Heat dissipating sound insulation sheet and method for manufacturing same

Abstract

Disclosed is a heat dissipating sound insulation sheet 1 which includes sound insulation sheet layers 2a-2e and thermally conductive sheet layers 3a-3e, wherein: the thermally conductive sheet layers 3a-3e contain a matrix resin and a thermally conductive filler; and a plurality of the sound insulation sheet layers 2a-2e and a plurality of the thermally conductive sheet layers 3a-3e are stacked facing the thickness direction of the heat dissipating sound insulation sheet 1. In this manufacturing method, a thermally conductive composition and the sound insulation sheet are placed on a base material sheet, and another base material sheet is placed thereon so as to subject the thermally conductive composition to roll rolling and to subsequently obtain a single multilayer sheet of the sound insulation sheet layer and the thermally conductive sheet layer. A plurality of single multilayer sheets are stacked so as to obtain a laminate of the multilayer sheets, and the heat dissipating sound insulation sheet is obtained by cutting the laminate of the multilayer sheets in the thickness direction. As a result, the present invention provides: a heat dissipating sound insulation sheet which has thermal conductivity and sound insulation properties in a balanced manner; and a method for manufacturing the same.

Description

Heat dissipation and soundproofing sheet and its manufacturing method

[0001] The present invention relates to a heat-dissipating and sound-proofing sheet having thermal conductivity and soundproofing properties, and a method for producing the same.

[0002] The driving noise of compressors used in air conditioners for electric vehicles is unpleasant, so soundproofing is performed using soundproofing materials. Glass wool is a well-known soundproofing material. Patent Document 1 proposes a soundproof sheet including a nonwoven fabric layer containing an ultrafine fiber layer and a thick fiber layer, and a glass wool layer. Patent Document 2 proposes a soundproof panel including a flame-retardant tarpaulin sheet and a glass wool molded sheet.

[0003] JP 2022-135554 A JP 2021-067087 A

[0004] However, the sound absorption coefficient of the soundproof sheets of the above-mentioned prior art is still insufficient, and the thermal conductivity has not been improved, so further improvement is required.

[0005] In order to solve the above-mentioned problems of the prior art, the present invention provides a heat-dissipating and sound-proofing sheet having a good balance between thermal conductivity and soundproofing properties, and a method for manufacturing the same.

[0006] One embodiment of the present invention relates to a heat-dissipating soundproof sheet including a soundproof sheet layer and a thermally conductive sheet layer, wherein the thermally conductive sheet layer is a sheet layer including a matrix resin and a thermally conductive filler, and the soundproof sheet layer and the thermally conductive sheet layer are laminated in multiple layers facing in the thickness direction of the heat-dissipating soundproof sheet.

[0007] Another embodiment of the present invention relates to a method for producing the heat-dissipating soundproof sheet, which includes placing a thermally conductive composition and a soundproof sheet on a base sheet, placing another base sheet on top of the thermally conductive composition and rolling the thermally conductive composition to form a laminated single sheet of a soundproof sheet layer and a thermally conductive sheet layer, stacking a plurality of the single laminate sheets to form a multi-layer laminate sheet, and cutting the multi-layer laminate sheet in the thickness direction to obtain the heat-dissipating soundproof sheet.

[0008] The heat-dissipating and soundproofing sheet of the present invention comprises a soundproofing sheet layer and a thermally conductive sheet layer, the thermally conductive sheet layer being a sheet layer of a composition containing a matrix resin and a thermally conductive filler, and the soundproofing sheet layer and the thermally conductive sheet layer being laminated in multiple layers facing the thickness direction of the heat-dissipating and soundproofing sheet, thereby providing a heat-dissipating and soundproofing sheet with a good balance between thermal conductivity and soundproofing properties, and a method for manufacturing the same.

