Molded body, joining method, and method for manufacturing molded body

Abstract

A molded body (1A) has: a first portion (10) composed of a first material containing a first thermoplastic resin (A1) and a dielectric filler (B) that generates heat by application of a high-frequency electric field; and a second portion (20) composed of a second material different from the first material of the first portion (10).

Description

Technical Field

[0001] This invention relates to molded bodies, joining methods, and methods for manufacturing molded bodies. Background Technology

[0002] In recent years, as a method for bonding objects that are usually difficult to bond together, methods such as dielectric heating treatment, induction heating treatment, ultrasonic welding treatment, or laser welding treatment have been proposed.

[0003] For example, Patent Document 1 describes a technique for fusing the body of an electrofusion joint to the parts to be joined using electromagnetic induction. Furthermore, Patent Document 1 describes embedding a magnetic alloy body near the joint surface of the electrofusion joint body, and applying a high-frequency current to the magnetic alloy body via electromagnetic induction, thereby causing the magnetic alloy body to heat up.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: International Publication No. 92 / 09842 Summary of the Invention

[0007] The technical problem that the invention aims to solve

[0008] The desired is a molded body and a joining method that can join with a bonded body (other molded articles) by a different method, without using the induction heating method described in Patent Document 1, which requires embedding a magnetic alloy body in the body to weld the body and the joined parts.

[0009] The purpose of this invention is to provide a molded body that can be bonded to a substrate (other molded articles) without the use of adhesives by high-frequency medium heating and is difficult to deform during bonding, to provide a bonding method using the molded body, and to provide a manufacturing method of the molded body.

[0010] Technical solutions for solving technical problems

[0011] According to one aspect of the present invention, a molded body is provided, comprising: a first portion comprising a first material including a first thermoplastic resin (A1) and a dielectric filler (B) that is heated by the application of a high-frequency electric field; and a second portion comprising a second material different from the first material of the first portion.

[0012] In one embodiment of the present invention, it is preferred that the volume content of the medium filler (B) in the first part is 5% by volume or more and 50% by volume or less.

[0013] In one embodiment of the present invention, it is preferred that the molded body is not a sheet.

[0014] In one embodiment of the present invention, it is preferred that the flow initiation temperature of the first portion is above 80°C and below 300°C.

[0015] In one embodiment of the present invention, it is preferred that the flow start temperature of the second part is 100°C or higher, or that the second part does not have a flow start temperature.

[0016] In one embodiment of the present invention, it is preferred that the flow start temperature T1 of the first part and the flow start temperature T2 of the second part satisfy the following calculation formula (Formula 2): T1 < T2… (Formula 2).

[0017] In one embodiment of the present invention, preferably, the dielectric property DP1 of the first portion and the dielectric property DP2 of the second portion satisfy the following calculation formula (Formula 1), wherein the dielectric property DP1 and the dielectric property DP2 are the values ​​of the dielectric property (tanδ / ε'r) of the first portion and the second portion, respectively.

[0018] DP1>DP2…(Equation 1),

[0019] The dielectric loss tangent at tanδ is 23℃ and 40.68MHz.

[0020] ε'r is the relative permittivity at 23℃ and 40.68MHz.

[0021] In one embodiment of the present invention, it is preferred that the second material of the second portion comprises a second thermoplastic resin (A2).

[0022] In one embodiment of the present invention, it is preferred that the main composition of the first thermoplastic resin (A1) is the same as that of the second thermoplastic resin (A2).

[0023] In one embodiment of the present invention, the molded body is preferably used for bonding the body to be bonded to the surface of the first portion of the molded body.

[0024] In one embodiment of the present invention, it is preferred that the molded body is used by bringing the electrodes of the dielectric heating device into contact with the surface of the molded body other than the first portion.

[0025] According to one aspect of the present invention, a bonding method is provided, which is a bonding method for bonding any one of the molded bodies of the aforementioned aspect of the present invention with a substrate different from the molded body, comprising: a step of bringing the substrate into contact with the surface of the first portion; a step of bringing the electrode of a dielectric heating device into contact with a surface other than the first portion; and a step of applying a high-frequency electric field to the molded body using the dielectric heating device and bonding the molded body with the substrate.

[0026] According to one aspect of the present invention, a method for manufacturing a molded body is provided, wherein any of the molded bodies of the aforementioned aspect of the present invention is manufactured, and the molded body is shaped using the first material and the second material and by a multi-color molding method.

[0027] According to one aspect of the present invention, a method for manufacturing a molded body is provided, wherein any of the molded bodies of the aforementioned aspect of the present invention is manufactured by using a first molded body composed of one of the first material and the second material, and the other of the first material and the second material, and manufacturing the molded body by an insert molding method.

[0028] According to one aspect of the present invention, a method for manufacturing a molded body is provided, wherein any of the molded bodies of the aforementioned aspect of the present invention is manufactured, the first molded body is formed using one of the first material and the second material by injection molding or compression molding, and the molded body is manufactured using the other of the first material and the second material and the first molded body by insert molding.

[0029] According to one aspect of the present invention, a molded body is provided that can be bonded to a substrate (other molded articles) without the use of adhesives via high-frequency medium heating, and is resistant to deformation during bonding. According to one aspect of the present invention, a bonding method using this molded body is provided. According to one aspect of the present invention, a method for manufacturing this molded body is provided. Attached Figure Description

[0030] Figure 1A This is a schematic perspective view showing an example of the shape of a molded body according to one embodiment.

[0031] Figure 1B This is a schematic perspective view showing an example of the shape of a molded body according to one embodiment.

[0032] Figure 1C This is a schematic perspective view showing an example of the shape of a molded body according to one embodiment.

[0033] Figure 2AThis is a schematic perspective view showing an example of the shape of a joint obtained by joining a molded body of one embodiment with a bonded body.

[0034] Figure 2B This is a schematic perspective view showing an example of the shape of a joint obtained by joining a molded body of one embodiment with a bonded body.

[0035] Figure 2C This is a schematic perspective view showing an example of the shape of a joint obtained by joining a molded body of one embodiment with a bonded body.

[0036] Figure 3 This is a schematic diagram illustrating a high-frequency dielectric heating process using a molded body and a dielectric heating device according to one embodiment.

[0037] Figure 4A This is a top view of the molded body produced in the embodiment.

[0038] Figure 4B yes Figure 4A A side view of the molded body. Detailed Implementation

[0039] The molded body of this embodiment has a first part and a second part. The first part is made of a first material comprising a first thermoplastic resin (A1) and a dielectric filler (B) that generates heat upon application of a high-frequency electric field. The second part is made of a second material different from the first material of the first part. It should be noted that a high-frequency electric field refers to an electric field that is high-frequency and reverses direction.

[0040] <Part One>

[0041] The first part is composed of a first material comprising a first thermoplastic resin (A1) and a dielectric filler (B) that is heated by the application of a high-frequency electric field.

[0042] <First thermoplastic resin (A1)>

[0043] (Thermoplastic resin)

[0044] The type of the first thermoplastic resin (A1) is not limited.

