KR102165850B1 - Heat radiating film and heat radiating adhesive tape - Google Patents

Abstract

A thermally radiating film containing a urethane resin and a thermally conductive filler, and having a thermal conductivity of 0.5W/m·K or more, a thermal emissivity of 0.85 or more, a tensile strength of 5N/20mm or more, and a film thickness of 10 to 30 μm.

Description

Heat radiation film and heat radiation adhesive tape {HEAT RADIATING FILM AND HEAT RADIATING ADHESIVE TAPE}

The present invention relates to a heat radiation film and a heat radiation adhesive tape. More specifically, the present invention relates to a heat-radiating film and a heat-radiating adhesive tape that can be suitably used for applications where it is desired to release heat from parts that generate heat due to power consumption of electric devices and electronic devices.

Components constituting electric devices, electronic devices, and the like, have increased power consumption due to improved integration and improved operation speed, and as a result, the amount of heat generated is increasing. When the calorific value increases, the temperature of the component itself increases. Since an increase in the temperature of a component leads to malfunction of the component, a decrease in life due to a failure, and the occurrence of an image to a user, it is desired to suppress the increase in temperature.

As a means of suppressing the temperature increase, a technique of bringing a heat sink into contact with a component is known. By bringing the heat sink into contact with the component, heat generated in the component is conducted to the heat sink, and as a result, it is possible to suppress an increase in temperature of the component.

A material having high thermal conductivity such as metal is used for the heat sink. However, if the difference between the heat sink temperature and the outside temperature is small, the heat accumulated on the heat sink is not discharged and remains accumulated on the heat sink. Therefore, there is still room for improvement in the heat sink as a means of suppressing the temperature increase.

A technology for solving the problem of the heat sink has been proposed in Japanese Patent No. 28 07198 (Patent Document 1). In Patent Document 1, it is proposed to use a laminate of a sheet made of a heat-radiative material having a high heat emissivity and a sheet made of a heat-conductive material having a high heat conductivity as a radiator. In Patent Document 1, cordierite, aluminum titanate, β-spodumine, ceramics, carbon black, carbon fibers, and the like are mentioned as the heat-radiating material, and ferrite is mentioned as the thermally conductive material. In addition, in Patent Document 1, the two types of sheets are maintained in shape by a vulcanized silicon body, and each has a thickness of 1 mm.

Japanese Patent No. 2807198

Even in the heat dissipation body of the said patent document 1, it is not enough for suppression of temperature rise of a component, and further improvement has been demanded. In addition, electric and electronic devices are further required to be thinner, and for this reason, thinner heat sinks are also required. From this point of view, the radiator of Patent Document 1 has a limit in thinning in the range that can be handled.

In this way, according to the present invention, a urethane-based resin and a thermally conductive filler are included and have a thermal conductivity of 0.5 W/m·K or more, a thermal emissivity of 0.85 or more, a tensile strength of 5 N/20 mm or more, and a film thickness of 10 to 30 μm. A heat-radiative film is provided.

Further, according to the present invention, there is provided a thermally radiating adhesive tape including the thermally radiating film and an adhesive layer in the thickness direction.

Advantageous Effects of Invention According to the present invention, it is possible to provide a thin-film heat-radiating film and a heat-radiating adhesive tape capable of further suppressing the temperature increase of components constituting electric devices, electronic devices, and the like.

In addition,

(1) At least one thermally conductive filler is from alumina, titania, zirconia, ferrite, silica, zinc oxide, magnesium oxide, aluminum carbide, silicon carbide, aluminum nitride, boron nitride, carbon black, graphite, carbon fiber and melamine cyanurate. Is chosen,

(2) The thermally conductive filler is a filler A selected from alumina, titania, zirconia, ferrite, silica, zinc oxide, magnesium oxide, aluminum carbide, silicon carbide, aluminum nitride, boron nitride and melamine cyanurate, and carbon black, graphite. And a combination of filler B selected from carbon fibers, or a filler C selected from alumina, titania, zirconia, ferrite, silica, zinc oxide, magnesium oxide, aluminum carbide, silicon carbide, aluminum nitride and boron nitride, and melamine cyanurate It is a combination with the filler D of

(3) 100 to 600 parts by weight of the thermally conductive filler is included with respect to 100 parts by weight of the urethane resin,

(4) 0.5 to 30 parts by weight of filler B is included with respect to 100 parts by weight of filler A, and 1 to 200 parts by weight of filler D is included with respect to 100 parts by weight of filler C,

(5) a thermally conductive filler,

ㆍA combination of a filler selected from alumina, silicon carbide, aluminum nitride, and melamine cyanurate with a filler of carbon black, or

ㆍIt is a combination of alumina filler and melamine cyanurate filler.

(6) When the urethane resin has a thickness of 25 μm, it has a tensile strength of 5N/20 mm or more.

