Laminate and method for manufacturing laminate

Abstract

To provide a laminate which is excellent in heat durability, and a method for manufacturing a laminate.SOLUTION: A laminate includes a first resin layer (31), a first conductive layer (32), an insulation layer (33), and a second conductive layer (34) in this order, wherein the first resin layer has a storage part, the first conductive layer is arranged in the storage part of the first resin layer, and has an adhesive layer (35) in at least any one of between the first conductive layer and the insulation layer, and the insulation layer and the second conductive layer, the adhesive layer contains a solid joining agent containing an amorphous thermoplastic resin which is at least one selected from a thermoplastic epoxy resin and a phenoxy resin as a main component, and the amorphous thermoplastic resin has an epoxy equivalent of 1,600 or more or does not contain an epoxy group, and has heat of fusion of 15 J / g or less.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present disclosure relates to a laminate and a method for making the laminate. [Background technology]

[0002] A power module (PM) installed in a hybrid vehicle or the like includes a laminate (also called a housing) of a resin molded part and a metal. Conventionally, housings are manufactured by arranging a conductive layer and an insulating layer in a mold, and then injecting resin into the mold to form a molding (hereinafter, also referred to as insert molding) (see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-122959 Summary of the Invention [Problem to be solved by the invention]

[0004] Typically, a heat sink with elements brazed to it is attached to the housing used in a PM. From the viewpoint of improving manufacturing efficiency, it is desirable to simultaneously bond the heat sink to the housing and the elements, etc. to the heat sink. However, heat is applied to the housing when the elements, etc. are brazed to the heat sink. The present inventors have now discovered that in a housing manufactured by the conventional insert molding disclosed in Patent Document 1, the conductive layer is embedded in the resin layer, and therefore when the laminate is placed in a high-temperature environment, heated, etc., it is unable to fully alleviate the internal stress caused by the difference in linear expansion coefficients between the conductive layer and the resin layer, resulting in the generation of cracks and deformation of the conductive layer and resin layer, and therefore there is room for improvement in its thermal durability.

[0005] An object of one embodiment of the present disclosure is to provide a laminate having excellent thermal durability, and a method for producing the laminate. [Means for solving the problem]

[0006] <1> A first resin layer; A first conductive layer; An insulating layer; A second conductive layer; and In this order, the first resin layer has a housing portion, the first conductive layer is disposed within the housing portion of the first resin layer; A laminate comprising an adhesive layer at least either between the first conductive layer and the insulating layer or between the insulating layer and the second conductive layer, the adhesive layer containing a solid adhesive agent mainly composed of an amorphous thermoplastic resin which is at least one type selected from a thermoplastic epoxy resin and a phenoxy resin, the amorphous thermoplastic resin having an epoxy equivalent of 1,600 or more, or the amorphous thermoplastic resin does not contain an epoxy group, and the amorphous thermoplastic resin has a heat of fusion of 15 J / g or less. <2> The housing portion includes a concave portion or a concave-convex portion. <1> The laminate according to claim 1. <3> the first conductive layer, the insulating layer and the second conductive layer are disposed within the housing portion of the first resin layer; <1> The laminate according to claim 1. <4> The area of ​​the housing portion of the first resin layer is equal to or larger than the area of ​​the first conductive layer. <1> or <2> The laminate according to claim 1. <5> a second resin layer on the opposite side of the second conductive layer to the insulating layer; Optionally, the adhesive layer is provided at least one between the first resin layer and the first conductive layer and between the second conductive layer and the second resin layer. <1> from <4> 13. The laminate according to claim 12 . <6> The first resin layer is a cured product of a resin composition containing a thermosetting resin. <1> from <5> 13. The laminate according to claim 12 . <7> The thermosetting resin includes an unsaturated polyester. <6> The laminate according to claim 1. <8> the first resin layer has a fixing portion that fixes the first conductive layer, the insulating layer, and the second conductive layer; <1> from <7> 13. The laminate according to claim 12 . <9> a pre-bonding process for preparing a laminate in which a first resin layer having a storage portion, a first conductive layer disposed in the storage portion of the first resin layer, an insulating layer, and a second conductive layer are arranged in this order, the pre-bonding process including disposing a solid adhesive agent at least between the first conductive layer and the insulating layer and between the insulating layer and the second conductive layer, the solid adhesive agent being mainly composed of at least one amorphous thermoplastic resin selected from a thermoplastic epoxy resin and a phenoxy resin; a bonding process in which the laminate is heated and pressurized to melt the solid bonding agent and bond the first conductive layer to the insulating layer and / or bond the insulating layer to the second conductive layer; A method for producing a laminate, comprising: A method for producing a laminate, wherein the amorphous thermoplastic resin has an epoxy equivalent of 1,600 or more, or the amorphous thermoplastic resin does not contain an epoxy group, and the heat of fusion of the amorphous thermoplastic resin is 15 J / g or less. <10> The heating and pressurization are carried out under conditions of 100°C to 400°C and 0.01 MPa to 20 MPa. <9> A method for producing the laminate described in claim 1. <11> The solid bonding agent before melting has any shape selected from the group consisting of a film, a rod, a pellet, and a powder. <9> or <10> A method for producing the laminate described in claim 1. Effect of the Invention

[0007] According to one embodiment of the present disclosure, it is possible to provide a laminate having excellent thermal durability and a method for manufacturing the laminate. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view showing one embodiment of a laminate according to the present disclosure. [Diagram 2] FIG. 2 is a perspective view showing another embodiment of the laminate of the present disclosure. [Diagram 3] FIG. 3 is a perspective view showing one embodiment of a laminate of the present disclosure. [Figure 4] FIG. 4 is a cross-sectional view showing another embodiment of the laminate of the present disclosure. [Diagram 5] FIG. 5 is a cross-sectional view showing another embodiment of the laminate of the present disclosure. [Figure 6] FIG. 6 is a perspective view showing one embodiment of a first resin layer included in the laminate of the present disclosure. [Figure 7] FIG. 7 is a perspective view showing one embodiment of a first resin layer included in the laminate of the present disclosure. [Figure 8] FIG. 8 is a perspective view showing another embodiment of the laminate of the present disclosure. [Figure 9] FIG. 9 is a schematic cross-sectional view of a state in which a first member and a second member are bonded via an adhesive layer containing a solid adhesive. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, the embodiments for carrying out the present disclosure will be described in detail. However, the present disclosure is not limited to the following embodiments. In the following embodiments, the components (including element steps, etc.) are not essential unless otherwise specified. The same applies to the numerical values ​​and their ranges, and do not limit the present disclosure.

[0010] In this disclosure, the term "process" includes not only a process that is independent of other processes, but also a process that cannot be clearly distinguished from other processes, as long as the purpose of the process is achieved. In this disclosure, a numerical range indicated using "~" includes the numerical values ​​before and after "~" as the minimum and maximum values, respectively. In the present disclosure, in which numerical ranges are described in stages, the upper or lower limit value described in one numerical range may be replaced with the upper or lower limit value of another numerical range described in stages. In addition, in the numerical ranges described in the present disclosure, the upper or lower limit of the numerical ranges may be replaced with values ​​shown in the examples. In the present disclosure, each component may contain multiple types of the corresponding substance. When multiple substances corresponding to each component are present in the composition, the content or amount of each component means the total content or amount of the multiple substances present in the composition, unless otherwise specified. In this disclosure, the term "layer" includes cases where the layer is formed over the entire area when the area in which the layer exists is observed, as well as cases where the layer is formed over only a portion of the area. When an embodiment of the present disclosure is described with reference to the drawings, the configuration of the embodiment is not limited to the configuration shown in the drawings. In addition, the size of the members in each drawing is conceptual, and the relative relationship between the sizes of the members is not limited to this. In this disclosure, bonding means connecting two objects together, and adhesion and welding are subordinate concepts. Adhesion means joining two adherends (objects to be bonded) together using an organic material such as tape or adhesive (curable resin, thermoplastic resin, etc.). Welding means joining by utilizing entanglement and crystallization due to molecular diffusion that occurs during the process of contact pressure application and cooling, or by utilizing intermolecular interactions with the base material that occur during melting, when the surface of a thermoplastic resin or the like is melted by heat.

[0011] [Laminate] The laminate of the present disclosure comprises, in this order, a first resin layer, a first conductive layer, an insulating layer, and a second conductive layer, the first resin layer having a housing portion, and the first conductive layer being disposed within the housing portion of the first resin layer.

[0012] The laminate of the present disclosure has excellent thermal durability. The reason why the above effect is exhibited is not clear, but is presumed to be as follows. The laminate of the present disclosure can be manufactured by preparing each layer individually and laminating them, rather than by insert molding. Therefore, in a laminate manufactured by insert molding, the first conductive layer is embedded in the first resin layer and is completely adhered to the first resin layer, whereas in the laminate of the present disclosure, the first resin layer has a housing portion, so that the first conductive layer is not completely adhered to the first resin layer, and the internal stress generated during heating can be relaxed. It is presumed that this can suppress the occurrence of cracks and deformation of the conductive layer and resin layer, improving heat durability. Furthermore, the first resin layer has a housing portion, which is difficult to form by insert molding, and it is presumed that this improves thermal durability.

[0013] The laminate of the present disclosure may further include a second resin layer on the side of the second conductive layer opposite the insulating layer.

