JP2011005797A - Heat insulating material for electronic part and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing a heat insulating material 10 for electronic parts which can be manufactured by extrusion molding in which a solvent is not used and production processes are reduced, and which is excellent in molding processing and also excellent in economical efficiency.SOLUTION: The heat insulating material for electronic parts is prepared by laminating a back surface layer, a foamed layer and a pressure-sensitive adhesive layer, in this order, wherein thermal conductivity at 25°C is 0.20 W/(m K) or less, a total thickness is 100 to 500 μm and the thickness of the pressure-sensitive adhesive layer occupies 2.0 to 40% of the total thickness, further, three layers of the back surface layer, foamed layer and pressure-sensitive adhesive layer are manufactured according to a multilayer coextrusion molding method, and the foaming is performed simultaneously with the film forming such that the foaming ratio of the foamed layer becomes 1.1 to 3.0 times.

Description

  The present invention relates to a heat insulating material for an electronic component, and more specifically, eliminates the influence of external heat and temperature change on the electronic component, maintains the use temperature of the electronic component appropriately, and has good adhesion to the surface of the electronic component. It is related with the heat insulating material for electronic components, and its manufacturing method.

  In the present specification, “ratio”, “part”, “%” and the like indicating the composition are based on mass unless otherwise specified, and the “/” mark indicates that they are integrally laminated. “EVA” is “ethylene-vinyl acetate copolymer”, “LDPE” is “low density polyethylene”, “LLDPE” is “linear low density polyethylene”, “HDPE” is “high density polyethylene”, and “ “MFR” is an abbreviation, functional expression, common name, or industry term for “melt flow rate”.

(Background Art) Conventionally, there are many electronic components whose performance and characteristics change depending on the use environment, outside temperature, and the like. For example, various batteries, such as a secondary battery, and a display device are mentioned. Various types of batteries, including secondary batteries such as lithium-ion batteries, are used in electronic devices such as digital cameras, mobile phones, and notebook computers. Their discharge and charge characteristics depend on the temperature of the outside air during discharge or charge. Varies depending on For this reason, there are restrictions on the temperature conditions under which an appropriate electromotive force can be obtained. If the temperature conditions are deviated, it may be difficult to obtain a practically sufficient electromotive force. The heat generated by the light emitting action in the display area of the natural light display device or the heat from the light source such as the backlight of the non-light emitting display device may cause deterioration or malfunction of the peripheral drive circuit elements. Excellent heat insulation that eliminates the effects of external heat and temperature changes on electronic components. Also, even if it is a foam, it has good appearance, good surface slipperiness, workability and mechanical suitability during use. Is also necessary. In addition, because it is installed between electronic parts and exterior parts or other adjacent external parts, it is rich in elasticity and elasticity, is foldable and lightweight, has good adhesion to the surface of electronic parts, etc. In some cases, it must be easy to peel off. However, it must not be expensive to manufacture.
Therefore, the heat insulating material for electronic parts has a good appearance even if it is a foam, has a good surface slipperiness, and is excellent in workability and mechanical suitability during use, and between the electronic parts and the exterior parts and other adjacent external parts. Because it is installed in between, it has good adhesion to the surface of electronic parts, etc., is rich in elasticity and elasticity, is foldable and lightweight, and eliminates the influence of external heat and temperature changes on electronic parts There is a need for a method of manufacturing a heat insulating material for electronic parts that can be manufactured by extrusion molding that does not use a solvent, has few manufacturing steps, has excellent molding processability, and is economical. Yes.

JP 2002-179846 A JP 2001-31487 A

  (Prior Art) Conventionally, a heat insulating material made of a composition comprising 20 to 90% by mass of rubber and 10 to 80% by mass of a resin foam is known (for example, see Patent Document 1). Further, there is known an electronic component heat insulating member that includes an outer skin that forms a gap having an airtight structure with the surface of the electronic component, and that maintains the gap in a vacuum or low pressure state (see, for example, Patent Document 2). .) However, since the thickness of the heat insulating portion is increased, it is difficult to realize downsizing and high-density mounting of the electronic device, and there are problems that the manufacturing process is complicated and the cost is high.