[0045] The first thermoplastic resin (A1) is preferably selected from at least one group consisting of polyolefin resins, styrene resins, polyacetal resins, polycarbonate resins, polyacrylic resins, polyamide resins, polyimide resins, polyvinyl acetate resins, phenoxy resins, and polyester resins, for example, from the perspective of easy melting and having specified heat resistance.

[0046] In the molded body of this embodiment, the first thermoplastic resin (A1) is preferably a polyolefin resin. If the first thermoplastic resin (A1) is a polyolefin resin, the first part is easily melted when a high-frequency electric field is applied, and the molded body of this embodiment can be easily bonded to the bonded body.

[0047] In this specification, polyolefin resins include polyolefin resins having polar sites and polyolefin resins not having polar sites. Where the presence or absence of polar sites is determined, the resins are described as either polyolefin resins having polar sites or polyolefin resins not having polar sites.

[0048] The first thermoplastic resin (A1) is preferably a polyolefin resin having polar sites. The first thermoplastic resin (A1) may also be a polyolefin resin without polar sites.

[0049] (Polyolefin resins)

[0050] Examples of thermoplastic polyolefin resins include resins composed of homopolymers of polyethylene, polypropylene, polybutene, and polymethylpentene, and α-olefin resins composed of copolymers of monomers selected from the group consisting of ethylene, propylene, butene, hexene, octene, and 4-methylpentene. Thermoplastic polyolefin resins can be a single resin or a combination of two or more resins.

[0051] (Polyolefin resins with polar sites)

[0052] The polar sites in polyolefin resins are not particularly limited to any site that can impart polarity to the polyolefin resin. Polyolefin resins with polar sites exhibit higher adhesive strength relative to the substrate and are therefore preferred.

[0053] The polyolefin thermoplastic resin with polar sites can also be a copolymer of an olefin monomer and a monomer with polar sites. Furthermore, the polyolefin thermoplastic resin with polar sites can also be a resin in which polar sites are introduced into an olefin polymer obtained by polymerization of an olefin monomer through modification by additional reactions or the like.

[0054] There are no particular restrictions on the types of olefin monomers that constitute polyolefin resins with polar sites. Examples of olefin monomers include ethylene, propylene, butene, hexene, octene, and 4-methyl-1-pentene. One of these olefin monomers can be used alone, or in combination of two or more.

[0055] From the perspective of excellent mechanical strength and stable adhesive properties, ethylene and propylene are preferred among olefin monomers.

[0056] In polyolefin resins with polar sites, the olefin-derived constituent units are preferably derived from ethylene or propylene.

[0057] Examples of polar sites include hydroxyl, carboxyl, vinyl acetate, and anhydride structures. Examples of polar sites also include acid-modified structures introduced into polyolefin resins through acid modification.

[0058] The acid-denaturing structure, as a polar site, is a site introduced by acid denaturing the thermoplastic resin (e.g., a polyolefin resin). Examples of compounds used in acid denaturing the thermoplastic resin (e.g., a polyolefin resin) include unsaturated carboxylic acid derivatives derived from any one of unsaturated carboxylic acids, anhydrides of unsaturated carboxylic acids, and esters of unsaturated carboxylic acids. In this specification, polyolefin resins having an acid-denaturing structure are sometimes referred to as acid-denaturing polyolefin resins.

[0059] Examples of unsaturated carboxylic acids include acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, and citraconic acid.

[0060] Examples of anhydrides that are unsaturated carboxylic acids include maleic anhydride, itaconic anhydride, and citraconic anhydride.

[0061] Examples of esters of unsaturated carboxylic acids include methyl acrylate, ethyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, dimethyl maleate, monomethyl maleate, dimethyl fumarate, diethyl fumarate, dimethyl itaconic acid, diethyl itaconic acid, dimethyl citrate, diethyl citrate, and dimethyl tetrahydrophthalic anhydride.

[0062] When the thermoplastic resin (A1) 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 constituent units derived from the monomer having a polar site, more preferably 4% by mass or more, further preferably 5% by mass or more, and even more preferably 6% by mass or more. Furthermore, the copolymer preferably contains 30% by mass or less of the constituent units derived from the monomer having a polar site, more preferably 25% by mass or less, further preferably 20% by mass or less, and particularly preferably 15% by mass or less.

[0063] By including at least 2% by mass of monomers derived from polar sites in the copolymer, the adhesive strength of the first part of the molded article is improved. Furthermore, by including at least 30% by mass of monomers derived from polar sites in the copolymer, excessive tackiness of the thermoplastic resin can be prevented. As a result, it is easier to prevent the molding and processing of the molded article from becoming difficult.

[0064] When the polyolefin resin (A1) as the first thermoplastic resin has an acid-modified structure, the acid-based denaturation rate is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and even more preferably 0.2% by mass or more.

[0065] When the polyolefin resin (A1) as the first thermoplastic resin has an acid-modified structure, the acid-based modification rate is preferably 30% by mass or less, more preferably 20% by mass or less, and even more preferably 10% by mass or less.

[0066] When the first thermoplastic resin (A1) has an acid-modified structure, the adhesive strength of the first part of the molded article is improved by having an acid-based modification rate of 0.01% by mass or more. Furthermore, by having an acid-based modification rate of 30% by mass or less, it is possible to prevent the first thermoplastic resin (A1) from becoming too viscous. As a result, it is easy to prevent the molding and processing of the molded article from becoming difficult.

[0067] In this specification, the denaturation rate is the percentage of the mass of the acid-derived portion relative to the total mass of the acid-modified polyolefin.

[0068] (Polyolefins with maleic anhydride structure)

[0069] The polyolefin resin, which is the first thermoplastic resin (A1), more preferably has an anhydride structure as a polar site. The maleic anhydride structure is more preferably a polar site. The maleic anhydride structure can be a group introduced by grafting and modifying the thermoplastic resin, or it can be a maleic anhydride copolymer obtained by copolymerizing a monomer containing the maleic anhydride structure.

[0070] When the maleic anhydride structure is a group introduced by grafting modification of the thermoplastic resin, the denaturation rate of the maleic anhydride based on the polyolefin having the maleic anhydride structure is preferably in the same range as the denaturation rate when the polyolefin resin as the first thermoplastic resin (A1) has an acid-denaturing structure. The effect obtained by being within this range is also the same as when the polyolefin resin as the first thermoplastic resin (A1) has an acid-denaturing structure.

[0071] When the polyolefin having a maleic anhydride structure is a copolymer of an olefin monomer and a monomer containing a maleic anhydride structure, the proportion of constituent units derived from the monomer containing a maleic anhydride structure in the copolymer is preferably in the same range as the proportion of constituent units derived from the monomer having a polar site in the case of a copolymer of an olefin monomer and a monomer having a polar site. The effect obtained by being in this range is also the same as in the case where the polyolefin resin (A1) as the first thermoplastic resin is a copolymer of an olefin monomer and a monomer having a polar site.

[0072] The olefin-derived constituent units in polyolefins having a maleic anhydride structure are preferably derived from ethylene or propylene. That is, polyolefins having a maleic anhydride structure are preferably polyethylene resins or polypropylene resins having a maleic anhydride structure.

[0073] <Media Packing (B)>

[0074] The dielectric filler (B) is a filler that generates heat through the application of a high-frequency electric field.

