Curable adhesive composition and laminate

Abstract

The present invention provides a curable adhesive composition and a laminate capable of shortening the process time when a composite member for heat-resistant applications is manufactured. The curable adhesive composition according to the present invention comprises a thermosetting component and a thermoplastic component, wherein the calorific value which is determined by DSC at 25-300°C before heat treatment is 10 mJ / mg or greater, the ratio between the calorific values before and after heat treatment at 150°C for 5 min (calorific value after heat treatment / calorific value before heat treatment) is smaller than 1.0, and the storage elastic modulus which is determined by DMA at 150°C after heat treatment at 150°C for 5 min is 1×105 Pa or higher.

Description

S硬化性 Adhesive Composition and Laminate

[0001] The present invention relates to a curable adhesive composition and a laminate.

[0002] As a means for joining dissimilar materials to obtain a composite member, there is a method of using an adhesive (see, for example, Patent Documents 1 to 4). Although a thermoplastic resin or a thermosetting resin can be used as the adhesive, each has drawbacks. Thermoplastic resins enable rapid adhesion but are inferior in heat resistance to thermosetting resins. Thermosetting resins are excellent in heat resistance, but since they require a certain amount of time to complete curing, the process time during manufacturing becomes long. When manufacturing a composite member for heat-resistant applications, shortening the process time has been an issue for the above reasons.

[0003] JP-A-2019-9203 JP-A-2016-29701 JP-A-2008-144160 JP-A-2017-19900

[0004] The present invention has been made in view of the above circumstances, and an object thereof is to provide a curable adhesive composition capable of shortening the process time when manufacturing a composite member for heat-resistant applications, and a laminate having the curable adhesive composition.

[0005] The present invention includes the following aspects. [1] A curable adhesive composition containing a thermosetting component and a thermoplastic component, having a heat generation amount by DSC between 25 and 300 °C of 10 mJ / mg or more before heat treatment, a heat generation amount ratio (heat generation amount after heat treatment / heat generation amount before heat treatment) of less than 1.0 before and after heat treatment at 150 °C / 5 min, and a storage elastic modulus by DMA at 150 °C after heat treatment at 150 °C / 5 min of 1 × 10 ,

[0005] , ５[1] A curable adhesive composition characterized by having a Pa of 10 or more. [2] The curable adhesive composition according to [1], further comprising a curing agent, wherein the thermoplastic component is in a ratio of 10 to 500 parts by mass and the curing agent is in a ratio of 1 to 10 parts by mass per 100 parts by mass of the thermosetting component, and the thermoplastic component is an elastomer. [3] The curable adhesive composition according to [1] or [2], characterized in that the thermosetting component is one or more selected from the group consisting of epoxy resin, bismaleimide resin, and phenol resin. [4] The curable adhesive composition according to any one of [1] to [3], characterized in that the thermosetting component is one or more selected from the group consisting of epoxy resin, bismaleimide resin, and resolphenol resin. [5] The curable adhesive composition according to any one of [1] to [4], characterized in that the thermoplastic component is one or more selected from the group consisting of uncrosslinked acrylic rubber, uncrosslinked nitrile rubber, polyamide elastomer, and polyolefin elastomer. [6] A curable adhesive composition according to any one of [1] to [5], further comprising a curing agent, wherein the curing agent is one or more selected from the group consisting of aromatic diamines, aliphatic diamines, and imidazoles. [7] A curable adhesive composition according to any one of [1] to [6], characterized in that a test piece having a layer structure of "polyimide film / curable adhesive composition / SUS foil / curable adhesive composition / polyimide film" is prepared using the curable adhesive composition, and the adhesive strength measured by a T-type peel test between the polyimide films on both sides after heat treatment at 150°C / 5 min is 3 N / cm or more. [8] A laminate characterized in that a curable adhesive composition according to any one of [1] to [7] is laminated on one or more core materials selected from the group consisting of resin film, metal foil, and porous body.

[0006] According to the present invention, it becomes possible to shorten the process time when manufacturing composite materials for heat-resistant applications.

[0007] This is a cross-sectional view showing the first example of a laminate. This is a cross-sectional view showing the second example of a laminate.

[0008] The present invention will be described below based on preferred embodiments.

[0009] The curable adhesive composition of this embodiment is a curable adhesive composition comprising a thermosetting component and a thermoplastic component.

