Adhesive for high-frequency dielectric heating

Abstract

To provide an adhesive for high-frequency dielectric heating, capable of being adhered to glass with high adhesive strength even by small energy consumption, and hardly reducing adhesive force with time.SOLUTION: An adhesive (adhesive sheet 1A) for high-frequency dielectric heating contains at least a thermoplastic resin (A), and a dielectric filler (B) generating heat by application of a high-frequency electric field. The adhesive (adhesive sheet 1A) for high-frequency dielectric heating is such that: the thermoplastic resin (A) contains at least a first thermoplastic resin (A1) and a second thermoplastic resin (A2); the first thermoplastic resin (A1) is a silane-modified thermoplastic resin; and the second thermoplastic resin (A2) is silane-unmodified thermoplastic resin.SELECTED DRAWING: Figure 1A

Description

Technical Field

[0001] The present invention relates to an adhesive for high-frequency dielectric heating.

Background Art

[0002] In recent years, as a method for adhering adherends that are generally difficult to adhere, for example, an adhesive obtained by blending a heat-generating material in a predetermined resin is interposed between the adherends, and dielectric heat treatment, induction heat treatment, ultrasonic welding treatment, or laser welding treatment is performed. A method has been proposed. As an adhesive method when using glass as an adherend, there are the following techniques.

[0003] For example, Patent Document 1 describes a thermoplastic resin composition for adhering glass and an inorganic reinforced thermoplastic resin. The thermoplastic resin composition contains a heat-generating body that generates heat by high-frequency induction and a thermoplastic resin having a melting point of 90°C to 200°C modified with a monomer containing a functional group that reacts with an inorganic substance in the presence of moisture.

[0004] Also, as another adhesive method, for example, Patent Document 2 describes a glass adhesion sheet for adhering to a glass surface by a vacuum lamination method. This glass adhesion sheet contains a silane-modified polyethylene-based resin obtained by graft-polymerizing an ethylenically unsaturated silane compound onto low-density polyethylene.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] When using the thermoplastic resin composition described in Patent Document 1, a large amount of energy is consumed for adhesion to glass. When using the glass adhesion sheet described in Patent Document 2, the pressure holding time during vacuum lamination required for adhesion to glass is long. In addition, it is also required that the composition and sheet used for adhesion to glass do not reduce the adhesive strength during storage from the time of manufacture until use.

[0007] An object of the present invention is to provide an adhesive for high-frequency dielectric heating that can adhere to glass with high adhesive strength even with less energy consumption and is less likely to reduce the adhesive strength over time.

Means for Solving the Problems

[0008] According to one aspect of the present invention, there is provided an adhesive for high-frequency dielectric heating, wherein the adhesive for high-frequency dielectric heating contains at least a thermoplastic resin (A) and a dielectric material that generates heat when a high-frequency electric field is applied, the thermoplastic resin (A) includes at least a first thermoplastic resin (A1) and a second thermoplastic resin (A2), the first thermoplastic resin (A1) is a silane-modified thermoplastic resin, and the second thermoplastic resin (A2) is a non-silane-modified thermoplastic resin.

[0009] In the adhesive for high-frequency dielectric heating according to one aspect of the present invention, the first thermoplastic resin (A1) is preferably a silane-modified polyolefin-based resin.

[0010] In the adhesive for high-frequency dielectric heating according to one aspect of the present invention, the second thermoplastic resin (A2) is preferably a non-silane-modified polyolefin-based resin.

[0011] In the adhesive for high-frequency dielectric heating according to one aspect of the present invention, the second thermoplastic resin (A2) preferably has a polar site.

[0012] In the adhesive for high-frequency dielectric heating according to one aspect of the present invention, the polar site of the second thermoplastic resin (A2) is preferably an acidic site.

[0013] In the adhesive for high-frequency dielectric heating according to one aspect of the present invention, the acidic site of the second thermoplastic resin (A2) preferably has an acid anhydride structure.

[0014] In the adhesive for high-frequency dielectric heating according to one aspect of the present invention, the main composition of the first thermoplastic resin (A1) is preferably ethylene or propylene.

[0015] In the adhesive for high-frequency dielectric heating according to one aspect of the present invention, the main composition of the second thermoplastic resin (A2) is preferably ethylene or propylene.

[0016] In the adhesive for high-frequency dielectric heating according to one aspect of the present invention, the main composition of the first thermoplastic resin (A1) and the main composition of the second thermoplastic resin (A2) are preferably the same.

[0017] In the adhesive for high-frequency dielectric heating according to one aspect of the present invention, the volume content of the first thermoplastic resin (A1) in the thermoplastic resin (A) contained in the adhesive for high-frequency dielectric heating is preferably 15% by volume or more and 80% by volume or less.

[0018] In the adhesive for high-frequency dielectric heating according to one aspect of the present invention, the MFR of the thermoplastic resin (A) at 190 ° C is preferably 2 g / 10 min or more and 50 g / 10 min or less.

[0019] In the adhesive for high-frequency dielectric heating according to one aspect of the present invention, the volume content of the dielectric material in the adhesive for high-frequency dielectric heating is preferably 5% by volume or more and 50% by volume or less.

[0020] In the adhesive for high-frequency dielectric heating according to one aspect of the present invention, the dielectric material is preferably a dielectric filler (B).

[0021] In the adhesive for high-frequency dielectric heating according to one aspect of the present invention, it is preferable that the dielectric filler (B) contains at least any one selected from the group consisting of zinc oxide, silicon carbide, barium titanate, and titanium oxide.

[0022] In the adhesive for high-frequency dielectric heating according to one aspect of the present invention, the volume average particle diameter of the dielectric filler (B) is preferably 1 μm or more and 30 μm or less. The volume average particle diameter is the volume average particle diameter calculated according to JIS Z 8819-2:2001 from the measurement of the particle size distribution of the dielectric filler (B) by the laser diffraction / scattering method.

[0023] The adhesive for high-frequency dielectric heating according to one aspect of the present invention is preferably an adhesive sheet.

[0024] According to one aspect of the present invention, it is possible to provide an adhesive for high-frequency dielectric heating that can adhere to glass with high adhesive strength even with low energy consumption and is less likely to have a decrease in adhesive force over time.

Brief Description of the Drawings

[0025]

Figure 1A

Figure 1B

Figure 1C

Figure 2

Figure 3A

Figure 3B

Figure 3C

Embodiments for Carrying Out the Invention

[0026] [Adhesive for high-frequency dielectric heating] The adhesive for high-frequency dielectric heating according to the present embodiment contains at least a thermoplastic resin (A) and a dielectric material that generates heat when a high-frequency electric field is applied. The thermoplastic resin (A) includes at least a first thermoplastic resin (A1) and a second thermoplastic resin (A2). The first thermoplastic resin (A1) is a silane-modified thermoplastic resin, and the second thermoplastic resin (A2) is another thermoplastic resin different from the silane-modified thermoplastic resin. A high-frequency electric field is an electric field whose direction reverses at a high frequency.

[0027] The dielectric material is a material that generates heat when a high-frequency electric field is applied, and preferably a material that generates heat when a high-frequency electric field with a frequency range of 3 MHz or more and 300 MHz or less is applied. The dielectric material is preferably at least one of a dielectric resin and a dielectric filler (B). From the viewpoint of easily suppressing the deterioration of the dielectric material contained in the high-frequency dielectric heating adhesive sheet when the high-frequency dielectric heating adhesive sheet is processed, the dielectric material is more preferably the dielectric filler (B). Hereinafter, a case where the high-frequency dielectric heating adhesive sheet according to the present embodiment contains a dielectric filler (B) as a dielectric material will be described.

[0028] [Thermoplastic resin (A)] In the present embodiment, the adhesive for high-frequency dielectric heating contains at least two types of thermoplastic resins (A). In the present embodiment, the adhesive for high-frequency dielectric heating includes at least a first thermoplastic resin (A1) and a second thermoplastic resin (A2).

[0029] In this embodiment, the first thermoplastic resin (A1) is a silane-modified thermoplastic resin. The silane-modified thermoplastic resin as the first thermoplastic resin (A1) is not particularly limited as long as it is a silane-modified thermoplastic resin. For example, it is preferably at least one selected from the group consisting of a copolymer of a silyl group-containing compound and a thermoplastic resin, and a silane-modified thermoplastic resin obtained by graft polymerization of a thermoplastic resin with a silyl group-containing compound.

[0030] In this embodiment, the second thermoplastic resin (A2) is a non-silane-modified thermoplastic resin. The second thermoplastic resin (A2) is not particularly limited as long as it is a non-silane-modified thermoplastic resin.

[0031] An adhesive for high-frequency dielectric heating containing a silane-modified thermoplastic resin as the thermoplastic resin (A) is likely to obtain a high adhesive force to glass. However, an adhesive for high-frequency dielectric heating containing only a silane-modified thermoplastic resin as the thermoplastic resin is likely to cause a decrease in adhesiveness. This decrease in adhesiveness is considered to occur because the silane-modified thermoplastic resin is easy to absorb water, and the cross-linking reaction between the reactive groups of the silane-modified thermoplastic resin proceeds over time. When the adhesive for high-frequency dielectric heating contains not only a silane-modified thermoplastic resin but also a non-silane-modified thermoplastic resin as the thermoplastic resin, an unintended decrease in adhesiveness over time is suppressed. Since the adhesive for high-frequency dielectric heating according to this embodiment also contains a non-silane-modified thermoplastic resin, it is considered that the absorption of water by the adhesive for high-frequency dielectric heating is suppressed, and the reactive groups are separated from each other, making it difficult for the cross-linking reaction to proceed. In addition, when the adhesive for high-frequency dielectric heating contains a silane-modified thermoplastic resin and a non-silane-modified thermoplastic resin, it is easy to adjust the viscosity of the adhesive for high-frequency dielectric heating and easy to impart processability to the adhesive for high-frequency dielectric heating.

