. 2 parts by mass of BASF resin "Luwax AF29 Micropowder" (polyethylene fine powder wax), 1 part by mass of Lubrizol dispersant "Solspurs 24000GR", 55 parts by mass of the above polyurethane resin A (polyurethane resin) (nonvolatile content) NV = 30%), 13 parts by mass of methyl ethyl ketone, 9 parts by mass of ethyl acetate, 5 parts by mass of isopropyl alcohol, and 5 parts by mass of propylene glycol monomethyl ether were added and wet-dispersed with a sand mill for about 1 hour. Heat radiation by adding 5 parts by mass of Sumika Bayer Urethane's isocyanate-based curing agent "Sumijour N3300" (nonvolatile content NV = 40%) and 40 parts by mass of Showa Denko's diluent "Ethyl acetate". Ink A was prepared. The content of the heat-irradiating filler in the solid content of the heat-radiating ink A was 58% by mass.

(Heat radiation ink B)
As a thermal radioactive filler, 20 parts by mass of Alumina manufactured by Showa Denko KK (average particle size by Coulter counter method: 2 μm) and synthetic silica “Silohobic 704” manufactured by Fuji Silicia (silane coupling treatment: by Coulter counter method). Using 5 parts by mass of an average particle size of 3.5 μm) and 2 parts by mass of a spherical silicone resin bead “Tospearl 2000B” (average particle size of 6 μm by the Coulter counter method) manufactured by Momentive Performance Materials, manufactured by BASF. 2 parts by mass of the resin "Luwax AF29 Micropowder" (polyethylene fine powder wax, modifier), 1 part by mass of the dispersant "Solspurs 24000GR" manufactured by Lubrizol, and 55 parts by mass of the above polyester resin A (nonvolatile content NV). . = 30%), 13 parts by mass of methyl ethyl ketone, 9 parts by mass of ethyl acetate, 5 parts by mass of isopropyl alcohol, 5 parts by mass of propylene glycol monomethyl ether, and wet-dispersed with a sand mill for about 1 hour. Heat radiation ink B is prepared by adding 5 parts by mass of the isocyanate-based curing agent "Sumijour N3300" (nonvolatile content NV = 40%) manufactured by Showa Denko Corporation and 40 parts by mass of the diluent "Ethyl acetate" manufactured by Showa Denko Corporation. bottom. The content of the heat-irradiating filler in the solid content of the heat-radiating ink B was 58% by mass.

(Heat radiation ink C)
As a thermal radioactive filler, 20 parts by mass of silicon carbide particles manufactured by Shinano Electric Smelting Co., Ltd. (average particle diameter by Coulter counter method: 4 μm) and synthetic silica "Silohobic 704" manufactured by Fuji Silicia Co., Ltd. (silane coupling treatment: Coulter) 5 parts by mass of "Tospearl 2000B" (spherical silicone resin beads: average particle size of 6 μm by the Coulter counter method) manufactured by Momentive Performance Materials Co., Ltd. using 5 parts by mass with an average particle size of 3.5 μm by the counter method. , BASF resin "Luwax AF29 Micropowder" (polyethylene fine powder wax) by 2 parts by mass, Lubrizol dispersant "Solspurs 24000GR" by 1 part by mass, acrylic resin A by 55 parts by mass (nonvolatile content NV) . = 30%), 13 parts by mass of methyl ethyl ketone, 9 parts by mass of ethyl acetate, 5 parts by mass of isopropyl alcohol, 5 parts by mass of propylene glycol monomethyl ether, and wet-dispersed with a sand mill for about 1 hour. Prepare thermal radiation ink C by adding 5 parts by mass of an isocyanate-based curing agent "Coronate L-55E" (nonvolatile content NV = 40%) and 40 parts by mass of a diluent "ethyl acetate" manufactured by Showa Denko. did. The content of the heat-irradiating filler in the solid content of the heat-radiating ink C was 58% by mass.

(Heat radiation ink D)
As thermal radioactive fillers, 12 parts by mass of carbon black manufactured by Mitsubishi Chemical Co., Ltd. (average particle size by Coulter counter method: 0.5 μm) and alumina manufactured by Showa Denko Co., Ltd. (average particle size by Coulter counter method: 2 μm) are 8 parts. 5 parts by mass and 5 parts by mass of synthetic silica "Silohobic 704" manufactured by Fuji Silicia (silane coupling treatment: average particle size 3.5 μm by Coulter counter method) and "Tospearl 2000B" manufactured by Momentive Performance Materials. (Spherical silicone resin beads: average particle diameter of 6 μm by the Coulter counter method) by 2 parts by mass, BASF resin "Luwax AF29 Micropower" (polyethylene fine powder wax) by 2 parts by mass, dispersant manufactured by Lubrizol. Add 1 part by mass of "Sol Spurs 24000GR", 55 parts by mass of the above polyurethane resin A (polyurethane resin), 13 parts by mass of methyl ethyl ketone, 9 parts by mass of ethyl acetate, 5 parts by mass of isopropyl alcohol, and 5 parts by mass of propylene glycol monomethyl ether. Then, in a product wet-dispersed with a sand mill for about 1 hour, 5 parts by mass of the isocyanate-based curing agent "Sumijuru N3300" (nonvolatile content NV = 40%) manufactured by Sumika Bayer Urethane Co., Ltd., a diluent manufactured by Showa Denko Co., Ltd. 40 parts by mass of "ethyl acetate" was added to prepare a thermal radiation ink D. The content of the heat-irradiating filler in the solid content of the heat-radiating ink D was 58% by mass.