In the case of having any one of them, it is possible to provide a thin-film heat-radiating film and a heat-radiating adhesive tape capable of further suppressing an increase in temperature of a component.

1 is a schematic cross-sectional view of a heat radiation adhesive tape of the present invention.
Figure 2 is a schematic cross-sectional view of the heat radiation adhesive tape of the present invention.
3 is a schematic cross-sectional view of the heat-radiating adhesive tape of the present invention.
4 is a schematic explanatory diagram of a heat dissipation effect test of an embodiment.
5 is a graph showing changes over time in measurement temperature in heat radiation effect tests of the heat radiation adhesive tapes of Example 1 and Comparative Example 1. FIG.

(Heat radiation film)

The heat-radiating film means a film having a thickness of 10 to 30 μm containing a urethane-based resin and a thermally conductive filler. In addition, the thermally radiating film has a thermal conductivity of 0.5W/m·K or more, a thermal emissivity of 0.85 or more, and a tensile strength of 5N/20mm or more.

When the thermally radiative film has the thermal conductivity, thermal emissivity, tensile strength, and film thickness within the above ranges, it is possible to suppress an increase in temperature of the component, and to realize a thin film within a range that can be handled. Here, the range that can be handled refers to a handleability such that, at the time of attaching to a part, cutting does not easily occur in a film that interferes with the operation.

The thermal conductivity is more preferably 0.5 W/m·K or more, and still more preferably 1.0 W/m·K or more. The thermal emissivity is more preferably 0.85 or more, and even more preferably 0.88 or more. In the range of these preferable thermal conductivity and thermal emissivity, it is possible to provide a film capable of further suppressing the temperature increase of the component. Thermal conductivity can take values such as 0.5W/mㆍK, 1.0W/mㆍK, 1.5W/mㆍK, 2.0W/mㆍK, 2.5W/mㆍK, and 3.0W/mㆍK. . The heat emissivity can be 0.85, 0.86, 0.87, 0.88, 0.89, 0.90, 0.91, 0.92, 0.95.

The tensile strength is more preferably 5N/20mm or more, and even more preferably 10N/20mm or more. The film thickness is more preferably 10 to 30 µm, and still more preferably 10 to 25 µm. In the range of these preferable tensile strengths and film thicknesses, handling is easier, and a thin film can be provided. Tensile strength can be 10N/20mm, 15N/20mm, 20N/20mm, 25N/20mm, 30N/20mm, 35N/20mm, 40N/20mm. The film thickness may be 10 µm, 15 µm, 20 µm, or 25 µm.

(a) urethane resin

The urethane-based resin is not particularly limited as long as it can take the shape of a film with a thickness of 30 μm, and can provide a tensile strength of 5 N/20 mm or more to the film. Among these urethane-based resins, a resin having a tensile strength of 5N/20 mm or more when the thickness is 25 µm is more preferable. Tensile strength is 5N/20mm, 10N/20mm, 15N/20mm, 20N/20mm, 25N/20mm, 30N/20mm, 35N/20mm, 40N at a thickness of 30㎛ and/or 25㎛ It can take /20mm.

As a urethane resin, for example,

(1) Polylactone ester polyol obtained by ring-opening polymerization of caprolactone and diisocyanate (e.g., tolylene diisocyanate, diphenylmethane diisocyanate, naphthalene diisocyanate, hexamethylene diisocyanate, etc.) Caprolactone-type polyurethane elastomer synthesized by reaction,

(2) Dicarboxylic acid (e.g., adipic acid, phthalic acid, etc.) and a glycol (e.g., polypropylene glycol) dicarboxylic acid ester polyol and diisocyanate synthesized by polyaddition reaction Boxy acid ester type polyurethane elastomer,

(3) polyether-type polyurethane elastomer synthesized by polyaddition reaction of polyether polyols such as polytetramethylene glycol and polyalkylene glycol (e.g., polypropylene glycol) with diisocyanate, and

(4) polycarbonate polyol,

Can be mentioned. The urethane resin may be a mixture of these (1) to (4).

The urethane resin may have a functional group such as a carboxyl group and an amino group. In particular, by having a carboxyl group, the dispersibility of the thermally conductive filler can be improved.

It is preferable that the urethane elastomer has a weight average molecular weight of 10,000 to 200,000. If it is a molecular weight in this range, handling is more easy, and a thin film can be obtained.

As urethane resins, commercially available products include polyurethane elastomers such as DAIFERAMINE MAU series (models 5022, 4308HV, 9022, etc.) or RESAMINE ME series (models ME-44ELP, ME-8105LP, etc.) of Dainichiseika Color & Chemicals Mfg.Co., Ltd. An elastomer derived from a reaction product of a precursor and an isocyanate crosslinking agent such as CORONATE L-55E of Nippon Ployurethane Industry Co., Ltd. and TAKENATE D-160N of Mitsui Chemicals, Inc., KURAMIRON U1000 of KURARAY CO., LTD. Series (model numbers 1180, 1190, etc.) and 9000 series (model numbers 9180, 9185, etc.) elastomers.