[0032] The thermoplastic resins in the first thermoplastic resin (A1) and the second thermoplastic resin (A2) are each independently preferably at least one selected from the group consisting of polyolefin resins, styrene resins, polyacetal resins, polycarbonate resins, poly(meth)acrylic resins, polyamide resins, polyimide resins, polyvinyl acetate resins, phenoxy resins, and polyester resins, from the viewpoints of, for example, being easily meltable and having a predetermined heat resistance.

[0033] The thermoplastic resin in the silane-modified thermoplastic resin is preferably a polyolefin resin. That is, the first thermoplastic resin (A1) is preferably a silane-modified polyolefin resin. If the first thermoplastic resin (A1) is a silane-modified polyolefin, it is excellent in moldability, and it is easy to obtain an adhesive for high-frequency dielectric heating that is easily melted by high-frequency dielectric heating and has high adhesiveness. The moldability of the adhesive for high-frequency dielectric heating means the ease of processing the adhesive for high-frequency dielectric heating into a desired form (for example, a sheet or a molded body). In this specification, the adhesive for high-frequency dielectric heating according to this embodiment whose form is an adhesive sheet may sometimes be referred to as a high-frequency dielectric heating adhesive sheet.

[0034] The thermoplastic resin in the unmodified silane thermoplastic resin is preferably a polyolefin resin. That is, the second thermoplastic resin (A2) is preferably an unmodified silane polyolefin resin. If the second thermoplastic resin (A2) is an unmodified silane polyolefin resin, it is excellent in moldability, and it is easy to obtain an adhesive for high-frequency dielectric heating that is easily melted by high-frequency dielectric heating and has high adhesiveness. Since the polyolefin itself has high hydrophobicity, the unmodified silane polyolefin resin also shows a high effect in suppressing the deterioration of the adhesive performance over time.

[0035] It is more preferable that the first thermoplastic resin (A1) is a silane-modified polyolefin resin and the second thermoplastic resin (A2) is an unmodified silane polyolefin resin. The silane-modified polyolefin resin and the unmodified silane polyolefin resin have excellent compatibility. Therefore, by containing the silane-modified polyolefin resin and the unmodified silane polyolefin resin, it becomes easier to obtain an adhesive for high-frequency dielectric heating that has excellent moldability, high adhesiveness, and is less likely to cause a decrease in adhesive performance over time.

[0036] The silane-modified polyolefin resin is not particularly limited, but is preferably at least one selected from the group consisting of a copolymer of a silyl group-containing compound and an olefin, and a silane-modified polyolefin obtained by graft-polymerizing a polyolefin with a silyl group-containing compound.

[0037] The olefin copolymerized with the silyl group-containing compound is preferably, for example, an α-olefin having 2 to 20 carbon atoms. The α-olefin having 2 to 20 carbon atoms is preferably at least one olefin selected from the group consisting of ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-heptene, 4-methyl-1-pentene, 4-methyl-1-hexene, and 4,4-dimethyl-1-pentene, and more preferably at least one olefin of ethylene and propylene. The olefin copolymerized with the silyl group-containing compound may be one kind or two or more kinds. Examples of the polyolefin to be graft-polymerized with the silyl group-containing compound include homopolymers of the above olefins and copolymers of two or more olefins. A homopolymer or copolymer having a monomer unit derived from at least one of ethylene and propylene is preferable. It is also preferable that the silane-modified polyolefin is obtained by graft-polymerizing a polyolefin having a reactive group in advance with a silyl group-containing compound.

[0038] Examples of the silyl group-containing compound include vinyl silanes such as vinyltrimethoxysilane, vinyltriethoxysilane, vinyltripropoxysilane, vinyltriisopropoxysilane, vinyltributoxysilane, vinyltriphenoxysilane, vinyltribenzyloxysilane, vinyltrimethylenedioxysilane, vinylpropionyloxysilane, vinyltriacetoxysilane, vinyltricarboxysilane, vinyltriacetylsilane, vinyltrichlorosilane, vinyltris(methylethylketoxime)silane, vinyltriisopropenoxysilane, and vinylmethyldimethoxysilane; (meth)acrylic silanes such as (meth)acryloxymethyltrimethoxysilane; and styryl silanes such as styryltrimethoxysilane. In this specification, “(meth)acrylic” is a notation used when representing both “acrylic” and “methacrylic”, and the same applies to other similar terms.

[0039] The polyolefin resin in the first thermoplastic resin (A1) and the second thermoplastic resin (A2) is preferably, for example, a resin composed of a homopolymer such as polyethylene, polypropylene, polybutene, and polymethylpentene, and an α-olefin resin composed of a copolymer of monomers selected from the group consisting of ethylene, propylene, butene, hexene, octene, 4-methylpentene, and the like.

[0040] From the viewpoint of obtaining an adhesive for high-frequency dielectric heating having excellent mechanical strength, high moldability, and stable adhesion characteristics, the main composition of the first thermoplastic resin (A1) is preferably ethylene or propylene.

[0041] From the viewpoint of obtaining an adhesive for high-frequency dielectric heating having excellent mechanical strength, high moldability, and stable adhesion characteristics, the main composition of the second thermoplastic resin (A2) is preferably ethylene or propylene.

[0042] In this specification, the "main composition of the thermoplastic resin" means, for example, when the thermoplastic resin is a polymer, among the repeating units contained in the polymer, it is the repeating unit most contained in the polymer. If the thermoplastic resin is a polymer derived from a single monomer, the monomer unit (repeating unit) is the "main composition of the thermoplastic resin". When the thermoplastic resin is a copolymer, the repeating unit most contained in the polymer is the "main composition of the thermoplastic resin". When the thermoplastic resin is a copolymer, in the copolymer, the "main composition of the thermoplastic resin" is a repeating unit (monomer unit) contained at 30% by mass or more, in one aspect, a repeating unit contained more than 30% by mass, in another aspect, a repeating unit contained at 40% by mass or more, and in still another aspect, a repeating unit contained at 50% by mass or more. Also, when the thermoplastic resin is a copolymer, the most contained repeating unit may be two or more kinds.

[0043] It is preferable that the main composition of the first thermoplastic resin (A1) and the main composition of the second thermoplastic resin (A2) are the same. For example, when the first thermoplastic resin (A1) is a silane-modified polypropylene containing 50% by mass or more of propylene units as repeating units, and the second thermoplastic resin (A2) is also a maleic anhydride-modified polypropylene containing 50% by mass or more of propylene units as repeating units, the main composition (repeating unit) of the first thermoplastic resin (A1) and the main composition (repeating unit) of the second thermoplastic resin are both propylene, and the main compositions of the first thermoplastic resin (A1) and the second thermoplastic resin are the same. Since the main composition of the first thermoplastic resin (A1) and the main composition of the second thermoplastic resin (A2) are the same, the compatibility between the first thermoplastic resin (A1) and the second thermoplastic resin (A2) is improved, and it becomes easier to separate the reactive groups of the first thermoplastic resin (A1) from each other.

[0044] The volume content of the first thermoplastic resin (A1) in the thermoplastic resin (A) contained in the adhesive for high-frequency dielectric heating is preferably 15% by volume or more, more preferably 25% by volume or more, and still more preferably 40% by volume or more. The volume content of the first thermoplastic resin (A1) in the thermoplastic resin (A) contained in the adhesive for high-frequency dielectric heating is preferably 80% by volume or less, more preferably 70% by volume or less, and still more preferably 60% by volume or less. When the volume content of the first thermoplastic resin (A1) in the thermoplastic resin (A) is 15% by volume or more, it is easy to obtain adhesiveness to glass. When the volume content of the first thermoplastic resin (A1) in the thermoplastic resin (A) is 80% by volume or less, it is easy to obtain storage stability.

[0045] The volume content of the second thermoplastic resin (A2) in the thermoplastic resin (A) contained in the adhesive for high-frequency dielectric heating is preferably 20% by volume or more, more preferably 30% by volume or more, and still more preferably 40% by volume or more. The volume content of the second thermoplastic resin (A2) in the thermoplastic resin (A) contained in the adhesive for high-frequency dielectric heating is preferably 85% by volume or less, more preferably 75% by volume or less, and still more preferably 60% by volume or less. When the volume content of the second thermoplastic resin (A2) in the thermoplastic resin (A) is 20% by volume or more, the storage stability of the adhesive for high-frequency dielectric heating is easily obtained. When the volume content of the second thermoplastic resin (A2) in the thermoplastic resin (A) is 85% by volume or less, it is easy to prevent a decrease in adhesiveness to glass.

[0046] However, the total of the volume content of the first thermoplastic resin (A1) and the volume content of the second thermoplastic resin (A2) in the thermoplastic resin (A) contained in the adhesive for high-frequency dielectric heating is 100% by mass or less.

[0047] The volume ratio of the first thermoplastic resin (A1) to the second thermoplastic resin (A2) in the adhesive for high-frequency dielectric heating is preferably from 15:85 to 80:20, more preferably from 25:75 to 70:30, and even more preferably from 40:60 to 60:40.

[0048] The second thermoplastic resin (A2) preferably has a polar moiety. Examples of the polar moiety include a hydroxyl group, a carboxyl group, an epoxy group, an acryloyl group, an acetoxy group, a sulfo group, a phospho group, a phenol group, a vinyl acetate structure, and an acid anhydride structure. The polar moiety may be introduced into the resin by copolymerization or by modification. The thermoplastic resin having a polar moiety is preferable because it exhibits high adhesive strength to the adherend. The second thermoplastic resin (A2) is preferably a polyolefin resin having a polar moiety.