[0075] The dielectric filler (B) is preferably a filler that generates heat when a high-frequency electric field with a frequency range of 3 MHz or higher and 300 MHz or lower is applied. The dielectric filler (B) is preferably a filler that generates heat when a high-frequency electric field with a frequency range of 3 MHz or higher and 300 MHz or lower is applied, such as 13.56 MHz, 27.12 MHz, or 40.68 MHz.

[0076] (type)

[0077] The dielectric filler (B) is preferably one or a combination of two or more inorganic materials with water of crystallization, such as zinc oxide, silicon carbide (SiC), anatase titanium dioxide, barium titanate, barium zirconate titanate, lead titanate, potassium niobate, rutile titanium dioxide, hydrated aluminum silicate, hydrated aluminosilicates of alkali metals, or hydrated aluminosilicates of alkaline earth metals.

[0078] The media filler (B) preferably comprises at least one selected from the group consisting of zinc oxide, silicon carbide, barium titanate and titanium dioxide.

[0079] Among the exemplified media fillers, a wide variety are available, allowing selection based on various shapes and sizes. These fillers can improve the adhesive and mechanical properties of the molded body according to the application. Therefore, zinc oxide is more preferred as the media filler (B). By using zinc oxide as the media filler (B), a molded body with a colorless first portion can be obtained. Zinc oxide has a relatively low density among media fillers; therefore, when using a molded body with a first portion containing zinc oxide as the media filler (B) to bond the molded body to the substrate, the total weight of the bonded body is less likely to increase compared to using a molded body containing other media fillers. Zinc oxide has relatively low hardness in ceramics, thus minimizing the risk of damaging the molded body manufacturing equipment. Zinc oxide is an inert oxide, therefore causing minimal damage to the thermoplastic resin even when mixed with it.

[0080] Furthermore, the titanium dioxide used as the dielectric filler (B) is preferably at least one of anatase titanium dioxide and rutile titanium dioxide, and from the perspective of excellent dielectric properties, anatase titanium dioxide is more preferred.

[0081] (volume content)

[0082] The volume content of the medium filler (B) in the first part is preferably 5% or more, more preferably 8% or more, and even more preferably 10% or more.

[0083] The volume content of the medium filler (B) in the first part is preferably 50% or less, more preferably 40% or less, even more preferably 35% or less, and even more preferably 25% or less.

[0084] With the medium filler (B) in the first part having a volume content of 5% or more, the heating properties of the first part are improved, making it easier to firmly bond the molded body to the bonded body.

[0085] With the volume content of the medium filler (B) in the first part being less than 50% by volume, the fluidity of the first material during molding is difficult to decrease, and the formability of the molded body is also difficult to decrease.

[0086] It should be noted that the first part of the molded body in this embodiment contains thermoplastic resin (A1) and medium filler (B). Therefore, relative to the total volume of thermoplastic resin (A1) and medium filler (B), the volume content of medium filler (B) is preferably 5% or more, more preferably 8% or more, and even more preferably 10% or more.

[0087] The volume content of the media filler (B) is preferably 50% or less, more preferably 40% or less, further preferably 35% or less, and even more preferably 25% or less, relative to the total volume of the thermoplastic resin (A1) and the media filler (B).

[0088] (Average particle size)

[0089] The volume average particle size of the media filler (B) is preferably 1 μm or more, more preferably 2 μm or more, and even more preferably 3 μm or more.

[0090] The volume average particle size of the media filler (B) is preferably 30 μm or less, more preferably 25 μm or less, and even more preferably 20 μm or less.

[0091] With the medium filler (B) having a volume average particle size of 1 μm or more, the first part of the molded body exhibits high heating performance when a high-frequency electric field is applied, and the first part of the molded body can be firmly bonded to the substrate in a short time.

[0092] With the medium filler (B) having a volume average particle size of 30 μm or less, the first part of the molded body exhibits high thermal performance when a high-frequency electric field is applied, enabling the first part of the molded body to bond firmly to the substrate in a short time. Furthermore, the volume average particle size of the medium filler (B) of 30 μm or less prevents a decrease in the strength of the first part of the molded body.

[0093] The volume average particle size of the media filler (B) was determined by the following method: the particle size distribution of the media filler (B) was determined by laser diffraction and scattering, and the volume average particle size was calculated based on the results of the particle size distribution determination and JIS Z 8819-2:2001.

[0094] (additive)

[0095] The first part of the molded article in this embodiment may or may not contain additives. When the first part contains additives, examples of additives include, for instance, tackifiers, plasticizers, waxes, colorants, antioxidants, UV absorbers, antibacterial agents, coupling agents, viscosity modifiers, organic fillers, and inorganic fillers. The organic and inorganic fillers used as additives differ from those used as media fillers.

[0096] Tackifiers and plasticizers can improve the melting and bonding properties of the first part of the molded article of this embodiment.

[0097] Examples of tackifiers include rosin derivatives, polyterpene resins, aromatic modified terpene resins, hydrides of aromatic modified terpene resins, terpene phenolic resins, coumarone-indene resins, aliphatic petroleum resins, aromatic petroleum resins, and hydrides of aromatic petroleum resins.

[0098] Examples of plasticizers include petroleum-based process oils, natural oils, dialkyl dicarboxylic acids, and low molecular weight liquid polymers. Examples of petroleum-based process oils include paraffin-based, naphthenic, and aromatic process oils. Examples of natural oils include castor oil and tall oil. Examples of dialkyl dicarboxylic acids include dibutyl phthalate, dioctyl phthalate, and dibutyl adipate. Examples of low molecular weight liquid polymers include liquid polybutene and liquid polyisoprene.

[0099] When the first part of the molded body in this embodiment contains an additive, the content of the additive in the first part is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, and even more preferably 0.1% by mass or more, based on the total amount of the first part. Furthermore, the content of the additive in the first part is preferably 20% by mass or less, more preferably 15% by mass or less, and even more preferably 10% by mass or less.

[0100] The first portion of the molded body in this embodiment preferably does not contain solvent. With a molded body having a solvent-free first portion, it is difficult to generate VOC (Volatile Organic Compounds) problems caused by the adhesive used in bonding with the bonded body.

[0101] The first part of the molded body in this embodiment preferably does not contain carbon or carbon compounds with carbon as the main component (such as carbon black) and conductive materials such as metals. The first part of the molded body in this embodiment preferably does not contain, for example, carbon steel, α iron, γ iron, δ iron, copper, brass, aluminum, iron-nickel alloys, iron-nickel-chromium alloys, carbon fibers, and carbon black.

[0102] When the first part of the molded body in this embodiment contains a conductive material, the content of the conductive material in the first part is preferably 20% by mass or less, more preferably 10% by mass or less, even more preferably 5% by mass or less, even more preferably 1% by mass or less, and even more preferably 0.1% by mass or less, based on the total amount of the first part of the molded body in this embodiment.

[0103] In this embodiment, the content of conductive material in the first part of the molded body is particularly preferably 0 by mass.

[0104] If the content of conductive material in the first part of the molded body in this embodiment is 20% by mass or less, it is easy to prevent adverse situations such as electrical insulation breakdown and carbonization of the bonded part and the bonded body during dielectric heating treatment.

