JP6044243B2 - Adhesive composition and adhesive sheet using it - Google Patents

Description

The present invention relates to an adhesive composition, and more specifically, it can bond metals to each other, a metal to an organic material, and an organic material to an organic material, and has toughness and excellent adhesive strength even in a high temperature environment. The present invention relates to an adhesive composition that can be retained and has excellent water resistance, and an adhesive sheet using the same.

Conventionally, as a joining method for integrating two adherends, there are occlusion, welding, and a bonding method using an adhesive or an adhesive, which are widely used in each field depending on the application. In recent years, in transport-related applications such as automobiles, weight reduction of vehicle bodies and widespread use of hybrid vehicles and electric vehicles have been promoted as solutions to problems such as reduction _{of carbon dioxide CO 2 emissions to prevent global warming.} Therefore, there is an increasing tendency to use lightweight aluminum, magnesium, and FRP (CFRP: Carbon Fiber Reinforced Plastics, GFRP: Glass Fiber Reinforced Plastics) for the vehicle body.

By the way, in the conventional welding method, it is very difficult to weld different materials such as aluminum and iron, and welding itself is impossible for FRP of glass fiber and carbon fiber, and these materials (adhesive bodies). A joining method is required that has the joining strength of welding and identification. As a joining method between materials that cannot be joined by welding or the like, there is a method using an adhesive, but as an adhesive for joining such materials, there are metals, metals and organic materials, and organic materials and organic materials. It is required that the adhesive strength is strong so that it can be used for structural purposes, and that the adhesive strength does not deteriorate due to temperature changes.

A thermosetting resin such as an epoxy resin is generally used as an adhesive that satisfies the above requirements. However, although the epoxy adhesive has high mechanical strength after curing, it is inferior in toughness, and when the epoxy adhesive is used for applications such as aircraft and automobiles, a decrease in adhesive strength due to brittle fracture becomes a problem. In some cases. In response to such problems, attempts have been made to add flexibility to the epoxy adhesive by adding a thermoplastic resin or the like to the epoxy resin (for example, Japanese Patent Application Laid-Open No. 2003-82034).

However, when a flexible thermoplastic resin as proposed in Japanese Patent Application Laid-Open No. 2003-82034 is added to the epoxy adhesive, the heat resistance and water resistance of the adhesive are impaired, so that the adhesive is subjected to a high temperature environment. There are problems that the use is limited and that it cannot be used for applications that require water resistance.

Japanese Unexamined Patent Publication No. 2003-82034

By adding a specific acrylic resin to the epoxy resin, the present inventors have toughness, can maintain excellent adhesive strength even in a high temperature environment, and have excellent water resistance. We obtained the finding that an adhesive can be realized. The present invention is based on such findings.

Therefore, an object of the present invention is that metals can be bonded to each other, metals to organic materials, organic materials to organic materials, toughness, excellent adhesive strength even in a high temperature environment, and water resistance. It is also to provide an excellent adhesive composition.

Another object of the present invention is to provide an adhesive sheet using the above-mentioned adhesive composition.

The adhesive composition according to the present invention is an adhesive composition containing an epoxy resin, an acrylic resin, and a curing agent.
The acrylic resin is characterized by comprising a binary copolymer of methyl methacrylate-butyl acrylate-methyl methacrylate or a modified product thereof.

Further, according to the aspect of the present invention, the epoxy resin may be a bisphenol type epoxy resin.

Further, according to the aspect of the present invention, the epoxy resin is two kinds of bisphenol, a bisphenol type epoxy resin which is liquid at room temperature and a bisphenol type epoxy resin which is solid at room temperature and has a glass transition temperature in the range of 50 to 150 ° C. It may be made of a type epoxy resin.

Further, according to the aspect of the present invention, the blending ratio of the epoxy resin and the acrylic resin may be 100: 4 to 100:20.

Further, according to the aspect of the present invention, the bisphenol type epoxy resin which is liquid at room temperature and the bisphenol type epoxy resin which is solid at room temperature may be contained in a ratio of 1: 100 to 100: 1.

Further, according to the aspect of the present invention, the epoxy resin may be contained in an amount of 140 to 260 parts by mass, the acrylic resin may be contained in an amount of 10 to 50 parts by mass, and the curing agent may be contained in an amount of 1 to 30 parts by mass. ..

