Adhesive sheet

Abstract

The present invention provides an adhesive sheet in which a release liner can be easily peeled off from an adhesive surface of the adhesive sheet when the release liner is peeled off, and which has excellent transferability and is not susceptible to overflow of an adhesive. In addition, the present invention also provides a method for manufacturing a laminate, which is not liable to cause overflow of the adhesive when the members are bonded to each other via the adhesive sheet to manufacture the laminate. The adhesive sheet (1) has an elastic modulus (G '(A1)) of 1 * 103 to 5 * 106 Pa at 20 DEG C before being irradiated with active energy rays, an elastic modulus (G' (A2)) of 1 * 104 Pa or less at 80 DEG C, an elastic modulus (G '(B1)) of 1 * 103 Pa or more at 20 DEG C after being irradiated with active energy rays, an elastic modulus (G' (B2)) of 1 * 103 Pa or more at 80 DEG C, and an elastic modulus (E ') of 1 * 108 to 1 * 1011 Pa at 20 DEG C after being thermally cured.

Description

Technical Field

[0001] This invention relates to adhesive sheets. Background Technology

[0002] In recent years, for example, in order to bond metal components to other components, thermosetting double-sided adhesive sheets that can be cured by heating to exert adhesive force and thus strongly bond the components to each other are sometimes used. As such thermosetting adhesive sheets, adhesive sheets containing, for example, thermosetting resin and curing agent are known (see, for example, Patent Documents 1-3).

[0003] Double-sided adhesive sheets used for bonding and fixing components to each other typically have release liner on both adhesive surfaces to protect the adhesive surfaces until use. Furthermore, when using a double-sided adhesive sheet, first, the release liner on one side is peeled off, and the exposed adhesive surface is adhered to one component; then, the release liner on the other side is peeled off, and the exposed adhesive surface is adhered to another component.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2012-197427

[0007] Patent Document 2: Japanese Patent Application Publication No. 2019-39005

[0008] Patent Document 3: Japanese Patent Application Publication No. 7-157535 Summary of the Invention

[0009] The problem that the invention aims to solve

[0010] While thermosetting adhesive sheets achieve a strong bond to components through heat curing, they are typically soft materials before curing. Therefore, when applying one adhesive side of a double-sided adhesive sheet to a component and then peeling off the release liner from the other adhesive side, the following problem arises: sometimes the release liner doesn't peel off from the adhesive side of the adhesive sheet, but rather the adhesive sheet peels off from the bonded component along with the release liner, resulting in poor transferability of the adhesive sheet. Therefore, adhesive sheets require easy removal of the release liner from the adhesive side and excellent transferability.

[0011] Furthermore, after the thermosetting adhesive sheet is applied to the component as described above, it is heated to cure the adhesive sheet and bond it firmly to the component. However, when the components, which are the adhered objects, are applied to each other via the thermosetting adhesive sheet, or when the thermosetting adhesive sheet is heated to cure, the adhesive in the adhesive sheet may sometimes flow due to pressure and heat, and overflow from between the components, i.e., glue overflow occurs.

[0012] Therefore, for thermosetting adhesive sheets, it is required that the release liner can be easily peeled off from the adhesive surface of the adhesive sheet when it is peeled off, that the transferability is excellent, and that adhesive spillage is not likely to occur. It should be noted that, regarding the adhesive sheets disclosed in Patent Documents 1 to 3, none of them mention having all of these properties, and no thermosetting adhesive sheet possessing the properties satisfied by the thermosetting adhesive sheet of the present invention described later is disclosed.

[0013] This invention was conceived against this background, and its object is to provide an adhesive sheet that allows for easy peeling of the release liner from the adhesive surface of the adhesive sheet during peeling, exhibits excellent transferability, and is less prone to adhesive overflow. Furthermore, another object of this invention is to provide a method for manufacturing a laminate that minimizes adhesive overflow when bonding components together using the adhesive sheet to create a laminate.

[0014] Problem Solving Methods

[0015] To achieve the above-mentioned objectives, the inventors conducted in-depth research and discovered that adhesive sheets with elastic moduli G' at 20°C before and after irradiation with active energy rays, elastic moduli G' at 80°C, and elastic moduli E' at 20°C after thermosetting, respectively, fall within specific ranges. These sheets exhibit excellent transferability and are less prone to adhesive overflow when the release liner is peeled off from the adhesive surface. This invention is based on the above insights.

[0016] That is, the present invention provides an adhesive sheet whose elastic modulus G'(A1) at 20°C before irradiation by active energy rays is 1×10⁻⁶. 3 ~5×10 6 The elastic modulus G'(A2) at Pa and 80℃ is 1×10 4 Below Pa, the elastic modulus G'(B1) at 20°C after irradiation with active energy rays is greater than the above-mentioned elastic modulus G'(A1), and the elastic modulus G'(B2) at 80°C is 1×10⁻⁶. 3 Pa or above

[0017] The elastic modulus E' of the thermosetting material at 20°C is 1×10⁻⁶. 8 ~1×10 11 Pa.

[0018] The adhesive sheet described above can be used, for example, as follows: First, the release liner is peeled off from one adhesive side of the adhesive sheet, so that the exposed adhesive side is adhered and sealed to an object to be adhered. Next, at least a portion of the adhesive sheet is cured by irradiation with active energy rays, and then the release liner is peeled off from the other adhesive side. Then, another object to be adhered is attached to the exposed adhesive side, and the adhesive sheet is heated to thermally cure it. In this way, the adhesive sheet described above can be used to bond objects to each other.

[0019] Here, the adhesive sheet of the present invention has an elastic modulus G'(A1) of 1×10 at 20°C before irradiation with active energy rays. 3 It has a hardness of over Pa and moderate hardness near room temperature, thus functioning as a sheet when bonded to the substrate. Furthermore, by setting the elastic modulus G'(A1) to 5 × 10⁻⁶... 6 Below Pa, when the adhesive side of the adhesive sheet is attached to the substrate, it easily adheres tightly to the substrate. The elastic modulus G'(A2) at 80°C before irradiation with active energy rays is set to 1×10⁻⁶. 4 Below Pa, it exhibits excellent followability and adhesion to the substrate during thermosetting.

[0020] Furthermore, the aforementioned adhesive sheet exhibits superior peelability and transferability when the release liner on the other side is to be peeled off from the adhesive sheet after irradiation with active energy rays at 20°C, as the elastic modulus G'(B1) is greater than that of the aforementioned elastic modulus G'(A1). Moreover, by setting the elastic modulus G'(B2) at 80°C after irradiation with active energy rays to 1×10⁻⁶, the adhesive sheet achieves this further. 3 When pressure and heat are applied before thermosetting, the adhesive will have sufficient hardness, resulting in low fluidity and reducing the likelihood of adhesive overflowing between components. Furthermore, by achieving an elastic modulus E' of 1×10⁻⁶ at 20°C after thermosetting... 8 ~1×10 11 Pa has moderate softness and excellent adhesion between the adhered objects.

[0021] The elastic modulus G'(B1) at 20°C is preferably greater than 1×10⁻⁶. 3 Pa and is 5 × 10 8 When the elastic modulus G'(B1) at 20°C is within the above range, it has moderate hardness. When the release liner on the other side is peeled off after irradiation with active energy rays, the adhesive sheet has excellent transferability to the one adhered object, and the release liner on the other side is easily peeled off, resulting in even better transferability.

[0022] In addition, the present invention provides an adhesive sheet (sometimes referred to as "adhesive sheet X") having the following regions (A) and (B) in the surface direction.

[0023] Region (A): The elastic modulus G'(A1) at 20℃ is 1×10⁻⁶. 3 ~5×10 6 The elastic modulus G'(A2) at Pa and 80℃ is 1×10 4 Areas below Pa

[0024] Region (B): The elastic modulus G'(B1) at 20℃ is greater than the above elastic modulus G'(A1), and the elastic modulus G'(B2) at 80℃ is 1×10⁻⁶. 3 Areas above Pa

[0025] Before irradiation with active energy rays, the entire surface of the adhesive sheet of the present invention is the aforementioned region (A). For the adhesive sheet X having both region (A) and region (B), region (B) can be formed, for example, by irradiating a portion of the adhesive sheet of the present invention with active energy rays. When one side of the adhesive sheet X is to be adhered to the substrate and the release liner on the other side is to be peeled off from the adhesive sheet X, the release liner exhibits excellent peelability due to the presence of region (A). Furthermore, the presence of region (B) results in excellent adhesion and transferability between region (B) and the substrate. Moreover, the elastic modulus G'(B2) at 80°C is 1 × 10⁻⁶. 3 In areas above Pa (B), when pressure and heat are applied before thermosetting, the adhesive has sufficient hardness, resulting in low fluidity and reducing the likelihood of adhesive overflowing between components. Furthermore, the elastic modulus G'(A2) at 80°C is 1×10⁻⁶. 4 The region below Pa (A) exhibits excellent followability and adhesion to the substrate during thermosetting.

[0026] The adhesive sheet X preferably has the region (B) at one end in the surface direction.

[0027] The adhesive sheet described above preferably contains epoxy resin as a thermosetting component. Furthermore, the adhesive sheet preferably contains epoxy resin (a) with an epoxy equivalent of 200-800 g / eq and rubber-modified epoxy resin (b).

[0028] In the above-mentioned adhesive sheet, 0.5 to 30 parts by weight of epoxy curing agent (c) are preferably contained relative to 100 parts by weight of epoxy resin.

[0029] The adhesive sheet described above preferably contains a multifunctional compound (d) having two or more reactive double bonds within the molecule.

[0030] The aforementioned multifunctional compound (d) preferably has a (meth)acryloyl group and / or a (meth)acrylamide group.

[0031] The adhesive sheet preferably contains 0.1 to 12 parts by weight of the polyfunctional compound (d) relative to 100 parts by weight of the epoxy resin.

[0032] The adhesive sheet preferably contains 0.1 to 5 parts by weight of photopolymerization initiator (e) relative to 100 parts by weight of the epoxy resin.

[0033] The adhesive sheet is preferably used for bonding components to each other, wherein at least one of the components is a metal component.

[0034] The aforementioned adhesive sheet is preferably used for bonding metal components to each other, or for bonding metal components to fiber-reinforced resin components.

[0035] In addition, the present invention provides a method for manufacturing a laminate, wherein the laminate is a laminate formed by bonding a first adherend and a second adherend via an adhesive sheet, and the manufacturing method comprises:

[0036] The process of irradiating a portion of the adhesive sheet with active energy radiation curing and thermosetting properties that is bonded to the first adhered object with active energy radiation to cure it, or the process of bonding the adhesive sheet to the first adhered object after irradiating a portion of the adhesive sheet with active energy radiation to cure it.