  In order to solve the above-described problems, the present inventors have made extensive studies and have completed the present invention. Its purpose is good appearance even with foam, good surface slipperiness, excellent workability and mechanical suitability during use, and it is installed between electronic parts and exterior parts or other adjacent outside Therefore, it has good adhesion to the surface of electronic parts, etc., is rich in elasticity and stretchability, is foldable and lightweight, and has excellent heat insulation that eliminates the effects of external heat and temperature changes on electronic parts In addition, there is provided a method for manufacturing a heat insulating material for electronic parts that can be manufactured by extrusion molding that uses no solvent, has few manufacturing steps, has excellent molding processability, and is excellent in economic efficiency. That is.

In order to solve the above problems, a heat insulating material for an electronic component according to the first aspect of the present invention is a heat insulating material for an electronic component that restricts heat conduction between the electronic component and the outside, and includes a back layer and a foam layer. And the adhesive layer are laminated in order, and the thermal conductivity at 25 ° C. is 0.20 W / m · K or less.
The heat insulating material for electronic parts according to the invention of claim 2 is such that the total thickness of the heat insulating material for electronic parts is 200 to 500 μm, and 5.0 to 30% of the total thickness is the thickness of the adhesive layer. Is.
The manufacturing method of the heat insulating material for electronic components concerning the invention of Claim 3 is a manufacturing method of the heat insulating material for electronic components in any one of Claims 1-2, Comprising: At least a back surface layer, a foam layer, and an adhesion layer Three layers are formed by a multi-layer coextrusion molding method, and foamed so that the foaming ratio of the foamed layer is 1.1 to 3.0 times at the same time as the film formation.

According to the first aspect of the present invention, even if it is a foam, the appearance is good, the surface is slippery, the workability and mechanical suitability at the time of use are excellent, the electronic parts and the exterior parts and other adjacent external parts Because it is installed in between, it has good adhesion to the surface of electronic parts, etc., is highly elastic and stretchable, is foldable and lightweight, and has the effect of external heat and temperature changes on the electronic parts. It has the effect of eliminating heat insulation.
According to the second aspect of the present invention, the surface of an electronic component or the like has better adhesion and the effect of excellent heat insulation.
According to the third aspect of the present invention, at least three layers can be formed in one step by a known inflation film forming method, and the effect of being manufactured at a lower cost is achieved.

It is sectional drawing of the heat insulating material for electronic components which shows one Example of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  (Insulation Material for Electronic Parts) As shown in FIG. 1, the insulation material for electronic parts 10 of the present invention comprises a back layer 11, a foam layer 13 and an adhesive layer 19, and has a thermal conductivity at 25 ° C. of 0.20 W / Sufficient heat insulation is obtained by setting it as m * K or less. When it exceeds 0.20 W / m · K, there is a possibility that sufficient heat insulating properties cannot be obtained.

  Since the heat insulating material 10 for electronic parts is provided with the back layer 11 and the adhesive layer 19 on both sides of the foam layer 13, it has excellent heat insulating properties and can provide adhesion to the surface of the electronic part by the adhesive layer 19. . Moreover, if the total thickness of the heat insulating material 10 for electronic parts shall be 200-500 micrometers, and less than 200 micrometers, the amount of gas to be contained will be insufficient and a foaming feeling will be insufficient, and if it exceeds 500 micrometers, since it becomes impossible to respond to size reduction of an electronic device, it is unpreferable. The thickness of the adhesive layer 19 is preferably in the range of 5.0 to 30% of the total total thickness. If the thickness of the pressure-sensitive adhesive layer 19 is less than 5.0% of the total thickness, the pressure-sensitive adhesiveness may be insufficient and the foamed layer 13 may not be supported, which is not preferable. Further, if it exceeds 30% of the whole, the rigidity of the heat insulating material 10 for electronic parts is insufficient, which is not preferable.

  Since the heat insulating material 10 for electronic parts is usually wound and stored as a long belt shape, the back layer 11 and the adhesive layer 19 that are wound and adjacent to each other may be in close contact and may not be rewound. In the electronic component heat insulating material 10 of the present invention, the adhesive force (rewinding force) between the back surface layer 11 and the adhesive layer 19 is small, and even when the electronic component heat insulating material 10 overlaps, it is easily separated. Workability is high.