[0014] The laminate of the present disclosure comprises an adhesive layer at least one between the first conductive layer and the insulating layer and between the insulating layer and the second conductive layer, and may further optionally comprise an adhesive layer at least one between the first resin layer and the first conductive layer and between the second conductive layer and the second resin layer. From the viewpoint of thermal durability, the adhesive layer is preferably disposed within the housing portion of the first resin layer.

[0015] The laminate of the present disclosure may include a heat sink on the surface of the first conductive layer facing the first resin layer or on the surface of the second conductive layer facing the second resin layer. From the viewpoint of thermal durability, the heat sink is preferably disposed within the housing portion of the first resin layer.

[0016] (First resin layer) The first resin layer has a housing portion, and the first conductive layer is disposed in the housing portion. From the viewpoint of thermal durability, the housing portion preferably includes a concave portion or an uneven portion. The housing portion including the concave and convex portions means that the housing portion includes concave and convex portions. The concave portions may be stepped.

[0017] From the viewpoint of thermal durability, the first conductive layer, the insulating layer and the second conductive layer are preferably disposed within the housing portion of the first resin layer. When the accommodation portion includes a stepped recess, the first conductive layer, the insulating layer and the second conductive layer may be accommodated in the same layer or in different layers. 3 to 5 show an embodiment in which a first conductive layer, an insulating layer and a second conductive layer are accommodated in different levels of a stepped recess.

[0018] Moreover, the first resin layer may have one storage section, or may have two or more storage sections. The first resin layer 100 shown in FIG. Each of the accommodation portions 101 of the first resin layer 100 shown in FIG. 6 includes a concave portion 102A and a convex portion 102B. When the first resin layer has multiple storage sections, the first conductive layer 105 may be placed in some of the storage sections as shown in FIG. 7, or the first conductive layer 105 may be placed in all of the storage sections. Furthermore, the insulating layer and the second conductive layer do not need to be laminated on the first conductive layers arranged in all of the housing parts, but may be laminated on all of the first conductive layers arranged in the housing parts as shown in Fig. 8. In Fig. 8, the insulating layer is not shown, and the second conductive layer is indicated by the reference numeral 106.

[0019] The area of ​​the accommodation portion of the first resin layer is preferably equal to or larger than the area of ​​the first conductive layer. The ratio of the area of ​​the first conductive layer to the area of ​​the accommodation portion of the first resin layer (area of ​​the first conductive layer / accommodation portion of the first resin layer) is preferably 1.01 or more. This allows the first conductive layer to be easily disposed in the accommodation portion of the first resin layer. In addition, the area ratio is preferably 2.00 or less. This tends to suppress the occurrence of misalignment of the first conductive layer on the first resin layer. When the first resin layer has a storage portion, it is preferable that the size of the storage portion be appropriately changed depending on the size of the first conductive layer, the use of the laminate, etc. The area of ​​the storage portion is, for example, 1 cm2 ~1000cm 2 It can be said that: The depth of the housing part is preferably at least equal to or greater than the thickness of the first conductive layer, more preferably equal to or greater than the sum of the thicknesses of the first conductive layer, the insulating layer, and the second conductive layer, even more preferably equal to or greater than the sum of the thicknesses of the first conductive layer, the insulating layer, the second conductive layer, and the adhesive layer, and particularly preferably equal to or greater than the sum of the thicknesses of the first conductive layer, the insulating layer, the second conductive layer, the adhesive layer, and the heat sink. The thickness of the housing part can be, for example, 0.1 mm to 100 mm. The depth of the housing portion may be less than the total thickness of the first conductive layer, the insulating layer, the second conductive layer, the adhesive layer, and the heat sink.

[0020] From the viewpoint of thermal durability, the first resin layer is preferably a cured product of a resin composition containing a thermosetting resin. The type of thermosetting resin is not particularly limited, and may be any resin having one or more functional groups in one molecule that can be used in a crosslinking reaction by heating. Examples of functional groups include epoxy groups, acryloyl groups, methacryloyl groups, hydroxy groups, vinyl groups, carboxy groups, amino groups, maleimide groups, acid anhydride groups, thiol groups, thionyl groups, amide groups, and imide groups. Examples of the thermosetting resin include a phenol resin, an unsaturated imide resin, a cyanate resin, an isocyanate resin, a benzoxazine resin, an oxetane resin, an amino resin, an unsaturated polyester resin, an acrylic resin, a dicyclopentadiene resin, a silicone resin, a triazine resin, a melamine resin, a resorcinol resin, an epoxy resin, etc. Among the above, from the viewpoint of thermal durability, it is preferable to include one or more selected from an unsaturated polyester and a phenol resin, and it is more preferable to include an unsaturated polyester. The resin composition may contain one type of thermosetting resin alone or two or more types of thermosetting resins.

[0021] The unsaturated polyester can be obtained by polycondensation (esterification) of a polyhydric alcohol with an unsaturated polybasic acid, a saturated polybasic acid, or the like.

[0022] The polyhydric alcohol is not particularly limited, and conventionally known polyhydric alcohols can be used. Examples of polyhydric alcohols include ethylene glycol, propylene glycol, butanediol, diethylene glycol, dipropylene glycol, triethylene glycol, pentanediol, hexanediol, neopentanediol, hydrogenated bisphenol A, bisphenol A, and glycerin. These may be used alone or in combination of two or more.

[0023] The unsaturated polybasic acid is not particularly limited, and conventionally known acids can be used. Examples of the unsaturated polybasic acid include maleic anhydride, fumaric acid, citraconic acid, itaconic acid, etc. These can be used alone or in combination. The saturated polybasic acid is not particularly limited, and conventionally known acids can be used. Examples of the saturated polybasic acid include phthalic anhydride, isophthalic acid, terephthalic acid, HET acid, succinic acid, adipic acid, sebacic acid, tetrachlorophthalic anhydride, tetrabromophthalic anhydride, and endomethylenetetrahydrophthalic anhydride. These may be used alone or in combination of two or more.

[0024] The unsaturated polyester may be one synthesized by a known method using the above-mentioned raw materials, or a commercially available product may be used. The unsaturated polyester can be obtained by polycondensing a polyhydric alcohol with an unsaturated polybasic acid, a saturated polybasic acid, or the like in an atmosphere of an inert gas such as nitrogen at a temperature of 140° C. to 230° C. The polycondensation reaction may be carried out under pressurized or reduced pressure conditions. In the polycondensation reaction, a crosslinking agent and a catalyst may be used, if necessary. Examples of the crosslinking agent include styrene monomer, diallyl phthalate monomer, diallyl phthalate prepolymer, methyl methacrylate, triallyl isocyanurate, etc. These may be used alone or in combination. Examples of the catalyst include manganese acetate, dibutyltin oxide, stannous oxalate, zinc acetate, cobalt acetate, etc. These may be used alone or in combination of two or more.

[0025] From the viewpoint of thermal durability, the number average molecular weight of the thermosetting resin is preferably 1,000 to 10,000, and more preferably 1,500 to 5,000. In the present disclosure, the number average molecular weight is a weight average molecular weight in terms of polystyrene measured by gel permeation chromatography (GPC).

[0026] From the viewpoint of thermal durability, the content of the thermosetting resin relative to the total mass of the resin composition is preferably 10% by mass to 60% by mass, more preferably 20% by mass to 50% by mass, and even more preferably 20% by mass to 40% by mass.

[0027] The resin composition may contain a thermoplastic resin, an elastomer, or the like. Specific examples of thermoplastic resins include polyimide resin, polyamideimide resin, polyamide resin, polyetherimide resin, polybenzoxazole resin, polybenzimidazole resin, polystyrene resin, acrylonitrile-butadiene-styrene copolymer resin, acrylonitrile-styrene copolymer resin, polyethylene resin, polypropylene resin, polyvinyl chloride resin, polyvinylidene chloride resin, polycarbonate resin, (meth)acrylic resin, polyester resin, polyacetal resin, polyphenylene sulfide resin (PPS), and the like. Specific examples of the elastomer include silicone rubber, styrene butadiene rubber (SBR), nitrile rubber (NBR), and urethane rubber.

[0028] The resin composition may contain various additives such as a curing agent, a curing accelerator, a filler, a release agent, a flame retardant, a colorant, a plasticizer, a silane coupling agent, a rust inhibitor, a copper damage inhibitor, a reducing agent, an antioxidant, a tackifier resin, an ultraviolet absorber, an antifoaming agent, a leveling adjuster, and a solvent.

[0029] The first resin layer may have a fixing portion that fixes the first conductive layer, the insulating layer, and the second conductive layer. When the first resin layer has the fixing portion, it tends to be possible to suppress the occurrence of positional deviation of the first conductive layer, the insulating layer, and the second conductive layer on the first resin layer.

[0030] The first resin layer and the second resin layer may have either an insertion portion or an opening. When the first resin layer has either an insertion portion or an opening, and the second resin layer has at least the other, the first resin layer and the second resin layer can be fitted together by inserting the insertion portion into the opening.

[0031] (First Conductive Layer and Second Conductive Layer) The first conductive layer and the second conductive layer may include at least one of a metal and a metal oxide. Examples of the metal include silver, gold, copper, palladium, platinum, titanium, chromium, nickel, aluminum, zirconium, tungsten, vanadium, rhodium, iridium, and alloys thereof. Examples of metal oxides include zinc oxide (ZnO), tin oxide (SnO2), indium tin oxide (ITO), aluminum oxide (Al2O3), and titanium oxide (TiO2).