[0037] The process of attaching the second adherend to the adhesive sheet; and

[0038] The process of heating the above-mentioned adhesive sheet to heat it and cure it.

[0039] Preferably, at least one of the first and second adherents is a metal component.

[0040] The combination of the first adherend and the second adherend is preferably a combination of metal components or a combination of metal components and fiber-reinforced resin components.

[0041] The portion of the aforementioned surface direction is preferably one end of the surface direction.

[0042] The effects of the invention

[0043] Regarding the adhesive sheet of the present invention, when the release liner is peeled off, it is easy to peel off from the adhesive surface of the adhesive sheet, exhibits excellent transferability, and is less prone to adhesive overflow. Furthermore, according to the method for manufacturing a laminate according to the present invention, when a laminate is manufactured by bonding components together via the adhesive sheet, adhesive overflow is less likely to occur. Attached Figure Description

[0044] Figure 1 This is a cross-sectional schematic diagram of an adhesive sheet according to one embodiment of the present invention.

[0045] Figure 2 This is a flowchart illustrating the process of manufacturing a laminate according to one embodiment of the present invention.

[0046] Figure 3 This is a flowchart illustrating other processes of a method for manufacturing a laminate according to one embodiment of the present invention.

[0047] Symbol Explanation

[0048] 1, 1' Adhesive sheet

[0049] 2, 3 Peeling Liners

[0050] 4 First Adhesive

[0051] 5 Second Adhesive

[0052] 11 Curing Department

[0053] 12 Non-cured part Detailed Implementation

[0054] [Adhesive sheet]

[0055] The adhesive sheet of the present invention exhibits both active energy radiation curing and thermosetting properties. The adhesive sheet is preferably a double-sided adhesive sheet, and more preferably a so-called "substrate-free" double-sided adhesive sheet without a substrate. Substrate-free double-sided adhesive sheets do not suffer from problems caused by the use of a substrate, such as interlayer damage, and also exhibit excellent conformability to the adhered object. The adhesive sheet can be used as a single layer for bonding components, or multiple layers can be stacked for bonding components. Furthermore, a substrate layer can be bonded to the adhesive sheet for use as a single-sided adhesive sheet.

[0056] Figure 1 This is a cross-sectional schematic diagram illustrating one embodiment of the adhesive sheet of the present invention. Figure 1 The adhesive sheet 1 shown is a double-sided adhesive sheet. Release liner 2 and 3 are respectively attached to the adhesive surfaces on both sides of the adhesive sheet 1.

[0057] The adhesive sheet described above can be used, for example, as follows: First, the release liner is peeled off from one adhesive side of the adhesive sheet, so that the exposed adhesive side is adhered and sealed to an object to be adhered to. Next, at least a portion of the adhesive sheet is cured by irradiation with active energy rays, and then the release liner is peeled off from the other adhesive side. Then, another object to be adhered to the exposed adhesive side, and the adhesive sheet is heated to thermally cure it. In this way, the adhesive sheet described above can be used to bond objects to each other.

[0058] The adhesive sheet of the present invention has an elastic modulus G' (sometimes referred to as "elastic modulus G'(A1)") of 1 × 10⁻⁶ at 20°C before irradiation with active energy rays. 3 ~5×10 6 Pa, preferably 1×10 4 ~3×10 6 Pa, more preferably 5 × 10 Pa 4 ~2×10 6 Pa. By making the elastic modulus G'(A1) at 20°C before irradiation with active energy rays 1×10⁻⁶. 3 It has a hardness of over Pa and moderate hardness near room temperature, allowing it to function as a sheet when bonded to the substrate. Furthermore, by setting the elastic modulus G'(A1) at 20°C to 5 × 10⁻⁶... 6 When the adhesive surface of the adhesive sheet is below Pa, it is easy to adhere to the substrate when the adhesive side of one side is attached to the substrate.

[0059] The adhesive sheet of the present invention has an elastic modulus G' (sometimes referred to as "elastic modulus G'(A2)") of 1 × 10⁻⁶ at 80°C before irradiation by active energy rays. 4 Pa or less, preferably 8×10 Pa 3 Pa or less, more preferably 5×10 Pa 3 Below Pa. The elastic modulus G'(A2) at 80℃ before irradiation with active energy rays is made to be 1×10. 4 It exhibits excellent conformability to the substrate during thermosetting and excellent adhesion to the substrate. The elastic modulus G'(A2) is, for example, 1 Pa or more.

[0060] The elastic modulus G' (sometimes referred to as "elastic modulus G'(B1)") of the adhesive sheet of the present invention at 20°C after irradiation with active energy rays is greater than the above-mentioned elastic modulus G'(A1). By making the elastic modulus G'(B1) at 20°C greater than the elastic modulus G'(A1), the peelability and transferability are excellent when the release liner on the other side is to be peeled off from the adhesive sheet after irradiation with active energy rays.

[0061] The ratio of the elastic modulus G'(B1) to the elastic modulus G'(A1) of the adhesive sheet of the present invention [elastic modulus G'(B1) / elastic modulus G'(A1)] is preferably 1.5 or more, more preferably 5 or more, and even more preferably 10 or more. When the ratio is 1.5 or more, the peelability and transferability are better when peeling the release liner on the other side from the adhesive sheet after irradiation with active energy rays. Furthermore, the ratio is, for example, 1000 or less, preferably 500 or less, and more preferably 300 or less. When the ratio is 1000 or less, the adhesion between the adhesive sheet and the adhered object is better and the transferability is better when peeling the release liner on the other side from the adhesive sheet after irradiation with active energy rays.

[0062] The elastic modulus G'(B1) at 20°C is preferably greater than 1×10⁻⁶. 3 Pa and is 5 × 10 8 Pa or less, more preferably 1×10 Pa 4 ~1×10 8 Pa, more preferably 1×10 5 ~7×10 7 When the elastic modulus G'(B1) at 20°C is within the above range, it has moderate hardness. When the release liner on the other side is peeled off after irradiation with active energy rays, the adhesive sheet has excellent transferability to the one of the adhered objects, and it is easy to peel off the release liner on the other side, resulting in even better transferability.

[0063] The adhesive sheet of the present invention has an elastic modulus G' (sometimes referred to as "elastic modulus G'(B2)") of 1 × 10⁻⁶ at 80°C after irradiation with active energy rays. 3 Pa or higher, preferably 1.5 × 10 Pa 3 Pa or higher, more preferably 2×10 Pa 3 Pa or higher. The elastic modulus G'(B2) at 80℃ after irradiation with active energy rays is 1×10⁻⁶. 3 When pressure and heat are applied before thermosetting at a pressure above Pa, the adhesive has sufficient hardness, resulting in low fluidity and reducing the likelihood of adhesive overflowing between components. The elastic modulus G'(B2) is, for example, 1 × 10⁻⁶. 6 Pa or less, preferably 1×10 5 Below Pa. The elastic modulus G'(B2) is 1×10. 6 When the pressure is below Pa, it exhibits excellent adhesion to the substrate before thermosetting.

[0064] The elastic modulus E' of the adhesive sheet of the present invention at 20°C after thermosetting is 1×10⁻⁶. 8 ~1×10 11 Pa, preferably 5 × 10 8 ~1×10 10Pa, more preferably 7 × 10 Pa 8 ~5×10 9 Pa. By ensuring that the elastic modulus E' at 20°C after thermosetting is within the above range, it exhibits moderate softness and excellent adhesion between the adhered materials.

[0065] The elastic modulus G' at 20°C and the elastic modulus G' at 80°C mentioned above are the elastic moduli of the adhesive sheet before heat curing, and the elastic modulus E' at 20°C mentioned above is the elastic modulus of the adhesive sheet after heat curing. The above elastic moduli can be determined by dynamic viscoelasticity (DMA) measurement, in the form of storage modulus at 20°C or 80°C.

[0066] It should be noted that, in this specification, "before irradiation by active energy rays" refers to the state in which the adhesive sheet has not been completely cured by active energy rays without irradiation, and refers to the state in which the adhesive sheet has the curability of active energy rays. That is, "before irradiation by active energy rays" can be of type A or type B. In addition, "before irradiation by active energy rays" is preferably the state before the above-mentioned adhesive sheet is attached to the first substrate. Furthermore, in this specification, "before heat curing" refers to the state in which the adhesive sheet has not undergone curing treatment, or has been partially cured in a manner that reduces the reaction rate to less than 50%. Specifically, for the reaction rate of the adhesive sheet, a differential scanning calorimeter (DSC) can be used to measure the heat release [J / g] of the adhesive sheet (object) and the material obtained by heating the object at a temperature capable of thermal curing (heated material) from 0°C to 300°C at a heating rate of 10°C / min. The heat release of the object from 0°C to 300°C is taken as "heat release of the object", and the heat release of the heated material from 0°C to 300°C is taken as "heat release after heating". The calculation is performed according to the following formula.

[0067] Reaction rate = Heat released after heating [J / g] ÷ Heat released by the target substance [J / g] × 100

[0068] The adhesive sheet described above has the property of curing by heat. Therefore, the adhesive sheet preferably contains a thermosetting resin.

[0069] The aforementioned thermosetting resin is a resin having thermosetting functional groups. Examples of such thermosetting resins include: epoxy resin, phenolic resin, amino resin, unsaturated polyester resin, polyurethane resin, silicone resin, thermosetting polyimide resin, melamine resin, alkyd resin, etc. Only one of the aforementioned thermosetting resins may be used, or two or more may be used.

[0070] Examples of epoxy resins mentioned above include: bisphenol-type epoxy resins, hydrogenated bisphenol-type epoxy resins, spirocyclic epoxy resins, naphthalene-type epoxy resins, biphenyl-type epoxy resins, fluorene-type epoxy resins, terpene-type epoxy resins, glycidyl ether-type epoxy resins, glycidyl amine-type epoxy resins, phenolic varnish-type epoxy resins, trihydroxyphenylmethane-type epoxy resins, tetraphenylol ethylene-type epoxy resins, hydantoin-type epoxy resins, and triglycidyl isocyanurate-type epoxy resins. Furthermore, the aforementioned epoxy resins can be modified epoxy resins such as urethane-modified epoxy resins and rubber-modified epoxy resins.

[0071] Examples of bisphenol-type epoxy resins include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, brominated bisphenol A type epoxy resin, and bisphenol AF type epoxy resin. Examples of glycidyl ether type epoxy resins include tris(glycidyloxyphenyl)methane and tetra(glycidyloxyphenyl)ethane. Examples of glycidylamine type epoxy resins include tetraglycidyldiaminodiphenylmethane. Examples of phenolic varnish type epoxy resins include cresol phenolic varnish type epoxy resin, phenolic varnish type epoxy resin, α-naphthol phenolic varnish type epoxy resin, brominated phenolic varnish type epoxy resin, and o-cresol phenolic varnish type epoxy resin. From the viewpoint of excellent processability, bisphenol-type epoxy resins are preferred, and bisphenol A type epoxy resins are more preferred.