  (Manufacturing method) The manufacturing method of the heat insulating material 10 for electronic components of this invention is formed by forming a back layer 11, a foam layer 13 and an adhesive layer 19 by a multi-layer coextrusion molding method, and simultaneously with the film formation, the foaming is performed. By foaming so that the expansion ratio of the layers is 1.1 to 3.0 times, at least three layers can be formed in one step, the number of manufacturing steps is reduced, and the cost is excellent and the cost is excellent. In addition, by forming a film by the multilayer coextrusion molding method, even if it is a foam, the appearance is good, the surface slipperiness is good, the workability and mechanical suitability at the time of use are excellent, and also when it is reused , Easy to peel. Furthermore, since no solvent is used in the coextrusion molding method, there is little fire hazard and environmental burden.

  (Back layer) Any material can be used as the back layer 11 as long as it is a thermoplastic resin, that is, a resin that softens reversibly at a high temperature. Specific examples of the thermoplastic resin include, for example, polyolefin resins such as polyethylene and polypropylene, polyamide resins, polyester resins such as polybutylene terephthalate and polyethylene terephthalate, polyphenylene ether resins such as vinyl chloride, polyphenylene ether and modified polyphenylene ether, Examples thereof include styrene resins such as polystyrene and heat-resistant polystyrene, acrylic resins, acrylonitrile / butadiene / styrene resins, and polycarbonate. These resins may be used alone or in combination of two or more.

  By providing the back layer 11, the foam layer 13 can be prevented from directly contacting the die lip, and the occurrence of resinous deposits (meani) on the die lip generated from the foam layer 13 during film formation can be prevented. In addition, when these thermoplastic resins are used as the back layer 11, an acid-modified resin or the like is formed between the foam layer 13 and the back layer 11 (thermoplastic resin) when forming a film by a multilayer coextrusion molding method. An adhesive resin may be used.

  (Foaming layer) The foaming layer 13 is formed by foaming a composition comprising a thermoplastic resin and a foaming agent, preferably a chemical foaming agent, simultaneously with the film formation by the multilayer coextrusion method, and the foaming ratio is 1.1. ˜3.0 times.

  (MFR of foam layer) The foam layer 13 in the laminate of the present invention is constituted by adding a foaming agent to a base resin made of a thermoplastic resin. The base resin preferably has a low MFR exhibiting high melt strength and melt elasticity, and preferably has an MFR of 0.5 to 2.0 g / 10 min. If the MFR is less than this range, the expansion ratio cannot be obtained, and if it exceeds this range, the bubble shape becomes poor.

  (Foaming agent) The chemical foaming agent is preferably an inorganic foaming agent. Organic foaming agents are undesirable because they generate decomposition gases such as ammonia gas, nitrogen gas, and carbon monoxide gas, and decomposition residues and sublimation substances cause contamination and corrosion of processing machines and metal products. . As the inorganic foaming agent used in the present invention, a foaming agent composed of sodium hydrogen carbonate whose generated gas is carbon dioxide and water vapor is suitable.

  (Addition amount) In the present invention, the above foaming agent is added in the range of 0.1 to 2.0% by mass. By adding 0.1 to 2.0% by mass of a foaming agent to the base resin, a foamed layer having a foaming ratio of 1.1 to 3.0 times can be obtained. If the expansion ratio is less than this range, the buffering property is insufficient, and if it exceeds this range, it is difficult to obtain closed cells and the surface state is deteriorated. By setting the expansion ratio to 1.1 to 3.0 times, a buffer function, handling suitability, and strength can be realized. A more preferable addition of the blowing agent is 0.2 to 1.0% by mass. If the amount is less than 0.1% by mass, the dispersion is poor and sufficient foaming cannot be obtained. If the amount exceeds 2.0% by mass, fine foaming cannot be realized, and may not easily occur during production.

  (Meani) Extrusion molding method has a defect that when it is extruded from a die, resinous deposits (Mayani) such as extruded resin composition and its oxide are generated at the outlet (die lip) of the die. Must. By providing the surface layer 11, it is possible to prevent the occurrence of resinous deposits on the die lip during the molding process, and the productivity can be improved.

  The foaming agent is generally added using a high-concentration master batch and mixed with the base resin to obtain a desired addition concentration. What is necessary is just to determine suitably the density | concentration of a masterbatch so that the foaming agent density | concentration in the foaming layer 13 may become the range of 0.1-2.0 mass%. Further, any of the back layer 11, the foam layer 13 and the adhesive layer 19 may be used within a range that does not affect the function, for example, a lubricant, a plasticizer, a filler, an antistatic agent, an antiblocking agent, a crosslinking agent, and an antioxidant. Additives such as ultraviolet absorbers, light stabilizers, colorants such as dyes and pigments, and others may be added.