[0010] The curable adhesive composition of this embodiment generates 10 mJ / mg or more of heat by DSC at a temperature of 25 to 300°C before heat treatment. This amount of heat generation serves as an indicator that the curable adhesive composition is thermosetting.

[0011] The curable adhesive composition of this embodiment has a heat generation ratio (heat generation after heat treatment / heat generation before heat treatment) of less than 1.0 before and after 150°C / 5min heat treatment. This heat generation ratio is an indicator of the degree to which thermal curing progresses (reactivity) during 5min heat treatment at 150°C. The smaller the heat generation ratio (closer to 0), the more the thermal curing of the thermosetting component has progressed and the more cured it has become. When the heat generation ratio becomes 0, the heat generation after heat treatment is 0 mJ / mg, which means that thermal curing has progressed completely during 5min heat treatment at 150°C. The amount of heat generated can be measured by differential scanning calorimetry (DSC) as described in the examples below.

[0012] The curable adhesive composition of this embodiment has a storage modulus of elasticity determined by DMA at 150°C after heat treatment at 150°C / 5 min, which is 1 × 10⁻⁶. ５ It is Pa or higher. This storage modulus is an indicator of hardness (hardness) after heat treatment at 150°C for 5 min. The larger the value of the storage modulus, the harder the hardened product obtained after heat treatment at 150°C for 5 min. The storage modulus can be measured by dynamic viscoelasticity measurement (DMA) as shown in the examples described later.

[0013] The curable adhesive composition of this embodiment may be a paint such as a solution, dispersion, or solvent-free liquid before heat treatment. However, if the paint contains a volatile solvent, the drying step of the paint will be included in the process time in the manufacturing method of the composite member using the composition. For this reason, it is preferable that the composition be a solid, such as a sheet, obtained by drying the paint before heat treatment. If the curable adhesive composition of this embodiment is a solid after drying, the drying does not contribute to the thermal curing of the thermosetting component and therefore does not constitute heat treatment. In other words, when obtaining a solid curable adhesive composition by drying, it is necessary to select temperature conditions such that the thermal curing of the thermosetting component does not proceed.

[0014] In the curable adhesive composition of this embodiment (hereinafter sometimes simply referred to as "curable adhesive composition"), the proportion of thermoplastic components is preferably 10 to 500 parts by mass, and more preferably 30 to 450 parts by mass, per 100 parts by mass of thermosetting components. The inclusion of thermosetting components provides rapid curing, and the inclusion of thermoplastic components provides stress relaxation. If the proportion of thermoplastic components is below the lower limit, the flexibility of the curable adhesive composition decreases, making it difficult to handle, such as in sheet formation. If the proportion of thermoplastic components exceeds the upper limit, thermal curing becomes difficult, rapid curing deteriorates, and a decrease in storage modulus and adhesive strength is more likely to occur.

[0015] Examples of thermoplastic resins used in curable adhesive compositions include polyolefin resins and their modified products, polyester resins, (meth)acrylic resins, styrene resins, ionomer resins, polyacrylonitrile, polyamide resins, ethylene-vinyl acetate resins, ethylene-acrylic acid resins, ethylene-ethyl acrylate resins, ethylene-vinyl alcohol resins, chlorine resins, fluororesins, polycarbonate resins, modified polyphenylene ether resins, cellulose resins, thermoplastic elastomers, polyphenylene sulfide resins, polyetherimide resins, polyetheretherketone resins, thermoplastic polyimide resins, and uncrosslinked rubber.

[0016] Examples of polyolefin resins and their modified products include polyethylene, polypropylene, and polymethylpentene resin. Examples of polyester resins include polyethylene terephthalate and polybutylene terephthalate. Examples of (meth)acrylic resins include polymethyl methacrylate and polyethyl methacrylate. Examples of styrene resins include polystyrene, acrylonitrile-butadiene-styrene resin, acrylonitrile-acrylic rubber-styrene resin, acrylonitrile-ethylene rubber-styrene resin, (meth)acrylic acid ester-styrene resin, and styrene-butadiene-styrene resin. Examples of polyamide resins include 6-nylon, 6,6-nylon, 6T-PA, 9T-PA, and MXD6®-nylon. Examples of chlorine resins include polyvinyl chloride and polyvinylidene chloride. Examples of fluororesins include polyvinyl fluoride and polyvinylidene fluoride.