[0072] As the aforementioned thermosetting resin, epoxy resin is preferred. The epoxy resin preferably comprises an epoxy resin with an epoxy equivalent of 200-800 g / eq, and more preferably further comprises a rubber-modified epoxy resin. It should be noted that in this specification, the epoxy resin with an epoxy equivalent of 200-800 g / eq is sometimes referred to as "epoxy resin (a)" and the rubber-modified epoxy resin as "rubber-modified epoxy resin (b)". If epoxy resin (a) is included, the crosslinking points in epoxy resin (a) have a suitable distance between each other, thus making it easier for the elastic modulus G' of the adhesive sheet at 20°C to reach the aforementioned range. Furthermore, if both epoxy resin (a) and rubber-modified epoxy resin (b) are included, the adhesive sheet containing epoxy resin (a) can be strengthened and toughened, thereby maintaining the sheet shape more stably. Only one type of epoxy resin (a) and rubber-modified epoxy resin (b) may be used, or two or more types may be used.

[0073] It should be noted that epoxy resin (a) and rubber-modified epoxy resin (b) are different resins. For example, epoxy resin (a) can be any epoxy resin other than rubber-modified epoxy resin, and the epoxy equivalent of rubber-modified epoxy resin (b) can be less than 200 g / eq or more than 800 g / eq.

[0074] (Epoxy Resin(a))

[0075] The epoxy equivalent of the epoxy resin (a) is 200-800 g / eq, preferably 200-500 g / eq, and more preferably 200-400 g / eq. If the epoxy equivalent is 200 g / eq or higher, the adhesive sheet has moderate hardness, making it easy to peel off the release liner and reducing the likelihood of adhesive spillage. If the epoxy equivalent is 800 g / eq or lower, the adhesive sheet has moderate flexibility, exhibiting excellent adhesion to the adhered object when one adhesive side of the adhesive sheet is bonded to it, and superior transfer properties when peeling off the release liner bonded to the other adhesive side.

[0076] The epoxy resin (a) can be a solid epoxy resin at room temperature, a liquid epoxy resin at room temperature, or a semi-solid epoxy resin at room temperature. From the viewpoint of easily obtaining an adhesive sheet with excellent transfer properties and less tendency to overflow, a semi-solid epoxy resin is preferred. It should be noted that "semi-solid" refers to a substance that is solid at 20°C and liquid at 40°C. Furthermore, from the viewpoint of easily obtaining an adhesive sheet with excellent transfer properties and less tendency to overflow, the softening point of the epoxy resin (a) is preferably 70°C or lower. Additionally, the epoxy resin (a) is preferably a semi-solid epoxy resin or an epoxy resin with a softening point of 70°C or lower.

[0077] Of the epoxy resins (a), bisphenol type epoxy resins are preferred from the viewpoint of excellent processability and ease of acquisition, and bisphenol A type epoxy resins are more preferred.

[0078] (Rubber-modified epoxy resin (b))

[0079] Rubber-modified epoxy resin (b) contains a rubber component in the epoxy resin. Examples of such rubber components include: butadiene rubber, acrylic rubber, silicone rubber, butyl rubber, isoprene rubber, styrene rubber, chloroprene rubber, NBR, SBR, IR, EPR, carboxyl-terminated butadiene-acrylonitrile copolymer rubber (CTBN), and styrene-butadiene elastomers. Only one or more of these rubber components may be used. From the viewpoint of more sufficiently strengthening the adhesive sheet, rubber-modified epoxy resin (b) is preferably CTBN-modified epoxy resin.

[0080] The above-mentioned resins can be cited as epoxy resins in rubber-modified epoxy resin (b). Among them, bisphenol type epoxy resin is preferred, and bisphenol A type epoxy resin is more preferred.

[0081] The epoxy equivalent of the rubber-modified epoxy resin (b) is preferably 1000~2000 g / eq, more preferably 1200~1800 g / eq. When the epoxy equivalent is within the above range, the elastic modulus G' of the adhesive sheet at 20°C easily reaches the above range. In addition, if the epoxy equivalent is 1000 g / eq or more, the adhesive sheet has moderate hardness, is easy to peel off when the release liner is peeled off, and is less prone to adhesive overflow.

[0082] Rubber-modified epoxy resins (b) can be commercially available. Examples of commercially available CTBN-modified bisphenol A type epoxy resins include: trade names "HyPoxRK84L", "HyPoxRK820", "HyPoxRA1340", "HyPoxRA16213", "HyPoxRA840", "HyPoxRA95" (all manufactured by HUNTSMAN), and "EPR-1630" (manufactured by ADEKA Co., Ltd.). Examples of commercially available CTBN-modified bisphenol F type epoxy resins include: trade names "HyPoxRF1320", "HyPoxRF1341", "HyPoxRF928", and "HyPoxRF933" (all manufactured by HUNTSMAN). Commercially available CTBN-modified glycol-type epoxy resins include: "HyPoxRM20" and "HyPoxRM22" (both manufactured by HUNTSMAN). Commercially available other rubber-modified epoxy resins (b) include: "TSR-960" (manufactured by DIC Corporation), "EPR-1415-1," "EPR-2000," and "EPR-2007" (all NBR-modified epoxy resins manufactured by ADEKA Corporation).

[0083] The mass ratio of epoxy resin (a) to rubber-modified epoxy resin (b) [former:replacement] is preferably 20:80 to 80:20, more preferably 30:70 to 70:30, and even more preferably 40:60 to 60:40. When the proportion of epoxy resin (a) is 20 or more, the transferability of the adhesive sheet is better. When the proportion of rubber-modified epoxy resin (b) is 20 or more, the peelability when peeling the release liner from one side of the adhesive sheet is better.

[0084] The content ratio of the thermosetting resin (especially epoxy resin) in the adhesive sheet relative to the total amount of the adhesive sheet (100% by mass) is preferably 60% by mass or more, more preferably 70% by mass or more. The above-mentioned content ratio is preferably 95% by mass or less, more preferably 90% by mass or less. Furthermore, the total content ratio of epoxy resin (a) and rubber-modified epoxy resin (b) is preferably within the above-mentioned range.

[0085] (Epoxy curing agent (c))

[0086] When the adhesive sheet contains epoxy resin (particularly epoxy resin (a) and rubber-modified epoxy resin (b)) as the thermosetting resin, the adhesive sheet preferably contains epoxy curing agent (c). Epoxy curing agent (c) promotes the polymerization of epoxy groups in the epoxy resin upon heating. Epoxy curing agent (c) may be used in only one form or in two or more forms.

[0087] As an epoxy curing agent (c), known or conventional curing agents that can be used for curing epoxy resins can be used, such as: urea compounds, amine compounds, acid anhydride compounds, amide compounds, hydrazide curing agents, imidazole curing agents, imidazoleline compounds, triphenylphosphine compounds, thermal alkali-generating agents, trihaloborane compounds, carboxylic acid compounds, phenolic resin compounds, polythiol curing agents, etc.

[0088] Examples of urea compounds include: 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU), N'-phenyl-N,N-dimethylurea, 1,1'-(methyl-1,3-phenylene)bis(3,3'-dimethylurea), 3-(4-chlorophenyl)-1,1-dimethylurea, N'-[3-[[[(dimethylamino)carbonyl]amino]methyl]-3,5,5-trimethylcyclohexyl]-N,N'-dimethylurea, and 3,3'-[methylenebis-(1,3-phenylene)]bis(1,1-dimethylurea).

[0089] Examples of amine compounds include ethylenediamine, propylenediamine, diethylenetriamine, triethylenetetramine, their amine adducts, m-phenylenediamine, diaminodiphenylmethane, and diaminodiphenyl sulfone.

[0090] Examples of acid anhydride compounds include: methyltetrahydrophthalic anhydride (4-methyltetrahydrophthalic anhydride, 3-methyltetrahydrophthalic anhydride, etc.), methylhexahydrophthalic anhydride (4-methylhexahydrophthalic anhydride, 3-methylhexahydrophthalic anhydride, etc.), dodecenylsuccinic anhydride, methylmethylenetetrahydrophthalic anhydride, phthalic anhydride, maleic anhydride, tetrahydrophthalic anhydride, and hexahydrophthalic anhydride. Dicarboxylic anhydride, methylcyclohexene dicarboxylic anhydride, pyromellitic anhydride, trimellitic anhydride, benzophenone tetracarboxylic anhydride, nadic anhydride, methyl nadic anhydride, hydrogenated methyl nadic anhydride, 4-(4-methyl-3-pentenyl)tetrahydrophthalic anhydride, succinic anhydride, adipic anhydride, sebacic anhydride, dodecanoic anhydride, methylcyclohexene tetracarboxylic anhydride, vinyl ether-maleic anhydride copolymer, alkylstyrene-maleic anhydride copolymer, etc.

[0091] Examples of amide compounds include dicyandiamide and polyamide.

[0092] Examples of acylhydrazides include adipic acid dihydrazides and other dihydrazides.

[0093] Examples of imidazole compounds include: 2-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-undecylimidazole, and 1-cyanoethyl-2-phenylimidazole. Trimethicone salts, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-triazine, 2,4-diamino-6-[2'-undecylimidazolyl-(1')]-ethyl-triazine, 2,4-diamino-6-[2'-ethyl-4'-methylimidazolyl-(1')]-ethyl-triazine, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-triazine isocyanuric acid adduct, 2-phenyl-4,5-dihydroxymethylimidazolium, 2-phenyl-4-methyl-5-hydroxymethylimidazolium, etc.

[0094] Examples of imidazoline compounds include: methylimidazoline, 2-ethyl-4-methylimidazoline, ethylimidazoline, isopropylimidazoline, 2,4-dimethylimidazoline, phenylimidazoline, undecylimidazoline, heptadecanylimidazoline, 2-phenyl-4-methylimidazoline, etc.

[0095] Examples of triphenylphosphine compounds include: triphenylphosphine, tributylphosphine, tris(p-methylphenyl)phosphine, tris(nonylphenyl)phosphine, diphenyltolylphosphine, tetraphenylphosphine bromide, methyltriphenylphosphine, methyltriphenylphosphine chloride, methoxymethyltriphenylphosphine, and benzyltriphenylphosphine chloride. Triphenylphosphine compounds also include those possessing both a triphenylphosphine structure and a triphenylborane structure. Examples of such compounds include: tetraphenylphosphine tetraphenylborate, tetraphenylphosphine tetrap-tolylborate, benzyltriphenylphosphine tetraphenylborate, and triphenylphosphine triphenylborane.

