Heat exchanger

Abstract

To provide a heat exchanger having superior heat resistance, LLC (antifreeze) resistance, water resistance, and durability.SOLUTION: A heat exchanger 1 of the present invention comprises an outer package member 2 that is provided with a heat-medium inlet 24 and a heat-medium outlet 25, in which a heat medium, that flowed in from the heat-medium inlet 24, flows the inside and flows out from the heat medium outlet 25. The outer package member 2: is constituted by outer package laminate members L1 that contain a metal heat-transfer layer and a thermal fusion layer made of resin and provided on one surface of the heat-transfer layer; and is formed of the outer package laminate members L1 that are overlapped with the mutual thermal fusion layers joined together and integrated along the peripheral edges thereof. The heat-transfer laye and the thermal fusion layer of the outer package laminate member L1 are laminated via an inner adhesive layer constituted of an acid-modified polyolefin adhesive containing an acid-modified polyolefin resin.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a heat exchanger manufactured using a laminate material such as a laminate sheet in which a resin layer is laminated on a metal layer. [Background technology]

[0002] As electronic devices such as smartphones and personal computers become smaller and more powerful, it is becoming increasingly important to take measures to prevent heat generation around the CPU of these devices. Some models incorporate water-cooled coolers or heat pipes to reduce the thermal load on electronic components such as the CPU, and technologies have been proposed to prevent heat from building up inside the housing and avoid the adverse effects of heat.

[0003] Furthermore, battery modules installed in electric vehicles and hybrid vehicles generate a lot of heat due to repeated charging and discharging. For this reason, similar to the electronic devices mentioned above, technologies have been proposed for battery modules to incorporate water-cooled coolers and heat pipes to avoid the adverse effects of heat.

[0004] Furthermore, measures such as installing cooling plates or heat sinks have been proposed to prevent heat generation in power modules made of silicon carbide (SiC) and the like.

[0005] Incidentally, electronic devices such as the above-mentioned smartphones and personal computers have thin housings and limited space for installing components, so there is a demand for water-cooling cooling devices and heat exchangers such as heat pipes that are incorporated for cooling purposes to be as thin, small, and compact as possible.

[0006] However, because conventional heat exchangers are manufactured by processing metal materials, there is a limit to how thin they can be made, and they end up being too large.

[0007] Therefore, the present applicant has proposed a heat exchanger that can be made thinner by using a metal laminate material for the outer packaging material and inner core material (see Patent Document 1 below). [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Japanese Patent Publication No. 2020-3132 Summary of the Invention [Problem to be solved by the invention]

[0009] However, since heat exchangers using the above-mentioned metal laminate material join different materials, namely a metal foil and a resin layer, it has been found that the corrosion resistance and durability of the heat exchanger against the heat medium in a hot environment can be affected depending on the bonding method selected.

[0010] The preferred embodiments of the present invention have been made in light of the above and / or other deficiencies in the related art, and provide significant improvements over existing methods and / or apparatus.

[0011] The present invention has been made in view of the above technical background, and aims to provide a heat exchanger that is resistant to delamination, film peeling, and corrosion of the metal layer even when exposed to high temperature conditions, and that has excellent heat resistance, corrosion resistance, and durability.

[0012] Other objects and advantages of the present invention will be apparent from the following preferred embodiments. [Means for solving the problem]

[0013] In order to achieve the above object, the present invention provides the following means.

[0014] [1] A heat exchanger having a heat medium inlet and a heat medium outlet, and an outer packaging material through which a heat medium flowing in from the heat medium inlet flows and flows out from the heat medium outlet, The outer packaging material is formed by an outer packaging laminate material including a metal heat transfer layer and a resin heat seal layer provided on one surface of the heat transfer layer, and the outer packaging laminate materials are stacked and the heat seal layers are joined together along the periphery to form an integrated product. A heat exchanger characterized in that the heat transfer layer and heat-sealing layer of the outer laminate material are laminated via an inner adhesive layer composed of an acid-modified polyolefin-based adhesive containing an acid-modified polyolefin-based resin.

[0015] [2] The heat exchanger according to the preceding paragraph 1, wherein the acid-modified polyolefin adhesive contains a polyolefin resin having a carboxyl group as a base component and a polyfunctional isocyanate compound as a curing agent.

[0016] [3] The heat exchanger according to item 2 above, wherein the ratio of the number of isocyanato groups contained in the polyfunctional isocyanate compound to the number of carboxyl groups contained in the polyolefin resin is 1 to 20.

[0017] [4] The heat exchanger according to item 2 or 3 above, wherein the polyfunctional isocyanate compound contains an aliphatic isocyanate and an aromatic isocyanate.

[0018] [5] The heat exchanger according to any one of the above items 1 to 4, wherein the inner adhesive layer contains one or more metal salts made of at least one metal of Groups 7, 12, and 14.

[0019] [6] The heat exchanger according to any one of the above items 1 to 5, wherein a protective layer is laminated on the other surface of the heat transfer layer of the outer packaging material.

[0020] [7] An inner core material is disposed inside the outer packaging material, the inner core material is made of an inner core laminate material including a metal heat transfer layer and a resin heat fusion layer provided on both sides of the heat transfer layer, and has an uneven portion; the heat-sealing layers on the bottom surfaces of the recesses and the top surfaces of the protrusions of the inner core material are joined together with the heat-sealing layer of the outer cover material; 7. The heat exchanger according to any one of items 1 to 6 above, wherein the heat-sealing layer of the outer packaging material and the heat-sealing layer of the inner core material are formed from the same type of resin. [Effects of the Invention]

[0021] According to the invention of [1], the inner adhesive layer is made of an acid-modified polyolefin adhesive containing an acid-modified polyolefin resin, which has good heat resistance and can maintain strong adhesive strength even in high-temperature environments, making it possible to provide a heat exchanger that is excellent in heat resistance, LLC (antifreeze) resistance, water resistance, and durability.

[0022] According to the invention [2], the acid-modified polyolefin adhesive has a polyolefin resin having a carboxyl group as the main component and a polyfunctional isocyanate compound as the curing agent, so that the reactivity of the polyolefin resin having a carboxyl group can be increased by the polyfunctional isocyanate compound.

[0023] According to the invention [3], by setting the ratio of the number of isocyanato groups contained in the polyfunctional isocyanate compound to the number of carboxyl groups contained in the polyolefin resin to 1 to 20, it is possible to provide a heat exchanger that has excellent adhesion, heat resistance, LLC (antifreeze) resistance, and water resistance.

[0024] According to the invention of [4], the polyfunctional isocyanate compound contains an aliphatic isocyanate and an aromatic isocyanate, and the aliphatic isocyanate can impart excellent adhesiveness, while the aromatic isocyanate can improve heat resistance, LLC (antifreeze) resistance, and water resistance.

[0025] According to the invention [5], the inner adhesive layer contains one or more metal salts made of at least one metal of Groups 7, 12, and 14, so that isocyanato groups and carboxyl groups can be efficiently crosslinked.

[0026] According to the invention [6], a protective layer is laminated on the other surface of the heat transfer layer of the outer packaging material, so that corrosion of the other surface of the heat transfer layer can be suppressed.