(b) thermally conductive filler

The thermally conductive filler is not particularly limited as long as it can provide a film with a thermal conductivity of 0.5 W/m·K or more and a thermal emissivity of 0.85 or more. Specifically, at least one selected from alumina, titania, zirconia, ferrite, silica, zinc oxide, magnesium oxide, aluminum carbide, silicon carbide, aluminum nitride, boron nitride, carbon black, graphite, carbon fiber and melamine cyanurate. Thermal conductivity can take values such as 0.5W/mㆍK, 1.0W/mㆍK, 1.5W/mㆍK, 2.0W/mㆍK, 2.5W/mㆍK, and 3.0W/mㆍK. . The heat emissivity can be 0.85, 0.86, 0.87, 0.88, 0.89, 0.90, 0.91, 0.92, 0.95.

The thermally conductive filler,

Filler A selected from alumina, titania, zirconia, ferrite, silica, zinc oxide, magnesium oxide, aluminum carbide, silicon carbide, aluminum nitride, boron nitride and melamine cyanurate, and a filler selected from carbon black, graphite and carbon fiber Combination with B, or

Combination of filler C selected from alumina, titania, zirconia, ferrite, silica, zinc oxide, magnesium oxide, aluminum carbide, silicon carbide, aluminum nitride and boron nitride, and filler D of melamine cyanurate

It is preferable in order to improve the efficiency of heat conduction and heat radiation.

For example, the combination of filler A and filler B,

Alumina/carbon black, titania/carbon black, zirconia/carbon black, ferrite/carbon black, silica/carbon black, zinc oxide/carbon black, magnesium oxide/carbon black, aluminum carbide/carbon black, silicon carbide/carbon black, nitriding Aluminum/carbon black, boron nitride/carbon black and melamine cyanurate/carbon black

Alumina/graphite, titania/graphite, zirconia/graphite, ferrite/graphite, silica/graphite, zinc oxide/graphite, magnesium oxide/graphite, aluminum carbide/graphite, silicon carbide/graphite, aluminum nitride/graphite, boron nitride/graphite, Melamine cyanurate/graphite

Alumina/carbon fiber, titania/carbon fiber, zirconia/carbon fiber, ferrite/carbon fiber, silica/carbon fiber, zinc oxide/carbon fiber, magnesium oxide/carbon fiber, aluminum carbide/carbon fiber, silicon carbide/carbon fiber, nitriding Aluminum/carbon fiber, boron nitride/carbon fiber, melamine cyanurate/carbon fiber

Can be mentioned.

The combination of filler C and filler D,

Alumina/melamine cyanurate, titania/melamine cyanurate, zirconia/melamine cyanurate, ferrite/melamine cyanurate, silica/melamine cyanurate, zinc oxide/melamine cyanurate, magnesium oxide/melamine cyanurate , Aluminum carbide/melamine cyanurate, silicon carbide/melamine cyanurate, aluminum nitride/melamine cyanurate, boron nitride/melamine cyanurate

Can be mentioned.

A more preferred combination is,

ㆍA combination of a filler selected from alumina, silicon carbide, aluminum nitride, and melamine cyanurate with a filler of carbon black, or

ㆍIt is a combination of alumina filler and melamine cyanurate filler.

It is preferable that the thermally conductive filler has a small particle diameter in order to improve the efficiency of thermal conduction. For example, the particle diameter is preferably 20 µm or less, and more preferably 10 µm or less. It is preferable that the lower limit of the particle size is 0.1 µm from the viewpoint of easiness of work and availability. The particle diameter may take 0.1㎛, 1㎛, 5㎛, 10㎛, 15㎛, 20㎛.

The particle diameter can be measured by a laser diffraction/scattering method.

(c) Urethane resin and thermally conductive filler

The content ratio of the urethane-based resin and the thermally conductive filler is not particularly limited as long as it is capable of providing a predetermined thermal conductivity, thermal radiation, tensile strength and film thickness to the film. For example, the thermally conductive filler is preferably contained within the range of 100 to 600 parts by weight, and more preferably contained within the range of 200 to 500 parts by weight based on 100 parts by weight of the urethane resin.

When a combination of the filler A and the filler B is used as the thermally conductive filler, the filler B is preferably contained in an amount of 0.5 to 30 parts by weight based on 100 parts by weight of the filler A. The content of the filler B may take 0.5 parts by weight, 10 parts by weight, 15 parts by weight, 20 parts by weight, 25 parts by weight, and 30 parts by weight. Further, in the case of using a combination of the filler C and the filler D, it is preferable that the filler D contains 1 to 200 parts by weight based on 100 parts by weight of the filler C. The content of the filler D may take 1 part by weight, 50 parts by weight, 100 parts by weight, 150 parts by weight, and 200 parts by weight.