(Heat radiation ink E)
As a thermal radioactive filler, 5 parts by mass of carbon black manufactured by Mitsubishi Chemical Co., Ltd. (average particle size by the Coulter counter method: 0.5 μm) and synthetic silica "Silohobic 704" manufactured by Fuji Silicia Co., Ltd. (silane coupling treatment: Coulter) 5 parts by mass of "Tospearl 2000B" (spherical silicone resin beads: average particle size of 6 μm by the Coulter counter method) manufactured by Momentive Performance Materials Co., Ltd. using 5 parts by mass with an average particle size of 3.5 μm by the counter method. , BASF resin "Luwax AF29 Micropowder" (polyethylene fine powder wax) by 2 parts by mass, Lubrizol dispersant "Solspurs 24000GR" by 1 part by mass, polyurethane resin A (polyurethane resin) by 55 parts by mass (nonvolatile). (NV = 30%), 13 parts by mass of methyl ethyl ketone, 9 parts by mass of ethyl acetate, 5 parts by mass of isopropyl alcohol, 5 parts by mass of propylene glycol monomethyl ether, and wet-dispersed with a sand mill for about 1 hour. , Add 5 parts by mass of Sumika Bayer Urethane's isocyanate-based curing agent "Sumijour N3300" (nonvolatile content NV = 40%) and 40 parts by mass of Showa Denko's diluent "Ethyl acetate" to heat. Radiation ink E was prepared. The content of the heat-irradiating filler in the solid content of the heat-radiating ink E was 38% by mass.

(Heat radiation ink F)
As a thermal radioactive filler, 35 parts by mass of carbon black manufactured by Mitsubishi Chemical Co., Ltd. (average particle size by the Coulter counter method: 0.5 μm) and synthetic silica "Silohobic 704" manufactured by Fuji Silicia Co., Ltd. (silane coupling treatment: Coulter) 5 parts by mass of "Tospearl 2000B" (spherical silicone resin beads: average particle size of 6 μm by the Coulter counter method) manufactured by Momentive Performance Materials Co., Ltd. using 5 parts by mass with an average particle size of 3.5 μm by the counter method. , BASF resin "Luwax AF29 Micropowder" (polyethylene fine powder wax) by 2 parts by mass, Lubrizol dispersant "Solspurs 24000GR" by 1 part by mass, polyurethane resin A (polyurethane resin) by 55 parts by mass (nonvolatile). (NV = 30%), 13 parts by mass of methyl ethyl ketone, 9 parts by mass of ethyl acetate, 5 parts by mass of isopropyl alcohol, 5 parts by mass of propylene glycol monomethyl ether, and wet-dispersed with a sand mill for about 1 hour. , Add 5 parts by mass of Sumika Bayer Urethane's isocyanate-based curing agent "Sumijour N3300" (nonvolatile content NV = 40%) and 40 parts by mass of Showa Denko's diluent "Ethyl acetate" to heat. Radiation ink F was prepared. The content of the heat-irradiating filler in the solid content of the heat-radiating ink F was 68% by mass.

(Heat radiation ink G)
As a thermally radioactive filler, 1 part by mass of carbon black manufactured by Mitsubishi Chemical Co., Ltd. (average particle size by the Coulter counter method: 0.5 μm) and synthetic silica "Silohobic 704" manufactured by Fuji Silicia Co., Ltd. (silane coupling treatment: Coulter) 5 parts by mass of "Tospearl 2000B" (spherical silicone resin beads: average particle size of 6 μm by the Coulter counter method) manufactured by Momentive Performance Materials Co., Ltd. using 5 parts by mass with an average particle size of 3.5 μm by the counter method. , BASF resin "Luwax AF29 Micropowder" (polyethylene fine powder wax) by 2 parts by mass, Lubrizol dispersant "Solspurs 24000GR" by 1 part by mass, polyurethane resin A (polyurethane resin) by 55 parts by mass (nonvolatile). (NV = 30%), 13 parts by mass of methyl ethyl ketone, 9 parts by mass of ethyl acetate, 5 parts by mass of isopropyl alcohol, 5 parts by mass of propylene glycol monomethyl ether, and wet-dispersed with a sand mill for about 1 hour. Heat radiation by adding 5 parts by mass of Sumika Bayer Urethane's isocyanate meter curing agent "Sumijuru N3300" (nonvolatile content NV = 40%) and 40 parts by mass of Showa Denko's diluent "Ethyl acetate". Ink G was prepared. The content of the heat-irradiating filler in the solid content of the heat-radiating ink G was 29% by mass.

(Heat radiation ink H)
As a thermal radioactive filler, 90 parts by mass of carbon black manufactured by Mitsubishi Chemical Co., Ltd. (average particle size by the Coulter counter method: 0.5 μm) and synthetic silica "Silohobic 704" manufactured by Fuji Silicia Co., Ltd. (silane coupling treatment: Coulter) 5 parts by mass of "Tospearl 2000B" (spherical silicone resin beads: average particle size of 6 μm by the Coulter counter method) manufactured by Momentive Performance Materials Co., Ltd. using 5 parts by mass with an average particle size of 3.5 μm by the counter method. , BASF resin "Luwax AF29 Micropowder" (polyurethane fine powder wax) by 2 parts by mass, Lubrizol dispersant "Solspurs 24000GR" by 1 part, polyurethane resin A (polyurethane resin) by 55 parts by mass (nonvolatile content) NV = 30%), 13 parts of methyl ethyl ketone, 9 parts by mass of ethyl acetate, 5 parts by mass of isopropyl alcohol, 5 parts by mass of propylene glycol monomethyl ether were added, and the mixture was wet-dispersed with a sand mill for about 1 hour. Heat radiation ink by adding 5 parts by mass of the isocyanate-based curing agent "Sumidur N3300" (nonvolatile content NV = 40%) manufactured by Bayer Urethane Co., Ltd. and 40 parts by mass of the diluent "ethyl acetate" manufactured by Showa Denko Co., Ltd. H was prepared. The content of the heat-irradiating filler in the solid content of the heat-radiating ink A was 83% by mass.

