JP6383582B2 - Adhesive structure - Google Patents

Description

The present invention relates to an adhesive structure (hereinafter also referred to as “adhesive structure”) between an adhesive sheet and an adherend.

  Conventionally, an adhesive method has been widely adopted as a method for bonding members together. As this type of adhesive, a hot melt adhesive or the like is known (Patent Document 1, etc.).

  By the way, the adhesive sometimes protrudes from the adhesion region. Therefore, in recent years, an adhesive sheet in which an adhesive is formed in a sheet shape has been widely adopted. When such an adhesive sheet is used, the adhesive region can be determined by processing it into a predetermined shape in advance, so that the adhesive can be prevented from protruding from the adhesive region.

JP 2007-66768 A

  However, the conventional adhesive sheet does not have sufficient adhesive effect at a temperature close to room temperature, and there is still room for improvement. Further, when the adhesive sheet is bonded to the adherend, a heat press treatment such as thermosetting or hot melt bonding is often required, which may cause thermal damage to the adherend. Therefore, there is a demand for an adhesive structure that can firmly bond the adhesive sheet and the adherend even at a temperature close to room temperature.

  The present invention has been made in view of the above-described problems, and an object thereof is to provide an adhesive structure that is excellent in adhesiveness between an adhesive sheet and an adherend even at a relatively low temperature such as room temperature. .

  The present invention has been made in order to solve the above-described problem, and includes an adherend and an adhesive sheet laminated on the adherend, and between the adherend and the adhesive sheet. An adhesive structure comprising a component constituting the adherend and a component constituting the adhesive sheet, and comprising a curing reaction layer formed by causing a curing reaction of the component constituting the adhesive sheet.

  ADVANTAGE OF THE INVENTION According to this invention, the adhesive structure excellent in the adhesiveness of an adhesive sheet and a to-be-adhered body can be provided even at comparatively low temperature like normal temperature.

FIG. 1 is a schematic cross-sectional view of an adhesive structure according to an embodiment of the present invention. FIG. 2 is a diagram showing a cross-sectional observation result of the adhesion structure of Reference Example 3. FIG. 3 is a diagram showing a cross-sectional observation result of the adhesion structure of Comparative Example 3. FIG. 4 is a diagram showing the relationship between the thickness and the elastic modulus of the adhesion structures of Reference Example 3 and Comparative Example 3.

  Hereinafter, an embodiment of an adhesive structure according to the present invention will be described with reference to the drawings.

  As shown in FIG. 1, the adhesive structure according to this embodiment includes an adherend 10 and an adhesive sheet 20 laminated on the adherend 10. Further, this adhesive structure includes a component constituting the adherend 10 and a component constituting the adhesive sheet 20 between the adherend 10 and the adhesive sheet 20, and constitutes the adhesive sheet 20. A component to be cured includes a curing reaction layer 11 formed by causing a curing reaction. In the present embodiment, the curing reaction layer 11 is formed by a part of components constituting the adhesive sheet 20 penetrating into the surface layer of the adherend 10 and transferring and curing.

  In this embodiment, the curing reaction layer 11 is formed between the adherend 10 and the adhesive sheet 20, so that the adhesive sheet 20 and the adherend are bonded even at a relatively low temperature such as normal temperature. Adhesive structure excellent in adhesiveness with 10 is obtained. The reason why an adhesive structure excellent in adhesiveness between the adhesive sheet 20 and the adherend 10 can be obtained even at a relatively low temperature is considered as follows.

  In normal interfacial adhesion, an intermolecular force acts between the adhesive sheet 20 and the adherend 10 to bond the adhesive sheet 20 and the adherend 10. On the other hand, in the present embodiment, since a part of the components constituting the adhesive sheet 20 penetrates, shifts and hardens in the adherend 10, the adhesive sheet 20 and the adherend 10 are bonded by chemical bonding. ing.

  When the adhesive interface between the adhesive sheet 20 and the adherend 10 is broken, that is, when the adhesive sheet 20 and the adherend 10 are peeled off, the chemical bond is cut or broken rather than the energy necessary for cutting the intermolecular force. Since the energy required for pulling out the molecules is larger, the adhesive structure using the chemical bond according to the present embodiment is more suitable for the adhesive sheet 20 and the adherend 10 than the interfacial adhesion using ordinary intermolecular force. It is considered that the adhesive strength of is high.

  As described above, in the adhesive structure of the present embodiment, the adhesive sheet 20 and the adherend 10 are firmly bonded to each other rather than normal interface bonding. Moreover, since the adhesive sheet 20 and the adherend 10 are firmly bonded to each other in the bonding structure of the present embodiment, it is considered that water and electrolytes can be prevented from entering the bonding interface. Therefore, it is considered that the adhesive structure of the present embodiment not only has excellent adhesion between the adhesive sheet 20 and the adherend 10 but also has good water resistance.

  Hereafter, each layer which comprises the adhesion structure of this embodiment is demonstrated in detail.

(Adhesive sheet)
The adhesive sheet 20 of the present embodiment includes an adhesive layer (hereinafter, also referred to as an adhesive layer of the present embodiment) formed of a resin composition.