(d) other ingredients

The film may contain other components within a range that does not interfere with the effects of the present invention. As other components, a coloring agent, an antistatic agent, an antioxidant, etc. are mentioned.

(e) The planar shape of the heat radiation film

The heat-radiating film is not particularly limited, and may take a planar shape according to the requirements of a device desiring heat radiation.

(Heat Radiation Adhesive Tape)

(a) adhesive layer

The heat-radiating adhesive tape means, for example, that the heat-radiating film 1 and the pressure-sensitive adhesive layer 2 are provided in the thickness direction as shown in the schematic cross-sectional view of FIG. 1. The thickness of the pressure-sensitive adhesive layer can be, for example, in the range of 3 to 50 µm. The pressure-sensitive adhesive layer may be formed on the entire surface of the thermal radiation film, or may be partially formed in a predetermined pattern. The film thickness can be 3 μm, 10 μm, 20 μm, 30 μm, 40 μm, and 50 μm.

The pressure-sensitive adhesive layer is not particularly limited, and a layer made of a known pressure-sensitive adhesive can be used. For example, an acrylic pressure-sensitive adhesive is mentioned.

As the acrylic pressure-sensitive adhesive, for example, a pressure-sensitive adhesive obtained by polymerizing an acrylic monomer optionally in the presence of a polymerization initiator, or a commercially available pressure-sensitive adhesive can be used.

(a-1) acrylic monomer

It is preferable that the acrylic monomer contains an alkyl (meth)acrylate having an alkyl group having 1 to 10 carbon atoms as a main component (50% by weight or more). In addition, (meth)acrylate means methacrylate or acrylate. do.

As an alkyl (meth)acrylate having an alkyl group having 1 to 14 carbon atoms, for example, methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl(meth)acrylate, sec-butyl(meth)acrylate, t-butyl(meth)acrylate, n-octyl(meth)acrylate, isooctyl(meth)acrylate, 2-ethylhexyl(meth)acrylate ) Acrylate, isononyl (meth)acrylate, dodecyl (meth)acrylate, and the like. These alkyl (meth)acrylates may be used alone or in combination of two or more. Among these alkyl (meth)acrylates, alkyl (meth)acrylates having an alkyl group having 1 to 8 carbon atoms are preferred, alkyl (meth)acrylates having an alkyl group having 1 to 4 carbon atoms are more preferred, and n-butyl ( Meth)acrylate is more preferable, and n-butyl acrylate is particularly preferable.

Other acrylic monomers include carboxyl group-containing monomers such as acrylic acid, methacrylic acid, and carboxy ethyl acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate. ) Acrylate, 6-hydroxyhexyl (meth)acrylate, and hydroxyl group-containing monomers such as (4-hydroxymethylcyclohexyl)-methylacrylate. These other (meth)acrylates may be used alone or in combination of two or more. It is preferable that the (meth)acrylate contains both a carboxyl group-containing monomer and a hydroxyl group-containing monomer.

The acrylic monomer contains an alkyl (meth)acrylate having an alkyl group having 1 to 10 carbon atoms as a main component. Therefore, the acrylic monomer may be made of only alkyl (meth)acrylate without using other acrylic monomers. In addition, from the viewpoint of easily obtaining a pressure-sensitive adhesive composition having a desired performance, it is preferable that less than 50% by weight and 1% by weight or more of other acrylic monomers are contained, more preferably from 5 to 30% by weight, and from 5 to It is more preferable to contain 15% by weight. The content of the acrylic monomer may be 1% by weight, 5% by weight, 10% by weight, 30% by weight, 40% by weight, or 49% by weight.

Moreover, a vinyl monomer can be added to the (meth)acrylate as needed. Examples of vinyl-based monomers include itaconic acid, maleic acid, crotonic acid, maleic anhydride, itaconic anhydride, vinyl acetate, N-vinylpyrrolidone, N-vinylcarboxylic acid amides, styrene, and N-vinyl caprolactam. And the like. These vinyl monomers may be used alone or in combination of two or more.