[0096] Examples of heat-generating alkali agents include: 1,8-diazabicyclo[5.4.0]undecene-7 (DBU) or its salts, 1,5-diazabicyclo[4.3.0]nonene-5 (DBN) or its salts.

[0097] Examples of trihaloborane compounds include trichloroborane.

[0098] The epoxy curing agent (c) is preferably a latent curing agent. Latent curing agents exert their curing agent function through the heat during heat curing; therefore, the adhesive sheets in their pre-cured state exhibit excellent storage stability, adhesion, and transferability. Furthermore, the epoxy curing agent (c) can be a microencapsulated curing agent.

[0099] As the epoxy curing agent (c), from the viewpoint that the adhesive strength of the bonded sheet becomes higher after heat curing, an amide compound is preferred, and dicyandiamide is more preferred. Furthermore, as the epoxy curing agent (c), it is preferable to include a urea compound and / or an imidazole compound. Further, it is particularly preferable to include a urea compound and / or an imidazole compound in addition to an amide compound. The urea compound and the imidazole compound (especially the urea compound) function as curing accelerators when the epoxy resin reacts with the amide compound, thus promoting the reaction rate.

[0100] The content of epoxy curing agent (c) in the above-mentioned adhesive sheet is preferably 0.5 to 30 parts by weight relative to 100 parts by weight of the total amount of epoxy resin (especially 100 parts by weight of epoxy resin (a) and rubber-modified epoxy resin (b)), more preferably 1 to 20 parts by weight, even more preferably 4 to 16 parts by weight, and particularly preferably 4.5 to 15 parts by weight. If the above content is within the above range, the adhesive strength of the adhesive sheet after heat curing becomes higher.

[0101] The content of amide compounds in the adhesive sheet is preferably 0.5 to 20 parts by mass relative to 100 parts by mass of the total epoxy resin (particularly 100 parts by mass of epoxy resin (a) and rubber-modified epoxy resin (b)), more preferably 1 to 15 parts by mass, and even more preferably 2 to 10 parts by mass. If the content is within the above range, the adhesive strength of the adhesive sheet after thermosetting becomes higher.

[0102] The content of urea compounds and / or imidazole compounds in the adhesive sheet is preferably 1 to 10 parts by weight relative to 100 parts by weight of the total epoxy resin (especially the total of 100 parts by weight of epoxy resin (a) and rubber-modified epoxy resin (b)), more preferably 1.5 to 8 parts by weight, and even more preferably 2 to 7 parts by weight. If the above content is within the above range, the adhesive strength of the adhesive sheet after thermosetting becomes higher.

[0103] (Multifunctional compound (d))

[0104] The adhesive sheet described above preferably contains a multifunctional compound (d) having two or more reactive double bonds within its molecule. One or more multifunctional compounds (d) may be used.

[0105] The multifunctional compound (d) is preferably a compound that is cured by active energy rays. That is, the reactive double bond preferably has an active energy ray polymerizable group. By including such a multifunctional compound (d), the adhesive sheet has active energy ray curability.

[0106] Examples of polymerizable groups for the aforementioned active energy rays include vinyl, propylene, isopropylene, (meth)acryloyl (acryloyl and / or methacryloyl), and (meth)acrylamido (acrylamido and / or methacrylamido). From the viewpoint of rapid reaction, (meth)acryloyl and (meth)acrylamido are preferred. It should be noted that in this specification, "(meth)acryloyl" refers to "acryloyl" or "methacryloyl," or both. The same applies to "(meth)acrylic acid."

[0107] Examples of multifunctional compounds (d) having the above-mentioned (meth)acryloyl group include: 1,6-hexanediol di(meth)acrylate, polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, pentaerythritol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate, and other multifunctional (meth)acrylates. The average molar number of ethylene glycol or propylene glycol added to polyethylene glycol di(meth)acrylate and polypropylene glycol di(meth)acrylate is not particularly limited, but is preferably 2 to 10, more preferably 2 to 6.

[0108] Examples of multifunctional compounds (d) having the above-mentioned (meth)acrylamide group include: methylene bis(meth)acrylamide, ethylene bis(meth)acrylamide, diallyl (meth)acrylamide, N-[tris(3-(meth)acrylamide propoxymethyl)methyl](meth)acrylamide, N,N-bis(2-(meth)acrylamide ethyl)(meth)acrylamide, 4,7,10-trioxo-1,13-tetanebis(meth)acrylamide, N,N'-1,2-ethanediylbis[N-(2-(meth)acrylamide ethyl)](meth)acrylamide, and other multifunctional (meth)acrylamides.

[0109] The number of reactive double bonds in the multifunctional compound (d) is 2 or more, preferably 2 to 6, more preferably 2 to 4, and even more preferably 2 to 3.

[0110] The multifunctional compound (d) is preferably a low molecular weight compound, and its molecular weight is not particularly limited, but is preferably 50 to 500. When the molecular weight is within the above range, the elastic modulus G' of the adhesive sheet after irradiation with active energy rays becomes appropriate, and the transferability is better.

[0111] The content of the multifunctional compound (d) in the adhesive sheet is preferably 0.1 to 12 parts by mass relative to 100 parts by mass of the total amount of epoxy resin (especially 100 parts by mass of epoxy resin (a) and rubber-modified epoxy resin (b)), more preferably 1 to 10 parts by mass. When the content is within the above range, the elastic modulus G' of the adhesive sheet after irradiation with active energy rays becomes moderate, and the transferability is better.

[0112] (Photopolymerization initiator(e))

[0113] The adhesive sheet described above may contain a photopolymerization initiator (e). When a photopolymerization initiator (e) is present, the curing of the adhesive sheet based on irradiation with active energy rays is promoted. Preferably, the photopolymerization initiator (e) is included together with a multifunctional compound (d). Only one photopolymerization initiator (e) may be used, or two or more may be used.

[0114] As for photopolymerization initiators (e), there are no particular limitations, but examples include: benzoin ether photopolymerization initiators, acetophenone photopolymerization initiators, α-keto alcohol photopolymerization initiators, aromatic sulfonyl chloride photopolymerization initiators, photoactive oxime photopolymerization initiators, benzoin photopolymerization initiators, benzoyl photopolymerization initiators, benzophenone photopolymerization initiators, ketal photopolymerization initiators, thioxanone photopolymerization initiators, etc. In addition, examples include: acylphosphine oxide photopolymerization initiators and titanocene photopolymerization initiators. Examples of benzoin ether photopolymerization initiators include: benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, benzoin isopropyl ether, benzoin isobutyl ether, 2,2-dimethoxy-1,2-diphenylethane-1-one, and anisole methyl ether, etc. Examples of acetophenone-based photopolymerization initiators include: 2,2-diethoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 1-hydroxycyclohexylphenyl ketone, 4-phenoxydichloroacetophenone, and 4-(tert-butyl)dichloroacetophenone. Examples of α-keto-alcohol-based photopolymerization initiators include: 2-methyl-2-hydroxyphenylacetone and 1-[4-(2-hydroxyethyl)phenyl]-2-methylpropane-1-one. Examples of aromatic sulfonyl chloride-based photopolymerization initiators include: 2-naphthalenesulfonyl chloride. Examples of photoactive oxime-based photopolymerization initiators include: 1-phenyl-1,1-propanedione-2-(O-ethoxycarbonyl)-oxime. Examples of benzoin-based photopolymerization initiators include: benzoin. Examples of benzoinyl-based photopolymerization initiators include: benzoinyl. Examples of benzophenone-based photopolymerization initiators include: benzophenone, benzoylbenzoic acid, 3,3'-dimethyl-4-methoxybenzophenone, polyvinylbenzophenone, and α-hydroxycyclohexylphenyl ketone. Examples of ketal-based photopolymerization initiators include: benzoin dimethyl ether. Examples of thioxanthone-based photopolymerization initiators include: thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone, 2,4-diisopropylthioxanthone, and dodecylthioxanthone. Examples of phosphine oxide-based photopolymerization initiators include: 2,4,6-trimethylbenzoyl-diphenylphosphine oxide and bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide. Examples of the above-mentioned titanium ceramsite photopolymerization initiators include bis(η5-2,4-cyclopentadien-1-yl)-bis(2,6-difluoro-3-(1H-pyrrole-1-yl)-phenyl)titanium.

[0115] The content of the photopolymerization initiator (e) in the above-mentioned adhesive sheet is preferably 0.1 to 10 parts by mass relative to 100 parts by mass of the total amount of epoxy resin (especially 100 parts by mass of epoxy resin (a) and rubber-modified epoxy resin (b)), more preferably 0.5 to 5 parts by mass. When the above content is within the above range, the curing of the adhesive sheet under irradiation with active energy rays is moderately promoted.

[0116] (filler)

[0117] The aforementioned adhesive sheet preferably contains filler. If filler is included, it is easier to achieve the aforementioned ranges for the elastic modulus G'(A2) and elastic modulus G'(B2) of the adhesive sheet. Only one type of filler may be used, or two or more types may be used. Inorganic fillers and organic fillers are examples of fillers.

[0118] Examples of materials that can be used as constituent materials of the aforementioned inorganic fillers include: aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, calcium silicate, magnesium silicate, calcium oxide, magnesium oxide, aluminum oxide, aluminum nitride, aluminum borate whiskers, boron nitride, and silicon dioxide (crystalline silicon dioxide, amorphous silicon dioxide, etc.). Additionally, other materials that can be used as constituent materials of the aforementioned inorganic fillers include: elemental metals such as aluminum, gold, silver, copper, and nickel, alloys, amorphous carbon black, and graphite.

[0119] In addition to the aforementioned constituent materials, other inorganic fillers that can be used as fillers include: mica, talc, kaolin, wollastonite, feldspar, diorite, chlorite, bentonite, montmorillonite, dolomite, quartz, cubic quartz, hollow ceramic beads, hollow glass beads, and glass beads.

[0120] Examples of materials that can be used as constituent materials of the aforementioned organic fillers include: polymethyl methacrylate (PMMA), polyimide, polyamide-imide, polyether ether ketone, polyether-imide, polyester-imide, etc.

[0121] The shape of the filler is not particularly limited and can be various shapes such as spherical, sheet-like (scale-like), dendritic, fibrous, irregular (polyhedral).

[0122] As the filler mentioned above, inorganic filler is preferred, and silica filler is more preferred.