  From the viewpoint of improving adhesiveness, the thickness of the adhesive layer constituting the adhesive sheet 20 of the present embodiment is preferably 1 μm or more, more preferably 5 μm or more, and particularly preferably 10 μm or more. Moreover, 5000 micrometers or less are preferable, 2000 micrometers or less are more preferable, and 1000 micrometers or less are especially preferable.

  The adhesive layer constituting the adhesive sheet 20 of this embodiment preferably exhibits a peel strength of 3N / 10 mm or more with respect to the adherend 10. The peel strength can be determined by the method described in Examples described later.

  When the storage elastic modulus of the adhesive layer constituting the adhesive sheet 20 of this embodiment is excessively low, the adhesive force at normal temperature is difficult to be exhibited. On the other hand, when the storage elastic modulus is excessive, the adhesion to the adherend 10 tends to be lowered, and the adhesive force is hardly exhibited.

  Accordingly, the adhesive layer has a storage elastic modulus (G ′) at 40 ° C. of 0.01 MPa or more and 50 MPa or less from the viewpoint of exhibiting excellent adhesiveness at normal temperature (for example, 23 ° C.) to the adherend 10. It is preferable.

  About this storage elastic modulus, it calculates | requires by the measurement on the following conditions.

<Measurement conditions of storage elastic modulus (G ')>
・ Equipment used: manufactured by TA Instruments Japan, Inc., trade name "ARES-2 KFRT"
・ Measurement mode: Temperature dependence test of dynamic viscoelasticity, using 8mm parallel plate ・ Measurement temperature range: 30 ° C to 200 ° C
・ Raising rate: 10 ° C / min
・ Vibration frequency: 1Hz
・ Distortion: 0.5%

  The adhesive sheet 20 of this embodiment can be used, for example, as a sealing material for a polymer electrolyte membrane for fuel cells. The polymer electrolyte membrane for a fuel cell is a polymer electrolyte membrane used for a fuel cell that generates power by reaction between hydrogen and oxygen.

  The form of the adhesive sheet 20 of the present embodiment may be a single-layer structure having only the adhesive layer of the present embodiment. In addition to the adhesive layer of the present embodiment, a substrate or other adhesive layer may be used. Furthermore, a multilayer structure may be included. The adhesive layer of this embodiment is bonded to the adherend 10 via the curing reaction layer 11.

  When the adhesive sheet 20 of the present embodiment has a multilayer structure including the adhesive layer of the present embodiment and a base material, the base material is usually a film made of a resin having good affinity with the resin composition. For example, a fiber sheet made of the resin or the resin can be used. Among them, a film or a nonwoven fabric made of polyethylene terephthalate (PET) resin or polyethylene naphthalate resin and having a thickness of 10 μm or more and 200 μm or less is suitable as a constituent material of the substrate. Not only such a polyester resin sheet, but also other resins such as polyamide resin and polyimide resin, and polymer sheets made of polymers such as silicone rubber and fluorine rubber can be used as the constituent material of the substrate. Furthermore, a laminate sheet obtained by laminating different materials may be adopted as the material for forming the base material.

  The substrate may be a single layer or a plurality of layers.

  The base material may be subjected to various treatments such as an antistatic treatment as necessary.

  The surface of the adhesive layer constituting the adhesive sheet 20 of the present embodiment may be protected by a release sheet. Although it does not specifically limit as a peeling sheet, A plastic film etc. are mentioned.

  Although it does not specifically limit as thickness of the whole adhesive sheet 20 of this embodiment, From viewpoints of a moldability etc., 1 micrometer or more is preferable, 5 micrometers or more are more preferable, and 10 micrometers or more are especially preferable. Moreover, 5000 micrometers or less are preferable, 2000 micrometers or less are more preferable, and 1000 micrometers or less are especially preferable.

  The resin composition as a component constituting the adhesive sheet 20 of the present embodiment, that is, the resin composition forming the adhesive layer includes a component that causes a curing reaction. The component preferably includes a component that can migrate into the surface layer of the adherend 10. Further, the component is in an uncured state before transferring into the surface layer of the adherend 10.

  The content of the component that can be transferred into the surface layer of the adherend 10 is 1% by weight or more in the solid component of the resin composition forming the adhesive layer of the present embodiment, from the viewpoint of adhesiveness and moldability. Preferably, 5% by weight or more is more preferable, and 10% by weight or more is particularly preferable. Moreover, 50 weight% or less is preferable, 40 weight% or less is more preferable, and 30 weight% or less is especially preferable. The content is a content contained in the adhesive sheet 20 (adhesive layer) before being laminated on the adherend 10.

  The molecular weight of the component that can be transferred into the surface layer of the adherend 10 is preferably 100 or more, more preferably 200 or more, and particularly preferably 300 or more. Moreover, 10,000 or less are preferable and 5000 or less are more preferable.

  The component that can migrate into the surface layer of the adherend 10 preferably contains a component that causes a curing reaction using an acid as a catalyst. When the acid component is present on the surface of the adherend 10 or when the acid component is included in the adherend 10, the component is cured in the curing reaction layer 11 using the acid component as a catalyst. Time and bonding time can be shortened.

  Examples of the component that undergoes a curing reaction using the acid as a catalyst include cationically polymerizable compounds. Since the cationic polymerizable compound undergoes ring-opening polymerization using an acid as a catalyst to cause a curing reaction even at room temperature, the room temperature adhesion can be improved.