  (Adhesion layer) As the resin used for the adhesion layer 19, a styrene thermoplastic elastomer, a soft propylene polymer, and an ethylene / α-olefin copolymer produced under a metallocene catalyst can be suitably used. These resins may be used alone or in combination of two or more.

  Examples of the styrene thermoplastic elastomer include a hydrogenated diene copolymer and a styrene-isobutylene block copolymer. Vinyl aromatic compounds used in the hydrogenated diene copolymer are styrene, t-butylstyrene, α-methylstyrene, p-methylstyrene, divinylbenzene, 1,1-diphenylstyrene, N, N-diethyl-p. -Aminoethyl styrene, vinyl pyridine, etc. are mentioned, Styrene and (alpha) -methylstyrene are especially preferable. Conjugated dienes are 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 2-methyl-1,3-pentadiene, 1,3-hexadiene, 4,5- Examples include diethyl-1,3-octadiene, 3-butyl-1,3-octadiene, chloroprene, etc. In order to obtain a hydrogenated diene copolymer having excellent physical properties, 1,3-butadiene, isoprene 1,3-pentadiene is preferred.

  The hydrogenated diene copolymer includes the vinyl aromatic compound polymer block (A), a conjugated diene polymer, or a random copolymer block (B) of a vinyl aromatic compound and a conjugated diene, and a vinyl aromatic compound. The conjugated diene is obtained by hydrogenating a diene block copolymer containing at least (A) and (B) of the tapered block (C) in which the vinyl aromatic compound gradually increases. Here, the diene block copolymer preferably has a configuration of (A)-(B), (A)-(B)-(A), or (A)-(B)-(C). Further, the block (A) and the block (B) do not necessarily need to be clearly distinguished, and a tapered portion where the vinyl aromatic compound gradually decreases as the block (A) shifts to the block (B). A configuration having Furthermore, in the hydrogenated diene copolymer of the present invention, 80% or more, preferably 90% or more of the conjugated diene portion of the block (B) needs to be hydrogenated and saturated. Here, when the hydrogenation rate is 80% or less, the heat resistance and weather resistance are poor.

  The styrene-isobutylene block copolymer is a (A)-(B)-(A) triblock copolymer in which the hard segment is composed of a polystyrene compound (A) and the soft segment is composed of polyisobutylene (B). is there. By making the soft segment polyisobutylene, no double bond is contained. Polystyrene compounds of the styrene-isobutylene block copolymer include styrene, o-, m-, p-methylstyrene, α-methylstyrene, β-methylstyrene, 2,6-dimethylstyrene, 2,4-dimethyl. Styrene, α-methyl-o-methylstyrene, α-methyl-m-methylstyrene, α-methyl-p-methylstyrene, β-methyl-o-methylstyrene, β-methyl-m-methylstyrene, β-methyl -P-methylstyrene, 2,4,6-trimethylstyrene, α-methyl-2,6-dimethylstyrene, α-methyl-2,4-dimethylstyrene, β-methyl-2,6-dimethylstyrene, β- Examples include methyl-2,4-dimethylstyrene. These may be used alone or in combination of two or more.

The soft propylene polymer has a melting point measured by differential scanning calorimetry of less than 120 ° C. or no melting point is observed. Here, the fact that the melting point is not observed means that a crystal melting peak having a heat of crystal melting of 1 J / g or more is not observed in the range of −40 ° C. to 200 ° C.
The soft propylene polymer has a propylene-derived constitutional unit of 40 to 100 mol%, an ethylene-derived constitutional unit of 0 to 30 mol%, and a C4 to C20 α-olefin-derived constitutional unit of 0 to 30 mol%. (Wherein the total of propylene, ethylene, and α-olefin having 4 to 20 carbon atoms is 100 mol%). More preferably, the structural unit derived from propylene is 60 to 80 mol%, the structural unit derived from ethylene is 12 to 23 mol%, and the structural unit derived from an α-olefin having 4 to 20 carbon atoms is in the range of 0 to 20 mol%. is there. The soft propylene polymer of the present invention can be produced using a metallocene catalyst for the production of isotactic polypropylene. For example, Mitsui Chemical's Notio has been promoted, and one grade is selected as appropriate. Or it can blend and use.