[0123] Silica fillers can also undergo surface treatments such as hydrophobication. Examples of hydrophobication agents include: methyltrichlorosilane, dimethyldichlorosilane, trimethylchlorosilane, hexamethyldisilazane, methyltrialkoxysilane, dimethyldialkoxysilane, trimethylalkoxysilane, ethyltrichlorosilane, propyltrichlorosilane, hexyltrichlorosilane, long-chain alkyltrichlorosilane, ethyltrialkoxysilane, propyltrialkoxysilane, hexyltrialkoxysilane, long-chain alkyltrialkoxysilane, methacryloxysilane, fluoroalkylsilane, perfluoroalkylsilane, and other organosilicon compounds; dimethylpolysiloxane (silicone oil), methylphenylpolysiloxane, methylhydropolysiloxane, amino-modified organosilicon, and other organosilicon compounds.

[0124] The average particle size of the filler is preferably 50 nm or less, more preferably 40 nm or less. When the average particle size is 50 nm or less, adhesive overflow is less likely to occur. The average particle size of the filler is preferably 7 nm or more, more preferably 10 nm or more. When the average particle size is 7 nm or more, the bulk density is high and the processability is excellent. It should be noted that the average particle size of the inorganic filler can be determined, for example, using a photometric particle size analyzer (e.g., trade name "LA-910", manufactured by Horiba Manufacturing Co., Ltd.).

[0125] The specific surface area of ​​the above-mentioned filler is preferably 30 m². 2 / g or more, preferably 100m 2 / g or more. The above specific surface area is 30m². 2 When the density is above a certain level (g), adhesive overflow is less likely to occur. From the viewpoint of selecting particles with high bulk density and excellent processability, the specific surface area of ​​the above-mentioned filler is preferably 500 m². 2 / g or less, preferably 350m 2 / g or less.

[0126] The specific surface area of ​​the filler per 100g of the above-mentioned adhesive sheet is preferably 600~6000m². 2 More preferably 800~5000m 2 The specific surface area mentioned above is 600 m². 2 At the above levels, adhesive overflow is less likely to occur. The specific surface area is 6000 m². 2 In the following cases, it exhibits excellent conformability to the unevenness of the adhered object and excellent shear adhesion.

[0127] The filler content in the aforementioned adhesive sheet is preferably 0.5 to 20 parts by mass relative to 100 parts by mass of the total epoxy resin (particularly 100 parts by mass of epoxy resin (a) and rubber-modified epoxy resin (b)), more preferably 1 to 10 parts by mass, and even more preferably 2 to 8 parts by mass. When the content is 0.5 parts by mass or more, the elastic modulus G'(A2) and elastic modulus G'(B2) of the adhesive sheet can be improved, and the overflow of the adhesive can be further suppressed. When the content is 20 parts by mass or less, the transferability of the adhesive sheet is even better.

[0128] The adhesive sheet described above may also contain a colorant. The colorant may be a pigment or a dye. Examples of colorants include black, cyan, magenta, and yellow colorants. The adhesive sheet may contain only one type of colorant or more. The proportion of the colorant in the adhesive sheet relative to the total amount (100% by mass) of the adhesive sheet is preferably 0.05 to 5% by mass, more preferably 0.1 to 2% by mass.

[0129] Without impairing the effects of the present invention, the adhesive sheet may also contain other components besides those described above. Examples of such other components include: other curing accelerators, thermoplastic resins, tackifying resins (rosin derivatives, polyterpene resins, petroleum resins, oil-soluble phenols, etc.), anti-aging agents, antioxidants, plasticizers, softeners, surfactants, antistatic agents, surface lubricants, leveling agents, light stabilizers, ultraviolet absorbers, polymerization inhibitors, flame retardants, silane coupling agents, ion scavengers, foils, etc. Only one of the above-mentioned components may be used, or two or more may be used.

[0130] The thickness of the adhesive sheet is not particularly limited, but is preferably 10-1000 μm, more preferably 30-750 μm, and even more preferably 50-500 μm. When the thickness is 10 μm or more, the adhesion is better when the adhesive sheet is used to bond components together.

[0131] For the aforementioned adhesive sheet, two pieces of AL alloy A5052, polished with 100-grit sandpaper, are used. One adhesive surface is adhered to the polished surface of one AL alloy A5052 piece, and then subjected to active energy X-ray irradiation. The other adhesive surface is then adhered to the polished surface of the other AL alloy A5052 piece. The two adhesive surfaces are held together by the two AL alloy A5052 pieces and then thermo-cured. The shear bond strength, measured at a tensile speed of 1.3 mm / min and a peel angle of 0°, is preferably 5 MPa or more, more preferably 7 MPa or more, more preferably 10 MPa or more, and even more preferably 15 MPa. When the shear bond strength is 1 MPa or more, the adhesion between the components is excellent. It should be noted that the active energy X-ray irradiation only needs to be performed on at least a portion of the adhesive sheet; preferably, the shear bond strength after irradiating the entire surface of the adhesive sheet is within the aforementioned range. It should be noted that, generally, the shear bonding force after irradiating a portion of the adhesive sheet with active energy rays is higher than the shear bonding force after irradiating the entire surface of the adhesive sheet with active energy rays.

[0132] The adhesive sheet of the present invention is preferably used for bonding components to each other. The adhesive sheet exhibits excellent adhesion to metals, therefore, it is preferably used for bonding metal components. Furthermore, it is preferably used for bonding metal components to each other. Additionally, the adhesive sheet of the present invention also exhibits excellent adhesion between components made of different materials. Therefore, the adhesive sheet of the present invention is also preferably used for bonding metal components to fiber-reinforced resin components. As the reinforcing fiber, known or commonly used reinforcing fibers can be cited, including: carbon fiber, glass fiber, aramid fiber, boron fiber, graphite fiber, silicon carbide fiber, high-strength polyethylene fiber, tungsten carbide fiber, and poly(p-phenylene benzo[a]ethylene]ethylene. PBO fiber, etc.

[0133] For the aforementioned adhesive sheet, a release liner (septum) can be adhered to the surface (adhesive surface) of the adhesive sheet until use. It should be noted that each adhesive surface on both sides of the adhesive sheet can be protected by two separate release liners, or by a single release liner with both sides serving as release surfaces, wound into a roll (wound). The release liner can be used as a protective material for the adhesive sheet and is peeled off when attached to the adhered object. It should be noted that the release liner is not always necessary.

[0134] As the release liner mentioned above, conventional release paper or the like can be used, without particular limitation. Examples include: substrates with a release treatment layer, low-adhesion substrates formed of fluoropolymers, and low-adhesion substrates formed of non-polar polymers. Examples of substrates with a release treatment layer include: plastic films and papers that have undergone surface treatment with release agents such as silicones, long-chain alkyl groups, fluorine compounds, and molybdenum sulfide. Examples of fluoropolymers among the low-adhesion substrates formed of fluoropolymers include: polytetrafluoroethylene, polychlorotrifluoroethylene, polyvinylidene fluoride, polyvinylidene fluoride, tetrafluoroethylene-hexafluoropropylene copolymer, and chlorofluoroethylene-vinylidene fluoride copolymer. Examples of non-polar polymers include: olefin resins (e.g., polyethylene, polypropylene). It should be noted that the release liner can be formed by known or conventional methods. Furthermore, the thickness of the release liner is not particularly limited.

[0135] The aforementioned adhesive sheet can be manufactured, for example, by applying (coating) an adhesive composition for forming the adhesive sheet onto a release liner, and drying the resulting adhesive composition layer as needed to allow it to solidify. The aforementioned adhesive composition can be, for example, made by mixing various of the aforementioned components, such as epoxy resin (a), rubber-modified epoxy resin (b), epoxy curing agent (C), multifunctional compound (d), photopolymerization initiator (e), and the aforementioned filler. Alternatively, it can be made by dissolving / dispersing the aforementioned components in a solvent such as an organic solvent and mixing them.

[0136] The adhesive sheet described above can be used, for example, as follows: First, the release liner is peeled off from one adhesive side of the adhesive sheet, so that the exposed adhesive side is adhered and sealed to an object to be adhered. Next, at least a portion of the adhesive sheet is cured by irradiation with active energy rays, and then the release liner is peeled off from the other adhesive side. Then, another object to be adhered is attached to the exposed adhesive side, and the adhesive sheet is heated to thermally cure it. In this way, the adhesive sheet described above can be used to bond objects to each other.

[0137] Therefore, regarding the adhesive sheet of the present invention, when the adhesive surface of one side of the adhesive sheet is adhered to a component and irradiated with active energy rays, and then the release liner adhered to the other adhesive surface is peeled off, the adhesive sheet exhibits excellent transferability. The adhesive sheet will not peel off from the adhered component along with the release liner, and the release liner can be easily peeled off from the adhesive surface of the adhesive sheet. Furthermore, after the adhesive sheet of the present invention is adhered to the substrate, it is heated to cure the adhesive sheet, thereby achieving a strong bond with the component. When components that are substrates are adhered to each other via the adhesive sheet, or when the adhesive sheet is heated to cure, the adhesive in the adhesive sheet is less likely to leak out between the components due to pressure or heat.

[0138] [Manufacturing method of laminated bodies]

[0139] According to the manufacturing method of the laminate of the present invention, a laminate formed by bonding a first adherend and a second adherend via an adhesive sheet can be manufactured. The manufacturing method includes at least the following steps: irradiating the adhesive sheet (curable adhesive sheet) bonded to the first adherend with active energy rays to cure it (active energy ray irradiation step); bonding the second adherend to the adhesive sheet (second bonding step); and heating the adhesive sheet to thermally cure it (thermal curing step). It should be noted that in the manufacturing method of the present invention, each step can be performed by the same person or by different persons.

[0140] The above-described manufacturing method may include, prior to the active energy ray irradiation step, a step of attaching the first adherend to the adhesive surface of one side of the cured adhesive sheet, which serves as a double-sided adhesive sheet (first attachment step). Alternatively, the above-described manufacturing method may replace the active energy ray irradiation step by including a step of irradiating a portion of the adhesive sheet in the surface direction with active energy rays to cure it, and then attaching the adhesive sheet to the first adherend (active energy ray irradiation / first attachment step).

[0141] The aforementioned curable adhesive sheet exhibits both active energy radiation curing and thermosetting properties. The adhesive sheet of the present invention can be used as the aforementioned curable adhesive sheet.

[0142] Figure 2 and Figure 3 The process of manufacturing a laminate according to one embodiment of the present invention is shown. Hereinafter, along with... Figure 2 and Figure 3 The flowchart shown illustrates the manufacturing method of the present invention. It should be noted that... Figure 2 and Figure 3 The use of Figure 1 The adhesive sheet shown is an example of a curable adhesive sheet.