[Creation of thermal radiation metal substrate]
(Creation of thermal radiation metal base material A)
Electrolytic copper foil CF-T8G-DK-18 manufactured by Fukuda Metal Foil Powder Industry Co., Ltd. (Thickness: 18.0 μm, single-sided roughening treatment, surface roughness of roughened surface (erased surface): Ra = 1.00 / Rz = 7.70, surface roughness of roughened untreated surface: Ra = 0.16 / Rz = 1.10, thermal conductivity 15%, thermal conductivity 385 W / m · K) is applied to the metal substrate (A). Then, heat radiation ink A is gravure-coated on the erasing surface so that the drying thickness of the ink film portion is 3.0 μm, dried at 100 ° C. for 1 minute, and heat radiation having a heat radiation layer composed of heat radiation ink A. A metal substrate A was obtained. The thickness of the ink coating film portion was measured by magnifying the cross section 2500 times with a microscope.

(Creation of thermal radiation metal base material B)
Electrolytic copper foil CF-T8G-DK-35 manufactured by Fukuda Metal Foil Powder Industry Co., Ltd. (Thickness: 35.0 μm, single-sided roughening treatment, surface roughness of roughened surface (erased surface): Ra = 1.64 / Rz = 10.50, surface roughness of roughened untreated surface: Ra = 0.18 / Rz = 1.3, thermal conductivity 15%, thermal conductivity 385 W / m · K) is used as the metal substrate (A). Then, heat radiation ink A is gravure-coated on the erasing surface so that the drying thickness of the ink film portion is 3.0 μm, dried at 100 ° C. for 1 minute, and heat radiation having a heat radiation layer composed of heat radiation ink A. A metal substrate B was obtained. The thickness of the ink coating film portion was measured by magnifying the cross section 2500 times with a microscope.

[Creation of thermal radiation metal base material C]
Electrolytic copper foil CF-T8G-DK-18 manufactured by Fukuda Metal Foil Powder Industry Co., Ltd. (Thickness: 18.0 μm, single-sided roughening treatment, surface roughness of roughened surface (erased surface): Ra = 1.00 / Rz = 7.70, surface roughness of roughened untreated surface: Ra = 0.16 / Rz = 1.10, thermal conductivity 15%, thermal conductivity 385 W / m · K) is applied to the metal substrate (A). Then, heat radiation ink A is gravure-coated on the erasing surface so that the drying thickness of the ink film portion is 5.0 μm, dried at 100 ° C. for 1 minute, and heat radiation having a heat radiation layer composed of heat radiation ink A. A metal substrate C was obtained. The thickness of the ink coating film portion was measured by magnifying the cross section 2500 times with a microscope.

[Creation of thermal radiation metal base material D]
Electrolytic copper foil CF-T8G-DK-18 manufactured by Fukuda Metal Foil Powder Industry Co., Ltd. (Thickness: 18.0 μm, single-sided roughening treatment, surface roughness of roughened surface (erased surface): Ra = 1.00 / Rz = 7.70, surface roughness of roughened untreated surface: Ra = 0.16 / Rz = 1.10, thermal conductivity 15%, thermal conductivity 385 W / m · K) is applied to the metal substrate (A). Then, the heat radiation ink B is gravure-coated on the erasing surface so that the drying thickness of the ink film portion is 5.0 μm, dried at 100 ° C. for 1 minute, and heat radiation having a heat radiation layer composed of the heat radiation ink B. A metal substrate D was obtained. The thickness of the ink coating film portion was measured by magnifying the cross section 2500 times with a microscope.

[Creation of thermal radiation metal base material E]
Electrolytic copper foil CF-T8G-DK-18 manufactured by Fukuda Metal Foil Powder Industry Co., Ltd. (Thickness: 18.0 μm, single-sided roughening treatment, surface roughness of roughened surface (erased surface): Ra = 1.00 / Rz = 7.70, surface roughness of roughened untreated surface: Ra = 0.16 / Rz = 1.10, thermal conductivity 15%, thermal conductivity 385 W / m · K) is applied to the metal substrate (A). Then, heat radiation ink C is gravure-coated on the erasable surface so that the drying thickness of the ink film portion is 5.0 μm, dried at 100 ° C. for 1 minute, and heat radiation having a heat radiation layer composed of heat radiation ink B. A metal substrate E was obtained. The thickness of the ink coating film portion was measured by magnifying the cross section 2500 times with a microscope.

[Creation of thermal radiation metal base material F]
Electrolytic copper foil CF-T8G-DK-18 manufactured by Fukuda Metal Foil Powder Industry Co., Ltd. (Thickness: 18.0 μm, single-sided roughening treatment, surface roughness of roughened surface (erased surface): Ra = 1.00 / Rz = 7.70, surface roughness of roughened untreated surface: Ra = 0.16 / Rz = 1.10, thermal conductivity 15%, thermal conductivity 385 W / m · K) is applied to the metal substrate (A). Then, heat radiation ink D is gravure-coated on the erasable surface so that the drying thickness of the ink film portion is 5.0 μm, dried at 100 ° C. for 1 minute, and heat radiation having a heat radiation layer composed of heat radiation ink B. A metal substrate F was obtained. The thickness of the ink coating film portion was measured by magnifying the cross section 2500 times with a microscope.