  Examples of the cationic polymerizable compound include cyclic ether compounds. The cyclic ether compound is preferably at least one selected from the group consisting of an epoxy compound and an oxetane compound.

  Examples of the oxetane compound include 3-ethyl-3-hydroxymethyloxetane such as “Aron oxetane OXT-101” manufactured by Toa Gosei Co., Ltd .; 2-ethylhexyl oxetane such as “Aron oxetane OXT-212” manufactured by Toa Gosei Co., Ltd. Xylylenebisoxetane such as “Aron oxetane OXT-121” manufactured by Toa Gosei Co .; 3-ethyl-3 {[3-ethyloxetane-3-yl] such as “Aron oxetane OXT-221” manufactured by Toa Gosei Co., Ltd. Methoxy] oxetane; and the like.

  Examples of the epoxy compound include epoxy resins such as bisphenol A type epoxy resin, bisphenol F type epoxy resin, cresol novolac type epoxy resin, alicyclic epoxy resin, and phenol novolac type epoxy resin.

  The epoxy resin is an effective component for causing the resin composition forming the adhesive layer to exhibit tackiness.

  The epoxy resin is preferably a bisphenol A type epoxy resin in that it is effective for imparting tackiness and toughness to the resin composition and imparting excellent moisture and heat resistance, and among them, the Japanese Industrial Standard (JIS) K 7234 Bisphenol A type epoxy resins having a softening point of 130 ° C. or higher and 150 ° C. or lower determined by the ring and ball method are preferred.

  The epoxy resin preferably has a molecular weight of 3000 to 5000 and an epoxy equivalent determined by JIS K 7236 of 2000 to 3500 g / eq.

  The epoxy resin is preferably contained in the resin composition in a state in which at least a part of the epoxy groups are not ring-opened (unreacted state) before the curing reaction layer is formed. In this case, it can suppress by the presence of an epoxy group that the resin composition used for formation of an adhesive bond layer deteriorates with wet heat, and physical properties, such as adhesive strength and tensile strength, fall.

In addition, it can confirm that an epoxy group remains without ring-opening using a Fourier transform infrared spectrophotometer (FTIR), and specifically, the peak which shows presence of an epoxy group is 925. It can be confirmed by appearing at ˜899 cm ⁻¹ .

Further, if it is necessary to confirm whether the peak appearing at 925 to 899 cm ⁻¹ is due to an epoxy group, the resin composition may be heated again to a temperature above the softening point of the epoxy resin and then subjected to FTIR measurement. It can be confirmed that the peak is due to the epoxy group by changing in relation to the peak height and the peak height due to the hydroxyl group appearing at 3650 to 3140 cm ⁻¹ .

  The resin composition forming the adhesive layer of the present embodiment includes, in addition to the components that can be transferred into the surface layer of the adherend 10 as described above, a polyester resin; an acrylic resin; a styrene-ethylene- It is preferable that the main component resin includes a rubber-based resin such as butylene-styrene block copolymer (SEBS); a polyurethane-based resin;

Examples of polyester resins include crystalline polyester resins.
As the crystalline polyester resin, one obtained by dehydration condensation of a polyvalent carboxylic acid and a polyol can be employed. When the resin composition contains an epoxy resin in a state where some of the epoxy groups are not ring-opened (unreacted state), the crystalline polyester resin is hydrolyzed to have a hydroxyl group or a carboxyl group at the molecular end. Can be made to react with the unreacted epoxy group to form a long chain again. Thereby, it can suppress that the resin composition which forms an adhesive bond layer heat-heat-deteriorates, and physical properties, such as adhesive force and tensile strength, fall.

  In the present specification, the crystalline polyester resin is derived from a peak derived from crystallization or / and from crystal melting in measurement by differential scanning calorimetry (DSC) analysis among polyesters containing polyvalent carboxylic acid and polyol. Polyester showing a peak. On the other hand, the amorphous polyester resin refers to a resin that does not show a peak derived from crystallization and a peak derived from crystal melting as measured by DSC analysis.

  Therefore, when it is necessary to determine whether the polyester resin is a crystalline polyester resin or an amorphous polyester resin, the determination can be made by confirming the peak derived from crystallization and the peak derived from crystal melting by DSC analysis.

  Examples of the polyvalent carboxylic acid constituting the crystalline polyester resin include terephthalic acid, isophthalic acid, orthophthalic acid, 1,4-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, and 2,6-naphthalenedicarboxylic acid. Aromatic dicarboxylic acids such as 2,7-naphthalenedicarboxylic acid and biphenyldicarboxylic acid; aromatic oxycarboxylic acids such as p-oxybenzoic acid and p- (hydroxyethoxy) benzoic acid; succinic acid, adipic acid, azelaic acid, Saturated aliphatic dicarboxylic acids such as sebacic acid and dodecane dicarboxylic acid; unsaturated aliphatic dicarboxylic acids such as fumaric acid, maleic acid and itaconic acid; unsaturated alicyclic dicarboxylic acids such as tetrahydrophthalic acid; hexahydrophthalic acid, 1 , 2-Cyclohexanedicarboxylic acid, 1,3-cyclohexanedicar Phosphate, alicyclic dicarboxylic acids such as 1,4-cyclohexanedicarboxylic acid; trimellitic acid, trimesic acid, tricarboxylic acids such as trimellitic acid and pyromellitic acid.