[0105] In the first part of the molded article of this embodiment, the total content of thermoplastic resin (A) and media filler (B) is preferably 80% by mass or more, more preferably 90% by mass or more, and even more preferably 99% by mass or more.

[0106] <Part Two>

[0107] In the molded body of this embodiment, the second part is made of a second material.

[0108] The second material is not particularly limited. Preferably, the second material comprises at least one material selected from the group consisting of, for example, organic materials, inorganic materials, and naturally derived materials. Examples of organic materials include thermoplastic resins and thermosetting resins. Examples of inorganic materials include ceramics, glass, and metals. Examples of naturally derived materials include wood, paper, leather, and stone.

[0109] In the molded article of this embodiment, the first material and the second material are different. The first material and the second material are different in that all components contained in the first material and all components contained in the second material are inconsistent. For example, if the first material is a material containing polypropylene and zinc oxide and the second material is a material containing only polypropylene, the second material does not contain zinc oxide. Therefore, all components in the first material and the second material are inconsistent, and the first material and the second material are different.

[0110] The second material in the second part can also be a composite material of fiber and plastic materials, namely fiber-reinforced plastics (FRP). 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 and nylon 66, etc.), epoxy resin, melamine resin, phenolic resin, acrylic resin, polyester resin (polyethylene terephthalate (PET resin) and polybutylene terephthalate resin (PBT resin), etc.), polyacetal resin (POM resin), polymethyl methacrylate resin, and polystyrene resin. The fiber in the fiber-reinforced resin is at least one selected from the group consisting of, for example, glass fiber, Kevlar fiber, and carbon fiber.

[0111] Furthermore, the second material in the second part can also be a composite material of organic filler or inorganic filler and plastic material, i.e., the filler contains resin.

[0112] Furthermore, the second material in the second part can also be a resin that does not contain organic or inorganic fillers.

[0113] <Second thermoplastic resin (A2)>

[0114] The second material in the second part preferably comprises a second thermoplastic resin (A2).

[0115] The type of the second thermoplastic resin (A2) is not limited, but the second thermoplastic resin (A2) is preferably a thermoplastic resin selected from the thermoplastic resins listed in the description of the first thermoplastic resin (A1), for example.

[0116] When the second material in the second part contains the second thermoplastic resin (A2), it is preferable that the main composition of the first thermoplastic resin (A1) in the first part is the same as the main composition of the second thermoplastic resin (A2).

[0117] "The main component of the thermoplastic resin" refers, for example, in the case where the thermoplastic resin is a polymer, the most abundant repeating unit among the repeating units contained in that polymer. If the thermoplastic resin is a polymer derived from a single monomer, then that monomer unit (repeating unit) is the "main component of the thermoplastic resin". In the case where the thermoplastic resin is a copolymer, the most abundant repeating unit in that polymer is the "main component of the thermoplastic resin". In the case where the thermoplastic resin is a copolymer, the "main component of the thermoplastic resin" in that copolymer contains 30% by mass or more of repeating units (monomer units), in one embodiment it contains more than 30% by mass of repeating units, in another embodiment it contains more than 40% by mass of repeating units, and in yet another embodiment it contains more than 50% by mass of repeating units. Furthermore, in the case where the thermoplastic resin is a copolymer, the most abundant repeating unit can also be two or more types.

[0118] The second material in the second part preferably does not contain a dielectric filler that generates heat when a high-frequency electric field is applied.

[0119] <Morphology and characteristics of molded objects>

[0120] The shape of the molded body in this embodiment is not particularly limited.

[0121] Figure 1A , Figure 1B as well as Figure 1C The diagram shown is a schematic perspective view of an example of the shape of the molded body according to this embodiment.

[0122] Figure 1A The molded body 1A shown is cubic in shape. The molded body 1A has a first part 10 and a second part 20 with a volume larger than the first part 10.

[0123] Figure 1B The molded body 1B shown is also a cube. The first part 10 of molded body 1B and molded body 1A occupy different positions and proportions within the cube. In molded body 1A, the first part 10 is in complete contact with the bottom surface of the second part 20. In contrast, in molded body 1B, the first part 10 is located at a corner of the cube and is in contact with the second part 20.

[0124] The molded body of this embodiment may also have multiple first parts 10.

[0125] For example, Figure 1CThe molded body 1C shown has a hollow, generally cylindrical second portion 20 with a portion cut off along the axial direction, and two first portions 10 that contact the two end faces of the cut-off section of the second portion 20. The number of first portions in the molded body is not limited to two, and may be three or more.

[0126] The form of the molded body of the present invention is not limited to the examples shown in molded bodies 1A, 1B, and 1C. Furthermore, in the examples shown in molded bodies 1A, 1B, and 1C, the first part 10 and the second part 20 are in direct contact. However, the present invention is not limited to the scheme in which the first part and the second part are in direct contact, and the first part and the second part may also be in contact through other parts (such as a third part).

[0127] The molded body in this embodiment is not a sheet. Sheets generally refer to leaf-shaped articles with a uniform thickness of less than 1 mm, 2 mm, or 5 mm.

[0128] The flow initiation temperature of the first part is preferably 80°C or higher, more preferably 100°C or higher, even more preferably 120°C or higher, and even more preferably 140°C or higher.

[0129] The flow start temperature of the first part is preferably below 300°C, more preferably below 250°C, and even more preferably below 200°C.

[0130] If the flow initiation temperature of the first part is above 80°C, the joint between the molded body and the bonded body can easily obtain the heat resistance required in everyday life. For example, when boiling water comes into contact with the first part, deformation of the first part is easily prevented, resulting in the molded body and the bonded body being difficult to separate.

[0131] If the flow start temperature of the first part is below 300°C, it is easy to prevent the time for melting the first thermoplastic resin (A1) in the first part from becoming longer when the molded body is joined to the bonded body, and it is also easy to obtain the bonding strength between the molded body and the bonded body.

[0132] Preferably, the flow start temperature of the second part is above 100°C, or the second part does not have a flow start temperature.

[0133] When the second part has a flow initiation temperature, the flow initiation temperature of the second part is more preferably 120°C or higher, more preferably 140°C or higher, even more preferably 150°C or higher, and even more preferably 160°C or higher.

[0134] When the second part is composed of ceramics or curable resins, there is no upper limit to the flow start temperature of the second part.

[0135] If the flow start temperature of the second part is above 100°C or the second part does not have a flow start temperature, it is easy to join the molded body and the bonded body without damaging the shape of the molded body.

[0136] The flow start temperature T1 of the first part and the flow start temperature T2 of the second part preferably satisfy the relationship of the following calculation formula (Equation 2).

[0137] T1 < T2…(Equation 2)

[0138] If the relationship of the calculation formula (Formula 2) is satisfied, it is easy to join the molded body and the bonded body without damaging the shape of the molded body.

[0139] The dielectric properties DP1 of the first part and DP2 of the second part preferably satisfy the following calculation formula (Formula 1).

[0140] Dielectric property DP1 is the value of the dielectric property (tanδ / ε'r) for the first part, and dielectric property DP2 is the value of the dielectric property (tanδ / ε'r) for the second part.