(a-2) polymerization initiator

As an optionally used polymerization initiator, for example, 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-methylpropionamidine) disulfide, 2,2'-azobis(4- Methoxy-2,4-dimethylvaleronitrile), 2,2'-azobis (2,4-dimethylvaleronitrile), 2,2'-azobis (2-methylbutyronitrile), 1,1 '-Azobis(cyclohexane-1-carbonitrile), 2,2'-azobis(2,4,4-trimethylpentane), dimethyl-2,2'-azobis(2-methyl propionate), 2,2'-azobis [2-methyl-N-(phenylmethyl)-propion amidine]dihydrochloride, 2,2'-azobis [2-(3,4,5,6-tetrahydropyrimidine) Azo polymerization initiators such as -2-yl)propane]dihydrochloride and 2,2'-azobis[2-(2-imidazolin-2-yl)propane]; Persulfate-based polymerization initiators such as potassium persulfate and ammonium persulfate; Benzoyl peroxide, hydrogen peroxide, t-butylhydroperoxide, di-t-butyl peroxide, t-butylperoxy benzoate, dicumyl peroxide, 1,1-bis(t-butylperoxy)-3, Peroxide polymerization initiators such as 3,5-trimethylcyclohexane, 1,1-bis(t-butylperoxy)cyclo dodecane, 3,3,5-trimethyl cyclohexanoyl peroxide, and t-butylperoxy pivalate ; And redox-based polymerization initiators composed of persulfate and sodium hydrogen sulfite. These polymerization initiators may be used alone or in combination of two or more.

The polymerization initiator is preferably used in the range of 0.005 to 1 parts by weight based on 100 parts by weight of the acrylic monomer. By using the polymerization initiator in this range, it is possible to form an acrylic pressure-sensitive adhesive having improved adhesive properties. Further, the amount of the polymerization initiator used is more preferably in the range of 0.1 to 0.5 parts by weight. The amount of the polymerization initiator may be 0.005 parts by weight, 0.01 parts by weight, 0.1 parts by weight, 0.5 parts by weight, or 1 part by weight.

(a-3) organic solvent

From the viewpoint of the ease of formation of the pressure-sensitive adhesive layer, an organic solvent may be contained. It does not specifically limit as this organic solvent, A well-known organic solvent which can be used for an adhesive composition is mentioned. For example, aliphatic hydrocarbons such as hexane and heptane, esters such as methyl acetate, ethyl acetate, and propyl acetate, and aromatic hydrocarbons such as toluene, xylene, and ethylbenzene may be mentioned. These organic solvents may be used alone or in combination of two or more.

In the case of using an organic solvent, it is preferable to prepare the use ratio so that the solid content of the acrylic pressure-sensitive adhesive is 10% by weight or more. In addition, it is more preferable that the ratio is prepared so that the solid content is 20 to 50% by weight.

(a-4) other ingredients

The acrylic pressure-sensitive adhesive may have a crosslinked structure in order to improve the shape stability of the pressure-sensitive adhesive layer. In order to impart a crosslinked structure, for example, an isocyanate-based crosslinking agent and an aluminum chelate-based crosslinking agent may be used in a range of 0.01 to 10 parts by weight based on 100 parts by weight of the acrylic pressure-sensitive adhesive. The amount of the crosslinking agent may be 0.01 parts by weight, 0.1 parts by weight, 1.0 parts by weight, 5.0 parts by weight, or 10 parts by weight.

Moreover, the acrylic adhesive may contain a thermal conductive filler in order to improve the thermal conductivity of an adhesive layer. All of the thermally conductive fillers listed in the description of the thermally radiating film can be used for this filler. The thermally conductive filler can be used in the range of 50 to 500 parts by weight based on 100 parts by weight of the acrylic pressure-sensitive adhesive. The amount of the thermally conductive filler may be 50 parts by weight, 100 parts by weight, 200 parts by weight, 350 parts by weight, or 500 parts by weight.

(b) a sheet containing a thermally conductive material

The heat-radiating adhesive tape may further include a sheet containing a heat-conductive material selected from copper, aluminum and graphite between the heat-radiative film and the pressure-sensitive adhesive layer in order to improve the thermal conductivity of the tape. As a specific configuration, as shown in Fig. 2, the sheet 3 is directly adhered to the heat-radiative film 1, and as shown in Fig. 3, the sheet 3 is attached to the heat-radiating film 1 through the pressure-sensitive adhesive layer 4 A configuration to make it close is mentioned.

This sheet can be used as it is, in the case where the sheet-like shape can be maintained only by a thermally conductive material such as copper foil. Moreover, in the case of using a particulate thermally conductive material, it can be made into a sheet shape by mixing with a resin binder.

The thickness of the sheet is not particularly limited as long as it does not impair thermal conductivity, and may be, for example, 10 to 5000 µm.

(Use of heat radiation film and heat radiation adhesive tape)

The heat-radiating film and the heat-radiating adhesive tape can be used in any application as long as it is desired to release the generated heat to the outside. For example, it may be used for heat dissipation of electric equipment such as motors and lighting, and electronic equipment such as LSI, IC, and resistance. In particular, in recent years, it is suitable for use in a cell phone, which is remarkably thinned, and displays such as liquid crystal and organic EL, in order to be able to utilize the film and tape of the present invention that are thin films.