[0032] From the viewpoint of electrical conductivity, the average thickness of the first conductive layer and the second conductive layer can be appropriately set depending on the application, etc. In consideration of ease of arrangement on the concave or convex portion of the first resin layer, it is preferably 0.1 mm to 10 mm. In the present disclosure, the average thickness is determined by measuring the thickness at two points on a layer with a measuring device and averaging these values.

[0033] The materials contained in the first conductive layer and the second conductive layer, the average thicknesses of the layers, etc. may be the same or different.

[0034] (insulating layer) The insulating layer is preferably a cured product of a resin composition containing an insulating resin. Examples of the insulating resin include thermoplastic resin, thermosetting resin, and curable resin such as photocurable resin.

[0035] The photocurable resin may be any resin having one or more unsaturated bonds in one molecule that undergo a crosslinking reaction when exposed to light. Specific examples of the photocurable resin include acrylic resin, urethane resin, polyester resin, polyether resin, epoxy resin, polybutadiene resin, polyimide resin, polyamide resin, silicone resin, and fluororesin. The thermoplastic resin and the thermosetting resin have been described above, so a description thereof will be omitted here.

[0036] The resin composition may contain various additives such as a curing agent, a curing accelerator, a photopolymerization initiator, a filler, a release agent, a flame retardant, a colorant, a plasticizer, a silane coupling agent, a rust inhibitor, a copper damage inhibitor, a reducing agent, an antioxidant, a tackifier resin, an ultraviolet absorber, an antifoaming agent, a leveling adjuster, and a solvent.

[0037] From the viewpoint of insulation, the average thickness of the insulating layer can be appropriately set depending on the application, etc. In consideration of ease of arrangement in the concave or convex portions of the first resin layer, it is preferably 0.01 mm to 10 mm.

[0038] (Second resin layer) The laminate of the present disclosure may further include a second resin layer on the opposite side of the second conductive layer to the insulating layer. By including the second resin layer, it is possible to prevent the first conductive layer, the insulating layer, and the second conductive layer from being misaligned on the first resin layer. The second resin layer may have a concave portion, a convex portion, or an uneven portion. The concave portion, the convex portion, or the uneven portion provided in the second resin layer may be provided to correspond to the shape of the second conductive layer. By having the concave portion of the second resin layer and the shape of the second conductive layer correspond to each other, the position of the second conductive layer can be fixed by the second resin layer. For example, when the total thickness of the first conductive layer, the insulating layer, and the second conductive layer is greater than the depth of the recess in the first resin layer, the second resin layer may be provided with a recess that matches the shape of the second conductive layer. In this case, the area of ​​the recess in the second resin layer is preferably equal to or greater than the area of ​​the second conductive layer. In addition, when the total thickness of the first conductive layer, the insulating layer, and the second conductive layer is smaller than the depth of the recess in the first resin layer, the second resin layer may have a convex portion at a position corresponding to the second conductive layer. The number of convex portions may be one or more than two.

[0039] The second resin layer is preferably a cured product of a resin composition containing a thermosetting resin. The thermosetting resin and the resin composition have been described above, and therefore will not be described here.

[0040] The second resin layer may have a fixing portion that fixes the first conductive layer, the insulating layer, and the second conductive layer. When the second resin layer has the fixing portion, it tends to be possible to suppress the first conductive layer, the insulating layer, and the second conductive layer from being displaced from each other on the first resin layer.

[0041] (adhesive layer) The laminate of the present disclosure includes an adhesive layer at least one between the first conductive layer and the insulating layer, between the insulating layer and the second conductive layer, between the first resin layer and the first conductive layer, and between the second conductive layer and the second resin layer. The first resin layer and the second resin layer may be bonded to each other by adjusting the size of an adhesive layer provided between any of the layers.

[0042] The adhesive layer may include an intermediate layer of an insulator, and in that case, the adhesive layer is preferably made of three layers of a bonding material, an intermediate layer, and another bonding material from the viewpoint of adhesion and insulation. By including the intermediate layer of an insulator, defects such as insulating pinholes are less likely to occur, and insulation properties can be improved. Examples of resins for the intermediate layer include polyimide resin, polyamideimide resin, polyamide resin, polyetherimide resin, polybenzoxazole resin, polybenzimidazole resin, polystyrene resin, acrylonitrile-butadiene-styrene copolymer resin, acrylonitrile-styrene copolymer resin, polyethylene resin, polypropylene resin, polyvinyl chloride resin, polyvinylidene chloride resin, polycarbonate resin, (meth)acrylic resin, polyester resin, polyacetal resin, polyphenylene sulfide resin (PPS), phenolic resin, and the like. The adhesive layer contains a solid adhesive, which can prevent the thickness of the adhesive layer from changing when the first conductive layer, the adhesive layer, the insulating layer, etc. are laminated on the surface of the first resin layer, and can prevent the distance between the first conductive layer and the insulating layer, the distance between the first conductive layer and the second conductive layer, the distance between the second conductive layer and the insulating layer, etc. from changing.

[0043] (Solid adhesive) The solid bonding agent is mainly composed of at least one amorphous thermoplastic resin selected from a thermoplastic epoxy resin and a phenoxy resin, and the amorphous thermoplastic resin has an epoxy equivalent of 1,600 or more, or the amorphous thermoplastic resin does not contain an epoxy group, and the heat of fusion of the amorphous thermoplastic resin is 15 J / g or less.

[0044] The term "solid" in the solid adhesive means that the adhesive is solid at room temperature, i.e., has no fluidity when exposed to no pressure at 23° C. It is desirable that the solid adhesive is capable of retaining its shape without deformation for 30 days or more when exposed to no pressure at 23° C., and is also resistant to deterioration.

[0045] The "main component" means a component that is contained in the largest amount of resin components in the solid bonding agent and that accounts for 50% by mass or more of the resin components in the solid bonding agent. The solid bonding agent preferably contains 50% by mass or more of the resin components, more preferably 70% by mass or more, even more preferably 80% by mass or more, and particularly preferably 90% by mass or more.

[0046] In the present disclosure, the amorphous resin is a resin that has a melting point (Tm) but does not have a clear endothermic peak associated with melting or has a very small endothermic peak in a measurement using a differential scanning calorimeter (DSC). The heat of fusion is calculated from the area of ​​the endothermic peak of the DSC and the mass of the thermoplastic resin component. When an inorganic filler or the like is contained in the solid bonding agent, the heat of fusion is calculated from the mass of the resin component excluding the inorganic filler.

[0047] Specifically, the term "non-crystalline thermoplastic resin" in the present disclosure refers to a resin having properties measured by the following procedure. 2 to 10 mg of a sample is weighed out, placed in an aluminum pan, and heated from 23°C to 200°C or higher at 10°C / min using a DSC (DSC8231 manufactured by Rigaku Corporation) to obtain a DSC curve. When the heat of fusion is calculated from the area of ​​the endothermic peak at the time of melting obtained from the DSC curve and the weighed value, a resin having a heat of fusion of 15 J / g or less is regarded as an amorphous thermoplastic resin.

[0048] In order to fully impart the properties of an amorphous thermoplastic resin to the solid bonding agent, the content of the amorphous thermoplastic resin in the resin components in the solid bonding agent is preferably 60 mass % or more, more preferably 70 mass % or more, even more preferably 80 mass % or more, and most preferably 90 mass % or more.

[0049] The heat of fusion is 15 J / g or less, preferably 11 J / g or less, more preferably 7 J / g or less, and even more preferably 4 J / g or less, and most preferably the endothermic peak upon melting is below the detection limit.

[0050] The epoxy equivalent is 1,600 or more, preferably 2,000 or more, more preferably 5,000 or more, and even more preferably 9,000 or more, and most preferably above the detection limit so that substantially no epoxy groups are detected.

[0051] By using this solid adhesive, the sudden viscosity drop seen with conventional hot melt adhesives does not occur when heated, and the adhesive does not reach a low viscosity state (0.001 to 100 Pa s) even in high temperature ranges exceeding 200° C. Therefore, the solid adhesive does not flow out of the laminate even in a molten state, and the thickness of the adhesive layer can be stably secured, making it possible to stably obtain high adhesive strength.

[0052] The epoxy equivalent in this disclosure (the mass of the resin containing 1 mole of epoxy groups) is the epoxy equivalent value of the thermoplastic epoxy resin or phenoxy resin component contained in the solid adhesive before bonding, and is a value (unit: "g / eq.") measured by the method specified in JIS K 7236:2001. Specifically, the epoxy equivalent of the resin is measured using a potentiometric titration device, using cyclohexanone as a solvent, adding a brominated tetraethylammonium acetate solution to the resin, and using a 0.1 mol / L perchloric acid-acetic acid solution. For solvent-diluted products (resin varnishes), the value is calculated as a solid content conversion value based on the non-volatile content. The epoxy equivalent of a mixture of two or more resins can also be calculated from the content and epoxy equivalent of each resin.

