JP2022063652A - Film-like adhesive, joined body, and methods for producing them - Google Patents

Abstract

To provide a film-like adhesive which can satisfy both of excellent morphological stability at high temperature and retention of sufficient adhesive strength in a high temperature and high humidity state.SOLUTION: A film-like adhesive 1 including an inorganic fiber substrate 5 is provided, comprising: an upper region 2 which is comprised of a first thermosetting adhesive and is exposed from one principal surface 2a of the film-like adhesive 1; a lower region 3 which is comprised of a second thermosetting adhesive and is exposed from another principal surface 3a of the film-like adhesive 1; and an intermediate region 4 located between the upper region 2 and the lower region 3 and including the inorganic fiber substrate 5, wherein surface tack force in the one principal surface 2a and the another principal surface 3a is 0.12 N or more.SELECTED DRAWING: Figure 1

Description

The present invention relates to film-like adhesives, bonded bodies and methods for producing them.

Conventionally, in the field of precision electronic devices, various adhesives have been used for joining members (for example, joining different kinds of members). These adhesives are required to have excellent morphological stability at high temperature (storage elastic modulus at high temperature) and bonding reliability capable of maintaining sufficient adhesive strength in high temperature and high humidity conditions after bonding. Has been done.

For example, Patent Document 1 discloses an adhesive using an epoxy group-containing acrylic resin, and it is said that the use of the adhesive can suppress interfacial peeling that occurs under high temperature and high humidity conditions.

Japanese Unexamined Patent Publication No. 2007-11249

However, with the technique of Patent Document 1, it is difficult to maintain sufficient adhesive strength under high temperature and high humidity conditions, and there is still room for improvement in order to put it into practical use. Further, as a means for improving the morphological stability at high temperature, it is conceivable to highly fill the inorganic filler, but along with this, the wettability of the surface (adhesive surface) of the adhesive is lowered and the adhesive strength is lowered. .. Therefore, in this method, it is difficult to achieve both excellent morphological stability at high temperature and maintenance of sufficient adhesive strength in a high temperature and high humidity state (for example, 85 ° C. and 85% RH).

Therefore, the present invention provides a film-like adhesive and a method for producing the same, and the film-like adhesive, which can achieve both excellent morphological stability at high temperature and maintenance of sufficient adhesive strength in a high temperature and high humidity state. It is an object of the present invention to provide a bonded body using an agent and a method for producing the same.

One aspect of the present invention relates to the film-like adhesives shown below [1] to [5].

[1] A film-like adhesive containing an inorganic fiber base material, which comprises a first thermosetting adhesive, has an upper region exposed from one main surface of the film-like adhesive, and a second thermosetting. It comprises a lower region made of a sex adhesive and exposed from the other main surface of the film-like adhesive, and an intermediate region located between the upper region and the lower region and containing the inorganic fiber substrate. , A film-like adhesive having a surface tack force of 0.12 N or more on one main surface and the other main surface.

[2] The intermediate region is continuous with the upper region and is continuous with the first thermosetting adhesive, and is continuous with the lower region and contains the second thermosetting adhesive. The film-like adhesive according to [1], which comprises.

[3] The film-like adhesive according to [1] or [2], wherein the inorganic fiber base material is a glass fiber base material.

[4] The film-like adhesive according to any one of [1] to [3], wherein the ratio of the thickness of the inorganic fiber base material to the thickness of the film-like adhesive is 0.1 to 0.9. ..

[5] The content of the inorganic filler in the first thermosetting adhesive is 30% by mass or less, and the content of the inorganic filler in the second thermosetting adhesive is 30% by mass or less. 1] The film-like adhesive according to any one of [4].

According to the film-like adhesive on the side surface, it is possible to achieve both excellent morphological stability at high temperature and maintenance of sufficient adhesive strength in a high temperature and high humidity state. Here, having excellent morphological stability at high temperature means that the cured product obtained by curing the film-shaped adhesive exhibits high strength even at high temperature, and specifically, the cured product has high strength. It means that it shows an excellent storage elastic modulus in the dynamic viscoelasticity measurement at 170 ° C.

Another aspect of the present invention relates to a method for producing a film-like adhesive shown in the following [6] to [7].

[6] The method for producing a film-like adhesive according to any one of [1] to [5], which has a surface tack force of 0.12 N or more and is composed of a first thermosetting adhesive. A step of bonding the adhesive film of 1 and the second adhesive film having a surface tack force of 0.12N or more and made of a second thermosetting adhesive via the inorganic fiber base material. A method for producing a film-like adhesive.

[7] The ratio of the thickness of the inorganic fiber base material to the total thickness of the first adhesive film and the second adhesive film is 0.1 to 0.9, according to [6]. How to make a film-like adhesive.

Another aspect of the present invention is a method for manufacturing a bonded body, comprising a first member, a second member, and a joint portion for joining the first member and the second member to each other. The film-like adhesive according to any one of [1] to [5] is interposed between the first member and the second member to form the first member and the second member. The present invention relates to a method for manufacturing a bonded body, which comprises a step of thermocompression bonding.

Another aspect of the present invention includes a first member, a second member, and a joint portion for joining the first member and the second member to each other, and the joint portion is [1]. ] To [5], the present invention relates to a bonded body, which comprises a cured body of the film-like adhesive according to any one of [5].

According to the present invention, a film-like adhesive and a method for producing the same, and the film-like adhesive, which can achieve both excellent morphological stability at high temperature and maintenance of sufficient adhesive strength in a high temperature and high humidity state, and the film-like adhesive. It is possible to provide a bonded body using an agent and a method for producing the same.

FIG. 1 is a schematic cross-sectional view showing a film-like adhesive according to an embodiment. FIG. 2 is a partially enlarged view of a cross section of the film-like adhesive shown in FIG. FIG. 3 is a schematic cross-sectional view showing a method for producing a film-like adhesive according to an embodiment. FIG. 4 is a schematic cross-sectional view showing a joined body of one embodiment.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings as the case may be. However, the present invention is not limited to the following embodiments. In the present specification, the numerical range indicated by using "-" indicates a range including the numerical values before and after "-" as the minimum value and the maximum value, respectively. In addition, the upper limit value and the lower limit value described individually can be arbitrarily combined. Further, in the present specification, "(meth) acrylate" means at least one of acrylate and the corresponding methacrylate. The same applies to other similar expressions such as "(meth) acryloyl". Further, "(poly)" means both with and without the prefix of "poly".

<Film-like adhesive>
As shown in FIG. 1, the film-like adhesive 1 of one embodiment is exposed from the upper region 2 exposed from one main surface 2a of the film-like adhesive 1 and from the other main surface 3a of the film-like adhesive. The lower region 3 is located between the upper region 2 and the lower region 3, and includes an intermediate region 4 containing the inorganic fiber base material 5.