  Examples of the polyol constituting the crystalline polyester resin include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4- Butanediol, 2,3-butanediol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, 3-methyl-1,5-pentanediol, 2-butyl-2-ethyl-1,3 -Aliphatic glycols such as propanediol; Oligoalkylene glycols such as diethylene glycol, triethylene glycol, dipropylene glycol; Fats such as 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol Cyclic glycol; polyethylene glycol Polyalkylene ether glycols such as polypropylene, polypropylene glycol and polytetramethylene glycol; Triols such as trimethylolethane, trimethylolpropane, glycerin and pentaerythritol; Ethylene oxide adducts and propylene oxide adducts of bisphenol A, hydrogenated bisphenol A Examples thereof include ethylene oxide adducts and propylene oxide adducts.

  It is considered that the crystalline polyester resin has a molecular chain that is less susceptible to attack by water in the crystalline region than the amorphous region, and is less susceptible to degradation due to hydrolysis or the like. Therefore, as the crystalline polyester resin, the higher the melting point and the higher the crystallinity, the higher the moisture and heat resistance of the adhesive layer tends to be improved.

  On the other hand, when the crystalline polyester resin, which is the main component resin of the resin composition forming the adhesive layer of the present embodiment, has a high melting point with an excessively high degree of crystallinity, it has good room temperature adhesion. It tends to be difficult to obtain an adhesive layer.

  Therefore, from the viewpoint of improving the heat and humidity resistance and room temperature adhesion of the adhesive layer, the crystalline polyester resin preferably has a melting point of more than 90 ° C and less than 150 ° C, and a melting point of more than 100 ° C and less than 140 ° C. More preferably, it is more than 105 ° C and less than 130 ° C.

  The crystalline polyester resin preferably has a glass transition temperature (hereinafter also referred to as “Tg”) in the range of −100 ° C. to 30 ° C., and in the range of −80 ° C. to −20 ° C. More preferably it is.

  By adopting a crystalline polyester resin having a Tg within the above range as the main component resin of the resin composition, the adhesive layer is more elastic than the case where a crystalline polyester resin having a Tg outside the above range is used. And can improve cohesion and exhibit excellent adhesiveness.

  In this embodiment, the adhesive layer excellent in cold resistance can be formed by making Tg of crystalline polyester resin 30 degrees C or less.

  Moreover, in this embodiment, the normal temperature adhesiveness of an adhesive bond layer can be made favorable by making crystalline polyester resin whose Tg is 30 degrees C or less into the main component resin of the said resin composition.

  When such a suitable crystalline polyester resin is contained in the adhesive layer, the adhesive sheet 20 of this embodiment can be suitable for a sealing material. For example, when the periphery of the polymer electrolyte membrane for fuel cells is sealed using the adhesive sheet 20 of the present embodiment, it is possible to provide a reliable seal while suppressing the risk of thermal damage to the polymer electrolyte membrane.

  Moreover, in this embodiment, it can suppress that an adhesive bond layer becomes too flexible by employ | adopting the crystalline polyester resin whose Tg is -100 degreeC or more as a main component resin of the said resin composition.

  And since it can suppress that the softening temperature as the whole resin composition becomes low too much by employ | adopting the above crystalline polyester resins, a high adhesive strength can be exhibited in an adhesive bond layer.

  In the present specification, the melting point and the glass transition temperature (Tg) can be measured using, for example, a DSC analyzer.

  More specifically, the sample (crystalline polyester resin) is heated at a rate of 5 ° C./min while flowing nitrogen gas from a temperature lower than 30K or higher than the predicted melting point or glass transition temperature to a temperature higher than 30K. The melting point and glass transition temperature can be determined from the DSC curve obtained when the temperature is raised.

  The glass transition temperature (Tg) can be determined based on the method described in JIS K7121: 1987 “Method for measuring plastic transition temperature”.

  The number average molecular weight of the crystalline polyester resin is preferably 10,000 to 50,000. It is preferable that the crystalline polyester resin as the main component resin of the resin composition has such a molecular weight. By setting the molecular weight of the crystalline polyester resin to 10,000 or more, the adhesive layer may be prevented from becoming brittle. This is because the adhesive layer can exhibit excellent toughness. On the other hand, by adopting a crystalline polyester resin having a number average molecular weight of 50000 or less, the adhesive layer can be made excellent in normal temperature adhesiveness.

  That is, by adopting such a crystalline polyester resin, it is possible to make the adhesive sheet have a low possibility of causing thermal damage to the adherend and exhibit excellent adhesiveness and sealability.

  In this specification, the number average molecular weight of crystalline polyester resin can be calculated | required as a styrene conversion value by a gel permeation chromatography (GPC) method.

  As the crystalline polyester resin exhibiting the above characteristics, those obtained by reacting terephthalic acid, isophthalic acid, butanediol, and polyoxytetramethylene glycol are preferable. Among them, terephthalic acid is 25 to 40 mol%, isophthalic acid is 10 to 20 mol%, butanediol is 35 to 50 mol%, and polyoxytetramethylene glycol having an average number of repetitions of 10 to 20 is composed of 5 to 15 mol%. The crystalline polyester resin is preferred.