Example

Hereinafter, the present invention will be further described using examples, but the present invention is not limited to the following examples. In addition, the order of implementation of the method of measuring the thermal conductivity, thermal emissivity and tensile strength of the thermally radiating film, and the heat dissipation effect test method of the thermally radiating adhesive tape is as follows.

(Thermal conductivity)

The measurement of the thermal conductivity is carried out using the normal method thermal conductivity measurement device GH-1 of Ulvac-Riko Inc. The heat-radiating film is picked up with an aluminum plate having a diameter of 50 mm, the clamping material is set in a measuring device, and the thermal conductivity is measured in accordance with ASTM E1530.

(Heat emissivity)

The measurement of heat emissivity is carried out using a heat emissivity meter D&S AERD of Kyoto Electronics Manufacturing Co., Ltd. A measurement sample is obtained by cutting the heat-radiative film into a size of 60 mm in width and length. After calibrating the thermal emissivity meter with a standard sample, measure the thermal emissivity by setting the measurement sample in the thermal emissivity meter.

(The tensile strength)

A measurement sample is obtained by cutting the heat-radiative film into a size of 20 mm in width and 100 mm in length. Shimadzu Corporation. Autograph AGS-H is set so that both sides of the measurement sample are fixed, and the measurement sample is pulled at a tensile speed of 300 mm/min. The force when the measurement sample is broken is measured, and the obtained value is taken as the tensile strength (N/20mm).

(Heating effect test)

A heater (output 10 W, width 25 mm, length 50 mm) is formed in the center of the lower surface of a 70 µm-thick copper foil (150 mm in width and length) using a 10 µm-thick adhesive. A thermocouple is installed in the center of the heater, and the thermocouple is placed on an insulating material, and then the heater is heated with a constant power (10W). The temperature after 15 minutes of heating is measured. The obtained temperature is taken as the reference temperature.

Next, after attaching a heat-radiative adhesive tape on the copper foil, the temperature after heating 15 minutes is measured in the same manner as in the measurement procedure of the reference temperature. Fig. 4(a) and (b) show schematic diagrams of the installation situation at the time of measurement. Fig. 4(a) is a plan view, and Fig. 4(b) is a side view. In the figure, a denotes a heat radiation adhesive tape, b denotes a copper foil, c denotes a heater, d denotes a thermocouple, and e denotes a heat insulating material.

The heat dissipation effect is evaluated using the value obtained by subtracting the reference temperature from the measured temperature. A case where the subtraction value is -10°C or less is evaluated as ◯ because the heat dissipation effect is large, and a case higher than -10°C is evaluated as x because the heat dissipation effect is insufficient.

Example One

(Heat radiation film)

To 286 parts by weight of a urethane resin precursor (DAIFERAMINE MAU-5022 of Daiichiseika Color & Chemicals Mfg. Co., Ltd., 35% by weight solid content, 60 to 70 thousand weight average molecular weight), an isocyanate-based crosslinking agent (Nippon Ployurethane Industry Co., Ltd.) CORONATE L-55E, solid content 55% by weight) 57 parts by weight, alumina (AL-47H by SHOWA DENKO KK, particle diameter 2 μm) 400 parts by weight and carbon black (CB4873 by Taihei Chemical Industrial Co., Ltd.) 12 parts by weight Part was added and stirred. After stirring, the composition for producing a heat-radiative film was obtained by defoaming.

The obtained composition was applied on a release liner to a predetermined thickness. The obtained coating film was dried at 100° C. for 2 minutes and then cured at 40° C. for 3 days to obtain a heat-radiating film having a thickness of 25 μm.

(Heat Radiation Adhesive Tape)

91 parts by weight of n-butyl acrylate, 8 parts by weight of acrylic acid, 1 part by weight of 2-hydroxyethyl methacrylate, 0.2 parts by weight of azobisisobutyronitrile (AIBN, polymerization initiator), solvent (ethyl acetate: toluene = 9 :1 (weight ratio)) 150 parts by weight were mixed. The obtained mixture was reacted at 85° C. for 5 hours in a nitrogen stream to obtain an acrylic pressure-sensitive adhesive having a solid content of 40% by weight and a viscosity of 7000 mP·s.

To 100 parts by weight of the acrylic pressure-sensitive adhesive, 1 part by weight of an isocyanate-based crosslinking agent (CORONATE L-55E from Nippon Ployurethane Industry Co., Ltd.) and 120 parts by weight of alumina (AL-47H from SHOWA DENKO K.K) were added and stirred. After stirring, the composition for producing an adhesive layer was obtained by defoaming.

The obtained composition was applied on a release liner to a predetermined thickness. The obtained coating film was dried at 100° C. for 2 minutes to form a pressure-sensitive adhesive layer having a thickness of 25 μm. After transferring the pressure-sensitive adhesive layer to the heat-radiative film, the heat-radiating pressure-sensitive adhesive tape was obtained by curing the pressure-sensitive adhesive layer at 40° C. for 3 days.