[0009] FIG. 1A is a schematic perspective view of a heat-dissipating and sound-proof sheet according to one embodiment of the present invention, and FIG. 1B is a schematic cross-sectional view taken along line II of FIG. 1A. FIG. 2A is a schematic cross-sectional process diagram of a heat-dissipating and sound-proof sheet according to one embodiment of the present invention, showing a process in which a thermally conductive sheet is placed on a substrate sheet. FIG. 2B is a schematic cross-sectional process diagram of the same, showing a process in which a thermally conductive sheet, a soundproofing sheet, and a substrate sheet are placed on a substrate sheet. FIG. 2C is a schematic cross-sectional process diagram of the same, showing a process in which the sheet has been rolled from the state of FIG. 2B and the soundproofing sheet has been pressed into the heat-conductive sheet. FIG. 2D is a schematic cross-sectional process diagram of the same, showing a process in which the upper substrate sheet has been peeled off from the state of FIG. 2C. FIG. 2E is a schematic cross-sectional process diagram of the same, showing a process in which a laminate of a soundproofing sheet and a thermally conductive sheet has been laminated from the state of FIG. 2D. FIG. 2F is a schematic cross-sectional process diagram of the same, showing a process in which an end portion has been cut from the state of FIG. 2E. Figure 2G is a schematic cross-sectional process diagram of the same, showing the process of cutting the multi-layer laminated sheet from the state of Figure 2F in the thickness direction to form a heat-dissipating, sound-proof sheet. Figures 3A-B are schematic explanatory diagrams showing a method for measuring the thermal conductivity of a sample in one embodiment of the present invention. Figure 4 is a graph showing the normal incidence sound absorption coefficient of an embodiment of the present invention and a comparative example.

[0010] The present invention provides a heat-dissipating soundproof sheet including a soundproof sheet layer and a thermally conductive sheet layer. The thermally conductive sheet layer is a sheet layer of a composition including a matrix resin and a thermally conductive filler, and the matrix resin is preferably a thermosetting resin. Thermosetting resins exhibit little dimensional change even when heated and have high durability. Thermally conductive fillers are preferred because of their high thermal conductivity.

[0011] The soundproof sheet layer and the thermally conductive sheet layer are laminated in multiple layers facing the thickness direction (cross-sectional direction) of the heat-dissipating soundproof sheet. This allows for a practical level of soundproofing and high thermal conductivity in the thickness direction. Furthermore, thermal conductivity and soundproofing are inversely proportional, meaning that increasing thermal conductivity reduces soundproofing, and increasing soundproofing reduces thermal conductivity. However, the present invention provides a heat-dissipating soundproof sheet with a good balance between thermal conductivity and soundproofing. The multiple layers may be any number of layers, as long as each layer is two or more, for example, 2 to 1,000 layers.

[0012] The soundproof sheet layer and the thermally conductive sheet layer are preferably laminated in parallel (striped) configuration, which is easy to fabricate, provides a practical level of soundproofing, and increases thermal conductivity in the thickness direction.

[0013] The soundproof sheet layer is preferably a glass wool sheet layer, a rock wool sheet layer, a ceramic fiber sheet layer, a synthetic fiber nonwoven fabric sheet layer, or a foamed resin sheet layer. These sheets have high soundproofing properties. The synthetic fiber is preferably a polyester such as polyethylene terephthalate, a polyolefin such as polypropylene, or a polyamide such as nylon 6, and is preferably in the form of a nonwoven fabric, woven fabric, knitted fabric, mat, or the like. The foamed resin sheet layer is preferably made of silicone, polyurethane, or other resin, and the foaming ratio is preferably 1.1 to 5 times.

[0014] The thickness of each soundproof sheet layer is preferably 0.5 to 10 mm, more preferably 1 to 9 mm, and even more preferably 2 to 8 mm, to provide suitable soundproofing properties.

[0015] The matrix resin is preferably a cured silicone resin. The silicone resin is preferably silicone rubber or silicone gel. Silicone resin is heat resistant and is safe for shielding noise sources such as compressors and motors that generate heat. Among these, addition reaction curing silicone rubber is preferred because it can be cured at a relatively low temperature and cures uniformly throughout. For example, it can be heated and cured at 100 to 120°C for 10 to 15 minutes.

[0016] The thickness of the thermally conductive sheet layer is preferably 0.5 to 5 mm, more preferably 0.7 to 4.5 mm, and even more preferably 1 to 4 mm. This thickness can increase the thermal conductivity and improve the heat dissipation characteristics.