Further, according to the aspect of the present invention, the binary copolymer may contain a methyl methacrylate unit and a butyl acrylate unit in a ratio of 1: 1 to 50: 1.

Further, the adhesive sheet according to another aspect of the present invention is an adhesive sheet obtained by laminating a first release paper, an adhesive layer, and a second release paper in this order, and the adhesive layer is the above-mentioned adhesive. It comprises an agent composition.

Further, according to the aspect of the present invention, the adhesive layer may further contain a core material, and the adhesive may be impregnated in the core material.

Further, the bonding method according to another aspect of the present invention is a method of bonding the first adherend and the second adherend using the above-mentioned adhesive sheet.
The first release paper and the second release paper are peeled off and removed from the adhesive sheet to expose the adhesive layer.
The adhesive layer is sandwiched between the first adherend and the second adherend to temporarily fix the first adherend and the second adherend.
The adhesive layer is cured by heating to bond the first adherend and the second adherend.

Further, according to the present invention, a bonded body obtained by the above-mentioned bonding method is also provided.

According to the present invention, since a specific acrylic resin is added to the epoxy resin, the metals can be adhered to each other, the metal and the organic material, and the organic material and the organic material can be adhered to each other, and the epoxy resin has toughness and high temperature. It is possible to realize an adhesive composition that can maintain excellent adhesive strength even in an environment and has excellent water resistance.

It is sectional drawing by one Embodiment of the adhesive sheet by this invention. It is sectional drawing by another embodiment of the adhesive sheet by this invention. It is a surface observation photograph of the pressure-sensitive adhesive of Example 1 and Example 4.

The adhesive composition according to the present invention contains an epoxy resin, an acrylic resin, and a curing agent as essential components. Hereinafter, each component constituting the adhesive composition will be described.

<Epoxy resin>
The epoxy resin used in the adhesive composition according to the present invention means a prepolymer having at least one epoxy group or glycidyl group cured by a cross-linking polymerization reaction in combination with a curing agent. Examples of such epoxy resins include bisphenol A type epoxy resins, bisphenol F type epoxy resins and other bisphenol type epoxy resins, novolac epoxy resins, cresol novolac epoxy resins and other novolak type epoxy resins, biphenyl type epoxy resins and stillben type epoxys. Examples thereof include resins, triphenol methane-type epoxy resins, alkyl-modified triphenol methane-type epoxy resins, triazine nuclei-containing epoxy resins, dicyclopentadiene-modified phenol-type epoxy resins, and other epoxy resins. Novolak type phenol resin such as bisphenol A novolak resin, phenol resin such as resolephenol resin, resin having triazine ring such as urea (urea) resin, melamine resin, unsaturated polyester resin, bismaleimide resin, polyurethane resin, diallyl phthalate resin , Silicon resin, resin having a benzoxazine ring, cyanate ester resin and the like. Among these epoxy-based resins, in the present invention, an epoxy resin having a rigid structure such as a biphenyl skeleton, a bisphenol skeleton, or a stillben skeleton as a main chain is preferable, a bisphenol type epoxy resin is more preferable, and a bisphenol A type is particularly preferable. It is an epoxy resin.

The above-mentioned bisphenol A type epoxy resin includes a liquid at room temperature and a solid at room temperature depending on the number of repeating units of the bisphenol skeleton. The bisphenol A type epoxy resin having a main chain of 0 to 1 is liquid at room temperature, and the bisphenol A type epoxy resin having a main chain of 2 to 10 is solid at room temperature. Such a bisphenol A type epoxy resin having a relatively low molecular weight has crystallinity, and even a solid one that crystallizes at room temperature rapidly melts and changes to a low-viscosity liquid at a temperature equal to or higher than the melting point. Therefore, in the step of joining the adherends, the adhesive adheres to the adherend by heating and solidifies, so that the adhesive and the adherend are firmly adhered to each other, so that the adhesive strength can be increased. Further, such a bisphenol A type epoxy resin having a relatively low molecular weight has a high crosslink density, so that it has high mechanical strength, good chemical resistance, high curability, and hygroscopicity (because the free volume is small). ) Is also small.