[0017] Examples of thermoplastic elastomers include olefin-based elastomers, glycidyl-modified olefin-based elastomers, maleic acid-modified olefin-based elastomers, vinyl chloride-based elastomers, styrene-based elastomers, urethane-based elastomers, polyester-based elastomers, and polyamide-based elastomers.

[0018] Examples of uncrosslinked rubbers include diene rubbers and their hydrogenated products, olefin rubbers, halogen-containing rubbers, silicone rubbers, sulfur-containing rubbers, and fluororubber. Examples of diene rubbers and their hydrogenated products include natural rubber, isoprene rubber, epoxidized natural rubber, styrene-butadiene rubber, butadiene rubber, nitrile rubber, hydrogenated NBR, and hydrogenated SBR. Examples of olefin rubbers include ethylene propylene rubber, maleic acid-modified ethylene propylene rubber, butyl rubber, copolymers of isobutylene and aromatic vinyl or diene monomers, acrylic rubber, and ionomers. Examples of halogen-containing rubbers include Br-IIR, CI-IIR, brominated isobutylene-p-methylstyrene copolymer, chloroprene rubber, hydrin rubber, chlorosulfonated polyethylene rubber, chlorinated polyethylene rubber, and maleic acid-modified chlorinated polyethylene rubber. Examples of silicone rubbers include methyl vinyl silicone rubber, dimethyl silicone rubber, and methylphenyl vinyl silicone rubber. Examples of sulfur-containing rubbers include polysulfide rubber. Examples of fluororubbers include vinylidene fluoride rubber, fluorinated vinyl ether rubber, tetrafluoroethylene-propylene rubber, fluorinated silicone rubber, and fluorinated phosphazene rubber.

[0019] In particular, it is preferable that the thermoplastic component is an elastomer (thermoplastic elastomer). Furthermore, it is preferable that the thermoplastic component is one or more selected from the group consisting of uncrosslinked acrylic rubber, uncrosslinked nitrile rubber, polyamide elastomer, and polyolefin elastomer. Acrylic rubber is a synthetic rubber mainly composed of acrylic acid ester, but it may also be a rubbery copolymer (ANM) of acrylic acid ester and acrylonitrile. By including a rubber component such as an elastomer in the thermoplastic component, flexibility can be imparted to the adhesive.

[0020] The thermoplastic component, such as an elastomer, may be a modified resin having thermosetting functional groups such as epoxy groups. For example, a monomer having a glycidyl group may be copolymerized with the thermoplastic component. This makes it easier to mix with thermosetting components such as epoxy resins.

[0021] It is preferable that the thermosetting component is one or more selected from the group consisting of epoxy resins, bismaleimide resins, and phenolic resins. More preferably, the thermosetting component is one or more selected from the group consisting of epoxy resins, bismaleimide resins, and resolphenolic resins.

[0022] Examples of epoxy resins include compounds containing two or more epoxy groups in their molecule. Specific examples of epoxy resins are not limited to bisphenol-type epoxy resins, glycidyl ethers of polyhydric alcohols or polyhydric phenols, glycidyl esters of polyhydric carboxylic acids, glycidylamine-type epoxy resins, and novolac-type epoxy resins. Epoxy resins may also contain polycyclic skeletons such as dicyclopentadiene, naphthalene, and biphenyl skeletons. From the viewpoint of ease of handling of the curable adhesive composition, liquid epoxy resins are preferred. Using liquid epoxy resins allows for the development of tackiness without reducing the ratio of thermosetting components, thus enabling both rapid curing and tackiness.

[0023] Examples of bismaleimide resins include compounds containing two maleimide groups in their molecule. The linking groups connecting the two or more maleimide groups may include one or more selected from aliphatic hydrocarbon groups, aromatic hydrocarbon groups, ether bonds, siloxane bonds, and the like.

[0024] Examples of phenolic resins include novolac phenolic resins and resol phenolic resins. Examples of phenols used as raw materials for phenolic resins include phenols; alkyl-substituted phenols such as cresol and p-t-butylphenol; phenolic compounds having functional groups containing heteroatoms such as nitro groups, halogen groups, amino groups, and cyano groups; and polycyclic phenolic compounds having skeletons such as naphthalene and anthracene. Among phenolic resins, resol phenolic resins are preferred. Novolac phenolic resins can be converted into thermosetting resins by reacting them with curing agents such as formaldehyde and hexamethylenetetramine.