[0017] When the thickness of one soundproof sheet layer is S and the thickness of the thermally conductive sheet layer is T, it is preferable that S ≥ T. If the thicknesses of both layers satisfy the above relationship, a good balance between heat dissipation characteristics (thermal conductivity) and soundproofing properties is achieved.

[0018] The thermal conductivity of the thermally conductive sheet layer in accordance with ISO 22007-2:2008, hot disk method, is preferably 0.5 to 20 W / m K, more preferably 0.5 to 18 W / m K, and even more preferably 0.6 to 15 W / m K. This improves the heat dissipation characteristics.

[0019] The tack value of the thermally conductive sheet layer is preferably 0.3 N or more, more preferably 0.3 to 20 N, and even more preferably 0.4 to 18 N. This increases the adhesion to the heat-generating equipment that generates noise, improving the heat dissipation characteristics. Furthermore, it increases the adhesive strength with the soundproof sheet layer, allowing for lamination and integration without the use of adhesive. The tack value is a numerical value that expresses stickiness, and can be measured using a tackiness tester or tackiness checker.

[0020] The thickness of the heat-dissipating and sound-proof sheet is preferably 1 to 50 mm, more preferably 2 to 45 mm, and even more preferably 3 to 40 mm. This thickness is effective in blocking noise sources.

[0021] The interface between the soundproof sheet layer and the thermally conductive sheet layer may be bonded with a primer. Bonding with a primer can further strengthen the unity between the soundproof sheet layer and the thermally conductive sheet layer. As the primer, an epoxy resin, a silane coupling agent, a hot melt adhesive sheet, etc. can be used. The silane coupling agent is a compound having a structure of R(CH ３ ) ａ Si(OR') ４－ａ (R is an unsubstituted or substituted organic group having 1 to 20 carbon atoms, R' is an alkyl group having 1 to 4 carbon atoms, and a is 0 or 1), or a partial hydrolyzate thereof. ３ )ａ Si(OR') ４－ａ Examples of alkoxysilane compounds (hereinafter simply referred to as "silanes") represented by the formula (R is an unsubstituted or substituted organic group having 1 to 20 carbon atoms, R' is an alkyl group having 1 to 4 carbon atoms, and a is 0 or 1) include methyltrimethoxysilane, ethyltrimethoxysilane, propyltrimethoxysilane, butyltrimethoxysilane, pentyltrimethoxysilane, hexyltrimethoxysilane, hexyltriethoxysilane, octyltrimethoxysilane, octyltriethoxysilane, decyltrimethoxysilane, decyltriethoxysilane, dodecyltrimethoxysilane, dodecyltriethoxysilane, hexadecyltrimethoxysilane, hexadecyltriethoxysilane, octadecyltrimethoxysilane, and octadecyltriethoxysilane. These silane compounds can be used alone or in combination.

[0022] The method for producing the heat-dissipating, sound-proof sheet of the present invention preferably includes the following steps. (1) Step for producing a laminated single sheet: A thermally conductive composition and a sound-proof sheet are placed on a substrate sheet, and then another substrate sheet is placed on top of that and the thermally conductive composition is rolled to form a laminated single sheet of a sound-proof sheet layer and a thermally conductive sheet layer. At this time, the sound-proof sheet layer and the thermally conductive sheet layer may be pressurized and heated to harden the thermally conductive sheet layer, or the interface between the two layers may be bonded with a primer. (2) Step for producing a multi-layered laminate sheet: A plurality of the above-mentioned single laminate sheets are laminated to form a multi-layered laminate sheet. At this time, the thermally conductive sheet layer may be further hardened by heating, or the interfaces between the single laminate sheets may be bonded with a primer. (3) Step for cutting: The above-mentioned multi-layered laminate sheet is cut in the thickness direction to obtain a heat-dissipating, sound-proof sheet.

[0023] The thermally conductive sheet layer is preferably prepared by adding 100 to 3,500 parts by mass of a thermally conductive filler to 100 parts by mass of a matrix resin and mixing them to form a compound composition. The thermally conductive filler is preferably inorganic particles such as aluminum oxide (alumina), zinc oxide, magnesium oxide, aluminum nitride, boron nitride, aluminum hydroxide, or silicon carbide.