[Creation of thermal radiation metal base material G]
Rolled copper foil SNA-RCF-DT 18 manufactured by Fukuda Metal Foil Powder Industry Co., Ltd. (thickness: 18.0 μm, surface roughness (both sides): Ra = 0.10 / Rz = 0.70, heat radiation rate 15%, Heat radiation ink A is gravure-coated on one side with a heat conductivity of 385 W / m · K) so that the drying thickness of the ink film portion is 3.0 μm, dried at 100 ° C. for 1 minute, and consists of heat radiation ink A. A thermal radiation metal substrate G having a thermal radiation layer was obtained. The thickness of the ink coating film portion was measured by magnifying the cross section 2500 times with a microscope.

[Creation of thermal radiation metal base material H]
Electrolytic copper foil CF-PLFA-18 manufactured by Fukuda Metal Foil Powder Industry Co., Ltd. (thickness: 18.0 μm, surface roughness (both sides): Ra = 0.13 / Rz = 0.80, heat radiation rate 15%, heat Heat radiant ink A is gravure-coated on one side with a conductivity of 385 W / m · K) so that the drying thickness of the ink film portion is 3.0 μm, dried at 100 ° C. for 1 minute, and the heat composed of the heat radiant ink A is obtained. A heat-radiating metal substrate H having a radiation layer was obtained. The thickness of the ink coating film portion was measured by magnifying the cross section 2500 times with a microscope.

[Creation of thermal radiation metal substrate I]
Aluminum foil made by UACF Co., Ltd. SK Aluminum 20 (thickness: 20.0 μm, surface roughness of roughened surface (erased surface): Ra = 0.34 / Rz = 3.58, roughened untreated surface Surface roughness: Ra = 0.30 / Rz = 1.70, heat radiation rate 8%, heat radiation conductivity 230 W / m · K), heat radiation ink A is applied to the mask surface, and the dry thickness of the ink film portion is 3. It was gravure-coated to a size of 0.0 μm and dried at 100 ° C. for 1 minute to obtain a heat-radiating metal substrate I having a heat-radiating layer made of heat-radiating ink A. The thickness of the ink coating film portion was measured by magnifying the cross section 2500 times with a microscope.

[Creation of thermal radiation metal base material J]
Electrolytic copper foil CF-T8G-DK-18 manufactured by Fukuda Metal Foil Powder Industry Co., Ltd. (thickness: 18.0 μm, single-sided roughening treatment, surface roughness of roughened surface (erased surface): Ra = 1.00 / Rz = 7.70, surface roughness of roughened untreated surface: Ra = 0.16 / Rz = 1.10, heat radiation rate 15%, heat radiation conductivity 385 W / m · K) The ink E was gravure-coated so that the drying thickness of the ink film portion was 3.0 μm, and dried at 100 ° C. for 1 minute to obtain a heat-radiating metal base material J having a heat-radiating layer made of the heat-radiating ink E. The thickness of the ink coating film portion was measured by magnifying the cross section 2500 times with a microscope.

[Creation of thermal radiation metal base material K]
Electrolytic copper foil CF-T8G-DK-18 manufactured by Fukuda Metal Foil Powder Industry Co., Ltd. (thickness: 18.0 μm, single-sided roughening treatment, surface roughness of roughened surface (erased surface): Ra = 1.00 / Rz = 7.70, surface roughness of roughened untreated surface: Ra = 0.16 / Rz = 1.10, heat radiation rate 15%, heat radiation conductivity 385 W / m · K) The ink F was gravure-coated so that the drying thickness of the ink film portion was 3.0 μm, and dried at 100 ° C. for 1 minute to obtain a heat-radiating metal base material K having a heat-radiating layer made of the heat-radiating ink F. The thickness of the ink coating film portion was measured by magnifying the cross section 2500 times with a microscope.

[Creation of thermal radiation metal base material L]
Electrolytic copper foil CF-T8G-DK-9 manufactured by Fukuda Metal Foil Powder Industry Co., Ltd. (thickness: 9.0 μm, single-sided roughening treatment, surface roughness of roughened surface (erased surface): Ra = 0.80 / Rz = 5.90, surface roughness of roughened untreated surface: Ra = 0.16 / Rz = 1.10, heat radiation rate 15%, heat radiation conductivity 385 W / m · K) The ink A was gravure-coated so that the drying thickness of the ink film portion was 5.0 μm, and dried at 100 ° C. for 1 minute to obtain a heat-radiating metal base material L having a heat-radiating layer made of the heat-radiating ink A. The thickness of the ink coating film portion was measured by magnifying the cross section 2500 times with a microscope.

[Creation of thermal radiation metal base material M]
Electrolytic copper foil CF-T8G-DK-50 manufactured by Fukuda Metal Foil Powder Industry Co., Ltd. (thickness: 50.0 μm, single-sided roughening treatment, surface roughness of roughened surface (erased surface): Ra = 1.70 / Rz = 11.20, surface roughness of roughened untreated surface: Ra = 0.20 / Rz = 1.40, heat radiation rate 15%, heat radiation conductivity 385 W / m · K) Ink A was gravure-coated so that the drying thickness of the ink film portion was 5.0 μm, and dried at 100 ° C. for 1 minute to obtain a heat-radiating metal base material M having a heat-radiating layer made of heat-radiating ink A. The thickness of the ink coating film portion was measured by magnifying the cross section 2500 times with a microscope.