In the present invention, as the bisphenol A type epoxy resin, it is preferable to use the above-mentioned bisphenol A type epoxy resin that is solid at room temperature and the bisphenol A type epoxy resin that is liquid at room temperature in combination. By using both a solid and a liquid at room temperature, it is possible to improve the flexibility and film-forming property while maintaining the mechanical strength. Therefore, the mechanical strength inherent in the resin (adhesive composition) is obtained. It is possible to obtain an adhesive sheet having excellent flexibility and film-forming property while maintaining the above. As a result, the bonding strength between the adherends can be improved. The bisphenol A type epoxy resin that is solid at room temperature preferably has a glass transition temperature in the range of 50 to 150 ° C. from the viewpoint of mechanical strength, heat resistance, and film forming property. Specifically, as the bisphenol A type epoxy resin having a main chain of 0 to 1 which is liquid at room temperature, JER828 manufactured by Japan Epoxy Resin Co., Ltd. is a bisphenol A type epoxy resin having a main chain of 2 to 10 which is solid at room temperature. Examples of the resin include JER1001 manufactured by Japan Epoxy Resin Co., Ltd.

The mixing ratio of the bisphenol A type epoxy resin that is solid at room temperature and the bisphenol A type epoxy resin that is liquid at room temperature depends on the application in which the adhesive is used, but the ratio is 1: 100 to 100: 1 on a mass basis. It is preferable that it is contained in. By setting the blending ratio of both in the above range, an adhesive having more excellent adhesive strength can be obtained.

<Acrylic resin>
As the acrylic resin contained in the adhesive composition according to the present invention, a binary copolymer of methyl methacrylate-butyl acrylate-methyl methacrylate or a modified product thereof is used. A binary block copolymer composed of such a methacrylic acid ester polymer block (hereinafter, may be abbreviated as MMA) and a butyl acrylate polymer block (hereinafter, may be abbreviated as BA) is described above. By adding it to the epoxy resin, it is possible to realize an adhesive having toughness, maintaining excellent adhesive strength even in a high temperature environment, and having excellent water resistance. The reason is not clear, but it can be estimated as follows.

In the MMA-BA-MMA binary copolymer, the MMA portion is a "hard" segment and the BA portion is a "soft" segment. In conventional adhesives, acrylic resin is added to impart toughness (flexibility) to epoxy resin, but the addition of acrylic resin reduces the heat resistance of the adhesive itself. Was. In the case of an acrylic resin having both a "hard" segment and a "soft" segment as described above, the "hard" segment portion contributes to heat resistance, and the "soft" segment portion contributes to toughness or flexibility. It is considered that an adhesive having toughness, capable of maintaining excellent adhesive strength even in a high temperature environment, and having excellent water resistance can be realized.

The above-mentioned MMA-BA-MMA binary copolymer can be produced by using general living radical polymerization. Of these, from the viewpoint of ease of control of the polymerization reaction, it can be suitably produced by primitive mobile radical polymerization. The atom transfer radical polymerization method is a polymerization method using an organic halide or a sulfonyl halide compound as an initiator and a metal complex as a catalyst. When producing a binary copolymer of MMA-BA-MMA by the living radical polymerization method, a method of sequentially adding monomer units, a method of polymerizing the next polymer block using a pre-synthesized polymer as a polymer initiator, Examples thereof include a method of bonding separately polymerized polymer blocks by a reaction, but it is preferable to produce a binary copolymer of MMA-BA-MMA by a method of sequentially adding monomer units.

In the method for producing a binary copolymer of MMA-BA-MMA by sequential addition of monomer units, the order of addition of the methacrylic acid ester constituting the MMA block and butyl acrylate constituting the BA block is described first. A method of adding a butyl acrylate monomer after polymerizing a methacrylic acid ester monomer to the above, and a method of adding a methacrylic acid ester monomer after polymerizing a butyl acrylate monomer first can be mentioned. It is easier to control the polymerization by polymerizing the MMA block from the polymerization end of the BA block. The ratio of MMA and BA can be controlled by the amount of monomer input during the living radical polymerization reaction. The ratio of MMA block to BA block in the binary copolymer of MMA-BA-MMA is that as the ratio of BA block increases, the toughness and flexibility of the adhesive improve, while the ratio of MMA block increases. , The heat resistance of the adhesive is improved. In the present invention, from the viewpoint of the toughness and heat resistance of the adhesive, the ratio of the MMA block to the BA block is preferably 1: 1 to 50: 1 in terms of the number of monomer units.