[0027] According to the invention of [7], the heat exchanger is provided with an inner core material placed inside the outer packaging material, and the inner core material is composed of an inner core laminate material including a metal heat transfer layer and a resin heat fusion layer provided on both sides of the heat transfer layer, and has uneven portions, and the heat fusion layers on the bottom of the concave portions and the top of the convex portions of the inner core material are joined together with the heat fusion layer of the outer packaging material, and the heat fusion layer of the outer packaging material and the heat fusion layer of the inner core material are formed from the same type of resin, making it easier to heat fusion the outer packaging material and the inner core material at their contact points, and therefore a heat exchanger that is resistant to internal pressure can be provided. [Brief explanation of the drawings]

[0028] [Figure 1] FIG. 1 is a perspective view showing the heat exchanger of this embodiment. [Figure 2] FIG. 2 shows a heat exchanger of this embodiment, where FIG. 2(a) is a plan view, FIG. 2(b) is a cross-sectional view taken along line AA in FIG. 2(a), and FIG. 2(c) is a cross-sectional view taken along line BB in FIG. 2(a). [Figure 3] FIG. 3 is an exploded perspective view of the heat exchanger of this embodiment. [Figure 4] FIG. 4 is an enlarged cross-sectional view of the part surrounded by the dashed line in FIG. 2(b). [Figure 5] FIG. 5 is an enlarged cross-sectional view of the portion surrounded by the dashed line in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0029] In this embodiment, the left-right direction in FIG. 2(a) is referred to as the "horizontal direction," the up-down direction as the "vertical direction," the left direction as the "front direction," and the right direction as the "rear direction."

[0030] The heat exchanger of the present invention is used for heat exchange in electronic devices, batteries, etc., and is particularly used for cooling vehicle batteries.

[0031] The heat exchanger of the present invention also has excellent corrosion resistance against LLC (long life coolant), which will be described later.

[0032] In the heat exchanger of the present invention, a cooling liquid such as cooling water or antifreeze liquid is used as a heat medium, and in particular, LLC is used.

[0033] LLC is an antifreeze whose main component is ethylene glycol and contains anti-rust additives for various metals (iron, aluminum, copper).

[0034] As shown in Figures 1 to 3, the heat exchanger 1 of this embodiment comprises an outer packaging material 2, an inner core material 3 placed inside the outer packaging material 2, and a header 4 placed at one lateral end inside the outer packaging material 2.

[0035] The outer packaging material of the present invention is the outer shape of a heat exchanger, and is provided with a heat medium inlet and a heat medium outlet, and is configured so that the heat medium that flows in through the heat medium inlet flows inside and flows out through the heat medium outlet.It is formed by overlapping the outer packaging laminate material described below and joining and integrating the heat-sealed layers of each other along the peripheral edges.

[0036] As shown in FIG. 3, the outer packaging material 2 of this embodiment is made up of a tray member 20 that is rectangular in plan view, and a cover member 21 that is also rectangular in plan view.

[0037] The tray member 20 has a recess formed downward in the entire middle region except for the outer peripheral edge portion using cold forming techniques such as deep drawing or bulging forming to form a recessed portion 22 that is rectangular in plan view, and a flange portion 23 that protrudes outward is integrally formed on the outer periphery of the opening edge of the recessed portion 22.

[0038] As shown in FIG. 2(b), the side walls on the short sides of the tray member 20 are formed so as to open outward at an angle θ2 relative to the horizontal direction, and as shown in FIG. 2(c), the side walls on the long sides of the tray member 20 are formed so as to open outward at an angle θ2 relative to the vertical direction.

[0039] The tray member 20 is provided with a heat medium inlet 24 and a heat medium outlet 25 at one end in the lateral direction.

[0040] The cover member 21 is configured so that its outer peripheral edge corresponds to the outer peripheral edge of the flange portion 23 of the tray member 20 .

[0041] The tray member 20 and the cover member 21 are made of an outer packaging laminate material L1, which is a laminate sheet, and the cover member 21 is overlapped on the tray member 20 from above, and the heat-sealing layers 53 described later at the outer peripheral edges of both members 20 and 21 are joined together by heat sealing, thereby forming the outer packaging material 2.

[0042] The outer packaging laminate material of the present invention comprises a metal heat transfer layer and a resin heat-sealing layer provided on one side of the heat transfer layer, and is characterized in that the heat transfer layer and the heat-sealing layer are laminated via an inner adhesive layer composed of an acid-modified polyolefin adhesive containing an acid-modified polyolefin resin.

[0043] 5, the outer envelope laminate material L1 of this embodiment has a configuration in which a heat-sealing layer 53 made of a heat-sealing resin film or a heat-sealing resin sheet is laminated on the inner surface of a heat-transfer layer 51 made of metal (metal foil) via an inner adhesive layer 52, and a protective layer 55 made of a heat-resistant resin film or a heat-resistant resin sheet is laminated on the outer surface of the heat-transfer layer 51 via an outer adhesive layer 54. The term "foil" is used to include film, thin plate, and sheet.

[0044] In this embodiment, copper foil, aluminum foil, stainless steel foil, nickel foil, nickel-plated copper foil, clad metal made of nickel and copper foil, etc. can be suitably used as the heat transfer layer 51, and the thickness of the heat transfer layer 51 is preferably 20 μm to 200 μm. Note that the terms "copper," "aluminum," and "nickel" are used to mean alloys thereof as well.

[0045] It is more preferable to use an aluminum foil having a thickness of 40 μm to 150 μm for the heat transfer layer 51.

[0046] Furthermore, the heat transfer layer 51 of this embodiment preferably has a Vickers hardness of 40HV to 200HV in accordance with JIS Z 2244. If the Vickers hardness is too hard, exceeding 200HV, handling and molding processability will be impaired, and processability will decrease, which is not preferred. Conversely, if the Vickers hardness is less than 40HV, buckling deformation or the like may occur on the surface of the outer packaging material 2 depending on the usage form.

[0047] Furthermore, the heat transfer layer 51 of this embodiment must have an elongation of 0.1% to 20% in accordance with JIS K 7127. If the elongation is less than 0.1%, the material will be too hard, which will result in poor handling and molding processability, and reduced processability, which is undesirable. Conversely, if the elongation exceeds 20%, the material will not be hard enough, which may make it difficult to reliably prevent the formation of harmful uneven deformations on the surface of the outer packaging material 2 due to stress, which is undesirable.

[0048] Furthermore, by subjecting the heat transfer layer 51 to a surface treatment such as chemical conversion treatment, the durability of the heat transfer layer 51 can be further improved, such as by preventing corrosion of the heat transfer layer 51 and improving adhesion to resin.

[0049] The chemical conversion treatment is carried out, for example, as follows: A water solution of any one of the following 1) to 3) is applied to the surface of the metal foil that has been subjected to a degreasing treatment, and then the surface is dried to carry out the chemical conversion treatment.

[0050] 1) An aqueous solution of a mixture containing phosphoric acid, chromic acid, and at least one compound selected from the group consisting of metal salts of fluorides and non-metal salts of fluorides.

[0051] 2) An aqueous solution of a mixture containing phosphoric acid, at least one resin selected from the group consisting of acrylic resins, chitosan derivative resins, and phenolic resins, and at least one compound selected from the group consisting of chromic acid and chromium (III) salts.

[0052] 3) An aqueous solution of a mixture containing phosphoric acid, at least one resin selected from the group consisting of acrylic resins, chitosan derivative resins, and phenolic resins, at least one compound selected from the group consisting of chromic acid and chromium (III) salts, and at least one compound selected from the group consisting of metal salts of fluorides and non-metal salts of fluorides.