  The ethylene / α-olefin copolymer used in the present invention is a copolymer of ethylene and an α-olefin having 3 to 8 carbon atoms produced in the presence of a metallocene catalyst, and has a density of 0.91 or less. A thing can be used suitably. A density exceeding 0.91 is not preferable because the adhesive strength is insufficient.

  A known tackifier such as rosin and a rosin derivative, a polyterpene resin, a terpene phenol resin, a petroleum resin, or a polyethylene wax may be added to the adhesive layer 19 as long as the characteristics of the present invention are not impaired.

  (Manufacturing method) As a manufacturing method of the heat insulating material 10 for electronic components, there exist an inflation film forming method, a T-die film forming method, etc., Preferably it is an inflation film forming method. In the T-die film forming method, since the molten resin is rapidly cooled immediately after being discharged from the T-die, the transparency becomes high and it is difficult to obtain a matte texture. The inflation film forming method is preferable because cooling can be performed gradually and a matte surface with low gloss can be obtained.

  (Thickness) The electronic component heat insulating material 10 is a laminated body having a three-layer structure of a back layer 11 / foamed layer 13 / adhesive layer 19, and the total thickness is preferably 200 μm to 500 μm. If it is less than 200 μm, the amount of gas contained is small and the foaming feeling is insufficient. The thickness of the adhesive layer 19 is set to 2.0 to 40% of the total thickness of the adhesive laminate 10. If it is less than this range, the foam of the foamed layer 13 will pop or become uneven, and the appearance will be poor, and if it exceeds this range, the thickness of the foamed layer 13 will be relatively thin and the buffer function will be reduced.

  EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention further in detail, it is not limited to this.

Example 1 Using the composition of the following back layer 11, foam layer 13, and adhesive layer 19, using an inflation coextrusion film forming machine, the back layer 11 was foamed at 30 ° C. at a film forming temperature of 230 ° C. The pressure-sensitive adhesive laminate 10 of Example 1 having a total thickness of 300 μm composed of three layers of 235 μm and the pressure-sensitive adhesive layer 19 of 35 μm was obtained.
<Back layer> LDPE (density = 0.919 g / cm ³ , MFR = 2.0 g / 10 min, tensile modulus = 115 MPa)
<Foamed layer> LDPE (density = 0.919 g / cm ³ , MFR = 2.0 g / 10 min, tensile elastic modulus = 115 MPa) 97 parts by mass, Nitto Kako Co., Ltd. foaming agent masterbatch, Fine Blow S 3 parts by mass of -20N (20% master batch) was prepared.
<Adhesion layer> Kraton MD6649 made by Kraton polymer (MFR = 15 g / 10 min (190 ° C.)).
The foaming ratio of (second layer) of the laminate was 1.8 times. The physical properties are shown in Table 1.

(Example 2) Using the composition of the following back layer 11, foam layer 13, and adhesive layer 19, using an inflation coextrusion film forming machine, the back layer 11 was foamed at 15 ° C. at a film forming temperature of 230 ° C. A pressure-sensitive adhesive laminate 10 of Example 2 having a total thickness of 300 μm consisting of 3 layers of 270 μm and a pressure-sensitive adhesive layer 19 of 15 μm was obtained.
<Back side layer> 100 parts by mass of low density polyethylene resin (density = 0.919 g / cm ³ , MFR = 2.0 g / 10 min, tensile elastic modulus = 115 MPa) was adjusted.
<Foamed layer> 97 parts by mass of a low-density polyethylene resin (density = 0.919 g / cm ³ , MFR = 2.0 g / 10 min, tensile modulus = 115 MPa), a foaming agent masterbatch manufactured by Nitto Chemical Industries, 3 parts by mass of Fine Blow S-20N (20% master batch) was adjusted.
<Adhesion layer> 100 parts by mass of Dynalon 1320P (styrene content = 10%, MFR = 3.5 g / 10 min (230 ° C.)) manufactured by JSR Corporation was adjusted.
The expansion ratio of the (second layer) of the laminate was 2.0 times. The physical properties are shown in Table 1.