The upper region 2, the lower region 3 and the intermediate region 4 have a predetermined thickness in the direction perpendicular to the main surface of the film-like adhesive 1, and the upper region 2, the intermediate region 4, and the lower region 3 are thick in this order. They are lined up in the vertical direction (the direction perpendicular to the main surface). The upper region 2, the lower region 3 and the intermediate region 4 extend in a direction parallel to the main surface of the film-like adhesive 1, and are, for example, in a layered state.

The upper region 2 and the lower region 3 are made of a thermosetting adhesive. Hereinafter, depending on the case, the thermosetting adhesive constituting the upper region 2 is referred to as a first thermosetting adhesive, and the thermosetting adhesive constituting the lower region 3 is referred to as a second thermosetting adhesive. .. The first thermosetting adhesive and the second thermosetting adhesive may have the same composition or different compositions. Further, the first thermosetting adhesive and the second thermosetting adhesive constituting the upper region 2 and the lower region 3 may contain inorganic fibers derived from the inorganic fiber base material 5. Details of the thermosetting adhesive will be described later.

The thickness of the upper region 2 and the thickness of the lower region 3 (each thickness) are preferably 1 μm or more, more preferably 2 μm or more, and further preferably 2 μm or more from the viewpoint that sufficient adhesive strength can be easily obtained. It is 10 μm or more. The thickness of the upper region 2 and the thickness of the lower region 3 (each thickness) are, for example, 40 μm or less, and may be 30 μm or less or 20 μm or less.

The thickness of the upper region 2 and the thickness of the lower region 3 can be measured by, for example, the following methods. First, the film-like adhesive 1 is sandwiched between two pieces of glass (thickness: about 1 mm). Next, a resin composition consisting of 100 g of a bisphenol A type epoxy resin (trade name: JER811, manufactured by Mitsubishi Chemical Corporation) and 10 g of a curing agent (trade name: Epomount curing agent, manufactured by Refine Tech Co., Ltd.) is cast. .. Then, the cross section is polished using a polishing machine, and the thickness of each region is measured using a scanning electron microscope (SEM, trade name: SE-8020, manufactured by Hitachi High-Tech Science Co., Ltd.).

The thickness of the upper region 2 and the thickness of the lower region 3 may be the same or different. The ratio of the thickness of the upper region 2 to the thickness of the lower region 3 may be 0.2 or more, 0.5 or more, or 1 or more from the viewpoint of maintaining the adhesive strength. The ratio of the thickness of the upper region 2 to the thickness of the lower region 3 may be 3 or less, 2.5 or less, or 2 or less from the viewpoint of maintaining the adhesive strength.

The intermediate region 4 is a region including the inorganic fiber base material 5, and the thickness of the intermediate region 4 is equal to the thickness of the inorganic fiber base material 5.

The inorganic fiber base material 5 is a base material made of inorganic fibers, and has, for example, a network structure in which a plurality of inorganic fibers are entangled with each other. The inorganic fiber base material 5 tends to have a low coefficient of thermal expansion and excellent morphological stability at high temperatures as compared with a cured product of a thermosetting adhesive. Therefore, the film-like adhesive 1 is provided with a region containing the inorganic fiber base material 5 as the intermediate region 4, so that excellent morphological stability at high temperature and maintenance of sufficient adhesive strength in a high temperature and high humidity state can be achieved. It can be compatible.

Examples of the inorganic fiber constituting the inorganic fiber base material 5 include glass fiber, metal fiber (silver fiber, aluminum fiber, etc.), ceramic fiber, and the like. Among these, from the viewpoint of being more excellent in morphological stability at high temperature, and from the viewpoint that the coefficient of thermal expansion of the film-like adhesive 1 as a whole can be made smaller and the adhesive strength can be more easily maintained in a high temperature and high humidity state. , Glass fiber is preferred. Examples of glass as a material for glass fibers include E glass, C glass, A glass, S glass, D glass, NE glass, T glass, H glass and the like. Among these, T glass is preferable from the viewpoint that the coefficient of thermal expansion of the inorganic fiber base material 5 can be made smaller, and thereby the coefficient of thermal expansion of the film-like adhesive 1 as a whole can be made smaller. The inorganic fiber base material (glass fiber base material) composed of glass fibers may be a glass woven fabric or a glass non-woven fabric.

The inorganic fiber base material 5 has, for example, a flat plate shape. The thickness of the inorganic fiber base material 5 (thickness of the intermediate region 4) is preferably 1 μm or more from the viewpoint of being superior in morphological stability at high temperature and from the viewpoint of making it easier to maintain the adhesive strength in a high temperature and high humidity state. It is more preferably 5 μm or more, still more preferably 10 μm or more. The thickness of the inorganic fiber base material 5 (thickness of the intermediate region 4) may be 50 μm or less, 45 μm or less, or 40 μm or less.

The ratio of the thickness of the inorganic fiber base material 5 to the thickness (total thickness) of the film-like adhesive 1 is superior in terms of morphological stability at high temperature and makes it easier to maintain the adhesive strength in a high temperature and high humidity state. From the viewpoint, it is preferably 0.1 or more, more preferably 0.2 or more, and further preferably 0.3 or more. The ratio of the thickness of the inorganic fiber base material 5 to the thickness (total thickness) of the film-like adhesive 1 is preferably 0.9 or less, more preferably 0, from the viewpoint of easily obtaining sufficient adhesive strength. It is 0.7 or less, more preferably 0.5 or less. From these viewpoints, the ratio of the thickness of the inorganic fiber base material 5 to the thickness (total thickness) of the film-like adhesive 1 is preferably 0.1 to 0.9.

The intermediate region 4 is continuous with, for example, one or both of the regions adjacent to the intermediate region 4 (hereinafter referred to as “adjacent region”) and contains a thermosetting adhesive (hereinafter referred to as “adhesive-containing region”). ") Is included. As shown in FIG. 2, the intermediate region 4 may include an adhesive-containing region 6A continuous with the upper region 2, may include an adhesive-containing region 6B continuous with the lower region 3, and may include an adhesive-containing region 6B. And the adhesive-containing region 6C continuous with the lower region 3 may be included. In the film-like adhesive 1 shown in FIG. 2, the adhesive-containing region 6A and the adhesive-containing region 6B are continuous to form the adhesive-containing region 6C. From the viewpoint of obtaining better adhesive strength, it is preferable that the intermediate region 4 includes an adhesive-containing region continuous with both of the adjacent regions.

The adhesive-containing region contains at least a part of the inorganic fiber base material 5 and a thermosetting adhesive impregnated in the inorganic fiber base material 5. The thermosetting adhesive contained in the adhesive-containing region is preferably the same as the thermosetting adhesive contained in the adjacent region. That is, the thermosetting adhesive contained in the adhesive-containing region 6A continuous with the upper region 2 is preferably the first thermosetting adhesive, and is contained in the adhesive-containing region 6B continuous with the lower region 3. The thermosetting adhesive is preferably a second thermosetting adhesive. In this case, peeling inside the film-like adhesive 1 is less likely to occur.