[0049] When the adhesive for high-frequency dielectric heating contains the first thermoplastic resin (A1) and the second thermoplastic resin (A2) having a polar moiety, the volume ratio of the first thermoplastic resin (A1) to the second thermoplastic resin (A2) having a polar moiety in the adhesive for high-frequency dielectric heating is preferably from 15:85 to 80:20, more preferably from 25:75 to 70:30, and even more preferably from 40:60 to 60:40.

[0050] The polar moiety of the second thermoplastic resin (A2) is also preferably an acidic moiety. The second thermoplastic resin (A2) is more preferably a polyolefin resin having an acidic moiety. Examples of the acidic moiety of the second thermoplastic resin (A2) include a carboxyl group, a sulfo group, a phospho group, a phenol group, and an acid anhydride structure. By the second thermoplastic resin (A2) having an acidic moiety, it is possible to suppress a decrease in adhesive performance accompanying a decrease in the proportion of the silane-modified thermoplastic resin in the adhesive for high-frequency dielectric heating.

[0051] The second thermoplastic resin (A2) is preferably a resin having an acid-modified structure as a polar site, and more preferably a polyolefin resin having an acid-modified structure. The acid-modified structure as a polar site is a site introduced by acid-modifying a thermoplastic resin (for example, a polyolefin resin). Examples of the compound used for acid-modifying a thermoplastic resin (for example, a polyolefin resin) include an unsaturated carboxylic acid derivative component derived from any of an unsaturated carboxylic acid, an acid anhydride of an unsaturated carboxylic acid, and an ester of an unsaturated carboxylic acid. In this specification, a polyolefin resin having an acid-modified structure may be referred to as an acid-modified polyolefin resin.

[0052] Examples of the unsaturated carboxylic acid include acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, and citraconic acid.

[0053] Examples of the acid anhydride of an unsaturated carboxylic acid include acid anhydrides of unsaturated carboxylic acids such as maleic anhydride, itaconic anhydride, and citraconic anhydride.

[0054] Examples of the ester of an unsaturated carboxylic acid include esters of unsaturated carboxylic acids such as methyl acrylate, ethyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, dimethyl maleate, monomethyl maleate, dimethyl fumarate, diethyl fumarate, dimethyl itaconate, diethyl itaconate, dimethyl citraconate, diethyl citraconate, and dimethyl tetrahydrophthalic anhydride.

[0055] (Polyolefin resin having a polar site) The polar site in the polyolefin resin having a polar site is not particularly limited as long as it can impart polarity to the polyolefin resin. The polyolefin resin having a polar site is preferable because it exhibits high adhesive strength to an adherend. The polyolefin resin having a polar site may be a copolymer of an olefin monomer and a monomer having a polar site. Further, the polyolefin resin having a polar site may be a resin in which a polar site is introduced into an olefin polymer obtained by polymerization of an olefin monomer by modification such as an addition reaction.

[0056] The type of the olefin monomer constituting the polyolefin resin having a polar site is not particularly limited. Examples of the olefin monomer include ethylene, propylene, butene, hexene, octene, 4-methyl-1-pentene, and the like. The olefin monomer may be used alone or in combination of two or more. From the viewpoint of obtaining an adhesive for high-frequency dielectric heating having excellent mechanical strength and stable adhesion characteristics, at least one of ethylene and propylene is preferable as the olefin monomer. The structural unit derived from olefin in the polyolefin resin having a polar site is preferably a structural unit derived from ethylene or propylene.

[0057] When the polyolefin resin as the second thermoplastic resin (A2) is a copolymer of an olefin monomer and a monomer having a polar site, the copolymer preferably contains 2% by mass or more of the structural unit derived from the monomer having a polar site, more preferably 4% by mass or more, still more preferably 5% by mass or more, and even more preferably 6% by mass or more. Further, the copolymer preferably contains 30% by mass or less of the structural unit derived from the monomer having a polar site, more preferably 25% by mass or less, still more preferably 20% by mass or less, and even more preferably 15% by mass or less. When the copolymer contains 2% by mass or more of structural units derived from a monomer having a polar moiety, the adhesive strength of the adhesive for high-frequency dielectric heating is improved. Further, when the copolymer contains 30% by mass or less of structural units derived from a monomer having a polar moiety, it is possible to suppress the tack of the second thermoplastic resin (A2) from becoming too strong. As a result, it becomes easier to prevent the molding process of the adhesive for high-frequency dielectric heating from becoming difficult.

[0058] When the polyolefin resin as the second thermoplastic resin (A2) is a copolymer of an olefin monomer and a monomer having an acidic moiety, the ratio of the structural units derived from the monomer having an acidic moiety in the copolymer is preferably in the same range as the ratio of the structural units derived from the monomer having a polar moiety in the case of a copolymer of an olefin monomer and a monomer having a polar moiety, and the effects obtained within this range are also the same as those in the case where the polyolefin resin as the second thermoplastic resin (A2) is a copolymer of an olefin monomer and a monomer having a polar moiety.

[0059] When the polyolefin resin as the second thermoplastic resin (A2) has an acid-modified structure, the modification rate by acid is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and still more preferably 0.2% by mass or more. When the polyolefin resin as the second thermoplastic resin (A2) has an acid-modified structure, the modification rate by acid is preferably 30% by mass or less, more preferably 20% by mass or less, and still more preferably 10% by mass or less. When the second thermoplastic resin (A2) has an acid-modified structure, when the modification rate by acid is 0.01% by mass or more, the adhesive strength of the adhesive for high-frequency dielectric heating is improved. Further, when the modification rate by acid is 30% by mass or less, it is possible to suppress the tack of the second thermoplastic resin (A2) from becoming too strong. As a result, it becomes easier to prevent the molding process of the adhesive for high-frequency dielectric heating from becoming difficult. In this specification, the modification rate by acid is the percentage of the mass of the portion derived from acid with respect to the total mass of the acid-modified polyolefin.

[0060] It is also preferable that the acidic site of the second thermoplastic resin (A2) has an acid anhydride structure. The second thermoplastic resin (A2) is more preferably a polyolefin resin having an acid anhydride structure. Since the second thermoplastic resin (A2) has an acid anhydride structure, the interaction with the dielectric filler (B) can be suppressed, so that an increase in torque and gelation during sheet molding of the adhesive for high-frequency dielectric heating can be suppressed. The acid anhydride structure is more preferably a maleic anhydride structure. The maleic anhydride structure may be a group introduced by graft-modifying a thermoplastic resin, or may be a maleic anhydride copolymer obtained by copolymerizing a monomer containing a maleic anhydride structure.

[0061] In the maleic anhydride-modified polyolefin, the modification rate by maleic anhydride is preferably in the same range as the modification rate when the polyolefin resin as the second thermoplastic resin (A2) has an acid-modified structure, and the effects obtained within this range are also the same as those when the polyolefin resin as the second thermoplastic resin (A2) has an acid-modified structure. When the maleic anhydride-modified polyolefin is a copolymer of an olefin monomer and a monomer containing a maleic anhydride structure, the proportion of the structural unit derived from the monomer containing a maleic anhydride structure in the copolymer is preferably in the same range as the proportion of the structural unit derived from the monomer having a polar site when it is a copolymer of an olefin monomer and a monomer having a polar site, and the effects obtained within this range are also the same as those when the polyolefin resin as the second thermoplastic resin (A2) is a copolymer of an olefin monomer and a monomer having a polar site.

[0062] The structural unit derived from olefin in the maleic anhydride-modified polyolefin is preferably a structural unit derived from ethylene or propylene. That is, the maleic anhydride-modified polyolefin is preferably a maleic anhydride-modified polyethylene resin or a maleic anhydride-modified polypropylene resin.

[0063] (MFR of the thermoplastic resin) The MFR of the thermoplastic resin (A) at 190°C is preferably 2 g / 10 min or more, more preferably 2.5 g / 10 min or more, and even more preferably 3 g / 10 min or more. The MFR of the thermoplastic resin (A) at 190°C is preferably 50 g / 10 min or less, more preferably 30 g / 10 min or less, and even more preferably 20 g / 10 min or less. When the MFR of the thermoplastic resin (A) at 190°C is 2 g / 10 min or more, the sheet formability is excellent, and at the time of bonding, since the wetting spread of the adhesive for high-frequency dielectric heating is good, the bonding strength can be easily obtained in a short time. When the MFR of the thermoplastic resin (A) at 190°C is 50 g / 10 min or less, it is easy to suppress the viscosity of the adhesive for high-frequency dielectric heating from becoming too low during the dielectric heat treatment. If the viscosity of the adhesive for high-frequency dielectric heating becomes too low, the amount of resin between the adherends decreases during bonding and it becomes difficult to obtain the bonding strength. However, by suppressing the viscosity decrease, the bonding strength can be easily obtained. The MFR of the thermoplastic resin (A) at 190°C can be measured by the method described in the items of the examples described later.

[0064] <Dielectric filler (B)> The dielectric filler (B) is a filler that generates heat when a high-frequency electric field is applied. The dielectric filler (B) is preferably a filler that generates heat when a high-frequency electric field in the frequency range of 3 MHz or more and 300 MHz or less is applied. Among the frequency ranges of 3 MHz or more and 300 MHz or less, the dielectric filler (B) is preferably a filler that generates heat when a high-frequency electric field such as a frequency of 13.56 MHz, 27.12 MHz, or 40.68 MHz is applied.

[0065] (Type) The dielectric filler (B) is preferably one kind alone or a combination of two or more kinds of inorganic materials having crystal water such as zinc oxide, silicon carbide (SiC), anatase titanium oxide, barium titanate, barium zirconate titanate, lead titanate, potassium niobate, rutile titanium oxide, hydrated aluminum silicate, hydrated aluminosilicate of an alkali metal, or inorganic materials having crystal water such as hydrated aluminosilicate of an alkaline earth metal.