[0143] Figure 2 This diagram illustrates the process involving the aforementioned active energy ray irradiation step. First, as... Figure 2 As shown in (a), the release liner 2 on one side is peeled off from the adhesive sheet 1. Then, as... Figure 2As shown in (b), the exposed adhesive surface 1a is attached to the first substrate 4 (first attachment step). Next, with the release liner 3 attached to the adhesive surface 1b and oxygen isolated, a portion of the adhesive sheet 1 in the surface direction is irradiated with active energy rays L to form a cured portion 11 (active energy ray irradiation step). By irradiating a portion of the uncured portion 12 that has not been irradiated with active energy rays L in the surface direction, a cured portion 11 that has been cured by active energy ray irradiation and an uncured portion 12 that has not been cured by active energy ray irradiation are formed. Therefore, after heat curing, the adhesive sheet has high adhesion to the substrate, and the substrate and adhesive sheet are not easily peeled off in the resulting laminate.

[0144] Figure 3 This diagram illustrates a process in which the above-mentioned active energy ray irradiation / first attachment step is replaced by the above-mentioned active energy ray irradiation step. Firstly, as... Figure 3 As shown in (a), in a state where the adhesive sheet 1 is held between two release liner sheets 2 and 3 and isolated from oxygen, a portion of the adhesive sheet 1 is irradiated with an active energy ray L in the face direction to form a cured portion 11. By irradiating a portion in the face direction with an active energy ray, a cured portion 11 that has been cured by the active energy ray irradiation and a non-cured portion 12 that has not been cured by the active energy ray irradiation are formed. Therefore, after heat curing, the adhesive sheet has high adhesion to the adhered object, and the adhered object is not easily peeled off from the adhesive sheet in the resulting laminate. Furthermore, as Figure 3 As shown in (b), peel the release liner 2 from the adhesive sheet 1 on one side. Then, as... Figure 3 As shown in (c), the exposed adhesive surface 1a is attached to the first adherend 4 (active energy ray irradiation / first attachment process).

[0145] exist Figure 2 (c) and Figure 3 In (a), the adhesive sheet 1 after being irradiated with active energy ray L has the following region (A) and the following region (B).

[0146] Region (A): The elastic modulus G'(A1) at 20℃ is 1×10⁻⁶. 3 ~5×10 6 The elastic modulus G'(A2) at Pa and 80℃ is 1×10 4 Areas below Pa

[0147] Region (B): The elastic modulus G'(B1) at 20℃ is greater than the above elastic modulus G'(A1), and the elastic modulus G'(B2) at 80℃ is 1×10⁻⁶. 3 Areas above Pa

[0148] Before irradiation by the active energy ray L, the entire surface of the adhesive sheet 1 in the surface direction corresponds to the aforementioned region (A) of the uncured portion 12; the cured portion 11 formed by irradiation by the active energy ray L corresponds to the aforementioned region (B). Therefore, Figure 2 (c) and Figure 3 (a) shows adhesive sheet 1, which is the adhesive sheet X mentioned above.

[0149] The portion in the aforementioned surface direction is preferably one end in the surface direction (especially the outer peripheral edge). That is, the cured portion 11 (region (B)) is preferably located at one end in the surface direction of the adhesive sheet 1 (especially the outer peripheral edge). By irradiating the end in the surface direction (especially the outer peripheral edge) with active energy rays, during heat curing, it is less likely for the adhesive to overflow from the end that is the cured portion, and since the other areas are non-cured portions, the adhesion to the adhered object is excellent. The width of the aforementioned outer peripheral edge from the outer periphery is not particularly limited, for example, it is 0.5 to 10 mm. Figure 2 (c) shows an example where the cured portion 11 is formed by irradiating only the outer peripheral edge with active energy rays. The uncured portion 12 is the area that was not irradiated with active energy rays.

[0150] It should be noted that, Figure 2 (c) and Figure 3 The irradiation by the active energy rays in (a) is performed on at least a portion of the surface of the cured adhesive sheet, but it can also be performed on the entire surface. Although the cured portion 11 has poorer adhesion to the adhered object than the uncured portion 12, the transferability when peeling off the release liner 3 can be sufficiently ensured by having the above-mentioned elastic modulus G'(B1).

[0151] Examples of such active energy rays include alpha rays, beta rays, gamma rays, neutron rays, electron beams and other ionizing radiation, as well as ultraviolet rays and ultraviolet lasers.

[0152] Next, as Figure 2 (d) and Figure 3 As shown in (d), the release liner 3 is peeled off to expose the adhesive surface 1b. At this time, by peeling the release liner 3 from the cured portion 11, the release liner 3 can be peeled off relatively easily even in the uncured portion 12, and the uncured portion 12 is fully adhered to the first adhered object 4, thus resulting in excellent transferability.

[0153] Next, as Figure 2 (e) and Figure 3 As shown in (e), the second adherend 5 is bonded to the exposed adhesive surface 1b of the adhesive sheet 1 (second bonding step). At this time, the adhesion between the non-cured portion 12 and the second adherend 5 is excellent. Furthermore, as... Figure 2 (f) and Figure 3As shown in (f), the adhesive sheet 1 is heated to thermally cure it, forming adhesive sheet 1' (thermal curing process). In the thermal curing process, the cured portion 11 is cured by irradiation with active energy rays, making it less likely for adhesive to overflow from the cured portion 11 side. On the other hand, although adhesive may overflow from the non-cured portion 12 side of the adhesive sheet 1, for example, if the shape of the adhesive sheet 1 is annular and the cured portion 11 is on the outer periphery and the non-cured portion 12 side is on the inner periphery, even if adhesive overflow occurs from the non-cured portion 12 side, it will not be noticeable in appearance, so there is no problem.

[0154] The first and second adherends are not particularly limited, and suitable materials to be bonded can be selected. Since the adhesive sheet exhibits excellent adhesion to metals, it is preferable that at least one of the first and second adherends is a metal component. Furthermore, since the adhesive sheet also exhibits excellent adhesion to components made of different materials, the combination of the first and second adherends is preferably a combination of metal components, or a combination of a metal component and a fiber-reinforced resin component.

[0155] Example

[0156] The present invention will be described in more detail below with reference to embodiments, but the present invention is not limited to these embodiments in any way. It should be noted that the composition of each component constituting the adhesive sheet in the embodiments and comparative examples is shown in the table. In the table, the units of each value representing the composition of the adhesive sheet are relative "parts by mass" within the adhesive sheet.

[0157] Example 1

[0158] (Making of adhesive sheets)

[0159] 3.5 parts by weight of silica filler (trade name "Aerosil RY-200", manufactured by Nippon Aerosil Co., Ltd.) were added to 50 parts by weight of bisphenol A type epoxy resin (trade name "jER-834", manufactured by Mitsubishi Chemical Co., Ltd.) that had been heated at 60°C for 1 hour. The mixture was stirred at 2000 rpm for 3 minutes using a planetary stirrer (trade name "Awatori Rintaro", manufactured by TIHNKY Co., Ltd.) to obtain a silica filler dispersion. 53.5 parts by weight of silica filler dispersion, 50 parts by weight of rubber-modified epoxy resin (trade name "HyPoxRK84L", manufactured by HUNTSMAN), 3.5 parts by weight of polyethylene glycol diacrylate (n=4) (manufactured by Tokyo Chemical Industry Co., Ltd.), 0.5 parts by weight of 1-hydroxycyclohexylphenyl ketone (trade name "Omnirad 184", manufactured by IGM Resins) and 0.5 parts by weight of 2,2-dimethoxy-2-phenylacetophenone (trade name "Omnirad 651", manufactured by IGM Resins) were added to a small mixer (trade name "Xplore", manufactured by DSM) and mixed at 80°C for 15 minutes. In addition, 3.8 parts by weight of a dicyandiamide curing agent (trade name "Omicure DDA-50", manufactured by HUNTSMAN) and 5 parts by weight of 1,1'-(4-methyl-1,3-phenylene)bis(3,3'-dimethylurea) (trade name "Omicure U-24M", manufactured by HUNTSMAN) were added and mixed at 80°C for 5 minutes to obtain the compound.

[0160] Next, the above-mentioned compound was sandwiched between two PET release liners with a thickness of 75 μm that had undergone release treatment, and pressure was applied at 60°C for 1 minute to achieve a thickness of 0.1 mm, thus producing an adhesive sheet.

[0161] (Determination of elastic modulus G' before ultraviolet irradiation)

[0162] The double-sided release liner was peeled off from the prepared adhesive sheet, and the layers were stacked until the thickness reached more than 1 mm. Test pieces were then cut out at a diameter of 8 mm. Dynamic viscoelasticity was measured using a rheometer (trade name "ARES G2", manufactured by TA Instruments) at a frequency of 1 Hz, a heating rate of 5 °C / min, and a measurement temperature range of 0–100 °C. Measurements were stopped even at temperatures below 100 °C if the elastic modulus reached below 1 kPa. Furthermore, the temperature at which the elastic modulus reached below 1 kPa was below 80 °C, and the elastic modulus at 80 °C was recorded as below 1 kPa. The elastic modulus G' at 20 °C and 80 °C before UV irradiation was measured as described above.

[0163] (Determination of elastic modulus G' after ultraviolet irradiation)

[0164] The manufactured adhesive sheet, while held between two peel-off sheets, was subjected to ultraviolet irradiation using a device (trade name "FL15BL", manufactured by Toshiba Corporation) at 1500 mJ / m². 2 The adhesive sheet was subjected to ultraviolet irradiation under the same conditions. For the ultraviolet-irradiated adhesive sheet obtained in this manner, the elastic modulus G' after ultraviolet irradiation was measured at 20°C and 80°C, in the same manner as before ultraviolet irradiation.

[0165] (Evaluation of transferability)

[0166] The prepared adhesive sheet was cut into pieces 10mm wide and 50mm long. SUS304BA, cleaned with ethyl acetate, was used as the substrate. The release liner on one side of the cut adhesive sheet was peeled off, and the adhesive surface was attached to the substrate. Then, an ultraviolet irradiation device (trade name "FL15BL", manufactured by Toshiba Corporation) was used at 1500mJ / m². 2 The adhesive sheet was subjected to ultraviolet irradiation under certain conditions. After standing at room temperature for 5 minutes, when the release liner on the other side was peeled off, the situation where adhesive residue remained on the adhered object was evaluated as "○", and the situation where adhesive residue remained on the release liner on the other side or on both the adhered object and the release liner on the other side was evaluated as "×".