[0053] The melting point of the amorphous thermoplastic resin, which is the main component of the solid bonding agent, is preferably 50°C to 400°C, more preferably 60°C to 350°C, and even more preferably 70°C to 300°C. By having a melting point in the range of 50°C to 400°C, the solid bonding agent can be efficiently deformed and melted by heating and effectively wet and spread on the bonding surface, thereby obtaining high adhesive strength. In the present disclosure, the melting point of the amorphous thermoplastic resin means the temperature at which the solid substantially softens to become thermoplastic, and becomes meltable and bondable.

[0054] In a bonded body containing a conventional thermosetting adhesive, it is difficult to disassemble the bonded body, and it is difficult to separate and recycle the different materials that constitute the bonded body (i.e., poor recyclability). In addition, when a thermosetting adhesive is used, it is difficult to reattach the bonded body when there is a misalignment of the bonded part during the manufacturing process of the bonded body, or when the adherend has a defect and needs to be replaced (i.e., poor repairability), and it is inconvenient. On the other hand, the solid adhesive can be softened and melted by heat, and the two adherends can be easily separated, so it is excellent in recyclability. In addition, since the solid adhesive is thermoplastic, it can be reversibly softened, melted, and hardened (solidified) repeatedly, and it is also excellent in repairability.

[0055] <Thermoplastic epoxy resin> The thermoplastic epoxy resin is preferably a polymer of (a) a bifunctional epoxy resin monomer or oligomer and (b) a bifunctional compound having two identical or different functional groups selected from the group consisting of a phenolic hydroxyl group, a carboxyl group, a mercapto group, an isocyanate group, and a cyanate ester group. By using such a compound, the polymerization reaction to form a linear polymer proceeds preferentially, making it possible to form a thermoplastic epoxy resin having desired properties.

[0056] The (a) bifunctional epoxy resin monomer or oligomer refers to an epoxy resin monomer or oligomer having two epoxy groups in the molecule. Examples of the (a) bifunctional epoxy resin monomer or oligomer include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bifunctional phenol novolac type epoxy resin, bisphenol AD ​​type epoxy resin, biphenyl type epoxy resin, bifunctional naphthalene type epoxy resin, bifunctional alicyclic epoxy resin, bifunctional glycidyl ester type epoxy resin (e.g., diglycidyl phthalate, diglycidyl tetrahydrophthalate, dimer acid diglycidyl ester, etc.), bifunctional glycidyl amine type epoxy resin (e.g., diglycidyl aniline, diglycidyl toluidine, etc.), bifunctional heterocyclic epoxy resin, bifunctional diaryl sulfone type epoxy resin, hydroquinone type epoxy resin (e.g., hydroquinone diglycidyl ether, etc.), , 2,5-di-tert-butylhydroquinone diglycidyl ether, resorcinol diglycidyl ether, etc.), bifunctional alkylene glycidyl ether compounds (for example, butanediol diglycidyl ether, butenediol diglycidyl ether, butynediol diglycidyl ether, etc.), bifunctional glycidyl group-containing hydantoin compounds (for example, 1,3-diglycidyl-5,5-dialkylhydantoin, 1-glycidyl-3-(glycidoxyalkyl)-5,5-dialkylhydantoin, etc.), bifunctional glycidyl group-containing siloxanes (for example, 1,3-bis(3-glycidoxypropyl)-1,1,3,3-tetramethyldisiloxane, α,β-bis(3-glycidoxypropyl)polydimethylsiloxane, etc.), and modified products thereof. Among these, bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol S type epoxy resins, and biphenyl type epoxy resins are preferred in terms of reactivity and workability.

[0057] Examples of the (b) bifunctional compound having a phenolic hydroxyl group include mononuclear aromatic dihydroxy compounds having one benzene ring, such as catechol, resorcin, and hydroquinone; bisphenol compounds, such as bis(4-hydroxyphenyl)propane (bisphenol A), bis(4-hydroxyphenyl)methane (bisphenol F), and bis(4-hydroxyphenyl)ethane (bisphenol AD); compounds having a condensed ring, such as dihydroxynaphthalene; bifunctional phenol compounds having an allyl group introduced therein, such as diallyl resorcin, diallyl bisphenol A, and triallyl dihydroxybiphenyl; and dibutyl bisphenol A.

[0058] Examples of the (b) bifunctional compound having a carboxyl group include adipic acid, succinic acid, malonic acid, cyclohexanedicarboxylic acid, phthalic acid, isophthalic acid, and terephthalic acid.

[0059] Examples of the (b) bifunctional compound having a mercapto group include ethylene glycol bisthioglycolate and ethylene glycol bisthiopropionate.

[0060] Examples of the (b) bifunctional compound having an isocyanate group include diphenylmethane diisocyanate (MDI), isophorone diisocyanate (IPDI), hexamethylene diisocyanate (HMDI), and tolylene diisocyanate (TDI).

[0061] Examples of the (b) bifunctional compound having a cyanate ester group include 2,2-bis(4-cyanatophenyl)propane, 1,1-bis(4-cyanatophenyl)ethane, and bis(4-cyanatophenyl)methane.

[0062] Among the above (b), bifunctional compounds having a phenolic hydroxyl group are preferred because they can form thermoplastic polymers with suitable properties. Bifunctional compounds having two phenolic hydroxyl groups and a bisphenol structure or a biphenyl structure are preferred from the viewpoints of heat resistance and adhesiveness, and bisphenol A, bisphenol F and bisphenol S are preferred from the viewpoints of heat resistance and cost.

[0063] When the (a) is a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, a bisphenol S type epoxy resin, or a biphenyl type epoxy resin, and the (b) is bisphenol A, bisphenol F, or bisphenol S, the polymer obtained by polymerization of the (a) and (b) has a main chain having a paraphenylene structure and an ether bond as a main skeleton, and the main chain is connected with an alkylene group, and the hydroxyl group generated by polyaddition is arranged in a side chain. The linear structure resulting from the main skeleton having the paraphenylene structure and the ether bond can increase the mechanical strength of the polymer after polymerization, and the hydroxyl group arranged in the side chain can improve the adhesion to the substrate. As a result, it is possible to achieve a high level of adhesive strength equivalent to that of a thermosetting resin while maintaining workability. Furthermore, recycling and repair are possible by softening and melting with heat, and the recyclability and repairability, which are problems with thermosetting resins, can be improved.

[0064] Phenoxy resin Phenoxy resin is a polyhydroxy polyether synthesized from a bisphenol compound and epichlorohydrin, and has thermoplasticity. As a method for producing phenoxy resin, a method by direct reaction of a dihydric phenol compound with epichlorohydrin and a method by addition polymerization reaction of a diglycidyl ether of a dihydric phenol compound with a dihydric phenol compound are known, but the phenoxy resin may be obtained by either method. In the case of direct reaction of a dihydric phenol compound with epichlorohydrin, examples of the dihydric phenol compound include phenol compounds such as bisphenol A, bisphenol F, bisphenol S, biphenol, biphenylenediol, and fluorenediphenyl. Among these, bisphenol A, bisphenol F, and bisphenol S are preferred from the viewpoints of cost, adhesiveness, viscosity, and heat resistance. In addition to the dihydric phenol compound, aliphatic glycols such as ethylene glycol, propylene glycol, and diethylene glycol may be included in the above direct reaction. These may be used alone or in combination of two or more. Phenoxy resin has a chemical structure similar to that of epoxy resin, and has a structure in which a paraphenylene structure and an ether bond are linked together in the main chain, and hydroxyl groups are arranged in the side chains.

[0065] <Thermoplastic epoxy resin and phenoxy resin> The weight average molecular weight of the thermoplastic epoxy resin and the phenoxy resin is preferably 10,000 to 500,000, more preferably 18,000 to 300,000, and even more preferably 20,000 to 200,000, as a value calculated in terms of polystyrene by GPC (gel permeation chromatography). The weight average molecular weight is a standard polystyrene-equivalent value calculated from the elution peak position detected by GPC. When the weight average molecular weight is within the above range, the balance between thermoplasticity and heat resistance is good, so that a bonded body can be efficiently formed by melting, and the heat resistance of the bonded body can also be improved. When the weight average molecular weight is 10,000 or more, the heat resistance is excellent, and when it is 500,000 or less, the viscosity during melting is low and the adhesiveness is high.

[0066] <Method for manufacturing solid adhesive> The method for producing the solid adhesive is not particularly limited, but for example, it can be obtained by heating and polymerizing a monomer or oligomer of a bifunctional epoxy compound. A solvent may be added during polymerization to reduce the viscosity and facilitate stirring. If a solvent is added, it must be removed, and the solid adhesive may be obtained by drying or polymerization or both on a release film or the like.

[0067] If necessary, other additives can be blended into the solid bonding agent within a range that does not impair the effects of the present invention. The blending amount of the additive with respect to the total amount of the amorphous thermoplastic resin is preferably 50% by volume or less, more preferably 30% by volume or less, even more preferably 20% by volume or less, and most preferably 10% by volume or less. In the present disclosure, the volume % of the additive represents the volume ratio of the additive contained before polymerization of the monomer or oligomer of the bifunctional epoxy compound based on the volume of the total amount of the amorphous thermoplastic resin, and the volume of the additive can be obtained by dividing the mass of the additive contained by the true specific gravity of the additive.