  The content of the crystalline polyester resin is preferably 50% by weight or more, more preferably 60% by weight or more, and particularly preferably 70% by weight or more in the solid component of the resin composition from the viewpoint of adhesiveness.

  The resin composition forming the adhesive layer of this embodiment may further contain an isocyanate-based crosslinking agent in addition to the crystalline polyester resin and the component that can be transferred to the adherend 10. In this case, the resin composition contains the crystalline polyester resin in a state of being crosslinked by an isocyanate-based crosslinking agent. The resin composition forming the adhesive layer of the present embodiment can improve the heat and moisture resistance of the adhesive sheet 20 by containing an isocyanate-based crosslinking agent.

  As the isocyanate-based crosslinking agent, those having reactivity with polar groups such as hydroxyl groups of the crystalline polyester resin can be used. For example, hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), xylylene diisocyanate ( XDI) and the like, and aromatic isocyanates such as tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), and tolidine diisocyanate (TODI).

  The isocyanate-based crosslinking agent is preferably xylylene diisocyanate, and the blending ratio of the isocyanate-based crosslinking agent is preferably 1 part by weight or more and 12 parts by weight or less with respect to 100 parts by weight of the crystalline polyester resin. More preferred is 8 parts by weight or less.

  The resin composition forming the adhesive layer of this embodiment can contain a resin component other than the resin components shown above within a range that does not significantly impair the effects of this embodiment. For example, a tackifier such as a terpene resin can be added to impart further room temperature adhesion.

  The resin composition forming the adhesive layer of the present embodiment includes general plastic compounding agents such as anti-aging agents, antioxidants, flame retardants, fillers, colorants, processing aids, and the like. In the range which does not impair the effect of, it can contain suitably.

  Among these, from the viewpoint of improving the cohesive strength of the resin composition and improving the water vapor barrier property and gas barrier property, it is preferable to contain an inorganic filler such as plate-like mineral particles. In particular, talc powder having an average particle diameter (median diameter by laser diffraction method) of 1 to 10 μm is preferable in that it can be obtained at low cost.

  Further, the talc powder to be contained in the resin composition may be surface-treated with a fatty acid, a silane coupling agent, or the like, but improves the cohesive strength of the resin composition by using a functional group on the surface. From the viewpoint, it is preferable to use an untreated one.

  When the talc powder is contained in the resin composition, the content of the talc powder is preferably 10 parts by weight or more and 50 parts by weight or less, and 20 parts by weight or more and 30 parts by weight or less with respect to 100 parts by weight of the crystalline polyester resin. The following is more preferable.

  The adhesive sheet 20 of the present embodiment is prepared by, for example, appropriately dissolving or dispersing the resin composition in a solvent to prepare a coating liquid, applying the coating liquid on a substrate, and a temperature of 80 ° C. to 150 ° C. Obtained by drying in the range for 1 to 10 minutes. Examples of a method for applying the coating liquid include known coating methods such as a die coating method and a roll coating method.

(Adherent)
The adherend 10 of this embodiment includes the curing reaction layer 11 as described above.

  From the viewpoint of adhesiveness, the thickness of the curing reaction layer 11 is preferably 1 nm or more, more preferably 5 nm or more, and particularly preferably 10 nm or more. Moreover, from an adhesive viewpoint, 5000 nm or less is preferable, 1000 nm or less is more preferable, and 500 nm or less is especially preferable. The thickness of the curing reaction layer can be measured by cross-sectional observation using a transmission electron microscope (TEM).

  The adherend 10 of the present embodiment is not particularly limited as long as a part of the components constituting the adhesive sheet 20 can be transferred, and examples thereof include a polymer electrolyte membrane and a polymer electrolyte membrane for fuel cells.

  Specific examples of the polymer electrolyte membrane include a polymer electrolyte membrane made of perfluorocarbon sulfonic acid resin. As the polymer electrolyte membrane made of perfluorocarbon sulfonic acid resin, for example, those using the product name “Nafion” manufactured by DuPont, those using the product name “Flemion” manufactured by Asahi Kasei Corporation, Asahi Glass Co., Ltd. The product name “Aciplex” manufactured by the manufacturer can be used.

  The perfluorocarbon sulfonic acid resin is, for example, a resin having a polymer structure represented by the following formula (1). Regarding m, n and x in the formula (1), for example, in the above-mentioned “Nafion”, m ≧ 1, n = 2, and x = 5 to 13.5, and in “Aciplex”, m = 0, 1 , N = 2 to 5, x = 1.5 to 14, and in “Flemion”, m = 0, 1, and n = 1 to 5.

  In the present embodiment, it is preferable that an acid component is present on the surface of the adherend 10. When the component that migrates from the adhesive sheet 20 into the surface layer of the adherend 10 includes a component that causes a curing reaction using an acid as a catalyst, the adhesive sheet 20 and the adherend 10 are laminated when the adherend 10 is laminated. The curing reaction can be promoted by an acid component present on the surface.