[0053] The above chemical conversion coating has a chromium deposition amount (per side) of 0.1 mg / m 2 ~50mg / m 2 It is preferable to set the concentration to 2 mg / m 2 ~20mg / m 2 It is even more preferable to set it to

[0054] As shown in FIG. 5, an inner adhesive layer 52 is laminated on the inner surface of the heat transfer layer 51 of this embodiment.

[0055] The inner adhesive layer of the present invention is characterized by being composed of an acid-modified polyolefin adhesive containing an acid-modified polyolefin resin, and being laminated between the heat-conductive layer and the heat-sealing layer of the outer laminate material.

[0056] The acid-modified polyolefin adhesive of the present invention is heat-resistant and contains a polyolefin resin having a carboxyl group.

[0057] The acid-modified polyolefin adhesive of this embodiment contains a polyolefin resin having a carboxyl group as a base component and a polyfunctional isocyanate compound as a curing agent.

[0058] In this embodiment, the polyolefin resin having a carboxyl group is not particularly limited as long as it contains a carboxyl group in its molecular structure. The term "carboxyl group" as used herein includes not only structural units derived from carboxylic acids but also structural units derived from carboxylic anhydrides. Examples of such resins include those obtained by graft-polymerizing a monomer having a carboxyl group onto a polyolefin, those obtained by copolymerizing a monomer having a carboxyl group with an olefin, and those obtained by copolymerizing a combination thereof.

[0059] Examples of the monomer having a carboxyl group include ethylenically unsaturated carboxylic acids such as acrylic acid and methacrylic acid, ethylenically unsaturated carboxylic anhydrides such as maleic anhydride, citraconic anhydride and itaconic anhydride, and carboxyl group-containing ethylenically unsaturated carboxylic acid esters such as β-carboxyethyl (meth)acrylate, among which maleic anhydride is more preferred.

[0060] Furthermore, the polymer may contain an ethylenically unsaturated carboxylic acid ester having no carboxyl group as a monomer unit. Examples of the ethylenically unsaturated carboxylic acid ester having no carboxyl group include ester compounds of acrylic acid or methacrylic acid with an alcohol having 1 to 20 carbon atoms having no carboxyl group, such as methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, hexyl (meth)acrylate, octyl (meth)acrylate, decyl (meth)acrylate, dodecyl (meth)acrylate, lauryl (meth)acrylate, and stearyl (meth)acrylate. Mixtures of these may also be used.

[0061] In this specification, the phrase "a polyolefin resin having a carboxyl group contains ~ as a monomer unit" refers to "containing ~ as a raw material monomer when polymerizing the polyolefin resin having a carboxyl group."

[0062] Examples of polyolefin resins include those containing monoolefins such as ethylene, propylene, butene, pentene, hexene, heptene, octene, and 4-methyl-1-pentene as monomer units, and those containing alicyclic olefins such as cyclopentene and cyclohexene as monomer units, linear or cyclic polyolefins such as 1,4-hexadiene, 1,5-hexadiene, divinylbenzene, 1,3-cyclopentadiene, 1,3-cyclohexadiene, and 5-vinyl-2-norbornene, and aromatic vinyl compounds such as styrene and substituted styrene. Among these, polyolefin resins are preferred from the viewpoint of adhesion to polyolefin substrates, and polypropylene resins containing propylene or ethylene and propylene as monomer units are particularly preferred in consideration of heat resistance and corrosion resistance.

[0063] The polyolefin resin having a carboxyl group preferably contains a polyolefin resin having a carboxyl group with an MFR (melt mass-flow rate) of 5 g / 10 min to 42 g / 10 min. If the MFR is 5 g / 10 min or more, the adhesive strength of the inner adhesive layer made of an acid-modified polyolefin adhesive containing the acid-modified polyolefin resin is less likely to decrease due to water or LLC (antifreeze), and if the MFR is 42 g / 10 min or less, the operability of the acid-modified polyolefin adhesive during application is good.

[0064] In this specification, the MFR is a value obtained under conditions of, for example, a temperature of 230°C for polypropylene resins or a temperature of 190°C for polyethylene resins, and a load of 2160 g, as determined by the method described in JIS K7210. The MFR of polyolefin resins having carboxyl groups measured at 230°C is more preferably 8 g / 10 min to 40 g / 10 min, and even more preferably 12 g / 10 min to 40 g / 10 min.

[0065] The acid value of the carboxyl-containing polyolefin resin is preferably 3 to 60 mgKOH / g, more preferably 4 to 30 mgKOH / g. If the acid value is 3 mgKOH / g or more, the adhesive strength of the inner adhesive layer made of the acid-modified polyolefin adhesive containing the acid-modified polyolefin resin is less likely to be reduced by water or LLC (antifreeze liquid). If the acid value is 60 mgKOH / g or less, the operability during application of the acid-modified polyolefin adhesive is improved. The acid value in this specification is a value measured in accordance with JIS K0070 (1992).

[0066] The polyfunctional isocyanate compound of the present invention is blended as a curing agent in the acid-modified polyolefin adhesive, and is not particularly limited as long as it is a polyisocyanate containing two or more isocyanato groups or a polymer thereof.

[0067] The polyfunctional isocyanate compound of the present invention may be a polymer of a saturated aliphatic polyisocyanate, a polymer of a saturated alicyclic polyisocyanate, or a polymer of an aromatic polyisocyanate. Note that the aromatic polyisocyanate refers to a polyisocyanate having an aromatic ring somewhere in its structural formula.

[0068] Examples of the saturated aliphatic polyisocyanate polymers include polymers of saturated aliphatic diisocyanates such as hexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, etc. These may be used alone or in combination of two or more.

[0069] Examples of the polymer form include allophanate polymers, isocyanurates, biuret-modified products, etc. Of these, allophanate polymers and isocyanurates are preferred, and isocyanurates are more preferred.

[0070] Examples of the saturated alicyclic polyisocyanate polymers include polymers of saturated alicyclic diisocyanates such as 1,4-cyclohexane diisocyanate, isophorone diisocyanate, methylene bis(4-cyclohexyl isocyanate), 1,3-bis(isocyanatomethyl)cyclohexane, 1,4-bis(isocyanatomethyl)cyclohexane, norbornane diisocyanate, etc. These may be used alone or in combination of two or more.

[0071] Examples of the polymer form include allophanate polymers, isocyanurates, biuret-modified products, etc. Among these, allophanate polymers and isocyanurates are preferred, and isocyanurates are more preferred.

[0072] Examples of aromatic polyisocyanate polymers include aromatic diisocyanate polymers such as tolylene diisocyanate (TDI), diphenylmethane-4,4'-diisocyanate (MDI), xylylene diisocyanate (XDI), etc. These may be used alone or in combination of two or more.

[0073] Examples of the form of the polymer include allophanate polymers, isocyanurates, biuret-modified products, and polymeric MDI. Among these, allophanate polymers, isocyanurates, and polymeric MDI are preferred, and polymeric MDI is more preferred. Polymeric MDI can also be suitably used as a polymeric MDI mixture containing monomeric MDI.

[0074] The above multimers may be used alone or in combination of two or more. Among these, multimers of polyisocyanates, such as allophanate multimers, isocyanurates, and biuret-modified products, are more preferred. By using polyisocyanates as multimers, the acid-modified polyolefin adhesives exhibit excellent LLC (antifreeze) resistance. The reason for this is unclear, but it is presumed to be due to the excellent LLC (antifreeze) resistance of the structures of isocyanurates and allophanate multimers. Among these polyisocyanate multimers, isocyanurates of polyisocyanates are particularly preferred. This is because isocyanurates exhibit excellent LLC (antifreeze) resistance.