Example 2

A heat-radiating adhesive tape was obtained in the same manner as in Example 1 except that the addition amount of alumina contained in the composition for producing a heat-radiative film was 200 parts by weight.

Example 3

A heat-radiating adhesive tape was obtained in the same manner as in Example 1 except that the addition amount of alumina contained in the composition for producing a heat-radiative film was 500 parts by weight.

Example 4

Except for the addition amount of alumina contained in the composition for producing a heat-spinning film is 180 parts by weight, and 80 parts by weight of melamine cyanurate (MC-6000, particle diameter of 2 μm) instead of carbon black was added. In the same manner as in Example 1, a heat-radiating adhesive tape was obtained.

Example 5

A heat-radiating adhesive tape in the same manner as in Example 1, except that 170 parts by weight of melamine cyanurate (MC-6000 of NISSAN CHEMICAL INDUSTRIES, LTD., particle diameter 2 μm) was added instead of alumina contained in the composition for producing a heat-radiative film. Got it.

Example 6

A heat-radiating adhesive tape was obtained in the same manner as in Example 1 except that aluminum nitride (H grade, particle diameter of 1 μm) was added instead of alumina contained in the composition for producing a heat-radiative film.

Example 7

A heat-radiating adhesive tape was obtained in the same manner as in Example 1 except that silicon carbide (H3000 manufactured by Shin-Etsu Denki Seylene, particle diameter 4 µm) was added instead of alumina contained in the composition for producing a heat-radiative film.

Example 8

131 parts by weight of a urethane-based thermoplastic resin (KURAMIRON U1190 of KURARAY CO., LTD., solid content 100% by weight) was dissolved in 131 parts by weight of N,N'-dimethylformamide at 60°C. To the obtained solution, 400 parts by weight of alumina (AL-47H of SHOWA DENKO K.K., particle diameter of 2 µm) and 12 parts by weight of carbon black (CB4873 of Taihei Chemical Industrial Co., Ltd.) were added and stirred. After stirring, the composition for producing a heat-radiative film was obtained by defoaming.

The obtained composition was applied on a release liner to a predetermined thickness. The obtained coating film was dried at 150° C. for 3 minutes and then cured at 40° C. for 3 days to obtain a heat-radiating film having a thickness of 25 μm.

Except using the said film, it carried out similarly to Example 1, and obtained the heat-radiating adhesive tape.

Example 9

As the urethane-based thermoplastic resin, a heat-radiating adhesive tape was obtained in the same manner as in Example 8, except that KURAMIRON U9185 (solid content 100% by weight) of KURARAY CO., LTD. was used.

Comparative Example 1

A heat-radiating adhesive tape was obtained in the same manner as in Example 1 except that alumina was not added to the composition for producing a heat-radiative film.

Comparative example 2

A heat-radiative film was attempted to be prepared in the same manner as in Example 1, except that the amount of alumina contained in the composition for producing a heat-radiative film was 700 parts by weight, but the film could not be formed.

Comparative Example 3

A heat-radiating adhesive tape was obtained in the same manner as in Example 1 except that carbon black was not added to the composition for producing a heat-radiative film.

Comparative example 4

In the same manner as in Example 1, except that 150 parts by weight of melamine cyanurate (MC-6000 of NISSAN CHEMICAL INDUSTRIES, LTD., particle size 2 μm) was added without adding alumina and carbon black to the composition for producing a heat-radiative film. A heat radiation adhesive tape was obtained.

Comparative Example 5

A heat-radiating adhesive tape was obtained in the same manner as in Example 1 except that 200 parts by weight of aluminum (11-0018 of Toyo Aluminum K.K.) was added without adding alumina and carbon black to the composition for producing a heat-radiating film.

Comparative example 6

Epoxy resin (YP-50EK35 of NIPPON STEEL SUMIKIN CHEMICAL CO., LTD., 35% by weight solid content, about 70,000 weight average molecular weight) 286 parts by weight of alumina (AL-47H of SHOWA DENKO KK, particle diameter 2㎛) 200 The weight part and 12 weight part of carbon black (CB4873 of Taihei Chemical Industrial Co., Ltd.) were added and stirred. After stirring, the composition for producing a heat-radiative film was obtained by defoaming.

Except for using the said composition for film production, it carried out similarly to Example 1, and obtained the heat-radiating film. The obtained film did not have sufficient tensile strength.

Comparative Example 7

A heat-radiative film was attempted to be produced in the same manner as in Comparative Example 6 except that the amount of alumina contained in the composition for producing a heat-radiative film was 400 parts by weight, but the film could not be formed into a film.