[0167] (Evaluation of glue overflow)

[0168] The prepared adhesive sheet, while held between two release liner sheets, was subjected to ultraviolet irradiation at 1500 mJ / m² using a device (trade name "FL15BL", manufactured by Toshiba Corporation). 2 The adhesive sheet was subjected to ultraviolet irradiation under specific conditions. Next, an 8.0 mm diameter adhesive sheet was cut, and the release liner on one side was peeled off. The exposed adhesive side was then attached to a glass slide (trade name "S1225", manufactured by Matsunami Glass Industry Co., Ltd.). Then, the release liner on the other side was peeled off, and the exposed adhesive side was attached to another glass slide. The two slides were heated in an oven at 100°C for 1 hour while being pressed against each other with a force of 6 kPa. After natural cooling, the adhesive sheet was observed through the glass slide. Adhesive sheets with a diameter of 8.5 mm or less were rated as "○", and those with a diameter greater than 8.5 mm were rated as "×".

[0169] (Determination of elastic modulus E')

[0170] The prepared adhesive sheet, while held between two release liner sheets, was subjected to ultraviolet irradiation at 1500 mJ / m² using a device (trade name "FL15BL", manufactured by Toshiba Corporation).2 The adhesive sheet was subjected to ultraviolet irradiation under certain conditions, followed by heating in an oven at 100°C for 1 hour to cure. After curing, the adhesive sheet was cut into 5mm wide and 50mm long pieces, and the release liner on both sides was removed. Next, the dynamic viscoelasticity was measured using a rheometer (trade name "RSA G2", manufactured by TA Instruments) at a frequency of 1Hz, a heating rate of 5°C / min, and a measurement temperature range of -50 to 150°C. The elastic modulus E' at 80°C after thermosetting was measured as described above.

[0171] Examples 2-7, Comparative Examples 1-2

[0172] The types and proportions of various raw materials used in the preparation of the adhesive composition were changed as shown in Table 1. Otherwise, an adhesive sheet was prepared in the same manner as in Example 1. Furthermore, the elastic modulus G' before and after ultraviolet irradiation, the transferability, the excess adhesive, and the elastic modulus E' after thermosetting were measured on the obtained adhesive sheet in the same manner as in Example 1.

[0173] The evaluation results for each evaluation are shown in Table 1.

[0174]

[0175] Examples 8-9, Comparative Examples 3-4

[0176] (Making of adhesive sheets)

[0177] The types and amounts of various raw materials used in the preparation of the adhesive composition were changed as shown in Table 2. Otherwise, the adhesive sheet was prepared in the same manner as in Example 1.

[0178] (Determination of elastic modulus G' before electron beam irradiation)

[0179] For the above-mentioned adhesive sheet, the elastic modulus G' at 20°C and 80°C before ultraviolet irradiation was measured in the same manner as in Example 1.

[0180] (Determination of elastic modulus G' after electron beam irradiation)

[0181] For the aforementioned adhesive sheet, electron beam irradiation was performed at 100 kGy using an electron beam device (trade name "EC300", manufactured by ESI) instead of ultraviolet irradiation. Otherwise, the elastic modulus G' at 20°C and 80°C after electron beam irradiation was measured in the same manner as in Example 1.

[0182] (Evaluation of transferability)

[0183] Electron beam irradiation was performed at 100 kGy using an electron beam device (trade name "EC300", manufactured by ESI) instead of ultraviolet irradiation. Otherwise, the transferability was evaluated in the same manner as in Example 1.

[0184] (Evaluation of glue overflow)

[0185] The adhesive sheet was subjected to electron beam irradiation at 100 kGy using an electron beam device (trade name "EC300", manufactured by ESI) instead of ultraviolet irradiation. Otherwise, the excess adhesive was evaluated in the same manner as in Example 1.

[0186] (Determination of elastic modulus E')

[0187] For the above-mentioned adhesive sheet, electron beam irradiation was performed at 100 kGy using an electron beam device (trade name "EC300", manufactured by ESI) instead of ultraviolet irradiation. Otherwise, the elastic modulus E' after thermosetting at 80°C was measured in the same manner as in Example 1.

[0188] The evaluation results for each evaluation are shown in Table 2.

[0189]

[0190] Example 10, Comparative Examples 5-6

[0191] (Making of adhesive sheets)

[0192] The types and amounts of various raw materials used in the preparation of the adhesive composition were changed as shown in Table 3. Otherwise, the adhesive sheet was prepared in the same manner as in Example 1.

[0193] (Determination of elastic modulus G' before UV laser irradiation)

[0194] For the above-mentioned adhesive sheet, the elastic modulus G' at 20°C and 80°C before UV laser irradiation was measured in the same manner as in Example 1.

[0195] (Determination of elastic modulus G' after UV laser irradiation)

[0196] For the aforementioned bonded sheet, a 355nm UV pulsed laser irradiation device was used instead of ultraviolet irradiation at 40kHz to achieve a 6900mJ / cm² intensity. 2 The elastic modulus G' of UV laser irradiation was measured at 20°C and 80°C, in the same manner as in Example 1.

[0197] (Evaluation of transferability)

[0198] A 355nm UV pulsed laser irradiation device was used instead of ultraviolet irradiation at 40kHz to achieve 6900mJ / cm². 2 The transferability was evaluated in the same manner as in Example 1, except that it was subjected to UV laser irradiation.

[0199] (Evaluation of glue overflow)

[0200] For the aforementioned bonded sheet, a 355nm UV pulsed laser irradiation device was used instead of ultraviolet irradiation at 40kHz to achieve a 6900mJ / cm² intensity. 2 The product was subjected to UV laser irradiation, and the overflow of adhesive was evaluated in the same manner as in Example 1.

[0201] (Determination of elastic modulus E')

[0202] For the aforementioned bonded sheet, a 355nm UV pulsed laser irradiation device was used instead of ultraviolet irradiation at 40kHz to achieve a 6900mJ / cm² intensity. 2 The product was subjected to UV laser irradiation, and the elastic modulus E' at 80°C after thermosetting was measured in the same manner as in Example 1.

[0203] The evaluation results for each evaluation are shown in Table 3.

[0204]

[0205] As shown in Tables 1-3, the adhesive sheets of the present invention exhibit excellent transferability after irradiation with active energy rays, and no adhesive overflow occurs during thermosetting. On the other hand, when the elastic modulus G' at 20°C after irradiation with active energy rays is lower than the elastic modulus G' at 20°C before irradiation with active energy rays, the transferability after irradiation with active energy rays is poor (Comparative Examples 2, 4, and 6). Furthermore, when the elastic modulus G' at 80°C after irradiation with active energy rays is less than 1 × 10⁻⁶, the transferability is poor. 3 In the case of Pa, adhesive overflow occurred during heat curing (Comparative Examples 1, 3, and 5).

[0206] Examples 11-13

[0207] (Evaluation of transferability)

[0208] For the adhesive sheets of Examples 1-3, test sheets with a width of 10 mm and a length of 50 mm were cut out. SUS304BA, cleaned with ethyl acetate, was used as the substrate. The release liner on one side of the cut adhesive sheet was peeled off, and the adhesive surface was attached to the substrate. Then, only a 1 mm wide annular portion from the outer periphery of the test sheet was subjected to ultraviolet irradiation, otherwise, ultraviolet irradiation was performed in the same manner as in Examples 1-3. After standing at room temperature for 5 minutes, when the release liner on the other side was peeled off, the situation where adhesive residue remained on the substrate was evaluated as "○", and the situation where residue remained on the release liner on the other side or on both the substrate and the release liner on the other side was evaluated as "×". It should be noted that the situation where the entire surface of the test sheet was ultraviolet irradiated as in Examples 1-3 was defined as "overall irradiation", and the situation where only the annular portion of the outer periphery of the test sheet was ultraviolet irradiated was defined as "partial irradiation". The transferability evaluation results of "overall irradiation" are the results of Examples 1-3.

[0209] (Evaluation of glue overflow)

[0210] The prepared adhesive sheet, held between two release liner sheets, was subjected to ultraviolet irradiation at 1500 mJ / m² using a UV irradiation device (trade name "FL15BL", manufactured by Toshiba Corporation). 2 Under the specified conditions, only a 1mm wide annular portion of the adhesive sheet was subjected to ultraviolet irradiation. Next, an 8.0mm section was cut from the adhesive sheet, and the release liner on one side was peeled off, exposing the adhesive side to a glass slide (trade name "S1225", manufactured by Matsunami Glass Industry Co., Ltd.). Then, the release liner on the other side was peeled off, exposing the adhesive side to another glass slide. The two glass slides were heated in an oven at 100°C for 1 hour while being pressed with a force of 6 kPa. After natural cooling, the adhesive sheet was observed through the glass slide; if no adhesive overflow was observed from the ultraviolet-irradiated periphery, it was rated as "○". It should be noted that the evaluation results for "overall irradiation" are the results of Examples 1-3.

[0211] (Shear adhesion)

[0212] The basic operation was carried out based on JIS K6850:1999. Specifically, firstly, an AL alloy A5052 with a width of 25mm × length of 100mm × thickness of 1.6mm was ground three times each at 45° and 135° relative to the length direction using 100-grit sandpaper. The ground surface was cleaned with ethyl acetate and air-dried for 30 minutes to obtain the substrate. On the other hand, the adhesive sheet prepared in Examples 1-3 was cut into pieces with a width of 25mm × length of 12.5mm. The release liner on one side of the cut adhesive sheet was peeled off, and the adhesive surface was attached to the substrate. Next, an ultraviolet irradiation device (trade name "FL15BL", manufactured by Toshiba Corporation) was used at 1500mJ / m 2 Under the conditions described above, the entire surface of the adhesive sheet, or only a 1mm wide annular portion around the outer periphery of the test piece, was irradiated with ultraviolet light to obtain "fully irradiated" and "partially irradiated" samples. Next, the release liner on the other side was peeled off and attached to another substrate. When peeling off the release liner on the other side, the adhesive sheet was laminated at 60°C for 10 seconds without transfer, thus performing the transfer. The two substrates were temporarily fixed at approximately 2~7kPa. In the temporarily fixed state, the adhesive sheet was heated in an oven at 150°C for 1 hour to cure it. After natural cooling, the temporary fixation was removed, and a test piece was prepared. The two ends of the obtained test piece were fixed 25mm apart using the chuck of a tensile testing machine, and the testing machine was moved at a speed of 1.3mm / min until fracture occurred. The maximum stress was taken as the shear bond force.

[0213] The evaluation results for each evaluation are shown in Table 4.

[0214]

[0215] As shown in Table 4, partial irradiation of the adhesive sheet results in excellent transfer properties, no glue overflow, and a laminate with sufficiently high shear adhesion and higher adhesion compared to the case of whole irradiation.

[0216] The various raw materials shown in Tables 1-4 are described below.