  Examples of the acid component include compounds containing an acidic group. Examples of the compound containing an acidic group include ionic group-containing polyphenylene oxide, ionic group-containing polyether ketone, ionic group-containing polyether ether ketone, ionic group-containing polyether sulfone, and ionic group-containing polyether ether sulfone. , Ionic group-containing polyether phosphine oxide, ionic group-containing polyether ether phosphine oxide, ionic group-containing polyphenylene sulfide, ionic group-containing polyamide, ionic group-containing polyimide, ionic group-containing polyetherimide, ionic group -Containing polyimidazole, ionic group-containing polyoxazole, ionic group-containing polyphenylene, ionic group-containing polyazomethine, ionic group-containing polyimide azomethine, ionic group-containing polystyrene, ionic group-containing styrene Aromatic hydrocarbon-based polymer containing an ionic group such as ionic group-containing polyolefin polymer and its crosslinked product of such maleimide crosslinking copolymer.

The ionic group is not particularly limited as long as it can cause cationic polymerization, for example, sulfate ion (SO 4 ^_-2), trifluoromethyl sulfite ion (CF 3 _SO 3 ^_-), tetrafluoroborate (BF ₄ ⁻ ), hexafluorophosphate (PF ₆ ⁻ ), hexafluoroantimonate (SbF ₆ ⁻ ), tetrakis (pentafluorophenyl) borate [(C ₆ F ₅ ) ₄ B ⁻ ] and the like.

  Specific examples of the aromatic hydrocarbon polymer containing the ionic group include trade name “Selemion” manufactured by Asahi Glass Co., Ltd.

  The adherend 10 of the present embodiment may contain an antistatic agent, a filler, and the like as necessary.

  The adhesive structure of this embodiment is produced by laminating the adherend 10 and the adhesive sheet 20. The temperature at the time of laminating the adherend 10 and the adhesive sheet 20 may be normal temperature (for example, about room temperature) or higher than normal temperature. At the time of lamination, the adherend 10 and the adhesive sheet 20 may be superposed and these laminated bodies may be press-contacted. The pressure applied to the laminate may be a low pressure or a high pressure.

  The adhesive structure according to the present invention is not limited to the above embodiment. The adhesive structure according to the present invention can be variously modified without departing from the gist of the present invention.

EXAMPLES Next, although an Example , a reference example, and a comparative example are given and this invention is demonstrated in more detail, this invention is not limited to these. Unless otherwise indicated, “part” in the following means “part by weight”.

( Reference Example 1)
[Film substrate]
A 25 μm thick polyethylene terephthalate (PET) film (manufactured by Toray Industries, Inc.) was used as the film substrate.

[Adherent]
As the adherend, a tetrafluoroethylene / perfluoro [2- (fluorsulfonylethoxy) propyl vinyl ether] copolymer film (manufactured by DuPont, trade name “NAFION N-115”) was used.

[Preparation of adhesive sheet varnish]
Into a four-necked flask equipped with a mechanical stirrer with a stirring blade and a cooling tube, 350 parts of 1,3-dioxolane and 100 parts of a crystalline polyester resin (product name “Byron GM920” manufactured by Toyobo Co., Ltd.) are charged. , And stirred at a temperature of 60 ° C. After stirring for 1 hour, epoxy resin (Mitsubishi Chemical Corporation, trade name “JER1003”): 15 parts and epoxy resin (Mitsubishi Chemical Corporation, trade name “JER1004”): 10 parts are further added for 1 hour. Stir. And 25 parts of filler (trade name “LMS-200” manufactured by Fuji Talc Kogyo Co., Ltd.) was further added and stirred for 30 minutes. Thereafter, an isocyanate-based cross-linking agent (trade name “Takenate D-110N”, manufactured by Mitsui Takeda Chemical Co., Ltd.): 8 parts was further added and stirred for 10 minutes to obtain varnish A for an adhesive sheet.

[Preparation of adhesive sheet]
The adhesive sheet varnish A was degassed by vacuuming, and then applied onto a film substrate using an applicator and dried at 120 ° C. for 4 minutes. This obtained the adhesive sheet provided with the 20-micrometer-thick adhesive layer.

[Production of adhesive structure]
The adhesive sheet was attached by press-contacting a laminate in which the surface on the adhesive layer side of the adhesive sheet was laminated on the adherend. The affixing conditions were one reciprocation with a 2 kg weight roller at normal temperature (23 ° C.). Thereafter, the adhesive structure of Reference Example 1 was obtained by leaving it at room temperature (23 ° C.) for 60 minutes.

( Reference Example 2)
An adhesive sheet varnish B was obtained in the same manner as in Reference Example 1 except that no filler was added. And the adhesive structure of the reference example 2 was obtained like the said reference example 1 except having used the varnish B for adhesive sheets.

( Reference Example 3)
An adhesive sheet varnish C was obtained in the same manner as in Reference Example 1 except that the filler and the crosslinking agent were not added. And the adhesive structure of the reference example 3 was obtained like the said reference example 1 except having used the varnish C for adhesive sheets.

( Reference Example 4)
[Synthesis of acrylic resin]
In a flask equipped with a cooling tube, a nitrogen introducing tube, a thermometer and a stirrer, 2,2′-azobis {2- [1- (2-hydroxyethyl) -2-imidazolin-2-yl] as a polymerization initiator Propane} dihydrochloride: 0.279 g and ion-exchanged water: 100 g were added and stirred for 1 hour while introducing nitrogen gas. And the flask was kept at 60 degreeC.