[0024] A part or all of the inorganic particles are RaSi(OR') ４－ａ (wherein R is an unsubstituted or substituted organic group having 6 to 12 carbon atoms, R' is an alkyl group having 1 to 4 carbon atoms, and a is 0 or 1). Preferably, R is an alkyl group having 8 to 12 carbon atoms. This increases the affinity of the inorganic particles with the matrix resin, making them easier to mix with. Specific compounds are as described above.

[0025] The matrix resin of the present invention may contain other components as needed. For example, heat resistance improvers such as red iron oxide, titanium oxide, and cerium oxide, flame retardants, and flame retardant assistants may be added. Organic or inorganic particle pigments may be added for coloring or toning purposes. Alkoxy group-containing silicones may be added as materials for filler surface treatment, etc.

[0026] In one example, the heat-dissipating and sound-proof sheet of the present invention is placed around a compressor, a noise source, with the sound-proofing sheet layer and the thermally conductive sheet layer stacked in the direction toward the noise source. The heat-dissipating and sound-proof sheet is preferably placed around the compressor by directly wrapping the heat-dissipating and sound-proof sheet around the compressor or by molding the heat-dissipating and sound-proof sheet into a box shape and placing the compressor inside. For example, the heat-dissipating and sound-proof sheet can be directly wrapped around the compressor of an electric vehicle air conditioner, or molded into a box shape and placing the compressor inside. Heat generated by the compressor is transferred to the outside through the thermally conductive sheet layer, and this heat can be cooled by introducing air from outside the vehicle and / or by blowing air from a fan. Aluminum foil or stainless steel foil, which has high cooling properties, may also be placed in contact with the compressor.

[0027] The following description will be made with reference to the drawings. In the following drawings, the same reference numerals indicate the same parts. Fig. 1A is a schematic perspective view of a heat-dissipating and soundproof sheet 1 according to one embodiment of the present invention, and Fig. 1B is a schematic cross-sectional view taken along line II in Fig. 1A. This heat-dissipating and soundproof sheet 1 is formed by laminating soundproof sheets 2a-2e and thermally conductive sheets 3a-3e together.

[0028] Figures 2A-G are schematic cross-sectional process diagrams of a heat-dissipating, sound-proofing sheet according to one embodiment of the present invention. Figure 2A is a process diagram showing a thermally conductive sheet 3a placed on a base sheet (polyester film) 4. Figure 2B is a schematic cross-sectional process diagram showing a thermally conductive sheet 3a, a soundproofing sheet 2a, and a base sheet 5 placed on the base sheet 4. Figure 2C is a schematic cross-sectional process diagram showing a state in which the soundproofing sheet 2a is pressed into the thermally conductive sheet 3a after roll-rolling from the state shown in Figure 2B. Figure 2D is a schematic cross-sectional process diagram showing a state in which the upper base sheet has been peeled off from the state shown in Figure 2C. Figure 2E is a schematic cross-sectional process diagram showing a state in which the soundproofing sheets 2a-2c and the thermally conductive sheets 3a-3c are laminated together from the state shown in Figure 2D. In this process, it is preferable to heat and harden the thermally conductive sheet 3a. Figure 2F is a schematic cross-sectional process diagram showing a state in which the edge has been cut with a cutter 6 from the state shown in Figure 2E. FIG. 2G is a schematic cross-sectional process diagram of the same, showing a process for cutting the multi-layer laminated sheet from the state of FIG. 2F in the thickness direction with a cutter 6 to obtain the heat-dissipating soundproof sheet 1.

[0029] The present invention will be described below using examples, but is not limited to these examples. Various parameters were measured by the following methods.