[0141] DP1>DP2…(Equation 1)

[0142] (tanδ is the dielectric loss tangent at 23℃ and 40.68MHz)

[0143] ε'r is the relative permittivity at 23°C and a frequency of 40.68 MHz.

[0144] If the relationship of the calculation formula (Formula 1) is satisfied, it is easy to join the molded body and the bonded body without damaging the shape of the molded body.

[0145] The dielectric property (tanδ / ε'r) is the value obtained by dividing the dielectric loss tangent (tanδ) measured using an impedance material device by the relative permittivity (ε'r) measured using an impedance material device.

[0146] The dielectric loss tangent (tanδ) and relative permittivity (ε'r) of the first and second parts can be easily and accurately determined using an impedance material analyzer.

[0147] It should be noted that the detailed method for measuring the dielectric properties of the molded body is as follows. A first or second sheet is obtained by cutting or slicing from the molded body. For the sheet obtained in this way, the relative permittivity (ε'r) and dielectric loss tangent (tanδ) are measured using an RF impedance material analyzer E4991A (Agilent Technologies) at 23°C and a frequency of 40.68MHz, and the dielectric property (tanδ / ε'r) is calculated.

[0148] The dielectric property (tanδ / ε'r) of the first part is preferably 0.005 or more, more preferably 0.008 or more, and even more preferably 0.01 or more.

[0149] Furthermore, the dielectric property (tanδ / ε'r) of the first part is preferably 0.08 or less, and more preferably 0.05 or less.

[0150] The dielectric property (tanδ / ε'r) of the second part is preferably 0.01 or less, and more preferably 0.008 or less.

[0151] Furthermore, the dielectric properties (tanδ / ε'r) of the second part are typically above 0.

[0152] If the dielectric properties of the first part are 0.005 or higher, it can prevent the undesirable situation where the first part does not generate the required heat during dielectric heating treatment, making it difficult to firmly bond the molded body to the bonded body.

[0153] If the dielectric properties of the first part are below 0.08, it is difficult to cause damage to the bonded object that comes into contact with the first part.

[0154] If the dielectric properties of the second part are below 0.01, the heat generation of the second part can be suppressed, so that when the molded body is joined to the bonded body, it is easy to join without damaging the shape of the molded body.

[0155] <Method for manufacturing molded parts>

[0156] The manufacturing method of the molded body in this embodiment is not particularly limited.

[0157] For example, the molded body of this embodiment is preferably manufactured using a first material and a second material and by a multi-color molding method.

[0158] Furthermore, for example, the molded body of this embodiment is preferably manufactured using a first molded body composed of one of a first material and a second material, and the other of the first material and the second material, by means of an insert molding method.

[0159] For example, if the second material is metal or ceramic, a second part of metal or ceramic of the desired shape can be prepared in advance, and the molded body of this embodiment can be manufactured using the second part and the first material through insert molding.

[0160] Furthermore, for example, the molded body of this embodiment is preferably formed by using one of the first material and the second material and by injection molding or compression molding, and manufactured by using the other of the first material and the second material and the first molded body and by insert molding.

[0161] For example, a second material is used to form a first molded body using injection molding or compression molding. This first molded body corresponds to the second part. Next, a molded body can be manufactured using the first material and the first molded body using insert molding. The portion formed during insert molding, composed of the first material, corresponds to the first part.

[0162] <How to use the molded parts>

[0163] The molded body of this embodiment can be used for bonding with a substrate. Furthermore, the molded body of this embodiment can also be used for bonding multiple substrates to each other.

[0164] The molded body of this embodiment is preferably used for bonding the surface of the body to be bonded to the surface of the first part of the molded body.

[0165] The molded body of this embodiment is preferably used by contacting the electrode of the dielectric heating device with the surface of the molded body other than the first part. The part of the molded body other than the first part is, for example, a second part when the molded body is composed of a first part and a second part; at least one of the second and third parts when the molded body is composed of a first part, a second part, and a third part; and at least one of the second to Nth parts (N being an integer of 4 or more) when the molded body also has a third to Nth part. The molded body, other than the first part, preferably does not contain dielectric filler that is heated by the application of a high-frequency electric field. Furthermore, the part of the molded body other than the first part can also be, for example, a bonded body. When using a lattice electrode type high-frequency dielectric heating device described later, it is also preferable to contact the lattice electrode with the surface of the bonded body, which is the surface other than the first part.

[0166] The material of the bonded object is not particularly limited. The material of the bonded object can be any material from organic materials and inorganic materials (including metal materials, etc.), or it can be a composite material of organic and inorganic materials.

[0167] Organic materials used as the adhesive can include, for example, plastic and rubber materials. Examples of plastic materials include polypropylene resin, polyethylene resin, polyurethane resin, acrylonitrile-butadiene-styrene copolymer resin (ABS resin), polycarbonate resin (PC resin), polyamide resin (nylon 6 and nylon 66, etc.), polyester resin (polyethylene terephthalate (PET resin) and polybutylene terephthalate resin (PBT resin), etc.), polyacetal resin (POM resin), polymethyl methacrylate resin, and polystyrene resin. Examples of rubber materials include styrene-butadiene rubber (SBR), ethylene propylene rubber (EPR), and silicone rubber. Furthermore, the adhesive can also be a foamed organic material.

[0168] Inorganic materials used as the adhesive can include glass, cement, ceramics, and metals. Furthermore, the adhesive can also be a composite material of fibers and the aforementioned plastic materials, namely fiber-reinforced plastics (FRP). The plastic material in this fiber-reinforced resin is selected from at least one 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 and nylon 66, etc.), polyester resin (polyethylene terephthalate (PET resin) and polybutylene terephthalate resin (PBT resin), etc.), polyacetal resin (POM resin), polymethyl methacrylate resin, and polystyrene resin. The fibers in the fiber-reinforced resin can include, for example, glass fibers, Kevlar fibers, and carbon fibers.

[0169] When multiple adherends are bonded together using the molded body of this embodiment, the multiple adherends may be made of the same material or different materials, and their shapes and sizes may be the same or different. The shape of the adherends is not particularly limited, but it is preferable to have a surface that can contact the first part of the molded body of this embodiment. Examples of shapes include cubes, cuboids, pyramids, prisms, cylinders, cones, tubes, spheres, hemispheres, sheets, or plates.

[0170] Figure 2A , Figure 2B as well as Figure 2C The diagram shown is a schematic perspective view illustrating an example of the shape of a bonded body obtained by joining the molded body of this embodiment with the bonded body.

[0171] Figure 2AThis is a schematic perspective view of a joint 100A obtained by joining a molded body 1A with a bonded body 30. In the joint 100A, the bonded body 30 is joined to the surface of the first portion 10 of the molded body 1A located on the bottom side.

[0172] Figure 2B This is a schematic perspective view of the joint 100B obtained by joining the molded body 1B with the bonded body 30. In the joint 100B, the bonded body 30 is joined to the surface of the first portion 10 of the corner located on the bottom side of the molded body 1B.

[0173] Figure 2C This is a schematic perspective view of the joint 100C obtained by joining the molded body 1C with the bonded body 30. In the joint 100C, the bonded body 30 is joined to the surfaces of two first portions 10 of the molded body 1C located at the notches of the cylinder.