The above-mentioned binary copolymer of MMA-BA-MMA may be a modified product in which a functional group such as a carboxylic acid, a hydroxyl group, or an amide group is introduced into a part of the BA block or the MMA block. By using such a modified product, the heat resistance is further improved and the compatibility with the above-mentioned epoxy resin is also improved, so that the adhesive strength is further improved. Since it has a hydrophilic functional group, its water resistance tends to decrease.

When the MMA-BA-MMA binary copolymer is added to the above-mentioned epoxy resin, the MMA block portion is compatible with the epoxy resin and the BA block portion is not compatible with the epoxy resin. Self-organization occurs. As a result, a sea-island structure in which the epoxy resin is the sea and the acrylic resin is the island is developed before the resin is cured. Further, when the above-mentioned functional group is introduced into the MMA-BA-MMA binary copolymer, the compatibility between the epoxy resin and the acrylic resin is improved, so that the island portion becomes smaller and apparently. Both are in a state of being compatible with each other. By developing such a sea-island structure and an apparent compatible state, interfacial fracture can be avoided and excellent adhesive strength can be maintained. On the other hand, if the polarity of the acrylic resin is lowered by using an unmodified acrylic resin in which no functional group is introduced to reduce the compatibility with the epoxy resin, the epoxy resin will be produced, contrary to the above. Since the island and the sea-island structure in which the acrylic resin is the sea are developed, the water resistance of the adhesive sheet can be dramatically improved while maintaining the adhesive strength to some extent. When having such a sea-island structure, water intrusion from the interface between the pressure-sensitive adhesive (resin) and the adherend can be suppressed, so that a pressure-sensitive adhesive sheet having further excellent water resistance can be realized.

In order to express the sea-island structure as described above, an epoxy resin and an acrylic resin (MMA-BA-MMA binary copolymer) are blended at a ratio of 100: 4 to 100:20 on a mass basis. Is preferable. When both are mixed in the above ratio, the acrylic resin (islands) is dispersed in the epoxy resin (sea) in the form of nano-order level fine particles before the resin is cured, and the acrylic resin (islands) is apparently compatible. Is expressed. Excellent adhesive strength can be maintained by curing the resin while maintaining the apparent compatible state.

<Hardener>
The reaction between the acrylic resin and the epoxy resin proceeds by heating or the like to cure the adhesive composition, but in the present invention, a curing agent is contained in the adhesive composition in order to accelerate the curing reaction. .. Examples of the curing agent include aliphatic polyamines such as diethylenetriamine (DETA), triethylenetetramine (TETA), and metaxylerylene diamine (MXDA), diaminodiphenylmethane (DDM), m-phenylenediamine (MPDA), and diaminodiphenylsulfone ( In addition to aromatic polyamines such as DDS), amine-based curing agents such as polyamine compounds containing dicyandiamide (DICY) and organic acid dihydralide, and alicyclics such as hexahydrophthalic anhydride (HHPA) and methyltetrahydrophthalic anhydride (MTHPA). Acid anhydride-based curing agents such as aromatic acid anhydrides such as group acid anhydride (liquid acid anhydride), trimellitic anhydride (TMA), pyromellitic anhydride (PMDA), and benzophenone tetracarboxylic acid (BTDA). An example is a phenolic curing agent such as a phenol resin. In particular, dicyandiamide (DICY) is preferable because it is a latent curing agent and therefore has excellent storage stability and has a pot life of several weeks even when stored at room temperature. In addition, imidazoles may be included as a curing accelerator.

The content of the curing agent in the adhesive composition shall be 1 to 30 parts by mass when the content of the epoxy resin is 140 to 260 parts by mass and the content of the acrylic resin is 10 to 50 parts by mass. Is preferable. If the compounding ratio of the curing agent is less than this range, the heat resistance after joining is low, and the adhesive strength tends to deteriorate due to temperature changes. If the content of the curing agent exceeds this range, the storage stability (pot life) during the storage period is lowered when the adhesive sheet is stored until it is bonded to the adherend, and after the adhesive is cured. However, there is also a problem that the adhesive strength is lowered due to the residual unreacted curing agent.