[0030] <Thermal Conductivity> The thermal conductivity was measured using a hot disk (compliant with ISO 22007-2:2008). As shown in FIG. 3A, this thermal conductivity measuring device 11 sandwiches a polyimide film sensor 12 between two samples 13a and 13b. A constant power is applied to the sensor 12, causing it to generate a constant amount of heat, and the thermal characteristics are analyzed from the temperature rise of the sensor 12. The sensor 12 has a 7 mm diameter tip 14 and, as shown in FIG. 3B, a double spiral electrode structure, with an applied current electrode 15 and a resistance value electrode (temperature measurement electrode) 16 located at the bottom. The measurement sample can be obtained by rolling a degassed thermally conductive liquid composition to a thickness of 7 mm or more. The thermal conductivity is calculated using the following formula (Equation 1): <Tack Value> This was measured using a tackiness checker (manufactured by Toyo Seiki Co., Ltd.). The contact was pressed against an object with a certain pressure and time, and the stress when peeled off was detected using a load cell method. In the examples below, the pressure of the tackiness checker (manufactured by Toyo Seiki Co., Ltd.) was 5 N, and the time was 3 seconds. <Normal Incidence Sound Absorption Coefficient> The normal incidence sound absorption coefficient was measured in accordance with JIS A1405-2 (2007).

[0031] Example 1 1 Preparation of Thermally Conductive Silicone Rubber Sheet (1) Silicone Component A commercially available two-component room-temperature curing silicone rubber (addition reaction curing silicone rubber) was used as the silicone component. The two-component room-temperature curing silicone rubber had a base polymer component and a platinum-based metal catalyst pre-added as part A, and a base polymer component and a crosslinking component pre-added as part B. Part A and part B were used in a 50:50 ratio. (2) Thermally Conductive Particles (a) Small Particle Size Thermally Conductive Particles The small particle size thermally conductive particles were alumina with an average particle size of 1 μm that was surface-treated with a silane coupling agent. The amount added was 50 parts by weight per 100 parts by weight of the silicone component. The average particle size was measured using a laser diffraction / light scattering method, measuring the 50% mass particle size (the same applies below). The measuring instrument used was a Horiba, Ltd. laser diffraction / scattering particle distribution analyzer LA-950S2. (b) Medium-sized thermally conductive particles: The medium-sized thermally conductive particles were alumina with an average particle size of 3 μm, surface-treated with a silane coupling agent. The amount added was 200 parts by weight per 100 parts by weight of the silicone component. (c) Large-sized thermally conductive particles: Two types of large-sized thermally conductive particles were used, but neither was surface-treated with a silane coupling agent. (i) Alumina with an average particle size of 50 μm was used. The amount added was 200 parts by weight per 100 parts by weight of the silicone component. (d) Amount of thermally conductive particles: 50 parts by weight of small-sized thermally conductive particles, 200 parts by weight of medium-sized thermally conductive particles, and 200 parts by weight of large-sized thermally conductive particles were added to 100 parts by weight of the silicone component, for a total of 450 parts by weight. (3) Sheet characteristics: The compound was placed on a release-treated polyester film, and another release-treated polyester film was placed on top. The roll spacing was adjusted to a thickness of 5 mm using a constant speed roll, and the compound sandwiched between polyester films was passed through to obtain a sheet of a uniform thickness. The compound was then cured at 120°C for 10 minutes to form a silicone rubber sheet measuring 500 mm in length, 500 mm in width, and 5.0 mm thick. The thermal conductivity of the resulting heat dissipation sheet was 1.5 W / m·K, and the hardness was 15 Shore OO. The cut surface of this thermally conductive silicone sheet was measured using a tackiness checker, and the tack value was 0.8 N.2. Soundproofing sheet As a soundproofing sheet, glass wool (mass 1600 g / m), raw cotton for pressing, manufactured by Central Glass Fiber Co., Ltd. ２ 3. Preparation of Heat-Dissipating and Soundproof Sheet A heat-dissipating and soundproof sheet was prepared by the method shown in Figures 2A to 2G. The thickness of each soundproof sheet layer in this heat-dissipating and soundproof sheet was 5 mm, and the thickness of each thermally conductive sheet layer was 5 mm. 50 layers of each of the single-layer laminated sheets were stacked in parallel (striped) and cured at 120°C for 10 minutes without pressure. The resulting sheet had a length of 500 mm, a width of 500 mm, a thickness (thickness in the direction of noise generation) of 5 mm, and a mass of 4300 g / m ２ The tack value of the thermally conductive silicone sheet of this heat-dissipating and sound-proof sheet was also 0.8 N, the same as above.