[0066] The dielectric filler (B) preferably contains at least one selected from the group consisting of zinc oxide, silicon carbide, barium titanate, and titanium oxide.

[0067] Among the exemplified dielectric fillers, since the types are abundant, they can be selected from various shapes and sizes, and the adhesion characteristics and mechanical characteristics of the adhesive for high-frequency dielectric heating can be improved according to the application, the dielectric filler (B) is more preferably zinc oxide. By using zinc oxide as the dielectric filler (B), a colorless adhesive for high-frequency dielectric heating can be obtained. Since zinc oxide has a small density among the dielectric fillers, when a adherend is joined using an adhesive for high-frequency dielectric heating containing zinc oxide as the dielectric filler (B), the total weight of the joined body is less likely to increase compared to the case of using an adhesive containing other dielectric fillers. Since zinc oxide does not have too high a hardness among ceramics, it is difficult to damage the manufacturing equipment for the adhesive for high-frequency dielectric heating. Since zinc oxide is an inert oxide, even when blended with a thermoplastic resin, the damage to the thermoplastic resin is small. Also, the titanium oxide as the dielectric filler (B) is preferably at least one of anatase titanium oxide and rutile titanium oxide, and more preferably anatase titanium oxide from the viewpoint of excellent dielectric properties.

[0068] (Volume content) The volume content of the dielectric filler (B) in the adhesive for high-frequency dielectric heating is preferably 5% by volume or more, more preferably 8% by volume or more, and even more preferably 10% by volume or more. The volume content of the dielectric filler (B) in the adhesive for high-frequency dielectric heating is preferably 50% by volume or less, more preferably 40% by volume or less, still more preferably 35% by volume or less, and even more preferably 25% by volume or less. When the volume content of the dielectric filler (B) in the adhesive for high-frequency dielectric heating is 5% by volume or more, the heat generation property is improved, and it is easy to firmly bond the adhesive for high-frequency dielectric heating and the adherend made of glass. When the volume content of the dielectric filler (B) in the adhesive for high-frequency dielectric heating is 50% by volume or less, it is easy to obtain flexibility as a sheet and it is easy to prevent a decrease in toughness, so that the adhesive for high-frequency dielectric heating can be easily processed into a desired shape in a subsequent process.

[0069] In addition, since the adhesive for high-frequency dielectric heating according to the present embodiment contains the thermoplastic resin (A) and the dielectric filler (B), the volume content of the dielectric filler (B) is preferably 5% by volume or more, more preferably 8% by volume or more, still more preferably 10% by volume or more with respect to the total volume of the thermoplastic resin (A) and the dielectric filler (B). The volume content of the dielectric filler (B) is preferably 50% by volume or less, more preferably 40% by volume or less, still more preferably 35% by volume or less, and even more preferably 25% by volume or less with respect to the total volume of the thermoplastic resin (A) and the dielectric filler (B).

[0070] In the above, the volume content of the dielectric material in the adhesive layer has been described for the case where the dielectric material is the dielectric filler (B). The volume content of the dielectric material in the adhesive layer is not limited to the case where the dielectric material is the dielectric filler (B), and it is preferably in the same range as the volume content of the dielectric filler (B) in the adhesive layer even in the case of a dielectric material other than the dielectric filler (B). That is, the volume content of the dielectric material in the adhesive layer is preferably 5% by volume or more and preferably 50% by volume or less.

[0071] (Average particle diameter) The volume average particle diameter of the dielectric filler (B) is preferably 1 μm or more, more preferably 2 μm or more, and even more preferably 3 μm or more. The volume average particle diameter of the dielectric filler (B) is preferably 30 μm or less, more preferably 25 μm or less, and even more preferably 20 μm or less. When the volume average particle diameter of the dielectric filler (B) is 1 μm or more, the adhesive for high-frequency dielectric heating exhibits high heat generation performance when a high-frequency electric field is applied, and the adhesive for high-frequency dielectric heating can firmly adhere to a glass adherend in a short time. When the volume average particle diameter of the dielectric filler (B) is 30 μm or less, the adhesive for high-frequency dielectric heating exhibits high heat generation performance when a high-frequency electric field is applied, and the adhesive for high-frequency dielectric heating can firmly adhere to a glass adherend in a short time. Further, when the volume average particle diameter of the dielectric filler (B) is 30 μm or less, a decrease in the strength of the adhesive for high-frequency dielectric heating can be prevented.

[0072] The volume average particle diameter of the dielectric filler (B) is measured by the following method. The particle size distribution of the dielectric filler (B) is measured by the laser diffraction / scattering method, and the volume average particle diameter is calculated according to JIS Z 8819-2:2001 from the results of the particle size distribution measurement.

[0073] When the adhesive for high-frequency dielectric heating according to the present embodiment is an adhesive sheet (high-frequency dielectric heating adhesive sheet), the average particle diameter D of the dielectric filler (B) F and the thickness T of the high-frequency dielectric heating adhesive sheet satisfy the relationship of 1 ≦ T / D F ≦ 2500, which is preferable. T / D F is preferably 1 or more, preferably 2 or more, preferably 5 or more, more preferably 10 or more, and even more preferably 20 or more. When T / D F is 1 or more, a decrease in the adhesive strength due to contact between the dielectric filler (B) and the adherend during adhesion can be prevented. T / D Fis preferably 2500 or less, preferably 2000 or less, preferably 1750 or less, more preferably 1000 or less, still more preferably 500 or less, even more preferably 100 or less, and even still more preferably 50 or less. T / D F If F is 2500 or less, the load on the sheet manufacturing apparatus can be suppressed during the production of the high-frequency dielectric heating adhesive sheet.

[0074] (Additive) The high-frequency dielectric heating adhesive according to the present embodiment may or may not contain an additive. When the high-frequency dielectric heating adhesive according to the present embodiment is a high-frequency dielectric heating adhesive sheet composed of a plurality of layers, at least one of the plurality of layers may or may not contain an additive. When at least one of the plurality of layers contains an additive, among the plurality of layers, the adhesive layer containing the high-frequency dielectric heating adhesive may or may not contain an additive.

[0075] When the high-frequency dielectric heating adhesive according to the present embodiment contains an additive, examples of the additive include tackifiers, plasticizers, waxes, colorants, antioxidants, ultraviolet absorbers, antibacterial agents, coupling agents, viscosity modifiers, organic fillers, and inorganic fillers. The organic filler and the inorganic filler as the additive are different from the dielectric material (dielectric filler).

[0076] The tackifier and the plasticizer can improve the melting characteristics and the adhesive characteristics of the high-frequency dielectric heating adhesive. Examples of the tackifier include rosin derivatives, polyterpene resins, aromatic-modified terpene resins, hydrogenated aromatic-modified terpene resins, terpene phenol resins, coumarone-indene resins, aliphatic petroleum resins, aromatic petroleum resins, and hydrogenated aromatic petroleum resins. Examples of the plasticizer include petroleum process oils, natural oils, dibasic acid dialkyls, and low molecular weight liquid polymers. Examples of the petroleum process oils include paraffinic process oils, naphthenic process oils, and aromatic process oils. Examples of the natural oils include castor oil and tall oil. Examples of the dibasic acid dialkyls include dibutyl phthalate, dioctyl phthalate, and dibutyl adipate. Examples of the low molecular weight liquid polymers include liquid polybutene and liquid polyisoprene.

[0077] When the high-frequency dielectric heating adhesive according to this embodiment contains an additive, the content of the additive in the high-frequency dielectric heating adhesive is usually preferably 0.01% by mass or more, more preferably 0.05% by mass or more, and still more preferably 0.1% by mass or more based on the total amount of the high-frequency dielectric heating adhesive. Also, the content of the additive in the high-frequency dielectric heating adhesive is preferably 20% by mass or less, more preferably 15% by mass or less, and still more preferably 10% by mass or less.

[0078] The high-frequency dielectric heating adhesive according to this embodiment preferably does not contain a solvent. According to the high-frequency dielectric heating adhesive that does not contain a solvent, problems of VOC (Volatile Organic Compounds) caused by the adhesive used for adhesion to the adherend are less likely to occur.

[0079] The high-frequency dielectric heating adhesive according to this embodiment preferably does not contain a conductive substance such as carbon or a carbon compound mainly composed of carbon (for example, carbon black) and metal. The adhesive layer preferably does not contain, for example, carbon steel, α-iron, γ-iron, δ-iron, copper, brass, aluminum, iron-nickel alloy, iron-nickel-chromium alloy, carbon fiber, and carbon black.

[0080] When the adhesive for high-frequency dielectric heating according to this embodiment contains a conductive substance, the content rate of the conductive substance in the adhesive is preferably 20% by mass or less, more preferably 10% by mass or less, still more preferably 5% by mass or less, even more preferably 1% by mass or less, and even still more preferably 0.1% by mass or less, each independently based on the total amount of the adhesive. The content rate of the conductive substance in the adhesive is particularly preferably 0% by mass. If the content rate of the conductive substance in the adhesive is 20% by mass or less, it becomes easier to prevent problems such as electrical breakdown and carbonization of the adhesive part and the adherend during dielectric heat treatment.

[0081] In the adhesive for high-frequency dielectric heating according to this embodiment, the total content rate of the thermoplastic resin (A) and the dielectric filler (B) is preferably 80% by mass or more, more preferably 90% by mass or more, and still more preferably 99% by mass or more.

[0082] <Form and properties of the adhesive for high-frequency dielectric heating> The form of the adhesive for high-frequency dielectric heating according to this embodiment is not particularly limited, but for example, it is a sheet or a molded body. In this specification, a molded body is not a sheet. A sheet generally refers to a single-leaf shape with a uniform thickness of 1 mm or less, 2 mm or less, or 5 mm or less.