[0075] The polyfunctional isocyanate compound of the present embodiment includes an aliphatic isocyanate and an aromatic isocyanate. The aliphatic isocyanate includes a saturated aliphatic isocyanate and a saturated alicyclic isocyanate.

[0076] In this embodiment, the polyfunctional isocyanate compound contains an aliphatic isocyanate and an aromatic isocyanate, and the aliphatic isocyanate can impart excellent adhesiveness, while the aromatic isocyanate can enhance heat resistance, LLC (antifreeze) resistance, and water resistance.

[0077] In this embodiment, the ratio of the number of isocyanato groups contained in the polyfunctional isocyanate compound to the number of carboxyl groups contained in the polyolefin resin (hereinafter also referred to as NCO / COOH ratio) is 1-20.

[0078] The inner adhesive layer containing an acid-modified polyolefin adhesive has an NCO / COOH ratio of 1 or more, which provides excellent adhesion; an NCO / COOH ratio of 10 or more provides excellent heat resistance; and an NCO / COOH ratio of 20 or less provides excellent LLC (antifreeze) resistance and water resistance, making it less susceptible to corrosion by heat transfer media such as coolant and antifreeze (e.g., LLC). The NCO / COOH ratio is preferably 10 or more and 20 or less. The NCO / COOH ratio is a value calculated based on JIS K6806 (2003).

[0079] By setting the ratio of the number of isocyanato groups contained in the polyfunctional isocyanate compound to the number of carboxyl groups contained in the polyolefin resin to be 1 to 20, it is possible to provide a heat exchanger that has excellent adhesion, heat resistance, LLC (antifreeze) resistance, and water resistance.

[0080] As described above, in this embodiment, the acid-modified polyolefin adhesive uses a polyolefin resin having a carboxyl group as the main component and a polyfunctional isocyanate compound as the curing agent, thereby enabling the reactivity of the polyolefin resin having a carboxyl group to be increased by the polyfunctional isocyanate compound.

[0081] The inner adhesive layer 52 of this embodiment also contains one or more metal salts made from at least one metal from groups 7, 12, and 14 of the periodic table.

[0082] The metal salt is blended as a reaction accelerator to accelerate the reaction between the polyolefin resin having a carboxyl group in the acid-modified polyolefin adhesive and the polyfunctional isocyanate compound.

[0083] As the metal salt, those containing at least one of the metal elements manganese of Group 7, zinc of Group 12, and tin of Group 14 may be used alone or in combination.

[0084] Examples of the metal salt that can be used in this embodiment include zinc neodecanoate, zinc 2-ethylhexanoate, zinc distearate, zinc acetylacetonate, manganese 2-ethylhexanoate, dibutyltin dilaurate, dioctyltin dilaurate, and dioctyltin diacetate, and it is preferable to use a metal carboxylate.

[0085] As a reaction accelerator other than the above metal salts, organic tin compounds such as dibutyltin dilaurate, dioctyltin dilaurate, and dioctyltin diacetate, and tertiary amines such as 2,4,6-tris(dimethylaminomethyl)phenol, dimethylaniline, dimethyl-p-toluidine, and N,N-di(β-hydroxyethyl)-p-toluidine may be used in combination.

[0086] Furthermore, the ratio of the metal salt to 100 parts by mass of the polyolefin resin having a carboxyl group is not particularly limited, but the content of the metal salt, converted into the mass of the metal, is preferably 0.0001 to 5 parts by mass to 100 parts by mass of the polyolefin resin having a carboxyl group.

[0087] When the amount is 0.0001 parts by mass or more, the adhesive strength of the inner adhesive layer of the present invention is less likely to be reduced by water or LLC (antifreeze liquid), and when the amount is 5 parts by mass or less, the adhesive strength under normal conditions is high.

[0088] The metal salt may be added during the production of the polyolefin resin having a carboxyl group, or may be added during the preparation of the adhesive.

[0089] In this embodiment, the inner adhesive layer 52 contains one or more metal salts made of at least one metal of Groups 7, 12, and 14, so that isocyanato groups and carboxyl groups can be efficiently crosslinked.

[0090] The acid-modified polyolefin adhesive of the present embodiment may also contain a solvent.

[0091] There are no particular limitations on the solvent, so long as it can dissolve or disperse a polyolefin resin having a carboxyl group, a polyfunctional isocyanate compound, and a metal salt of at least one metal from Groups 7, 12, and 14. Examples include aromatic organic solvents such as toluene and xylene, alicyclic organic solvents such as cyclohexane, methylcyclohexane, and ethylcyclohexane, aliphatic organic solvents such as n-hexane and n-heptane, ester organic solvents such as ethyl acetate, propyl acetate, and butyl acetate, and ketone organic solvents such as acetone, methyl ethyl ketone, and methyl butyl ketone. These can be used alone or in combination of two or more.

[0092] Among these, ethyl acetate, propyl acetate, butyl acetate, toluene, methylcyclohexane, and methyl ethyl ketone are preferred, with ethyl acetate, toluene, and methylcyclohexane being more preferred, particularly from the viewpoint of solubility of polyolefin resins having carboxyl groups.

[0093] In this embodiment, the solvent content in the acid-modified polyolefin adhesive is preferably 30 to 95% by mass, more preferably 40 to 90% by mass, and even more preferably 50 to 80% by mass, because a content of 30% by mass or more improves operability during application of the acid-modified polyolefin adhesive, and a content of 95% by mass or less improves thickness controllability of the laminate obtained by applying and curing the acid-modified polyolefin adhesive.

[0094] In this embodiment, the acid-modified polyolefin adhesive may contain additives such as a tackifier and a plasticizer, if necessary.

[0095] The tackifier is not particularly limited, but examples thereof include natural polyterpene resins and rosin resins, and petroleum-based aliphatic (C5) resins obtained from naphtha cracked oil fractions, aromatic (C9) resins, copolymer (C5 / C9) resins, and alicyclic resins. Hydrogenated resins obtained by hydrogenating the double bonds of these resins are also included. These tackifiers may be used alone or in combination of two or more.

[0096] The plasticizer is not particularly limited, but examples thereof include liquid rubbers such as polyisoprene and polybutene, and process oils.

[0097] Furthermore, thermoplastic resins and thermoplastic elastomers other than polyolefin resins having carboxyl groups may be added within a range that does not impair the effects of this embodiment. Examples of thermoplastic resins and thermoplastic elastomers that can be added include ethylene-vinyl acetate copolymer resins, ethylene-ethyl acrylate copolymer resins, SEBS (styrene-ethylene-butylene-styrene), and SEPS (styrene-ethylene-propylene-styrene).

[0098] In the acid-modified polyolefin adhesive of this embodiment, the total content of the polyolefin resin having a carboxyl group, the polyfunctional isocyanate compound, the metal salt of at least one metal of Groups 7, 12, and 14, and the solvent component is preferably 80% by mass or more, more preferably 90% by mass or more, even more preferably 95% by mass or more, and even more preferably 98% by mass or more.

[0099] In this embodiment, a heat-sealing layer 53 is laminated on the inner surface of the inner adhesive layer 52 .

[0100] The heat-sealable layer of the present invention constitutes the innermost layer of the outer packaging laminate material.

[0101] As shown in FIGS. 4 and 5, the heat-sealing layer 53 of this embodiment is laminated on the innermost side of the outer laminating material L1.