In addition, the adhesive composition may, if desired, include, for example, processability, heat resistance, weather resistance, mechanical properties, dimensional stability, antioxidant properties, slipperiness, releasability, flame retardancy, antifungal properties. For the purpose of improving and modifying properties, electrical properties, strength, etc., for example, lubricants, plasticizers, fillers, fillers, antioxidants, antiblocking agents, cross-linking agents, antioxidants, UV absorbers, etc. Light stabilizers, dyes, colorants such as pigments, and others may be added. Further, if necessary, a silane-based, titanium-based, aluminum-based or other coupling agent can be further included. This makes it possible to improve the adhesion between the resin and the adherend and the resin and the core material described later.

In the adhesive composition used in the present invention, each of the above-mentioned components can be mixed, and if necessary, kneaded and dispersed to prepare an adhesive. The mixing or dispersing method is not particularly limited, and ordinary kneading and dispersing machines such as a two-roll mill, a three-roll mill, a pebble mill, a tron mill, a Szegvari attritor, a high-speed impeller disperser, and a high-speed stone mill are used. High speed impact mills, desper, high speed mixers, ribbon blenders, coniders, intensive mixers, tumblers, blenders, despersers, homogenizers, ultrasonic dispersers, etc. can be applied. When a plurality of types are used as the hard epoxy resin, these are mixed and stirred first, then the curing agent is mixed and stirred, diluted with a solvent, and then the soft epoxy resin is mixed and stirred, and then the acrylic resin is mixed and stirred. Is preferably mixed and stirred.

<Adhesive sheet>
As shown in FIG. 1, the adhesive sheet according to the present invention has a layer structure in which a first release paper and a second release paper are provided on both sides of an adhesive layer made of the above adhesive composition. In this specification, the first paper pattern 21A and the second paper pattern 21B are collectively referred to as the paper pattern 21. As shown in FIG. 2, the adhesive layer may further contain a core material, and the core material may be impregnated with an adhesive. As the core material, a woven fabric or a non-woven fabric is preferable, and various conventionally known woven fabrics or non-woven fabrics can be used. Examples thereof include heat-resistant plastic fibers such as liquid crystal polymers, glass fibers, aramid fibers, and carbon fibers. , Woven cloth and non-woven fabric composed of these can be used.

When the adhesive layer contains a core material, the first release paper 21 and the core material 15, which will be described later, are run on top of each other using a coating machine, and the above-mentioned adhesive 13 composition is applied to the 15 surfaces of the core material. As a result, the core material 15 is impregnated, and after drying, the second release paper 21B is attached to the coated surface to obtain the adhesive sheet 1.

The method of applying the adhesive composition to the release paper is not particularly limited, and for example, roll coat, reverse roll coat, transfer roll coat, gravure coat, gravure reverse coat, comma coat, rod coat, blade. Coats, bar coats, wire bar coats, die coats, lip coats, dip coats, etc. can be applied. The composition is applied to the release surface of the first release paper 21A, or the first release paper 21A and the core material 15 on top of each other, applied to the core material 15 surface by the above coating method, dried, and then the second release. The paper pattern 21B may be pasted together. The viscosity of the composition (coating liquid) is adjusted to about 1 to 20000 centimeters of stokes (25 ° C.), preferably 1 to 2000 centimeters of stokes. When impregnated and applied to the core material 15, the viscosity is preferably low, and is 1 to 1000 cm Stokes.

The first paper pattern 21A and the second paper pattern 21B may be the same or different. As the release paper 21, conventionally known ones such as a release film, a separate paper, a separate film, a separate paper, a release film, and a release paper can be preferably used. Further, a material having a release layer formed on one side or both sides of a base material for release paper such as high-quality paper, coated paper, impregnated paper, and plastic film may be used. The release layer is not particularly limited as long as it is a material having releasability, but for example, silicone resin, organic resin modified silicone resin, fluororesin, aminoalkyd resin, melamine resin, acrylic resin, polyester resin and the like. There is. As these resins, any of emulsion type, solvent type and solvent-free type can be used.

The release layer is formed by applying a coating liquid in which the release layer components are dispersed and / or dissolved to one side of a base film for release paper, and heat-drying and / or curing. As a coating method, any known coating method can be applied, and examples thereof include roll coating, gravure coating, and spray coating. Further, the release layer may be formed on the entire surface or a part of at least one side of the base film, if necessary.