The intermediate region 4 includes an adhesive-containing region continuous with both adjacent regions (upper region 2 and lower region 3), and the thermosetting adhesive (first thermosetting adhesive and) contained in both adjacent regions. When the second thermosetting adhesives) are different from each other, the adhesive-containing region is a thermosetting adhesive contained in both adjacent regions (the first thermosetting adhesive and the second thermosetting adhesive). May include a mixed area.

The thickness of the film-like adhesive 1 may be 1 μm or more, and may be 80 μm or less.

The surface tacking force of both main surfaces 2a and 3a of the film-like adhesive 1 (the surface tacking force of the main surface 2a and the surface tacking force of the main surface 3a) is 0.12N or more. Since each of the main surfaces 2a and 3a of the film-shaped adhesive 1 has such a surface tacking force, the joining members can be temporarily fixed to each other by, for example, laminating, so that excellent work efficiency can be obtained. From such a viewpoint, the surface tack force of both main surfaces 2a and 3a of the film-like adhesive 1 may be 0.15N or more. The surface tacking force of both main surfaces 2a and 3a of the film-shaped adhesive 1 is such that even when the base material is arranged on the main surfaces 2a and 3a at the time of manufacturing the film-shaped adhesive 1, the base material is applied. From the viewpoint of easy peeling, it may be 5N or less. The surface tack force is a value measured by the method described in Examples.

The surface tacking forces of both main surfaces 2a and 3a of the film-shaped adhesive 1 may be the same or different. The surface tack force of both main surfaces 2a and 3a of the film-shaped adhesive 1 can be adjusted by the type and amount of components (thermoplastic resin, coupling agent, filler, etc.) contained in the thermosetting adhesive. ..

Next, the thermosetting adhesive contained in the film-shaped adhesive 1 will be described. The thermosetting adhesive described below is, for example, a thermosetting adhesive constituting the upper region 2, a thermosetting adhesive constituting the lower region 3, and a thermosetting adhesive that can be contained in the intermediate region 4. It is at least one kind of thermosetting adhesive selected from the group consisting of.

The thermosetting adhesive contains, for example, a thermoplastic resin, a polymerizable compound, and a thermal polymerization initiator. The thermosetting adhesive may contain a coupling agent, a filler and the like.

[Thermoplastic resin]
Examples of the thermoplastic resin include one or more resins selected from the group consisting of phenoxy resin, polyester resin, polyurethane resin, polyester urethane resin, butyral resin, and acrylic resin. The thermoplastic resin may be a polyester urethane resin from the viewpoint of improving flexibility. Among the polyester urethane resins, by using the polyester urethane resin having an aromatic polyester skeleton, there is a tendency that the bending resistance can be improved while maintaining the film-forming property.

The weight average molecular weight of the thermoplastic resin may be 2000 or more, 30,000 or more, or 50,000 or more from the viewpoint of film forming property. From the viewpoint of adhesive strength, the weight average molecular weight of the thermoplastic resin may be 300,000 or less, 200,000 or less, or 100,000 or less. The weight average molecular weight is a value measured by a gel permeation chromatograph (GPC) using a calibration curve made of standard polystyrene.

The Tg (glass transition point) of the thermoplastic resin may be 40 or more, 50 or more, or 60 or more from the viewpoint of film stability at room temperature. The Tg of the thermoplastic resin may be 200 ° C. or lower, 150 ° C. or lower, or 100 ° C. or lower from the viewpoint of material mixing at the time of resin production. The Tg is a value measured by the differential operation calorific value measurement.

The content of the thermoplastic resin may be 5% by mass or more, 10% by mass or more, or 15% by mass or more, based on the total mass of the thermosetting adhesive, and is 95% by mass or less, 90% by mass or less, Alternatively, it may be 85% by mass or less. The content of the thermoplastic resin may be 5 to 95% by mass based on the total mass of the thermosetting adhesive.

[Polymerizable compound]
The polymerizable compound is a compound that polymerizes by a radical, a cation, or an anion generated by a thermal polymerization initiator by heat. The polymerizable compound may be any of a monomer, an oligomer or a polymer. As the polymerizable compound, one kind of compound may be used alone, or a plurality of kinds of compounds may be used in combination.

The polymerizable compound has at least one polymerizable group. The polymerizable group is preferably a radically polymerizable group that reacts with a radical from the viewpoint of obtaining more excellent adhesive properties. That is, the polymerizable compound is preferably a radically polymerizable compound. In this case, a thermal radical polymerization initiator is used as the thermal polymerization initiator. Examples of the radically polymerizable group include a vinyl group, an allyl group, a styryl group, an alkenyl group, an alkenylene group, a (meth) acryloyl group, a maleimide group and the like.

The number of polymerizable groups of the polymerizable compound may be 2 or more from the viewpoint of obtaining the physical properties (for example, cross-linking density) necessary for reducing the connection resistance after the polymerization, and the curing shrinkage during the polymerization may be caused. From the viewpoint of further suppression, it may be 10 or less. From the viewpoint of maintaining a balance between the crosslink density and the effect shrinkage, the polymerizable compound having the number of polymerizable groups within the above range (2 to 10) is the same as the other polymerizable compound having the number of the polymerizable groups outside the above range. May be used in addition to.

Specific examples of the polymerizable compound include (meth) acrylate compound, maleimide compound, vinyl ether compound, allyl compound, styrene derivative, acrylamide derivative, nadiimide derivative, natural rubber, isoprene rubber, butyl rubber, nitrile rubber, butadiene rubber, and styrene-butadiene. Examples thereof include rubber, acrylonitrile-butadiene rubber, and carboxylated nitrile rubber.

Examples of the (meth) acrylate compound include epoxy (meth) acrylate, (poly) urethane (meth) acrylate, methyl (meth) acrylate, polyether (meth) acrylate, polyester (meth) acrylate, polybutadiene (meth) acrylate, and silicone acrylate. , Ethyl (meth) acrylate, 2-cyanoethyl (meth) acrylate, 2- (2-ethoxyethoxy) ethyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-hexyl ( Meta) acrylate, 2-hydroxyethyl (meth) acrylate, isopropyl (meth) acrylate, hydroxypropyl (meth) acrylate, isobutyl (meth) acrylate, isobornyl (meth) acrylate, isodecyl (meth) acrylate, isooctyl (meth) acrylate, n-lauryl (meth) acrylate, 2-methoxyethyl (meth) acrylate, 2-phenoxyethyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, 2- (meth) acryloyloxyethyl phosphate, N, N- Dimethylaminoethyl (meth) acrylate, N, N-dimethylaminopropyl (meth) acrylate, ethylene glycol diacrylate, diethylene glycol diacrylate, trimethylol propanetri (meth) acrylate, tetramethylol methanetetra (meth) acrylate, polyethylene glycol di. (Meta) acrylate, polyalkylene glycol di (meth) acrylate, cyclohexyl (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, neopentyl glycol di (meth) acrylate, pentaerythritol (Meta) acrylate, dipentaerythritol hexa (meth) acrylate, isocyanuric acid-modified bifunctional (meth) acrylate, isocyanuric acid-modified trifunctional (meth) acrylate, tricyclodecanyl acrylate, dimethylol-tricyclodecanediacrylate, 2- Hydroxy-1,3-diacryloxypropane, 2,2-bis [4- (acryloxymethoxy) phenyl] propane, 2,2-bis [4- (acryloxypolyethoxy) phenyl] propane, 2,2- Di (meth) acryloyloxydiethyl phosphate, 2- (meth) a Examples thereof include cryloyloxyethyl acid phosphate and the like.