[0102] A film or sheet made of a polyolefin resin such as polyethylene or polypropylene, or a modified resin thereof, a fluorine-based resin, a polyester resin, a vinyl chloride resin, etc. can be suitably used as the heat-sealing layer 53. The thickness of the heat-sealing layer 53 is preferably 10 μm to 80 μm.

[0103] As the heat-sealing layer 53, it is particularly preferable to use a film made of non-oriented polypropylene (CPP) having a thickness of 20 μm to 40 μm.

[0104] As described above, in this embodiment, the heat transfer layer 51 and the heat-sealing layer 53 are laminated and bonded via the inner adhesive layer 52 composed of an acid-modified polyolefin-based adhesive containing an acid-modified polyolefin-based resin, and this bonding can be performed using known methods such as heat lamination and dry lamination.

[0105] The heat lamination method is a method in which a solvent-free adhesive is heated and melted on the bonding surface of the object to be adhered or heated and extruded together with the object to form an adhesive layer between the metal foil and the resin film.

[0106] The dry lamination method is a method in which a solvent-containing adhesive is applied to the adhesive surface of an object to be adhered, allowed to dry, and then the adhesive surface of another object is placed on top of the adhesive and pressed together, thereby forming an adhesive layer between the metal foil and the resin film.

[0107] In this embodiment, the dry lamination method is used because the dry lamination method has better heat resistance, but the present invention is not limited to this, and the heat lamination method may be used without using a polyfunctional isocyanate compound, and an acid-modified polyolefin resin may be used as the adhesive.

[0108] In this embodiment, as shown in FIGS. 4 and 5, a protective layer 55 is laminated on the outer surface of the heat transfer layer 51 via an outer adhesive layer 54.

[0109] The outer adhesive layer of the present invention serves to bond the heat transfer layer to the protective layer described below.

[0110] In this embodiment, the above-mentioned acid-modified polyolefin adhesives, urethane adhesives, acrylic adhesives, epoxy adhesives, and olefin adhesives can be used for the outer adhesive layer 54. In particular, in consideration of heat resistance and corrosion resistance, it is preferable to use the above-mentioned acid-modified polyolefin adhesives.

[0111] The protective layer of the present invention constitutes the outermost layer of the outer packaging laminate.

[0112] In this embodiment, the protective layer 55 can be suitably made of a film or sheet made of heat-resistant resin such as polyester resin (PET, PBT, PEN, etc.), polyamide resin (PA6, PA66, etc.), or polyolefin resin (HDPE, LLDPE, OPP, CPP, etc.).

[0113] The above abbreviations have the following meanings:

[0114] "PET" is polyethylene terephthalate, "PBT" is polybutylene terephthalate, "PEN" is polyethylene naphthalate, "PA6" is nylon 6, "PA66" is nylon 66, "HDPE" is high-density polyethylene, "LLDPE" is linear low-density polyethylene, "OPP" is oriented polypropylene, and "CPP" is unoriented polypropylene.

[0115] The heat-resistant resin used for the protective layer 55 does not melt at the heating temperature used for heat-sealing the outer packaging material 2 and the inner core material 3. It is preferable to use a heat-resistant resin with a melting point that is 10°C or more higher than the melting point of the heat-sealing resin, and it is particularly preferable to use a heat-resistant resin with a melting point that is 20°C or more higher than the melting point of the heat-sealing resin.

[0116] The thickness of the protective layer 55 is preferably 5 μm to 50 μm, and more preferably 10 μm to 25 μm.

[0117] In this manner, in this embodiment, the protective layer 55 is laminated on the outer surface of the heat transfer layer 51 via the outer adhesive layer 54, so that corrosion of the outer surface of the heat transfer layer 51 can be suppressed.

[0118] In this embodiment, the tray member 20 and cover member 21 of the outer packaging material 2 are formed from the outer packaging laminate material L1, and an inner core material 3 is disposed inside the outer packaging material 2.

[0119] The inner core material of the present invention is placed inside the outer packaging material, is composed of an inner core laminate material, has uneven portions, and the heat-sealed layers on the bottom surfaces of the recesses and the top surfaces of the protrusions of the inner core material are bonded together with the heat-sealed layer of the outer packaging material.

[0120] The inner laminate material of the present invention includes a metal heat transfer layer and resin heat fusion layers provided on both sides of the heat transfer layer.

[0121] As shown in FIG. 4, the inner laminate material L2 of this embodiment is composed of a heat transfer layer 61 and heat-sealing layers 62, 62 made of a resin film or resin sheet laminated on both sides of the heat transfer layer 61 via an adhesive.

[0122] In this embodiment, the heat transfer layer 61 can be suitably made of copper foil, aluminum foil, stainless steel foil, nickel foil, nickel-plated copper foil, clad metal made of nickel and copper foil, etc., and the thickness of the heat transfer layer 61 should preferably be 20 μm to 200 μm.

[0123] It is more preferable to use an aluminum foil having a thickness of 20 μm to 150 μm for the heat transfer layer 61.

[0124] Furthermore, the heat transfer layer 61 of this embodiment preferably has a Vickers hardness of 40HV to 200HV in accordance with JIS Z 2244. If the Vickers hardness is too hard, exceeding 200HV, handling and molding processability deteriorate, and processability decreases, which is not preferable. Conversely, if the Vickers hardness is less than 40HV, buckling deformation or the like may occur in the inner core material 3 depending on the usage form.

[0125] Furthermore, the heat transfer layer 61 of this embodiment must have an elongation of 5% to 40% in accordance with JIS K 7127. If the elongation is less than 5%, the material will be too hard, which will result in poor handling and molding processability, and reduced processability, which is undesirable. Conversely, if the elongation exceeds 40%, the hardness will be insufficient, which may make it difficult to reliably prevent harmful deformation such as buckling deformation in the inner core material 3, which is undesirable.

[0126] Similarly to the heat transfer layer 51, the heat transfer layer 61 is also subjected to the chemical conversion treatment.

[0127] The heat-sealing layer 62 of this embodiment can be suitably a film or sheet made of a polyolefin resin such as polyethylene or polypropylene, or a modified resin thereof, a fluorine-based resin, a polyester resin, a vinyl chloride resin, etc. The thickness of the heat-sealing layer 62 is preferably 10 μm to 80 μm.

[0128] As the heat-sealing layer 62, it is particularly preferable to use a film made of non-oriented polypropylene (CPP) having a thickness of 20 μm to 40 μm.

[0129] In this embodiment, the above-mentioned acid-modified polyolefin adhesive, urethane adhesive, acrylic adhesive, epoxy adhesive, and olefin adhesive can be used as the adhesive for bonding the heat-transfer layer 61 and the thermal fusion layer 62. In particular, it is preferable to use the above-mentioned acid-modified polyolefin adhesive in consideration of heat resistance and corrosion resistance.

[0130] In this embodiment, the inner core material 3 composed of the above-mentioned inner core laminate material L2 is arranged inside the recessed portion 22 of the tray member 20, in an area excluding one lateral end portion of the recessed portion 22, as shown in Figures 2 and 3, and an inflow / outflow passage 11 is formed in the gap between the inner core material 3 and the outer packaging material 2.

[0131] As shown in Figure 2(a), the inner core material 3 has a trapezoidal shape when viewed from above, and is inclined horizontally from both vertices of the front end edge at an inclination angle θ1, with the width gradually narrowing from the front end to the rear end.As shown in Figure 2(b), the inner core material 3 has a corrugated horizontal cross section with alternating recesses 35 and protrusions 36, and is formed so that the bottom surfaces (bottom walls) of the recesses 35 and the top surfaces (top walls) of the protrusions 36 are flat.