[0025] The molecular weight of the thermosetting component before curing is preferably in the range of 150 to 3000. If the molecular weight of the thermosetting component is smaller than the lower limit, the curing reaction will be too fast, affecting storage stability. If the molecular weight of the thermosetting component is larger than the upper limit, the curing reaction will not proceed easily, and the thermosetting component will easily separate in the curable adhesive composition.

[0026] The curable adhesive composition of this embodiment preferably contains a curing agent. When the thermosetting component is a main agent that contributes to thermosetting, the curing agent is a substance that reacts with the main agent to promote or adjust curing. If the thermosetting component has thermosetting properties on its own, the addition of a curing agent may be omitted. A ratio of 1 to 10 parts by mass of curing agent per 100 parts by mass of thermosetting component is preferred. If there is too little curing agent, the rapid curing properties will be poor. If there is too much curing agent, storage stability will decrease and foaming due to heating will easily occur.

[0027] The curing agent may be one or more selected from the group consisting of aromatic diamines, aliphatic diamines, and imidazoles. When the thermosetting component is an epoxy resin, a stable B-stage state can be ensured by incorporating aromatic diamines in an amount of about 0.1 to 0.5 times the epoxy equivalent. The imidazoles may be unsubstituted imidazole compounds or imidazole compounds having substituents such as alkyl groups.

[0028] It is preferable to select imidazole compounds whose reaction initiation temperature is 70°C or higher, and whose reaction initiation temperature is higher than the boiling point of the solvent, and it is preferable to select compounds that are insoluble in the solvent. Examples of solvents include methyl ethyl ketone (MEK) and tetrahydrofuran (THF). When aromatic diamines and imidazole compounds are used in combination as curing agents, the curing reaction proceeds slowly at room temperature, and a long pot life can be achieved.

[0029] The adhesive strength of the curable adhesive composition of this embodiment is preferably 3 N / cm or more, measured using, for example, a polyimide film as the adherend, by the following method. A test specimen is prepared having a layer structure of "polyimide film / curable adhesive composition / SUS foil / curable adhesive composition / polyimide film". After heat-treating the prepared test specimen at 150°C for 5 min, the adhesive strength is measured by a T-shaped peel test between the polyimide films on both sides.

[0030] The laminate formed using the curable adhesive composition of this embodiment is a laminate in which the curable adhesive composition is laminated on a core material. As shown in Figure 1, adhesive layers 12 made of the curable adhesive composition may be laminated on both sides of the core material 11. As shown in Figure 2, adhesive layers 12 made of the curable adhesive composition may be laminated on one side of the core material 11. The curable adhesive composition of this embodiment can also be used as a single-layer adhesive film and adhesive sheet. It is also possible to form an adhesive layer by applying the curable adhesive composition onto a release film.

[0031] The core material can be one or more selected from the group consisting of resin film, metal foil, and porous material. The core material may be a composite material of two or more materials. Multiple core materials may be stacked and laminated. The thickness of the core material is not particularly limited, but can be in the range of 10 to 100 μm.

[0032] If the core material is made of a porous material, the core material can be impregnated with adhesive. If the core material is not made of a porous material, the core material can be laminated without impregnating it with adhesive. In the case of a porous material made of nonwoven fabric or the like, adhesive may be impregnated on only one side, leaving a gap layer on the opposite side of the porous material that is not impregnated with adhesive. The thickness of the adhesive layer is not particularly limited, but is generally in the range of 10 to 100 μm.

[0033] Examples of resins used in the core resin film include polyolefin resins and their modified products, polyester resins, (meth)acrylic resins, styrene resins, ionomer resins, polyacrylonitrile, polyamide resins, ethylene-vinyl acetate resins, ethylene-acrylic acid resins, ethylene-ethyl acrylate resins, ethylene-vinyl alcohol resins, chlorine resins, fluororesins, polycarbonate resins, modified polyphenylene ether resins, cellulose resins, thermoplastic elastomers, polyphenylene sulfide resins, polyetherimide resins, polyetheretherketone resins, thermoplastic polyimide resins, and uncrosslinked rubber.