Maleimide compounds include 1-methyl-2,4-bismaleimidebenzene, N, N'-m-phenylene bismaleimide, N, N'-p-phenylene bismaleimide, N, N'-m-toluylene bismaleimide. , N, N'-4,4-biphenylene bismaleimide, N, N'-4,4- (3,3'-dimethyl-biphenylene) bismaleimide, N, N'-4,4- (3,3') -Dimethyldiphenylmethane) bismaleimide, N, N'-4,4- (3,3'-diethyldiphenylmethane) bismaleimide, N, N'-4,4-diphenylmethane bismaleimide, N, N'-4,4- Diphenylpropane bismaleimide, N, N'-4,4-diphenylether bismaleimide, N, N'-3,3-diphenylsulfone bismaleimide, 2,2-bis (4- (4-maleimidephenoxy) phenyl) propane, 2,2-bis (3-s-butyl-4-8 (4-maleimidephenoxy) phenyl) propane, 1,1-bis (4- (4-maleimidephenoxy) phenyl) decane, 4,4'-cyclohexili Examples thereof include den-bis (1- (4 maleimide phenoxy) -2-cyclohexyl) benzene, 2,2'-bis (4- (4-maleimide phenoxy) phenyl) hexafluoropropane and the like.

Examples of the vinyl ether compound include diethylene glycol divinyl ether, dipropylene glycol divinyl ether, cyclohexanedimethanol divinyl ether, and trimethylolpropane trivinyl ether.

Examples of the allyl compound include 1,3-diallyl phthalate, 1,2-diallyl phthalate, and triallyl isocyanurate.

The polymerizable compound may be a (meth) acrylate compound from the viewpoint of excellent curing reaction rate and better physical properties after curing. The content of the (meth) acrylate compound may be, for example, 10 to 40% by mass, and 40 to 70% by mass, based on the total mass of the polymerizable compound, from the viewpoint of obtaining better physical properties after curing. It may be present, and may be 70 to 100% by mass.

The polymerizable compound can balance the crosslink density and the curing shrinkage, and it is easier to achieve both excellent morphological stability at high temperature and maintenance of adhesive strength in high temperature and high humidity conditions. It may be a compound in which a radical polymerizable group such as a vinyl group, an allyl group, or a (meth) acryloyl group is introduced into the terminal or side chain of a thermoplastic resin (thermoplastic polymer) such as an acrylic resin, a phenoxy resin, or a polyurethane resin. The compound in which a radically polymerizable group is introduced into the terminal or side chain of the thermoplastic resin may be a (poly) urethane (meth) acrylate compound from the viewpoint of obtaining better adhesive properties.

The weight average molecular weight of the compound having a radically polymerizable group introduced into the terminal or side chain of the thermoplastic resin may be 3000 or more, 5000 or more, or 10000 or more from the viewpoint of excellent balance between the crosslink density and the curing shrinkage. The weight average molecular weight of the compound having a radically polymerizable group introduced into the terminal or side chain of the thermoplastic resin may be 1,000,000 or less, 500,000 or less, or 250,000 or less from the viewpoint of excellent compatibility with other components. The weight average molecular weight is a value measured by a gel permeation chromatograph (GPC) using a calibration curve using standard polystyrene.

The content of the compound having a radically polymerizable group introduced into the terminal or side chain of the thermoplastic resin is, for example, 20 to 40 based on the total mass of the polymerizable compound from the viewpoint of better balance between the crosslink density and the curing shrinkage. It may be% by mass, 40 to 60% by mass, or 60 to 80% by mass.

The polymerizable compound has a high Tg (glass transition) such as a (meth) acrylate compound having a tricyclodecane skeleton from the viewpoint of further improving the cohesive force and further improving the heat resistance (for example, excellent morphological stability at high temperature). It may be a compound having a point). The content of the compound having a high Tg is, for example, 1 based on the total mass of the polymerizable compound from the viewpoint of further improving the cohesive force and further improving the heat resistance (for example, excellent morphological stability at high temperature). It may be up to 30% by mass, 30 to 60% by mass, or 60 to 95% by mass.

The polymerizable compound may be a (meth) acrylate compound having a phosphoric acid ester structure from the viewpoint of improving the adhesive strength to the surface of an inorganic substance (metal or the like). A thermosetting adhesive containing such a polymerizable compound is suitably used for, for example, bonding circuit electrodes to each other.

The (meth) acrylate compound having a phosphoric acid ester structure has, for example, a structure represented by the following formula (1).

In formula (1), n represents an integer of 1 to 3, and R ² represents a hydrogen atom or a methyl group.

The (meth) acrylate compound having a phosphoric acid ester structure can be obtained, for example, by reacting anhydrous phosphoric acid with 2-hydroxyethyl (meth) acrylate. Specific examples of the (meth) acrylate compound having a phosphoric acid ester structure include mono (2- (meth) acryloyloxyethyl) acid phosphate, di (2- (meth) acryloyloxyethyl) acid phosphate and the like. ..

The content of the (meth) acrylate compound having a phosphoric acid ester structure is 1 to 7% by mass based on the total mass of the polymerizable compound from the viewpoint of further improving the adhesive strength to the surface of the inorganic substance (metal or the like). It may be 7 to 14% by mass, or 14 to 28% by mass.

The content of the polymerizable compound is 10% by mass or more based on the total mass of the thermosetting adhesive from the viewpoint of facilitating the acquisition of better morphological stability at high temperature and the viewpoint of excellent adhesive strength. It may be 20% by mass or more, and may be 30% by mass or more. The content of the polymerizable compound is based on the total mass of the thermosetting adhesive from the viewpoint that curing shrinkage during polymerization can be suppressed and sufficient adhesive strength can be easily maintained in a high temperature and high humidity state. It may be 90% by mass or less, 80% by mass or less, and 70% by mass or less. From these viewpoints, the content of the polymerizable compound may be 10 to 90% by mass, 20 to 80% by mass, or 30 to 70% by mass based on the total mass of the thermosetting adhesive. May be.