[0083] (High-frequency dielectric heating adhesive sheet) The adhesive for high-frequency dielectric heating according to this embodiment is preferably an adhesive sheet (high-frequency dielectric heating adhesive sheet). The high-frequency dielectric heating adhesive sheet according to this embodiment, in one aspect, is composed of only one adhesive layer made of the adhesive for high-frequency dielectric heating according to this embodiment, and in another aspect, may be composed of a plurality of layers. When the high-frequency dielectric heating adhesive sheet consists of only one adhesive layer, since the adhesive layer itself corresponds to the high-frequency dielectric heating adhesive sheet, the form and properties of the high-frequency dielectric heating adhesive sheet correspond to the form and properties of the adhesive layer.

[0084] The high-frequency dielectric heating adhesive sheet according to this embodiment, in one aspect, consists of only one layer of an adhesive layer with high-frequency dielectric adhesiveness. Note that the high-frequency dielectric heating adhesive sheet is not limited to the aspect of consisting of only one layer of the adhesive layer. Another aspect of the high-frequency dielectric heating adhesive sheet includes an aspect where layers other than the adhesive layer are laminated. As described above, since the high-frequency dielectric heating adhesive sheet may consist of only one layer of an adhesive layer with high-frequency dielectric adhesiveness, in this specification, the term "high-frequency dielectric heating adhesive sheet" and the term "adhesive layer" can be interchanged with each other in some cases. Schematic diagrams of a plurality of aspects of the high-frequency dielectric heating adhesive sheet according to this embodiment are illustrated in FIGS. 1A to 1C.

[0085] The high-frequency dielectric heating adhesive sheet 1A shown in FIG. 1A is composed of only a single adhesive layer 10. The high-frequency dielectric heating adhesive sheet 1A has a first surface 11 and a second surface 12 opposite to the first surface 11. The high-frequency dielectric heating adhesive sheet preferably consists of only a single adhesive layer. By consisting of only a single adhesive layer, the thickness of the high-frequency dielectric heating adhesive sheet can be reduced, and it can be easily formed.

[0086] The high-frequency dielectric heating adhesive sheet 1B shown in FIG. 1B has an adhesive layer 10 and a base material 30 that supports the adhesive layer 10. Similar to the high-frequency dielectric heating adhesive sheet 1A, the adhesive layer 10 has a first surface 11. The base material 30 is not particularly limited as long as it can support the adhesive layer 10. For example, it includes at least one resin film or resin sheet selected from the group consisting of polyolefin resins such as polyethylene resin and polypropylene resin, polyester resins such as polybutylene terephthalate resin and polyethylene terephthalate resin, acetate resin, ABS resin, polystyrene resin, and vinyl chloride resin. The base material 30 may contain a dielectric filler (B), and the dielectric filler (B) in the adhesive layer 10 and the dielectric filler in the base material 30 may be the same as or different from each other.

[0087] The high-frequency dielectric heating adhesive sheet 1C shown in FIG. 1C has an adhesive layer 10, an adhesive layer 20, and an intermediate layer 40 disposed between the adhesive layer 10 and the adhesive layer 20. The high-frequency dielectric heating adhesive sheet 1C has a first surface 11 and a second surface 21 opposite to the first surface 11. In the high-frequency dielectric heating adhesive sheet 1C, the adhesive layer 10 may be referred to as the first adhesive layer, and the adhesive layer 20 may be referred to as the second adhesive layer. In the high-frequency dielectric heating adhesive sheet having a configuration in which an intermediate layer is disposed between the first adhesive layer and the second adhesive layer, it is sufficient that the first adhesive layer satisfies the conditions of the adhesive layer of the high-frequency dielectric heating adhesive sheet according to the present embodiment. In one aspect, both the first adhesive layer and the second adhesive layer are layers having the same composition and characteristics. In one aspect, the second adhesive layer is a high-frequency dielectric heating adhesive layer that is different from the first adhesive layer in at least one of composition and characteristics. In one aspect, the second adhesive layer is a layer of a general adhesive that is not a high-frequency dielectric heating adhesive layer. Examples of the second adhesive layer that is not a high-frequency dielectric heating adhesive layer include a layer of a drying and solidifying type adhesive in which water or a solvent evaporates and dries and solidifies, or a layer of an adhesive formed from an adhesive (pressure-sensitive adhesive).

[0088] · Thickness of the high-frequency dielectric heating adhesive sheet The thickness of the high-frequency dielectric heating adhesive sheet according to the present embodiment is preferably 5 μm or more, more preferably 10 μm or more, further preferably 30 μm or more, and even more preferably 50 μm or more. If the thickness of the high-frequency dielectric heating adhesive sheet is 5 μm or more, when adhering to the adherend, the high-frequency dielectric heating adhesive sheet easily follows the unevenness of the adherend, and the adhesive strength is easily developed. When the high-frequency dielectric heating adhesive sheet has a multilayer structure composed of a plurality of layers, the thickness of the adhesive layer is preferably 5 μm or more, more preferably 10 μm or more, further preferably 30 μm or more, and even more preferably 50 μm or more. When the high-frequency dielectric heating adhesive sheet is a sheet having a multilayer structure, if the thickness of the adhesive layer is 5 μm or more, when adhering to the adherend, the adhesive layer easily follows the unevenness of the adherend, and the adhesive strength is easily developed. The upper limit of the thickness of the high-frequency dielectric heating adhesive sheet is not particularly limited. As the thickness of the high-frequency dielectric heating adhesive sheet increases, the weight of the entire bonded body obtained by bonding the high-frequency dielectric heating adhesive sheet and the adherend also increases. Therefore, the high-frequency dielectric heating adhesive sheet preferably has a thickness within a range that causes no problems in actual use. Considering the practicality and moldability of the high-frequency dielectric heating adhesive sheet, the thickness of the high-frequency dielectric heating adhesive sheet is preferably 2000 μm or less, more preferably 1000 μm or less, and even more preferably 600 μm or less.

[0089] As an adhesive sheet for high-frequency dielectric heating, compared with the case of using a liquid adhesive that requires coating, it is easier to handle and the workability during bonding with the adherend is also improved.

[0090] In addition, as an adhesive sheet for high-frequency dielectric heating, the sheet thickness and the like can be appropriately controlled. Therefore, the adhesive sheet can also be applied in a roll-to-roll manner, and by punching or the like, the adhesive sheet can be processed into an arbitrary area and shape according to the adhesion area with the adherend and the shape of the adherend. Therefore, the adhesive sheet as an adhesive for high-frequency dielectric heating has great advantages also from the viewpoint of the manufacturing process.

[0091] (Molded body) The adhesive for high-frequency dielectric heating according to the present embodiment is preferably a molded body. The form of the molded body according to the present embodiment is not particularly limited. FIGS. 3A to 3C show schematic perspective views showing examples of the form of the molded body according to the present embodiment. The molded body according to the present embodiment may be a molded body composed of a single part obtained by molding the adhesive for high-frequency dielectric heating according to the present embodiment, or may be a molded body composed of a plurality of parts. For example, a molded body having a first part made of the adhesive for high-frequency dielectric heating (first material) according to the present embodiment and a second part made of a second material different from the first material of the first part can be mentioned.

[0092] The shape of the molded body 1D shown in FIG. 3A is a cube. The molded body 1D has a first part 10D and a second part 20D having a volume larger than that of the first part 10D.

[0093] The shape of the molded body 1E shown in FIG. 3B is also a cube. The molded body 1D and the molded body 1E differ in the position and ratio of the first part occupying the cube. In the molded body 1D, the first part 10D is in contact with the entire bottom surface of the second part 20D. On the other hand, in the molded body 1E, the first part 10E is located at the corner of the cube and is in contact with the second part 20E.

[0094] The molded body according to the present embodiment may have a plurality of first parts. For example, the molded body 1F shown in FIG. 3C has a hollow substantially cylindrical second part 20F that is partially cut out along the axial direction, and two first parts 10F that are in contact with the two cut end faces of the cylinder of the second part 20F. The number of first parts in the molded body is not limited to two, and may be three or more.

[0095] The form of the molded body according to the present invention is not limited to the examples shown in the molded bodies 1D, 1E, and 1F. Also, in the examples shown in the molded bodies 1D, 1E, and 1F, the first part and the second part are in direct contact, but the present invention is not limited to the aspect in which the first part and the second part are in direct contact, and the first part and the second part may be in contact via other parts (for example, a third part, etc.).

[0096] In the molded body according to the present embodiment, the second part is made of a second material. The second material is not particularly limited. The second material preferably contains at least one material selected from the group consisting of, for example, organic materials, inorganic materials, and natural-derived materials. Examples of organic materials include thermoplastic resins and thermosetting resins. Examples of inorganic materials include ceramics, glass, and metals. Examples of natural-derived materials include wood, paper, leather, and stone. In the molded body according to this embodiment, the first material and the second material are different. That the first material and the second material are different means that all the components contained in the first material and all the components contained in the second material do not match. For example, when the first material is a material containing a silane-modified thermoplastic resin (first thermoplastic resin (A1)), another thermoplastic resin different from the silane-modified thermoplastic resin (second thermoplastic resin (A2)), and zinc oxide, and the second material is a material containing only the silane-modified thermoplastic resin, since the second material does not contain other thermoplastic resins and zinc oxide, all the components do not match between the first material and the second material, and the first material and the second material are different.