(Example 3) Using the composition of the following back layer 11, foam layer 13, and adhesive layer 19, using an inflation coextrusion film forming machine, the back layer 11 was foamed at a film forming temperature of 230 ° C, 15 µm. The pressure-sensitive adhesive laminate 10 of Example 3 having a total thickness of 300 μm consisting of three layers of 230 μm for the layer 13 and 55 μm for the pressure-sensitive adhesive layer 19 was obtained.
<Back side layer> 100 parts by mass of low density polyethylene resin (density = 0.919 g / cm ³ , MFR = 2.0 g / 10 min, tensile elastic modulus = 115 MPa) was adjusted.
<Foamed layer> 97 parts by mass of a low-density polyethylene resin (density = 0.919 g / cm ³ , MFR = 2.0 g / 10 min, tensile modulus = 115 MPa), a foaming agent masterbatch manufactured by Nitto Chemical Industries, 3 parts by mass of Fine Blow S-20N (20% master batch) was adjusted.
<Adhesion layer> 20 parts by mass of Kraton MD6649 (MFR = 15 g / 10 min (190 ° C.)) made of Kraton polymer, linear low density polyethylene resin, Kernel KS340T manufactured by Nippon Polyethylene Co., Ltd. (density = 0.880 g / 80 parts by mass of cm ³ , MFR = 3.5 g / 10 min) was adjusted.
The foaming ratio of (second layer) of the laminate was 1.8 times. The physical properties are shown in Table 1.

(Example 4) Using the composition of the following back layer 11, foam layer 13, and adhesive layer 19, using an inflation coextrusion film forming machine, the back layer 11 was foamed by 20 µm at a film forming temperature of 230 ° C. The pressure-sensitive adhesive laminate 10 of Example 4 having a total thickness of 300 μm consisting of three layers of 230 μm for the layer 13 and 50 μm for the pressure-sensitive adhesive layer 19 was obtained.
<Back side layer> 100 parts by mass of low density polyethylene resin (density = 0.919 g / cm ³ , MFR = 2.0 g / 10 min, tensile elastic modulus = 115 MPa) was adjusted.
<Foamed layer> 97 parts by mass of a low-density polyethylene resin (density = 0.919 g / cm ³ , MFR = 2.0 g / 10 min, tensile modulus = 115 MPa), a foaming agent masterbatch manufactured by Nitto Chemical Industries, 3 parts by mass of Fine Blow S-20N (20% master batch) was adjusted.
-<Adhesion layer> 100 mass parts of Mitsui Chemicals Co., Ltd. Notio PN-2060 (MFR = 6g / 10min (230 degreeC)) was adjusted.
The foaming ratio of (second layer) of the laminate was 1.8 times. The physical properties are shown in Table 1.

(Comparative Example 1) Using the composition of the following back layer 11, foam layer 13, and adhesive layer 19, using an inflation coextrusion film forming machine, the back layer 11 was foamed at 10 ° C. at a film forming temperature of 160 ° C. The pressure-sensitive adhesive laminate 10 of Comparative Example 1 having a total thickness of 50 μm consisting of three layers of 30 μm for the layer 13 and 10 μm for the pressure-sensitive adhesive layer 19 was obtained.
<Back side layer> 100 parts by mass of low density polyethylene resin (density = 0.919 g / cm ³ , MFR = 2.0 g / 10 min, tensile elastic modulus = 115 MPa) was adjusted.
<Foamed layer> 100 parts by mass of low density polyethylene resin (density = 0.919 g / cm ³ , MFR = 2.0 g / 10 min, tensile modulus = 115 MPa) was adjusted.
<Adhesion layer> Low-density polyethylene resin (density = 0.919 g / cm ³ , MFR = 2.0 g / 10 min, tensile elastic modulus = 115 MPa) was adjusted to 100 parts by mass.
The physical properties of the laminate are shown in Table 1.