[0034] One or both sides of the resin film may be subjected to processing such as coating, corona treatment, plasma treatment, ozone treatment, flame treatment, or vapor deposition. Examples of metal foils include aluminum foil, copper foil, silver foil, gold foil, platinum foil, tin foil, zinc foil, titanium foil, iron foil, stainless steel foil, and alloy foil. One or both sides of the metal foil may be subjected to processing such as plating, chemical treatment, or painting.

[0035] Examples of porous materials include nonwoven fabrics, woven fabrics, metal meshes, and foamed resin sheets. Furthermore, a core material for a porous material can be obtained by punching holes in a core material of a non-porous material such as a resin film or metal foil. The porous material may contain closed cells, but it is preferable to contain open cells (cells that connect to at least one surface), and may also contain through-cells (cells that connect to both surfaces).

[0036] Fibers used as raw materials for nonwoven and woven fabrics include synthetic fibers, metal fibers, animal fibers, plant fibers, and mineral fibers. Specific examples of fiber materials include engineering plastics such as polyphenylene sulfide (PPS) resin, polyethylene terephthalate (PET) resin, polybutylene terephthalate (PBT) resin, and polyamide (PA) resin, as well as polytetrafluoroethylene (PTFE) resin, glass, ceramics, and metals.

[0037] As metals used as raw materials for the metal mesh, there are aluminum, copper, silver, gold, platinum, tin, zinc, titanium, iron, stainless steel, alloys, and the like. As resins used as raw materials for the foamed resin sheet, there are various resins exemplified as raw materials for the above-described resin film.

[0038] For example, when it is desired to provide electrical insulation in the thickness direction of the adhesive sheet, it is desirable to use a sheet obtained by laminating an adhesive sheet and a resin film. When it is desired to provide conductivity and / or heat conductivity to the adhesive sheet, it is desirable to use a sheet obtained by laminating or coating the adhesive sheet with a metal foil, a metal paste, or the like. When it is desired to provide heat insulation and bonding strength to the adhesive sheet, it is desirable to use a sheet obtained by laminating the adhesive sheet and a porous body.

[0039] For a laminate formed by laminating a metal layer and an adhesive, electrodes can be connected to the metal portions at both ends thereof, and energization and heating can be performed. Since local and instantaneous heating can be performed, heating and curing in a relatively short time can be expected compared to oven heating. The metal layer is not limited to a porous body such as a metal mesh, and may be a metal foil, a conductive paste, or the like.

[0040] By including additives such as a release component and a foaming agent in the adhesive layer, after the adhesive sheet is bonded to the adherend, a mechanism for facilitating peeling can be provided by heat treatment at an appropriate timing.

[0041] Additives for the adhesive layer (curable adhesive composition) are not particularly limited, and examples include inorganic fillers, flame retardants, conductivity-imparting agents, crystal nucleating agents, ultraviolet absorbers, antioxidants, vibration damping agents, antibacterial agents, insect repellents, deodorants, anti-coloring agents, heat stabilizers, antistatic agents, plasticizers, lubricants, coloring agents, foaming agents, foam suppressants, coupling agents, tackifying resins (tackifiers), and the like.

[0042] When the adhesive layer consists only of a thermoplastic resin, it has no curability, so it softens during heating and causes a strength reduction. By containing a thermosetting resin excellent in rapid curability in the adhesive layer, heat resistance and process shortening can be achieved simultaneously.

[0043] When using the curable adhesive composition of this embodiment as a sheet adhesive, it is desirable to temporarily bond the sheet adhesive to the adherend and then arbitrarily adjust the timing of adhesive curing by heating, ultraviolet rays (UV), or the like. Therefore, as the adhesive, it is preferable to use a type of curing agent that is cured by applying external energy such as heating or UV rather than a type of adhesive that is cured by mixing a main agent and a curing agent and curing at room temperature.

[0044] Hereinafter, the present invention will be specifically described with reference to examples.

[0045] (1) Production of paint for forming an adhesive layer Each component was mixed with the composition shown in Tables 1 to 6 to obtain a paint for forming an adhesive layer using methyl ethyl ketone (MEK) as a liquid medium. Each component used in the production of the paint for forming an adhesive layer is as follows. A plurality of types of epoxy resins (thermosetting resins) were distinguished by assigning numbers from 1 to 4.