[0174] <Jointing Method>

[0175] The joining method of this embodiment is the joining method of the molded body of this embodiment.

[0176] The bonding method of this embodiment is a bonding method that bonds the molded body of this embodiment and a substrate different from the molded body. Preferably, it includes a step of bringing the substrate into contact with the surface of the first part, a step of bringing the electrode of the dielectric heating device into contact with the surface other than the first part, and a step of applying a high-frequency electric field to the molded body using the dielectric heating device and bonding the molded body and the substrate.

[0177] Hereinafter, as an example of the joining method of this embodiment, a scheme in which a molded body having a first part and a second part is joined with a bonded body will be described, but the present invention is not limited to this scheme.

[0178] One embodiment of the bonding method includes the following steps P1, P2, and P3.

[0179] Process P1

[0180] Step P1 is the step of bringing the substrate into contact with the surface of the first part. The substrate only needs to come into contact with a portion of the surface of the first part of the molded body of this embodiment, multiple portions of the surface of the first part, or the entire surface of the first part.

[0181] Process P2

[0182] Process P2 is a process that brings the electrodes of the medium heating device into contact with the surface of the molded body that is in contact with the bonded body in process P1, excluding the first part (the second part).

[0183] Process P3

[0184] Step P3 is a step in which a high-frequency electric field is applied to a molded body using a dielectric heating device, and the molded body is bonded to the substrate. In step P3, a high-frequency electric field, for example, between 3 MHz and 300 MHz, is applied to bond the molded body and the substrate. Furthermore, a high-frequency electric field can be applied to the molded body, for example, by using a dielectric heating bonding device. It should be noted that in this specification, "dielectric heating device" is sometimes referred to as a "dielectric heating bonding device" or a "high-frequency dielectric heating device."

[0185] Figure 3 The diagram shown is a schematic diagram illustrating the high-frequency dielectric heating process of a molded body 1A using one embodiment of this invention and a dielectric heating bonding device 50, which is a dielectric heating device.

[0186] (Medium heating bonding device)

[0187] Figure 3 The diagram shown is a schematic of the medium heating and bonding device 50.

[0188] The dielectric heating bonding device 50 includes a first high-frequency electric field applying electrode 51, a second high-frequency electric field applying electrode 52, and a high-frequency power supply 53.

[0189] The first high-frequency electric field applying electrode 51 and the second high-frequency electric field applying electrode 52 are arranged opposite to each other. Both the first high-frequency electric field applying electrode 51 and the second high-frequency electric field applying electrode 52 have a stamping mechanism. This stamping mechanism allows for pressurization of the molded body 1A and the bonded body 30 between the first high-frequency electric field applying electrode 51 and the second high-frequency electric field applying electrode 52. Figure 3 As shown, the first portion 10 of the molded body 1A is in contact with the bonded body 30, but not with the first high-frequency electric field applying electrode 51 and the second high-frequency electric field applying electrode 52 of the dielectric heating bonding device 50. Furthermore, as... Figure 3 As shown, the second part 20 of the molded body 1A, excluding the first part 10, is in contact with the first high-frequency electric field application electrode 51.

[0190] When the first high-frequency electric field applying electrode 51 and the second high-frequency electric field applying electrode 52 constitute a pair of parallel plate electrodes, this electrode configuration is sometimes referred to as a parallel plate configuration.

[0191] The application of the high-frequency electric field is preferably performed using a parallel-plate type high-frequency dielectric heating device. If a parallel-plate type high-frequency dielectric heating device is used, the high-frequency electric field penetrates the first part located between the electrodes, thus heating the first part as a whole, enabling the bonded body to be joined to the molded body in a short time.

[0192] A high-frequency power supply 53 is connected to the first high-frequency electric field applying electrode 51 and the second high-frequency electric field applying electrode 52, for example, to apply a high-frequency electric field with a frequency of 13.56 MHz, 27.12 MHz or 40.68 MHz.

[0193] Medium heating bonding device 50 Figure 3 As shown, the molding body 1A, which is in contact with the bonded body 30, undergoes dielectric heating treatment. Furthermore, in addition to dielectric heating treatment, the dielectric heating bonding apparatus 50 also bonds the molding body 1A to the bonded body 30 by applying pressure based on the first high-frequency electric field application electrode 51 and the second high-frequency electric field application electrode 52. It should be noted that the molding body 1A and the bonded body 30 can also be bonded without applying pressure.

[0194] When a high-frequency electric field is applied between the first high-frequency electric field applying electrode 51 and the second high-frequency electric field applying electrode 52, the dielectric filler (not shown) dispersed in the first part 10 of the molded body 1A absorbs high-frequency energy.

[0195] Then, the medium filler acts as a heat source, and the thermoplastic resin component melts through the heating of the medium filler. Even with short processing time, the molded body 1A and the bonded body 30 can be firmly bonded together.

[0196] The first high-frequency electric field applying electrode 51 and the second high-frequency electric field applying electrode 52 have stamping mechanisms, and therefore also function as stamping devices. Thus, by applying pressure in the compression direction based on the first high-frequency electric field applying electrode 51 and the second high-frequency electric field applying electrode 52, and by heating and melting the first portion 10 of the molded body 1A, the molded body 1A and the bonded body 30 can be bonded more firmly. It should be noted that the molded body 1A and the bonded body 30 can be bonded even without applying pressure.

[0197] (High-frequency dielectric heating bonding conditions)

[0198] The conditions for high-frequency dielectric heating bonding can be appropriately changed, but the following conditions are preferred.

[0199] The output of the high-frequency electric field is preferably 10W or more, more preferably 30W or more, even more preferably 50W or more, and even more preferably 80W or more.

[0200] The output of the high-frequency electric field is preferably 50,000W or less, more preferably 20,000W or less, even more preferably 15,000W or less, even more preferably 10,000W or less, and even more preferably 1,000W or less.

[0201] If the output of the high-frequency electric field is above 10W, it can prevent the undesirable situation of the temperature being difficult to rise during the heating treatment of the medium, thus making it easy to obtain good adhesion.

[0202] If the output of the high-frequency electric field is below 50,000W, it is easy to prevent the adverse situation of temperature control becoming difficult in the dielectric heating process.

[0203] The application time of the high-frequency electric field is preferably more than 1 second.

[0204] The application time of the high-frequency electric field is preferably less than 180 seconds, more preferably less than 120 seconds, even more preferably less than 100 seconds, even more preferably less than 80 seconds, and even more preferably less than 60 seconds, less than 45 seconds, less than 35 seconds, less than 25 seconds or less than 10 seconds.

[0205] If the high-frequency electric field is applied for more than 1 second, it can prevent the undesirable situation that the temperature is difficult to rise during the heating treatment of the medium, thus making it easy to obtain good adhesion.

[0206] If the application time of the high-frequency electric field is less than 180 seconds, it is easy to prevent adverse conditions such as decreased manufacturing efficiency or increased manufacturing cost of the joint that bonds the molded body and the bonded body in this embodiment, and thermal deterioration of the bonded body.