[0032] (Comparative Example 1) As Comparative Example 1, the glass wool single sheet (mass 1600 g / m) of Example 1 was used. ２ , thickness 5 mm) was used.

[0033] (Comparative Example 2) As Comparative Example 2, the thermally conductive silicone rubber sheet of Example 1 (mass 12960 g / m ２ , thickness 5 mm) was used.

[0034] A graph of the normal incidence sound absorption coefficients of the heat-dissipating and soundproofing sheets obtained in Example 1 and Comparative Examples 1 and 2 is shown in Figure 4. A higher normal incidence sound absorption coefficient indicates a better sound absorption coefficient. As is clear from Figure 4, the heat-dissipating and soundproofing sheet of Example 1 had a lower sound absorption coefficient than the glass wool-only sheet of Comparative Example 1, but in the frequency range of 1.3 kHz or higher, it was higher than the thermally conductive silicone rubber-only sheet of Comparative Example 2, confirming that this heat-dissipating and soundproofing sheet has a good balance of thermal conductivity and soundproofing properties.

[0035] The heat-dissipating and sound-proof sheet of the present invention is suitable for use in noise reduction measures for compressors of air conditioners in electric vehicles, compressors of heat pumps, and the like.

[0036] REFERENCE SIGNS LIST 1 Heat dissipation and soundproofing sheet 2a-2e Soundproofing sheet layer 3a-3e Thermally conductive sheet layer 4, 5 Base sheet 6 Cutter 11 Thermal conductivity measuring device 12 Sensor 13a, 13b Sample 14 Sensor tip 15 Applied current electrode 16 Resistance value electrode (temperature measurement electrode)

Claims

1. A heat-dissipating, soundproofing sheet comprising a soundproofing sheet layer and a thermally conductive sheet layer, the thermally conductive sheet layer being a sheet layer containing a matrix resin and a thermally conductive filler, the soundproofing sheet layer and the thermally conductive sheet layer being laminated in a plurality of layers oriented in the thickness direction of the heat-dissipating, soundproofing sheet.

2. The heat dissipating and soundproofing sheet according to claim 1, wherein the soundproofing sheet layer and the thermally conductive sheet layer are laminated in parallel.

3. The heat dissipating soundproof sheet according to claim 1 or 2, wherein the soundproof sheet layer is at least one sheet layer selected from the group consisting of a glass wool sheet layer, a rock wool sheet layer, a ceramic fiber sheet layer, a synthetic fiber sheet layer, and a foamed resin sheet layer.

4. A heat-dissipating, soundproof sheet according to any one of claims 1 to 3, wherein the soundproof sheet layer has a thickness of 0.5 to 10 mm per layer.

5. A heat dissipating and soundproofing sheet according to any one of claims 1 to 4, wherein the matrix resin is a cured silicone resin.

6. The heat dissipating and soundproofing sheet according to any one of claims 1 to 5, wherein the thermally conductive sheet layer has a thickness of 0.5 to 5 mm per layer.

7. A heat dissipating and soundproofing sheet according to any one of claims 1 to 6, wherein the thermal conductivity of the thermally conductive sheet layer in accordance with ISO 22007-2:2008, hot disk method, is 0.5 W / m·K or more.

8. The heat dissipating and soundproofing sheet according to any one of claims 1 to 7, wherein the thermally conductive sheet layer has a tack value of 0.3 N or more.

9. The heat-dissipating and soundproofing sheet according to any one of claims 1 to 8, wherein the thickness of the heat-dissipating and soundproofing sheet in the noise generation direction is 1 to 50 mm.

10. A method for producing a heat dissipation and soundproof sheet according to any one of claims 1 to 9, comprising: placing a thermally conductive composition and a soundproof sheet on a base sheet; placing another base sheet on top of the thermally conductive composition and rolling the thermally conductive composition to form a laminated single sheet of a soundproof sheet layer and a heat conductive sheet layer; stacking a plurality of the single laminate sheets to form a multilayer laminate sheet; and cutting the multilayer laminate sheet in the thickness direction to obtain the heat dissipation and soundproof sheet.

Images