[0046] - Epoxy resin - 1: Trade name jER (registered trademark) 828 (Mw = 370) - Epoxy resin - 2: Trade name jER (registered trademark) 1004 (Mw = 1650) - Epoxy resin - 3: Trade name jER (registered trademark) 1007 (Mn = 2900) - Epoxy resin - 4: Trade name jER (registered trademark) 1010 (Mn = 5500) - Acrylic rubber (modified with carboxyl group, epoxy group, hydroxyl group, thermoplastic resin) - Aromatic diamine (curing agent) - Imidazole (curing agent and curing accelerator) - Bismaleimide resin (thermosetting resin) - Aliphatic diamine (curing agent) - Phenolic resin (resole phenol, thermosetting resin) - Nitrile rubber (modified with carboxyl group, thermoplastic resin) - Polyamide resin (modified with carboxyl group, thermoplastic resin) - Polyolefin resin (modified with epoxy group, thermoplastic resin)

[0047] (2) Manufacturing of the adhesive film A polyethylene terephthalate (PET) film with a release treatment and a thickness of 38 μm was coated with the adhesive layer forming paint manufactured in (1) above, and then dried in a hot air circulating oven set to 100°C to obtain a sheet-like adhesive composition with a thickness of 20 μm on one side of the release PET film. In the cases where "annealing treatment is performed" was indicated in Tables 1 to 6, an annealing treatment was performed at 60°C for 72 hours to produce the B-stage adhesive sheet.

[0048] (3) Manufacturing of laminates SUS fiber porous material (basis weight 50 g / m²) ２ After applying the adhesive layer-forming coating prepared in (1) above onto a 35 μm thick sheet, it was dried in a hot air circulating oven set to 100°C to obtain a sheet impregnated with SUS fiber porous material and adhesive.

[0049] (4) DSC Measurement The adhesive layer of the adhesive film manufactured in (2) above was removed and the differential scanning heat quantity (DSC) of the adhesive was measured. The device used was a DSC7020 manufactured by Hitachi High-Tech Science Corporation. Under the conditions of a measurement weight of 10 mg and a heating rate of 10 °C / min, the amount of heat generated (mJ / mg) per 1 mg of adhesive from the curing start temperature to 300 °C was measured.

[0050] "DSC-1" is the result measured before heat treatment of the adhesive film. "DSC-2" is the result measured after heat treatment at 150°C for 5 minutes. "DSC ratio" is the ratio of DSC-2 to DSC-1. "DSC ratio (un-annealed ratio)" is the ratio of DSC-2 measured after annealing treatment to DSC-1 measured without annealing treatment. The un-annealed examples corresponding to Examples 2, 5, 9, and 11 are Examples 1, 4, 8, and 10, respectively. "DSC evaluation" was judged as good (A) if the value of DSC-1 was 10 mJ / mg or more and the DSC ratio was less than 1.0, indicating that the curing reaction had progressed sufficiently. Otherwise, it was judged as poor (D).

[0051] (5) DMA Measurement The adhesive layer of the adhesive film manufactured in (2) above was removed and dynamic viscoelasticity (DMA) measurement of the adhesive was performed. The apparatus used was a DMA6100 manufactured by Hitachi High-Tech Science Corporation. The storage modulus (E') at 150°C was measured under the conditions of a heating rate of 5°C / min, a load of 10 mN, and a frequency of 10 Hz.

[0052] "DMA-1" is the result measured before heat treatment of the adhesive film. "DMA-2" is the result measured after heat treatment at 150°C for 5 min. "DMA ratio" is the ratio of DMA-2 to DMA-1. "DMA ratio (unannealed ratio)" is the ratio of DMA-2 measured after annealing treatment to DMA-1 measured without annealing treatment. The unannealed examples corresponding to Examples 2, 5, 9, and 11 are Examples 1, 4, 8, and 10, respectively. "DMA evaluation" is the value of DMA-2, which is 2 × 10⁻⁶. ６ If Pa or higher, it's excellent (A), 1 x 10 ５ Pa or more 2×10 ６ If it is less than Pa, it is good (B), 1 x 10 ５ If the value was less than Pa, it was classified as defective (D).