(Comparative Example 2) Using the composition of the following back layer 11, foam layer 13 and adhesive layer 19, using an inflation coextrusion film forming machine, the back layer 11 was foamed at a film forming temperature of 160 ° C. by 10 μm. The pressure-sensitive adhesive laminate 10 of Comparative Example 2 having a total thickness of 50 μm consisting of three layers of 30 μm for the layer 13 and 10 μm for the pressure-sensitive adhesive layer 19 was obtained.
<Back side layer> 100 parts by mass of low density polyethylene resin (density = 0.923 g / cm ³ , MFR = 4.0 g / 10 min) was adjusted.
<Foamed layer> Low-density polyethylene resin (density = 0.923 g / cm ³ , MFR = 4.0 g / 10 min) was adjusted to 100 parts by mass.
-<Adhesion layer> Ethylene-methyl methacrylate copolymer resin, Aclift XM790 manufactured by Sumitomo Chemical Co., Ltd. (methyl methacrylate content = 16%, density = 0.930 g / cm ³ , MFR = 7.0 g / 10 Min) was adjusted to 100 parts by mass.
The physical properties of the laminate are shown in Table 1.

(Measurement method) Foaming magnification was determined by forming the pressure-sensitive adhesive laminates 10 of Examples and Comparative Examples and allowing them to stand at 23 ° C. for 1 day, then cutting in the thickness direction, photographing the cut surface with an optical microscope, and foaming. The expansion ratio was calculated from the area ratio of the foamed portion and the unfoamed portion of the layer 13.
The initial adhesive strength was 1 reciprocating after 1 layer reciprocation using a rubber roll (weight 2 kg, width 45 mm, roll diameter 95 mm, rubber hardness 80 ± 5 Hs) specified in JIS Z0237 on a methacryl plate having a thickness of 3 mm. The peel strength was measured at a tensile speed of 300 mm / min.
The unwinding force was cut out in a state where 10 or more laminates were overlapped, cut into a 25 mm width strip, and the peel strength on the front and back surfaces was measured at a pulling speed of 300 mm / min.
The thermal conductivity (λ) was calculated from the equation of λ = αρC using the density (ρ), thermal diffusivity (α), and specific heat capacity (C) of the laminate. Specific gravity, thermal diffusivity, and specific heat capacity were determined by the methods described below. Specific gravity measured the density of the laminated body using electronic hydrometer MD-300S (made by Alpha Mirage Co., Ltd.). For the thermal diffusivity, the thermal diffusivity at 25 ° C. was measured using a thermal diffusivity measuring apparatus LFA447 Nanoflash (manufactured by NETZSCH). The measurement direction was perpendicular to the laminate surface. The specific heat capacity was calculated based on JIS K 7123, and the specific heat capacity at 25 ° C. was calculated with a differential scanning calorimeter EXSTAR6000 (manufactured by Seiko Instruments Inc.).

(Evaluation results) All of the heat insulating materials 10 for electronic components of Examples 1 to 4 can be manufactured at a low cost in one short process, and the thermal conductivity at 25 ° C is 0.20 W / m · K or less. It showed good heat insulation. When attached to a stainless steel curved surface, it has elasticity, so it can be firmly attached and attached, there is no occurrence of wrinkles, floats, etc., and it is protected from contamination until use, so dust and dirt can be mixed in There was not, and it was pasted neatly.
Although all the heat insulating materials 10 for electronic parts of Comparative Examples 1 and 2 could be manufactured in a short process at a low cost, the heat conductivity at 25 ° C. was 0.20 W / m · K or more, and the heat insulating properties were poor. It was.

  (Industrial Applicability) The present invention includes various batteries such as a secondary battery such as a lithium ion battery and display devices such as a plasma display. The batteries and devices include digital cameras, mobile phones, laptop computers, etc. It can be used for electronic equipment. However, it is not particularly limited as long as it is excellent in heat insulating properties, adheres well to the article surface, and can be peeled off.

10: Adhesive laminate 11: Back layer 13: Foam layer 19: Adhesive layer

Claims (3)

A heat insulating material for electronic parts that restricts heat conduction between the electronic parts and the outside, wherein a back layer, a foam layer and an adhesive layer are laminated in order, and the thermal conductivity at 25 ° C. is 0.20 W / m · K or less. There is a heat insulating material for electronic parts. 2. The heat insulating material for electronic parts according to claim 1, wherein the total thickness of the heat insulating material for electronic parts is 200 to 500 μm, and 5.0 to 30% of the total thickness is the thickness of the adhesive layer. It is a manufacturing method of the heat insulating material for electronic components in any one of Claims 1-2, Comprising: At least 3 layers of a back surface layer, a foaming layer, and an adhesion layer are formed into a film by multilayer coextrusion molding, At the same time, foaming is performed so that the foaming ratio of the foamed layer is 1.1 to 3.0 times.

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