[Thermal polymerization initiator]
The thermal polymerization initiator is a polymerization initiator (thermal radical polymerization initiator, thermal cationic polymerization initiator or thermal anionic polymerization initiator) that generates radicals, cations or anions by heat. The thermal polymerization initiator is preferably a thermal radical polymerization initiator from the viewpoint of obtaining more excellent adhesive properties. As the thermal polymerization initiator, one kind of compound may be used alone, or a plurality of kinds of compounds may be used in combination.

The thermal radical polymerization initiator decomposes by heat to generate free radicals. That is, the thermal radical polymerization initiator is a compound that generates radicals by applying thermal energy from the outside. The thermal radical polymerization initiator can be arbitrarily selected from conventionally known compounds such as organic peroxides and azo compounds.

Specific examples of the thermal polymerization initiator include 1,1,3,3-tetramethylbutylperoxyneodecanoate, di (4-t-butylcyclohexyl) peroxydicarbonate, and di (2-ethylhexyl) peroxy. Dicarbonate, Cumylperoxyneodecanoate, Dilauroyl peroxide, 1-cyclohexyl-1-methylethylperoxyneodecanoate, t-hexylperoxyneodecanoate, t-butylperoxyneodecanoate , T-Butylperoxypivalate, 1,1,3,3-Tetramethylbutylperoxy-2-ethylhexanoate, 2,5-dimethyl-2,5-di (2-ethylhexanoylperoxy) Hexanoate, t-hexylperoxy-2-ethylhexanoate, t-butylperoxy-2-ethylhexanoate, t-butylperoxyneoheptanoate, t-amylperoxy-2-ethylhexanoate , Di-t-butylperoxyhexahydroterephthalate, t-amylperoxy-3,5,5-trimethylhexanoate, 3-hydroxy-1,1-dimethylbutylperoxyneodecanoate, t-amylper Oxyneodecanoate, di (3-methylbenzoyl) peroxide, dibenzoyl peroxide, di (4-methylbenzoyl) peroxide, t-hexylperoxyisopropyl monocarbonate, t-butylperoxymaleic acid, t- Butylperoxy-3,5,5-trimethylhexanoate, t-butylperoxylaurate, 2,5-dimethyl-2,5-di (3-methylbenzoylperoxy) hexane, t-butylperoxy- 2-Ethylhexyl monocarbonate, t-hexylperoxybenzoate, 2,5-dimethyl-2,5-di (benzoylperoxy) hexane, t-butylperoxybenzoate, dibutylperoxytrimethyl adipate, t-amylperoxynormal Organic peroxides such as octoate, t-amylperoxyisononanoate, t-amylperoxybenzoate; 2,2'-azobis-2,4-dimethylvaleronitrile, 1,1'-azobis (1-acetoxy). -1-phenylethane), 2,2'-azobisisobutyronitrile, 2,2'-azobis (2-methylbutyronitrile), 4,4'-azobis (4-cyanovaleric acid), 1,1 '-Azobis (1-cyclohexanecarbonitrile) And the like, azo compounds and the like can be mentioned.

The content of the thermal polymerization initiator may be 0.1 part by mass or more, 0.5 part by mass or more, or 1 part by mass or more with respect to 100 parts by mass of the polymerizable compound from the viewpoint of being more excellent in quick curing. .. The content of the thermal polymerization initiator may be 50 parts by mass or less, 25 parts by mass or less, or 10 parts by mass or less with respect to 100 parts by mass of the polymerizable compound from the viewpoint of being more excellent in storage stability. From these viewpoints, the content of the thermal polymerization initiator may be 0.1 to 50 parts by mass with respect to 100 parts by mass of the polymerizable compound.

[Coupling agent]
Examples of the coupling agent include a silane coupling agent having an organic functional group such as a (meth) acryloyl group, a mercapto group, an amino group and an imidazole group, a tetraalkoxy titanate derivative, a polydialkyl titanate derivative and the like. One type of coupling agent may be used alone, or a plurality of types may be used in combination. When the thermosetting adhesive contains a coupling agent, the adhesiveness tends to be further improved. The content of the coupling agent may be 0.1% by mass or more, 20% by mass or less, and 0.1 to 20% by mass based on the total mass of the thermosetting adhesive. good. In addition, in this specification, a silane coupling agent having a polymerizable group such as a (meth) acryloyl group is not included in the polymerizable compound.

[Filler]
Examples of the filler include non-conductive fillers (for example, non-conductive particles). The filler may be either an inorganic filler or an organic filler. Examples of the inorganic filler include metal oxide fine particles such as silica fine particles, alumina fine particles, silica-alumina fine particles, titania fine particles, and zirconia fine particles; and inorganic fine particles such as nitride fine particles. Examples of the organic filler include organic fine particles such as silicone fine particles, methacrylate-butadiene-styrene fine particles, acrylic-silicone fine particles, polyamide fine particles, and polyimide fine particles. These fine particles may have a uniform structure or may have a core-shell type structure.

The content of the filler may be, for example, 5% by mass or more, 10% by mass or more, or 15% by mass or more, and 30% by mass or less, 28% by mass or less, or based on the total mass of the thermosetting adhesive. It may be 25% by mass or less. In particular, from the viewpoint of further improving the morphological stability at high temperature, the lower limit of the content of the inorganic filler is preferably the above value, and from the viewpoint of obtaining more excellent adhesive strength, the content of the inorganic filler is The upper limit is preferably the above value.

[Other ingredients]
The thermosetting adhesive may further contain components (other components) other than the above-mentioned components. Examples of other components include softeners, accelerators, deterioration inhibitors, colorants, flame retardants, thixotropic agents and the like. The content of other components may be 0.1 to 50% by mass based on the total mass of the thermosetting adhesive.

According to the film-like adhesive 1 described above, it is possible to achieve both excellent morphological stability at high temperature and maintenance of sufficient adhesive strength in a high temperature and high humidity state. Further, since the film-shaped adhesive 1 contains the inorganic fiber base material 5, the film-shaped adhesive 1 can improve the visibility during work and facilitate the work process. Therefore, by using the film-shaped adhesive 1, it is possible to easily produce a bonded body having excellent morphological stability of the bonded portion at high temperature and excellent bonding reliability in a high temperature and high humidity state.

The film-like adhesive 1 is particularly preferably used for bonding members (different types of members) made of different materials.

Although the film-like adhesive 1 has been described above, the film-like adhesive of the present invention is not limited to the above-described embodiment.

For example, the film-like adhesive may include other regions between the upper region and the intermediate region and / or between the lower region and the intermediate region. For example, the film-like adhesive may include a region consisting of a thermosetting adhesive other than the first thermosetting adhesive between the upper region and the intermediate region, and may be provided between the lower region and the intermediate region. May be provided with a region made of a thermosetting adhesive other than the second thermosetting adhesive.