[Creation of thermal radiation metal base material N]
Electrolytic copper foil CF-T8G-DK-35 manufactured by Fukuda Metal Foil Powder Industry Co., Ltd. (Thickness: 35.0 μm, single-sided roughening treatment, surface roughness of roughened surface (erased surface): Ra = 1.64 / Rz = 10.50, surface roughness of roughened untreated surface: Ra = 0.18 / Rz = 1.30, heat radiation rate 15%, thermal conductivity 385W / mK), DIC stock The adhesive layer surface of the company's black matte single-sided tape "IL-05BMF" (heat radiation layer 4 μm / 2 μm PET / 2 μm adhesive layer) is attached, and the heat radiation metal base material N (heat radiation layer / PET / adhesive layer) having a heat radiation layer is attached. / Electrolytic copper foil) was obtained. The thickness of each layer of the black matte single-sided tape was measured by magnifying the cross section 2500 times with a microscope.

[Creation of thermal radiation metal base material O]
Electrolytic copper foil CF-T8G-DK-18 manufactured by Fukuda Metal Foil Powder Industry Co., Ltd. (Thickness: 18.0 μm, single-sided roughening treatment, surface roughness of roughened surface (erased surface): Ra = 1.00 / Rz = 7.70, surface roughness of roughened untreated surface: Ra = 0.16 / Rz = 1.10, thermal conductivity 15%, thermal conductivity 385 W / m · K) is applied to the metal substrate (A). Then, the heat radiation ink G is gravure-coated on the erasing surface so that the drying thickness of the ink film portion is 3.0 μm, dried at 100 ° C. for 1 minute, and heat radiation having a heat radiation layer composed of the heat radiation ink G. A metal substrate O was obtained. The thickness of the ink coating film portion was measured by magnifying the cross section 2500 times with a microscope.

[Creation of thermal radiation metal base material P]
Electrolytic copper foil CF-T8G-DK-18 manufactured by Fukuda Metal Foil Powder Industry Co., Ltd. (Thickness: 18.0 μm, single-sided roughening treatment, surface roughness of roughened surface (erased surface): Ra = 1.00 / Rz = 7.70, surface roughness of roughened untreated surface: Ra = 0.16 / Rz = 1.10, thermal conductivity 15%, thermal conductivity 385 W / m · K) is applied to the metal substrate (A). Then, the heat radiation ink H is gravure-coated on the erasing surface so that the drying thickness of the ink film portion is 3.0 μm, dried at 100 ° C. for 1 minute, and heat radiation having a heat radiation layer composed of the heat radiation ink H. A metal substrate P was obtained. The thickness of the ink coating film portion was measured by magnifying the cross section 2500 times with a microscope.

[Adhesive composition adjustment]
(Adhesive Composition A Adjustment)
In a reaction vessel equipped with a cooling tube, a stirrer, a thermometer and a dropping funnel, 96.0 parts by mass of n-butyl acrylate, 0.1 part by mass of 2-hydroxyethyl acrylate, 3.9 parts by mass of acrylic acid, and polymerization. 0.1 part by mass of 2,2'-azobisisobutylnitrile and 100 parts by mass of ethyl acetate were supplied as an initiator, the inside of the reaction vessel was replaced with nitrogen, and then polymerized at 80 ° C. for 12 hours to achieve weight averaging. An acrylic polymer solution having a molecular weight of 600,000 was obtained.

Next, 10 parts by mass of the polymerized rosin pentaerythritol ester (Pencel D-135, softening point 135 ° C., manufactured by Arakawa Chemical Industry Co., Ltd.) with respect to 100 parts by mass of the solid content of the acrylic polymer solution having a weight average molecular weight of 600,000. And 10 parts by mass of disproportionate rosin lysering ester (manufactured by Arakawa Chemical Industry Co., Ltd., super ester A-100, softening point 100 ° C.), and the solid content concentration is adjusted to 45% by mass using ethyl acetate. As a result, an acrylic pressure-sensitive adhesive composition (1) was obtained.
Next, the acrylic pressure-sensitive adhesive composition (1) 100 parts by mass (solid content 45 parts by mass) and an isocyanate-based cross-linking agent (manufactured by DIC Corporation, Burnock NC-40, solid content 40% by mass, ethyl acetate solution). The pressure-sensitive adhesive composition A was obtained by mixing 2 parts by mass and mixing them for 10 minutes using a dispersion stirrer.

(Preparation of Adhesive Composition B)
60 parts by mass of butyl acrylate, 35.95 parts by mass of 2-ethylhexyl acrylate, 4.0 parts by mass of acrylic acid, 4-hydroxy in a reaction vessel equipped with a stirrer, a reflux cooler, a thermometer, a dropping funnel and a nitrogen gas inlet. 0.05 parts by mass of butyl acrylate and 0.2 parts by mass of 2,2'-azobisisobutylnitrile as a polymerization initiator were dissolved in a mixed solvent of 50 parts by mass of ethyl acetate and 20 parts by mass of n-hexane, and they were dissolved. Was polymerized at 70 ° C. for 8 hours to obtain an acrylic copolymer solution having a weight average molecular weight of 700,000.

Next, 20 parts by mass of the polymerized rosin ester resin (D-125 manufactured by Arakawa Chemical Industry Co., Ltd.) was added to 100 parts by mass of the solid content of the acrylic copolymer having a weight average molecular weight of 700,000, and the disproportionated rosin ester. (A100 manufactured by Arakawa Chemical Industry Co., Ltd.) was added in an amount of 10 parts by mass, and the solid content concentration was adjusted to 45% by mass using ethyl acetate to obtain an acrylic pressure-sensitive adhesive composition (2).
Next, the acrylic pressure-sensitive adhesive composition (2) 100 parts by mass (solid content 45 parts by mass) and an isocyanate-based cross-linking agent (manufactured by DIC Corporation, Barnock NC-40, solid content 40% by mass, ethyl acetate solution). Was mixed with 1.7 parts by mass, and they were mixed for 10 minutes using a dispersion stirrer to obtain a pressure-sensitive adhesive composition B.