The peeling force of the first and second paper patterns is preferably about 1 to 2000 mN / cm, more preferably 100 to 1000 mN / cm with respect to the adhesive sheet. When the peeling force of the release layer is less than 1 mN / cm, the peeling force from the adhesive sheet or the adherend is weak, and the release layer may be peeled off or partially floated. If it is larger than 2000 mN / cm, the release layer has a strong peeling force and is difficult to peel off. From the viewpoint of stable releasability and processability, an addition and / or polycondensation type curable silicone resin for release paper containing polydimethylsiloxane as a main component is preferable.

<Adhesion method of adherend>
In the bonding with the adherend, the first release paper 21A and the second release paper 21B of the adhesive sheet 1 are peeled off and removed to expose the adhesive layer 11. The exposed adhesive layer 11 is sandwiched between two same or different first and second adherends and held by the adhesiveness of the adhesive layer 11. Next, the adhesive layer 11 can be cured by heating or pressurizing and heating, so that the first adherend and the second adherend can be firmly adhered to each other. As described above, by using the adhesive sheet according to the present invention, the adherends can be temporarily fixed to each other by utilizing the initial adhesiveness, and then the adherend is thermally cured by, for example, a batch method. Since the above can be bonded, steps such as preheating can be omitted, and productivity is significantly improved.

The adherend is not particularly limited, and examples thereof include a metal, an inorganic material, an organic material, a composite material combining these, and a laminated material.

The heating temperature at the time of curing is about 60 ° C. to 250 ° C., preferably 100 ° C. to 180 ° C. The heating time is 1 to 240 minutes, preferably 10 to 120 minutes. The adhesive layer 11 of the cured adhesive sheet 1 has initial adhesiveness, does not require a process such as preheating, and can hold the adherend only by the adhesive force, so that the workability is good and the cost is low. Further, by selecting the material of the adhesive layer and the blending ratio thereof, it is possible to bond the metals to each other, the metal to the organic material, and the organic material to the organic material. Furthermore, strong adhesive strength due to the epoxy resin is obtained, and this adhesive strength does not easily deteriorate even with temperature changes, and because of the acrylic resin, the brittleness is low, and excellent shear strength and high shear resistance are obtained. Since it has impact resistance and heat resistance, it can be used for structural applications.

<Combination>
By using the adhesive sheet according to the present invention, materials (adhesive bodies) such as FRP of glass fiber and carbon fiber and dissimilar metals, which are difficult to bond by the conventional welding method, can be strongly bonded. It is possible to obtain a bond with and a bond between FRP and CFRP. These bonded bodies can maintain excellent adhesive strength without being subjected to temperature changes, have low brittleness, and have excellent shear strength, high impact resistance, and heat resistance, so that they are used in fields such as automobiles, aircraft, and ships. It can be used not only in the fields of electronic devices, electronic device housings, home appliances, infrastructure structures, lifeline building materials, general building materials, and the like.

The present invention will be described in more detail with reference to Examples, but the present invention is not limited to the contents of these Examples. Each composition of each layer is a mass part of the solid content excluding the solvent.

Examples 1-20 and Comparative Examples 1-8
<Preparation of adhesive composition>
According to the compositions shown in Tables 1 and 2 below, a curing agent and a curing accelerator are added to the bisphenol A type epoxy resin and mixed by a stirrer, and then an acrylic resin is added to the mixture and mixed to obtain an adhesive. Was prepared. In Table 1 below,
JER828, JER1001 and JER1009 are bisphenol A type epoxy resins manufactured by Mitsubishi Chemical Corporation.
W-197C is an ethyl acrylate-methyl methacrylate copolymer manufactured by Negami Kogyo Co., Ltd.
SK Dyne 1495 is an acrylic-vinyl acetate copolymer manufactured by Soken Kagaku Co., Ltd.
LC # 6500 is a polymethyl methacrylate manufactured by Toei Kasei Co., Ltd.
M53, M22 and M22 are binary copolymers of methyl methacrylate-butyl acrylate-methyl methacrylate manufactured by Arkema.
M22N and SM4032X10 are binary copolymers of modified methyl methacrylate-butyl acrylate-methyl methacrylate introduced by Arkema.
DICY7 is a dicyandiamide manufactured by Mitsubishi Chemical Corporation.
HIPA-2E4MZ is an inclusion imidazole manufactured by Nippon Soda Co., Ltd.
Amicure MY-H and Amicure PN-50 are amine adducts manufactured by Ajinomoto Fine-Techno.
FXR-1030 is a urea adduct manufactured by Ajinomoto Fine Techno Co., Ltd.
R202 is made of Evonik silica.
KBM-403 represents a silane coupling agent manufactured by Shin-Etsu Silicone Co., Ltd., respectively.