[0068] Examples of the additives include viscosity modifiers, inorganic fillers, organic fillers (resin powders), antifoaming agents, coupling agents such as silane coupling agents, and pigments. These additives may be used alone or in combination of two or more. Examples of the viscosity modifiers include reactive diluents. Examples of the inorganic fillers include spherical fused silica, metal powders such as iron, silica sand, talc, calcium carbonate, mica, acid clay, diatomaceous earth, kaolin, quartz, titanium oxide, silica, phenolic resin microballoons, and glass balloons.

[0069] The solid bonding agent thus obtained has a low content of unreacted monomer or terminal epoxy groups, or is substantially free of unreacted monomer or terminal epoxy groups, and therefore has excellent storage stability and can be stored for long periods at room temperature.

[0070] The form of the solid adhesive before melting is not particularly limited, but it is preferable that the solid adhesive has any shape selected from the group consisting of a film, a rod, a pellet, and a powder. At least one side of the outer shape of the solid adhesive is preferably 5 mm or less, more preferably 3 mm or less, even more preferably 1 mm or less, particularly preferably 0.5 mm or less, and most preferably 0.3 mm or less. By sandwiching a solid adhesive having at least one side of the outer shape of 5 mm or less between a first member and a second member and applying heat and pressure, the solid adhesive can efficiently spread over the bonding surface, thereby obtaining a high adhesive strength.

[0071] It is more preferable that the solid adhesive before melting has a film shape. The film-shaped solid adhesive can bond these metal members while reliably holding the members to be bonded at a predetermined interval over the entire bonding surface. Therefore, the film-shaped solid adhesive is particularly advantageous in terms of the dimensional stability of the laminate. The thickness of the film-shaped solid adhesive is preferably 10 μm to 5 mm, more preferably 20 μm to 3 mm, and even more preferably 30 μm to 0.5 mm. By making the thickness of the film-shaped solid adhesive 10 μm or more, it is possible to more reliably prevent electrolytic corrosion between the first member and the second member and ensure adhesive strength. By making the thickness of the film-shaped solid adhesive 5 mm or less, it is possible to increase the adhesive strength in the shear direction of the bonding surface.

[0072] The solid adhesive may have tackiness to the extent that the adhesive strength and heat resistance are not impaired. In this case, the solid adhesive can be temporarily fixed to the substrate in the laminate preparation step.

[0073] From the viewpoint of adhesiveness, the average thickness of the adhesive layer is preferably from 1 μm to 5000 μm, more preferably from 20 μm to 1000 μm, and even more preferably from 50 μm to 800 μm.

[0074] (heat sink) The laminate of the present disclosure may include a heat sink on the surface of the first conductive layer facing the first resin layer or on the surface of the second conductive layer facing the second resin layer. As the heat sink, a conventionally known one can be used, and an element or the like may be adhered thereto.

[0075] (Application) The laminate of the present disclosure can be suitably used in the production of a power module (PM). The applications of the laminate of the present disclosure are not limited to PM applications, and it can also be used in electrical equipment parts, control system parts, drive system parts, low-current related parts, home appliances, cosmetic parts, and the like.

[0076] Hereinafter, one embodiment of the laminate etc. of the present disclosure will be described with reference to Fig. 1 to Fig. 6. Note that the disclosed laminate is not limited to the form shown in Figs.

[0077] FIG. 1 is a perspective view showing one embodiment of a laminate of the present disclosure, and FIG. 2 is a perspective view showing another embodiment of a laminate of the present disclosure. 1 and 2, the adhesive layers between the layers are not shown. The laminate 10 shown in FIG. 1 includes a first resin layer 11, a first conductive layer 12, an insulating layer 13, a second conductive layer 14, and a second resin layer 16, in this order. The laminate 20 shown in FIG. 2 includes a first resin layer 21, a first conductive layer 22, an insulating layer 23, a second conductive layer 24, and a second resin layer 26 in this order. 1 and 2, the second resin layer may have an opening. This allows a heat sink or the like to be placed on the surface of the second conductive layer, etc. The shape of the opening is not particularly limited, and is preferably adjusted appropriately depending on the application. 1 and 2, the first conductive layer and the second conductive layer may protrude from the outer periphery of the first resin layer and the second resin layer, thereby allowing connection to another member such as wiring.

[0078] FIG. 3 is a cross-sectional view showing one embodiment of a laminate of the present disclosure. The laminate 30 shown in Figure 3 includes a first resin layer 31, an adhesive layer 35, a first conductive layer 32, an adhesive layer 35, an insulating layer 33, an adhesive layer 35, a second conductive layer 34, an adhesive layer 35, and a second resin layer 36. As shown in FIG. 3, the first resin layer 31 has an accommodating portion including a stepped recess, and an adhesive layer 35, a first conductive layer 32, an adhesive layer 35, an insulating layer 33, an adhesive layer 35, a second conductive layer 34 and an adhesive layer 35 are arranged within the accommodating portion. In Fig. 3, the first conductive layer, the insulating layer and the second conductive layer are accommodated in different levels of a stepped recess, thereby improving heat durability. In the laminate 30 shown in FIG. 3, the first resin layer 31 and the second resin layer are bonded together by an adhesive layer .

[0079] FIG. 4 is a cross-sectional view showing another embodiment of the laminate of the present disclosure. The laminate 40 shown in FIG. 4 comprises a first resin layer 41, an adhesive layer 45, a first conductive layer 42, an adhesive layer 45, an insulating layer 43, an adhesive layer 45, a second conductive layer 44, an adhesive layer 45, and a second resin layer 46. As shown in FIG. 4, the first resin layer 41 has an accommodating portion including a stepped recess, and an adhesive layer 45, a first conductive layer 42, an adhesive layer 45, an insulating layer 43, an adhesive layer 45, a second conductive layer 44 and an adhesive layer 45 are arranged within the accommodating portion. 4, the first conductive layer, the insulating layer, and the second conductive layer are accommodated in different levels of a stepped recess, thereby improving heat durability. As shown in FIG. 4, the first resin layer 41 has an insertion portion 47, which is inserted into an opening (not shown) of the second resin layer . In the laminate 40 shown in FIG. 4, the first resin layer 41 and the second resin layer 46 are bonded together by an adhesive layer 45.

[0080] FIG. 5 is a cross-sectional view showing another embodiment of the laminate of the present disclosure. The laminate 50 shown in Figure 5 includes a first resin layer 51, a heat sink 57, an adhesive layer 55, a first conductive layer 52, an adhesive layer 55, an insulating layer 53, an adhesive layer 55, a second conductive layer 54, an adhesive layer 55, and a second resin layer 56. As shown in FIG. 5, the first resin layer 51 has an accommodating portion including a stepped recess, and a heat sink 57, an adhesive layer 55, a first conductive layer 52, an adhesive layer 55, an insulating layer 53, an adhesive layer 55, a second conductive layer 54 and an adhesive layer 55 are arranged within the accommodating portion. 5, the first conductive layer, the insulating layer, and the second conductive layer are accommodated in different levels of a stepped recess, thereby improving heat durability. In the laminate 50 shown in FIG. 5, the first resin layer 51 and the second resin layer 56 are bonded together by an adhesive layer 55.

[0081] FIG. 6 is a perspective view showing one embodiment of a first resin layer included in the laminate of the present disclosure. As shown in FIG. 6, the first resin layer 100 has a plurality of accommodating portions 101, and the accommodating portions 101 include concave portions 102A and convex portions 102B. The first resin layer 100 also includes a fixing portion 103 and an opening portion 104 . 6, the first resin layer 100 may have an opening between the accommodation portions 101. This allows a separate member such as wiring to be connected to the first resin layer or the like disposed on the first resin layer 100.

[0082] As shown in Figures 3 to 6, the adhesive layer, the first conductive layer, the insulating layer, and the second conductive layer may have different outer peripheries. When the adhesive layer, the first conductive layer, the insulating layer, and the second conductive layer have different outer peripheries, it is preferable that the inner periphery of the recessed portion of the first resin layer is equal to or larger than the periphery of the layer having the largest outer periphery among the adhesive layer, the first conductive layer, the insulating layer, and the second conductive layer.

[0083] [Method of manufacturing laminate] The method for producing a laminate according to the present disclosure includes a preparation step of preparing a first resin layer having a storage portion on at least one surface thereof; A lamination step of laminating a first conductive layer, an insulating layer and a second conductive layer on a surface of the first resin layer, In the lamination step, at least the first conductive layer is disposed in the housing portion of the first resin layer.

[0084] According to the method for producing a laminate of the present disclosure, a laminate having excellent thermal durability can be produced. The reason why the above-mentioned effect is exhibited is not clear, but is presumed to be as follows. The method for producing the laminate of the present disclosure is not insert molding, but rather manufacturing by preparing each layer individually and laminating them. Therefore, in a laminate produced by insert molding, the first conductive layer is embedded in the first resin layer and is completely adhered to the first resin layer, whereas in a laminate produced by the manufacturing method of the present disclosure, the first resin layer and the first conductive layer are not completely adhered to each other, which allows the internal stress generated during heating to be alleviated. It is presumed that this can suppress the occurrence of cracks and deformation of the conductive layer and resin layer, improving heat durability.

[0085] The method for producing a laminate of the present disclosure can include a second lamination step of further laminating a second resin layer on the side of the second conductive layer opposite the insulating layer.

[0086] (preparation process) The first resin layer has been described above, so a description thereof will be omitted here. The method for producing the first resin layer is not particularly limited, and the first resin layer can be produced by insert molding or the like.