[Making a heat-dissipating adhesive sheet]
(Example 1)
The pressure-sensitive adhesive composition A is applied onto a release liner "PET 38 x 1 A3" manufactured by Nippa Corporation using a roll coater so that the thickness of the pressure-sensitive adhesive layer after drying is 5 μm, and the temperature is 80 ° C. The pressure-sensitive adhesive layer was formed by drying in a dryer for 3 minutes. Next, the pressure-sensitive adhesive layer obtained above was bonded to the non-heat-radiating layer surface of the heat-radiating metal substrate A using a laminator and cured in an environment of 40 ° C. for 48 hours to obtain a heat-dissipating pressure-sensitive adhesive sheet (X-1). ) Was produced.

(Example 2)
A heat-dissipating adhesive sheet (X-2) was produced in the same manner as in Example 1 except that the heat-radiating metal base material B was used instead of the heat-radiating metal base material A.

(Example 3)
A heat-dissipating adhesive sheet (X-3) was produced by the same method as in Example 1 except that the heat-radiating metal base material C was used instead of the heat-radiating metal base material A.

(Example 4)
A heat-dissipating adhesive sheet (X-4) was produced in the same manner as in Example 1 except that the heat-radiating metal base material D was used instead of the heat-radiating metal base material A.

(Example 5)
A heat-dissipating adhesive sheet (X-5) was produced in the same manner as in Example 1 except that the heat-radiating metal base material E was used instead of the heat-radiating metal base material A.

(Example 6)
A heat-dissipating adhesive sheet (X-6) was produced in the same manner as in Example 1 except that the heat-radiating metal base material F was used instead of the heat-radiating metal base material A.

(Example 7)
A heat-dissipating adhesive sheet (X-metal 7) was produced in the same manner as in Example 1 except that the heat-radiating metal base material G was used instead of the heat-radiating metal base material A.

(Example 8)
A heat-dissipating adhesive sheet (X-8) was produced in the same manner as in Example 1 except that the heat-radiating metal base material H was used instead of the heat-radiating metal base material A.

(Example 9)
A heat-dissipating adhesive sheet (X-9) was produced in the same manner as in Example 1 except that the heat-radiating metal base material I was used instead of the heat-radiating metal base material A.

(Example 10)
A heat-dissipating pressure-sensitive adhesive sheet was produced in the same manner as in Example 1 except that the thickness of the pressure-sensitive adhesive layer after drying was changed to 10 μm.

(Example 11)
A heat-dissipating pressure-sensitive adhesive sheet was produced in the same manner as in Example 1 except that the thickness of the pressure-sensitive adhesive layer after drying was changed to 2 μm.

(Example 12)
A heat-dissipating pressure-sensitive adhesive sheet (X-12) was produced in the same manner as in Example 1 except that the pressure-sensitive adhesive composition B was used instead of the pressure-sensitive adhesive composition A.

(Example 13)
A heat-dissipating adhesive sheet (X-13) was produced in the same manner as in Example 1 except that the heat-radiating metal base material J was used instead of the heat-radiating metal base material A.

(Example 14)
A heat-dissipating adhesive sheet (X-14) was produced in the same manner as in Example 1 except that the heat-radiating metal base material K was used instead of the heat-radiating metal base material A.

(Comparative Example 1)
A heat-radiating adhesive sheet (X') is used in the same manner as in Example 1 except that the heat-radiating metal base material L is used instead of the heat-radiating metal base material A and the thickness of the pressure-sensitive adhesive layer after drying is changed to 3 μm. -1) was produced.

(Comparative Example 2)
A heat-dissipating adhesive sheet (X'-2) was produced by the same method as in Example 1 except that the heat-radiating metal base material M was used instead of the heat-radiating metal base material A.

(Comparative Example 3)
A heat-radiating adhesive sheet (X') is used in the same manner as in Example 1 except that the heat-radiating metal base material N is used instead of the heat-radiating metal base material A and the thickness of the pressure-sensitive adhesive layer after drying is changed to 50 μm. -3) was prepared.

(Comparative Example 4)
Electrolytic copper foil CF-T8G-DK-18 manufactured by Fukuda Metal Foil Powder Industry Co., Ltd. instead of thermal radiation metal base material A (thickness: 18.0 μm / single-side roughness treatment, average of roughened surface (erased surface) Surface roughness (Ra) = 1.00 / Rz = 7.70, average roughness (Ra) of roughened untreated surface (Ra) = 0.16 / Rz = 1.10, thermal radiation rate 15%, thermal conductivity 385W A heat-dissipating adhesive sheet (X'-4) was produced in the same manner as in Example 1 except that / m · K) was used.

(Comparative Example 5)
A heat-dissipating adhesive sheet (X'-5) was produced in the same manner as in Example 1 except that the heat-radiating metal base material O was used instead of the heat-radiating metal base material A.

(Comparative Example 6)
A heat-dissipating adhesive sheet (X'-6) was produced in the same manner as in Example 1 except that the heat-radiating metal base material P was used instead of the heat-radiating metal base material A.