Comparative Example 8

200 parts by weight of an acrylic resin (ACRYDIC A-804 from DIC, 50% by weight solid content), 2 parts by weight of an isocyanate-based crosslinking agent (CORONATE L-55E by Nippon Ployurethane Industry Co., Ltd., 55% by weight solid content), alumina (SHOWA 200 parts by weight of DENKO KK's AL-47H, particle diameter of 2 µm) and 12 parts by weight of carbon black (CB4873 of Taihei Chemical Industrial Co., Ltd.) were added and stirred. After stirring, the composition for producing a heat-radiative film was obtained by defoaming.

A heat-radiative film was obtained in the same manner as in Example 1, except that the composition for film production was used. The obtained film did not have sufficient tensile strength.

Comparative Example 9

A heat-radiative film was attempted to be produced in the same manner as in Comparative Example 8 except that the amount of alumina contained in the composition for producing a heat-radiative film was 400 parts by weight, but the film could not be formed.

Comparative Example 10

100 parts by weight of a polyester-based thermoplastic resin (ER-1082 from Mitsubishi Rayon Co., Ltd., solid content 100% by weight, weight average molecular weight of about 30,000) was dissolved in 100 parts by weight of ethyl acetate at 50°C. To the obtained solution, 200 parts by weight of alumina (AL-47H of SHOWA DENKO K.K., particle diameter of 2 µm) and 12 parts by weight of carbon black (CB4873 of Taihei Chemical Industrial Co., Ltd.) were added and stirred. After stirring, the composition for producing a heat-radiative film was obtained by defoaming.

The obtained composition was applied on a release liner to a predetermined thickness. The obtained coating film was dried at 100° C. for 3 minutes and then cured at 40° C. for 3 days to obtain a thermally radiating film having a thickness of 25 μm. The obtained film did not have sufficient tensile strength.

Comparative Example 11

A heat-radiative film was attempted to be produced in the same manner as in Comparative Example 10 except that the amount of alumina contained in the composition for producing a heat-radiative film was 400 parts by weight, but the film could not be formed.

Table 1 shows the results of various tests of the obtained heat-radiative film and heat-radiative adhesive tape, together with the material type and amount used.

Fig. 5 shows a graph showing the change over time of the measurement temperature in the heat dissipation effect test of the heat-radiating adhesive tapes of Example 1 and Comparative Example 1. In Fig. 5, a graph of a heat-radiating adhesive tape not provided with a heat-radiating film is also combined and shown.

From Table 1 and FIG. 5, it was confirmed that the heat-radiating film of the Example having a thermal conductivity of 0.5 W/m·K or more, a thermal emissivity of 0.85 or more, a tensile strength of 5 N/20 mm or more, and a film thickness of 10 to 30 μm has a high heat radiation effect Has become.

1: heat radiation film
2, 4: adhesive layer
3: Thermally conductive material (sheet)
a: heat radiation adhesive tape
b: copper foil
c: heater
d: thermocouple
e: insulation

Claims (9)

It includes a urethane-based resin and a thermally conductive filler, has a thermal conductivity of 0.5W/m·K or more, a thermal emissivity of 0.85 or more, a tensile strength of 5N/20mm or more, and a film thickness of 10 to 30㎛,
The thermally conductive filler,
ㆍFiller A selected from alumina, titania, zirconia, ferrite, silica, zinc oxide, magnesium oxide, aluminum carbide, silicon carbide, aluminum nitride, boron nitride and melamine cyanurate, and carbon black, graphite and carbon fiber Combination with filler B, or
It is a combination of a filler C selected from alumina, titania, zirconia, ferrite, silica, zinc oxide, magnesium oxide, aluminum carbide, silicon carbide, aluminum nitride and boron nitride, and filler D of melamine cyanurate,
The thermally conductive filler is a thermal radiation film containing 100 to 600 parts by weight based on 100 parts by weight of the urethane-based resin. delete delete The heat-radiating film according to claim 1, wherein the filler B is included in an amount of 0.5 to 30 parts by weight, and the filler D is included in an amount of 1 to 200 parts by weight with respect to 100 parts by weight of the filler C. . The method of claim 1, wherein the thermally conductive filler,
ㆍA combination of a filler selected from alumina, silicon carbide, aluminum nitride, and melamine cyanurate with a filler of carbon black, or
ㆍThermal radiation film which is a combination of alumina filler and melamine cyanurate filler. The thermally radiating film according to claim 1, wherein the urethane-based resin has a tensile strength of 5N/20mm or more when the thickness of the urethane-based resin is 25 μm. A heat radiation adhesive tape comprising the heat radiation film according to claim 1 and an adhesive layer in the thickness direction. The thermally radiating adhesive tape according to claim 7, further comprising a sheet comprising a thermally conductive material selected from copper, aluminum, and graphite between the thermally radiating film and the pressure-sensitive adhesive layer. The heat-radiating adhesive tape according to claim 8, further comprising a pressure-sensitive adhesive layer between the heat-radiating film and the sheet containing a heat-conductive material.

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