[0132] Furthermore, as shown in Figure 4, the inner core material 3 of this embodiment is formed so that the relationship FP≧{(H / 2)+T} holds when the distance between adjacent recesses 35 is FP, the height of the inner core material 3 is H, and the thickness of the inner core laminate material L2 is T.

[0133] Furthermore, the heat-sealing layer 62 constituting the bottom surface of the recessed portion 35 and the top surface of the protruding portion 36 and the heat-sealing layer 53 of the outer packaging material 2 are joined together by heat sealing.

[0134] In this embodiment, the heat-sealing layer 62 of the inner core material 3 and the heat-sealing layer 53 of the outer packaging material 2 are made of the same type of resin.

[0135] In this embodiment, the inner core material 3 is placed inside the outer packaging material 2, and the inner core material 3 is composed of an inner core laminate material L2 including a metal heat transfer layer 61 and a resin heat-sealing layer 62 provided on both sides of the heat transfer layer 61, and has uneven portions, and the heat-sealing layer 62 on the bottom surface of the recessed portion 35 and the top surface of the protruding portion 36 of the inner core material 3 is bonded integrally with the heat-sealing layer 53 of the outer packaging material 2, and since the heat-sealing layer 62 of the inner core material 3 and the heat-sealing layer 53 of the outer packaging material 2 are made of the same type of resin, it is easier to heat-seal the outer packaging material 2 and the inner core material 3 at their contact points, and therefore a heat exchanger 1 that is resistant to internal pressure can be provided.

[0136] The inner core 3 of this embodiment is formed so that its peak and valley directions are parallel to the vertical direction, and multiple intermediate flow paths 37 are formed as tunnels and grooves formed by the peaks and valleys of the inner core 3. These intermediate flow paths 37 are configured to allow the heat transfer medium that has flowed into the inlet / outlet passages 11 to flow smoothly from one end to the other end in the vertical direction of the outer packaging material 2.

[0137] The orientation of the inner core 3, the planar shape of the inner core 3 itself, and the concave-convex shape are not limited to those in this embodiment, and for example, the cross section in the vertical direction may be convex.

[0138] In this embodiment, as shown in FIGS. 2 and 3, a header 4 is provided inside the outer packaging material 2 .

[0139] The header 4 of this embodiment includes an inlet header 41 and an outlet header 42. The inlet header 41 and the outlet header 42 are separated by a partition wall 45, and the inlet header 41 and the outlet header 42 each have an opening 43 on one side.

[0140] The inlet header 41 and the outlet header 42 are provided with a pair of pipe sections 44. These pipe sections 44 communicate with the inside of the header 4, and are configured so that the heat transfer medium can pass between the inside of the pipe sections 44 and the inside of the header 4.

[0141] These pipe portions 44 are inserted into the heat transfer medium inlet 24 and the heat transfer medium outlet 25 formed in the outer packaging material 2 .

[0142] The headers 4 of this embodiment are arranged inside the outer packaging material 2 near the heat transfer medium inlet 24 and near the heat transfer medium outlet 25 so that the openings 43 face the inner core material 3. The inlet header 41 is arranged corresponding to one of the inlet and outlet channels (inlet channel) 11 via the opening 43, and the outlet header 42 is arranged corresponding to one of the inlet and outlet channels (outlet channel) 11 via the opening 43.

[0143] In this way, by providing the headers 4 near the heat medium inlet 24 and the heat medium outlet 25 inside the outer packaging material 2, the flow velocity distribution in the flow paths inside the heat exchanger 1 can be made uniform.

[0144] Furthermore, it is preferable to use the same type of resin for the header 4 as the resin that constitutes the heat-sealing layer 53 of the outer packaging material 2 and the heat-sealing layer 62 of the inner core material 3. Specifically, polyolefin resins such as polyethylene and polypropylene, or modified resins thereof, fluorine-based resins, polyester-based resins, vinyl chloride resins, etc. can be suitably used.

[0145] In this embodiment, the header 4 is made of a resin molded product that can be heat-sealed to the heat-sealing layer 53 of the outer laminate material L1, and the heat-sealing layer 53 of the outer laminate material L1 and the header 4 are made of the same type of resin.

[0146] In this way, the header 4 is composed of a heat-sealable resin molded product that can be heat-sealed to the heat-sealing layer 53 of the outer laminate material L1, and since the heat-sealing layer 53 of the outer laminate material L1 and the header 4 are formed from the same type of resin, it becomes easier to heat-seal the outer wrapper material 2 and the header 4 at their contact points, so that the header 4 can be fixed to the heat exchanger 1.

[0147] The arrangement of the headers 4 is not limited to that of this embodiment, and for example, the inlet header 41 and the outlet header 42 may be arranged on opposite sides.

[0148] In the heat exchanger 1 configured as described above, the coolant flows from one pipe section 44 into the inlet header 41, and then flows into one of the inlet and outlet channels (inlet channel) 11. The coolant then passes through multiple intermediate flow paths 37 and flows into the other inlet and outlet channel (outlet channel) 11. The coolant then flows into the outlet header 42 through the opening 43 and flows out from the other pipe section 44. By circulating the coolant inside the outer packaging material 2 in this way, heat is exchanged between the coolant and a heat exchange target component, such as a battery, located outside the outer packaging material 2 via the outer packaging material 2 and the inner core material 3, thereby cooling the heat exchange target component.

[0149] As described above, this embodiment includes a molded container-shaped outer packaging material 2 that is provided with a heat transfer medium inlet 24 and a heat transfer medium outlet 25, and through which the heat transfer medium that flows in from the heat transfer medium inlet 24 flows inside and flows out from the heat transfer medium outlet 25. The outer packaging material 2 is composed of an outer packaging laminate material L1 that includes a metal heat transfer layer 51 and a resin heat-sealing layer 53 that is provided on one side of the heat transfer layer 51. The outer packaging laminate materials L1 are stacked and the heat-sealing layers 53 are joined together along the periphery to form a container-like shape. The heat transfer layer 51 and the heat-sealing layer 53 of the outer packaging laminate material L1 are laminated via an inner adhesive layer 52 that is made of an acid-modified polyolefin adhesive that includes an acid-modified polyolefin resin. This provides good heat resistance and enables the heat exchanger 1 to maintain strong adhesive strength even in high-temperature environments, thereby providing a heat exchanger 1 that is excellent in heat resistance, LLC (antifreeze) resistance, water resistance, and durability.

[0150] In the above embodiment, the outer packaging material 2 is formed into a container shape by overlapping the outer packaging laminate materials L1 and joining the heat-sealed layers 53 of each material along its periphery by heat sealing, and the inner core material 3 is formed from the inner core laminate material L2 and has irregularities, with the heat-sealed layers 62 on the bottoms of the recesses 35 and the tops of the protrusions 36 of the inner core material 3 being joined together with the heat-sealed layer 53 of the outer packaging material 2. However, this is not limiting, and the heat-sealed layers 53 may be heat-sealed along the periphery of the overlapping outer packaging laminate materials L1 to form the outer packaging material 2 into a container shape, and the heat-sealed periphery may be physically joined by double seaming to form a double-seamed structure. This double-seamed structure not only maintains hermeticity against internal pressure, but also improves the pressure resistance of the heat exchanger and allows for a more compact heat exchanger. [Example]

[0151] Next, specific examples of the present invention will be described, but the present invention is not particularly limited to these examples.