[Surface roughness of the surface of the heat radiating adhesive sheet on the heat radiating zone side (Ra, Rz)]
The maximum height roughness (Rz) and the arithmetic mean roughness (Ra) of the surface of the heat radiating adhesive sheet obtained in Examples and Comparative Examples on the heat radiating zone side were measured based on JIS B0601: 2013. The measurement is obtained by measuring Rz and Ra at any three points (each 50 μm in length × 50 μm in width) on the surface of the heat radiating adhesive sheet on the heat radiating layer side based on JIS B0601: 2013. The average value of the Rz of the three points was taken as the Rz of the surface of the heat radiating adhesive sheet on the heat radiating zone side, and the average value of the three points of Ra was taken as Ra of the surface of the heat radiating adhesive sheet on the heat radiating zone side.

[Heat emissivity of heat-dissipating adhesive sheet]
The heat-dissipating adhesive sheet obtained in Examples and Comparative Examples was cut into a size of 40 mm in width × 50 mm in length and attached to an aluminum plate (40 mm in width × 50 mm in length, 0.7 mm in thickness) as a test piece. .. Using this test piece, the far-infrared spectral emissivity / FT-IR method was used to measure from the surface on the thermal radiation layer side with an integrated measurement wavelength range of 4 to 20 μm and a measurement temperature of 50 ° C.

[Thinness]
The thickness of the heat-dissipating adhesive sheet obtained in Examples and Comparative Examples was measured in units of 0.1 μm using “Digimicro MF-501”, “MCF-101” and “MS-31G” manufactured by Nikon Corporation.
⊚: The heat-dissipating adhesive sheet having a thickness of less than 30 μm was evaluated as having excellent thin performance.
◯: The heat-dissipating adhesive sheet having a thickness of 30 μm or more and less than 50 μm was evaluated as having sufficiently thin performance for practical use.
X: A heat-dissipating adhesive sheet having a thickness of 50 μm or more was evaluated as not having sufficient thin performance.

[Evaluation method of pasting workability]
The heat-dissipating adhesive sheet obtained in Examples and Comparative Examples was cut into a size of 50 mm in width × 100 mm in length and used as a test tape.

The release liner was peeled off from one end of the test tape (heat-dissipating adhesive sheet) and attached onto a glass plate having a width of 70 mm and a thickness of 1 mm, and crimped with a finger.
Next, after peeling off all the remaining release liners, all of the test tapes were attached to the glass plate by moving a finger toward the other end of the test tape (heat dissipation adhesive sheet).

The range of 10 mm at both ends of the test tape was excluded from the observation target, and the presence or absence of wrinkles (presence or absence of air bubbles) in a range other than the above was visually observed from the glass surface side and evaluated based on the following evaluation criteria.
⊚: The heat-dissipating adhesive sheet had no wrinkles, air bubbles or breaks, and had excellent sticking workability.
〇: It was confirmed that wrinkles, air bubbles, and creases were generated in one place on the heat-dissipating adhesive sheet, but it had sufficient sticking workability for practical use.
Δ: It was confirmed that wrinkles, bubbles, and creases were generated in two or more and less than five places on the heat-dissipating adhesive sheet, which may cause a problem in practical use.
X: It was confirmed that wrinkles, dexterity, and creases occurred in five or more places on the heat-dissipating adhesive sheet, and it was evaluated that there was a practical problem and the adhesive performance was not sufficient.

[Evaluation method of resilience resistance]
Two heat-dissipating adhesive sheets obtained in Examples and Comparative Examples were prepared by cutting them into a size of 20 mm in width × 50 mm in length. A PET having a width of 19 mm, a length of 49 mm, and a thickness of 500 μm was prepared, and the PET was pouched with the two heat-dissipating adhesive sheets. At that time, the ends of the heat-dissipating adhesive sheet were attached so as to be in close contact with each other with a width of 0.5 mm, and the attached ends were crimped by reciprocating once with a 2 kg roller. This pouch product was used as a test piece.

The test piece was allowed to stand in an environment of 23 ° C. and 50% RH for 1 hour, then put into an environmental tester at 60 ° C. and 90% RH, and left for 72 hours. After that, it was taken out to room temperature, and the presence or absence of floating (threading of the adhesive layer) or peeling of the heat-dissipating adhesive sheet at the corners of the test piece was visually confirmed and evaluated according to the following evaluation criteria.
⊚: No floating or peeling of the test tape was confirmed, and it was evaluated as having excellent resilience resistance.
◯: A slight floating of the test tape was confirmed, but no peeling occurred, and it was evaluated that the test tape had sufficient resilience resistance for practical use.
X: It was evaluated that the test tape was peeled off and did not have sufficient resilience resistance.

[Evaluation method of printability]
For the thermal radiation metal substrate used in the examples and comparative examples, a thermal radiation metal substrate (width 1000 mm × length 1000 mm) immediately after the thermal radiation layer was printed and formed was prepared, and printing unevenness was visually observed while shining reflected light. Observed at. In addition, the adhesion of the thermal radiation layer of the thermal radiation metal substrate immediately after the thermal radiation layer was printed and formed was confirmed by the following procedure. First, Nichiban cellophane tape (registered trademark) (No. 405, width 24 mm) was attached to the heat radiation layer and rubbed with the pad of the thumb 5 or 6 times for pressure bonding. After crimping, it was vigorously peeled off in the 180 ° direction at a peeling speed of about 50 m / min. When peeled off, it was observed whether or not the thermal radiation zone was detached. Evaluate according to the following evaluation criteria.
⊚: There was no printing unevenness or poor adhesion, and it was evaluated as having excellent printability.
◯: Although there was no printing unevenness, there was a part with poor adhesion, but it was evaluated as having sufficient printability in actual use.
X: It was evaluated that printing unevenness and poor adhesion occurred and the printability was not sufficient for actual use.