  Further, butyl acrylate (n-butyl acrylate) (BA): 66 parts, acrylonitrile (AN): 29 parts, acrylic acid (AA): 5 parts, 1-dodecanethiol as a chain transfer agent: 0.04 parts, Then, 2 parts of sodium polyoxyethylene lauryl ether sulfate as an emulsifier was added to 41 parts of ion-exchanged water and emulsified to obtain an emulsion of a monomer raw material.

  Then, 400 g of the monomer raw material emulsion was gradually dropped into the flask over 3 hours to proceed the emulsion polymerization reaction. After completion of dropping of the monomer raw material emulsion, the flask was further kept at 60 ° C. for 3 hours for aging. The aqueous dispersion (emulsion) of the acrylic resin thus polymerized was dried to obtain an acrylic resin. The resulting acrylic resin had a weight average molecular weight of 1,000,000.

[Preparation of adhesive sheet varnish]
Into a four-necked flask equipped with a mechanical stirrer with a stirring blade and a cooling tube, 350 parts of ethyl acetate and 100 parts of the acrylic resin were charged and stirred under a temperature condition of 60 ° C. After stirring for 1 hour, 15 parts of epoxy resin (trade name “JER1003”, manufactured by Mitsubishi Chemical Corporation): 10 parts and epoxy resin (trade name “JER1004”, manufactured by Mitsubishi Chemical Corporation): 10 parts were further added. The mixture was stirred for a time to obtain an adhesive sheet varnish D.

[Production of adhesive structure]
The adhesive structure of Reference Example 4 was obtained in the same manner as Reference Example 1 except that the varnish D for adhesive sheet was used.

( Reference Example 5)
[Preparation of adhesive sheet varnish]
To a four-necked flask equipped with a mechanical stirrer with a stirring blade and a cooling tube, 350 parts of toluene and 100 parts of SEBS resin (manufactured by Asahi Kasei Chemicals Co., Ltd., trade name “Tuftec H1041”): Stirred under conditions. After stirring for 1 hour, 15 parts of epoxy resin (trade name “JER1003”, manufactured by Mitsubishi Chemical Corporation): 10 parts and epoxy resin (trade name “JER1004”, manufactured by Mitsubishi Chemical Corporation): 10 parts were further added. The mixture was stirred for a time to obtain an adhesive sheet varnish E.

[Production of adhesive structure]
The adhesive structure of Reference Example 5 was obtained in the same manner as Reference Example 1 except that the adhesive sheet varnish E was used.

(Example 6)
An adhesive sheet varnish F was produced in the same manner as in Reference Example 1 except that 25 parts of oxetane resin (trade name “Aron Oxetane OXT-221” manufactured by Toa Gosei Co., Ltd.) was added instead of the epoxy resin. And the adhesive structure of Example 6 was obtained like the said reference example 1 except having used the varnish F for adhesive sheets.

(Comparative Example 1)
An adhesive sheet varnish G was prepared in the same manner as in Reference Example 1 except that no epoxy resin was added. And the adhesive structure of the comparative example 1 was obtained like the said reference example 1 except having used the varnish G for adhesive sheets.

(Comparative Example 2)
An adhesive sheet varnish H was prepared in the same manner as in Reference Example 1 except that the epoxy resin and the filler were not added. And the adhesive structure of the comparative example 2 was obtained like the said reference example 1 except having used the varnish H for adhesive sheets.

(Comparative Example 3)
An adhesive sheet varnish I was prepared in the same manner as in Reference Example 1 except that the epoxy resin, the filler, and the isocyanate crosslinking agent were not added. And the adhesive structure of the comparative example 2 was obtained like the said reference example 1 except having used the varnish I for adhesive sheets.

(Comparative Example 4)
An adhesive sheet varnish J was obtained in the same manner as in Reference Example 4 except that no epoxy resin was added. And the adhesive structure of the comparative example 4 was obtained like the said reference example 1 except having used the varnish J for adhesive sheets.

(Comparative Example 5)
An adhesive sheet varnish K was obtained in the same manner as in Reference Example 5 except that no epoxy resin was added. And the adhesive structure of the comparative example 5 was obtained like the said reference example 1 except having used the varnish K for adhesive sheets.

(Comparative Example 6)
The adhesive structure of Comparative Example 6 was obtained in the same manner as in Reference Example 3 except that a PET film “Lumirror S10” (thickness: 100 μm) manufactured by Toray Industries, Inc. was used as the adherend.

The following evaluation was performed on the adhesive structures of Reference Examples 1 to 5, Example 6, and Comparative Examples 1 to 6.

(Normal temperature adhesiveness)
The adhesive structure was cut into a sample having a length of 100 mm and a width of 10 mm. The surface on the adherend side of this sample was attached to a stainless steel plate with a double-sided tape. 60 minutes after pasting, the adhesive sheet was peeled off from the adherend using an autograph (“AG-X” manufactured by Shimadzu Corporation), and the peel strength (N / 10 mm) was measured. It can be evaluated that the higher the measured numerical value, the higher the adhesive strength. The peeling conditions were a tensile speed of 10 mm / min and a peeling angle of 180 degrees.