<Making an adhesive sheet>
The obtained adhesive was applied to the surface of a core material (Veckles MBBK6FZSO, manufactured by Kuraray Co., Ltd.), which was superposed on a sepa film (SP-PET 03BU, manufactured by Tohcello Co., Ltd.), with a comma coater, and the coating amount was 100 g / m ² . An adhesive sheet was produced by impregnating the core material with an adhesive to form an adhesive layer, and then adhering a sepa film (SP-PET 01BU, manufactured by Tohcello Co., Ltd.) on the adhesive layer. ..

<Making a bonded body>
The obtained adhesive sheet is cut into 25 mm × 12.5 mm, one sepa film is peeled off to expose the adhesive layer, and the iron plate (length 100 mm × width 25 mm × thickness 1.5 mm) which is one adherend is exposed. ) Was pasted on the tip. The sepa film is peeled off from the adhesive sheet attached to the iron plate to expose the adhesive layer, and the tip of the other adherend, the iron plate (length 100 mm x width 25 mm x thickness 1.5 mm), is attached to the adhesive layer portion. I pasted the part.

Next, a load of 3 kg was applied onto the temporarily fixed adherend, and the adhesive layer was heat-cured at 130 ° C. for 2 hours to obtain a bonded body.

<Adhesive strength evaluation>
For each of the obtained bonded bodies, the adhesive strength under each of the following environments was evaluated.
(1) Initial Adhesive Strength For each of Examples 1 to 14 and Comparative Examples 1 to 5, the samples obtained above were prepared under the environments of 23 ° C., 80 ° C., and 50% RH. Both ends were fixed to Tencilon (RTA-1T manufactured by Orientec), pulled at 1 mm / min, and the shear strength was measured. The evaluation results are as shown in Table 3 below.

Further, for each of Examples 15 to 20 and Comparative Examples 6 to 8, both ends of the sample were fixed to Tencilon (RTA-1T manufactured by Orientec) in an environment of 23 ° C. and 50% RH, and 1 mm / mm. The tensile strength was measured at min. The evaluation results are as shown in Table 4 below.

(2) Adhesive strength after storage in a high-temperature hot water environment Each of the bonded products of Examples 15 to 20 and Comparative Examples 6 to 8 was immersed in distilled water and allowed to stand in an environment of 80 ° C. for 720 hours. The bonded product was removed from the distilled water and allowed to stand in a 50% RH environment at 23 ° C. for 24 hours. Subsequently, the shear strength was measured in the same manner as above. The evaluation results are as shown in Table 4 below.

(3) Adhesive strength after storage in a high temperature and high humidity environment For each of Examples 15 to 20 and Comparative Examples 6 to 8, the bonded products were allowed to stand in an environment of 50 ° C. and 95% RH for 720 hours, and then 23 ° C. It was allowed to stand for 24 hours in an environment of 50% RH. Subsequently, the shear strength was measured in the same manner as above. The evaluation results are as shown in Table 4 below.

<Evaluation of initial adhesiveness>
For each of Examples 15 to 20 and Comparative Examples 6 to 8, test samples were prepared as follows in order to evaluate the initial adhesiveness of the adhesive composition. In the process for producing the adhesive sheet described above, the test piece was prepared in the same manner as the adhesive sheet described above, except that the corona-treated surface of the PET film (E-5100, manufactured by Toyobo Co., Ltd.) was bonded instead of one of the sepa films. Made. The obtained test piece was allowed to stand in an environment of 23 ° C. and 50% RH for 24 hours, then cut into 25 mm × 250 mm, and the sepa film was peeled off to expose the adhesive layer. An aluminum plate (6061) whose surface has been cleaned is placed, and the adhesive sheet and the aluminum plate are bonded to each other by reciprocating once at a crimping speed of about 5 mm / sec using a manual crimping device (JIS0237). A test sample was obtained.