[0097] (Method for manufacturing an adhesive for high-frequency dielectric heating) The adhesive for high-frequency dielectric heating according to this embodiment can be manufactured, for example, by mixing the above-described components. When the adhesive for high-frequency dielectric heating according to this embodiment is an adhesive sheet, the manufacturing method is not particularly limited. For example, it can be manufactured as follows. A single-layer high-frequency dielectric heating adhesive sheet is prepared by premixing the above-described components and kneading them using a known kneading device such as an extruder and a hot roll, and can be manufactured by a known molding method such as extrusion molding, calender molding, injection molding, and casting molding. When the high-frequency dielectric heating adhesive sheet according to this embodiment has a multilayer structure, for example, it can be manufactured by premixing the above-described components and using a coextrusion method using a multilayer extruder. Also, by separately producing single-layer sheets of each layer (for example, the first adhesive layer, the intermediate layer, and the second adhesive layer) constituting the high-frequency dielectric heating adhesive sheet according to this embodiment and laminating and stacking a plurality of single-layer sheets, a multilayer sheet can also be manufactured. When laminating a plurality of single-layer sheets, for example, a hot laminator is used. In addition, the high-frequency dielectric heating adhesive sheet according to this embodiment can also be manufactured by hot extrusion coating or hot melt coating in which a molten adhesive layer is coated on a base material, or by wet coating in which a coating solution in which an adhesive layer composition is dispersed or dissolved in a solvent is coated on a base material.

[0098] When the adhesive for high-frequency dielectric heating according to the present embodiment is a molded body, the manufacturing method is not particularly limited. For example, it can be manufactured as follows. When the molded body according to the present embodiment is a molded body composed of a single part obtained by molding an adhesive for high-frequency dielectric heating (first material), it can be manufactured by a single-color molding method. When the molded body according to the present embodiment is a multi-color molded body having a plurality of parts such as the molded bodies shown in FIGS. 3A to 3C, it can be manufactured by a multi-color molding method using a plurality of materials (for example, the first material and the second material). Alternatively, a molded body composed of a single part obtained by molding an adhesive for high-frequency dielectric heating (first material) may be fitted into another molded body to manufacture a multi-color molded body.

[0099] In addition, a multi-color molded body can be manufactured by an insert molding method using a first molded body made of one of the first material and the second material and the other of the first material and the second material. For example, even when the material of the second material is metal or ceramic, a second part made of metal or ceramic having a desired shape may be prepared, and the molded body according to the present embodiment may be manufactured by an insert molding method using this second part and the first material.

[0100] In addition, for example, the molded body according to the present embodiment can be manufactured by an insert molding method using a first molded body molded by an injection molding method or a compression molding method using one of the first material and the second material and the other of the first material and the second material and the first molded body. For example, the first molded body is molded by an injection molding method or a compression molding method using the second material. This first molded body corresponds to the second part. Next, the molded body may be manufactured by an insert molding method using the first material and the first molded body. The part made of the first material formed during insert molding corresponds to the first part.

[0101] (Method of using the adhesive for high-frequency dielectric heating) The adhesive for high-frequency dielectric heating according to the present embodiment can be used for adhesion to an adherend. In addition, the adhesive for high-frequency dielectric heating according to the present embodiment can also be used for adhesion between a plurality of adherends. The material of the adherend is not particularly limited. The material of the adherend may be any of organic materials and inorganic materials (including metal materials, etc.), or a composite material of an organic material and an inorganic material. Examples of the organic material as the material of the adherend include plastic materials and rubber materials. Examples of the plastic material include polypropylene resin, polyethylene resin, polyurethane resin, acrylonitrile-butadiene-styrene copolymer resin (ABS resin), polycarbonate resin (PC resin), polyamide resin (nylon 6, nylon 66, etc.), polyester resin (polyethylene terephthalate (PET resin), polybutylene terephthalate resin (PBT resin), etc.), polyacetal resin (POM resin), polymethyl methacrylate resin, and polystyrene resin. Examples of the rubber material include styrene-butadiene rubber (SBR), ethylene-propylene rubber (EPR), and silicone rubber. Further, the adherend may be a foam material of an organic material. Examples of the inorganic material as the material of the adherend include glass materials, cement materials, ceramic materials, and metal materials. Further, the adherend may be a fiber-reinforced resin (Fiber Reinforced Plastics, FRP) which is a composite material of a fiber and the above-described plastic material. The plastic material in this fiber-reinforced resin is at least one selected from the group consisting of, for example, polypropylene resin, polyethylene resin, polyurethane resin, acrylonitrile-butadiene-styrene copolymer resin (ABS resin), polycarbonate resin (PC resin), polyamide resin (nylon 6, nylon 66, etc.), polyester resin (polyethylene terephthalate (PET resin), polybutylene terephthalate resin (PBT resin), etc.), polyacetal resin (POM resin), polymethyl methacrylate resin, and polystyrene resin. Examples of the fiber in the fiber-reinforced resin include glass fiber, Kevlar fiber, and carbon fiber. When a plurality of adherends are adhered to each other using the adhesive for high-frequency dielectric heating according to the present embodiment, the plurality of adherends may be of the same material or different materials from each other. The adhesive for high-frequency dielectric heating according to this embodiment can be suitably used for adhering to a glass adherend. When adhering a plurality of adherends to each other, if at least one of the adherends is made of glass, the adhesive for high-frequency dielectric heating according to this embodiment can firmly adhere to the glass adherend. The shape of the adherend is not particularly limited, but it preferably has a surface to which the adhesive for high-frequency dielectric heating can be bonded, and is preferably sheet-shaped or plate-shaped. When adhering a plurality of adherends to each other, the shapes and dimensions of these adherends may be the same or different from each other.

[0102] [Adhesion method] The adhesion method according to this embodiment is an adhesion method using the adhesive for high-frequency dielectric heating according to this embodiment. Hereinafter, as an example of the adhesion method according to this embodiment, a mode of adhering a first adherend and a second adherend using a high-frequency dielectric heating adhesive sheet composed of a single adhesive layer will be described, but the present invention is not limited to this mode. The material of the second adherend is also not particularly limited.

[0103] The adhesion method according to one aspect of this embodiment includes the following steps P1 and P2.

[0104] · Step P1 Step P1 is a step of sandwiching the high-frequency dielectric heating adhesive sheet according to this embodiment between the first adherend and the second adherend. In step P1, the first adherend made of glass is brought into contact with the first surface of the high-frequency dielectric heating adhesive sheet. Also, in step P1, the second adherend is brought into contact with the second surface of the high-frequency dielectric heating adhesive sheet.

[0105] The high-frequency dielectric heating adhesive sheet may be sandwiched between a first adherend and a second adherend so as to be able to bond the first adherend and the second adherend. The high-frequency dielectric heating adhesive sheet may be sandwiched at a part, at a plurality of locations, or over the entire surface between the first adherend and the second adherend. From the viewpoint of improving the bonding strength between the first adherend and the second adherend, it is preferable to sandwich the high-frequency dielectric heating adhesive sheet over the entire bonding surface between the first adherend and the second adherend. Further, as one aspect of sandwiching the high-frequency dielectric heating adhesive sheet at a part between the first adherend and the second adherend, there is an aspect in which the high-frequency dielectric heating adhesive sheet is arranged in a frame shape along the outer periphery of the bonding surface between the first adherend and the second adherend and sandwiched between the first adherend and the second adherend. By arranging the high-frequency dielectric heating adhesive sheet in a frame shape in this way, the bonding strength between the first adherend and the second adherend can be obtained, and the weight of the joined body can be reduced as compared with the case where the high-frequency dielectric heating adhesive sheet is arranged over the entire bonding surface. Further, according to one aspect of sandwiching the high-frequency dielectric heating adhesive sheet at a part between the first adherend and the second adherend, the size of the high-frequency dielectric heating adhesive sheet to be used can be reduced, so that the high-frequency dielectric heating treatment time can be shortened as compared with the case where the high-frequency dielectric heating adhesive sheet is arranged over the entire bonding surface.

[0106] · Step P2 Step P2 is a step of applying a high-frequency electric field of 3 MHz or more and 300 MHz or less to the high-frequency dielectric heating adhesive sheet sandwiched between the first adherend and the second adherend in Step P1, and bonding the first adherend and the second adherend with the high-frequency dielectric heating adhesive sheet. For example, by using a dielectric heating bonding device, a high-frequency electric field can be applied to the high-frequency dielectric heating adhesive sheet. In this specification, the "dielectric heating device" may sometimes be referred to as a "dielectric heating bonding device" or a "high-frequency dielectric heating device".

[0107] FIG. 2 shows a schematic diagram for explaining the high-frequency dielectric heating treatment using the high-frequency dielectric heating adhesive sheet and the dielectric heating device according to the present embodiment.

[0108] (Dielectric heating bonding device) Figure 2 shows a schematic diagram of the dielectric heating adhesion device 50. The dielectric heating adhesion device 50 includes a first high-frequency electric field application electrode 51, a second high-frequency electric field application electrode 52, and a high-frequency power supply 53. The first high-frequency electric field application electrode 51 and the second high-frequency electric field application electrode 52 are arranged opposite to each other. The first high-frequency electric field application electrode 51 and the second high-frequency electric field application electrode 52 have a pressing mechanism. By this pressing mechanism, the first adherend 110, the high-frequency dielectric heating adhesive sheet 1A, and the second adherend 120 can be pressure-treated between the first high-frequency electric field application electrode 51 and the second high-frequency electric field application electrode 52.

[0109] When the first high-frequency electric field application electrode 51 and the second high-frequency electric field application electrode 52 constitute a pair of parallel flat electrodes, such a form of electrode arrangement may be referred to as a parallel plate type. It is also preferable to use a parallel plate type high-frequency dielectric heating device for applying the high-frequency electric field. In the case of a parallel plate type high-frequency dielectric heating device, since the high-frequency electric field penetrates the high-frequency dielectric heating adhesive sheet located between the electrodes, the entire high-frequency dielectric heating adhesive sheet can be heated, and the adherend and the high-frequency dielectric heating adhesive sheet can be adhered in a short time.