[0207] The frequency of the applied high-frequency electric field is preferably 1 kHz or higher, more preferably 1 MHz or higher, even more preferably 5 MHz or higher, and even more preferably 10 MHz or higher.

[0208] The frequency of the applied high-frequency electric field is preferably below 300 MHz, more preferably below 100 MHz, further preferably below 80 MHz, and even more preferably below 50 MHz. Specifically, the industrial frequency bands of 13.56 MHz, 27.12 MHz, or 40.68 MHz allocated by the International Telecommunication Union can also be used in the bonding method of this embodiment.

[0209] (Effects of this implementation method)

[0210] According to this embodiment, a molded article can be provided that can be bonded to a substrate (other molded articles) without the use of adhesives by high-frequency medium heating and is difficult to deform during bonding. Furthermore, according to this embodiment, a bonding method using this molded article can be provided. According to this embodiment, a method for manufacturing this molded article can be provided.

[0211] Compared to adhesives that require application, the molded body of this embodiment is easier to handle and its workability is improved when bonding with the substrate.

[0212] The first part of the molded body in this embodiment has superior water and moisture resistance compared to general adhesives.

[0213] In this embodiment, the first part of the molded body is heated by applying a high-frequency electric field. Therefore, when the high-frequency electric field is applied, the first part is heated locally rather than the entire molded body. As a result, the molded body according to this embodiment easily prevents undesirable situations such as the entire molded body and the adhered body melting during bonding.

[0214] According to the bonding method of the molded body using this embodiment, it is possible to heat only a specified portion (the first part) from the outside using a medium heating bonding device. Therefore, the bonding method of the molded body using this embodiment is effective even when the bonded body is a large and complex three-dimensional structure or a thick and complex three-dimensional structure, and high dimensional accuracy is required.

[0215] [Variations on the implementation method]

[0216] This invention is not limited to the embodiments described. This invention includes modifications and improvements within the scope of achieving the objectives of this invention.

[0217] In the described embodiment, it is exemplified that when the second material in the second part comprises the second thermoplastic resin (A2), it is preferable that the main composition of the first thermoplastic resin (A1) in the first part is the same as the main composition of the second thermoplastic resin (A2). However, in another embodiment of the invention, for example, the main composition of the first thermoplastic resin (A1) and the main composition of the second thermoplastic resin (A2) are different.

[0218] The molded body may also have an adhesive portion. By having an adhesive portion, when the molded body is brought into contact with the substrate and a high-frequency electric field is applied, misalignment can be prevented and it can be positioned accurately. The adhesive portion may also be provided on the surface of the molded body. Furthermore, the adhesive portion may be provided partially relative to the surface of the molded body. Even without an adhesive portion, the molded body can be firmly bonded to the substrate through the first portion.

[0219] High-frequency dielectric heating treatment is not limited to using the dielectric heating bonding device with electrodes arranged opposite each other as described in the embodiments; lattice electrode type high-frequency dielectric heating devices can also be used. A lattice electrode type high-frequency dielectric heating device has lattice electrodes in which electrodes of a first polarity and electrodes of a second polarity opposite to the first polarity are alternately arranged on the same plane at constant intervals.

[0220] The application of the high-frequency electric field is preferably performed using a lattice electrode type high-frequency dielectric heating device. By using a lattice electrode type high-frequency dielectric heating device, regardless of the thickness of the substrate, a high-frequency electric field can be applied from a position closer to the first part, either from the surface side of the substrate or the surface side of the second part, thereby enabling the molding body to be bonded to the substrate. Furthermore, by using a lattice electrode type high-frequency dielectric heating device, energy savings can be achieved in the manufacturing of the bonded body.

[0221] It should be noted that, for the sake of simplicity, the figure illustrates a scheme using a dielectric heating and bonding device that arranges the electrodes opposite each other.

[0222] Example

[0223] The present invention will now be described in more detail with reference to specific embodiments. However, the present invention is not limited to these embodiments.

[0224] [Making the Molded Object]

[0225] (Example 1)

[0226] The molded body of Example 1 is made by following the steps below.

[0227] First, the first material for forming the first part and the second material for forming the second part are premixed in separate containers according to the compositions (volume %) shown in Table 1. The premixed materials are fed into the hopper of a 30mm φ twin-screw extruder, the cylinder temperature is set to above 200°C and below 230°C, and the die temperature is set to 230°C, to melt and homogenize the premixed materials. After cooling the melt-homogenized materials, granular particles of the first material and granular particles of the second material are produced by shearing.

[0228] Using granular particles of both the first and second materials, a two-color injection molding machine is used to produce... Figure 4A as well as Figure 4B The molded body of Example 1 with the shape shown. Figure 4A as well as Figure 4B The shapes of the first part 10 and the second part 20 of the molded body produced in the embodiment are shown in the figure.

[0229] (Example 2)

[0230] The molded body of Example 2 was made in the same manner as the molded body of Example 1, except that the composition of the first material was changed to the composition (volume %) shown in Table 1 and the material prepared as the second material with the composition shown in Table 1 was used.

[0231] (Example 3)

[0232] The molding method of the molded body in Example 3 is different from that in Example 1.

[0233] First, using the same second material as in Example 1, an injection molding machine is used to manufacture... Figure 4A as well as Figure 4B The first molded body of Embodiment 3 is shown in the shape of the second part 20. Next, using this first molded body and the same first material as in Embodiment 1, an insert molding machine is used to manufacture... Figure 4A as well as Figure 4B The molded body of Example 3 with the shape shown.

[0234] (Example 4)

[0235] The molded body of Example 4 differs from that of Example 2 in terms of the molding method and the composition of the second material.

[0236] First, prepare the second material with the composition shown in Table 1. Next, using this second material, manufacture the product using a compression molding method with a heated compression molding machine. Figure 4A as well as Figure 4B The first molded body of Embodiment 4 is shown in the shape of the second part 20. Next, using this first molded body and the same first material as in Embodiment 2, an insert molding machine is used to manufacture... Figure 4A as well as Figure 4B The molded body of Example 4 with the shape shown.

[0237] (Comparative Example 1)

[0238] The molded body of Comparative Example 1 was manufactured in the same manner as the molded body of Example 1, except that it used a second material with the same composition (volume %) as the first material. That is, in Comparative Example 1, a molded body having a first part and a second part formed of materials with the same composition was manufactured.

[0239] The materials used as the first material and the second material, as shown in Table 1, are as follows:

[0240] PP: Polypropylene (MFR = 7.0 g / 10 minutes)

[0241] m-PP: Maleic anhydride-modified polypropylene (MFR = 9.0 g / 10 min)

[0242] PA6: Nylon 6

[0243] • Zinc oxide (ZnO): Zinc oxide with a volume average particle size of 11 μm. Manufactured by Sakai Chemical Industry Co., Ltd., product name "LP-ZINC11".

[0244] · Fiberglass

[0245] • Epoxy resin prepreg: Uncured material impregnated with epoxy resin in glass fibers (glass fiber content 70% by volume).

[0246] (Volume average particle size of the media packing)

[0247] The particle size distribution of the media filler was determined by laser diffraction and scattering. Based on the particle size distribution measurement results, the volume average particle size was calculated using JIS Z 8819-2:2001 as the standard. The calculated volume average particle size of zinc oxide (ZnO) was 11 μm.