(water resistant)
The water resistance of the adhesive structure was evaluated by a hot water adhesion test. First, the adhesive structure was cut into a sample having a length of 100 mm and a width of 10 mm. After immersing this sample in 90 ° C. water for 5 hours, the water was wiped off, and the presence or absence of peeling between the adhesive sheet and the adherend was visually confirmed to evaluate the adhesive strength. When peeling was not seen at all, it was judged that the adhesive strength was high and the water resistance was good, and in Tables 1 and 2, it was indicated as “A”. When peeling was confirmed, it was judged that the adhesive strength was low and the water resistance was not good, and in Tables 1 and 2, it was indicated as “B”.

  The evaluation results are shown in Tables 1 and 2.

Also from the above results, according to Reference Examples 1 to 5 and Example 6, it was found that an adhesive structure excellent in adhesiveness between the adhesive sheet and the adherend was obtained even at room temperature. Moreover, it turned out that the adhesive structure of Reference Examples 1-5 and Example 6 has favorable water resistance.

Further, whether or not the curing reaction layer was formed could be confirmed as follows. Here, only Reference Example 3 and Comparative Example 3 were evaluated.

(Section observation using TEM)
The cross-section of the adhesion structure was prepared by a freezing ultrathin section method, and heavy metal staining (osmium staining and ruthenium staining) containing Os (osmium) and Ru (ruthenium) was performed. And the cross-section observation of the adhesion | attachment structure was performed using Hitachi TEM "H-7650". Since the cured reaction layer is strongly dyed by heavy metal staining, when a low luminance layer is confirmed when a cross-section is observed using a TEM, it can be determined that the low luminance layer is a curing reaction layer. The direct magnification was 3000 times.

FIG. 2 shows a cross-sectional observation result of the adhesive structure of Reference Example 3, and FIG. 3 shows a cross-sectional observation result of the adhesive structure of Comparative Example 3. In the adhesion structure of Reference Example 3, as shown in FIG. 2, since a low luminance layer was confirmed, it was determined that a curing reaction layer was formed. The thickness of the curing reaction layer was 60 μm. On the other hand, in the adhesive structure of Comparative Example 3, as shown in FIG. 3, since the low luminance layer was not confirmed, it was determined that the curing reaction layer was not formed.

(Elastic modulus)
First, the cross-section of the adhesive structure is turned up and fixed to a sample fixing base dedicated to AFM (Atomic Force Microscope). AFM “MEP-3D-SA-J” manufactured by Asylum Technology and cantilever “OMCL-” manufactured by Olympus Using AC240TS-C3 ″ (material: Si, spring constant: 1 N / m), a force curve in the contact mode was measured in a direction perpendicular to the interface between the adhesive sheet and the adherend at intervals of 15 nm. The measurement conditions were a cantilever moving speed: 4 μm / second and a maximum indentation load: 100 nN.

Then, from the Force-Ind curve obtained from the force curve, the software Igropro6.22A MFP3D101010 + 11313 attached to the AFM apparatus was analyzed based on the Hertz theory attached to obtain the elastic modulus. Note that Tip Geometry = Sphere, Radius = 10 nm, Select = Fused Silica, ν _Tip = 0.17, E _Tip = 74.9 GPa, ν _Sample = 0.33, Force tab Low = 10%, Force tab High = Calculated at 90%.

In FIG. 4, the relationship between the thickness of the adhesion structure of the reference example 3 and the comparative example 3 and an elasticity modulus was shown. In FIG. 4, the vicinity of the measurement position 450 nm to 550 nm corresponds to the vicinity of the adhesion interface of each adhesion structure. As can be seen from FIG. 4, in Reference Example 3, the elastic modulus was higher than that in Comparative Example 3 in the vicinity of the adhesion interface (450 nm to 550 nm). This phenomenon in which the elastic modulus increases is considered to indicate that the curing reaction layer is formed in Reference Example 3.

10 adherend 11 curing reaction layer 20 adhesive sheet

Claims (7)

The adherend,
An adhesive sheet laminated on the adherend,
Between the adherend and the adhesive sheet, the component constituting the adherend and the component constituting the adhesive sheet are included, and the component constituting the adhesive sheet is formed by causing a curing reaction. A curing reaction layer ,
The curing reaction layer is formed by a part of the components constituting the adhesive sheet moving into the surface layer of the adherend and curing,
The component migrating to the surface of the adherend from the adhesive sheet, oxetane compound, adhesive structure. Wherein the acid component is present on the surface of the adherend, the adhesive structure of claim 1. The acid component is a compound containing an acidic group, the adhesive structure of claim 2. The curing thickness of the reaction layer is 1nm or more 5000nm or less, the adhesion structure according to any one of claims 1 to 3. The adherend is a polymer electrolyte membrane, the adhesion structure according to any one of claims 1 to 4. The adherend is a polymer electrolyte membrane for fuel cells,
The adhesive sheet is a sealing material of the polymer electrolyte membrane for a fuel cell, adhesion structure according to claim 5. The adhesive sheet includes an adhesive layer containing a component that causes a curing reaction, and a base material,
Said adhesive layer, said through the curing reaction layer is bonded to an adherend, adhesion structure according to any one of claims 1 to 6.