[0152] Example 1 Outer packaging laminate material: PET12 / Outer adhesive layer / AL120 / Inner adhesive layer / CPP30 Inner core laminate material: CPP30 / adhesive / AL120 / adhesive / CPP30 Two outer laminate materials L1 were prepared, each of which had a heat transfer layer 51 made of 120 μm thick AL (aluminum) foil, a heat-sealing layer 53 made of 30 μm thick CPP (non-oriented polypropylene) film on the inner side of the heat transfer layer 51, with an inner adhesive layer 52 described later sandwiched between them, and a protective layer 55 made of 12 μm thick PET (polyethylene terephthalate) film on the outer side of the heat transfer layer 51, with an outer adhesive layer 54 made of a maleic acid-modified polypropylene adhesive whose main component is polypropylene having carboxyl groups derived from maleic acid.

[0153] Here, the following maleic acid modified polypropylene adhesive was used as the inner adhesive layer 52.

[0154] The maleic acid-modified polypropylene adhesive was a mixture of 15 parts by mass of polypropylene with an MFR of 40 g / 10 min at 230 °C and an acid value of 5.7 mg KOH / g as the main polypropylene resin, 3 parts by mass of hexamethylene diisocyanate (HDI), a polymer of saturated aliphatic diisocyanate, 2.3 parts by mass of isophorone diisocyanate (IPDI), a polymer of saturated alicyclic diisocyanate, and 0.2 parts by mass of diphenylmethane-4,4'-diisocyanate (MDI), a polymer of aromatic diisocyanate, as the curing agent polyfunctional isocyanate compound, 0.02 parts by mass of tin carboxylate (dibutyltin diuranate) as the metal carboxylate, and 85 parts by mass of a 9:1 mixture of toluene and ethyl acetate as the solvent, with a ratio of the number of isocyanate groups to the number of carboxyl groups of 14 (see Table 1). The maleic acid-modified polypropylene adhesive for the outer adhesive layer 54 was the same as that for the inner adhesive layer 52 .

[0155] The inner core laminate material L2 was prepared with a heat transfer layer 61 made of 120 μm thick AL (aluminum) foil and heat-sealing layers 62 made of 30 μm thick CPP (non-oriented polypropylene) film attached to both sides of the heat transfer layer 61 via a maleic acid-modified polypropylene adhesive.

[0156] The maleic acid-modified polypropylene adhesive of the inner core laminating material L2 was the same as that of the inner adhesive layer 52.

[0157] The outer laminate material L1 was used to produce a tray member 20 and a cover member 21 corresponding to this embodiment shown in Figures 1 to 3. That is, one of the outer laminate materials L1 was deep-drawn to produce a tray member 20 having a recessed portion 22 measuring 80 mm in length, 160 mm in width, 4 mm in depth, and a corner angle of 10° (the opening angle θ2 of the side wall of the tray member 20 shown in Figures 2(b) and (C) is 10°), with a flange portion 23 formed around the entire periphery of the opening edge of the recessed portion 22.

[0158] Furthermore, two holes with a diameter of φ13 mm were formed in the front end (lateral end) of the tray member 20 in a vertical direction, to serve as a heat medium inlet 24 and a heat medium outlet 25 .

[0159] The other outer laminate material L1 was cut to a length of 80 mm and a width of 160 mm to prepare a cover member 21.

[0160] Furthermore, the above-mentioned inner core laminate material L2 was used to produce the inner core material 3 of this embodiment shown in Figures 3 and 4. That is, the inner core laminate material L2 was subjected to embossing roll processing to produce a corrugated rectangular inner core material 3 with a spacing FP between adjacent recesses 35 of 4 mm, a height H of the inner core material 3 of 4 mm, and a thickness T of the inner core laminate material L2 of 0.186 mm.

[0161] The inner core 3 was then cut to a length of 76 mm in the longitudinal direction (the direction of the mountains and valleys) and 120 mm in the transverse direction. As shown in Figure 2(a), the inner core 3 was then trimmed so that both vertices of the front edge were inclined transversely at an angle θ1 of 3°, producing a trapezoidal inner core 3 whose width gradually narrows from one end (front end) to the other end (rear end).

[0162] As shown in Figure 3, a header 4 was produced by injection molding using a propylene-ethylene random copolymer (MFR of 15 g / 10 min at 230°C according to JIS K7210). The header 4 was 80 mm long, 20 mm wide, and 2 mm thick, and the pipe section 44 had an inner diameter of 8 mm, an outer diameter of 11 mm, and a height of 5 mm. A partition wall 45 was provided inside the header 4 to separate the inlet header 41 and the outlet header 42.

[0163] Next, the header 4 was placed in the front end of the recessed portion 22 of the tray member 20. At this time, the pair of pipes 44 were placed facing downward so as to enter the heat transfer medium inlet 24 and the heat transfer medium outlet 25 formed in the tray member 20. Furthermore, the inner core material 3 was placed adjacent to the header 4 on the rear side of the header 4 within the recessed portion 22. The inner core material 3 was placed so that its intermediate flow paths 37 (in the direction of the peaks and valleys) were parallel to the longitudinal direction of the header 4. At this time, the gaps between the outer packaging material 2 and both long sides of the inner core material 3 were made equal.

[0164] Next, the cover member 21 was placed so as to close the recessed portion 22 of the tray member 20 from above.

[0165] In this way, a non-bonded heat exchanger mock-up was produced, and the mock-up was subjected to a heat sealing process using upper and lower sealing molds that fit the shape of the mock-up under heat sealing conditions of a temperature of 200°C, a pressure of 0.3 MPa, and a time of 6 seconds to thermally bond (heat seal) the joints between each part.Then, the seal width (flange width) of the molded outer periphery was trimmed to 5 mm all around, thereby producing heat exchanger 1 of Example 1.

[0166] <Example 2> The heat exchanger 1 was manufactured in the same manner as in Example 1, except that the inner adhesive layer 52 was made of a maleic acid-modified polypropylene adhesive using polypropylene with an MFR of 12 g / 10 min at 230°C and an acid value of 5.7 mg KOH / g.

[0167] <Comparative Example 1> The heat exchanger 1 was produced in the same manner as in Example 1, except that the inner adhesive layer 52 was made of polypropylene having an MFR of 40 g / 10 min at 230°C and an acid value of 56 mg KOH / g, and a maleic acid-modified polypropylene adhesive in which the ratio of the number of isocyanato groups to the number of carboxyl groups was 0.6.

[0168] <Comparative Example 2> The heat exchanger 1 was produced in the same manner as in Example 1, except that the inner adhesive layer 52 was made of polypropylene having an MFR of 40 g / 10 min at 230°C, an acid value of 3.4 mg KOH / g, and a maleic acid-modified polypropylene adhesive in which the ratio of the number of isocyanato groups to the number of carboxyl groups was 29.

[0169] <Comparative Example 3> The heat exchanger 1 was produced in the same manner as in Example 1, except that the inner adhesive layer 52 was made of the following urethane adhesive (polyester polyol).

[0170] The urethane adhesive is a mixture of 3 parts by mass of hexamethylene diisocyanate (HDI), a polymer of saturated aliphatic diisocyanate, as the curing agent polyfunctional isocyanate compound, 2.3 parts by mass of isophorone diisocyanate (IPDI), a polymer of saturated alicyclic diisocyanate, and 0.2 parts by mass of tolylene diisocyanate (TDI), a polymer of aromatic diisocyanate, 0.02 parts by mass of tin carboxylate as the metal carboxylate, and 85 parts by mass of a 9:1 mixture of toluene and ethyl acetate as the solvent, with a ratio of the number of isocyanate groups to the number of hydroxyl groups of 10 (see Table 1).