[0110] A high-frequency power supply 53 for applying a high-frequency electric field of, for example, about 13.56 MHz, about 27.12 MHz, or about 40.68 MHz is connected to each of the first high-frequency electric field application electrode 51 and the second high-frequency electric field application electrode 52. As shown in FIG. 2, the dielectric heating and bonding apparatus 50 performs dielectric heating through the high-frequency dielectric heating and bonding sheet 1A sandwiched between the first adherend 110 and the second adherend 120. Further, in addition to the dielectric heating process, the dielectric heating and bonding apparatus 50 bonds the first adherend 110 and the second adherend 120 by a pressing process using the first high-frequency electric field application electrode 51 and the second high-frequency electric field application electrode 52. Note that, without performing the pressing process, the first adherend 110 and the second adherend 120 may be bonded by pressing only with, for example, the weight of the bonding sheet or the adherend. Note that the first adherend 110 and the second adherend 120 may be bonded without performing the pressing process.

[0111] When a high-frequency electric field is applied between the first high-frequency electric field application electrode 51 and the second high-frequency electric field application electrode 52, a dielectric filler (not shown) dispersed in the adhesive component in the high-frequency dielectric heating and bonding sheet 1A absorbs high-frequency energy. Then, the dielectric filler functions as a heat source, and the heat generated by the dielectric filler melts the thermoplastic resin component, and finally, the first adherend 110 and the second adherend 120 can be firmly bonded even in a short-time process.

[0112] Since the first high-frequency electric field application electrode 51 and the second high-frequency electric field application electrode 52 have a pressing mechanism, they also function as a pressing device. Therefore, by pressing in the compression direction by the first high-frequency electric field application electrode 51 and the second high-frequency electric field application electrode 52 and heating and melting the high-frequency dielectric heating and bonding sheet 1A, the first adherend 110 and the second adherend 120 can be bonded more firmly.

[0113] (High-frequency dielectric heating and bonding conditions) The high-frequency dielectric heating and bonding conditions can be changed as appropriate, but are preferably the following conditions.

[0114] The output of the high-frequency electric field is preferably 10 W or more, more preferably 30 W or more, still more preferably 50 W or more, and even more preferably 80 W or more. The output of the high-frequency electric field is preferably 50,000 W or less, more preferably 20,000 W or less, still more preferably 15,000 W or less, even more preferably 10,000 W or less, and yet even more preferably 1,000 W or less. If the output of the high-frequency electric field is 10 W or more, it is possible to prevent the problem that the temperature hardly rises during the dielectric heat treatment, so that a good adhesive force can be easily obtained. If the output of the high-frequency electric field is 50,000 W or less, it is easy to prevent the problem that temperature control by the dielectric heat treatment becomes difficult.

[0115] The application time of the high-frequency electric field is preferably 1 second or more. The application time of the high-frequency electric field is preferably 300 seconds or less, more preferably 240 seconds or less, still more preferably 180 seconds or less, even more preferably 120 seconds or less, and yet even more preferably 100 seconds or less. If the application time of the high-frequency electric field is 1 second or more, it is possible to prevent the problem that the temperature hardly rises during the dielectric heat treatment, so that a good adhesive force can be easily obtained. If the application time of the high-frequency electric field is 300 seconds or less, it is easy to prevent problems such as a decrease in the production efficiency of the bonded body obtained by bonding the first adherend and the second adherend, an increase in the production cost, and further thermal deterioration of the adherend.

[0116] The frequency of the high-frequency electric field to be applied is preferably 1 kHz or more, more preferably 1 MHz or more, still more preferably 5 MHz or more, and even more preferably 10 MHz or more. The frequency of the high-frequency electric field to be applied is preferably 300 MHz or less, more preferably 100 MHz or less, still more preferably 80 MHz or less, and even more preferably 50 MHz or less. Specifically, the industrial frequency bands 13.56 MHz, 27.12 MHz, or 40.68 MHz assigned by the International Telecommunication Union are also used in the high-frequency dielectric heating bonding method (bonding method) of the present embodiment.

[0117] (Effects of this Embodiment) According to the adhesive for high-frequency dielectric heating according to this embodiment, even with low energy consumption, it can adhere to glass with high adhesive strength. Furthermore, the adhesive for high-frequency dielectric heating according to this embodiment is an adhesive whose adhesive force is difficult to decrease over time and also has excellent long-term storage stability.

[0118] The adhesive for high-frequency dielectric heating according to this embodiment is superior in water resistance and moisture resistance compared to general adhesives.

[0119] Since the adhesive for high-frequency dielectric heating according to this embodiment is heated by the application of a high-frequency electric field, the adhesive for high-frequency dielectric heating is locally heated. Therefore, according to the adhesive for high-frequency dielectric heating according to this embodiment, it is easy to prevent the problem that the entire adherend melts during adhesion to the adherend.

[0120] According to the bonding method using the adhesive for high-frequency dielectric heating according to this embodiment, only a predetermined portion can be locally heated from the outside by a dielectric heating bonding apparatus. Therefore, even when the adherend is a large and complex three-dimensional structure or a thick and complex three-dimensional structure, etc., and higher dimensional accuracy is required, the bonding method using the adhesive for high-frequency dielectric heating according to this embodiment is effective.

[0121] 〔Modifications of the Embodiment〕 The present invention is not limited to the above-described embodiment. The present invention can include modifications, improvements, etc. within the scope that can achieve the object of the present invention.

[0122] The high-frequency dielectric heating adhesive sheet may have an adhesive portion. By having an adhesive portion, when sandwiching the high-frequency dielectric heating adhesive sheet between adherends, displacement can be prevented and it can be arranged at an accurate position. The adhesive portion may be provided on one surface of the high-frequency dielectric heating adhesive sheet or on both surfaces. Also, the adhesive portion may be provided partially with respect to the surface of the high-frequency dielectric heating adhesive sheet. Even when the high-frequency dielectric heating adhesive sheet does not have an adhesive portion, the first adherend and the second adherend can be firmly adhered.

[0123] The high-frequency dielectric heat treatment is not limited to the dielectric heat bonding apparatus in which the electrodes described in the above embodiment are arranged to face each other, and a grid electrode type high-frequency dielectric heating apparatus may be used. The grid electrode type high-frequency dielectric heating apparatus has a grid electrode in which electrodes of a first polarity and electrodes of a second polarity opposite to the electrodes of the first polarity are alternately arranged on the same plane at regular intervals. For example, when manufacturing a joined body by overlapping and bonding the end portion of the first adherend and the end portion of the second adherend, a grid electrode type high-frequency dielectric heating apparatus is arranged on the first adherend side or the second adherend side to apply a high-frequency electric field.

[0124] When bonding the first adherend and the second adherend using a grid electrode type high-frequency dielectric heating apparatus, a first grid electrode is arranged on the first adherend side, and a second grid electrode is arranged on the second adherend side, and the first adherend, the adhesive for high-frequency dielectric heating, and the second adherend are sandwiched between the first grid electrode and the second grid electrode, and a high-frequency electric field may be applied simultaneously.

[0125] When bonding the first adherend and the second adherend using a grid electrode type high-frequency dielectric heating apparatus, a grid electrode may be arranged on one surface side of the first adherend and the second adherend to apply a high-frequency electric field, and then a grid electrode may be arranged on the other surface side of the first adherend and the second adherend to apply a high-frequency electric field.

[0126] It is also preferable to use a grid electrode type high-frequency dielectric heating apparatus for applying the high-frequency electric field. By using a grid electrode type high-frequency dielectric heating apparatus, the first adherend and the second adherend are not affected by the thickness, and dielectric heating is performed from the adherend side where the distance to the surface layer side of the first adherend and the second adherend, for example, the adhesive for high-frequency dielectric heating, is short, so that the adherends can be bonded to each other. Further, by using a grid electrode type high-frequency dielectric heating apparatus, energy saving in the manufacture of the joined body can be realized.

[0127] In the figure, for the sake of simplicity, an embodiment using a dielectric heat bonding apparatus in which electrodes are arranged to face each other is illustrated.

Example

[0128] Hereinafter, the present invention will be described in more detail with reference to examples. The present invention is not limited to these examples at all.

[0129] [Preparation of Adhesive for High-Frequency Dielectric Heating] (Examples 1 to 5 and Comparative Examples 1 to 2) The materials shown in Table 1 were preliminarily mixed. The preliminarily mixed materials were supplied to the hopper of a 30 mmφ twin-screw extruder, the cylinder set temperature was set to 180°C or higher and 200°C or lower, the die temperature was set to 200°C, and the preliminarily mixed materials were melt-kneaded. After cooling the melt-kneaded materials, the materials were cut to produce granular pellets. Next, the produced granular pellets were put into the hopper of a single-screw extruder equipped with a T-die, and under the conditions of a cylinder temperature of 200°C and a die temperature of 200°C, a film-like melt-kneaded product was extruded from the T-die and cooled by a cooling roll to produce sheets of the adhesive for high-frequency dielectric heating (high-frequency dielectric heating adhesive sheet) with a thickness of 400 μm according to Examples 1 to 5 and Comparative Examples 1 to 2, respectively.