For example, the film-like adhesive may include a plurality of regions containing an inorganic fiber base material as an intermediate region. For example, in the film-like adhesive, a region containing an inorganic fiber base material, a region made of a thermosetting adhesive, and a region containing an inorganic fiber base material are arranged in this order between an upper region and a lower region. May include.

<Manufacturing method of film-like adhesive>
The method for producing the film-shaped adhesive 1 includes, for example, as shown in FIG. 3, a step of bonding the first adhesive film 11 and the second adhesive film 21 via the inorganic fiber base material 5. The method for producing the film-shaped adhesive 1 may further include a step of preparing the first adhesive film 11, the second adhesive film 21, and the inorganic fiber base material 5.

The first adhesive film 11 is made of a first thermosetting adhesive, and the second adhesive film 21 is made of a second thermosetting adhesive. The first adhesive film 11 and the second adhesive film 21 have a surface tack force of 0.12 N or more. The surface tacking force of the first adhesive film 11 and the surface tacking force of the second adhesive film 21 may be the same as the surface tacking force of both main surfaces 2a and 3a of the film-like adhesive 1.

The first adhesive film 11 and the second adhesive film 21 are formed on the base materials 12 and 22, for example, as shown in FIG. That is, in the method for producing the film-like adhesive 1, an adhesive film with a base material (first adhesive film with a base material 10, second) including a base material and an adhesive film formed on the base material. 20) of the adhesive film with a base material may be used.

The adhesive film with a base material can be prepared, for example, by the following method. First, each component contained in the above-mentioned thermosetting adhesive is added to a solvent (for example, an organic solvent) and dissolved or dispersed by stirring, mixing, kneading, etc. to form a varnish composition (a varnish of a thermosetting adhesive). ) Is prepared. Then, the varnish composition is applied onto the mold-released substrate using a knife coater, a roll coater, an applicator, a comma coater, a die coater, etc., and then the solvent is volatilized by heating to form a thermosetting adhesive. Form a layer (adhesive film) composed of. As a result, an adhesive film with a substrate is obtained.

As the solvent used for preparing the varnish composition, a solvent having a property of uniformly dissolving or dispersing each component is preferable, and for example, toluene, acetone, methyl ethyl ketone, methyl isobutyl ketone, ethyl acetate, propyl acetate, butyl acetate and the like are used. Can be mentioned. These solvents can be used alone or in combination of two or more. Stirring and mixing and kneading in the preparation of the varnish composition can be carried out by using, for example, a stirrer, a raider, a three-roll, a ball mill, a bead mill or a homodisper.

The base material is not particularly limited as long as it has heat resistance that can withstand the heating conditions when the solvent is volatilized. For example, stretched polypropylene (OPP), polyethylene terephthalate (PET), polyethylene naphthalate, and polyethylene isophthalate are used. , Polybutylene terephthalate, polyolefin, polyacetate, polycarbonate, polyphenylene sulfide, polyamide, polyimide, cellulose, ethylene / vinyl acetate copolymer, polyvinyl chloride, polyvinylidene chloride, synthetic rubber, liquid crystal polymer, etc. Film) can be used.

The heating conditions (drying conditions) for volatilizing the solvent from the varnish composition applied to the substrate are preferably conditions in which the solvent is sufficiently volatilized. The heating condition (drying condition) may be, for example, 40 ° C. or higher and 120 ° C. or lower for 0.1 minute or longer and 10 minutes or shorter. Further, a part of the solvent may remain on the adhesive film without being removed. The content of the solvent in the adhesive film may be, for example, 0.01% by mass or less based on the total mass of the adhesive film.

The thickness of the first adhesive film 11 and the thickness of the second adhesive film 21 are 1 μm or more and 5 μm or more or from the viewpoint that the thickness of the upper region 2 and the lower region 3 can be easily adjusted within the above-mentioned range. It may be 10 μm or more, and may be 50 μm or less, 45 μm or less, or 40 μm or less.

The thickness of the first adhesive film 11 and the thickness of the second adhesive film 21 may be the same or different. The ratio of the thickness of the first adhesive film 11 to the thickness of the second adhesive film 21 is 0 from the viewpoint that the ratio of the thickness of the upper region 2 to the thickness of the lower region 3 can be easily adjusted within the above-mentioned range. It may be .2 or more, 0.5 or more or 1 or more, and may be 3 or less, 2.5 or less or 2 or less.

The ratio of the thickness of the inorganic fiber base material 5 to the total thickness of the first adhesive film 11 and the second adhesive film 21 is the ratio of the thickness of the inorganic fiber base material 5 to the thickness (total thickness) of the film-like adhesive film 1. From the viewpoint of making it easy to adjust the thickness ratio of 5 to the above range, it may be 0.1 or more, 0.2 or more or 0.3 or more, and 0.9, 0.7 or less or 0.5 or less. It may be there. From the above viewpoint, the ratio of the thickness of the inorganic fiber base material 5 to the total thickness of the first adhesive film 11 and the second adhesive film 21 may be 0.1 to 0.9.

The step of bonding the first adhesive film 11 and the second adhesive film 21 via the inorganic fiber base material 5 may be performed, for example, under pressure. Specifically, for example, as shown in FIG. 3, the surface of the adhesive film 10 with a first substrate on the side of the first adhesive film 11 and the second surface of the adhesive film 20 with a second substrate. The first adhesive film with a base material 10, the inorganic fiber base material 5, and the second adhesive film with a base material 20 are laminated in this order so that the surfaces of the adhesive film 21 on the side of the first base material face each other. Then, by pressurizing in the laminating direction (direction indicated by the arrow in FIG. 3) by a heating press, roll laminating, vacuum laminating, etc., the first adhesive film 11 and the second adhesive film 21 are made of an inorganic fiber group. It may be bonded via the material 5. By removing the base materials 12 and 22 after bonding, the film-like adhesive 1 shown in FIG. 1 can be obtained.

The pressure at the time of pressurization may be, for example, 0.25 to 2 MPa. The temperature at the time of pressurization may be 23 to 70 ° C.

<Joint body and its manufacturing method>
As shown in FIG. 4, the joint body 30 of one embodiment includes a first member 31, a second member 32, and a joint portion 33 that joins the first member 31 and the second member 32 to each other. To be equipped.

The first member 31 and the second member 32 may be the same or different from each other. The first member 31 and the second member 32 are preferably different types of members made of different materials. The first member 31 and the second member 32 are inorganic substrates such as semiconductors, glass, and ceramics; polyimide substrates represented by TCP (Tape Carrier Package), FPC (Flexible Printed Circuit), COF (Chip On Film), and the like. It may be a substrate such as polycarbonate, polyester, or polyether sulfone. These may be a plurality of combinations.