[0171] Each heat exchanger 1 manufactured as described above was subjected to various evaluations based on the following evaluation methods.

[0172] <Repeated pressure resistance test> Five heat exchangers were prepared for each of Examples 1 and 2 and Comparative Examples 1 to 3. Tap water was passed through each heat exchanger at room temperature (23°C) under a water pressure of 0 MPa to 0.2 MPa, and the appearance of each heat exchanger was observed after 15,000 cycles, and an evaluation was made of whether swelling or peeling occurred in any area. The results were evaluated based on the following criteria.

[0173] (Judgment criteria) "○": No peeling occurred (good) "△": Peeling between outer packaging material 2 and inner core material 3 occurred in 1 out of 5 (passed) "X": Peeling between the outer packaging material 2 and the inner core material 3 occurred in two or more out of five pieces (failed).

[0174] <High temperature and pressure resistance test> (Evaluation of whether delamination occurs when used in a high-temperature, internally pressurized environment) Five heat exchangers each of Examples 1 and 2 and Comparative Examples 1 to 3 were prepared, and each heat exchanger was filled with a 50 vol / vol% LLC aqueous solution and heated to 90°C. An internal pressure of 0.13 MPa was applied and maintained for 250 hours, and the appearance of each heat exchanger was observed to evaluate whether swelling or peeling had occurred in any areas.

[0175] (Judgment criteria) "○": No peeling occurred (good) "△": Peeling between outer packaging material 2 and inner core material 3 occurred in 1 out of 5 (passed) "X": Peeling between the outer packaging material 2 and the inner core material 3 occurred in two or more out of five pieces (failed).

[0176] <Method for measuring laminate strength at high temperatures> A test piece measuring 15 mm wide and 150 mm long was cut out from the obtained outer packaging material 2, and the aluminum foil (heat transfer layer 51) and the heat-sealing layer 53 were peeled off in a region extending 10 mm inward from one end of the test piece in the longitudinal direction.

[0177] In accordance with JIS K6854-3 (1999), a Shimadzu Strograph (AGS-5kNX) was used to clamp and fix the aluminum foil-containing laminate with one chuck, and the peeled heat-sealed layer 53 with the other chuck. The laminate was then held at 90°C for 1 minute, and then subjected to T-peel at a tensile speed of 100 mm / min in the same 90°C environment. The peel strength was measured, and the value at which this measurement value stabilized was taken as the "laminate strength at high temperatures (N / 15 mm width)." The measurement results were evaluated based on the following criteria.

[0178] (Judgment criteria) "〇"...Lamination strength is "3.0N / 15mm width" or more "△": Laminate strength is "1.5N / 15mm width" or more but less than "3.0N / 15mm width" "×"...Laminate strength is less than "1.5N / 15mm width".

[0179] <Overall Judgment> The overall evaluation was given as "Good" if the evaluation was "Good" in all of the above repeated pressure resistance test, high-temperature pressure resistance test, and high-temperature laminate strength measurement method, and as "Poor" if the evaluation was not "Good" in any one of them. The results are shown in Table 1.

[0180] [Table 1]

[0181] In Table 1, "HDI" stands for hexamethylene diisocyanate, "IPDI" stands for isophorone diisocyanate, "MDI" stands for diphenylmethane-4,4'-diisocyanate, and "TDI" stands for tolylene diisocyanate.

[0182] As is clear from Table 1, Examples 1 and 2 received a rating of "○" in all of the repeated pressure resistance tests, high-temperature pressure resistance tests, and laminate strength measurements at high temperatures, demonstrating excellent heat resistance, LLC (antifreeze) resistance, water resistance, and durability.

[0183] On the other hand, in Comparative Examples 1 to 3, no "○" rating was obtained in any of the repeated pressure resistance tests, high-temperature pressure resistance tests, and laminate strength measurements at high temperatures, indicating that sufficient heat resistance, LLC (antifreeze) resistance, water resistance, and durability were not obtained. [Industrial Applicability]

[0184] The heat exchanger of the present invention can be used as a cooler (cooling device) to prevent heat generation around the CPU and battery of smartphones and personal computers, around the display of LCD TVs, OLED TVs, and plasma TVs, around the power module and battery of automobiles, as well as a heater (heating device) for floor heating and snow removal.

[0185] This application claims priority from Japanese Patent Application No. 2020-084937, filed on May 14, 2020, the disclosure of which is incorporated herein by reference in its entirety.

[0186] It should be understood that the terms and expressions used herein are used for the purpose of explanation and not for limiting interpretation, and do not exclude any equivalents of the features shown and described herein, but also allow various modifications within the claimed scope of the present invention. [Explanation of symbols]

[0187] 1: Heat exchanger 2:Outer packaging material 24: Heat medium inlet 25: Heat medium outlet 3: Inner core material 35: Recess 36: Convex 4: Header 51, 61: Heat transfer layer 52: Inner adhesive layer 53, 62: Heat-sealing layer 55: Protective layer L1: outer laminate material L2: Inner laminate material

Claims

1. A heat exchanger having a heat medium inlet and a heat medium outlet, and including an outer packaging material through which a heat medium flowing in from the heat medium inlet flows and flows out from the heat medium outlet, The outer packaging material is formed by an outer packaging laminate material including a metal heat transfer layer and a resin heat seal layer provided on one surface of the heat transfer layer, and the outer packaging laminate materials are stacked and the heat seal layers are joined together along the periphery to form an integrated product. The heat transfer layer and the heat sealing layer of the outer laminate material are laminated via an inner adhesive layer made of an acid-modified polyolefin-based adhesive containing an acid-modified polyolefin-based resin, an inner core material disposed inside the outer packaging material; the inner core material is composed of an inner core laminate material including a metal heat transfer layer and a resin heat fusion layer provided on both sides of the heat transfer layer; A heat exchanger characterized in that the heat transfer layer and the heat fusion layer of the inner core laminate material are bonded together with an acid-modified polyolefin-based adhesive containing an acid-modified polyolefin-based resin.

2. 2. The heat exchanger according to claim 1, wherein the acid-modified polyolefin adhesive contains a polyolefin resin having a carboxyl group as a base component and a polyfunctional isocyanate compound as a curing agent.

3. 3. The heat exchanger according to claim 2, wherein the ratio of the number of isocyanato groups contained in said polyfunctional isocyanate compound to the number of carboxyl groups contained in said polyolefin resin is 1 to 20.

4. 4. The heat exchanger according to claim 2, wherein the polyfunctional isocyanate compound contains an aliphatic isocyanate and an aromatic isocyanate.

5. The heat exchanger according to any one of claims 1 to 4, wherein the inner adhesive layer contains one or more metal salts made of at least one metal of Groups 7, 12 and 14.

6. 6. The heat exchanger according to claim 1, wherein a protective layer is laminated on the other surface of the heat transfer layer of the outer packaging material.

7. The inner core material has an uneven portion, the heat-sealing layers on the bottom surfaces of the recesses and the top surfaces of the protrusions of the inner core material are joined together with the heat-sealing layer of the outer cover material; 7. The heat exchanger according to claim 1, wherein the heat-sealing layer of the outer covering material and the heat-sealing layer of the inner core material are made of the same type of resin.

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