[0217] (Bisphenol type epoxy resin)

[0218] jER-834: Trade name "jER-834", semi-solid bisphenol A type epoxy resin, epoxy equivalent 230~270g / eq, manufactured by Mitsubishi Chemical Corporation.

[0219] (Rubber-modified epoxy resin)

[0220] HyPoxRK84L: Trade name "HyPoxRK84L", an epoxy resin obtained by reacting bisphenol A type epoxy with CTBN, epoxy equivalent 1250~1500 g / eq, manufactured by HUNTSMAN.

[0221] (Epoxy curing agent)

[0222] Omicure DDA-50: Trade name "Omicure DDA-50", dicyandiamide, manufactured by HUNTSMAN.

[0223] Omicure U-24M: Trade name "Omicure U-24M", 1,1'-(4-methyl-1,3-phenylene)bis(3,3'-dimethylurea), manufactured by HUNTSMAN.

[0224] (Multifunctional compounds)

[0225] PGDA: Polyethylene glycol diacrylate (average addition molar number 4)

[0226] 1,6-HDDA: 1,6-hexanediol diacrylate

[0227] TMPTA: Trimethylolpropane triacrylate

[0228] (Photopolymerization initiator)

[0229] Omnirad 651: Trade name "Omnirad 651", manufactured by IGM Resins BV.

[0230] Omnirad 184: Trade name "Omnirad 184", manufactured by IGM Resins BV.

[0231] (filler)

[0232] Aerosil RY-200: Trade name "Aerosil RY-200", hydrophobic treated fumed silica, specific surface area 175~225m². 2 / g, average particle size 12nm, manufactured by Nippon Aerosil Co., Ltd.

[0233] The following are variations of the present invention.

[0234] [Note 1] An adhesive sheet having an elastic modulus G'(A1) of 1 × 10⁻⁶ at 20°C before irradiation with active energy rays. 3 ~5×10 6 The elastic modulus G'(A2) at Pa and 80℃ is 1×10 4Below Pa, the elastic modulus G'(B1) at 20°C after irradiation with active energy rays is greater than the elastic modulus G'(A1), and the elastic modulus G'(B2) at 80°C is 1×10⁻⁶. 3 Pa or above

[0235] The elastic modulus E' of the adhesive sheet at 20°C after thermosetting is 1×10⁻⁶. 8 ~1×10 11 Pa.

[0236] [Appendix 2] According to the adhesive sheet described in Appendix 1, wherein,

[0237] The elastic modulus G'(B1) at 20°C exceeds 1×10⁻⁶. 3 Pa and is 5 × 10 8 Below Pa.

[0238] [Appendix 3] An adhesive sheet having the following regions (A) and (B) in the surface direction,

[0239] Region (A): The elastic modulus G'(A1) at 20℃ is 1×10⁻⁶. 3 ~5×10 6 The elastic modulus G'(A2) at Pa and 80℃ is 1×10 4 Areas below Pa;

[0240] Region (B): The elastic modulus G'(B1) at 20℃ is greater than the elastic modulus G'(A1), and the elastic modulus G'(B2) at 80℃ is 1×10⁻⁶. 3 Areas above Pa.

[0241] [Appendix 4] An adhesive sheet having:

[0242] The following areas (A) of the adhesive sheet described in Appendix 1 or 2 that were not irradiated by active energy rays, and

[0243] The region (B) is formed by irradiating a portion of the surface direction within the aforementioned region (A) with active energy rays.

[0244] Region (A): The elastic modulus G'(A1) at 20℃ is 1×10⁻⁶. 3 ~5×10 6 The elastic modulus G'(A2) at Pa and 80℃ is 1×10 4 Areas below Pa;

[0245] Region (B): The elastic modulus G'(B1) at 20℃ is greater than the above elastic modulus G'(A1), and the elastic modulus G'(B2) at 80℃ is 1×10⁻⁶. 3 Areas above Pa.

[0246] [Note 5] The adhesive sheet according to Note 3 or 4 has the region (B) at one end in the direction of the surface.

[0247] [Note 6] The adhesive sheet according to any one of Notes 1 to 5 contains epoxy resin as a thermosetting component.

[0248] [Appendix 7] According to the adhesive sheet described in Appendix 6, wherein,

[0249] The epoxy resin contains epoxy resin (a) with an epoxy equivalent of 200~800 g / eq and rubber-modified epoxy resin (b).

[0250] [Appendix 8] The adhesive sheet according to Appendix 6 or 7, wherein,

[0251] Relative to 100 parts by weight of the epoxy resin, it contains 0.5 to 30 parts by weight of epoxy curing agent (c).

[0252] [Note 9] According to the adhesive sheet described in Note 8, wherein,

[0253] The epoxy curing agent (c) contains dicyandiamide.

[0254] [Note 10] The adhesive sheet according to any one of Notes 1 to 9 contains a multifunctional compound (d) having two or more reactive double bonds in the molecule.

[0255] [Note 11] According to the adhesive sheet described in Note 10, wherein,

[0256] The multifunctional compound (d) has (meth)acryloyl and / or (meth)acrylamide groups.

[0257] [Note 12] According to the adhesive sheet described in Note 10 or 11, wherein,

[0258] The epoxy resin contains 0.1 to 12 parts by weight of the multifunctional compound (d) relative to 100 parts by weight.

[0259] [Note 13] The adhesive sheet according to any one of Notes 10 to 12, wherein,

[0260] Relative to 100 parts by weight of the epoxy resin, it contains 0.1 to 5 parts by weight of photopolymerization initiator (e).

[0261] [Note 14] The adhesive sheet according to any one of Notes 1 to 13 is used for bonding components to each other, at least one of which is a metal component.

[0262] [Note 15] The adhesive sheet according to Note 14 is used for bonding metal components to each other or for bonding metal components to fiber-reinforced resin components.

[0263] [Appendix 16] A method for manufacturing a laminate, wherein the laminate is formed by bonding a first adherend and a second adherend together via an adhesive sheet.

[0264] The manufacturing method comprises:

[0265] The process of irradiating a portion of the adhesive sheet, which has active energy radiation curing and thermosetting properties, onto a surface direction after it is adhered to the first adhered object to cure it, or the process of adhering the adhesive sheet to the first adhered object after irradiating a portion of the adhesive sheet onto a surface direction to cure it.

[0266] The process of attaching the second adherend to the adhesive sheet; and

[0267] The process of heating the adhesive sheet to thermally cure it.

[0268] [Appendix 17] According to the manufacturing method described in Appendix 16, wherein,

[0269] At least one of the first adhered object and the second adhered object is a metal component.

[0270] [Appendix 18] According to the manufacturing method described in Appendix 17, wherein,

[0271] The combination of the first adherend and the second adherend is a combination of metal components or a combination of metal components and fiber-reinforced resin components.

[0272] [Appendix 19] The manufacturing method according to any one of Appendices 16 to 18, wherein,

[0273] A portion of the surface direction is one end of the surface direction.

Claims

1. An adhesive sheet having an elastic modulus G'(A1) of 1 × 10⁻⁶ at 20°C before irradiation by active energy rays. 3 ~5×10 6 The elastic modulus G'(A2) at Pa and 80℃ is 1×10 4 Below Pa, the elastic modulus G'(B1) at 20°C after irradiation with active energy rays is greater than the elastic modulus G'(A1), and the elastic modulus G'(B2) at 80°C is 1×10⁻⁶. 3 Pa or above The elastic modulus E' of the adhesive sheet at 20°C after thermosetting is 1×10⁻⁶. 8 ~1×10 11 Pa.

2. The adhesive sheet according to claim 1, wherein, The elastic modulus G'(B1) at 20°C exceeds 1×10⁻⁶. 3 Pa and is 5 × 10 8 Below Pa.

3. An adhesive sheet having, in the surface direction, the following regions (A) and (B), Region (A): The elastic modulus G'(A1) at 20℃ is 1×10⁻⁶. 3 ~5×10 6 The elastic modulus G'(A2) at Pa and 80℃ is 1×10 4 Areas below Pa; Region (B): The elastic modulus G'(B1) at 20℃ is greater than the elastic modulus G'(A1), and the elastic modulus G'(B2) at 80℃ is 1×10⁻⁶. 3 Areas above Pa.

4. The adhesive sheet according to claim 3, wherein the region (B) is located at one end in the surface direction.

5. The adhesive sheet according to any one of claims 1 to 4, wherein it comprises epoxy resin as a thermosetting component.

6. The adhesive sheet according to claim 5, wherein, The epoxy resin contains epoxy resin (a) with an epoxy equivalent of 200~800 g / eq and rubber-modified epoxy resin (b).

7. The adhesive sheet according to claim 6, wherein, Relative to 100 parts by weight of the epoxy resin, it contains 0.5 to 30 parts by weight of epoxy curing agent (c).

8. The adhesive sheet according to claim 7, wherein, The epoxy curing agent (c) contains dicyandiamide.

9. The adhesive sheet according to any one of claims 1 to 4, wherein it contains a polyfunctional compound (d) having two or more reactive double bonds in the molecule.

10. The adhesive sheet according to claim 9, wherein, The multifunctional compound (d) has (meth)acryloyl and / or (meth)acrylamide groups.

11. The adhesive sheet according to claim 9, wherein, The epoxy resin contains 0.1 to 12 parts by weight of the multifunctional compound (d) relative to 100 parts by weight.

12. The adhesive sheet according to claim 9, wherein, Relative to 100 parts by weight of the epoxy resin, it contains 0.1 to 5 parts by weight of photopolymerization initiator (e).

13. The adhesive sheet according to any one of claims 1 to 4, for bonding components to each other, wherein at least one of the components is a metal component.

14. The adhesive sheet according to claim 13, used for bonding metal components to each other, or for bonding metal components to fiber-reinforced resin components.

15. A method for manufacturing a laminate, wherein the laminate is formed by bonding a first adherend and a second adherend together via an adhesive sheet. The manufacturing method comprises: The process of irradiating a portion of the adhesive sheet, which has active energy radiation curing and thermosetting properties, with active energy radiation to cure it after it is adhered to the first substrate, or the process of adhering the adhesive sheet to the first substrate after irradiating a portion of the adhesive sheet with active energy radiation to cure it. The process of attaching the second adherend to the adhesive sheet; and The process of heating the adhesive sheet to thermally cure it.

16. The manufacturing method according to claim 15, wherein, At least one of the first adhered object and the second adhered object is a metal component.

17. The manufacturing method according to claim 16, wherein, The combination of the first adherend and the second adherend is a combination of metal components or a combination of metal components and fiber-reinforced resin components.

18. The manufacturing method according to any one of claims 15 to 17, wherein, A portion of the surface direction is one end of the surface direction.

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