The joint portion 33 contains a cured product of the film-like adhesive 1. The joint portion 33 is located, for example, on the side of the first member 31, a region 34 made of a cured product of the first thermosetting adhesive, and is located on the side of the second member 32, and has a second thermosetting property. It includes a region 35 made of a cured product of the adhesive and a region 36 located between these regions and containing an inorganic fiber substrate. Although not shown, the region 36 containing the inorganic fiber substrate is, for example, a cured product of a thermosetting adhesive (for example, a cured product of a first thermosetting adhesive, a second thermosetting adhesive). It contains a cured product, a cured product of a mixture of a first thermosetting adhesive and a second thermosetting adhesive).

The bonded body 30 is manufactured, for example, by interposing a film-like adhesive 1 between the first member 31 and the second member 32 and thermocompression bonding the first member 31 and the second member 32. can do. Specifically, after arranging the film-like adhesive 1 between the first member 31 and the second member 32 which are arranged so as to face each other, the first member 31 and the first member 31 and while heating the film-like adhesive 1. / Or by pressing the second member 32 in the thickness direction of the film-like adhesive 1, the first member 31, the film-like adhesive 1 and the second member 32 are crimped. At this time, the thermosetting adhesive in the film-shaped adhesive 1 is cured to form the joint portion 33, and the first member 31 and the second member 32 are joined by the joint portion 33.

The pressure at the time of pressurization may be, for example, 0.25 to 10 MPa. The temperature at the time of pressurization may be 70 to 300 ° C.

Hereinafter, the contents of the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples.

<Preparation of thermosetting adhesive varnish (varnish composition) 1 to 3>
The components shown below were mixed in the blending amounts (parts by mass) shown in Table 1 to obtain varnish compositions 1 to 3.
(A) Thermoplastic resin A1: Polyester urethane resin (trade name: UR-8210, manufactured by Toyobo Co., Ltd.)
A2: Polyester urethane resin (trade name: UR-4800, manufactured by Toyobo Co., Ltd.)
(B) Radical polymerizable compound B1: Diacrylate having a tricyclodecane skeleton (trade name: DCP-A, manufactured by Kyoeisha Chemical Co., Ltd.)
B2: Polyurethane acrylate (trade name: UN-5500, manufactured by Negami Kogyo Co., Ltd.)
B3: 2-methacryloyloxyethyl acid phosphate (trade name: Light Ester P-2M, manufactured by Kyoeisha Chemical Co., Ltd.)
(C) Radical polymerization initiator C1: Benzoyl peroxide (trade name: Niper BMT-K40, manufactured by NOF CORPORATION)
(D) Coupling agent D1: 3-methacryloxypropyltrimethoxysilane (trade name: KBM503, manufactured by Shin-Etsu Chemical Co., Ltd.)
(E) Filler E1: Silica fine particles (trade name: R805, manufactured by Nippon Aerosil Co., Ltd., average particle size (primary particle size): 12 nm)
E2: Titanium particles (trade name: Typake CR-50, manufactured by Ishihara Sangyo Co., Ltd.)
(F) Solvent F1: Methyl ethyl ketone

<Examples 1 and 2>
(Preparation of the first adhesive film)
The varnish composition 1 was applied to a PET film 1 having a thickness of 50 μm (trade name: Purex film UH4U, manufactured by Teijin Limited) using a coating device. At this time, the thickness after drying was adjusted to be the value shown in Table 2. Next, hot air drying was performed at 70 ° C. for 3 minutes to prepare a first adhesive film 1 having the thickness shown in Table 2 on the PET film 1. Further, the first adhesive film 2 was produced in the same manner except that the varnish composition 2 was used instead of the varnish composition 1.

(Preparation of second adhesive film)
The varnish composition 1 was applied to a PET film 2 having a thickness of 38 μm (trade name: A-3171-38, manufactured by Teijin Limited) using a coating device. At this time, the thickness after drying was adjusted to be the value shown in Table 2. Next, hot air drying was performed at 70 ° C. for 3 minutes to prepare a second adhesive film 1 having the thickness shown in Table 2 on the PET film 2. Further, the second adhesive film 2 was produced in the same manner except that the varnish composition 2 was used instead of the varnish composition 1.

(Making a film-like adhesive)
A glass cloth (trade name: 1017, thickness: 16 μm, manufactured by Nitto Boseki Co., Ltd.) as an inorganic fiber base material is placed on the first adhesive film 1 obtained above, and the first (first of the glass cloth) is placed on the first adhesive film 1. The second adhesive film 1 obtained above was placed on the surface opposite to the adhesive film), and laminated with a hot roll laminator. As a result, the film-like adhesive of Example 1 was obtained. Further, in the same manner as in Example 2 except that the first adhesive film 2 and the second adhesive film 2 are used instead of the first adhesive film 1 and the second adhesive film 1. A film-like adhesive was obtained. When the first adhesive film and the second adhesive film do not peel off after the film-like adhesive is produced, the laminating property is evaluated as good (laminatability ◯), and the first adhesion is performed. When the agent film and the second adhesive film were peeled off, the laminating property was evaluated as poor (laminating property ×).

(Measurement of surface tack force)
The surface tack force of both main surfaces of the film-like adhesive of Examples 1 and 2 was measured using a tack tester (device name: TAC-II Co., Ltd., manufactured by Resuka Co., Ltd.) at a measurement temperature of 30 ° C. and a load of 20 gf (load control). ), And the measurement was carried out under the condition of a pulling speed of 5 mm / s. The film-like adhesive was cut into 20 mm × 20 mm squares, fixed so that the probe of the tack tester was pressed against the main surface of the film-like adhesive, and each measurement was performed 5 times. The average value of 5 times is calculated, and the case where the surface tack force (average value) of both main surfaces is 0.12N or more and 5N or less is regarded as tackiness ○, and the surface tack force (average value) of one or both main surfaces is The case where it was less than 0.12N or more than 5N was defined as tackiness ×. The results are shown in Table 2.

(Measurement of film-like adhesive thickness)
The thickness of the film-like adhesive of Examples 1 and 2 was measured by the following method. The results are shown in Table 2. To determine the thickness of the film-like adhesive, first, the PET film 2 is peeled off from the film-like adhesive (film-like adhesive with a base material) to which the base material (PET film 1 and PET film 2) is attached, and then the film-like adhesive is adhered. The total thickness of the agent and the PET film 1 was measured using a contact-type thickness measuring device. Then, the PET film 1 was peeled off, the thickness of only the PET film 1 was measured in the same manner, and the value obtained by subtracting the thickness of the PET film 1 from the total thickness was taken as the thickness of the film-like adhesive.