The peel peeling strength (N / cm) of the test sample obtained above was measured at 180 ° and 300 mm / min using Tencilon (RTA-1T manufactured by Orientec). The evaluation results are as shown in Table 4 below.

<Evaluation of film forming property>
For the adhesives of Examples 1 to 20 and Comparative Examples 1 to 8, use a sepa film (SP-PET 01BU, manufactured by Tohcello Co., Ltd.) and apply the adhesive to a comma coater so that ^{the coating amount after drying is 50 g / m 2.} And dried at 100 ° C. for 3 minutes, and the appearance of the coated surface was observed. The evaluation criteria are as follows.
◯: The coating film has a uniform thickness (± 5 μm) ×: There are places where the adhesive is not applied due to the adhesive repelling on the surface of the sepa film. The evaluation results are as shown in Tables 3 and 4 below. It was.

<Evaluation of storage stability>
For the adhesives of Examples 15 to 20 and Comparative Examples 6 to 8, the same test samples as those used for the evaluation of the initial adhesiveness of Examples were allowed to stand in an environment of 23 ° C. and 50% RH for one month. , The presence or absence of tack on the surface of the adhesive layer from which the sepa film was peeled off was examined. The presence or absence of tack is determined in the same manner as in the evaluation of initial adhesiveness described above, and those having an initial adhesive force of 50% or more with respect to the initial adhesive force after preparation of the test sample are marked with tack (○). did. The evaluation results are as shown in Table 4 below.

Further, in order to confirm the compatible state of the adhesives used in Examples 15 and 17, the coating amount after drying on the sepa film (SP-PET 01BU, manufactured by Tohcello Co., Ltd.) is 50 g / m ^2. The adhesive was applied to the film with a comma coater and heated at 100 ° C. for 2 hours to cure the adhesive, and the surface of the adhesive was observed using an electron microscope (SU3500, manufactured by Hitachi High-Tech). FIG. 3 is an electron micrograph obtained.

1: Adhesive sheet 11: Adhesive layer 13: Adhesive 15: Core material 21: Paper pattern 21A: First paper pattern 21B: Second paper pattern

Claims (8)

An adhesive composition for adhering metals to each other, metals to organic materials, or organic materials to each other.
It contains an epoxy resin, an acrylic resin, and a curing agent.
The acrylic resin, methyl methacrylate - butyl acrylate - Ri Do from 2 terpolymer or a modified product of methyl methacrylate,
The epoxy resin is characterized by comprising two types of bisphenol type epoxy resins, a bisphenol type epoxy resin that is liquid at room temperature and a bisphenol type epoxy resin that is solid at room temperature with a glass transition temperature in the range of 50 to 150 ° C. , Adhesive composition. Wherein the bisphenol type epoxy resin liquid at room temperature, the is a solid at room temperature bisphenol epoxy resins, 1: 100 to 100: contained in a ratio of 1, the adhesive composition according to claim 1. The adhesive composition according to claim 1 or 2 , wherein the epoxy resin is contained in an amount of 140 to 260 parts by mass, the acrylic resin is contained in an amount of 10 to 50 parts by mass, and the curing agent is contained in an amount of 1 to 30 parts by mass. Stuff. The adhesive composition according to any one of claims 1 to 3 , wherein the binary copolymer contains a methyl methacrylate unit and a butyl acrylate unit in a ratio of 1: 1 to 50: 1. An adhesive sheet obtained by laminating a first release paper, an adhesive layer, and a second release paper in this order, wherein the adhesive layer is the adhesive according to any one of claims 1 to 4. An adhesive sheet containing the composition. The adhesive sheet according to claim 5 , wherein the adhesive layer further contains a core material, and the adhesive is impregnated in the core material. A method of adhering a first adherend and a second adherend using the adhesive sheet according to claim 5 or 6.
The first release paper and the second release paper are peeled off and removed from the adhesive sheet to expose the adhesive layer.
The adhesive layer is sandwiched between the first adherend and the second adherend to temporarily fix the first adherend and the second adherend.
A method comprising bonding the first adherend and the second adherend by curing the adhesive layer by heating. A bonded body in which a first adherend and a second adherend are bonded via a layer made of a cured product of the adhesive composition according to any one of claims 1 to 4 .