[Adhesive strength]
The heat-dissipating adhesive sheets obtained in Examples and Comparative Examples were cut into a width of 25 mm and a length of 100 mm, and test pieces were prepared. This test piece is attached to a wet-polished stainless steel plate, pressurized once with a 2 kg roller, left at 23 ° C. and 50% RH for 1 hour, and peeled off at a speed of 300 mm / min in the 180 ° direction. It was measured. It was evaluated according to the following evaluation criteria.
⊚: 12N / 25mm or more 〇: 9N / 25mm or more and less than 12N / 25mm ×: less than 9N / 25mm

[Heat dissipation]
Two heat-dissipating adhesive sheets obtained in Examples and Comparative Examples were prepared by cutting them into a width of 40 mm and a length of 40 mm. Next, one graphite sheet manufactured by Kaneka Corporation (thickness: 30 μm, thermal conductivity 1500 W / m · K) cut into 39 mm × 39 mm was prepared. Subsequently, the release liners of the two heat-dissipating adhesive sheets were peeled off, and the graphite sheets were pouched with these. At that time, the ends of the heat-dissipating adhesive sheet were attached so as to be in close contact with each other with a width of 0.5 mm, and the attached ends were reciprocated once with a 2 kg roller to crimp them. This pouch product was used as a test piece.

The above test piece prepared using the heat dissipation adhesive sheets of Examples and Comparative Examples was attached to the opposite surface of the thermometer of a silicon rubber heater equipped with a thermometer (the surface area of the heat generating portion is 5 cm in length and 5 cm in width). .. At that time, they were pressed and crimped with a finger so that bubbles did not remain at the interface between the heater and the heat radiating adhesive sheet of the test piece as much as possible.

Next, under an atmosphere of 23 ° C. and 50% RH, 3.0 W of electric power was applied to the heater, and the temperature of the heater after 15 minutes was measured with a thermometer.
⊚: The heater having a temperature difference of less than 50 ° C. before and after the application of electric power was evaluated as having excellent heat dissipation performance.
◯: The heater having a temperature difference of 55 ° C. or higher and lower than 60 ° C. before and after the application of electric power was evaluated as having sufficient heat dissipation performance for practical use.
X: The heater having a temperature difference of 60 ° C. or more before and after the application of electric power was evaluated as not having sufficient heat dissipation performance.

The evaluation results are shown in Tables 1 to 3 below.

In Examples 1 to 14, the heat emissivity was high and the heat dissipation was excellent, and the thinness, the sticking workability, and the repulsion resistance were excellent. In particular, Examples 1 and 6 have high heat emissivity and excellent heat dissipation, and are thin, have excellent sticking workability, and have excellent resilience resistance.

On the other hand, in Comparative Example 1, the heat emissivity of the sheet was in a desired range, but the thickness of the metal base material was thinner than the predetermined range, so that the heat dissipation property was lowered and the sticking workability was also lowered. In Comparative Example 2, since the thickness of the metal base material was thicker than the predetermined range, the thinness and the resilience resistance were lowered. In Comparative Example 3, a resin layer was provided between the heat radiating layer and the metal base material, and the thinness, resilience resistance and heat dissipation were lowered. In Comparative Example 4, there was no heat radiating layer, the heat emissivity of the surface of the sheet on the heat radiating layer side was low, and the heat dissipation was lowered. In Comparative Examples 5 and 6, the heat emissivity of the surface of the sheet on the heat radiating zone side was low and the heat dissipation was lowered.

Claims (11)

Heat dissipation having a thermal radiant layer (B) containing a thermal radiant filler on one surface side of the metal substrate (A) and an adhesive layer (C) on the other surface side of the metal substrate (A). It is an adhesive sheet,
The heat radiant layer (B) is in direct contact with the one surface of the metal substrate (A).
The thickness of the metal substrate (A) is 10 μm to 38 μm, and the thickness is 10 μm to 38 μm.
A heat-dissipating adhesive sheet with a heat emissivity of 80% or more. The heat-dissipating adhesive sheet according to claim 1, wherein the surface roughness (Ra) of the surface of the metal substrate (A) on the heat radiating zone side is 0.1 μm to 2.0 μm. The heat-dissipating adhesive sheet according to claim 1 or 2, wherein the average surface roughness (Ra) of the surface of the sheet on the heat radiating layer (B) side is 0.2 μm to 2.0 μm. The heat-dissipating adhesive sheet according to any one of claims 1 to 3, wherein the heat-radiating filler contains at least one of carbon black and an inorganic oxide. Whether the thermal radioactive filler is a metal oxide, hydroxide or carbonate selected from the group consisting of aluminum (Al), titanium (Ti), magnesium (Mg), silicon (Si) and calcium (Ca). The heat-dissipating adhesive sheet according to any one of claims 1 to 4, which comprises one or more types of calcium. 5. The thermal radioactive filler comprises one or more oxides of a metal selected from the group consisting of aluminum (Al), titanium (Ti), magnesium (Mg), silicon (Si) and calcium (Ca). Heat dissipation adhesive sheet described in The heat-dissipating adhesive sheet according to any one of claims 1 to 6, wherein the heat radiating layer (B) is a printing layer. The heat-dissipating adhesive sheet according to any one of claims 1 to 7, wherein the content of the heat-radiating filler in the heat-radiating layer (B) is 5% by mass to 80% by mass. The heat-dissipating adhesive sheet according to any one of claims 1 to 8, wherein the heat radiating layer (B) has a thickness of 2 μm to 10 μm. A laminate having a heat radiating sheet on a surface of the heat radiating adhesive sheet according to any one of claims 1 to 9 having the pressure-sensitive adhesive layer (C). The laminate according to claim 10, wherein the heat radiating sheet is a graphite sheet, a graphene sheet, or a silicon rubber sheet.