(Preparation of bonded body)
Evaluation joints were prepared using the film-like adhesives of Examples 1 and 2, respectively. Specifically, a film-like adhesive is applied between the aluminum foil (trade name: XPH1Y251-025, manufactured by Kunshan Hanshin Electronics Co., Ltd.) and the copper foil (trade name: XPH0A01-025, manufactured by Kunshan Hanshin Denshi Co., Ltd.). Using a thermocompression bonding device (heating method: pulse heat type, manufactured by Ohashi Seisakusho Co., Ltd.), heat and pressurize at 130 ° C. and 2 MPa for 10 seconds to cure the film-like adhesive to a width of 1 mm. The aluminum foil and the copper foil were joined together. As a result, a joint (evaluation joint) including an aluminum foil, a copper foil, and a joint (a joint made of a cured body of a film-like adhesive) for joining them was produced. In addition, when manufacturing the bonded body, it is easy to confirm the place where the film-like adhesive is placed, and the visibility (workability) is good when the alignment is easy (visibility ○). ), And when it was difficult to confirm the location where the film-like adhesive was placed and the alignment was not easy, the visibility (workability) was evaluated as poor (visibility ×). Since the film-like adhesives of Examples 1 and 2 contain an inorganic fiber base material, it is easy to confirm the place (existence place) where the film-like adhesive is placed, and the visibility is evaluated as ◯. ..

<Comparative Example 1>
The first adhesive film 3 and the second adhesive film 3 were produced in the same manner as in Example 1 except that the thickness of the adhesive film was adjusted to 20 μm. Next, the first adhesive film 3 and the second adhesive film 3 shown in Table 2 were laminated by laminating with a hot roll laminator without using an inorganic fiber base material. As a result, the film-like adhesive of Comparative Example 1 was obtained. Then, a bonded body of Comparative Example 1 was obtained in the same manner as in Examples 1 and 2 except that the obtained film-like adhesive was used. The laminating property, tackiness, thickness and visibility of the film-shaped adhesive were evaluated in the same manner as in Examples 1 and 2.

<Comparative Example 2>
(Preparation of a third adhesive film)
The varnish composition 3 was applied to a PET film 2 having a thickness of 38 μm (trade name: A-3171-38, manufactured by Teijin Limited) using a coating device. At this time, the thickness after drying was adjusted to be 15 μm. Then, it was dried with hot air at 70 ° C. for 3 minutes to prepare a third adhesive film 1 having a thickness of 15 μm.

(Making a film-like adhesive)
A film-like adhesive of Comparative Example 2 was obtained in the same manner as in Examples 1 and 2 except that the third adhesive film 1 was used instead of the inorganic fiber base material. Then, a bonded body of Comparative Example 2 was obtained in the same manner as in Examples 1 and 2 except that the obtained film-like adhesive was used. The laminating property, tackiness, thickness and visibility of the film-shaped adhesive were evaluated in the same manner as in Examples 1 and 2.

<Evaluation>
(Evaluation of morphological stability)
The PET film 2 was peeled off from the film-like adhesives of Examples and Comparative Examples, and the film-like adhesive was fixed on the heat-resistant plate. The film-shaped adhesive fixed on the heat-resistant plate was placed in an oven at 180 ° C. for 1 hour to be cured to obtain a cured product of the film-shaped adhesive. Next, using DMA (device name: RSA-G2, manufactured by TA Instruments), dynamic viscoelasticity measurement was performed under the condition of a temperature rise rate of 10 ° C./min, and the film-like adhesive was cured at 170 ° C. The storage elastic modulus of the body was determined. In this evaluation, when the storage elastic modulus is 1 × 10 ⁸ Pa or more, it is evaluated as having excellent morphological stability at high temperature (morphological stability ○), and when the storage elastic modulus is less than 1 × 10 ⁸ Pa. In addition, it was evaluated as being inferior in morphological stability at high temperature (morphological stability ×). The results are shown in Table 2.

(Evaluation of adhesive strength)
The bonded products of Examples and Comparative Examples were placed in a constant temperature bath set under the conditions of 85 ° C. and 85% RH, and after 100 hours, they were taken out and the adhesive strength was measured. The adhesive strength (bonding strength) of the bonded body was measured by a 90-degree peeling method according to JIS-Z0237. The measurement by the 90-degree peeling method was carried out using Tensilon UTM-4 (manufactured by Toyo Baldwin Co., Ltd.) under the conditions of a peeling speed of 50 mm / min and 25 ° C. In this evaluation, when the adhesive strength after the high temperature and high humidity test is 8 N / cm or more, it is evaluated that sufficient adhesive strength can be maintained in the high temperature and high humidity state (adhesive strength 〇), and the adhesive is adhered. When the strength was less than 8 N / cm, it was evaluated that sufficient adhesive strength could not be maintained in a high temperature and high humidity state (adhesive strength ×). The results are shown in Table 2.

1 ... film-like adhesive, 2 ... upper region, 2a ... one main surface, 3 ... lower region, 3a ... other main surface, 4 ... intermediate region, 5 ... inorganic fiber base material, 11 ... first adhesive Film, 21 ... second adhesive film, 30 ... joint, 31 ... first member, 32 ... second member, 33 ... joint.

Claims (9)

A film-like adhesive containing an inorganic fiber base material,
An upper region made of a first thermosetting adhesive and exposed from one main surface of the film-like adhesive,
A lower region comprising a second thermosetting adhesive and exposed from the other main surface of the film-like adhesive.
An intermediate region located between the upper region and the lower region and containing the inorganic fiber substrate.
A film-like adhesive having a surface tack force of 0.12 N or more on one main surface and the other main surface. The intermediate region includes a region continuous with the upper region and containing the first thermosetting adhesive and a region continuous with the lower region and containing the second thermosetting adhesive. , The film-like adhesive according to claim 1. The film-like adhesive according to claim 1 or 2, wherein the inorganic fiber base material is a glass fiber base material. The film-like adhesive according to any one of claims 1 to 3, wherein the ratio of the thickness of the inorganic fiber base material to the thickness of the film-like adhesive is 0.1 to 0.9. The content of the inorganic filler in the first thermosetting adhesive is 30% by mass or less, and the content is 30% by mass or less.
The film-like adhesive according to any one of claims 1 to 4, wherein the content of the inorganic filler in the second thermosetting adhesive is 30% by mass or less. The method for producing a film-like adhesive according to any one of claims 1 to 5.
A first adhesive film having a surface tack force of 0.12 N or more and made of a first thermosetting adhesive, and a second thermosetting adhesive having a surface tack force of 0.12 N or more. A method for producing a film-like adhesive, which comprises a step of adhering a second adhesive film comprising the same, via the inorganic fiber base material. The film form according to claim 6, wherein the ratio of the thickness of the inorganic fiber base material to the total thickness of the first adhesive film and the second adhesive film is 0.1 to 0.9. How to make an adhesive. A method for manufacturing a joined body, comprising: a first member, a second member, and a joint portion for joining the first member and the second member to each other.
The film-like adhesive according to any one of claims 1 to 5 is interposed between the first member and the second member to heat the first member and the second member. A method for manufacturing a bonded body, which comprises a process of crimping. A first member, a second member, and a joint portion for joining the first member and the second member to each other are provided.
A bonded body comprising the cured product of the film-like adhesive according to any one of claims 1 to 5.

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