[0130] The descriptions of the thermoplastic resins and fillers shown in Table 1 are as follows. · Silane-modified PP: Silane-modified polypropylene, manufactured by Mitsubishi Chemical Corporation, product name "Linkron PM700N" · Silane-modified PE: Silane-modified polyethylene, manufactured by Mitsubishi Chemical Corporation, product name "Linkron SS732N" · m-PP: Maleic anhydride-modified polypropylene, manufactured by Mitsubishi Chemical Corporation, product name "Modic P565" · PP: Polypropylene, manufactured by Prime Polymer Co., Ltd., product name "Prime Polypro F-744NP" · m-PE: Maleic anhydride-modified polyethylene, manufactured by Mitsubishi Chemical Corporation, product name "Modic M545" · Zinc oxide (ZnO): Zinc oxide with a volume average particle diameter of 11 μm. Manufactured by Sakai Chemical Industry Co., Ltd., product name "LP-ZINC11"

[0131] (MFR: Melt flow rate) The MFR of the thermoplastic resin at 190 °C was measured using a falling-type flow tester (manufactured by Shimadzu Corporation, model number "CFT-100D") in accordance with JIS K 7210-1:2014. When using a mixture of multiple types of thermoplastic resins, the multiple types of resins were melt-kneaded by a twin-screw extruder at the ratios shown in Table 1 to produce mixed resin pellets, and the MFR of the mixed resin pellets was measured in the same manner as described above.

[0132] (Volume average particle diameter of the dielectric filler) The particle size distribution of the dielectric filler was measured by the laser diffraction / scattering method. The volume average particle diameter was calculated in accordance with JIS Z 8819-2:2001 from the results of the particle size distribution measurement. The calculated volume average particle diameter of zinc oxide (ZnO) was 11 μm.

[0133] [Evaluation of the high-frequency dielectric heating adhesive sheet] The high-frequency dielectric heating adhesive sheet was evaluated as shown below, and the evaluation results are shown in Table 1.

[0134] (Adhesive strength (tensile shear strength)) As one index for evaluating the high-frequency adhesiveness, the adhesive strength (tensile shear strength) was evaluated. The produced high-frequency dielectric heating adhesive sheet was cut into a size of 25 mm × 12.5 mm. The cut high-frequency dielectric heating adhesive sheet was placed between soda-lime glasses (25 mm × 100 mm × 3 mm (thickness)) as a pair of adherends (the first adherend and the second adherend) so as to coincide with the overlapping portion of the adherends. After arranging in this manner, the pair of adherends and the high-frequency dielectric heating adhesive sheet were fixed between the electrodes of a high-frequency dielectric heating apparatus (manufactured by Yamamoto Vinita Co., Ltd., product name "YRP-400T-A"). The area of each of the pair of electrodes of the high-frequency dielectric heating apparatus was 800 mm 2 (= 40 mm × 20 mm), and the pair of electrodes was arranged so as to cover the overlapping portion of the adherends (soda-lime glasses). While in the fixed state, a high-frequency electric field was applied under the following high-frequency application conditions to bond the high-frequency dielectric heating adhesive sheet and the adherends, and a test piece for evaluating the adhesive strength was produced. In addition, the fabricated high-frequency dielectric heating adhesive sheet was separately stored for a long time under high-temperature and high-humidity conditions (stored for one week under the conditions of 50°C and 95% RH), and then test pieces for adhesive strength evaluation were fabricated in the same manner as above.

[0135] · High-frequency application conditions Frequency: 40.68 MHz Output: 150 W Application time: 20 seconds Pressing pressure: 0.5 MPa The pressing pressure during high-frequency application is the pressure applied to the joint between the first adherend and the second adherend.

[0136] The test piece fabricated using the high-frequency dielectric heating adhesive sheet before long-term storage under high-temperature and high-humidity conditions was used as the test piece before the acceleration test, and the test piece fabricated using the high-frequency dielectric heating adhesive sheet after long-term storage was used as the test piece after the acceleration test. Using these test pieces, the tensile shear strength (unit: MPa) as the adhesive strength was measured. For the measurement of the tensile shear strength, a universal tensile testing machine (manufactured by Instron, product name "Instron 5581") was used. The tensile speed in the measurement of the tensile shear strength was set to 10 mm / min. Note that ">4.0" in the table means that the tensile shear strength exceeded 4.0 MPa. The tensile shear strength was measured in accordance with JIS K 6850:1999.

[0137]

Table 1

[0138] Since the high-frequency dielectric heating adhesive sheets of Examples 1 to 5 contain a silane-modified thermoplastic resin and a non-silane-modified thermoplastic resin as the thermoplastic resin, even with low energy consumption, glass adherends can be adhered with high adhesive strength, the tensile shear strength before the acceleration test is high, and the tensile shear strength after the acceleration test is also equal to or higher, and the adhesive strength does not decrease over time, making it an adhesive sheet with high long-term storage stability. Since the high-frequency dielectric heating adhesive sheet of Comparative Example 1 contains a silane-modified thermoplastic resin as the thermoplastic resin, the tensile shear strength before the acceleration test was high. However, the high-frequency dielectric heating adhesive sheet of Comparative Example 1 does not contain a thermoplastic resin that is not silane-modified, and the tensile shear strength after the acceleration test decreased significantly. Thus, the high-frequency dielectric heating adhesive sheet of Comparative Example 1 was an adhesive sheet with an adhesive strength that easily decreased over time and had low long-term storage stability. Since the high-frequency dielectric heating adhesive sheet of Comparative Example 2 does not contain a silane-modified thermoplastic resin as the thermoplastic resin, it did not adhere to the glass.

Description of Reference Numerals

[0139] 10…Adhesive layer (first adhesive layer), 10D…First part, 10E…First part, 10F…First part, 11…First surface, 12…Second surface, 110…First adherend, 120…Second adherend, 1A…High-frequency dielectric heating adhesive sheet, 1B…High-frequency dielectric heating adhesive sheet, 1C…High-frequency dielectric heating adhesive sheet, 1D…Molded body, 1E…Molded body, 1F…Molded body, 20…Adhesive layer (second adhesive layer), 20D…Second part, 20E…Second part, 20F…Second part, 21…Second surface, 30…Base material, 40…Intermediate layer, 50…Dielectric heating adhesive device, 51…First high-frequency electric field application electrode, 52…Second high-frequency electric field application electrode, 53…High-frequency power supply.

Claims

Claim 1 An adhesive for high-frequency dielectric heating, wherein the adhesive for high-frequency dielectric heating contains at least a thermoplastic resin (A) and a dielectric material that generates heat when a high-frequency electric field with a frequency range of 3 MHz or more and 300 MHz or less is applied, the thermoplastic resin (A) contains at least a first thermoplastic resin (A1) and a second thermoplastic resin (A2), the first thermoplastic resin (A1) is a silane-modified thermoplastic resin, the second thermoplastic resin (A2) is an unmodified silane thermoplastic resin, the second thermoplastic resin (A2) has a polar part, the dielectric material is a dielectric filler (B), the dielectric filler (B) is zinc oxide, An adhesive for high-frequency dielectric heating. Claim 2 In the adhesive for high-frequency dielectric heating according to Claim 1, the first thermoplastic resin (A1) is a silane-modified polyolefin resin, An adhesive for high-frequency dielectric heating. Claim 3 In the adhesive for high-frequency dielectric heating according to Claim 1 or Claim 2, the second thermoplastic resin (A2) is an unmodified silane polyolefin resin, An adhesive for high-frequency dielectric heating. Claim 4 In the adhesive for high-frequency dielectric heating according to any one of Claims 1 to 3, the polar part of the second thermoplastic resin (A2) is an acidic part, An adhesive for high-frequency dielectric heating. Claim 5 In the adhesive for high-frequency dielectric heating according to Claim 4, the acidic part of the second thermoplastic resin (A2) is an acid anhydride structure, An adhesive for high-frequency dielectric heating. Claim 6 In the adhesive for high-frequency dielectric heating according to any one of Claims 1 to 5, the most frequently contained repeating unit in the polymer of the first thermoplastic resin (A1) is ethylene or propylene, An adhesive for high-frequency dielectric heating. Claim 7 In the adhesive for high-frequency dielectric heating according to any one of Claims 1 to 6, the most frequently contained repeating unit in the polymer of the second thermoplastic resin (A2) is ethylene or propylene, An adhesive for high-frequency dielectric heating. Claim 8 In the adhesive for high-frequency dielectric heating according to any one of Claims 1 to 7, the most frequently contained repeating unit in the polymer of the first thermoplastic resin (A1) and the most frequently contained repeating unit in the polymer of the second thermoplastic resin (A2) are the same, An adhesive for high-frequency dielectric heating. Claim 9 In the adhesive for high-frequency dielectric heating according to any one of claims 1 to 8, The volume content of the first thermoplastic resin (A1) in the thermoplastic resin (A) contained in the adhesive for high-frequency dielectric heating is 15% by volume or more and 80% by volume or less. Adhesive for high-frequency dielectric heating.

10. In the adhesive for high-frequency dielectric heating according to any one of claims 1 to 9, The MFR of the thermoplastic resin (A) at 190 ° C is 2 g / 10 min or more and 50 g / 10 min or less. Adhesive for high-frequency dielectric heating.

11. In the adhesive for high-frequency dielectric heating according to any one of claims 1 to 10, The volume content of the dielectric material in the adhesive for high-frequency dielectric heating is 5% by volume or more and 50% by volume or less. Adhesive for high-frequency dielectric heating.

12. In the adhesive for high-frequency dielectric heating according to any one of claims 1 to 11, The volume average particle diameter of the dielectric filler (B) is 1 μm or more and 30 μm or less, The volume average particle diameter is the volume average particle diameter calculated in accordance with JIS Z 8819-2: 2001 from the results of measuring the particle size distribution of the dielectric filler (B) by the laser diffraction / scattering method. Adhesive for high-frequency dielectric heating.

13. The adhesive for high-frequency dielectric heating is an adhesive sheet. The adhesive for high-frequency dielectric heating according to any one of claims 1 to 12.

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