[0087] (Lamination process) The method for producing a laminate according to the present disclosure includes a lamination step of laminating a first conductive layer, an insulating layer, and a second conductive layer on a surface of a first resin layer. In the lamination step, at least a first conductive layer is disposed in the receiving portion of the first resin layer. It is preferable that a first insulating layer and a second conductive layer are disposed in the receiving portion of the resin layer.

[0088] The lamination of the first conductive layer, the insulating layer, and the second conductive layer onto the surface of the first resin layer can be carried out by disposing an adhesive layer between each layer and heating. When an adhesive layer is disposed between each layer, it is preferable that the adhesive layer is disposed in the receiving portion of the first resin layer together with the first conductive layer, the insulating layer and the second conductive layer in the lamination step.

[0089] In the lamination step, a heat sink may be disposed on the side of the first conductive layer opposite the insulating layer or on the side of the second conductive layer opposite the insulating layer. When a heat sink is provided, it is preferable to place the heat sink in the receiving portion of the first resin layer together with the first conductive layer, the insulating layer and the second conductive layer in the lamination step.

[0090] The first conductive layer, the second conductive layer, the insulating layer, the adhesive layer, and the heat sink have been described above, so description thereof will be omitted here. The first conductive layer, the second conductive layer, the insulating layer, the adhesive layer and the heat sink may be prepared by a conventional method or may be commercially available.

[0091] (Second lamination process) The second resin layer has been described above, so a description thereof will be omitted here. The method for producing the second resin layer is not particularly limited, and the second resin layer can be produced by insert molding or the like.

[0092] The second resin layer can be laminated by disposing an adhesive layer between the second resin layer and the second conductive layer and heating the resulting layer. The first resin layer and the second resin layer may be bonded to each other by an adhesive layer.

[0093] When the first resin layer has either an insertion portion or an opening, and the second resin layer has at least the other, the first resin layer and the second resin layer can be fitted together by inserting the insertion portion into the opening.

[0094] The lamination step using a solid bonding agent and the second lamination step will now be described in more detail.

[0095] <Pre-joining process> In the pre-bonding process, a laminate is formed in which a first member, a solid adhesive containing as a main component at least one amorphous thermoplastic resin selected from a thermoplastic epoxy resin and a phenoxy resin, and a second member are arranged in this order. In the laminate, the first member and the solid adhesive, and the solid adhesive and the second member are not bonded to each other, and each is an independent member superimposed on top of the other.

[0096] <Joining process> In the bonding step, the laminate is heated and pressurized to melt the solid bonding agent, and then the temperature is lowered to solidify the solid bonding agent, thereby bonding the first member and the second member.

[0097] The temperature for the heating and pressurization is preferably 100° C. to 400° C., more preferably 120° C. to 350° C., and even more preferably 150° C. to 300° C. By heating at 100° C. to 400° C., the solid bonding agent is efficiently deformed and melted and effectively wets and spreads over the bonding surface, thereby obtaining high adhesive strength.

[0098] The pressure in the heating and pressing is preferably 0.01 MPa to 20 MPa, more preferably 0.1 MPa to 10 MPa, and even more preferably 0.2 MPa to 5 MPa. The pressure here means the average pressure at the joining surfaces of the first member and the second member. By applying pressure at 0.01 MPa to 20 MPa, the solid bonding agent is efficiently deformed and effectively wets and spreads over the joining surfaces, so that high adhesive strength can be obtained. When at least one of the first member and the second member contains a thermoplastic resin on the joining surface, by applying pressure at 0.01 MPa to 20 MPa, the solid bonding agent and the thermoplastic resin of the member are made compatible with each other, so that high adhesive strength can be obtained.

[0099] The main components of the solid adhesive, thermoplastic epoxy resin and phenoxy resin, have low cohesive strength within the resin and contain hydroxyl groups, which give them strong interaction with the base material and enable them to bond dissimilar materials with greater adhesive strength than conventional crystalline hot melt adhesives.

[0100] The bonding of the first and second components utilizes the phase change (solid-liquid-solid) of the solid bonding agent, and as no chemical reaction is involved, the bonding can be completed in a shorter time than with conventional thermosetting epoxy resins.

[0101] High adhesive strength may be obtained by performing a suitable pretreatment on the first member or the second member, or on both. Pretreatment is preferably a pretreatment for cleaning the surface of the substrate or a pretreatment for making the surface uneven. Only one type of pretreatment may be performed, or two or more types may be performed. As a specific method for these pretreatments, a known method can be used.

[0102] Specifically, when the material of the member is metal, at least one treatment selected from the group consisting of degreasing, UV ozone treatment, blasting, polishing, plasma treatment, and etching is preferable, and when the material of the member is resin, at least one treatment selected from the group consisting of degreasing, UV ozone treatment, blasting, polishing, plasma treatment, and corona discharge treatment is preferable.

[0103] In the bonded body 1 shown in FIG. 9, the first member 3 and the second member 4 are bonded and integrated via the adhesive layer 2 formed by melting and then solidifying the solid adhesive, and the bonded body 1 of the first member 3 and the second member 4 exhibits excellent bond strength. The bond strength is affected by many factors, such as the thickness of the adhesive layer, the molecular weight and chemical structure of the polymer constituting the adhesive, the mechanical properties, and the viscoelastic properties, in addition to the strength of the interfacial interaction acting between the adhesive layer and the substrate. Therefore, although the details of the mechanism by which the bonded body of the present disclosure exhibits excellent bond strength are not clear, it is speculated that the main factors are the low cohesive force of the amorphous thermoplastic resin constituting the adhesive layer and the presence of hydroxyl groups in the resin, which form chemical bonds or intermolecular forces such as hydrogen bonds and van der Waals forces at the interface between the adhesive layer and the first member and the interface between the adhesive layer and the second member. However, in a bonded body, the state or characteristics of the interface of the bonded body are difficult to analyze because they are due to an extremely thin chemical structure having a thickness of less than a nanometer level, and it is impossible or impractical with current technology to identify the state or characteristics of the interface of the bonded body of the present disclosure and express it in a manner that distinguishes it from a bonded body that does not contain the solid bonding agent of the present disclosure.

[0104] The laminate of the present disclosure, in which the adhesive layer contains an amorphous thermoplastic resin, has excellent recyclability and repairability, and the laminate can be easily disassembled by heating the bonded body to easily separate the first and second components, i.e., the first (second) conductive layer and insulating layer. EXAMPLES

[0105] Practical test examples and comparative test examples related to the present invention are shown below, but the present invention is not limited thereto. In the following examples, the first member and the second member are collectively referred to as a joining base material.

[0106] <Joining base material> The following bonding materials were used: 《PPS (resin)》 An injection molded article (length 45 mm x width 10 mm x thickness 3 mm) obtained by injection molding polyphenylene sulfide (DIC Corporation, FZ-1130-D5) (resin temperature: 300°C, mold temperature: 140°C) was used. It was used without surface treatment. "copper" The surface of copper (C1100 (tough pitch copper) was wiped with methyl ethyl ketone to degrease it, and a test piece with a width of 18 mm, a length of 45 mm, and a thickness of 3 mm was obtained.

[0107] Weight average molecular weight, heat of fusion and epoxy equivalent of thermoplastic epoxy resin and phenoxy resin The weight average molecular weight, heat of fusion and epoxy equivalent of the thermoplastic epoxy resin and the phenoxy resin were measured by the following procedures.

[0108] (Weight average molecular weight) The thermoplastic epoxy resin and the phenoxy resin were dissolved in tetrahydrofuran, and the measurement was carried out under the following conditions using Prominence 501 (manufactured by Showa Science Co., Ltd., Detector: Shodex (registered trademark) RI-501 (manufactured by Showa Denko K.K.)). Column: Showa Denko LF-804 x 2 Column temperature: 40℃ Sample: 0.4% by mass of resin in tetrahydrofuran Flow rate: 1mL / min Eluent: Tetrahydrofuran Calibration method: Conversion using standard polystyrene

[0109] (Heat of fusion) 2 to 10 mg of thermoplastic epoxy resin and phenoxy resin were weighed out and placed in an aluminum pan, and the temperature was raised from 23°C to 200°C at 10°C / min using a DSC (DSC8231 manufactured by Rigaku Corporation) to obtain a DSC curve. The heat of fusion was calculated from the area of ​​the endothermic peak at the time of melting in the obtained DSC curve and the weighed value.

[0110] (epoxy equivalent) The measured values ​​obtained in accordance with JIS K 7236:2001 were converted into values ​​based on the resin solids. In the case of simple mixtures that did not involve reactions, the values ​​were calculated from the epoxy equivalent and content of each.