[0053] (6) Bonding strength with SUS fibers A 50 μm thick polyimide film was laminated to one side of the impregnated sheet manufactured in (3) above at 80°C. A 50 μm thick polyimide film was similarly laminated to the other side of the impregnated sheet to obtain a laminate for bonding strength measurement. Subsequently, the laminate for bonding strength measurement was cut to a width of 100 mm × length of 100 mm and hot-pressed at a temperature of 150°C, a pressure of 0.2 MPa, and for 5 min to obtain a sample for bonding strength measurement. The ends of the polyimide films on both sides of the sample for bonding strength measurement were fixed, and the T-peel strength was measured using a universal tensile testing machine at a tensile speed of 50 mm / min.

[0054] For the "Post-Curing Evaluation (SUS Fiber)," the obtained "Bonding Strength (N / cm)" value was evaluated as follows: poor (D) if less than 3 N / cm, acceptable (C) if 3 N / cm or more and less than 5 N / cm, good (B) if 5 N / cm or more and less than 8 N / cm, and excellent (A) if 8 N / cm or more.

[0055] (7) Bonding strength with SUS foil A double-sided adhesive sheet was prepared by laminating the adhesive film manufactured in (2) above onto both sides of the SUS foil. A polyimide film with a thickness of 50 μm was laminated to one side of the double-sided adhesive sheet at 80°C. A polyimide film with a thickness of 50 μm was similarly laminated to the other side of the double-sided adhesive sheet to obtain a laminate for bonding strength measurement. The "bonding strength (N / cm)" was measured by obtaining a sample for bonding strength measurement in the same manner as in (6) above and measuring the T-peel strength. The "post-curing evaluation (SUS foil)" was evaluated using the same criteria as in (6) above.

[0056] (8) Overall evaluation If the "DSC evaluation" was good (A), the overall evaluation was good (B). Furthermore, if the "DMA evaluation" was excellent (A), the overall evaluation was also excellent (A). If the "DSC evaluation" was poor (D), the overall evaluation was also poor (D). Comparative examples 10 to 11 were given a poor overall evaluation (D) because the adhesive film could not be manufactured due to poor formation as described in (2) above.

[0057]

[0058]

[0059]

[0060]

[0061]

[0062]

[0063] The curable adhesive composition of the present invention makes it possible to shorten the process time when manufacturing composite components for heat-resistant applications.

[0064] 11...Core material, 12...Adhesive layer.

Claims

1. A curable adhesive composition comprising a thermosetting component and a thermoplastic component, wherein the heat generation by DSC between 25 and 300°C before heat treatment is 10 mJ / mg or more, the heat generation ratio before and after 150°C / 5 min heat treatment (heat generation after heat treatment / heat generation before heat treatment) is less than 1.0, and the storage modulus by DMA at 150°C after 150°C / 5 min heat treatment is 1 × 10⁻⁶ ５ A curable adhesive composition characterized by having a pressure of Pa or higher.

2. The curable adhesive composition according to claim 1, further comprising a curing agent, wherein the thermoplastic component is present in a ratio of 10 to 500 parts by mass and the curing agent in a ratio of 1 to 10 parts by mass per 100 parts by mass of the thermosetting component, and the thermoplastic component is an elastomer.

3. The curable adhesive composition according to claim 1, characterized in that the thermosetting component is one or more selected from the group consisting of epoxy resin, bismaleimide resin, and phenolic resin.

4. The curable adhesive composition according to claim 1, characterized in that the thermosetting component is one or more selected from the group consisting of epoxy resin, bismaleimide resin, and resolphenol resin.

5. The curable adhesive composition according to claim 1, characterized in that the thermoplastic component is one or more selected from the group consisting of uncrosslinked acrylic rubber, uncrosslinked nitrile rubber, polyamide elastomer, and polyolefin elastomer.

6. The curable adhesive composition according to claim 1, further comprising a curing agent, wherein the curing agent is one or more selected from the group consisting of aromatic diamines, aliphatic diamines, and imidazoles.

7. The curable adhesive composition according to claim 1, characterized in that a test specimen having a layer structure of "polyimide film / curable adhesive composition / SUS foil / curable adhesive composition / polyimide film" is prepared using the curable adhesive composition, and the adhesive strength measured by a T-shaped peel test between the polyimide films on both sides after heat treatment at 150°C for 5 min is 3 N / cm or more.

8. A laminate characterized in that a curable adhesive composition according to any one of claims 1 to 7 is laminated onto one or more core materials selected from the group consisting of resin film, metal foil, and porous body.

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