[0248] (Flow start temperature)

[0249] The flow initiation temperature of the first and second parts of the molded body was measured using a descending flow meter (Shimadzu Corporation, model "CFT-100D"). A load of 5.0 kg was set, and a mold with a φ2.0 mm orifice, a length of 5.0 mm, and an inner diameter of 11.329 mm were used. The first and second parts of the molded body were each cut into 2 mm × 2 mm × 2 mm pieces to prepare test samples. While increasing the temperature of the test samples at a rate of 10 °C / min, the stroke displacement velocity (mm / min) that changed with the temperature increase was measured, obtaining a temperature dependence graph of the stroke displacement velocity of the samples. In this graph, the temperature at which the stroke displacement velocity begins to rise again after reaching the peak value obtained at the low temperature side is defined as the flow initiation temperature. Table 1 shows the flow initiation temperatures of the first and second parts.

[0250] (Dielectric properties)

[0251] The shaped body was cut to obtain sheets of 10mm × 10mm × 2mm each for the first and second parts. For the obtained sheets, a dielectric material testing fixture 16453A (Agilent Technologies) was installed in an RF impedance material analyzer E4991A (Agilent Technologies) and the relative permittivity (ε'r) and dielectric loss tangent (tanδ) were measured using the parallel plate method at 23°C and a frequency of 40.68MHz. Based on the measurement results, the dielectric properties (tanδ / ε'r) were calculated. Table 1 shows the dielectric properties (tanδ / ε'r) of the first and second parts.

[0252] [Evaluation Methods for Molded Objects]

[0253] The molded objects were evaluated using the methods shown below. The evaluation results are shown in Table 1.

[0254] (Evaluation of the applicability of high-frequency bonding)

[0255] Test specimens were prepared by bonding a molded body to a glass fiber reinforced polypropylene substrate to evaluate high-frequency adhesion. The substrate was 25 mm wide, 100 mm long, and 2 mm thick. The first part of the molded body and the substrate were overlapped between electrodes of a high-frequency dielectric heating device. One electrode of the high-frequency dielectric heating device was brought into contact with the second part of the molded body, and the other electrode was brought into contact with the substrate, without contacting the first part. After arranging the electrodes, molded body, and substrate in this manner, a high-frequency electric field was applied under the following high-frequency application conditions to bond the molded body and substrate, thus preparing the test specimen.

[0256] High-frequency application conditions

[0257] Frequency: 40.68MHz

[0258] Output: 200W

[0259] Application time: 10 seconds

[0260] The high-frequency adhesion of the molded body is evaluated according to the following criteria.

[0261] A: It can join the molded part to the bonded part without any problems.

[0262] F: The molded body is severely deformed or the molten material adheres to the electrode.

[0263] (Evaluation of adhesive strength (tensile shear force))

[0264] The tensile shear force of the test pieces obtained in the "Evaluation of Suitability of High-Frequency Adhesion" was determined using a universal tensile test. The tensile shear force was determined according to JIS K 6850:1999. The tensile shear force was measured at 25°C and a tensile speed of 100 mm / min.

[0265] The measured tensile shear force was used as the adhesive force of the molded body for evaluation. Regarding Comparative Example 1, the tensile shear force was not measured because the shape of the molded body was deformed.

[0266] A: Adhesion strength is above 0.5 MPa

[0267] F: Adhesion strength is less than 0.5 MPa.

[0268] Table 1

[0269]

[0270] The molded bodies of Examples 1 to 4 are molded bodies that can be bonded to the substrate by high-frequency medium heating, and do not deform during bonding. Furthermore, it is known that the molded bodies of Examples 1 to 4 can firmly bond the molded body to the substrate without using adhesive sheets.

[0271] Explanation of reference numerals in the attached figures

[0272] 1A: Molded body;

[0273] 1B: Molded body;

[0274] 1C: Molded body;

[0275] 10: Part One;

[0276] 20: Part Two;

[0277] 30: The substrate being bonded;

[0278] 50: Medium heating bonding device;

[0279] 51: Electrode to which the first high-frequency electric field is applied;

[0280] 52: Electrode for applying the second high-frequency electric field;

[0281] 53: High-frequency power supply;

[0282] 100A: Joint body;

[0283] 100B: Joint body;

[0284] 100C: Conjugate.

Claims

1. A shaped body, which shaped body is not a sheet, characterized in that, having: a first portion composed of a first material containing a first thermoplastic resin (A1) and a dielectric filler (B) that generates heat by application of a high-frequency electric field; a second portion composed of a second material different from the first material of the first portion; a dielectric property DP1 of the first portion is 0.005 or more, a dielectric property DP2 of the second portion is 0.01 or less, and the dielectric property DP1 of the first portion and the dielectric property DP2 of the second portion satisfy the following relation of a calculation formula (Formula 1), the dielectric property DP1 and the dielectric property DP2 are values of the dielectric property (tan δ / ε'r) of the first portion and the second portion, respectively, DP1 > DP2... (Formula 1), tan δ is a dielectric loss tangent at 23°C and a frequency of 40.68 MHz, ε'r is a relative dielectric constant at 23°C and a frequency of 40.68 MHz.

2. The molded body according to claim 1, a volume content of the dielectric filler (B) in the first portion is 5 vol% or more and 50 vol% or less.

3. The molded body according to claim 1, a flow start temperature of the first portion is 80°C or more and 300°C or less.

4. The molded body according to claim 1, a flow start temperature of the second portion is 100°C or more, or the second portion does not have a flow start temperature.

5. The molded body according to claim 1, a flow start temperature T1 of the first portion and a flow start temperature T2 of the second portion satisfy the following relation of a calculation formula (Formula 2), T1 < T2... (Formula 2).

6. The molded body according to any one of claims 1 to 5, the second material of the second portion contains a second thermoplastic resin (A2).

7. The molded body according to claim 6, a main component of the first thermoplastic resin (A1) and a main component of the second thermoplastic resin (A2) are the same.

8. The molded body according to any one of claims 1 to 5, for joining a bonded body to a surface of the first portion of the molded body.

9. The molded body according to any one of claims 1 to 5, the molded body is used by bringing an electrode of a dielectric heating device into contact with a surface other than the first portion of the molded body.

10. A bonding method of bonding the molded body according to any one of claims 1 to 9 and a bonded body different from the molded body, characterized by, comprising: a step of bringing the bonded body into contact with a surface of the first portion; a step of bringing an electrode of a dielectric heating device into contact with a surface other than the first portion; a step of applying a high-frequency electric field to the molded body using the dielectric heating device and joining the molded body to the bonded body.

11. A method for manufacturing a molded body according to any one of claims 1 to 9, characterized by, using the first material and the second material and molding the molded body by a multi-color molding method.

12. A method for manufacturing a molded body according to any one of claims 1 to 9, characterized by, The first molded body is molded using one of the first material and the second material by injection molding or compression molding, 13. A method for manufacturing a molded body of any one of claims 1 to 9, characterized by, molding a first molded body using one of the first material and the second material by injection molding or compression molding, manufacturing the molded body using the other of the first material and the second material and the first molded body by insert molding.

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