[0111] <Test Example 1> (Solid adhesive P-1) In a reaction apparatus equipped with a stirrer, a reflux condenser, a gas inlet tube, and a thermometer, 203 g (1.0 equivalent) of jER (registered trademark) 1007 (manufactured by Mitsubishi Chemical Corporation, bisphenol A type epoxy resin, weight average molecular weight about 10,000), 12.5 g (1.0 equivalent) of bisphenol S, 2.4 g of triphenylphosphine, and 1,000 g of methyl ethyl ketone were charged, and the temperature was raised to 100° C. while stirring under a nitrogen atmosphere. After visually confirming that the mixture had dissolved, the mixture was cooled to 40° C. to obtain a resin composition with a solid content of about 20% by mass. The solvent was removed from the resin composition to obtain a solid. A non-adhesive fluororesin film (Nitoflon (registered trademark) No. 900UL, manufactured by Nitto Denko Corporation) was placed on the upper and lower plates of a press machine, and the solid was placed on the non-adhesive fluororesin film of the lower plate. The press machine was then heated to 160°C, and the resin composition was heat-compressed for 2 hours to obtain a solid adhesive (P-1) in the form of a film with a thickness of 100 μm and a solid content of 100% by mass. The weight-average molecular weight was about 37,000. The epoxy equivalent was above the detection limit. No heat of fusion peak was detected by DSC.

[0112] (zygote) The following one type of bonded body (resin / metal) was produced.

[0113] Resin / Metal The solid adhesive P-1, cut to a size of 10 x 15 mm, was placed on the copper base material (first member), and then the PPS base material (second member) was quickly placed on top of it. The overlap between these base materials was 10 mm wide and 5 mm deep. The solid adhesive P-1 was placed so as to cover the entire overlapping area between the base materials. In other words, the first member and the second member were not in direct contact with each other, but the solid adhesive was interposed between them, and an unbonded laminate was prepared.

[0114] A high-frequency induction welding machine (Seidensha Denshi Kogyo Co., Ltd., oscillator UH-2.5K, press JIIP30S) was used to heat the metal by high-frequency induction, and the test pieces were joined together by heating and pressurization. The applied pressure was 110 N (pressure 2.2 MPa), and the oscillation frequency was 900 kHz. The oscillation time was 6 seconds.

[0115] A bonded body for open time evaluation was prepared by the following procedure. The solid bonding agent P-1 cut to a size of 10 x 15 mm was placed on the copper base material (first member), and then left to stand for three days, and the PPS base material (second member) was placed on top of it. The overlapping area between these base materials was 10 mm wide and 5 mm deep. The solid bonding agent P-1 was placed so as to cover the entire overlapping area between the base materials. In other words, an unbonded laminate was prepared in a state where the first member and the second member were not in direct contact with each other, but the solid bonding agent was interposed between them.

[0116] A high-frequency induction welding machine (Seidensha Denshi Kogyo Co., Ltd., oscillator UH-2.5K, press JIIP30S) was used to heat the metal by high-frequency induction, and the test pieces were joined together by heating and pressurization. The applied pressure was 110 N (pressure 2.2 MPa), and the oscillation frequency was 900 kHz. The oscillation time was 5 seconds.

[0117] <Test Example 2> (Solid adhesive P-2) A reactor equipped with a stirrer, reflux condenser, gas inlet tube, and thermometer was charged with 20 g of Phenototo (registered trademark) YP-50S (manufactured by Nippon Steel Chemical & Material Co., Ltd., phenoxy resin, weight average molecular weight about 50,000) and 80 g of cyclohexanone, and the temperature was raised to 60°C while stirring. Dissolution was confirmed by visual inspection, and the mixture was cooled to 40°C to obtain a resin composition with a solid content of 20% by mass. The solvent was removed from the resin composition to obtain a solid. A non-adhesive fluororesin film (Nitoflon (registered trademark) No. 900UL, manufactured by Nitto Denko Corporation) was placed on the upper and lower plates of a press machine, and the solid was placed on the non-adhesive fluororesin film of the lower plate. The press machine was heated to 160°C, and the resin composition was heated and compressed for 2 hours to obtain a solid adhesive (P-2) in the form of a film with a thickness of 100 μm and a solid content of 100% by mass. The weight average molecular weight was 50,000, and the epoxy equivalent was above the detection limit. No heat of fusion peak was detected in DSC.

[0118] (zygote) The bonded bodies and bonded bodies for open time evaluation shown in Table 1 were prepared in the same manner as in Experimental Test Example 1, except that P-2 was used as the solid bonding agent.

[0119] <Test Example 3> (Solid adhesive P-3) The resin composition P-2 and crystalline epoxy resin YSLV-80XY (manufactured by Nippon Steel Chemical & Material Co., Ltd.) were mixed in a mass ratio of 98 to 2 to obtain a solid bonding agent (P-3). The weight average molecular weight was 36,000, the epoxy equivalent was 9600 g / eq, and the heat of fusion was 2 J / g.

[0120] (zygote) The bonded bodies and bonded bodies for open time evaluation shown in Table 1 were produced in the same manner as in Experimental Test Example 1, except that P-3 was used as the solid bonding agent.

[0121] <Test Example 4> (Solid adhesive P-4) The resin composition P-2 and a crystalline epoxy resin YSLV-80XY (manufactured by Nippon Steel Chemical & Material Co., Ltd.) were mixed in a mass ratio of 94 to 6 to obtain a solid bonding agent (P-4). The weight average molecular weight was 35,000, the epoxy equivalent was 2100 g / eq, and the heat of fusion was 4 J / g.

[0122] (zygote) The bonded bodies and bonded bodies for open time evaluation shown in Table 1 were prepared in the same manner as in Experimental Test Example 1, except that P-4 was used as the solid bonding agent.

[0123] <Test Example 5> (Solid adhesive P-5) The resin composition P-2 and crystalline epoxy resin YSLV-80XY (manufactured by Nippon Steel Chemical & Material Co., Ltd.) were mixed in a mass ratio of 89:11 to obtain a solid bonding agent (P-5). The weight average molecular weight was 33,000, the epoxy equivalent was 1745 g / eq, and the heat of fusion was 11 J / g.

[0124] (zygote) The bonded bodies and bonded bodies for open time evaluation shown in Table 1 were prepared in the same manner as in Experimental Test Example 1, except that P-5 was used as the solid bonding agent.

[0125] <Test Example 6> (Solid adhesive P-6) In a reaction apparatus equipped with a stirrer, a reflux condenser, a gas inlet tube, and a thermometer, 203 g (1.0 equivalent) of jER (registered trademark) 1007 (manufactured by Mitsubishi Chemical Corporation, bisphenol A type epoxy resin, molecular weight about 4060), 12.5 g (0.6 equivalent) of bisphenol S (molecular weight 250), 2.4 g of triphenylphosphine, and 1,000 g of methyl ethyl ketone were charged, and the temperature was raised to 100 ° C. while stirring under a nitrogen atmosphere. After visually confirming that the mixture had dissolved, the mixture was cooled to 40 ° C. to obtain a resin composition with a solid content of about 20 mass %. The solvent was removed from the resin composition to obtain a solid. A non-adhesive fluororesin film (Nitoflon (registered trademark) No. 900UL, manufactured by Nitto Denko Corporation) was placed on the upper and lower plates of a press machine, and the solid was placed on the non-adhesive fluororesin film of the lower plate. The press machine was then heated to 160°C, and the resin composition was heat-compressed for 2 hours to obtain a solid adhesive (P-6) in the form of a film with a thickness of 100 μm and a solid content of 100% by mass. The weight-average molecular weight was about 30,000, and the epoxy equivalent was above the detection limit. No heat of fusion peak was detected by DSC.

[0126] (zygote) The bonded bodies and bonded bodies for open time evaluation shown in Table 1 were prepared in the same manner as in Experimental Test Example 1, except that P-6 was used as the solid bonding agent.

[0127] Comparative Test Example 1 (Solid adhesive Q-1) Two liquid components of the thermosetting liquid epoxy adhesive E-250 (Konishi Co., Ltd., two-liquid type consisting of bisphenol-type epoxy resin and amine curing agent) were mixed, applied to a release film, and cured at 100°C for 1 hour. The mixture was then cooled and peeled off from the release film to obtain a 100μm thick solid adhesive film (Q-1). No heat of fusion peak was detected by DSC. The epoxy equivalent and weight average molecular weight could not be measured because the product was insoluble in the solvent.

[0128] (zygote) A bonded body and a bonded body for open time evaluation shown in Table 1 were produced in the same manner as in Experimental Test Example 1, except that Q-1 was used as the solid bonding agent.

[0129] Comparative Test Example 2 (Solid adhesive Q-2) An amorphous polycarbonate film (Iupilon (registered trademark) FE2000, manufactured by Mitsubishi Engineering Plastics Corporation, thickness 100 μm) was used as the solid joint Q-2. No heat of fusion peak was detected in DSC.

[0130] (zygote) The bonded bodies and bonded bodies for open time evaluation shown in Table 1 were prepared in the same manner as in Experimental Test Example 1, except that Q-2 was used as the solid bonding agent.

[0131] Comparative Test Example 3 (Solid adhesive Q-3) Crystalline epoxy resin YSLV-80XY (manufactured by Nippon Steel Chemical & Material Co., Ltd.) was used as the solid bonding agent (Q-3). The epoxy equivalent was 192 g / eq. The weight average molecular weight was 340. The heat of fusion was 70 J / g.

[0132] (zygote) The bonded bodies and bonded bodies for open time evaluation shown in Table 1 were prepared in the same manner as in Experimental Test Example 1, except that Q-3 was used as the solid bonding agent.

[0133] Comparative Test Example 4 (zygote) Two liquid components of thermosetting liquid epoxy adhesive E-250 (Konishi Co., Ltd., two-liquid type consisting of bisphenol-type epoxy resin and amine curing agent) were mixed, applied to the first and second members similar to those in the above-mentioned Experimental Test Example 1, and bonded together within one minute. After that, the members were fixed with clips and left to stand in a 100°C oven for one hour to cure the adhesive components, and then cooled to room temperature to produce a bonded body shown in Table 1. A bonded body for open time evaluation was also produced in the same manner as above, except that the thermosetting liquid epoxy adhesive E-250 was applied to the first and second members, left to stand for three days, and then bonded together.

[0134] Comparative Test Example 5 In a flask, 203 g (1.0 equivalent) of jER (registered trademark) 1007 (manufactured by Mitsubishi Chemical Corporation, bisphenol A type epoxy resin, weight average molecular weight about 10,000), 12.5 g (1.0 equivalent) of bisphenol S, 2.4 g of triphenylphosphine, and 1,000 g of methyl ethyl ketone were charged and stirred at room temperature to obtain a liquid resin composition with a solid content of about 20 mass%. The liquid resin composition was bar-coated on a second member similar to that in the above-mentioned Example 1 of the practical test, dried at room temperature for 30 minutes, and then left to stand in an oven at 160°C for 2 hours to form a solid thermoplastic epoxy resin polymer coating layer with a thickness of 100 μm on the surface of the second member. The weight average molecular weight of the coating layer was about 40,000. The epoxy equivalent was above the detection limit. No heat of fusion peak was detected in DSC.

[0135] (zygote) A bonded body shown in Table 1 was prepared in the same manner as in Example Test 1, except that the first member was placed directly on the second member having the coating layer. For open time evaluation, a bonded body for open time evaluation was also prepared in the same manner as above, except that a thermoplastic epoxy resin polymer coating layer was formed on the surface of the second member, left to stand for 3 days, and then laminated with the first member.

[0136] Comparative Test Example 6 A reaction apparatus equipped with a stirrer, a reflux condenser, a gas inlet tube, and a thermometer was charged with 20 g of Phenototo (registered trademark) YP-50S (manufactured by Nippon Steel Chemical & Material Co., Ltd., phenoxy resin, weight average molecular weight about 50,000) and 80 g of cyclohexanone, and the mixture was heated to 60°C while stirring, and the mixture was confirmed to have dissolved by visual inspection, and cooled to 40°C to obtain a liquid resin composition with a solid content of 20% by mass. The liquid resin composition was bar-coated on a second member similar to that in the above-mentioned Experimental Test Example 1, and the mixture was left to stand in an oven at 70°C for 30 minutes to form a phenoxy resin coating layer with a thickness of 100 μm on the surface of the second member. The weight average molecular weight of the coating layer was about 50,000. The epoxy equivalent was above the detection limit. No heat of fusion peak was detected by DSC.

[0137] (zygote) A joint shown in Table 1 was produced in the same manner as in Example Test 1, except that the first member was placed directly on the second member having the phenoxy resin coating layer. For open time evaluation, a joint for open time evaluation was also produced in the same manner as above, except that the phenoxy resin coating layer was formed on the surface of the second member, left to stand for 3 days, and then laminated with the first member.

[0138] Comparative Test Example 7 (zygote) Except for using a crystalline polyamide-based hot melt adhesive film NT-120 (manufactured by Nihon Matai Co., Ltd., thickness 100 μm) as the solid adhesive, the bonded body and the bonded body for open time evaluation shown in Table 1 were prepared in the same manner as in Example Test 1. The heat of fusion was 60 J / g.

[0139] [Shear adhesive strength] The bonded bodies obtained in the working test examples 1 to 6 and the comparative test examples 1 to 7 were allowed to stand at the measurement temperature (23°C or 80°C) for 30 minutes or more, and then a tensile shear adhesive strength test was carried out in an atmosphere of 23°C and 80°C in accordance with ISO 19095 using a tensile tester (Universal testing machine autograph "AG-X plus" (manufactured by Shimadzu Corporation); load cell 10kN, tensile speed 10mm / min) to measure the bond strength. The measurement results are shown in Table 1.

[0140] [Joining process time] The bonding process time was measured as follows. The time from the start point when the bonding agent first contacted one or both of the substrates that constitute the bonded body to the end point when the fabrication of the bonded body was completed was taken as the starting point, and the time from the start point to the end point was taken as the end point. The heating and pressing times were averaged from the respective values ​​for the bonded bodies shown in Table 1.

[0141] [Recyclability] The bonded bodies shown in Table 1 were placed on a hot plate at 200°C and heated for 1 minute, after which it was judged whether they could be easily peeled off with a force of 1 N or less. If they could be peeled off, they were rated as good (OK), and if they could not be peeled off, they were rated as unsuitable (NG).

[0142] [Repairability] Of the test pieces in which the joint surface had broken after the tensile shear strength test at 23°C (a layer of the joint solid remained on the surface of the first member or the second member, or both), the first member was placed on the second member, and a joint was produced in the same manner as in the practical test example 1, to obtain a repair joint. The shear adhesive strength of the repair joint at 23°C was measured in the same manner as in the test method, and if it was 80% or more of the first shear adhesive strength, it was judged as good (OK), and if it was less than 80%, it was judged as unsuitable (NG).

[0143] [Open Time Evaluation] The tensile shear adhesive strength test was carried out at 23° C. using the bonded bodies for open time evaluation. If the shear adhesive strength was 80% or more compared to the test pieces prepared by the methods of the practical test example and comparative test example, it was rated as good (OK), and if it was less than 80%, it was rated as unsuitable (NG). A good open time evaluation (OK) means that the open time is long and the convenience is excellent.

[0144] [Table 1-1] [Table 1-2]

[0145] According to the present invention, a laminate in which a first conductive layer and / or a second conductive layer (first component) is firmly bonded to an insulating layer (second component) can be produced with a short bonding process time and a long open time. [Industrial Applicability]

[0146] The present invention can be used in a method for producing a laminate. [Explanation of symbols]

[0147] 10, 20, 30, 40, 50: laminate, 11, 21, 31, 41, 51: first resin layer, 12, 22, 32, 42, 52: first conductive layer, 13, 23, 33, 43, 53: insulating layer, 14, 24, 34, 44, 54: second conductive layer, 15, 25, 35, 45, 55: adhesive layer, 16, 26, 36, 46, 56: second resin layer, 47: insertion portion, 57: heat sink, 100: first resin layer, 101: storage portion, 102A: concave portion, 102B: convex portion, 103: fixing portion, 104: opening, 105: first conductive layer, 106: second conductive layer

Claims

1. a first resin layer; a first conductive layer; and an insulating layer; a second conductive layer; and In this order, the first resin layer has a housing portion, the first conductive layer is disposed in the housing portion of the first resin layer; A laminate comprising an adhesive layer at least between the first conductive layer and the insulating layer and between the insulating layer and the second conductive layer, the adhesive layer containing a solid adhesive agent mainly composed of an amorphous thermoplastic resin that is at least one selected from a thermoplastic epoxy resin and a phenoxy resin, the amorphous thermoplastic resin having an epoxy equivalent of 1,600 or more, or the amorphous thermoplastic resin does not contain an epoxy group, and the heat of fusion of the amorphous thermoplastic resin is 15 J / g or less.

2. The laminate according to claim 1 , wherein the accommodation portion includes a recessed portion or an uneven portion.

3. The laminate according to claim 1 , wherein the first conductive layer, the insulating layer, and the second conductive layer are disposed within the housing portion of the first resin layer.

4. The laminate according to claim 1 , wherein the area of ​​the housing portion of the first resin layer is equal to or greater than the area of ​​the first conductive layer.

5. a second resin layer on the opposite side of the second conductive layer from the insulating layer; 3. The laminate according to claim 1, further comprising an adhesive layer between the first resin layer and the first conductive layer, and between the second conductive layer and the second resin layer.

6. The laminate according to claim 1 or 2, wherein the first resin layer is a cured product of a resin composition containing a thermosetting resin.

7. The laminate of claim 6 , wherein the thermosetting resin comprises an unsaturated polyester.

8. The laminate according to claim 1 or 2, wherein the first resin layer has a fixing portion that fixes the first conductive layer, the insulating layer, and the second conductive layer.

9. a pre-bonding process for preparing a laminate including a first resin layer having a housing portion, a first conductive layer disposed in the housing portion of the first resin layer, an insulating layer, and a second conductive layer, arranged in this order, wherein a solid adhesive is disposed at least either between the first conductive layer and the insulating layer or between the insulating layer and the second conductive layer, and the solid adhesive is mainly composed of an amorphous thermoplastic resin that is at least one type selected from a thermoplastic epoxy resin and a phenoxy resin; a bonding step of heating and pressurizing the laminate to melt the solid adhesive and bond the first conductive layer to the insulating layer and / or bond the insulating layer to the second conductive layer; A method for producing a laminate, comprising: a method for producing a laminate, wherein the amorphous thermoplastic resin has an epoxy equivalent of 1,600 or more, or the amorphous thermoplastic resin does not contain an epoxy group, and the amorphous thermoplastic resin has a heat of fusion of 15 J / g or less.

10. The method for producing a laminate according to claim 9, wherein the heating and pressing are carried out under conditions of 100°C to 400°C and 0.01 MPa to 20 MPa.

11. The method for producing a laminate according to claim 9 or 10, wherein the solid binder before being melted has any shape selected from the group consisting of a film, a rod, a pellet, and a powder.

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